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
33 RCSID("$FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $");
36 #include <security/pam_appl.h>
44 #include "monitor_wrap.h"
52 extern ServerOptions options;
56 #ifdef USE_POSIX_THREADS
59 * Avoid namespace clash when *not* using pthreads for systems *with*
60 * pthreads, which unconditionally define pthread_t via sys/types.h
63 typedef pthread_t sp_pthread_t;
66 * Simulate threads with processes.
68 typedef pid_t sp_pthread_t;
71 pthread_exit(void *value __unused)
77 pthread_create(sp_pthread_t *thread, const void *attr __unused,
78 void *(*thread_start)(void *), void *arg)
82 switch ((pid = fork())) {
84 error("fork(): %s", strerror(errno));
96 pthread_cancel(sp_pthread_t thread)
98 return (kill(thread, SIGTERM));
102 pthread_join(sp_pthread_t thread, void **value __unused)
106 waitpid(thread, &status, 0);
112 static pam_handle_t *sshpam_handle;
113 static int sshpam_err;
114 static int sshpam_authenticated;
115 static int sshpam_new_authtok_reqd;
116 static int sshpam_session_open;
117 static int sshpam_cred_established;
120 sp_pthread_t pam_thread;
126 static void sshpam_free_ctx(void *);
129 * Conversation function for authentication thread.
132 sshpam_thread_conv(int n,
133 const struct pam_message **msg,
134 struct pam_response **resp,
138 struct pam_ctxt *ctxt;
142 if (n <= 0 || n > PAM_MAX_NUM_MSG)
143 return (PAM_CONV_ERR);
144 *resp = xmalloc(n * sizeof **resp);
145 buffer_init(&buffer);
146 for (i = 0; i < n; ++i) {
147 resp[i]->resp_retcode = 0;
148 resp[i]->resp = NULL;
149 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
150 case PAM_PROMPT_ECHO_OFF:
151 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
152 ssh_msg_send(ctxt->pam_csock,
153 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
154 ssh_msg_recv(ctxt->pam_csock, &buffer);
155 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
157 resp[i]->resp = buffer_get_string(&buffer, NULL);
159 case PAM_PROMPT_ECHO_ON:
160 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
161 ssh_msg_send(ctxt->pam_csock,
162 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
163 ssh_msg_recv(ctxt->pam_csock, &buffer);
164 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
166 resp[i]->resp = buffer_get_string(&buffer, NULL);
169 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
170 ssh_msg_send(ctxt->pam_csock,
171 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
174 buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
175 ssh_msg_send(ctxt->pam_csock,
176 PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
181 buffer_clear(&buffer);
183 buffer_free(&buffer);
184 return (PAM_SUCCESS);
190 buffer_free(&buffer);
191 return (PAM_CONV_ERR);
195 * Authentication thread.
198 sshpam_thread(void *ctxtp)
200 struct pam_ctxt *ctxt = ctxtp;
202 struct pam_conv sshpam_conv = { sshpam_thread_conv, ctxt };
203 #ifndef USE_POSIX_THREADS
204 const char *pam_user;
206 pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user);
207 setproctitle("%s [pam]", pam_user);
210 buffer_init(&buffer);
211 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
212 (const void *)&sshpam_conv);
213 if (sshpam_err != PAM_SUCCESS)
215 sshpam_err = pam_authenticate(sshpam_handle, 0);
216 if (sshpam_err != PAM_SUCCESS)
218 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
219 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD)
221 buffer_put_cstring(&buffer, "OK");
222 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
223 buffer_free(&buffer);
227 buffer_put_cstring(&buffer,
228 pam_strerror(sshpam_handle, sshpam_err));
229 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
230 buffer_free(&buffer);
233 return (NULL); /* Avoid warning for non-pthread case */
237 sshpam_thread_cleanup(void *ctxtp)
239 struct pam_ctxt *ctxt = ctxtp;
241 pthread_cancel(ctxt->pam_thread);
242 pthread_join(ctxt->pam_thread, NULL);
243 close(ctxt->pam_psock);
244 close(ctxt->pam_csock);
248 sshpam_null_conv(int n,
249 const struct pam_message **msg,
250 struct pam_response **resp,
254 return (PAM_CONV_ERR);
257 static struct pam_conv null_conv = { sshpam_null_conv, NULL };
260 sshpam_cleanup(void *arg)
263 debug("PAM: cleanup");
264 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
265 if (sshpam_cred_established) {
266 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
267 sshpam_cred_established = 0;
269 if (sshpam_session_open) {
270 pam_close_session(sshpam_handle, PAM_SILENT);
271 sshpam_session_open = 0;
273 sshpam_authenticated = sshpam_new_authtok_reqd = 0;
274 pam_end(sshpam_handle, sshpam_err);
275 sshpam_handle = NULL;
279 sshpam_init(const char *user)
281 extern u_int utmp_len;
282 const char *pam_rhost, *pam_user;
284 if (sshpam_handle != NULL) {
285 /* We already have a PAM context; check if the user matches */
286 sshpam_err = pam_get_item(sshpam_handle,
287 PAM_USER, (const void **)&pam_user);
288 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
290 fatal_remove_cleanup(sshpam_cleanup, NULL);
291 pam_end(sshpam_handle, sshpam_err);
292 sshpam_handle = NULL;
294 debug("PAM: initializing for \"%s\"", user);
295 sshpam_err = pam_start("sshd", user, &null_conv, &sshpam_handle);
296 if (sshpam_err != PAM_SUCCESS)
298 pam_rhost = get_remote_name_or_ip(utmp_len,
299 options.verify_reverse_mapping);
300 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
301 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
302 if (sshpam_err != PAM_SUCCESS) {
303 pam_end(sshpam_handle, sshpam_err);
304 sshpam_handle = NULL;
307 fatal_add_cleanup(sshpam_cleanup, NULL);
312 sshpam_init_ctx(Authctxt *authctxt)
314 struct pam_ctxt *ctxt;
317 /* Refuse to start if we don't have PAM enabled */
318 if (!options.use_pam)
322 if (sshpam_init(authctxt->user) == -1) {
323 error("PAM: initialization failed");
327 ctxt = xmalloc(sizeof *ctxt);
330 /* Start the authentication thread */
331 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
332 error("PAM: failed create sockets: %s", strerror(errno));
336 ctxt->pam_psock = socks[0];
337 ctxt->pam_csock = socks[1];
338 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
339 error("PAM: failed to start authentication thread: %s",
346 fatal_add_cleanup(sshpam_thread_cleanup, ctxt);
351 sshpam_query(void *ctx, char **name, char **info,
352 u_int *num, char ***prompts, u_int **echo_on)
355 struct pam_ctxt *ctxt = ctx;
360 buffer_init(&buffer);
363 *prompts = xmalloc(sizeof(char *));
366 *echo_on = xmalloc(sizeof(u_int));
367 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
368 type = buffer_get_char(&buffer);
369 msg = buffer_get_string(&buffer, NULL);
371 case PAM_PROMPT_ECHO_ON:
372 case PAM_PROMPT_ECHO_OFF:
374 **prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
375 plen += sprintf(**prompts + plen, "%s", msg);
376 **echo_on = (type == PAM_PROMPT_ECHO_ON);
381 /* accumulate messages */
382 **prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
383 plen += sprintf(**prompts + plen, "%s", msg);
386 case PAM_NEW_AUTHTOK_REQD:
387 sshpam_new_authtok_reqd = 1;
391 if (**prompts != NULL) {
392 /* drain any accumulated messages */
393 #if 0 /* XXX - not compatible with privsep */
394 packet_start(SSH2_MSG_USERAUTH_BANNER);
395 packet_put_cstring(**prompts);
396 packet_put_cstring("");
403 if (type == PAM_SUCCESS) {
410 error("PAM: %s", msg);
422 /* XXX - see also comment in auth-chall.c:verify_response */
424 sshpam_respond(void *ctx, u_int num, char **resp)
427 struct pam_ctxt *ctxt = ctx;
429 debug2("PAM: %s", __func__);
430 switch (ctxt->pam_done) {
432 sshpam_authenticated = 1;
440 error("PAM: expected one response, got %u", num);
443 buffer_init(&buffer);
444 buffer_put_cstring(&buffer, *resp);
445 ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer);
446 buffer_free(&buffer);
451 sshpam_free_ctx(void *ctxtp)
453 struct pam_ctxt *ctxt = ctxtp;
455 fatal_remove_cleanup(sshpam_thread_cleanup, ctxt);
456 sshpam_thread_cleanup(ctxtp);
459 * We don't call sshpam_cleanup() here because we may need the PAM
460 * handle at a later stage, e.g. when setting up a session. It's
461 * still on the cleanup list, so pam_end() *will* be called before
462 * the server process terminates.
466 KbdintDevice sshpam_device = {
474 KbdintDevice mm_sshpam_device = {
483 * This replaces auth-pam.c
486 start_pam(const char *user)
488 if (!options.use_pam)
489 fatal("PAM: initialisation requested when UsePAM=no");
491 if (sshpam_init(user) == -1)
492 fatal("PAM: initialisation failed");
498 fatal_remove_cleanup(sshpam_cleanup, NULL);
499 sshpam_cleanup(NULL);
503 do_pam_account(const char *user, const char *ruser)
510 do_pam_session(const char *user, const char *tty)
512 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
513 (const void *)&null_conv);
514 if (sshpam_err != PAM_SUCCESS)
515 fatal("PAM: failed to set PAM_CONV: %s",
516 pam_strerror(sshpam_handle, sshpam_err));
517 debug("PAM: setting PAM_TTY to \"%s\"", tty);
518 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
519 if (sshpam_err != PAM_SUCCESS)
520 fatal("PAM: failed to set PAM_TTY: %s",
521 pam_strerror(sshpam_handle, sshpam_err));
522 sshpam_err = pam_open_session(sshpam_handle, 0);
523 if (sshpam_err != PAM_SUCCESS)
524 fatal("PAM: pam_open_session(): %s",
525 pam_strerror(sshpam_handle, sshpam_err));
526 sshpam_session_open = 1;
530 do_pam_setcred(int init)
532 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
533 (const void *)&null_conv);
534 if (sshpam_err != PAM_SUCCESS)
535 fatal("PAM: failed to set PAM_CONV: %s",
536 pam_strerror(sshpam_handle, sshpam_err));
538 debug("PAM: establishing credentials");
539 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
541 debug("PAM: reinitializing credentials");
542 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
544 if (sshpam_err == PAM_SUCCESS) {
545 sshpam_cred_established = 1;
548 if (sshpam_authenticated)
549 fatal("PAM: pam_setcred(): %s",
550 pam_strerror(sshpam_handle, sshpam_err));
552 debug("PAM: pam_setcred(): %s",
553 pam_strerror(sshpam_handle, sshpam_err));
557 is_pam_password_change_required(void)
559 return (sshpam_new_authtok_reqd);
563 pam_chauthtok_conv(int n,
564 const struct pam_message **msg,
565 struct pam_response **resp,
568 char input[PAM_MAX_MSG_SIZE];
571 if (n <= 0 || n > PAM_MAX_NUM_MSG)
572 return (PAM_CONV_ERR);
573 *resp = xmalloc(n * sizeof **resp);
574 for (i = 0; i < n; ++i) {
575 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
576 case PAM_PROMPT_ECHO_OFF:
578 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
580 resp[i]->resp_retcode = PAM_SUCCESS;
582 case PAM_PROMPT_ECHO_ON:
583 fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
584 fgets(input, sizeof input, stdin);
585 resp[i]->resp = xstrdup(input);
586 resp[i]->resp_retcode = PAM_SUCCESS;
590 fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
591 resp[i]->resp_retcode = PAM_SUCCESS;
597 return (PAM_SUCCESS);
603 return (PAM_CONV_ERR);
607 * XXX this should be done in the authentication phase, but ssh1 doesn't
611 do_pam_chauthtok(void)
613 struct pam_conv pam_conv = { pam_chauthtok_conv, NULL };
616 fatal("PAM: chauthtok not supprted with privsep");
617 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
618 (const void *)&pam_conv);
619 if (sshpam_err != PAM_SUCCESS)
620 fatal("PAM: failed to set PAM_CONV: %s",
621 pam_strerror(sshpam_handle, sshpam_err));
622 debug("PAM: changing password");
623 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
624 if (sshpam_err != PAM_SUCCESS)
625 fatal("PAM: pam_chauthtok(): %s",
626 pam_strerror(sshpam_handle, sshpam_err));
630 print_pam_messages(void)
636 fetch_pam_environment(void)
638 #ifdef HAVE_PAM_GETENVLIST
639 debug("PAM: retrieving environment");
640 return (pam_getenvlist(sshpam_handle));
647 free_pam_environment(char **env)
651 for (envp = env; *envp; envp++)