1/*-
2 * Copyright (c) 2002 Networks Associates Technology, Inc.
3 * All rights reserved.
4 *
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.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
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.
18 *
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
29 * SUCH DAMAGE.
30 */
31/*
32 * Copyright (c) 2003,2004 Damien Miller <djm@mindrot.org>
33 * Copyright (c) 2003,2004 Darren Tucker <dtucker@zip.com.au>
34 *
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.
38 *
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.
46 */
47
48/* Based on $xFreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
49#include "includes.h"
| 1/*-
2 * Copyright (c) 2002 Networks Associates Technology, Inc.
3 * All rights reserved.
4 *
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.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
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.
18 *
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
29 * SUCH DAMAGE.
30 */
31/*
32 * Copyright (c) 2003,2004 Damien Miller <djm@mindrot.org>
33 * Copyright (c) 2003,2004 Darren Tucker <dtucker@zip.com.au>
34 *
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.
38 *
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.
46 */
47
48/* Based on $xFreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
49#include "includes.h"
|
52
53#ifdef USE_PAM
54#if defined(HAVE_SECURITY_PAM_APPL_H)
55#include <security/pam_appl.h>
56#elif defined (HAVE_PAM_PAM_APPL_H)
57#include <pam/pam_appl.h>
58#endif
59
60/* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */
61#ifdef PAM_SUN_CODEBASE
62# define sshpam_const /* Solaris, HP-UX, AIX */
63#else
64# define sshpam_const const /* LinuxPAM, OpenPAM */
65#endif
66
67#include "auth.h"
68#include "auth-pam.h"
69#include "buffer.h"
70#include "bufaux.h"
71#include "canohost.h"
72#include "log.h"
73#include "monitor_wrap.h"
74#include "msg.h"
75#include "packet.h"
76#include "misc.h"
77#include "servconf.h"
78#include "ssh2.h"
79#include "xmalloc.h"
80#include "auth-options.h"
81
82extern ServerOptions options;
83extern Buffer loginmsg;
84extern int compat20;
85extern u_int utmp_len;
86
87/* so we don't silently change behaviour */
88#ifdef USE_POSIX_THREADS
89# error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
90#endif
91
92/*
93 * Formerly known as USE_POSIX_THREADS, using this is completely unsupported
94 * and generally a bad idea. Use at own risk and do not expect support if
95 * this breaks.
96 */
97#ifdef UNSUPPORTED_POSIX_THREADS_HACK
98#include <pthread.h>
99/*
100 * Avoid namespace clash when *not* using pthreads for systems *with*
101 * pthreads, which unconditionally define pthread_t via sys/types.h
102 * (e.g. Linux)
103 */
104typedef pthread_t sp_pthread_t;
105#else
106typedef pid_t sp_pthread_t;
107#endif
108
109struct pam_ctxt {
110 sp_pthread_t pam_thread;
111 int pam_psock;
112 int pam_csock;
113 int pam_done;
114};
115
116static void sshpam_free_ctx(void *);
117static struct pam_ctxt *cleanup_ctxt;
118
119#ifndef UNSUPPORTED_POSIX_THREADS_HACK
120/*
121 * Simulate threads with processes.
122 */
123
124static int sshpam_thread_status = -1;
125static mysig_t sshpam_oldsig;
126
127static void
128sshpam_sigchld_handler(int sig)
129{
130 signal(SIGCHLD, SIG_DFL);
131 if (cleanup_ctxt == NULL)
132 return; /* handler called after PAM cleanup, shouldn't happen */
133 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG)
134 <= 0) {
135 /* PAM thread has not exitted, privsep slave must have */
136 kill(cleanup_ctxt->pam_thread, SIGTERM);
137 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0)
138 <= 0)
139 return; /* could not wait */
140 }
141 if (WIFSIGNALED(sshpam_thread_status) &&
142 WTERMSIG(sshpam_thread_status) == SIGTERM)
143 return; /* terminated by pthread_cancel */
144 if (!WIFEXITED(sshpam_thread_status))
145 fatal("PAM: authentication thread exited unexpectedly");
146 if (WEXITSTATUS(sshpam_thread_status) != 0)
147 fatal("PAM: authentication thread exited uncleanly");
148}
149
150static void
151pthread_exit(void *value __unused)
152{
153 _exit(0);
154}
155
156static int
157pthread_create(sp_pthread_t *thread, const void *attr __unused,
158 void *(*thread_start)(void *), void *arg)
159{
160 pid_t pid;
161 struct pam_ctxt *ctx = arg;
162
163 sshpam_thread_status = -1;
164 switch ((pid = fork())) {
165 case -1:
166 error("fork(): %s", strerror(errno));
167 return (-1);
168 case 0:
169 close(ctx->pam_psock);
170 ctx->pam_psock = -1;
171 thread_start(arg);
172 _exit(1);
173 default:
174 *thread = pid;
175 close(ctx->pam_csock);
176 ctx->pam_csock = -1;
177 sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
178 return (0);
179 }
180}
181
182static int
183pthread_cancel(sp_pthread_t thread)
184{
185 signal(SIGCHLD, sshpam_oldsig);
186 return (kill(thread, SIGTERM));
187}
188
189static int
190pthread_join(sp_pthread_t thread, void **value __unused)
191{
192 int status;
193
194 if (sshpam_thread_status != -1)
195 return (sshpam_thread_status);
196 signal(SIGCHLD, sshpam_oldsig);
197 waitpid(thread, &status, 0);
198 return (status);
199}
200#endif
201
202
203static pam_handle_t *sshpam_handle = NULL;
204static int sshpam_err = 0;
205static int sshpam_authenticated = 0;
206static int sshpam_session_open = 0;
207static int sshpam_cred_established = 0;
208static int sshpam_account_status = -1;
209static char **sshpam_env = NULL;
210static Authctxt *sshpam_authctxt = NULL;
211static const char *sshpam_password = NULL;
212static char badpw[] = "\b\n\r\177INCORRECT";
213
214/* Some PAM implementations don't implement this */
215#ifndef HAVE_PAM_GETENVLIST
216static char **
217pam_getenvlist(pam_handle_t *pamh)
218{
219 /*
220 * XXX - If necessary, we can still support envrionment passing
221 * for platforms without pam_getenvlist by searching for known
222 * env vars (e.g. KRB5CCNAME) from the PAM environment.
223 */
224 return NULL;
225}
226#endif
227
228/*
229 * Some platforms, notably Solaris, do not enforce password complexity
230 * rules during pam_chauthtok() if the real uid of the calling process
231 * is 0, on the assumption that it's being called by "passwd" run by root.
232 * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
233 * the right thing.
234 */
235#ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
236static int
237sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
238{
239 int result;
240
241 if (sshpam_authctxt == NULL)
242 fatal("PAM: sshpam_authctxt not initialized");
243 if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
244 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
245 result = pam_chauthtok(pamh, flags);
246 if (setreuid(0, -1) == -1)
247 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
248 return result;
249}
250# define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b)))
251#endif
252
253void
254sshpam_password_change_required(int reqd)
255{
256 debug3("%s %d", __func__, reqd);
257 if (sshpam_authctxt == NULL)
258 fatal("%s: PAM authctxt not initialized", __func__);
259 sshpam_authctxt->force_pwchange = reqd;
260 if (reqd) {
261 no_port_forwarding_flag |= 2;
262 no_agent_forwarding_flag |= 2;
263 no_x11_forwarding_flag |= 2;
264 } else {
265 no_port_forwarding_flag &= ~2;
266 no_agent_forwarding_flag &= ~2;
267 no_x11_forwarding_flag &= ~2;
268 }
269}
270
271/* Import regular and PAM environment from subprocess */
272static void
273import_environments(Buffer *b)
274{
275 char *env;
276 u_int i, num_env;
277 int err;
278
279 debug3("PAM: %s entering", __func__);
280
281#ifndef UNSUPPORTED_POSIX_THREADS_HACK
282 /* Import variables set by do_pam_account */
283 sshpam_account_status = buffer_get_int(b);
284 sshpam_password_change_required(buffer_get_int(b));
285
286 /* Import environment from subprocess */
287 num_env = buffer_get_int(b);
288 sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env));
289 debug3("PAM: num env strings %d", num_env);
290 for(i = 0; i < num_env; i++)
291 sshpam_env[i] = buffer_get_string(b, NULL);
292
293 sshpam_env[num_env] = NULL;
294
295 /* Import PAM environment from subprocess */
296 num_env = buffer_get_int(b);
297 debug("PAM: num PAM env strings %d", num_env);
298 for(i = 0; i < num_env; i++) {
299 env = buffer_get_string(b, NULL);
300
301#ifdef HAVE_PAM_PUTENV
302 /* Errors are not fatal here */
303 if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
304 error("PAM: pam_putenv: %s",
305 pam_strerror(sshpam_handle, sshpam_err));
306 }
307#endif
308 }
309#endif
310}
311
312/*
313 * Conversation function for authentication thread.
314 */
315static int
316sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
317 struct pam_response **resp, void *data)
318{
319 Buffer buffer;
320 struct pam_ctxt *ctxt;
321 struct pam_response *reply;
322 int i;
323
324 debug3("PAM: %s entering, %d messages", __func__, n);
325 *resp = NULL;
326
327 if (data == NULL) {
328 error("PAM: conversation function passed a null context");
329 return (PAM_CONV_ERR);
330 }
331 ctxt = data;
332 if (n <= 0 || n > PAM_MAX_NUM_MSG)
333 return (PAM_CONV_ERR);
334
335 if ((reply = malloc(n * sizeof(*reply))) == NULL)
336 return (PAM_CONV_ERR);
337 memset(reply, 0, n * sizeof(*reply));
338
339 buffer_init(&buffer);
340 for (i = 0; i < n; ++i) {
341 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
342 case PAM_PROMPT_ECHO_OFF:
343 buffer_put_cstring(&buffer,
344 PAM_MSG_MEMBER(msg, i, msg));
345 if (ssh_msg_send(ctxt->pam_csock,
346 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
347 goto fail;
348 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
349 goto fail;
350 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
351 goto fail;
352 reply[i].resp = buffer_get_string(&buffer, NULL);
353 break;
354 case PAM_PROMPT_ECHO_ON:
355 buffer_put_cstring(&buffer,
356 PAM_MSG_MEMBER(msg, i, msg));
357 if (ssh_msg_send(ctxt->pam_csock,
358 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
359 goto fail;
360 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
361 goto fail;
362 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
363 goto fail;
364 reply[i].resp = buffer_get_string(&buffer, NULL);
365 break;
366 case PAM_ERROR_MSG:
367 buffer_put_cstring(&buffer,
368 PAM_MSG_MEMBER(msg, i, msg));
369 if (ssh_msg_send(ctxt->pam_csock,
370 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
371 goto fail;
372 break;
373 case PAM_TEXT_INFO:
374 buffer_put_cstring(&buffer,
375 PAM_MSG_MEMBER(msg, i, msg));
376 if (ssh_msg_send(ctxt->pam_csock,
377 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
378 goto fail;
379 break;
380 default:
381 goto fail;
382 }
383 buffer_clear(&buffer);
384 }
385 buffer_free(&buffer);
386 *resp = reply;
387 return (PAM_SUCCESS);
388
389 fail:
390 for(i = 0; i < n; i++) {
391 if (reply[i].resp != NULL)
392 xfree(reply[i].resp);
393 }
394 xfree(reply);
395 buffer_free(&buffer);
396 return (PAM_CONV_ERR);
397}
398
399/*
400 * Authentication thread.
401 */
402static void *
403sshpam_thread(void *ctxtp)
404{
405 struct pam_ctxt *ctxt = ctxtp;
406 Buffer buffer;
407 struct pam_conv sshpam_conv;
408 int flags = (options.permit_empty_passwd == 0 ?
409 PAM_DISALLOW_NULL_AUTHTOK : 0);
410#ifndef UNSUPPORTED_POSIX_THREADS_HACK
411 extern char **environ;
412 char **env_from_pam;
413 u_int i;
414 const char *pam_user;
415 const char **ptr_pam_user = &pam_user;
416
417 pam_get_item(sshpam_handle, PAM_USER,
418 (sshpam_const void **)ptr_pam_user);
419 environ[0] = NULL;
420
421 if (sshpam_authctxt != NULL) {
422 setproctitle("%s [pam]",
423 sshpam_authctxt->valid ? pam_user : "unknown");
424 }
425#endif
426
427 sshpam_conv.conv = sshpam_thread_conv;
428 sshpam_conv.appdata_ptr = ctxt;
429
430 if (sshpam_authctxt == NULL)
431 fatal("%s: PAM authctxt not initialized", __func__);
432
433 buffer_init(&buffer);
434 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
435 (const void *)&sshpam_conv);
436 if (sshpam_err != PAM_SUCCESS)
437 goto auth_fail;
438 sshpam_err = pam_authenticate(sshpam_handle, flags);
439 if (sshpam_err != PAM_SUCCESS)
440 goto auth_fail;
441
442 if (compat20) {
443 if (!do_pam_account())
444 goto auth_fail;
445 if (sshpam_authctxt->force_pwchange) {
446 sshpam_err = pam_chauthtok(sshpam_handle,
447 PAM_CHANGE_EXPIRED_AUTHTOK);
448 if (sshpam_err != PAM_SUCCESS)
449 goto auth_fail;
450 sshpam_password_change_required(0);
451 }
452 }
453
454 buffer_put_cstring(&buffer, "OK");
455
456#ifndef UNSUPPORTED_POSIX_THREADS_HACK
457 /* Export variables set by do_pam_account */
458 buffer_put_int(&buffer, sshpam_account_status);
459 buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
460
461 /* Export any environment strings set in child */
462 for(i = 0; environ[i] != NULL; i++)
463 ; /* Count */
464 buffer_put_int(&buffer, i);
465 for(i = 0; environ[i] != NULL; i++)
466 buffer_put_cstring(&buffer, environ[i]);
467
468 /* Export any environment strings set by PAM in child */
469 env_from_pam = pam_getenvlist(sshpam_handle);
470 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
471 ; /* Count */
472 buffer_put_int(&buffer, i);
473 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
474 buffer_put_cstring(&buffer, env_from_pam[i]);
475#endif /* UNSUPPORTED_POSIX_THREADS_HACK */
476
477 /* XXX - can't do much about an error here */
478 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
479 buffer_free(&buffer);
480 pthread_exit(NULL);
481
482 auth_fail:
483 buffer_put_cstring(&buffer,
484 pam_strerror(sshpam_handle, sshpam_err));
485 /* XXX - can't do much about an error here */
486 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
487 buffer_free(&buffer);
488 pthread_exit(NULL);
489
490 return (NULL); /* Avoid warning for non-pthread case */
491}
492
493void
494sshpam_thread_cleanup(void)
495{
496 struct pam_ctxt *ctxt = cleanup_ctxt;
497
498 debug3("PAM: %s entering", __func__);
499 if (ctxt != NULL && ctxt->pam_thread != 0) {
500 pthread_cancel(ctxt->pam_thread);
501 pthread_join(ctxt->pam_thread, NULL);
502 close(ctxt->pam_psock);
503 close(ctxt->pam_csock);
504 memset(ctxt, 0, sizeof(*ctxt));
505 cleanup_ctxt = NULL;
506 }
507}
508
509static int
510sshpam_null_conv(int n, sshpam_const struct pam_message **msg,
511 struct pam_response **resp, void *data)
512{
513 debug3("PAM: %s entering, %d messages", __func__, n);
514 return (PAM_CONV_ERR);
515}
516
517static struct pam_conv null_conv = { sshpam_null_conv, NULL };
518
519static int
520sshpam_store_conv(int n, sshpam_const struct pam_message **msg,
521 struct pam_response **resp, void *data)
522{
523 struct pam_response *reply;
524 int i;
525 size_t len;
526
527 debug3("PAM: %s called with %d messages", __func__, n);
528 *resp = NULL;
529
530 if (n <= 0 || n > PAM_MAX_NUM_MSG)
531 return (PAM_CONV_ERR);
532
533 if ((reply = malloc(n * sizeof(*reply))) == NULL)
534 return (PAM_CONV_ERR);
535 memset(reply, 0, n * sizeof(*reply));
536
537 for (i = 0; i < n; ++i) {
538 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
539 case PAM_ERROR_MSG:
540 case PAM_TEXT_INFO:
541 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
542 buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
543 buffer_append(&loginmsg, "\n", 1 );
544 reply[i].resp_retcode = PAM_SUCCESS;
545 break;
546 default:
547 goto fail;
548 }
549 }
550 *resp = reply;
551 return (PAM_SUCCESS);
552
553 fail:
554 for(i = 0; i < n; i++) {
555 if (reply[i].resp != NULL)
556 xfree(reply[i].resp);
557 }
558 xfree(reply);
559 return (PAM_CONV_ERR);
560}
561
562static struct pam_conv store_conv = { sshpam_store_conv, NULL };
563
564void
565sshpam_cleanup(void)
566{
567 debug("PAM: cleanup");
568 if (sshpam_handle == NULL)
569 return;
570 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
571 if (sshpam_cred_established) {
572 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
573 sshpam_cred_established = 0;
574 }
575 if (sshpam_session_open) {
576 pam_close_session(sshpam_handle, PAM_SILENT);
577 sshpam_session_open = 0;
578 }
579 sshpam_authenticated = 0;
580 pam_end(sshpam_handle, sshpam_err);
581 sshpam_handle = NULL;
582}
583
584static int
585sshpam_init(Authctxt *authctxt)
586{
587 extern char *__progname;
588 const char *pam_rhost, *pam_user, *user = authctxt->user;
589 const char **ptr_pam_user = &pam_user;
590
591 if (sshpam_handle != NULL) {
592 /* We already have a PAM context; check if the user matches */
593 sshpam_err = pam_get_item(sshpam_handle,
594 PAM_USER, (sshpam_const void **)ptr_pam_user);
595 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
596 return (0);
597 pam_end(sshpam_handle, sshpam_err);
598 sshpam_handle = NULL;
599 }
600 debug("PAM: initializing for \"%s\"", user);
601 sshpam_err =
602 pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
603 sshpam_authctxt = authctxt;
604
605 if (sshpam_err != PAM_SUCCESS) {
606 pam_end(sshpam_handle, sshpam_err);
607 sshpam_handle = NULL;
608 return (-1);
609 }
610 pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
611 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
612 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
613 if (sshpam_err != PAM_SUCCESS) {
614 pam_end(sshpam_handle, sshpam_err);
615 sshpam_handle = NULL;
616 return (-1);
617 }
618#ifdef PAM_TTY_KLUDGE
619 /*
620 * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
621 * sshd doesn't set the tty until too late in the auth process and
622 * may not even set one (for tty-less connections)
623 */
624 debug("PAM: setting PAM_TTY to \"ssh\"");
625 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
626 if (sshpam_err != PAM_SUCCESS) {
627 pam_end(sshpam_handle, sshpam_err);
628 sshpam_handle = NULL;
629 return (-1);
630 }
631#endif
632 return (0);
633}
634
635static void *
636sshpam_init_ctx(Authctxt *authctxt)
637{
638 struct pam_ctxt *ctxt;
639 int socks[2];
640
641 debug3("PAM: %s entering", __func__);
642 /* Refuse to start if we don't have PAM enabled */
643 if (!options.use_pam)
644 return NULL;
645
646 /* Initialize PAM */
647 if (sshpam_init(authctxt) == -1) {
648 error("PAM: initialization failed");
649 return (NULL);
650 }
651
652 ctxt = xmalloc(sizeof *ctxt);
653 memset(ctxt, 0, sizeof(*ctxt));
654
655 /* Start the authentication thread */
656 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
657 error("PAM: failed create sockets: %s", strerror(errno));
658 xfree(ctxt);
659 return (NULL);
660 }
661 ctxt->pam_psock = socks[0];
662 ctxt->pam_csock = socks[1];
663 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
664 error("PAM: failed to start authentication thread: %s",
665 strerror(errno));
666 close(socks[0]);
667 close(socks[1]);
668 xfree(ctxt);
669 return (NULL);
670 }
671 cleanup_ctxt = ctxt;
672 return (ctxt);
673}
674
675static int
676sshpam_query(void *ctx, char **name, char **info,
677 u_int *num, char ***prompts, u_int **echo_on)
678{
679 Buffer buffer;
680 struct pam_ctxt *ctxt = ctx;
681 size_t plen;
682 u_char type;
683 char *msg;
684 size_t len, mlen;
685
686 debug3("PAM: %s entering", __func__);
687 buffer_init(&buffer);
688 *name = xstrdup("");
689 *info = xstrdup("");
690 *prompts = xmalloc(sizeof(char *));
691 **prompts = NULL;
692 plen = 0;
693 *echo_on = xmalloc(sizeof(u_int));
694 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
695 type = buffer_get_char(&buffer);
696 msg = buffer_get_string(&buffer, NULL);
697 mlen = strlen(msg);
698 switch (type) {
699 case PAM_PROMPT_ECHO_ON:
700 case PAM_PROMPT_ECHO_OFF:
701 *num = 1;
702 len = plen + mlen + 1;
703 **prompts = xrealloc(**prompts, len);
704 strlcpy(**prompts + plen, msg, len - plen);
705 plen += mlen;
706 **echo_on = (type == PAM_PROMPT_ECHO_ON);
707 xfree(msg);
708 return (0);
709 case PAM_ERROR_MSG:
710 case PAM_TEXT_INFO:
711 /* accumulate messages */
712 len = plen + mlen + 2;
713 **prompts = xrealloc(**prompts, len);
714 strlcpy(**prompts + plen, msg, len - plen);
715 plen += mlen;
716 strlcat(**prompts + plen, "\n", len - plen);
717 plen++;
718 xfree(msg);
719 break;
| 52
53#ifdef USE_PAM
54#if defined(HAVE_SECURITY_PAM_APPL_H)
55#include <security/pam_appl.h>
56#elif defined (HAVE_PAM_PAM_APPL_H)
57#include <pam/pam_appl.h>
58#endif
59
60/* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */
61#ifdef PAM_SUN_CODEBASE
62# define sshpam_const /* Solaris, HP-UX, AIX */
63#else
64# define sshpam_const const /* LinuxPAM, OpenPAM */
65#endif
66
67#include "auth.h"
68#include "auth-pam.h"
69#include "buffer.h"
70#include "bufaux.h"
71#include "canohost.h"
72#include "log.h"
73#include "monitor_wrap.h"
74#include "msg.h"
75#include "packet.h"
76#include "misc.h"
77#include "servconf.h"
78#include "ssh2.h"
79#include "xmalloc.h"
80#include "auth-options.h"
81
82extern ServerOptions options;
83extern Buffer loginmsg;
84extern int compat20;
85extern u_int utmp_len;
86
87/* so we don't silently change behaviour */
88#ifdef USE_POSIX_THREADS
89# error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
90#endif
91
92/*
93 * Formerly known as USE_POSIX_THREADS, using this is completely unsupported
94 * and generally a bad idea. Use at own risk and do not expect support if
95 * this breaks.
96 */
97#ifdef UNSUPPORTED_POSIX_THREADS_HACK
98#include <pthread.h>
99/*
100 * Avoid namespace clash when *not* using pthreads for systems *with*
101 * pthreads, which unconditionally define pthread_t via sys/types.h
102 * (e.g. Linux)
103 */
104typedef pthread_t sp_pthread_t;
105#else
106typedef pid_t sp_pthread_t;
107#endif
108
109struct pam_ctxt {
110 sp_pthread_t pam_thread;
111 int pam_psock;
112 int pam_csock;
113 int pam_done;
114};
115
116static void sshpam_free_ctx(void *);
117static struct pam_ctxt *cleanup_ctxt;
118
119#ifndef UNSUPPORTED_POSIX_THREADS_HACK
120/*
121 * Simulate threads with processes.
122 */
123
124static int sshpam_thread_status = -1;
125static mysig_t sshpam_oldsig;
126
127static void
128sshpam_sigchld_handler(int sig)
129{
130 signal(SIGCHLD, SIG_DFL);
131 if (cleanup_ctxt == NULL)
132 return; /* handler called after PAM cleanup, shouldn't happen */
133 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG)
134 <= 0) {
135 /* PAM thread has not exitted, privsep slave must have */
136 kill(cleanup_ctxt->pam_thread, SIGTERM);
137 if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0)
138 <= 0)
139 return; /* could not wait */
140 }
141 if (WIFSIGNALED(sshpam_thread_status) &&
142 WTERMSIG(sshpam_thread_status) == SIGTERM)
143 return; /* terminated by pthread_cancel */
144 if (!WIFEXITED(sshpam_thread_status))
145 fatal("PAM: authentication thread exited unexpectedly");
146 if (WEXITSTATUS(sshpam_thread_status) != 0)
147 fatal("PAM: authentication thread exited uncleanly");
148}
149
150static void
151pthread_exit(void *value __unused)
152{
153 _exit(0);
154}
155
156static int
157pthread_create(sp_pthread_t *thread, const void *attr __unused,
158 void *(*thread_start)(void *), void *arg)
159{
160 pid_t pid;
161 struct pam_ctxt *ctx = arg;
162
163 sshpam_thread_status = -1;
164 switch ((pid = fork())) {
165 case -1:
166 error("fork(): %s", strerror(errno));
167 return (-1);
168 case 0:
169 close(ctx->pam_psock);
170 ctx->pam_psock = -1;
171 thread_start(arg);
172 _exit(1);
173 default:
174 *thread = pid;
175 close(ctx->pam_csock);
176 ctx->pam_csock = -1;
177 sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
178 return (0);
179 }
180}
181
182static int
183pthread_cancel(sp_pthread_t thread)
184{
185 signal(SIGCHLD, sshpam_oldsig);
186 return (kill(thread, SIGTERM));
187}
188
189static int
190pthread_join(sp_pthread_t thread, void **value __unused)
191{
192 int status;
193
194 if (sshpam_thread_status != -1)
195 return (sshpam_thread_status);
196 signal(SIGCHLD, sshpam_oldsig);
197 waitpid(thread, &status, 0);
198 return (status);
199}
200#endif
201
202
203static pam_handle_t *sshpam_handle = NULL;
204static int sshpam_err = 0;
205static int sshpam_authenticated = 0;
206static int sshpam_session_open = 0;
207static int sshpam_cred_established = 0;
208static int sshpam_account_status = -1;
209static char **sshpam_env = NULL;
210static Authctxt *sshpam_authctxt = NULL;
211static const char *sshpam_password = NULL;
212static char badpw[] = "\b\n\r\177INCORRECT";
213
214/* Some PAM implementations don't implement this */
215#ifndef HAVE_PAM_GETENVLIST
216static char **
217pam_getenvlist(pam_handle_t *pamh)
218{
219 /*
220 * XXX - If necessary, we can still support envrionment passing
221 * for platforms without pam_getenvlist by searching for known
222 * env vars (e.g. KRB5CCNAME) from the PAM environment.
223 */
224 return NULL;
225}
226#endif
227
228/*
229 * Some platforms, notably Solaris, do not enforce password complexity
230 * rules during pam_chauthtok() if the real uid of the calling process
231 * is 0, on the assumption that it's being called by "passwd" run by root.
232 * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
233 * the right thing.
234 */
235#ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
236static int
237sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
238{
239 int result;
240
241 if (sshpam_authctxt == NULL)
242 fatal("PAM: sshpam_authctxt not initialized");
243 if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
244 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
245 result = pam_chauthtok(pamh, flags);
246 if (setreuid(0, -1) == -1)
247 fatal("%s: setreuid failed: %s", __func__, strerror(errno));
248 return result;
249}
250# define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b)))
251#endif
252
253void
254sshpam_password_change_required(int reqd)
255{
256 debug3("%s %d", __func__, reqd);
257 if (sshpam_authctxt == NULL)
258 fatal("%s: PAM authctxt not initialized", __func__);
259 sshpam_authctxt->force_pwchange = reqd;
260 if (reqd) {
261 no_port_forwarding_flag |= 2;
262 no_agent_forwarding_flag |= 2;
263 no_x11_forwarding_flag |= 2;
264 } else {
265 no_port_forwarding_flag &= ~2;
266 no_agent_forwarding_flag &= ~2;
267 no_x11_forwarding_flag &= ~2;
268 }
269}
270
271/* Import regular and PAM environment from subprocess */
272static void
273import_environments(Buffer *b)
274{
275 char *env;
276 u_int i, num_env;
277 int err;
278
279 debug3("PAM: %s entering", __func__);
280
281#ifndef UNSUPPORTED_POSIX_THREADS_HACK
282 /* Import variables set by do_pam_account */
283 sshpam_account_status = buffer_get_int(b);
284 sshpam_password_change_required(buffer_get_int(b));
285
286 /* Import environment from subprocess */
287 num_env = buffer_get_int(b);
288 sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env));
289 debug3("PAM: num env strings %d", num_env);
290 for(i = 0; i < num_env; i++)
291 sshpam_env[i] = buffer_get_string(b, NULL);
292
293 sshpam_env[num_env] = NULL;
294
295 /* Import PAM environment from subprocess */
296 num_env = buffer_get_int(b);
297 debug("PAM: num PAM env strings %d", num_env);
298 for(i = 0; i < num_env; i++) {
299 env = buffer_get_string(b, NULL);
300
301#ifdef HAVE_PAM_PUTENV
302 /* Errors are not fatal here */
303 if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
304 error("PAM: pam_putenv: %s",
305 pam_strerror(sshpam_handle, sshpam_err));
306 }
307#endif
308 }
309#endif
310}
311
312/*
313 * Conversation function for authentication thread.
314 */
315static int
316sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
317 struct pam_response **resp, void *data)
318{
319 Buffer buffer;
320 struct pam_ctxt *ctxt;
321 struct pam_response *reply;
322 int i;
323
324 debug3("PAM: %s entering, %d messages", __func__, n);
325 *resp = NULL;
326
327 if (data == NULL) {
328 error("PAM: conversation function passed a null context");
329 return (PAM_CONV_ERR);
330 }
331 ctxt = data;
332 if (n <= 0 || n > PAM_MAX_NUM_MSG)
333 return (PAM_CONV_ERR);
334
335 if ((reply = malloc(n * sizeof(*reply))) == NULL)
336 return (PAM_CONV_ERR);
337 memset(reply, 0, n * sizeof(*reply));
338
339 buffer_init(&buffer);
340 for (i = 0; i < n; ++i) {
341 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
342 case PAM_PROMPT_ECHO_OFF:
343 buffer_put_cstring(&buffer,
344 PAM_MSG_MEMBER(msg, i, msg));
345 if (ssh_msg_send(ctxt->pam_csock,
346 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
347 goto fail;
348 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
349 goto fail;
350 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
351 goto fail;
352 reply[i].resp = buffer_get_string(&buffer, NULL);
353 break;
354 case PAM_PROMPT_ECHO_ON:
355 buffer_put_cstring(&buffer,
356 PAM_MSG_MEMBER(msg, i, msg));
357 if (ssh_msg_send(ctxt->pam_csock,
358 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
359 goto fail;
360 if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
361 goto fail;
362 if (buffer_get_char(&buffer) != PAM_AUTHTOK)
363 goto fail;
364 reply[i].resp = buffer_get_string(&buffer, NULL);
365 break;
366 case PAM_ERROR_MSG:
367 buffer_put_cstring(&buffer,
368 PAM_MSG_MEMBER(msg, i, msg));
369 if (ssh_msg_send(ctxt->pam_csock,
370 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
371 goto fail;
372 break;
373 case PAM_TEXT_INFO:
374 buffer_put_cstring(&buffer,
375 PAM_MSG_MEMBER(msg, i, msg));
376 if (ssh_msg_send(ctxt->pam_csock,
377 PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
378 goto fail;
379 break;
380 default:
381 goto fail;
382 }
383 buffer_clear(&buffer);
384 }
385 buffer_free(&buffer);
386 *resp = reply;
387 return (PAM_SUCCESS);
388
389 fail:
390 for(i = 0; i < n; i++) {
391 if (reply[i].resp != NULL)
392 xfree(reply[i].resp);
393 }
394 xfree(reply);
395 buffer_free(&buffer);
396 return (PAM_CONV_ERR);
397}
398
399/*
400 * Authentication thread.
401 */
402static void *
403sshpam_thread(void *ctxtp)
404{
405 struct pam_ctxt *ctxt = ctxtp;
406 Buffer buffer;
407 struct pam_conv sshpam_conv;
408 int flags = (options.permit_empty_passwd == 0 ?
409 PAM_DISALLOW_NULL_AUTHTOK : 0);
410#ifndef UNSUPPORTED_POSIX_THREADS_HACK
411 extern char **environ;
412 char **env_from_pam;
413 u_int i;
414 const char *pam_user;
415 const char **ptr_pam_user = &pam_user;
416
417 pam_get_item(sshpam_handle, PAM_USER,
418 (sshpam_const void **)ptr_pam_user);
419 environ[0] = NULL;
420
421 if (sshpam_authctxt != NULL) {
422 setproctitle("%s [pam]",
423 sshpam_authctxt->valid ? pam_user : "unknown");
424 }
425#endif
426
427 sshpam_conv.conv = sshpam_thread_conv;
428 sshpam_conv.appdata_ptr = ctxt;
429
430 if (sshpam_authctxt == NULL)
431 fatal("%s: PAM authctxt not initialized", __func__);
432
433 buffer_init(&buffer);
434 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
435 (const void *)&sshpam_conv);
436 if (sshpam_err != PAM_SUCCESS)
437 goto auth_fail;
438 sshpam_err = pam_authenticate(sshpam_handle, flags);
439 if (sshpam_err != PAM_SUCCESS)
440 goto auth_fail;
441
442 if (compat20) {
443 if (!do_pam_account())
444 goto auth_fail;
445 if (sshpam_authctxt->force_pwchange) {
446 sshpam_err = pam_chauthtok(sshpam_handle,
447 PAM_CHANGE_EXPIRED_AUTHTOK);
448 if (sshpam_err != PAM_SUCCESS)
449 goto auth_fail;
450 sshpam_password_change_required(0);
451 }
452 }
453
454 buffer_put_cstring(&buffer, "OK");
455
456#ifndef UNSUPPORTED_POSIX_THREADS_HACK
457 /* Export variables set by do_pam_account */
458 buffer_put_int(&buffer, sshpam_account_status);
459 buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
460
461 /* Export any environment strings set in child */
462 for(i = 0; environ[i] != NULL; i++)
463 ; /* Count */
464 buffer_put_int(&buffer, i);
465 for(i = 0; environ[i] != NULL; i++)
466 buffer_put_cstring(&buffer, environ[i]);
467
468 /* Export any environment strings set by PAM in child */
469 env_from_pam = pam_getenvlist(sshpam_handle);
470 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
471 ; /* Count */
472 buffer_put_int(&buffer, i);
473 for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
474 buffer_put_cstring(&buffer, env_from_pam[i]);
475#endif /* UNSUPPORTED_POSIX_THREADS_HACK */
476
477 /* XXX - can't do much about an error here */
478 ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
479 buffer_free(&buffer);
480 pthread_exit(NULL);
481
482 auth_fail:
483 buffer_put_cstring(&buffer,
484 pam_strerror(sshpam_handle, sshpam_err));
485 /* XXX - can't do much about an error here */
486 ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
487 buffer_free(&buffer);
488 pthread_exit(NULL);
489
490 return (NULL); /* Avoid warning for non-pthread case */
491}
492
493void
494sshpam_thread_cleanup(void)
495{
496 struct pam_ctxt *ctxt = cleanup_ctxt;
497
498 debug3("PAM: %s entering", __func__);
499 if (ctxt != NULL && ctxt->pam_thread != 0) {
500 pthread_cancel(ctxt->pam_thread);
501 pthread_join(ctxt->pam_thread, NULL);
502 close(ctxt->pam_psock);
503 close(ctxt->pam_csock);
504 memset(ctxt, 0, sizeof(*ctxt));
505 cleanup_ctxt = NULL;
506 }
507}
508
509static int
510sshpam_null_conv(int n, sshpam_const struct pam_message **msg,
511 struct pam_response **resp, void *data)
512{
513 debug3("PAM: %s entering, %d messages", __func__, n);
514 return (PAM_CONV_ERR);
515}
516
517static struct pam_conv null_conv = { sshpam_null_conv, NULL };
518
519static int
520sshpam_store_conv(int n, sshpam_const struct pam_message **msg,
521 struct pam_response **resp, void *data)
522{
523 struct pam_response *reply;
524 int i;
525 size_t len;
526
527 debug3("PAM: %s called with %d messages", __func__, n);
528 *resp = NULL;
529
530 if (n <= 0 || n > PAM_MAX_NUM_MSG)
531 return (PAM_CONV_ERR);
532
533 if ((reply = malloc(n * sizeof(*reply))) == NULL)
534 return (PAM_CONV_ERR);
535 memset(reply, 0, n * sizeof(*reply));
536
537 for (i = 0; i < n; ++i) {
538 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
539 case PAM_ERROR_MSG:
540 case PAM_TEXT_INFO:
541 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
542 buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
543 buffer_append(&loginmsg, "\n", 1 );
544 reply[i].resp_retcode = PAM_SUCCESS;
545 break;
546 default:
547 goto fail;
548 }
549 }
550 *resp = reply;
551 return (PAM_SUCCESS);
552
553 fail:
554 for(i = 0; i < n; i++) {
555 if (reply[i].resp != NULL)
556 xfree(reply[i].resp);
557 }
558 xfree(reply);
559 return (PAM_CONV_ERR);
560}
561
562static struct pam_conv store_conv = { sshpam_store_conv, NULL };
563
564void
565sshpam_cleanup(void)
566{
567 debug("PAM: cleanup");
568 if (sshpam_handle == NULL)
569 return;
570 pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
571 if (sshpam_cred_established) {
572 pam_setcred(sshpam_handle, PAM_DELETE_CRED);
573 sshpam_cred_established = 0;
574 }
575 if (sshpam_session_open) {
576 pam_close_session(sshpam_handle, PAM_SILENT);
577 sshpam_session_open = 0;
578 }
579 sshpam_authenticated = 0;
580 pam_end(sshpam_handle, sshpam_err);
581 sshpam_handle = NULL;
582}
583
584static int
585sshpam_init(Authctxt *authctxt)
586{
587 extern char *__progname;
588 const char *pam_rhost, *pam_user, *user = authctxt->user;
589 const char **ptr_pam_user = &pam_user;
590
591 if (sshpam_handle != NULL) {
592 /* We already have a PAM context; check if the user matches */
593 sshpam_err = pam_get_item(sshpam_handle,
594 PAM_USER, (sshpam_const void **)ptr_pam_user);
595 if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
596 return (0);
597 pam_end(sshpam_handle, sshpam_err);
598 sshpam_handle = NULL;
599 }
600 debug("PAM: initializing for \"%s\"", user);
601 sshpam_err =
602 pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
603 sshpam_authctxt = authctxt;
604
605 if (sshpam_err != PAM_SUCCESS) {
606 pam_end(sshpam_handle, sshpam_err);
607 sshpam_handle = NULL;
608 return (-1);
609 }
610 pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
611 debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
612 sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
613 if (sshpam_err != PAM_SUCCESS) {
614 pam_end(sshpam_handle, sshpam_err);
615 sshpam_handle = NULL;
616 return (-1);
617 }
618#ifdef PAM_TTY_KLUDGE
619 /*
620 * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
621 * sshd doesn't set the tty until too late in the auth process and
622 * may not even set one (for tty-less connections)
623 */
624 debug("PAM: setting PAM_TTY to \"ssh\"");
625 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
626 if (sshpam_err != PAM_SUCCESS) {
627 pam_end(sshpam_handle, sshpam_err);
628 sshpam_handle = NULL;
629 return (-1);
630 }
631#endif
632 return (0);
633}
634
635static void *
636sshpam_init_ctx(Authctxt *authctxt)
637{
638 struct pam_ctxt *ctxt;
639 int socks[2];
640
641 debug3("PAM: %s entering", __func__);
642 /* Refuse to start if we don't have PAM enabled */
643 if (!options.use_pam)
644 return NULL;
645
646 /* Initialize PAM */
647 if (sshpam_init(authctxt) == -1) {
648 error("PAM: initialization failed");
649 return (NULL);
650 }
651
652 ctxt = xmalloc(sizeof *ctxt);
653 memset(ctxt, 0, sizeof(*ctxt));
654
655 /* Start the authentication thread */
656 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
657 error("PAM: failed create sockets: %s", strerror(errno));
658 xfree(ctxt);
659 return (NULL);
660 }
661 ctxt->pam_psock = socks[0];
662 ctxt->pam_csock = socks[1];
663 if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
664 error("PAM: failed to start authentication thread: %s",
665 strerror(errno));
666 close(socks[0]);
667 close(socks[1]);
668 xfree(ctxt);
669 return (NULL);
670 }
671 cleanup_ctxt = ctxt;
672 return (ctxt);
673}
674
675static int
676sshpam_query(void *ctx, char **name, char **info,
677 u_int *num, char ***prompts, u_int **echo_on)
678{
679 Buffer buffer;
680 struct pam_ctxt *ctxt = ctx;
681 size_t plen;
682 u_char type;
683 char *msg;
684 size_t len, mlen;
685
686 debug3("PAM: %s entering", __func__);
687 buffer_init(&buffer);
688 *name = xstrdup("");
689 *info = xstrdup("");
690 *prompts = xmalloc(sizeof(char *));
691 **prompts = NULL;
692 plen = 0;
693 *echo_on = xmalloc(sizeof(u_int));
694 while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
695 type = buffer_get_char(&buffer);
696 msg = buffer_get_string(&buffer, NULL);
697 mlen = strlen(msg);
698 switch (type) {
699 case PAM_PROMPT_ECHO_ON:
700 case PAM_PROMPT_ECHO_OFF:
701 *num = 1;
702 len = plen + mlen + 1;
703 **prompts = xrealloc(**prompts, len);
704 strlcpy(**prompts + plen, msg, len - plen);
705 plen += mlen;
706 **echo_on = (type == PAM_PROMPT_ECHO_ON);
707 xfree(msg);
708 return (0);
709 case PAM_ERROR_MSG:
710 case PAM_TEXT_INFO:
711 /* accumulate messages */
712 len = plen + mlen + 2;
713 **prompts = xrealloc(**prompts, len);
714 strlcpy(**prompts + plen, msg, len - plen);
715 plen += mlen;
716 strlcat(**prompts + plen, "\n", len - plen);
717 plen++;
718 xfree(msg);
719 break;
|
768 switch (ctxt->pam_done) {
769 case 1:
770 sshpam_authenticated = 1;
771 return (0);
772 case 0:
773 break;
774 default:
775 return (-1);
776 }
777 if (num != 1) {
778 error("PAM: expected one response, got %u", num);
779 return (-1);
780 }
781 buffer_init(&buffer);
782 if (sshpam_authctxt->valid &&
783 (sshpam_authctxt->pw->pw_uid != 0 ||
784 options.permit_root_login == PERMIT_YES))
785 buffer_put_cstring(&buffer, *resp);
786 else
787 buffer_put_cstring(&buffer, badpw);
788 if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
789 buffer_free(&buffer);
790 return (-1);
791 }
792 buffer_free(&buffer);
793 return (1);
794}
795
796static void
797sshpam_free_ctx(void *ctxtp)
798{
799 struct pam_ctxt *ctxt = ctxtp;
800
801 debug3("PAM: %s entering", __func__);
802 sshpam_thread_cleanup();
803 xfree(ctxt);
804 /*
805 * We don't call sshpam_cleanup() here because we may need the PAM
806 * handle at a later stage, e.g. when setting up a session. It's
807 * still on the cleanup list, so pam_end() *will* be called before
808 * the server process terminates.
809 */
810}
811
812KbdintDevice sshpam_device = {
813 "pam",
814 sshpam_init_ctx,
815 sshpam_query,
816 sshpam_respond,
817 sshpam_free_ctx
818};
819
820KbdintDevice mm_sshpam_device = {
821 "pam",
822 mm_sshpam_init_ctx,
823 mm_sshpam_query,
824 mm_sshpam_respond,
825 mm_sshpam_free_ctx
826};
827
828/*
829 * This replaces auth-pam.c
830 */
831void
832start_pam(Authctxt *authctxt)
833{
834 if (!options.use_pam)
835 fatal("PAM: initialisation requested when UsePAM=no");
836
837 if (sshpam_init(authctxt) == -1)
838 fatal("PAM: initialisation failed");
839}
840
841void
842finish_pam(void)
843{
844 sshpam_cleanup();
845}
846
847u_int
848do_pam_account(void)
849{
850 debug("%s: called", __func__);
851 if (sshpam_account_status != -1)
852 return (sshpam_account_status);
853
854 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
855 debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
856 pam_strerror(sshpam_handle, sshpam_err));
857
858 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
859 sshpam_account_status = 0;
860 return (sshpam_account_status);
861 }
862
863 if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
864 sshpam_password_change_required(1);
865
866 sshpam_account_status = 1;
867 return (sshpam_account_status);
868}
869
870void
871do_pam_set_tty(const char *tty)
872{
873 if (tty != NULL) {
874 debug("PAM: setting PAM_TTY to \"%s\"", tty);
875 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
876 if (sshpam_err != PAM_SUCCESS)
877 fatal("PAM: failed to set PAM_TTY: %s",
878 pam_strerror(sshpam_handle, sshpam_err));
879 }
880}
881
882void
883do_pam_setcred(int init)
884{
885 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
886 (const void *)&store_conv);
887 if (sshpam_err != PAM_SUCCESS)
888 fatal("PAM: failed to set PAM_CONV: %s",
889 pam_strerror(sshpam_handle, sshpam_err));
890 if (init) {
891 debug("PAM: establishing credentials");
892 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
893 } else {
894 debug("PAM: reinitializing credentials");
895 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
896 }
897 if (sshpam_err == PAM_SUCCESS) {
898 sshpam_cred_established = 1;
899 return;
900 }
901 if (sshpam_authenticated)
902 fatal("PAM: pam_setcred(): %s",
903 pam_strerror(sshpam_handle, sshpam_err));
904 else
905 debug("PAM: pam_setcred(): %s",
906 pam_strerror(sshpam_handle, sshpam_err));
907}
908
909static int
910sshpam_tty_conv(int n, sshpam_const struct pam_message **msg,
911 struct pam_response **resp, void *data)
912{
913 char input[PAM_MAX_MSG_SIZE];
914 struct pam_response *reply;
915 int i;
916
917 debug3("PAM: %s called with %d messages", __func__, n);
918
919 *resp = NULL;
920
921 if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
922 return (PAM_CONV_ERR);
923
924 if ((reply = malloc(n * sizeof(*reply))) == NULL)
925 return (PAM_CONV_ERR);
926 memset(reply, 0, n * sizeof(*reply));
927
928 for (i = 0; i < n; ++i) {
929 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
930 case PAM_PROMPT_ECHO_OFF:
931 reply[i].resp =
932 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
933 RP_ALLOW_STDIN);
934 reply[i].resp_retcode = PAM_SUCCESS;
935 break;
936 case PAM_PROMPT_ECHO_ON:
937 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
938 fgets(input, sizeof input, stdin);
939 if ((reply[i].resp = strdup(input)) == NULL)
940 goto fail;
941 reply[i].resp_retcode = PAM_SUCCESS;
942 break;
943 case PAM_ERROR_MSG:
944 case PAM_TEXT_INFO:
945 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
946 reply[i].resp_retcode = PAM_SUCCESS;
947 break;
948 default:
949 goto fail;
950 }
951 }
952 *resp = reply;
953 return (PAM_SUCCESS);
954
955 fail:
956 for(i = 0; i < n; i++) {
957 if (reply[i].resp != NULL)
958 xfree(reply[i].resp);
959 }
960 xfree(reply);
961 return (PAM_CONV_ERR);
962}
963
964static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
965
966/*
967 * XXX this should be done in the authentication phase, but ssh1 doesn't
968 * support that
969 */
970void
971do_pam_chauthtok(void)
972{
973 if (use_privsep)
974 fatal("Password expired (unable to change with privsep)");
975 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
976 (const void *)&tty_conv);
977 if (sshpam_err != PAM_SUCCESS)
978 fatal("PAM: failed to set PAM_CONV: %s",
979 pam_strerror(sshpam_handle, sshpam_err));
980 debug("PAM: changing password");
981 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
982 if (sshpam_err != PAM_SUCCESS)
983 fatal("PAM: pam_chauthtok(): %s",
984 pam_strerror(sshpam_handle, sshpam_err));
985}
986
987void
988do_pam_session(void)
989{
990 debug3("PAM: opening session");
991 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
992 (const void *)&store_conv);
993 if (sshpam_err != PAM_SUCCESS)
994 fatal("PAM: failed to set PAM_CONV: %s",
995 pam_strerror(sshpam_handle, sshpam_err));
996 sshpam_err = pam_open_session(sshpam_handle, 0);
997 if (sshpam_err == PAM_SUCCESS)
998 sshpam_session_open = 1;
999 else {
1000 sshpam_session_open = 0;
1001 disable_forwarding();
1002 error("PAM: pam_open_session(): %s",
1003 pam_strerror(sshpam_handle, sshpam_err));
1004 }
1005
1006}
1007
1008int
1009is_pam_session_open(void)
1010{
1011 return sshpam_session_open;
1012}
1013
1014/*
1015 * Set a PAM environment string. We need to do this so that the session
1016 * modules can handle things like Kerberos/GSI credentials that appear
1017 * during the ssh authentication process.
1018 */
1019int
1020do_pam_putenv(char *name, char *value)
1021{
1022 int ret = 1;
1023#ifdef HAVE_PAM_PUTENV
1024 char *compound;
1025 size_t len;
1026
1027 len = strlen(name) + strlen(value) + 2;
1028 compound = xmalloc(len);
1029
1030 snprintf(compound, len, "%s=%s", name, value);
1031 ret = pam_putenv(sshpam_handle, compound);
1032 xfree(compound);
1033#endif
1034
1035 return (ret);
1036}
1037
1038char **
1039fetch_pam_child_environment(void)
1040{
1041 return sshpam_env;
1042}
1043
1044char **
1045fetch_pam_environment(void)
1046{
1047 return (pam_getenvlist(sshpam_handle));
1048}
1049
1050void
1051free_pam_environment(char **env)
1052{
1053 char **envp;
1054
1055 if (env == NULL)
1056 return;
1057
1058 for (envp = env; *envp; envp++)
1059 xfree(*envp);
1060 xfree(env);
1061}
1062
1063/*
1064 * "Blind" conversation function for password authentication. Assumes that
1065 * echo-off prompts are for the password and stores messages for later
1066 * display.
1067 */
1068static int
1069sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg,
1070 struct pam_response **resp, void *data)
1071{
1072 struct pam_response *reply;
1073 int i;
1074 size_t len;
1075
1076 debug3("PAM: %s called with %d messages", __func__, n);
1077
1078 *resp = NULL;
1079
1080 if (n <= 0 || n > PAM_MAX_NUM_MSG)
1081 return (PAM_CONV_ERR);
1082
1083 if ((reply = malloc(n * sizeof(*reply))) == NULL)
1084 return (PAM_CONV_ERR);
1085 memset(reply, 0, n * sizeof(*reply));
1086
1087 for (i = 0; i < n; ++i) {
1088 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1089 case PAM_PROMPT_ECHO_OFF:
1090 if (sshpam_password == NULL)
1091 goto fail;
1092 if ((reply[i].resp = strdup(sshpam_password)) == NULL)
1093 goto fail;
1094 reply[i].resp_retcode = PAM_SUCCESS;
1095 break;
1096 case PAM_ERROR_MSG:
1097 case PAM_TEXT_INFO:
1098 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
1099 if (len > 0) {
1100 buffer_append(&loginmsg,
1101 PAM_MSG_MEMBER(msg, i, msg), len);
1102 buffer_append(&loginmsg, "\n", 1);
1103 }
1104 if ((reply[i].resp = strdup("")) == NULL)
1105 goto fail;
1106 reply[i].resp_retcode = PAM_SUCCESS;
1107 break;
1108 default:
1109 goto fail;
1110 }
1111 }
1112 *resp = reply;
1113 return (PAM_SUCCESS);
1114
1115 fail:
1116 for(i = 0; i < n; i++) {
1117 if (reply[i].resp != NULL)
1118 xfree(reply[i].resp);
1119 }
1120 xfree(reply);
1121 return (PAM_CONV_ERR);
1122}
1123
1124static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
1125
1126/*
1127 * Attempt password authentication via PAM
1128 */
1129int
1130sshpam_auth_passwd(Authctxt *authctxt, const char *password)
1131{
1132 int flags = (options.permit_empty_passwd == 0 ?
1133 PAM_DISALLOW_NULL_AUTHTOK : 0);
1134
1135 if (!options.use_pam || sshpam_handle == NULL)
1136 fatal("PAM: %s called when PAM disabled or failed to "
1137 "initialise.", __func__);
1138
1139 sshpam_password = password;
1140 sshpam_authctxt = authctxt;
1141
1142 /*
1143 * If the user logging in is invalid, or is root but is not permitted
1144 * by PermitRootLogin, use an invalid password to prevent leaking
1145 * information via timing (eg if the PAM config has a delay on fail).
1146 */
1147 if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
1148 options.permit_root_login != PERMIT_YES))
1149 sshpam_password = badpw;
1150
1151 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1152 (const void *)&passwd_conv);
1153 if (sshpam_err != PAM_SUCCESS)
1154 fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
1155 pam_strerror(sshpam_handle, sshpam_err));
1156
1157 sshpam_err = pam_authenticate(sshpam_handle, flags);
1158 sshpam_password = NULL;
1159 if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
1160 debug("PAM: password authentication accepted for %.100s",
1161 authctxt->user);
1162 return 1;
1163 } else {
1164 debug("PAM: password authentication failed for %.100s: %s",
1165 authctxt->valid ? authctxt->user : "an illegal user",
1166 pam_strerror(sshpam_handle, sshpam_err));
1167 return 0;
1168 }
1169}
1170#endif /* USE_PAM */
| 778 switch (ctxt->pam_done) {
779 case 1:
780 sshpam_authenticated = 1;
781 return (0);
782 case 0:
783 break;
784 default:
785 return (-1);
786 }
787 if (num != 1) {
788 error("PAM: expected one response, got %u", num);
789 return (-1);
790 }
791 buffer_init(&buffer);
792 if (sshpam_authctxt->valid &&
793 (sshpam_authctxt->pw->pw_uid != 0 ||
794 options.permit_root_login == PERMIT_YES))
795 buffer_put_cstring(&buffer, *resp);
796 else
797 buffer_put_cstring(&buffer, badpw);
798 if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
799 buffer_free(&buffer);
800 return (-1);
801 }
802 buffer_free(&buffer);
803 return (1);
804}
805
806static void
807sshpam_free_ctx(void *ctxtp)
808{
809 struct pam_ctxt *ctxt = ctxtp;
810
811 debug3("PAM: %s entering", __func__);
812 sshpam_thread_cleanup();
813 xfree(ctxt);
814 /*
815 * We don't call sshpam_cleanup() here because we may need the PAM
816 * handle at a later stage, e.g. when setting up a session. It's
817 * still on the cleanup list, so pam_end() *will* be called before
818 * the server process terminates.
819 */
820}
821
822KbdintDevice sshpam_device = {
823 "pam",
824 sshpam_init_ctx,
825 sshpam_query,
826 sshpam_respond,
827 sshpam_free_ctx
828};
829
830KbdintDevice mm_sshpam_device = {
831 "pam",
832 mm_sshpam_init_ctx,
833 mm_sshpam_query,
834 mm_sshpam_respond,
835 mm_sshpam_free_ctx
836};
837
838/*
839 * This replaces auth-pam.c
840 */
841void
842start_pam(Authctxt *authctxt)
843{
844 if (!options.use_pam)
845 fatal("PAM: initialisation requested when UsePAM=no");
846
847 if (sshpam_init(authctxt) == -1)
848 fatal("PAM: initialisation failed");
849}
850
851void
852finish_pam(void)
853{
854 sshpam_cleanup();
855}
856
857u_int
858do_pam_account(void)
859{
860 debug("%s: called", __func__);
861 if (sshpam_account_status != -1)
862 return (sshpam_account_status);
863
864 sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
865 debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
866 pam_strerror(sshpam_handle, sshpam_err));
867
868 if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
869 sshpam_account_status = 0;
870 return (sshpam_account_status);
871 }
872
873 if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
874 sshpam_password_change_required(1);
875
876 sshpam_account_status = 1;
877 return (sshpam_account_status);
878}
879
880void
881do_pam_set_tty(const char *tty)
882{
883 if (tty != NULL) {
884 debug("PAM: setting PAM_TTY to \"%s\"", tty);
885 sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
886 if (sshpam_err != PAM_SUCCESS)
887 fatal("PAM: failed to set PAM_TTY: %s",
888 pam_strerror(sshpam_handle, sshpam_err));
889 }
890}
891
892void
893do_pam_setcred(int init)
894{
895 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
896 (const void *)&store_conv);
897 if (sshpam_err != PAM_SUCCESS)
898 fatal("PAM: failed to set PAM_CONV: %s",
899 pam_strerror(sshpam_handle, sshpam_err));
900 if (init) {
901 debug("PAM: establishing credentials");
902 sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
903 } else {
904 debug("PAM: reinitializing credentials");
905 sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
906 }
907 if (sshpam_err == PAM_SUCCESS) {
908 sshpam_cred_established = 1;
909 return;
910 }
911 if (sshpam_authenticated)
912 fatal("PAM: pam_setcred(): %s",
913 pam_strerror(sshpam_handle, sshpam_err));
914 else
915 debug("PAM: pam_setcred(): %s",
916 pam_strerror(sshpam_handle, sshpam_err));
917}
918
919static int
920sshpam_tty_conv(int n, sshpam_const struct pam_message **msg,
921 struct pam_response **resp, void *data)
922{
923 char input[PAM_MAX_MSG_SIZE];
924 struct pam_response *reply;
925 int i;
926
927 debug3("PAM: %s called with %d messages", __func__, n);
928
929 *resp = NULL;
930
931 if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
932 return (PAM_CONV_ERR);
933
934 if ((reply = malloc(n * sizeof(*reply))) == NULL)
935 return (PAM_CONV_ERR);
936 memset(reply, 0, n * sizeof(*reply));
937
938 for (i = 0; i < n; ++i) {
939 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
940 case PAM_PROMPT_ECHO_OFF:
941 reply[i].resp =
942 read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
943 RP_ALLOW_STDIN);
944 reply[i].resp_retcode = PAM_SUCCESS;
945 break;
946 case PAM_PROMPT_ECHO_ON:
947 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
948 fgets(input, sizeof input, stdin);
949 if ((reply[i].resp = strdup(input)) == NULL)
950 goto fail;
951 reply[i].resp_retcode = PAM_SUCCESS;
952 break;
953 case PAM_ERROR_MSG:
954 case PAM_TEXT_INFO:
955 fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
956 reply[i].resp_retcode = PAM_SUCCESS;
957 break;
958 default:
959 goto fail;
960 }
961 }
962 *resp = reply;
963 return (PAM_SUCCESS);
964
965 fail:
966 for(i = 0; i < n; i++) {
967 if (reply[i].resp != NULL)
968 xfree(reply[i].resp);
969 }
970 xfree(reply);
971 return (PAM_CONV_ERR);
972}
973
974static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
975
976/*
977 * XXX this should be done in the authentication phase, but ssh1 doesn't
978 * support that
979 */
980void
981do_pam_chauthtok(void)
982{
983 if (use_privsep)
984 fatal("Password expired (unable to change with privsep)");
985 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
986 (const void *)&tty_conv);
987 if (sshpam_err != PAM_SUCCESS)
988 fatal("PAM: failed to set PAM_CONV: %s",
989 pam_strerror(sshpam_handle, sshpam_err));
990 debug("PAM: changing password");
991 sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
992 if (sshpam_err != PAM_SUCCESS)
993 fatal("PAM: pam_chauthtok(): %s",
994 pam_strerror(sshpam_handle, sshpam_err));
995}
996
997void
998do_pam_session(void)
999{
1000 debug3("PAM: opening session");
1001 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1002 (const void *)&store_conv);
1003 if (sshpam_err != PAM_SUCCESS)
1004 fatal("PAM: failed to set PAM_CONV: %s",
1005 pam_strerror(sshpam_handle, sshpam_err));
1006 sshpam_err = pam_open_session(sshpam_handle, 0);
1007 if (sshpam_err == PAM_SUCCESS)
1008 sshpam_session_open = 1;
1009 else {
1010 sshpam_session_open = 0;
1011 disable_forwarding();
1012 error("PAM: pam_open_session(): %s",
1013 pam_strerror(sshpam_handle, sshpam_err));
1014 }
1015
1016}
1017
1018int
1019is_pam_session_open(void)
1020{
1021 return sshpam_session_open;
1022}
1023
1024/*
1025 * Set a PAM environment string. We need to do this so that the session
1026 * modules can handle things like Kerberos/GSI credentials that appear
1027 * during the ssh authentication process.
1028 */
1029int
1030do_pam_putenv(char *name, char *value)
1031{
1032 int ret = 1;
1033#ifdef HAVE_PAM_PUTENV
1034 char *compound;
1035 size_t len;
1036
1037 len = strlen(name) + strlen(value) + 2;
1038 compound = xmalloc(len);
1039
1040 snprintf(compound, len, "%s=%s", name, value);
1041 ret = pam_putenv(sshpam_handle, compound);
1042 xfree(compound);
1043#endif
1044
1045 return (ret);
1046}
1047
1048char **
1049fetch_pam_child_environment(void)
1050{
1051 return sshpam_env;
1052}
1053
1054char **
1055fetch_pam_environment(void)
1056{
1057 return (pam_getenvlist(sshpam_handle));
1058}
1059
1060void
1061free_pam_environment(char **env)
1062{
1063 char **envp;
1064
1065 if (env == NULL)
1066 return;
1067
1068 for (envp = env; *envp; envp++)
1069 xfree(*envp);
1070 xfree(env);
1071}
1072
1073/*
1074 * "Blind" conversation function for password authentication. Assumes that
1075 * echo-off prompts are for the password and stores messages for later
1076 * display.
1077 */
1078static int
1079sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg,
1080 struct pam_response **resp, void *data)
1081{
1082 struct pam_response *reply;
1083 int i;
1084 size_t len;
1085
1086 debug3("PAM: %s called with %d messages", __func__, n);
1087
1088 *resp = NULL;
1089
1090 if (n <= 0 || n > PAM_MAX_NUM_MSG)
1091 return (PAM_CONV_ERR);
1092
1093 if ((reply = malloc(n * sizeof(*reply))) == NULL)
1094 return (PAM_CONV_ERR);
1095 memset(reply, 0, n * sizeof(*reply));
1096
1097 for (i = 0; i < n; ++i) {
1098 switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
1099 case PAM_PROMPT_ECHO_OFF:
1100 if (sshpam_password == NULL)
1101 goto fail;
1102 if ((reply[i].resp = strdup(sshpam_password)) == NULL)
1103 goto fail;
1104 reply[i].resp_retcode = PAM_SUCCESS;
1105 break;
1106 case PAM_ERROR_MSG:
1107 case PAM_TEXT_INFO:
1108 len = strlen(PAM_MSG_MEMBER(msg, i, msg));
1109 if (len > 0) {
1110 buffer_append(&loginmsg,
1111 PAM_MSG_MEMBER(msg, i, msg), len);
1112 buffer_append(&loginmsg, "\n", 1);
1113 }
1114 if ((reply[i].resp = strdup("")) == NULL)
1115 goto fail;
1116 reply[i].resp_retcode = PAM_SUCCESS;
1117 break;
1118 default:
1119 goto fail;
1120 }
1121 }
1122 *resp = reply;
1123 return (PAM_SUCCESS);
1124
1125 fail:
1126 for(i = 0; i < n; i++) {
1127 if (reply[i].resp != NULL)
1128 xfree(reply[i].resp);
1129 }
1130 xfree(reply);
1131 return (PAM_CONV_ERR);
1132}
1133
1134static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
1135
1136/*
1137 * Attempt password authentication via PAM
1138 */
1139int
1140sshpam_auth_passwd(Authctxt *authctxt, const char *password)
1141{
1142 int flags = (options.permit_empty_passwd == 0 ?
1143 PAM_DISALLOW_NULL_AUTHTOK : 0);
1144
1145 if (!options.use_pam || sshpam_handle == NULL)
1146 fatal("PAM: %s called when PAM disabled or failed to "
1147 "initialise.", __func__);
1148
1149 sshpam_password = password;
1150 sshpam_authctxt = authctxt;
1151
1152 /*
1153 * If the user logging in is invalid, or is root but is not permitted
1154 * by PermitRootLogin, use an invalid password to prevent leaking
1155 * information via timing (eg if the PAM config has a delay on fail).
1156 */
1157 if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
1158 options.permit_root_login != PERMIT_YES))
1159 sshpam_password = badpw;
1160
1161 sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
1162 (const void *)&passwd_conv);
1163 if (sshpam_err != PAM_SUCCESS)
1164 fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
1165 pam_strerror(sshpam_handle, sshpam_err));
1166
1167 sshpam_err = pam_authenticate(sshpam_handle, flags);
1168 sshpam_password = NULL;
1169 if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
1170 debug("PAM: password authentication accepted for %.100s",
1171 authctxt->user);
1172 return 1;
1173 } else {
1174 debug("PAM: password authentication failed for %.100s: %s",
1175 authctxt->valid ? authctxt->user : "an illegal user",
1176 pam_strerror(sshpam_handle, sshpam_err));
1177 return 0;
1178 }
1179}
1180#endif /* USE_PAM */
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