crypto/openssh/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  * Copyright (c) 2003,2004 Damien Miller <djm@mindrot.org>
  33  * Copyright (c) 2003,2004 Darren Tucker <dtucker@zip.com.au>
  34  *
  35  * Permission to use, copy, modify, and distribute this software for any
  36  * purpose with or without fee is hereby granted, provided that the above
  37  * copyright notice and this permission notice appear in all copies.
  38  *
  39  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  40  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  41  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  42  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  43  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  44  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  45  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  46  */
  47
  48 /* Based on FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des */
  49
  50 #include "includes.h"
  51
  52 #include <sys/types.h>
  53 #include <sys/stat.h>
  54 #include <sys/wait.h>
  55
  56 #include <errno.h>
  57 #include <signal.h>
  58 #include <stdarg.h>
  59 #include <string.h>
  60 #include <unistd.h>
  61
  62 #ifdef USE_PAM
  63 #if defined(HAVE_SECURITY_PAM_APPL_H)
  64 #include <security/pam_appl.h>
  65 #elif defined (HAVE_PAM_PAM_APPL_H)
  66 #include <pam/pam_appl.h>
  67 #endif
  68
  69 /* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */
  70 #ifdef PAM_SUN_CODEBASE
  71 # define sshpam_const           /* Solaris, HP-UX, SunOS */
  72 #else
  73 # define sshpam_const   const   /* LinuxPAM, OpenPAM, AIX */
  74 #endif
  75
  76 /* Ambiguity in spec: is it an array of pointers or a pointer to an array? */
  77 #ifdef PAM_SUN_CODEBASE
  78 # define PAM_MSG_MEMBER(msg, n, member) ((*(msg))[(n)].member)
  79 #else
  80 # define PAM_MSG_MEMBER(msg, n, member) ((msg)[(n)]->member)
  81 #endif
  82
  83 #include "xmalloc.h"
  84 #include "buffer.h"
  85 #include "key.h"
  86 #include "hostfile.h"
  87 #include "auth.h"
  88 #include "auth-pam.h"
  89 #include "canohost.h"
  90 #include "log.h"
  91 #include "msg.h"
  92 #include "packet.h"
  93 #include "misc.h"
  94 #include "servconf.h"
  95 #include "ssh2.h"
  96 #include "auth-options.h"
  97 #ifdef GSSAPI
  98 #include "ssh-gss.h"
  99 #endif
 100 #include "monitor_wrap.h"
 101
 102 extern ServerOptions options;
 103 extern Buffer loginmsg;
 104 extern int compat20;
 105 extern u_int utmp_len;
 106
 107 /* so we don't silently change behaviour */
 108 #ifdef USE_POSIX_THREADS
 109 # error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
 110 #endif
 111
 112 /*
 113  * Formerly known as USE_POSIX_THREADS, using this is completely unsupported
 114  * and generally a bad idea.  Use at own risk and do not expect support if
 115  * this breaks.
 116  */
 117 #ifdef UNSUPPORTED_POSIX_THREADS_HACK
 118 #include <pthread.h>
 119 /*
 120  * Avoid namespace clash when *not* using pthreads for systems *with*
 121  * pthreads, which unconditionally define pthread_t via sys/types.h
 122  * (e.g. Linux)
 123  */
 124 typedef pthread_t sp_pthread_t;
 125 #else
 126 typedef pid_t sp_pthread_t;
 127 #endif
 128
 129 struct pam_ctxt {
 130         sp_pthread_t     pam_thread;
 131         int              pam_psock;
 132         int              pam_csock;
 133         int              pam_done;
 134 };
 135
 136 static void sshpam_free_ctx(void *);
 137 static struct pam_ctxt *cleanup_ctxt;
 138
 139 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
 140 /*
 141  * Simulate threads with processes.
 142  */
 143
 144 static int sshpam_thread_status = -1;
 145 static mysig_t sshpam_oldsig;
 146
 147 static void
 148 sshpam_sigchld_handler(int sig)
 149 {
 150         signal(SIGCHLD, SIG_DFL);
 151         if (cleanup_ctxt == NULL)
 152                 return; /* handler called after PAM cleanup, shouldn't happen */
 153         if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG)
 154             <= 0) {
 155                 /* PAM thread has not exitted, privsep slave must have */
 156                 kill(cleanup_ctxt->pam_thread, SIGTERM);
 157                 while (waitpid(cleanup_ctxt->pam_thread,
 158                     &sshpam_thread_status, 0) == -1) {
 159                         if (errno == EINTR)
 160                                 continue;
 161                         return;
 162                 }
 163         }
 164         if (WIFSIGNALED(sshpam_thread_status) &&
 165             WTERMSIG(sshpam_thread_status) == SIGTERM)
 166                 return; /* terminated by pthread_cancel */
 167         if (!WIFEXITED(sshpam_thread_status))
 168                 sigdie("PAM: authentication thread exited unexpectedly");
 169         if (WEXITSTATUS(sshpam_thread_status) != 0)
 170                 sigdie("PAM: authentication thread exited uncleanly");
 171 }
 172
 173 /* ARGSUSED */
 174 static void
 175 pthread_exit(void *value)
 176 {
 177         _exit(0);
 178 }
 179
 180 /* ARGSUSED */
 181 static int
 182 pthread_create(sp_pthread_t *thread, const void *attr,
 183     void *(*thread_start)(void *), void *arg)
 184 {
 185         pid_t pid;
 186         struct pam_ctxt *ctx = arg;
 187
 188         sshpam_thread_status = -1;
 189         switch ((pid = fork())) {
 190         case -1:
 191                 error("fork(): %s", strerror(errno));
 192                 return (-1);
 193         case 0:
 194                 close(ctx->pam_psock);
 195                 ctx->pam_psock = -1;
 196                 thread_start(arg);
 197                 _exit(1);
 198         default:
 199                 *thread = pid;
 200                 close(ctx->pam_csock);
 201                 ctx->pam_csock = -1;
 202                 sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
 203                 return (0);
 204         }
 205 }
 206
 207 static int
 208 pthread_cancel(sp_pthread_t thread)
 209 {
 210         signal(SIGCHLD, sshpam_oldsig);
 211         return (kill(thread, SIGTERM));
 212 }
 213
 214 /* ARGSUSED */
 215 static int
 216 pthread_join(sp_pthread_t thread, void **value)
 217 {
 218         int status;
 219
 220         if (sshpam_thread_status != -1)
 221                 return (sshpam_thread_status);
 222         signal(SIGCHLD, sshpam_oldsig);
 223         while (waitpid(thread, &status, 0) == -1) {
 224                 if (errno == EINTR)
 225                         continue;
 226                 fatal("%s: waitpid: %s", __func__, strerror(errno));
 227         }
 228         return (status);
 229 }
 230 #endif
 231
 232
 233 static pam_handle_t *sshpam_handle = NULL;
 234 static int sshpam_err = 0;
 235 static int sshpam_authenticated = 0;
 236 static int sshpam_session_open = 0;
 237 static int sshpam_cred_established = 0;
 238 static int sshpam_account_status = -1;
 239 static int sshpam_maxtries_reached = 0;
 240 static char **sshpam_env = NULL;
 241 static Authctxt *sshpam_authctxt = NULL;
 242 static const char *sshpam_password = NULL;
 243
 244 /* Some PAM implementations don't implement this */
 245 #ifndef HAVE_PAM_GETENVLIST
 246 static char **
 247 pam_getenvlist(pam_handle_t *pamh)
 248 {
 249         /*
 250          * XXX - If necessary, we can still support envrionment passing
 251          * for platforms without pam_getenvlist by searching for known
 252          * env vars (e.g. KRB5CCNAME) from the PAM environment.
 253          */
 254          return NULL;
 255 }
 256 #endif
 257
 258 /*
 259  * Some platforms, notably Solaris, do not enforce password complexity
 260  * rules during pam_chauthtok() if the real uid of the calling process
 261  * is 0, on the assumption that it's being called by "passwd" run by root.
 262  * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
 263  * the right thing.
 264  */
 265 #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
 266 static int
 267 sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
 268 {
 269         int result;
 270
 271         if (sshpam_authctxt == NULL)
 272                 fatal("PAM: sshpam_authctxt not initialized");
 273         if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
 274                 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
 275         result = pam_chauthtok(pamh, flags);
 276         if (setreuid(0, -1) == -1)
 277                 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
 278         return result;
 279 }
 280 # define pam_chauthtok(a,b)     (sshpam_chauthtok_ruid((a), (b)))
 281 #endif
 282
 283 void
 284 sshpam_password_change_required(int reqd)
 285 {
 286         debug3("%s %d", __func__, reqd);
 287         if (sshpam_authctxt == NULL)
 288                 fatal("%s: PAM authctxt not initialized", __func__);
 289         sshpam_authctxt->force_pwchange = reqd;
 290         if (reqd) {
 291                 no_port_forwarding_flag |= 2;
 292                 no_agent_forwarding_flag |= 2;
 293                 no_x11_forwarding_flag |= 2;
 294         } else {
 295                 no_port_forwarding_flag &= ~2;
 296                 no_agent_forwarding_flag &= ~2;
 297                 no_x11_forwarding_flag &= ~2;
 298         }
 299 }
 300
 301 /* Import regular and PAM environment from subprocess */
 302 static void
 303 import_environments(Buffer *b)
 304 {
 305         char *env;
 306         u_int i, num_env;
 307         int err;
 308
 309         debug3("PAM: %s entering", __func__);
 310
 311 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
 312         /* Import variables set by do_pam_account */
 313         sshpam_account_status = buffer_get_int(b);
 314         sshpam_password_change_required(buffer_get_int(b));
 315
 316         /* Import environment from subprocess */
 317         num_env = buffer_get_int(b);
 318         if (num_env > 1024)
 319                 fatal("%s: received %u environment variables, expected <= 1024",
 320                     __func__, num_env);
 321         sshpam_env = xcalloc(num_env + 1, sizeof(*sshpam_env));
 322         debug3("PAM: num env strings %d", num_env);
 323         for(i = 0; i < num_env; i++)
 324                 sshpam_env[i] = buffer_get_string(b, NULL);
 325
 326         sshpam_env[num_env] = NULL;
 327
 328         /* Import PAM environment from subprocess */
 329         num_env = buffer_get_int(b);
 330         debug("PAM: num PAM env strings %d", num_env);
 331         for(i = 0; i < num_env; i++) {
 332                 env = buffer_get_string(b, NULL);
 333
 334 #ifdef HAVE_PAM_PUTENV
 335                 /* Errors are not fatal here */
 336                 if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
 337                         error("PAM: pam_putenv: %s",
 338                             pam_strerror(sshpam_handle, sshpam_err));
 339                 }
 340 #endif
 341         }
 342 #endif
 343 }
 344
 345 /*
 346  * Conversation function for authentication thread.
 347  */
 348 static int
 349 sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
 350     struct pam_response **resp, void *data)
 351 {
 352         Buffer buffer;
 353         struct pam_ctxt *ctxt;
 354         struct pam_response *reply;
 355         int i;
 356
 357         debug3("PAM: %s entering, %d messages", __func__, n);
 358         *resp = NULL;
 359
 360         if (data == NULL) {
 361                 error("PAM: conversation function passed a null context");
 362                 return (PAM_CONV_ERR);
 363         }
 364         ctxt = data;
 365         if (n <= 0 || n > PAM_MAX_NUM_MSG)
 366                 return (PAM_CONV_ERR);
 367
 368         if ((reply = calloc(n, sizeof(*reply))) == NULL)
 369                 return (PAM_CONV_ERR);
 370
 371         buffer_init(&buffer);
 372         for (i = 0; i < n; ++i) {
 373                 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
 374                 case PAM_PROMPT_ECHO_OFF:
 375                 case PAM_PROMPT_ECHO_ON:
 376                         buffer_put_cstring(&buffer,
 377                             PAM_MSG_MEMBER(msg, i, msg));
 378                         if (ssh_msg_send(ctxt->pam_csock,
 379                             PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
 380                                 goto fail;
 381                         if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
 382                                 goto fail;
 383                         if (buffer_get_char(&buffer) != PAM_AUTHTOK)
 384                                 goto fail;
 385                         reply[i].resp = buffer_get_string(&buffer, NULL);
 386                         break;
 387                 case PAM_ERROR_MSG:
 388                 case PAM_TEXT_INFO:
 389                         buffer_put_cstring(&buffer,
 390                             PAM_MSG_MEMBER(msg, i, msg));
 391                         if (ssh_msg_send(ctxt->pam_csock,
 392                             PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
 393                                 goto fail;
 394                         break;
 395                 default:
 396                         goto fail;
 397                 }
 398                 buffer_clear(&buffer);
 399         }
 400         buffer_free(&buffer);
 401         *resp = reply;
 402         return (PAM_SUCCESS);
 403
 404  fail:
 405         for(i = 0; i < n; i++) {
 406                 free(reply[i].resp);
 407         }
 408         free(reply);
 409         buffer_free(&buffer);
 410         return (PAM_CONV_ERR);
 411 }
 412
 413 /*
 414  * Authentication thread.
 415  */
 416 static void *
 417 sshpam_thread(void *ctxtp)
 418 {
 419         struct pam_ctxt *ctxt = ctxtp;
 420         Buffer buffer;
 421         struct pam_conv sshpam_conv;
 422         int flags = (options.permit_empty_passwd == 0 ?
 423             PAM_DISALLOW_NULL_AUTHTOK : 0);
 424 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
 425         extern char **environ;
 426         char **env_from_pam;
 427         u_int i;
 428         const char *pam_user;
 429         const char **ptr_pam_user = &pam_user;
 430         char *tz = getenv("TZ");
 431
 432         sshpam_err = pam_get_item(sshpam_handle, PAM_USER,
 433             (sshpam_const void **)ptr_pam_user);
 434         if (sshpam_err != PAM_SUCCESS)
 435                 goto auth_fail;
 436
 437         environ[0] = NULL;
 438         if (tz != NULL)
 439                 if (setenv("TZ", tz, 1) == -1)
 440                         error("PAM: could not set TZ environment: %s",
 441                             strerror(errno));
 442
 443         if (sshpam_authctxt != NULL) {
 444                 setproctitle("%s [pam]",
 445                     sshpam_authctxt->valid ? pam_user : "unknown");
 446         }
 447 #endif
 448
 449         sshpam_conv.conv = sshpam_thread_conv;
 450         sshpam_conv.appdata_ptr = ctxt;
 451
 452         if (sshpam_authctxt == NULL)
 453                 fatal("%s: PAM authctxt not initialized", __func__);
 454
 455         buffer_init(&buffer);
 456         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 457             (const void *)&sshpam_conv);
 458         if (sshpam_err != PAM_SUCCESS)
 459                 goto auth_fail;
 460         sshpam_err = pam_authenticate(sshpam_handle, flags);
 461         if (sshpam_err == PAM_MAXTRIES)
 462                 sshpam_set_maxtries_reached(1);
 463         if (sshpam_err != PAM_SUCCESS)
 464                 goto auth_fail;
 465
 466         if (compat20) {
 467                 if (!do_pam_account()) {
 468                         sshpam_err = PAM_ACCT_EXPIRED;
 469                         goto auth_fail;
 470                 }
 471                 if (sshpam_authctxt->force_pwchange) {
 472                         sshpam_err = pam_chauthtok(sshpam_handle,
 473                             PAM_CHANGE_EXPIRED_AUTHTOK);
 474                         if (sshpam_err != PAM_SUCCESS)
 475                                 goto auth_fail;
 476                         sshpam_password_change_required(0);
 477                 }
 478         }
 479
 480         buffer_put_cstring(&buffer, "OK");
 481
 482 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
 483         /* Export variables set by do_pam_account */
 484         buffer_put_int(&buffer, sshpam_account_status);
 485         buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
 486
 487         /* Export any environment strings set in child */
 488         for(i = 0; environ[i] != NULL; i++)
 489                 ; /* Count */
 490         buffer_put_int(&buffer, i);
 491         for(i = 0; environ[i] != NULL; i++)
 492                 buffer_put_cstring(&buffer, environ[i]);
 493
 494         /* Export any environment strings set by PAM in child */
 495         env_from_pam = pam_getenvlist(sshpam_handle);
 496         for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
 497                 ; /* Count */
 498         buffer_put_int(&buffer, i);
 499         for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
 500                 buffer_put_cstring(&buffer, env_from_pam[i]);
 501 #endif /* UNSUPPORTED_POSIX_THREADS_HACK */
 502
 503         /* XXX - can't do much about an error here */
 504         ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
 505         buffer_free(&buffer);
 506         pthread_exit(NULL);
 507
 508  auth_fail:
 509         buffer_put_cstring(&buffer,
 510             pam_strerror(sshpam_handle, sshpam_err));
 511         /* XXX - can't do much about an error here */
 512         if (sshpam_err == PAM_ACCT_EXPIRED)
 513                 ssh_msg_send(ctxt->pam_csock, PAM_ACCT_EXPIRED, &buffer);
 514         else if (sshpam_maxtries_reached)
 515                 ssh_msg_send(ctxt->pam_csock, PAM_MAXTRIES, &buffer);
 516         else
 517                 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
 518         buffer_free(&buffer);
 519         pthread_exit(NULL);
 520
 521         return (NULL); /* Avoid warning for non-pthread case */
 522 }
 523
 524 void
 525 sshpam_thread_cleanup(void)
 526 {
 527         struct pam_ctxt *ctxt = cleanup_ctxt;
 528
 529         debug3("PAM: %s entering", __func__);
 530         if (ctxt != NULL && ctxt->pam_thread != 0) {
 531                 pthread_cancel(ctxt->pam_thread);
 532                 pthread_join(ctxt->pam_thread, NULL);
 533                 close(ctxt->pam_psock);
 534                 close(ctxt->pam_csock);
 535                 memset(ctxt, 0, sizeof(*ctxt));
 536                 cleanup_ctxt = NULL;
 537         }
 538 }
 539
 540 static int
 541 sshpam_null_conv(int n, sshpam_const struct pam_message **msg,
 542     struct pam_response **resp, void *data)
 543 {
 544         debug3("PAM: %s entering, %d messages", __func__, n);
 545         return (PAM_CONV_ERR);
 546 }
 547
 548 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
 549
 550 static int
 551 sshpam_store_conv(int n, sshpam_const struct pam_message **msg,
 552     struct pam_response **resp, void *data)
 553 {
 554         struct pam_response *reply;
 555         int i;
 556         size_t len;
 557
 558         debug3("PAM: %s called with %d messages", __func__, n);
 559         *resp = NULL;
 560
 561         if (n <= 0 || n > PAM_MAX_NUM_MSG)
 562                 return (PAM_CONV_ERR);
 563
 564         if ((reply = calloc(n, sizeof(*reply))) == NULL)
 565                 return (PAM_CONV_ERR);
 566
 567         for (i = 0; i < n; ++i) {
 568                 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
 569                 case PAM_ERROR_MSG:
 570                 case PAM_TEXT_INFO:
 571                         len = strlen(PAM_MSG_MEMBER(msg, i, msg));
 572                         buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
 573                         buffer_append(&loginmsg, "\n", 1 );
 574                         reply[i].resp_retcode = PAM_SUCCESS;
 575                         break;
 576                 default:
 577                         goto fail;
 578                 }
 579         }
 580         *resp = reply;
 581         return (PAM_SUCCESS);
 582
 583  fail:
 584         for(i = 0; i < n; i++) {
 585                 free(reply[i].resp);
 586         }
 587         free(reply);
 588         return (PAM_CONV_ERR);
 589 }
 590
 591 static struct pam_conv store_conv = { sshpam_store_conv, NULL };
 592
 593 void
 594 sshpam_cleanup(void)
 595 {
 596         if (sshpam_handle == NULL || (use_privsep && !mm_is_monitor()))
 597                 return;
 598         debug("PAM: cleanup");
 599         pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
 600         if (sshpam_session_open) {
 601                 debug("PAM: closing session");
 602                 pam_close_session(sshpam_handle, PAM_SILENT);
 603                 sshpam_session_open = 0;
 604         }
 605         if (sshpam_cred_established) {
 606                 debug("PAM: deleting credentials");
 607                 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
 608                 sshpam_cred_established = 0;
 609         }
 610         sshpam_authenticated = 0;
 611         pam_end(sshpam_handle, sshpam_err);
 612         sshpam_handle = NULL;
 613 }
 614
 615 static int
 616 sshpam_init(Authctxt *authctxt)
 617 {
 618         extern char *__progname;
 619         const char *pam_rhost, *pam_user, *user = authctxt->user;
 620         const char **ptr_pam_user = &pam_user;
 621         struct ssh *ssh = active_state; /* XXX */
 622
 623         if (sshpam_handle != NULL) {
 624                 /* We already have a PAM context; check if the user matches */
 625                 sshpam_err = pam_get_item(sshpam_handle,
 626                     PAM_USER, (sshpam_const void **)ptr_pam_user);
 627                 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
 628                         return (0);
 629                 pam_end(sshpam_handle, sshpam_err);
 630                 sshpam_handle = NULL;
 631         }
 632         debug("PAM: initializing for \"%s\"", user);
 633         sshpam_err =
 634             pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
 635         sshpam_authctxt = authctxt;
 636
 637         if (sshpam_err != PAM_SUCCESS) {
 638                 pam_end(sshpam_handle, sshpam_err);
 639                 sshpam_handle = NULL;
 640                 return (-1);
 641         }
 642         pam_rhost = auth_get_canonical_hostname(ssh, options.use_dns);
 643         debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
 644         sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
 645         if (sshpam_err != PAM_SUCCESS) {
 646                 pam_end(sshpam_handle, sshpam_err);
 647                 sshpam_handle = NULL;
 648                 return (-1);
 649         }
 650 #ifdef PAM_TTY_KLUDGE
 651         /*
 652          * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
 653          * sshd doesn't set the tty until too late in the auth process and
 654          * may not even set one (for tty-less connections)
 655          */
 656         debug("PAM: setting PAM_TTY to \"ssh\"");
 657         sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
 658         if (sshpam_err != PAM_SUCCESS) {
 659                 pam_end(sshpam_handle, sshpam_err);
 660                 sshpam_handle = NULL;
 661                 return (-1);
 662         }
 663 #endif
 664         return (0);
 665 }
 666
 667 static void *
 668 sshpam_init_ctx(Authctxt *authctxt)
 669 {
 670         struct pam_ctxt *ctxt;
 671         int socks[2];
 672
 673         debug3("PAM: %s entering", __func__);
 674         /*
 675          * Refuse to start if we don't have PAM enabled or do_pam_account
 676          * has previously failed.
 677          */
 678         if (!options.use_pam || sshpam_account_status == 0)
 679                 return NULL;
 680
 681         /* Initialize PAM */
 682         if (sshpam_init(authctxt) == -1) {
 683                 error("PAM: initialization failed");
 684                 return (NULL);
 685         }
 686
 687         ctxt = xcalloc(1, sizeof *ctxt);
 688
 689         /* Start the authentication thread */
 690         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
 691                 error("PAM: failed create sockets: %s", strerror(errno));
 692                 free(ctxt);
 693                 return (NULL);
 694         }
 695         ctxt->pam_psock = socks[0];
 696         ctxt->pam_csock = socks[1];
 697         if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
 698                 error("PAM: failed to start authentication thread: %s",
 699                     strerror(errno));
 700                 close(socks[0]);
 701                 close(socks[1]);
 702                 free(ctxt);
 703                 return (NULL);
 704         }
 705         cleanup_ctxt = ctxt;
 706         return (ctxt);
 707 }
 708
 709 static int
 710 sshpam_query(void *ctx, char **name, char **info,
 711     u_int *num, char ***prompts, u_int **echo_on)
 712 {
 713         struct ssh *ssh = active_state; /* XXX */
 714         Buffer buffer;
 715         struct pam_ctxt *ctxt = ctx;
 716         size_t plen;
 717         u_char type;
 718         char *msg;
 719         size_t len, mlen;
 720
 721         debug3("PAM: %s entering", __func__);
 722         buffer_init(&buffer);
 723         *name = xstrdup("");
 724         *info = xstrdup("");
 725         *prompts = xmalloc(sizeof(char *));
 726         **prompts = NULL;
 727         plen = 0;
 728         *echo_on = xmalloc(sizeof(u_int));
 729         while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
 730                 type = buffer_get_char(&buffer);
 731                 msg = buffer_get_string(&buffer, NULL);
 732                 mlen = strlen(msg);
 733                 switch (type) {
 734                 case PAM_PROMPT_ECHO_ON:
 735                 case PAM_PROMPT_ECHO_OFF:
 736                         *num = 1;
 737                         len = plen + mlen + 1;
 738                         **prompts = xreallocarray(**prompts, 1, len);
 739                         strlcpy(**prompts + plen, msg, len - plen);
 740                         plen += mlen;
 741                         **echo_on = (type == PAM_PROMPT_ECHO_ON);
 742                         free(msg);
 743                         return (0);
 744                 case PAM_ERROR_MSG:
 745                 case PAM_TEXT_INFO:
 746                         /* accumulate messages */
 747                         len = plen + mlen + 2;
 748                         **prompts = xreallocarray(**prompts, 1, len);
 749                         strlcpy(**prompts + plen, msg, len - plen);
 750                         plen += mlen;
 751                         strlcat(**prompts + plen, "\n", len - plen);
 752                         plen++;
 753                         free(msg);
 754                         break;
 755                 case PAM_ACCT_EXPIRED:
 756                 case PAM_MAXTRIES:
 757                         if (type == PAM_ACCT_EXPIRED)
 758                                 sshpam_account_status = 0;
 759                         if (type == PAM_MAXTRIES)
 760                                 sshpam_set_maxtries_reached(1);
 761                         /* FALLTHROUGH */
 762                 case PAM_AUTH_ERR:
 763                         debug3("PAM: %s", pam_strerror(sshpam_handle, type));
 764                         if (**prompts != NULL && strlen(**prompts) != 0) {
 765                                 *info = **prompts;
 766                                 **prompts = NULL;
 767                                 *num = 0;
 768                                 **echo_on = 0;
 769                                 ctxt->pam_done = -1;
 770                                 free(msg);
 771                                 return 0;
 772                         }
 773                         /* FALLTHROUGH */
 774                 case PAM_SUCCESS:
 775                         if (**prompts != NULL) {
 776                                 /* drain any accumulated messages */
 777                                 debug("PAM: %s", **prompts);
 778                                 buffer_append(&loginmsg, **prompts,
 779                                     strlen(**prompts));
 780                                 free(**prompts);
 781                                 **prompts = NULL;
 782                         }
 783                         if (type == PAM_SUCCESS) {
 784                                 if (!sshpam_authctxt->valid ||
 785                                     (sshpam_authctxt->pw->pw_uid == 0 &&
 786                                     options.permit_root_login != PERMIT_YES))
 787                                         fatal("Internal error: PAM auth "
 788                                             "succeeded when it should have "
 789                                             "failed");
 790                                 import_environments(&buffer);
 791                                 *num = 0;
 792                                 **echo_on = 0;
 793                                 ctxt->pam_done = 1;
 794                                 free(msg);
 795                                 return (0);
 796                         }
 797                         error("PAM: %s for %s%.100s from %.100s", msg,
 798                             sshpam_authctxt->valid ? "" : "illegal user ",
 799                             sshpam_authctxt->user,
 800                             auth_get_canonical_hostname(ssh, options.use_dns));
 801                         /* FALLTHROUGH */
 802                 default:
 803                         *num = 0;
 804                         **echo_on = 0;
 805                         free(msg);
 806                         ctxt->pam_done = -1;
 807                         return (-1);
 808                 }
 809         }
 810         return (-1);
 811 }
 812
 813 /*
 814  * Returns a junk password of identical length to that the user supplied.
 815  * Used to mitigate timing attacks against crypt(3)/PAM stacks that
 816  * vary processing time in proportion to password length.
 817  */
 818 static char *
 819 fake_password(const char *wire_password)
 820 {
 821         const char junk[] = "\b\n\r\177INCORRECT";
 822         char *ret = NULL;
 823         size_t i, l = wire_password != NULL ? strlen(wire_password) : 0;
 824
 825         if (l >= INT_MAX)
 826                 fatal("%s: password length too long: %zu", __func__, l);
 827
 828         ret = malloc(l + 1);
 829         for (i = 0; i < l; i++)
 830                 ret[i] = junk[i % (sizeof(junk) - 1)];
 831         ret[i] = '\0';
 832         return ret;
 833 }
 834
 835 /* XXX - see also comment in auth-chall.c:verify_response */
 836 static int
 837 sshpam_respond(void *ctx, u_int num, char **resp)
 838 {
 839         Buffer buffer;
 840         struct pam_ctxt *ctxt = ctx;
 841         char *fake;
 842
 843         debug2("PAM: %s entering, %u responses", __func__, num);
 844         switch (ctxt->pam_done) {
 845         case 1:
 846                 sshpam_authenticated = 1;
 847                 return (0);
 848         case 0:
 849                 break;
 850         default:
 851                 return (-1);
 852         }
 853         if (num != 1) {
 854                 error("PAM: expected one response, got %u", num);
 855                 return (-1);
 856         }
 857         buffer_init(&buffer);
 858         if (sshpam_authctxt->valid &&
 859             (sshpam_authctxt->pw->pw_uid != 0 ||
 860             options.permit_root_login == PERMIT_YES))
 861                 buffer_put_cstring(&buffer, *resp);
 862         else {
 863                 fake = fake_password(*resp);
 864                 buffer_put_cstring(&buffer, fake);
 865                 free(fake);
 866         }
 867         if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
 868                 buffer_free(&buffer);
 869                 return (-1);
 870         }
 871         buffer_free(&buffer);
 872         return (1);
 873 }
 874
 875 static void
 876 sshpam_free_ctx(void *ctxtp)
 877 {
 878         struct pam_ctxt *ctxt = ctxtp;
 879
 880         debug3("PAM: %s entering", __func__);
 881         sshpam_thread_cleanup();
 882         free(ctxt);
 883         /*
 884          * We don't call sshpam_cleanup() here because we may need the PAM
 885          * handle at a later stage, e.g. when setting up a session.  It's
 886          * still on the cleanup list, so pam_end() *will* be called before
 887          * the server process terminates.
 888          */
 889 }
 890
 891 KbdintDevice sshpam_device = {
 892         "pam",
 893         sshpam_init_ctx,
 894         sshpam_query,
 895         sshpam_respond,
 896         sshpam_free_ctx
 897 };
 898
 899 KbdintDevice mm_sshpam_device = {
 900         "pam",
 901         mm_sshpam_init_ctx,
 902         mm_sshpam_query,
 903         mm_sshpam_respond,
 904         mm_sshpam_free_ctx
 905 };
 906
 907 /*
 908  * This replaces auth-pam.c
 909  */
 910 void
 911 start_pam(Authctxt *authctxt)
 912 {
 913         if (!options.use_pam)
 914                 fatal("PAM: initialisation requested when UsePAM=no");
 915
 916         if (sshpam_init(authctxt) == -1)
 917                 fatal("PAM: initialisation failed");
 918 }
 919
 920 void
 921 finish_pam(void)
 922 {
 923         sshpam_cleanup();
 924 }
 925
 926 u_int
 927 do_pam_account(void)
 928 {
 929         debug("%s: called", __func__);
 930         if (sshpam_account_status != -1)
 931                 return (sshpam_account_status);
 932
 933         sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
 934         debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
 935             pam_strerror(sshpam_handle, sshpam_err));
 936
 937         if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
 938                 sshpam_account_status = 0;
 939                 return (sshpam_account_status);
 940         }
 941
 942         if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
 943                 sshpam_password_change_required(1);
 944
 945         sshpam_account_status = 1;
 946         return (sshpam_account_status);
 947 }
 948
 949 void
 950 do_pam_set_tty(const char *tty)
 951 {
 952         if (tty != NULL) {
 953                 debug("PAM: setting PAM_TTY to \"%s\"", tty);
 954                 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
 955                 if (sshpam_err != PAM_SUCCESS)
 956                         fatal("PAM: failed to set PAM_TTY: %s",
 957                             pam_strerror(sshpam_handle, sshpam_err));
 958         }
 959 }
 960
 961 void
 962 do_pam_setcred(int init)
 963 {
 964         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 965             (const void *)&store_conv);
 966         if (sshpam_err != PAM_SUCCESS)
 967                 fatal("PAM: failed to set PAM_CONV: %s",
 968                     pam_strerror(sshpam_handle, sshpam_err));
 969         if (init) {
 970                 debug("PAM: establishing credentials");
 971                 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
 972         } else {
 973                 debug("PAM: reinitializing credentials");
 974                 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
 975         }
 976         if (sshpam_err == PAM_SUCCESS) {
 977                 sshpam_cred_established = 1;
 978                 return;
 979         }
 980         if (sshpam_authenticated)
 981                 fatal("PAM: pam_setcred(): %s",
 982                     pam_strerror(sshpam_handle, sshpam_err));
 983         else
 984                 debug("PAM: pam_setcred(): %s",
 985                     pam_strerror(sshpam_handle, sshpam_err));
 986 }
 987
 988 static int
 989 sshpam_tty_conv(int n, sshpam_const struct pam_message **msg,
 990     struct pam_response **resp, void *data)
 991 {
 992         char input[PAM_MAX_MSG_SIZE];
 993         struct pam_response *reply;
 994         int i;
 995
 996         debug3("PAM: %s called with %d messages", __func__, n);
 997
 998         *resp = NULL;
 999
1000         if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
1001                 return (PAM_CONV_ERR);
1002
1003         if ((reply = calloc(n, sizeof(*reply))) == NULL)
1004                 return (PAM_CONV_ERR);
1005
1006         for (i = 0; i < n; ++i) {
1007                 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1008                 case PAM_PROMPT_ECHO_OFF:
1009                         reply[i].resp =
1010                             read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
1011                             RP_ALLOW_STDIN);
1012                         reply[i].resp_retcode = PAM_SUCCESS;
1013                         break;
1014                 case PAM_PROMPT_ECHO_ON:
1015                         fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
1016                         if (fgets(input, sizeof input, stdin) == NULL)
1017                                 input[0] = '\0';
1018                         if ((reply[i].resp = strdup(input)) == NULL)
1019                                 goto fail;
1020                         reply[i].resp_retcode = PAM_SUCCESS;
1021                         break;
1022                 case PAM_ERROR_MSG:
1023                 case PAM_TEXT_INFO:
1024                         fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
1025                         reply[i].resp_retcode = PAM_SUCCESS;
1026                         break;
1027                 default:
1028                         goto fail;
1029                 }
1030         }
1031         *resp = reply;
1032         return (PAM_SUCCESS);
1033
1034  fail:
1035         for(i = 0; i < n; i++) {
1036                 free(reply[i].resp);
1037         }
1038         free(reply);
1039         return (PAM_CONV_ERR);
1040 }
1041
1042 static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
1043
1044 /*
1045  * XXX this should be done in the authentication phase, but ssh1 doesn't
1046  * support that
1047  */
1048 void
1049 do_pam_chauthtok(void)
1050 {
1051         if (use_privsep)
1052                 fatal("Password expired (unable to change with privsep)");
1053         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1054             (const void *)&tty_conv);
1055         if (sshpam_err != PAM_SUCCESS)
1056                 fatal("PAM: failed to set PAM_CONV: %s",
1057                     pam_strerror(sshpam_handle, sshpam_err));
1058         debug("PAM: changing password");
1059         sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
1060         if (sshpam_err != PAM_SUCCESS)
1061                 fatal("PAM: pam_chauthtok(): %s",
1062                     pam_strerror(sshpam_handle, sshpam_err));
1063 }
1064
1065 void
1066 do_pam_session(void)
1067 {
1068         debug3("PAM: opening session");
1069         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1070             (const void *)&store_conv);
1071         if (sshpam_err != PAM_SUCCESS)
1072                 fatal("PAM: failed to set PAM_CONV: %s",
1073                     pam_strerror(sshpam_handle, sshpam_err));
1074         sshpam_err = pam_open_session(sshpam_handle, 0);
1075         if (sshpam_err == PAM_SUCCESS)
1076                 sshpam_session_open = 1;
1077         else {
1078                 sshpam_session_open = 0;
1079                 disable_forwarding();
1080                 error("PAM: pam_open_session(): %s",
1081                     pam_strerror(sshpam_handle, sshpam_err));
1082         }
1083
1084 }
1085
1086 int
1087 is_pam_session_open(void)
1088 {
1089         return sshpam_session_open;
1090 }
1091
1092 /*
1093  * Set a PAM environment string. We need to do this so that the session
1094  * modules can handle things like Kerberos/GSI credentials that appear
1095  * during the ssh authentication process.
1096  */
1097 int
1098 do_pam_putenv(char *name, char *value)
1099 {
1100         int ret = 1;
1101 #ifdef HAVE_PAM_PUTENV
1102         char *compound;
1103         size_t len;
1104
1105         len = strlen(name) + strlen(value) + 2;
1106         compound = xmalloc(len);
1107
1108         snprintf(compound, len, "%s=%s", name, value);
1109         ret = pam_putenv(sshpam_handle, compound);
1110         free(compound);
1111 #endif
1112
1113         return (ret);
1114 }
1115
1116 char **
1117 fetch_pam_child_environment(void)
1118 {
1119         return sshpam_env;
1120 }
1121
1122 char **
1123 fetch_pam_environment(void)
1124 {
1125         return (pam_getenvlist(sshpam_handle));
1126 }
1127
1128 void
1129 free_pam_environment(char **env)
1130 {
1131         char **envp;
1132
1133         if (env == NULL)
1134                 return;
1135
1136         for (envp = env; *envp; envp++)
1137                 free(*envp);
1138         free(env);
1139 }
1140
1141 /*
1142  * "Blind" conversation function for password authentication.  Assumes that
1143  * echo-off prompts are for the password and stores messages for later
1144  * display.
1145  */
1146 static int
1147 sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg,
1148     struct pam_response **resp, void *data)
1149 {
1150         struct pam_response *reply;
1151         int i;
1152         size_t len;
1153
1154         debug3("PAM: %s called with %d messages", __func__, n);
1155
1156         *resp = NULL;
1157
1158         if (n <= 0 || n > PAM_MAX_NUM_MSG)
1159                 return (PAM_CONV_ERR);
1160
1161         if ((reply = calloc(n, sizeof(*reply))) == NULL)
1162                 return (PAM_CONV_ERR);
1163
1164         for (i = 0; i < n; ++i) {
1165                 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1166                 case PAM_PROMPT_ECHO_OFF:
1167                         if (sshpam_password == NULL)
1168                                 goto fail;
1169                         if ((reply[i].resp = strdup(sshpam_password)) == NULL)
1170                                 goto fail;
1171                         reply[i].resp_retcode = PAM_SUCCESS;
1172                         break;
1173                 case PAM_ERROR_MSG:
1174                 case PAM_TEXT_INFO:
1175                         len = strlen(PAM_MSG_MEMBER(msg, i, msg));
1176                         if (len > 0) {
1177                                 buffer_append(&loginmsg,
1178                                     PAM_MSG_MEMBER(msg, i, msg), len);
1179                                 buffer_append(&loginmsg, "\n", 1);
1180                         }
1181                         if ((reply[i].resp = strdup("")) == NULL)
1182                                 goto fail;
1183                         reply[i].resp_retcode = PAM_SUCCESS;
1184                         break;
1185                 default:
1186                         goto fail;
1187                 }
1188         }
1189         *resp = reply;
1190         return (PAM_SUCCESS);
1191
1192  fail:
1193         for(i = 0; i < n; i++) {
1194                 free(reply[i].resp);
1195         }
1196         free(reply);
1197         return (PAM_CONV_ERR);
1198 }
1199
1200 static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
1201
1202 /*
1203  * Attempt password authentication via PAM
1204  */
1205 int
1206 sshpam_auth_passwd(Authctxt *authctxt, const char *password)
1207 {
1208         int flags = (options.permit_empty_passwd == 0 ?
1209             PAM_DISALLOW_NULL_AUTHTOK : 0);
1210         char *fake = NULL;
1211
1212         if (!options.use_pam || sshpam_handle == NULL)
1213                 fatal("PAM: %s called when PAM disabled or failed to "
1214                     "initialise.", __func__);
1215
1216         sshpam_password = password;
1217         sshpam_authctxt = authctxt;
1218
1219         /*
1220          * If the user logging in is invalid, or is root but is not permitted
1221          * by PermitRootLogin, use an invalid password to prevent leaking
1222          * information via timing (eg if the PAM config has a delay on fail).
1223          */
1224         if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
1225             options.permit_root_login != PERMIT_YES))
1226                 sshpam_password = fake = fake_password(password);
1227
1228         sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1229             (const void *)&passwd_conv);
1230         if (sshpam_err != PAM_SUCCESS)
1231                 fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
1232                     pam_strerror(sshpam_handle, sshpam_err));
1233
1234         sshpam_err = pam_authenticate(sshpam_handle, flags);
1235         sshpam_password = NULL;
1236         free(fake);
1237         if (sshpam_err == PAM_MAXTRIES)
1238                 sshpam_set_maxtries_reached(1);
1239         if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
1240                 debug("PAM: password authentication accepted for %.100s",
1241                     authctxt->user);
1242                 return 1;
1243         } else {
1244                 debug("PAM: password authentication failed for %.100s: %s",
1245                     authctxt->valid ? authctxt->user : "an illegal user",
1246                     pam_strerror(sshpam_handle, sshpam_err));
1247                 return 0;
1248         }
1249 }
1250
1251 int
1252 sshpam_get_maxtries_reached(void)
1253 {
1254         return sshpam_maxtries_reached;
1255 }
1256
1257 void
1258 sshpam_set_maxtries_reached(int reached)
1259 {
1260         if (reached == 0 || sshpam_maxtries_reached)
1261                 return;
1262         sshpam_maxtries_reached = 1;
1263         options.password_authentication = 0;
1264         options.kbd_interactive_authentication = 0;
1265         options.challenge_response_authentication = 0;
1266 }
1267 #endif /* USE_PAM */