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7cac2b65 | 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. | |
3c0ef626 | 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 | * | |
7cac2b65 | 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. | |
3c0ef626 | 30 | */ |
31 | ||
7cac2b65 | 32 | /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */ |
3c0ef626 | 33 | #include "includes.h" |
7cac2b65 | 34 | RCSID("$Id$"); |
3c0ef626 | 35 | |
36 | #ifdef USE_PAM | |
540d72c3 | 37 | #if defined(HAVE_SECURITY_PAM_APPL_H) |
7cac2b65 | 38 | #include <security/pam_appl.h> |
540d72c3 | 39 | #elif defined (HAVE_PAM_PAM_APPL_H) |
40 | #include <pam/pam_appl.h> | |
41 | #endif | |
7cac2b65 | 42 | |
350391c5 | 43 | #include "auth.h" |
3c0ef626 | 44 | #include "auth-pam.h" |
7cac2b65 | 45 | #include "buffer.h" |
46 | #include "bufaux.h" | |
3c0ef626 | 47 | #include "canohost.h" |
7cac2b65 | 48 | #include "log.h" |
49 | #include "monitor_wrap.h" | |
50 | #include "msg.h" | |
51 | #include "packet.h" | |
3c0ef626 | 52 | #include "readpass.h" |
7cac2b65 | 53 | #include "servconf.h" |
54 | #include "ssh2.h" | |
55 | #include "xmalloc.h" | |
56 | #include "auth-options.h" | |
3c0ef626 | 57 | |
7cac2b65 | 58 | extern ServerOptions options; |
540d72c3 | 59 | extern Buffer loginmsg; |
60 | extern int compat20; | |
d03f4262 | 61 | |
7cac2b65 | 62 | #ifdef USE_POSIX_THREADS |
63 | #include <pthread.h> | |
64 | /* | |
540d72c3 | 65 | * Avoid namespace clash when *not* using pthreads for systems *with* |
66 | * pthreads, which unconditionally define pthread_t via sys/types.h | |
7cac2b65 | 67 | * (e.g. Linux) |
68 | */ | |
540d72c3 | 69 | typedef pthread_t sp_pthread_t; |
7cac2b65 | 70 | #else |
540d72c3 | 71 | typedef pid_t sp_pthread_t; |
72 | #endif | |
73 | ||
74 | struct pam_ctxt { | |
75 | sp_pthread_t pam_thread; | |
76 | int pam_psock; | |
77 | int pam_csock; | |
78 | int pam_done; | |
79 | }; | |
80 | ||
81 | static void sshpam_free_ctx(void *); | |
82 | static struct pam_ctxt *cleanup_ctxt; | |
83 | ||
84 | #ifndef USE_POSIX_THREADS | |
7cac2b65 | 85 | /* |
86 | * Simulate threads with processes. | |
87 | */ | |
540d72c3 | 88 | |
89 | static int sshpam_thread_status = -1; | |
90 | static mysig_t sshpam_oldsig; | |
91 | ||
92 | static void | |
93 | sshpam_sigchld_handler(int sig) | |
94 | { | |
95 | if (cleanup_ctxt == NULL) | |
96 | return; /* handler called after PAM cleanup, shouldn't happen */ | |
97 | if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0) == -1) | |
98 | return; /* couldn't wait for process */ | |
99 | if (WIFSIGNALED(sshpam_thread_status) && | |
100 | WTERMSIG(sshpam_thread_status) == SIGTERM) | |
101 | return; /* terminated by pthread_cancel */ | |
102 | if (!WIFEXITED(sshpam_thread_status)) | |
103 | fatal("PAM: authentication thread exited unexpectedly"); | |
104 | if (WEXITSTATUS(sshpam_thread_status) != 0) | |
105 | fatal("PAM: authentication thread exited uncleanly"); | |
106 | } | |
3c0ef626 | 107 | |
7cac2b65 | 108 | static void |
109 | pthread_exit(void *value __unused) | |
110 | { | |
111 | _exit(0); | |
112 | } | |
3c0ef626 | 113 | |
7cac2b65 | 114 | static int |
115 | pthread_create(sp_pthread_t *thread, const void *attr __unused, | |
116 | void *(*thread_start)(void *), void *arg) | |
117 | { | |
118 | pid_t pid; | |
119 | ||
120 | switch ((pid = fork())) { | |
121 | case -1: | |
122 | error("fork(): %s", strerror(errno)); | |
123 | return (-1); | |
124 | case 0: | |
125 | thread_start(arg); | |
126 | _exit(1); | |
127 | default: | |
128 | *thread = pid; | |
540d72c3 | 129 | sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler); |
7cac2b65 | 130 | return (0); |
131 | } | |
132 | } | |
3c0ef626 | 133 | |
7cac2b65 | 134 | static int |
135 | pthread_cancel(sp_pthread_t thread) | |
3c0ef626 | 136 | { |
540d72c3 | 137 | signal(SIGCHLD, sshpam_oldsig); |
7cac2b65 | 138 | return (kill(thread, SIGTERM)); |
3c0ef626 | 139 | } |
140 | ||
7cac2b65 | 141 | static int |
142 | pthread_join(sp_pthread_t thread, void **value __unused) | |
3c0ef626 | 143 | { |
7cac2b65 | 144 | int status; |
145 | ||
540d72c3 | 146 | if (sshpam_thread_status != -1) |
147 | return (sshpam_thread_status); | |
148 | signal(SIGCHLD, sshpam_oldsig); | |
7cac2b65 | 149 | waitpid(thread, &status, 0); |
150 | return (status); | |
3c0ef626 | 151 | } |
7cac2b65 | 152 | #endif |
153 | ||
154 | ||
29d88157 | 155 | static pam_handle_t *sshpam_handle = NULL; |
156 | static int sshpam_err = 0; | |
157 | static int sshpam_authenticated = 0; | |
29d88157 | 158 | static int sshpam_session_open = 0; |
159 | static int sshpam_cred_established = 0; | |
540d72c3 | 160 | static int sshpam_account_status = -1; |
161 | static char **sshpam_env = NULL; | |
162 | static int *force_pwchange; | |
163 | ||
164 | /* Some PAM implementations don't implement this */ | |
165 | #ifndef HAVE_PAM_GETENVLIST | |
166 | static char ** | |
167 | pam_getenvlist(pam_handle_t *pamh) | |
168 | { | |
169 | /* | |
170 | * XXX - If necessary, we can still support envrionment passing | |
171 | * for platforms without pam_getenvlist by searching for known | |
172 | * env vars (e.g. KRB5CCNAME) from the PAM environment. | |
173 | */ | |
174 | return NULL; | |
175 | } | |
176 | #endif | |
7cac2b65 | 177 | |
540d72c3 | 178 | void |
179 | pam_password_change_required(int reqd) | |
180 | { | |
181 | debug3("%s %d", __func__, reqd); | |
182 | *force_pwchange = reqd; | |
183 | if (reqd) { | |
184 | no_port_forwarding_flag |= 2; | |
185 | no_agent_forwarding_flag |= 2; | |
186 | no_x11_forwarding_flag |= 2; | |
187 | } else { | |
188 | no_port_forwarding_flag &= ~2; | |
189 | no_agent_forwarding_flag &= ~2; | |
190 | no_x11_forwarding_flag &= ~2; | |
191 | } | |
192 | } | |
7cac2b65 | 193 | |
540d72c3 | 194 | /* Import regular and PAM environment from subprocess */ |
195 | static void | |
196 | import_environments(Buffer *b) | |
197 | { | |
198 | char *env; | |
199 | u_int i, num_env; | |
200 | int err; | |
201 | ||
202 | debug3("PAM: %s entering", __func__); | |
203 | ||
204 | /* Import variables set by do_pam_account */ | |
205 | sshpam_account_status = buffer_get_int(b); | |
206 | pam_password_change_required(buffer_get_int(b)); | |
207 | ||
208 | /* Import environment from subprocess */ | |
209 | num_env = buffer_get_int(b); | |
210 | sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env)); | |
211 | debug3("PAM: num env strings %d", num_env); | |
212 | for(i = 0; i < num_env; i++) | |
213 | sshpam_env[i] = buffer_get_string(b, NULL); | |
214 | ||
215 | sshpam_env[num_env] = NULL; | |
216 | ||
217 | /* Import PAM environment from subprocess */ | |
218 | num_env = buffer_get_int(b); | |
219 | debug("PAM: num PAM env strings %d", num_env); | |
220 | for(i = 0; i < num_env; i++) { | |
221 | env = buffer_get_string(b, NULL); | |
222 | ||
223 | #ifdef HAVE_PAM_PUTENV | |
224 | /* Errors are not fatal here */ | |
225 | if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { | |
226 | error("PAM: pam_putenv: %s", | |
227 | pam_strerror(sshpam_handle, sshpam_err)); | |
228 | } | |
229 | #endif | |
230 | } | |
231 | } | |
3c0ef626 | 232 | |
233 | /* | |
7cac2b65 | 234 | * Conversation function for authentication thread. |
3c0ef626 | 235 | */ |
7cac2b65 | 236 | static int |
237 | sshpam_thread_conv(int n, const struct pam_message **msg, | |
238 | struct pam_response **resp, void *data) | |
3c0ef626 | 239 | { |
7cac2b65 | 240 | Buffer buffer; |
241 | struct pam_ctxt *ctxt; | |
29d88157 | 242 | struct pam_response *reply; |
7cac2b65 | 243 | int i; |
244 | ||
540d72c3 | 245 | debug3("PAM: %s entering, %d messages", __func__, n); |
29d88157 | 246 | *resp = NULL; |
247 | ||
7cac2b65 | 248 | ctxt = data; |
249 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
250 | return (PAM_CONV_ERR); | |
29d88157 | 251 | |
252 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
253 | return (PAM_CONV_ERR); | |
254 | memset(reply, 0, n * sizeof(*reply)); | |
255 | ||
7cac2b65 | 256 | buffer_init(&buffer); |
257 | for (i = 0; i < n; ++i) { | |
7cac2b65 | 258 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { |
259 | case PAM_PROMPT_ECHO_OFF: | |
540d72c3 | 260 | buffer_put_cstring(&buffer, |
29d88157 | 261 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 262 | if (ssh_msg_send(ctxt->pam_csock, |
263 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
264 | goto fail; | |
265 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
266 | goto fail; | |
7cac2b65 | 267 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
268 | goto fail; | |
29d88157 | 269 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 270 | break; |
271 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 272 | buffer_put_cstring(&buffer, |
29d88157 | 273 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 274 | if (ssh_msg_send(ctxt->pam_csock, |
275 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
276 | goto fail; | |
277 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
278 | goto fail; | |
7cac2b65 | 279 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
280 | goto fail; | |
29d88157 | 281 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 282 | break; |
283 | case PAM_ERROR_MSG: | |
540d72c3 | 284 | buffer_put_cstring(&buffer, |
29d88157 | 285 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 286 | if (ssh_msg_send(ctxt->pam_csock, |
287 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
288 | goto fail; | |
7cac2b65 | 289 | break; |
290 | case PAM_TEXT_INFO: | |
540d72c3 | 291 | buffer_put_cstring(&buffer, |
29d88157 | 292 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 293 | if (ssh_msg_send(ctxt->pam_csock, |
294 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
295 | goto fail; | |
7cac2b65 | 296 | break; |
297 | default: | |
298 | goto fail; | |
3c0ef626 | 299 | } |
7cac2b65 | 300 | buffer_clear(&buffer); |
3c0ef626 | 301 | } |
7cac2b65 | 302 | buffer_free(&buffer); |
29d88157 | 303 | *resp = reply; |
7cac2b65 | 304 | return (PAM_SUCCESS); |
29d88157 | 305 | |
7cac2b65 | 306 | fail: |
29d88157 | 307 | for(i = 0; i < n; i++) { |
308 | if (reply[i].resp != NULL) | |
309 | xfree(reply[i].resp); | |
310 | } | |
311 | xfree(reply); | |
7cac2b65 | 312 | buffer_free(&buffer); |
313 | return (PAM_CONV_ERR); | |
3c0ef626 | 314 | } |
315 | ||
7cac2b65 | 316 | /* |
317 | * Authentication thread. | |
318 | */ | |
319 | static void * | |
320 | sshpam_thread(void *ctxtp) | |
3c0ef626 | 321 | { |
7cac2b65 | 322 | struct pam_ctxt *ctxt = ctxtp; |
323 | Buffer buffer; | |
324 | struct pam_conv sshpam_conv; | |
325 | #ifndef USE_POSIX_THREADS | |
540d72c3 | 326 | extern char **environ; |
327 | char **env_from_pam; | |
328 | u_int i; | |
7cac2b65 | 329 | const char *pam_user; |
330 | ||
331 | pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user); | |
332 | setproctitle("%s [pam]", pam_user); | |
540d72c3 | 333 | environ[0] = NULL; |
7cac2b65 | 334 | #endif |
3c0ef626 | 335 | |
7cac2b65 | 336 | sshpam_conv.conv = sshpam_thread_conv; |
337 | sshpam_conv.appdata_ptr = ctxt; | |
338 | ||
339 | buffer_init(&buffer); | |
340 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
341 | (const void *)&sshpam_conv); | |
342 | if (sshpam_err != PAM_SUCCESS) | |
343 | goto auth_fail; | |
344 | sshpam_err = pam_authenticate(sshpam_handle, 0); | |
345 | if (sshpam_err != PAM_SUCCESS) | |
346 | goto auth_fail; | |
540d72c3 | 347 | |
348 | if (compat20) { | |
349 | if (!do_pam_account()) | |
350 | goto auth_fail; | |
351 | if (*force_pwchange) { | |
352 | sshpam_err = pam_chauthtok(sshpam_handle, | |
353 | PAM_CHANGE_EXPIRED_AUTHTOK); | |
354 | if (sshpam_err != PAM_SUCCESS) | |
355 | goto auth_fail; | |
356 | pam_password_change_required(0); | |
357 | } | |
358 | } | |
359 | ||
7cac2b65 | 360 | buffer_put_cstring(&buffer, "OK"); |
540d72c3 | 361 | |
362 | #ifndef USE_POSIX_THREADS | |
363 | /* Export variables set by do_pam_account */ | |
364 | buffer_put_int(&buffer, sshpam_account_status); | |
365 | buffer_put_int(&buffer, *force_pwchange); | |
366 | ||
367 | /* Export any environment strings set in child */ | |
368 | for(i = 0; environ[i] != NULL; i++) | |
369 | ; /* Count */ | |
370 | buffer_put_int(&buffer, i); | |
371 | for(i = 0; environ[i] != NULL; i++) | |
372 | buffer_put_cstring(&buffer, environ[i]); | |
373 | ||
374 | /* Export any environment strings set by PAM in child */ | |
375 | env_from_pam = pam_getenvlist(sshpam_handle); | |
376 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
377 | ; /* Count */ | |
378 | buffer_put_int(&buffer, i); | |
379 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
380 | buffer_put_cstring(&buffer, env_from_pam[i]); | |
381 | #endif /* USE_POSIX_THREADS */ | |
382 | ||
383 | /* XXX - can't do much about an error here */ | |
7cac2b65 | 384 | ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); |
385 | buffer_free(&buffer); | |
386 | pthread_exit(NULL); | |
387 | ||
388 | auth_fail: | |
389 | buffer_put_cstring(&buffer, | |
390 | pam_strerror(sshpam_handle, sshpam_err)); | |
540d72c3 | 391 | /* XXX - can't do much about an error here */ |
7cac2b65 | 392 | ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); |
393 | buffer_free(&buffer); | |
394 | pthread_exit(NULL); | |
540d72c3 | 395 | |
7cac2b65 | 396 | return (NULL); /* Avoid warning for non-pthread case */ |
397 | } | |
3c0ef626 | 398 | |
540d72c3 | 399 | void |
400 | sshpam_thread_cleanup(void) | |
7cac2b65 | 401 | { |
540d72c3 | 402 | struct pam_ctxt *ctxt = cleanup_ctxt; |
403 | ||
404 | debug3("PAM: %s entering", __func__); | |
405 | if (ctxt != NULL && ctxt->pam_thread != 0) { | |
406 | pthread_cancel(ctxt->pam_thread); | |
407 | pthread_join(ctxt->pam_thread, NULL); | |
408 | close(ctxt->pam_psock); | |
409 | close(ctxt->pam_csock); | |
410 | memset(ctxt, 0, sizeof(*ctxt)); | |
411 | cleanup_ctxt = NULL; | |
412 | } | |
3c0ef626 | 413 | } |
414 | ||
7cac2b65 | 415 | static int |
416 | sshpam_null_conv(int n, const struct pam_message **msg, | |
417 | struct pam_response **resp, void *data) | |
3c0ef626 | 418 | { |
540d72c3 | 419 | debug3("PAM: %s entering, %d messages", __func__, n); |
7cac2b65 | 420 | return (PAM_CONV_ERR); |
421 | } | |
3c0ef626 | 422 | |
7cac2b65 | 423 | static struct pam_conv null_conv = { sshpam_null_conv, NULL }; |
3c0ef626 | 424 | |
540d72c3 | 425 | void |
426 | sshpam_cleanup(void) | |
7cac2b65 | 427 | { |
7cac2b65 | 428 | debug("PAM: cleanup"); |
29d88157 | 429 | if (sshpam_handle == NULL) |
430 | return; | |
7cac2b65 | 431 | pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); |
432 | if (sshpam_cred_established) { | |
433 | pam_setcred(sshpam_handle, PAM_DELETE_CRED); | |
434 | sshpam_cred_established = 0; | |
435 | } | |
436 | if (sshpam_session_open) { | |
437 | pam_close_session(sshpam_handle, PAM_SILENT); | |
438 | sshpam_session_open = 0; | |
439 | } | |
540d72c3 | 440 | sshpam_authenticated = 0; |
7cac2b65 | 441 | pam_end(sshpam_handle, sshpam_err); |
442 | sshpam_handle = NULL; | |
443 | } | |
3c0ef626 | 444 | |
7cac2b65 | 445 | static int |
446 | sshpam_init(const char *user) | |
447 | { | |
448 | extern u_int utmp_len; | |
449 | extern char *__progname; | |
450 | const char *pam_rhost, *pam_user; | |
451 | ||
452 | if (sshpam_handle != NULL) { | |
453 | /* We already have a PAM context; check if the user matches */ | |
454 | sshpam_err = pam_get_item(sshpam_handle, | |
455 | PAM_USER, (const void **)&pam_user); | |
456 | if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) | |
457 | return (0); | |
7cac2b65 | 458 | pam_end(sshpam_handle, sshpam_err); |
459 | sshpam_handle = NULL; | |
460 | } | |
461 | debug("PAM: initializing for \"%s\"", user); | |
462 | sshpam_err = | |
463 | pam_start(SSHD_PAM_SERVICE, user, &null_conv, &sshpam_handle); | |
464 | if (sshpam_err != PAM_SUCCESS) { | |
465 | pam_end(sshpam_handle, sshpam_err); | |
466 | sshpam_handle = NULL; | |
467 | return (-1); | |
3c0ef626 | 468 | } |
7cac2b65 | 469 | pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); |
470 | debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); | |
471 | sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); | |
472 | if (sshpam_err != PAM_SUCCESS) { | |
473 | pam_end(sshpam_handle, sshpam_err); | |
474 | sshpam_handle = NULL; | |
475 | return (-1); | |
476 | } | |
477 | #ifdef PAM_TTY_KLUDGE | |
540d72c3 | 478 | /* |
479 | * Some silly PAM modules (e.g. pam_time) require a TTY to operate. | |
480 | * sshd doesn't set the tty until too late in the auth process and | |
7cac2b65 | 481 | * may not even set one (for tty-less connections) |
540d72c3 | 482 | */ |
7cac2b65 | 483 | debug("PAM: setting PAM_TTY to \"ssh\""); |
484 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); | |
485 | if (sshpam_err != PAM_SUCCESS) { | |
486 | pam_end(sshpam_handle, sshpam_err); | |
487 | sshpam_handle = NULL; | |
488 | return (-1); | |
489 | } | |
490 | #endif | |
7cac2b65 | 491 | return (0); |
3c0ef626 | 492 | } |
493 | ||
7cac2b65 | 494 | static void * |
495 | sshpam_init_ctx(Authctxt *authctxt) | |
3c0ef626 | 496 | { |
7cac2b65 | 497 | struct pam_ctxt *ctxt; |
498 | int socks[2]; | |
3c0ef626 | 499 | |
540d72c3 | 500 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 501 | /* Refuse to start if we don't have PAM enabled */ |
502 | if (!options.use_pam) | |
503 | return NULL; | |
3c0ef626 | 504 | |
7cac2b65 | 505 | /* Initialize PAM */ |
506 | if (sshpam_init(authctxt->user) == -1) { | |
507 | error("PAM: initialization failed"); | |
508 | return (NULL); | |
3c0ef626 | 509 | } |
510 | ||
7cac2b65 | 511 | ctxt = xmalloc(sizeof *ctxt); |
540d72c3 | 512 | memset(ctxt, 0, sizeof(*ctxt)); |
513 | ||
514 | force_pwchange = &(authctxt->force_pwchange); | |
7cac2b65 | 515 | |
516 | /* Start the authentication thread */ | |
517 | if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { | |
518 | error("PAM: failed create sockets: %s", strerror(errno)); | |
519 | xfree(ctxt); | |
520 | return (NULL); | |
521 | } | |
522 | ctxt->pam_psock = socks[0]; | |
523 | ctxt->pam_csock = socks[1]; | |
524 | if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { | |
525 | error("PAM: failed to start authentication thread: %s", | |
526 | strerror(errno)); | |
527 | close(socks[0]); | |
528 | close(socks[1]); | |
529 | xfree(ctxt); | |
530 | return (NULL); | |
531 | } | |
540d72c3 | 532 | cleanup_ctxt = ctxt; |
7cac2b65 | 533 | return (ctxt); |
534 | } | |
535 | ||
536 | static int | |
537 | sshpam_query(void *ctx, char **name, char **info, | |
538 | u_int *num, char ***prompts, u_int **echo_on) | |
539 | { | |
540 | Buffer buffer; | |
541 | struct pam_ctxt *ctxt = ctx; | |
542 | size_t plen; | |
543 | u_char type; | |
544 | char *msg; | |
545 | size_t len; | |
546 | ||
540d72c3 | 547 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 548 | buffer_init(&buffer); |
549 | *name = xstrdup(""); | |
550 | *info = xstrdup(""); | |
551 | *prompts = xmalloc(sizeof(char *)); | |
552 | **prompts = NULL; | |
553 | plen = 0; | |
554 | *echo_on = xmalloc(sizeof(u_int)); | |
555 | while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { | |
556 | type = buffer_get_char(&buffer); | |
557 | msg = buffer_get_string(&buffer, NULL); | |
558 | switch (type) { | |
559 | case PAM_PROMPT_ECHO_ON: | |
560 | case PAM_PROMPT_ECHO_OFF: | |
561 | *num = 1; | |
562 | len = plen + strlen(msg) + 1; | |
563 | **prompts = xrealloc(**prompts, len); | |
564 | plen += snprintf(**prompts + plen, len, "%s", msg); | |
565 | **echo_on = (type == PAM_PROMPT_ECHO_ON); | |
566 | xfree(msg); | |
567 | return (0); | |
568 | case PAM_ERROR_MSG: | |
569 | case PAM_TEXT_INFO: | |
570 | /* accumulate messages */ | |
540d72c3 | 571 | len = plen + strlen(msg) + 2; |
7cac2b65 | 572 | **prompts = xrealloc(**prompts, len); |
540d72c3 | 573 | plen += snprintf(**prompts + plen, len, "%s\n", msg); |
7cac2b65 | 574 | xfree(msg); |
3c0ef626 | 575 | break; |
7cac2b65 | 576 | case PAM_SUCCESS: |
577 | case PAM_AUTH_ERR: | |
578 | if (**prompts != NULL) { | |
579 | /* drain any accumulated messages */ | |
540d72c3 | 580 | debug("PAM: %s", **prompts); |
581 | buffer_append(&loginmsg, **prompts, | |
582 | strlen(**prompts)); | |
7cac2b65 | 583 | xfree(**prompts); |
584 | **prompts = NULL; | |
585 | } | |
586 | if (type == PAM_SUCCESS) { | |
540d72c3 | 587 | import_environments(&buffer); |
7cac2b65 | 588 | *num = 0; |
589 | **echo_on = 0; | |
590 | ctxt->pam_done = 1; | |
591 | xfree(msg); | |
592 | return (0); | |
593 | } | |
594 | error("PAM: %s", msg); | |
540d72c3 | 595 | /* FALLTHROUGH */ |
3c0ef626 | 596 | default: |
7cac2b65 | 597 | *num = 0; |
598 | **echo_on = 0; | |
599 | xfree(msg); | |
600 | ctxt->pam_done = -1; | |
601 | return (-1); | |
602 | } | |
3c0ef626 | 603 | } |
7cac2b65 | 604 | return (-1); |
3c0ef626 | 605 | } |
606 | ||
7cac2b65 | 607 | /* XXX - see also comment in auth-chall.c:verify_response */ |
608 | static int | |
609 | sshpam_respond(void *ctx, u_int num, char **resp) | |
3c0ef626 | 610 | { |
7cac2b65 | 611 | Buffer buffer; |
612 | struct pam_ctxt *ctxt = ctx; | |
613 | ||
540d72c3 | 614 | debug2("PAM: %s entering, %d responses", __func__, num); |
7cac2b65 | 615 | switch (ctxt->pam_done) { |
616 | case 1: | |
617 | sshpam_authenticated = 1; | |
618 | return (0); | |
619 | case 0: | |
620 | break; | |
621 | default: | |
622 | return (-1); | |
3c0ef626 | 623 | } |
7cac2b65 | 624 | if (num != 1) { |
625 | error("PAM: expected one response, got %u", num); | |
626 | return (-1); | |
627 | } | |
628 | buffer_init(&buffer); | |
629 | buffer_put_cstring(&buffer, *resp); | |
540d72c3 | 630 | if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { |
631 | buffer_free(&buffer); | |
632 | return (-1); | |
633 | } | |
7cac2b65 | 634 | buffer_free(&buffer); |
635 | return (1); | |
3c0ef626 | 636 | } |
637 | ||
7cac2b65 | 638 | static void |
639 | sshpam_free_ctx(void *ctxtp) | |
3c0ef626 | 640 | { |
7cac2b65 | 641 | struct pam_ctxt *ctxt = ctxtp; |
350391c5 | 642 | |
540d72c3 | 643 | debug3("PAM: %s entering", __func__); |
644 | sshpam_thread_cleanup(); | |
7cac2b65 | 645 | xfree(ctxt); |
646 | /* | |
647 | * We don't call sshpam_cleanup() here because we may need the PAM | |
648 | * handle at a later stage, e.g. when setting up a session. It's | |
649 | * still on the cleanup list, so pam_end() *will* be called before | |
650 | * the server process terminates. | |
651 | */ | |
3c0ef626 | 652 | } |
653 | ||
7cac2b65 | 654 | KbdintDevice sshpam_device = { |
655 | "pam", | |
656 | sshpam_init_ctx, | |
657 | sshpam_query, | |
658 | sshpam_respond, | |
659 | sshpam_free_ctx | |
660 | }; | |
661 | ||
662 | KbdintDevice mm_sshpam_device = { | |
663 | "pam", | |
664 | mm_sshpam_init_ctx, | |
665 | mm_sshpam_query, | |
666 | mm_sshpam_respond, | |
667 | mm_sshpam_free_ctx | |
668 | }; | |
3c0ef626 | 669 | |
670 | /* | |
7cac2b65 | 671 | * This replaces auth-pam.c |
3c0ef626 | 672 | */ |
7cac2b65 | 673 | void |
674 | start_pam(const char *user) | |
3c0ef626 | 675 | { |
7cac2b65 | 676 | if (!options.use_pam) |
677 | fatal("PAM: initialisation requested when UsePAM=no"); | |
678 | ||
679 | if (sshpam_init(user) == -1) | |
680 | fatal("PAM: initialisation failed"); | |
3c0ef626 | 681 | } |
682 | ||
7cac2b65 | 683 | void |
684 | finish_pam(void) | |
3c0ef626 | 685 | { |
540d72c3 | 686 | sshpam_cleanup(); |
3c0ef626 | 687 | } |
688 | ||
7cac2b65 | 689 | u_int |
690 | do_pam_account(void) | |
3c0ef626 | 691 | { |
540d72c3 | 692 | if (sshpam_account_status != -1) |
693 | return (sshpam_account_status); | |
694 | ||
7cac2b65 | 695 | sshpam_err = pam_acct_mgmt(sshpam_handle, 0); |
540d72c3 | 696 | debug3("PAM: %s pam_acct_mgmt = %d", __func__, sshpam_err); |
7cac2b65 | 697 | |
540d72c3 | 698 | if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) { |
699 | sshpam_account_status = 0; | |
700 | return (sshpam_account_status); | |
7cac2b65 | 701 | } |
3c0ef626 | 702 | |
540d72c3 | 703 | if (sshpam_err == PAM_NEW_AUTHTOK_REQD) |
704 | pam_password_change_required(1); | |
3c0ef626 | 705 | |
540d72c3 | 706 | sshpam_account_status = 1; |
707 | return (sshpam_account_status); | |
7cac2b65 | 708 | } |
3c0ef626 | 709 | |
7cac2b65 | 710 | void |
711 | do_pam_set_tty(const char *tty) | |
712 | { | |
713 | if (tty != NULL) { | |
714 | debug("PAM: setting PAM_TTY to \"%s\"", tty); | |
715 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); | |
716 | if (sshpam_err != PAM_SUCCESS) | |
717 | fatal("PAM: failed to set PAM_TTY: %s", | |
718 | pam_strerror(sshpam_handle, sshpam_err)); | |
719 | } | |
720 | } | |
3c0ef626 | 721 | |
7cac2b65 | 722 | void |
723 | do_pam_setcred(int init) | |
724 | { | |
725 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
726 | (const void *)&null_conv); | |
727 | if (sshpam_err != PAM_SUCCESS) | |
728 | fatal("PAM: failed to set PAM_CONV: %s", | |
729 | pam_strerror(sshpam_handle, sshpam_err)); | |
730 | if (init) { | |
731 | debug("PAM: establishing credentials"); | |
732 | sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); | |
733 | } else { | |
734 | debug("PAM: reinitializing credentials"); | |
735 | sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); | |
736 | } | |
737 | if (sshpam_err == PAM_SUCCESS) { | |
738 | sshpam_cred_established = 1; | |
739 | return; | |
740 | } | |
741 | if (sshpam_authenticated) | |
742 | fatal("PAM: pam_setcred(): %s", | |
743 | pam_strerror(sshpam_handle, sshpam_err)); | |
744 | else | |
745 | debug("PAM: pam_setcred(): %s", | |
746 | pam_strerror(sshpam_handle, sshpam_err)); | |
3c0ef626 | 747 | } |
748 | ||
7cac2b65 | 749 | static int |
540d72c3 | 750 | pam_tty_conv(int n, const struct pam_message **msg, |
7cac2b65 | 751 | struct pam_response **resp, void *data) |
23987cb8 | 752 | { |
7cac2b65 | 753 | char input[PAM_MAX_MSG_SIZE]; |
29d88157 | 754 | struct pam_response *reply; |
23987cb8 | 755 | int i; |
756 | ||
540d72c3 | 757 | debug3("PAM: %s called with %d messages", __func__, n); |
758 | ||
29d88157 | 759 | *resp = NULL; |
760 | ||
540d72c3 | 761 | if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) |
7cac2b65 | 762 | return (PAM_CONV_ERR); |
29d88157 | 763 | |
764 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
765 | return (PAM_CONV_ERR); | |
766 | memset(reply, 0, n * sizeof(*reply)); | |
767 | ||
7cac2b65 | 768 | for (i = 0; i < n; ++i) { |
769 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
770 | case PAM_PROMPT_ECHO_OFF: | |
29d88157 | 771 | reply[i].resp = |
540d72c3 | 772 | read_passphrase(PAM_MSG_MEMBER(msg, i, msg), |
7cac2b65 | 773 | RP_ALLOW_STDIN); |
29d88157 | 774 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 775 | break; |
776 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 777 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
7cac2b65 | 778 | fgets(input, sizeof input, stdin); |
29d88157 | 779 | reply[i].resp = xstrdup(input); |
780 | reply[i].resp_retcode = PAM_SUCCESS; | |
7cac2b65 | 781 | break; |
782 | case PAM_ERROR_MSG: | |
783 | case PAM_TEXT_INFO: | |
540d72c3 | 784 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
29d88157 | 785 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 786 | break; |
787 | default: | |
788 | goto fail; | |
789 | } | |
23987cb8 | 790 | } |
29d88157 | 791 | *resp = reply; |
7cac2b65 | 792 | return (PAM_SUCCESS); |
29d88157 | 793 | |
7cac2b65 | 794 | fail: |
29d88157 | 795 | for(i = 0; i < n; i++) { |
796 | if (reply[i].resp != NULL) | |
797 | xfree(reply[i].resp); | |
798 | } | |
799 | xfree(reply); | |
7cac2b65 | 800 | return (PAM_CONV_ERR); |
23987cb8 | 801 | } |
802 | ||
540d72c3 | 803 | static struct pam_conv tty_conv = { pam_tty_conv, NULL }; |
804 | ||
7cac2b65 | 805 | /* |
806 | * XXX this should be done in the authentication phase, but ssh1 doesn't | |
807 | * support that | |
808 | */ | |
809 | void | |
810 | do_pam_chauthtok(void) | |
811 | { | |
7cac2b65 | 812 | if (use_privsep) |
813 | fatal("Password expired (unable to change with privsep)"); | |
814 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
540d72c3 | 815 | (const void *)&tty_conv); |
7cac2b65 | 816 | if (sshpam_err != PAM_SUCCESS) |
817 | fatal("PAM: failed to set PAM_CONV: %s", | |
818 | pam_strerror(sshpam_handle, sshpam_err)); | |
819 | debug("PAM: changing password"); | |
820 | sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); | |
821 | if (sshpam_err != PAM_SUCCESS) | |
822 | fatal("PAM: pam_chauthtok(): %s", | |
823 | pam_strerror(sshpam_handle, sshpam_err)); | |
824 | } | |
825 | ||
540d72c3 | 826 | static int |
827 | pam_store_conv(int n, const struct pam_message **msg, | |
828 | struct pam_response **resp, void *data) | |
829 | { | |
830 | struct pam_response *reply; | |
831 | int i; | |
832 | size_t len; | |
833 | ||
834 | debug3("PAM: %s called with %d messages", __func__, n); | |
835 | *resp = NULL; | |
836 | ||
837 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
838 | return (PAM_CONV_ERR); | |
839 | ||
840 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
841 | return (PAM_CONV_ERR); | |
842 | memset(reply, 0, n * sizeof(*reply)); | |
843 | ||
844 | for (i = 0; i < n; ++i) { | |
845 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
846 | case PAM_ERROR_MSG: | |
847 | case PAM_TEXT_INFO: | |
848 | len = strlen(PAM_MSG_MEMBER(msg, i, msg)); | |
849 | buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len); | |
850 | buffer_append(&loginmsg, "\n", 1 ); | |
851 | reply[i].resp_retcode = PAM_SUCCESS; | |
852 | break; | |
853 | default: | |
854 | goto fail; | |
855 | } | |
856 | } | |
857 | *resp = reply; | |
858 | return (PAM_SUCCESS); | |
859 | ||
860 | fail: | |
861 | for(i = 0; i < n; i++) { | |
862 | if (reply[i].resp != NULL) | |
863 | xfree(reply[i].resp); | |
864 | } | |
865 | xfree(reply); | |
866 | return (PAM_CONV_ERR); | |
867 | } | |
868 | ||
869 | static struct pam_conv store_conv = { pam_store_conv, NULL }; | |
870 | ||
871 | void | |
872 | do_pam_session(void) | |
873 | { | |
874 | debug3("PAM: opening session"); | |
875 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
876 | (const void *)&store_conv); | |
877 | if (sshpam_err != PAM_SUCCESS) | |
878 | fatal("PAM: failed to set PAM_CONV: %s", | |
879 | pam_strerror(sshpam_handle, sshpam_err)); | |
880 | sshpam_err = pam_open_session(sshpam_handle, 0); | |
881 | if (sshpam_err != PAM_SUCCESS) | |
882 | fatal("PAM: pam_open_session(): %s", | |
883 | pam_strerror(sshpam_handle, sshpam_err)); | |
884 | sshpam_session_open = 1; | |
885 | } | |
886 | ||
887 | /* | |
7cac2b65 | 888 | * Set a PAM environment string. We need to do this so that the session |
5598e598 | 889 | * modules can handle things like Kerberos/GSI credentials that appear |
890 | * during the ssh authentication process. | |
891 | */ | |
7cac2b65 | 892 | int |
540d72c3 | 893 | do_pam_putenv(char *name, char *value) |
7cac2b65 | 894 | { |
895 | int ret = 1; | |
540d72c3 | 896 | #ifdef HAVE_PAM_PUTENV |
5598e598 | 897 | char *compound; |
7cac2b65 | 898 | size_t len; |
905081a4 | 899 | |
7cac2b65 | 900 | len = strlen(name) + strlen(value) + 2; |
901 | compound = xmalloc(len); | |
902 | ||
903 | snprintf(compound, len, "%s=%s", name, value); | |
904 | ret = pam_putenv(sshpam_handle, compound); | |
905 | xfree(compound); | |
905081a4 | 906 | #endif |
7cac2b65 | 907 | |
908 | return (ret); | |
5598e598 | 909 | } |
910 | ||
540d72c3 | 911 | char ** |
912 | fetch_pam_child_environment(void) | |
3c0ef626 | 913 | { |
540d72c3 | 914 | return sshpam_env; |
3c0ef626 | 915 | } |
916 | ||
7cac2b65 | 917 | char ** |
918 | fetch_pam_environment(void) | |
3c0ef626 | 919 | { |
7cac2b65 | 920 | return (pam_getenvlist(sshpam_handle)); |
7cac2b65 | 921 | } |
3c0ef626 | 922 | |
7cac2b65 | 923 | void |
924 | free_pam_environment(char **env) | |
925 | { | |
926 | char **envp; | |
3c0ef626 | 927 | |
7cac2b65 | 928 | if (env == NULL) |
929 | return; | |
3c0ef626 | 930 | |
7cac2b65 | 931 | for (envp = env; *envp; envp++) |
932 | xfree(*envp); | |
933 | xfree(env); | |
3c0ef626 | 934 | } |
935 | ||
936 | #endif /* USE_PAM */ |