source/nsswitch/pam_winbind.c

   1 /* pam_winbind module
   2
   3    Copyright Andrew Tridgell <tridge@samba.org> 2000
   4
   5    largely based on pam_userdb by Christian Gafton <gafton@redhat.com>
   6 */
   7
   8 #include "pam_winbind.h"
   9
  10 /* prototypes from common.c */
  11 void init_request(struct winbindd_request *req,int rq_type);
  12 int write_sock(void *buffer, int count);
  13 int read_reply(struct winbindd_response *response);
  14
  15 /* some syslogging */
  16 static void _pam_log(int err, const char *format, ...)
  17 {
  18         va_list args;
  19
  20         va_start(args, format);
  21         openlog(MODULE_NAME, LOG_CONS|LOG_PID, LOG_AUTH);
  22         vsyslog(err, format, args);
  23         va_end(args);
  24         closelog();
  25 }
  26
  27 static int ctrl  = 0;
  28
  29 static int _pam_parse(int argc, const char **argv)
  30 {
  31      /* step through arguments */
  32      for (ctrl = 0; argc-- > 0; ++argv) {
  33
  34           /* generic options */
  35
  36           if (!strcmp(*argv,"debug"))
  37                ctrl |= PAM_DEBUG_ARG;
  38           else if (!strcasecmp(*argv, "use_authtok"))
  39               ctrl |= PAM_USE_AUTHTOK_ARG;
  40           else if (!strcasecmp(*argv, "unknown_ok"))
  41               ctrl |= PAM_UNKNOWN_OK_ARG;
  42           else {
  43                _pam_log(LOG_ERR, "pam_parse: unknown option; %s", *argv);
  44           }
  45      }
  46
  47      return ctrl;
  48 }
  49
  50 static int winbind_request(enum winbindd_cmd req_type,
  51                            struct winbindd_request *request,
  52                            struct winbindd_response *response)
  53 {
  54         /* Fill in request and send down pipe */
  55         init_request(request, req_type);
  56
  57         if (write_sock(request, sizeof(*request)) == -1) {
  58                 return -2;
  59         }
  60
  61         /* Wait for reply */
  62         if (read_reply(response) == -1) {
  63                 return -2;
  64         }
  65
  66         /* Copy reply data from socket */
  67         if (response->result != WINBINDD_OK) {
  68                 return 1;
  69         }
  70
  71         return 0;
  72 }
  73
  74 /* talk to winbindd */
  75 static int winbind_auth_request(const char *user, const char *pass)
  76 {
  77         struct winbindd_request request;
  78         struct winbindd_response response;
  79
  80         ZERO_STRUCT(request);
  81
  82         strncpy(request.data.auth.user, user,
  83                 sizeof(request.data.auth.user)-1);
  84
  85         strncpy(request.data.auth.pass, pass,
  86                 sizeof(request.data.auth.pass)-1);
  87
  88         return winbind_request(WINBINDD_PAM_AUTH, &request, &response);
  89 }
  90
  91 /* talk to winbindd */
  92 static int winbind_chauthtok_request(const char *user, const char *oldpass,
  93                                      const char *newpass)
  94 {
  95         struct winbindd_request request;
  96         struct winbindd_response response;
  97
  98         ZERO_STRUCT(request);
  99
 100         if (request.data.chauthtok.user == NULL) return -2;
 101
 102         strncpy(request.data.chauthtok.user, user,
 103                 sizeof(request.data.chauthtok.user) - 1);
 104
 105         if (oldpass != NULL) {
 106             strncpy(request.data.chauthtok.oldpass, oldpass,
 107                     sizeof(request.data.chauthtok.oldpass) - 1);
 108         } else {
 109             request.data.chauthtok.oldpass[0] = '\0';
 110         }
 111
 112         if (newpass != NULL) {
 113             strncpy(request.data.chauthtok.newpass, newpass,
 114                     sizeof(request.data.chauthtok.newpass) - 1);
 115         } else {
 116             request.data.chauthtok.newpass[0] = '\0';
 117         }
 118
 119         return winbind_request(WINBINDD_PAM_CHAUTHTOK, &request, &response);
 120 }
 121
 122 /*
 123  * Looks up an user name and checks the password
 124  *
 125  * return values:
 126  *       1  = User not found
 127  *       0  = OK
 128  *      -1  = Password incorrect
 129  *      -2  = System error
 130  */
 131 static int user_lookup(const char *user, const char *pass)
 132 {
 133         return winbind_auth_request(user, pass);
 134 }
 135
 136 /*
 137  * Checks if a user has an account
 138  *
 139  * return values:
 140  *       1  = User not found
 141  *       0  = OK
 142  *      -1  = System error
 143  */
 144 static int valid_user(const char *user)
 145 {
 146         if (getpwnam(user)) return 0;
 147         return 1;
 148 }
 149
 150 /* --- authentication management functions --- */
 151
 152 /* Attempt a conversation */
 153
 154 static int converse(pam_handle_t *pamh, int nargs,
 155                     struct pam_message **message,
 156                     struct pam_response **response)
 157 {
 158     int retval;
 159     struct pam_conv *conv;
 160
 161     retval = pam_get_item(pamh, PAM_CONV, (const void **) &conv ) ;
 162     if (retval == PAM_SUCCESS) {
 163         retval = conv->conv(nargs, (const struct pam_message **)message,
 164                             response, conv->appdata_ptr);
 165     }
 166
 167     return retval; /* propagate error status */
 168 }
 169
 170
 171 static char *_pam_delete(register char *xx)
 172 {
 173     _pam_overwrite(xx);
 174     _pam_drop(xx);
 175     return NULL;
 176 }
 177
 178 /*
 179  * This is a conversation function to obtain the user's password
 180  */
 181 static int auth_conversation(pam_handle_t *pamh)
 182 {
 183     struct pam_message msg, *pmsg;
 184     struct pam_response *resp;
 185     int retval;
 186     char * token = NULL;
 187
 188     pmsg = &msg;
 189     msg.msg_style = PAM_PROMPT_ECHO_OFF;
 190     msg.msg = "Password: ";
 191
 192     /* so call the conversation expecting i responses */
 193     resp = NULL;
 194     retval = converse(pamh, 1, &pmsg, &resp);
 195
 196     if (resp != NULL) {
 197         char * const item;
 198         /* interpret the response */
 199         if (retval == PAM_SUCCESS) {     /* a good conversation */
 200             token = x_strdup(resp[0].resp);
 201             if (token == NULL) {
 202                 return PAM_AUTHTOK_RECOVER_ERR;
 203             }
 204         }
 205
 206         /* set the auth token */
 207         retval = pam_set_item(pamh, PAM_AUTHTOK, token);
 208         token = _pam_delete(token);   /* clean it up */
 209         if ( (retval != PAM_SUCCESS) ||
 210              (retval = pam_get_item(pamh, PAM_AUTHTOK, (const void **) &item)) != PAM_SUCCESS ) {
 211             return retval;
 212         }
 213
 214         _pam_drop_reply(resp, 1);
 215     } else {
 216         retval = (retval == PAM_SUCCESS)
 217             ? PAM_AUTHTOK_RECOVER_ERR:retval ;
 218     }
 219
 220     return retval;
 221 }
 222
 223 PAM_EXTERN
 224 int pam_sm_authenticate(pam_handle_t *pamh, int flags,
 225                         int argc, const char **argv)
 226 {
 227      const char *username;
 228      const char *password;
 229      int retval = PAM_AUTH_ERR;
 230
 231      /* parse arguments */
 232      ctrl = _pam_parse(argc, argv);
 233
 234      /* Get the username */
 235      retval = pam_get_user(pamh, &username, NULL);
 236      if ((retval != PAM_SUCCESS) || (!username)) {
 237         if (ctrl & PAM_DEBUG_ARG)
 238             _pam_log(LOG_DEBUG,"can not get the username");
 239         return PAM_SERVICE_ERR;
 240      }
 241
 242      if ((ctrl & PAM_USE_AUTHTOK_ARG) == 0) {
 243          /* Converse just to be sure we have the password */
 244          retval = auth_conversation(pamh);
 245          if (retval != PAM_SUCCESS) {
 246              _pam_log(LOG_ERR, "could not obtain password for `%s'",
 247                       username);
 248              return PAM_CONV_ERR;
 249          }
 250      }
 251
 252      /* Get the password */
 253      retval = pam_get_item(pamh, PAM_AUTHTOK, (const void **) &password);
 254      if (retval != PAM_SUCCESS) {
 255          _pam_log(LOG_ERR, "Could not retrive user's password");
 256          return PAM_AUTHTOK_ERR;
 257      }
 258
 259      if (ctrl & PAM_DEBUG_ARG)
 260          _pam_log(LOG_INFO, "Verify user `%s' with password `%s'",
 261                   username, password);
 262
 263      /* Now use the username to look up password */
 264      retval = user_lookup(username, password);
 265      switch (retval) {
 266          case -2:
 267              /* some sort of system error. The log was already printed */
 268              return PAM_SERVICE_ERR;
 269          case -1:
 270              /* incorrect password */
 271              _pam_log(LOG_WARNING, "user `%s' denied access (incorrect password)", username);
 272              return PAM_AUTH_ERR;
 273          case 1:
 274                  /* the user does not exist */
 275              if (ctrl & PAM_DEBUG_ARG)
 276                  _pam_log(LOG_NOTICE, "user `%s' not found",
 277                           username);
 278              if (ctrl & PAM_UNKNOWN_OK_ARG) {
 279                  return PAM_IGNORE;
 280              }
 281              return PAM_USER_UNKNOWN;
 282          case 0:
 283              /* Otherwise, the authentication looked good */
 284              _pam_log(LOG_NOTICE, "user '%s' granted access", username);
 285              return PAM_SUCCESS;
 286          default:
 287              /* we don't know anything about this return value */
 288              _pam_log(LOG_ERR, "internal module error (retval = %d, user = `%s'",
 289                       retval, username);
 290              return PAM_SERVICE_ERR;
 291      }
 292      /* should not be reached */
 293      return PAM_IGNORE;
 294 }
 295
 296 PAM_EXTERN
 297 int pam_sm_setcred(pam_handle_t *pamh, int flags,
 298                    int argc, const char **argv)
 299 {
 300     return PAM_SUCCESS;
 301 }
 302
 303 /*
 304  * Account management. We want to verify that the account exists
 305  * before returning PAM_SUCCESS
 306  */
 307 PAM_EXTERN
 308 int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
 309                    int argc, const char **argv)
 310 {
 311     const char *username;
 312     int retval = PAM_USER_UNKNOWN;
 313
 314     /* parse arguments */
 315     ctrl = _pam_parse(argc, argv);
 316
 317     /* Get the username */
 318     retval = pam_get_user(pamh, &username, NULL);
 319     if ((retval != PAM_SUCCESS) || (!username)) {
 320         if (ctrl & PAM_DEBUG_ARG)
 321             _pam_log(LOG_DEBUG,"can not get the username");
 322         return PAM_SERVICE_ERR;
 323     }
 324
 325     /* Verify the username */
 326     retval = valid_user(username);
 327     switch (retval) {
 328         case -1:
 329             /* some sort of system error. The log was already printed */
 330             return PAM_SERVICE_ERR;
 331         case 1:
 332             /* the user does not exist */
 333             if (ctrl & PAM_DEBUG_ARG)
 334                 _pam_log(LOG_NOTICE, "user `%s' not found",
 335                          username);
 336             if (ctrl & PAM_UNKNOWN_OK_ARG)
 337                 return PAM_IGNORE;
 338             return PAM_USER_UNKNOWN;
 339         case 0:
 340             /* Otherwise, the authentication looked good */
 341             _pam_log(LOG_NOTICE, "user '%s' granted access", username);
 342             return PAM_SUCCESS;
 343         default:
 344             /* we don't know anything about this return value */
 345             _pam_log(LOG_ERR, "internal module error (retval = %d, user = `%s'",
 346                      retval, username);
 347             return PAM_SERVICE_ERR;
 348     }
 349
 350     /* should not be reached */
 351     return PAM_IGNORE;
 352 }
 353
 354
 355 PAM_EXTERN
 356 int pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc,
 357                      const char **argv)
 358 {
 359     int retval;
 360     char *newpw, *oldpw;
 361     const char *user;
 362
 363     /* Get name of a user */
 364
 365     retval = pam_get_user(pamh, &user, "Username: ");
 366
 367     if (retval != PAM_SUCCESS) {
 368         return retval;
 369     }
 370
 371     /* XXX check in domain format */
 372
 373     /* Perform preliminary check and store requested password for updating
 374        later on */
 375
 376     if (flags & PAM_PRELIM_CHECK) {
 377         struct pam_message msg[3], *pmsg[3];
 378         struct pam_response *resp;
 379
 380         /* Converse to ensure we have the current password */
 381
 382         retval = auth_conversation(pamh);
 383
 384         if (retval != PAM_SUCCESS) {
 385             return retval;
 386         }
 387
 388         /* Obtain and verify current password */
 389
 390         pmsg[0] = &msg[0];
 391         msg[0].msg_style = PAM_TEXT_INFO;
 392         msg[0].msg = "Changing password for user %s";
 393
 394         pmsg[1] = &msg[1];
 395         msg[1].msg_style = PAM_PROMPT_ECHO_OFF;
 396         msg[1].msg = "New NT password: ";
 397
 398         pmsg[2] = &msg[2];
 399         msg[2].msg_style = PAM_PROMPT_ECHO_OFF;
 400         msg[2].msg = "Retype new NT password: ";
 401
 402         resp = NULL;
 403
 404         retval = converse(pamh, 3, pmsg, &resp);
 405
 406         if (resp != NULL) {
 407
 408             if (retval == PAM_SUCCESS) {
 409
 410                 /* Check password entered correctly */
 411
 412                 if (strcmp(resp[1].resp, resp[2].resp) != 0) {
 413                     struct pam_response *resp2;
 414
 415                     msg[0].msg_style = PAM_ERROR_MSG;
 416                     msg[0].msg = "Sorry, passwords do not match";
 417
 418                     converse(pamh, 1, pmsg, &resp2);
 419
 420                     _pam_drop_reply(resp, 3);
 421                     _pam_drop_reply(resp2, 1);
 422
 423                     return PAM_AUTHTOK_RECOVER_ERR;
 424                 }
 425
 426                 /* Store passwords */
 427
 428                 retval = pam_set_item(pamh, PAM_OLDAUTHTOK, resp[1].resp);
 429                 _pam_drop_reply(resp, 3);
 430             }
 431         }
 432
 433         /* XXX What happens if root? */
 434         /* XXX try first pass and use first pass args */
 435
 436         return retval;
 437     }
 438
 439     if (flags & PAM_UPDATE_AUTHTOK) {
 440
 441         retval = pam_get_item(pamh, PAM_OLDAUTHTOK, (const void **)&newpw);
 442         if (retval != PAM_SUCCESS) {
 443             return PAM_AUTHTOK_ERR;
 444         }
 445
 446         retval = pam_get_item(pamh, PAM_AUTHTOK, (const void **)&oldpw);
 447         if (retval != PAM_SUCCESS) {
 448             return PAM_AUTHTOK_ERR;
 449         }
 450
 451         fprintf(stderr, "oldpw = %s, newpw = %s\n", oldpw, newpw);
 452
 453         if (retval == PAM_SUCCESS &&
 454             winbind_chauthtok_request(user, oldpw, newpw) == 0) {
 455             return PAM_SUCCESS;
 456         }
 457
 458         return PAM_AUTHTOK_ERR;
 459     }
 460
 461     return PAM_SERVICE_ERR;
 462 }
 463
 464 /* HP added session open and close handlers to always return success */
 465 PAM_EXTERN
 466 int pam_sm_open_session(pam_handle_t *pamh, int flags,
 467                 int argc, const char **argv)
 468 {
 469         /* parse arguments */
 470         ctrl = _pam_parse(argc, argv);
 471         if (ctrl & PAM_DEBUG_ARG)
 472                 _pam_log(LOG_DEBUG,"libpam_winbind:pam_sm_open_session handler") ;
 473         return PAM_SUCCESS;
 474 }
 475
 476 PAM_EXTERN
 477 int pam_sm_close_session(pam_handle_t *pamh, int flags,
 478                 int argc, const char **argv)
 479 {
 480         /* parse arguments */
 481         ctrl = _pam_parse(argc, argv);
 482         if (ctrl & PAM_DEBUG_ARG)
 483                 _pam_log(LOG_DEBUG,"libpam_winbind:pam_sm_close_session handler");
 484         return PAM_SUCCESS;
 485 }
 486 /* end HP add */
 487
 488 #ifdef PAM_STATIC
 489
 490 /* static module data */
 491
 492 struct pam_module _pam_winbind_modstruct = {
 493      MODULE_NAME,
 494      pam_sm_authenticate,
 495      pam_sm_setcred,
 496      pam_sm_acct_mgmt,
 497      pam_sm_open_session,
 498      pam_sm_close_session,
 499      pam_sm_chauthtok
 500 };
 501
 502 #endif
 503
 504 /*
 505  * Copyright (c) Andrew Tridgell <tridge@samba.org> 2000
 506  * Copyright (c) Tim Potter      <tpot@samba.org>   2000
 507  *
 508  * Redistribution and use in source and binary forms, with or without
 509  * modification, are permitted provided that the following conditions
 510  * are met:
 511  * 1. Redistributions of source code must retain the above copyright
 512  *    notice, and the entire permission notice in its entirety,
 513  *    including the disclaimer of warranties.
 514  * 2. Redistributions in binary form must reproduce the above copyright
 515  *    notice, this list of conditions and the following disclaimer in the
 516  *    documentation and/or other materials provided with the distribution.
 517  * 3. The name of the author may not be used to endorse or promote
 518  *    products derived from this software without specific prior
 519  *    written permission.
 520  *
 521  * ALTERNATIVELY, this product may be distributed under the terms of
 522  * the GNU Public License, in which case the provisions of the GPL are
 523  * required INSTEAD OF the above restrictions.  (This clause is
 524  * necessary due to a potential bad interaction between the GPL and
 525  * the restrictions contained in a BSD-style copyright.)
 526  *
 527  * THIS SOFTWARE IS PROVIDED `AS IS'' AND ANY EXPRESS OR IMPLIED
 528  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 529  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 530  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 531  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 532  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 533  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 534  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 535  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 536  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 537  * OF THE POSSIBILITY OF SUCH DAMAGE.
 538  */