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