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 /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
37 #include <security/pam_appl.h>
45 #include "monitor_wrap.h"
53 extern ServerOptions options;
57 #ifdef USE_POSIX_THREADS
60 * Avoid namespace clash when *not* using pthreads for systems *with*
61 * pthreads, which unconditionally define pthread_t via sys/types.h
64 typedef pthread_t sp_pthread_t;
67 * Simulate threads with processes.
69 typedef pid_t sp_pthread_t;
72 pthread_exit(void *value __unused)
78 pthread_create(sp_pthread_t *thread, const void *attr __unused,
79 void *(*thread_start)(void *), void *arg)
83 switch ((pid = fork())) {
85 error("fork(): %s", strerror(errno));
97 pthread_cancel(sp_pthread_t thread)
99 return (kill(thread, SIGTERM));
103 pthread_join(sp_pthread_t thread, void **value __unused)
107 waitpid(thread, &status, 0);
113 static pam_handle_t *sshpam_handle;
114 static int sshpam_err;
115 static int sshpam_authenticated;
116 static int sshpam_new_authtok_reqd;
117 static int sshpam_session_open;
118 static int sshpam_cred_established;
121 sp_pthread_t pam_thread;
127 static void sshpam_free_ctx(void *);
130 * Conversation function for authentication thread.
133 sshpam_thread_conv(int n,
134 const struct pam_message **msg,
135 struct pam_response **resp,
139 struct pam_ctxt *ctxt;
143 if (n <= 0 || n > PAM_MAX_NUM_MSG)
144 return (PAM_CONV_ERR);
145 *resp = xmalloc(n * sizeof **resp);
146 buffer_init(&buffer);
147 for (i = 0; i < n; ++i) {
148 resp[i]->resp_retcode = 0;
149 resp[i]->resp = NULL;
150 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
151 case PAM_PROMPT_ECHO_OFF:
152 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
153 ssh_msg_send(ctxt->pam_csock,
154 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
155 ssh_msg_recv(ctxt->pam_csock, &buffer);
156 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
158 resp[i]->resp = buffer_get_string(&buffer, NULL);
160 case PAM_PROMPT_ECHO_ON:
161 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
162 ssh_msg_send(ctxt->pam_csock,
163 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
164 ssh_msg_recv(ctxt->pam_csock, &buffer);
165 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
167 resp[i]->resp = buffer_get_string(&buffer, NULL);
170 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
171 ssh_msg_send(ctxt->pam_csock,
172 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
175 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
176 ssh_msg_send(ctxt->pam_csock,
177 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
182 buffer_clear(&buffer);
184 buffer_free(&buffer);
185 return (PAM_SUCCESS);
191 buffer_free(&buffer);
192 return (PAM_CONV_ERR);
196 * Authentication thread.
199 sshpam_thread(void *ctxtp)
201 struct pam_ctxt *ctxt = ctxtp;
203 struct pam_conv sshpam_conv = { sshpam_thread_conv, ctxt };
204 #ifndef USE_POSIX_THREADS
205 const char *pam_user;
207 pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user);
208 setproctitle("%s [pam]", pam_user);
211 buffer_init(&buffer);
212 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
213 (const void *)&sshpam_conv);
214 if (sshpam_err != PAM_SUCCESS)
216 sshpam_err = pam_authenticate(sshpam_handle, 0);
217 if (sshpam_err != PAM_SUCCESS)
219 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
220 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD)
222 buffer_put_cstring(&buffer, "OK");
223 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
224 buffer_free(&buffer);
228 buffer_put_cstring(&buffer,
229 pam_strerror(sshpam_handle, sshpam_err));
230 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
231 buffer_free(&buffer);
234 return (NULL); /* Avoid warning for non-pthread case */
238 sshpam_thread_cleanup(void *ctxtp)
240 struct pam_ctxt *ctxt = ctxtp;
242 pthread_cancel(ctxt->pam_thread);
243 pthread_join(ctxt->pam_thread, NULL);
244 close(ctxt->pam_psock);
245 close(ctxt->pam_csock);
249 sshpam_null_conv(int n,
250 const struct pam_message **msg,
251 struct pam_response **resp,
255 return (PAM_CONV_ERR);
258 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
261 sshpam_cleanup(void *arg)
264 debug("PAM: cleanup");
265 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
266 if (sshpam_cred_established) {
267 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
268 sshpam_cred_established = 0;
270 if (sshpam_session_open) {
271 pam_close_session(sshpam_handle, PAM_SILENT);
272 sshpam_session_open = 0;
274 sshpam_authenticated = sshpam_new_authtok_reqd = 0;
275 pam_end(sshpam_handle, sshpam_err);
276 sshpam_handle = NULL;
280 sshpam_init(const char *user)
282 extern u_int utmp_len;
283 const char *pam_rhost, *pam_user;
285 if (sshpam_handle != NULL) {
286 /* We already have a PAM context; check if the user matches */
287 sshpam_err = pam_get_item(sshpam_handle,
288 PAM_USER, (const void **)&pam_user);
289 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
291 fatal_remove_cleanup(sshpam_cleanup, NULL);
292 pam_end(sshpam_handle, sshpam_err);
293 sshpam_handle = NULL;
295 debug("PAM: initializing for \"%s\"", user);
296 sshpam_err = pam_start("sshd", user, &null_conv, &sshpam_handle);
297 if (sshpam_err != PAM_SUCCESS) {
298 pam_end(sshpam_handle, sshpam_err);
299 sshpam_handle = NULL;
302 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
303 pam_rhost = get_remote_name_or_ip(utmp_len,
304 options.verify_reverse_mapping);
305 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
306 if (sshpam_err != PAM_SUCCESS) {
307 pam_end(sshpam_handle, sshpam_err);
308 sshpam_handle = NULL;
311 #ifdef PAM_TTY_KLUDGE
313 * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
314 * sshd doesn't set the tty until too late in the auth process and
315 * may not even set one (for tty-less connections)
317 debug("PAM: setting PAM_TTY to \"ssh\"");
318 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
319 if (sshpam_err != PAM_SUCCESS) {
320 pam_end(sshpam_handle, sshpam_err);
321 sshpam_handle = NULL;
325 fatal_add_cleanup(sshpam_cleanup, NULL);
330 sshpam_init_ctx(Authctxt *authctxt)
332 struct pam_ctxt *ctxt;
335 /* Refuse to start if we don't have PAM enabled */
336 if (!options.use_pam)
340 if (sshpam_init(authctxt->user) == -1) {
341 error("PAM: initialization failed");
345 ctxt = xmalloc(sizeof *ctxt);
348 /* Start the authentication thread */
349 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
350 error("PAM: failed create sockets: %s", strerror(errno));
354 ctxt->pam_psock = socks[0];
355 ctxt->pam_csock = socks[1];
356 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
357 error("PAM: failed to start authentication thread: %s",
364 fatal_add_cleanup(sshpam_thread_cleanup, ctxt);
369 sshpam_query(void *ctx, char **name, char **info,
370 u_int *num, char ***prompts, u_int **echo_on)
373 struct pam_ctxt *ctxt = ctx;
378 buffer_init(&buffer);
381 *prompts = xmalloc(sizeof(char *));
384 *echo_on = xmalloc(sizeof(u_int));
385 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
386 type = buffer_get_char(&buffer);
387 msg = buffer_get_string(&buffer, NULL);
389 case PAM_PROMPT_ECHO_ON:
390 case PAM_PROMPT_ECHO_OFF:
392 **prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
393 plen += sprintf(**prompts + plen, "%s", msg);
394 **echo_on = (type == PAM_PROMPT_ECHO_ON);
399 /* accumulate messages */
400 **prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
401 plen += sprintf(**prompts + plen, "%s", msg);
404 case PAM_NEW_AUTHTOK_REQD:
405 sshpam_new_authtok_reqd = 1;
409 if (**prompts != NULL) {
410 /* drain any accumulated messages */
411 #if 0 /* XXX - not compatible with privsep */
412 packet_start(SSH2_MSG_USERAUTH_BANNER);
413 packet_put_cstring(**prompts);
414 packet_put_cstring("");
421 if (type == PAM_SUCCESS) {
428 error("PAM: %s", msg);
440 /* XXX - see also comment in auth-chall.c:verify_response */
442 sshpam_respond(void *ctx, u_int num, char **resp)
445 struct pam_ctxt *ctxt = ctx;
447 debug2("PAM: %s", __func__);
448 switch (ctxt->pam_done) {
450 sshpam_authenticated = 1;
458 error("PAM: expected one response, got %u", num);
461 buffer_init(&buffer);
462 buffer_put_cstring(&buffer, *resp);
463 ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer);
464 buffer_free(&buffer);
469 sshpam_free_ctx(void *ctxtp)
471 struct pam_ctxt *ctxt = ctxtp;
473 fatal_remove_cleanup(sshpam_thread_cleanup, ctxt);
474 sshpam_thread_cleanup(ctxtp);
477 * We don't call sshpam_cleanup() here because we may need the PAM
478 * handle at a later stage, e.g. when setting up a session. It's
479 * still on the cleanup list, so pam_end() *will* be called before
480 * the server process terminates.
484 KbdintDevice sshpam_device = {
492 KbdintDevice mm_sshpam_device = {
501 * This replaces auth-pam.c
504 start_pam(const char *user)
506 if (!options.use_pam)
507 fatal("PAM: initialisation requested when UsePAM=no");
509 if (sshpam_init(user) == -1)
510 fatal("PAM: initialisation failed");
516 fatal_remove_cleanup(sshpam_cleanup, NULL);
517 sshpam_cleanup(NULL);
521 do_pam_account(const char *user, const char *ruser)
528 do_pam_session(const char *user, const char *tty)
530 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
531 (const void *)&null_conv);
532 if (sshpam_err != PAM_SUCCESS)
533 fatal("PAM: failed to set PAM_CONV: %s",
534 pam_strerror(sshpam_handle, sshpam_err));
535 debug("PAM: setting PAM_TTY to \"%s\"", tty);
536 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
537 if (sshpam_err != PAM_SUCCESS)
538 fatal("PAM: failed to set PAM_TTY: %s",
539 pam_strerror(sshpam_handle, sshpam_err));
540 sshpam_err = pam_open_session(sshpam_handle, 0);
541 if (sshpam_err != PAM_SUCCESS)
542 fatal("PAM: pam_open_session(): %s",
543 pam_strerror(sshpam_handle, sshpam_err));
544 sshpam_session_open = 1;
548 do_pam_setcred(int init)
550 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
551 (const void *)&null_conv);
552 if (sshpam_err != PAM_SUCCESS)
553 fatal("PAM: failed to set PAM_CONV: %s",
554 pam_strerror(sshpam_handle, sshpam_err));
556 debug("PAM: establishing credentials");
557 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
559 debug("PAM: reinitializing credentials");
560 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
562 if (sshpam_err == PAM_SUCCESS) {
563 sshpam_cred_established = 1;
566 if (sshpam_authenticated)
567 fatal("PAM: pam_setcred(): %s",
568 pam_strerror(sshpam_handle, sshpam_err));
570 debug("PAM: pam_setcred(): %s",
571 pam_strerror(sshpam_handle, sshpam_err));
575 is_pam_password_change_required(void)
577 return (sshpam_new_authtok_reqd);
581 pam_chauthtok_conv(int n,
582 const struct pam_message **msg,
583 struct pam_response **resp,
586 char input[PAM_MAX_MSG_SIZE];
589 if (n <= 0 || n > PAM_MAX_NUM_MSG)
590 return (PAM_CONV_ERR);
591 *resp = xmalloc(n * sizeof **resp);
592 for (i = 0; i < n; ++i) {
593 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
594 case PAM_PROMPT_ECHO_OFF:
596 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
598 resp[i]->resp_retcode = PAM_SUCCESS;
600 case PAM_PROMPT_ECHO_ON:
601 fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
602 fgets(input, sizeof input, stdin);
603 resp[i]->resp = xstrdup(input);
604 resp[i]->resp_retcode = PAM_SUCCESS;
608 fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
609 resp[i]->resp_retcode = PAM_SUCCESS;
615 return (PAM_SUCCESS);
621 return (PAM_CONV_ERR);
625 * XXX this should be done in the authentication phase, but ssh1 doesn't
629 do_pam_chauthtok(void)
631 struct pam_conv pam_conv = { pam_chauthtok_conv, NULL };
634 fatal("PAM: chauthtok not supprted with privsep");
635 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
636 (const void *)&pam_conv);
637 if (sshpam_err != PAM_SUCCESS)
638 fatal("PAM: failed to set PAM_CONV: %s",
639 pam_strerror(sshpam_handle, sshpam_err));
640 debug("PAM: changing password");
641 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
642 if (sshpam_err != PAM_SUCCESS)
643 fatal("PAM: pam_chauthtok(): %s",
644 pam_strerror(sshpam_handle, sshpam_err));
648 print_pam_messages(void)
654 fetch_pam_environment(void)
656 #ifdef HAVE_PAM_GETENVLIST
657 debug("PAM: retrieving environment");
658 return (pam_getenvlist(sshpam_handle));
665 free_pam_environment(char **env)
672 for (envp = env; *envp; envp++)