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