src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2014 */
   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(uschar *, BOOL, uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(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.  Charaters 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 #ifndef nelements
  98 # define nelements(arr) (sizeof(arr) / sizeof(*arr))
  99 #endif
 100
 101 /*************************************************
 102 *            Local statics and tables            *
 103 *************************************************/
 104
 105 /* Table of item names, and corresponding switch numbers. The names must be in
 106 alphabetical order. */
 107
 108 static uschar *item_table[] = {
 109   US"acl",
 110   US"certextract",
 111   US"dlfunc",
 112   US"extract",
 113   US"filter",
 114   US"hash",
 115   US"hmac",
 116   US"if",
 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"substr",
 131   US"tr" };
 132
 133 enum {
 134   EITEM_ACL,
 135   EITEM_CERTEXTRACT,
 136   EITEM_DLFUNC,
 137   EITEM_EXTRACT,
 138   EITEM_FILTER,
 139   EITEM_HASH,
 140   EITEM_HMAC,
 141   EITEM_IF,
 142   EITEM_LENGTH,
 143   EITEM_LISTEXTRACT,
 144   EITEM_LOOKUP,
 145   EITEM_MAP,
 146   EITEM_NHASH,
 147   EITEM_PERL,
 148   EITEM_PRVS,
 149   EITEM_PRVSCHECK,
 150   EITEM_READFILE,
 151   EITEM_READSOCK,
 152   EITEM_REDUCE,
 153   EITEM_RUN,
 154   EITEM_SG,
 155   EITEM_SUBSTR,
 156   EITEM_TR };
 157
 158 /* Tables of operator names, and corresponding switch numbers. The names must be
 159 in alphabetical order. There are two tables, because underscore is used in some
 160 cases to introduce arguments, whereas for other it is part of the name. This is
 161 an historical mis-design. */
 162
 163 static uschar *op_table_underscore[] = {
 164   US"from_utf8",
 165   US"local_part",
 166   US"quote_local_part",
 167   US"reverse_ip",
 168   US"time_eval",
 169   US"time_interval"};
 170
 171 enum {
 172   EOP_FROM_UTF8,
 173   EOP_LOCAL_PART,
 174   EOP_QUOTE_LOCAL_PART,
 175   EOP_REVERSE_IP,
 176   EOP_TIME_EVAL,
 177   EOP_TIME_INTERVAL };
 178
 179 static uschar *op_table_main[] = {
 180   US"address",
 181   US"addresses",
 182   US"base62",
 183   US"base62d",
 184   US"domain",
 185   US"escape",
 186   US"eval",
 187   US"eval10",
 188   US"expand",
 189   US"h",
 190   US"hash",
 191   US"hex2b64",
 192   US"hexquote",
 193   US"l",
 194   US"lc",
 195   US"length",
 196   US"listcount",
 197   US"listnamed",
 198   US"mask",
 199   US"md5",
 200   US"nh",
 201   US"nhash",
 202   US"quote",
 203   US"randint",
 204   US"rfc2047",
 205   US"rfc2047d",
 206   US"rxquote",
 207   US"s",
 208   US"sha1",
 209   US"sha256",
 210   US"stat",
 211   US"str2b64",
 212   US"strlen",
 213   US"substr",
 214   US"uc",
 215   US"utf8clean" };
 216
 217 enum {
 218   EOP_ADDRESS =  sizeof(op_table_underscore)/sizeof(uschar *),
 219   EOP_ADDRESSES,
 220   EOP_BASE62,
 221   EOP_BASE62D,
 222   EOP_DOMAIN,
 223   EOP_ESCAPE,
 224   EOP_EVAL,
 225   EOP_EVAL10,
 226   EOP_EXPAND,
 227   EOP_H,
 228   EOP_HASH,
 229   EOP_HEX2B64,
 230   EOP_HEXQUOTE,
 231   EOP_L,
 232   EOP_LC,
 233   EOP_LENGTH,
 234   EOP_LISTCOUNT,
 235   EOP_LISTNAMED,
 236   EOP_MASK,
 237   EOP_MD5,
 238   EOP_NH,
 239   EOP_NHASH,
 240   EOP_QUOTE,
 241   EOP_RANDINT,
 242   EOP_RFC2047,
 243   EOP_RFC2047D,
 244   EOP_RXQUOTE,
 245   EOP_S,
 246   EOP_SHA1,
 247   EOP_SHA256,
 248   EOP_STAT,
 249   EOP_STR2B64,
 250   EOP_STRLEN,
 251   EOP_SUBSTR,
 252   EOP_UC,
 253   EOP_UTF8CLEAN };
 254
 255
 256 /* Table of condition names, and corresponding switch numbers. The names must
 257 be in alphabetical order. */
 258
 259 static uschar *cond_table[] = {
 260   US"<",
 261   US"<=",
 262   US"=",
 263   US"==",     /* Backward compatibility */
 264   US">",
 265   US">=",
 266   US"acl",
 267   US"and",
 268   US"bool",
 269   US"bool_lax",
 270   US"crypteq",
 271   US"def",
 272   US"eq",
 273   US"eqi",
 274   US"exists",
 275   US"first_delivery",
 276   US"forall",
 277   US"forany",
 278   US"ge",
 279   US"gei",
 280   US"gt",
 281   US"gti",
 282   US"inlist",
 283   US"inlisti",
 284   US"isip",
 285   US"isip4",
 286   US"isip6",
 287   US"ldapauth",
 288   US"le",
 289   US"lei",
 290   US"lt",
 291   US"lti",
 292   US"match",
 293   US"match_address",
 294   US"match_domain",
 295   US"match_ip",
 296   US"match_local_part",
 297   US"or",
 298   US"pam",
 299   US"pwcheck",
 300   US"queue_running",
 301   US"radius",
 302   US"saslauthd"
 303 };
 304
 305 enum {
 306   ECOND_NUM_L,
 307   ECOND_NUM_LE,
 308   ECOND_NUM_E,
 309   ECOND_NUM_EE,
 310   ECOND_NUM_G,
 311   ECOND_NUM_GE,
 312   ECOND_ACL,
 313   ECOND_AND,
 314   ECOND_BOOL,
 315   ECOND_BOOL_LAX,
 316   ECOND_CRYPTEQ,
 317   ECOND_DEF,
 318   ECOND_STR_EQ,
 319   ECOND_STR_EQI,
 320   ECOND_EXISTS,
 321   ECOND_FIRST_DELIVERY,
 322   ECOND_FORALL,
 323   ECOND_FORANY,
 324   ECOND_STR_GE,
 325   ECOND_STR_GEI,
 326   ECOND_STR_GT,
 327   ECOND_STR_GTI,
 328   ECOND_INLIST,
 329   ECOND_INLISTI,
 330   ECOND_ISIP,
 331   ECOND_ISIP4,
 332   ECOND_ISIP6,
 333   ECOND_LDAPAUTH,
 334   ECOND_STR_LE,
 335   ECOND_STR_LEI,
 336   ECOND_STR_LT,
 337   ECOND_STR_LTI,
 338   ECOND_MATCH,
 339   ECOND_MATCH_ADDRESS,
 340   ECOND_MATCH_DOMAIN,
 341   ECOND_MATCH_IP,
 342   ECOND_MATCH_LOCAL_PART,
 343   ECOND_OR,
 344   ECOND_PAM,
 345   ECOND_PWCHECK,
 346   ECOND_QUEUE_RUNNING,
 347   ECOND_RADIUS,
 348   ECOND_SASLAUTHD
 349 };
 350
 351
 352 /* Types of table entry */
 353
 354 enum vtypes {
 355   vtype_int,            /* value is address of int */
 356   vtype_filter_int,     /* ditto, but recognized only when filtering */
 357   vtype_ino,            /* value is address of ino_t (not always an int) */
 358   vtype_uid,            /* value is address of uid_t (not always an int) */
 359   vtype_gid,            /* value is address of gid_t (not always an int) */
 360   vtype_bool,           /* value is address of bool */
 361   vtype_stringptr,      /* value is address of pointer to string */
 362   vtype_msgbody,        /* as stringptr, but read when first required */
 363   vtype_msgbody_end,    /* ditto, the end of the message */
 364   vtype_msgheaders,     /* the message's headers, processed */
 365   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 366   vtype_localpart,      /* extract local part from string */
 367   vtype_domain,         /* extract domain from string */
 368   vtype_string_func,    /* value is string returned by given function */
 369   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 370   vtype_tode,           /* value not used; generate tod in epoch format */
 371   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 372   vtype_todf,           /* value not used; generate full tod */
 373   vtype_todl,           /* value not used; generate log tod */
 374   vtype_todlf,          /* value not used; generate log file datestamp tod */
 375   vtype_todzone,        /* value not used; generate time zone only */
 376   vtype_todzulu,        /* value not used; generate zulu tod */
 377   vtype_reply,          /* value not used; get reply from headers */
 378   vtype_pid,            /* value not used; result is pid */
 379   vtype_host_lookup,    /* value not used; get host name */
 380   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 381   vtype_pspace,         /* partition space; value is T/F for spool/log */
 382   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 383   vtype_cert            /* SSL certificate */
 384   #ifndef DISABLE_DKIM
 385   ,vtype_dkim           /* Lookup of value in DKIM signature */
 386   #endif
 387 };
 388
 389 /* Type for main variable table */
 390
 391 typedef struct {
 392   const char *name;
 393   enum vtypes type;
 394   void       *value;
 395 } var_entry;
 396
 397 /* Type for entries pointing to address/length pairs. Not currently
 398 in use. */
 399
 400 typedef struct {
 401   uschar **address;
 402   int  *length;
 403 } alblock;
 404
 405 static uschar * fn_recipients(void);
 406
 407 /* This table must be kept in alphabetical order. */
 408
 409 static var_entry var_table[] = {
 410   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 411      they will be confused with user-creatable ACL variables. */
 412   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 413   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 414   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 415   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 416   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 417   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 418   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 419   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 420   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 421   { "acl_narg",            vtype_int,         &acl_narg },
 422   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 423   { "address_data",        vtype_stringptr,   &deliver_address_data },
 424   { "address_file",        vtype_stringptr,   &address_file },
 425   { "address_pipe",        vtype_stringptr,   &address_pipe },
 426   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 427   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 428   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 429   { "authentication_failed",vtype_int,        &authentication_failed },
 430 #ifdef WITH_CONTENT_SCAN
 431   { "av_failed",           vtype_int,         &av_failed },
 432 #endif
 433 #ifdef EXPERIMENTAL_BRIGHTMAIL
 434   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 435   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 436   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 437   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 438 #endif
 439   { "body_linecount",      vtype_int,         &body_linecount },
 440   { "body_zerocount",      vtype_int,         &body_zerocount },
 441   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 442   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 443   { "caller_gid",          vtype_gid,         &real_gid },
 444   { "caller_uid",          vtype_uid,         &real_uid },
 445   { "compile_date",        vtype_stringptr,   &version_date },
 446   { "compile_number",      vtype_stringptr,   &version_cnumber },
 447   { "csa_status",          vtype_stringptr,   &csa_status },
 448 #ifdef EXPERIMENTAL_DCC
 449   { "dcc_header",          vtype_stringptr,   &dcc_header },
 450   { "dcc_result",          vtype_stringptr,   &dcc_result },
 451 #endif
 452 #ifdef WITH_OLD_DEMIME
 453   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 454   { "demime_reason",       vtype_stringptr,   &demime_reason },
 455 #endif
 456 #ifndef DISABLE_DKIM
 457   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 458   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 459   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 460   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 461   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 462   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 463   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 464   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 465   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 466   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 467   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 468   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 469   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 470   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 471   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 472   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 473   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 474   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 475   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 476   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 477 #endif
 478 #ifdef EXPERIMENTAL_DMARC
 479   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 480   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 481   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 482   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 483   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 484 #endif
 485   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 486   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 487   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 488   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 489   { "domain",              vtype_stringptr,   &deliver_domain },
 490   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 491   { "exim_gid",            vtype_gid,         &exim_gid },
 492   { "exim_path",           vtype_stringptr,   &exim_path },
 493   { "exim_uid",            vtype_uid,         &exim_uid },
 494 #ifdef WITH_OLD_DEMIME
 495   { "found_extension",     vtype_stringptr,   &found_extension },
 496 #endif
 497   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 498   { "home",                vtype_stringptr,   &deliver_home },
 499   { "host",                vtype_stringptr,   &deliver_host },
 500   { "host_address",        vtype_stringptr,   &deliver_host_address },
 501   { "host_data",           vtype_stringptr,   &host_data },
 502   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 503   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 504   { "inode",               vtype_ino,         &deliver_inode },
 505   { "interface_address",   vtype_stringptr,   &interface_address },
 506   { "interface_port",      vtype_int,         &interface_port },
 507   { "item",                vtype_stringptr,   &iterate_item },
 508   #ifdef LOOKUP_LDAP
 509   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 510   #endif
 511   { "load_average",        vtype_load_avg,    NULL },
 512   { "local_part",          vtype_stringptr,   &deliver_localpart },
 513   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 514   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 515   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 516   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 517   { "local_user_gid",      vtype_gid,         &local_user_gid },
 518   { "local_user_uid",      vtype_uid,         &local_user_uid },
 519   { "localhost_number",    vtype_int,         &host_number },
 520   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 521   { "log_space",           vtype_pspace,      (void *)FALSE },
 522   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 523   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 524 #ifdef WITH_CONTENT_SCAN
 525   { "malware_name",        vtype_stringptr,   &malware_name },
 526 #endif
 527   { "max_received_linelength", vtype_int,     &max_received_linelength },
 528   { "message_age",         vtype_int,         &message_age },
 529   { "message_body",        vtype_msgbody,     &message_body },
 530   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 531   { "message_body_size",   vtype_int,         &message_body_size },
 532   { "message_exim_id",     vtype_stringptr,   &message_id },
 533   { "message_headers",     vtype_msgheaders,  NULL },
 534   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 535   { "message_id",          vtype_stringptr,   &message_id },
 536   { "message_linecount",   vtype_int,         &message_linecount },
 537   { "message_size",        vtype_int,         &message_size },
 538 #ifdef WITH_CONTENT_SCAN
 539   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 540   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 541   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 542   { "mime_charset",        vtype_stringptr,   &mime_charset },
 543   { "mime_content_description", vtype_stringptr, &mime_content_description },
 544   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 545   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 546   { "mime_content_size",   vtype_int,         &mime_content_size },
 547   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 548   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 549   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 550   { "mime_filename",       vtype_stringptr,   &mime_filename },
 551   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 552   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 553   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 554   { "mime_part_count",     vtype_int,         &mime_part_count },
 555 #endif
 556   { "n0",                  vtype_filter_int,  &filter_n[0] },
 557   { "n1",                  vtype_filter_int,  &filter_n[1] },
 558   { "n2",                  vtype_filter_int,  &filter_n[2] },
 559   { "n3",                  vtype_filter_int,  &filter_n[3] },
 560   { "n4",                  vtype_filter_int,  &filter_n[4] },
 561   { "n5",                  vtype_filter_int,  &filter_n[5] },
 562   { "n6",                  vtype_filter_int,  &filter_n[6] },
 563   { "n7",                  vtype_filter_int,  &filter_n[7] },
 564   { "n8",                  vtype_filter_int,  &filter_n[8] },
 565   { "n9",                  vtype_filter_int,  &filter_n[9] },
 566   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 567   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 568   { "originator_gid",      vtype_gid,         &originator_gid },
 569   { "originator_uid",      vtype_uid,         &originator_uid },
 570   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 571   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 572   { "pid",                 vtype_pid,         NULL },
 573   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 574 #ifdef EXPERIMENTAL_PROXY
 575   { "proxy_host_address",  vtype_stringptr,   &proxy_host_address },
 576   { "proxy_host_port",     vtype_int,         &proxy_host_port },
 577   { "proxy_session",       vtype_bool,        &proxy_session },
 578   { "proxy_target_address",vtype_stringptr,   &proxy_target_address },
 579   { "proxy_target_port",   vtype_int,         &proxy_target_port },
 580 #endif
 581   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 582   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 583   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 584   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 585   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 586   { "rcpt_count",          vtype_int,         &rcpt_count },
 587   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 588   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 589   { "received_count",      vtype_int,         &received_count },
 590   { "received_for",        vtype_stringptr,   &received_for },
 591   { "received_ip_address", vtype_stringptr,   &interface_address },
 592   { "received_port",       vtype_int,         &interface_port },
 593   { "received_protocol",   vtype_stringptr,   &received_protocol },
 594   { "received_time",       vtype_int,         &received_time },
 595   { "recipient_data",      vtype_stringptr,   &recipient_data },
 596   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 597   { "recipients",          vtype_string_func, &fn_recipients },
 598   { "recipients_count",    vtype_int,         &recipients_count },
 599 #ifdef WITH_CONTENT_SCAN
 600   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 601 #endif
 602   { "reply_address",       vtype_reply,       NULL },
 603   { "return_path",         vtype_stringptr,   &return_path },
 604   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 605   { "router_name",         vtype_stringptr,   &router_name },
 606   { "runrc",               vtype_int,         &runrc },
 607   { "self_hostname",       vtype_stringptr,   &self_hostname },
 608   { "sender_address",      vtype_stringptr,   &sender_address },
 609   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 610   { "sender_address_domain", vtype_domain,    &sender_address },
 611   { "sender_address_local_part", vtype_localpart, &sender_address },
 612   { "sender_data",         vtype_stringptr,   &sender_data },
 613   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 614   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 615   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 616   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 617   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 618   { "sender_host_name",    vtype_host_lookup, NULL },
 619   { "sender_host_port",    vtype_int,         &sender_host_port },
 620   { "sender_ident",        vtype_stringptr,   &sender_ident },
 621   { "sender_rate",         vtype_stringptr,   &sender_rate },
 622   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 623   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 624   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 625   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 626   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 627   { "sending_port",        vtype_int,         &sending_port },
 628   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 629   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 630   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 631   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 632   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 633   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 634   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 635   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 636   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 637   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 638   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 639   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 640   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 641   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 642   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 643 #ifdef WITH_CONTENT_SCAN
 644   { "spam_bar",            vtype_stringptr,   &spam_bar },
 645   { "spam_report",         vtype_stringptr,   &spam_report },
 646   { "spam_score",          vtype_stringptr,   &spam_score },
 647   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 648 #endif
 649 #ifdef EXPERIMENTAL_SPF
 650   { "spf_guess",           vtype_stringptr,   &spf_guess },
 651   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 652   { "spf_received",        vtype_stringptr,   &spf_received },
 653   { "spf_result",          vtype_stringptr,   &spf_result },
 654   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 655 #endif
 656   { "spool_directory",     vtype_stringptr,   &spool_directory },
 657   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 658   { "spool_space",         vtype_pspace,      (void *)TRUE },
 659 #ifdef EXPERIMENTAL_SRS
 660   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 661   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 662   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 663   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 664   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 665   { "srs_status",          vtype_stringptr,   &srs_status },
 666 #endif
 667   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 668
 669   /* The non-(in,out) variables are now deprecated */
 670   { "tls_bits",            vtype_int,         &tls_in.bits },
 671   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 672   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 673
 674   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 675   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 676   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 677   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 678   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 679   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 680   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 681 #if defined(SUPPORT_TLS)
 682   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 683 #endif
 684   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 685   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 686   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 687   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 688   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 689   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 690   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 691 #if defined(SUPPORT_TLS)
 692   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 693 #endif
 694
 695   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 696 #if defined(SUPPORT_TLS)
 697   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 698 #endif
 699
 700   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 701   { "tod_epoch",           vtype_tode,        NULL },
 702   { "tod_epoch_l",         vtype_todel,       NULL },
 703   { "tod_full",            vtype_todf,        NULL },
 704   { "tod_log",             vtype_todl,        NULL },
 705   { "tod_logfile",         vtype_todlf,       NULL },
 706   { "tod_zone",            vtype_todzone,     NULL },
 707   { "tod_zulu",            vtype_todzulu,     NULL },
 708 #ifdef EXPERIMENTAL_TPDA
 709   { "tpda_defer_errno",     vtype_int,         &tpda_defer_errno },
 710   { "tpda_defer_errstr",    vtype_stringptr,   &tpda_defer_errstr },
 711   { "tpda_delivery_confirmation", vtype_stringptr,   &tpda_delivery_confirmation },
 712   { "tpda_delivery_domain", vtype_stringptr,   &tpda_delivery_domain },
 713   { "tpda_delivery_fqdn",   vtype_stringptr,   &tpda_delivery_fqdn },
 714   { "tpda_delivery_ip",     vtype_stringptr,   &tpda_delivery_ip },
 715   { "tpda_delivery_local_part",vtype_stringptr,&tpda_delivery_local_part },
 716   { "tpda_delivery_port",   vtype_int,         &tpda_delivery_port },
 717 #endif
 718   { "transport_name",      vtype_stringptr,   &transport_name },
 719   { "value",               vtype_stringptr,   &lookup_value },
 720   { "version_number",      vtype_stringptr,   &version_string },
 721   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 722   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 723   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 724   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 725   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 726   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 727 };
 728
 729 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
 730 static uschar var_buffer[256];
 731 static BOOL malformed_header;
 732
 733 /* For textual hashes */
 734
 735 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 736                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 737                                "0123456789";
 738
 739 enum { HMAC_MD5, HMAC_SHA1 };
 740
 741 /* For numeric hashes */
 742
 743 static unsigned int prime[] = {
 744   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 745  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 746  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 747
 748 /* For printing modes in symbolic form */
 749
 750 static uschar *mtable_normal[] =
 751   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 752
 753 static uschar *mtable_setid[] =
 754   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 755
 756 static uschar *mtable_sticky[] =
 757   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 758
 759
 760
 761 /*************************************************
 762 *           Tables for UTF-8 support             *
 763 *************************************************/
 764
 765 /* Table of the number of extra characters, indexed by the first character
 766 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 767 0x3d. */
 768
 769 static uschar utf8_table1[] = {
 770   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 771   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 772   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 773   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 774
 775 /* These are the masks for the data bits in the first byte of a character,
 776 indexed by the number of additional bytes. */
 777
 778 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 779
 780 /* Get the next UTF-8 character, advancing the pointer. */
 781
 782 #define GETUTF8INC(c, ptr) \
 783   c = *ptr++; \
 784   if ((c & 0xc0) == 0xc0) \
 785     { \
 786     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 787     int s = 6*a; \
 788     c = (c & utf8_table2[a]) << s; \
 789     while (a-- > 0) \
 790       { \
 791       s -= 6; \
 792       c |= (*ptr++ & 0x3f) << s; \
 793       } \
 794     }
 795
 796
 797 /*************************************************
 798 *           Binary chop search on a table        *
 799 *************************************************/
 800
 801 /* This is used for matching expansion items and operators.
 802
 803 Arguments:
 804   name        the name that is being sought
 805   table       the table to search
 806   table_size  the number of items in the table
 807
 808 Returns:      the offset in the table, or -1
 809 */
 810
 811 static int
 812 chop_match(uschar *name, uschar **table, int table_size)
 813 {
 814 uschar **bot = table;
 815 uschar **top = table + table_size;
 816
 817 while (top > bot)
 818   {
 819   uschar **mid = bot + (top - bot)/2;
 820   int c = Ustrcmp(name, *mid);
 821   if (c == 0) return mid - table;
 822   if (c > 0) bot = mid + 1; else top = mid;
 823   }
 824
 825 return -1;
 826 }
 827
 828
 829
 830 /*************************************************
 831 *          Check a condition string              *
 832 *************************************************/
 833
 834 /* This function is called to expand a string, and test the result for a "true"
 835 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 836 forced fail or lookup defer.
 837
 838 We used to release all store used, but this is not not safe due
 839 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 840 is reasonably careful to release what it can.
 841
 842 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 843
 844 Arguments:
 845   condition     the condition string
 846   m1            text to be incorporated in panic error
 847   m2            ditto
 848
 849 Returns:        TRUE if condition is met, FALSE if not
 850 */
 851
 852 BOOL
 853 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 854 {
 855 int rc;
 856 uschar *ss = expand_string(condition);
 857 if (ss == NULL)
 858   {
 859   if (!expand_string_forcedfail && !search_find_defer)
 860     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 861       "for %s %s: %s", condition, m1, m2, expand_string_message);
 862   return FALSE;
 863   }
 864 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 865   strcmpic(ss, US"false") != 0;
 866 return rc;
 867 }
 868
 869
 870
 871
 872 /*************************************************
 873 *        Pseudo-random number generation         *
 874 *************************************************/
 875
 876 /* Pseudo-random number generation.  The result is not "expected" to be
 877 cryptographically strong but not so weak that someone will shoot themselves
 878 in the foot using it as a nonce in some email header scheme or whatever
 879 weirdness they'll twist this into.  The result should ideally handle fork().
 880
 881 However, if we're stuck unable to provide this, then we'll fall back to
 882 appallingly bad randomness.
 883
 884 If SUPPORT_TLS is defined then this will not be used except as an emergency
 885 fallback.
 886
 887 Arguments:
 888   max       range maximum
 889 Returns     a random number in range [0, max-1]
 890 */
 891
 892 #ifdef SUPPORT_TLS
 893 # define vaguely_random_number vaguely_random_number_fallback
 894 #endif
 895 int
 896 vaguely_random_number(int max)
 897 {
 898 #ifdef SUPPORT_TLS
 899 # undef vaguely_random_number
 900 #endif
 901   static pid_t pid = 0;
 902   pid_t p2;
 903 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 904   struct timeval tv;
 905 #endif
 906
 907   p2 = getpid();
 908   if (p2 != pid)
 909     {
 910     if (pid != 0)
 911       {
 912
 913 #ifdef HAVE_ARC4RANDOM
 914       /* cryptographically strong randomness, common on *BSD platforms, not
 915       so much elsewhere.  Alas. */
 916       arc4random_stir();
 917 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 918 #ifdef HAVE_SRANDOMDEV
 919       /* uses random(4) for seeding */
 920       srandomdev();
 921 #else
 922       gettimeofday(&tv, NULL);
 923       srandom(tv.tv_sec | tv.tv_usec | getpid());
 924 #endif
 925 #else
 926       /* Poor randomness and no seeding here */
 927 #endif
 928
 929       }
 930     pid = p2;
 931     }
 932
 933 #ifdef HAVE_ARC4RANDOM
 934   return arc4random() % max;
 935 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 936   return random() % max;
 937 #else
 938   /* This one returns a 16-bit number, definitely not crypto-strong */
 939   return random_number(max);
 940 #endif
 941 }
 942
 943
 944
 945
 946 /*************************************************
 947 *             Pick out a name from a string      *
 948 *************************************************/
 949
 950 /* If the name is too long, it is silently truncated.
 951
 952 Arguments:
 953   name      points to a buffer into which to put the name
 954   max       is the length of the buffer
 955   s         points to the first alphabetic character of the name
 956   extras    chars other than alphanumerics to permit
 957
 958 Returns:    pointer to the first character after the name
 959
 960 Note: The test for *s != 0 in the while loop is necessary because
 961 Ustrchr() yields non-NULL if the character is zero (which is not something
 962 I expected). */
 963
 964 static uschar *
 965 read_name(uschar *name, int max, uschar *s, uschar *extras)
 966 {
 967 int ptr = 0;
 968 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
 969   {
 970   if (ptr < max-1) name[ptr++] = *s;
 971   s++;
 972   }
 973 name[ptr] = 0;
 974 return s;
 975 }
 976
 977
 978
 979 /*************************************************
 980 *     Pick out the rest of a header name         *
 981 *************************************************/
 982
 983 /* A variable name starting $header_ (or just $h_ for those who like
 984 abbreviations) might not be the complete header name because headers can
 985 contain any printing characters in their names, except ':'. This function is
 986 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
 987 on the end, if the name was terminated by white space.
 988
 989 Arguments:
 990   name      points to a buffer in which the name read so far exists
 991   max       is the length of the buffer
 992   s         points to the first character after the name so far, i.e. the
 993             first non-alphameric character after $header_xxxxx
 994
 995 Returns:    a pointer to the first character after the header name
 996 */
 997
 998 static uschar *
 999 read_header_name(uschar *name, int max, uschar *s)
1000 {
1001 int prelen = Ustrchr(name, '_') - name + 1;
1002 int ptr = Ustrlen(name) - prelen;
1003 if (ptr > 0) memmove(name, name+prelen, ptr);
1004 while (mac_isgraph(*s) && *s != ':')
1005   {
1006   if (ptr < max-1) name[ptr++] = *s;
1007   s++;
1008   }
1009 if (*s == ':') s++;
1010 name[ptr++] = ':';
1011 name[ptr] = 0;
1012 return s;
1013 }
1014
1015
1016
1017 /*************************************************
1018 *           Pick out a number from a string      *
1019 *************************************************/
1020
1021 /* Arguments:
1022   n     points to an integer into which to put the number
1023   s     points to the first digit of the number
1024
1025 Returns:  a pointer to the character after the last digit
1026 */
1027
1028 static uschar *
1029 read_number(int *n, uschar *s)
1030 {
1031 *n = 0;
1032 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1033 return s;
1034 }
1035
1036
1037
1038 /*************************************************
1039 *        Extract keyed subfield from a string    *
1040 *************************************************/
1041
1042 /* The yield is in dynamic store; NULL means that the key was not found.
1043
1044 Arguments:
1045   key       points to the name of the key
1046   s         points to the string from which to extract the subfield
1047
1048 Returns:    NULL if the subfield was not found, or
1049             a pointer to the subfield's data
1050 */
1051
1052 static uschar *
1053 expand_getkeyed(uschar *key, uschar *s)
1054 {
1055 int length = Ustrlen(key);
1056 while (isspace(*s)) s++;
1057
1058 /* Loop to search for the key */
1059
1060 while (*s != 0)
1061   {
1062   int dkeylength;
1063   uschar *data;
1064   uschar *dkey = s;
1065
1066   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1067   dkeylength = s - dkey;
1068   while (isspace(*s)) s++;
1069   if (*s == '=') while (isspace((*(++s))));
1070
1071   data = string_dequote(&s);
1072   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1073     return data;
1074
1075   while (isspace(*s)) s++;
1076   }
1077
1078 return NULL;
1079 }
1080
1081
1082
1083 static var_entry *
1084 find_var_ent(uschar * name)
1085 {
1086 int first = 0;
1087 int last = var_table_size;
1088
1089 while (last > first)
1090   {
1091   int middle = (first + last)/2;
1092   int c = Ustrcmp(name, var_table[middle].name);
1093
1094   if (c > 0) { first = middle + 1; continue; }
1095   if (c < 0) { last = middle; continue; }
1096   return &var_table[middle];
1097   }
1098 return NULL;
1099 }
1100
1101 /*************************************************
1102 *   Extract numbered subfield from string        *
1103 *************************************************/
1104
1105 /* Extracts a numbered field from a string that is divided by tokens - for
1106 example a line from /etc/passwd is divided by colon characters.  First field is
1107 numbered one.  Negative arguments count from the right. Zero returns the whole
1108 string. Returns NULL if there are insufficient tokens in the string
1109
1110 ***WARNING***
1111 Modifies final argument - this is a dynamically generated string, so that's OK.
1112
1113 Arguments:
1114   field       number of field to be extracted,
1115                 first field = 1, whole string = 0, last field = -1
1116   separators  characters that are used to break string into tokens
1117   s           points to the string from which to extract the subfield
1118
1119 Returns:      NULL if the field was not found,
1120               a pointer to the field's data inside s (modified to add 0)
1121 */
1122
1123 static uschar *
1124 expand_gettokened (int field, uschar *separators, uschar *s)
1125 {
1126 int sep = 1;
1127 int count;
1128 uschar *ss = s;
1129 uschar *fieldtext = NULL;
1130
1131 if (field == 0) return s;
1132
1133 /* Break the line up into fields in place; for field > 0 we stop when we have
1134 done the number of fields we want. For field < 0 we continue till the end of
1135 the string, counting the number of fields. */
1136
1137 count = (field > 0)? field : INT_MAX;
1138
1139 while (count-- > 0)
1140   {
1141   size_t len;
1142
1143   /* Previous field was the last one in the string. For a positive field
1144   number, this means there are not enough fields. For a negative field number,
1145   check that there are enough, and scan back to find the one that is wanted. */
1146
1147   if (sep == 0)
1148     {
1149     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1150     if ((-field) == (INT_MAX - count - 1)) return s;
1151     while (field++ < 0)
1152       {
1153       ss--;
1154       while (ss[-1] != 0) ss--;
1155       }
1156     fieldtext = ss;
1157     break;
1158     }
1159
1160   /* Previous field was not last in the string; save its start and put a
1161   zero at its end. */
1162
1163   fieldtext = ss;
1164   len = Ustrcspn(ss, separators);
1165   sep = ss[len];
1166   ss[len] = 0;
1167   ss += len + 1;
1168   }
1169
1170 return fieldtext;
1171 }
1172
1173
1174 static uschar *
1175 expand_getlistele(int field, uschar * list)
1176 {
1177 uschar * tlist= list;
1178 int sep= 0;
1179 uschar dummy;
1180
1181 if(field<0)
1182 {
1183   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1184   sep= 0;
1185 }
1186 if(field==0) return NULL;
1187 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1188 return string_nextinlist(&list, &sep, NULL, 0);
1189 }
1190
1191
1192 /* Certificate fields, by name.  Worry about by-OID later */
1193 /* Names are chosen to not have common prefixes */
1194
1195 #ifdef SUPPORT_TLS
1196 typedef struct
1197 {
1198 uschar * name;
1199 int      namelen;
1200 uschar * (*getfn)(void * cert, uschar * mod);
1201 } certfield;
1202 static certfield certfields[] =
1203 {                       /* linear search; no special order */
1204   { US"version",         7,  &tls_cert_version },
1205   { US"serial_number",   13, &tls_cert_serial_number },
1206   { US"subject",         7,  &tls_cert_subject },
1207   { US"notbefore",       9,  &tls_cert_not_before },
1208   { US"notafter",        8,  &tls_cert_not_after },
1209   { US"issuer",          6,  &tls_cert_issuer },
1210   { US"signature",       9,  &tls_cert_signature },
1211   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1212   { US"subj_altname",    12, &tls_cert_subject_altname },
1213   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1214   { US"crl_uri",         7,  &tls_cert_crl_uri },
1215 };
1216
1217 static uschar *
1218 expand_getcertele(uschar * field, uschar * certvar)
1219 {
1220 var_entry * vp;
1221 certfield * cp;
1222
1223 if (!(vp = find_var_ent(certvar)))
1224   {
1225   expand_string_message =
1226     string_sprintf("no variable named \"%s\"", certvar);
1227   return NULL;          /* Unknown variable name */
1228   }
1229 /* NB this stops us passing certs around in variable.  Might
1230 want to do that in future */
1231 if (vp->type != vtype_cert)
1232   {
1233   expand_string_message =
1234     string_sprintf("\"%s\" is not a certificate", certvar);
1235   return NULL;          /* Unknown variable name */
1236   }
1237 if (!*(void **)vp->value)
1238   return NULL;
1239
1240 if (*field >= '0' && *field <= '9')
1241   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1242
1243 for(cp = certfields;
1244     cp < certfields + nelements(certfields);
1245     cp++)
1246   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1247     {
1248     uschar * modifier = *(field += cp->namelen) == ','
1249       ? ++field : NULL;
1250     return (*cp->getfn)( *(void **)vp->value, modifier );
1251     }
1252
1253 expand_string_message =
1254   string_sprintf("bad field selector \"%s\" for certextract", field);
1255 return NULL;
1256 }
1257 #endif  /*SUPPORT_TLS*/
1258
1259 /*************************************************
1260 *        Extract a substring from a string       *
1261 *************************************************/
1262
1263 /* Perform the ${substr or ${length expansion operations.
1264
1265 Arguments:
1266   subject     the input string
1267   value1      the offset from the start of the input string to the start of
1268                 the output string; if negative, count from the right.
1269   value2      the length of the output string, or negative (-1) for unset
1270                 if value1 is positive, unset means "all after"
1271                 if value1 is negative, unset means "all before"
1272   len         set to the length of the returned string
1273
1274 Returns:      pointer to the output string, or NULL if there is an error
1275 */
1276
1277 static uschar *
1278 extract_substr(uschar *subject, int value1, int value2, int *len)
1279 {
1280 int sublen = Ustrlen(subject);
1281
1282 if (value1 < 0)    /* count from right */
1283   {
1284   value1 += sublen;
1285
1286   /* If the position is before the start, skip to the start, and adjust the
1287   length. If the length ends up negative, the substring is null because nothing
1288   can precede. This falls out naturally when the length is unset, meaning "all
1289   to the left". */
1290
1291   if (value1 < 0)
1292     {
1293     value2 += value1;
1294     if (value2 < 0) value2 = 0;
1295     value1 = 0;
1296     }
1297
1298   /* Otherwise an unset length => characters before value1 */
1299
1300   else if (value2 < 0)
1301     {
1302     value2 = value1;
1303     value1 = 0;
1304     }
1305   }
1306
1307 /* For a non-negative offset, if the starting position is past the end of the
1308 string, the result will be the null string. Otherwise, an unset length means
1309 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1310
1311 else
1312   {
1313   if (value1 > sublen)
1314     {
1315     value1 = sublen;
1316     value2 = 0;
1317     }
1318   else if (value2 < 0) value2 = sublen;
1319   }
1320
1321 /* Cut the length down to the maximum possible for the offset value, and get
1322 the required characters. */
1323
1324 if (value1 + value2 > sublen) value2 = sublen - value1;
1325 *len = value2;
1326 return subject + value1;
1327 }
1328
1329
1330
1331
1332 /*************************************************
1333 *            Old-style hash of a string          *
1334 *************************************************/
1335
1336 /* Perform the ${hash expansion operation.
1337
1338 Arguments:
1339   subject     the input string (an expanded substring)
1340   value1      the length of the output string; if greater or equal to the
1341                 length of the input string, the input string is returned
1342   value2      the number of hash characters to use, or 26 if negative
1343   len         set to the length of the returned string
1344
1345 Returns:      pointer to the output string, or NULL if there is an error
1346 */
1347
1348 static uschar *
1349 compute_hash(uschar *subject, int value1, int value2, int *len)
1350 {
1351 int sublen = Ustrlen(subject);
1352
1353 if (value2 < 0) value2 = 26;
1354 else if (value2 > Ustrlen(hashcodes))
1355   {
1356   expand_string_message =
1357     string_sprintf("hash count \"%d\" too big", value2);
1358   return NULL;
1359   }
1360
1361 /* Calculate the hash text. We know it is shorter than the original string, so
1362 can safely place it in subject[] (we know that subject is always itself an
1363 expanded substring). */
1364
1365 if (value1 < sublen)
1366   {
1367   int c;
1368   int i = 0;
1369   int j = value1;
1370   while ((c = (subject[j])) != 0)
1371     {
1372     int shift = (c + j++) & 7;
1373     subject[i] ^= (c << shift) | (c >> (8-shift));
1374     if (++i >= value1) i = 0;
1375     }
1376   for (i = 0; i < value1; i++)
1377     subject[i] = hashcodes[(subject[i]) % value2];
1378   }
1379 else value1 = sublen;
1380
1381 *len = value1;
1382 return subject;
1383 }
1384
1385
1386
1387
1388 /*************************************************
1389 *             Numeric hash of a string           *
1390 *************************************************/
1391
1392 /* Perform the ${nhash expansion operation. The first characters of the
1393 string are treated as most important, and get the highest prime numbers.
1394
1395 Arguments:
1396   subject     the input string
1397   value1      the maximum value of the first part of the result
1398   value2      the maximum value of the second part of the result,
1399                 or negative to produce only a one-part result
1400   len         set to the length of the returned string
1401
1402 Returns:  pointer to the output string, or NULL if there is an error.
1403 */
1404
1405 static uschar *
1406 compute_nhash (uschar *subject, int value1, int value2, int *len)
1407 {
1408 uschar *s = subject;
1409 int i = 0;
1410 unsigned long int total = 0; /* no overflow */
1411
1412 while (*s != 0)
1413   {
1414   if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
1415   total += prime[i--] * (unsigned int)(*s++);
1416   }
1417
1418 /* If value2 is unset, just compute one number */
1419
1420 if (value2 < 0)
1421   {
1422   s = string_sprintf("%d", total % value1);
1423   }
1424
1425 /* Otherwise do a div/mod hash */
1426
1427 else
1428   {
1429   total = total % (value1 * value2);
1430   s = string_sprintf("%d/%d", total/value2, total % value2);
1431   }
1432
1433 *len = Ustrlen(s);
1434 return s;
1435 }
1436
1437
1438
1439
1440
1441 /*************************************************
1442 *     Find the value of a header or headers      *
1443 *************************************************/
1444
1445 /* Multiple instances of the same header get concatenated, and this function
1446 can also return a concatenation of all the header lines. When concatenating
1447 specific headers that contain lists of addresses, a comma is inserted between
1448 them. Otherwise we use a straight concatenation. Because some messages can have
1449 pathologically large number of lines, there is a limit on the length that is
1450 returned. Also, to avoid massive store use which would result from using
1451 string_cat() as it copies and extends strings, we do a preliminary pass to find
1452 out exactly how much store will be needed. On "normal" messages this will be
1453 pretty trivial.
1454
1455 Arguments:
1456   name          the name of the header, without the leading $header_ or $h_,
1457                 or NULL if a concatenation of all headers is required
1458   exists_only   TRUE if called from a def: test; don't need to build a string;
1459                 just return a string that is not "" and not "0" if the header
1460                 exists
1461   newsize       return the size of memory block that was obtained; may be NULL
1462                 if exists_only is TRUE
1463   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1464                 other than concatenating, will be done on the header. Also used
1465                 for $message_headers_raw.
1466   charset       name of charset to translate MIME words to; used only if
1467                 want_raw is false; if NULL, no translation is done (this is
1468                 used for $bh_ and $bheader_)
1469
1470 Returns:        NULL if the header does not exist, else a pointer to a new
1471                 store block
1472 */
1473
1474 static uschar *
1475 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1476   uschar *charset)
1477 {
1478 BOOL found = name == NULL;
1479 int comma = 0;
1480 int len = found? 0 : Ustrlen(name);
1481 int i;
1482 uschar *yield = NULL;
1483 uschar *ptr = NULL;
1484
1485 /* Loop for two passes - saves code repetition */
1486
1487 for (i = 0; i < 2; i++)
1488   {
1489   int size = 0;
1490   header_line *h;
1491
1492   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1493     {
1494     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1495       {
1496       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1497         {
1498         int ilen;
1499         uschar *t;
1500
1501         if (exists_only) return US"1";      /* don't need actual string */
1502         found = TRUE;
1503         t = h->text + len;                  /* text to insert */
1504         if (!want_raw)                      /* unless wanted raw, */
1505           while (isspace(*t)) t++;          /* remove leading white space */
1506         ilen = h->slen - (t - h->text);     /* length to insert */
1507
1508         /* Unless wanted raw, remove trailing whitespace, including the
1509         newline. */
1510
1511         if (!want_raw)
1512           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1513
1514         /* Set comma = 1 if handling a single header and it's one of those
1515         that contains an address list, except when asked for raw headers. Only
1516         need to do this once. */
1517
1518         if (!want_raw && name != NULL && comma == 0 &&
1519             Ustrchr("BCFRST", h->type) != NULL)
1520           comma = 1;
1521
1522         /* First pass - compute total store needed; second pass - compute
1523         total store used, including this header. */
1524
1525         size += ilen + comma + 1;  /* +1 for the newline */
1526
1527         /* Second pass - concatentate the data, up to a maximum. Note that
1528         the loop stops when size hits the limit. */
1529
1530         if (i != 0)
1531           {
1532           if (size > header_insert_maxlen)
1533             {
1534             ilen -= size - header_insert_maxlen - 1;
1535             comma = 0;
1536             }
1537           Ustrncpy(ptr, t, ilen);
1538           ptr += ilen;
1539
1540           /* For a non-raw header, put in the comma if needed, then add
1541           back the newline we removed above, provided there was some text in
1542           the header. */
1543
1544           if (!want_raw && ilen > 0)
1545             {
1546             if (comma != 0) *ptr++ = ',';
1547             *ptr++ = '\n';
1548             }
1549           }
1550         }
1551       }
1552     }
1553
1554   /* At end of first pass, return NULL if no header found. Then truncate size
1555   if necessary, and get the buffer to hold the data, returning the buffer size.
1556   */
1557
1558   if (i == 0)
1559     {
1560     if (!found) return NULL;
1561     if (size > header_insert_maxlen) size = header_insert_maxlen;
1562     *newsize = size + 1;
1563     ptr = yield = store_get(*newsize);
1564     }
1565   }
1566
1567 /* That's all we do for raw header expansion. */
1568
1569 if (want_raw)
1570   {
1571   *ptr = 0;
1572   }
1573
1574 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1575 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1576 function can return an error with decoded data if the charset translation
1577 fails. If decoding fails, it returns NULL. */
1578
1579 else
1580   {
1581   uschar *decoded, *error;
1582   if (ptr > yield && ptr[-1] == '\n') ptr--;
1583   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1584   *ptr = 0;
1585   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1586     newsize, &error);
1587   if (error != NULL)
1588     {
1589     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1590       "    input was: %s\n", error, yield);
1591     }
1592   if (decoded != NULL) yield = decoded;
1593   }
1594
1595 return yield;
1596 }
1597
1598
1599
1600
1601 /*************************************************
1602 *               Return list of recipients        *
1603 *************************************************/
1604 /* A recipients list is available only during system message filtering,
1605 during ACL processing after DATA, and while expanding pipe commands
1606 generated from a system filter, but not elsewhere. */
1607
1608 static uschar *
1609 fn_recipients(void)
1610 {
1611 if (!enable_dollar_recipients) return NULL; else
1612   {
1613   int size = 128;
1614   int ptr = 0;
1615   int i;
1616   uschar * s = store_get(size);
1617   for (i = 0; i < recipients_count; i++)
1618     {
1619     if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1620     s = string_cat(s, &size, &ptr, recipients_list[i].address,
1621       Ustrlen(recipients_list[i].address));
1622     }
1623   s[ptr] = 0;     /* string_cat() leaves room */
1624   return s;
1625   }
1626 }
1627
1628
1629 /*************************************************
1630 *               Find value of a variable         *
1631 *************************************************/
1632
1633 /* The table of variables is kept in alphabetic order, so we can search it
1634 using a binary chop. The "choplen" variable is nothing to do with the binary
1635 chop.
1636
1637 Arguments:
1638   name          the name of the variable being sought
1639   exists_only   TRUE if this is a def: test; passed on to find_header()
1640   skipping      TRUE => skip any processing evaluation; this is not the same as
1641                   exists_only because def: may test for values that are first
1642                   evaluated here
1643   newsize       pointer to an int which is initially zero; if the answer is in
1644                 a new memory buffer, *newsize is set to its size
1645
1646 Returns:        NULL if the variable does not exist, or
1647                 a pointer to the variable's contents, or
1648                 something non-NULL if exists_only is TRUE
1649 */
1650
1651 static uschar *
1652 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1653 {
1654 var_entry * vp;
1655 uschar *s, *domain;
1656 uschar **ss;
1657 void * val;
1658
1659 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1660 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1661 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1662 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1663 (this gave backwards compatibility at the changeover). There may be built-in
1664 variables whose names start acl_ but they should never start in this way. This
1665 slightly messy specification is a consequence of the history, needless to say.
1666
1667 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1668 set, in which case give an error. */
1669
1670 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1671      !isalpha(name[5]))
1672   {
1673   tree_node *node =
1674     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1675   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1676   }
1677
1678 /* Handle $auth<n> variables. */
1679
1680 if (Ustrncmp(name, "auth", 4) == 0)
1681   {
1682   uschar *endptr;
1683   int n = Ustrtoul(name + 4, &endptr, 10);
1684   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1685     return (auth_vars[n-1] == NULL)? US"" : auth_vars[n-1];
1686   }
1687
1688 /* For all other variables, search the table */
1689
1690 if (!(vp = find_var_ent(name)))
1691   return NULL;          /* Unknown variable name */
1692
1693 /* Found an existing variable. If in skipping state, the value isn't needed,
1694 and we want to avoid processing (such as looking up the host name). */
1695
1696 if (skipping)
1697   return US"";
1698
1699 val = vp->value;
1700 switch (vp->type)
1701   {
1702   case vtype_filter_int:
1703   if (!filter_running) return NULL;
1704   /* Fall through */
1705   /* VVVVVVVVVVVV */
1706   case vtype_int:
1707   sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1708   return var_buffer;
1709
1710   case vtype_ino:
1711   sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1712   return var_buffer;
1713
1714   case vtype_gid:
1715   sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1716   return var_buffer;
1717
1718   case vtype_uid:
1719   sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1720   return var_buffer;
1721
1722   case vtype_bool:
1723   sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1724   return var_buffer;
1725
1726   case vtype_stringptr:                      /* Pointer to string */
1727   s = *((uschar **)(val));
1728   return (s == NULL)? US"" : s;
1729
1730   case vtype_pid:
1731   sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1732   return var_buffer;
1733
1734   case vtype_load_avg:
1735   sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1736   return var_buffer;
1737
1738   case vtype_host_lookup:                    /* Lookup if not done so */
1739   if (sender_host_name == NULL && sender_host_address != NULL &&
1740       !host_lookup_failed && host_name_lookup() == OK)
1741     host_build_sender_fullhost();
1742   return (sender_host_name == NULL)? US"" : sender_host_name;
1743
1744   case vtype_localpart:                      /* Get local part from address */
1745   s = *((uschar **)(val));
1746   if (s == NULL) return US"";
1747   domain = Ustrrchr(s, '@');
1748   if (domain == NULL) return s;
1749   if (domain - s > sizeof(var_buffer) - 1)
1750     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1751         " in string expansion", sizeof(var_buffer));
1752   Ustrncpy(var_buffer, s, domain - s);
1753   var_buffer[domain - s] = 0;
1754   return var_buffer;
1755
1756   case vtype_domain:                         /* Get domain from address */
1757   s = *((uschar **)(val));
1758   if (s == NULL) return US"";
1759   domain = Ustrrchr(s, '@');
1760   return (domain == NULL)? US"" : domain + 1;
1761
1762   case vtype_msgheaders:
1763   return find_header(NULL, exists_only, newsize, FALSE, NULL);
1764
1765   case vtype_msgheaders_raw:
1766   return find_header(NULL, exists_only, newsize, TRUE, NULL);
1767
1768   case vtype_msgbody:                        /* Pointer to msgbody string */
1769   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1770   ss = (uschar **)(val);
1771   if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1772     {
1773     uschar *body;
1774     off_t start_offset = SPOOL_DATA_START_OFFSET;
1775     int len = message_body_visible;
1776     if (len > message_size) len = message_size;
1777     *ss = body = store_malloc(len+1);
1778     body[0] = 0;
1779     if (vp->type == vtype_msgbody_end)
1780       {
1781       struct stat statbuf;
1782       if (fstat(deliver_datafile, &statbuf) == 0)
1783         {
1784         start_offset = statbuf.st_size - len;
1785         if (start_offset < SPOOL_DATA_START_OFFSET)
1786           start_offset = SPOOL_DATA_START_OFFSET;
1787         }
1788       }
1789     lseek(deliver_datafile, start_offset, SEEK_SET);
1790     len = read(deliver_datafile, body, len);
1791     if (len > 0)
1792       {
1793       body[len] = 0;
1794       if (message_body_newlines)   /* Separate loops for efficiency */
1795         {
1796         while (len > 0)
1797           { if (body[--len] == 0) body[len] = ' '; }
1798         }
1799       else
1800         {
1801         while (len > 0)
1802           { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1803         }
1804       }
1805     }
1806   return (*ss == NULL)? US"" : *ss;
1807
1808   case vtype_todbsdin:                       /* BSD inbox time of day */
1809   return tod_stamp(tod_bsdin);
1810
1811   case vtype_tode:                           /* Unix epoch time of day */
1812   return tod_stamp(tod_epoch);
1813
1814   case vtype_todel:                          /* Unix epoch/usec time of day */
1815   return tod_stamp(tod_epoch_l);
1816
1817   case vtype_todf:                           /* Full time of day */
1818   return tod_stamp(tod_full);
1819
1820   case vtype_todl:                           /* Log format time of day */
1821   return tod_stamp(tod_log_bare);            /* (without timezone) */
1822
1823   case vtype_todzone:                        /* Time zone offset only */
1824   return tod_stamp(tod_zone);
1825
1826   case vtype_todzulu:                        /* Zulu time */
1827   return tod_stamp(tod_zulu);
1828
1829   case vtype_todlf:                          /* Log file datestamp tod */
1830   return tod_stamp(tod_log_datestamp_daily);
1831
1832   case vtype_reply:                          /* Get reply address */
1833   s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1834     headers_charset);
1835   if (s != NULL) while (isspace(*s)) s++;
1836   if (s == NULL || *s == 0)
1837     {
1838     *newsize = 0;                            /* For the *s==0 case */
1839     s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1840     }
1841   if (s != NULL)
1842     {
1843     uschar *t;
1844     while (isspace(*s)) s++;
1845     for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1846     while (t > s && isspace(t[-1])) t--;
1847     *t = 0;
1848     }
1849   return (s == NULL)? US"" : s;
1850
1851   case vtype_string_func:
1852     {
1853     uschar * (*fn)() = val;
1854     return fn();
1855     }
1856
1857   case vtype_pspace:
1858     {
1859     int inodes;
1860     sprintf(CS var_buffer, "%d",
1861       receive_statvfs(val == (void *)TRUE, &inodes));
1862     }
1863   return var_buffer;
1864
1865   case vtype_pinodes:
1866     {
1867     int inodes;
1868     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1869     sprintf(CS var_buffer, "%d", inodes);
1870     }
1871   return var_buffer;
1872
1873   case vtype_cert:
1874   return *(void **)val ? US"<cert>" : US"";
1875
1876   #ifndef DISABLE_DKIM
1877   case vtype_dkim:
1878   return dkim_exim_expand_query((int)(long)val);
1879   #endif
1880
1881   }
1882
1883 return NULL;  /* Unknown variable. Silences static checkers. */
1884 }
1885
1886
1887
1888
1889 void
1890 modify_variable(uschar *name, void * value)
1891 {
1892 var_entry * vp;
1893 if ((vp = find_var_ent(name))) vp->value = value;
1894 return;          /* Unknown variable name, fail silently */
1895 }
1896
1897
1898
1899
1900
1901 /*************************************************
1902 *           Read and expand substrings           *
1903 *************************************************/
1904
1905 /* This function is called to read and expand argument substrings for various
1906 expansion items. Some have a minimum requirement that is less than the maximum;
1907 in these cases, the first non-present one is set to NULL.
1908
1909 Arguments:
1910   sub        points to vector of pointers to set
1911   n          maximum number of substrings
1912   m          minimum required
1913   sptr       points to current string pointer
1914   skipping   the skipping flag
1915   check_end  if TRUE, check for final '}'
1916   name       name of item, for error message
1917   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1918              the store.
1919
1920 Returns:     0 OK; string pointer updated
1921              1 curly bracketing error (too few arguments)
1922              2 too many arguments (only if check_end is set); message set
1923              3 other error (expansion failure)
1924 */
1925
1926 static int
1927 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1928   BOOL check_end, uschar *name, BOOL *resetok)
1929 {
1930 int i;
1931 uschar *s = *sptr;
1932
1933 while (isspace(*s)) s++;
1934 for (i = 0; i < n; i++)
1935   {
1936   if (*s != '{')
1937     {
1938     if (i < m) return 1;
1939     sub[i] = NULL;
1940     break;
1941     }
1942   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok);
1943   if (sub[i] == NULL) return 3;
1944   if (*s++ != '}') return 1;
1945   while (isspace(*s)) s++;
1946   }
1947 if (check_end && *s++ != '}')
1948   {
1949   if (s[-1] == '{')
1950     {
1951     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1952       "(max is %d)", name, n);
1953     return 2;
1954     }
1955   return 1;
1956   }
1957
1958 *sptr = s;
1959 return 0;
1960 }
1961
1962
1963
1964
1965 /*************************************************
1966 *     Elaborate message for bad variable         *
1967 *************************************************/
1968
1969 /* For the "unknown variable" message, take a look at the variable's name, and
1970 give additional information about possible ACL variables. The extra information
1971 is added on to expand_string_message.
1972
1973 Argument:   the name of the variable
1974 Returns:    nothing
1975 */
1976
1977 static void
1978 check_variable_error_message(uschar *name)
1979 {
1980 if (Ustrncmp(name, "acl_", 4) == 0)
1981   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
1982     (name[4] == 'c' || name[4] == 'm')?
1983       (isalpha(name[5])?
1984         US"6th character of a user-defined ACL variable must be a digit or underscore" :
1985         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
1986       ) :
1987       US"user-defined ACL variables must start acl_c or acl_m");
1988 }
1989
1990
1991
1992 /*
1993 Load args from sub array to globals, and call acl_check().
1994 Sub array will be corrupted on return.
1995
1996 Returns:       OK         access is granted by an ACCEPT verb
1997                DISCARD    access is granted by a DISCARD verb
1998                FAIL       access is denied
1999                FAIL_DROP  access is denied; drop the connection
2000                DEFER      can't tell at the moment
2001                ERROR      disaster
2002 */
2003 static int
2004 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2005 {
2006 int i;
2007 uschar *tmp;
2008 int sav_narg = acl_narg;
2009 int ret;
2010 extern int acl_where;
2011
2012 if(--nsub > sizeof(acl_arg)/sizeof(*acl_arg)) nsub = sizeof(acl_arg)/sizeof(*acl_arg);
2013 for (i = 0; i < nsub && sub[i+1]; i++)
2014   {
2015   tmp = acl_arg[i];
2016   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2017   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2018   }
2019 acl_narg = i;
2020 while (i < nsub)
2021   {
2022   sub[i+1] = acl_arg[i];
2023   acl_arg[i++] = NULL;
2024   }
2025
2026 DEBUG(D_expand)
2027   debug_printf("expanding: acl: %s  arg: %s%s\n",
2028     sub[0],
2029     acl_narg>0 ? acl_arg[0] : US"<none>",
2030     acl_narg>1 ? " +more"   : "");
2031
2032 ret = acl_eval(acl_where, sub[0], user_msgp, &tmp);
2033
2034 for (i = 0; i < nsub; i++)
2035   acl_arg[i] = sub[i+1];        /* restore old args */
2036 acl_narg = sav_narg;
2037
2038 return ret;
2039 }
2040
2041
2042
2043
2044 /*************************************************
2045 *        Read and evaluate a condition           *
2046 *************************************************/
2047
2048 /*
2049 Arguments:
2050   s        points to the start of the condition text
2051   resetok  points to a BOOL which is written false if it is unsafe to
2052            free memory. Certain condition types (acl) may have side-effect
2053            allocation which must be preserved.
2054   yield    points to a BOOL to hold the result of the condition test;
2055            if NULL, we are just reading through a condition that is
2056            part of an "or" combination to check syntax, or in a state
2057            where the answer isn't required
2058
2059 Returns:   a pointer to the first character after the condition, or
2060            NULL after an error
2061 */
2062
2063 static uschar *
2064 eval_condition(uschar *s, BOOL *resetok, BOOL *yield)
2065 {
2066 BOOL testfor = TRUE;
2067 BOOL tempcond, combined_cond;
2068 BOOL *subcondptr;
2069 BOOL sub2_honour_dollar = TRUE;
2070 int i, rc, cond_type, roffset;
2071 int_eximarith_t num[2];
2072 struct stat statbuf;
2073 uschar name[256];
2074 uschar *sub[10];
2075
2076 const pcre *re;
2077 const uschar *rerror;
2078
2079 for (;;)
2080   {
2081   while (isspace(*s)) s++;
2082   if (*s == '!') { testfor = !testfor; s++; } else break;
2083   }
2084
2085 /* Numeric comparisons are symbolic */
2086
2087 if (*s == '=' || *s == '>' || *s == '<')
2088   {
2089   int p = 0;
2090   name[p++] = *s++;
2091   if (*s == '=')
2092     {
2093     name[p++] = '=';
2094     s++;
2095     }
2096   name[p] = 0;
2097   }
2098
2099 /* All other conditions are named */
2100
2101 else s = read_name(name, 256, s, US"_");
2102
2103 /* If we haven't read a name, it means some non-alpha character is first. */
2104
2105 if (name[0] == 0)
2106   {
2107   expand_string_message = string_sprintf("condition name expected, "
2108     "but found \"%.16s\"", s);
2109   return NULL;
2110   }
2111
2112 /* Find which condition we are dealing with, and switch on it */
2113
2114 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
2115 switch(cond_type)
2116   {
2117   /* def: tests for a non-empty variable, or for the existence of a header. If
2118   yield == NULL we are in a skipping state, and don't care about the answer. */
2119
2120   case ECOND_DEF:
2121   if (*s != ':')
2122     {
2123     expand_string_message = US"\":\" expected after \"def\"";
2124     return NULL;
2125     }
2126
2127   s = read_name(name, 256, s+1, US"_");
2128
2129   /* Test for a header's existence. If the name contains a closing brace
2130   character, this may be a user error where the terminating colon has been
2131   omitted. Set a flag to adjust a subsequent error message in this case. */
2132
2133   if (Ustrncmp(name, "h_", 2) == 0 ||
2134       Ustrncmp(name, "rh_", 3) == 0 ||
2135       Ustrncmp(name, "bh_", 3) == 0 ||
2136       Ustrncmp(name, "header_", 7) == 0 ||
2137       Ustrncmp(name, "rheader_", 8) == 0 ||
2138       Ustrncmp(name, "bheader_", 8) == 0)
2139     {
2140     s = read_header_name(name, 256, s);
2141     /* {-for-text-editors */
2142     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2143     if (yield != NULL) *yield =
2144       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2145     }
2146
2147   /* Test for a variable's having a non-empty value. A non-existent variable
2148   causes an expansion failure. */
2149
2150   else
2151     {
2152     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2153     if (value == NULL)
2154       {
2155       expand_string_message = (name[0] == 0)?
2156         string_sprintf("variable name omitted after \"def:\"") :
2157         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2158       check_variable_error_message(name);
2159       return NULL;
2160       }
2161     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2162     }
2163
2164   return s;
2165
2166
2167   /* first_delivery tests for first delivery attempt */
2168
2169   case ECOND_FIRST_DELIVERY:
2170   if (yield != NULL) *yield = deliver_firsttime == testfor;
2171   return s;
2172
2173
2174   /* queue_running tests for any process started by a queue runner */
2175
2176   case ECOND_QUEUE_RUNNING:
2177   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2178   return s;
2179
2180
2181   /* exists:  tests for file existence
2182        isip:  tests for any IP address
2183       isip4:  tests for an IPv4 address
2184       isip6:  tests for an IPv6 address
2185         pam:  does PAM authentication
2186      radius:  does RADIUS authentication
2187    ldapauth:  does LDAP authentication
2188     pwcheck:  does Cyrus SASL pwcheck authentication
2189   */
2190
2191   case ECOND_EXISTS:
2192   case ECOND_ISIP:
2193   case ECOND_ISIP4:
2194   case ECOND_ISIP6:
2195   case ECOND_PAM:
2196   case ECOND_RADIUS:
2197   case ECOND_LDAPAUTH:
2198   case ECOND_PWCHECK:
2199
2200   while (isspace(*s)) s++;
2201   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2202
2203   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2204   if (sub[0] == NULL) return NULL;
2205   /* {-for-text-editors */
2206   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2207
2208   if (yield == NULL) return s;   /* No need to run the test if skipping */
2209
2210   switch(cond_type)
2211     {
2212     case ECOND_EXISTS:
2213     if ((expand_forbid & RDO_EXISTS) != 0)
2214       {
2215       expand_string_message = US"File existence tests are not permitted";
2216       return NULL;
2217       }
2218     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2219     break;
2220
2221     case ECOND_ISIP:
2222     case ECOND_ISIP4:
2223     case ECOND_ISIP6:
2224     rc = string_is_ip_address(sub[0], NULL);
2225     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2226              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2227     break;
2228
2229     /* Various authentication tests - all optionally compiled */
2230
2231     case ECOND_PAM:
2232     #ifdef SUPPORT_PAM
2233     rc = auth_call_pam(sub[0], &expand_string_message);
2234     goto END_AUTH;
2235     #else
2236     goto COND_FAILED_NOT_COMPILED;
2237     #endif  /* SUPPORT_PAM */
2238
2239     case ECOND_RADIUS:
2240     #ifdef RADIUS_CONFIG_FILE
2241     rc = auth_call_radius(sub[0], &expand_string_message);
2242     goto END_AUTH;
2243     #else
2244     goto COND_FAILED_NOT_COMPILED;
2245     #endif  /* RADIUS_CONFIG_FILE */
2246
2247     case ECOND_LDAPAUTH:
2248     #ifdef LOOKUP_LDAP
2249       {
2250       /* Just to keep the interface the same */
2251       BOOL do_cache;
2252       int old_pool = store_pool;
2253       store_pool = POOL_SEARCH;
2254       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2255         &expand_string_message, &do_cache);
2256       store_pool = old_pool;
2257       }
2258     goto END_AUTH;
2259     #else
2260     goto COND_FAILED_NOT_COMPILED;
2261     #endif  /* LOOKUP_LDAP */
2262
2263     case ECOND_PWCHECK:
2264     #ifdef CYRUS_PWCHECK_SOCKET
2265     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2266     goto END_AUTH;
2267     #else
2268     goto COND_FAILED_NOT_COMPILED;
2269     #endif  /* CYRUS_PWCHECK_SOCKET */
2270
2271     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2272         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2273     END_AUTH:
2274     if (rc == ERROR || rc == DEFER) return NULL;
2275     *yield = (rc == OK) == testfor;
2276     #endif
2277     }
2278   return s;
2279
2280
2281   /* call ACL (in a conditional context).  Accept true, deny false.
2282   Defer is a forced-fail.  Anything set by message= goes to $value.
2283   Up to ten parameters are used; we use the braces round the name+args
2284   like the saslauthd condition does, to permit a variable number of args.
2285   See also the expansion-item version EITEM_ACL and the traditional
2286   acl modifier ACLC_ACL.
2287   Since the ACL may allocate new global variables, tell our caller to not
2288   reclaim memory.
2289   */
2290
2291   case ECOND_ACL:
2292     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2293     {
2294     uschar *user_msg;
2295     BOOL cond = FALSE;
2296     int size = 0;
2297     int ptr = 0;
2298
2299     while (isspace(*s)) s++;
2300     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2301
2302     switch(read_subs(sub, sizeof(sub)/sizeof(*sub), 1,
2303       &s, yield == NULL, TRUE, US"acl", resetok))
2304       {
2305       case 1: expand_string_message = US"too few arguments or bracketing "
2306         "error for acl";
2307       case 2:
2308       case 3: return NULL;
2309       }
2310
2311     *resetok = FALSE;
2312     if (yield != NULL) switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
2313         {
2314         case OK:
2315           cond = TRUE;
2316         case FAIL:
2317           lookup_value = NULL;
2318           if (user_msg)
2319             {
2320             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2321             lookup_value[ptr] = '\0';
2322             }
2323           *yield = cond == testfor;
2324           break;
2325
2326         case DEFER:
2327           expand_string_forcedfail = TRUE;
2328         default:
2329           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2330           return NULL;
2331         }
2332     return s;
2333     }
2334
2335
2336   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2337
2338      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2339
2340   However, the last two are optional. That is why the whole set is enclosed
2341   in their own set of braces. */
2342
2343   case ECOND_SASLAUTHD:
2344   #ifndef CYRUS_SASLAUTHD_SOCKET
2345   goto COND_FAILED_NOT_COMPILED;
2346   #else
2347   while (isspace(*s)) s++;
2348   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2349   switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd", resetok))
2350     {
2351     case 1: expand_string_message = US"too few arguments or bracketing "
2352       "error for saslauthd";
2353     case 2:
2354     case 3: return NULL;
2355     }
2356   if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2357   if (yield != NULL)
2358     {
2359     int rc;
2360     rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2361       &expand_string_message);
2362     if (rc == ERROR || rc == DEFER) return NULL;
2363     *yield = (rc == OK) == testfor;
2364     }
2365   return s;
2366   #endif /* CYRUS_SASLAUTHD_SOCKET */
2367
2368
2369   /* symbolic operators for numeric and string comparison, and a number of
2370   other operators, all requiring two arguments.
2371
2372   crypteq:           encrypts plaintext and compares against an encrypted text,
2373                        using crypt(), crypt16(), MD5 or SHA-1
2374   inlist/inlisti:    checks if first argument is in the list of the second
2375   match:             does a regular expression match and sets up the numerical
2376                        variables if it succeeds
2377   match_address:     matches in an address list
2378   match_domain:      matches in a domain list
2379   match_ip:          matches a host list that is restricted to IP addresses
2380   match_local_part:  matches in a local part list
2381   */
2382
2383   case ECOND_MATCH_ADDRESS:
2384   case ECOND_MATCH_DOMAIN:
2385   case ECOND_MATCH_IP:
2386   case ECOND_MATCH_LOCAL_PART:
2387 #ifndef EXPAND_LISTMATCH_RHS
2388     sub2_honour_dollar = FALSE;
2389 #endif
2390     /* FALLTHROUGH */
2391
2392   case ECOND_CRYPTEQ:
2393   case ECOND_INLIST:
2394   case ECOND_INLISTI:
2395   case ECOND_MATCH:
2396
2397   case ECOND_NUM_L:     /* Numerical comparisons */
2398   case ECOND_NUM_LE:
2399   case ECOND_NUM_E:
2400   case ECOND_NUM_EE:
2401   case ECOND_NUM_G:
2402   case ECOND_NUM_GE:
2403
2404   case ECOND_STR_LT:    /* String comparisons */
2405   case ECOND_STR_LTI:
2406   case ECOND_STR_LE:
2407   case ECOND_STR_LEI:
2408   case ECOND_STR_EQ:
2409   case ECOND_STR_EQI:
2410   case ECOND_STR_GT:
2411   case ECOND_STR_GTI:
2412   case ECOND_STR_GE:
2413   case ECOND_STR_GEI:
2414
2415   for (i = 0; i < 2; i++)
2416     {
2417     /* Sometimes, we don't expand substrings; too many insecure configurations
2418     created using match_address{}{} and friends, where the second param
2419     includes information from untrustworthy sources. */
2420     BOOL honour_dollar = TRUE;
2421     if ((i > 0) && !sub2_honour_dollar)
2422       honour_dollar = FALSE;
2423
2424     while (isspace(*s)) s++;
2425     if (*s != '{')
2426       {
2427       if (i == 0) goto COND_FAILED_CURLY_START;
2428       expand_string_message = string_sprintf("missing 2nd string in {} "
2429         "after \"%s\"", name);
2430       return NULL;
2431       }
2432     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2433         honour_dollar, resetok);
2434     if (sub[i] == NULL) return NULL;
2435     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2436
2437     /* Convert to numerical if required; we know that the names of all the
2438     conditions that compare numbers do not start with a letter. This just saves
2439     checking for them individually. */
2440
2441     if (!isalpha(name[0]) && yield != NULL)
2442       {
2443       if (sub[i][0] == 0)
2444         {
2445         num[i] = 0;
2446         DEBUG(D_expand)
2447           debug_printf("empty string cast to zero for numerical comparison\n");
2448         }
2449       else
2450         {
2451         num[i] = expanded_string_integer(sub[i], FALSE);
2452         if (expand_string_message != NULL) return NULL;
2453         }
2454       }
2455     }
2456
2457   /* Result not required */
2458
2459   if (yield == NULL) return s;
2460
2461   /* Do an appropriate comparison */
2462
2463   switch(cond_type)
2464     {
2465     case ECOND_NUM_E:
2466     case ECOND_NUM_EE:
2467     tempcond = (num[0] == num[1]);
2468     break;
2469
2470     case ECOND_NUM_G:
2471     tempcond = (num[0] > num[1]);
2472     break;
2473
2474     case ECOND_NUM_GE:
2475     tempcond = (num[0] >= num[1]);
2476     break;
2477
2478     case ECOND_NUM_L:
2479     tempcond = (num[0] < num[1]);
2480     break;
2481
2482     case ECOND_NUM_LE:
2483     tempcond = (num[0] <= num[1]);
2484     break;
2485
2486     case ECOND_STR_LT:
2487     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2488     break;
2489
2490     case ECOND_STR_LTI:
2491     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2492     break;
2493
2494     case ECOND_STR_LE:
2495     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2496     break;
2497
2498     case ECOND_STR_LEI:
2499     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2500     break;
2501
2502     case ECOND_STR_EQ:
2503     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2504     break;
2505
2506     case ECOND_STR_EQI:
2507     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2508     break;
2509
2510     case ECOND_STR_GT:
2511     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2512     break;
2513
2514     case ECOND_STR_GTI:
2515     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2516     break;
2517
2518     case ECOND_STR_GE:
2519     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2520     break;
2521
2522     case ECOND_STR_GEI:
2523     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2524     break;
2525
2526     case ECOND_MATCH:   /* Regular expression match */
2527     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2528       NULL);
2529     if (re == NULL)
2530       {
2531       expand_string_message = string_sprintf("regular expression error in "
2532         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2533       return NULL;
2534       }
2535     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2536     break;
2537
2538     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2539     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2540     goto MATCHED_SOMETHING;
2541
2542     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2543     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2544       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2545     goto MATCHED_SOMETHING;
2546
2547     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2548     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2549       {
2550       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2551         sub[0]);
2552       return NULL;
2553       }
2554     else
2555       {
2556       unsigned int *nullcache = NULL;
2557       check_host_block cb;
2558
2559       cb.host_name = US"";
2560       cb.host_address = sub[0];
2561
2562       /* If the host address starts off ::ffff: it is an IPv6 address in
2563       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2564       addresses. */
2565
2566       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2567         cb.host_address + 7 : cb.host_address;
2568
2569       rc = match_check_list(
2570              &sub[1],                   /* the list */
2571              0,                         /* separator character */
2572              &hostlist_anchor,          /* anchor pointer */
2573              &nullcache,                /* cache pointer */
2574              check_host,                /* function for testing */
2575              &cb,                       /* argument for function */
2576              MCL_HOST,                  /* type of check */
2577              sub[0],                    /* text for debugging */
2578              NULL);                     /* where to pass back data */
2579       }
2580     goto MATCHED_SOMETHING;
2581
2582     case ECOND_MATCH_LOCAL_PART:
2583     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2584       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2585     /* Fall through */
2586     /* VVVVVVVVVVVV */
2587     MATCHED_SOMETHING:
2588     switch(rc)
2589       {
2590       case OK:
2591       tempcond = TRUE;
2592       break;
2593
2594       case FAIL:
2595       tempcond = FALSE;
2596       break;
2597
2598       case DEFER:
2599       expand_string_message = string_sprintf("unable to complete match "
2600         "against \"%s\": %s", sub[1], search_error_message);
2601       return NULL;
2602       }
2603
2604     break;
2605
2606     /* Various "encrypted" comparisons. If the second string starts with
2607     "{" then an encryption type is given. Default to crypt() or crypt16()
2608     (build-time choice). */
2609     /* }-for-text-editors */
2610
2611     case ECOND_CRYPTEQ:
2612     #ifndef SUPPORT_CRYPTEQ
2613     goto COND_FAILED_NOT_COMPILED;
2614     #else
2615     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2616       {
2617       int sublen = Ustrlen(sub[1]+5);
2618       md5 base;
2619       uschar digest[16];
2620
2621       md5_start(&base);
2622       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2623
2624       /* If the length that we are comparing against is 24, the MD5 digest
2625       is expressed as a base64 string. This is the way LDAP does it. However,
2626       some other software uses a straightforward hex representation. We assume
2627       this if the length is 32. Other lengths fail. */
2628
2629       if (sublen == 24)
2630         {
2631         uschar *coded = auth_b64encode((uschar *)digest, 16);
2632         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2633           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2634         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2635         }
2636       else if (sublen == 32)
2637         {
2638         int i;
2639         uschar coded[36];
2640         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2641         coded[32] = 0;
2642         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2643           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2644         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2645         }
2646       else
2647         {
2648         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2649           "fail\n  crypted=%s\n", sub[1]+5);
2650         tempcond = FALSE;
2651         }
2652       }
2653
2654     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2655       {
2656       int sublen = Ustrlen(sub[1]+6);
2657       sha1 base;
2658       uschar digest[20];
2659
2660       sha1_start(&base);
2661       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2662
2663       /* If the length that we are comparing against is 28, assume the SHA1
2664       digest is expressed as a base64 string. If the length is 40, assume a
2665       straightforward hex representation. Other lengths fail. */
2666
2667       if (sublen == 28)
2668         {
2669         uschar *coded = auth_b64encode((uschar *)digest, 20);
2670         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2671           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2672         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2673         }
2674       else if (sublen == 40)
2675         {
2676         int i;
2677         uschar coded[44];
2678         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2679         coded[40] = 0;
2680         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2681           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2682         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2683         }
2684       else
2685         {
2686         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2687           "fail\n  crypted=%s\n", sub[1]+6);
2688         tempcond = FALSE;
2689         }
2690       }
2691
2692     else   /* {crypt} or {crypt16} and non-{ at start */
2693            /* }-for-text-editors */
2694       {
2695       int which = 0;
2696       uschar *coded;
2697
2698       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2699         {
2700         sub[1] += 7;
2701         which = 1;
2702         }
2703       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2704         {
2705         sub[1] += 9;
2706         which = 2;
2707         }
2708       else if (sub[1][0] == '{')                /* }-for-text-editors */
2709         {
2710         expand_string_message = string_sprintf("unknown encryption mechanism "
2711           "in \"%s\"", sub[1]);
2712         return NULL;
2713         }
2714
2715       switch(which)
2716         {
2717         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2718         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2719         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2720         }
2721
2722       #define STR(s) # s
2723       #define XSTR(s) STR(s)
2724       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2725         "  subject=%s\n  crypted=%s\n",
2726         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2727         coded, sub[1]);
2728       #undef STR
2729       #undef XSTR
2730
2731       /* If the encrypted string contains fewer than two characters (for the
2732       salt), force failure. Otherwise we get false positives: with an empty
2733       string the yield of crypt() is an empty string! */
2734
2735       tempcond = (Ustrlen(sub[1]) < 2)? FALSE :
2736         (Ustrcmp(coded, sub[1]) == 0);
2737       }
2738     break;
2739     #endif  /* SUPPORT_CRYPTEQ */
2740
2741     case ECOND_INLIST:
2742     case ECOND_INLISTI:
2743       {
2744       int sep = 0;
2745       uschar *save_iterate_item = iterate_item;
2746       int (*compare)(const uschar *, const uschar *);
2747
2748       tempcond = FALSE;
2749       if (cond_type == ECOND_INLISTI)
2750         compare = strcmpic;
2751       else
2752         compare = (int (*)(const uschar *, const uschar *)) strcmp;
2753
2754       while ((iterate_item = string_nextinlist(&sub[1], &sep, NULL, 0)) != NULL)
2755         if (compare(sub[0], iterate_item) == 0)
2756           {
2757           tempcond = TRUE;
2758           break;
2759           }
2760       iterate_item = save_iterate_item;
2761       }
2762
2763     }   /* Switch for comparison conditions */
2764
2765   *yield = tempcond == testfor;
2766   return s;    /* End of comparison conditions */
2767
2768
2769   /* and/or: computes logical and/or of several conditions */
2770
2771   case ECOND_AND:
2772   case ECOND_OR:
2773   subcondptr = (yield == NULL)? NULL : &tempcond;
2774   combined_cond = (cond_type == ECOND_AND);
2775
2776   while (isspace(*s)) s++;
2777   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2778
2779   for (;;)
2780     {
2781     while (isspace(*s)) s++;
2782     /* {-for-text-editors */
2783     if (*s == '}') break;
2784     if (*s != '{')                                      /* }-for-text-editors */
2785       {
2786       expand_string_message = string_sprintf("each subcondition "
2787         "inside an \"%s{...}\" condition must be in its own {}", name);
2788       return NULL;
2789       }
2790
2791     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2792       {
2793       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2794         expand_string_message, name);
2795       return NULL;
2796       }
2797     while (isspace(*s)) s++;
2798
2799     /* {-for-text-editors */
2800     if (*s++ != '}')
2801       {
2802       /* {-for-text-editors */
2803       expand_string_message = string_sprintf("missing } at end of condition "
2804         "inside \"%s\" group", name);
2805       return NULL;
2806       }
2807
2808     if (yield != NULL)
2809       {
2810       if (cond_type == ECOND_AND)
2811         {
2812         combined_cond &= tempcond;
2813         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2814         }                                       /* evaluate any more */
2815       else
2816         {
2817         combined_cond |= tempcond;
2818         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2819         }                                       /* evaluate any more */
2820       }
2821     }
2822
2823   if (yield != NULL) *yield = (combined_cond == testfor);
2824   return ++s;
2825
2826
2827   /* forall/forany: iterates a condition with different values */
2828
2829   case ECOND_FORALL:
2830   case ECOND_FORANY:
2831     {
2832     int sep = 0;
2833     uschar *save_iterate_item = iterate_item;
2834
2835     while (isspace(*s)) s++;
2836     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2837     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2838     if (sub[0] == NULL) return NULL;
2839     /* {-for-text-editors */
2840     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2841
2842     while (isspace(*s)) s++;
2843     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2844
2845     sub[1] = s;
2846
2847     /* Call eval_condition once, with result discarded (as if scanning a
2848     "false" part). This allows us to find the end of the condition, because if
2849     the list it empty, we won't actually evaluate the condition for real. */
2850
2851     if (!(s = eval_condition(sub[1], resetok, NULL)))
2852       {
2853       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2854         expand_string_message, name);
2855       return NULL;
2856       }
2857     while (isspace(*s)) s++;
2858
2859     /* {-for-text-editors */
2860     if (*s++ != '}')
2861       {
2862       /* {-for-text-editors */
2863       expand_string_message = string_sprintf("missing } at end of condition "
2864         "inside \"%s\"", name);
2865       return NULL;
2866       }
2867
2868     if (yield != NULL) *yield = !testfor;
2869     while ((iterate_item = string_nextinlist(&sub[0], &sep, NULL, 0)) != NULL)
2870       {
2871       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2872       if (!eval_condition(sub[1], resetok, &tempcond))
2873         {
2874         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2875           expand_string_message, name);
2876         iterate_item = save_iterate_item;
2877         return NULL;
2878         }
2879       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2880         tempcond? "true":"false");
2881
2882       if (yield != NULL) *yield = (tempcond == testfor);
2883       if (tempcond == (cond_type == ECOND_FORANY)) break;
2884       }
2885
2886     iterate_item = save_iterate_item;
2887     return s;
2888     }
2889
2890
2891   /* The bool{} expansion condition maps a string to boolean.
2892   The values supported should match those supported by the ACL condition
2893   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2894   of true/false.  Note that Router "condition" rules have a different
2895   interpretation, where general data can be used and only a few values
2896   map to FALSE.
2897   Note that readconf.c boolean matching, for boolean configuration options,
2898   only matches true/yes/false/no.
2899   The bool_lax{} condition matches the Router logic, which is much more
2900   liberal. */
2901   case ECOND_BOOL:
2902   case ECOND_BOOL_LAX:
2903     {
2904     uschar *sub_arg[1];
2905     uschar *t, *t2;
2906     uschar *ourname;
2907     size_t len;
2908     BOOL boolvalue = FALSE;
2909     while (isspace(*s)) s++;
2910     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2911     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2912     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2913       {
2914       case 1: expand_string_message = string_sprintf(
2915                   "too few arguments or bracketing error for %s",
2916                   ourname);
2917       /*FALLTHROUGH*/
2918       case 2:
2919       case 3: return NULL;
2920       }
2921     t = sub_arg[0];
2922     while (isspace(*t)) t++;
2923     len = Ustrlen(t);
2924     if (len)
2925       {
2926       /* trailing whitespace: seems like a good idea to ignore it too */
2927       t2 = t + len - 1;
2928       while (isspace(*t2)) t2--;
2929       if (t2 != (t + len))
2930         {
2931         *++t2 = '\0';
2932         len = t2 - t;
2933         }
2934       }
2935     DEBUG(D_expand)
2936       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
2937     /* logic for the lax case from expand_check_condition(), which also does
2938     expands, and the logic is both short and stable enough that there should
2939     be no maintenance burden from replicating it. */
2940     if (len == 0)
2941       boolvalue = FALSE;
2942     else if (*t == '-'
2943              ? Ustrspn(t+1, "0123456789") == len-1
2944              : Ustrspn(t,   "0123456789") == len)
2945       {
2946       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
2947       /* expand_check_condition only does a literal string "0" check */
2948       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
2949         boolvalue = TRUE;
2950       }
2951     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
2952       boolvalue = TRUE;
2953     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
2954       boolvalue = FALSE;
2955     else if (cond_type == ECOND_BOOL_LAX)
2956       boolvalue = TRUE;
2957     else
2958       {
2959       expand_string_message = string_sprintf("unrecognised boolean "
2960        "value \"%s\"", t);
2961       return NULL;
2962       }
2963     if (yield != NULL) *yield = (boolvalue == testfor);
2964     return s;
2965     }
2966
2967   /* Unknown condition */
2968
2969   default:
2970   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2971   return NULL;
2972   }   /* End switch on condition type */
2973
2974 /* Missing braces at start and end of data */
2975
2976 COND_FAILED_CURLY_START:
2977 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2978 return NULL;
2979
2980 COND_FAILED_CURLY_END:
2981 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2982   name);
2983 return NULL;
2984
2985 /* A condition requires code that is not compiled */
2986
2987 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2988     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2989     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2990 COND_FAILED_NOT_COMPILED:
2991 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2992   name);
2993 return NULL;
2994 #endif
2995 }
2996
2997
2998
2999
3000 /*************************************************
3001 *          Save numerical variables              *
3002 *************************************************/
3003
3004 /* This function is called from items such as "if" that want to preserve and
3005 restore the numbered variables.
3006
3007 Arguments:
3008   save_expand_string    points to an array of pointers to set
3009   save_expand_nlength   points to an array of ints for the lengths
3010
3011 Returns:                the value of expand max to save
3012 */
3013
3014 static int
3015 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3016 {
3017 int i;
3018 for (i = 0; i <= expand_nmax; i++)
3019   {
3020   save_expand_nstring[i] = expand_nstring[i];
3021   save_expand_nlength[i] = expand_nlength[i];
3022   }
3023 return expand_nmax;
3024 }
3025
3026
3027
3028 /*************************************************
3029 *           Restore numerical variables          *
3030 *************************************************/
3031
3032 /* This function restored saved values of numerical strings.
3033
3034 Arguments:
3035   save_expand_nmax      the number of strings to restore
3036   save_expand_string    points to an array of pointers
3037   save_expand_nlength   points to an array of ints
3038
3039 Returns:                nothing
3040 */
3041
3042 static void
3043 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3044   int *save_expand_nlength)
3045 {
3046 int i;
3047 expand_nmax = save_expand_nmax;
3048 for (i = 0; i <= expand_nmax; i++)
3049   {
3050   expand_nstring[i] = save_expand_nstring[i];
3051   expand_nlength[i] = save_expand_nlength[i];
3052   }
3053 }
3054
3055
3056
3057
3058
3059 /*************************************************
3060 *            Handle yes/no substrings            *
3061 *************************************************/
3062
3063 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3064 alternative substrings that depend on whether or not the condition was true,
3065 or the lookup or extraction succeeded. The substrings always have to be
3066 expanded, to check their syntax, but "skipping" is set when the result is not
3067 needed - this avoids unnecessary nested lookups.
3068
3069 Arguments:
3070   skipping       TRUE if we were skipping when this item was reached
3071   yes            TRUE if the first string is to be used, else use the second
3072   save_lookup    a value to put back into lookup_value before the 2nd expansion
3073   sptr           points to the input string pointer
3074   yieldptr       points to the output string pointer
3075   sizeptr        points to the output string size
3076   ptrptr         points to the output string pointer
3077   type           "lookup" or "if" or "extract" or "run", for error message
3078   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3079                 the store.
3080
3081 Returns:         0 OK; lookup_value has been reset to save_lookup
3082                  1 expansion failed
3083                  2 expansion failed because of bracketing error
3084 */
3085
3086 static int
3087 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
3088   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3089 {
3090 int rc = 0;
3091 uschar *s = *sptr;    /* Local value */
3092 uschar *sub1, *sub2;
3093
3094 /* If there are no following strings, we substitute the contents of $value for
3095 lookups and for extractions in the success case. For the ${if item, the string
3096 "true" is substituted. In the fail case, nothing is substituted for all three
3097 items. */
3098
3099 while (isspace(*s)) s++;
3100 if (*s == '}')
3101   {
3102   if (type[0] == 'i')
3103     {
3104     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
3105     }
3106   else
3107     {
3108     if (yes && lookup_value != NULL)
3109       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
3110         Ustrlen(lookup_value));
3111     lookup_value = save_lookup;
3112     }
3113   s++;
3114   goto RETURN;
3115   }
3116
3117 /* The first following string must be braced. */
3118
3119 if (*s++ != '{') goto FAILED_CURLY;
3120
3121 /* Expand the first substring. Forced failures are noticed only if we actually
3122 want this string. Set skipping in the call in the fail case (this will always
3123 be the case if we were already skipping). */
3124
3125 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3126 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3127 expand_string_forcedfail = FALSE;
3128 if (*s++ != '}') goto FAILED_CURLY;
3129
3130 /* If we want the first string, add it to the output */
3131
3132 if (yes)
3133   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
3134
3135 /* If this is called from a lookup or an extract, we want to restore $value to
3136 what it was at the start of the item, so that it has this value during the
3137 second string expansion. For the call from "if" or "run" to this function,
3138 save_lookup is set to lookup_value, so that this statement does nothing. */
3139
3140 lookup_value = save_lookup;
3141
3142 /* There now follows either another substring, or "fail", or nothing. This
3143 time, forced failures are noticed only if we want the second string. We must
3144 set skipping in the nested call if we don't want this string, or if we were
3145 already skipping. */
3146
3147 while (isspace(*s)) s++;
3148 if (*s == '{')
3149   {
3150   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3151   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3152   expand_string_forcedfail = FALSE;
3153   if (*s++ != '}') goto FAILED_CURLY;
3154
3155   /* If we want the second string, add it to the output */
3156
3157   if (!yes)
3158     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
3159   }
3160
3161 /* If there is no second string, but the word "fail" is present when the use of
3162 the second string is wanted, set a flag indicating it was a forced failure
3163 rather than a syntactic error. Swallow the terminating } in case this is nested
3164 inside another lookup or if or extract. */
3165
3166 else if (*s != '}')
3167   {
3168   uschar name[256];
3169   s = read_name(name, sizeof(name), s, US"_");
3170   if (Ustrcmp(name, "fail") == 0)
3171     {
3172     if (!yes && !skipping)
3173       {
3174       while (isspace(*s)) s++;
3175       if (*s++ != '}') goto FAILED_CURLY;
3176       expand_string_message =
3177         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3178       expand_string_forcedfail = TRUE;
3179       goto FAILED;
3180       }
3181     }
3182   else
3183     {
3184     expand_string_message =
3185       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3186     goto FAILED;
3187     }
3188   }
3189
3190 /* All we have to do now is to check on the final closing brace. */
3191
3192 while (isspace(*s)) s++;
3193 if (*s++ == '}') goto RETURN;
3194
3195 /* Get here if there is a bracketing failure */
3196
3197 FAILED_CURLY:
3198 rc++;
3199
3200 /* Get here for other failures */
3201
3202 FAILED:
3203 rc++;
3204
3205 /* Update the input pointer value before returning */
3206
3207 RETURN:
3208 *sptr = s;
3209 return rc;
3210 }
3211
3212
3213
3214
3215 /*************************************************
3216 *    Handle MD5 or SHA-1 computation for HMAC    *
3217 *************************************************/
3218
3219 /* These are some wrapping functions that enable the HMAC code to be a bit
3220 cleaner. A good compiler will spot the tail recursion.
3221
3222 Arguments:
3223   type         HMAC_MD5 or HMAC_SHA1
3224   remaining    are as for the cryptographic hash functions
3225
3226 Returns:       nothing
3227 */
3228
3229 static void
3230 chash_start(int type, void *base)
3231 {
3232 if (type == HMAC_MD5)
3233   md5_start((md5 *)base);
3234 else
3235   sha1_start((sha1 *)base);
3236 }
3237
3238 static void
3239 chash_mid(int type, void *base, uschar *string)
3240 {
3241 if (type == HMAC_MD5)
3242   md5_mid((md5 *)base, string);
3243 else
3244   sha1_mid((sha1 *)base, string);
3245 }
3246
3247 static void
3248 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3249 {
3250 if (type == HMAC_MD5)
3251   md5_end((md5 *)base, string, length, digest);
3252 else
3253   sha1_end((sha1 *)base, string, length, digest);
3254 }
3255
3256
3257
3258
3259
3260 /********************************************************
3261 * prvs: Get last three digits of days since Jan 1, 1970 *
3262 ********************************************************/
3263
3264 /* This is needed to implement the "prvs" BATV reverse
3265    path signing scheme
3266
3267 Argument: integer "days" offset to add or substract to
3268           or from the current number of days.
3269
3270 Returns:  pointer to string containing the last three
3271           digits of the number of days since Jan 1, 1970,
3272           modified by the offset argument, NULL if there
3273           was an error in the conversion.
3274
3275 */
3276
3277 static uschar *
3278 prvs_daystamp(int day_offset)
3279 {
3280 uschar *days = store_get(32);                /* Need at least 24 for cases */
3281 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3282   (time(NULL) + day_offset*86400)/86400);
3283 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3284 }
3285
3286
3287
3288 /********************************************************
3289 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3290 ********************************************************/
3291
3292 /* This is needed to implement the "prvs" BATV reverse
3293    path signing scheme
3294
3295 Arguments:
3296   address RFC2821 Address to use
3297       key The key to use (must be less than 64 characters
3298           in size)
3299   key_num Single-digit key number to use. Defaults to
3300           '0' when NULL.
3301
3302 Returns:  pointer to string containing the first three
3303           bytes of the final hash in hex format, NULL if
3304           there was an error in the process.
3305 */
3306
3307 static uschar *
3308 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3309 {
3310 uschar *hash_source, *p;
3311 int size = 0,offset = 0,i;
3312 sha1 sha1_base;
3313 void *use_base = &sha1_base;
3314 uschar innerhash[20];
3315 uschar finalhash[20];
3316 uschar innerkey[64];
3317 uschar outerkey[64];
3318 uschar *finalhash_hex = store_get(40);
3319
3320 if (key_num == NULL)
3321   key_num = US"0";
3322
3323 if (Ustrlen(key) > 64)
3324   return NULL;
3325
3326 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3327 string_cat(hash_source,&size,&offset,daystamp,3);
3328 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3329 hash_source[offset] = '\0';
3330
3331 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3332
3333 memset(innerkey, 0x36, 64);
3334 memset(outerkey, 0x5c, 64);
3335
3336 for (i = 0; i < Ustrlen(key); i++)
3337   {
3338   innerkey[i] ^= key[i];
3339   outerkey[i] ^= key[i];
3340   }
3341
3342 chash_start(HMAC_SHA1, use_base);
3343 chash_mid(HMAC_SHA1, use_base, innerkey);
3344 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3345
3346 chash_start(HMAC_SHA1, use_base);
3347 chash_mid(HMAC_SHA1, use_base, outerkey);
3348 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3349
3350 p = finalhash_hex;
3351 for (i = 0; i < 3; i++)
3352   {
3353   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3354   *p++ = hex_digits[finalhash[i] & 0x0f];
3355   }
3356 *p = '\0';
3357
3358 return finalhash_hex;
3359 }
3360
3361
3362
3363
3364 /*************************************************
3365 *        Join a file onto the output string      *
3366 *************************************************/
3367
3368 /* This is used for readfile and after a run expansion. It joins the contents
3369 of a file onto the output string, globally replacing newlines with a given
3370 string (optionally). The file is closed at the end.
3371
3372 Arguments:
3373   f            the FILE
3374   yield        pointer to the expandable string
3375   sizep        pointer to the current size
3376   ptrp         pointer to the current position
3377   eol          newline replacement string, or NULL
3378
3379 Returns:       new value of string pointer
3380 */
3381
3382 static uschar *
3383 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3384 {
3385 int eollen;
3386 uschar buffer[1024];
3387
3388 eollen = (eol == NULL)? 0 : Ustrlen(eol);
3389
3390 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
3391   {
3392   int len = Ustrlen(buffer);
3393   if (eol != NULL && buffer[len-1] == '\n') len--;
3394   yield = string_cat(yield, sizep, ptrp, buffer, len);
3395   if (buffer[len] != 0)
3396     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3397   }
3398
3399 if (yield != NULL) yield[*ptrp] = 0;
3400
3401 return yield;
3402 }
3403
3404
3405
3406
3407 /*************************************************
3408 *          Evaluate numeric expression           *
3409 *************************************************/
3410
3411 /* This is a set of mutually recursive functions that evaluate an arithmetic
3412 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3413 these functions that is called from elsewhere is eval_expr, whose interface is:
3414
3415 Arguments:
3416   sptr        pointer to the pointer to the string - gets updated
3417   decimal     TRUE if numbers are to be assumed decimal
3418   error       pointer to where to put an error message - must be NULL on input
3419   endket      TRUE if ')' must terminate - FALSE for external call
3420
3421 Returns:      on success: the value of the expression, with *error still NULL
3422               on failure: an undefined value, with *error = a message
3423 */
3424
3425 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3426
3427
3428 static int_eximarith_t
3429 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3430 {
3431 uschar *s = *sptr;
3432 int_eximarith_t x = eval_op_or(&s, decimal, error);
3433 if (*error == NULL)
3434   {
3435   if (endket)
3436     {
3437     if (*s != ')')
3438       *error = US"expecting closing parenthesis";
3439     else
3440       while (isspace(*(++s)));
3441     }
3442   else if (*s != 0) *error = US"expecting operator";
3443   }
3444 *sptr = s;
3445 return x;
3446 }
3447
3448
3449 static int_eximarith_t
3450 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3451 {
3452 register int c;
3453 int_eximarith_t n;
3454 uschar *s = *sptr;
3455 while (isspace(*s)) s++;
3456 c = *s;
3457 if (isdigit(c))
3458   {
3459   int count;
3460   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3461   s += count;
3462   switch (tolower(*s))
3463     {
3464     default: break;
3465     case 'k': n *= 1024; s++; break;
3466     case 'm': n *= 1024*1024; s++; break;
3467     case 'g': n *= 1024*1024*1024; s++; break;
3468     }
3469   while (isspace (*s)) s++;
3470   }
3471 else if (c == '(')
3472   {
3473   s++;
3474   n = eval_expr(&s, decimal, error, 1);
3475   }
3476 else
3477   {
3478   *error = US"expecting number or opening parenthesis";
3479   n = 0;
3480   }
3481 *sptr = s;
3482 return n;
3483 }
3484
3485
3486 static int_eximarith_t
3487 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3488 {
3489 uschar *s = *sptr;
3490 int_eximarith_t x;
3491 while (isspace(*s)) s++;
3492 if (*s == '+' || *s == '-' || *s == '~')
3493   {
3494   int op = *s++;
3495   x = eval_op_unary(&s, decimal, error);
3496   if (op == '-') x = -x;
3497     else if (op == '~') x = ~x;
3498   }
3499 else
3500   {
3501   x = eval_number(&s, decimal, error);
3502   }
3503 *sptr = s;
3504 return x;
3505 }
3506
3507
3508 static int_eximarith_t
3509 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3510 {
3511 uschar *s = *sptr;
3512 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3513 if (*error == NULL)
3514   {
3515   while (*s == '*' || *s == '/' || *s == '%')
3516     {
3517     int op = *s++;
3518     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3519     if (*error != NULL) break;
3520     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3521      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3522      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3523      * -N*M is INT_MIN will yielf INT_MIN.
3524      * Since we don't support floating point, this is somewhat simpler.
3525      * Ideally, we'd return an error, but since we overflow for all other
3526      * arithmetic, consistency suggests otherwise, but what's the correct value
3527      * to use?  There is none.
3528      * The C standard guarantees overflow for unsigned arithmetic but signed
3529      * overflow invokes undefined behaviour; in practice, this is overflow
3530      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3531      * that long/longlong larger than int are available, or we could just work
3532      * with larger types.  We should consider whether to guarantee 32bit eval
3533      * and 64-bit working variables, with errors returned.  For now ...
3534      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3535      * can just let the other invalid results occur otherwise, as they have
3536      * until now.  For this one case, we can coerce.
3537      */
3538     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3539       {
3540       DEBUG(D_expand)
3541         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3542             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3543       x = EXIM_ARITH_MAX;
3544       continue;
3545       }
3546     if (op == '*')
3547       x *= y;
3548     else
3549       {
3550       if (y == 0)
3551         {
3552         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3553         x = 0;
3554         break;
3555         }
3556       if (op == '/')
3557         x /= y;
3558       else
3559         x %= y;
3560       }
3561     }
3562   }
3563 *sptr = s;
3564 return x;
3565 }
3566
3567
3568 static int_eximarith_t
3569 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3570 {
3571 uschar *s = *sptr;
3572 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3573 if (*error == NULL)
3574   {
3575   while (*s == '+' || *s == '-')
3576     {
3577     int op = *s++;
3578     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3579     if (*error != NULL) break;
3580     if (op == '+') x += y; else x -= y;
3581     }
3582   }
3583 *sptr = s;
3584 return x;
3585 }
3586
3587
3588 static int_eximarith_t
3589 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3590 {
3591 uschar *s = *sptr;
3592 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3593 if (*error == NULL)
3594   {
3595   while ((*s == '<' || *s == '>') && s[1] == s[0])
3596     {
3597     int_eximarith_t y;
3598     int op = *s++;
3599     s++;
3600     y = eval_op_sum(&s, decimal, error);
3601     if (*error != NULL) break;
3602     if (op == '<') x <<= y; else x >>= y;
3603     }
3604   }
3605 *sptr = s;
3606 return x;
3607 }
3608
3609
3610 static int_eximarith_t
3611 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3612 {
3613 uschar *s = *sptr;
3614 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3615 if (*error == NULL)
3616   {
3617   while (*s == '&')
3618     {
3619     int_eximarith_t y;
3620     s++;
3621     y = eval_op_shift(&s, decimal, error);
3622     if (*error != NULL) break;
3623     x &= y;
3624     }
3625   }
3626 *sptr = s;
3627 return x;
3628 }
3629
3630
3631 static int_eximarith_t
3632 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3633 {
3634 uschar *s = *sptr;
3635 int_eximarith_t x = eval_op_and(&s, decimal, error);
3636 if (*error == NULL)
3637   {
3638   while (*s == '^')
3639     {
3640     int_eximarith_t y;
3641     s++;
3642     y = eval_op_and(&s, decimal, error);
3643     if (*error != NULL) break;
3644     x ^= y;
3645     }
3646   }
3647 *sptr = s;
3648 return x;
3649 }
3650
3651
3652 static int_eximarith_t
3653 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3654 {
3655 uschar *s = *sptr;
3656 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3657 if (*error == NULL)
3658   {
3659   while (*s == '|')
3660     {
3661     int_eximarith_t y;
3662     s++;
3663     y = eval_op_xor(&s, decimal, error);
3664     if (*error != NULL) break;
3665     x |= y;
3666     }
3667   }
3668 *sptr = s;
3669 return x;
3670 }
3671
3672
3673
3674 /*************************************************
3675 *                 Expand string                  *
3676 *************************************************/
3677
3678 /* Returns either an unchanged string, or the expanded string in stacking pool
3679 store. Interpreted sequences are:
3680
3681    \...                    normal escaping rules
3682    $name                   substitutes the variable
3683    ${name}                 ditto
3684    ${op:string}            operates on the expanded string value
3685    ${item{arg1}{arg2}...}  expands the args and then does the business
3686                              some literal args are not enclosed in {}
3687
3688 There are now far too many operators and item types to make it worth listing
3689 them here in detail any more.
3690
3691 We use an internal routine recursively to handle embedded substrings. The
3692 external function follows. The yield is NULL if the expansion failed, and there
3693 are two cases: if something collapsed syntactically, or if "fail" was given
3694 as the action on a lookup failure. These can be distinguised by looking at the
3695 variable expand_string_forcedfail, which is TRUE in the latter case.
3696
3697 The skipping flag is set true when expanding a substring that isn't actually
3698 going to be used (after "if" or "lookup") and it prevents lookups from
3699 happening lower down.
3700
3701 Store usage: At start, a store block of the length of the input plus 64
3702 is obtained. This is expanded as necessary by string_cat(), which might have to
3703 get a new block, or might be able to expand the original. At the end of the
3704 function we can release any store above that portion of the yield block that
3705 was actually used. In many cases this will be optimal.
3706
3707 However: if the first item in the expansion is a variable name or header name,
3708 we reset the store before processing it; if the result is in fresh store, we
3709 use that without copying. This is helpful for expanding strings like
3710 $message_headers which can get very long.
3711
3712 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3713 since resetting the store at the end of the expansion will free store that was
3714 allocated by the plugin code as well as the slop after the expanded string. So
3715 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3716 and, given the acl condition, ${if }. This is an unfortunate consequence of
3717 string expansion becoming too powerful.
3718
3719 Arguments:
3720   string         the string to be expanded
3721   ket_ends       true if expansion is to stop at }
3722   left           if not NULL, a pointer to the first character after the
3723                  expansion is placed here (typically used with ket_ends)
3724   skipping       TRUE for recursive calls when the value isn't actually going
3725                  to be used (to allow for optimisation)
3726   honour_dollar  TRUE if $ is to be expanded,
3727                  FALSE if it's just another character
3728   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3729                  the store.
3730
3731 Returns:         NULL if expansion fails:
3732                    expand_string_forcedfail is set TRUE if failure was forced
3733                    expand_string_message contains a textual error message
3734                  a pointer to the expanded string on success
3735 */
3736
3737 static uschar *
3738 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
3739   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3740 {
3741 int ptr = 0;
3742 int size = Ustrlen(string)+ 64;
3743 int item_type;
3744 uschar *yield = store_get(size);
3745 uschar *s = string;
3746 uschar *save_expand_nstring[EXPAND_MAXN+1];
3747 int save_expand_nlength[EXPAND_MAXN+1];
3748 BOOL resetok = TRUE;
3749
3750 expand_string_forcedfail = FALSE;
3751 expand_string_message = US"";
3752
3753 while (*s != 0)
3754   {
3755   uschar *value;
3756   uschar name[256];
3757
3758   /* \ escapes the next character, which must exist, or else
3759   the expansion fails. There's a special escape, \N, which causes
3760   copying of the subject verbatim up to the next \N. Otherwise,
3761   the escapes are the standard set. */
3762
3763   if (*s == '\\')
3764     {
3765     if (s[1] == 0)
3766       {
3767       expand_string_message = US"\\ at end of string";
3768       goto EXPAND_FAILED;
3769       }
3770
3771     if (s[1] == 'N')
3772       {
3773       uschar *t = s + 2;
3774       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3775       yield = string_cat(yield, &size, &ptr, t, s - t);
3776       if (*s != 0) s += 2;
3777       }
3778
3779     else
3780       {
3781       uschar ch[1];
3782       ch[0] = string_interpret_escape(&s);
3783       s++;
3784       yield = string_cat(yield, &size, &ptr, ch, 1);
3785       }
3786
3787     continue;
3788     }
3789
3790   /*{*/
3791   /* Anything other than $ is just copied verbatim, unless we are
3792   looking for a terminating } character. */
3793
3794   /*{*/
3795   if (ket_ends && *s == '}') break;
3796
3797   if (*s != '$' || !honour_dollar)
3798     {
3799     yield = string_cat(yield, &size, &ptr, s++, 1);
3800     continue;
3801     }
3802
3803   /* No { after the $ - must be a plain name or a number for string
3804   match variable. There has to be a fudge for variables that are the
3805   names of header fields preceded by "$header_" because header field
3806   names can contain any printing characters except space and colon.
3807   For those that don't like typing this much, "$h_" is a synonym for
3808   "$header_". A non-existent header yields a NULL value; nothing is
3809   inserted. */  /*}*/
3810
3811   if (isalpha((*(++s))))
3812     {
3813     int len;
3814     int newsize = 0;
3815
3816     s = read_name(name, sizeof(name), s, US"_");
3817
3818     /* If this is the first thing to be expanded, release the pre-allocated
3819     buffer. */
3820
3821     if (ptr == 0 && yield != NULL)
3822       {
3823       if (resetok) store_reset(yield);
3824       yield = NULL;
3825       size = 0;
3826       }
3827
3828     /* Header */
3829
3830     if (Ustrncmp(name, "h_", 2) == 0 ||
3831         Ustrncmp(name, "rh_", 3) == 0 ||
3832         Ustrncmp(name, "bh_", 3) == 0 ||
3833         Ustrncmp(name, "header_", 7) == 0 ||
3834         Ustrncmp(name, "rheader_", 8) == 0 ||
3835         Ustrncmp(name, "bheader_", 8) == 0)
3836       {
3837       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3838       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3839       s = read_header_name(name, sizeof(name), s);
3840       value = find_header(name, FALSE, &newsize, want_raw, charset);
3841
3842       /* If we didn't find the header, and the header contains a closing brace
3843       character, this may be a user error where the terminating colon
3844       has been omitted. Set a flag to adjust the error message in this case.
3845       But there is no error here - nothing gets inserted. */
3846
3847       if (value == NULL)
3848         {
3849         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3850         continue;
3851         }
3852       }
3853
3854     /* Variable */
3855
3856     else
3857       {
3858       value = find_variable(name, FALSE, skipping, &newsize);
3859       if (value == NULL)
3860         {
3861         expand_string_message =
3862           string_sprintf("unknown variable name \"%s\"", name);
3863           check_variable_error_message(name);
3864         goto EXPAND_FAILED;
3865         }
3866       }
3867
3868     /* If the data is known to be in a new buffer, newsize will be set to the
3869     size of that buffer. If this is the first thing in an expansion string,
3870     yield will be NULL; just point it at the new store instead of copying. Many
3871     expansion strings contain just one reference, so this is a useful
3872     optimization, especially for humungous headers. */
3873
3874     len = Ustrlen(value);
3875     if (yield == NULL && newsize != 0)
3876       {
3877       yield = value;
3878       size = newsize;
3879       ptr = len;
3880       }
3881     else yield = string_cat(yield, &size, &ptr, value, len);
3882
3883     continue;
3884     }
3885
3886   if (isdigit(*s))
3887     {
3888     int n;
3889     s = read_number(&n, s);
3890     if (n >= 0 && n <= expand_nmax)
3891       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3892         expand_nlength[n]);
3893     continue;
3894     }
3895
3896   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
3897
3898   if (*s != '{')                                                        /*}*/
3899     {
3900     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
3901     goto EXPAND_FAILED;
3902     }
3903
3904   /* After { there can be various things, but they all start with
3905   an initial word, except for a number for a string match variable. */
3906
3907   if (isdigit((*(++s))))
3908     {
3909     int n;
3910     s = read_number(&n, s);             /*{*/
3911     if (*s++ != '}')
3912       {                                 /*{*/
3913       expand_string_message = US"} expected after number";
3914       goto EXPAND_FAILED;
3915       }
3916     if (n >= 0 && n <= expand_nmax)
3917       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3918         expand_nlength[n]);
3919     continue;
3920     }
3921
3922   if (!isalpha(*s))
3923     {
3924     expand_string_message = US"letter or digit expected after ${";      /*}*/
3925     goto EXPAND_FAILED;
3926     }
3927
3928   /* Allow "-" in names to cater for substrings with negative
3929   arguments. Since we are checking for known names after { this is
3930   OK. */
3931
3932   s = read_name(name, sizeof(name), s, US"_-");
3933   item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
3934
3935   switch(item_type)
3936     {
3937     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
3938     If the ACL returns accept or reject we return content set by "message ="
3939     There is currently no limit on recursion; this would have us call
3940     acl_check_internal() directly and get a current level from somewhere.
3941     See also the acl expansion condition ECOND_ACL and the traditional
3942     acl modifier ACLC_ACL.
3943     Assume that the function has side-effects on the store that must be preserved.
3944     */
3945
3946     case EITEM_ACL:
3947       /* ${acl {name} {arg1}{arg2}...} */
3948       {
3949       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
3950       uschar *user_msg;
3951
3952       switch(read_subs(sub, 10, 1, &s, skipping, TRUE, US"acl", &resetok))
3953         {
3954         case 1: goto EXPAND_FAILED_CURLY;
3955         case 2:
3956         case 3: goto EXPAND_FAILED;
3957         }
3958       if (skipping) continue;
3959
3960       resetok = FALSE;
3961       switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
3962         {
3963         case OK:
3964         case FAIL:
3965           DEBUG(D_expand)
3966             debug_printf("acl expansion yield: %s\n", user_msg);
3967           if (user_msg)
3968             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
3969           continue;
3970
3971         case DEFER:
3972           expand_string_forcedfail = TRUE;
3973         default:
3974           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
3975           goto EXPAND_FAILED;
3976         }
3977       }
3978
3979     /* Handle conditionals - preserve the values of the numerical expansion
3980     variables in case they get changed by a regular expression match in the
3981     condition. If not, they retain their external settings. At the end
3982     of this "if" section, they get restored to their previous values. */
3983
3984     case EITEM_IF:
3985       {
3986       BOOL cond = FALSE;
3987       uschar *next_s;
3988       int save_expand_nmax =
3989         save_expand_strings(save_expand_nstring, save_expand_nlength);
3990
3991       while (isspace(*s)) s++;
3992       next_s = eval_condition(s, &resetok, skipping? NULL : &cond);
3993       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
3994
3995       DEBUG(D_expand)
3996         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
3997           cond? "true" : "false");
3998
3999       s = next_s;
4000
4001       /* The handling of "yes" and "no" result strings is now in a separate
4002       function that is also used by ${lookup} and ${extract} and ${run}. */
4003
4004       switch(process_yesno(
4005                skipping,                     /* were previously skipping */
4006                cond,                         /* success/failure indicator */
4007                lookup_value,                 /* value to reset for string2 */
4008                &s,                           /* input pointer */
4009                &yield,                       /* output pointer */
4010                &size,                        /* output size */
4011                &ptr,                         /* output current point */
4012                US"if",                       /* condition type */
4013                &resetok))
4014         {
4015         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4016         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4017         }
4018
4019       /* Restore external setting of expansion variables for continuation
4020       at this level. */
4021
4022       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4023         save_expand_nlength);
4024       continue;
4025       }
4026
4027     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4028     expanding an internal string that isn't actually going to be used. All we
4029     need to do is check the syntax, so don't do a lookup at all. Preserve the
4030     values of the numerical expansion variables in case they get changed by a
4031     partial lookup. If not, they retain their external settings. At the end
4032     of this "lookup" section, they get restored to their previous values. */
4033
4034     case EITEM_LOOKUP:
4035       {
4036       int stype, partial, affixlen, starflags;
4037       int expand_setup = 0;
4038       int nameptr = 0;
4039       uschar *key, *filename, *affix;
4040       uschar *save_lookup_value = lookup_value;
4041       int save_expand_nmax =
4042         save_expand_strings(save_expand_nstring, save_expand_nlength);
4043
4044       if ((expand_forbid & RDO_LOOKUP) != 0)
4045         {
4046         expand_string_message = US"lookup expansions are not permitted";
4047         goto EXPAND_FAILED;
4048         }
4049
4050       /* Get the key we are to look up for single-key+file style lookups.
4051       Otherwise set the key NULL pro-tem. */
4052
4053       while (isspace(*s)) s++;
4054       if (*s == '{')                                    /*}*/
4055         {
4056         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4057         if (key == NULL) goto EXPAND_FAILED;            /*{*/
4058         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4059         while (isspace(*s)) s++;
4060         }
4061       else key = NULL;
4062
4063       /* Find out the type of database */
4064
4065       if (!isalpha(*s))
4066         {
4067         expand_string_message = US"missing lookup type";
4068         goto EXPAND_FAILED;
4069         }
4070
4071       /* The type is a string that may contain special characters of various
4072       kinds. Allow everything except space or { to appear; the actual content
4073       is checked by search_findtype_partial. */         /*}*/
4074
4075       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4076         {
4077         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4078         s++;
4079         }
4080       name[nameptr] = 0;
4081       while (isspace(*s)) s++;
4082
4083       /* Now check for the individual search type and any partial or default
4084       options. Only those types that are actually in the binary are valid. */
4085
4086       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4087         &starflags);
4088       if (stype < 0)
4089         {
4090         expand_string_message = search_error_message;
4091         goto EXPAND_FAILED;
4092         }
4093
4094       /* Check that a key was provided for those lookup types that need it,
4095       and was not supplied for those that use the query style. */
4096
4097       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4098         {
4099         if (key == NULL)
4100           {
4101           expand_string_message = string_sprintf("missing {key} for single-"
4102             "key \"%s\" lookup", name);
4103           goto EXPAND_FAILED;
4104           }
4105         }
4106       else
4107         {
4108         if (key != NULL)
4109           {
4110           expand_string_message = string_sprintf("a single key was given for "
4111             "lookup type \"%s\", which is not a single-key lookup type", name);
4112           goto EXPAND_FAILED;
4113           }
4114         }
4115
4116       /* Get the next string in brackets and expand it. It is the file name for
4117       single-key+file lookups, and the whole query otherwise. In the case of
4118       queries that also require a file name (e.g. sqlite), the file name comes
4119       first. */
4120
4121       if (*s != '{') goto EXPAND_FAILED_CURLY;
4122       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4123       if (filename == NULL) goto EXPAND_FAILED;
4124       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4125       while (isspace(*s)) s++;
4126
4127       /* If this isn't a single-key+file lookup, re-arrange the variables
4128       to be appropriate for the search_ functions. For query-style lookups,
4129       there is just a "key", and no file name. For the special query-style +
4130       file types, the query (i.e. "key") starts with a file name. */
4131
4132       if (key == NULL)
4133         {
4134         while (isspace(*filename)) filename++;
4135         key = filename;
4136
4137         if (mac_islookup(stype, lookup_querystyle))
4138           {
4139           filename = NULL;
4140           }
4141         else
4142           {
4143           if (*filename != '/')
4144             {
4145             expand_string_message = string_sprintf(
4146               "absolute file name expected for \"%s\" lookup", name);
4147             goto EXPAND_FAILED;
4148             }
4149           while (*key != 0 && !isspace(*key)) key++;
4150           if (*key != 0) *key++ = 0;
4151           }
4152         }
4153
4154       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4155       the entry was not found. Note that there is no search_close() function.
4156       Files are left open in case of re-use. At suitable places in higher logic,
4157       search_tidyup() is called to tidy all open files. This can save opening
4158       the same file several times. However, files may also get closed when
4159       others are opened, if too many are open at once. The rule is that a
4160       handle should not be used after a second search_open().
4161
4162       Request that a partial search sets up $1 and maybe $2 by passing
4163       expand_setup containing zero. If its value changes, reset expand_nmax,
4164       since new variables will have been set. Note that at the end of this
4165       "lookup" section, the old numeric variables are restored. */
4166
4167       if (skipping)
4168         lookup_value = NULL;
4169       else
4170         {
4171         void *handle = search_open(filename, stype, 0, NULL, NULL);
4172         if (handle == NULL)
4173           {
4174           expand_string_message = search_error_message;
4175           goto EXPAND_FAILED;
4176           }
4177         lookup_value = search_find(handle, filename, key, partial, affix,
4178           affixlen, starflags, &expand_setup);
4179         if (search_find_defer)
4180           {
4181           expand_string_message =
4182             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4183               string_printing2(key, FALSE), search_error_message);
4184           goto EXPAND_FAILED;
4185           }
4186         if (expand_setup > 0) expand_nmax = expand_setup;
4187         }
4188
4189       /* The handling of "yes" and "no" result strings is now in a separate
4190       function that is also used by ${if} and ${extract}. */
4191
4192       switch(process_yesno(
4193                skipping,                     /* were previously skipping */
4194                lookup_value != NULL,         /* success/failure indicator */
4195                save_lookup_value,            /* value to reset for string2 */
4196                &s,                           /* input pointer */
4197                &yield,                       /* output pointer */
4198                &size,                        /* output size */
4199                &ptr,                         /* output current point */
4200                US"lookup",                   /* condition type */
4201                &resetok))
4202         {
4203         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4204         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4205         }
4206
4207       /* Restore external setting of expansion variables for carrying on
4208       at this level, and continue. */
4209
4210       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4211         save_expand_nlength);
4212       continue;
4213       }
4214
4215     /* If Perl support is configured, handle calling embedded perl subroutines,
4216     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4217     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4218     arguments (defined below). */
4219
4220     #define EXIM_PERL_MAX_ARGS 8
4221
4222     case EITEM_PERL:
4223     #ifndef EXIM_PERL
4224     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4225       "is not included in this binary";
4226     goto EXPAND_FAILED;
4227
4228     #else   /* EXIM_PERL */
4229       {
4230       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4231       uschar *new_yield;
4232
4233       if ((expand_forbid & RDO_PERL) != 0)
4234         {
4235         expand_string_message = US"Perl calls are not permitted";
4236         goto EXPAND_FAILED;
4237         }
4238
4239       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4240            US"perl", &resetok))
4241         {
4242         case 1: goto EXPAND_FAILED_CURLY;
4243         case 2:
4244         case 3: goto EXPAND_FAILED;
4245         }
4246
4247       /* If skipping, we don't actually do anything */
4248
4249       if (skipping) continue;
4250
4251       /* Start the interpreter if necessary */
4252
4253       if (!opt_perl_started)
4254         {
4255         uschar *initerror;
4256         if (opt_perl_startup == NULL)
4257           {
4258           expand_string_message = US"A setting of perl_startup is needed when "
4259             "using the Perl interpreter";
4260           goto EXPAND_FAILED;
4261           }
4262         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4263         initerror = init_perl(opt_perl_startup);
4264         if (initerror != NULL)
4265           {
4266           expand_string_message =
4267             string_sprintf("error in perl_startup code: %s\n", initerror);
4268           goto EXPAND_FAILED;
4269           }
4270         opt_perl_started = TRUE;
4271         }
4272
4273       /* Call the function */
4274
4275       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4276       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4277         sub_arg[0], sub_arg + 1);
4278
4279       /* NULL yield indicates failure; if the message pointer has been set to
4280       NULL, the yield was undef, indicating a forced failure. Otherwise the
4281       message will indicate some kind of Perl error. */
4282
4283       if (new_yield == NULL)
4284         {
4285         if (expand_string_message == NULL)
4286           {
4287           expand_string_message =
4288             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4289               "failure", sub_arg[0]);
4290           expand_string_forcedfail = TRUE;
4291           }
4292         goto EXPAND_FAILED;
4293         }
4294
4295       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4296       set during a callback from Perl. */
4297
4298       expand_string_forcedfail = FALSE;
4299       yield = new_yield;
4300       continue;
4301       }
4302     #endif /* EXIM_PERL */
4303
4304     /* Transform email address to "prvs" scheme to use
4305        as BATV-signed return path */
4306
4307     case EITEM_PRVS:
4308       {
4309       uschar *sub_arg[3];
4310       uschar *p,*domain;
4311
4312       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4313         {
4314         case 1: goto EXPAND_FAILED_CURLY;
4315         case 2:
4316         case 3: goto EXPAND_FAILED;
4317         }
4318
4319       /* If skipping, we don't actually do anything */
4320       if (skipping) continue;
4321
4322       /* sub_arg[0] is the address */
4323       domain = Ustrrchr(sub_arg[0],'@');
4324       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4325         {
4326         expand_string_message = US"prvs first argument must be a qualified email address";
4327         goto EXPAND_FAILED;
4328         }
4329
4330       /* Calculate the hash. The second argument must be a single-digit
4331       key number, or unset. */
4332
4333       if (sub_arg[2] != NULL &&
4334           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4335         {
4336         expand_string_message = US"prvs second argument must be a single digit";
4337         goto EXPAND_FAILED;
4338         }
4339
4340       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4341       if (p == NULL)
4342         {
4343         expand_string_message = US"prvs hmac-sha1 conversion failed";
4344         goto EXPAND_FAILED;
4345         }
4346
4347       /* Now separate the domain from the local part */
4348       *domain++ = '\0';
4349
4350       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4351       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4352       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4353       string_cat(yield,&size,&ptr,p,6);
4354       string_cat(yield,&size,&ptr,US"=",1);
4355       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4356       string_cat(yield,&size,&ptr,US"@",1);
4357       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4358
4359       continue;
4360       }
4361
4362     /* Check a prvs-encoded address for validity */
4363
4364     case EITEM_PRVSCHECK:
4365       {
4366       uschar *sub_arg[3];
4367       int mysize = 0, myptr = 0;
4368       const pcre *re;
4369       uschar *p;
4370
4371       /* TF: Ugliness: We want to expand parameter 1 first, then set
4372          up expansion variables that are used in the expansion of
4373          parameter 2. So we clone the string for the first
4374          expansion, where we only expand parameter 1.
4375
4376          PH: Actually, that isn't necessary. The read_subs() function is
4377          designed to work this way for the ${if and ${lookup expansions. I've
4378          tidied the code.
4379       */
4380
4381       /* Reset expansion variables */
4382       prvscheck_result = NULL;
4383       prvscheck_address = NULL;
4384       prvscheck_keynum = NULL;
4385
4386       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4387         {
4388         case 1: goto EXPAND_FAILED_CURLY;
4389         case 2:
4390         case 3: goto EXPAND_FAILED;
4391         }
4392
4393       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4394                               TRUE,FALSE);
4395
4396       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4397         {
4398         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4399         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4400         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4401         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4402         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4403
4404         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4405         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4406         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4407         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4408         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4409
4410         /* Set up expansion variables */
4411         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4412         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4413         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4414         prvscheck_address[myptr] = '\0';
4415         prvscheck_keynum = string_copy(key_num);
4416
4417         /* Now expand the second argument */
4418         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4419           {
4420           case 1: goto EXPAND_FAILED_CURLY;
4421           case 2:
4422           case 3: goto EXPAND_FAILED;
4423           }
4424
4425         /* Now we have the key and can check the address. */
4426
4427         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4428           daystamp);
4429
4430         if (p == NULL)
4431           {
4432           expand_string_message = US"hmac-sha1 conversion failed";
4433           goto EXPAND_FAILED;
4434           }
4435
4436         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4437         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4438
4439         if (Ustrcmp(p,hash) == 0)
4440           {
4441           /* Success, valid BATV address. Now check the expiry date. */
4442           uschar *now = prvs_daystamp(0);
4443           unsigned int inow = 0,iexpire = 1;
4444
4445           (void)sscanf(CS now,"%u",&inow);
4446           (void)sscanf(CS daystamp,"%u",&iexpire);
4447
4448           /* When "iexpire" is < 7, a "flip" has occured.
4449              Adjust "inow" accordingly. */
4450           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4451
4452           if (iexpire >= inow)
4453             {
4454             prvscheck_result = US"1";
4455             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4456             }
4457             else
4458             {
4459             prvscheck_result = NULL;
4460             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4461             }
4462           }
4463         else
4464           {
4465           prvscheck_result = NULL;
4466           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4467           }
4468
4469         /* Now expand the final argument. We leave this till now so that
4470         it can include $prvscheck_result. */
4471
4472         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4473           {
4474           case 1: goto EXPAND_FAILED_CURLY;
4475           case 2:
4476           case 3: goto EXPAND_FAILED;
4477           }
4478
4479         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4480           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4481         else
4482           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4483
4484         /* Reset the "internal" variables afterwards, because they are in
4485         dynamic store that will be reclaimed if the expansion succeeded. */
4486
4487         prvscheck_address = NULL;
4488         prvscheck_keynum = NULL;
4489         }
4490       else
4491         {
4492         /* Does not look like a prvs encoded address, return the empty string.
4493            We need to make sure all subs are expanded first, so as to skip over
4494            the entire item. */
4495
4496         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4497           {
4498           case 1: goto EXPAND_FAILED_CURLY;
4499           case 2:
4500           case 3: goto EXPAND_FAILED;
4501           }
4502         }
4503
4504       continue;
4505       }
4506
4507     /* Handle "readfile" to insert an entire file */
4508
4509     case EITEM_READFILE:
4510       {
4511       FILE *f;
4512       uschar *sub_arg[2];
4513
4514       if ((expand_forbid & RDO_READFILE) != 0)
4515         {
4516         expand_string_message = US"file insertions are not permitted";
4517         goto EXPAND_FAILED;
4518         }
4519
4520       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4521         {
4522         case 1: goto EXPAND_FAILED_CURLY;
4523         case 2:
4524         case 3: goto EXPAND_FAILED;
4525         }
4526
4527       /* If skipping, we don't actually do anything */
4528
4529       if (skipping) continue;
4530
4531       /* Open the file and read it */
4532
4533       f = Ufopen(sub_arg[0], "rb");
4534       if (f == NULL)
4535         {
4536         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4537         goto EXPAND_FAILED;
4538         }
4539
4540       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4541       (void)fclose(f);
4542       continue;
4543       }
4544
4545     /* Handle "readsocket" to insert data from a Unix domain socket */
4546
4547     case EITEM_READSOCK:
4548       {
4549       int fd;
4550       int timeout = 5;
4551       int save_ptr = ptr;
4552       FILE *f;
4553       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4554       uschar *arg;
4555       uschar *sub_arg[4];
4556
4557       if ((expand_forbid & RDO_READSOCK) != 0)
4558         {
4559         expand_string_message = US"socket insertions are not permitted";
4560         goto EXPAND_FAILED;
4561         }
4562
4563       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4564       because there may be a string for expansion on failure. */
4565
4566       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4567         {
4568         case 1: goto EXPAND_FAILED_CURLY;
4569         case 2:                             /* Won't occur: no end check */
4570         case 3: goto EXPAND_FAILED;
4571         }
4572
4573       /* Sort out timeout, if given */
4574
4575       if (sub_arg[2] != NULL)
4576         {
4577         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4578         if (timeout < 0)
4579           {
4580           expand_string_message = string_sprintf("bad time value %s",
4581             sub_arg[2]);
4582           goto EXPAND_FAILED;
4583           }
4584         }
4585       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4586
4587       /* If skipping, we don't actually do anything. Otherwise, arrange to
4588       connect to either an IP or a Unix socket. */
4589
4590       if (!skipping)
4591         {
4592         /* Handle an IP (internet) domain */
4593
4594         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4595           {
4596           int port;
4597           uschar *server_name = sub_arg[0] + 5;
4598           uschar *port_name = Ustrrchr(server_name, ':');
4599
4600           /* Sort out the port */
4601
4602           if (port_name == NULL)
4603             {
4604             expand_string_message =
4605               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4606             goto EXPAND_FAILED;
4607             }
4608           *port_name++ = 0;           /* Terminate server name */
4609
4610           if (isdigit(*port_name))
4611             {
4612             uschar *end;
4613             port = Ustrtol(port_name, &end, 0);
4614             if (end != port_name + Ustrlen(port_name))
4615               {
4616               expand_string_message =
4617                 string_sprintf("invalid port number %s", port_name);
4618               goto EXPAND_FAILED;
4619               }
4620             }
4621           else
4622             {
4623             struct servent *service_info = getservbyname(CS port_name, "tcp");
4624             if (service_info == NULL)
4625               {
4626               expand_string_message = string_sprintf("unknown port \"%s\"",
4627                 port_name);
4628               goto EXPAND_FAILED;
4629               }
4630             port = ntohs(service_info->s_port);
4631             }
4632
4633           if ((fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4634                   timeout, NULL, &expand_string_message)) < 0)
4635               goto SOCK_FAIL;
4636           }
4637
4638         /* Handle a Unix domain socket */
4639
4640         else
4641           {
4642           int rc;
4643           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4644             {
4645             expand_string_message = string_sprintf("failed to create socket: %s",
4646               strerror(errno));
4647             goto SOCK_FAIL;
4648             }
4649
4650           sockun.sun_family = AF_UNIX;
4651           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4652             sub_arg[0]);
4653
4654           sigalrm_seen = FALSE;
4655           alarm(timeout);
4656           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4657           alarm(0);
4658           if (sigalrm_seen)
4659             {
4660             expand_string_message = US "socket connect timed out";
4661             goto SOCK_FAIL;
4662             }
4663           if (rc < 0)
4664             {
4665             expand_string_message = string_sprintf("failed to connect to socket "
4666               "%s: %s", sub_arg[0], strerror(errno));
4667             goto SOCK_FAIL;
4668             }
4669           }
4670
4671         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4672
4673         /* Allow sequencing of test actions */
4674         if (running_in_test_harness) millisleep(100);
4675
4676         /* Write the request string, if not empty */
4677
4678         if (sub_arg[1][0] != 0)
4679           {
4680           int len = Ustrlen(sub_arg[1]);
4681           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4682             sub_arg[1]);
4683           if (write(fd, sub_arg[1], len) != len)
4684             {
4685             expand_string_message = string_sprintf("request write to socket "
4686               "failed: %s", strerror(errno));
4687             goto SOCK_FAIL;
4688             }
4689           }
4690
4691         /* Shut down the sending side of the socket. This helps some servers to
4692         recognise that it is their turn to do some work. Just in case some
4693         system doesn't have this function, make it conditional. */
4694
4695         #ifdef SHUT_WR
4696         shutdown(fd, SHUT_WR);
4697         #endif
4698
4699         if (running_in_test_harness) millisleep(100);
4700
4701         /* Now we need to read from the socket, under a timeout. The function
4702         that reads a file can be used. */
4703
4704         f = fdopen(fd, "rb");
4705         sigalrm_seen = FALSE;
4706         alarm(timeout);
4707         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4708         alarm(0);
4709         (void)fclose(f);
4710
4711         /* After a timeout, we restore the pointer in the result, that is,
4712         make sure we add nothing from the socket. */
4713
4714         if (sigalrm_seen)
4715           {
4716           ptr = save_ptr;
4717           expand_string_message = US "socket read timed out";
4718           goto SOCK_FAIL;
4719           }
4720         }
4721
4722       /* The whole thing has worked (or we were skipping). If there is a
4723       failure string following, we need to skip it. */
4724
4725       if (*s == '{')
4726         {
4727         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4728           goto EXPAND_FAILED;
4729         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4730         while (isspace(*s)) s++;
4731         }
4732       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4733       continue;
4734
4735       /* Come here on failure to create socket, connect socket, write to the
4736       socket, or timeout on reading. If another substring follows, expand and
4737       use it. Otherwise, those conditions give expand errors. */
4738
4739       SOCK_FAIL:
4740       if (*s != '{') goto EXPAND_FAILED;
4741       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4742       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok);
4743       if (arg == NULL) goto EXPAND_FAILED;
4744       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4745       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4746       while (isspace(*s)) s++;
4747       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4748       continue;
4749       }
4750
4751     /* Handle "run" to execute a program. */
4752
4753     case EITEM_RUN:
4754       {
4755       FILE *f;
4756       uschar *arg;
4757       uschar **argv;
4758       pid_t pid;
4759       int fd_in, fd_out;
4760       int lsize = 0;
4761       int lptr = 0;
4762
4763       if ((expand_forbid & RDO_RUN) != 0)
4764         {
4765         expand_string_message = US"running a command is not permitted";
4766         goto EXPAND_FAILED;
4767         }
4768
4769       while (isspace(*s)) s++;
4770       if (*s != '{') goto EXPAND_FAILED_CURLY;
4771       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4772       if (arg == NULL) goto EXPAND_FAILED;
4773       while (isspace(*s)) s++;
4774       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4775
4776       if (skipping)   /* Just pretend it worked when we're skipping */
4777         {
4778         runrc = 0;
4779         }
4780       else
4781         {
4782         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4783             arg,                                /* raw command */
4784             FALSE,                              /* don't expand the arguments */
4785             0,                                  /* not relevant when... */
4786             NULL,                               /* no transporting address */
4787             US"${run} expansion",               /* for error messages */
4788             &expand_string_message))            /* where to put error message */
4789           {
4790           goto EXPAND_FAILED;
4791           }
4792
4793         /* Create the child process, making it a group leader. */
4794
4795         pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4796
4797         if (pid < 0)
4798           {
4799           expand_string_message =
4800             string_sprintf("couldn't create child process: %s", strerror(errno));
4801           goto EXPAND_FAILED;
4802           }
4803
4804         /* Nothing is written to the standard input. */
4805
4806         (void)close(fd_in);
4807
4808         /* Read the pipe to get the command's output into $value (which is kept
4809         in lookup_value). Read during execution, so that if the output exceeds
4810         the OS pipe buffer limit, we don't block forever. */
4811
4812         f = fdopen(fd_out, "rb");
4813         sigalrm_seen = FALSE;
4814         alarm(60);
4815         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4816         alarm(0);
4817         (void)fclose(f);
4818
4819         /* Wait for the process to finish, applying the timeout, and inspect its
4820         return code for serious disasters. Simple non-zero returns are passed on.
4821         */
4822
4823         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4824           {
4825           if (sigalrm_seen == TRUE || runrc == -256)
4826             {
4827             expand_string_message = string_sprintf("command timed out");
4828             killpg(pid, SIGKILL);       /* Kill the whole process group */
4829             }
4830
4831           else if (runrc == -257)
4832             expand_string_message = string_sprintf("wait() failed: %s",
4833               strerror(errno));
4834
4835           else
4836             expand_string_message = string_sprintf("command killed by signal %d",
4837               -runrc);
4838
4839           goto EXPAND_FAILED;
4840           }
4841         }
4842
4843       /* Process the yes/no strings; $value may be useful in both cases */
4844
4845       switch(process_yesno(
4846                skipping,                     /* were previously skipping */
4847                runrc == 0,                   /* success/failure indicator */
4848                lookup_value,                 /* value to reset for string2 */
4849                &s,                           /* input pointer */
4850                &yield,                       /* output pointer */
4851                &size,                        /* output size */
4852                &ptr,                         /* output current point */
4853                US"run",                      /* condition type */
4854                &resetok))
4855         {
4856         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4857         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4858         }
4859
4860       continue;
4861       }
4862
4863     /* Handle character translation for "tr" */
4864
4865     case EITEM_TR:
4866       {
4867       int oldptr = ptr;
4868       int o2m;
4869       uschar *sub[3];
4870
4871       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
4872         {
4873         case 1: goto EXPAND_FAILED_CURLY;
4874         case 2:
4875         case 3: goto EXPAND_FAILED;
4876         }
4877
4878       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4879       o2m = Ustrlen(sub[2]) - 1;
4880
4881       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4882         {
4883         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4884         if (m != NULL)
4885           {
4886           int o = m - sub[1];
4887           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4888           }
4889         }
4890
4891       continue;
4892       }
4893
4894     /* Handle "hash", "length", "nhash", and "substr" when they are given with
4895     expanded arguments. */
4896
4897     case EITEM_HASH:
4898     case EITEM_LENGTH:
4899     case EITEM_NHASH:
4900     case EITEM_SUBSTR:
4901       {
4902       int i;
4903       int len;
4904       uschar *ret;
4905       int val[2] = { 0, -1 };
4906       uschar *sub[3];
4907
4908       /* "length" takes only 2 arguments whereas the others take 2 or 3.
4909       Ensure that sub[2] is set in the ${length } case. */
4910
4911       sub[2] = NULL;
4912       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
4913              TRUE, name, &resetok))
4914         {
4915         case 1: goto EXPAND_FAILED_CURLY;
4916         case 2:
4917         case 3: goto EXPAND_FAILED;
4918         }
4919
4920       /* Juggle the arguments if there are only two of them: always move the
4921       string to the last position and make ${length{n}{str}} equivalent to
4922       ${substr{0}{n}{str}}. See the defaults for val[] above. */
4923
4924       if (sub[2] == NULL)
4925         {
4926         sub[2] = sub[1];
4927         sub[1] = NULL;
4928         if (item_type == EITEM_LENGTH)
4929           {
4930           sub[1] = sub[0];
4931           sub[0] = NULL;
4932           }
4933         }
4934
4935       for (i = 0; i < 2; i++)
4936         {
4937         if (sub[i] == NULL) continue;
4938         val[i] = (int)Ustrtol(sub[i], &ret, 10);
4939         if (*ret != 0 || (i != 0 && val[i] < 0))
4940           {
4941           expand_string_message = string_sprintf("\"%s\" is not a%s number "
4942             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
4943           goto EXPAND_FAILED;
4944           }
4945         }
4946
4947       ret =
4948         (item_type == EITEM_HASH)?
4949           compute_hash(sub[2], val[0], val[1], &len) :
4950         (item_type == EITEM_NHASH)?
4951           compute_nhash(sub[2], val[0], val[1], &len) :
4952           extract_substr(sub[2], val[0], val[1], &len);
4953
4954       if (ret == NULL) goto EXPAND_FAILED;
4955       yield = string_cat(yield, &size, &ptr, ret, len);
4956       continue;
4957       }
4958
4959     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
4960     This code originally contributed by Steve Haslam. It currently supports
4961     the use of MD5 and SHA-1 hashes.
4962
4963     We need some workspace that is large enough to handle all the supported
4964     hash types. Use macros to set the sizes rather than be too elaborate. */
4965
4966     #define MAX_HASHLEN      20
4967     #define MAX_HASHBLOCKLEN 64
4968
4969     case EITEM_HMAC:
4970       {
4971       uschar *sub[3];
4972       md5 md5_base;
4973       sha1 sha1_base;
4974       void *use_base;
4975       int type, i;
4976       int hashlen;      /* Number of octets for the hash algorithm's output */
4977       int hashblocklen; /* Number of octets the hash algorithm processes */
4978       uschar *keyptr, *p;
4979       unsigned int keylen;
4980
4981       uschar keyhash[MAX_HASHLEN];
4982       uschar innerhash[MAX_HASHLEN];
4983       uschar finalhash[MAX_HASHLEN];
4984       uschar finalhash_hex[2*MAX_HASHLEN];
4985       uschar innerkey[MAX_HASHBLOCKLEN];
4986       uschar outerkey[MAX_HASHBLOCKLEN];
4987
4988       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
4989         {
4990         case 1: goto EXPAND_FAILED_CURLY;
4991         case 2:
4992         case 3: goto EXPAND_FAILED;
4993         }
4994
4995       if (Ustrcmp(sub[0], "md5") == 0)
4996         {
4997         type = HMAC_MD5;
4998         use_base = &md5_base;
4999         hashlen = 16;
5000         hashblocklen = 64;
5001         }
5002       else if (Ustrcmp(sub[0], "sha1") == 0)
5003         {
5004         type = HMAC_SHA1;
5005         use_base = &sha1_base;
5006         hashlen = 20;
5007         hashblocklen = 64;
5008         }
5009       else
5010         {
5011         expand_string_message =
5012           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5013         goto EXPAND_FAILED;
5014         }
5015
5016       keyptr = sub[1];
5017       keylen = Ustrlen(keyptr);
5018
5019       /* If the key is longer than the hash block length, then hash the key
5020       first */
5021
5022       if (keylen > hashblocklen)
5023         {
5024         chash_start(type, use_base);
5025         chash_end(type, use_base, keyptr, keylen, keyhash);
5026         keyptr = keyhash;
5027         keylen = hashlen;
5028         }
5029
5030       /* Now make the inner and outer key values */
5031
5032       memset(innerkey, 0x36, hashblocklen);
5033       memset(outerkey, 0x5c, hashblocklen);
5034
5035       for (i = 0; i < keylen; i++)
5036         {
5037         innerkey[i] ^= keyptr[i];
5038         outerkey[i] ^= keyptr[i];
5039         }
5040
5041       /* Now do the hashes */
5042
5043       chash_start(type, use_base);
5044       chash_mid(type, use_base, innerkey);
5045       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5046
5047       chash_start(type, use_base);
5048       chash_mid(type, use_base, outerkey);
5049       chash_end(type, use_base, innerhash, hashlen, finalhash);
5050
5051       /* Encode the final hash as a hex string */
5052
5053       p = finalhash_hex;
5054       for (i = 0; i < hashlen; i++)
5055         {
5056         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5057         *p++ = hex_digits[finalhash[i] & 0x0f];
5058         }
5059
5060       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
5061         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
5062
5063       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
5064       }
5065
5066     continue;
5067
5068     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5069     We have to save the numerical variables and restore them afterwards. */
5070
5071     case EITEM_SG:
5072       {
5073       const pcre *re;
5074       int moffset, moffsetextra, slen;
5075       int roffset;
5076       int emptyopt;
5077       const uschar *rerror;
5078       uschar *subject;
5079       uschar *sub[3];
5080       int save_expand_nmax =
5081         save_expand_strings(save_expand_nstring, save_expand_nlength);
5082
5083       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5084         {
5085         case 1: goto EXPAND_FAILED_CURLY;
5086         case 2:
5087         case 3: goto EXPAND_FAILED;
5088         }
5089
5090       /* Compile the regular expression */
5091
5092       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5093         NULL);
5094
5095       if (re == NULL)
5096         {
5097         expand_string_message = string_sprintf("regular expression error in "
5098           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5099         goto EXPAND_FAILED;
5100         }
5101
5102       /* Now run a loop to do the substitutions as often as necessary. It ends
5103       when there are no more matches. Take care over matches of the null string;
5104       do the same thing as Perl does. */
5105
5106       subject = sub[0];
5107       slen = Ustrlen(sub[0]);
5108       moffset = moffsetextra = 0;
5109       emptyopt = 0;
5110
5111       for (;;)
5112         {
5113         int ovector[3*(EXPAND_MAXN+1)];
5114         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5115           PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
5116         int nn;
5117         uschar *insert;
5118
5119         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5120         is not necessarily the end. We want to repeat the match from one
5121         character further along, but leaving the basic offset the same (for
5122         copying below). We can't be at the end of the string - that was checked
5123         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5124         finished; copy the remaining string and end the loop. */
5125
5126         if (n < 0)
5127           {
5128           if (emptyopt != 0)
5129             {
5130             moffsetextra = 1;
5131             emptyopt = 0;
5132             continue;
5133             }
5134           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
5135           break;
5136           }
5137
5138         /* Match - set up for expanding the replacement. */
5139
5140         if (n == 0) n = EXPAND_MAXN + 1;
5141         expand_nmax = 0;
5142         for (nn = 0; nn < n*2; nn += 2)
5143           {
5144           expand_nstring[expand_nmax] = subject + ovector[nn];
5145           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5146           }
5147         expand_nmax--;
5148
5149         /* Copy the characters before the match, plus the expanded insertion. */
5150
5151         yield = string_cat(yield, &size, &ptr, subject + moffset,
5152           ovector[0] - moffset);
5153         insert = expand_string(sub[2]);
5154         if (insert == NULL) goto EXPAND_FAILED;
5155         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
5156
5157         moffset = ovector[1];
5158         moffsetextra = 0;
5159         emptyopt = 0;
5160
5161         /* If we have matched an empty string, first check to see if we are at
5162         the end of the subject. If so, the loop is over. Otherwise, mimic
5163         what Perl's /g options does. This turns out to be rather cunning. First
5164         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5165         string at the same point. If this fails (picked up above) we advance to
5166         the next character. */
5167
5168         if (ovector[0] == ovector[1])
5169           {
5170           if (ovector[0] == slen) break;
5171           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5172           }
5173         }
5174
5175       /* All done - restore numerical variables. */
5176
5177       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5178         save_expand_nlength);
5179       continue;
5180       }
5181
5182     /* Handle keyed and numbered substring extraction. If the first argument
5183     consists entirely of digits, then a numerical extraction is assumed. */
5184
5185     case EITEM_EXTRACT:
5186       {
5187       int i;
5188       int j = 2;
5189       int field_number = 1;
5190       BOOL field_number_set = FALSE;
5191       uschar *save_lookup_value = lookup_value;
5192       uschar *sub[3];
5193       int save_expand_nmax =
5194         save_expand_strings(save_expand_nstring, save_expand_nlength);
5195
5196       /* Read the arguments */
5197
5198       for (i = 0; i < j; i++)
5199         {
5200         while (isspace(*s)) s++;
5201         if (*s == '{')                                          /*}*/
5202           {
5203           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5204           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5205           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5206
5207           /* After removal of leading and trailing white space, the first
5208           argument must not be empty; if it consists entirely of digits
5209           (optionally preceded by a minus sign), this is a numerical
5210           extraction, and we expect 3 arguments. */
5211
5212           if (i == 0)
5213             {
5214             int len;
5215             int x = 0;
5216             uschar *p = sub[0];
5217
5218             while (isspace(*p)) p++;
5219             sub[0] = p;
5220
5221             len = Ustrlen(p);
5222             while (len > 0 && isspace(p[len-1])) len--;
5223             p[len] = 0;
5224
5225             if (*p == 0 && !skipping)
5226               {
5227               expand_string_message = US"first argument of \"extract\" must "
5228                 "not be empty";
5229               goto EXPAND_FAILED;
5230               }
5231
5232             if (*p == '-')
5233               {
5234               field_number = -1;
5235               p++;
5236               }
5237             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5238             if (*p == 0)
5239               {
5240               field_number *= x;
5241               j = 3;               /* Need 3 args */
5242               field_number_set = TRUE;
5243               }
5244             }
5245           }
5246         else goto EXPAND_FAILED_CURLY;
5247         }
5248
5249       /* Extract either the numbered or the keyed substring into $value. If
5250       skipping, just pretend the extraction failed. */
5251
5252       lookup_value = skipping? NULL : field_number_set?
5253         expand_gettokened(field_number, sub[1], sub[2]) :
5254         expand_getkeyed(sub[0], sub[1]);
5255
5256       /* If no string follows, $value gets substituted; otherwise there can
5257       be yes/no strings, as for lookup or if. */
5258
5259       switch(process_yesno(
5260                skipping,                     /* were previously skipping */
5261                lookup_value != NULL,         /* success/failure indicator */
5262                save_lookup_value,            /* value to reset for string2 */
5263                &s,                           /* input pointer */
5264                &yield,                       /* output pointer */
5265                &size,                        /* output size */
5266                &ptr,                         /* output current point */
5267                US"extract",                  /* condition type */
5268                &resetok))
5269         {
5270         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5271         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5272         }
5273
5274       /* All done - restore numerical variables. */
5275
5276       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5277         save_expand_nlength);
5278
5279       continue;
5280       }
5281
5282     /* return the Nth item from a list */
5283
5284     case EITEM_LISTEXTRACT:
5285       {
5286       int i;
5287       int field_number = 1;
5288       uschar *save_lookup_value = lookup_value;
5289       uschar *sub[2];
5290       int save_expand_nmax =
5291         save_expand_strings(save_expand_nstring, save_expand_nlength);
5292
5293       /* Read the field & list arguments */
5294
5295       for (i = 0; i < 2; i++)
5296         {
5297         while (isspace(*s)) s++;
5298         if (*s != '{')                                  /*}*/
5299           goto EXPAND_FAILED_CURLY;
5300
5301         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5302         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5303         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5304
5305         /* After removal of leading and trailing white space, the first
5306         argument must be numeric and nonempty. */
5307
5308         if (i == 0)
5309           {
5310           int len;
5311           int x = 0;
5312           uschar *p = sub[0];
5313
5314           while (isspace(*p)) p++;
5315           sub[0] = p;
5316
5317           len = Ustrlen(p);
5318           while (len > 0 && isspace(p[len-1])) len--;
5319           p[len] = 0;
5320
5321           if (!*p && !skipping)
5322             {
5323             expand_string_message = US"first argument of \"listextract\" must "
5324               "not be empty";
5325             goto EXPAND_FAILED;
5326             }
5327
5328           if (*p == '-')
5329             {
5330             field_number = -1;
5331             p++;
5332             }
5333           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5334           if (*p)
5335             {
5336             expand_string_message = US"first argument of \"listextract\" must "
5337               "be numeric";
5338             goto EXPAND_FAILED;
5339             }
5340           field_number *= x;
5341           }
5342         }
5343
5344       /* Extract the numbered element into $value. If
5345       skipping, just pretend the extraction failed. */
5346
5347       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5348
5349       /* If no string follows, $value gets substituted; otherwise there can
5350       be yes/no strings, as for lookup or if. */
5351
5352       switch(process_yesno(
5353                skipping,                     /* were previously skipping */
5354                lookup_value != NULL,         /* success/failure indicator */
5355                save_lookup_value,            /* value to reset for string2 */
5356                &s,                           /* input pointer */
5357                &yield,                       /* output pointer */
5358                &size,                        /* output size */
5359                &ptr,                         /* output current point */
5360                US"extract",                  /* condition type */
5361                &resetok))
5362         {
5363         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5364         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5365         }
5366
5367       /* All done - restore numerical variables. */
5368
5369       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5370         save_expand_nlength);
5371
5372       continue;
5373       }
5374
5375 #ifdef SUPPORT_TLS
5376     case EITEM_CERTEXTRACT:
5377       {
5378       uschar *save_lookup_value = lookup_value;
5379       uschar *sub[2];
5380       int save_expand_nmax =
5381         save_expand_strings(save_expand_nstring, save_expand_nlength);
5382
5383       /* Read the field argument */
5384       while (isspace(*s)) s++;
5385       if (*s != '{')                                    /*}*/
5386         goto EXPAND_FAILED_CURLY;
5387       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5388       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5389       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5390       /* strip spaces fore & aft */
5391       {
5392       int len;
5393       uschar *p = sub[0];
5394
5395       while (isspace(*p)) p++;
5396       sub[0] = p;
5397
5398       len = Ustrlen(p);
5399       while (len > 0 && isspace(p[len-1])) len--;
5400       p[len] = 0;
5401       }
5402
5403       /* inspect the cert argument */
5404       while (isspace(*s)) s++;
5405       if (*s != '{')                                    /*}*/
5406         goto EXPAND_FAILED_CURLY;
5407       if (*++s != '$')
5408         {
5409         expand_string_message = US"second argument of \"certextract\" must "
5410           "be a certificate variable";
5411         goto EXPAND_FAILED;
5412         }
5413       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5414       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5415       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5416
5417       if (skipping)
5418         lookup_value = NULL;
5419       else
5420         {
5421         lookup_value = expand_getcertele(sub[0], sub[1]);
5422         if (*expand_string_message) goto EXPAND_FAILED;
5423         }
5424       switch(process_yesno(
5425                skipping,                     /* were previously skipping */
5426                lookup_value != NULL,         /* success/failure indicator */
5427                save_lookup_value,            /* value to reset for string2 */
5428                &s,                           /* input pointer */
5429                &yield,                       /* output pointer */
5430                &size,                        /* output size */
5431                &ptr,                         /* output current point */
5432                US"extract",                  /* condition type */
5433                &resetok))
5434         {
5435         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5436         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5437         }
5438
5439       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5440         save_expand_nlength);
5441       continue;
5442       }
5443 #endif  /*SUPPORT_TLS*/
5444
5445     /* Handle list operations */
5446
5447     case EITEM_FILTER:
5448     case EITEM_MAP:
5449     case EITEM_REDUCE:
5450       {
5451       int sep = 0;
5452       int save_ptr = ptr;
5453       uschar outsep[2] = { '\0', '\0' };
5454       uschar *list, *expr, *temp;
5455       uschar *save_iterate_item = iterate_item;
5456       uschar *save_lookup_value = lookup_value;
5457
5458       while (isspace(*s)) s++;
5459       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5460
5461       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5462       if (list == NULL) goto EXPAND_FAILED;
5463       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5464
5465       if (item_type == EITEM_REDUCE)
5466         {
5467         while (isspace(*s)) s++;
5468         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5469         temp = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5470         if (temp == NULL) goto EXPAND_FAILED;
5471         lookup_value = temp;
5472         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5473         }
5474
5475       while (isspace(*s)) s++;
5476       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5477
5478       expr = s;
5479
5480       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5481       if scanning a "false" part). This allows us to find the end of the
5482       condition, because if the list is empty, we won't actually evaluate the
5483       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5484       the normal internal expansion function. */
5485
5486       if (item_type == EITEM_FILTER)
5487         {
5488         temp = eval_condition(expr, &resetok, NULL);
5489         if (temp != NULL) s = temp;
5490         }
5491       else
5492         {
5493         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5494         }
5495
5496       if (temp == NULL)
5497         {
5498         expand_string_message = string_sprintf("%s inside \"%s\" item",
5499           expand_string_message, name);
5500         goto EXPAND_FAILED;
5501         }
5502
5503       while (isspace(*s)) s++;
5504       if (*s++ != '}')
5505         {                                               /*{*/
5506         expand_string_message = string_sprintf("missing } at end of condition "
5507           "or expression inside \"%s\"", name);
5508         goto EXPAND_FAILED;
5509         }
5510
5511       while (isspace(*s)) s++;                          /*{*/
5512       if (*s++ != '}')
5513         {                                               /*{*/
5514         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5515           name);
5516         goto EXPAND_FAILED;
5517         }
5518
5519       /* If we are skipping, we can now just move on to the next item. When
5520       processing for real, we perform the iteration. */
5521
5522       if (skipping) continue;
5523       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5524         {
5525         *outsep = (uschar)sep;      /* Separator as a string */
5526
5527         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5528
5529         if (item_type == EITEM_FILTER)
5530           {
5531           BOOL condresult;
5532           if (eval_condition(expr, &resetok, &condresult) == NULL)
5533             {
5534             iterate_item = save_iterate_item;
5535             lookup_value = save_lookup_value;
5536             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5537               expand_string_message, name);
5538             goto EXPAND_FAILED;
5539             }
5540           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5541             condresult? "true":"false");
5542           if (condresult)
5543             temp = iterate_item;    /* TRUE => include this item */
5544           else
5545             continue;               /* FALSE => skip this item */
5546           }
5547
5548         /* EITEM_MAP and EITEM_REDUCE */
5549
5550         else
5551           {
5552           temp = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5553           if (temp == NULL)
5554             {
5555             iterate_item = save_iterate_item;
5556             expand_string_message = string_sprintf("%s inside \"%s\" item",
5557               expand_string_message, name);
5558             goto EXPAND_FAILED;
5559             }
5560           if (item_type == EITEM_REDUCE)
5561             {
5562             lookup_value = temp;      /* Update the value of $value */
5563             continue;                 /* and continue the iteration */
5564             }
5565           }
5566
5567         /* We reach here for FILTER if the condition is true, always for MAP,
5568         and never for REDUCE. The value in "temp" is to be added to the output
5569         list that is being created, ensuring that any occurrences of the
5570         separator character are doubled. Unless we are dealing with the first
5571         item of the output list, add in a space if the new item begins with the
5572         separator character, or is an empty string. */
5573
5574         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5575           yield = string_cat(yield, &size, &ptr, US" ", 1);
5576
5577         /* Add the string in "temp" to the output list that we are building,
5578         This is done in chunks by searching for the separator character. */
5579
5580         for (;;)
5581           {
5582           size_t seglen = Ustrcspn(temp, outsep);
5583             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5584
5585           /* If we got to the end of the string we output one character
5586           too many; backup and end the loop. Otherwise arrange to double the
5587           separator. */
5588
5589           if (temp[seglen] == '\0') { ptr--; break; }
5590           yield = string_cat(yield, &size, &ptr, outsep, 1);
5591           temp += seglen + 1;
5592           }
5593
5594         /* Output a separator after the string: we will remove the redundant
5595         final one at the end. */
5596
5597         yield = string_cat(yield, &size, &ptr, outsep, 1);
5598         }   /* End of iteration over the list loop */
5599
5600       /* REDUCE has generated no output above: output the final value of
5601       $value. */
5602
5603       if (item_type == EITEM_REDUCE)
5604         {
5605         yield = string_cat(yield, &size, &ptr, lookup_value,
5606           Ustrlen(lookup_value));
5607         lookup_value = save_lookup_value;  /* Restore $value */
5608         }
5609
5610       /* FILTER and MAP generate lists: if they have generated anything, remove
5611       the redundant final separator. Even though an empty item at the end of a
5612       list does not count, this is tidier. */
5613
5614       else if (ptr != save_ptr) ptr--;
5615
5616       /* Restore preserved $item */
5617
5618       iterate_item = save_iterate_item;
5619       continue;
5620       }
5621
5622
5623     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
5624     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5625     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5626     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5627
5628     #define EXPAND_DLFUNC_MAX_ARGS 8
5629
5630     case EITEM_DLFUNC:
5631     #ifndef EXPAND_DLFUNC
5632     expand_string_message = US"\"${dlfunc\" encountered, but this facility "    /*}*/
5633       "is not included in this binary";
5634     goto EXPAND_FAILED;
5635
5636     #else   /* EXPAND_DLFUNC */
5637       {
5638       tree_node *t;
5639       exim_dlfunc_t *func;
5640       uschar *result;
5641       int status, argc;
5642       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5643
5644       if ((expand_forbid & RDO_DLFUNC) != 0)
5645         {
5646         expand_string_message =
5647           US"dynamically-loaded functions are not permitted";
5648         goto EXPAND_FAILED;
5649         }
5650
5651       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5652            TRUE, US"dlfunc", &resetok))
5653         {
5654         case 1: goto EXPAND_FAILED_CURLY;
5655         case 2:
5656         case 3: goto EXPAND_FAILED;
5657         }
5658
5659       /* If skipping, we don't actually do anything */
5660
5661       if (skipping) continue;
5662
5663       /* Look up the dynamically loaded object handle in the tree. If it isn't
5664       found, dlopen() the file and put the handle in the tree for next time. */
5665
5666       t = tree_search(dlobj_anchor, argv[0]);
5667       if (t == NULL)
5668         {
5669         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5670         if (handle == NULL)
5671           {
5672           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5673             argv[0], dlerror());
5674           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5675           goto EXPAND_FAILED;
5676           }
5677         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5678         Ustrcpy(t->name, argv[0]);
5679         t->data.ptr = handle;
5680         (void)tree_insertnode(&dlobj_anchor, t);
5681         }
5682
5683       /* Having obtained the dynamically loaded object handle, look up the
5684       function pointer. */
5685
5686       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5687       if (func == NULL)
5688         {
5689         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5690           "%s", argv[1], argv[0], dlerror());
5691         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5692         goto EXPAND_FAILED;
5693         }
5694
5695       /* Call the function and work out what to do with the result. If it
5696       returns OK, we have a replacement string; if it returns DEFER then
5697       expansion has failed in a non-forced manner; if it returns FAIL then
5698       failure was forced; if it returns ERROR or any other value there's a
5699       problem, so panic slightly. In any case, assume that the function has
5700       side-effects on the store that must be preserved. */
5701
5702       resetok = FALSE;
5703       result = NULL;
5704       for (argc = 0; argv[argc] != NULL; argc++);
5705       status = func(&result, argc - 2, &argv[2]);
5706       if(status == OK)
5707         {
5708         if (result == NULL) result = US"";
5709         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5710         continue;
5711         }
5712       else
5713         {
5714         expand_string_message = result == NULL ? US"(no message)" : result;
5715         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5716           else if(status != FAIL)
5717             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5718               argv[0], argv[1], status, expand_string_message);
5719         goto EXPAND_FAILED;
5720         }
5721       }
5722     #endif /* EXPAND_DLFUNC */
5723     }   /* EITEM_* switch */
5724
5725   /* Control reaches here if the name is not recognized as one of the more
5726   complicated expansion items. Check for the "operator" syntax (name terminated
5727   by a colon). Some of the operators have arguments, separated by _ from the
5728   name. */
5729
5730   if (*s == ':')
5731     {
5732     int c;
5733     uschar *arg = NULL;
5734     uschar *sub;
5735     var_entry *vp = NULL;
5736
5737     /* Owing to an historical mis-design, an underscore may be part of the
5738     operator name, or it may introduce arguments.  We therefore first scan the
5739     table of names that contain underscores. If there is no match, we cut off
5740     the arguments and then scan the main table. */
5741
5742     if ((c = chop_match(name, op_table_underscore,
5743         sizeof(op_table_underscore)/sizeof(uschar *))) < 0)
5744       {
5745       arg = Ustrchr(name, '_');
5746       if (arg != NULL) *arg = 0;
5747       c = chop_match(name, op_table_main,
5748         sizeof(op_table_main)/sizeof(uschar *));
5749       if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
5750       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
5751       }
5752
5753     /* Deal specially with operators that might take a certificate variable
5754     as we do not want to do the usual expansion. For most, expand the string.*/
5755     switch(c)
5756       {
5757 #ifdef SUPPORT_TLS
5758       case EOP_MD5:
5759       case EOP_SHA1:
5760       case EOP_SHA256:
5761         if (s[1] == '$')
5762           {
5763           uschar * s1 = s;
5764           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
5765                   FALSE, &resetok);
5766           if (!sub)       goto EXPAND_FAILED;           /*{*/
5767           if (*s1 != '}') goto EXPAND_FAILED_CURLY;
5768           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
5769             {
5770             s = s1+1;
5771             break;
5772             }
5773           vp = NULL;
5774           }
5775         /*FALLTHROUGH*/
5776 #endif
5777       default:
5778         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5779         if (!sub) goto EXPAND_FAILED;
5780         s++;
5781         break;
5782       }
5783
5784     /* If we are skipping, we don't need to perform the operation at all.
5785     This matters for operations like "mask", because the data may not be
5786     in the correct format when skipping. For example, the expression may test
5787     for the existence of $sender_host_address before trying to mask it. For
5788     other operations, doing them may not fail, but it is a waste of time. */
5789
5790     if (skipping && c >= 0) continue;
5791
5792     /* Otherwise, switch on the operator type */
5793
5794     switch(c)
5795       {
5796       case EOP_BASE62:
5797         {
5798         uschar *t;
5799         unsigned long int n = Ustrtoul(sub, &t, 10);
5800         if (*t != 0)
5801           {
5802           expand_string_message = string_sprintf("argument for base62 "
5803             "operator is \"%s\", which is not a decimal number", sub);
5804           goto EXPAND_FAILED;
5805           }
5806         t = string_base62(n);
5807         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5808         continue;
5809         }
5810
5811       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
5812
5813       case EOP_BASE62D:
5814         {
5815         uschar buf[16];
5816         uschar *tt = sub;
5817         unsigned long int n = 0;
5818         while (*tt != 0)
5819           {
5820           uschar *t = Ustrchr(base62_chars, *tt++);
5821           if (t == NULL)
5822             {
5823             expand_string_message = string_sprintf("argument for base62d "
5824               "operator is \"%s\", which is not a base %d number", sub,
5825               BASE_62);
5826             goto EXPAND_FAILED;
5827             }
5828           n = n * BASE_62 + (t - base62_chars);
5829           }
5830         (void)sprintf(CS buf, "%ld", n);
5831         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
5832         continue;
5833         }
5834
5835       case EOP_EXPAND:
5836         {
5837         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
5838         if (expanded == NULL)
5839           {
5840           expand_string_message =
5841             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
5842               expand_string_message);
5843           goto EXPAND_FAILED;
5844           }
5845         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
5846         continue;
5847         }
5848
5849       case EOP_LC:
5850         {
5851         int count = 0;
5852         uschar *t = sub - 1;
5853         while (*(++t) != 0) { *t = tolower(*t); count++; }
5854         yield = string_cat(yield, &size, &ptr, sub, count);
5855         continue;
5856         }
5857
5858       case EOP_UC:
5859         {
5860         int count = 0;
5861         uschar *t = sub - 1;
5862         while (*(++t) != 0) { *t = toupper(*t); count++; }
5863         yield = string_cat(yield, &size, &ptr, sub, count);
5864         continue;
5865         }
5866
5867       case EOP_MD5:
5868 #ifdef SUPPORT_TLS
5869         if (vp && *(void **)vp->value)
5870           {
5871           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
5872           yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5873           }
5874         else
5875 #endif
5876           {
5877           md5 base;
5878           uschar digest[16];
5879           int j;
5880           char st[33];
5881           md5_start(&base);
5882           md5_end(&base, sub, Ustrlen(sub), digest);
5883           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
5884           yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5885           }
5886         continue;
5887
5888       case EOP_SHA1:
5889 #ifdef SUPPORT_TLS
5890         if (vp && *(void **)vp->value)
5891           {
5892           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
5893           yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5894           }
5895         else
5896 #endif
5897           {
5898           sha1 base;
5899           uschar digest[20];
5900           int j;
5901           char st[41];
5902           sha1_start(&base);
5903           sha1_end(&base, sub, Ustrlen(sub), digest);
5904           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
5905           yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5906           }
5907         continue;
5908
5909       case EOP_SHA256:
5910 #ifdef SUPPORT_TLS
5911         if (vp && *(void **)vp->value)
5912           {
5913           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
5914           yield = string_cat(yield, &size, &ptr, cp, (int)Ustrlen(cp));
5915           }
5916         else
5917 #endif
5918           expand_string_message = US"sha256 only supported for certificates";
5919         continue;
5920
5921       /* Convert hex encoding to base64 encoding */
5922
5923       case EOP_HEX2B64:
5924         {
5925         int c = 0;
5926         int b = -1;
5927         uschar *in = sub;
5928         uschar *out = sub;
5929         uschar *enc;
5930
5931         for (enc = sub; *enc != 0; enc++)
5932           {
5933           if (!isxdigit(*enc))
5934             {
5935             expand_string_message = string_sprintf("\"%s\" is not a hex "
5936               "string", sub);
5937             goto EXPAND_FAILED;
5938             }
5939           c++;
5940           }
5941
5942         if ((c & 1) != 0)
5943           {
5944           expand_string_message = string_sprintf("\"%s\" contains an odd "
5945             "number of characters", sub);
5946           goto EXPAND_FAILED;
5947           }
5948
5949         while ((c = *in++) != 0)
5950           {
5951           if (isdigit(c)) c -= '0';
5952           else c = toupper(c) - 'A' + 10;
5953           if (b == -1)
5954             {
5955             b = c << 4;
5956             }
5957           else
5958             {
5959             *out++ = b | c;
5960             b = -1;
5961             }
5962           }
5963
5964         enc = auth_b64encode(sub, out - sub);
5965         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
5966         continue;
5967         }
5968
5969       /* Convert octets outside 0x21..0x7E to \xXX form */
5970
5971       case EOP_HEXQUOTE:
5972         {
5973         uschar *t = sub - 1;
5974         while (*(++t) != 0)
5975           {
5976           if (*t < 0x21 || 0x7E < *t)
5977             yield = string_cat(yield, &size, &ptr,
5978               string_sprintf("\\x%02x", *t), 4);
5979           else
5980             yield = string_cat(yield, &size, &ptr, t, 1);
5981           }
5982         continue;
5983         }
5984
5985       /* count the number of list elements */
5986
5987       case EOP_LISTCOUNT:
5988         {
5989         int cnt = 0;
5990         int sep = 0;
5991         uschar * cp;
5992         uschar buffer[256];
5993
5994         while (string_nextinlist(&sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
5995         cp = string_sprintf("%d", cnt);
5996         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5997         continue;
5998         }
5999
6000       /* expand a named list given the name */
6001       /* handles nested named lists; requotes as colon-sep list */
6002
6003       case EOP_LISTNAMED:
6004         {
6005         tree_node *t = NULL;
6006         uschar * list;
6007         int sep = 0;
6008         uschar * item;
6009         uschar * suffix = US"";
6010         BOOL needsep = FALSE;
6011         uschar buffer[256];
6012
6013         if (*sub == '+') sub++;
6014         if (arg == NULL)        /* no-argument version */
6015           {
6016           if (!(t = tree_search(addresslist_anchor, sub)) &&
6017               !(t = tree_search(domainlist_anchor,  sub)) &&
6018               !(t = tree_search(hostlist_anchor,    sub)))
6019             t = tree_search(localpartlist_anchor, sub);
6020           }
6021         else switch(*arg)       /* specific list-type version */
6022           {
6023           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6024           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6025           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6026           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6027           default:
6028             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6029             goto EXPAND_FAILED;
6030           }
6031
6032         if(!t)
6033           {
6034           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6035             sub, !arg?""
6036               : *arg=='a'?"address "
6037               : *arg=='d'?"domain "
6038               : *arg=='h'?"host "
6039               : *arg=='l'?"localpart "
6040               : 0);
6041           goto EXPAND_FAILED;
6042           }
6043
6044         list = ((namedlist_block *)(t->data.ptr))->string;
6045
6046         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6047           {
6048           uschar * buf = US" : ";
6049           if (needsep)
6050             yield = string_cat(yield, &size, &ptr, buf, 3);
6051           else
6052             needsep = TRUE;
6053
6054           if (*item == '+')     /* list item is itself a named list */
6055             {
6056             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6057             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6058             }
6059           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6060             {
6061             char * cp;
6062             char tok[3];
6063             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6064             while ((cp= strpbrk((const char *)item, tok)))
6065               {
6066               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
6067               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6068                 {
6069                 yield = string_cat(yield, &size, &ptr, US"::", 2);
6070                 item = (uschar *)cp;
6071                 }
6072               else              /* sep in item; should already be doubled; emit once */
6073                 {
6074                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
6075                 if (*cp == sep) cp++;
6076                 item = (uschar *)cp;
6077                 }
6078               }
6079             }
6080           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
6081           }
6082         continue;
6083         }
6084
6085       /* mask applies a mask to an IP address; for example the result of
6086       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6087
6088       case EOP_MASK:
6089         {
6090         int count;
6091         uschar *endptr;
6092         int binary[4];
6093         int mask, maskoffset;
6094         int type = string_is_ip_address(sub, &maskoffset);
6095         uschar buffer[64];
6096
6097         if (type == 0)
6098           {
6099           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6100            sub);
6101           goto EXPAND_FAILED;
6102           }
6103
6104         if (maskoffset == 0)
6105           {
6106           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6107             sub);
6108           goto EXPAND_FAILED;
6109           }
6110
6111         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6112
6113         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6114           {
6115           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6116             sub);
6117           goto EXPAND_FAILED;
6118           }
6119
6120         /* Convert the address to binary integer(s) and apply the mask */
6121
6122         sub[maskoffset] = 0;
6123         count = host_aton(sub, binary);
6124         host_mask(count, binary, mask);
6125
6126         /* Convert to masked textual format and add to output. */
6127
6128         yield = string_cat(yield, &size, &ptr, buffer,
6129           host_nmtoa(count, binary, mask, buffer, '.'));
6130         continue;
6131         }
6132
6133       case EOP_ADDRESS:
6134       case EOP_LOCAL_PART:
6135       case EOP_DOMAIN:
6136         {
6137         uschar *error;
6138         int start, end, domain;
6139         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6140           FALSE);
6141         if (t != NULL)
6142           {
6143           if (c != EOP_DOMAIN)
6144             {
6145             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6146             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
6147             }
6148           else if (domain != 0)
6149             {
6150             domain += start;
6151             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
6152             }
6153           }
6154         continue;
6155         }
6156
6157       case EOP_ADDRESSES:
6158         {
6159         uschar outsep[2] = { ':', '\0' };
6160         uschar *address, *error;
6161         int save_ptr = ptr;
6162         int start, end, domain;  /* Not really used */
6163
6164         while (isspace(*sub)) sub++;
6165         if (*sub == '>') { *outsep = *++sub; ++sub; }
6166         parse_allow_group = TRUE;
6167
6168         for (;;)
6169           {
6170           uschar *p = parse_find_address_end(sub, FALSE);
6171           uschar saveend = *p;
6172           *p = '\0';
6173           address = parse_extract_address(sub, &error, &start, &end, &domain,
6174             FALSE);
6175           *p = saveend;
6176
6177           /* Add the address to the output list that we are building. This is
6178           done in chunks by searching for the separator character. At the
6179           start, unless we are dealing with the first address of the output
6180           list, add in a space if the new address begins with the separator
6181           character, or is an empty string. */
6182
6183           if (address != NULL)
6184             {
6185             if (ptr != save_ptr && address[0] == *outsep)
6186               yield = string_cat(yield, &size, &ptr, US" ", 1);
6187
6188             for (;;)
6189               {
6190               size_t seglen = Ustrcspn(address, outsep);
6191               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
6192
6193               /* If we got to the end of the string we output one character
6194               too many. */
6195
6196               if (address[seglen] == '\0') { ptr--; break; }
6197               yield = string_cat(yield, &size, &ptr, outsep, 1);
6198               address += seglen + 1;
6199               }
6200
6201             /* Output a separator after the string: we will remove the
6202             redundant final one at the end. */
6203
6204             yield = string_cat(yield, &size, &ptr, outsep, 1);
6205             }
6206
6207           if (saveend == '\0') break;
6208           sub = p + 1;
6209           }
6210
6211         /* If we have generated anything, remove the redundant final
6212         separator. */
6213
6214         if (ptr != save_ptr) ptr--;
6215         parse_allow_group = FALSE;
6216         continue;
6217         }
6218
6219
6220       /* quote puts a string in quotes if it is empty or contains anything
6221       other than alphamerics, underscore, dot, or hyphen.
6222
6223       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6224       be quoted in order to be a valid local part.
6225
6226       In both cases, newlines and carriage returns are converted into \n and \r
6227       respectively */
6228
6229       case EOP_QUOTE:
6230       case EOP_QUOTE_LOCAL_PART:
6231       if (arg == NULL)
6232         {
6233         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6234         uschar *t = sub - 1;
6235
6236         if (c == EOP_QUOTE)
6237           {
6238           while (!needs_quote && *(++t) != 0)
6239             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6240           }
6241         else  /* EOP_QUOTE_LOCAL_PART */
6242           {
6243           while (!needs_quote && *(++t) != 0)
6244             needs_quote = !isalnum(*t) &&
6245               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6246               (*t != '.' || t == sub || t[1] == 0);
6247           }
6248
6249         if (needs_quote)
6250           {
6251           yield = string_cat(yield, &size, &ptr, US"\"", 1);
6252           t = sub - 1;
6253           while (*(++t) != 0)
6254             {
6255             if (*t == '\n')
6256               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
6257             else if (*t == '\r')
6258               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
6259             else
6260               {
6261               if (*t == '\\' || *t == '"')
6262                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
6263               yield = string_cat(yield, &size, &ptr, t, 1);
6264               }
6265             }
6266           yield = string_cat(yield, &size, &ptr, US"\"", 1);
6267           }
6268         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
6269         continue;
6270         }
6271
6272       /* quote_lookuptype does lookup-specific quoting */
6273
6274       else
6275         {
6276         int n;
6277         uschar *opt = Ustrchr(arg, '_');
6278
6279         if (opt != NULL) *opt++ = 0;
6280
6281         n = search_findtype(arg, Ustrlen(arg));
6282         if (n < 0)
6283           {
6284           expand_string_message = search_error_message;
6285           goto EXPAND_FAILED;
6286           }
6287
6288         if (lookup_list[n]->quote != NULL)
6289           sub = (lookup_list[n]->quote)(sub, opt);
6290         else if (opt != NULL) sub = NULL;
6291
6292         if (sub == NULL)
6293           {
6294           expand_string_message = string_sprintf(
6295             "\"%s\" unrecognized after \"${quote_%s\"",
6296             opt, arg);
6297           goto EXPAND_FAILED;
6298           }
6299
6300         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
6301         continue;
6302         }
6303
6304       /* rx quote sticks in \ before any non-alphameric character so that
6305       the insertion works in a regular expression. */
6306
6307       case EOP_RXQUOTE:
6308         {
6309         uschar *t = sub - 1;
6310         while (*(++t) != 0)
6311           {
6312           if (!isalnum(*t))
6313             yield = string_cat(yield, &size, &ptr, US"\\", 1);
6314           yield = string_cat(yield, &size, &ptr, t, 1);
6315           }
6316         continue;
6317         }
6318
6319       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6320       prescribed by the RFC, if there are characters that need to be encoded */
6321
6322       case EOP_RFC2047:
6323         {
6324         uschar buffer[2048];
6325         uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6326           buffer, sizeof(buffer), FALSE);
6327         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
6328         continue;
6329         }
6330
6331       /* RFC 2047 decode */
6332
6333       case EOP_RFC2047D:
6334         {
6335         int len;
6336         uschar *error;
6337         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6338           headers_charset, '?', &len, &error);
6339         if (error != NULL)
6340           {
6341           expand_string_message = error;
6342           goto EXPAND_FAILED;
6343           }
6344         yield = string_cat(yield, &size, &ptr, decoded, len);
6345         continue;
6346         }
6347
6348       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6349       underscores */
6350
6351       case EOP_FROM_UTF8:
6352         {
6353         while (*sub != 0)
6354           {
6355           int c;
6356           uschar buff[4];
6357           GETUTF8INC(c, sub);
6358           if (c > 255) c = '_';
6359           buff[0] = c;
6360           yield = string_cat(yield, &size, &ptr, buff, 1);
6361           }
6362         continue;
6363         }
6364
6365           /* replace illegal UTF-8 sequences by replacement character  */
6366
6367       #define UTF8_REPLACEMENT_CHAR US"?"
6368
6369       case EOP_UTF8CLEAN:
6370         {
6371         int seq_len, index = 0;
6372         int bytes_left = 0;
6373         uschar seq_buff[4];                     /* accumulate utf-8 here */
6374
6375         while (*sub != 0)
6376           {
6377           int complete;
6378           long codepoint;
6379           uschar c;
6380
6381           complete = 0;
6382           c = *sub++;
6383           if (bytes_left)
6384             {
6385             if ((c & 0xc0) != 0x80)
6386               {
6387                     /* wrong continuation byte; invalidate all bytes */
6388               complete = 1; /* error */
6389               }
6390             else
6391               {
6392               codepoint = (codepoint << 6) | (c & 0x3f);
6393               seq_buff[index++] = c;
6394               if (--bytes_left == 0)            /* codepoint complete */
6395                 {
6396                 if(codepoint > 0x10FFFF)        /* is it too large? */
6397                   complete = -1;        /* error */
6398                 else
6399                   {             /* finished; output utf-8 sequence */
6400                   yield = string_cat(yield, &size, &ptr, seq_buff, seq_len);
6401                   index = 0;
6402                   }
6403                 }
6404               }
6405             }
6406           else  /* no bytes left: new sequence */
6407             {
6408             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
6409               {
6410               yield = string_cat(yield, &size, &ptr, &c, 1);
6411               continue;
6412               }
6413             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
6414               {
6415               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
6416                 complete = -1;
6417               else
6418                 {
6419                   bytes_left = 1;
6420                   codepoint = c & 0x1f;
6421                 }
6422               }
6423             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
6424               {
6425               bytes_left = 2;
6426               codepoint = c & 0x0f;
6427               }
6428             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
6429               {
6430               bytes_left = 3;
6431               codepoint = c & 0x07;
6432               }
6433             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
6434               complete = -1;
6435
6436             seq_buff[index++] = c;
6437             seq_len = bytes_left + 1;
6438             }           /* if(bytes_left) */
6439
6440           if (complete != 0)
6441             {
6442             bytes_left = index = 0;
6443             yield = string_cat(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
6444             }
6445           if ((complete == 1) && ((c & 0x80) == 0))
6446             { /* ASCII character follows incomplete sequence */
6447               yield = string_cat(yield, &size, &ptr, &c, 1);
6448             }
6449           }
6450         continue;
6451         }
6452
6453       /* escape turns all non-printing characters into escape sequences. */
6454
6455       case EOP_ESCAPE:
6456         {
6457         uschar *t = string_printing(sub);
6458         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6459         continue;
6460         }
6461
6462       /* Handle numeric expression evaluation */
6463
6464       case EOP_EVAL:
6465       case EOP_EVAL10:
6466         {
6467         uschar *save_sub = sub;
6468         uschar *error = NULL;
6469         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
6470         if (error != NULL)
6471           {
6472           expand_string_message = string_sprintf("error in expression "
6473             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
6474               save_sub);
6475           goto EXPAND_FAILED;
6476           }
6477         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
6478         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6479         continue;
6480         }
6481
6482       /* Handle time period formating */
6483
6484       case EOP_TIME_EVAL:
6485         {
6486         int n = readconf_readtime(sub, 0, FALSE);
6487         if (n < 0)
6488           {
6489           expand_string_message = string_sprintf("string \"%s\" is not an "
6490             "Exim time interval in \"%s\" operator", sub, name);
6491           goto EXPAND_FAILED;
6492           }
6493         sprintf(CS var_buffer, "%d", n);
6494         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6495         continue;
6496         }
6497
6498       case EOP_TIME_INTERVAL:
6499         {
6500         int n;
6501         uschar *t = read_number(&n, sub);
6502         if (*t != 0) /* Not A Number*/
6503           {
6504           expand_string_message = string_sprintf("string \"%s\" is not a "
6505             "positive number in \"%s\" operator", sub, name);
6506           goto EXPAND_FAILED;
6507           }
6508         t = readconf_printtime(n);
6509         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6510         continue;
6511         }
6512
6513       /* Convert string to base64 encoding */
6514
6515       case EOP_STR2B64:
6516         {
6517         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
6518         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
6519         continue;
6520         }
6521
6522       /* strlen returns the length of the string */
6523
6524       case EOP_STRLEN:
6525         {
6526         uschar buff[24];
6527         (void)sprintf(CS buff, "%d", Ustrlen(sub));
6528         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
6529         continue;
6530         }
6531
6532       /* length_n or l_n takes just the first n characters or the whole string,
6533       whichever is the shorter;
6534
6535       substr_m_n, and s_m_n take n characters from offset m; negative m take
6536       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6537       takes the rest, either to the right or to the left.
6538
6539       hash_n or h_n makes a hash of length n from the string, yielding n
6540       characters from the set a-z; hash_n_m makes a hash of length n, but
6541       uses m characters from the set a-zA-Z0-9.
6542
6543       nhash_n returns a single number between 0 and n-1 (in text form), while
6544       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6545       between 0 and n-1 and the second between 0 and m-1. */
6546
6547       case EOP_LENGTH:
6548       case EOP_L:
6549       case EOP_SUBSTR:
6550       case EOP_S:
6551       case EOP_HASH:
6552       case EOP_H:
6553       case EOP_NHASH:
6554       case EOP_NH:
6555         {
6556         int sign = 1;
6557         int value1 = 0;
6558         int value2 = -1;
6559         int *pn;
6560         int len;
6561         uschar *ret;
6562
6563         if (arg == NULL)
6564           {
6565           expand_string_message = string_sprintf("missing values after %s",
6566             name);
6567           goto EXPAND_FAILED;
6568           }
6569
6570         /* "length" has only one argument, effectively being synonymous with
6571         substr_0_n. */
6572
6573         if (c == EOP_LENGTH || c == EOP_L)
6574           {
6575           pn = &value2;
6576           value2 = 0;
6577           }
6578
6579         /* The others have one or two arguments; for "substr" the first may be
6580         negative. The second being negative means "not supplied". */
6581
6582         else
6583           {
6584           pn = &value1;
6585           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6586           }
6587
6588         /* Read up to two numbers, separated by underscores */
6589
6590         ret = arg;
6591         while (*arg != 0)
6592           {
6593           if (arg != ret && *arg == '_' && pn == &value1)
6594             {
6595             pn = &value2;
6596             value2 = 0;
6597             if (arg[1] != 0) arg++;
6598             }
6599           else if (!isdigit(*arg))
6600             {
6601             expand_string_message =
6602               string_sprintf("non-digit after underscore in \"%s\"", name);
6603             goto EXPAND_FAILED;
6604             }
6605           else *pn = (*pn)*10 + *arg++ - '0';
6606           }
6607         value1 *= sign;
6608
6609         /* Perform the required operation */
6610
6611         ret =
6612           (c == EOP_HASH || c == EOP_H)?
6613              compute_hash(sub, value1, value2, &len) :
6614           (c == EOP_NHASH || c == EOP_NH)?
6615              compute_nhash(sub, value1, value2, &len) :
6616              extract_substr(sub, value1, value2, &len);
6617
6618         if (ret == NULL) goto EXPAND_FAILED;
6619         yield = string_cat(yield, &size, &ptr, ret, len);
6620         continue;
6621         }
6622
6623       /* Stat a path */
6624
6625       case EOP_STAT:
6626         {
6627         uschar *s;
6628         uschar smode[12];
6629         uschar **modetable[3];
6630         int i;
6631         mode_t mode;
6632         struct stat st;
6633
6634         if ((expand_forbid & RDO_EXISTS) != 0)
6635           {
6636           expand_string_message = US"Use of the stat() expansion is not permitted";
6637           goto EXPAND_FAILED;
6638           }
6639
6640         if (stat(CS sub, &st) < 0)
6641           {
6642           expand_string_message = string_sprintf("stat(%s) failed: %s",
6643             sub, strerror(errno));
6644           goto EXPAND_FAILED;
6645           }
6646         mode = st.st_mode;
6647         switch (mode & S_IFMT)
6648           {
6649           case S_IFIFO: smode[0] = 'p'; break;
6650           case S_IFCHR: smode[0] = 'c'; break;
6651           case S_IFDIR: smode[0] = 'd'; break;
6652           case S_IFBLK: smode[0] = 'b'; break;
6653           case S_IFREG: smode[0] = '-'; break;
6654           default: smode[0] = '?'; break;
6655           }
6656
6657         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
6658         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
6659         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
6660
6661         for (i = 0; i < 3; i++)
6662           {
6663           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
6664           mode >>= 3;
6665           }
6666
6667         smode[10] = 0;
6668         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
6669           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
6670           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
6671           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
6672           (long)st.st_gid, st.st_size, (long)st.st_atime,
6673           (long)st.st_mtime, (long)st.st_ctime);
6674         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6675         continue;
6676         }
6677
6678       /* vaguely random number less than N */
6679
6680       case EOP_RANDINT:
6681         {
6682         int_eximarith_t max;
6683         uschar *s;
6684
6685         max = expanded_string_integer(sub, TRUE);
6686         if (expand_string_message != NULL)
6687           goto EXPAND_FAILED;
6688         s = string_sprintf("%d", vaguely_random_number((int)max));
6689         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6690         continue;
6691         }
6692
6693       /* Reverse IP, including IPv6 to dotted-nibble */
6694
6695       case EOP_REVERSE_IP:
6696         {
6697         int family, maskptr;
6698         uschar reversed[128];
6699
6700         family = string_is_ip_address(sub, &maskptr);
6701         if (family == 0)
6702           {
6703           expand_string_message = string_sprintf(
6704               "reverse_ip() not given an IP address [%s]", sub);
6705           goto EXPAND_FAILED;
6706           }
6707         invert_address(reversed, sub);
6708         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
6709         continue;
6710         }
6711
6712       /* Unknown operator */
6713
6714       default:
6715       expand_string_message =
6716         string_sprintf("unknown expansion operator \"%s\"", name);
6717       goto EXPAND_FAILED;
6718       }
6719     }
6720
6721   /* Handle a plain name. If this is the first thing in the expansion, release
6722   the pre-allocated buffer. If the result data is known to be in a new buffer,
6723   newsize will be set to the size of that buffer, and we can just point at that
6724   store instead of copying. Many expansion strings contain just one reference,
6725   so this is a useful optimization, especially for humungous headers
6726   ($message_headers). */
6727                                                 /*{*/
6728   if (*s++ == '}')
6729     {
6730     int len;
6731     int newsize = 0;
6732     if (ptr == 0)
6733       {
6734       if (resetok) store_reset(yield);
6735       yield = NULL;
6736       size = 0;
6737       }
6738     value = find_variable(name, FALSE, skipping, &newsize);
6739     if (value == NULL)
6740       {
6741       expand_string_message =
6742         string_sprintf("unknown variable in \"${%s}\"", name);
6743       check_variable_error_message(name);
6744       goto EXPAND_FAILED;
6745       }
6746     len = Ustrlen(value);
6747     if (yield == NULL && newsize != 0)
6748       {
6749       yield = value;
6750       size = newsize;
6751       ptr = len;
6752       }
6753     else yield = string_cat(yield, &size, &ptr, value, len);
6754     continue;
6755     }
6756
6757   /* Else there's something wrong */
6758
6759   expand_string_message =
6760     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
6761     "in a variable reference)", name);
6762   goto EXPAND_FAILED;
6763   }
6764
6765 /* If we hit the end of the string when ket_ends is set, there is a missing
6766 terminating brace. */
6767
6768 if (ket_ends && *s == 0)
6769   {
6770   expand_string_message = malformed_header?
6771     US"missing } at end of string - could be header name not terminated by colon"
6772     :
6773     US"missing } at end of string";
6774   goto EXPAND_FAILED;
6775   }
6776
6777 /* Expansion succeeded; yield may still be NULL here if nothing was actually
6778 added to the string. If so, set up an empty string. Add a terminating zero. If
6779 left != NULL, return a pointer to the terminator. */
6780
6781 if (yield == NULL) yield = store_get(1);
6782 yield[ptr] = 0;
6783 if (left != NULL) *left = s;
6784
6785 /* Any stacking store that was used above the final string is no longer needed.
6786 In many cases the final string will be the first one that was got and so there
6787 will be optimal store usage. */
6788
6789 if (resetok) store_reset(yield + ptr + 1);
6790 else if (resetok_p) *resetok_p = FALSE;
6791
6792 DEBUG(D_expand)
6793   {
6794   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
6795     yield);
6796   if (skipping) debug_printf("skipping: result is not used\n");
6797   }
6798 return yield;
6799
6800 /* This is the failure exit: easiest to program with a goto. We still need
6801 to update the pointer to the terminator, for cases of nested calls with "fail".
6802 */
6803
6804 EXPAND_FAILED_CURLY:
6805 expand_string_message = malformed_header?
6806   US"missing or misplaced { or } - could be header name not terminated by colon"
6807   :
6808   US"missing or misplaced { or }";
6809
6810 /* At one point, Exim reset the store to yield (if yield was not NULL), but
6811 that is a bad idea, because expand_string_message is in dynamic store. */
6812
6813 EXPAND_FAILED:
6814 if (left != NULL) *left = s;
6815 DEBUG(D_expand)
6816   {
6817   debug_printf("failed to expand: %s\n", string);
6818   debug_printf("   error message: %s\n", expand_string_message);
6819   if (expand_string_forcedfail) debug_printf("failure was forced\n");
6820   }
6821 if (resetok_p) *resetok_p = resetok;
6822 return NULL;
6823 }
6824
6825
6826 /* This is the external function call. Do a quick check for any expansion
6827 metacharacters, and if there are none, just return the input string.
6828
6829 Argument: the string to be expanded
6830 Returns:  the expanded string, or NULL if expansion failed; if failure was
6831           due to a lookup deferring, search_find_defer will be TRUE
6832 */
6833
6834 uschar *
6835 expand_string(uschar *string)
6836 {
6837 search_find_defer = FALSE;
6838 malformed_header = FALSE;
6839 return (Ustrpbrk(string, "$\\") == NULL)? string :
6840   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
6841 }
6842
6843
6844
6845 /*************************************************
6846 *              Expand and copy                   *
6847 *************************************************/
6848
6849 /* Now and again we want to expand a string and be sure that the result is in a
6850 new bit of store. This function does that.
6851
6852 Argument: the string to be expanded
6853 Returns:  the expanded string, always in a new bit of store, or NULL
6854 */
6855
6856 uschar *
6857 expand_string_copy(uschar *string)
6858 {
6859 uschar *yield = expand_string(string);
6860 if (yield == string) yield = string_copy(string);
6861 return yield;
6862 }
6863
6864
6865
6866 /*************************************************
6867 *        Expand and interpret as an integer      *
6868 *************************************************/
6869
6870 /* Expand a string, and convert the result into an integer.
6871
6872 Arguments:
6873   string  the string to be expanded
6874   isplus  TRUE if a non-negative number is expected
6875
6876 Returns:  the integer value, or
6877           -1 for an expansion error               ) in both cases, message in
6878           -2 for an integer interpretation error  ) expand_string_message
6879           expand_string_message is set NULL for an OK integer
6880 */
6881
6882 int_eximarith_t
6883 expand_string_integer(uschar *string, BOOL isplus)
6884 {
6885 return expanded_string_integer(expand_string(string), isplus);
6886 }
6887
6888
6889 /*************************************************
6890  *         Interpret string as an integer        *
6891  *************************************************/
6892
6893 /* Convert a string (that has already been expanded) into an integer.
6894
6895 This function is used inside the expansion code.
6896
6897 Arguments:
6898   s       the string to be expanded
6899   isplus  TRUE if a non-negative number is expected
6900
6901 Returns:  the integer value, or
6902           -1 if string is NULL (which implies an expansion error)
6903           -2 for an integer interpretation error
6904           expand_string_message is set NULL for an OK integer
6905 */
6906
6907 static int_eximarith_t
6908 expanded_string_integer(uschar *s, BOOL isplus)
6909 {
6910 int_eximarith_t value;
6911 uschar *msg = US"invalid integer \"%s\"";
6912 uschar *endptr;
6913
6914 /* If expansion failed, expand_string_message will be set. */
6915
6916 if (s == NULL) return -1;
6917
6918 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
6919 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
6920 systems, so we set it zero ourselves. */
6921
6922 errno = 0;
6923 expand_string_message = NULL;               /* Indicates no error */
6924
6925 /* Before Exim 4.64, strings consisting entirely of whitespace compared
6926 equal to 0.  Unfortunately, people actually relied upon that, so preserve
6927 the behaviour explicitly.  Stripping leading whitespace is a harmless
6928 noop change since strtol skips it anyway (provided that there is a number
6929 to find at all). */
6930 if (isspace(*s))
6931   {
6932   while (isspace(*s)) ++s;
6933   if (*s == '\0')
6934     {
6935       DEBUG(D_expand)
6936        debug_printf("treating blank string as number 0\n");
6937       return 0;
6938     }
6939   }
6940
6941 value = strtoll(CS s, CSS &endptr, 10);
6942
6943 if (endptr == s)
6944   {
6945   msg = US"integer expected but \"%s\" found";
6946   }
6947 else if (value < 0 && isplus)
6948   {
6949   msg = US"non-negative integer expected but \"%s\" found";
6950   }
6951 else
6952   {
6953   switch (tolower(*endptr))
6954     {
6955     default:
6956       break;
6957     case 'k':
6958       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
6959       else value *= 1024;
6960       endptr++;
6961       break;
6962     case 'm':
6963       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
6964       else value *= 1024*1024;
6965       endptr++;
6966       break;
6967     case 'g':
6968       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
6969       else value *= 1024*1024*1024;
6970       endptr++;
6971       break;
6972     }
6973   if (errno == ERANGE)
6974     msg = US"absolute value of integer \"%s\" is too large (overflow)";
6975   else
6976     {
6977     while (isspace(*endptr)) endptr++;
6978     if (*endptr == 0) return value;
6979     }
6980   }
6981
6982 expand_string_message = string_sprintf(CS msg, s);
6983 return -2;
6984 }
6985
6986
6987 /*************************************************
6988 **************************************************
6989 *             Stand-alone test program           *
6990 **************************************************
6991 *************************************************/
6992
6993 #ifdef STAND_ALONE
6994
6995
6996 BOOL
6997 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
6998 {
6999 int ovector[3*(EXPAND_MAXN+1)];
7000 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7001   ovector, sizeof(ovector)/sizeof(int));
7002 BOOL yield = n >= 0;
7003 if (n == 0) n = EXPAND_MAXN + 1;
7004 if (yield)
7005   {
7006   int nn;
7007   expand_nmax = (setup < 0)? 0 : setup + 1;
7008   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7009     {
7010     expand_nstring[expand_nmax] = subject + ovector[nn];
7011     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7012     }
7013   expand_nmax--;
7014   }
7015 return yield;
7016 }
7017
7018
7019 int main(int argc, uschar **argv)
7020 {
7021 int i;
7022 uschar buffer[1024];
7023
7024 debug_selector = D_v;
7025 debug_file = stderr;
7026 debug_fd = fileno(debug_file);
7027 big_buffer = malloc(big_buffer_size);
7028
7029 for (i = 1; i < argc; i++)
7030   {
7031   if (argv[i][0] == '+')
7032     {
7033     debug_trace_memory = 2;
7034     argv[i]++;
7035     }
7036   if (isdigit(argv[i][0]))
7037     debug_selector = Ustrtol(argv[i], NULL, 0);
7038   else
7039     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7040         Ustrlen(argv[i]))
7041       {
7042       #ifdef LOOKUP_LDAP
7043       eldap_default_servers = argv[i];
7044       #endif
7045       #ifdef LOOKUP_MYSQL
7046       mysql_servers = argv[i];
7047       #endif
7048       #ifdef LOOKUP_PGSQL
7049       pgsql_servers = argv[i];
7050       #endif
7051       #ifdef EXPERIMENTAL_REDIS
7052       redis_servers = argv[i];
7053       #endif
7054       }
7055   #ifdef EXIM_PERL
7056   else opt_perl_startup = argv[i];
7057   #endif
7058   }
7059
7060 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7061
7062 expand_nstring[1] = US"string 1....";
7063 expand_nlength[1] = 8;
7064 expand_nmax = 1;
7065
7066 #ifdef EXIM_PERL
7067 if (opt_perl_startup != NULL)
7068   {
7069   uschar *errstr;
7070   printf("Starting Perl interpreter\n");
7071   errstr = init_perl(opt_perl_startup);
7072   if (errstr != NULL)
7073     {
7074     printf("** error in perl_startup code: %s\n", errstr);
7075     return EXIT_FAILURE;
7076     }
7077   }
7078 #endif /* EXIM_PERL */
7079
7080 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7081   {
7082   void *reset_point = store_get(0);
7083   uschar *yield = expand_string(buffer);
7084   if (yield != NULL)
7085     {
7086     printf("%s\n", yield);
7087     store_reset(reset_point);
7088     }
7089   else
7090     {
7091     if (search_find_defer) printf("search_find deferred\n");
7092     printf("Failed: %s\n", expand_string_message);
7093     if (expand_string_forcedfail) printf("Forced failure\n");
7094     printf("\n");
7095     }
7096   }
7097
7098 search_tidyup();
7099
7100 return 0;
7101 }
7102
7103 #endif
7104
7105 /* vi: aw ai sw=2
7106 */
7107 /* End of expand.c */