src/pam/afs_setcred.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afsconfig.h>
  11 #include <afs/param.h>
  12
  13 #include <roken.h>
  14
  15 #include <security/pam_appl.h>
  16 #include <security/pam_modules.h>
  17
  18 #include <afs/sys_prototypes.h>
  19 #include <afs/kautils.h>
  20
  21 #include "afs_message.h"
  22 #include "afs_pam_msg.h"
  23 #include "afs_util.h"
  24
  25
  26
  27 #define RET(x) { retcode = (x); goto out; }
  28
  29 #if defined(AFS_KERBEROS_ENV)
  30 extern char *ktc_tkt_string(void);
  31 #endif
  32
  33 extern int
  34 pam_sm_setcred(pam_handle_t * pamh, int flags, int argc, const char **argv)
  35 {
  36     int retcode = PAM_SUCCESS;
  37     int errcode = PAM_SUCCESS;
  38     int origmask;
  39     int logmask = LOG_UPTO(LOG_INFO);
  40     int nowarn = 0;
  41     int use_first_pass = 1;     /* use the password passed in by auth */
  42     int try_first_pass = 0;
  43     int ignore_uid = 0;
  44     uid_t ignore_uid_id = 0;
  45     int refresh_token = 0;
  46     int set_expires = 0;        /* the default is to not to set the env variable */
  47     int use_klog = 0;
  48     int i;
  49     PAM_CONST struct pam_conv *pam_convp = NULL;
  50     char my_password_buf[256];
  51     char *cell_ptr = NULL;
  52     char sbuffer[100];
  53     char *torch_password = NULL;
  54     int auth_ok = 0;
  55     PAM_CONST char *user = NULL;
  56     const char *password = NULL;
  57     int password_expires = -1;
  58     char *reason = NULL;
  59     struct passwd *upwd = NULL;
  60 #if !(defined(AFS_LINUX20_ENV) || defined(AFS_FBSD_ENV) || defined(AFS_DFBSD_ENV) || defined(AFS_NBSD_ENV))
  61     char upwd_buf[2048];       /* size is a guess. */
  62     struct passwd unix_pwd;
  63 #endif
  64
  65 #ifndef AFS_SUN5_ENV
  66     openlog(pam_afs_ident, LOG_CONS, LOG_AUTH);
  67 #endif
  68     origmask = setlogmask(logmask);
  69
  70     /*
  71      * Parse the user options.  Log an error for any unknown options.
  72      */
  73     for (i = 0; i < argc; i++) {
  74         if (strcasecmp(argv[i], "debug") == 0) {
  75             logmask |= LOG_MASK(LOG_DEBUG);
  76             (void)setlogmask(logmask);
  77         } else if (strcasecmp(argv[i], "nowarn") == 0) {
  78             nowarn = 1;
  79         } else if (strcasecmp(argv[i], "use_first_pass") == 0) {
  80             use_first_pass = 1; /* practically redundant */
  81         } else if (strcasecmp(argv[i], "try_first_pass") == 0) {
  82             try_first_pass = 1;
  83         } else if (strcasecmp(argv[i], "ignore_root") == 0) {
  84             ignore_uid = 1;
  85             ignore_uid_id = 0;
  86         } else if (strcasecmp(argv[i], "ignore_uid") == 0) {
  87             i++;
  88             if (i == argc) {
  89                 pam_afs_syslog(LOG_ERR, PAMAFS_IGNOREUID,
  90                                "ignore_uid missing argument");
  91                 ignore_uid = 0;
  92             } else {
  93                 ignore_uid = 1;
  94                 ignore_uid_id = (uid_t) strtol(argv[i], NULL, 10);
  95                 if (ignore_uid_id > IGNORE_MAX) {
  96                     ignore_uid = 0;
  97                     pam_afs_syslog(LOG_ERR, PAMAFS_IGNOREUID, argv[i]);
  98                 }
  99             }
 100         } else if (strcasecmp(argv[i], "cell") == 0) {
 101             i++;
 102             if (i == argc) {
 103                 pam_afs_syslog(LOG_ERR, PAMAFS_OTHERCELL,
 104                                "cell missing argument");
 105             } else {
 106                 cell_ptr = (char *)argv[i];
 107                 pam_afs_syslog(LOG_INFO, PAMAFS_OTHERCELL, cell_ptr);
 108             }
 109         } else if (strcasecmp(argv[i], "no_unlog") == 0) {
 110             ;
 111         } else if (strcasecmp(argv[i], "refresh_token") == 0) {
 112             refresh_token = 1;
 113         } else if (strcasecmp(argv[i], "set_token") == 0) {
 114             ;
 115         } else if (strcasecmp(argv[i], "dont_fork") == 0) {
 116             ;
 117         } else if (strcasecmp(argv[i], "use_klog") == 0) {
 118             use_klog = 1;
 119         } else if (strcasecmp(argv[i], "setenv_password_expires") == 0) {
 120             set_expires = 1;
 121         } else {
 122             pam_afs_syslog(LOG_ERR, PAMAFS_UNKNOWNOPT, argv[i]);
 123         }
 124     }
 125
 126     if (use_first_pass)
 127         try_first_pass = 0;
 128
 129     if (logmask & LOG_MASK(LOG_DEBUG))
 130         pam_afs_syslog(LOG_DEBUG, PAMAFS_OPTIONS, nowarn, use_first_pass,
 131                        try_first_pass, ignore_uid, ignore_uid_id, 8, 8, 8, 8);
 132     /* Try to get the user-interaction info, if available. */
 133     errcode = pam_get_item(pamh, PAM_CONV, (PAM_CONST void **)&pam_convp);
 134     if (errcode != PAM_SUCCESS) {
 135         if (logmask & LOG_MASK(LOG_DEBUG))
 136             pam_afs_syslog(LOG_DEBUG, PAMAFS_NO_USER_INT);
 137         pam_convp = NULL;
 138     }
 139
 140     /* Who are we trying to authenticate here? */
 141     if ((errcode =
 142          pam_get_user(pamh, (PAM_CONST char **)&user,
 143                       "AFS username:")) != PAM_SUCCESS) {
 144         pam_afs_syslog(LOG_ERR, PAMAFS_NOUSER, errcode);
 145         RET(PAM_USER_UNKNOWN);
 146     }
 147     /*
 148      * If the user has a "local" (or via nss, possibly nss_dce) pwent,
 149      * and its uid==0, and "ignore_root" was given in pam.conf,
 150      * ignore the user.
 151      */
 152     /* enhanced: use "ignore_uid <number>" to specify the largest uid
 153      * which should be ignored by this module
 154      */
 155 #if     defined(AFS_HPUX_ENV) || defined(AFS_DARWIN100_ENV) || defined(AFS_SUN5_ENV)
 156 #if     defined(AFS_HPUX110_ENV) || defined(AFS_DARWIN100_ENV) || defined(AFS_SUN5_ENV)
 157     i = getpwnam_r(user, &unix_pwd, upwd_buf, sizeof(upwd_buf), &upwd);
 158 #else /* AFS_HPUX110_ENV */
 159     i = getpwnam_r(user, &unix_pwd, upwd_buf, sizeof(upwd_buf));
 160     if (i == 0)                 /* getpwnam_r success */
 161         upwd = &unix_pwd;
 162 #endif /* AFS_HPUX110_ENV */
 163     if (ignore_uid && i == 0 && upwd && upwd->pw_uid <= ignore_uid_id) {
 164         pam_afs_syslog(LOG_INFO, PAMAFS_IGNORINGROOT, user);
 165         RET(PAM_AUTH_ERR);
 166     }
 167 #else
 168 #if     defined(AFS_LINUX20_ENV) || defined(AFS_FBSD_ENV) || defined(AFS_DFBSD_ENV) || defined(AFS_NBSD_ENV)
 169     upwd = getpwnam(user);
 170 #else
 171     upwd = getpwnam_r(user, &unix_pwd, upwd_buf, sizeof(upwd_buf));
 172 #endif
 173     if (ignore_uid && upwd != NULL && upwd->pw_uid <= ignore_uid_id) {
 174         pam_afs_syslog(LOG_INFO, PAMAFS_IGNORINGROOT, user);
 175         RET(PAM_AUTH_ERR);
 176     }
 177 #endif
 178
 179     if (flags & PAM_DELETE_CRED) {
 180         if (logmask & LOG_MASK(LOG_DEBUG))
 181             pam_afs_syslog(LOG_DEBUG, PAMAFS_DELCRED, user);
 182
 183         RET(PAM_SUCCESS);
 184     } else if (flags & PAM_REINITIALIZE_CRED) {
 185
 186         if (logmask & LOG_MASK(LOG_DEBUG))
 187             pam_afs_syslog(LOG_DEBUG, PAMAFS_REINITCRED, user);
 188         RET(PAM_SUCCESS);
 189
 190     } else {                    /* flags are PAM_REFRESH_CRED, PAM_ESTABLISH_CRED, unknown */
 191
 192         if (logmask & LOG_MASK(LOG_DEBUG))
 193             pam_afs_syslog(LOG_DEBUG, PAMAFS_ESTABCRED, user);
 194
 195         errcode = pam_get_data(pamh, pam_afs_lh, (const void **)&password);
 196         if (errcode != PAM_SUCCESS || password == NULL) {
 197             if (use_first_pass) {
 198                 pam_afs_syslog(LOG_ERR, PAMAFS_PASSWD_REQ, user);
 199                 RET(PAM_AUTH_ERR);
 200             }
 201             password = NULL;    /* In case it isn't already NULL */
 202             if (logmask & LOG_MASK(LOG_DEBUG))
 203                 pam_afs_syslog(LOG_DEBUG, PAMAFS_NOFIRSTPASS, user);
 204         } else if (password[0] == '\0') {
 205             /* Actually we *did* get one but it was empty. */
 206             /* So don't use it. */
 207             password = NULL;
 208             if (use_first_pass) {
 209                 pam_afs_syslog(LOG_ERR, PAMAFS_PASSWD_REQ, user);
 210                 RET(PAM_NEW_AUTHTOK_REQD);
 211             }
 212             if (logmask & LOG_MASK(LOG_DEBUG))
 213                 pam_afs_syslog(LOG_DEBUG, PAMAFS_NILPASSWORD, user);
 214         } else {
 215             if (logmask & LOG_MASK(LOG_DEBUG))
 216                 pam_afs_syslog(LOG_DEBUG, PAMAFS_GOTPASS, user);
 217         }
 218         if (!(use_first_pass || try_first_pass)) {
 219             password = NULL;
 220         }
 221
 222       try_auth:
 223         if (password == NULL) {
 224             char *prompt_password;
 225
 226             if (use_first_pass)
 227                 RET(PAM_AUTH_ERR);      /* shouldn't happen */
 228             if (try_first_pass)
 229                 try_first_pass = 0;     /* we come back if try_first_pass==1 below */
 230
 231             if (pam_convp == NULL || pam_convp->conv == NULL) {
 232                 pam_afs_syslog(LOG_ERR, PAMAFS_CANNOT_PROMPT);
 233                 RET(PAM_AUTH_ERR);
 234             }
 235
 236             errcode =
 237                 pam_afs_prompt(pam_convp, &prompt_password, 0, PAMAFS_PWD_PROMPT);
 238             if (errcode != PAM_SUCCESS || prompt_password == NULL) {
 239                 pam_afs_syslog(LOG_ERR, PAMAFS_GETPASS_FAILED);
 240                 RET(PAM_AUTH_ERR);
 241             }
 242             if (prompt_password[0] == '\0') {
 243                 if (logmask & LOG_MASK(LOG_DEBUG))
 244                     pam_afs_syslog(LOG_DEBUG, PAMAFS_NILPASSWORD);
 245                 RET(PAM_NEW_AUTHTOK_REQD);
 246             }
 247             /*
 248              * We aren't going to free the password later (we will wipe it,
 249              * though), because the storage for it if we get it from other
 250              * paths may belong to someone else.  Since we do need to free
 251              * this storage, copy it to a buffer that won't need to be freed
 252              * later, and free this storage now.
 253              */
 254
 255             strncpy(my_password_buf, prompt_password, sizeof(my_password_buf));
 256             my_password_buf[sizeof(my_password_buf) - 1] = '\0';
 257             memset(prompt_password, 0, strlen(prompt_password));
 258             free(prompt_password);
 259             password = torch_password = my_password_buf;
 260         }
 261         /*
 262          * We only set a PAG here, if we haven't got one before in
 263          * pam_sm_authenticate() or if it was destroyed by the application
 264          */
 265         if ((!refresh_token) && (getPAG() == -1)) {
 266             if (logmask & LOG_MASK(LOG_DEBUG))
 267                 syslog(LOG_DEBUG, "New PAG created in pam_setcred()");
 268             setpag();
 269 #ifdef AFS_KERBEROS_ENV
 270             ktc_newpag();
 271 #endif
 272         }
 273
 274         if (flags & PAM_REFRESH_CRED) {
 275             if (use_klog) {
 276                 auth_ok = !do_klog(user, password, "00:00:01", cell_ptr);
 277                 ktc_ForgetAllTokens();
 278             } else {
 279                 if (ka_VerifyUserPassword(KA_USERAUTH_VERSION, (char *)user,    /* kerberos name */
 280                                           NULL, /* instance */
 281                                           cell_ptr,     /* realm */
 282                                           (char*)password,      /* password */
 283                                           0,    /* spare 2 */
 284                                           &reason       /* error string */
 285                     )) {
 286                     pam_afs_syslog(LOG_ERR, PAMAFS_LOGIN_FAILED, user,
 287                                    reason);
 288                 } else {
 289                     auth_ok = 1;
 290                 }
 291             }
 292         }
 293
 294         if (flags & PAM_ESTABLISH_CRED) {
 295             if (use_klog)
 296                 auth_ok = !do_klog(user, password, NULL, cell_ptr);
 297             else {
 298                 if (ka_UserAuthenticateGeneral(KA_USERAUTH_VERSION, (char *)user,       /* kerberos name */
 299                                                NULL,    /* instance */
 300                                                cell_ptr,        /* realm */
 301                                                (char*)password, /* password */
 302                                                0,       /* default lifetime */
 303                                                &password_expires, 0,    /* spare 2 */
 304                                                &reason  /* error string */
 305                     )) {
 306                     pam_afs_syslog(LOG_ERR, PAMAFS_LOGIN_FAILED, user,
 307                                    reason);
 308                 } else {
 309                     auth_ok = 1;
 310                 }
 311             }
 312         }
 313
 314         if (!auth_ok && try_first_pass) {
 315             password = NULL;
 316             goto try_auth;
 317         }
 318
 319         /* pam_sm_authenticate should have set this
 320          * if (auth_ok && !got_authtok) {
 321          *     torch_password = NULL;
 322          *     (void) pam_set_item(pamh, PAM_AUTHTOK, password);
 323          * }
 324          */
 325
 326         if (auth_ok) {
 327             if (set_expires && !use_klog && (password_expires >= 0)) {
 328                 strcpy(sbuffer, "PASSWORD_EXPIRES=");
 329                 strcat(sbuffer, cv2string(&sbuffer[100], password_expires));
 330                 errcode = pam_putenv(pamh, sbuffer);
 331                 if (errcode != PAM_SUCCESS)
 332                     pam_afs_syslog(LOG_ERR, PAMAFS_PASSEXPFAIL, user);
 333             }
 334 #if defined(AFS_KERBEROS_ENV)
 335             if (upwd) {
 336                 if (chown(ktc_tkt_string(), upwd->pw_uid, upwd->pw_gid) < 0)
 337                     pam_afs_syslog(LOG_ERR, PAMAFS_CHOWNKRB, user);
 338                 sprintf(sbuffer, "KRBTKFILE=%s", ktc_tkt_string());
 339                 errcode = pam_putenv(pamh, sbuffer);
 340                 if (errcode != PAM_SUCCESS)
 341                     pam_afs_syslog(LOG_ERR, PAMAFS_KRBFAIL, user);
 342             }
 343 #endif
 344
 345             RET(PAM_SUCCESS);
 346         } else {
 347             RET(PAM_CRED_ERR);
 348         }
 349     }
 350
 351   out:
 352     if (password && torch_password)
 353         memset(torch_password, 0, strlen(torch_password));
 354     (void)setlogmask(origmask);
 355 #ifndef AFS_SUN5_ENV
 356     closelog();
 357 #endif
 358     return retcode;
 359 }