auth-pam.c

   1 /*-
   2  * Copyright (c) 2002 Networks Associates Technology, Inc.
   3  * All rights reserved.
   4  *
   5  * This software was developed for the FreeBSD Project by ThinkSec AS and
   6  * NAI Labs, the Security Research Division of Network Associates, Inc.
   7  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
   8  * DARPA CHATS research program.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
  33 #include "includes.h"
  34 RCSID("$Id$");
  35
  36 #ifdef USE_PAM
  37 #include <security/pam_appl.h>
  38
  39 #include "auth.h"
  40 #include "auth-pam.h"
  41 #include "buffer.h"
  42 #include "bufaux.h"
  43 #include "canohost.h"
  44 #include "log.h"
  45 #include "monitor_wrap.h"
  46 #include "msg.h"
  47 #include "packet.h"
  48 #include "readpass.h"
  49 #include "servconf.h"
  50 #include "ssh2.h"
  51 #include "xmalloc.h"
  52
  53 extern ServerOptions options;
  54
  55 #define __unused
  56
  57 #ifdef USE_POSIX_THREADS
  58 #include <pthread.h>
  59 /*
  60  * Avoid namespace clash when *not* using pthreads for systems *with*
  61  * pthreads, which unconditionally define pthread_t via sys/types.h
  62  * (e.g. Linux)
  63  */
  64 typedef pthread_t sp_pthread_t;
  65 #else
  66 /*
  67  * Simulate threads with processes.
  68  */
  69 typedef pid_t sp_pthread_t;
  70
  71 static void
  72 pthread_exit(void *value __unused)
  73 {
  74         _exit(0);
  75 }
  76
  77 static int
  78 pthread_create(sp_pthread_t *thread, const void *attr __unused,
  79     void *(*thread_start)(void *), void *arg)
  80 {
  81         pid_t pid;
  82
  83         switch ((pid = fork())) {
  84         case -1:
  85                 error("fork(): %s", strerror(errno));
  86                 return (-1);
  87         case 0:
  88                 thread_start(arg);
  89                 _exit(1);
  90         default:
  91                 *thread = pid;
  92                 return (0);
  93         }
  94 }
  95
  96 static int
  97 pthread_cancel(sp_pthread_t thread)
  98 {
  99         return (kill(thread, SIGTERM));
 100 }
 101
 102 static int
 103 pthread_join(sp_pthread_t thread, void **value __unused)
 104 {
 105         int status;
 106
 107         waitpid(thread, &status, 0);
 108         return (status);
 109 }
 110 #endif
 111
 112
 113 static pam_handle_t *sshpam_handle;
 114 static int sshpam_err;
 115 static int sshpam_authenticated;
 116 static int sshpam_new_authtok_reqd;
 117 static int sshpam_session_open;
 118 static int sshpam_cred_established;
 119
 120 struct pam_ctxt {
 121         sp_pthread_t     pam_thread;
 122         int              pam_psock;
 123         int              pam_csock;
 124         int              pam_done;
 125 };
 126
 127 static void sshpam_free_ctx(void *);
 128
 129 /*
 130  * Conversation function for authentication thread.
 131  */
 132 static int
 133 sshpam_thread_conv(int n,
 134          const struct pam_message **msg,
 135          struct pam_response **resp,
 136          void *data)
 137 {
 138         Buffer buffer;
 139         struct pam_ctxt *ctxt;
 140         int i;
 141
 142         ctxt = data;
 143         if (n <= 0 || n > PAM_MAX_NUM_MSG)
 144                 return (PAM_CONV_ERR);
 145         *resp = xmalloc(n * sizeof **resp);
 146         buffer_init(&buffer);
 147         for (i = 0; i < n; ++i) {
 148                 resp[i]->resp_retcode = 0;
 149                 resp[i]->resp = NULL;
 150                 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
 151                 case PAM_PROMPT_ECHO_OFF:
 152                         buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
 153                         ssh_msg_send(ctxt->pam_csock,
 154                             PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
 155                         ssh_msg_recv(ctxt->pam_csock, &buffer);
 156                         if (buffer_get_char(&buffer) != PAM_AUTHTOK)
 157                                 goto fail;
 158                         resp[i]->resp = buffer_get_string(&buffer, NULL);
 159                         break;
 160                 case PAM_PROMPT_ECHO_ON:
 161                         buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
 162                         ssh_msg_send(ctxt->pam_csock,
 163                             PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
 164                         ssh_msg_recv(ctxt->pam_csock, &buffer);
 165                         if (buffer_get_char(&buffer) != PAM_AUTHTOK)
 166                                 goto fail;
 167                         resp[i]->resp = buffer_get_string(&buffer, NULL);
 168                         break;
 169                 case PAM_ERROR_MSG:
 170                         buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
 171                         ssh_msg_send(ctxt->pam_csock,
 172                             PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
 173                         break;
 174                 case PAM_TEXT_INFO:
 175                         buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
 176                         ssh_msg_send(ctxt->pam_csock,
 177                             PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
 178                         break;
 179                 default:
 180                         goto fail;
 181                 }
 182                 buffer_clear(&buffer);
 183         }
 184         buffer_free(&buffer);
 185         return (PAM_SUCCESS);
 186  fail:
 187         while (i)
 188                 xfree(resp[--i]);
 189         xfree(*resp);
 190         *resp = NULL;
 191         buffer_free(&buffer);
 192         return (PAM_CONV_ERR);
 193 }
 194
 195 /*
 196  * Authentication thread.
 197  */
 198 static void *
 199 sshpam_thread(void *ctxtp)
 200 {
 201         struct pam_ctxt *ctxt = ctxtp;
 202         Buffer buffer;
 203         struct pam_conv sshpam_conv = { sshpam_thread_conv, ctxt };
 204 #ifndef USE_POSIX_THREADS
 205         const char *pam_user;
 206
 207         pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user);
 208         setproctitle("%s [pam]", pam_user);
 209 #endif
 210
 211         buffer_init(&buffer);
 212         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 213             (const void *)&sshpam_conv);
 214         if (sshpam_err != PAM_SUCCESS)
 215                 goto auth_fail;
 216         sshpam_err = pam_authenticate(sshpam_handle, 0);
 217         if (sshpam_err != PAM_SUCCESS)
 218                 goto auth_fail;
 219         sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
 220         if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD)
 221                 goto auth_fail;
 222         buffer_put_cstring(&buffer, "OK");
 223         ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
 224         buffer_free(&buffer);
 225         pthread_exit(NULL);
 226
 227  auth_fail:
 228         buffer_put_cstring(&buffer,
 229             pam_strerror(sshpam_handle, sshpam_err));
 230         ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
 231         buffer_free(&buffer);
 232         pthread_exit(NULL);
 233
 234         return (NULL); /* Avoid warning for non-pthread case */
 235 }
 236
 237 static void
 238 sshpam_thread_cleanup(void *ctxtp)
 239 {
 240         struct pam_ctxt *ctxt = ctxtp;
 241
 242         pthread_cancel(ctxt->pam_thread);
 243         pthread_join(ctxt->pam_thread, NULL);
 244         close(ctxt->pam_psock);
 245         close(ctxt->pam_csock);
 246 }
 247
 248 static int
 249 sshpam_null_conv(int n,
 250          const struct pam_message **msg,
 251          struct pam_response **resp,
 252          void *data)
 253 {
 254
 255         return (PAM_CONV_ERR);
 256 }
 257
 258 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
 259
 260 static void
 261 sshpam_cleanup(void *arg)
 262 {
 263         (void)arg;
 264         debug("PAM: cleanup");
 265         pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
 266         if (sshpam_cred_established) {
 267                 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
 268                 sshpam_cred_established = 0;
 269         }
 270         if (sshpam_session_open) {
 271                 pam_close_session(sshpam_handle, PAM_SILENT);
 272                 sshpam_session_open = 0;
 273         }
 274         sshpam_authenticated = sshpam_new_authtok_reqd = 0;
 275         pam_end(sshpam_handle, sshpam_err);
 276         sshpam_handle = NULL;
 277 }
 278
 279 static int
 280 sshpam_init(const char *user)
 281 {
 282         extern u_int utmp_len;
 283         const char *pam_rhost, *pam_user;
 284
 285         if (sshpam_handle != NULL) {
 286                 /* We already have a PAM context; check if the user matches */
 287                 sshpam_err = pam_get_item(sshpam_handle,
 288                     PAM_USER, (const void **)&pam_user);
 289                 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
 290                         return (0);
 291                 fatal_remove_cleanup(sshpam_cleanup, NULL);
 292                 pam_end(sshpam_handle, sshpam_err);
 293                 sshpam_handle = NULL;
 294         }
 295         debug("PAM: initializing for \"%s\"", user);
 296         sshpam_err = pam_start("sshd", user, &null_conv, &sshpam_handle);
 297         if (sshpam_err != PAM_SUCCESS) {
 298                 pam_end(sshpam_handle, sshpam_err);
 299                 sshpam_handle = NULL;
 300                 return (-1);
 301         }
 302         pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
 303         debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
 304         sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
 305         if (sshpam_err != PAM_SUCCESS) {
 306         pam_end(sshpam_handle, sshpam_err);
 307                 sshpam_handle = NULL;
 308                 return (-1);
 309         }
 310 #ifdef PAM_TTY_KLUDGE
 311         /*
 312          * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
 313          * sshd doesn't set the tty until too late in the auth process and
 314          * may not even set one (for tty-less connections)
 315          */
 316         debug("PAM: setting PAM_TTY to \"ssh\"");
 317         sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
 318         if (sshpam_err != PAM_SUCCESS) {
 319                 pam_end(sshpam_handle, sshpam_err);
 320                 sshpam_handle = NULL;
 321                 return (-1);
 322         }
 323 #endif
 324         fatal_add_cleanup(sshpam_cleanup, NULL);
 325         return (0);
 326 }
 327
 328 static void *
 329 sshpam_init_ctx(Authctxt *authctxt)
 330 {
 331         struct pam_ctxt *ctxt;
 332         int socks[2];
 333
 334         /* Refuse to start if we don't have PAM enabled */
 335         if (!options.use_pam)
 336                 return NULL;
 337
 338         /* Initialize PAM */
 339         if (sshpam_init(authctxt->user) == -1) {
 340                 error("PAM: initialization failed");
 341                 return (NULL);
 342         }
 343
 344         ctxt = xmalloc(sizeof *ctxt);
 345         ctxt->pam_done = 0;
 346
 347         /* Start the authentication thread */
 348         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
 349                 error("PAM: failed create sockets: %s", strerror(errno));
 350                 xfree(ctxt);
 351                 return (NULL);
 352         }
 353         ctxt->pam_psock = socks[0];
 354         ctxt->pam_csock = socks[1];
 355         if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
 356                 error("PAM: failed to start authentication thread: %s",
 357                     strerror(errno));
 358                 close(socks[0]);
 359                 close(socks[1]);
 360                 xfree(ctxt);
 361                 return (NULL);
 362         }
 363         fatal_add_cleanup(sshpam_thread_cleanup, ctxt);
 364         return (ctxt);
 365 }
 366
 367 static int
 368 sshpam_query(void *ctx, char **name, char **info,
 369     u_int *num, char ***prompts, u_int **echo_on)
 370 {
 371         Buffer buffer;
 372         struct pam_ctxt *ctxt = ctx;
 373         size_t plen;
 374         u_char type;
 375         char *msg;
 376
 377         buffer_init(&buffer);
 378         *name = xstrdup("");
 379         *info = xstrdup("");
 380         *prompts = xmalloc(sizeof(char *));
 381         **prompts = NULL;
 382         plen = 0;
 383         *echo_on = xmalloc(sizeof(u_int));
 384         while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
 385                 type = buffer_get_char(&buffer);
 386                 msg = buffer_get_string(&buffer, NULL);
 387                 switch (type) {
 388                 case PAM_PROMPT_ECHO_ON:
 389                 case PAM_PROMPT_ECHO_OFF:
 390                         *num = 1;
 391                         **prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
 392                         plen += sprintf(**prompts + plen, "%s", msg);
 393                         **echo_on = (type == PAM_PROMPT_ECHO_ON);
 394                         xfree(msg);
 395                         return (0);
 396                 case PAM_ERROR_MSG:
 397                 case PAM_TEXT_INFO:
 398                         /* accumulate messages */
 399                         **prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
 400                         plen += sprintf(**prompts + plen, "%s", msg);
 401                         xfree(msg);
 402                         break;
 403                 case PAM_NEW_AUTHTOK_REQD:
 404                         sshpam_new_authtok_reqd = 1;
 405                         /* FALLTHROUGH */
 406                 case PAM_SUCCESS:
 407                 case PAM_AUTH_ERR:
 408                         if (**prompts != NULL) {
 409                                 /* drain any accumulated messages */
 410 #if 0 /* XXX - not compatible with privsep */
 411                                 packet_start(SSH2_MSG_USERAUTH_BANNER);
 412                                 packet_put_cstring(**prompts);
 413                                 packet_put_cstring("");
 414                                 packet_send();
 415                                 packet_write_wait();
 416 #endif
 417                                 xfree(**prompts);
 418                                 **prompts = NULL;
 419                         }
 420                         if (type == PAM_SUCCESS) {
 421                                 *num = 0;
 422                                 **echo_on = 0;
 423                                 ctxt->pam_done = 1;
 424                                 xfree(msg);
 425                                 return (0);
 426                         }
 427                         error("PAM: %s", msg);
 428                 default:
 429                         *num = 0;
 430                         **echo_on = 0;
 431                         xfree(msg);
 432                         ctxt->pam_done = -1;
 433                         return (-1);
 434                 }
 435         }
 436         return (-1);
 437 }
 438
 439 /* XXX - see also comment in auth-chall.c:verify_response */
 440 static int
 441 sshpam_respond(void *ctx, u_int num, char **resp)
 442 {
 443         Buffer buffer;
 444         struct pam_ctxt *ctxt = ctx;
 445
 446         debug2("PAM: %s", __func__);
 447         switch (ctxt->pam_done) {
 448         case 1:
 449                 sshpam_authenticated = 1;
 450                 return (0);
 451         case 0:
 452                 break;
 453         default:
 454                 return (-1);
 455         }
 456         if (num != 1) {
 457                 error("PAM: expected one response, got %u", num);
 458                 return (-1);
 459         }
 460         buffer_init(&buffer);
 461         buffer_put_cstring(&buffer, *resp);
 462         ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer);
 463         buffer_free(&buffer);
 464         return (1);
 465 }
 466
 467 static void
 468 sshpam_free_ctx(void *ctxtp)
 469 {
 470         struct pam_ctxt *ctxt = ctxtp;
 471
 472         fatal_remove_cleanup(sshpam_thread_cleanup, ctxt);
 473         sshpam_thread_cleanup(ctxtp);
 474         xfree(ctxt);
 475         /*
 476          * We don't call sshpam_cleanup() here because we may need the PAM
 477          * handle at a later stage, e.g. when setting up a session.  It's
 478          * still on the cleanup list, so pam_end() *will* be called before
 479          * the server process terminates.
 480          */
 481 }
 482
 483 KbdintDevice sshpam_device = {
 484         "pam",
 485         sshpam_init_ctx,
 486         sshpam_query,
 487         sshpam_respond,
 488         sshpam_free_ctx
 489 };
 490
 491 KbdintDevice mm_sshpam_device = {
 492         "pam",
 493         mm_sshpam_init_ctx,
 494         mm_sshpam_query,
 495         mm_sshpam_respond,
 496         mm_sshpam_free_ctx
 497 };
 498
 499 /*
 500  * This replaces auth-pam.c
 501  */
 502 void
 503 start_pam(const char *user)
 504 {
 505         if (!options.use_pam)
 506                 fatal("PAM: initialisation requested when UsePAM=no");
 507
 508         if (sshpam_init(user) == -1)
 509                 fatal("PAM: initialisation failed");
 510 }
 511
 512 void
 513 finish_pam(void)
 514 {
 515         fatal_remove_cleanup(sshpam_cleanup, NULL);
 516         sshpam_cleanup(NULL);
 517 }
 518
 519 int
 520 do_pam_account(const char *user, const char *ruser)
 521 {
 522         /* XXX */
 523         return (1);
 524 }
 525
 526 void
 527 do_pam_session(const char *user, const char *tty)
 528 {
 529         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 530             (const void *)&null_conv);
 531         if (sshpam_err != PAM_SUCCESS)
 532                 fatal("PAM: failed to set PAM_CONV: %s",
 533                     pam_strerror(sshpam_handle, sshpam_err));
 534         debug("PAM: setting PAM_TTY to \"%s\"", tty);
 535         sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
 536         if (sshpam_err != PAM_SUCCESS)
 537                 fatal("PAM: failed to set PAM_TTY: %s",
 538                     pam_strerror(sshpam_handle, sshpam_err));
 539         sshpam_err = pam_open_session(sshpam_handle, 0);
 540         if (sshpam_err != PAM_SUCCESS)
 541                 fatal("PAM: pam_open_session(): %s",
 542                     pam_strerror(sshpam_handle, sshpam_err));
 543         sshpam_session_open = 1;
 544 }
 545
 546 void
 547 do_pam_setcred(int init)
 548 {
 549         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 550             (const void *)&null_conv);
 551         if (sshpam_err != PAM_SUCCESS)
 552                 fatal("PAM: failed to set PAM_CONV: %s",
 553                     pam_strerror(sshpam_handle, sshpam_err));
 554         if (init) {
 555                 debug("PAM: establishing credentials");
 556                 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
 557         } else {
 558                 debug("PAM: reinitializing credentials");
 559                 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
 560         }
 561         if (sshpam_err == PAM_SUCCESS) {
 562                 sshpam_cred_established = 1;
 563                 return;
 564         }
 565         if (sshpam_authenticated)
 566                 fatal("PAM: pam_setcred(): %s",
 567                     pam_strerror(sshpam_handle, sshpam_err));
 568         else
 569                 debug("PAM: pam_setcred(): %s",
 570                     pam_strerror(sshpam_handle, sshpam_err));
 571 }
 572
 573 int
 574 is_pam_password_change_required(void)
 575 {
 576         return (sshpam_new_authtok_reqd);
 577 }
 578
 579 static int
 580 pam_chauthtok_conv(int n,
 581          const struct pam_message **msg,
 582          struct pam_response **resp,
 583          void *data)
 584 {
 585         char input[PAM_MAX_MSG_SIZE];
 586         int i;
 587
 588         if (n <= 0 || n > PAM_MAX_NUM_MSG)
 589                 return (PAM_CONV_ERR);
 590         *resp = xmalloc(n * sizeof **resp);
 591         for (i = 0; i < n; ++i) {
 592                 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
 593                 case PAM_PROMPT_ECHO_OFF:
 594                         resp[i]->resp =
 595                             read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
 596                             RP_ALLOW_STDIN);
 597                         resp[i]->resp_retcode = PAM_SUCCESS;
 598                         break;
 599                 case PAM_PROMPT_ECHO_ON:
 600                         fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
 601                         fgets(input, sizeof input, stdin);
 602                         resp[i]->resp = xstrdup(input);
 603                         resp[i]->resp_retcode = PAM_SUCCESS;
 604                         break;
 605                 case PAM_ERROR_MSG:
 606                 case PAM_TEXT_INFO:
 607                         fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
 608                         resp[i]->resp_retcode = PAM_SUCCESS;
 609                         break;
 610                 default:
 611                         goto fail;
 612                 }
 613         }
 614         return (PAM_SUCCESS);
 615  fail:
 616         while (i)
 617                 xfree(resp[--i]);
 618         xfree(*resp);
 619         *resp = NULL;
 620         return (PAM_CONV_ERR);
 621 }
 622
 623 /*
 624  * XXX this should be done in the authentication phase, but ssh1 doesn't
 625  * support that
 626  */
 627 void
 628 do_pam_chauthtok(void)
 629 {
 630         struct pam_conv pam_conv = { pam_chauthtok_conv, NULL };
 631
 632         if (use_privsep)
 633                 fatal("PAM: chauthtok not supprted with privsep");
 634         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 635             (const void *)&pam_conv);
 636         if (sshpam_err != PAM_SUCCESS)
 637                 fatal("PAM: failed to set PAM_CONV: %s",
 638                     pam_strerror(sshpam_handle, sshpam_err));
 639         debug("PAM: changing password");
 640         sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
 641         if (sshpam_err != PAM_SUCCESS)
 642                 fatal("PAM: pam_chauthtok(): %s",
 643                     pam_strerror(sshpam_handle, sshpam_err));
 644 }
 645
 646 void
 647 print_pam_messages(void)
 648 {
 649         /* XXX */
 650 }
 651
 652 char **
 653 fetch_pam_environment(void)
 654 {
 655 #ifdef HAVE_PAM_GETENVLIST
 656         debug("PAM: retrieving environment");
 657         return (pam_getenvlist(sshpam_handle));
 658 #else
 659         return (NULL);
 660 #endif
 661 }
 662
 663 void
 664 free_pam_environment(char **env)
 665 {
 666         char **envp;
 667
 668         if (env == NULL)
 669                 return;
 670
 671         for (envp = env; *envp; envp++)
 672                 xfree(*envp);
 673         xfree(env);
 674 }
 675
 676 #endif /* USE_PAM */