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>
59 /* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */
60 #ifdef PAM_SUN_CODEBASE
61 # define sshpam_const /* Solaris, HP-UX, AIX */
63 # define sshpam_const const /* LinuxPAM, OpenPAM */
72 #include "monitor_wrap.h"
79 #include "auth-options.h"
81 extern ServerOptions options;
82 extern Buffer loginmsg;
84 extern u_int utmp_len;
86 /* so we don't silently change behaviour */
87 #ifdef USE_POSIX_THREADS
88 # error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
92 * Formerly known as USE_POSIX_THREADS, using this is completely unsupported
93 * and generally a bad idea. Use at own risk and do not expect support if
96 #ifdef UNSUPPORTED_POSIX_THREADS_HACK
99 * Avoid namespace clash when *not* using pthreads for systems *with*
100 * pthreads, which unconditionally define pthread_t via sys/types.h
103 typedef pthread_t sp_pthread_t;
105 typedef pid_t sp_pthread_t;
109 sp_pthread_t pam_thread;
115 static void sshpam_free_ctx(void *);
116 static struct pam_ctxt *cleanup_ctxt;
118 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
120 * Simulate threads with processes.
123 static int sshpam_thread_status = -1;
124 static mysig_t sshpam_oldsig;
127 sshpam_sigchld_handler(int sig)
129 signal(SIGCHLD, SIG_DFL);
130 if (cleanup_ctxt == NULL)
131 return; /* handler called after PAM cleanup, shouldn't happen */
132 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG)
134 /* PAM thread has not exitted, privsep slave must have */
135 kill(cleanup_ctxt->pam_thread, SIGTERM);
136 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0)
138 return; /* could not wait */
140 if (WIFSIGNALED(sshpam_thread_status) &&
141 WTERMSIG(sshpam_thread_status) == SIGTERM)
142 return; /* terminated by pthread_cancel */
143 if (!WIFEXITED(sshpam_thread_status))
144 fatal("PAM: authentication thread exited unexpectedly");
145 if (WEXITSTATUS(sshpam_thread_status) != 0)
146 fatal("PAM: authentication thread exited uncleanly");
150 pthread_exit(void *value __unused)
156 pthread_create(sp_pthread_t *thread, const void *attr __unused,
157 void *(*thread_start)(void *), void *arg)
160 struct pam_ctxt *ctx = arg;
162 sshpam_thread_status = -1;
163 switch ((pid = fork())) {
165 error("fork(): %s", strerror(errno));
168 close(ctx->pam_psock);
174 close(ctx->pam_csock);
176 sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
182 pthread_cancel(sp_pthread_t thread)
184 signal(SIGCHLD, sshpam_oldsig);
185 return (kill(thread, SIGTERM));
189 pthread_join(sp_pthread_t thread, void **value __unused)
193 if (sshpam_thread_status != -1)
194 return (sshpam_thread_status);
195 signal(SIGCHLD, sshpam_oldsig);
196 waitpid(thread, &status, 0);
202 static pam_handle_t *sshpam_handle = NULL;
203 static int sshpam_err = 0;
204 static int sshpam_authenticated = 0;
205 static int sshpam_session_open = 0;
206 static int sshpam_cred_established = 0;
207 static int sshpam_account_status = -1;
208 static char **sshpam_env = NULL;
209 static Authctxt *sshpam_authctxt = NULL;
210 static const char *sshpam_password = NULL;
211 static char badpw[] = "\b\n\r\177INCORRECT";
213 /* Some PAM implementations don't implement this */
214 #ifndef HAVE_PAM_GETENVLIST
216 pam_getenvlist(pam_handle_t *pamh)
219 * XXX - If necessary, we can still support envrionment passing
220 * for platforms without pam_getenvlist by searching for known
221 * env vars (e.g. KRB5CCNAME) from the PAM environment.
228 * Some platforms, notably Solaris, do not enforce password complexity
229 * rules during pam_chauthtok() if the real uid of the calling process
230 * is 0, on the assumption that it's being called by "passwd" run by root.
231 * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
234 #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
236 sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
240 if (sshpam_authctxt == NULL)
241 fatal("PAM: sshpam_authctxt not initialized");
242 if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
243 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
244 result = pam_chauthtok(pamh, flags);
245 if (setreuid(0, -1) == -1)
246 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
249 # define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b)))
253 sshpam_password_change_required(int reqd)
255 debug3("%s %d", __func__, reqd);
256 if (sshpam_authctxt == NULL)
257 fatal("%s: PAM authctxt not initialized", __func__);
258 sshpam_authctxt->force_pwchange = reqd;
260 no_port_forwarding_flag |= 2;
261 no_agent_forwarding_flag |= 2;
262 no_x11_forwarding_flag |= 2;
264 no_port_forwarding_flag &= ~2;
265 no_agent_forwarding_flag &= ~2;
266 no_x11_forwarding_flag &= ~2;
270 /* Import regular and PAM environment from subprocess */
272 import_environments(Buffer *b)
278 debug3("PAM: %s entering", __func__);
280 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
281 /* Import variables set by do_pam_account */
282 sshpam_account_status = buffer_get_int(b);
283 sshpam_password_change_required(buffer_get_int(b));
285 /* Import environment from subprocess */
286 num_env = buffer_get_int(b);
287 sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env));
288 debug3("PAM: num env strings %d", num_env);
289 for(i = 0; i < num_env; i++)
290 sshpam_env[i] = buffer_get_string(b, NULL);
292 sshpam_env[num_env] = NULL;
294 /* Import PAM environment from subprocess */
295 num_env = buffer_get_int(b);
296 debug("PAM: num PAM env strings %d", num_env);
297 for(i = 0; i < num_env; i++) {
298 env = buffer_get_string(b, NULL);
300 #ifdef HAVE_PAM_PUTENV
301 /* Errors are not fatal here */
302 if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
303 error("PAM: pam_putenv: %s",
304 pam_strerror(sshpam_handle, sshpam_err));
312 * Conversation function for authentication thread.
315 sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
316 struct pam_response **resp, void *data)
319 struct pam_ctxt *ctxt;
320 struct pam_response *reply;
323 debug3("PAM: %s entering, %d messages", __func__, n);
327 error("PAM: conversation function passed a null context");
328 return (PAM_CONV_ERR);
331 if (n <= 0 || n > PAM_MAX_NUM_MSG)
332 return (PAM_CONV_ERR);
334 if ((reply = malloc(n * sizeof(*reply))) == NULL)
335 return (PAM_CONV_ERR);
336 memset(reply, 0, n * sizeof(*reply));
338 buffer_init(&buffer);
339 for (i = 0; i < n; ++i) {
340 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
341 case PAM_PROMPT_ECHO_OFF:
342 buffer_put_cstring(&buffer,
343 PAM_MSG_MEMBER(msg, i, msg));
344 if (ssh_msg_send(ctxt->pam_csock,
345 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
347 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
349 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
351 reply[i].resp = buffer_get_string(&buffer, NULL);
353 case PAM_PROMPT_ECHO_ON:
354 buffer_put_cstring(&buffer,
355 PAM_MSG_MEMBER(msg, i, msg));
356 if (ssh_msg_send(ctxt->pam_csock,
357 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
359 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
361 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
363 reply[i].resp = buffer_get_string(&buffer, NULL);
366 buffer_put_cstring(&buffer,
367 PAM_MSG_MEMBER(msg, i, msg));
368 if (ssh_msg_send(ctxt->pam_csock,
369 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
373 buffer_put_cstring(&buffer,
374 PAM_MSG_MEMBER(msg, i, msg));
375 if (ssh_msg_send(ctxt->pam_csock,
376 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
382 buffer_clear(&buffer);
384 buffer_free(&buffer);
386 return (PAM_SUCCESS);
389 for(i = 0; i < n; i++) {
390 if (reply[i].resp != NULL)
391 xfree(reply[i].resp);
394 buffer_free(&buffer);
395 return (PAM_CONV_ERR);
399 * Authentication thread.
402 sshpam_thread(void *ctxtp)
404 struct pam_ctxt *ctxt = ctxtp;
406 struct pam_conv sshpam_conv;
407 int flags = (options.permit_empty_passwd == 0 ?
408 PAM_DISALLOW_NULL_AUTHTOK : 0);
409 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
410 extern char **environ;
413 const char *pam_user;
414 const char **ptr_pam_user = &pam_user;
416 pam_get_item(sshpam_handle, PAM_USER,
417 (sshpam_const void **)ptr_pam_user);
420 if (sshpam_authctxt != NULL) {
421 setproctitle("%s [pam]",
422 sshpam_authctxt->valid ? pam_user : "unknown");
426 sshpam_conv.conv = sshpam_thread_conv;
427 sshpam_conv.appdata_ptr = ctxt;
429 if (sshpam_authctxt == NULL)
430 fatal("%s: PAM authctxt not initialized", __func__);
432 buffer_init(&buffer);
433 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
434 (const void *)&sshpam_conv);
435 if (sshpam_err != PAM_SUCCESS)
437 sshpam_err = pam_authenticate(sshpam_handle, flags);
438 if (sshpam_err != PAM_SUCCESS)
442 if (!do_pam_account())
444 if (sshpam_authctxt->force_pwchange) {
445 sshpam_err = pam_chauthtok(sshpam_handle,
446 PAM_CHANGE_EXPIRED_AUTHTOK);
447 if (sshpam_err != PAM_SUCCESS)
449 sshpam_password_change_required(0);
453 buffer_put_cstring(&buffer, "OK");
455 #ifndef UNSUPPORTED_POSIX_THREADS_HACK
456 /* Export variables set by do_pam_account */
457 buffer_put_int(&buffer, sshpam_account_status);
458 buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
460 /* Export any environment strings set in child */
461 for(i = 0; environ[i] != NULL; i++)
463 buffer_put_int(&buffer, i);
464 for(i = 0; environ[i] != NULL; i++)
465 buffer_put_cstring(&buffer, environ[i]);
467 /* Export any environment strings set by PAM in child */
468 env_from_pam = pam_getenvlist(sshpam_handle);
469 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
471 buffer_put_int(&buffer, i);
472 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
473 buffer_put_cstring(&buffer, env_from_pam[i]);
474 #endif /* UNSUPPORTED_POSIX_THREADS_HACK */
476 /* XXX - can't do much about an error here */
477 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
478 buffer_free(&buffer);
482 buffer_put_cstring(&buffer,
483 pam_strerror(sshpam_handle, sshpam_err));
484 /* XXX - can't do much about an error here */
485 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
486 buffer_free(&buffer);
489 return (NULL); /* Avoid warning for non-pthread case */
493 sshpam_thread_cleanup(void)
495 struct pam_ctxt *ctxt = cleanup_ctxt;
497 debug3("PAM: %s entering", __func__);
498 if (ctxt != NULL && ctxt->pam_thread != 0) {
499 pthread_cancel(ctxt->pam_thread);
500 pthread_join(ctxt->pam_thread, NULL);
501 close(ctxt->pam_psock);
502 close(ctxt->pam_csock);
503 memset(ctxt, 0, sizeof(*ctxt));
509 sshpam_null_conv(int n, sshpam_const struct pam_message **msg,
510 struct pam_response **resp, void *data)
512 debug3("PAM: %s entering, %d messages", __func__, n);
513 return (PAM_CONV_ERR);
516 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
519 sshpam_store_conv(int n, sshpam_const struct pam_message **msg,
520 struct pam_response **resp, void *data)
522 struct pam_response *reply;
526 debug3("PAM: %s called with %d messages", __func__, n);
529 if (n <= 0 || n > PAM_MAX_NUM_MSG)
530 return (PAM_CONV_ERR);
532 if ((reply = malloc(n * sizeof(*reply))) == NULL)
533 return (PAM_CONV_ERR);
534 memset(reply, 0, n * sizeof(*reply));
536 for (i = 0; i < n; ++i) {
537 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
540 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
541 buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
542 buffer_append(&loginmsg, "\n", 1 );
543 reply[i].resp_retcode = PAM_SUCCESS;
550 return (PAM_SUCCESS);
553 for(i = 0; i < n; i++) {
554 if (reply[i].resp != NULL)
555 xfree(reply[i].resp);
558 return (PAM_CONV_ERR);
561 static struct pam_conv store_conv = { sshpam_store_conv, NULL };
566 debug("PAM: cleanup");
567 if (sshpam_handle == NULL)
569 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
570 if (sshpam_cred_established) {
571 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
572 sshpam_cred_established = 0;
574 if (sshpam_session_open) {
575 pam_close_session(sshpam_handle, PAM_SILENT);
576 sshpam_session_open = 0;
578 sshpam_authenticated = 0;
579 pam_end(sshpam_handle, sshpam_err);
580 sshpam_handle = NULL;
584 sshpam_init(Authctxt *authctxt)
586 extern char *__progname;
587 const char *pam_rhost, *pam_user, *user = authctxt->user;
588 const char **ptr_pam_user = &pam_user;
590 if (sshpam_handle != NULL) {
591 /* We already have a PAM context; check if the user matches */
592 sshpam_err = pam_get_item(sshpam_handle,
593 PAM_USER, (sshpam_const void **)ptr_pam_user);
594 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
596 pam_end(sshpam_handle, sshpam_err);
597 sshpam_handle = NULL;
599 debug("PAM: initializing for \"%s\"", user);
601 pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
602 sshpam_authctxt = authctxt;
604 if (sshpam_err != PAM_SUCCESS) {
605 pam_end(sshpam_handle, sshpam_err);
606 sshpam_handle = NULL;
609 pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
610 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
611 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
612 if (sshpam_err != PAM_SUCCESS) {
613 pam_end(sshpam_handle, sshpam_err);
614 sshpam_handle = NULL;
617 #ifdef PAM_TTY_KLUDGE
619 * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
620 * sshd doesn't set the tty until too late in the auth process and
621 * may not even set one (for tty-less connections)
623 debug("PAM: setting PAM_TTY to \"ssh\"");
624 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
625 if (sshpam_err != PAM_SUCCESS) {
626 pam_end(sshpam_handle, sshpam_err);
627 sshpam_handle = NULL;
635 sshpam_init_ctx(Authctxt *authctxt)
637 struct pam_ctxt *ctxt;
640 debug3("PAM: %s entering", __func__);
641 /* Refuse to start if we don't have PAM enabled */
642 if (!options.use_pam)
646 if (sshpam_init(authctxt) == -1) {
647 error("PAM: initialization failed");
651 ctxt = xmalloc(sizeof *ctxt);
652 memset(ctxt, 0, sizeof(*ctxt));
654 /* Start the authentication thread */
655 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
656 error("PAM: failed create sockets: %s", strerror(errno));
660 ctxt->pam_psock = socks[0];
661 ctxt->pam_csock = socks[1];
662 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
663 error("PAM: failed to start authentication thread: %s",
675 sshpam_query(void *ctx, char **name, char **info,
676 u_int *num, char ***prompts, u_int **echo_on)
679 struct pam_ctxt *ctxt = ctx;
685 debug3("PAM: %s entering", __func__);
686 buffer_init(&buffer);
689 *prompts = xmalloc(sizeof(char *));
692 *echo_on = xmalloc(sizeof(u_int));
693 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
694 type = buffer_get_char(&buffer);
695 msg = buffer_get_string(&buffer, NULL);
698 case PAM_PROMPT_ECHO_ON:
699 case PAM_PROMPT_ECHO_OFF:
701 len = plen + mlen + 1;
702 **prompts = xrealloc(**prompts, len);
703 strlcpy(**prompts + plen, msg, len - plen);
705 **echo_on = (type == PAM_PROMPT_ECHO_ON);
710 /* accumulate messages */
711 len = plen + mlen + 2;
712 **prompts = xrealloc(**prompts, len);
713 strlcpy(**prompts + plen, msg, len - plen);
715 strlcat(**prompts + plen, "\n", len - plen);
720 debug3("PAM: PAM_AUTH_ERR");
721 if (**prompts != NULL && strlen(**prompts) != 0) {
731 if (**prompts != NULL) {
732 /* drain any accumulated messages */
733 debug("PAM: %s", **prompts);
734 buffer_append(&loginmsg, **prompts,
739 if (type == PAM_SUCCESS) {
740 if (!sshpam_authctxt->valid ||
741 (sshpam_authctxt->pw->pw_uid == 0 &&
742 options.permit_root_login != PERMIT_YES))
743 fatal("Internal error: PAM auth "
744 "succeeded when it should have "
746 import_environments(&buffer);
753 error("PAM: %s for %s%.100s from %.100s", msg,
754 sshpam_authctxt->valid ? "" : "illegal user ",
755 sshpam_authctxt->user,
756 get_remote_name_or_ip(utmp_len, options.use_dns));
769 /* XXX - see also comment in auth-chall.c:verify_response */
771 sshpam_respond(void *ctx, u_int num, char **resp)
774 struct pam_ctxt *ctxt = ctx;
776 debug2("PAM: %s entering, %u responses", __func__, num);
777 switch (ctxt->pam_done) {
779 sshpam_authenticated = 1;
787 error("PAM: expected one response, got %u", num);
790 buffer_init(&buffer);
791 if (sshpam_authctxt->valid &&
792 (sshpam_authctxt->pw->pw_uid != 0 ||
793 options.permit_root_login == PERMIT_YES))
794 buffer_put_cstring(&buffer, *resp);
796 buffer_put_cstring(&buffer, badpw);
797 if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
798 buffer_free(&buffer);
801 buffer_free(&buffer);
806 sshpam_free_ctx(void *ctxtp)
808 struct pam_ctxt *ctxt = ctxtp;
810 debug3("PAM: %s entering", __func__);
811 sshpam_thread_cleanup();
814 * We don't call sshpam_cleanup() here because we may need the PAM
815 * handle at a later stage, e.g. when setting up a session. It's
816 * still on the cleanup list, so pam_end() *will* be called before
817 * the server process terminates.
821 KbdintDevice sshpam_device = {
829 KbdintDevice mm_sshpam_device = {
838 * This replaces auth-pam.c
841 start_pam(Authctxt *authctxt)
843 if (!options.use_pam)
844 fatal("PAM: initialisation requested when UsePAM=no");
846 if (sshpam_init(authctxt) == -1)
847 fatal("PAM: initialisation failed");
859 debug("%s: called", __func__);
860 if (sshpam_account_status != -1)
861 return (sshpam_account_status);
863 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
864 debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
865 pam_strerror(sshpam_handle, sshpam_err));
867 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
868 sshpam_account_status = 0;
869 return (sshpam_account_status);
872 if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
873 sshpam_password_change_required(1);
875 sshpam_account_status = 1;
876 return (sshpam_account_status);
880 do_pam_set_tty(const char *tty)
883 debug("PAM: setting PAM_TTY to \"%s\"", tty);
884 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
885 if (sshpam_err != PAM_SUCCESS)
886 fatal("PAM: failed to set PAM_TTY: %s",
887 pam_strerror(sshpam_handle, sshpam_err));
892 do_pam_setcred(int init)
894 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
895 (const void *)&store_conv);
896 if (sshpam_err != PAM_SUCCESS)
897 fatal("PAM: failed to set PAM_CONV: %s",
898 pam_strerror(sshpam_handle, sshpam_err));
900 debug("PAM: establishing credentials");
901 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
903 debug("PAM: reinitializing credentials");
904 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
906 if (sshpam_err == PAM_SUCCESS) {
907 sshpam_cred_established = 1;
910 if (sshpam_authenticated)
911 fatal("PAM: pam_setcred(): %s",
912 pam_strerror(sshpam_handle, sshpam_err));
914 debug("PAM: pam_setcred(): %s",
915 pam_strerror(sshpam_handle, sshpam_err));
919 sshpam_tty_conv(int n, sshpam_const struct pam_message **msg,
920 struct pam_response **resp, void *data)
922 char input[PAM_MAX_MSG_SIZE];
923 struct pam_response *reply;
926 debug3("PAM: %s called with %d messages", __func__, n);
930 if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
931 return (PAM_CONV_ERR);
933 if ((reply = malloc(n * sizeof(*reply))) == NULL)
934 return (PAM_CONV_ERR);
935 memset(reply, 0, n * sizeof(*reply));
937 for (i = 0; i < n; ++i) {
938 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
939 case PAM_PROMPT_ECHO_OFF:
941 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
943 reply[i].resp_retcode = PAM_SUCCESS;
945 case PAM_PROMPT_ECHO_ON:
946 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
947 fgets(input, sizeof input, stdin);
948 if ((reply[i].resp = strdup(input)) == NULL)
950 reply[i].resp_retcode = PAM_SUCCESS;
954 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
955 reply[i].resp_retcode = PAM_SUCCESS;
962 return (PAM_SUCCESS);
965 for(i = 0; i < n; i++) {
966 if (reply[i].resp != NULL)
967 xfree(reply[i].resp);
970 return (PAM_CONV_ERR);
973 static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
976 * XXX this should be done in the authentication phase, but ssh1 doesn't
980 do_pam_chauthtok(void)
983 fatal("Password expired (unable to change with privsep)");
984 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
985 (const void *)&tty_conv);
986 if (sshpam_err != PAM_SUCCESS)
987 fatal("PAM: failed to set PAM_CONV: %s",
988 pam_strerror(sshpam_handle, sshpam_err));
989 debug("PAM: changing password");
990 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
991 if (sshpam_err != PAM_SUCCESS)
992 fatal("PAM: pam_chauthtok(): %s",
993 pam_strerror(sshpam_handle, sshpam_err));
999 debug3("PAM: opening session");
1000 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1001 (const void *)&store_conv);
1002 if (sshpam_err != PAM_SUCCESS)
1003 fatal("PAM: failed to set PAM_CONV: %s",
1004 pam_strerror(sshpam_handle, sshpam_err));
1005 sshpam_err = pam_open_session(sshpam_handle, 0);
1006 if (sshpam_err == PAM_SUCCESS)
1007 sshpam_session_open = 1;
1009 sshpam_session_open = 0;
1010 disable_forwarding();
1011 error("PAM: pam_open_session(): %s",
1012 pam_strerror(sshpam_handle, sshpam_err));
1018 is_pam_session_open(void)
1020 return sshpam_session_open;
1024 * Set a PAM environment string. We need to do this so that the session
1025 * modules can handle things like Kerberos/GSI credentials that appear
1026 * during the ssh authentication process.
1029 do_pam_putenv(char *name, char *value)
1032 #ifdef HAVE_PAM_PUTENV
1036 len = strlen(name) + strlen(value) + 2;
1037 compound = xmalloc(len);
1039 snprintf(compound, len, "%s=%s", name, value);
1040 ret = pam_putenv(sshpam_handle, compound);
1048 fetch_pam_child_environment(void)
1054 fetch_pam_environment(void)
1056 return (pam_getenvlist(sshpam_handle));
1060 free_pam_environment(char **env)
1067 for (envp = env; *envp; envp++)
1073 * "Blind" conversation function for password authentication. Assumes that
1074 * echo-off prompts are for the password and stores messages for later
1078 sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg,
1079 struct pam_response **resp, void *data)
1081 struct pam_response *reply;
1085 debug3("PAM: %s called with %d messages", __func__, n);
1089 if (n <= 0 || n > PAM_MAX_NUM_MSG)
1090 return (PAM_CONV_ERR);
1092 if ((reply = malloc(n * sizeof(*reply))) == NULL)
1093 return (PAM_CONV_ERR);
1094 memset(reply, 0, n * sizeof(*reply));
1096 for (i = 0; i < n; ++i) {
1097 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1098 case PAM_PROMPT_ECHO_OFF:
1099 if (sshpam_password == NULL)
1101 if ((reply[i].resp = strdup(sshpam_password)) == NULL)
1103 reply[i].resp_retcode = PAM_SUCCESS;
1107 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
1109 buffer_append(&loginmsg,
1110 PAM_MSG_MEMBER(msg, i, msg), len);
1111 buffer_append(&loginmsg, "\n", 1);
1113 if ((reply[i].resp = strdup("")) == NULL)
1115 reply[i].resp_retcode = PAM_SUCCESS;
1122 return (PAM_SUCCESS);
1125 for(i = 0; i < n; i++) {
1126 if (reply[i].resp != NULL)
1127 xfree(reply[i].resp);
1130 return (PAM_CONV_ERR);
1133 static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
1136 * Attempt password authentication via PAM
1139 sshpam_auth_passwd(Authctxt *authctxt, const char *password)
1141 int flags = (options.permit_empty_passwd == 0 ?
1142 PAM_DISALLOW_NULL_AUTHTOK : 0);
1144 if (!options.use_pam || sshpam_handle == NULL)
1145 fatal("PAM: %s called when PAM disabled or failed to "
1146 "initialise.", __func__);
1148 sshpam_password = password;
1149 sshpam_authctxt = authctxt;
1152 * If the user logging in is invalid, or is root but is not permitted
1153 * by PermitRootLogin, use an invalid password to prevent leaking
1154 * information via timing (eg if the PAM config has a delay on fail).
1156 if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
1157 options.permit_root_login != PERMIT_YES))
1158 sshpam_password = badpw;
1160 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1161 (const void *)&passwd_conv);
1162 if (sshpam_err != PAM_SUCCESS)
1163 fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
1164 pam_strerror(sshpam_handle, sshpam_err));
1166 sshpam_err = pam_authenticate(sshpam_handle, flags);
1167 sshpam_password = NULL;
1168 if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
1169 debug("PAM: password authentication accepted for %.100s",
1173 debug("PAM: password authentication failed for %.100s: %s",
1174 authctxt->valid ? authctxt->user : "an illegal user",
1175 pam_strerror(sshpam_handle, sshpam_err));
1179 #endif /* USE_PAM */