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 */
52 #include <sys/types.h>
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>
69 /* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */
70 #ifdef PAM_SUN_CODEBASE
71 # define sshpam_const /* Solaris, HP-UX, AIX */
73 # define sshpam_const const /* LinuxPAM, OpenPAM */
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)
80 # define PAM_MSG_MEMBER(msg, n, member) ((msg)[(n)]->member)
96 #include "auth-options.h"
100 #include "monitor_wrap.h"
102 extern ServerOptions options;
103 extern Buffer loginmsg;
105 extern u_int utmp_len;
107 /* so we don't silently change behaviour */
108 #ifdef USE_POSIX_THREADS
109 # error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
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
117 #ifdef UNSUPPORTED_POSIX_THREADS_HACK
120 * Avoid namespace clash when *not* using pthreads for systems *with*
121 * pthreads, which unconditionally define pthread_t via sys/types.h
124 typedef pthread_t sp_pthread_t;
126 typedef pid_t sp_pthread_t;
130 sp_pthread_t pam_thread;
136 static void sshpam_free_ctx(void *);
137 static struct pam_ctxt *cleanup_ctxt;
139 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
141 * Simulate threads with processes.
144 static int sshpam_thread_status = -1;
145 static mysig_t sshpam_oldsig;
148 sshpam_sigchld_handler(int sig)
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)
155 /* PAM thread has not exitted, privsep slave must have */
156 kill(cleanup_ctxt->pam_thread, SIGTERM);
157 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0)
159 return; /* could not wait */
161 if (WIFSIGNALED(sshpam_thread_status) &&
162 WTERMSIG(sshpam_thread_status) == SIGTERM)
163 return; /* terminated by pthread_cancel */
164 if (!WIFEXITED(sshpam_thread_status))
165 sigdie("PAM: authentication thread exited unexpectedly");
166 if (WEXITSTATUS(sshpam_thread_status) != 0)
167 sigdie("PAM: authentication thread exited uncleanly");
172 pthread_exit(void *value)
179 pthread_create(sp_pthread_t *thread, const void *attr,
180 void *(*thread_start)(void *), void *arg)
183 struct pam_ctxt *ctx = arg;
185 sshpam_thread_status = -1;
186 switch ((pid = fork())) {
188 error("fork(): %s", strerror(errno));
191 close(ctx->pam_psock);
197 close(ctx->pam_csock);
199 sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
205 pthread_cancel(sp_pthread_t thread)
207 signal(SIGCHLD, sshpam_oldsig);
208 return (kill(thread, SIGTERM));
213 pthread_join(sp_pthread_t thread, void **value)
217 if (sshpam_thread_status != -1)
218 return (sshpam_thread_status);
219 signal(SIGCHLD, sshpam_oldsig);
220 waitpid(thread, &status, 0);
226 static pam_handle_t *sshpam_handle = NULL;
227 static int sshpam_err = 0;
228 static int sshpam_authenticated = 0;
229 static int sshpam_session_open = 0;
230 static int sshpam_cred_established = 0;
231 static int sshpam_account_status = -1;
232 static char **sshpam_env = NULL;
233 static Authctxt *sshpam_authctxt = NULL;
234 static const char *sshpam_password = NULL;
235 static char badpw[] = "\b\n\r\177INCORRECT";
237 /* Some PAM implementations don't implement this */
238 #ifndef HAVE_PAM_GETENVLIST
240 pam_getenvlist(pam_handle_t *pamh)
243 * XXX - If necessary, we can still support envrionment passing
244 * for platforms without pam_getenvlist by searching for known
245 * env vars (e.g. KRB5CCNAME) from the PAM environment.
252 * Some platforms, notably Solaris, do not enforce password complexity
253 * rules during pam_chauthtok() if the real uid of the calling process
254 * is 0, on the assumption that it's being called by "passwd" run by root.
255 * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
258 #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
260 sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
264 if (sshpam_authctxt == NULL)
265 fatal("PAM: sshpam_authctxt not initialized");
266 if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
267 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
268 result = pam_chauthtok(pamh, flags);
269 if (setreuid(0, -1) == -1)
270 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
273 # define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b)))
277 sshpam_password_change_required(int reqd)
279 debug3("%s %d", __func__, reqd);
280 if (sshpam_authctxt == NULL)
281 fatal("%s: PAM authctxt not initialized", __func__);
282 sshpam_authctxt->force_pwchange = reqd;
284 no_port_forwarding_flag |= 2;
285 no_agent_forwarding_flag |= 2;
286 no_x11_forwarding_flag |= 2;
288 no_port_forwarding_flag &= ~2;
289 no_agent_forwarding_flag &= ~2;
290 no_x11_forwarding_flag &= ~2;
294 /* Import regular and PAM environment from subprocess */
296 import_environments(Buffer *b)
302 debug3("PAM: %s entering", __func__);
304 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
305 /* Import variables set by do_pam_account */
306 sshpam_account_status = buffer_get_int(b);
307 sshpam_password_change_required(buffer_get_int(b));
309 /* Import environment from subprocess */
310 num_env = buffer_get_int(b);
312 fatal("%s: received %u environment variables, expected <= 1024",
314 sshpam_env = xcalloc(num_env + 1, sizeof(*sshpam_env));
315 debug3("PAM: num env strings %d", num_env);
316 for(i = 0; i < num_env; i++)
317 sshpam_env[i] = buffer_get_string(b, NULL);
319 sshpam_env[num_env] = NULL;
321 /* Import PAM environment from subprocess */
322 num_env = buffer_get_int(b);
323 debug("PAM: num PAM env strings %d", num_env);
324 for(i = 0; i < num_env; i++) {
325 env = buffer_get_string(b, NULL);
327 #ifdef HAVE_PAM_PUTENV
328 /* Errors are not fatal here */
329 if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
330 error("PAM: pam_putenv: %s",
331 pam_strerror(sshpam_handle, sshpam_err));
339 * Conversation function for authentication thread.
342 sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
343 struct pam_response **resp, void *data)
346 struct pam_ctxt *ctxt;
347 struct pam_response *reply;
350 debug3("PAM: %s entering, %d messages", __func__, n);
354 error("PAM: conversation function passed a null context");
355 return (PAM_CONV_ERR);
358 if (n <= 0 || n > PAM_MAX_NUM_MSG)
359 return (PAM_CONV_ERR);
361 if ((reply = calloc(n, sizeof(*reply))) == NULL)
362 return (PAM_CONV_ERR);
364 buffer_init(&buffer);
365 for (i = 0; i < n; ++i) {
366 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
367 case PAM_PROMPT_ECHO_OFF:
368 buffer_put_cstring(&buffer,
369 PAM_MSG_MEMBER(msg, i, msg));
370 if (ssh_msg_send(ctxt->pam_csock,
371 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
373 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
375 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
377 reply[i].resp = buffer_get_string(&buffer, NULL);
379 case PAM_PROMPT_ECHO_ON:
380 buffer_put_cstring(&buffer,
381 PAM_MSG_MEMBER(msg, i, msg));
382 if (ssh_msg_send(ctxt->pam_csock,
383 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
385 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
387 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
389 reply[i].resp = buffer_get_string(&buffer, NULL);
392 buffer_put_cstring(&buffer,
393 PAM_MSG_MEMBER(msg, i, msg));
394 if (ssh_msg_send(ctxt->pam_csock,
395 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
399 buffer_put_cstring(&buffer,
400 PAM_MSG_MEMBER(msg, i, msg));
401 if (ssh_msg_send(ctxt->pam_csock,
402 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
408 buffer_clear(&buffer);
410 buffer_free(&buffer);
412 return (PAM_SUCCESS);
415 for(i = 0; i < n; i++) {
419 buffer_free(&buffer);
420 return (PAM_CONV_ERR);
424 * Authentication thread.
427 sshpam_thread(void *ctxtp)
429 struct pam_ctxt *ctxt = ctxtp;
431 struct pam_conv sshpam_conv;
432 int flags = (options.permit_empty_passwd == 0 ?
433 PAM_DISALLOW_NULL_AUTHTOK : 0);
434 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
435 extern char **environ;
438 const char *pam_user;
439 const char **ptr_pam_user = &pam_user;
440 char *tz = getenv("TZ");
442 sshpam_err = pam_get_item(sshpam_handle, PAM_USER,
443 (sshpam_const void **)ptr_pam_user);
444 if (sshpam_err != PAM_SUCCESS)
449 if (setenv("TZ", tz, 1) == -1)
450 error("PAM: could not set TZ environment: %s",
453 if (sshpam_authctxt != NULL) {
454 setproctitle("%s [pam]",
455 sshpam_authctxt->valid ? pam_user : "unknown");
459 sshpam_conv.conv = sshpam_thread_conv;
460 sshpam_conv.appdata_ptr = ctxt;
462 if (sshpam_authctxt == NULL)
463 fatal("%s: PAM authctxt not initialized", __func__);
465 buffer_init(&buffer);
466 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
467 (const void *)&sshpam_conv);
468 if (sshpam_err != PAM_SUCCESS)
470 sshpam_err = pam_authenticate(sshpam_handle, flags);
471 if (sshpam_err != PAM_SUCCESS)
475 if (!do_pam_account()) {
476 sshpam_err = PAM_ACCT_EXPIRED;
479 if (sshpam_authctxt->force_pwchange) {
480 sshpam_err = pam_chauthtok(sshpam_handle,
481 PAM_CHANGE_EXPIRED_AUTHTOK);
482 if (sshpam_err != PAM_SUCCESS)
484 sshpam_password_change_required(0);
488 buffer_put_cstring(&buffer, "OK");
490 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
491 /* Export variables set by do_pam_account */
492 buffer_put_int(&buffer, sshpam_account_status);
493 buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
495 /* Export any environment strings set in child */
496 for(i = 0; environ[i] != NULL; i++)
498 buffer_put_int(&buffer, i);
499 for(i = 0; environ[i] != NULL; i++)
500 buffer_put_cstring(&buffer, environ[i]);
502 /* Export any environment strings set by PAM in child */
503 env_from_pam = pam_getenvlist(sshpam_handle);
504 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
506 buffer_put_int(&buffer, i);
507 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
508 buffer_put_cstring(&buffer, env_from_pam[i]);
509 #endif /* UNSUPPORTED_POSIX_THREADS_HACK */
511 /* XXX - can't do much about an error here */
512 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
513 buffer_free(&buffer);
517 buffer_put_cstring(&buffer,
518 pam_strerror(sshpam_handle, sshpam_err));
519 /* XXX - can't do much about an error here */
520 if (sshpam_err == PAM_ACCT_EXPIRED)
521 ssh_msg_send(ctxt->pam_csock, PAM_ACCT_EXPIRED, &buffer);
523 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
524 buffer_free(&buffer);
527 return (NULL); /* Avoid warning for non-pthread case */
531 sshpam_thread_cleanup(void)
533 struct pam_ctxt *ctxt = cleanup_ctxt;
535 debug3("PAM: %s entering", __func__);
536 if (ctxt != NULL && ctxt->pam_thread != 0) {
537 pthread_cancel(ctxt->pam_thread);
538 pthread_join(ctxt->pam_thread, NULL);
539 close(ctxt->pam_psock);
540 close(ctxt->pam_csock);
541 memset(ctxt, 0, sizeof(*ctxt));
547 sshpam_null_conv(int n, sshpam_const struct pam_message **msg,
548 struct pam_response **resp, void *data)
550 debug3("PAM: %s entering, %d messages", __func__, n);
551 return (PAM_CONV_ERR);
554 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
557 sshpam_store_conv(int n, sshpam_const struct pam_message **msg,
558 struct pam_response **resp, void *data)
560 struct pam_response *reply;
564 debug3("PAM: %s called with %d messages", __func__, n);
567 if (n <= 0 || n > PAM_MAX_NUM_MSG)
568 return (PAM_CONV_ERR);
570 if ((reply = calloc(n, sizeof(*reply))) == NULL)
571 return (PAM_CONV_ERR);
573 for (i = 0; i < n; ++i) {
574 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
577 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
578 buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
579 buffer_append(&loginmsg, "\n", 1 );
580 reply[i].resp_retcode = PAM_SUCCESS;
587 return (PAM_SUCCESS);
590 for(i = 0; i < n; i++) {
594 return (PAM_CONV_ERR);
597 static struct pam_conv store_conv = { sshpam_store_conv, NULL };
602 if (sshpam_handle == NULL || (use_privsep && !mm_is_monitor()))
604 debug("PAM: cleanup");
605 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
606 if (sshpam_session_open) {
607 debug("PAM: closing session");
608 pam_close_session(sshpam_handle, PAM_SILENT);
609 sshpam_session_open = 0;
611 if (sshpam_cred_established) {
612 debug("PAM: deleting credentials");
613 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
614 sshpam_cred_established = 0;
616 sshpam_authenticated = 0;
617 pam_end(sshpam_handle, sshpam_err);
618 sshpam_handle = NULL;
622 sshpam_init(Authctxt *authctxt)
624 extern char *__progname;
625 const char *pam_rhost, *pam_user, *user = authctxt->user;
626 const char **ptr_pam_user = &pam_user;
628 if (sshpam_handle != NULL) {
629 /* We already have a PAM context; check if the user matches */
630 sshpam_err = pam_get_item(sshpam_handle,
631 PAM_USER, (sshpam_const void **)ptr_pam_user);
632 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
634 pam_end(sshpam_handle, sshpam_err);
635 sshpam_handle = NULL;
637 debug("PAM: initializing for \"%s\"", user);
639 pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
640 sshpam_authctxt = authctxt;
642 if (sshpam_err != PAM_SUCCESS) {
643 pam_end(sshpam_handle, sshpam_err);
644 sshpam_handle = NULL;
647 pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
648 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
649 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
650 if (sshpam_err != PAM_SUCCESS) {
651 pam_end(sshpam_handle, sshpam_err);
652 sshpam_handle = NULL;
655 #ifdef PAM_TTY_KLUDGE
657 * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
658 * sshd doesn't set the tty until too late in the auth process and
659 * may not even set one (for tty-less connections)
661 debug("PAM: setting PAM_TTY to \"ssh\"");
662 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
663 if (sshpam_err != PAM_SUCCESS) {
664 pam_end(sshpam_handle, sshpam_err);
665 sshpam_handle = NULL;
673 sshpam_init_ctx(Authctxt *authctxt)
675 struct pam_ctxt *ctxt;
678 debug3("PAM: %s entering", __func__);
680 * Refuse to start if we don't have PAM enabled or do_pam_account
681 * has previously failed.
683 if (!options.use_pam || sshpam_account_status == 0)
687 if (sshpam_init(authctxt) == -1) {
688 error("PAM: initialization failed");
692 ctxt = xcalloc(1, sizeof *ctxt);
694 /* Start the authentication thread */
695 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
696 error("PAM: failed create sockets: %s", strerror(errno));
700 ctxt->pam_psock = socks[0];
701 ctxt->pam_csock = socks[1];
702 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
703 error("PAM: failed to start authentication thread: %s",
715 sshpam_query(void *ctx, char **name, char **info,
716 u_int *num, char ***prompts, u_int **echo_on)
719 struct pam_ctxt *ctxt = ctx;
725 debug3("PAM: %s entering", __func__);
726 buffer_init(&buffer);
729 *prompts = xmalloc(sizeof(char *));
732 *echo_on = xmalloc(sizeof(u_int));
733 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
734 type = buffer_get_char(&buffer);
735 msg = buffer_get_string(&buffer, NULL);
738 case PAM_PROMPT_ECHO_ON:
739 case PAM_PROMPT_ECHO_OFF:
741 len = plen + mlen + 1;
742 **prompts = xreallocarray(**prompts, 1, len);
743 strlcpy(**prompts + plen, msg, len - plen);
745 **echo_on = (type == PAM_PROMPT_ECHO_ON);
750 /* accumulate messages */
751 len = plen + mlen + 2;
752 **prompts = xreallocarray(**prompts, 1, len);
753 strlcpy(**prompts + plen, msg, len - plen);
755 strlcat(**prompts + plen, "\n", len - plen);
759 case PAM_ACCT_EXPIRED:
760 sshpam_account_status = 0;
763 debug3("PAM: %s", pam_strerror(sshpam_handle, type));
764 if (**prompts != NULL && strlen(**prompts) != 0) {
775 if (**prompts != NULL) {
776 /* drain any accumulated messages */
777 debug("PAM: %s", **prompts);
778 buffer_append(&loginmsg, **prompts,
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 "
790 import_environments(&buffer);
797 error("PAM: %s for %s%.100s from %.100s", msg,
798 sshpam_authctxt->valid ? "" : "illegal user ",
799 sshpam_authctxt->user,
800 get_remote_name_or_ip(utmp_len, options.use_dns));
813 /* XXX - see also comment in auth-chall.c:verify_response */
815 sshpam_respond(void *ctx, u_int num, char **resp)
818 struct pam_ctxt *ctxt = ctx;
820 debug2("PAM: %s entering, %u responses", __func__, num);
821 switch (ctxt->pam_done) {
823 sshpam_authenticated = 1;
831 error("PAM: expected one response, got %u", num);
834 buffer_init(&buffer);
835 if (sshpam_authctxt->valid &&
836 (sshpam_authctxt->pw->pw_uid != 0 ||
837 options.permit_root_login == PERMIT_YES))
838 buffer_put_cstring(&buffer, *resp);
840 buffer_put_cstring(&buffer, badpw);
841 if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
842 buffer_free(&buffer);
845 buffer_free(&buffer);
850 sshpam_free_ctx(void *ctxtp)
852 struct pam_ctxt *ctxt = ctxtp;
854 debug3("PAM: %s entering", __func__);
855 sshpam_thread_cleanup();
858 * We don't call sshpam_cleanup() here because we may need the PAM
859 * handle at a later stage, e.g. when setting up a session. It's
860 * still on the cleanup list, so pam_end() *will* be called before
861 * the server process terminates.
865 KbdintDevice sshpam_device = {
873 KbdintDevice mm_sshpam_device = {
882 * This replaces auth-pam.c
885 start_pam(Authctxt *authctxt)
887 if (!options.use_pam)
888 fatal("PAM: initialisation requested when UsePAM=no");
890 if (sshpam_init(authctxt) == -1)
891 fatal("PAM: initialisation failed");
903 debug("%s: called", __func__);
904 if (sshpam_account_status != -1)
905 return (sshpam_account_status);
907 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
908 debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
909 pam_strerror(sshpam_handle, sshpam_err));
911 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
912 sshpam_account_status = 0;
913 return (sshpam_account_status);
916 if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
917 sshpam_password_change_required(1);
919 sshpam_account_status = 1;
920 return (sshpam_account_status);
924 do_pam_set_tty(const char *tty)
927 debug("PAM: setting PAM_TTY to \"%s\"", tty);
928 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
929 if (sshpam_err != PAM_SUCCESS)
930 fatal("PAM: failed to set PAM_TTY: %s",
931 pam_strerror(sshpam_handle, sshpam_err));
936 do_pam_setcred(int init)
938 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
939 (const void *)&store_conv);
940 if (sshpam_err != PAM_SUCCESS)
941 fatal("PAM: failed to set PAM_CONV: %s",
942 pam_strerror(sshpam_handle, sshpam_err));
944 debug("PAM: establishing credentials");
945 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
947 debug("PAM: reinitializing credentials");
948 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
950 if (sshpam_err == PAM_SUCCESS) {
951 sshpam_cred_established = 1;
954 if (sshpam_authenticated)
955 fatal("PAM: pam_setcred(): %s",
956 pam_strerror(sshpam_handle, sshpam_err));
958 debug("PAM: pam_setcred(): %s",
959 pam_strerror(sshpam_handle, sshpam_err));
963 sshpam_tty_conv(int n, sshpam_const struct pam_message **msg,
964 struct pam_response **resp, void *data)
966 char input[PAM_MAX_MSG_SIZE];
967 struct pam_response *reply;
970 debug3("PAM: %s called with %d messages", __func__, n);
974 if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
975 return (PAM_CONV_ERR);
977 if ((reply = calloc(n, sizeof(*reply))) == NULL)
978 return (PAM_CONV_ERR);
980 for (i = 0; i < n; ++i) {
981 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
982 case PAM_PROMPT_ECHO_OFF:
984 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
986 reply[i].resp_retcode = PAM_SUCCESS;
988 case PAM_PROMPT_ECHO_ON:
989 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
990 if (fgets(input, sizeof input, stdin) == NULL)
992 if ((reply[i].resp = strdup(input)) == NULL)
994 reply[i].resp_retcode = PAM_SUCCESS;
998 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
999 reply[i].resp_retcode = PAM_SUCCESS;
1006 return (PAM_SUCCESS);
1009 for(i = 0; i < n; i++) {
1010 free(reply[i].resp);
1013 return (PAM_CONV_ERR);
1016 static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
1019 * XXX this should be done in the authentication phase, but ssh1 doesn't
1023 do_pam_chauthtok(void)
1026 fatal("Password expired (unable to change with privsep)");
1027 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1028 (const void *)&tty_conv);
1029 if (sshpam_err != PAM_SUCCESS)
1030 fatal("PAM: failed to set PAM_CONV: %s",
1031 pam_strerror(sshpam_handle, sshpam_err));
1032 debug("PAM: changing password");
1033 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
1034 if (sshpam_err != PAM_SUCCESS)
1035 fatal("PAM: pam_chauthtok(): %s",
1036 pam_strerror(sshpam_handle, sshpam_err));
1040 do_pam_session(void)
1042 debug3("PAM: opening session");
1043 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1044 (const void *)&store_conv);
1045 if (sshpam_err != PAM_SUCCESS)
1046 fatal("PAM: failed to set PAM_CONV: %s",
1047 pam_strerror(sshpam_handle, sshpam_err));
1048 sshpam_err = pam_open_session(sshpam_handle, 0);
1049 if (sshpam_err == PAM_SUCCESS)
1050 sshpam_session_open = 1;
1052 sshpam_session_open = 0;
1053 disable_forwarding();
1054 error("PAM: pam_open_session(): %s",
1055 pam_strerror(sshpam_handle, sshpam_err));
1061 is_pam_session_open(void)
1063 return sshpam_session_open;
1067 * Set a PAM environment string. We need to do this so that the session
1068 * modules can handle things like Kerberos/GSI credentials that appear
1069 * during the ssh authentication process.
1072 do_pam_putenv(char *name, char *value)
1075 #ifdef HAVE_PAM_PUTENV
1079 len = strlen(name) + strlen(value) + 2;
1080 compound = xmalloc(len);
1082 snprintf(compound, len, "%s=%s", name, value);
1083 ret = pam_putenv(sshpam_handle, compound);
1091 fetch_pam_child_environment(void)
1097 fetch_pam_environment(void)
1099 return (pam_getenvlist(sshpam_handle));
1103 free_pam_environment(char **env)
1110 for (envp = env; *envp; envp++)
1116 * "Blind" conversation function for password authentication. Assumes that
1117 * echo-off prompts are for the password and stores messages for later
1121 sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg,
1122 struct pam_response **resp, void *data)
1124 struct pam_response *reply;
1128 debug3("PAM: %s called with %d messages", __func__, n);
1132 if (n <= 0 || n > PAM_MAX_NUM_MSG)
1133 return (PAM_CONV_ERR);
1135 if ((reply = calloc(n, sizeof(*reply))) == NULL)
1136 return (PAM_CONV_ERR);
1138 for (i = 0; i < n; ++i) {
1139 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1140 case PAM_PROMPT_ECHO_OFF:
1141 if (sshpam_password == NULL)
1143 if ((reply[i].resp = strdup(sshpam_password)) == NULL)
1145 reply[i].resp_retcode = PAM_SUCCESS;
1149 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
1151 buffer_append(&loginmsg,
1152 PAM_MSG_MEMBER(msg, i, msg), len);
1153 buffer_append(&loginmsg, "\n", 1);
1155 if ((reply[i].resp = strdup("")) == NULL)
1157 reply[i].resp_retcode = PAM_SUCCESS;
1164 return (PAM_SUCCESS);
1167 for(i = 0; i < n; i++) {
1168 free(reply[i].resp);
1171 return (PAM_CONV_ERR);
1174 static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
1177 * Attempt password authentication via PAM
1180 sshpam_auth_passwd(Authctxt *authctxt, const char *password)
1182 int flags = (options.permit_empty_passwd == 0 ?
1183 PAM_DISALLOW_NULL_AUTHTOK : 0);
1185 if (!options.use_pam || sshpam_handle == NULL)
1186 fatal("PAM: %s called when PAM disabled or failed to "
1187 "initialise.", __func__);
1189 sshpam_password = password;
1190 sshpam_authctxt = authctxt;
1193 * If the user logging in is invalid, or is root but is not permitted
1194 * by PermitRootLogin, use an invalid password to prevent leaking
1195 * information via timing (eg if the PAM config has a delay on fail).
1197 if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
1198 options.permit_root_login != PERMIT_YES))
1199 sshpam_password = badpw;
1201 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1202 (const void *)&passwd_conv);
1203 if (sshpam_err != PAM_SUCCESS)
1204 fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
1205 pam_strerror(sshpam_handle, sshpam_err));
1207 sshpam_err = pam_authenticate(sshpam_handle, flags);
1208 sshpam_password = NULL;
1209 if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
1210 debug("PAM: password authentication accepted for %.100s",
1214 debug("PAM: password authentication failed for %.100s: %s",
1215 authctxt->valid ? authctxt->user : "an illegal user",
1216 pam_strerror(sshpam_handle, sshpam_err));
1220 #endif /* USE_PAM */