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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; | |
12a403af | 61 | extern u_int utmp_len; |
d03f4262 | 62 | |
7cac2b65 | 63 | #ifdef USE_POSIX_THREADS |
64 | #include <pthread.h> | |
65 | /* | |
540d72c3 | 66 | * Avoid namespace clash when *not* using pthreads for systems *with* |
67 | * pthreads, which unconditionally define pthread_t via sys/types.h | |
7cac2b65 | 68 | * (e.g. Linux) |
69 | */ | |
540d72c3 | 70 | typedef pthread_t sp_pthread_t; |
7cac2b65 | 71 | #else |
540d72c3 | 72 | typedef pid_t sp_pthread_t; |
73 | #endif | |
74 | ||
75 | struct pam_ctxt { | |
76 | sp_pthread_t pam_thread; | |
77 | int pam_psock; | |
78 | int pam_csock; | |
79 | int pam_done; | |
80 | }; | |
81 | ||
82 | static void sshpam_free_ctx(void *); | |
83 | static struct pam_ctxt *cleanup_ctxt; | |
84 | ||
85 | #ifndef USE_POSIX_THREADS | |
7cac2b65 | 86 | /* |
87 | * Simulate threads with processes. | |
88 | */ | |
540d72c3 | 89 | |
90 | static int sshpam_thread_status = -1; | |
91 | static mysig_t sshpam_oldsig; | |
92 | ||
93 | static void | |
94 | sshpam_sigchld_handler(int sig) | |
95 | { | |
96 | if (cleanup_ctxt == NULL) | |
97 | return; /* handler called after PAM cleanup, shouldn't happen */ | |
98 | if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0) == -1) | |
99 | return; /* couldn't wait for process */ | |
100 | if (WIFSIGNALED(sshpam_thread_status) && | |
101 | WTERMSIG(sshpam_thread_status) == SIGTERM) | |
102 | return; /* terminated by pthread_cancel */ | |
103 | if (!WIFEXITED(sshpam_thread_status)) | |
104 | fatal("PAM: authentication thread exited unexpectedly"); | |
105 | if (WEXITSTATUS(sshpam_thread_status) != 0) | |
106 | fatal("PAM: authentication thread exited uncleanly"); | |
107 | } | |
3c0ef626 | 108 | |
7cac2b65 | 109 | static void |
110 | pthread_exit(void *value __unused) | |
111 | { | |
112 | _exit(0); | |
113 | } | |
3c0ef626 | 114 | |
7cac2b65 | 115 | static int |
116 | pthread_create(sp_pthread_t *thread, const void *attr __unused, | |
117 | void *(*thread_start)(void *), void *arg) | |
118 | { | |
119 | pid_t pid; | |
120 | ||
12a403af | 121 | sshpam_thread_status = -1; |
7cac2b65 | 122 | switch ((pid = fork())) { |
123 | case -1: | |
124 | error("fork(): %s", strerror(errno)); | |
125 | return (-1); | |
126 | case 0: | |
127 | thread_start(arg); | |
128 | _exit(1); | |
129 | default: | |
130 | *thread = pid; | |
540d72c3 | 131 | sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler); |
7cac2b65 | 132 | return (0); |
133 | } | |
134 | } | |
3c0ef626 | 135 | |
7cac2b65 | 136 | static int |
137 | pthread_cancel(sp_pthread_t thread) | |
3c0ef626 | 138 | { |
540d72c3 | 139 | signal(SIGCHLD, sshpam_oldsig); |
7cac2b65 | 140 | return (kill(thread, SIGTERM)); |
3c0ef626 | 141 | } |
142 | ||
7cac2b65 | 143 | static int |
144 | pthread_join(sp_pthread_t thread, void **value __unused) | |
3c0ef626 | 145 | { |
7cac2b65 | 146 | int status; |
147 | ||
540d72c3 | 148 | if (sshpam_thread_status != -1) |
149 | return (sshpam_thread_status); | |
150 | signal(SIGCHLD, sshpam_oldsig); | |
7cac2b65 | 151 | waitpid(thread, &status, 0); |
152 | return (status); | |
3c0ef626 | 153 | } |
7cac2b65 | 154 | #endif |
155 | ||
156 | ||
29d88157 | 157 | static pam_handle_t *sshpam_handle = NULL; |
158 | static int sshpam_err = 0; | |
159 | static int sshpam_authenticated = 0; | |
29d88157 | 160 | static int sshpam_session_open = 0; |
161 | static int sshpam_cred_established = 0; | |
540d72c3 | 162 | static int sshpam_account_status = -1; |
163 | static char **sshpam_env = NULL; | |
12a403af | 164 | static Authctxt *sshpam_authctxt = NULL; |
540d72c3 | 165 | |
166 | /* Some PAM implementations don't implement this */ | |
167 | #ifndef HAVE_PAM_GETENVLIST | |
168 | static char ** | |
169 | pam_getenvlist(pam_handle_t *pamh) | |
170 | { | |
171 | /* | |
172 | * XXX - If necessary, we can still support envrionment passing | |
173 | * for platforms without pam_getenvlist by searching for known | |
174 | * env vars (e.g. KRB5CCNAME) from the PAM environment. | |
175 | */ | |
176 | return NULL; | |
177 | } | |
178 | #endif | |
7cac2b65 | 179 | |
540d72c3 | 180 | void |
181 | pam_password_change_required(int reqd) | |
182 | { | |
183 | debug3("%s %d", __func__, reqd); | |
12a403af | 184 | if (sshpam_authctxt == NULL) |
185 | fatal("%s: PAM authctxt not initialized", __func__); | |
186 | sshpam_authctxt->force_pwchange = reqd; | |
540d72c3 | 187 | if (reqd) { |
188 | no_port_forwarding_flag |= 2; | |
189 | no_agent_forwarding_flag |= 2; | |
190 | no_x11_forwarding_flag |= 2; | |
191 | } else { | |
192 | no_port_forwarding_flag &= ~2; | |
193 | no_agent_forwarding_flag &= ~2; | |
194 | no_x11_forwarding_flag &= ~2; | |
195 | } | |
196 | } | |
7cac2b65 | 197 | |
540d72c3 | 198 | /* Import regular and PAM environment from subprocess */ |
199 | static void | |
200 | import_environments(Buffer *b) | |
201 | { | |
202 | char *env; | |
203 | u_int i, num_env; | |
204 | int err; | |
205 | ||
206 | debug3("PAM: %s entering", __func__); | |
207 | ||
12a403af | 208 | #ifndef USE_POSIX_THREADS |
540d72c3 | 209 | /* Import variables set by do_pam_account */ |
210 | sshpam_account_status = buffer_get_int(b); | |
211 | pam_password_change_required(buffer_get_int(b)); | |
212 | ||
213 | /* Import environment from subprocess */ | |
214 | num_env = buffer_get_int(b); | |
215 | sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env)); | |
216 | debug3("PAM: num env strings %d", num_env); | |
217 | for(i = 0; i < num_env; i++) | |
218 | sshpam_env[i] = buffer_get_string(b, NULL); | |
219 | ||
220 | sshpam_env[num_env] = NULL; | |
221 | ||
222 | /* Import PAM environment from subprocess */ | |
223 | num_env = buffer_get_int(b); | |
224 | debug("PAM: num PAM env strings %d", num_env); | |
225 | for(i = 0; i < num_env; i++) { | |
226 | env = buffer_get_string(b, NULL); | |
227 | ||
228 | #ifdef HAVE_PAM_PUTENV | |
229 | /* Errors are not fatal here */ | |
230 | if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { | |
231 | error("PAM: pam_putenv: %s", | |
232 | pam_strerror(sshpam_handle, sshpam_err)); | |
233 | } | |
234 | #endif | |
235 | } | |
12a403af | 236 | #endif |
540d72c3 | 237 | } |
3c0ef626 | 238 | |
239 | /* | |
7cac2b65 | 240 | * Conversation function for authentication thread. |
3c0ef626 | 241 | */ |
7cac2b65 | 242 | static int |
243 | sshpam_thread_conv(int n, const struct pam_message **msg, | |
244 | struct pam_response **resp, void *data) | |
3c0ef626 | 245 | { |
7cac2b65 | 246 | Buffer buffer; |
247 | struct pam_ctxt *ctxt; | |
29d88157 | 248 | struct pam_response *reply; |
7cac2b65 | 249 | int i; |
250 | ||
540d72c3 | 251 | debug3("PAM: %s entering, %d messages", __func__, n); |
29d88157 | 252 | *resp = NULL; |
253 | ||
7cac2b65 | 254 | ctxt = data; |
255 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
256 | return (PAM_CONV_ERR); | |
29d88157 | 257 | |
258 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
259 | return (PAM_CONV_ERR); | |
260 | memset(reply, 0, n * sizeof(*reply)); | |
261 | ||
7cac2b65 | 262 | buffer_init(&buffer); |
263 | for (i = 0; i < n; ++i) { | |
7cac2b65 | 264 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { |
265 | case PAM_PROMPT_ECHO_OFF: | |
540d72c3 | 266 | buffer_put_cstring(&buffer, |
29d88157 | 267 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 268 | if (ssh_msg_send(ctxt->pam_csock, |
269 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
270 | goto fail; | |
271 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
272 | goto fail; | |
7cac2b65 | 273 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
274 | goto fail; | |
29d88157 | 275 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 276 | break; |
277 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 278 | buffer_put_cstring(&buffer, |
29d88157 | 279 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 280 | if (ssh_msg_send(ctxt->pam_csock, |
281 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
282 | goto fail; | |
283 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
284 | goto fail; | |
7cac2b65 | 285 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
286 | goto fail; | |
29d88157 | 287 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 288 | break; |
289 | case PAM_ERROR_MSG: | |
540d72c3 | 290 | buffer_put_cstring(&buffer, |
29d88157 | 291 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 292 | if (ssh_msg_send(ctxt->pam_csock, |
293 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
294 | goto fail; | |
7cac2b65 | 295 | break; |
296 | case PAM_TEXT_INFO: | |
540d72c3 | 297 | buffer_put_cstring(&buffer, |
29d88157 | 298 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 299 | if (ssh_msg_send(ctxt->pam_csock, |
300 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
301 | goto fail; | |
7cac2b65 | 302 | break; |
303 | default: | |
304 | goto fail; | |
3c0ef626 | 305 | } |
7cac2b65 | 306 | buffer_clear(&buffer); |
3c0ef626 | 307 | } |
7cac2b65 | 308 | buffer_free(&buffer); |
29d88157 | 309 | *resp = reply; |
7cac2b65 | 310 | return (PAM_SUCCESS); |
29d88157 | 311 | |
7cac2b65 | 312 | fail: |
29d88157 | 313 | for(i = 0; i < n; i++) { |
314 | if (reply[i].resp != NULL) | |
315 | xfree(reply[i].resp); | |
316 | } | |
317 | xfree(reply); | |
7cac2b65 | 318 | buffer_free(&buffer); |
319 | return (PAM_CONV_ERR); | |
3c0ef626 | 320 | } |
321 | ||
7cac2b65 | 322 | /* |
323 | * Authentication thread. | |
324 | */ | |
325 | static void * | |
326 | sshpam_thread(void *ctxtp) | |
3c0ef626 | 327 | { |
7cac2b65 | 328 | struct pam_ctxt *ctxt = ctxtp; |
329 | Buffer buffer; | |
330 | struct pam_conv sshpam_conv; | |
331 | #ifndef USE_POSIX_THREADS | |
540d72c3 | 332 | extern char **environ; |
333 | char **env_from_pam; | |
334 | u_int i; | |
7cac2b65 | 335 | const char *pam_user; |
336 | ||
337 | pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user); | |
338 | setproctitle("%s [pam]", pam_user); | |
540d72c3 | 339 | environ[0] = NULL; |
7cac2b65 | 340 | #endif |
3c0ef626 | 341 | |
7cac2b65 | 342 | sshpam_conv.conv = sshpam_thread_conv; |
343 | sshpam_conv.appdata_ptr = ctxt; | |
344 | ||
12a403af | 345 | if (sshpam_authctxt == NULL) |
346 | fatal("%s: PAM authctxt not initialized", __func__); | |
347 | ||
7cac2b65 | 348 | buffer_init(&buffer); |
349 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
350 | (const void *)&sshpam_conv); | |
351 | if (sshpam_err != PAM_SUCCESS) | |
352 | goto auth_fail; | |
353 | sshpam_err = pam_authenticate(sshpam_handle, 0); | |
354 | if (sshpam_err != PAM_SUCCESS) | |
355 | goto auth_fail; | |
540d72c3 | 356 | |
357 | if (compat20) { | |
358 | if (!do_pam_account()) | |
359 | goto auth_fail; | |
12a403af | 360 | if (sshpam_authctxt->force_pwchange) { |
540d72c3 | 361 | sshpam_err = pam_chauthtok(sshpam_handle, |
362 | PAM_CHANGE_EXPIRED_AUTHTOK); | |
363 | if (sshpam_err != PAM_SUCCESS) | |
364 | goto auth_fail; | |
365 | pam_password_change_required(0); | |
366 | } | |
367 | } | |
368 | ||
7cac2b65 | 369 | buffer_put_cstring(&buffer, "OK"); |
540d72c3 | 370 | |
371 | #ifndef USE_POSIX_THREADS | |
372 | /* Export variables set by do_pam_account */ | |
373 | buffer_put_int(&buffer, sshpam_account_status); | |
12a403af | 374 | buffer_put_int(&buffer, sshpam_authctxt->force_pwchange); |
540d72c3 | 375 | |
376 | /* Export any environment strings set in child */ | |
377 | for(i = 0; environ[i] != NULL; i++) | |
378 | ; /* Count */ | |
379 | buffer_put_int(&buffer, i); | |
380 | for(i = 0; environ[i] != NULL; i++) | |
381 | buffer_put_cstring(&buffer, environ[i]); | |
382 | ||
383 | /* Export any environment strings set by PAM in child */ | |
384 | env_from_pam = pam_getenvlist(sshpam_handle); | |
385 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
386 | ; /* Count */ | |
387 | buffer_put_int(&buffer, i); | |
388 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
389 | buffer_put_cstring(&buffer, env_from_pam[i]); | |
390 | #endif /* USE_POSIX_THREADS */ | |
391 | ||
392 | /* XXX - can't do much about an error here */ | |
7cac2b65 | 393 | ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); |
394 | buffer_free(&buffer); | |
395 | pthread_exit(NULL); | |
396 | ||
397 | auth_fail: | |
398 | buffer_put_cstring(&buffer, | |
399 | pam_strerror(sshpam_handle, sshpam_err)); | |
540d72c3 | 400 | /* XXX - can't do much about an error here */ |
7cac2b65 | 401 | ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); |
402 | buffer_free(&buffer); | |
403 | pthread_exit(NULL); | |
540d72c3 | 404 | |
7cac2b65 | 405 | return (NULL); /* Avoid warning for non-pthread case */ |
406 | } | |
3c0ef626 | 407 | |
540d72c3 | 408 | void |
409 | sshpam_thread_cleanup(void) | |
7cac2b65 | 410 | { |
540d72c3 | 411 | struct pam_ctxt *ctxt = cleanup_ctxt; |
412 | ||
413 | debug3("PAM: %s entering", __func__); | |
414 | if (ctxt != NULL && ctxt->pam_thread != 0) { | |
415 | pthread_cancel(ctxt->pam_thread); | |
416 | pthread_join(ctxt->pam_thread, NULL); | |
417 | close(ctxt->pam_psock); | |
418 | close(ctxt->pam_csock); | |
419 | memset(ctxt, 0, sizeof(*ctxt)); | |
420 | cleanup_ctxt = NULL; | |
421 | } | |
3c0ef626 | 422 | } |
423 | ||
7cac2b65 | 424 | static int |
425 | sshpam_null_conv(int n, const struct pam_message **msg, | |
426 | struct pam_response **resp, void *data) | |
3c0ef626 | 427 | { |
540d72c3 | 428 | debug3("PAM: %s entering, %d messages", __func__, n); |
7cac2b65 | 429 | return (PAM_CONV_ERR); |
430 | } | |
3c0ef626 | 431 | |
7cac2b65 | 432 | static struct pam_conv null_conv = { sshpam_null_conv, NULL }; |
3c0ef626 | 433 | |
540d72c3 | 434 | void |
435 | sshpam_cleanup(void) | |
7cac2b65 | 436 | { |
7cac2b65 | 437 | debug("PAM: cleanup"); |
29d88157 | 438 | if (sshpam_handle == NULL) |
439 | return; | |
7cac2b65 | 440 | pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); |
441 | if (sshpam_cred_established) { | |
442 | pam_setcred(sshpam_handle, PAM_DELETE_CRED); | |
443 | sshpam_cred_established = 0; | |
444 | } | |
445 | if (sshpam_session_open) { | |
446 | pam_close_session(sshpam_handle, PAM_SILENT); | |
447 | sshpam_session_open = 0; | |
448 | } | |
540d72c3 | 449 | sshpam_authenticated = 0; |
7cac2b65 | 450 | pam_end(sshpam_handle, sshpam_err); |
451 | sshpam_handle = NULL; | |
452 | } | |
3c0ef626 | 453 | |
7cac2b65 | 454 | static int |
12a403af | 455 | sshpam_init(Authctxt *authctxt) |
7cac2b65 | 456 | { |
7cac2b65 | 457 | extern char *__progname; |
12a403af | 458 | const char *pam_rhost, *pam_user, *user = authctxt->user; |
7cac2b65 | 459 | |
460 | if (sshpam_handle != NULL) { | |
461 | /* We already have a PAM context; check if the user matches */ | |
462 | sshpam_err = pam_get_item(sshpam_handle, | |
463 | PAM_USER, (const void **)&pam_user); | |
464 | if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) | |
465 | return (0); | |
7cac2b65 | 466 | pam_end(sshpam_handle, sshpam_err); |
467 | sshpam_handle = NULL; | |
468 | } | |
469 | debug("PAM: initializing for \"%s\"", user); | |
470 | sshpam_err = | |
471 | pam_start(SSHD_PAM_SERVICE, user, &null_conv, &sshpam_handle); | |
12a403af | 472 | sshpam_authctxt = authctxt; |
473 | ||
7cac2b65 | 474 | if (sshpam_err != PAM_SUCCESS) { |
475 | pam_end(sshpam_handle, sshpam_err); | |
476 | sshpam_handle = NULL; | |
477 | return (-1); | |
3c0ef626 | 478 | } |
7cac2b65 | 479 | pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); |
480 | debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); | |
481 | sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); | |
482 | if (sshpam_err != PAM_SUCCESS) { | |
483 | pam_end(sshpam_handle, sshpam_err); | |
484 | sshpam_handle = NULL; | |
485 | return (-1); | |
486 | } | |
487 | #ifdef PAM_TTY_KLUDGE | |
540d72c3 | 488 | /* |
489 | * Some silly PAM modules (e.g. pam_time) require a TTY to operate. | |
490 | * sshd doesn't set the tty until too late in the auth process and | |
7cac2b65 | 491 | * may not even set one (for tty-less connections) |
540d72c3 | 492 | */ |
7cac2b65 | 493 | debug("PAM: setting PAM_TTY to \"ssh\""); |
494 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); | |
495 | if (sshpam_err != PAM_SUCCESS) { | |
496 | pam_end(sshpam_handle, sshpam_err); | |
497 | sshpam_handle = NULL; | |
498 | return (-1); | |
499 | } | |
500 | #endif | |
7cac2b65 | 501 | return (0); |
3c0ef626 | 502 | } |
503 | ||
7cac2b65 | 504 | static void * |
505 | sshpam_init_ctx(Authctxt *authctxt) | |
3c0ef626 | 506 | { |
7cac2b65 | 507 | struct pam_ctxt *ctxt; |
508 | int socks[2]; | |
3c0ef626 | 509 | |
540d72c3 | 510 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 511 | /* Refuse to start if we don't have PAM enabled */ |
512 | if (!options.use_pam) | |
513 | return NULL; | |
3c0ef626 | 514 | |
7cac2b65 | 515 | /* Initialize PAM */ |
12a403af | 516 | if (sshpam_init(authctxt) == -1) { |
7cac2b65 | 517 | error("PAM: initialization failed"); |
518 | return (NULL); | |
3c0ef626 | 519 | } |
520 | ||
7cac2b65 | 521 | ctxt = xmalloc(sizeof *ctxt); |
540d72c3 | 522 | memset(ctxt, 0, sizeof(*ctxt)); |
523 | ||
7cac2b65 | 524 | /* Start the authentication thread */ |
525 | if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { | |
526 | error("PAM: failed create sockets: %s", strerror(errno)); | |
527 | xfree(ctxt); | |
528 | return (NULL); | |
529 | } | |
530 | ctxt->pam_psock = socks[0]; | |
531 | ctxt->pam_csock = socks[1]; | |
532 | if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { | |
533 | error("PAM: failed to start authentication thread: %s", | |
534 | strerror(errno)); | |
535 | close(socks[0]); | |
536 | close(socks[1]); | |
537 | xfree(ctxt); | |
538 | return (NULL); | |
539 | } | |
540d72c3 | 540 | cleanup_ctxt = ctxt; |
7cac2b65 | 541 | return (ctxt); |
542 | } | |
543 | ||
544 | static int | |
545 | sshpam_query(void *ctx, char **name, char **info, | |
546 | u_int *num, char ***prompts, u_int **echo_on) | |
547 | { | |
548 | Buffer buffer; | |
549 | struct pam_ctxt *ctxt = ctx; | |
550 | size_t plen; | |
551 | u_char type; | |
552 | char *msg; | |
553 | size_t len; | |
554 | ||
540d72c3 | 555 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 556 | buffer_init(&buffer); |
557 | *name = xstrdup(""); | |
558 | *info = xstrdup(""); | |
559 | *prompts = xmalloc(sizeof(char *)); | |
560 | **prompts = NULL; | |
561 | plen = 0; | |
562 | *echo_on = xmalloc(sizeof(u_int)); | |
563 | while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { | |
564 | type = buffer_get_char(&buffer); | |
565 | msg = buffer_get_string(&buffer, NULL); | |
566 | switch (type) { | |
567 | case PAM_PROMPT_ECHO_ON: | |
568 | case PAM_PROMPT_ECHO_OFF: | |
569 | *num = 1; | |
570 | len = plen + strlen(msg) + 1; | |
571 | **prompts = xrealloc(**prompts, len); | |
572 | plen += snprintf(**prompts + plen, len, "%s", msg); | |
573 | **echo_on = (type == PAM_PROMPT_ECHO_ON); | |
574 | xfree(msg); | |
575 | return (0); | |
576 | case PAM_ERROR_MSG: | |
577 | case PAM_TEXT_INFO: | |
578 | /* accumulate messages */ | |
540d72c3 | 579 | len = plen + strlen(msg) + 2; |
7cac2b65 | 580 | **prompts = xrealloc(**prompts, len); |
540d72c3 | 581 | plen += snprintf(**prompts + plen, len, "%s\n", msg); |
7cac2b65 | 582 | xfree(msg); |
3c0ef626 | 583 | break; |
7cac2b65 | 584 | case PAM_SUCCESS: |
585 | case PAM_AUTH_ERR: | |
586 | if (**prompts != NULL) { | |
587 | /* drain any accumulated messages */ | |
540d72c3 | 588 | debug("PAM: %s", **prompts); |
589 | buffer_append(&loginmsg, **prompts, | |
590 | strlen(**prompts)); | |
7cac2b65 | 591 | xfree(**prompts); |
592 | **prompts = NULL; | |
593 | } | |
594 | if (type == PAM_SUCCESS) { | |
540d72c3 | 595 | import_environments(&buffer); |
7cac2b65 | 596 | *num = 0; |
597 | **echo_on = 0; | |
598 | ctxt->pam_done = 1; | |
599 | xfree(msg); | |
600 | return (0); | |
601 | } | |
12a403af | 602 | error("PAM: %s for %s%.100s from %.100s", msg, |
603 | sshpam_authctxt->valid ? "" : "illegal user ", | |
604 | sshpam_authctxt->user, | |
605 | get_remote_name_or_ip(utmp_len, options.use_dns)); | |
540d72c3 | 606 | /* FALLTHROUGH */ |
3c0ef626 | 607 | default: |
7cac2b65 | 608 | *num = 0; |
609 | **echo_on = 0; | |
610 | xfree(msg); | |
611 | ctxt->pam_done = -1; | |
612 | return (-1); | |
613 | } | |
3c0ef626 | 614 | } |
7cac2b65 | 615 | return (-1); |
3c0ef626 | 616 | } |
617 | ||
7cac2b65 | 618 | /* XXX - see also comment in auth-chall.c:verify_response */ |
619 | static int | |
620 | sshpam_respond(void *ctx, u_int num, char **resp) | |
3c0ef626 | 621 | { |
7cac2b65 | 622 | Buffer buffer; |
623 | struct pam_ctxt *ctxt = ctx; | |
624 | ||
540d72c3 | 625 | debug2("PAM: %s entering, %d responses", __func__, num); |
7cac2b65 | 626 | switch (ctxt->pam_done) { |
627 | case 1: | |
628 | sshpam_authenticated = 1; | |
629 | return (0); | |
630 | case 0: | |
631 | break; | |
632 | default: | |
633 | return (-1); | |
3c0ef626 | 634 | } |
7cac2b65 | 635 | if (num != 1) { |
636 | error("PAM: expected one response, got %u", num); | |
637 | return (-1); | |
638 | } | |
639 | buffer_init(&buffer); | |
640 | buffer_put_cstring(&buffer, *resp); | |
540d72c3 | 641 | if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { |
642 | buffer_free(&buffer); | |
643 | return (-1); | |
644 | } | |
7cac2b65 | 645 | buffer_free(&buffer); |
646 | return (1); | |
3c0ef626 | 647 | } |
648 | ||
7cac2b65 | 649 | static void |
650 | sshpam_free_ctx(void *ctxtp) | |
3c0ef626 | 651 | { |
7cac2b65 | 652 | struct pam_ctxt *ctxt = ctxtp; |
350391c5 | 653 | |
540d72c3 | 654 | debug3("PAM: %s entering", __func__); |
655 | sshpam_thread_cleanup(); | |
7cac2b65 | 656 | xfree(ctxt); |
657 | /* | |
658 | * We don't call sshpam_cleanup() here because we may need the PAM | |
659 | * handle at a later stage, e.g. when setting up a session. It's | |
660 | * still on the cleanup list, so pam_end() *will* be called before | |
661 | * the server process terminates. | |
662 | */ | |
3c0ef626 | 663 | } |
664 | ||
7cac2b65 | 665 | KbdintDevice sshpam_device = { |
666 | "pam", | |
667 | sshpam_init_ctx, | |
668 | sshpam_query, | |
669 | sshpam_respond, | |
670 | sshpam_free_ctx | |
671 | }; | |
672 | ||
673 | KbdintDevice mm_sshpam_device = { | |
674 | "pam", | |
675 | mm_sshpam_init_ctx, | |
676 | mm_sshpam_query, | |
677 | mm_sshpam_respond, | |
678 | mm_sshpam_free_ctx | |
679 | }; | |
3c0ef626 | 680 | |
681 | /* | |
7cac2b65 | 682 | * This replaces auth-pam.c |
3c0ef626 | 683 | */ |
7cac2b65 | 684 | void |
12a403af | 685 | start_pam(Authctxt *authctxt) |
3c0ef626 | 686 | { |
7cac2b65 | 687 | if (!options.use_pam) |
688 | fatal("PAM: initialisation requested when UsePAM=no"); | |
689 | ||
12a403af | 690 | if (sshpam_init(authctxt) == -1) |
7cac2b65 | 691 | fatal("PAM: initialisation failed"); |
3c0ef626 | 692 | } |
693 | ||
7cac2b65 | 694 | void |
695 | finish_pam(void) | |
3c0ef626 | 696 | { |
540d72c3 | 697 | sshpam_cleanup(); |
3c0ef626 | 698 | } |
699 | ||
7cac2b65 | 700 | u_int |
701 | do_pam_account(void) | |
3c0ef626 | 702 | { |
540d72c3 | 703 | if (sshpam_account_status != -1) |
704 | return (sshpam_account_status); | |
705 | ||
7cac2b65 | 706 | sshpam_err = pam_acct_mgmt(sshpam_handle, 0); |
540d72c3 | 707 | debug3("PAM: %s pam_acct_mgmt = %d", __func__, sshpam_err); |
7cac2b65 | 708 | |
540d72c3 | 709 | if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) { |
710 | sshpam_account_status = 0; | |
711 | return (sshpam_account_status); | |
7cac2b65 | 712 | } |
3c0ef626 | 713 | |
540d72c3 | 714 | if (sshpam_err == PAM_NEW_AUTHTOK_REQD) |
715 | pam_password_change_required(1); | |
3c0ef626 | 716 | |
540d72c3 | 717 | sshpam_account_status = 1; |
718 | return (sshpam_account_status); | |
7cac2b65 | 719 | } |
3c0ef626 | 720 | |
7cac2b65 | 721 | void |
722 | do_pam_set_tty(const char *tty) | |
723 | { | |
724 | if (tty != NULL) { | |
725 | debug("PAM: setting PAM_TTY to \"%s\"", tty); | |
726 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); | |
727 | if (sshpam_err != PAM_SUCCESS) | |
728 | fatal("PAM: failed to set PAM_TTY: %s", | |
729 | pam_strerror(sshpam_handle, sshpam_err)); | |
730 | } | |
731 | } | |
3c0ef626 | 732 | |
7cac2b65 | 733 | void |
734 | do_pam_setcred(int init) | |
735 | { | |
736 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
737 | (const void *)&null_conv); | |
738 | if (sshpam_err != PAM_SUCCESS) | |
739 | fatal("PAM: failed to set PAM_CONV: %s", | |
740 | pam_strerror(sshpam_handle, sshpam_err)); | |
741 | if (init) { | |
742 | debug("PAM: establishing credentials"); | |
743 | sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); | |
744 | } else { | |
745 | debug("PAM: reinitializing credentials"); | |
746 | sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); | |
747 | } | |
748 | if (sshpam_err == PAM_SUCCESS) { | |
749 | sshpam_cred_established = 1; | |
750 | return; | |
751 | } | |
752 | if (sshpam_authenticated) | |
753 | fatal("PAM: pam_setcred(): %s", | |
754 | pam_strerror(sshpam_handle, sshpam_err)); | |
755 | else | |
756 | debug("PAM: pam_setcred(): %s", | |
757 | pam_strerror(sshpam_handle, sshpam_err)); | |
3c0ef626 | 758 | } |
759 | ||
7cac2b65 | 760 | static int |
540d72c3 | 761 | pam_tty_conv(int n, const struct pam_message **msg, |
7cac2b65 | 762 | struct pam_response **resp, void *data) |
23987cb8 | 763 | { |
7cac2b65 | 764 | char input[PAM_MAX_MSG_SIZE]; |
29d88157 | 765 | struct pam_response *reply; |
23987cb8 | 766 | int i; |
767 | ||
540d72c3 | 768 | debug3("PAM: %s called with %d messages", __func__, n); |
769 | ||
29d88157 | 770 | *resp = NULL; |
771 | ||
540d72c3 | 772 | if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) |
7cac2b65 | 773 | return (PAM_CONV_ERR); |
29d88157 | 774 | |
775 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
776 | return (PAM_CONV_ERR); | |
777 | memset(reply, 0, n * sizeof(*reply)); | |
778 | ||
7cac2b65 | 779 | for (i = 0; i < n; ++i) { |
780 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
781 | case PAM_PROMPT_ECHO_OFF: | |
29d88157 | 782 | reply[i].resp = |
540d72c3 | 783 | read_passphrase(PAM_MSG_MEMBER(msg, i, msg), |
7cac2b65 | 784 | RP_ALLOW_STDIN); |
29d88157 | 785 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 786 | break; |
787 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 788 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
7cac2b65 | 789 | fgets(input, sizeof input, stdin); |
29d88157 | 790 | reply[i].resp = xstrdup(input); |
791 | reply[i].resp_retcode = PAM_SUCCESS; | |
7cac2b65 | 792 | break; |
793 | case PAM_ERROR_MSG: | |
794 | case PAM_TEXT_INFO: | |
540d72c3 | 795 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
29d88157 | 796 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 797 | break; |
798 | default: | |
799 | goto fail; | |
800 | } | |
23987cb8 | 801 | } |
29d88157 | 802 | *resp = reply; |
7cac2b65 | 803 | return (PAM_SUCCESS); |
29d88157 | 804 | |
7cac2b65 | 805 | fail: |
29d88157 | 806 | for(i = 0; i < n; i++) { |
807 | if (reply[i].resp != NULL) | |
808 | xfree(reply[i].resp); | |
809 | } | |
810 | xfree(reply); | |
7cac2b65 | 811 | return (PAM_CONV_ERR); |
23987cb8 | 812 | } |
813 | ||
540d72c3 | 814 | static struct pam_conv tty_conv = { pam_tty_conv, NULL }; |
815 | ||
7cac2b65 | 816 | /* |
817 | * XXX this should be done in the authentication phase, but ssh1 doesn't | |
818 | * support that | |
819 | */ | |
820 | void | |
821 | do_pam_chauthtok(void) | |
822 | { | |
7cac2b65 | 823 | if (use_privsep) |
824 | fatal("Password expired (unable to change with privsep)"); | |
825 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
540d72c3 | 826 | (const void *)&tty_conv); |
7cac2b65 | 827 | if (sshpam_err != PAM_SUCCESS) |
828 | fatal("PAM: failed to set PAM_CONV: %s", | |
829 | pam_strerror(sshpam_handle, sshpam_err)); | |
830 | debug("PAM: changing password"); | |
831 | sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); | |
832 | if (sshpam_err != PAM_SUCCESS) | |
833 | fatal("PAM: pam_chauthtok(): %s", | |
834 | pam_strerror(sshpam_handle, sshpam_err)); | |
835 | } | |
836 | ||
540d72c3 | 837 | static int |
838 | pam_store_conv(int n, const struct pam_message **msg, | |
839 | struct pam_response **resp, void *data) | |
840 | { | |
841 | struct pam_response *reply; | |
842 | int i; | |
843 | size_t len; | |
844 | ||
845 | debug3("PAM: %s called with %d messages", __func__, n); | |
846 | *resp = NULL; | |
847 | ||
848 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
849 | return (PAM_CONV_ERR); | |
850 | ||
851 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
852 | return (PAM_CONV_ERR); | |
853 | memset(reply, 0, n * sizeof(*reply)); | |
854 | ||
855 | for (i = 0; i < n; ++i) { | |
856 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
857 | case PAM_ERROR_MSG: | |
858 | case PAM_TEXT_INFO: | |
859 | len = strlen(PAM_MSG_MEMBER(msg, i, msg)); | |
860 | buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len); | |
861 | buffer_append(&loginmsg, "\n", 1 ); | |
862 | reply[i].resp_retcode = PAM_SUCCESS; | |
863 | break; | |
864 | default: | |
865 | goto fail; | |
866 | } | |
867 | } | |
868 | *resp = reply; | |
869 | return (PAM_SUCCESS); | |
870 | ||
871 | fail: | |
872 | for(i = 0; i < n; i++) { | |
873 | if (reply[i].resp != NULL) | |
874 | xfree(reply[i].resp); | |
875 | } | |
876 | xfree(reply); | |
877 | return (PAM_CONV_ERR); | |
878 | } | |
879 | ||
880 | static struct pam_conv store_conv = { pam_store_conv, NULL }; | |
881 | ||
882 | void | |
883 | do_pam_session(void) | |
884 | { | |
885 | debug3("PAM: opening session"); | |
886 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
887 | (const void *)&store_conv); | |
888 | if (sshpam_err != PAM_SUCCESS) | |
889 | fatal("PAM: failed to set PAM_CONV: %s", | |
890 | pam_strerror(sshpam_handle, sshpam_err)); | |
891 | sshpam_err = pam_open_session(sshpam_handle, 0); | |
892 | if (sshpam_err != PAM_SUCCESS) | |
893 | fatal("PAM: pam_open_session(): %s", | |
894 | pam_strerror(sshpam_handle, sshpam_err)); | |
895 | sshpam_session_open = 1; | |
896 | } | |
897 | ||
898 | /* | |
7cac2b65 | 899 | * Set a PAM environment string. We need to do this so that the session |
5598e598 | 900 | * modules can handle things like Kerberos/GSI credentials that appear |
901 | * during the ssh authentication process. | |
902 | */ | |
7cac2b65 | 903 | int |
540d72c3 | 904 | do_pam_putenv(char *name, char *value) |
7cac2b65 | 905 | { |
906 | int ret = 1; | |
540d72c3 | 907 | #ifdef HAVE_PAM_PUTENV |
5598e598 | 908 | char *compound; |
7cac2b65 | 909 | size_t len; |
905081a4 | 910 | |
7cac2b65 | 911 | len = strlen(name) + strlen(value) + 2; |
912 | compound = xmalloc(len); | |
913 | ||
914 | snprintf(compound, len, "%s=%s", name, value); | |
915 | ret = pam_putenv(sshpam_handle, compound); | |
916 | xfree(compound); | |
905081a4 | 917 | #endif |
7cac2b65 | 918 | |
919 | return (ret); | |
5598e598 | 920 | } |
921 | ||
540d72c3 | 922 | char ** |
923 | fetch_pam_child_environment(void) | |
3c0ef626 | 924 | { |
540d72c3 | 925 | return sshpam_env; |
3c0ef626 | 926 | } |
927 | ||
7cac2b65 | 928 | char ** |
929 | fetch_pam_environment(void) | |
3c0ef626 | 930 | { |
7cac2b65 | 931 | return (pam_getenvlist(sshpam_handle)); |
7cac2b65 | 932 | } |
3c0ef626 | 933 | |
7cac2b65 | 934 | void |
935 | free_pam_environment(char **env) | |
936 | { | |
937 | char **envp; | |
3c0ef626 | 938 | |
7cac2b65 | 939 | if (env == NULL) |
940 | return; | |
3c0ef626 | 941 | |
7cac2b65 | 942 | for (envp = env; *envp; envp++) |
943 | xfree(*envp); | |
944 | xfree(env); | |
3c0ef626 | 945 | } |
946 | ||
947 | #endif /* USE_PAM */ |