2 * Copyright (c) 2002 Networks Associates Technology, Inc.
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.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
32 * Copyright (c) 2003,2004 Damien Miller <djm@mindrot.org>
33 * Copyright (c) 2003,2004 Darren Tucker <dtucker@zip.com.au>
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.
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.
48 /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
53 #if defined(HAVE_SECURITY_PAM_APPL_H)
54 #include <security/pam_appl.h>
55 #elif defined (HAVE_PAM_PAM_APPL_H)
56 #include <pam/pam_appl.h>
65 #include "monitor_wrap.h"
72 #include "auth-options.h"
74 extern ServerOptions options;
75 extern Buffer loginmsg;
77 extern u_int utmp_len;
79 #ifdef USE_POSIX_THREADS
82 * Avoid namespace clash when *not* using pthreads for systems *with*
83 * pthreads, which unconditionally define pthread_t via sys/types.h
86 typedef pthread_t sp_pthread_t;
88 typedef pid_t sp_pthread_t;
92 sp_pthread_t pam_thread;
98 static void sshpam_free_ctx(void *);
99 static struct pam_ctxt *cleanup_ctxt;
101 #ifndef USE_POSIX_THREADS
103 * Simulate threads with processes.
106 static int sshpam_thread_status = -1;
107 static mysig_t sshpam_oldsig;
110 sshpam_sigchld_handler(int sig)
112 signal(SIGCHLD, SIG_DFL);
113 if (cleanup_ctxt == NULL)
114 return; /* handler called after PAM cleanup, shouldn't happen */
115 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG)
117 /* PAM thread has not exitted, privsep slave must have */
118 kill(cleanup_ctxt->pam_thread, SIGTERM);
119 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0)
121 return; /* could not wait */
123 if (WIFSIGNALED(sshpam_thread_status) &&
124 WTERMSIG(sshpam_thread_status) == SIGTERM)
125 return; /* terminated by pthread_cancel */
126 if (!WIFEXITED(sshpam_thread_status))
127 fatal("PAM: authentication thread exited unexpectedly");
128 if (WEXITSTATUS(sshpam_thread_status) != 0)
129 fatal("PAM: authentication thread exited uncleanly");
133 pthread_exit(void *value __unused)
139 pthread_create(sp_pthread_t *thread, const void *attr __unused,
140 void *(*thread_start)(void *), void *arg)
144 sshpam_thread_status = -1;
145 switch ((pid = fork())) {
147 error("fork(): %s", strerror(errno));
154 sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
160 pthread_cancel(sp_pthread_t thread)
162 signal(SIGCHLD, sshpam_oldsig);
163 return (kill(thread, SIGTERM));
167 pthread_join(sp_pthread_t thread, void **value __unused)
171 if (sshpam_thread_status != -1)
172 return (sshpam_thread_status);
173 signal(SIGCHLD, sshpam_oldsig);
174 waitpid(thread, &status, 0);
180 static pam_handle_t *sshpam_handle = NULL;
181 static int sshpam_err = 0;
182 static int sshpam_authenticated = 0;
183 static int sshpam_session_open = 0;
184 static int sshpam_cred_established = 0;
185 static int sshpam_account_status = -1;
186 static char **sshpam_env = NULL;
187 static Authctxt *sshpam_authctxt = NULL;
188 static const char *sshpam_password = NULL;
189 static char badpw[] = "\b\n\r\177INCORRECT";
191 /* Some PAM implementations don't implement this */
192 #ifndef HAVE_PAM_GETENVLIST
194 pam_getenvlist(pam_handle_t *pamh)
197 * XXX - If necessary, we can still support envrionment passing
198 * for platforms without pam_getenvlist by searching for known
199 * env vars (e.g. KRB5CCNAME) from the PAM environment.
206 * Some platforms, notably Solaris, do not enforce password complexity
207 * rules during pam_chauthtok() if the real uid of the calling process
208 * is 0, on the assumption that it's being called by "passwd" run by root.
209 * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
212 #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
214 sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
218 if (sshpam_authctxt == NULL)
219 fatal("PAM: sshpam_authctxt not initialized");
220 if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
221 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
222 result = pam_chauthtok(pamh, flags);
223 if (setreuid(0, -1) == -1)
224 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
227 # define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b)))
231 sshpam_password_change_required(int reqd)
233 debug3("%s %d", __func__, reqd);
234 if (sshpam_authctxt == NULL)
235 fatal("%s: PAM authctxt not initialized", __func__);
236 sshpam_authctxt->force_pwchange = reqd;
238 no_port_forwarding_flag |= 2;
239 no_agent_forwarding_flag |= 2;
240 no_x11_forwarding_flag |= 2;
242 no_port_forwarding_flag &= ~2;
243 no_agent_forwarding_flag &= ~2;
244 no_x11_forwarding_flag &= ~2;
248 /* Import regular and PAM environment from subprocess */
250 import_environments(Buffer *b)
256 debug3("PAM: %s entering", __func__);
258 #ifndef USE_POSIX_THREADS
259 /* Import variables set by do_pam_account */
260 sshpam_account_status = buffer_get_int(b);
261 sshpam_password_change_required(buffer_get_int(b));
263 /* Import environment from subprocess */
264 num_env = buffer_get_int(b);
265 sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env));
266 debug3("PAM: num env strings %d", num_env);
267 for(i = 0; i < num_env; i++)
268 sshpam_env[i] = buffer_get_string(b, NULL);
270 sshpam_env[num_env] = NULL;
272 /* Import PAM environment from subprocess */
273 num_env = buffer_get_int(b);
274 debug("PAM: num PAM env strings %d", num_env);
275 for(i = 0; i < num_env; i++) {
276 env = buffer_get_string(b, NULL);
278 #ifdef HAVE_PAM_PUTENV
279 /* Errors are not fatal here */
280 if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
281 error("PAM: pam_putenv: %s",
282 pam_strerror(sshpam_handle, sshpam_err));
290 * Conversation function for authentication thread.
293 sshpam_thread_conv(int n, struct pam_message **msg,
294 struct pam_response **resp, void *data)
297 struct pam_ctxt *ctxt;
298 struct pam_response *reply;
301 debug3("PAM: %s entering, %d messages", __func__, n);
305 error("PAM: conversation function passed a null context");
306 return (PAM_CONV_ERR);
309 if (n <= 0 || n > PAM_MAX_NUM_MSG)
310 return (PAM_CONV_ERR);
312 if ((reply = malloc(n * sizeof(*reply))) == NULL)
313 return (PAM_CONV_ERR);
314 memset(reply, 0, n * sizeof(*reply));
316 buffer_init(&buffer);
317 for (i = 0; i < n; ++i) {
318 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
319 case PAM_PROMPT_ECHO_OFF:
320 buffer_put_cstring(&buffer,
321 PAM_MSG_MEMBER(msg, i, msg));
322 if (ssh_msg_send(ctxt->pam_csock,
323 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
325 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
327 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
329 reply[i].resp = buffer_get_string(&buffer, NULL);
331 case PAM_PROMPT_ECHO_ON:
332 buffer_put_cstring(&buffer,
333 PAM_MSG_MEMBER(msg, i, msg));
334 if (ssh_msg_send(ctxt->pam_csock,
335 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
337 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
339 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
341 reply[i].resp = buffer_get_string(&buffer, NULL);
344 buffer_put_cstring(&buffer,
345 PAM_MSG_MEMBER(msg, i, msg));
346 if (ssh_msg_send(ctxt->pam_csock,
347 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
351 buffer_put_cstring(&buffer,
352 PAM_MSG_MEMBER(msg, i, msg));
353 if (ssh_msg_send(ctxt->pam_csock,
354 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
360 buffer_clear(&buffer);
362 buffer_free(&buffer);
364 return (PAM_SUCCESS);
367 for(i = 0; i < n; i++) {
368 if (reply[i].resp != NULL)
369 xfree(reply[i].resp);
372 buffer_free(&buffer);
373 return (PAM_CONV_ERR);
377 * Authentication thread.
380 sshpam_thread(void *ctxtp)
382 struct pam_ctxt *ctxt = ctxtp;
384 struct pam_conv sshpam_conv;
385 int flags = (options.permit_empty_passwd == 0 ?
386 PAM_DISALLOW_NULL_AUTHTOK : 0);
387 #ifndef USE_POSIX_THREADS
388 extern char **environ;
391 const char *pam_user;
393 pam_get_item(sshpam_handle, PAM_USER, (void **)&pam_user);
396 if (sshpam_authctxt != NULL) {
397 setproctitle("%s [pam]",
398 sshpam_authctxt->valid ? pam_user : "unknown");
402 sshpam_conv.conv = sshpam_thread_conv;
403 sshpam_conv.appdata_ptr = ctxt;
405 if (sshpam_authctxt == NULL)
406 fatal("%s: PAM authctxt not initialized", __func__);
408 buffer_init(&buffer);
409 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
410 (const void *)&sshpam_conv);
411 if (sshpam_err != PAM_SUCCESS)
413 sshpam_err = pam_authenticate(sshpam_handle, flags);
414 if (sshpam_err != PAM_SUCCESS)
418 if (!do_pam_account())
420 if (sshpam_authctxt->force_pwchange) {
421 sshpam_err = pam_chauthtok(sshpam_handle,
422 PAM_CHANGE_EXPIRED_AUTHTOK);
423 if (sshpam_err != PAM_SUCCESS)
425 sshpam_password_change_required(0);
429 buffer_put_cstring(&buffer, "OK");
431 #ifndef USE_POSIX_THREADS
432 /* Export variables set by do_pam_account */
433 buffer_put_int(&buffer, sshpam_account_status);
434 buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
436 /* Export any environment strings set in child */
437 for(i = 0; environ[i] != NULL; i++)
439 buffer_put_int(&buffer, i);
440 for(i = 0; environ[i] != NULL; i++)
441 buffer_put_cstring(&buffer, environ[i]);
443 /* Export any environment strings set by PAM in child */
444 env_from_pam = pam_getenvlist(sshpam_handle);
445 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
447 buffer_put_int(&buffer, i);
448 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
449 buffer_put_cstring(&buffer, env_from_pam[i]);
450 #endif /* USE_POSIX_THREADS */
452 /* XXX - can't do much about an error here */
453 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
454 buffer_free(&buffer);
458 buffer_put_cstring(&buffer,
459 pam_strerror(sshpam_handle, sshpam_err));
460 /* XXX - can't do much about an error here */
461 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
462 buffer_free(&buffer);
465 return (NULL); /* Avoid warning for non-pthread case */
469 sshpam_thread_cleanup(void)
471 struct pam_ctxt *ctxt = cleanup_ctxt;
473 debug3("PAM: %s entering", __func__);
474 if (ctxt != NULL && ctxt->pam_thread != 0) {
475 pthread_cancel(ctxt->pam_thread);
476 pthread_join(ctxt->pam_thread, NULL);
477 close(ctxt->pam_psock);
478 close(ctxt->pam_csock);
479 memset(ctxt, 0, sizeof(*ctxt));
485 sshpam_null_conv(int n, struct pam_message **msg,
486 struct pam_response **resp, void *data)
488 debug3("PAM: %s entering, %d messages", __func__, n);
489 return (PAM_CONV_ERR);
492 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
495 sshpam_store_conv(int n, struct pam_message **msg,
496 struct pam_response **resp, void *data)
498 struct pam_response *reply;
502 debug3("PAM: %s called with %d messages", __func__, n);
505 if (n <= 0 || n > PAM_MAX_NUM_MSG)
506 return (PAM_CONV_ERR);
508 if ((reply = malloc(n * sizeof(*reply))) == NULL)
509 return (PAM_CONV_ERR);
510 memset(reply, 0, n * sizeof(*reply));
512 for (i = 0; i < n; ++i) {
513 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
516 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
517 buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
518 buffer_append(&loginmsg, "\n", 1 );
519 reply[i].resp_retcode = PAM_SUCCESS;
526 return (PAM_SUCCESS);
529 for(i = 0; i < n; i++) {
530 if (reply[i].resp != NULL)
531 xfree(reply[i].resp);
534 return (PAM_CONV_ERR);
537 static struct pam_conv store_conv = { sshpam_store_conv, NULL };
542 debug("PAM: cleanup");
543 if (sshpam_handle == NULL)
545 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
546 if (sshpam_cred_established) {
547 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
548 sshpam_cred_established = 0;
550 if (sshpam_session_open) {
551 pam_close_session(sshpam_handle, PAM_SILENT);
552 sshpam_session_open = 0;
554 sshpam_authenticated = 0;
555 pam_end(sshpam_handle, sshpam_err);
556 sshpam_handle = NULL;
560 sshpam_init(Authctxt *authctxt)
562 extern char *__progname;
563 const char *pam_rhost, *pam_user, *user = authctxt->user;
565 if (sshpam_handle != NULL) {
566 /* We already have a PAM context; check if the user matches */
567 sshpam_err = pam_get_item(sshpam_handle,
568 PAM_USER, (void **)&pam_user);
569 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
571 pam_end(sshpam_handle, sshpam_err);
572 sshpam_handle = NULL;
574 debug("PAM: initializing for \"%s\"", user);
576 pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
577 sshpam_authctxt = authctxt;
579 if (sshpam_err != PAM_SUCCESS) {
580 pam_end(sshpam_handle, sshpam_err);
581 sshpam_handle = NULL;
584 pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
585 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
586 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
587 if (sshpam_err != PAM_SUCCESS) {
588 pam_end(sshpam_handle, sshpam_err);
589 sshpam_handle = NULL;
592 #ifdef PAM_TTY_KLUDGE
594 * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
595 * sshd doesn't set the tty until too late in the auth process and
596 * may not even set one (for tty-less connections)
598 debug("PAM: setting PAM_TTY to \"ssh\"");
599 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
600 if (sshpam_err != PAM_SUCCESS) {
601 pam_end(sshpam_handle, sshpam_err);
602 sshpam_handle = NULL;
610 sshpam_init_ctx(Authctxt *authctxt)
612 struct pam_ctxt *ctxt;
615 debug3("PAM: %s entering", __func__);
616 /* Refuse to start if we don't have PAM enabled */
617 if (!options.use_pam)
621 if (sshpam_init(authctxt) == -1) {
622 error("PAM: initialization failed");
626 ctxt = xmalloc(sizeof *ctxt);
627 memset(ctxt, 0, sizeof(*ctxt));
629 /* Start the authentication thread */
630 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
631 error("PAM: failed create sockets: %s", strerror(errno));
635 ctxt->pam_psock = socks[0];
636 ctxt->pam_csock = socks[1];
637 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
638 error("PAM: failed to start authentication thread: %s",
650 sshpam_query(void *ctx, char **name, char **info,
651 u_int *num, char ***prompts, u_int **echo_on)
654 struct pam_ctxt *ctxt = ctx;
660 debug3("PAM: %s entering", __func__);
661 buffer_init(&buffer);
664 *prompts = xmalloc(sizeof(char *));
667 *echo_on = xmalloc(sizeof(u_int));
668 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
669 type = buffer_get_char(&buffer);
670 msg = buffer_get_string(&buffer, NULL);
673 case PAM_PROMPT_ECHO_ON:
674 case PAM_PROMPT_ECHO_OFF:
676 len = plen + mlen + 1;
677 **prompts = xrealloc(**prompts, len);
678 strlcpy(**prompts + plen, msg, len - plen);
680 **echo_on = (type == PAM_PROMPT_ECHO_ON);
685 /* accumulate messages */
686 len = plen + mlen + 2;
687 **prompts = xrealloc(**prompts, len);
688 strlcpy(**prompts + plen, msg, len - plen);
690 strlcat(**prompts + plen, "\n", len - plen);
696 if (**prompts != NULL) {
697 /* drain any accumulated messages */
698 debug("PAM: %s", **prompts);
699 buffer_append(&loginmsg, **prompts,
704 if (type == PAM_SUCCESS) {
705 if (!sshpam_authctxt->valid ||
706 (sshpam_authctxt->pw->pw_uid == 0 &&
707 options.permit_root_login != PERMIT_YES))
708 fatal("Internal error: PAM auth "
709 "succeeded when it should have "
711 import_environments(&buffer);
718 error("PAM: %s for %s%.100s from %.100s", msg,
719 sshpam_authctxt->valid ? "" : "illegal user ",
720 sshpam_authctxt->user,
721 get_remote_name_or_ip(utmp_len, options.use_dns));
734 /* XXX - see also comment in auth-chall.c:verify_response */
736 sshpam_respond(void *ctx, u_int num, char **resp)
739 struct pam_ctxt *ctxt = ctx;
741 debug2("PAM: %s entering, %d responses", __func__, num);
742 switch (ctxt->pam_done) {
744 sshpam_authenticated = 1;
752 error("PAM: expected one response, got %u", num);
755 buffer_init(&buffer);
756 if (sshpam_authctxt->valid &&
757 (sshpam_authctxt->pw->pw_uid != 0 ||
758 options.permit_root_login == PERMIT_YES))
759 buffer_put_cstring(&buffer, *resp);
761 buffer_put_cstring(&buffer, badpw);
762 if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
763 buffer_free(&buffer);
766 buffer_free(&buffer);
771 sshpam_free_ctx(void *ctxtp)
773 struct pam_ctxt *ctxt = ctxtp;
775 debug3("PAM: %s entering", __func__);
776 sshpam_thread_cleanup();
779 * We don't call sshpam_cleanup() here because we may need the PAM
780 * handle at a later stage, e.g. when setting up a session. It's
781 * still on the cleanup list, so pam_end() *will* be called before
782 * the server process terminates.
786 KbdintDevice sshpam_device = {
794 KbdintDevice mm_sshpam_device = {
803 * This replaces auth-pam.c
806 start_pam(Authctxt *authctxt)
808 if (!options.use_pam)
809 fatal("PAM: initialisation requested when UsePAM=no");
811 if (sshpam_init(authctxt) == -1)
812 fatal("PAM: initialisation failed");
824 debug("%s: called", __func__);
825 if (sshpam_account_status != -1)
826 return (sshpam_account_status);
828 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
829 debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
830 pam_strerror(sshpam_handle, sshpam_err));
832 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
833 sshpam_account_status = 0;
834 return (sshpam_account_status);
837 if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
838 sshpam_password_change_required(1);
840 sshpam_account_status = 1;
841 return (sshpam_account_status);
845 do_pam_set_tty(const char *tty)
848 debug("PAM: setting PAM_TTY to \"%s\"", tty);
849 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
850 if (sshpam_err != PAM_SUCCESS)
851 fatal("PAM: failed to set PAM_TTY: %s",
852 pam_strerror(sshpam_handle, sshpam_err));
857 do_pam_setcred(int init)
859 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
860 (const void *)&store_conv);
861 if (sshpam_err != PAM_SUCCESS)
862 fatal("PAM: failed to set PAM_CONV: %s",
863 pam_strerror(sshpam_handle, sshpam_err));
865 debug("PAM: establishing credentials");
866 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
868 debug("PAM: reinitializing credentials");
869 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
871 if (sshpam_err == PAM_SUCCESS) {
872 sshpam_cred_established = 1;
875 if (sshpam_authenticated)
876 fatal("PAM: pam_setcred(): %s",
877 pam_strerror(sshpam_handle, sshpam_err));
879 debug("PAM: pam_setcred(): %s",
880 pam_strerror(sshpam_handle, sshpam_err));
884 sshpam_tty_conv(int n, struct pam_message **msg,
885 struct pam_response **resp, void *data)
887 char input[PAM_MAX_MSG_SIZE];
888 struct pam_response *reply;
891 debug3("PAM: %s called with %d messages", __func__, n);
895 if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
896 return (PAM_CONV_ERR);
898 if ((reply = malloc(n * sizeof(*reply))) == NULL)
899 return (PAM_CONV_ERR);
900 memset(reply, 0, n * sizeof(*reply));
902 for (i = 0; i < n; ++i) {
903 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
904 case PAM_PROMPT_ECHO_OFF:
906 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
908 reply[i].resp_retcode = PAM_SUCCESS;
910 case PAM_PROMPT_ECHO_ON:
911 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
912 fgets(input, sizeof input, stdin);
913 if ((reply[i].resp = strdup(input)) == NULL)
915 reply[i].resp_retcode = PAM_SUCCESS;
919 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
920 reply[i].resp_retcode = PAM_SUCCESS;
927 return (PAM_SUCCESS);
930 for(i = 0; i < n; i++) {
931 if (reply[i].resp != NULL)
932 xfree(reply[i].resp);
935 return (PAM_CONV_ERR);
938 static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
941 * XXX this should be done in the authentication phase, but ssh1 doesn't
945 do_pam_chauthtok(void)
948 fatal("Password expired (unable to change with privsep)");
949 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
950 (const void *)&tty_conv);
951 if (sshpam_err != PAM_SUCCESS)
952 fatal("PAM: failed to set PAM_CONV: %s",
953 pam_strerror(sshpam_handle, sshpam_err));
954 debug("PAM: changing password");
955 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
956 if (sshpam_err != PAM_SUCCESS)
957 fatal("PAM: pam_chauthtok(): %s",
958 pam_strerror(sshpam_handle, sshpam_err));
964 debug3("PAM: opening session");
965 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
966 (const void *)&store_conv);
967 if (sshpam_err != PAM_SUCCESS)
968 fatal("PAM: failed to set PAM_CONV: %s",
969 pam_strerror(sshpam_handle, sshpam_err));
970 sshpam_err = pam_open_session(sshpam_handle, 0);
971 if (sshpam_err == PAM_SUCCESS)
972 sshpam_session_open = 1;
974 sshpam_session_open = 0;
975 disable_forwarding();
976 error("PAM: pam_open_session(): %s",
977 pam_strerror(sshpam_handle, sshpam_err));
983 is_pam_session_open(void)
985 return sshpam_session_open;
989 * Set a PAM environment string. We need to do this so that the session
990 * modules can handle things like Kerberos/GSI credentials that appear
991 * during the ssh authentication process.
994 do_pam_putenv(char *name, char *value)
997 #ifdef HAVE_PAM_PUTENV
1001 len = strlen(name) + strlen(value) + 2;
1002 compound = xmalloc(len);
1004 snprintf(compound, len, "%s=%s", name, value);
1005 ret = pam_putenv(sshpam_handle, compound);
1013 fetch_pam_child_environment(void)
1019 fetch_pam_environment(void)
1021 return (pam_getenvlist(sshpam_handle));
1025 free_pam_environment(char **env)
1032 for (envp = env; *envp; envp++)
1038 * "Blind" conversation function for password authentication. Assumes that
1039 * echo-off prompts are for the password and stores messages for later
1043 sshpam_passwd_conv(int n, struct pam_message **msg,
1044 struct pam_response **resp, void *data)
1046 struct pam_response *reply;
1050 debug3("PAM: %s called with %d messages", __func__, n);
1054 if (n <= 0 || n > PAM_MAX_NUM_MSG)
1055 return (PAM_CONV_ERR);
1057 if ((reply = malloc(n * sizeof(*reply))) == NULL)
1058 return (PAM_CONV_ERR);
1059 memset(reply, 0, n * sizeof(*reply));
1061 for (i = 0; i < n; ++i) {
1062 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1063 case PAM_PROMPT_ECHO_OFF:
1064 if (sshpam_password == NULL)
1066 if ((reply[i].resp = strdup(sshpam_password)) == NULL)
1068 reply[i].resp_retcode = PAM_SUCCESS;
1072 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
1074 buffer_append(&loginmsg,
1075 PAM_MSG_MEMBER(msg, i, msg), len);
1076 buffer_append(&loginmsg, "\n", 1);
1078 if ((reply[i].resp = strdup("")) == NULL)
1080 reply[i].resp_retcode = PAM_SUCCESS;
1087 return (PAM_SUCCESS);
1090 for(i = 0; i < n; i++) {
1091 if (reply[i].resp != NULL)
1092 xfree(reply[i].resp);
1095 return (PAM_CONV_ERR);
1098 static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
1101 * Attempt password authentication via PAM
1104 sshpam_auth_passwd(Authctxt *authctxt, const char *password)
1106 int flags = (options.permit_empty_passwd == 0 ?
1107 PAM_DISALLOW_NULL_AUTHTOK : 0);
1109 if (!options.use_pam || sshpam_handle == NULL)
1110 fatal("PAM: %s called when PAM disabled or failed to "
1111 "initialise.", __func__);
1113 sshpam_password = password;
1114 sshpam_authctxt = authctxt;
1117 * If the user logging in is invalid, or is root but is not permitted
1118 * by PermitRootLogin, use an invalid password to prevent leaking
1119 * information via timing (eg if the PAM config has a delay on fail).
1121 if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
1122 options.permit_root_login != PERMIT_YES))
1123 sshpam_password = badpw;
1125 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1126 (const void *)&passwd_conv);
1127 if (sshpam_err != PAM_SUCCESS)
1128 fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
1129 pam_strerror(sshpam_handle, sshpam_err));
1131 sshpam_err = pam_authenticate(sshpam_handle, flags);
1132 sshpam_password = NULL;
1133 if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
1134 debug("PAM: password authentication accepted for %.100s",
1138 debug("PAM: password authentication failed for %.100s: %s",
1139 authctxt->valid ? authctxt->user : "an illegal user",
1140 pam_strerror(sshpam_handle, sshpam_err));
1144 #endif /* USE_PAM */