src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 #ifndef SUPPORT_CRYPTEQ
  21 #define SUPPORT_CRYPTEQ
  22 #endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 #include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 #ifdef CRYPT_H
  31 #include <crypt.h>
  32 #endif
  33 #ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 #endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Characters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef SUPPORT_I18N
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef SUPPORT_I18N
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef SUPPORT_I18N
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef SUPPORT_I18N
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base32",
 203   US"base32d",
 204   US"base62",
 205   US"base62d",
 206   US"base64",
 207   US"base64d",
 208   US"domain",
 209   US"escape",
 210   US"escape8bit",
 211   US"eval",
 212   US"eval10",
 213   US"expand",
 214   US"h",
 215   US"hash",
 216   US"hex2b64",
 217   US"hexquote",
 218   US"ipv6denorm",
 219   US"ipv6norm",
 220   US"l",
 221   US"lc",
 222   US"length",
 223   US"listcount",
 224   US"listnamed",
 225   US"mask",
 226   US"md5",
 227   US"nh",
 228   US"nhash",
 229   US"quote",
 230   US"randint",
 231   US"rfc2047",
 232   US"rfc2047d",
 233   US"rxquote",
 234   US"s",
 235   US"sha1",
 236   US"sha256",
 237   US"sha3",
 238   US"stat",
 239   US"str2b64",
 240   US"strlen",
 241   US"substr",
 242   US"uc",
 243   US"utf8clean" };
 244
 245 enum {
 246   EOP_ADDRESS =  nelem(op_table_underscore),
 247   EOP_ADDRESSES,
 248   EOP_BASE32,
 249   EOP_BASE32D,
 250   EOP_BASE62,
 251   EOP_BASE62D,
 252   EOP_BASE64,
 253   EOP_BASE64D,
 254   EOP_DOMAIN,
 255   EOP_ESCAPE,
 256   EOP_ESCAPE8BIT,
 257   EOP_EVAL,
 258   EOP_EVAL10,
 259   EOP_EXPAND,
 260   EOP_H,
 261   EOP_HASH,
 262   EOP_HEX2B64,
 263   EOP_HEXQUOTE,
 264   EOP_IPV6DENORM,
 265   EOP_IPV6NORM,
 266   EOP_L,
 267   EOP_LC,
 268   EOP_LENGTH,
 269   EOP_LISTCOUNT,
 270   EOP_LISTNAMED,
 271   EOP_MASK,
 272   EOP_MD5,
 273   EOP_NH,
 274   EOP_NHASH,
 275   EOP_QUOTE,
 276   EOP_RANDINT,
 277   EOP_RFC2047,
 278   EOP_RFC2047D,
 279   EOP_RXQUOTE,
 280   EOP_S,
 281   EOP_SHA1,
 282   EOP_SHA256,
 283   EOP_SHA3,
 284   EOP_STAT,
 285   EOP_STR2B64,
 286   EOP_STRLEN,
 287   EOP_SUBSTR,
 288   EOP_UC,
 289   EOP_UTF8CLEAN };
 290
 291
 292 /* Table of condition names, and corresponding switch numbers. The names must
 293 be in alphabetical order. */
 294
 295 static uschar *cond_table[] = {
 296   US"<",
 297   US"<=",
 298   US"=",
 299   US"==",     /* Backward compatibility */
 300   US">",
 301   US">=",
 302   US"acl",
 303   US"and",
 304   US"bool",
 305   US"bool_lax",
 306   US"crypteq",
 307   US"def",
 308   US"eq",
 309   US"eqi",
 310   US"exists",
 311   US"first_delivery",
 312   US"forall",
 313   US"forany",
 314   US"ge",
 315   US"gei",
 316   US"gt",
 317   US"gti",
 318   US"inlist",
 319   US"inlisti",
 320   US"isip",
 321   US"isip4",
 322   US"isip6",
 323   US"ldapauth",
 324   US"le",
 325   US"lei",
 326   US"lt",
 327   US"lti",
 328   US"match",
 329   US"match_address",
 330   US"match_domain",
 331   US"match_ip",
 332   US"match_local_part",
 333   US"or",
 334   US"pam",
 335   US"pwcheck",
 336   US"queue_running",
 337   US"radius",
 338   US"saslauthd"
 339 };
 340
 341 enum {
 342   ECOND_NUM_L,
 343   ECOND_NUM_LE,
 344   ECOND_NUM_E,
 345   ECOND_NUM_EE,
 346   ECOND_NUM_G,
 347   ECOND_NUM_GE,
 348   ECOND_ACL,
 349   ECOND_AND,
 350   ECOND_BOOL,
 351   ECOND_BOOL_LAX,
 352   ECOND_CRYPTEQ,
 353   ECOND_DEF,
 354   ECOND_STR_EQ,
 355   ECOND_STR_EQI,
 356   ECOND_EXISTS,
 357   ECOND_FIRST_DELIVERY,
 358   ECOND_FORALL,
 359   ECOND_FORANY,
 360   ECOND_STR_GE,
 361   ECOND_STR_GEI,
 362   ECOND_STR_GT,
 363   ECOND_STR_GTI,
 364   ECOND_INLIST,
 365   ECOND_INLISTI,
 366   ECOND_ISIP,
 367   ECOND_ISIP4,
 368   ECOND_ISIP6,
 369   ECOND_LDAPAUTH,
 370   ECOND_STR_LE,
 371   ECOND_STR_LEI,
 372   ECOND_STR_LT,
 373   ECOND_STR_LTI,
 374   ECOND_MATCH,
 375   ECOND_MATCH_ADDRESS,
 376   ECOND_MATCH_DOMAIN,
 377   ECOND_MATCH_IP,
 378   ECOND_MATCH_LOCAL_PART,
 379   ECOND_OR,
 380   ECOND_PAM,
 381   ECOND_PWCHECK,
 382   ECOND_QUEUE_RUNNING,
 383   ECOND_RADIUS,
 384   ECOND_SASLAUTHD
 385 };
 386
 387
 388 /* Types of table entry */
 389
 390 enum vtypes {
 391   vtype_int,            /* value is address of int */
 392   vtype_filter_int,     /* ditto, but recognized only when filtering */
 393   vtype_ino,            /* value is address of ino_t (not always an int) */
 394   vtype_uid,            /* value is address of uid_t (not always an int) */
 395   vtype_gid,            /* value is address of gid_t (not always an int) */
 396   vtype_bool,           /* value is address of bool */
 397   vtype_stringptr,      /* value is address of pointer to string */
 398   vtype_msgbody,        /* as stringptr, but read when first required */
 399   vtype_msgbody_end,    /* ditto, the end of the message */
 400   vtype_msgheaders,     /* the message's headers, processed */
 401   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 402   vtype_localpart,      /* extract local part from string */
 403   vtype_domain,         /* extract domain from string */
 404   vtype_string_func,    /* value is string returned by given function */
 405   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 406   vtype_tode,           /* value not used; generate tod in epoch format */
 407   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 408   vtype_todf,           /* value not used; generate full tod */
 409   vtype_todl,           /* value not used; generate log tod */
 410   vtype_todlf,          /* value not used; generate log file datestamp tod */
 411   vtype_todzone,        /* value not used; generate time zone only */
 412   vtype_todzulu,        /* value not used; generate zulu tod */
 413   vtype_reply,          /* value not used; get reply from headers */
 414   vtype_pid,            /* value not used; result is pid */
 415   vtype_host_lookup,    /* value not used; get host name */
 416   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 417   vtype_pspace,         /* partition space; value is T/F for spool/log */
 418   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 419   vtype_cert            /* SSL certificate */
 420   #ifndef DISABLE_DKIM
 421   ,vtype_dkim           /* Lookup of value in DKIM signature */
 422   #endif
 423 };
 424
 425 /* Type for main variable table */
 426
 427 typedef struct {
 428   const char *name;
 429   enum vtypes type;
 430   void       *value;
 431 } var_entry;
 432
 433 /* Type for entries pointing to address/length pairs. Not currently
 434 in use. */
 435
 436 typedef struct {
 437   uschar **address;
 438   int  *length;
 439 } alblock;
 440
 441 static uschar * fn_recipients(void);
 442
 443 /* This table must be kept in alphabetical order. */
 444
 445 static var_entry var_table[] = {
 446   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 447      they will be confused with user-creatable ACL variables. */
 448   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 449   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 450   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 451   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 452   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 453   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 454   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 455   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 456   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 457   { "acl_narg",            vtype_int,         &acl_narg },
 458   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 459   { "address_data",        vtype_stringptr,   &deliver_address_data },
 460   { "address_file",        vtype_stringptr,   &address_file },
 461   { "address_pipe",        vtype_stringptr,   &address_pipe },
 462   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 463   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 464   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 465   { "authentication_failed",vtype_int,        &authentication_failed },
 466 #ifdef WITH_CONTENT_SCAN
 467   { "av_failed",           vtype_int,         &av_failed },
 468 #endif
 469 #ifdef EXPERIMENTAL_BRIGHTMAIL
 470   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 471   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 472   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 473   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 474 #endif
 475   { "body_linecount",      vtype_int,         &body_linecount },
 476   { "body_zerocount",      vtype_int,         &body_zerocount },
 477   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 478   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 479   { "caller_gid",          vtype_gid,         &real_gid },
 480   { "caller_uid",          vtype_uid,         &real_uid },
 481   { "callout_address",     vtype_stringptr,   &callout_address },
 482   { "compile_date",        vtype_stringptr,   &version_date },
 483   { "compile_number",      vtype_stringptr,   &version_cnumber },
 484   { "config_dir",          vtype_stringptr,   &config_main_directory },
 485   { "config_file",         vtype_stringptr,   &config_main_filename },
 486   { "csa_status",          vtype_stringptr,   &csa_status },
 487 #ifdef EXPERIMENTAL_DCC
 488   { "dcc_header",          vtype_stringptr,   &dcc_header },
 489   { "dcc_result",          vtype_stringptr,   &dcc_result },
 490 #endif
 491 #ifndef DISABLE_DKIM
 492   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 493   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 494   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 495   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 496   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 497   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 498   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 499   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 500   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 501   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 502   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 503   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 504   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 505   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 506   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 507   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 508   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 509   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 510   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 511   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 512   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 513 #endif
 514 #ifdef EXPERIMENTAL_DMARC
 515   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 516   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 517   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 518   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 519   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 520 #endif
 521   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 522   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 523   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 524   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 525   { "domain",              vtype_stringptr,   &deliver_domain },
 526   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 527 #ifndef DISABLE_EVENT
 528   { "event_data",          vtype_stringptr,   &event_data },
 529
 530   /*XXX want to use generic vars for as many of these as possible*/
 531   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 532
 533   { "event_name",          vtype_stringptr,   &event_name },
 534 #endif
 535   { "exim_gid",            vtype_gid,         &exim_gid },
 536   { "exim_path",           vtype_stringptr,   &exim_path },
 537   { "exim_uid",            vtype_uid,         &exim_uid },
 538   { "exim_version",        vtype_stringptr,   &version_string },
 539   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 540   { "home",                vtype_stringptr,   &deliver_home },
 541   { "host",                vtype_stringptr,   &deliver_host },
 542   { "host_address",        vtype_stringptr,   &deliver_host_address },
 543   { "host_data",           vtype_stringptr,   &host_data },
 544   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 545   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 546   { "host_port",           vtype_int,         &deliver_host_port },
 547   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 548   { "inode",               vtype_ino,         &deliver_inode },
 549   { "interface_address",   vtype_stringptr,   &interface_address },
 550   { "interface_port",      vtype_int,         &interface_port },
 551   { "item",                vtype_stringptr,   &iterate_item },
 552   #ifdef LOOKUP_LDAP
 553   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 554   #endif
 555   { "load_average",        vtype_load_avg,    NULL },
 556   { "local_part",          vtype_stringptr,   &deliver_localpart },
 557   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 558   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 559   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 560   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 561   { "local_user_gid",      vtype_gid,         &local_user_gid },
 562   { "local_user_uid",      vtype_uid,         &local_user_uid },
 563   { "localhost_number",    vtype_int,         &host_number },
 564   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 565   { "log_space",           vtype_pspace,      (void *)FALSE },
 566   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 567   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 568 #ifdef WITH_CONTENT_SCAN
 569   { "malware_name",        vtype_stringptr,   &malware_name },
 570 #endif
 571   { "max_received_linelength", vtype_int,     &max_received_linelength },
 572   { "message_age",         vtype_int,         &message_age },
 573   { "message_body",        vtype_msgbody,     &message_body },
 574   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 575   { "message_body_size",   vtype_int,         &message_body_size },
 576   { "message_exim_id",     vtype_stringptr,   &message_id },
 577   { "message_headers",     vtype_msgheaders,  NULL },
 578   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 579   { "message_id",          vtype_stringptr,   &message_id },
 580   { "message_linecount",   vtype_int,         &message_linecount },
 581   { "message_size",        vtype_int,         &message_size },
 582 #ifdef SUPPORT_I18N
 583   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 584 #endif
 585 #ifdef WITH_CONTENT_SCAN
 586   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 587   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 588   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 589   { "mime_charset",        vtype_stringptr,   &mime_charset },
 590   { "mime_content_description", vtype_stringptr, &mime_content_description },
 591   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 592   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 593   { "mime_content_size",   vtype_int,         &mime_content_size },
 594   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 595   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 596   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 597   { "mime_filename",       vtype_stringptr,   &mime_filename },
 598   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 599   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 600   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 601   { "mime_part_count",     vtype_int,         &mime_part_count },
 602 #endif
 603   { "n0",                  vtype_filter_int,  &filter_n[0] },
 604   { "n1",                  vtype_filter_int,  &filter_n[1] },
 605   { "n2",                  vtype_filter_int,  &filter_n[2] },
 606   { "n3",                  vtype_filter_int,  &filter_n[3] },
 607   { "n4",                  vtype_filter_int,  &filter_n[4] },
 608   { "n5",                  vtype_filter_int,  &filter_n[5] },
 609   { "n6",                  vtype_filter_int,  &filter_n[6] },
 610   { "n7",                  vtype_filter_int,  &filter_n[7] },
 611   { "n8",                  vtype_filter_int,  &filter_n[8] },
 612   { "n9",                  vtype_filter_int,  &filter_n[9] },
 613   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 614   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 615   { "originator_gid",      vtype_gid,         &originator_gid },
 616   { "originator_uid",      vtype_uid,         &originator_uid },
 617   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 618   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 619   { "pid",                 vtype_pid,         NULL },
 620 #ifndef DISABLE_PRDR
 621   { "prdr_requested",      vtype_bool,        &prdr_requested },
 622 #endif
 623   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 624 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 625   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 626   { "proxy_external_port", vtype_int,         &proxy_external_port },
 627   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 628   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 629   { "proxy_session",       vtype_bool,        &proxy_session },
 630 #endif
 631   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 632   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 633   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 634   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 635   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 636   { "queue_name",          vtype_stringptr,   &queue_name },
 637   { "rcpt_count",          vtype_int,         &rcpt_count },
 638   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 639   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 640   { "received_count",      vtype_int,         &received_count },
 641   { "received_for",        vtype_stringptr,   &received_for },
 642   { "received_ip_address", vtype_stringptr,   &interface_address },
 643   { "received_port",       vtype_int,         &interface_port },
 644   { "received_protocol",   vtype_stringptr,   &received_protocol },
 645   { "received_time",       vtype_int,         &received_time },
 646   { "recipient_data",      vtype_stringptr,   &recipient_data },
 647   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 648   { "recipients",          vtype_string_func, &fn_recipients },
 649   { "recipients_count",    vtype_int,         &recipients_count },
 650 #ifdef WITH_CONTENT_SCAN
 651   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 652 #endif
 653   { "reply_address",       vtype_reply,       NULL },
 654   { "return_path",         vtype_stringptr,   &return_path },
 655   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 656   { "router_name",         vtype_stringptr,   &router_name },
 657   { "runrc",               vtype_int,         &runrc },
 658   { "self_hostname",       vtype_stringptr,   &self_hostname },
 659   { "sender_address",      vtype_stringptr,   &sender_address },
 660   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 661   { "sender_address_domain", vtype_domain,    &sender_address },
 662   { "sender_address_local_part", vtype_localpart, &sender_address },
 663   { "sender_data",         vtype_stringptr,   &sender_data },
 664   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 665   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 666   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 667   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 668   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 669   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 670   { "sender_host_name",    vtype_host_lookup, NULL },
 671   { "sender_host_port",    vtype_int,         &sender_host_port },
 672   { "sender_ident",        vtype_stringptr,   &sender_ident },
 673   { "sender_rate",         vtype_stringptr,   &sender_rate },
 674   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 675   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 676   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 677   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 678   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 679   { "sending_port",        vtype_int,         &sending_port },
 680   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 681   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 682   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 683   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 684   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 685   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 686   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 687   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 688   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 689   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 690   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 691   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 692   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 693   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 694   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 695 #ifdef WITH_CONTENT_SCAN
 696   { "spam_action",         vtype_stringptr,   &spam_action },
 697   { "spam_bar",            vtype_stringptr,   &spam_bar },
 698   { "spam_report",         vtype_stringptr,   &spam_report },
 699   { "spam_score",          vtype_stringptr,   &spam_score },
 700   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 701 #endif
 702 #ifdef EXPERIMENTAL_SPF
 703   { "spf_guess",           vtype_stringptr,   &spf_guess },
 704   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 705   { "spf_received",        vtype_stringptr,   &spf_received },
 706   { "spf_result",          vtype_stringptr,   &spf_result },
 707   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 708 #endif
 709   { "spool_directory",     vtype_stringptr,   &spool_directory },
 710   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 711   { "spool_space",         vtype_pspace,      (void *)TRUE },
 712 #ifdef EXPERIMENTAL_SRS
 713   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 714   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 715   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 716   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 717   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 718   { "srs_status",          vtype_stringptr,   &srs_status },
 719 #endif
 720   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 721
 722   /* The non-(in,out) variables are now deprecated */
 723   { "tls_bits",            vtype_int,         &tls_in.bits },
 724   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 725   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 726
 727   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 728   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 729   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 730   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 731   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 732   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 733   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 734 #if defined(SUPPORT_TLS)
 735   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 736 #endif
 737   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 738   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 739   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 740 #ifdef EXPERIMENTAL_DANE
 741   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 742 #endif
 743   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 744   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 745   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 746   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 747 #if defined(SUPPORT_TLS)
 748   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 749 #endif
 750 #ifdef EXPERIMENTAL_DANE
 751   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 752 #endif
 753
 754   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 755 #if defined(SUPPORT_TLS)
 756   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 757 #endif
 758
 759   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 760   { "tod_epoch",           vtype_tode,        NULL },
 761   { "tod_epoch_l",         vtype_todel,       NULL },
 762   { "tod_full",            vtype_todf,        NULL },
 763   { "tod_log",             vtype_todl,        NULL },
 764   { "tod_logfile",         vtype_todlf,       NULL },
 765   { "tod_zone",            vtype_todzone,     NULL },
 766   { "tod_zulu",            vtype_todzulu,     NULL },
 767   { "transport_name",      vtype_stringptr,   &transport_name },
 768   { "value",               vtype_stringptr,   &lookup_value },
 769   { "verify_mode",         vtype_stringptr,   &verify_mode },
 770   { "version_number",      vtype_stringptr,   &version_string },
 771   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 772   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 773   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 774   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 775   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 776   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 777 };
 778
 779 static int var_table_size = nelem(var_table);
 780 static uschar var_buffer[256];
 781 static BOOL malformed_header;
 782
 783 /* For textual hashes */
 784
 785 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 786                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 787                                "0123456789";
 788
 789 enum { HMAC_MD5, HMAC_SHA1 };
 790
 791 /* For numeric hashes */
 792
 793 static unsigned int prime[] = {
 794   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 795  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 796  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 797
 798 /* For printing modes in symbolic form */
 799
 800 static uschar *mtable_normal[] =
 801   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 802
 803 static uschar *mtable_setid[] =
 804   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 805
 806 static uschar *mtable_sticky[] =
 807   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 808
 809
 810
 811 /*************************************************
 812 *           Tables for UTF-8 support             *
 813 *************************************************/
 814
 815 /* Table of the number of extra characters, indexed by the first character
 816 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 817 0x3d. */
 818
 819 static uschar utf8_table1[] = {
 820   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 821   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 822   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 823   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 824
 825 /* These are the masks for the data bits in the first byte of a character,
 826 indexed by the number of additional bytes. */
 827
 828 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 829
 830 /* Get the next UTF-8 character, advancing the pointer. */
 831
 832 #define GETUTF8INC(c, ptr) \
 833   c = *ptr++; \
 834   if ((c & 0xc0) == 0xc0) \
 835     { \
 836     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 837     int s = 6*a; \
 838     c = (c & utf8_table2[a]) << s; \
 839     while (a-- > 0) \
 840       { \
 841       s -= 6; \
 842       c |= (*ptr++ & 0x3f) << s; \
 843       } \
 844     }
 845
 846
 847
 848 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 849
 850 /*************************************************
 851 *           Binary chop search on a table        *
 852 *************************************************/
 853
 854 /* This is used for matching expansion items and operators.
 855
 856 Arguments:
 857   name        the name that is being sought
 858   table       the table to search
 859   table_size  the number of items in the table
 860
 861 Returns:      the offset in the table, or -1
 862 */
 863
 864 static int
 865 chop_match(uschar *name, uschar **table, int table_size)
 866 {
 867 uschar **bot = table;
 868 uschar **top = table + table_size;
 869
 870 while (top > bot)
 871   {
 872   uschar **mid = bot + (top - bot)/2;
 873   int c = Ustrcmp(name, *mid);
 874   if (c == 0) return mid - table;
 875   if (c > 0) bot = mid + 1; else top = mid;
 876   }
 877
 878 return -1;
 879 }
 880
 881
 882
 883 /*************************************************
 884 *          Check a condition string              *
 885 *************************************************/
 886
 887 /* This function is called to expand a string, and test the result for a "true"
 888 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 889 forced fail or lookup defer.
 890
 891 We used to release all store used, but this is not not safe due
 892 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 893 is reasonably careful to release what it can.
 894
 895 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 896
 897 Arguments:
 898   condition     the condition string
 899   m1            text to be incorporated in panic error
 900   m2            ditto
 901
 902 Returns:        TRUE if condition is met, FALSE if not
 903 */
 904
 905 BOOL
 906 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 907 {
 908 int rc;
 909 uschar *ss = expand_string(condition);
 910 if (ss == NULL)
 911   {
 912   if (!expand_string_forcedfail && !search_find_defer)
 913     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 914       "for %s %s: %s", condition, m1, m2, expand_string_message);
 915   return FALSE;
 916   }
 917 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 918   strcmpic(ss, US"false") != 0;
 919 return rc;
 920 }
 921
 922
 923
 924
 925 /*************************************************
 926 *        Pseudo-random number generation         *
 927 *************************************************/
 928
 929 /* Pseudo-random number generation.  The result is not "expected" to be
 930 cryptographically strong but not so weak that someone will shoot themselves
 931 in the foot using it as a nonce in some email header scheme or whatever
 932 weirdness they'll twist this into.  The result should ideally handle fork().
 933
 934 However, if we're stuck unable to provide this, then we'll fall back to
 935 appallingly bad randomness.
 936
 937 If SUPPORT_TLS is defined then this will not be used except as an emergency
 938 fallback.
 939
 940 Arguments:
 941   max       range maximum
 942 Returns     a random number in range [0, max-1]
 943 */
 944
 945 #ifdef SUPPORT_TLS
 946 # define vaguely_random_number vaguely_random_number_fallback
 947 #endif
 948 int
 949 vaguely_random_number(int max)
 950 {
 951 #ifdef SUPPORT_TLS
 952 # undef vaguely_random_number
 953 #endif
 954   static pid_t pid = 0;
 955   pid_t p2;
 956 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 957   struct timeval tv;
 958 #endif
 959
 960   p2 = getpid();
 961   if (p2 != pid)
 962     {
 963     if (pid != 0)
 964       {
 965
 966 #ifdef HAVE_ARC4RANDOM
 967       /* cryptographically strong randomness, common on *BSD platforms, not
 968       so much elsewhere.  Alas. */
 969 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 970       arc4random_stir();
 971 #endif
 972 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 973 #ifdef HAVE_SRANDOMDEV
 974       /* uses random(4) for seeding */
 975       srandomdev();
 976 #else
 977       gettimeofday(&tv, NULL);
 978       srandom(tv.tv_sec | tv.tv_usec | getpid());
 979 #endif
 980 #else
 981       /* Poor randomness and no seeding here */
 982 #endif
 983
 984       }
 985     pid = p2;
 986     }
 987
 988 #ifdef HAVE_ARC4RANDOM
 989   return arc4random() % max;
 990 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 991   return random() % max;
 992 #else
 993   /* This one returns a 16-bit number, definitely not crypto-strong */
 994   return random_number(max);
 995 #endif
 996 }
 997
 998
 999
1000
1001 /*************************************************
1002 *             Pick out a name from a string      *
1003 *************************************************/
1004
1005 /* If the name is too long, it is silently truncated.
1006
1007 Arguments:
1008   name      points to a buffer into which to put the name
1009   max       is the length of the buffer
1010   s         points to the first alphabetic character of the name
1011   extras    chars other than alphanumerics to permit
1012
1013 Returns:    pointer to the first character after the name
1014
1015 Note: The test for *s != 0 in the while loop is necessary because
1016 Ustrchr() yields non-NULL if the character is zero (which is not something
1017 I expected). */
1018
1019 static const uschar *
1020 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1021 {
1022 int ptr = 0;
1023 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1024   {
1025   if (ptr < max-1) name[ptr++] = *s;
1026   s++;
1027   }
1028 name[ptr] = 0;
1029 return s;
1030 }
1031
1032
1033
1034 /*************************************************
1035 *     Pick out the rest of a header name         *
1036 *************************************************/
1037
1038 /* A variable name starting $header_ (or just $h_ for those who like
1039 abbreviations) might not be the complete header name because headers can
1040 contain any printing characters in their names, except ':'. This function is
1041 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1042 on the end, if the name was terminated by white space.
1043
1044 Arguments:
1045   name      points to a buffer in which the name read so far exists
1046   max       is the length of the buffer
1047   s         points to the first character after the name so far, i.e. the
1048             first non-alphameric character after $header_xxxxx
1049
1050 Returns:    a pointer to the first character after the header name
1051 */
1052
1053 static const uschar *
1054 read_header_name(uschar *name, int max, const uschar *s)
1055 {
1056 int prelen = Ustrchr(name, '_') - name + 1;
1057 int ptr = Ustrlen(name) - prelen;
1058 if (ptr > 0) memmove(name, name+prelen, ptr);
1059 while (mac_isgraph(*s) && *s != ':')
1060   {
1061   if (ptr < max-1) name[ptr++] = *s;
1062   s++;
1063   }
1064 if (*s == ':') s++;
1065 name[ptr++] = ':';
1066 name[ptr] = 0;
1067 return s;
1068 }
1069
1070
1071
1072 /*************************************************
1073 *           Pick out a number from a string      *
1074 *************************************************/
1075
1076 /* Arguments:
1077   n     points to an integer into which to put the number
1078   s     points to the first digit of the number
1079
1080 Returns:  a pointer to the character after the last digit
1081 */
1082 /*XXX consider expanding to int_eximarith_t.  But the test for
1083 "overbig numbers" in 0002 still needs to overflow it. */
1084
1085 static uschar *
1086 read_number(int *n, uschar *s)
1087 {
1088 *n = 0;
1089 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1090 return s;
1091 }
1092
1093 static const uschar *
1094 read_cnumber(int *n, const uschar *s)
1095 {
1096 *n = 0;
1097 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1098 return s;
1099 }
1100
1101
1102
1103 /*************************************************
1104 *        Extract keyed subfield from a string    *
1105 *************************************************/
1106
1107 /* The yield is in dynamic store; NULL means that the key was not found.
1108
1109 Arguments:
1110   key       points to the name of the key
1111   s         points to the string from which to extract the subfield
1112
1113 Returns:    NULL if the subfield was not found, or
1114             a pointer to the subfield's data
1115 */
1116
1117 static uschar *
1118 expand_getkeyed(uschar *key, const uschar *s)
1119 {
1120 int length = Ustrlen(key);
1121 while (isspace(*s)) s++;
1122
1123 /* Loop to search for the key */
1124
1125 while (*s != 0)
1126   {
1127   int dkeylength;
1128   uschar *data;
1129   const uschar *dkey = s;
1130
1131   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1132   dkeylength = s - dkey;
1133   while (isspace(*s)) s++;
1134   if (*s == '=') while (isspace((*(++s))));
1135
1136   data = string_dequote(&s);
1137   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1138     return data;
1139
1140   while (isspace(*s)) s++;
1141   }
1142
1143 return NULL;
1144 }
1145
1146
1147
1148 static var_entry *
1149 find_var_ent(uschar * name)
1150 {
1151 int first = 0;
1152 int last = var_table_size;
1153
1154 while (last > first)
1155   {
1156   int middle = (first + last)/2;
1157   int c = Ustrcmp(name, var_table[middle].name);
1158
1159   if (c > 0) { first = middle + 1; continue; }
1160   if (c < 0) { last = middle; continue; }
1161   return &var_table[middle];
1162   }
1163 return NULL;
1164 }
1165
1166 /*************************************************
1167 *   Extract numbered subfield from string        *
1168 *************************************************/
1169
1170 /* Extracts a numbered field from a string that is divided by tokens - for
1171 example a line from /etc/passwd is divided by colon characters.  First field is
1172 numbered one.  Negative arguments count from the right. Zero returns the whole
1173 string. Returns NULL if there are insufficient tokens in the string
1174
1175 ***WARNING***
1176 Modifies final argument - this is a dynamically generated string, so that's OK.
1177
1178 Arguments:
1179   field       number of field to be extracted,
1180                 first field = 1, whole string = 0, last field = -1
1181   separators  characters that are used to break string into tokens
1182   s           points to the string from which to extract the subfield
1183
1184 Returns:      NULL if the field was not found,
1185               a pointer to the field's data inside s (modified to add 0)
1186 */
1187
1188 static uschar *
1189 expand_gettokened (int field, uschar *separators, uschar *s)
1190 {
1191 int sep = 1;
1192 int count;
1193 uschar *ss = s;
1194 uschar *fieldtext = NULL;
1195
1196 if (field == 0) return s;
1197
1198 /* Break the line up into fields in place; for field > 0 we stop when we have
1199 done the number of fields we want. For field < 0 we continue till the end of
1200 the string, counting the number of fields. */
1201
1202 count = (field > 0)? field : INT_MAX;
1203
1204 while (count-- > 0)
1205   {
1206   size_t len;
1207
1208   /* Previous field was the last one in the string. For a positive field
1209   number, this means there are not enough fields. For a negative field number,
1210   check that there are enough, and scan back to find the one that is wanted. */
1211
1212   if (sep == 0)
1213     {
1214     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1215     if ((-field) == (INT_MAX - count - 1)) return s;
1216     while (field++ < 0)
1217       {
1218       ss--;
1219       while (ss[-1] != 0) ss--;
1220       }
1221     fieldtext = ss;
1222     break;
1223     }
1224
1225   /* Previous field was not last in the string; save its start and put a
1226   zero at its end. */
1227
1228   fieldtext = ss;
1229   len = Ustrcspn(ss, separators);
1230   sep = ss[len];
1231   ss[len] = 0;
1232   ss += len + 1;
1233   }
1234
1235 return fieldtext;
1236 }
1237
1238
1239 static uschar *
1240 expand_getlistele(int field, const uschar * list)
1241 {
1242 const uschar * tlist= list;
1243 int sep= 0;
1244 uschar dummy;
1245
1246 if(field<0)
1247   {
1248   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1249   sep= 0;
1250   }
1251 if(field==0) return NULL;
1252 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1253 return string_nextinlist(&list, &sep, NULL, 0);
1254 }
1255
1256
1257 /* Certificate fields, by name.  Worry about by-OID later */
1258 /* Names are chosen to not have common prefixes */
1259
1260 #ifdef SUPPORT_TLS
1261 typedef struct
1262 {
1263 uschar * name;
1264 int      namelen;
1265 uschar * (*getfn)(void * cert, uschar * mod);
1266 } certfield;
1267 static certfield certfields[] =
1268 {                       /* linear search; no special order */
1269   { US"version",         7,  &tls_cert_version },
1270   { US"serial_number",   13, &tls_cert_serial_number },
1271   { US"subject",         7,  &tls_cert_subject },
1272   { US"notbefore",       9,  &tls_cert_not_before },
1273   { US"notafter",        8,  &tls_cert_not_after },
1274   { US"issuer",          6,  &tls_cert_issuer },
1275   { US"signature",       9,  &tls_cert_signature },
1276   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1277   { US"subj_altname",    12, &tls_cert_subject_altname },
1278   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1279   { US"crl_uri",         7,  &tls_cert_crl_uri },
1280 };
1281
1282 static uschar *
1283 expand_getcertele(uschar * field, uschar * certvar)
1284 {
1285 var_entry * vp;
1286 certfield * cp;
1287
1288 if (!(vp = find_var_ent(certvar)))
1289   {
1290   expand_string_message =
1291     string_sprintf("no variable named \"%s\"", certvar);
1292   return NULL;          /* Unknown variable name */
1293   }
1294 /* NB this stops us passing certs around in variable.  Might
1295 want to do that in future */
1296 if (vp->type != vtype_cert)
1297   {
1298   expand_string_message =
1299     string_sprintf("\"%s\" is not a certificate", certvar);
1300   return NULL;          /* Unknown variable name */
1301   }
1302 if (!*(void **)vp->value)
1303   return NULL;
1304
1305 if (*field >= '0' && *field <= '9')
1306   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1307
1308 for(cp = certfields;
1309     cp < certfields + nelem(certfields);
1310     cp++)
1311   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1312     {
1313     uschar * modifier = *(field += cp->namelen) == ','
1314       ? ++field : NULL;
1315     return (*cp->getfn)( *(void **)vp->value, modifier );
1316     }
1317
1318 expand_string_message =
1319   string_sprintf("bad field selector \"%s\" for certextract", field);
1320 return NULL;
1321 }
1322 #endif  /*SUPPORT_TLS*/
1323
1324 /*************************************************
1325 *        Extract a substring from a string       *
1326 *************************************************/
1327
1328 /* Perform the ${substr or ${length expansion operations.
1329
1330 Arguments:
1331   subject     the input string
1332   value1      the offset from the start of the input string to the start of
1333                 the output string; if negative, count from the right.
1334   value2      the length of the output string, or negative (-1) for unset
1335                 if value1 is positive, unset means "all after"
1336                 if value1 is negative, unset means "all before"
1337   len         set to the length of the returned string
1338
1339 Returns:      pointer to the output string, or NULL if there is an error
1340 */
1341
1342 static uschar *
1343 extract_substr(uschar *subject, int value1, int value2, int *len)
1344 {
1345 int sublen = Ustrlen(subject);
1346
1347 if (value1 < 0)    /* count from right */
1348   {
1349   value1 += sublen;
1350
1351   /* If the position is before the start, skip to the start, and adjust the
1352   length. If the length ends up negative, the substring is null because nothing
1353   can precede. This falls out naturally when the length is unset, meaning "all
1354   to the left". */
1355
1356   if (value1 < 0)
1357     {
1358     value2 += value1;
1359     if (value2 < 0) value2 = 0;
1360     value1 = 0;
1361     }
1362
1363   /* Otherwise an unset length => characters before value1 */
1364
1365   else if (value2 < 0)
1366     {
1367     value2 = value1;
1368     value1 = 0;
1369     }
1370   }
1371
1372 /* For a non-negative offset, if the starting position is past the end of the
1373 string, the result will be the null string. Otherwise, an unset length means
1374 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1375
1376 else
1377   {
1378   if (value1 > sublen)
1379     {
1380     value1 = sublen;
1381     value2 = 0;
1382     }
1383   else if (value2 < 0) value2 = sublen;
1384   }
1385
1386 /* Cut the length down to the maximum possible for the offset value, and get
1387 the required characters. */
1388
1389 if (value1 + value2 > sublen) value2 = sublen - value1;
1390 *len = value2;
1391 return subject + value1;
1392 }
1393
1394
1395
1396
1397 /*************************************************
1398 *            Old-style hash of a string          *
1399 *************************************************/
1400
1401 /* Perform the ${hash expansion operation.
1402
1403 Arguments:
1404   subject     the input string (an expanded substring)
1405   value1      the length of the output string; if greater or equal to the
1406                 length of the input string, the input string is returned
1407   value2      the number of hash characters to use, or 26 if negative
1408   len         set to the length of the returned string
1409
1410 Returns:      pointer to the output string, or NULL if there is an error
1411 */
1412
1413 static uschar *
1414 compute_hash(uschar *subject, int value1, int value2, int *len)
1415 {
1416 int sublen = Ustrlen(subject);
1417
1418 if (value2 < 0) value2 = 26;
1419 else if (value2 > Ustrlen(hashcodes))
1420   {
1421   expand_string_message =
1422     string_sprintf("hash count \"%d\" too big", value2);
1423   return NULL;
1424   }
1425
1426 /* Calculate the hash text. We know it is shorter than the original string, so
1427 can safely place it in subject[] (we know that subject is always itself an
1428 expanded substring). */
1429
1430 if (value1 < sublen)
1431   {
1432   int c;
1433   int i = 0;
1434   int j = value1;
1435   while ((c = (subject[j])) != 0)
1436     {
1437     int shift = (c + j++) & 7;
1438     subject[i] ^= (c << shift) | (c >> (8-shift));
1439     if (++i >= value1) i = 0;
1440     }
1441   for (i = 0; i < value1; i++)
1442     subject[i] = hashcodes[(subject[i]) % value2];
1443   }
1444 else value1 = sublen;
1445
1446 *len = value1;
1447 return subject;
1448 }
1449
1450
1451
1452
1453 /*************************************************
1454 *             Numeric hash of a string           *
1455 *************************************************/
1456
1457 /* Perform the ${nhash expansion operation. The first characters of the
1458 string are treated as most important, and get the highest prime numbers.
1459
1460 Arguments:
1461   subject     the input string
1462   value1      the maximum value of the first part of the result
1463   value2      the maximum value of the second part of the result,
1464                 or negative to produce only a one-part result
1465   len         set to the length of the returned string
1466
1467 Returns:  pointer to the output string, or NULL if there is an error.
1468 */
1469
1470 static uschar *
1471 compute_nhash (uschar *subject, int value1, int value2, int *len)
1472 {
1473 uschar *s = subject;
1474 int i = 0;
1475 unsigned long int total = 0; /* no overflow */
1476
1477 while (*s != 0)
1478   {
1479   if (i == 0) i = nelem(prime) - 1;
1480   total += prime[i--] * (unsigned int)(*s++);
1481   }
1482
1483 /* If value2 is unset, just compute one number */
1484
1485 if (value2 < 0)
1486   {
1487   s = string_sprintf("%d", total % value1);
1488   }
1489
1490 /* Otherwise do a div/mod hash */
1491
1492 else
1493   {
1494   total = total % (value1 * value2);
1495   s = string_sprintf("%d/%d", total/value2, total % value2);
1496   }
1497
1498 *len = Ustrlen(s);
1499 return s;
1500 }
1501
1502
1503
1504
1505
1506 /*************************************************
1507 *     Find the value of a header or headers      *
1508 *************************************************/
1509
1510 /* Multiple instances of the same header get concatenated, and this function
1511 can also return a concatenation of all the header lines. When concatenating
1512 specific headers that contain lists of addresses, a comma is inserted between
1513 them. Otherwise we use a straight concatenation. Because some messages can have
1514 pathologically large number of lines, there is a limit on the length that is
1515 returned. Also, to avoid massive store use which would result from using
1516 string_cat() as it copies and extends strings, we do a preliminary pass to find
1517 out exactly how much store will be needed. On "normal" messages this will be
1518 pretty trivial.
1519
1520 Arguments:
1521   name          the name of the header, without the leading $header_ or $h_,
1522                 or NULL if a concatenation of all headers is required
1523   exists_only   TRUE if called from a def: test; don't need to build a string;
1524                 just return a string that is not "" and not "0" if the header
1525                 exists
1526   newsize       return the size of memory block that was obtained; may be NULL
1527                 if exists_only is TRUE
1528   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1529                 other than concatenating, will be done on the header. Also used
1530                 for $message_headers_raw.
1531   charset       name of charset to translate MIME words to; used only if
1532                 want_raw is false; if NULL, no translation is done (this is
1533                 used for $bh_ and $bheader_)
1534
1535 Returns:        NULL if the header does not exist, else a pointer to a new
1536                 store block
1537 */
1538
1539 static uschar *
1540 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1541   uschar *charset)
1542 {
1543 BOOL found = name == NULL;
1544 int comma = 0;
1545 int len = found? 0 : Ustrlen(name);
1546 int i;
1547 uschar *yield = NULL;
1548 uschar *ptr = NULL;
1549
1550 /* Loop for two passes - saves code repetition */
1551
1552 for (i = 0; i < 2; i++)
1553   {
1554   int size = 0;
1555   header_line *h;
1556
1557   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1558     {
1559     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1560       {
1561       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1562         {
1563         int ilen;
1564         uschar *t;
1565
1566         if (exists_only) return US"1";      /* don't need actual string */
1567         found = TRUE;
1568         t = h->text + len;                  /* text to insert */
1569         if (!want_raw)                      /* unless wanted raw, */
1570           while (isspace(*t)) t++;          /* remove leading white space */
1571         ilen = h->slen - (t - h->text);     /* length to insert */
1572
1573         /* Unless wanted raw, remove trailing whitespace, including the
1574         newline. */
1575
1576         if (!want_raw)
1577           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1578
1579         /* Set comma = 1 if handling a single header and it's one of those
1580         that contains an address list, except when asked for raw headers. Only
1581         need to do this once. */
1582
1583         if (!want_raw && name != NULL && comma == 0 &&
1584             Ustrchr("BCFRST", h->type) != NULL)
1585           comma = 1;
1586
1587         /* First pass - compute total store needed; second pass - compute
1588         total store used, including this header. */
1589
1590         size += ilen + comma + 1;  /* +1 for the newline */
1591
1592         /* Second pass - concatenate the data, up to a maximum. Note that
1593         the loop stops when size hits the limit. */
1594
1595         if (i != 0)
1596           {
1597           if (size > header_insert_maxlen)
1598             {
1599             ilen -= size - header_insert_maxlen - 1;
1600             comma = 0;
1601             }
1602           Ustrncpy(ptr, t, ilen);
1603           ptr += ilen;
1604
1605           /* For a non-raw header, put in the comma if needed, then add
1606           back the newline we removed above, provided there was some text in
1607           the header. */
1608
1609           if (!want_raw && ilen > 0)
1610             {
1611             if (comma != 0) *ptr++ = ',';
1612             *ptr++ = '\n';
1613             }
1614           }
1615         }
1616       }
1617     }
1618
1619   /* At end of first pass, return NULL if no header found. Then truncate size
1620   if necessary, and get the buffer to hold the data, returning the buffer size.
1621   */
1622
1623   if (i == 0)
1624     {
1625     if (!found) return NULL;
1626     if (size > header_insert_maxlen) size = header_insert_maxlen;
1627     *newsize = size + 1;
1628     ptr = yield = store_get(*newsize);
1629     }
1630   }
1631
1632 /* That's all we do for raw header expansion. */
1633
1634 if (want_raw)
1635   {
1636   *ptr = 0;
1637   }
1638
1639 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1640 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1641 function can return an error with decoded data if the charset translation
1642 fails. If decoding fails, it returns NULL. */
1643
1644 else
1645   {
1646   uschar *decoded, *error;
1647   if (ptr > yield && ptr[-1] == '\n') ptr--;
1648   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1649   *ptr = 0;
1650   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1651     newsize, &error);
1652   if (error != NULL)
1653     {
1654     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1655       "    input was: %s\n", error, yield);
1656     }
1657   if (decoded != NULL) yield = decoded;
1658   }
1659
1660 return yield;
1661 }
1662
1663
1664
1665
1666 /*************************************************
1667 *               Return list of recipients        *
1668 *************************************************/
1669 /* A recipients list is available only during system message filtering,
1670 during ACL processing after DATA, and while expanding pipe commands
1671 generated from a system filter, but not elsewhere. */
1672
1673 static uschar *
1674 fn_recipients(void)
1675 {
1676 if (!enable_dollar_recipients) return NULL; else
1677   {
1678   int size = 128;
1679   int ptr = 0;
1680   int i;
1681   uschar * s = store_get(size);
1682   for (i = 0; i < recipients_count; i++)
1683     {
1684     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1685     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1686     }
1687   s[ptr] = 0;     /* string_cat() leaves room */
1688   return s;
1689   }
1690 }
1691
1692
1693 /*************************************************
1694 *               Find value of a variable         *
1695 *************************************************/
1696
1697 /* The table of variables is kept in alphabetic order, so we can search it
1698 using a binary chop. The "choplen" variable is nothing to do with the binary
1699 chop.
1700
1701 Arguments:
1702   name          the name of the variable being sought
1703   exists_only   TRUE if this is a def: test; passed on to find_header()
1704   skipping      TRUE => skip any processing evaluation; this is not the same as
1705                   exists_only because def: may test for values that are first
1706                   evaluated here
1707   newsize       pointer to an int which is initially zero; if the answer is in
1708                 a new memory buffer, *newsize is set to its size
1709
1710 Returns:        NULL if the variable does not exist, or
1711                 a pointer to the variable's contents, or
1712                 something non-NULL if exists_only is TRUE
1713 */
1714
1715 static uschar *
1716 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1717 {
1718 var_entry * vp;
1719 uschar *s, *domain;
1720 uschar **ss;
1721 void * val;
1722
1723 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1724 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1725 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1726 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1727 (this gave backwards compatibility at the changeover). There may be built-in
1728 variables whose names start acl_ but they should never start in this way. This
1729 slightly messy specification is a consequence of the history, needless to say.
1730
1731 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1732 set, in which case give an error. */
1733
1734 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1735      !isalpha(name[5]))
1736   {
1737   tree_node *node =
1738     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1739   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1740   }
1741
1742 /* Handle $auth<n> variables. */
1743
1744 if (Ustrncmp(name, "auth", 4) == 0)
1745   {
1746   uschar *endptr;
1747   int n = Ustrtoul(name + 4, &endptr, 10);
1748   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1749     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1750   }
1751 else if (Ustrncmp(name, "regex", 5) == 0)
1752   {
1753   uschar *endptr;
1754   int n = Ustrtoul(name + 5, &endptr, 10);
1755   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1756     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1757   }
1758
1759 /* For all other variables, search the table */
1760
1761 if (!(vp = find_var_ent(name)))
1762   return NULL;          /* Unknown variable name */
1763
1764 /* Found an existing variable. If in skipping state, the value isn't needed,
1765 and we want to avoid processing (such as looking up the host name). */
1766
1767 if (skipping)
1768   return US"";
1769
1770 val = vp->value;
1771 switch (vp->type)
1772   {
1773   case vtype_filter_int:
1774     if (!filter_running) return NULL;
1775     /* Fall through */
1776     /* VVVVVVVVVVVV */
1777   case vtype_int:
1778     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1779     return var_buffer;
1780
1781   case vtype_ino:
1782     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1783     return var_buffer;
1784
1785   case vtype_gid:
1786     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1787     return var_buffer;
1788
1789   case vtype_uid:
1790     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1791     return var_buffer;
1792
1793   case vtype_bool:
1794     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1795     return var_buffer;
1796
1797   case vtype_stringptr:                      /* Pointer to string */
1798     return (s = *((uschar **)(val))) ? s : US"";
1799
1800   case vtype_pid:
1801     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1802     return var_buffer;
1803
1804   case vtype_load_avg:
1805     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1806     return var_buffer;
1807
1808   case vtype_host_lookup:                    /* Lookup if not done so */
1809     if (sender_host_name == NULL && sender_host_address != NULL &&
1810         !host_lookup_failed && host_name_lookup() == OK)
1811       host_build_sender_fullhost();
1812     return (sender_host_name == NULL)? US"" : sender_host_name;
1813
1814   case vtype_localpart:                      /* Get local part from address */
1815     s = *((uschar **)(val));
1816     if (s == NULL) return US"";
1817     domain = Ustrrchr(s, '@');
1818     if (domain == NULL) return s;
1819     if (domain - s > sizeof(var_buffer) - 1)
1820       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1821           " in string expansion", sizeof(var_buffer));
1822     Ustrncpy(var_buffer, s, domain - s);
1823     var_buffer[domain - s] = 0;
1824     return var_buffer;
1825
1826   case vtype_domain:                         /* Get domain from address */
1827     s = *((uschar **)(val));
1828     if (s == NULL) return US"";
1829     domain = Ustrrchr(s, '@');
1830     return (domain == NULL)? US"" : domain + 1;
1831
1832   case vtype_msgheaders:
1833     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1834
1835   case vtype_msgheaders_raw:
1836     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1837
1838   case vtype_msgbody:                        /* Pointer to msgbody string */
1839   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1840     ss = (uschar **)(val);
1841     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1842       {
1843       uschar *body;
1844       off_t start_offset = SPOOL_DATA_START_OFFSET;
1845       int len = message_body_visible;
1846       if (len > message_size) len = message_size;
1847       *ss = body = store_malloc(len+1);
1848       body[0] = 0;
1849       if (vp->type == vtype_msgbody_end)
1850         {
1851         struct stat statbuf;
1852         if (fstat(deliver_datafile, &statbuf) == 0)
1853           {
1854           start_offset = statbuf.st_size - len;
1855           if (start_offset < SPOOL_DATA_START_OFFSET)
1856             start_offset = SPOOL_DATA_START_OFFSET;
1857           }
1858         }
1859       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1860         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1861           strerror(errno));
1862       len = read(deliver_datafile, body, len);
1863       if (len > 0)
1864         {
1865         body[len] = 0;
1866         if (message_body_newlines)   /* Separate loops for efficiency */
1867           while (len > 0)
1868             { if (body[--len] == 0) body[len] = ' '; }
1869         else
1870           while (len > 0)
1871             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1872         }
1873       }
1874     return (*ss == NULL)? US"" : *ss;
1875
1876   case vtype_todbsdin:                       /* BSD inbox time of day */
1877     return tod_stamp(tod_bsdin);
1878
1879   case vtype_tode:                           /* Unix epoch time of day */
1880     return tod_stamp(tod_epoch);
1881
1882   case vtype_todel:                          /* Unix epoch/usec time of day */
1883     return tod_stamp(tod_epoch_l);
1884
1885   case vtype_todf:                           /* Full time of day */
1886     return tod_stamp(tod_full);
1887
1888   case vtype_todl:                           /* Log format time of day */
1889     return tod_stamp(tod_log_bare);            /* (without timezone) */
1890
1891   case vtype_todzone:                        /* Time zone offset only */
1892     return tod_stamp(tod_zone);
1893
1894   case vtype_todzulu:                        /* Zulu time */
1895     return tod_stamp(tod_zulu);
1896
1897   case vtype_todlf:                          /* Log file datestamp tod */
1898     return tod_stamp(tod_log_datestamp_daily);
1899
1900   case vtype_reply:                          /* Get reply address */
1901     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1902       headers_charset);
1903     if (s != NULL) while (isspace(*s)) s++;
1904     if (s == NULL || *s == 0)
1905       {
1906       *newsize = 0;                            /* For the *s==0 case */
1907       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1908       }
1909     if (s != NULL)
1910       {
1911       uschar *t;
1912       while (isspace(*s)) s++;
1913       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1914       while (t > s && isspace(t[-1])) t--;
1915       *t = 0;
1916       }
1917     return (s == NULL)? US"" : s;
1918
1919   case vtype_string_func:
1920     {
1921     uschar * (*fn)() = val;
1922     return fn();
1923     }
1924
1925   case vtype_pspace:
1926     {
1927     int inodes;
1928     sprintf(CS var_buffer, "%d",
1929       receive_statvfs(val == (void *)TRUE, &inodes));
1930     }
1931   return var_buffer;
1932
1933   case vtype_pinodes:
1934     {
1935     int inodes;
1936     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1937     sprintf(CS var_buffer, "%d", inodes);
1938     }
1939   return var_buffer;
1940
1941   case vtype_cert:
1942     return *(void **)val ? US"<cert>" : US"";
1943
1944 #ifndef DISABLE_DKIM
1945   case vtype_dkim:
1946     return dkim_exim_expand_query((int)(long)val);
1947 #endif
1948
1949   }
1950
1951 return NULL;  /* Unknown variable. Silences static checkers. */
1952 }
1953
1954
1955
1956
1957 void
1958 modify_variable(uschar *name, void * value)
1959 {
1960 var_entry * vp;
1961 if ((vp = find_var_ent(name))) vp->value = value;
1962 return;          /* Unknown variable name, fail silently */
1963 }
1964
1965
1966
1967
1968
1969
1970 /*************************************************
1971 *           Read and expand substrings           *
1972 *************************************************/
1973
1974 /* This function is called to read and expand argument substrings for various
1975 expansion items. Some have a minimum requirement that is less than the maximum;
1976 in these cases, the first non-present one is set to NULL.
1977
1978 Arguments:
1979   sub        points to vector of pointers to set
1980   n          maximum number of substrings
1981   m          minimum required
1982   sptr       points to current string pointer
1983   skipping   the skipping flag
1984   check_end  if TRUE, check for final '}'
1985   name       name of item, for error message
1986   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1987              the store.
1988
1989 Returns:     0 OK; string pointer updated
1990              1 curly bracketing error (too few arguments)
1991              2 too many arguments (only if check_end is set); message set
1992              3 other error (expansion failure)
1993 */
1994
1995 static int
1996 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1997   BOOL check_end, uschar *name, BOOL *resetok)
1998 {
1999 int i;
2000 const uschar *s = *sptr;
2001
2002 while (isspace(*s)) s++;
2003 for (i = 0; i < n; i++)
2004   {
2005   if (*s != '{')
2006     {
2007     if (i < m)
2008       {
2009       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2010         "(min is %d)", name, m);
2011       return 1;
2012       }
2013     sub[i] = NULL;
2014     break;
2015     }
2016   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2017     return 3;
2018   if (*s++ != '}') return 1;
2019   while (isspace(*s)) s++;
2020   }
2021 if (check_end && *s++ != '}')
2022   {
2023   if (s[-1] == '{')
2024     {
2025     expand_string_message = string_sprintf("Too many arguments for '%s' "
2026       "(max is %d)", name, n);
2027     return 2;
2028     }
2029   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2030   return 1;
2031   }
2032
2033 *sptr = s;
2034 return 0;
2035 }
2036
2037
2038
2039
2040 /*************************************************
2041 *     Elaborate message for bad variable         *
2042 *************************************************/
2043
2044 /* For the "unknown variable" message, take a look at the variable's name, and
2045 give additional information about possible ACL variables. The extra information
2046 is added on to expand_string_message.
2047
2048 Argument:   the name of the variable
2049 Returns:    nothing
2050 */
2051
2052 static void
2053 check_variable_error_message(uschar *name)
2054 {
2055 if (Ustrncmp(name, "acl_", 4) == 0)
2056   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2057     (name[4] == 'c' || name[4] == 'm')?
2058       (isalpha(name[5])?
2059         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2060         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2061       ) :
2062       US"user-defined ACL variables must start acl_c or acl_m");
2063 }
2064
2065
2066
2067 /*
2068 Load args from sub array to globals, and call acl_check().
2069 Sub array will be corrupted on return.
2070
2071 Returns:       OK         access is granted by an ACCEPT verb
2072                DISCARD    access is (apparently) granted by a DISCARD verb
2073                FAIL       access is denied
2074                FAIL_DROP  access is denied; drop the connection
2075                DEFER      can't tell at the moment
2076                ERROR      disaster
2077 */
2078 static int
2079 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2080 {
2081 int i;
2082 int sav_narg = acl_narg;
2083 int ret;
2084 uschar * dummy_logmsg;
2085 extern int acl_where;
2086
2087 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2088 for (i = 0; i < nsub && sub[i+1]; i++)
2089   {
2090   uschar * tmp = acl_arg[i];
2091   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2092   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2093   }
2094 acl_narg = i;
2095 while (i < nsub)
2096   {
2097   sub[i+1] = acl_arg[i];
2098   acl_arg[i++] = NULL;
2099   }
2100
2101 DEBUG(D_expand)
2102   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2103     sub[0],
2104     acl_narg>0 ? acl_arg[0] : US"<none>",
2105     acl_narg>1 ? " +more"   : "");
2106
2107 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2108
2109 for (i = 0; i < nsub; i++)
2110   acl_arg[i] = sub[i+1];        /* restore old args */
2111 acl_narg = sav_narg;
2112
2113 return ret;
2114 }
2115
2116
2117
2118
2119 /*************************************************
2120 *        Read and evaluate a condition           *
2121 *************************************************/
2122
2123 /*
2124 Arguments:
2125   s        points to the start of the condition text
2126   resetok  points to a BOOL which is written false if it is unsafe to
2127            free memory. Certain condition types (acl) may have side-effect
2128            allocation which must be preserved.
2129   yield    points to a BOOL to hold the result of the condition test;
2130            if NULL, we are just reading through a condition that is
2131            part of an "or" combination to check syntax, or in a state
2132            where the answer isn't required
2133
2134 Returns:   a pointer to the first character after the condition, or
2135            NULL after an error
2136 */
2137
2138 static const uschar *
2139 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2140 {
2141 BOOL testfor = TRUE;
2142 BOOL tempcond, combined_cond;
2143 BOOL *subcondptr;
2144 BOOL sub2_honour_dollar = TRUE;
2145 int i, rc, cond_type, roffset;
2146 int_eximarith_t num[2];
2147 struct stat statbuf;
2148 uschar name[256];
2149 const uschar *sub[10];
2150
2151 const pcre *re;
2152 const uschar *rerror;
2153
2154 for (;;)
2155   {
2156   while (isspace(*s)) s++;
2157   if (*s == '!') { testfor = !testfor; s++; } else break;
2158   }
2159
2160 /* Numeric comparisons are symbolic */
2161
2162 if (*s == '=' || *s == '>' || *s == '<')
2163   {
2164   int p = 0;
2165   name[p++] = *s++;
2166   if (*s == '=')
2167     {
2168     name[p++] = '=';
2169     s++;
2170     }
2171   name[p] = 0;
2172   }
2173
2174 /* All other conditions are named */
2175
2176 else s = read_name(name, 256, s, US"_");
2177
2178 /* If we haven't read a name, it means some non-alpha character is first. */
2179
2180 if (name[0] == 0)
2181   {
2182   expand_string_message = string_sprintf("condition name expected, "
2183     "but found \"%.16s\"", s);
2184   return NULL;
2185   }
2186
2187 /* Find which condition we are dealing with, and switch on it */
2188
2189 cond_type = chop_match(name, cond_table, nelem(cond_table));
2190 switch(cond_type)
2191   {
2192   /* def: tests for a non-empty variable, or for the existence of a header. If
2193   yield == NULL we are in a skipping state, and don't care about the answer. */
2194
2195   case ECOND_DEF:
2196   if (*s != ':')
2197     {
2198     expand_string_message = US"\":\" expected after \"def\"";
2199     return NULL;
2200     }
2201
2202   s = read_name(name, 256, s+1, US"_");
2203
2204   /* Test for a header's existence. If the name contains a closing brace
2205   character, this may be a user error where the terminating colon has been
2206   omitted. Set a flag to adjust a subsequent error message in this case. */
2207
2208   if (Ustrncmp(name, "h_", 2) == 0 ||
2209       Ustrncmp(name, "rh_", 3) == 0 ||
2210       Ustrncmp(name, "bh_", 3) == 0 ||
2211       Ustrncmp(name, "header_", 7) == 0 ||
2212       Ustrncmp(name, "rheader_", 8) == 0 ||
2213       Ustrncmp(name, "bheader_", 8) == 0)
2214     {
2215     s = read_header_name(name, 256, s);
2216     /* {-for-text-editors */
2217     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2218     if (yield != NULL) *yield =
2219       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2220     }
2221
2222   /* Test for a variable's having a non-empty value. A non-existent variable
2223   causes an expansion failure. */
2224
2225   else
2226     {
2227     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2228     if (value == NULL)
2229       {
2230       expand_string_message = (name[0] == 0)?
2231         string_sprintf("variable name omitted after \"def:\"") :
2232         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2233       check_variable_error_message(name);
2234       return NULL;
2235       }
2236     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2237     }
2238
2239   return s;
2240
2241
2242   /* first_delivery tests for first delivery attempt */
2243
2244   case ECOND_FIRST_DELIVERY:
2245   if (yield != NULL) *yield = deliver_firsttime == testfor;
2246   return s;
2247
2248
2249   /* queue_running tests for any process started by a queue runner */
2250
2251   case ECOND_QUEUE_RUNNING:
2252   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2253   return s;
2254
2255
2256   /* exists:  tests for file existence
2257        isip:  tests for any IP address
2258       isip4:  tests for an IPv4 address
2259       isip6:  tests for an IPv6 address
2260         pam:  does PAM authentication
2261      radius:  does RADIUS authentication
2262    ldapauth:  does LDAP authentication
2263     pwcheck:  does Cyrus SASL pwcheck authentication
2264   */
2265
2266   case ECOND_EXISTS:
2267   case ECOND_ISIP:
2268   case ECOND_ISIP4:
2269   case ECOND_ISIP6:
2270   case ECOND_PAM:
2271   case ECOND_RADIUS:
2272   case ECOND_LDAPAUTH:
2273   case ECOND_PWCHECK:
2274
2275   while (isspace(*s)) s++;
2276   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2277
2278   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2279   if (sub[0] == NULL) return NULL;
2280   /* {-for-text-editors */
2281   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2282
2283   if (yield == NULL) return s;   /* No need to run the test if skipping */
2284
2285   switch(cond_type)
2286     {
2287     case ECOND_EXISTS:
2288     if ((expand_forbid & RDO_EXISTS) != 0)
2289       {
2290       expand_string_message = US"File existence tests are not permitted";
2291       return NULL;
2292       }
2293     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2294     break;
2295
2296     case ECOND_ISIP:
2297     case ECOND_ISIP4:
2298     case ECOND_ISIP6:
2299     rc = string_is_ip_address(sub[0], NULL);
2300     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2301              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2302     break;
2303
2304     /* Various authentication tests - all optionally compiled */
2305
2306     case ECOND_PAM:
2307     #ifdef SUPPORT_PAM
2308     rc = auth_call_pam(sub[0], &expand_string_message);
2309     goto END_AUTH;
2310     #else
2311     goto COND_FAILED_NOT_COMPILED;
2312     #endif  /* SUPPORT_PAM */
2313
2314     case ECOND_RADIUS:
2315     #ifdef RADIUS_CONFIG_FILE
2316     rc = auth_call_radius(sub[0], &expand_string_message);
2317     goto END_AUTH;
2318     #else
2319     goto COND_FAILED_NOT_COMPILED;
2320     #endif  /* RADIUS_CONFIG_FILE */
2321
2322     case ECOND_LDAPAUTH:
2323     #ifdef LOOKUP_LDAP
2324       {
2325       /* Just to keep the interface the same */
2326       BOOL do_cache;
2327       int old_pool = store_pool;
2328       store_pool = POOL_SEARCH;
2329       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2330         &expand_string_message, &do_cache);
2331       store_pool = old_pool;
2332       }
2333     goto END_AUTH;
2334     #else
2335     goto COND_FAILED_NOT_COMPILED;
2336     #endif  /* LOOKUP_LDAP */
2337
2338     case ECOND_PWCHECK:
2339     #ifdef CYRUS_PWCHECK_SOCKET
2340     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2341     goto END_AUTH;
2342     #else
2343     goto COND_FAILED_NOT_COMPILED;
2344     #endif  /* CYRUS_PWCHECK_SOCKET */
2345
2346     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2347         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2348     END_AUTH:
2349     if (rc == ERROR || rc == DEFER) return NULL;
2350     *yield = (rc == OK) == testfor;
2351     #endif
2352     }
2353   return s;
2354
2355
2356   /* call ACL (in a conditional context).  Accept true, deny false.
2357   Defer is a forced-fail.  Anything set by message= goes to $value.
2358   Up to ten parameters are used; we use the braces round the name+args
2359   like the saslauthd condition does, to permit a variable number of args.
2360   See also the expansion-item version EITEM_ACL and the traditional
2361   acl modifier ACLC_ACL.
2362   Since the ACL may allocate new global variables, tell our caller to not
2363   reclaim memory.
2364   */
2365
2366   case ECOND_ACL:
2367     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2368     {
2369     uschar *sub[10];
2370     uschar *user_msg;
2371     BOOL cond = FALSE;
2372     int size = 0;
2373     int ptr = 0;
2374
2375     while (isspace(*s)) s++;
2376     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2377
2378     switch(read_subs(sub, nelem(sub), 1,
2379       &s, yield == NULL, TRUE, US"acl", resetok))
2380       {
2381       case 1: expand_string_message = US"too few arguments or bracketing "
2382         "error for acl";
2383       case 2:
2384       case 3: return NULL;
2385       }
2386
2387     *resetok = FALSE;   /* eval_acl() might allocate; do not reclaim */
2388     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2389         {
2390         case OK:
2391           cond = TRUE;
2392         case FAIL:
2393           lookup_value = NULL;
2394           if (user_msg)
2395             {
2396             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2397             lookup_value[ptr] = '\0';
2398             }
2399           *yield = cond == testfor;
2400           break;
2401
2402         case DEFER:
2403           expand_string_forcedfail = TRUE;
2404           /*FALLTHROUGH*/
2405         default:
2406           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2407           return NULL;
2408         }
2409     return s;
2410     }
2411
2412
2413   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2414
2415      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2416
2417   However, the last two are optional. That is why the whole set is enclosed
2418   in their own set of braces. */
2419
2420   case ECOND_SASLAUTHD:
2421 #ifndef CYRUS_SASLAUTHD_SOCKET
2422     goto COND_FAILED_NOT_COMPILED;
2423 #else
2424     {
2425     uschar *sub[4];
2426     while (isspace(*s)) s++;
2427     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2428     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2429                     resetok))
2430       {
2431       case 1: expand_string_message = US"too few arguments or bracketing "
2432         "error for saslauthd";
2433       case 2:
2434       case 3: return NULL;
2435       }
2436     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2437     if (yield != NULL)
2438       {
2439       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2440         &expand_string_message);
2441       if (rc == ERROR || rc == DEFER) return NULL;
2442       *yield = (rc == OK) == testfor;
2443       }
2444     return s;
2445     }
2446 #endif /* CYRUS_SASLAUTHD_SOCKET */
2447
2448
2449   /* symbolic operators for numeric and string comparison, and a number of
2450   other operators, all requiring two arguments.
2451
2452   crypteq:           encrypts plaintext and compares against an encrypted text,
2453                        using crypt(), crypt16(), MD5 or SHA-1
2454   inlist/inlisti:    checks if first argument is in the list of the second
2455   match:             does a regular expression match and sets up the numerical
2456                        variables if it succeeds
2457   match_address:     matches in an address list
2458   match_domain:      matches in a domain list
2459   match_ip:          matches a host list that is restricted to IP addresses
2460   match_local_part:  matches in a local part list
2461   */
2462
2463   case ECOND_MATCH_ADDRESS:
2464   case ECOND_MATCH_DOMAIN:
2465   case ECOND_MATCH_IP:
2466   case ECOND_MATCH_LOCAL_PART:
2467 #ifndef EXPAND_LISTMATCH_RHS
2468     sub2_honour_dollar = FALSE;
2469 #endif
2470     /* FALLTHROUGH */
2471
2472   case ECOND_CRYPTEQ:
2473   case ECOND_INLIST:
2474   case ECOND_INLISTI:
2475   case ECOND_MATCH:
2476
2477   case ECOND_NUM_L:     /* Numerical comparisons */
2478   case ECOND_NUM_LE:
2479   case ECOND_NUM_E:
2480   case ECOND_NUM_EE:
2481   case ECOND_NUM_G:
2482   case ECOND_NUM_GE:
2483
2484   case ECOND_STR_LT:    /* String comparisons */
2485   case ECOND_STR_LTI:
2486   case ECOND_STR_LE:
2487   case ECOND_STR_LEI:
2488   case ECOND_STR_EQ:
2489   case ECOND_STR_EQI:
2490   case ECOND_STR_GT:
2491   case ECOND_STR_GTI:
2492   case ECOND_STR_GE:
2493   case ECOND_STR_GEI:
2494
2495   for (i = 0; i < 2; i++)
2496     {
2497     /* Sometimes, we don't expand substrings; too many insecure configurations
2498     created using match_address{}{} and friends, where the second param
2499     includes information from untrustworthy sources. */
2500     BOOL honour_dollar = TRUE;
2501     if ((i > 0) && !sub2_honour_dollar)
2502       honour_dollar = FALSE;
2503
2504     while (isspace(*s)) s++;
2505     if (*s != '{')
2506       {
2507       if (i == 0) goto COND_FAILED_CURLY_START;
2508       expand_string_message = string_sprintf("missing 2nd string in {} "
2509         "after \"%s\"", name);
2510       return NULL;
2511       }
2512     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2513         honour_dollar, resetok);
2514     if (sub[i] == NULL) return NULL;
2515     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2516
2517     /* Convert to numerical if required; we know that the names of all the
2518     conditions that compare numbers do not start with a letter. This just saves
2519     checking for them individually. */
2520
2521     if (!isalpha(name[0]) && yield != NULL)
2522       if (sub[i][0] == 0)
2523         {
2524         num[i] = 0;
2525         DEBUG(D_expand)
2526           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2527         }
2528       else
2529         {
2530         num[i] = expanded_string_integer(sub[i], FALSE);
2531         if (expand_string_message != NULL) return NULL;
2532         }
2533     }
2534
2535   /* Result not required */
2536
2537   if (yield == NULL) return s;
2538
2539   /* Do an appropriate comparison */
2540
2541   switch(cond_type)
2542     {
2543     case ECOND_NUM_E:
2544     case ECOND_NUM_EE:
2545     tempcond = (num[0] == num[1]);
2546     break;
2547
2548     case ECOND_NUM_G:
2549     tempcond = (num[0] > num[1]);
2550     break;
2551
2552     case ECOND_NUM_GE:
2553     tempcond = (num[0] >= num[1]);
2554     break;
2555
2556     case ECOND_NUM_L:
2557     tempcond = (num[0] < num[1]);
2558     break;
2559
2560     case ECOND_NUM_LE:
2561     tempcond = (num[0] <= num[1]);
2562     break;
2563
2564     case ECOND_STR_LT:
2565     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2566     break;
2567
2568     case ECOND_STR_LTI:
2569     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2570     break;
2571
2572     case ECOND_STR_LE:
2573     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2574     break;
2575
2576     case ECOND_STR_LEI:
2577     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2578     break;
2579
2580     case ECOND_STR_EQ:
2581     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2582     break;
2583
2584     case ECOND_STR_EQI:
2585     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2586     break;
2587
2588     case ECOND_STR_GT:
2589     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2590     break;
2591
2592     case ECOND_STR_GTI:
2593     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2594     break;
2595
2596     case ECOND_STR_GE:
2597     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2598     break;
2599
2600     case ECOND_STR_GEI:
2601     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2602     break;
2603
2604     case ECOND_MATCH:   /* Regular expression match */
2605     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2606       NULL);
2607     if (re == NULL)
2608       {
2609       expand_string_message = string_sprintf("regular expression error in "
2610         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2611       return NULL;
2612       }
2613     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2614     break;
2615
2616     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2617     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2618     goto MATCHED_SOMETHING;
2619
2620     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2621     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2622       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2623     goto MATCHED_SOMETHING;
2624
2625     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2626     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2627       {
2628       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2629         sub[0]);
2630       return NULL;
2631       }
2632     else
2633       {
2634       unsigned int *nullcache = NULL;
2635       check_host_block cb;
2636
2637       cb.host_name = US"";
2638       cb.host_address = sub[0];
2639
2640       /* If the host address starts off ::ffff: it is an IPv6 address in
2641       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2642       addresses. */
2643
2644       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2645         cb.host_address + 7 : cb.host_address;
2646
2647       rc = match_check_list(
2648              &sub[1],                   /* the list */
2649              0,                         /* separator character */
2650              &hostlist_anchor,          /* anchor pointer */
2651              &nullcache,                /* cache pointer */
2652              check_host,                /* function for testing */
2653              &cb,                       /* argument for function */
2654              MCL_HOST,                  /* type of check */
2655              sub[0],                    /* text for debugging */
2656              NULL);                     /* where to pass back data */
2657       }
2658     goto MATCHED_SOMETHING;
2659
2660     case ECOND_MATCH_LOCAL_PART:
2661     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2662       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2663     /* Fall through */
2664     /* VVVVVVVVVVVV */
2665     MATCHED_SOMETHING:
2666     switch(rc)
2667       {
2668       case OK:
2669       tempcond = TRUE;
2670       break;
2671
2672       case FAIL:
2673       tempcond = FALSE;
2674       break;
2675
2676       case DEFER:
2677       expand_string_message = string_sprintf("unable to complete match "
2678         "against \"%s\": %s", sub[1], search_error_message);
2679       return NULL;
2680       }
2681
2682     break;
2683
2684     /* Various "encrypted" comparisons. If the second string starts with
2685     "{" then an encryption type is given. Default to crypt() or crypt16()
2686     (build-time choice). */
2687     /* }-for-text-editors */
2688
2689     case ECOND_CRYPTEQ:
2690     #ifndef SUPPORT_CRYPTEQ
2691     goto COND_FAILED_NOT_COMPILED;
2692     #else
2693     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2694       {
2695       int sublen = Ustrlen(sub[1]+5);
2696       md5 base;
2697       uschar digest[16];
2698
2699       md5_start(&base);
2700       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2701
2702       /* If the length that we are comparing against is 24, the MD5 digest
2703       is expressed as a base64 string. This is the way LDAP does it. However,
2704       some other software uses a straightforward hex representation. We assume
2705       this if the length is 32. Other lengths fail. */
2706
2707       if (sublen == 24)
2708         {
2709         uschar *coded = b64encode(digest, 16);
2710         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2711           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2712         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2713         }
2714       else if (sublen == 32)
2715         {
2716         int i;
2717         uschar coded[36];
2718         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2719         coded[32] = 0;
2720         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2721           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2722         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2723         }
2724       else
2725         {
2726         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2727           "fail\n  crypted=%s\n", sub[1]+5);
2728         tempcond = FALSE;
2729         }
2730       }
2731
2732     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2733       {
2734       int sublen = Ustrlen(sub[1]+6);
2735       hctx h;
2736       uschar digest[20];
2737
2738       sha1_start(&h);
2739       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2740
2741       /* If the length that we are comparing against is 28, assume the SHA1
2742       digest is expressed as a base64 string. If the length is 40, assume a
2743       straightforward hex representation. Other lengths fail. */
2744
2745       if (sublen == 28)
2746         {
2747         uschar *coded = b64encode(digest, 20);
2748         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2749           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2750         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2751         }
2752       else if (sublen == 40)
2753         {
2754         int i;
2755         uschar coded[44];
2756         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2757         coded[40] = 0;
2758         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2759           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2760         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2761         }
2762       else
2763         {
2764         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2765           "fail\n  crypted=%s\n", sub[1]+6);
2766         tempcond = FALSE;
2767         }
2768       }
2769
2770     else   /* {crypt} or {crypt16} and non-{ at start */
2771            /* }-for-text-editors */
2772       {
2773       int which = 0;
2774       uschar *coded;
2775
2776       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2777         {
2778         sub[1] += 7;
2779         which = 1;
2780         }
2781       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2782         {
2783         sub[1] += 9;
2784         which = 2;
2785         }
2786       else if (sub[1][0] == '{')                /* }-for-text-editors */
2787         {
2788         expand_string_message = string_sprintf("unknown encryption mechanism "
2789           "in \"%s\"", sub[1]);
2790         return NULL;
2791         }
2792
2793       switch(which)
2794         {
2795         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2796         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2797         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2798         }
2799
2800       #define STR(s) # s
2801       #define XSTR(s) STR(s)
2802       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2803         "  subject=%s\n  crypted=%s\n",
2804         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2805         coded, sub[1]);
2806       #undef STR
2807       #undef XSTR
2808
2809       /* If the encrypted string contains fewer than two characters (for the
2810       salt), force failure. Otherwise we get false positives: with an empty
2811       string the yield of crypt() is an empty string! */
2812
2813       if (coded)
2814         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2815       else if (errno == EINVAL)
2816         tempcond = FALSE;
2817       else
2818         {
2819         expand_string_message = string_sprintf("crypt error: %s\n",
2820           US strerror(errno));
2821         return NULL;
2822         }
2823       }
2824     break;
2825     #endif  /* SUPPORT_CRYPTEQ */
2826
2827     case ECOND_INLIST:
2828     case ECOND_INLISTI:
2829       {
2830       const uschar * list = sub[1];
2831       int sep = 0;
2832       uschar *save_iterate_item = iterate_item;
2833       int (*compare)(const uschar *, const uschar *);
2834
2835       DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2836
2837       tempcond = FALSE;
2838       compare = cond_type == ECOND_INLISTI
2839         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2840
2841       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2842         if (compare(sub[0], iterate_item) == 0)
2843           {
2844           tempcond = TRUE;
2845           break;
2846           }
2847       iterate_item = save_iterate_item;
2848       }
2849
2850     }   /* Switch for comparison conditions */
2851
2852   *yield = tempcond == testfor;
2853   return s;    /* End of comparison conditions */
2854
2855
2856   /* and/or: computes logical and/or of several conditions */
2857
2858   case ECOND_AND:
2859   case ECOND_OR:
2860   subcondptr = (yield == NULL)? NULL : &tempcond;
2861   combined_cond = (cond_type == ECOND_AND);
2862
2863   while (isspace(*s)) s++;
2864   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2865
2866   for (;;)
2867     {
2868     while (isspace(*s)) s++;
2869     /* {-for-text-editors */
2870     if (*s == '}') break;
2871     if (*s != '{')                                      /* }-for-text-editors */
2872       {
2873       expand_string_message = string_sprintf("each subcondition "
2874         "inside an \"%s{...}\" condition must be in its own {}", name);
2875       return NULL;
2876       }
2877
2878     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2879       {
2880       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2881         expand_string_message, name);
2882       return NULL;
2883       }
2884     while (isspace(*s)) s++;
2885
2886     /* {-for-text-editors */
2887     if (*s++ != '}')
2888       {
2889       /* {-for-text-editors */
2890       expand_string_message = string_sprintf("missing } at end of condition "
2891         "inside \"%s\" group", name);
2892       return NULL;
2893       }
2894
2895     if (yield != NULL)
2896       {
2897       if (cond_type == ECOND_AND)
2898         {
2899         combined_cond &= tempcond;
2900         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2901         }                                       /* evaluate any more */
2902       else
2903         {
2904         combined_cond |= tempcond;
2905         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2906         }                                       /* evaluate any more */
2907       }
2908     }
2909
2910   if (yield != NULL) *yield = (combined_cond == testfor);
2911   return ++s;
2912
2913
2914   /* forall/forany: iterates a condition with different values */
2915
2916   case ECOND_FORALL:
2917   case ECOND_FORANY:
2918     {
2919     const uschar * list;
2920     int sep = 0;
2921     uschar *save_iterate_item = iterate_item;
2922
2923     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2924
2925     while (isspace(*s)) s++;
2926     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2927     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2928     if (sub[0] == NULL) return NULL;
2929     /* {-for-text-editors */
2930     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2931
2932     while (isspace(*s)) s++;
2933     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2934
2935     sub[1] = s;
2936
2937     /* Call eval_condition once, with result discarded (as if scanning a
2938     "false" part). This allows us to find the end of the condition, because if
2939     the list it empty, we won't actually evaluate the condition for real. */
2940
2941     if (!(s = eval_condition(sub[1], resetok, NULL)))
2942       {
2943       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2944         expand_string_message, name);
2945       return NULL;
2946       }
2947     while (isspace(*s)) s++;
2948
2949     /* {-for-text-editors */
2950     if (*s++ != '}')
2951       {
2952       /* {-for-text-editors */
2953       expand_string_message = string_sprintf("missing } at end of condition "
2954         "inside \"%s\"", name);
2955       return NULL;
2956       }
2957
2958     if (yield != NULL) *yield = !testfor;
2959     list = sub[0];
2960     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2961       {
2962       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2963       if (!eval_condition(sub[1], resetok, &tempcond))
2964         {
2965         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2966           expand_string_message, name);
2967         iterate_item = save_iterate_item;
2968         return NULL;
2969         }
2970       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
2971         tempcond? "true":"false");
2972
2973       if (yield != NULL) *yield = (tempcond == testfor);
2974       if (tempcond == (cond_type == ECOND_FORANY)) break;
2975       }
2976
2977     iterate_item = save_iterate_item;
2978     return s;
2979     }
2980
2981
2982   /* The bool{} expansion condition maps a string to boolean.
2983   The values supported should match those supported by the ACL condition
2984   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2985   of true/false.  Note that Router "condition" rules have a different
2986   interpretation, where general data can be used and only a few values
2987   map to FALSE.
2988   Note that readconf.c boolean matching, for boolean configuration options,
2989   only matches true/yes/false/no.
2990   The bool_lax{} condition matches the Router logic, which is much more
2991   liberal. */
2992   case ECOND_BOOL:
2993   case ECOND_BOOL_LAX:
2994     {
2995     uschar *sub_arg[1];
2996     uschar *t, *t2;
2997     uschar *ourname;
2998     size_t len;
2999     BOOL boolvalue = FALSE;
3000     while (isspace(*s)) s++;
3001     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3002     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3003     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3004       {
3005       case 1: expand_string_message = string_sprintf(
3006                   "too few arguments or bracketing error for %s",
3007                   ourname);
3008       /*FALLTHROUGH*/
3009       case 2:
3010       case 3: return NULL;
3011       }
3012     t = sub_arg[0];
3013     while (isspace(*t)) t++;
3014     len = Ustrlen(t);
3015     if (len)
3016       {
3017       /* trailing whitespace: seems like a good idea to ignore it too */
3018       t2 = t + len - 1;
3019       while (isspace(*t2)) t2--;
3020       if (t2 != (t + len))
3021         {
3022         *++t2 = '\0';
3023         len = t2 - t;
3024         }
3025       }
3026     DEBUG(D_expand)
3027       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3028     /* logic for the lax case from expand_check_condition(), which also does
3029     expands, and the logic is both short and stable enough that there should
3030     be no maintenance burden from replicating it. */
3031     if (len == 0)
3032       boolvalue = FALSE;
3033     else if (*t == '-'
3034              ? Ustrspn(t+1, "0123456789") == len-1
3035              : Ustrspn(t,   "0123456789") == len)
3036       {
3037       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3038       /* expand_check_condition only does a literal string "0" check */
3039       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3040         boolvalue = TRUE;
3041       }
3042     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3043       boolvalue = TRUE;
3044     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3045       boolvalue = FALSE;
3046     else if (cond_type == ECOND_BOOL_LAX)
3047       boolvalue = TRUE;
3048     else
3049       {
3050       expand_string_message = string_sprintf("unrecognised boolean "
3051        "value \"%s\"", t);
3052       return NULL;
3053       }
3054     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3055         boolvalue? "true":"false");
3056     if (yield != NULL) *yield = (boolvalue == testfor);
3057     return s;
3058     }
3059
3060   /* Unknown condition */
3061
3062   default:
3063   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3064   return NULL;
3065   }   /* End switch on condition type */
3066
3067 /* Missing braces at start and end of data */
3068
3069 COND_FAILED_CURLY_START:
3070 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3071 return NULL;
3072
3073 COND_FAILED_CURLY_END:
3074 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3075   name);
3076 return NULL;
3077
3078 /* A condition requires code that is not compiled */
3079
3080 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3081     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3082     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3083 COND_FAILED_NOT_COMPILED:
3084 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3085   name);
3086 return NULL;
3087 #endif
3088 }
3089
3090
3091
3092
3093 /*************************************************
3094 *          Save numerical variables              *
3095 *************************************************/
3096
3097 /* This function is called from items such as "if" that want to preserve and
3098 restore the numbered variables.
3099
3100 Arguments:
3101   save_expand_string    points to an array of pointers to set
3102   save_expand_nlength   points to an array of ints for the lengths
3103
3104 Returns:                the value of expand max to save
3105 */
3106
3107 static int
3108 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3109 {
3110 int i;
3111 for (i = 0; i <= expand_nmax; i++)
3112   {
3113   save_expand_nstring[i] = expand_nstring[i];
3114   save_expand_nlength[i] = expand_nlength[i];
3115   }
3116 return expand_nmax;
3117 }
3118
3119
3120
3121 /*************************************************
3122 *           Restore numerical variables          *
3123 *************************************************/
3124
3125 /* This function restored saved values of numerical strings.
3126
3127 Arguments:
3128   save_expand_nmax      the number of strings to restore
3129   save_expand_string    points to an array of pointers
3130   save_expand_nlength   points to an array of ints
3131
3132 Returns:                nothing
3133 */
3134
3135 static void
3136 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3137   int *save_expand_nlength)
3138 {
3139 int i;
3140 expand_nmax = save_expand_nmax;
3141 for (i = 0; i <= expand_nmax; i++)
3142   {
3143   expand_nstring[i] = save_expand_nstring[i];
3144   expand_nlength[i] = save_expand_nlength[i];
3145   }
3146 }
3147
3148
3149
3150
3151
3152 /*************************************************
3153 *            Handle yes/no substrings            *
3154 *************************************************/
3155
3156 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3157 alternative substrings that depend on whether or not the condition was true,
3158 or the lookup or extraction succeeded. The substrings always have to be
3159 expanded, to check their syntax, but "skipping" is set when the result is not
3160 needed - this avoids unnecessary nested lookups.
3161
3162 Arguments:
3163   skipping       TRUE if we were skipping when this item was reached
3164   yes            TRUE if the first string is to be used, else use the second
3165   save_lookup    a value to put back into lookup_value before the 2nd expansion
3166   sptr           points to the input string pointer
3167   yieldptr       points to the output string pointer
3168   sizeptr        points to the output string size
3169   ptrptr         points to the output string pointer
3170   type           "lookup", "if", "extract", "run", "env", "listextract" or
3171                  "certextract" for error message
3172   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3173                 the store.
3174
3175 Returns:         0 OK; lookup_value has been reset to save_lookup
3176                  1 expansion failed
3177                  2 expansion failed because of bracketing error
3178 */
3179
3180 static int
3181 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3182   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3183 {
3184 int rc = 0;
3185 const uschar *s = *sptr;    /* Local value */
3186 uschar *sub1, *sub2;
3187 const uschar * errwhere;
3188
3189 /* If there are no following strings, we substitute the contents of $value for
3190 lookups and for extractions in the success case. For the ${if item, the string
3191 "true" is substituted. In the fail case, nothing is substituted for all three
3192 items. */
3193
3194 while (isspace(*s)) s++;
3195 if (*s == '}')
3196   {
3197   if (type[0] == 'i')
3198     {
3199     if (yes && !skipping)
3200       *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3201     }
3202   else
3203     {
3204     if (yes && lookup_value && !skipping)
3205       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3206     lookup_value = save_lookup;
3207     }
3208   s++;
3209   goto RETURN;
3210   }
3211
3212 /* The first following string must be braced. */
3213
3214 if (*s++ != '{')
3215   {
3216   errwhere = US"'yes' part did not start with '{'";
3217   goto FAILED_CURLY;
3218   }
3219
3220 /* Expand the first substring. Forced failures are noticed only if we actually
3221 want this string. Set skipping in the call in the fail case (this will always
3222 be the case if we were already skipping). */
3223
3224 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3225 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3226 expand_string_forcedfail = FALSE;
3227 if (*s++ != '}')
3228   {
3229   errwhere = US"'yes' part did not end with '}'";
3230   goto FAILED_CURLY;
3231   }
3232
3233 /* If we want the first string, add it to the output */
3234
3235 if (yes)
3236   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3237
3238 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3239 $value to what it was at the start of the item, so that it has this value
3240 during the second string expansion. For the call from "if" or "run" to this
3241 function, save_lookup is set to lookup_value, so that this statement does
3242 nothing. */
3243
3244 lookup_value = save_lookup;
3245
3246 /* There now follows either another substring, or "fail", or nothing. This
3247 time, forced failures are noticed only if we want the second string. We must
3248 set skipping in the nested call if we don't want this string, or if we were
3249 already skipping. */
3250
3251 while (isspace(*s)) s++;
3252 if (*s == '{')
3253   {
3254   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3255   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3256   expand_string_forcedfail = FALSE;
3257   if (*s++ != '}')
3258     {
3259     errwhere = US"'no' part did not start with '{'";
3260     goto FAILED_CURLY;
3261     }
3262
3263   /* If we want the second string, add it to the output */
3264
3265   if (!yes)
3266     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3267   }
3268
3269 /* If there is no second string, but the word "fail" is present when the use of
3270 the second string is wanted, set a flag indicating it was a forced failure
3271 rather than a syntactic error. Swallow the terminating } in case this is nested
3272 inside another lookup or if or extract. */
3273
3274 else if (*s != '}')
3275   {
3276   uschar name[256];
3277   /* deconst cast ok here as source is s anyway */
3278   s = US read_name(name, sizeof(name), s, US"_");
3279   if (Ustrcmp(name, "fail") == 0)
3280     {
3281     if (!yes && !skipping)
3282       {
3283       while (isspace(*s)) s++;
3284       if (*s++ != '}')
3285         {
3286         errwhere = US"did not close with '}' after forcedfail";
3287         goto FAILED_CURLY;
3288         }
3289       expand_string_message =
3290         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3291       expand_string_forcedfail = TRUE;
3292       goto FAILED;
3293       }
3294     }
3295   else
3296     {
3297     expand_string_message =
3298       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3299     goto FAILED;
3300     }
3301   }
3302
3303 /* All we have to do now is to check on the final closing brace. */
3304
3305 while (isspace(*s)) s++;
3306 if (*s++ != '}')
3307   {
3308   errwhere = US"did not close with '}'";
3309   goto FAILED_CURLY;
3310   }
3311
3312
3313 RETURN:
3314 /* Update the input pointer value before returning */
3315 *sptr = s;
3316 return rc;
3317
3318 FAILED_CURLY:
3319   /* Get here if there is a bracketing failure */
3320   expand_string_message = string_sprintf(
3321     "curly-bracket problem in conditional yes/no parsing: %s\n"
3322     " remaining string is '%s'", errwhere, --s);
3323   rc = 2;
3324   goto RETURN;
3325
3326 FAILED:
3327   /* Get here for other failures */
3328   rc = 1;
3329   goto RETURN;
3330 }
3331
3332
3333
3334
3335 /*************************************************
3336 *    Handle MD5 or SHA-1 computation for HMAC    *
3337 *************************************************/
3338
3339 /* These are some wrapping functions that enable the HMAC code to be a bit
3340 cleaner. A good compiler will spot the tail recursion.
3341
3342 Arguments:
3343   type         HMAC_MD5 or HMAC_SHA1
3344   remaining    are as for the cryptographic hash functions
3345
3346 Returns:       nothing
3347 */
3348
3349 static void
3350 chash_start(int type, void *base)
3351 {
3352 if (type == HMAC_MD5)
3353   md5_start((md5 *)base);
3354 else
3355   sha1_start((hctx *)base);
3356 }
3357
3358 static void
3359 chash_mid(int type, void *base, uschar *string)
3360 {
3361 if (type == HMAC_MD5)
3362   md5_mid((md5 *)base, string);
3363 else
3364   sha1_mid((hctx *)base, string);
3365 }
3366
3367 static void
3368 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3369 {
3370 if (type == HMAC_MD5)
3371   md5_end((md5 *)base, string, length, digest);
3372 else
3373   sha1_end((hctx *)base, string, length, digest);
3374 }
3375
3376
3377
3378
3379
3380 /********************************************************
3381 * prvs: Get last three digits of days since Jan 1, 1970 *
3382 ********************************************************/
3383
3384 /* This is needed to implement the "prvs" BATV reverse
3385    path signing scheme
3386
3387 Argument: integer "days" offset to add or substract to
3388           or from the current number of days.
3389
3390 Returns:  pointer to string containing the last three
3391           digits of the number of days since Jan 1, 1970,
3392           modified by the offset argument, NULL if there
3393           was an error in the conversion.
3394
3395 */
3396
3397 static uschar *
3398 prvs_daystamp(int day_offset)
3399 {
3400 uschar *days = store_get(32);                /* Need at least 24 for cases */
3401 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3402   (time(NULL) + day_offset*86400)/86400);
3403 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3404 }
3405
3406
3407
3408 /********************************************************
3409 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3410 ********************************************************/
3411
3412 /* This is needed to implement the "prvs" BATV reverse
3413    path signing scheme
3414
3415 Arguments:
3416   address RFC2821 Address to use
3417       key The key to use (must be less than 64 characters
3418           in size)
3419   key_num Single-digit key number to use. Defaults to
3420           '0' when NULL.
3421
3422 Returns:  pointer to string containing the first three
3423           bytes of the final hash in hex format, NULL if
3424           there was an error in the process.
3425 */
3426
3427 static uschar *
3428 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3429 {
3430 uschar *hash_source, *p;
3431 int size = 0,offset = 0,i;
3432 hctx h;
3433 uschar innerhash[20];
3434 uschar finalhash[20];
3435 uschar innerkey[64];
3436 uschar outerkey[64];
3437 uschar *finalhash_hex = store_get(40);
3438
3439 if (key_num == NULL)
3440   key_num = US"0";
3441
3442 if (Ustrlen(key) > 64)
3443   return NULL;
3444
3445 hash_source = string_catn(NULL, &size, &offset, key_num, 1);
3446 hash_source = string_catn(hash_source, &size, &offset, daystamp, 3);
3447 hash_source = string_cat(hash_source, &size, &offset, address);
3448 hash_source[offset] = '\0';
3449
3450 DEBUG(D_expand) debug_printf_indent("prvs: hash source is '%s'\n", hash_source);
3451
3452 memset(innerkey, 0x36, 64);
3453 memset(outerkey, 0x5c, 64);
3454
3455 for (i = 0; i < Ustrlen(key); i++)
3456   {
3457   innerkey[i] ^= key[i];
3458   outerkey[i] ^= key[i];
3459   }
3460
3461 chash_start(HMAC_SHA1, &h);
3462 chash_mid(HMAC_SHA1, &h, innerkey);
3463 chash_end(HMAC_SHA1, &h, hash_source, offset, innerhash);
3464
3465 chash_start(HMAC_SHA1, &h);
3466 chash_mid(HMAC_SHA1, &h, outerkey);
3467 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3468
3469 p = finalhash_hex;
3470 for (i = 0; i < 3; i++)
3471   {
3472   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3473   *p++ = hex_digits[finalhash[i] & 0x0f];
3474   }
3475 *p = '\0';
3476
3477 return finalhash_hex;
3478 }
3479
3480
3481
3482
3483 /*************************************************
3484 *        Join a file onto the output string      *
3485 *************************************************/
3486
3487 /* This is used for readfile/readsock and after a run expansion.
3488 It joins the contents of a file onto the output string, globally replacing
3489 newlines with a given string (optionally).
3490
3491 Arguments:
3492   f            the FILE
3493   yield        pointer to the expandable string
3494   sizep        pointer to the current size
3495   ptrp         pointer to the current position
3496   eol          newline replacement string, or NULL
3497
3498 Returns:       new value of string pointer
3499 */
3500
3501 static uschar *
3502 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3503 {
3504 uschar buffer[1024];
3505
3506 while (Ufgets(buffer, sizeof(buffer), f))
3507   {
3508   int len = Ustrlen(buffer);
3509   if (eol && buffer[len-1] == '\n') len--;
3510   yield = string_catn(yield, sizep, ptrp, buffer, len);
3511   if (eol && buffer[len])
3512     yield = string_cat(yield, sizep, ptrp, eol);
3513   }
3514
3515 if (yield) yield[*ptrp] = 0;
3516
3517 return yield;
3518 }
3519
3520
3521
3522
3523 /*************************************************
3524 *          Evaluate numeric expression           *
3525 *************************************************/
3526
3527 /* This is a set of mutually recursive functions that evaluate an arithmetic
3528 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3529 these functions that is called from elsewhere is eval_expr, whose interface is:
3530
3531 Arguments:
3532   sptr        pointer to the pointer to the string - gets updated
3533   decimal     TRUE if numbers are to be assumed decimal
3534   error       pointer to where to put an error message - must be NULL on input
3535   endket      TRUE if ')' must terminate - FALSE for external call
3536
3537 Returns:      on success: the value of the expression, with *error still NULL
3538               on failure: an undefined value, with *error = a message
3539 */
3540
3541 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3542
3543
3544 static int_eximarith_t
3545 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3546 {
3547 uschar *s = *sptr;
3548 int_eximarith_t x = eval_op_or(&s, decimal, error);
3549 if (*error == NULL)
3550   {
3551   if (endket)
3552     {
3553     if (*s != ')')
3554       *error = US"expecting closing parenthesis";
3555     else
3556       while (isspace(*(++s)));
3557     }
3558   else if (*s != 0) *error = US"expecting operator";
3559   }
3560 *sptr = s;
3561 return x;
3562 }
3563
3564
3565 static int_eximarith_t
3566 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3567 {
3568 register int c;
3569 int_eximarith_t n;
3570 uschar *s = *sptr;
3571 while (isspace(*s)) s++;
3572 c = *s;
3573 if (isdigit(c))
3574   {
3575   int count;
3576   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3577   s += count;
3578   switch (tolower(*s))
3579     {
3580     default: break;
3581     case 'k': n *= 1024; s++; break;
3582     case 'm': n *= 1024*1024; s++; break;
3583     case 'g': n *= 1024*1024*1024; s++; break;
3584     }
3585   while (isspace (*s)) s++;
3586   }
3587 else if (c == '(')
3588   {
3589   s++;
3590   n = eval_expr(&s, decimal, error, 1);
3591   }
3592 else
3593   {
3594   *error = US"expecting number or opening parenthesis";
3595   n = 0;
3596   }
3597 *sptr = s;
3598 return n;
3599 }
3600
3601
3602 static int_eximarith_t
3603 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3604 {
3605 uschar *s = *sptr;
3606 int_eximarith_t x;
3607 while (isspace(*s)) s++;
3608 if (*s == '+' || *s == '-' || *s == '~')
3609   {
3610   int op = *s++;
3611   x = eval_op_unary(&s, decimal, error);
3612   if (op == '-') x = -x;
3613     else if (op == '~') x = ~x;
3614   }
3615 else
3616   {
3617   x = eval_number(&s, decimal, error);
3618   }
3619 *sptr = s;
3620 return x;
3621 }
3622
3623
3624 static int_eximarith_t
3625 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3626 {
3627 uschar *s = *sptr;
3628 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3629 if (*error == NULL)
3630   {
3631   while (*s == '*' || *s == '/' || *s == '%')
3632     {
3633     int op = *s++;
3634     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3635     if (*error != NULL) break;
3636     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3637      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3638      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3639      * -N*M is INT_MIN will yield INT_MIN.
3640      * Since we don't support floating point, this is somewhat simpler.
3641      * Ideally, we'd return an error, but since we overflow for all other
3642      * arithmetic, consistency suggests otherwise, but what's the correct value
3643      * to use?  There is none.
3644      * The C standard guarantees overflow for unsigned arithmetic but signed
3645      * overflow invokes undefined behaviour; in practice, this is overflow
3646      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3647      * that long/longlong larger than int are available, or we could just work
3648      * with larger types.  We should consider whether to guarantee 32bit eval
3649      * and 64-bit working variables, with errors returned.  For now ...
3650      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3651      * can just let the other invalid results occur otherwise, as they have
3652      * until now.  For this one case, we can coerce.
3653      */
3654     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3655       {
3656       DEBUG(D_expand)
3657         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3658             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3659       x = EXIM_ARITH_MAX;
3660       continue;
3661       }
3662     if (op == '*')
3663       x *= y;
3664     else
3665       {
3666       if (y == 0)
3667         {
3668         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3669         x = 0;
3670         break;
3671         }
3672       if (op == '/')
3673         x /= y;
3674       else
3675         x %= y;
3676       }
3677     }
3678   }
3679 *sptr = s;
3680 return x;
3681 }
3682
3683
3684 static int_eximarith_t
3685 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3686 {
3687 uschar *s = *sptr;
3688 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3689 if (!*error)
3690   {
3691   while (*s == '+' || *s == '-')
3692     {
3693     int op = *s++;
3694     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3695     if (*error) break;
3696     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3697        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3698       {                 /* over-conservative check */
3699       *error = op == '+'
3700         ? US"overflow in sum" : US"overflow in difference";
3701       break;
3702       }
3703     if (op == '+') x += y; else x -= y;
3704     }
3705   }
3706 *sptr = s;
3707 return x;
3708 }
3709
3710
3711 static int_eximarith_t
3712 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3713 {
3714 uschar *s = *sptr;
3715 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3716 if (*error == NULL)
3717   {
3718   while ((*s == '<' || *s == '>') && s[1] == s[0])
3719     {
3720     int_eximarith_t y;
3721     int op = *s++;
3722     s++;
3723     y = eval_op_sum(&s, decimal, error);
3724     if (*error != NULL) break;
3725     if (op == '<') x <<= y; else x >>= y;
3726     }
3727   }
3728 *sptr = s;
3729 return x;
3730 }
3731
3732
3733 static int_eximarith_t
3734 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3735 {
3736 uschar *s = *sptr;
3737 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3738 if (*error == NULL)
3739   {
3740   while (*s == '&')
3741     {
3742     int_eximarith_t y;
3743     s++;
3744     y = eval_op_shift(&s, decimal, error);
3745     if (*error != NULL) break;
3746     x &= y;
3747     }
3748   }
3749 *sptr = s;
3750 return x;
3751 }
3752
3753
3754 static int_eximarith_t
3755 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3756 {
3757 uschar *s = *sptr;
3758 int_eximarith_t x = eval_op_and(&s, decimal, error);
3759 if (*error == NULL)
3760   {
3761   while (*s == '^')
3762     {
3763     int_eximarith_t y;
3764     s++;
3765     y = eval_op_and(&s, decimal, error);
3766     if (*error != NULL) break;
3767     x ^= y;
3768     }
3769   }
3770 *sptr = s;
3771 return x;
3772 }
3773
3774
3775 static int_eximarith_t
3776 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3777 {
3778 uschar *s = *sptr;
3779 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3780 if (*error == NULL)
3781   {
3782   while (*s == '|')
3783     {
3784     int_eximarith_t y;
3785     s++;
3786     y = eval_op_xor(&s, decimal, error);
3787     if (*error != NULL) break;
3788     x |= y;
3789     }
3790   }
3791 *sptr = s;
3792 return x;
3793 }
3794
3795
3796
3797 /*************************************************
3798 *                 Expand string                  *
3799 *************************************************/
3800
3801 /* Returns either an unchanged string, or the expanded string in stacking pool
3802 store. Interpreted sequences are:
3803
3804    \...                    normal escaping rules
3805    $name                   substitutes the variable
3806    ${name}                 ditto
3807    ${op:string}            operates on the expanded string value
3808    ${item{arg1}{arg2}...}  expands the args and then does the business
3809                              some literal args are not enclosed in {}
3810
3811 There are now far too many operators and item types to make it worth listing
3812 them here in detail any more.
3813
3814 We use an internal routine recursively to handle embedded substrings. The
3815 external function follows. The yield is NULL if the expansion failed, and there
3816 are two cases: if something collapsed syntactically, or if "fail" was given
3817 as the action on a lookup failure. These can be distinguished by looking at the
3818 variable expand_string_forcedfail, which is TRUE in the latter case.
3819
3820 The skipping flag is set true when expanding a substring that isn't actually
3821 going to be used (after "if" or "lookup") and it prevents lookups from
3822 happening lower down.
3823
3824 Store usage: At start, a store block of the length of the input plus 64
3825 is obtained. This is expanded as necessary by string_cat(), which might have to
3826 get a new block, or might be able to expand the original. At the end of the
3827 function we can release any store above that portion of the yield block that
3828 was actually used. In many cases this will be optimal.
3829
3830 However: if the first item in the expansion is a variable name or header name,
3831 we reset the store before processing it; if the result is in fresh store, we
3832 use that without copying. This is helpful for expanding strings like
3833 $message_headers which can get very long.
3834
3835 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3836 since resetting the store at the end of the expansion will free store that was
3837 allocated by the plugin code as well as the slop after the expanded string. So
3838 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3839 and, given the acl condition, ${if }. This is an unfortunate consequence of
3840 string expansion becoming too powerful.
3841
3842 Arguments:
3843   string         the string to be expanded
3844   ket_ends       true if expansion is to stop at }
3845   left           if not NULL, a pointer to the first character after the
3846                  expansion is placed here (typically used with ket_ends)
3847   skipping       TRUE for recursive calls when the value isn't actually going
3848                  to be used (to allow for optimisation)
3849   honour_dollar  TRUE if $ is to be expanded,
3850                  FALSE if it's just another character
3851   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3852                  the store.
3853
3854 Returns:         NULL if expansion fails:
3855                    expand_string_forcedfail is set TRUE if failure was forced
3856                    expand_string_message contains a textual error message
3857                  a pointer to the expanded string on success
3858 */
3859
3860 static uschar *
3861 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3862   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3863 {
3864 int ptr = 0;
3865 int size = Ustrlen(string)+ 64;
3866 uschar *yield = store_get(size);
3867 int item_type;
3868 const uschar *s = string;
3869 uschar *save_expand_nstring[EXPAND_MAXN+1];
3870 int save_expand_nlength[EXPAND_MAXN+1];
3871 BOOL resetok = TRUE;
3872
3873 expand_level++;
3874 DEBUG(D_expand)
3875   debug_printf_indent("/%s: %s\n", skipping ? "   scanning" : "considering", string);
3876
3877 expand_string_forcedfail = FALSE;
3878 expand_string_message = US"";
3879
3880 while (*s != 0)
3881   {
3882   uschar *value;
3883   uschar name[256];
3884
3885   /* \ escapes the next character, which must exist, or else
3886   the expansion fails. There's a special escape, \N, which causes
3887   copying of the subject verbatim up to the next \N. Otherwise,
3888   the escapes are the standard set. */
3889
3890   if (*s == '\\')
3891     {
3892     if (s[1] == 0)
3893       {
3894       expand_string_message = US"\\ at end of string";
3895       goto EXPAND_FAILED;
3896       }
3897
3898     if (s[1] == 'N')
3899       {
3900       const uschar * t = s + 2;
3901       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3902       yield = string_catn(yield, &size, &ptr, t, s - t);
3903       if (*s != 0) s += 2;
3904       }
3905
3906     else
3907       {
3908       uschar ch[1];
3909       ch[0] = string_interpret_escape(&s);
3910       s++;
3911       yield = string_catn(yield, &size, &ptr, ch, 1);
3912       }
3913
3914     continue;
3915     }
3916
3917   /*{*/
3918   /* Anything other than $ is just copied verbatim, unless we are
3919   looking for a terminating } character. */
3920
3921   /*{*/
3922   if (ket_ends && *s == '}') break;
3923
3924   if (*s != '$' || !honour_dollar)
3925     {
3926     yield = string_catn(yield, &size, &ptr, s++, 1);
3927     continue;
3928     }
3929
3930   /* No { after the $ - must be a plain name or a number for string
3931   match variable. There has to be a fudge for variables that are the
3932   names of header fields preceded by "$header_" because header field
3933   names can contain any printing characters except space and colon.
3934   For those that don't like typing this much, "$h_" is a synonym for
3935   "$header_". A non-existent header yields a NULL value; nothing is
3936   inserted. */  /*}*/
3937
3938   if (isalpha((*(++s))))
3939     {
3940     int len;
3941     int newsize = 0;
3942
3943     s = read_name(name, sizeof(name), s, US"_");
3944
3945     /* If this is the first thing to be expanded, release the pre-allocated
3946     buffer. */
3947
3948     if (ptr == 0 && yield != NULL)
3949       {
3950       if (resetok) store_reset(yield);
3951       yield = NULL;
3952       size = 0;
3953       }
3954
3955     /* Header */
3956
3957     if (Ustrncmp(name, "h_", 2) == 0 ||
3958         Ustrncmp(name, "rh_", 3) == 0 ||
3959         Ustrncmp(name, "bh_", 3) == 0 ||
3960         Ustrncmp(name, "header_", 7) == 0 ||
3961         Ustrncmp(name, "rheader_", 8) == 0 ||
3962         Ustrncmp(name, "bheader_", 8) == 0)
3963       {
3964       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3965       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3966       s = read_header_name(name, sizeof(name), s);
3967       value = find_header(name, FALSE, &newsize, want_raw, charset);
3968
3969       /* If we didn't find the header, and the header contains a closing brace
3970       character, this may be a user error where the terminating colon
3971       has been omitted. Set a flag to adjust the error message in this case.
3972       But there is no error here - nothing gets inserted. */
3973
3974       if (value == NULL)
3975         {
3976         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3977         continue;
3978         }
3979       }
3980
3981     /* Variable */
3982
3983     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
3984       {
3985       expand_string_message =
3986         string_sprintf("unknown variable name \"%s\"", name);
3987         check_variable_error_message(name);
3988       goto EXPAND_FAILED;
3989       }
3990
3991     /* If the data is known to be in a new buffer, newsize will be set to the
3992     size of that buffer. If this is the first thing in an expansion string,
3993     yield will be NULL; just point it at the new store instead of copying. Many
3994     expansion strings contain just one reference, so this is a useful
3995     optimization, especially for humungous headers. */
3996
3997     len = Ustrlen(value);
3998     if (yield == NULL && newsize != 0)
3999       {
4000       yield = value;
4001       size = newsize;
4002       ptr = len;
4003       }
4004     else yield = string_catn(yield, &size, &ptr, value, len);
4005
4006     continue;
4007     }
4008
4009   if (isdigit(*s))
4010     {
4011     int n;
4012     s = read_cnumber(&n, s);
4013     if (n >= 0 && n <= expand_nmax)
4014       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4015         expand_nlength[n]);
4016     continue;
4017     }
4018
4019   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4020
4021   if (*s != '{')                                                        /*}*/
4022     {
4023     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4024     goto EXPAND_FAILED;
4025     }
4026
4027   /* After { there can be various things, but they all start with
4028   an initial word, except for a number for a string match variable. */
4029
4030   if (isdigit((*(++s))))
4031     {
4032     int n;
4033     s = read_cnumber(&n, s);            /*{*/
4034     if (*s++ != '}')
4035       {                                 /*{*/
4036       expand_string_message = US"} expected after number";
4037       goto EXPAND_FAILED;
4038       }
4039     if (n >= 0 && n <= expand_nmax)
4040       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4041         expand_nlength[n]);
4042     continue;
4043     }
4044
4045   if (!isalpha(*s))
4046     {
4047     expand_string_message = US"letter or digit expected after ${";      /*}*/
4048     goto EXPAND_FAILED;
4049     }
4050
4051   /* Allow "-" in names to cater for substrings with negative
4052   arguments. Since we are checking for known names after { this is
4053   OK. */
4054
4055   s = read_name(name, sizeof(name), s, US"_-");
4056   item_type = chop_match(name, item_table, nelem(item_table));
4057
4058   switch(item_type)
4059     {
4060     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4061     If the ACL returns accept or reject we return content set by "message ="
4062     There is currently no limit on recursion; this would have us call
4063     acl_check_internal() directly and get a current level from somewhere.
4064     See also the acl expansion condition ECOND_ACL and the traditional
4065     acl modifier ACLC_ACL.
4066     Assume that the function has side-effects on the store that must be preserved.
4067     */
4068
4069     case EITEM_ACL:
4070       /* ${acl {name} {arg1}{arg2}...} */
4071       {
4072       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4073       uschar *user_msg;
4074
4075       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4076                       &resetok))
4077         {
4078         case 1: goto EXPAND_FAILED_CURLY;
4079         case 2:
4080         case 3: goto EXPAND_FAILED;
4081         }
4082       if (skipping) continue;
4083
4084       resetok = FALSE;
4085       switch(eval_acl(sub, nelem(sub), &user_msg))
4086         {
4087         case OK:
4088         case FAIL:
4089           DEBUG(D_expand)
4090             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4091           if (user_msg)
4092             yield = string_cat(yield, &size, &ptr, user_msg);
4093           continue;
4094
4095         case DEFER:
4096           expand_string_forcedfail = TRUE;
4097           /*FALLTHROUGH*/
4098         default:
4099           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4100           goto EXPAND_FAILED;
4101         }
4102       }
4103
4104     /* Handle conditionals - preserve the values of the numerical expansion
4105     variables in case they get changed by a regular expression match in the
4106     condition. If not, they retain their external settings. At the end
4107     of this "if" section, they get restored to their previous values. */
4108
4109     case EITEM_IF:
4110       {
4111       BOOL cond = FALSE;
4112       const uschar *next_s;
4113       int save_expand_nmax =
4114         save_expand_strings(save_expand_nstring, save_expand_nlength);
4115
4116       while (isspace(*s)) s++;
4117       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4118       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4119
4120       DEBUG(D_expand)
4121         {
4122         debug_printf_indent("|__condition: %.*s\n", (int)(next_s - s), s);
4123         debug_printf_indent("|_____result: %s\n", cond ? "true" : "false");
4124         }
4125
4126       s = next_s;
4127
4128       /* The handling of "yes" and "no" result strings is now in a separate
4129       function that is also used by ${lookup} and ${extract} and ${run}. */
4130
4131       switch(process_yesno(
4132                skipping,                     /* were previously skipping */
4133                cond,                         /* success/failure indicator */
4134                lookup_value,                 /* value to reset for string2 */
4135                &s,                           /* input pointer */
4136                &yield,                       /* output pointer */
4137                &size,                        /* output size */
4138                &ptr,                         /* output current point */
4139                US"if",                       /* condition type */
4140                &resetok))
4141         {
4142         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4143         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4144         }
4145
4146       /* Restore external setting of expansion variables for continuation
4147       at this level. */
4148
4149       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4150         save_expand_nlength);
4151       continue;
4152       }
4153
4154 #ifdef SUPPORT_I18N
4155     case EITEM_IMAPFOLDER:
4156       {                         /* ${imapfolder {name}{sep]{specials}} */
4157       uschar *sub_arg[3];
4158       uschar *encoded;
4159
4160       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4161                       &resetok))
4162         {
4163         case 1: goto EXPAND_FAILED_CURLY;
4164         case 2:
4165         case 3: goto EXPAND_FAILED;
4166         }
4167
4168       if (sub_arg[1] == NULL)           /* One argument */
4169         {
4170         sub_arg[1] = US"/";             /* default separator */
4171         sub_arg[2] = NULL;
4172         }
4173       else if (Ustrlen(sub_arg[1]) != 1)
4174         {
4175         expand_string_message =
4176           string_sprintf(
4177                 "IMAP folder separator must be one character, found \"%s\"",
4178                 sub_arg[1]);
4179         goto EXPAND_FAILED;
4180         }
4181
4182       if (!skipping)
4183         {
4184         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4185                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4186           goto EXPAND_FAILED;
4187         yield = string_cat(yield, &size, &ptr, encoded);
4188         }
4189       continue;
4190       }
4191 #endif
4192
4193     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4194     expanding an internal string that isn't actually going to be used. All we
4195     need to do is check the syntax, so don't do a lookup at all. Preserve the
4196     values of the numerical expansion variables in case they get changed by a
4197     partial lookup. If not, they retain their external settings. At the end
4198     of this "lookup" section, they get restored to their previous values. */
4199
4200     case EITEM_LOOKUP:
4201       {
4202       int stype, partial, affixlen, starflags;
4203       int expand_setup = 0;
4204       int nameptr = 0;
4205       uschar *key, *filename;
4206       const uschar *affix;
4207       uschar *save_lookup_value = lookup_value;
4208       int save_expand_nmax =
4209         save_expand_strings(save_expand_nstring, save_expand_nlength);
4210
4211       if ((expand_forbid & RDO_LOOKUP) != 0)
4212         {
4213         expand_string_message = US"lookup expansions are not permitted";
4214         goto EXPAND_FAILED;
4215         }
4216
4217       /* Get the key we are to look up for single-key+file style lookups.
4218       Otherwise set the key NULL pro-tem. */
4219
4220       while (isspace(*s)) s++;
4221       if (*s == '{')                                    /*}*/
4222         {
4223         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4224         if (!key) goto EXPAND_FAILED;                   /*{{*/
4225         if (*s++ != '}')
4226           {
4227           expand_string_message = US"missing '}' after lookup key";
4228           goto EXPAND_FAILED_CURLY;
4229           }
4230         while (isspace(*s)) s++;
4231         }
4232       else key = NULL;
4233
4234       /* Find out the type of database */
4235
4236       if (!isalpha(*s))
4237         {
4238         expand_string_message = US"missing lookup type";
4239         goto EXPAND_FAILED;
4240         }
4241
4242       /* The type is a string that may contain special characters of various
4243       kinds. Allow everything except space or { to appear; the actual content
4244       is checked by search_findtype_partial. */         /*}*/
4245
4246       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4247         {
4248         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4249         s++;
4250         }
4251       name[nameptr] = 0;
4252       while (isspace(*s)) s++;
4253
4254       /* Now check for the individual search type and any partial or default
4255       options. Only those types that are actually in the binary are valid. */
4256
4257       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4258         &starflags);
4259       if (stype < 0)
4260         {
4261         expand_string_message = search_error_message;
4262         goto EXPAND_FAILED;
4263         }
4264
4265       /* Check that a key was provided for those lookup types that need it,
4266       and was not supplied for those that use the query style. */
4267
4268       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4269         {
4270         if (key == NULL)
4271           {
4272           expand_string_message = string_sprintf("missing {key} for single-"
4273             "key \"%s\" lookup", name);
4274           goto EXPAND_FAILED;
4275           }
4276         }
4277       else
4278         {
4279         if (key != NULL)
4280           {
4281           expand_string_message = string_sprintf("a single key was given for "
4282             "lookup type \"%s\", which is not a single-key lookup type", name);
4283           goto EXPAND_FAILED;
4284           }
4285         }
4286
4287       /* Get the next string in brackets and expand it. It is the file name for
4288       single-key+file lookups, and the whole query otherwise. In the case of
4289       queries that also require a file name (e.g. sqlite), the file name comes
4290       first. */
4291
4292       if (*s != '{')
4293         {
4294         expand_string_message = US"missing '{' for lookup file-or-query arg";
4295         goto EXPAND_FAILED_CURLY;
4296         }
4297       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4298       if (filename == NULL) goto EXPAND_FAILED;
4299       if (*s++ != '}')
4300         {
4301         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4302         goto EXPAND_FAILED_CURLY;
4303         }
4304       while (isspace(*s)) s++;
4305
4306       /* If this isn't a single-key+file lookup, re-arrange the variables
4307       to be appropriate for the search_ functions. For query-style lookups,
4308       there is just a "key", and no file name. For the special query-style +
4309       file types, the query (i.e. "key") starts with a file name. */
4310
4311       if (!key)
4312         {
4313         while (isspace(*filename)) filename++;
4314         key = filename;
4315
4316         if (mac_islookup(stype, lookup_querystyle))
4317           filename = NULL;
4318         else
4319           {
4320           if (*filename != '/')
4321             {
4322             expand_string_message = string_sprintf(
4323               "absolute file name expected for \"%s\" lookup", name);
4324             goto EXPAND_FAILED;
4325             }
4326           while (*key != 0 && !isspace(*key)) key++;
4327           if (*key != 0) *key++ = 0;
4328           }
4329         }
4330
4331       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4332       the entry was not found. Note that there is no search_close() function.
4333       Files are left open in case of re-use. At suitable places in higher logic,
4334       search_tidyup() is called to tidy all open files. This can save opening
4335       the same file several times. However, files may also get closed when
4336       others are opened, if too many are open at once. The rule is that a
4337       handle should not be used after a second search_open().
4338
4339       Request that a partial search sets up $1 and maybe $2 by passing
4340       expand_setup containing zero. If its value changes, reset expand_nmax,
4341       since new variables will have been set. Note that at the end of this
4342       "lookup" section, the old numeric variables are restored. */
4343
4344       if (skipping)
4345         lookup_value = NULL;
4346       else
4347         {
4348         void *handle = search_open(filename, stype, 0, NULL, NULL);
4349         if (handle == NULL)
4350           {
4351           expand_string_message = search_error_message;
4352           goto EXPAND_FAILED;
4353           }
4354         lookup_value = search_find(handle, filename, key, partial, affix,
4355           affixlen, starflags, &expand_setup);
4356         if (search_find_defer)
4357           {
4358           expand_string_message =
4359             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4360               string_printing2(key, FALSE), search_error_message);
4361           goto EXPAND_FAILED;
4362           }
4363         if (expand_setup > 0) expand_nmax = expand_setup;
4364         }
4365
4366       /* The handling of "yes" and "no" result strings is now in a separate
4367       function that is also used by ${if} and ${extract}. */
4368
4369       switch(process_yesno(
4370                skipping,                     /* were previously skipping */
4371                lookup_value != NULL,         /* success/failure indicator */
4372                save_lookup_value,            /* value to reset for string2 */
4373                &s,                           /* input pointer */
4374                &yield,                       /* output pointer */
4375                &size,                        /* output size */
4376                &ptr,                         /* output current point */
4377                US"lookup",                   /* condition type */
4378                &resetok))
4379         {
4380         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4381         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4382         }
4383
4384       /* Restore external setting of expansion variables for carrying on
4385       at this level, and continue. */
4386
4387       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4388         save_expand_nlength);
4389       continue;
4390       }
4391
4392     /* If Perl support is configured, handle calling embedded perl subroutines,
4393     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4394     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4395     arguments (defined below). */
4396
4397     #define EXIM_PERL_MAX_ARGS 8
4398
4399     case EITEM_PERL:
4400     #ifndef EXIM_PERL
4401     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4402       "is not included in this binary";
4403     goto EXPAND_FAILED;
4404
4405     #else   /* EXIM_PERL */
4406       {
4407       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4408       uschar *new_yield;
4409
4410       if ((expand_forbid & RDO_PERL) != 0)
4411         {
4412         expand_string_message = US"Perl calls are not permitted";
4413         goto EXPAND_FAILED;
4414         }
4415
4416       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4417            US"perl", &resetok))
4418         {
4419         case 1: goto EXPAND_FAILED_CURLY;
4420         case 2:
4421         case 3: goto EXPAND_FAILED;
4422         }
4423
4424       /* If skipping, we don't actually do anything */
4425
4426       if (skipping) continue;
4427
4428       /* Start the interpreter if necessary */
4429
4430       if (!opt_perl_started)
4431         {
4432         uschar *initerror;
4433         if (opt_perl_startup == NULL)
4434           {
4435           expand_string_message = US"A setting of perl_startup is needed when "
4436             "using the Perl interpreter";
4437           goto EXPAND_FAILED;
4438           }
4439         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4440         initerror = init_perl(opt_perl_startup);
4441         if (initerror != NULL)
4442           {
4443           expand_string_message =
4444             string_sprintf("error in perl_startup code: %s\n", initerror);
4445           goto EXPAND_FAILED;
4446           }
4447         opt_perl_started = TRUE;
4448         }
4449
4450       /* Call the function */
4451
4452       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4453       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4454         sub_arg[0], sub_arg + 1);
4455
4456       /* NULL yield indicates failure; if the message pointer has been set to
4457       NULL, the yield was undef, indicating a forced failure. Otherwise the
4458       message will indicate some kind of Perl error. */
4459
4460       if (new_yield == NULL)
4461         {
4462         if (expand_string_message == NULL)
4463           {
4464           expand_string_message =
4465             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4466               "failure", sub_arg[0]);
4467           expand_string_forcedfail = TRUE;
4468           }
4469         goto EXPAND_FAILED;
4470         }
4471
4472       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4473       set during a callback from Perl. */
4474
4475       expand_string_forcedfail = FALSE;
4476       yield = new_yield;
4477       continue;
4478       }
4479     #endif /* EXIM_PERL */
4480
4481     /* Transform email address to "prvs" scheme to use
4482        as BATV-signed return path */
4483
4484     case EITEM_PRVS:
4485       {
4486       uschar *sub_arg[3];
4487       uschar *p,*domain;
4488
4489       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4490         {
4491         case 1: goto EXPAND_FAILED_CURLY;
4492         case 2:
4493         case 3: goto EXPAND_FAILED;
4494         }
4495
4496       /* If skipping, we don't actually do anything */
4497       if (skipping) continue;
4498
4499       /* sub_arg[0] is the address */
4500       domain = Ustrrchr(sub_arg[0],'@');
4501       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4502         {
4503         expand_string_message = US"prvs first argument must be a qualified email address";
4504         goto EXPAND_FAILED;
4505         }
4506
4507       /* Calculate the hash. The second argument must be a single-digit
4508       key number, or unset. */
4509
4510       if (sub_arg[2] != NULL &&
4511           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4512         {
4513         expand_string_message = US"prvs second argument must be a single digit";
4514         goto EXPAND_FAILED;
4515         }
4516
4517       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4518       if (p == NULL)
4519         {
4520         expand_string_message = US"prvs hmac-sha1 conversion failed";
4521         goto EXPAND_FAILED;
4522         }
4523
4524       /* Now separate the domain from the local part */
4525       *domain++ = '\0';
4526
4527       yield = string_catn(yield, &size, &ptr, US"prvs=", 5);
4528       yield = string_catn(yield, &size, &ptr, sub_arg[2] ? sub_arg[2] : US"0", 1);
4529       yield = string_catn(yield, &size, &ptr, prvs_daystamp(7), 3);
4530       yield = string_catn(yield, &size, &ptr, p, 6);
4531       yield = string_catn(yield, &size, &ptr, US"=", 1);
4532       yield = string_cat (yield, &size, &ptr, sub_arg[0]);
4533       yield = string_catn(yield, &size, &ptr, US"@", 1);
4534       yield = string_cat (yield, &size, &ptr, domain);
4535
4536       continue;
4537       }
4538
4539     /* Check a prvs-encoded address for validity */
4540
4541     case EITEM_PRVSCHECK:
4542       {
4543       uschar *sub_arg[3];
4544       int mysize = 0, myptr = 0;
4545       const pcre *re;
4546       uschar *p;
4547
4548       /* TF: Ugliness: We want to expand parameter 1 first, then set
4549          up expansion variables that are used in the expansion of
4550          parameter 2. So we clone the string for the first
4551          expansion, where we only expand parameter 1.
4552
4553          PH: Actually, that isn't necessary. The read_subs() function is
4554          designed to work this way for the ${if and ${lookup expansions. I've
4555          tidied the code.
4556       */
4557
4558       /* Reset expansion variables */
4559       prvscheck_result = NULL;
4560       prvscheck_address = NULL;
4561       prvscheck_keynum = NULL;
4562
4563       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4564         {
4565         case 1: goto EXPAND_FAILED_CURLY;
4566         case 2:
4567         case 3: goto EXPAND_FAILED;
4568         }
4569
4570       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4571                               TRUE,FALSE);
4572
4573       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4574         {
4575         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4576         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4577         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4578         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4579         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4580
4581         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4582         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4583         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4584         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4585         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4586
4587         /* Set up expansion variables */
4588         prvscheck_address = string_cat (NULL, &mysize, &myptr, local_part);
4589         prvscheck_address = string_catn(prvscheck_address, &mysize, &myptr, US"@", 1);
4590         prvscheck_address = string_cat (prvscheck_address, &mysize, &myptr, domain);
4591         prvscheck_address[myptr] = '\0';
4592         prvscheck_keynum = string_copy(key_num);
4593
4594         /* Now expand the second argument */
4595         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4596           {
4597           case 1: goto EXPAND_FAILED_CURLY;
4598           case 2:
4599           case 3: goto EXPAND_FAILED;
4600           }
4601
4602         /* Now we have the key and can check the address. */
4603
4604         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4605           daystamp);
4606
4607         if (p == NULL)
4608           {
4609           expand_string_message = US"hmac-sha1 conversion failed";
4610           goto EXPAND_FAILED;
4611           }
4612
4613         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4614         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4615
4616         if (Ustrcmp(p,hash) == 0)
4617           {
4618           /* Success, valid BATV address. Now check the expiry date. */
4619           uschar *now = prvs_daystamp(0);
4620           unsigned int inow = 0,iexpire = 1;
4621
4622           (void)sscanf(CS now,"%u",&inow);
4623           (void)sscanf(CS daystamp,"%u",&iexpire);
4624
4625           /* When "iexpire" is < 7, a "flip" has occured.
4626              Adjust "inow" accordingly. */
4627           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4628
4629           if (iexpire >= inow)
4630             {
4631             prvscheck_result = US"1";
4632             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4633             }
4634             else
4635             {
4636             prvscheck_result = NULL;
4637             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4638             }
4639           }
4640         else
4641           {
4642           prvscheck_result = NULL;
4643           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4644           }
4645
4646         /* Now expand the final argument. We leave this till now so that
4647         it can include $prvscheck_result. */
4648
4649         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4650           {
4651           case 1: goto EXPAND_FAILED_CURLY;
4652           case 2:
4653           case 3: goto EXPAND_FAILED;
4654           }
4655
4656         yield = string_cat(yield, &size, &ptr,
4657           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4658
4659         /* Reset the "internal" variables afterwards, because they are in
4660         dynamic store that will be reclaimed if the expansion succeeded. */
4661
4662         prvscheck_address = NULL;
4663         prvscheck_keynum = NULL;
4664         }
4665       else
4666         /* Does not look like a prvs encoded address, return the empty string.
4667            We need to make sure all subs are expanded first, so as to skip over
4668            the entire item. */
4669
4670         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4671           {
4672           case 1: goto EXPAND_FAILED_CURLY;
4673           case 2:
4674           case 3: goto EXPAND_FAILED;
4675           }
4676
4677       continue;
4678       }
4679
4680     /* Handle "readfile" to insert an entire file */
4681
4682     case EITEM_READFILE:
4683       {
4684       FILE *f;
4685       uschar *sub_arg[2];
4686
4687       if ((expand_forbid & RDO_READFILE) != 0)
4688         {
4689         expand_string_message = US"file insertions are not permitted";
4690         goto EXPAND_FAILED;
4691         }
4692
4693       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4694         {
4695         case 1: goto EXPAND_FAILED_CURLY;
4696         case 2:
4697         case 3: goto EXPAND_FAILED;
4698         }
4699
4700       /* If skipping, we don't actually do anything */
4701
4702       if (skipping) continue;
4703
4704       /* Open the file and read it */
4705
4706       f = Ufopen(sub_arg[0], "rb");
4707       if (f == NULL)
4708         {
4709         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4710         goto EXPAND_FAILED;
4711         }
4712
4713       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4714       (void)fclose(f);
4715       continue;
4716       }
4717
4718     /* Handle "readsocket" to insert data from a Unix domain socket */
4719
4720     case EITEM_READSOCK:
4721       {
4722       int fd;
4723       int timeout = 5;
4724       int save_ptr = ptr;
4725       FILE *f;
4726       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4727       uschar *arg;
4728       uschar *sub_arg[4];
4729
4730       if ((expand_forbid & RDO_READSOCK) != 0)
4731         {
4732         expand_string_message = US"socket insertions are not permitted";
4733         goto EXPAND_FAILED;
4734         }
4735
4736       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4737       because there may be a string for expansion on failure. */
4738
4739       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4740         {
4741         case 1: goto EXPAND_FAILED_CURLY;
4742         case 2:                             /* Won't occur: no end check */
4743         case 3: goto EXPAND_FAILED;
4744         }
4745
4746       /* Sort out timeout, if given */
4747
4748       if (sub_arg[2] != NULL)
4749         {
4750         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4751         if (timeout < 0)
4752           {
4753           expand_string_message = string_sprintf("bad time value %s",
4754             sub_arg[2]);
4755           goto EXPAND_FAILED;
4756           }
4757         }
4758       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4759
4760       /* If skipping, we don't actually do anything. Otherwise, arrange to
4761       connect to either an IP or a Unix socket. */
4762
4763       if (!skipping)
4764         {
4765         /* Handle an IP (internet) domain */
4766
4767         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4768           {
4769           int port;
4770           uschar *server_name = sub_arg[0] + 5;
4771           uschar *port_name = Ustrrchr(server_name, ':');
4772
4773           /* Sort out the port */
4774
4775           if (port_name == NULL)
4776             {
4777             expand_string_message =
4778               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4779             goto EXPAND_FAILED;
4780             }
4781           *port_name++ = 0;           /* Terminate server name */
4782
4783           if (isdigit(*port_name))
4784             {
4785             uschar *end;
4786             port = Ustrtol(port_name, &end, 0);
4787             if (end != port_name + Ustrlen(port_name))
4788               {
4789               expand_string_message =
4790                 string_sprintf("invalid port number %s", port_name);
4791               goto EXPAND_FAILED;
4792               }
4793             }
4794           else
4795             {
4796             struct servent *service_info = getservbyname(CS port_name, "tcp");
4797             if (service_info == NULL)
4798               {
4799               expand_string_message = string_sprintf("unknown port \"%s\"",
4800                 port_name);
4801               goto EXPAND_FAILED;
4802               }
4803             port = ntohs(service_info->s_port);
4804             }
4805
4806           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4807                   timeout, NULL, &expand_string_message);
4808           callout_address = NULL;
4809           if (fd < 0)
4810               goto SOCK_FAIL;
4811           }
4812
4813         /* Handle a Unix domain socket */
4814
4815         else
4816           {
4817           int rc;
4818           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4819             {
4820             expand_string_message = string_sprintf("failed to create socket: %s",
4821               strerror(errno));
4822             goto SOCK_FAIL;
4823             }
4824
4825           sockun.sun_family = AF_UNIX;
4826           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4827             sub_arg[0]);
4828
4829           sigalrm_seen = FALSE;
4830           alarm(timeout);
4831           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4832           alarm(0);
4833           if (sigalrm_seen)
4834             {
4835             expand_string_message = US "socket connect timed out";
4836             goto SOCK_FAIL;
4837             }
4838           if (rc < 0)
4839             {
4840             expand_string_message = string_sprintf("failed to connect to socket "
4841               "%s: %s", sub_arg[0], strerror(errno));
4842             goto SOCK_FAIL;
4843             }
4844           }
4845
4846         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4847
4848         /* Allow sequencing of test actions */
4849         if (running_in_test_harness) millisleep(100);
4850
4851         /* Write the request string, if not empty */
4852
4853         if (sub_arg[1][0] != 0)
4854           {
4855           int len = Ustrlen(sub_arg[1]);
4856           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4857             sub_arg[1]);
4858           if (write(fd, sub_arg[1], len) != len)
4859             {
4860             expand_string_message = string_sprintf("request write to socket "
4861               "failed: %s", strerror(errno));
4862             goto SOCK_FAIL;
4863             }
4864           }
4865
4866         /* Shut down the sending side of the socket. This helps some servers to
4867         recognise that it is their turn to do some work. Just in case some
4868         system doesn't have this function, make it conditional. */
4869
4870         #ifdef SHUT_WR
4871         shutdown(fd, SHUT_WR);
4872         #endif
4873
4874         if (running_in_test_harness) millisleep(100);
4875
4876         /* Now we need to read from the socket, under a timeout. The function
4877         that reads a file can be used. */
4878
4879         f = fdopen(fd, "rb");
4880         sigalrm_seen = FALSE;
4881         alarm(timeout);
4882         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4883         alarm(0);
4884         (void)fclose(f);
4885
4886         /* After a timeout, we restore the pointer in the result, that is,
4887         make sure we add nothing from the socket. */
4888
4889         if (sigalrm_seen)
4890           {
4891           ptr = save_ptr;
4892           expand_string_message = US "socket read timed out";
4893           goto SOCK_FAIL;
4894           }
4895         }
4896
4897       /* The whole thing has worked (or we were skipping). If there is a
4898       failure string following, we need to skip it. */
4899
4900       if (*s == '{')
4901         {
4902         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4903           goto EXPAND_FAILED;
4904         if (*s++ != '}')
4905           {
4906           expand_string_message = US"missing '}' closing failstring for readsocket";
4907           goto EXPAND_FAILED_CURLY;
4908           }
4909         while (isspace(*s)) s++;
4910         }
4911
4912     readsock_done:
4913       if (*s++ != '}')
4914         {
4915         expand_string_message = US"missing '}' closing readsocket";
4916         goto EXPAND_FAILED_CURLY;
4917         }
4918       continue;
4919
4920       /* Come here on failure to create socket, connect socket, write to the
4921       socket, or timeout on reading. If another substring follows, expand and
4922       use it. Otherwise, those conditions give expand errors. */
4923
4924       SOCK_FAIL:
4925       if (*s != '{') goto EXPAND_FAILED;
4926       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4927       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4928         goto EXPAND_FAILED;
4929       yield = string_cat(yield, &size, &ptr, arg);
4930       if (*s++ != '}')
4931         {
4932         expand_string_message = US"missing '}' closing failstring for readsocket";
4933         goto EXPAND_FAILED_CURLY;
4934         }
4935       while (isspace(*s)) s++;
4936       goto readsock_done;
4937       }
4938
4939     /* Handle "run" to execute a program. */
4940
4941     case EITEM_RUN:
4942       {
4943       FILE *f;
4944       uschar *arg;
4945       const uschar **argv;
4946       pid_t pid;
4947       int fd_in, fd_out;
4948       int lsize = 0, lptr = 0;
4949
4950       if ((expand_forbid & RDO_RUN) != 0)
4951         {
4952         expand_string_message = US"running a command is not permitted";
4953         goto EXPAND_FAILED;
4954         }
4955
4956       while (isspace(*s)) s++;
4957       if (*s != '{')
4958         {
4959         expand_string_message = US"missing '{' for command arg of run";
4960         goto EXPAND_FAILED_CURLY;
4961         }
4962       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4963       if (arg == NULL) goto EXPAND_FAILED;
4964       while (isspace(*s)) s++;
4965       if (*s++ != '}')
4966         {
4967         expand_string_message = US"missing '}' closing command arg of run";
4968         goto EXPAND_FAILED_CURLY;
4969         }
4970
4971       if (skipping)   /* Just pretend it worked when we're skipping */
4972         {
4973         runrc = 0;
4974         lookup_value = NULL;
4975         }
4976       else
4977         {
4978         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4979             arg,                                /* raw command */
4980             FALSE,                              /* don't expand the arguments */
4981             0,                                  /* not relevant when... */
4982             NULL,                               /* no transporting address */
4983             US"${run} expansion",               /* for error messages */
4984             &expand_string_message))            /* where to put error message */
4985           goto EXPAND_FAILED;
4986
4987         /* Create the child process, making it a group leader. */
4988
4989         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
4990           {
4991           expand_string_message =
4992             string_sprintf("couldn't create child process: %s", strerror(errno));
4993           goto EXPAND_FAILED;
4994           }
4995
4996         /* Nothing is written to the standard input. */
4997
4998         (void)close(fd_in);
4999
5000         /* Read the pipe to get the command's output into $value (which is kept
5001         in lookup_value). Read during execution, so that if the output exceeds
5002         the OS pipe buffer limit, we don't block forever. Remember to not release
5003         memory just allocated for $value. */
5004
5005         resetok = FALSE;
5006         f = fdopen(fd_out, "rb");
5007         sigalrm_seen = FALSE;
5008         alarm(60);
5009         lookup_value = cat_file(f, NULL, &lsize, &lptr, NULL);
5010         alarm(0);
5011         (void)fclose(f);
5012
5013         /* Wait for the process to finish, applying the timeout, and inspect its
5014         return code for serious disasters. Simple non-zero returns are passed on.
5015         */
5016
5017         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5018           {
5019           if (sigalrm_seen || runrc == -256)
5020             {
5021             expand_string_message = string_sprintf("command timed out");
5022             killpg(pid, SIGKILL);       /* Kill the whole process group */
5023             }
5024
5025           else if (runrc == -257)
5026             expand_string_message = string_sprintf("wait() failed: %s",
5027               strerror(errno));
5028
5029           else
5030             expand_string_message = string_sprintf("command killed by signal %d",
5031               -runrc);
5032
5033           goto EXPAND_FAILED;
5034           }
5035         }
5036
5037       /* Process the yes/no strings; $value may be useful in both cases */
5038
5039       switch(process_yesno(
5040                skipping,                     /* were previously skipping */
5041                runrc == 0,                   /* success/failure indicator */
5042                lookup_value,                 /* value to reset for string2 */
5043                &s,                           /* input pointer */
5044                &yield,                       /* output pointer */
5045                &size,                        /* output size */
5046                &ptr,                         /* output current point */
5047                US"run",                      /* condition type */
5048                &resetok))
5049         {
5050         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5051         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5052         }
5053
5054       continue;
5055       }
5056
5057     /* Handle character translation for "tr" */
5058
5059     case EITEM_TR:
5060       {
5061       int oldptr = ptr;
5062       int o2m;
5063       uschar *sub[3];
5064
5065       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5066         {
5067         case 1: goto EXPAND_FAILED_CURLY;
5068         case 2:
5069         case 3: goto EXPAND_FAILED;
5070         }
5071
5072       yield = string_cat(yield, &size, &ptr, sub[0]);
5073       o2m = Ustrlen(sub[2]) - 1;
5074
5075       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
5076         {
5077         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
5078         if (m != NULL)
5079           {
5080           int o = m - sub[1];
5081           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
5082           }
5083         }
5084
5085       continue;
5086       }
5087
5088     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5089     expanded arguments. */
5090
5091     case EITEM_HASH:
5092     case EITEM_LENGTH:
5093     case EITEM_NHASH:
5094     case EITEM_SUBSTR:
5095       {
5096       int i;
5097       int len;
5098       uschar *ret;
5099       int val[2] = { 0, -1 };
5100       uschar *sub[3];
5101
5102       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5103       Ensure that sub[2] is set in the ${length } case. */
5104
5105       sub[2] = NULL;
5106       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5107              TRUE, name, &resetok))
5108         {
5109         case 1: goto EXPAND_FAILED_CURLY;
5110         case 2:
5111         case 3: goto EXPAND_FAILED;
5112         }
5113
5114       /* Juggle the arguments if there are only two of them: always move the
5115       string to the last position and make ${length{n}{str}} equivalent to
5116       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5117
5118       if (sub[2] == NULL)
5119         {
5120         sub[2] = sub[1];
5121         sub[1] = NULL;
5122         if (item_type == EITEM_LENGTH)
5123           {
5124           sub[1] = sub[0];
5125           sub[0] = NULL;
5126           }
5127         }
5128
5129       for (i = 0; i < 2; i++)
5130         {
5131         if (sub[i] == NULL) continue;
5132         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5133         if (*ret != 0 || (i != 0 && val[i] < 0))
5134           {
5135           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5136             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5137           goto EXPAND_FAILED;
5138           }
5139         }
5140
5141       ret =
5142         (item_type == EITEM_HASH)?
5143           compute_hash(sub[2], val[0], val[1], &len) :
5144         (item_type == EITEM_NHASH)?
5145           compute_nhash(sub[2], val[0], val[1], &len) :
5146           extract_substr(sub[2], val[0], val[1], &len);
5147
5148       if (ret == NULL) goto EXPAND_FAILED;
5149       yield = string_catn(yield, &size, &ptr, ret, len);
5150       continue;
5151       }
5152
5153     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5154     This code originally contributed by Steve Haslam. It currently supports
5155     the use of MD5 and SHA-1 hashes.
5156
5157     We need some workspace that is large enough to handle all the supported
5158     hash types. Use macros to set the sizes rather than be too elaborate. */
5159
5160     #define MAX_HASHLEN      20
5161     #define MAX_HASHBLOCKLEN 64
5162
5163     case EITEM_HMAC:
5164       {
5165       uschar *sub[3];
5166       md5 md5_base;
5167       hctx sha1_ctx;
5168       void *use_base;
5169       int type, i;
5170       int hashlen;      /* Number of octets for the hash algorithm's output */
5171       int hashblocklen; /* Number of octets the hash algorithm processes */
5172       uschar *keyptr, *p;
5173       unsigned int keylen;
5174
5175       uschar keyhash[MAX_HASHLEN];
5176       uschar innerhash[MAX_HASHLEN];
5177       uschar finalhash[MAX_HASHLEN];
5178       uschar finalhash_hex[2*MAX_HASHLEN];
5179       uschar innerkey[MAX_HASHBLOCKLEN];
5180       uschar outerkey[MAX_HASHBLOCKLEN];
5181
5182       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5183         {
5184         case 1: goto EXPAND_FAILED_CURLY;
5185         case 2:
5186         case 3: goto EXPAND_FAILED;
5187         }
5188
5189       if (!skipping)
5190         {
5191         if (Ustrcmp(sub[0], "md5") == 0)
5192           {
5193           type = HMAC_MD5;
5194           use_base = &md5_base;
5195           hashlen = 16;
5196           hashblocklen = 64;
5197           }
5198         else if (Ustrcmp(sub[0], "sha1") == 0)
5199           {
5200           type = HMAC_SHA1;
5201           use_base = &sha1_ctx;
5202           hashlen = 20;
5203           hashblocklen = 64;
5204           }
5205         else
5206           {
5207           expand_string_message =
5208             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5209           goto EXPAND_FAILED;
5210           }
5211
5212         keyptr = sub[1];
5213         keylen = Ustrlen(keyptr);
5214
5215         /* If the key is longer than the hash block length, then hash the key
5216         first */
5217
5218         if (keylen > hashblocklen)
5219           {
5220           chash_start(type, use_base);
5221           chash_end(type, use_base, keyptr, keylen, keyhash);
5222           keyptr = keyhash;
5223           keylen = hashlen;
5224           }
5225
5226         /* Now make the inner and outer key values */
5227
5228         memset(innerkey, 0x36, hashblocklen);
5229         memset(outerkey, 0x5c, hashblocklen);
5230
5231         for (i = 0; i < keylen; i++)
5232           {
5233           innerkey[i] ^= keyptr[i];
5234           outerkey[i] ^= keyptr[i];
5235           }
5236
5237         /* Now do the hashes */
5238
5239         chash_start(type, use_base);
5240         chash_mid(type, use_base, innerkey);
5241         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5242
5243         chash_start(type, use_base);
5244         chash_mid(type, use_base, outerkey);
5245         chash_end(type, use_base, innerhash, hashlen, finalhash);
5246
5247         /* Encode the final hash as a hex string */
5248
5249         p = finalhash_hex;
5250         for (i = 0; i < hashlen; i++)
5251           {
5252           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5253           *p++ = hex_digits[finalhash[i] & 0x0f];
5254           }
5255
5256         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5257           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5258
5259         yield = string_catn(yield, &size, &ptr, finalhash_hex, hashlen*2);
5260         }
5261       continue;
5262       }
5263
5264     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5265     We have to save the numerical variables and restore them afterwards. */
5266
5267     case EITEM_SG:
5268       {
5269       const pcre *re;
5270       int moffset, moffsetextra, slen;
5271       int roffset;
5272       int emptyopt;
5273       const uschar *rerror;
5274       uschar *subject;
5275       uschar *sub[3];
5276       int save_expand_nmax =
5277         save_expand_strings(save_expand_nstring, save_expand_nlength);
5278
5279       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5280         {
5281         case 1: goto EXPAND_FAILED_CURLY;
5282         case 2:
5283         case 3: goto EXPAND_FAILED;
5284         }
5285
5286       /* Compile the regular expression */
5287
5288       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5289         NULL);
5290
5291       if (re == NULL)
5292         {
5293         expand_string_message = string_sprintf("regular expression error in "
5294           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5295         goto EXPAND_FAILED;
5296         }
5297
5298       /* Now run a loop to do the substitutions as often as necessary. It ends
5299       when there are no more matches. Take care over matches of the null string;
5300       do the same thing as Perl does. */
5301
5302       subject = sub[0];
5303       slen = Ustrlen(sub[0]);
5304       moffset = moffsetextra = 0;
5305       emptyopt = 0;
5306
5307       for (;;)
5308         {
5309         int ovector[3*(EXPAND_MAXN+1)];
5310         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5311           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5312         int nn;
5313         uschar *insert;
5314
5315         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5316         is not necessarily the end. We want to repeat the match from one
5317         character further along, but leaving the basic offset the same (for
5318         copying below). We can't be at the end of the string - that was checked
5319         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5320         finished; copy the remaining string and end the loop. */
5321
5322         if (n < 0)
5323           {
5324           if (emptyopt != 0)
5325             {
5326             moffsetextra = 1;
5327             emptyopt = 0;
5328             continue;
5329             }
5330           yield = string_catn(yield, &size, &ptr, subject+moffset, slen-moffset);
5331           break;
5332           }
5333
5334         /* Match - set up for expanding the replacement. */
5335
5336         if (n == 0) n = EXPAND_MAXN + 1;
5337         expand_nmax = 0;
5338         for (nn = 0; nn < n*2; nn += 2)
5339           {
5340           expand_nstring[expand_nmax] = subject + ovector[nn];
5341           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5342           }
5343         expand_nmax--;
5344
5345         /* Copy the characters before the match, plus the expanded insertion. */
5346
5347         yield = string_catn(yield, &size, &ptr, subject + moffset,
5348           ovector[0] - moffset);
5349         insert = expand_string(sub[2]);
5350         if (insert == NULL) goto EXPAND_FAILED;
5351         yield = string_cat(yield, &size, &ptr, insert);
5352
5353         moffset = ovector[1];
5354         moffsetextra = 0;
5355         emptyopt = 0;
5356
5357         /* If we have matched an empty string, first check to see if we are at
5358         the end of the subject. If so, the loop is over. Otherwise, mimic
5359         what Perl's /g options does. This turns out to be rather cunning. First
5360         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5361         string at the same point. If this fails (picked up above) we advance to
5362         the next character. */
5363
5364         if (ovector[0] == ovector[1])
5365           {
5366           if (ovector[0] == slen) break;
5367           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5368           }
5369         }
5370
5371       /* All done - restore numerical variables. */
5372
5373       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5374         save_expand_nlength);
5375       continue;
5376       }
5377
5378     /* Handle keyed and numbered substring extraction. If the first argument
5379     consists entirely of digits, then a numerical extraction is assumed. */
5380
5381     case EITEM_EXTRACT:
5382       {
5383       int i;
5384       int j;
5385       int field_number = 1;
5386       BOOL field_number_set = FALSE;
5387       uschar *save_lookup_value = lookup_value;
5388       uschar *sub[3];
5389       int save_expand_nmax =
5390         save_expand_strings(save_expand_nstring, save_expand_nlength);
5391
5392       /* While skipping we cannot rely on the data for expansions being
5393       available (eg. $item) hence cannot decide on numeric vs. keyed.
5394       Read a maximum of 5 arguments (including the yes/no) */
5395
5396       if (skipping)
5397         {
5398         while (isspace(*s)) s++;
5399         for (j = 5; j > 0 && *s == '{'; j--)
5400           {
5401           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5402             goto EXPAND_FAILED;                                 /*{*/
5403           if (*s++ != '}')
5404             {
5405             expand_string_message = US"missing '{' for arg of extract";
5406             goto EXPAND_FAILED_CURLY;
5407             }
5408           while (isspace(*s)) s++;
5409           }
5410         if (  Ustrncmp(s, "fail", 4) == 0
5411            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5412            )
5413           {
5414           s += 4;
5415           while (isspace(*s)) s++;
5416           }
5417         if (*s != '}')
5418           {
5419           expand_string_message = US"missing '}' closing extract";
5420           goto EXPAND_FAILED_CURLY;
5421           }
5422         }
5423
5424       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5425         {
5426         while (isspace(*s)) s++;
5427         if (*s == '{')                                          /*}*/
5428           {
5429           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5430           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5431           if (*s++ != '}')
5432             {
5433             expand_string_message = string_sprintf(
5434               "missing '}' closing arg %d of extract", i+1);
5435             goto EXPAND_FAILED_CURLY;
5436             }
5437
5438           /* After removal of leading and trailing white space, the first
5439           argument must not be empty; if it consists entirely of digits
5440           (optionally preceded by a minus sign), this is a numerical
5441           extraction, and we expect 3 arguments. */
5442
5443           if (i == 0)
5444             {
5445             int len;
5446             int x = 0;
5447             uschar *p = sub[0];
5448
5449             while (isspace(*p)) p++;
5450             sub[0] = p;
5451
5452             len = Ustrlen(p);
5453             while (len > 0 && isspace(p[len-1])) len--;
5454             p[len] = 0;
5455
5456             if (*p == 0)
5457               {
5458               expand_string_message = US"first argument of \"extract\" must "
5459                 "not be empty";
5460               goto EXPAND_FAILED;
5461               }
5462
5463             if (*p == '-')
5464               {
5465               field_number = -1;
5466               p++;
5467               }
5468             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5469             if (*p == 0)
5470               {
5471               field_number *= x;
5472               j = 3;               /* Need 3 args */
5473               field_number_set = TRUE;
5474               }
5475             }
5476           }
5477         else
5478           {
5479           expand_string_message = string_sprintf(
5480             "missing '{' for arg %d of extract", i+1);
5481           goto EXPAND_FAILED_CURLY;
5482           }
5483         }
5484
5485       /* Extract either the numbered or the keyed substring into $value. If
5486       skipping, just pretend the extraction failed. */
5487
5488       lookup_value = skipping? NULL : field_number_set?
5489         expand_gettokened(field_number, sub[1], sub[2]) :
5490         expand_getkeyed(sub[0], sub[1]);
5491
5492       /* If no string follows, $value gets substituted; otherwise there can
5493       be yes/no strings, as for lookup or if. */
5494
5495       switch(process_yesno(
5496                skipping,                     /* were previously skipping */
5497                lookup_value != NULL,         /* success/failure indicator */
5498                save_lookup_value,            /* value to reset for string2 */
5499                &s,                           /* input pointer */
5500                &yield,                       /* output pointer */
5501                &size,                        /* output size */
5502                &ptr,                         /* output current point */
5503                US"extract",                  /* condition type */
5504                &resetok))
5505         {
5506         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5507         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5508         }
5509
5510       /* All done - restore numerical variables. */
5511
5512       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5513         save_expand_nlength);
5514
5515       continue;
5516       }
5517
5518     /* return the Nth item from a list */
5519
5520     case EITEM_LISTEXTRACT:
5521       {
5522       int i;
5523       int field_number = 1;
5524       uschar *save_lookup_value = lookup_value;
5525       uschar *sub[2];
5526       int save_expand_nmax =
5527         save_expand_strings(save_expand_nstring, save_expand_nlength);
5528
5529       /* Read the field & list arguments */
5530
5531       for (i = 0; i < 2; i++)
5532         {
5533         while (isspace(*s)) s++;
5534         if (*s != '{')                                  /*}*/
5535           {
5536           expand_string_message = string_sprintf(
5537             "missing '{' for arg %d of listextract", i+1);
5538           goto EXPAND_FAILED_CURLY;
5539           }
5540
5541         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5542         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5543         if (*s++ != '}')
5544           {
5545           expand_string_message = string_sprintf(
5546             "missing '}' closing arg %d of listextract", i+1);
5547           goto EXPAND_FAILED_CURLY;
5548           }
5549
5550         /* After removal of leading and trailing white space, the first
5551         argument must be numeric and nonempty. */
5552
5553         if (i == 0)
5554           {
5555           int len;
5556           int x = 0;
5557           uschar *p = sub[0];
5558
5559           while (isspace(*p)) p++;
5560           sub[0] = p;
5561
5562           len = Ustrlen(p);
5563           while (len > 0 && isspace(p[len-1])) len--;
5564           p[len] = 0;
5565
5566           if (!*p && !skipping)
5567             {
5568             expand_string_message = US"first argument of \"listextract\" must "
5569               "not be empty";
5570             goto EXPAND_FAILED;
5571             }
5572
5573           if (*p == '-')
5574             {
5575             field_number = -1;
5576             p++;
5577             }
5578           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5579           if (*p)
5580             {
5581             expand_string_message = US"first argument of \"listextract\" must "
5582               "be numeric";
5583             goto EXPAND_FAILED;
5584             }
5585           field_number *= x;
5586           }
5587         }
5588
5589       /* Extract the numbered element into $value. If
5590       skipping, just pretend the extraction failed. */
5591
5592       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5593
5594       /* If no string follows, $value gets substituted; otherwise there can
5595       be yes/no strings, as for lookup or if. */
5596
5597       switch(process_yesno(
5598                skipping,                     /* were previously skipping */
5599                lookup_value != NULL,         /* success/failure indicator */
5600                save_lookup_value,            /* value to reset for string2 */
5601                &s,                           /* input pointer */
5602                &yield,                       /* output pointer */
5603                &size,                        /* output size */
5604                &ptr,                         /* output current point */
5605                US"listextract",              /* condition type */
5606                &resetok))
5607         {
5608         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5609         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5610         }
5611
5612       /* All done - restore numerical variables. */
5613
5614       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5615         save_expand_nlength);
5616
5617       continue;
5618       }
5619
5620 #ifdef SUPPORT_TLS
5621     case EITEM_CERTEXTRACT:
5622       {
5623       uschar *save_lookup_value = lookup_value;
5624       uschar *sub[2];
5625       int save_expand_nmax =
5626         save_expand_strings(save_expand_nstring, save_expand_nlength);
5627
5628       /* Read the field argument */
5629       while (isspace(*s)) s++;
5630       if (*s != '{')                                    /*}*/
5631         {
5632         expand_string_message = US"missing '{' for field arg of certextract";
5633         goto EXPAND_FAILED_CURLY;
5634         }
5635       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5636       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5637       if (*s++ != '}')
5638         {
5639         expand_string_message = US"missing '}' closing field arg of certextract";
5640         goto EXPAND_FAILED_CURLY;
5641         }
5642       /* strip spaces fore & aft */
5643       {
5644       int len;
5645       uschar *p = sub[0];
5646
5647       while (isspace(*p)) p++;
5648       sub[0] = p;
5649
5650       len = Ustrlen(p);
5651       while (len > 0 && isspace(p[len-1])) len--;
5652       p[len] = 0;
5653       }
5654
5655       /* inspect the cert argument */
5656       while (isspace(*s)) s++;
5657       if (*s != '{')                                    /*}*/
5658         {
5659         expand_string_message = US"missing '{' for cert variable arg of certextract";
5660         goto EXPAND_FAILED_CURLY;
5661         }
5662       if (*++s != '$')
5663         {
5664         expand_string_message = US"second argument of \"certextract\" must "
5665           "be a certificate variable";
5666         goto EXPAND_FAILED;
5667         }
5668       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5669       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5670       if (*s++ != '}')
5671         {
5672         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5673         goto EXPAND_FAILED_CURLY;
5674         }
5675
5676       if (skipping)
5677         lookup_value = NULL;
5678       else
5679         {
5680         lookup_value = expand_getcertele(sub[0], sub[1]);
5681         if (*expand_string_message) goto EXPAND_FAILED;
5682         }
5683       switch(process_yesno(
5684                skipping,                     /* were previously skipping */
5685                lookup_value != NULL,         /* success/failure indicator */
5686                save_lookup_value,            /* value to reset for string2 */
5687                &s,                           /* input pointer */
5688                &yield,                       /* output pointer */
5689                &size,                        /* output size */
5690                &ptr,                         /* output current point */
5691                US"certextract",              /* condition type */
5692                &resetok))
5693         {
5694         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5695         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5696         }
5697
5698       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5699         save_expand_nlength);
5700       continue;
5701       }
5702 #endif  /*SUPPORT_TLS*/
5703
5704     /* Handle list operations */
5705
5706     case EITEM_FILTER:
5707     case EITEM_MAP:
5708     case EITEM_REDUCE:
5709       {
5710       int sep = 0;
5711       int save_ptr = ptr;
5712       uschar outsep[2] = { '\0', '\0' };
5713       const uschar *list, *expr, *temp;
5714       uschar *save_iterate_item = iterate_item;
5715       uschar *save_lookup_value = lookup_value;
5716
5717       while (isspace(*s)) s++;
5718       if (*s++ != '{')
5719         {
5720         expand_string_message =
5721           string_sprintf("missing '{' for first arg of %s", name);
5722         goto EXPAND_FAILED_CURLY;
5723         }
5724
5725       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5726       if (list == NULL) goto EXPAND_FAILED;
5727       if (*s++ != '}')
5728         {
5729         expand_string_message =
5730           string_sprintf("missing '}' closing first arg of %s", name);
5731         goto EXPAND_FAILED_CURLY;
5732         }
5733
5734       if (item_type == EITEM_REDUCE)
5735         {
5736         uschar * t;
5737         while (isspace(*s)) s++;
5738         if (*s++ != '{')
5739           {
5740           expand_string_message = US"missing '{' for second arg of reduce";
5741           goto EXPAND_FAILED_CURLY;
5742           }
5743         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5744         if (!t) goto EXPAND_FAILED;
5745         lookup_value = t;
5746         if (*s++ != '}')
5747           {
5748           expand_string_message = US"missing '}' closing second arg of reduce";
5749           goto EXPAND_FAILED_CURLY;
5750           }
5751         }
5752
5753       while (isspace(*s)) s++;
5754       if (*s++ != '{')
5755         {
5756         expand_string_message =
5757           string_sprintf("missing '{' for last arg of %s", name);
5758         goto EXPAND_FAILED_CURLY;
5759         }
5760
5761       expr = s;
5762
5763       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5764       if scanning a "false" part). This allows us to find the end of the
5765       condition, because if the list is empty, we won't actually evaluate the
5766       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5767       the normal internal expansion function. */
5768
5769       if (item_type == EITEM_FILTER)
5770         {
5771         temp = eval_condition(expr, &resetok, NULL);
5772         if (temp != NULL) s = temp;
5773         }
5774       else
5775         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5776
5777       if (temp == NULL)
5778         {
5779         expand_string_message = string_sprintf("%s inside \"%s\" item",
5780           expand_string_message, name);
5781         goto EXPAND_FAILED;
5782         }
5783
5784       while (isspace(*s)) s++;
5785       if (*s++ != '}')
5786         {                                               /*{*/
5787         expand_string_message = string_sprintf("missing } at end of condition "
5788           "or expression inside \"%s\"", name);
5789         goto EXPAND_FAILED;
5790         }
5791
5792       while (isspace(*s)) s++;                          /*{*/
5793       if (*s++ != '}')
5794         {                                               /*{*/
5795         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5796           name);
5797         goto EXPAND_FAILED;
5798         }
5799
5800       /* If we are skipping, we can now just move on to the next item. When
5801       processing for real, we perform the iteration. */
5802
5803       if (skipping) continue;
5804       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5805         {
5806         *outsep = (uschar)sep;      /* Separator as a string */
5807
5808         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5809                           name, iterate_item, lookup_value);
5810
5811         if (item_type == EITEM_FILTER)
5812           {
5813           BOOL condresult;
5814           if (eval_condition(expr, &resetok, &condresult) == NULL)
5815             {
5816             iterate_item = save_iterate_item;
5817             lookup_value = save_lookup_value;
5818             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5819               expand_string_message, name);
5820             goto EXPAND_FAILED;
5821             }
5822           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5823             condresult? "true":"false");
5824           if (condresult)
5825             temp = iterate_item;    /* TRUE => include this item */
5826           else
5827             continue;               /* FALSE => skip this item */
5828           }
5829
5830         /* EITEM_MAP and EITEM_REDUCE */
5831
5832         else
5833           {
5834           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5835           temp = t;
5836           if (temp == NULL)
5837             {
5838             iterate_item = save_iterate_item;
5839             expand_string_message = string_sprintf("%s inside \"%s\" item",
5840               expand_string_message, name);
5841             goto EXPAND_FAILED;
5842             }
5843           if (item_type == EITEM_REDUCE)
5844             {
5845             lookup_value = t;         /* Update the value of $value */
5846             continue;                 /* and continue the iteration */
5847             }
5848           }
5849
5850         /* We reach here for FILTER if the condition is true, always for MAP,
5851         and never for REDUCE. The value in "temp" is to be added to the output
5852         list that is being created, ensuring that any occurrences of the
5853         separator character are doubled. Unless we are dealing with the first
5854         item of the output list, add in a space if the new item begins with the
5855         separator character, or is an empty string. */
5856
5857         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5858           yield = string_catn(yield, &size, &ptr, US" ", 1);
5859
5860         /* Add the string in "temp" to the output list that we are building,
5861         This is done in chunks by searching for the separator character. */
5862
5863         for (;;)
5864           {
5865           size_t seglen = Ustrcspn(temp, outsep);
5866
5867           yield = string_catn(yield, &size, &ptr, temp, seglen + 1);
5868
5869           /* If we got to the end of the string we output one character
5870           too many; backup and end the loop. Otherwise arrange to double the
5871           separator. */
5872
5873           if (temp[seglen] == '\0') { ptr--; break; }
5874           yield = string_catn(yield, &size, &ptr, outsep, 1);
5875           temp += seglen + 1;
5876           }
5877
5878         /* Output a separator after the string: we will remove the redundant
5879         final one at the end. */
5880
5881         yield = string_catn(yield, &size, &ptr, outsep, 1);
5882         }   /* End of iteration over the list loop */
5883
5884       /* REDUCE has generated no output above: output the final value of
5885       $value. */
5886
5887       if (item_type == EITEM_REDUCE)
5888         {
5889         yield = string_cat(yield, &size, &ptr, lookup_value);
5890         lookup_value = save_lookup_value;  /* Restore $value */
5891         }
5892
5893       /* FILTER and MAP generate lists: if they have generated anything, remove
5894       the redundant final separator. Even though an empty item at the end of a
5895       list does not count, this is tidier. */
5896
5897       else if (ptr != save_ptr) ptr--;
5898
5899       /* Restore preserved $item */
5900
5901       iterate_item = save_iterate_item;
5902       continue;
5903       }
5904
5905     case EITEM_SORT:
5906       {
5907       int sep = 0;
5908       const uschar *srclist, *cmp, *xtract;
5909       uschar *srcitem;
5910       const uschar *dstlist = NULL, *dstkeylist = NULL;
5911       uschar * tmp;
5912       uschar *save_iterate_item = iterate_item;
5913
5914       while (isspace(*s)) s++;
5915       if (*s++ != '{')
5916         {
5917         expand_string_message = US"missing '{' for list arg of sort";
5918         goto EXPAND_FAILED_CURLY;
5919         }
5920
5921       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5922       if (!srclist) goto EXPAND_FAILED;
5923       if (*s++ != '}')
5924         {
5925         expand_string_message = US"missing '}' closing list arg of sort";
5926         goto EXPAND_FAILED_CURLY;
5927         }
5928
5929       while (isspace(*s)) s++;
5930       if (*s++ != '{')
5931         {
5932         expand_string_message = US"missing '{' for comparator arg of sort";
5933         goto EXPAND_FAILED_CURLY;
5934         }
5935
5936       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5937       if (!cmp) goto EXPAND_FAILED;
5938       if (*s++ != '}')
5939         {
5940         expand_string_message = US"missing '}' closing comparator arg of sort";
5941         goto EXPAND_FAILED_CURLY;
5942         }
5943
5944       while (isspace(*s)) s++;
5945       if (*s++ != '{')
5946         {
5947         expand_string_message = US"missing '{' for extractor arg of sort";
5948         goto EXPAND_FAILED_CURLY;
5949         }
5950
5951       xtract = s;
5952       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5953       if (!tmp) goto EXPAND_FAILED;
5954       xtract = string_copyn(xtract, s - xtract);
5955
5956       if (*s++ != '}')
5957         {
5958         expand_string_message = US"missing '}' closing extractor arg of sort";
5959         goto EXPAND_FAILED_CURLY;
5960         }
5961                                                         /*{*/
5962       if (*s++ != '}')
5963         {                                               /*{*/
5964         expand_string_message = US"missing } at end of \"sort\"";
5965         goto EXPAND_FAILED;
5966         }
5967
5968       if (skipping) continue;
5969
5970       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5971         {
5972         uschar * dstitem;
5973         uschar * newlist = NULL;
5974         uschar * newkeylist = NULL;
5975         uschar * srcfield;
5976
5977         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
5978
5979         /* extract field for comparisons */
5980         iterate_item = srcitem;
5981         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5982                                           TRUE, &resetok))
5983            || !*srcfield)
5984           {
5985           expand_string_message = string_sprintf(
5986               "field-extract in sort: \"%s\"", xtract);
5987           goto EXPAND_FAILED;
5988           }
5989
5990         /* Insertion sort */
5991
5992         /* copy output list until new-item < list-item */
5993         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5994           {
5995           uschar * dstfield;
5996           uschar * expr;
5997           BOOL before;
5998
5999           /* field for comparison */
6000           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6001             goto sort_mismatch;
6002
6003           /* build and run condition string */
6004           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6005
6006           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6007           if (!eval_condition(expr, &resetok, &before))
6008             {
6009             expand_string_message = string_sprintf("comparison in sort: %s",
6010                 expr);
6011             goto EXPAND_FAILED;
6012             }
6013
6014           if (before)
6015             {
6016             /* New-item sorts before this dst-item.  Append new-item,
6017             then dst-item, then remainder of dst list. */
6018
6019             newlist = string_append_listele(newlist, sep, srcitem);
6020             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6021             srcitem = NULL;
6022
6023             newlist = string_append_listele(newlist, sep, dstitem);
6024             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6025
6026             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6027               {
6028               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6029                 goto sort_mismatch;
6030               newlist = string_append_listele(newlist, sep, dstitem);
6031               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6032               }
6033
6034             break;
6035             }
6036
6037           newlist = string_append_listele(newlist, sep, dstitem);
6038           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6039           }
6040
6041         /* If we ran out of dstlist without consuming srcitem, append it */
6042         if (srcitem)
6043           {
6044           newlist = string_append_listele(newlist, sep, srcitem);
6045           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6046           }
6047
6048         dstlist = newlist;
6049         dstkeylist = newkeylist;
6050
6051         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6052         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6053         }
6054
6055       if (dstlist)
6056         yield = string_cat(yield, &size, &ptr, dstlist);
6057
6058       /* Restore preserved $item */
6059       iterate_item = save_iterate_item;
6060       continue;
6061
6062       sort_mismatch:
6063         expand_string_message = US"Internal error in sort (list mismatch)";
6064         goto EXPAND_FAILED;
6065       }
6066
6067
6068     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6069     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6070     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6071     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6072
6073     #define EXPAND_DLFUNC_MAX_ARGS 8
6074
6075     case EITEM_DLFUNC:
6076 #ifndef EXPAND_DLFUNC
6077       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6078         "is not included in this binary";
6079       goto EXPAND_FAILED;
6080
6081 #else   /* EXPAND_DLFUNC */
6082       {
6083       tree_node *t;
6084       exim_dlfunc_t *func;
6085       uschar *result;
6086       int status, argc;
6087       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6088
6089       if ((expand_forbid & RDO_DLFUNC) != 0)
6090         {
6091         expand_string_message =
6092           US"dynamically-loaded functions are not permitted";
6093         goto EXPAND_FAILED;
6094         }
6095
6096       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6097            TRUE, US"dlfunc", &resetok))
6098         {
6099         case 1: goto EXPAND_FAILED_CURLY;
6100         case 2:
6101         case 3: goto EXPAND_FAILED;
6102         }
6103
6104       /* If skipping, we don't actually do anything */
6105
6106       if (skipping) continue;
6107
6108       /* Look up the dynamically loaded object handle in the tree. If it isn't
6109       found, dlopen() the file and put the handle in the tree for next time. */
6110
6111       t = tree_search(dlobj_anchor, argv[0]);
6112       if (t == NULL)
6113         {
6114         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6115         if (handle == NULL)
6116           {
6117           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6118             argv[0], dlerror());
6119           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6120           goto EXPAND_FAILED;
6121           }
6122         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6123         Ustrcpy(t->name, argv[0]);
6124         t->data.ptr = handle;
6125         (void)tree_insertnode(&dlobj_anchor, t);
6126         }
6127
6128       /* Having obtained the dynamically loaded object handle, look up the
6129       function pointer. */
6130
6131       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6132       if (func == NULL)
6133         {
6134         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6135           "%s", argv[1], argv[0], dlerror());
6136         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6137         goto EXPAND_FAILED;
6138         }
6139
6140       /* Call the function and work out what to do with the result. If it
6141       returns OK, we have a replacement string; if it returns DEFER then
6142       expansion has failed in a non-forced manner; if it returns FAIL then
6143       failure was forced; if it returns ERROR or any other value there's a
6144       problem, so panic slightly. In any case, assume that the function has
6145       side-effects on the store that must be preserved. */
6146
6147       resetok = FALSE;
6148       result = NULL;
6149       for (argc = 0; argv[argc] != NULL; argc++);
6150       status = func(&result, argc - 2, &argv[2]);
6151       if(status == OK)
6152         {
6153         if (result == NULL) result = US"";
6154         yield = string_cat(yield, &size, &ptr, result);
6155         continue;
6156         }
6157       else
6158         {
6159         expand_string_message = result == NULL ? US"(no message)" : result;
6160         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6161           else if(status != FAIL)
6162             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6163               argv[0], argv[1], status, expand_string_message);
6164         goto EXPAND_FAILED;
6165         }
6166       }
6167 #endif /* EXPAND_DLFUNC */
6168
6169     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6170       {
6171       uschar * key;
6172       uschar *save_lookup_value = lookup_value;
6173
6174       while (isspace(*s)) s++;
6175       if (*s != '{')                                    /*}*/
6176         goto EXPAND_FAILED;
6177
6178       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6179       if (!key) goto EXPAND_FAILED;                     /*{*/
6180       if (*s++ != '}')
6181         {
6182         expand_string_message = US"missing '{' for name arg of env";
6183         goto EXPAND_FAILED_CURLY;
6184         }
6185
6186       lookup_value = US getenv(CS key);
6187
6188       switch(process_yesno(
6189                skipping,                     /* were previously skipping */
6190                lookup_value != NULL,         /* success/failure indicator */
6191                save_lookup_value,            /* value to reset for string2 */
6192                &s,                           /* input pointer */
6193                &yield,                       /* output pointer */
6194                &size,                        /* output size */
6195                &ptr,                         /* output current point */
6196                US"env",                      /* condition type */
6197                &resetok))
6198         {
6199         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6200         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6201         }
6202       continue;
6203       }
6204     }   /* EITEM_* switch */
6205
6206   /* Control reaches here if the name is not recognized as one of the more
6207   complicated expansion items. Check for the "operator" syntax (name terminated
6208   by a colon). Some of the operators have arguments, separated by _ from the
6209   name. */
6210
6211   if (*s == ':')
6212     {
6213     int c;
6214     uschar *arg = NULL;
6215     uschar *sub;
6216     var_entry *vp = NULL;
6217
6218     /* Owing to an historical mis-design, an underscore may be part of the
6219     operator name, or it may introduce arguments.  We therefore first scan the
6220     table of names that contain underscores. If there is no match, we cut off
6221     the arguments and then scan the main table. */
6222
6223     if ((c = chop_match(name, op_table_underscore,
6224                         nelem(op_table_underscore))) < 0)
6225       {
6226       arg = Ustrchr(name, '_');
6227       if (arg != NULL) *arg = 0;
6228       c = chop_match(name, op_table_main, nelem(op_table_main));
6229       if (c >= 0) c += nelem(op_table_underscore);
6230       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6231       }
6232
6233     /* Deal specially with operators that might take a certificate variable
6234     as we do not want to do the usual expansion. For most, expand the string.*/
6235     switch(c)
6236       {
6237 #ifdef SUPPORT_TLS
6238       case EOP_MD5:
6239       case EOP_SHA1:
6240       case EOP_SHA256:
6241       case EOP_BASE64:
6242         if (s[1] == '$')
6243           {
6244           const uschar * s1 = s;
6245           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6246                   FALSE, &resetok);
6247           if (!sub)       goto EXPAND_FAILED;           /*{*/
6248           if (*s1 != '}')
6249             {
6250             expand_string_message =
6251               string_sprintf("missing '}' closing cert arg of %s", name);
6252             goto EXPAND_FAILED_CURLY;
6253             }
6254           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6255             {
6256             s = s1+1;
6257             break;
6258             }
6259           vp = NULL;
6260           }
6261         /*FALLTHROUGH*/
6262 #endif
6263       default:
6264         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6265         if (!sub) goto EXPAND_FAILED;
6266         s++;
6267         break;
6268       }
6269
6270     /* If we are skipping, we don't need to perform the operation at all.
6271     This matters for operations like "mask", because the data may not be
6272     in the correct format when skipping. For example, the expression may test
6273     for the existence of $sender_host_address before trying to mask it. For
6274     other operations, doing them may not fail, but it is a waste of time. */
6275
6276     if (skipping && c >= 0) continue;
6277
6278     /* Otherwise, switch on the operator type */
6279
6280     switch(c)
6281       {
6282       case EOP_BASE32:
6283         {
6284         uschar *t;
6285         unsigned long int n = Ustrtoul(sub, &t, 10);
6286         uschar * s = NULL;
6287         int sz = 0, i = 0;
6288
6289         if (*t != 0)
6290           {
6291           expand_string_message = string_sprintf("argument for base32 "
6292             "operator is \"%s\", which is not a decimal number", sub);
6293           goto EXPAND_FAILED;
6294           }
6295         for ( ; n; n >>= 5)
6296           s = string_catn(s, &sz, &i, &base32_chars[n & 0x1f], 1);
6297
6298         while (i > 0) yield = string_catn(yield, &size, &ptr, &s[--i], 1);
6299         continue;
6300         }
6301
6302       case EOP_BASE32D:
6303         {
6304         uschar *tt = sub;
6305         unsigned long int n = 0;
6306         uschar * s;
6307         while (*tt)
6308           {
6309           uschar * t = Ustrchr(base32_chars, *tt++);
6310           if (t == NULL)
6311             {
6312             expand_string_message = string_sprintf("argument for base32d "
6313               "operator is \"%s\", which is not a base 32 number", sub);
6314             goto EXPAND_FAILED;
6315             }
6316           n = n * 32 + (t - base32_chars);
6317           }
6318         s = string_sprintf("%ld", n);
6319         yield = string_cat(yield, &size, &ptr, s);
6320         continue;
6321         }
6322
6323       case EOP_BASE62:
6324         {
6325         uschar *t;
6326         unsigned long int n = Ustrtoul(sub, &t, 10);
6327         if (*t != 0)
6328           {
6329           expand_string_message = string_sprintf("argument for base62 "
6330             "operator is \"%s\", which is not a decimal number", sub);
6331           goto EXPAND_FAILED;
6332           }
6333         t = string_base62(n);
6334         yield = string_cat(yield, &size, &ptr, t);
6335         continue;
6336         }
6337
6338       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6339
6340       case EOP_BASE62D:
6341         {
6342         uschar buf[16];
6343         uschar *tt = sub;
6344         unsigned long int n = 0;
6345         while (*tt != 0)
6346           {
6347           uschar *t = Ustrchr(base62_chars, *tt++);
6348           if (t == NULL)
6349             {
6350             expand_string_message = string_sprintf("argument for base62d "
6351               "operator is \"%s\", which is not a base %d number", sub,
6352               BASE_62);
6353             goto EXPAND_FAILED;
6354             }
6355           n = n * BASE_62 + (t - base62_chars);
6356           }
6357         (void)sprintf(CS buf, "%ld", n);
6358         yield = string_cat(yield, &size, &ptr, buf);
6359         continue;
6360         }
6361
6362       case EOP_EXPAND:
6363         {
6364         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6365         if (expanded == NULL)
6366           {
6367           expand_string_message =
6368             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6369               expand_string_message);
6370           goto EXPAND_FAILED;
6371           }
6372         yield = string_cat(yield, &size, &ptr, expanded);
6373         continue;
6374         }
6375
6376       case EOP_LC:
6377         {
6378         int count = 0;
6379         uschar *t = sub - 1;
6380         while (*(++t) != 0) { *t = tolower(*t); count++; }
6381         yield = string_catn(yield, &size, &ptr, sub, count);
6382         continue;
6383         }
6384
6385       case EOP_UC:
6386         {
6387         int count = 0;
6388         uschar *t = sub - 1;
6389         while (*(++t) != 0) { *t = toupper(*t); count++; }
6390         yield = string_catn(yield, &size, &ptr, sub, count);
6391         continue;
6392         }
6393
6394       case EOP_MD5:
6395 #ifdef SUPPORT_TLS
6396         if (vp && *(void **)vp->value)
6397           {
6398           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6399           yield = string_cat(yield, &size, &ptr, cp);
6400           }
6401         else
6402 #endif
6403           {
6404           md5 base;
6405           uschar digest[16];
6406           int j;
6407           char st[33];
6408           md5_start(&base);
6409           md5_end(&base, sub, Ustrlen(sub), digest);
6410           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6411           yield = string_cat(yield, &size, &ptr, US st);
6412           }
6413         continue;
6414
6415       case EOP_SHA1:
6416 #ifdef SUPPORT_TLS
6417         if (vp && *(void **)vp->value)
6418           {
6419           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6420           yield = string_cat(yield, &size, &ptr, cp);
6421           }
6422         else
6423 #endif
6424           {
6425           hctx h;
6426           uschar digest[20];
6427           int j;
6428           char st[41];
6429           sha1_start(&h);
6430           sha1_end(&h, sub, Ustrlen(sub), digest);
6431           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6432           yield = string_catn(yield, &size, &ptr, US st, 40);
6433           }
6434         continue;
6435
6436       case EOP_SHA256:
6437 #ifdef EXIM_HAVE_SHA2
6438         if (vp && *(void **)vp->value)
6439           {
6440           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6441           yield = string_cat(yield, &size, &ptr, cp);
6442           }
6443         else
6444           {
6445           hctx h;
6446           blob b;
6447           char st[3];
6448
6449           if (!exim_sha_init(&h, HASH_SHA256))
6450             {
6451             expand_string_message = US"unrecognised sha256 variant";
6452             goto EXPAND_FAILED;
6453             }
6454           exim_sha_update(&h, sub, Ustrlen(sub));
6455           exim_sha_finish(&h, &b);
6456           while (b.len-- > 0)
6457             {
6458             sprintf(st, "%02X", *b.data++);
6459             yield = string_catn(yield, &size, &ptr, US st, 2);
6460             }
6461           }
6462 #else
6463           expand_string_message = US"sha256 only supported with TLS";
6464 #endif
6465         continue;
6466
6467       case EOP_SHA3:
6468 #ifdef EXIM_HAVE_SHA3
6469         {
6470         hctx h;
6471         blob b;
6472         char st[3];
6473         hashmethod m = !arg ? HASH_SHA3_256
6474           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6475           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6476           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6477           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6478           : HASH_BADTYPE;
6479
6480         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6481           {
6482           expand_string_message = US"unrecognised sha3 variant";
6483           goto EXPAND_FAILED;
6484           }
6485
6486         exim_sha_update(&h, sub, Ustrlen(sub));
6487         exim_sha_finish(&h, &b);
6488         while (b.len-- > 0)
6489           {
6490           sprintf(st, "%02X", *b.data++);
6491           yield = string_catn(yield, &size, &ptr, US st, 2);
6492           }
6493         }
6494         continue;
6495 #else
6496         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 +";
6497         goto EXPAND_FAILED;
6498 #endif
6499
6500       /* Convert hex encoding to base64 encoding */
6501
6502       case EOP_HEX2B64:
6503         {
6504         int c = 0;
6505         int b = -1;
6506         uschar *in = sub;
6507         uschar *out = sub;
6508         uschar *enc;
6509
6510         for (enc = sub; *enc != 0; enc++)
6511           {
6512           if (!isxdigit(*enc))
6513             {
6514             expand_string_message = string_sprintf("\"%s\" is not a hex "
6515               "string", sub);
6516             goto EXPAND_FAILED;
6517             }
6518           c++;
6519           }
6520
6521         if ((c & 1) != 0)
6522           {
6523           expand_string_message = string_sprintf("\"%s\" contains an odd "
6524             "number of characters", sub);
6525           goto EXPAND_FAILED;
6526           }
6527
6528         while ((c = *in++) != 0)
6529           {
6530           if (isdigit(c)) c -= '0';
6531           else c = toupper(c) - 'A' + 10;
6532           if (b == -1)
6533             {
6534             b = c << 4;
6535             }
6536           else
6537             {
6538             *out++ = b | c;
6539             b = -1;
6540             }
6541           }
6542
6543         enc = b64encode(sub, out - sub);
6544         yield = string_cat(yield, &size, &ptr, enc);
6545         continue;
6546         }
6547
6548       /* Convert octets outside 0x21..0x7E to \xXX form */
6549
6550       case EOP_HEXQUOTE:
6551         {
6552         uschar *t = sub - 1;
6553         while (*(++t) != 0)
6554           {
6555           if (*t < 0x21 || 0x7E < *t)
6556             yield = string_catn(yield, &size, &ptr,
6557               string_sprintf("\\x%02x", *t), 4);
6558           else
6559             yield = string_catn(yield, &size, &ptr, t, 1);
6560           }
6561         continue;
6562         }
6563
6564       /* count the number of list elements */
6565
6566       case EOP_LISTCOUNT:
6567         {
6568         int cnt = 0;
6569         int sep = 0;
6570         uschar * cp;
6571         uschar buffer[256];
6572
6573         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6574         cp = string_sprintf("%d", cnt);
6575         yield = string_cat(yield, &size, &ptr, cp);
6576         continue;
6577         }
6578
6579       /* expand a named list given the name */
6580       /* handles nested named lists; requotes as colon-sep list */
6581
6582       case EOP_LISTNAMED:
6583         {
6584         tree_node *t = NULL;
6585         const uschar * list;
6586         int sep = 0;
6587         uschar * item;
6588         uschar * suffix = US"";
6589         BOOL needsep = FALSE;
6590         uschar buffer[256];
6591
6592         if (*sub == '+') sub++;
6593         if (arg == NULL)        /* no-argument version */
6594           {
6595           if (!(t = tree_search(addresslist_anchor, sub)) &&
6596               !(t = tree_search(domainlist_anchor,  sub)) &&
6597               !(t = tree_search(hostlist_anchor,    sub)))
6598             t = tree_search(localpartlist_anchor, sub);
6599           }
6600         else switch(*arg)       /* specific list-type version */
6601           {
6602           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6603           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6604           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6605           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6606           default:
6607             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6608             goto EXPAND_FAILED;
6609           }
6610
6611         if(!t)
6612           {
6613           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6614             sub, !arg?""
6615               : *arg=='a'?"address "
6616               : *arg=='d'?"domain "
6617               : *arg=='h'?"host "
6618               : *arg=='l'?"localpart "
6619               : 0);
6620           goto EXPAND_FAILED;
6621           }
6622
6623         list = ((namedlist_block *)(t->data.ptr))->string;
6624
6625         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6626           {
6627           uschar * buf = US" : ";
6628           if (needsep)
6629             yield = string_catn(yield, &size, &ptr, buf, 3);
6630           else
6631             needsep = TRUE;
6632
6633           if (*item == '+')     /* list item is itself a named list */
6634             {
6635             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6636             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6637             }
6638           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6639             {
6640             char * cp;
6641             char tok[3];
6642             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6643             while ((cp= strpbrk((const char *)item, tok)))
6644               {
6645               yield = string_catn(yield, &size, &ptr, item, cp-(char *)item);
6646               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6647                 {
6648                 yield = string_catn(yield, &size, &ptr, US"::", 2);
6649                 item = (uschar *)cp;
6650                 }
6651               else              /* sep in item; should already be doubled; emit once */
6652                 {
6653                 yield = string_catn(yield, &size, &ptr, (uschar *)tok, 1);
6654                 if (*cp == sep) cp++;
6655                 item = (uschar *)cp;
6656                 }
6657               }
6658             }
6659           yield = string_cat(yield, &size, &ptr, item);
6660           }
6661         continue;
6662         }
6663
6664       /* mask applies a mask to an IP address; for example the result of
6665       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6666
6667       case EOP_MASK:
6668         {
6669         int count;
6670         uschar *endptr;
6671         int binary[4];
6672         int mask, maskoffset;
6673         int type = string_is_ip_address(sub, &maskoffset);
6674         uschar buffer[64];
6675
6676         if (type == 0)
6677           {
6678           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6679            sub);
6680           goto EXPAND_FAILED;
6681           }
6682
6683         if (maskoffset == 0)
6684           {
6685           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6686             sub);
6687           goto EXPAND_FAILED;
6688           }
6689
6690         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6691
6692         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6693           {
6694           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6695             sub);
6696           goto EXPAND_FAILED;
6697           }
6698
6699         /* Convert the address to binary integer(s) and apply the mask */
6700
6701         sub[maskoffset] = 0;
6702         count = host_aton(sub, binary);
6703         host_mask(count, binary, mask);
6704
6705         /* Convert to masked textual format and add to output. */
6706
6707         yield = string_catn(yield, &size, &ptr, buffer,
6708           host_nmtoa(count, binary, mask, buffer, '.'));
6709         continue;
6710         }
6711
6712       case EOP_IPV6NORM:
6713       case EOP_IPV6DENORM:
6714         {
6715         int type = string_is_ip_address(sub, NULL);
6716         int binary[4];
6717         uschar buffer[44];
6718
6719         switch (type)
6720           {
6721           case 6:
6722             (void) host_aton(sub, binary);
6723             break;
6724
6725           case 4:       /* convert to IPv4-mapped IPv6 */
6726             binary[0] = binary[1] = 0;
6727             binary[2] = 0x0000ffff;
6728             (void) host_aton(sub, binary+3);
6729             break;
6730
6731           case 0:
6732             expand_string_message =
6733               string_sprintf("\"%s\" is not an IP address", sub);
6734             goto EXPAND_FAILED;
6735           }
6736
6737         yield = string_catn(yield, &size, &ptr, buffer,
6738                   c == EOP_IPV6NORM
6739                     ? ipv6_nmtoa(binary, buffer)
6740                     : host_nmtoa(4, binary, -1, buffer, ':')
6741                   );
6742         continue;
6743         }
6744
6745       case EOP_ADDRESS:
6746       case EOP_LOCAL_PART:
6747       case EOP_DOMAIN:
6748         {
6749         uschar *error;
6750         int start, end, domain;
6751         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6752           FALSE);
6753         if (t != NULL)
6754           {
6755           if (c != EOP_DOMAIN)
6756             {
6757             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6758             yield = string_catn(yield, &size, &ptr, sub+start, end-start);
6759             }
6760           else if (domain != 0)
6761             {
6762             domain += start;
6763             yield = string_catn(yield, &size, &ptr, sub+domain, end-domain);
6764             }
6765           }
6766         continue;
6767         }
6768
6769       case EOP_ADDRESSES:
6770         {
6771         uschar outsep[2] = { ':', '\0' };
6772         uschar *address, *error;
6773         int save_ptr = ptr;
6774         int start, end, domain;  /* Not really used */
6775
6776         while (isspace(*sub)) sub++;
6777         if (*sub == '>') { *outsep = *++sub; ++sub; }
6778         parse_allow_group = TRUE;
6779
6780         for (;;)
6781           {
6782           uschar *p = parse_find_address_end(sub, FALSE);
6783           uschar saveend = *p;
6784           *p = '\0';
6785           address = parse_extract_address(sub, &error, &start, &end, &domain,
6786             FALSE);
6787           *p = saveend;
6788
6789           /* Add the address to the output list that we are building. This is
6790           done in chunks by searching for the separator character. At the
6791           start, unless we are dealing with the first address of the output
6792           list, add in a space if the new address begins with the separator
6793           character, or is an empty string. */
6794
6795           if (address != NULL)
6796             {
6797             if (ptr != save_ptr && address[0] == *outsep)
6798               yield = string_catn(yield, &size, &ptr, US" ", 1);
6799
6800             for (;;)
6801               {
6802               size_t seglen = Ustrcspn(address, outsep);
6803               yield = string_catn(yield, &size, &ptr, address, seglen + 1);
6804
6805               /* If we got to the end of the string we output one character
6806               too many. */
6807
6808               if (address[seglen] == '\0') { ptr--; break; }
6809               yield = string_catn(yield, &size, &ptr, outsep, 1);
6810               address += seglen + 1;
6811               }
6812
6813             /* Output a separator after the string: we will remove the
6814             redundant final one at the end. */
6815
6816             yield = string_catn(yield, &size, &ptr, outsep, 1);
6817             }
6818
6819           if (saveend == '\0') break;
6820           sub = p + 1;
6821           }
6822
6823         /* If we have generated anything, remove the redundant final
6824         separator. */
6825
6826         if (ptr != save_ptr) ptr--;
6827         parse_allow_group = FALSE;
6828         continue;
6829         }
6830
6831
6832       /* quote puts a string in quotes if it is empty or contains anything
6833       other than alphamerics, underscore, dot, or hyphen.
6834
6835       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6836       be quoted in order to be a valid local part.
6837
6838       In both cases, newlines and carriage returns are converted into \n and \r
6839       respectively */
6840
6841       case EOP_QUOTE:
6842       case EOP_QUOTE_LOCAL_PART:
6843       if (arg == NULL)
6844         {
6845         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6846         uschar *t = sub - 1;
6847
6848         if (c == EOP_QUOTE)
6849           {
6850           while (!needs_quote && *(++t) != 0)
6851             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6852           }
6853         else  /* EOP_QUOTE_LOCAL_PART */
6854           {
6855           while (!needs_quote && *(++t) != 0)
6856             needs_quote = !isalnum(*t) &&
6857               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6858               (*t != '.' || t == sub || t[1] == 0);
6859           }
6860
6861         if (needs_quote)
6862           {
6863           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6864           t = sub - 1;
6865           while (*(++t) != 0)
6866             {
6867             if (*t == '\n')
6868               yield = string_catn(yield, &size, &ptr, US"\\n", 2);
6869             else if (*t == '\r')
6870               yield = string_catn(yield, &size, &ptr, US"\\r", 2);
6871             else
6872               {
6873               if (*t == '\\' || *t == '"')
6874                 yield = string_catn(yield, &size, &ptr, US"\\", 1);
6875               yield = string_catn(yield, &size, &ptr, t, 1);
6876               }
6877             }
6878           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6879           }
6880         else yield = string_cat(yield, &size, &ptr, sub);
6881         continue;
6882         }
6883
6884       /* quote_lookuptype does lookup-specific quoting */
6885
6886       else
6887         {
6888         int n;
6889         uschar *opt = Ustrchr(arg, '_');
6890
6891         if (opt != NULL) *opt++ = 0;
6892
6893         n = search_findtype(arg, Ustrlen(arg));
6894         if (n < 0)
6895           {
6896           expand_string_message = search_error_message;
6897           goto EXPAND_FAILED;
6898           }
6899
6900         if (lookup_list[n]->quote != NULL)
6901           sub = (lookup_list[n]->quote)(sub, opt);
6902         else if (opt != NULL) sub = NULL;
6903
6904         if (sub == NULL)
6905           {
6906           expand_string_message = string_sprintf(
6907             "\"%s\" unrecognized after \"${quote_%s\"",
6908             opt, arg);
6909           goto EXPAND_FAILED;
6910           }
6911
6912         yield = string_cat(yield, &size, &ptr, sub);
6913         continue;
6914         }
6915
6916       /* rx quote sticks in \ before any non-alphameric character so that
6917       the insertion works in a regular expression. */
6918
6919       case EOP_RXQUOTE:
6920         {
6921         uschar *t = sub - 1;
6922         while (*(++t) != 0)
6923           {
6924           if (!isalnum(*t))
6925             yield = string_catn(yield, &size, &ptr, US"\\", 1);
6926           yield = string_catn(yield, &size, &ptr, t, 1);
6927           }
6928         continue;
6929         }
6930
6931       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6932       prescribed by the RFC, if there are characters that need to be encoded */
6933
6934       case EOP_RFC2047:
6935         {
6936         uschar buffer[2048];
6937         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6938           buffer, sizeof(buffer), FALSE);
6939         yield = string_cat(yield, &size, &ptr, string);
6940         continue;
6941         }
6942
6943       /* RFC 2047 decode */
6944
6945       case EOP_RFC2047D:
6946         {
6947         int len;
6948         uschar *error;
6949         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6950           headers_charset, '?', &len, &error);
6951         if (error != NULL)
6952           {
6953           expand_string_message = error;
6954           goto EXPAND_FAILED;
6955           }
6956         yield = string_catn(yield, &size, &ptr, decoded, len);
6957         continue;
6958         }
6959
6960       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6961       underscores */
6962
6963       case EOP_FROM_UTF8:
6964         {
6965         while (*sub != 0)
6966           {
6967           int c;
6968           uschar buff[4];
6969           GETUTF8INC(c, sub);
6970           if (c > 255) c = '_';
6971           buff[0] = c;
6972           yield = string_catn(yield, &size, &ptr, buff, 1);
6973           }
6974         continue;
6975         }
6976
6977           /* replace illegal UTF-8 sequences by replacement character  */
6978
6979       #define UTF8_REPLACEMENT_CHAR US"?"
6980
6981       case EOP_UTF8CLEAN:
6982         {
6983         int seq_len = 0, index = 0;
6984         int bytes_left = 0;
6985         long codepoint = -1;
6986         uschar seq_buff[4];                     /* accumulate utf-8 here */
6987
6988         while (*sub != 0)
6989           {
6990           int complete = 0;
6991           uschar c = *sub++;
6992
6993           if (bytes_left)
6994             {
6995             if ((c & 0xc0) != 0x80)
6996                     /* wrong continuation byte; invalidate all bytes */
6997               complete = 1; /* error */
6998             else
6999               {
7000               codepoint = (codepoint << 6) | (c & 0x3f);
7001               seq_buff[index++] = c;
7002               if (--bytes_left == 0)            /* codepoint complete */
7003                 if(codepoint > 0x10FFFF)        /* is it too large? */
7004                   complete = -1;        /* error (RFC3629 limit) */
7005                 else
7006                   {             /* finished; output utf-8 sequence */
7007                   yield = string_catn(yield, &size, &ptr, seq_buff, seq_len);
7008                   index = 0;
7009                   }
7010               }
7011             }
7012           else  /* no bytes left: new sequence */
7013             {
7014             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7015               {
7016               yield = string_catn(yield, &size, &ptr, &c, 1);
7017               continue;
7018               }
7019             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7020               {
7021               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7022                 complete = -1;
7023               else
7024                 {
7025                   bytes_left = 1;
7026                   codepoint = c & 0x1f;
7027                 }
7028               }
7029             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7030               {
7031               bytes_left = 2;
7032               codepoint = c & 0x0f;
7033               }
7034             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7035               {
7036               bytes_left = 3;
7037               codepoint = c & 0x07;
7038               }
7039             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7040               complete = -1;
7041
7042             seq_buff[index++] = c;
7043             seq_len = bytes_left + 1;
7044             }           /* if(bytes_left) */
7045
7046           if (complete != 0)
7047             {
7048             bytes_left = index = 0;
7049             yield = string_catn(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
7050             }
7051           if ((complete == 1) && ((c & 0x80) == 0))
7052                         /* ASCII character follows incomplete sequence */
7053               yield = string_catn(yield, &size, &ptr, &c, 1);
7054           }
7055         continue;
7056         }
7057
7058 #ifdef SUPPORT_I18N
7059       case EOP_UTF8_DOMAIN_TO_ALABEL:
7060         {
7061         uschar * error = NULL;
7062         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7063         if (error)
7064           {
7065           expand_string_message = string_sprintf(
7066             "error converting utf8 (%s) to alabel: %s",
7067             string_printing(sub), error);
7068           goto EXPAND_FAILED;
7069           }
7070         yield = string_cat(yield, &size, &ptr, s);
7071         continue;
7072         }
7073
7074       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7075         {
7076         uschar * error = NULL;
7077         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7078         if (error)
7079           {
7080           expand_string_message = string_sprintf(
7081             "error converting alabel (%s) to utf8: %s",
7082             string_printing(sub), error);
7083           goto EXPAND_FAILED;
7084           }
7085         yield = string_cat(yield, &size, &ptr, s);
7086         continue;
7087         }
7088
7089       case EOP_UTF8_LOCALPART_TO_ALABEL:
7090         {
7091         uschar * error = NULL;
7092         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7093         if (error)
7094           {
7095           expand_string_message = string_sprintf(
7096             "error converting utf8 (%s) to alabel: %s",
7097             string_printing(sub), error);
7098           goto EXPAND_FAILED;
7099           }
7100         yield = string_cat(yield, &size, &ptr, s);
7101         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield);
7102         continue;
7103         }
7104
7105       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7106         {
7107         uschar * error = NULL;
7108         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7109         if (error)
7110           {
7111           expand_string_message = string_sprintf(
7112             "error converting alabel (%s) to utf8: %s",
7113             string_printing(sub), error);
7114           goto EXPAND_FAILED;
7115           }
7116         yield = string_cat(yield, &size, &ptr, s);
7117         continue;
7118         }
7119 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7120
7121       /* escape turns all non-printing characters into escape sequences. */
7122
7123       case EOP_ESCAPE:
7124         {
7125         const uschar * t = string_printing(sub);
7126         yield = string_cat(yield, &size, &ptr, t);
7127         continue;
7128         }
7129
7130       case EOP_ESCAPE8BIT:
7131         {
7132         const uschar * s = sub;
7133         uschar c;
7134
7135         for (s = sub; (c = *s); s++)
7136           yield = c < 127 && c != '\\'
7137             ? string_catn(yield, &size, &ptr, s, 1)
7138             : string_catn(yield, &size, &ptr, string_sprintf("\\%03o", c), 4);
7139         continue;
7140         }
7141
7142       /* Handle numeric expression evaluation */
7143
7144       case EOP_EVAL:
7145       case EOP_EVAL10:
7146         {
7147         uschar *save_sub = sub;
7148         uschar *error = NULL;
7149         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7150         if (error != NULL)
7151           {
7152           expand_string_message = string_sprintf("error in expression "
7153             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7154               save_sub);
7155           goto EXPAND_FAILED;
7156           }
7157         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7158         yield = string_cat(yield, &size, &ptr, var_buffer);
7159         continue;
7160         }
7161
7162       /* Handle time period formating */
7163
7164       case EOP_TIME_EVAL:
7165         {
7166         int n = readconf_readtime(sub, 0, FALSE);
7167         if (n < 0)
7168           {
7169           expand_string_message = string_sprintf("string \"%s\" is not an "
7170             "Exim time interval in \"%s\" operator", sub, name);
7171           goto EXPAND_FAILED;
7172           }
7173         sprintf(CS var_buffer, "%d", n);
7174         yield = string_cat(yield, &size, &ptr, var_buffer);
7175         continue;
7176         }
7177
7178       case EOP_TIME_INTERVAL:
7179         {
7180         int n;
7181         uschar *t = read_number(&n, sub);
7182         if (*t != 0) /* Not A Number*/
7183           {
7184           expand_string_message = string_sprintf("string \"%s\" is not a "
7185             "positive number in \"%s\" operator", sub, name);
7186           goto EXPAND_FAILED;
7187           }
7188         t = readconf_printtime(n);
7189         yield = string_cat(yield, &size, &ptr, t);
7190         continue;
7191         }
7192
7193       /* Convert string to base64 encoding */
7194
7195       case EOP_STR2B64:
7196       case EOP_BASE64:
7197         {
7198 #ifdef SUPPORT_TLS
7199         uschar * s = vp && *(void **)vp->value
7200           ? tls_cert_der_b64(*(void **)vp->value)
7201           : b64encode(sub, Ustrlen(sub));
7202 #else
7203         uschar * s = b64encode(sub, Ustrlen(sub));
7204 #endif
7205         yield = string_cat(yield, &size, &ptr, s);
7206         continue;
7207         }
7208
7209       case EOP_BASE64D:
7210         {
7211         uschar * s;
7212         int len = b64decode(sub, &s);
7213         if (len < 0)
7214           {
7215           expand_string_message = string_sprintf("string \"%s\" is not "
7216             "well-formed for \"%s\" operator", sub, name);
7217           goto EXPAND_FAILED;
7218           }
7219         yield = string_cat(yield, &size, &ptr, s);
7220         continue;
7221         }
7222
7223       /* strlen returns the length of the string */
7224
7225       case EOP_STRLEN:
7226         {
7227         uschar buff[24];
7228         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7229         yield = string_cat(yield, &size, &ptr, buff);
7230         continue;
7231         }
7232
7233       /* length_n or l_n takes just the first n characters or the whole string,
7234       whichever is the shorter;
7235
7236       substr_m_n, and s_m_n take n characters from offset m; negative m take
7237       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7238       takes the rest, either to the right or to the left.
7239
7240       hash_n or h_n makes a hash of length n from the string, yielding n
7241       characters from the set a-z; hash_n_m makes a hash of length n, but
7242       uses m characters from the set a-zA-Z0-9.
7243
7244       nhash_n returns a single number between 0 and n-1 (in text form), while
7245       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7246       between 0 and n-1 and the second between 0 and m-1. */
7247
7248       case EOP_LENGTH:
7249       case EOP_L:
7250       case EOP_SUBSTR:
7251       case EOP_S:
7252       case EOP_HASH:
7253       case EOP_H:
7254       case EOP_NHASH:
7255       case EOP_NH:
7256         {
7257         int sign = 1;
7258         int value1 = 0;
7259         int value2 = -1;
7260         int *pn;
7261         int len;
7262         uschar *ret;
7263
7264         if (arg == NULL)
7265           {
7266           expand_string_message = string_sprintf("missing values after %s",
7267             name);
7268           goto EXPAND_FAILED;
7269           }
7270
7271         /* "length" has only one argument, effectively being synonymous with
7272         substr_0_n. */
7273
7274         if (c == EOP_LENGTH || c == EOP_L)
7275           {
7276           pn = &value2;
7277           value2 = 0;
7278           }
7279
7280         /* The others have one or two arguments; for "substr" the first may be
7281         negative. The second being negative means "not supplied". */
7282
7283         else
7284           {
7285           pn = &value1;
7286           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7287           }
7288
7289         /* Read up to two numbers, separated by underscores */
7290
7291         ret = arg;
7292         while (*arg != 0)
7293           {
7294           if (arg != ret && *arg == '_' && pn == &value1)
7295             {
7296             pn = &value2;
7297             value2 = 0;
7298             if (arg[1] != 0) arg++;
7299             }
7300           else if (!isdigit(*arg))
7301             {
7302             expand_string_message =
7303               string_sprintf("non-digit after underscore in \"%s\"", name);
7304             goto EXPAND_FAILED;
7305             }
7306           else *pn = (*pn)*10 + *arg++ - '0';
7307           }
7308         value1 *= sign;
7309
7310         /* Perform the required operation */
7311
7312         ret =
7313           (c == EOP_HASH || c == EOP_H)?
7314              compute_hash(sub, value1, value2, &len) :
7315           (c == EOP_NHASH || c == EOP_NH)?
7316              compute_nhash(sub, value1, value2, &len) :
7317              extract_substr(sub, value1, value2, &len);
7318
7319         if (ret == NULL) goto EXPAND_FAILED;
7320         yield = string_catn(yield, &size, &ptr, ret, len);
7321         continue;
7322         }
7323
7324       /* Stat a path */
7325
7326       case EOP_STAT:
7327         {
7328         uschar *s;
7329         uschar smode[12];
7330         uschar **modetable[3];
7331         int i;
7332         mode_t mode;
7333         struct stat st;
7334
7335         if ((expand_forbid & RDO_EXISTS) != 0)
7336           {
7337           expand_string_message = US"Use of the stat() expansion is not permitted";
7338           goto EXPAND_FAILED;
7339           }
7340
7341         if (stat(CS sub, &st) < 0)
7342           {
7343           expand_string_message = string_sprintf("stat(%s) failed: %s",
7344             sub, strerror(errno));
7345           goto EXPAND_FAILED;
7346           }
7347         mode = st.st_mode;
7348         switch (mode & S_IFMT)
7349           {
7350           case S_IFIFO: smode[0] = 'p'; break;
7351           case S_IFCHR: smode[0] = 'c'; break;
7352           case S_IFDIR: smode[0] = 'd'; break;
7353           case S_IFBLK: smode[0] = 'b'; break;
7354           case S_IFREG: smode[0] = '-'; break;
7355           default: smode[0] = '?'; break;
7356           }
7357
7358         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7359         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7360         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7361
7362         for (i = 0; i < 3; i++)
7363           {
7364           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7365           mode >>= 3;
7366           }
7367
7368         smode[10] = 0;
7369         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7370           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7371           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7372           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7373           (long)st.st_gid, st.st_size, (long)st.st_atime,
7374           (long)st.st_mtime, (long)st.st_ctime);
7375         yield = string_cat(yield, &size, &ptr, s);
7376         continue;
7377         }
7378
7379       /* vaguely random number less than N */
7380
7381       case EOP_RANDINT:
7382         {
7383         int_eximarith_t max;
7384         uschar *s;
7385
7386         max = expanded_string_integer(sub, TRUE);
7387         if (expand_string_message != NULL)
7388           goto EXPAND_FAILED;
7389         s = string_sprintf("%d", vaguely_random_number((int)max));
7390         yield = string_cat(yield, &size, &ptr, s);
7391         continue;
7392         }
7393
7394       /* Reverse IP, including IPv6 to dotted-nibble */
7395
7396       case EOP_REVERSE_IP:
7397         {
7398         int family, maskptr;
7399         uschar reversed[128];
7400
7401         family = string_is_ip_address(sub, &maskptr);
7402         if (family == 0)
7403           {
7404           expand_string_message = string_sprintf(
7405               "reverse_ip() not given an IP address [%s]", sub);
7406           goto EXPAND_FAILED;
7407           }
7408         invert_address(reversed, sub);
7409         yield = string_cat(yield, &size, &ptr, reversed);
7410         continue;
7411         }
7412
7413       /* Unknown operator */
7414
7415       default:
7416       expand_string_message =
7417         string_sprintf("unknown expansion operator \"%s\"", name);
7418       goto EXPAND_FAILED;
7419       }
7420     }
7421
7422   /* Handle a plain name. If this is the first thing in the expansion, release
7423   the pre-allocated buffer. If the result data is known to be in a new buffer,
7424   newsize will be set to the size of that buffer, and we can just point at that
7425   store instead of copying. Many expansion strings contain just one reference,
7426   so this is a useful optimization, especially for humungous headers
7427   ($message_headers). */
7428                                                 /*{*/
7429   if (*s++ == '}')
7430     {
7431     int len;
7432     int newsize = 0;
7433     if (ptr == 0)
7434       {
7435       if (resetok) store_reset(yield);
7436       yield = NULL;
7437       size = 0;
7438       }
7439     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7440       {
7441       expand_string_message =
7442         string_sprintf("unknown variable in \"${%s}\"", name);
7443       check_variable_error_message(name);
7444       goto EXPAND_FAILED;
7445       }
7446     len = Ustrlen(value);
7447     if (!yield && newsize)
7448       {
7449       yield = value;
7450       size = newsize;
7451       ptr = len;
7452       }
7453     else
7454       yield = string_catn(yield, &size, &ptr, value, len);
7455     continue;
7456     }
7457
7458   /* Else there's something wrong */
7459
7460   expand_string_message =
7461     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7462     "in a variable reference)", name);
7463   goto EXPAND_FAILED;
7464   }
7465
7466 /* If we hit the end of the string when ket_ends is set, there is a missing
7467 terminating brace. */
7468
7469 if (ket_ends && *s == 0)
7470   {
7471   expand_string_message = malformed_header?
7472     US"missing } at end of string - could be header name not terminated by colon"
7473     :
7474     US"missing } at end of string";
7475   goto EXPAND_FAILED;
7476   }
7477
7478 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7479 added to the string. If so, set up an empty string. Add a terminating zero. If
7480 left != NULL, return a pointer to the terminator. */
7481
7482 if (yield == NULL) yield = store_get(1);
7483 yield[ptr] = 0;
7484 if (left != NULL) *left = s;
7485
7486 /* Any stacking store that was used above the final string is no longer needed.
7487 In many cases the final string will be the first one that was got and so there
7488 will be optimal store usage. */
7489
7490 if (resetok) store_reset(yield + ptr + 1);
7491 else if (resetok_p) *resetok_p = FALSE;
7492
7493 DEBUG(D_expand)
7494   {
7495   debug_printf_indent("|__expanding: %.*s\n", (int)(s - string), string);
7496   debug_printf_indent("%s_____result: %s\n", skipping ? "|" : "\\", yield);
7497   if (skipping) debug_printf_indent("\\___skipping: result is not used\n");
7498   }
7499 expand_level--;
7500 return yield;
7501
7502 /* This is the failure exit: easiest to program with a goto. We still need
7503 to update the pointer to the terminator, for cases of nested calls with "fail".
7504 */
7505
7506 EXPAND_FAILED_CURLY:
7507 if (malformed_header)
7508   expand_string_message =
7509     US"missing or misplaced { or } - could be header name not terminated by colon";
7510
7511 else if (!expand_string_message || !*expand_string_message)
7512   expand_string_message = US"missing or misplaced { or }";
7513
7514 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7515 that is a bad idea, because expand_string_message is in dynamic store. */
7516
7517 EXPAND_FAILED:
7518 if (left != NULL) *left = s;
7519 DEBUG(D_expand)
7520   {
7521   debug_printf_indent("|failed to expand: %s\n", string);
7522   debug_printf_indent("%s___error message: %s\n",
7523     expand_string_forcedfail ? "|" : "\\", expand_string_message);
7524   if (expand_string_forcedfail) debug_printf_indent("\\failure was forced\n");
7525   }
7526 if (resetok_p) *resetok_p = resetok;
7527 expand_level--;
7528 return NULL;
7529 }
7530
7531
7532 /* This is the external function call. Do a quick check for any expansion
7533 metacharacters, and if there are none, just return the input string.
7534
7535 Argument: the string to be expanded
7536 Returns:  the expanded string, or NULL if expansion failed; if failure was
7537           due to a lookup deferring, search_find_defer will be TRUE
7538 */
7539
7540 uschar *
7541 expand_string(uschar *string)
7542 {
7543 search_find_defer = FALSE;
7544 malformed_header = FALSE;
7545 return (Ustrpbrk(string, "$\\") == NULL)? string :
7546   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7547 }
7548
7549
7550
7551 const uschar *
7552 expand_cstring(const uschar *string)
7553 {
7554 search_find_defer = FALSE;
7555 malformed_header = FALSE;
7556 return (Ustrpbrk(string, "$\\") == NULL)? string :
7557   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7558 }
7559
7560
7561
7562 /*************************************************
7563 *              Expand and copy                   *
7564 *************************************************/
7565
7566 /* Now and again we want to expand a string and be sure that the result is in a
7567 new bit of store. This function does that.
7568 Since we know it has been copied, the de-const cast is safe.
7569
7570 Argument: the string to be expanded
7571 Returns:  the expanded string, always in a new bit of store, or NULL
7572 */
7573
7574 uschar *
7575 expand_string_copy(const uschar *string)
7576 {
7577 const uschar *yield = expand_cstring(string);
7578 if (yield == string) yield = string_copy(string);
7579 return US yield;
7580 }
7581
7582
7583
7584 /*************************************************
7585 *        Expand and interpret as an integer      *
7586 *************************************************/
7587
7588 /* Expand a string, and convert the result into an integer.
7589
7590 Arguments:
7591   string  the string to be expanded
7592   isplus  TRUE if a non-negative number is expected
7593
7594 Returns:  the integer value, or
7595           -1 for an expansion error               ) in both cases, message in
7596           -2 for an integer interpretation error  ) expand_string_message
7597           expand_string_message is set NULL for an OK integer
7598 */
7599
7600 int_eximarith_t
7601 expand_string_integer(uschar *string, BOOL isplus)
7602 {
7603 return expanded_string_integer(expand_string(string), isplus);
7604 }
7605
7606
7607 /*************************************************
7608  *         Interpret string as an integer        *
7609  *************************************************/
7610
7611 /* Convert a string (that has already been expanded) into an integer.
7612
7613 This function is used inside the expansion code.
7614
7615 Arguments:
7616   s       the string to be expanded
7617   isplus  TRUE if a non-negative number is expected
7618
7619 Returns:  the integer value, or
7620           -1 if string is NULL (which implies an expansion error)
7621           -2 for an integer interpretation error
7622           expand_string_message is set NULL for an OK integer
7623 */
7624
7625 static int_eximarith_t
7626 expanded_string_integer(const uschar *s, BOOL isplus)
7627 {
7628 int_eximarith_t value;
7629 uschar *msg = US"invalid integer \"%s\"";
7630 uschar *endptr;
7631
7632 /* If expansion failed, expand_string_message will be set. */
7633
7634 if (s == NULL) return -1;
7635
7636 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7637 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7638 systems, so we set it zero ourselves. */
7639
7640 errno = 0;
7641 expand_string_message = NULL;               /* Indicates no error */
7642
7643 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7644 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7645 the behaviour explicitly.  Stripping leading whitespace is a harmless
7646 noop change since strtol skips it anyway (provided that there is a number
7647 to find at all). */
7648 if (isspace(*s))
7649   {
7650   while (isspace(*s)) ++s;
7651   if (*s == '\0')
7652     {
7653       DEBUG(D_expand)
7654        debug_printf_indent("treating blank string as number 0\n");
7655       return 0;
7656     }
7657   }
7658
7659 value = strtoll(CS s, CSS &endptr, 10);
7660
7661 if (endptr == s)
7662   {
7663   msg = US"integer expected but \"%s\" found";
7664   }
7665 else if (value < 0 && isplus)
7666   {
7667   msg = US"non-negative integer expected but \"%s\" found";
7668   }
7669 else
7670   {
7671   switch (tolower(*endptr))
7672     {
7673     default:
7674       break;
7675     case 'k':
7676       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7677       else value *= 1024;
7678       endptr++;
7679       break;
7680     case 'm':
7681       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7682       else value *= 1024*1024;
7683       endptr++;
7684       break;
7685     case 'g':
7686       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7687       else value *= 1024*1024*1024;
7688       endptr++;
7689       break;
7690     }
7691   if (errno == ERANGE)
7692     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7693   else
7694     {
7695     while (isspace(*endptr)) endptr++;
7696     if (*endptr == 0) return value;
7697     }
7698   }
7699
7700 expand_string_message = string_sprintf(CS msg, s);
7701 return -2;
7702 }
7703
7704
7705 /* These values are usually fixed boolean values, but they are permitted to be
7706 expanded strings.
7707
7708 Arguments:
7709   addr       address being routed
7710   mtype      the module type
7711   mname      the module name
7712   dbg_opt    debug selectors
7713   oname      the option name
7714   bvalue     the router's boolean value
7715   svalue     the router's string value
7716   rvalue     where to put the returned value
7717
7718 Returns:     OK     value placed in rvalue
7719              DEFER  expansion failed
7720 */
7721
7722 int
7723 exp_bool(address_item *addr,
7724   uschar *mtype, uschar *mname, unsigned dbg_opt,
7725   uschar *oname, BOOL bvalue,
7726   uschar *svalue, BOOL *rvalue)
7727 {
7728 uschar *expanded;
7729 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7730
7731 expanded = expand_string(svalue);
7732 if (expanded == NULL)
7733   {
7734   if (expand_string_forcedfail)
7735     {
7736     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7737     *rvalue = bvalue;
7738     return OK;
7739     }
7740   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7741       oname, mname, mtype, expand_string_message);
7742   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7743   return DEFER;
7744   }
7745
7746 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7747   expanded);
7748
7749 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7750   *rvalue = TRUE;
7751 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7752   *rvalue = FALSE;
7753 else
7754   {
7755   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7756     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7757   return DEFER;
7758   }
7759
7760 return OK;
7761 }
7762
7763
7764
7765 /* Avoid potentially exposing a password in a string about to be logged */
7766
7767 uschar *
7768 expand_hide_passwords(uschar * s)
7769 {
7770 return (  (  Ustrstr(s, "failed to expand") != NULL
7771           || Ustrstr(s, "expansion of ")    != NULL
7772           )
7773        && (  Ustrstr(s, "mysql")   != NULL
7774           || Ustrstr(s, "pgsql")   != NULL
7775           || Ustrstr(s, "redis")   != NULL
7776           || Ustrstr(s, "sqlite")  != NULL
7777           || Ustrstr(s, "ldap:")   != NULL
7778           || Ustrstr(s, "ldaps:")  != NULL
7779           || Ustrstr(s, "ldapi:")  != NULL
7780           || Ustrstr(s, "ldapdn:") != NULL
7781           || Ustrstr(s, "ldapm:")  != NULL
7782        )  )
7783   ? US"Temporary internal error" : s;
7784 }
7785
7786
7787
7788 /*************************************************
7789 * Error-checking for testsuite                   *
7790 *************************************************/
7791 typedef struct {
7792   const char *  filename;
7793   int           linenumber;
7794   uschar *      region_start;
7795   uschar *      region_end;
7796   const uschar *var_name;
7797   const uschar *var_data;
7798 } err_ctx;
7799
7800 static void
7801 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7802 {
7803 err_ctx * e = ctx;
7804 if (var_data >= e->region_start  &&  var_data < e->region_end)
7805   {
7806   e->var_name = CUS var_name;
7807   e->var_data = CUS var_data;
7808   }
7809 }
7810
7811 void
7812 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7813 {
7814 err_ctx e = {filename, linenumber, ptr, US ptr + len, NULL };
7815 int i;
7816 var_entry * v;
7817
7818 /* check acl_ variables */
7819 tree_walk(acl_var_c, assert_variable_notin, &e);
7820 tree_walk(acl_var_m, assert_variable_notin, &e);
7821
7822 /* check auth<n> variables */
7823 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7824   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7825
7826 /* check regex<n> variables */
7827 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7828   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7829
7830 /* check known-name variables */
7831 for (v = var_table; v < var_table + var_table_size; v++)
7832   if (v->type == vtype_stringptr)
7833     assert_variable_notin(US v->name, *(USS v->value), &e);
7834
7835 if (e.var_name)
7836   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7837     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7838     e.var_name, e.filename, e.linenumber, e.var_data);
7839 }
7840
7841
7842
7843 /*************************************************
7844 **************************************************
7845 *             Stand-alone test program           *
7846 **************************************************
7847 *************************************************/
7848
7849 #ifdef STAND_ALONE
7850
7851
7852 BOOL
7853 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7854 {
7855 int ovector[3*(EXPAND_MAXN+1)];
7856 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7857   ovector, nelem(ovector));
7858 BOOL yield = n >= 0;
7859 if (n == 0) n = EXPAND_MAXN + 1;
7860 if (yield)
7861   {
7862   int nn;
7863   expand_nmax = (setup < 0)? 0 : setup + 1;
7864   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7865     {
7866     expand_nstring[expand_nmax] = subject + ovector[nn];
7867     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7868     }
7869   expand_nmax--;
7870   }
7871 return yield;
7872 }
7873
7874
7875 int main(int argc, uschar **argv)
7876 {
7877 int i;
7878 uschar buffer[1024];
7879
7880 debug_selector = D_v;
7881 debug_file = stderr;
7882 debug_fd = fileno(debug_file);
7883 big_buffer = malloc(big_buffer_size);
7884
7885 for (i = 1; i < argc; i++)
7886   {
7887   if (argv[i][0] == '+')
7888     {
7889     debug_trace_memory = 2;
7890     argv[i]++;
7891     }
7892   if (isdigit(argv[i][0]))
7893     debug_selector = Ustrtol(argv[i], NULL, 0);
7894   else
7895     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7896         Ustrlen(argv[i]))
7897       {
7898 #ifdef LOOKUP_LDAP
7899       eldap_default_servers = argv[i];
7900 #endif
7901 #ifdef LOOKUP_MYSQL
7902       mysql_servers = argv[i];
7903 #endif
7904 #ifdef LOOKUP_PGSQL
7905       pgsql_servers = argv[i];
7906 #endif
7907 #ifdef LOOKUP_REDIS
7908       redis_servers = argv[i];
7909 #endif
7910       }
7911 #ifdef EXIM_PERL
7912   else opt_perl_startup = argv[i];
7913 #endif
7914   }
7915
7916 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7917
7918 expand_nstring[1] = US"string 1....";
7919 expand_nlength[1] = 8;
7920 expand_nmax = 1;
7921
7922 #ifdef EXIM_PERL
7923 if (opt_perl_startup != NULL)
7924   {
7925   uschar *errstr;
7926   printf("Starting Perl interpreter\n");
7927   errstr = init_perl(opt_perl_startup);
7928   if (errstr != NULL)
7929     {
7930     printf("** error in perl_startup code: %s\n", errstr);
7931     return EXIT_FAILURE;
7932     }
7933   }
7934 #endif /* EXIM_PERL */
7935
7936 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7937   {
7938   void *reset_point = store_get(0);
7939   uschar *yield = expand_string(buffer);
7940   if (yield != NULL)
7941     {
7942     printf("%s\n", yield);
7943     store_reset(reset_point);
7944     }
7945   else
7946     {
7947     if (search_find_defer) printf("search_find deferred\n");
7948     printf("Failed: %s\n", expand_string_message);
7949     if (expand_string_forcedfail) printf("Forced failure\n");
7950     printf("\n");
7951     }
7952   }
7953
7954 search_tidyup();
7955
7956 return 0;
7957 }
7958
7959 #endif
7960
7961 /* vi: aw ai sw=2
7962 */
7963 /* End of expand.c */