1 /* $OpenBSD: monitor.c,v 1.145 2015/02/20 22:17:21 djm Exp $ */
2 /*
3 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
4 * Copyright 2002 Markus Friedl <markus@openbsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "includes.h"
29
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include "openbsd-compat/sys-tree.h"
33 #include <sys/wait.h>
34
35 #include <errno.h>
36 #include <fcntl.h>
37 #ifdef HAVE_PATHS_H
38 #include <paths.h>
39 #endif
40 #include <pwd.h>
41 #include <signal.h>
42 #ifdef HAVE_STDINT_H
43 #include <stdint.h>
44 #endif
45 #include <stdlib.h>
46 #include <string.h>
47 #include <stdarg.h>
48 #include <stdio.h>
49 #include <unistd.h>
50 #ifdef HAVE_POLL_H
51 #include <poll.h>
52 #else
53 # ifdef HAVE_SYS_POLL_H
54 # include <sys/poll.h>
55 # endif
56 #endif
57
58 #ifdef SKEY
59 #include <skey.h>
60 #endif
61
62 #ifdef WITH_OPENSSL
63 #include <openssl/dh.h>
64 #endif
65
66 #include "openbsd-compat/sys-queue.h"
67 #include "atomicio.h"
68 #include "xmalloc.h"
69 #include "ssh.h"
70 #include "key.h"
71 #include "buffer.h"
72 #include "hostfile.h"
73 #include "auth.h"
74 #include "cipher.h"
75 #include "kex.h"
76 #include "dh.h"
77 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */
78 #undef TARGET_OS_MAC
79 #include "zlib.h"
80 #define TARGET_OS_MAC 1
81 #else
82 #include "zlib.h"
83 #endif
84 #include "packet.h"
85 #include "auth-options.h"
86 #include "sshpty.h"
87 #include "channels.h"
88 #include "session.h"
89 #include "sshlogin.h"
90 #include "canohost.h"
91 #include "log.h"
92 #include "misc.h"
93 #include "servconf.h"
94 #include "monitor.h"
95 #include "monitor_mm.h"
96 #ifdef GSSAPI
97 #include "ssh-gss.h"
98 #endif
99 #include "monitor_wrap.h"
100 #include "monitor_fdpass.h"
101 #include "compat.h"
102 #include "ssh2.h"
103 #include "roaming.h"
104 #include "authfd.h"
105 #include "match.h"
106 #include "ssherr.h"
107
108 #ifdef GSSAPI
109 static Gssctxt *gsscontext = NULL;
110 #endif
111
112 /* Imports */
113 extern ServerOptions options;
114 extern u_int utmp_len;
115 extern u_char session_id[];
116 extern Buffer auth_debug;
117 extern int auth_debug_init;
118 extern Buffer loginmsg;
119
120 /* State exported from the child */
121 static struct sshbuf *child_state;
122
123 /* Functions on the monitor that answer unprivileged requests */
124
125 int mm_answer_moduli(int, Buffer *);
126 int mm_answer_sign(int, Buffer *);
127 int mm_answer_pwnamallow(int, Buffer *);
128 int mm_answer_auth2_read_banner(int, Buffer *);
129 int mm_answer_authserv(int, Buffer *);
130 int mm_answer_authpassword(int, Buffer *);
131 int mm_answer_bsdauthquery(int, Buffer *);
132 int mm_answer_bsdauthrespond(int, Buffer *);
133 int mm_answer_skeyquery(int, Buffer *);
134 int mm_answer_skeyrespond(int, Buffer *);
135 int mm_answer_keyallowed(int, Buffer *);
136 int mm_answer_keyverify(int, Buffer *);
137 int mm_answer_pty(int, Buffer *);
138 int mm_answer_pty_cleanup(int, Buffer *);
139 int mm_answer_term(int, Buffer *);
140 int mm_answer_rsa_keyallowed(int, Buffer *);
141 int mm_answer_rsa_challenge(int, Buffer *);
142 int mm_answer_rsa_response(int, Buffer *);
143 int mm_answer_sesskey(int, Buffer *);
144 int mm_answer_sessid(int, Buffer *);
145
146 #ifdef USE_PAM
147 int mm_answer_pam_start(int, Buffer *);
148 int mm_answer_pam_account(int, Buffer *);
149 int mm_answer_pam_init_ctx(int, Buffer *);
150 int mm_answer_pam_query(int, Buffer *);
151 int mm_answer_pam_respond(int, Buffer *);
152 int mm_answer_pam_free_ctx(int, Buffer *);
153 #endif
154
155 #ifdef GSSAPI
156 int mm_answer_gss_setup_ctx(int, Buffer *);
157 int mm_answer_gss_accept_ctx(int, Buffer *);
158 int mm_answer_gss_userok(int, Buffer *);
159 int mm_answer_gss_checkmic(int, Buffer *);
160 #endif
161
162 #ifdef SSH_AUDIT_EVENTS
163 int mm_answer_audit_event(int, Buffer *);
164 int mm_answer_audit_command(int, Buffer *);
165 #endif
166
167 static int monitor_read_log(struct monitor *);
168
169 static Authctxt *authctxt;
170
171 #ifdef WITH_SSH1
172 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
173 #endif
174
175 /* local state for key verify */
176 static u_char *key_blob = NULL;
177 static u_int key_bloblen = 0;
178 static int key_blobtype = MM_NOKEY;
179 static char *hostbased_cuser = NULL;
180 static char *hostbased_chost = NULL;
181 static char *auth_method = "unknown";
182 static char *auth_submethod = NULL;
183 static u_int session_id2_len = 0;
184 static u_char *session_id2 = NULL;
185 static pid_t monitor_child_pid;
186
187 struct mon_table {
188 enum monitor_reqtype type;
189 int flags;
190 int (*f)(int, Buffer *);
191 };
192
193 #define MON_ISAUTH 0x0004 /* Required for Authentication */
194 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
195 #define MON_ONCE 0x0010 /* Disable after calling */
196 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
197
198 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
199
200 #define MON_PERMIT 0x1000 /* Request is permitted */
201
202 struct mon_table mon_dispatch_proto20[] = {
203 #ifdef WITH_OPENSSL
204 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
205 #endif
206 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
207 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
208 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
209 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
210 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
211 #ifdef USE_PAM
212 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
213 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
214 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
215 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
216 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
217 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
218 #endif
219 #ifdef SSH_AUDIT_EVENTS
220 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
221 #endif
222 #ifdef BSD_AUTH
223 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
224 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
225 #endif
226 #ifdef SKEY
227 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
228 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
229 #endif
230 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
231 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
232 #ifdef GSSAPI
233 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
234 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
235 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
236 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
237 #endif
238 {0, 0, NULL}
239 };
240
241 struct mon_table mon_dispatch_postauth20[] = {
242 #ifdef WITH_OPENSSL
243 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
244 #endif
245 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
246 {MONITOR_REQ_PTY, 0, mm_answer_pty},
247 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
248 {MONITOR_REQ_TERM, 0, mm_answer_term},
249 #ifdef SSH_AUDIT_EVENTS
250 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
251 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
252 #endif
253 {0, 0, NULL}
254 };
255
256 struct mon_table mon_dispatch_proto15[] = {
257 #ifdef WITH_SSH1
258 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
259 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
260 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
261 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
262 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
263 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
264 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
265 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
266 #ifdef BSD_AUTH
267 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
268 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
269 #endif
270 #ifdef SKEY
271 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
272 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
273 #endif
274 #ifdef USE_PAM
275 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
276 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
277 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
278 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
279 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
280 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
281 #endif
282 #ifdef SSH_AUDIT_EVENTS
283 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
284 #endif
285 #endif /* WITH_SSH1 */
286 {0, 0, NULL}
287 };
288
289 struct mon_table mon_dispatch_postauth15[] = {
290 #ifdef WITH_SSH1
291 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
292 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
293 {MONITOR_REQ_TERM, 0, mm_answer_term},
294 #ifdef SSH_AUDIT_EVENTS
295 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
296 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
297 #endif
298 #endif /* WITH_SSH1 */
299 {0, 0, NULL}
300 };
301
302 struct mon_table *mon_dispatch;
303
304 /* Specifies if a certain message is allowed at the moment */
305
306 static void
monitor_permit(struct mon_table * ent,enum monitor_reqtype type,int permit)307 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
308 {
309 while (ent->f != NULL) {
310 if (ent->type == type) {
311 ent->flags &= ~MON_PERMIT;
312 ent->flags |= permit ? MON_PERMIT : 0;
313 return;
314 }
315 ent++;
316 }
317 }
318
319 static void
monitor_permit_authentications(int permit)320 monitor_permit_authentications(int permit)
321 {
322 struct mon_table *ent = mon_dispatch;
323
324 while (ent->f != NULL) {
325 if (ent->flags & MON_AUTH) {
326 ent->flags &= ~MON_PERMIT;
327 ent->flags |= permit ? MON_PERMIT : 0;
328 }
329 ent++;
330 }
331 }
332
333 void
monitor_child_preauth(Authctxt * _authctxt,struct monitor * pmonitor)334 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
335 {
336 struct mon_table *ent;
337 int authenticated = 0, partial = 0;
338
339 debug3("preauth child monitor started");
340
341 close(pmonitor->m_recvfd);
342 close(pmonitor->m_log_sendfd);
343 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
344
345 authctxt = _authctxt;
346 memset(authctxt, 0, sizeof(*authctxt));
347
348 authctxt->loginmsg = &loginmsg;
349
350 if (compat20) {
351 mon_dispatch = mon_dispatch_proto20;
352
353 /* Permit requests for moduli and signatures */
354 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
355 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
356 } else {
357 mon_dispatch = mon_dispatch_proto15;
358
359 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
360 }
361
362 /* The first few requests do not require asynchronous access */
363 while (!authenticated) {
364 partial = 0;
365 auth_method = "unknown";
366 auth_submethod = NULL;
367 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
368
369 /* Special handling for multiple required authentications */
370 if (options.num_auth_methods != 0) {
371 if (!compat20)
372 fatal("AuthenticationMethods is not supported"
373 "with SSH protocol 1");
374 if (authenticated &&
375 !auth2_update_methods_lists(authctxt,
376 auth_method, auth_submethod)) {
377 debug3("%s: method %s: partial", __func__,
378 auth_method);
379 authenticated = 0;
380 partial = 1;
381 }
382 }
383
384 if (authenticated) {
385 if (!(ent->flags & MON_AUTHDECIDE))
386 fatal("%s: unexpected authentication from %d",
387 __func__, ent->type);
388 if (authctxt->pw->pw_uid == 0 &&
389 !auth_root_allowed(auth_method))
390 authenticated = 0;
391 #ifdef USE_PAM
392 /* PAM needs to perform account checks after auth */
393 if (options.use_pam && authenticated) {
394 Buffer m;
395
396 buffer_init(&m);
397 mm_request_receive_expect(pmonitor->m_sendfd,
398 MONITOR_REQ_PAM_ACCOUNT, &m);
399 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
400 buffer_free(&m);
401 }
402 #endif
403 }
404 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
405 auth_log(authctxt, authenticated, partial,
406 auth_method, auth_submethod);
407 if (!authenticated)
408 authctxt->failures++;
409 }
410 }
411
412 if (!authctxt->valid)
413 fatal("%s: authenticated invalid user", __func__);
414 if (strcmp(auth_method, "unknown") == 0)
415 fatal("%s: authentication method name unknown", __func__);
416
417 debug("%s: %s has been authenticated by privileged process",
418 __func__, authctxt->user);
419
420 mm_get_keystate(pmonitor);
421
422 /* Drain any buffered messages from the child */
423 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
424 ;
425
426 close(pmonitor->m_sendfd);
427 close(pmonitor->m_log_recvfd);
428 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
429 }
430
431 static void
monitor_set_child_handler(pid_t pid)432 monitor_set_child_handler(pid_t pid)
433 {
434 monitor_child_pid = pid;
435 }
436
437 static void
monitor_child_handler(int sig)438 monitor_child_handler(int sig)
439 {
440 kill(monitor_child_pid, sig);
441 }
442
443 void
monitor_child_postauth(struct monitor * pmonitor)444 monitor_child_postauth(struct monitor *pmonitor)
445 {
446 close(pmonitor->m_recvfd);
447 pmonitor->m_recvfd = -1;
448
449 monitor_set_child_handler(pmonitor->m_pid);
450 signal(SIGHUP, &monitor_child_handler);
451 signal(SIGTERM, &monitor_child_handler);
452 signal(SIGINT, &monitor_child_handler);
453 #ifdef SIGXFSZ
454 signal(SIGXFSZ, SIG_IGN);
455 #endif
456
457 if (compat20) {
458 mon_dispatch = mon_dispatch_postauth20;
459
460 /* Permit requests for moduli and signatures */
461 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
462 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
463 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
464 } else {
465 mon_dispatch = mon_dispatch_postauth15;
466 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
467 }
468 if (!no_pty_flag) {
469 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
470 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
471 }
472
473 for (;;)
474 monitor_read(pmonitor, mon_dispatch, NULL);
475 }
476
477 void
monitor_sync(struct monitor * pmonitor)478 monitor_sync(struct monitor *pmonitor)
479 {
480 if (options.compression) {
481 /* The member allocation is not visible, so sync it */
482 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
483 }
484 }
485
486 /* Allocation functions for zlib */
487 static void *
mm_zalloc(struct mm_master * mm,u_int ncount,u_int size)488 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
489 {
490 size_t len = (size_t) size * ncount;
491 void *address;
492
493 if (len == 0 || ncount > SIZE_MAX / size)
494 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
495
496 address = mm_malloc(mm, len);
497
498 return (address);
499 }
500
501 static void
mm_zfree(struct mm_master * mm,void * address)502 mm_zfree(struct mm_master *mm, void *address)
503 {
504 mm_free(mm, address);
505 }
506
507 static int
monitor_read_log(struct monitor * pmonitor)508 monitor_read_log(struct monitor *pmonitor)
509 {
510 Buffer logmsg;
511 u_int len, level;
512 char *msg;
513
514 buffer_init(&logmsg);
515
516 /* Read length */
517 buffer_append_space(&logmsg, 4);
518 if (atomicio(read, pmonitor->m_log_recvfd,
519 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
520 if (errno == EPIPE) {
521 buffer_free(&logmsg);
522 debug("%s: child log fd closed", __func__);
523 close(pmonitor->m_log_recvfd);
524 pmonitor->m_log_recvfd = -1;
525 return -1;
526 }
527 fatal("%s: log fd read: %s", __func__, strerror(errno));
528 }
529 len = buffer_get_int(&logmsg);
530 if (len <= 4 || len > 8192)
531 fatal("%s: invalid log message length %u", __func__, len);
532
533 /* Read severity, message */
534 buffer_clear(&logmsg);
535 buffer_append_space(&logmsg, len);
536 if (atomicio(read, pmonitor->m_log_recvfd,
537 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
538 fatal("%s: log fd read: %s", __func__, strerror(errno));
539
540 /* Log it */
541 level = buffer_get_int(&logmsg);
542 msg = buffer_get_string(&logmsg, NULL);
543 if (log_level_name(level) == NULL)
544 fatal("%s: invalid log level %u (corrupted message?)",
545 __func__, level);
546 do_log2(level, "%s [preauth]", msg);
547
548 buffer_free(&logmsg);
549 free(msg);
550
551 return 0;
552 }
553
554 int
monitor_read(struct monitor * pmonitor,struct mon_table * ent,struct mon_table ** pent)555 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
556 struct mon_table **pent)
557 {
558 Buffer m;
559 int ret;
560 u_char type;
561 struct pollfd pfd[2];
562
563 for (;;) {
564 memset(&pfd, 0, sizeof(pfd));
565 pfd[0].fd = pmonitor->m_sendfd;
566 pfd[0].events = POLLIN;
567 pfd[1].fd = pmonitor->m_log_recvfd;
568 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
569 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
570 if (errno == EINTR || errno == EAGAIN)
571 continue;
572 fatal("%s: poll: %s", __func__, strerror(errno));
573 }
574 if (pfd[1].revents) {
575 /*
576 * Drain all log messages before processing next
577 * monitor request.
578 */
579 monitor_read_log(pmonitor);
580 continue;
581 }
582 if (pfd[0].revents)
583 break; /* Continues below */
584 }
585
586 buffer_init(&m);
587
588 mm_request_receive(pmonitor->m_sendfd, &m);
589 type = buffer_get_char(&m);
590
591 debug3("%s: checking request %d", __func__, type);
592
593 while (ent->f != NULL) {
594 if (ent->type == type)
595 break;
596 ent++;
597 }
598
599 if (ent->f != NULL) {
600 if (!(ent->flags & MON_PERMIT))
601 fatal("%s: unpermitted request %d", __func__,
602 type);
603 ret = (*ent->f)(pmonitor->m_sendfd, &m);
604 buffer_free(&m);
605
606 /* The child may use this request only once, disable it */
607 if (ent->flags & MON_ONCE) {
608 debug2("%s: %d used once, disabling now", __func__,
609 type);
610 ent->flags &= ~MON_PERMIT;
611 }
612
613 if (pent != NULL)
614 *pent = ent;
615
616 return ret;
617 }
618
619 fatal("%s: unsupported request: %d", __func__, type);
620
621 /* NOTREACHED */
622 return (-1);
623 }
624
625 /* allowed key state */
626 static int
monitor_allowed_key(u_char * blob,u_int bloblen)627 monitor_allowed_key(u_char *blob, u_int bloblen)
628 {
629 /* make sure key is allowed */
630 if (key_blob == NULL || key_bloblen != bloblen ||
631 timingsafe_bcmp(key_blob, blob, key_bloblen))
632 return (0);
633 return (1);
634 }
635
636 static void
monitor_reset_key_state(void)637 monitor_reset_key_state(void)
638 {
639 /* reset state */
640 free(key_blob);
641 free(hostbased_cuser);
642 free(hostbased_chost);
643 key_blob = NULL;
644 key_bloblen = 0;
645 key_blobtype = MM_NOKEY;
646 hostbased_cuser = NULL;
647 hostbased_chost = NULL;
648 }
649
650 #ifdef WITH_OPENSSL
651 int
mm_answer_moduli(int sock,Buffer * m)652 mm_answer_moduli(int sock, Buffer *m)
653 {
654 DH *dh;
655 int min, want, max;
656
657 min = buffer_get_int(m);
658 want = buffer_get_int(m);
659 max = buffer_get_int(m);
660
661 debug3("%s: got parameters: %d %d %d",
662 __func__, min, want, max);
663 /* We need to check here, too, in case the child got corrupted */
664 if (max < min || want < min || max < want)
665 fatal("%s: bad parameters: %d %d %d",
666 __func__, min, want, max);
667
668 buffer_clear(m);
669
670 dh = choose_dh(min, want, max);
671 if (dh == NULL) {
672 buffer_put_char(m, 0);
673 return (0);
674 } else {
675 /* Send first bignum */
676 buffer_put_char(m, 1);
677 buffer_put_bignum2(m, dh->p);
678 buffer_put_bignum2(m, dh->g);
679
680 DH_free(dh);
681 }
682 mm_request_send(sock, MONITOR_ANS_MODULI, m);
683 return (0);
684 }
685 #endif
686
687 int
mm_answer_sign(int sock,Buffer * m)688 mm_answer_sign(int sock, Buffer *m)
689 {
690 struct ssh *ssh = active_state; /* XXX */
691 extern int auth_sock; /* XXX move to state struct? */
692 struct sshkey *key;
693 struct sshbuf *sigbuf;
694 u_char *p;
695 u_char *signature;
696 size_t datlen, siglen;
697 int r, keyid, is_proof = 0;
698 const char proof_req[] = "hostkeys-prove-00@openssh.com";
699
700 debug3("%s", __func__);
701
702 if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
703 (r = sshbuf_get_string(m, &p, &datlen)) != 0)
704 fatal("%s: buffer error: %s", __func__, ssh_err(r));
705
706 /*
707 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
708 * SHA384 (48 bytes) and SHA512 (64 bytes).
709 *
710 * Otherwise, verify the signature request is for a hostkey
711 * proof.
712 *
713 * XXX perform similar check for KEX signature requests too?
714 * it's not trivial, since what is signed is the hash, rather
715 * than the full kex structure...
716 */
717 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
718 /*
719 * Construct expected hostkey proof and compare it to what
720 * the client sent us.
721 */
722 if (session_id2_len == 0) /* hostkeys is never first */
723 fatal("%s: bad data length: %zu", __func__, datlen);
724 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
725 fatal("%s: no hostkey for index %d", __func__, keyid);
726 if ((sigbuf = sshbuf_new()) == NULL)
727 fatal("%s: sshbuf_new", __func__);
728 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
729 (r = sshbuf_put_string(sigbuf, session_id2,
730 session_id2_len) != 0) ||
731 (r = sshkey_puts(key, sigbuf)) != 0)
732 fatal("%s: couldn't prepare private key "
733 "proof buffer: %s", __func__, ssh_err(r));
734 if (datlen != sshbuf_len(sigbuf) ||
735 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
736 fatal("%s: bad data length: %zu, hostkey proof len %zu",
737 __func__, datlen, sshbuf_len(sigbuf));
738 sshbuf_free(sigbuf);
739 is_proof = 1;
740 }
741
742 /* save session id, it will be passed on the first call */
743 if (session_id2_len == 0) {
744 session_id2_len = datlen;
745 session_id2 = xmalloc(session_id2_len);
746 memcpy(session_id2, p, session_id2_len);
747 }
748
749 if ((key = get_hostkey_by_index(keyid)) != NULL) {
750 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen,
751 datafellows)) != 0)
752 fatal("%s: sshkey_sign failed: %s",
753 __func__, ssh_err(r));
754 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
755 auth_sock > 0) {
756 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
757 p, datlen, datafellows)) != 0) {
758 fatal("%s: ssh_agent_sign failed: %s",
759 __func__, ssh_err(r));
760 }
761 } else
762 fatal("%s: no hostkey from index %d", __func__, keyid);
763
764 debug3("%s: %s signature %p(%zu)", __func__,
765 is_proof ? "KEX" : "hostkey proof", signature, siglen);
766
767 sshbuf_reset(m);
768 if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
769 fatal("%s: buffer error: %s", __func__, ssh_err(r));
770
771 free(p);
772 free(signature);
773
774 mm_request_send(sock, MONITOR_ANS_SIGN, m);
775
776 /* Turn on permissions for getpwnam */
777 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
778
779 return (0);
780 }
781
782 /* Retrieves the password entry and also checks if the user is permitted */
783
784 int
mm_answer_pwnamallow(int sock,Buffer * m)785 mm_answer_pwnamallow(int sock, Buffer *m)
786 {
787 char *username;
788 struct passwd *pwent;
789 int allowed = 0;
790 u_int i;
791
792 debug3("%s", __func__);
793
794 if (authctxt->attempt++ != 0)
795 fatal("%s: multiple attempts for getpwnam", __func__);
796
797 username = buffer_get_string(m, NULL);
798
799 pwent = getpwnamallow(username);
800
801 authctxt->user = xstrdup(username);
802 setproctitle("%s [priv]", pwent ? username : "unknown");
803 free(username);
804
805 buffer_clear(m);
806
807 if (pwent == NULL) {
808 buffer_put_char(m, 0);
809 authctxt->pw = fakepw();
810 goto out;
811 }
812
813 allowed = 1;
814 authctxt->pw = pwent;
815 authctxt->valid = 1;
816
817 buffer_put_char(m, 1);
818 buffer_put_string(m, pwent, sizeof(struct passwd));
819 buffer_put_cstring(m, pwent->pw_name);
820 buffer_put_cstring(m, "*");
821 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
822 buffer_put_cstring(m, pwent->pw_gecos);
823 #endif
824 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
825 buffer_put_cstring(m, pwent->pw_class);
826 #endif
827 buffer_put_cstring(m, pwent->pw_dir);
828 buffer_put_cstring(m, pwent->pw_shell);
829
830 out:
831 buffer_put_string(m, &options, sizeof(options));
832
833 #define M_CP_STROPT(x) do { \
834 if (options.x != NULL) \
835 buffer_put_cstring(m, options.x); \
836 } while (0)
837 #define M_CP_STRARRAYOPT(x, nx) do { \
838 for (i = 0; i < options.nx; i++) \
839 buffer_put_cstring(m, options.x[i]); \
840 } while (0)
841 /* See comment in servconf.h */
842 COPY_MATCH_STRING_OPTS();
843 #undef M_CP_STROPT
844 #undef M_CP_STRARRAYOPT
845
846 /* Create valid auth method lists */
847 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) {
848 /*
849 * The monitor will continue long enough to let the child
850 * run to it's packet_disconnect(), but it must not allow any
851 * authentication to succeed.
852 */
853 debug("%s: no valid authentication method lists", __func__);
854 }
855
856 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
857 mm_request_send(sock, MONITOR_ANS_PWNAM, m);
858
859 /* For SSHv1 allow authentication now */
860 if (!compat20)
861 monitor_permit_authentications(1);
862 else {
863 /* Allow service/style information on the auth context */
864 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
865 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
866 }
867 #ifdef USE_PAM
868 if (options.use_pam)
869 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
870 #endif
871
872 return (0);
873 }
874
mm_answer_auth2_read_banner(int sock,Buffer * m)875 int mm_answer_auth2_read_banner(int sock, Buffer *m)
876 {
877 char *banner;
878
879 buffer_clear(m);
880 banner = auth2_read_banner();
881 buffer_put_cstring(m, banner != NULL ? banner : "");
882 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
883 free(banner);
884
885 return (0);
886 }
887
888 int
mm_answer_authserv(int sock,Buffer * m)889 mm_answer_authserv(int sock, Buffer *m)
890 {
891 monitor_permit_authentications(1);
892
893 authctxt->service = buffer_get_string(m, NULL);
894 authctxt->style = buffer_get_string(m, NULL);
895 debug3("%s: service=%s, style=%s",
896 __func__, authctxt->service, authctxt->style);
897
898 if (strlen(authctxt->style) == 0) {
899 free(authctxt->style);
900 authctxt->style = NULL;
901 }
902
903 return (0);
904 }
905
906 int
mm_answer_authpassword(int sock,Buffer * m)907 mm_answer_authpassword(int sock, Buffer *m)
908 {
909 static int call_count;
910 char *passwd;
911 int authenticated;
912 u_int plen;
913
914 passwd = buffer_get_string(m, &plen);
915 #if !defined(ANDROID)
916 /* Only authenticate if the context is valid */
917 authenticated = options.password_authentication &&
918 auth_password(authctxt, passwd);
919 #else
920 /* no password authentication in Android. */
921 authenticated = 0;
922 #endif
923 explicit_bzero(passwd, strlen(passwd));
924 free(passwd);
925
926 buffer_clear(m);
927 buffer_put_int(m, authenticated);
928
929 debug3("%s: sending result %d", __func__, authenticated);
930 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
931
932 call_count++;
933 if (plen == 0 && call_count == 1)
934 auth_method = "none";
935 else
936 auth_method = "password";
937
938 /* Causes monitor loop to terminate if authenticated */
939 return (authenticated);
940 }
941
942 #ifdef BSD_AUTH
943 int
mm_answer_bsdauthquery(int sock,Buffer * m)944 mm_answer_bsdauthquery(int sock, Buffer *m)
945 {
946 char *name, *infotxt;
947 u_int numprompts;
948 u_int *echo_on;
949 char **prompts;
950 u_int success;
951
952 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
953 &prompts, &echo_on) < 0 ? 0 : 1;
954
955 buffer_clear(m);
956 buffer_put_int(m, success);
957 if (success)
958 buffer_put_cstring(m, prompts[0]);
959
960 debug3("%s: sending challenge success: %u", __func__, success);
961 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
962
963 if (success) {
964 free(name);
965 free(infotxt);
966 free(prompts);
967 free(echo_on);
968 }
969
970 return (0);
971 }
972
973 int
mm_answer_bsdauthrespond(int sock,Buffer * m)974 mm_answer_bsdauthrespond(int sock, Buffer *m)
975 {
976 char *response;
977 int authok;
978
979 if (authctxt->as == 0)
980 fatal("%s: no bsd auth session", __func__);
981
982 response = buffer_get_string(m, NULL);
983 authok = options.challenge_response_authentication &&
984 auth_userresponse(authctxt->as, response, 0);
985 authctxt->as = NULL;
986 debug3("%s: <%s> = <%d>", __func__, response, authok);
987 free(response);
988
989 buffer_clear(m);
990 buffer_put_int(m, authok);
991
992 debug3("%s: sending authenticated: %d", __func__, authok);
993 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
994
995 if (compat20) {
996 auth_method = "keyboard-interactive";
997 auth_submethod = "bsdauth";
998 } else
999 auth_method = "bsdauth";
1000
1001 return (authok != 0);
1002 }
1003 #endif
1004
1005 #ifdef SKEY
1006 int
mm_answer_skeyquery(int sock,Buffer * m)1007 mm_answer_skeyquery(int sock, Buffer *m)
1008 {
1009 struct skey skey;
1010 char challenge[1024];
1011 u_int success;
1012
1013 success = _compat_skeychallenge(&skey, authctxt->user, challenge,
1014 sizeof(challenge)) < 0 ? 0 : 1;
1015
1016 buffer_clear(m);
1017 buffer_put_int(m, success);
1018 if (success)
1019 buffer_put_cstring(m, challenge);
1020
1021 debug3("%s: sending challenge success: %u", __func__, success);
1022 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
1023
1024 return (0);
1025 }
1026
1027 int
mm_answer_skeyrespond(int sock,Buffer * m)1028 mm_answer_skeyrespond(int sock, Buffer *m)
1029 {
1030 char *response;
1031 int authok;
1032
1033 response = buffer_get_string(m, NULL);
1034
1035 authok = (options.challenge_response_authentication &&
1036 authctxt->valid &&
1037 skey_haskey(authctxt->pw->pw_name) == 0 &&
1038 skey_passcheck(authctxt->pw->pw_name, response) != -1);
1039
1040 free(response);
1041
1042 buffer_clear(m);
1043 buffer_put_int(m, authok);
1044
1045 debug3("%s: sending authenticated: %d", __func__, authok);
1046 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
1047
1048 auth_method = "skey";
1049
1050 return (authok != 0);
1051 }
1052 #endif
1053
1054 #ifdef USE_PAM
1055 int
mm_answer_pam_start(int sock,Buffer * m)1056 mm_answer_pam_start(int sock, Buffer *m)
1057 {
1058 if (!options.use_pam)
1059 fatal("UsePAM not set, but ended up in %s anyway", __func__);
1060
1061 start_pam(authctxt);
1062
1063 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
1064
1065 return (0);
1066 }
1067
1068 int
mm_answer_pam_account(int sock,Buffer * m)1069 mm_answer_pam_account(int sock, Buffer *m)
1070 {
1071 u_int ret;
1072
1073 if (!options.use_pam)
1074 fatal("UsePAM not set, but ended up in %s anyway", __func__);
1075
1076 ret = do_pam_account();
1077
1078 buffer_put_int(m, ret);
1079 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1080
1081 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
1082
1083 return (ret);
1084 }
1085
1086 static void *sshpam_ctxt, *sshpam_authok;
1087 extern KbdintDevice sshpam_device;
1088
1089 int
mm_answer_pam_init_ctx(int sock,Buffer * m)1090 mm_answer_pam_init_ctx(int sock, Buffer *m)
1091 {
1092
1093 debug3("%s", __func__);
1094 authctxt->user = buffer_get_string(m, NULL);
1095 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
1096 sshpam_authok = NULL;
1097 buffer_clear(m);
1098 if (sshpam_ctxt != NULL) {
1099 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
1100 buffer_put_int(m, 1);
1101 } else {
1102 buffer_put_int(m, 0);
1103 }
1104 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
1105 return (0);
1106 }
1107
1108 int
mm_answer_pam_query(int sock,Buffer * m)1109 mm_answer_pam_query(int sock, Buffer *m)
1110 {
1111 char *name = NULL, *info = NULL, **prompts = NULL;
1112 u_int i, num = 0, *echo_on = 0;
1113 int ret;
1114
1115 debug3("%s", __func__);
1116 sshpam_authok = NULL;
1117 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
1118 if (ret == 0 && num == 0)
1119 sshpam_authok = sshpam_ctxt;
1120 if (num > 1 || name == NULL || info == NULL)
1121 ret = -1;
1122 buffer_clear(m);
1123 buffer_put_int(m, ret);
1124 buffer_put_cstring(m, name);
1125 free(name);
1126 buffer_put_cstring(m, info);
1127 free(info);
1128 buffer_put_int(m, num);
1129 for (i = 0; i < num; ++i) {
1130 buffer_put_cstring(m, prompts[i]);
1131 free(prompts[i]);
1132 buffer_put_int(m, echo_on[i]);
1133 }
1134 free(prompts);
1135 free(echo_on);
1136 auth_method = "keyboard-interactive";
1137 auth_submethod = "pam";
1138 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
1139 return (0);
1140 }
1141
1142 int
mm_answer_pam_respond(int sock,Buffer * m)1143 mm_answer_pam_respond(int sock, Buffer *m)
1144 {
1145 char **resp;
1146 u_int i, num;
1147 int ret;
1148
1149 debug3("%s", __func__);
1150 sshpam_authok = NULL;
1151 num = buffer_get_int(m);
1152 if (num > 0) {
1153 resp = xcalloc(num, sizeof(char *));
1154 for (i = 0; i < num; ++i)
1155 resp[i] = buffer_get_string(m, NULL);
1156 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
1157 for (i = 0; i < num; ++i)
1158 free(resp[i]);
1159 free(resp);
1160 } else {
1161 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
1162 }
1163 buffer_clear(m);
1164 buffer_put_int(m, ret);
1165 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
1166 auth_method = "keyboard-interactive";
1167 auth_submethod = "pam";
1168 if (ret == 0)
1169 sshpam_authok = sshpam_ctxt;
1170 return (0);
1171 }
1172
1173 int
mm_answer_pam_free_ctx(int sock,Buffer * m)1174 mm_answer_pam_free_ctx(int sock, Buffer *m)
1175 {
1176
1177 debug3("%s", __func__);
1178 (sshpam_device.free_ctx)(sshpam_ctxt);
1179 buffer_clear(m);
1180 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
1181 auth_method = "keyboard-interactive";
1182 auth_submethod = "pam";
1183 return (sshpam_authok == sshpam_ctxt);
1184 }
1185 #endif
1186
1187 int
mm_answer_keyallowed(int sock,Buffer * m)1188 mm_answer_keyallowed(int sock, Buffer *m)
1189 {
1190 Key *key;
1191 char *cuser, *chost;
1192 u_char *blob;
1193 u_int bloblen;
1194 enum mm_keytype type = 0;
1195 int allowed = 0;
1196
1197 debug3("%s entering", __func__);
1198
1199 type = buffer_get_int(m);
1200 cuser = buffer_get_string(m, NULL);
1201 chost = buffer_get_string(m, NULL);
1202 blob = buffer_get_string(m, &bloblen);
1203
1204 key = key_from_blob(blob, bloblen);
1205
1206 if ((compat20 && type == MM_RSAHOSTKEY) ||
1207 (!compat20 && type != MM_RSAHOSTKEY))
1208 fatal("%s: key type and protocol mismatch", __func__);
1209
1210 debug3("%s: key_from_blob: %p", __func__, key);
1211
1212 if (key != NULL && authctxt->valid) {
1213 /* These should not make it past the privsep child */
1214 if (key_type_plain(key->type) == KEY_RSA &&
1215 (datafellows & SSH_BUG_RSASIGMD5) != 0)
1216 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
1217
1218 switch (type) {
1219 case MM_USERKEY:
1220 allowed = options.pubkey_authentication &&
1221 !auth2_userkey_already_used(authctxt, key) &&
1222 match_pattern_list(sshkey_ssh_name(key),
1223 options.pubkey_key_types,
1224 strlen(options.pubkey_key_types), 0) == 1 &&
1225 user_key_allowed(authctxt->pw, key);
1226 pubkey_auth_info(authctxt, key, NULL);
1227 auth_method = "publickey";
1228 if (options.pubkey_authentication && allowed != 1)
1229 auth_clear_options();
1230 break;
1231 case MM_HOSTKEY:
1232 allowed = options.hostbased_authentication &&
1233 match_pattern_list(sshkey_ssh_name(key),
1234 options.hostbased_key_types,
1235 strlen(options.hostbased_key_types), 0) == 1 &&
1236 hostbased_key_allowed(authctxt->pw,
1237 cuser, chost, key);
1238 pubkey_auth_info(authctxt, key,
1239 "client user \"%.100s\", client host \"%.100s\"",
1240 cuser, chost);
1241 auth_method = "hostbased";
1242 break;
1243 #ifdef WITH_SSH1
1244 case MM_RSAHOSTKEY:
1245 key->type = KEY_RSA1; /* XXX */
1246 allowed = options.rhosts_rsa_authentication &&
1247 auth_rhosts_rsa_key_allowed(authctxt->pw,
1248 cuser, chost, key);
1249 if (options.rhosts_rsa_authentication && allowed != 1)
1250 auth_clear_options();
1251 auth_method = "rsa";
1252 break;
1253 #endif
1254 default:
1255 fatal("%s: unknown key type %d", __func__, type);
1256 break;
1257 }
1258 }
1259 if (key != NULL)
1260 key_free(key);
1261
1262 /* clear temporarily storage (used by verify) */
1263 monitor_reset_key_state();
1264
1265 if (allowed) {
1266 /* Save temporarily for comparison in verify */
1267 key_blob = blob;
1268 key_bloblen = bloblen;
1269 key_blobtype = type;
1270 hostbased_cuser = cuser;
1271 hostbased_chost = chost;
1272 } else {
1273 /* Log failed attempt */
1274 auth_log(authctxt, 0, 0, auth_method, NULL);
1275 free(blob);
1276 free(cuser);
1277 free(chost);
1278 }
1279
1280 debug3("%s: key %p is %s",
1281 __func__, key, allowed ? "allowed" : "not allowed");
1282
1283 buffer_clear(m);
1284 buffer_put_int(m, allowed);
1285 buffer_put_int(m, forced_command != NULL);
1286
1287 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1288
1289 if (type == MM_RSAHOSTKEY)
1290 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1291
1292 return (0);
1293 }
1294
1295 static int
monitor_valid_userblob(u_char * data,u_int datalen)1296 monitor_valid_userblob(u_char *data, u_int datalen)
1297 {
1298 Buffer b;
1299 char *p, *userstyle;
1300 u_int len;
1301 int fail = 0;
1302
1303 buffer_init(&b);
1304 buffer_append(&b, data, datalen);
1305
1306 if (datafellows & SSH_OLD_SESSIONID) {
1307 p = buffer_ptr(&b);
1308 len = buffer_len(&b);
1309 if ((session_id2 == NULL) ||
1310 (len < session_id2_len) ||
1311 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1312 fail++;
1313 buffer_consume(&b, session_id2_len);
1314 } else {
1315 p = buffer_get_string(&b, &len);
1316 if ((session_id2 == NULL) ||
1317 (len != session_id2_len) ||
1318 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1319 fail++;
1320 free(p);
1321 }
1322 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1323 fail++;
1324 p = buffer_get_cstring(&b, NULL);
1325 xasprintf(&userstyle, "%s%s%s", authctxt->user,
1326 authctxt->style ? ":" : "",
1327 authctxt->style ? authctxt->style : "");
1328 if (strcmp(userstyle, p) != 0) {
1329 logit("wrong user name passed to monitor: expected %s != %.100s",
1330 userstyle, p);
1331 fail++;
1332 }
1333 free(userstyle);
1334 free(p);
1335 buffer_skip_string(&b);
1336 if (datafellows & SSH_BUG_PKAUTH) {
1337 if (!buffer_get_char(&b))
1338 fail++;
1339 } else {
1340 p = buffer_get_cstring(&b, NULL);
1341 if (strcmp("publickey", p) != 0)
1342 fail++;
1343 free(p);
1344 if (!buffer_get_char(&b))
1345 fail++;
1346 buffer_skip_string(&b);
1347 }
1348 buffer_skip_string(&b);
1349 if (buffer_len(&b) != 0)
1350 fail++;
1351 buffer_free(&b);
1352 return (fail == 0);
1353 }
1354
1355 static int
monitor_valid_hostbasedblob(u_char * data,u_int datalen,char * cuser,char * chost)1356 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1357 char *chost)
1358 {
1359 Buffer b;
1360 char *p, *userstyle;
1361 u_int len;
1362 int fail = 0;
1363
1364 buffer_init(&b);
1365 buffer_append(&b, data, datalen);
1366
1367 p = buffer_get_string(&b, &len);
1368 if ((session_id2 == NULL) ||
1369 (len != session_id2_len) ||
1370 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1371 fail++;
1372 free(p);
1373
1374 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1375 fail++;
1376 p = buffer_get_cstring(&b, NULL);
1377 xasprintf(&userstyle, "%s%s%s", authctxt->user,
1378 authctxt->style ? ":" : "",
1379 authctxt->style ? authctxt->style : "");
1380 if (strcmp(userstyle, p) != 0) {
1381 logit("wrong user name passed to monitor: expected %s != %.100s",
1382 userstyle, p);
1383 fail++;
1384 }
1385 free(userstyle);
1386 free(p);
1387 buffer_skip_string(&b); /* service */
1388 p = buffer_get_cstring(&b, NULL);
1389 if (strcmp(p, "hostbased") != 0)
1390 fail++;
1391 free(p);
1392 buffer_skip_string(&b); /* pkalg */
1393 buffer_skip_string(&b); /* pkblob */
1394
1395 /* verify client host, strip trailing dot if necessary */
1396 p = buffer_get_string(&b, NULL);
1397 if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1398 p[len - 1] = '\0';
1399 if (strcmp(p, chost) != 0)
1400 fail++;
1401 free(p);
1402
1403 /* verify client user */
1404 p = buffer_get_string(&b, NULL);
1405 if (strcmp(p, cuser) != 0)
1406 fail++;
1407 free(p);
1408
1409 if (buffer_len(&b) != 0)
1410 fail++;
1411 buffer_free(&b);
1412 return (fail == 0);
1413 }
1414
1415 int
mm_answer_keyverify(int sock,Buffer * m)1416 mm_answer_keyverify(int sock, Buffer *m)
1417 {
1418 Key *key;
1419 u_char *signature, *data, *blob;
1420 u_int signaturelen, datalen, bloblen;
1421 int verified = 0;
1422 int valid_data = 0;
1423
1424 blob = buffer_get_string(m, &bloblen);
1425 signature = buffer_get_string(m, &signaturelen);
1426 data = buffer_get_string(m, &datalen);
1427
1428 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1429 !monitor_allowed_key(blob, bloblen))
1430 fatal("%s: bad key, not previously allowed", __func__);
1431
1432 key = key_from_blob(blob, bloblen);
1433 if (key == NULL)
1434 fatal("%s: bad public key blob", __func__);
1435
1436 switch (key_blobtype) {
1437 case MM_USERKEY:
1438 valid_data = monitor_valid_userblob(data, datalen);
1439 break;
1440 case MM_HOSTKEY:
1441 valid_data = monitor_valid_hostbasedblob(data, datalen,
1442 hostbased_cuser, hostbased_chost);
1443 break;
1444 default:
1445 valid_data = 0;
1446 break;
1447 }
1448 if (!valid_data)
1449 fatal("%s: bad signature data blob", __func__);
1450
1451 verified = key_verify(key, signature, signaturelen, data, datalen);
1452 debug3("%s: key %p signature %s",
1453 __func__, key, (verified == 1) ? "verified" : "unverified");
1454
1455 /* If auth was successful then record key to ensure it isn't reused */
1456 if (verified == 1)
1457 auth2_record_userkey(authctxt, key);
1458 else
1459 key_free(key);
1460
1461 free(blob);
1462 free(signature);
1463 free(data);
1464
1465 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1466
1467 monitor_reset_key_state();
1468
1469 buffer_clear(m);
1470 buffer_put_int(m, verified);
1471 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1472
1473 return (verified == 1);
1474 }
1475
1476 static void
mm_record_login(Session * s,struct passwd * pw)1477 mm_record_login(Session *s, struct passwd *pw)
1478 {
1479 socklen_t fromlen;
1480 struct sockaddr_storage from;
1481
1482 /*
1483 * Get IP address of client. If the connection is not a socket, let
1484 * the address be 0.0.0.0.
1485 */
1486 memset(&from, 0, sizeof(from));
1487 fromlen = sizeof(from);
1488 if (packet_connection_is_on_socket()) {
1489 if (getpeername(packet_get_connection_in(),
1490 (struct sockaddr *)&from, &fromlen) < 0) {
1491 debug("getpeername: %.100s", strerror(errno));
1492 cleanup_exit(255);
1493 }
1494 }
1495 /* Record that there was a login on that tty from the remote host. */
1496 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1497 get_remote_name_or_ip(utmp_len, options.use_dns),
1498 (struct sockaddr *)&from, fromlen);
1499 }
1500
1501 static void
mm_session_close(Session * s)1502 mm_session_close(Session *s)
1503 {
1504 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1505 if (s->ttyfd != -1) {
1506 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1507 session_pty_cleanup2(s);
1508 }
1509 session_unused(s->self);
1510 }
1511
1512 int
mm_answer_pty(int sock,Buffer * m)1513 mm_answer_pty(int sock, Buffer *m)
1514 {
1515 extern struct monitor *pmonitor;
1516 Session *s;
1517 int res, fd0;
1518
1519 debug3("%s entering", __func__);
1520
1521 buffer_clear(m);
1522 s = session_new();
1523 if (s == NULL)
1524 goto error;
1525 s->authctxt = authctxt;
1526 s->pw = authctxt->pw;
1527 s->pid = pmonitor->m_pid;
1528 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1529 if (res == 0)
1530 goto error;
1531 pty_setowner(authctxt->pw, s->tty);
1532
1533 buffer_put_int(m, 1);
1534 buffer_put_cstring(m, s->tty);
1535
1536 /* We need to trick ttyslot */
1537 if (dup2(s->ttyfd, 0) == -1)
1538 fatal("%s: dup2", __func__);
1539
1540 mm_record_login(s, authctxt->pw);
1541
1542 /* Now we can close the file descriptor again */
1543 close(0);
1544
1545 /* send messages generated by record_login */
1546 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1547 buffer_clear(&loginmsg);
1548
1549 mm_request_send(sock, MONITOR_ANS_PTY, m);
1550
1551 if (mm_send_fd(sock, s->ptyfd) == -1 ||
1552 mm_send_fd(sock, s->ttyfd) == -1)
1553 fatal("%s: send fds failed", __func__);
1554
1555 /* make sure nothing uses fd 0 */
1556 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1557 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1558 if (fd0 != 0)
1559 error("%s: fd0 %d != 0", __func__, fd0);
1560
1561 /* slave is not needed */
1562 close(s->ttyfd);
1563 s->ttyfd = s->ptyfd;
1564 /* no need to dup() because nobody closes ptyfd */
1565 s->ptymaster = s->ptyfd;
1566
1567 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1568
1569 return (0);
1570
1571 error:
1572 if (s != NULL)
1573 mm_session_close(s);
1574 buffer_put_int(m, 0);
1575 mm_request_send(sock, MONITOR_ANS_PTY, m);
1576 return (0);
1577 }
1578
1579 int
mm_answer_pty_cleanup(int sock,Buffer * m)1580 mm_answer_pty_cleanup(int sock, Buffer *m)
1581 {
1582 Session *s;
1583 char *tty;
1584
1585 debug3("%s entering", __func__);
1586
1587 tty = buffer_get_string(m, NULL);
1588 if ((s = session_by_tty(tty)) != NULL)
1589 mm_session_close(s);
1590 buffer_clear(m);
1591 free(tty);
1592 return (0);
1593 }
1594
1595 #ifdef WITH_SSH1
1596 int
mm_answer_sesskey(int sock,Buffer * m)1597 mm_answer_sesskey(int sock, Buffer *m)
1598 {
1599 BIGNUM *p;
1600 int rsafail;
1601
1602 /* Turn off permissions */
1603 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1604
1605 if ((p = BN_new()) == NULL)
1606 fatal("%s: BN_new", __func__);
1607
1608 buffer_get_bignum2(m, p);
1609
1610 rsafail = ssh1_session_key(p);
1611
1612 buffer_clear(m);
1613 buffer_put_int(m, rsafail);
1614 buffer_put_bignum2(m, p);
1615
1616 BN_clear_free(p);
1617
1618 mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1619
1620 /* Turn on permissions for sessid passing */
1621 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1622
1623 return (0);
1624 }
1625
1626 int
mm_answer_sessid(int sock,Buffer * m)1627 mm_answer_sessid(int sock, Buffer *m)
1628 {
1629 int i;
1630
1631 debug3("%s entering", __func__);
1632
1633 if (buffer_len(m) != 16)
1634 fatal("%s: bad ssh1 session id", __func__);
1635 for (i = 0; i < 16; i++)
1636 session_id[i] = buffer_get_char(m);
1637
1638 /* Turn on permissions for getpwnam */
1639 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1640
1641 return (0);
1642 }
1643
1644 int
mm_answer_rsa_keyallowed(int sock,Buffer * m)1645 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1646 {
1647 BIGNUM *client_n;
1648 Key *key = NULL;
1649 u_char *blob = NULL;
1650 u_int blen = 0;
1651 int allowed = 0;
1652
1653 debug3("%s entering", __func__);
1654
1655 auth_method = "rsa";
1656 if (options.rsa_authentication && authctxt->valid) {
1657 if ((client_n = BN_new()) == NULL)
1658 fatal("%s: BN_new", __func__);
1659 buffer_get_bignum2(m, client_n);
1660 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1661 BN_clear_free(client_n);
1662 }
1663 buffer_clear(m);
1664 buffer_put_int(m, allowed);
1665 buffer_put_int(m, forced_command != NULL);
1666
1667 /* clear temporarily storage (used by generate challenge) */
1668 monitor_reset_key_state();
1669
1670 if (allowed && key != NULL) {
1671 key->type = KEY_RSA; /* cheat for key_to_blob */
1672 if (key_to_blob(key, &blob, &blen) == 0)
1673 fatal("%s: key_to_blob failed", __func__);
1674 buffer_put_string(m, blob, blen);
1675
1676 /* Save temporarily for comparison in verify */
1677 key_blob = blob;
1678 key_bloblen = blen;
1679 key_blobtype = MM_RSAUSERKEY;
1680 }
1681 if (key != NULL)
1682 key_free(key);
1683
1684 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1685
1686 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1687 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1688 return (0);
1689 }
1690
1691 int
mm_answer_rsa_challenge(int sock,Buffer * m)1692 mm_answer_rsa_challenge(int sock, Buffer *m)
1693 {
1694 Key *key = NULL;
1695 u_char *blob;
1696 u_int blen;
1697
1698 debug3("%s entering", __func__);
1699
1700 if (!authctxt->valid)
1701 fatal("%s: authctxt not valid", __func__);
1702 blob = buffer_get_string(m, &blen);
1703 if (!monitor_allowed_key(blob, blen))
1704 fatal("%s: bad key, not previously allowed", __func__);
1705 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1706 fatal("%s: key type mismatch", __func__);
1707 if ((key = key_from_blob(blob, blen)) == NULL)
1708 fatal("%s: received bad key", __func__);
1709 if (key->type != KEY_RSA)
1710 fatal("%s: received bad key type %d", __func__, key->type);
1711 key->type = KEY_RSA1;
1712 if (ssh1_challenge)
1713 BN_clear_free(ssh1_challenge);
1714 ssh1_challenge = auth_rsa_generate_challenge(key);
1715
1716 buffer_clear(m);
1717 buffer_put_bignum2(m, ssh1_challenge);
1718
1719 debug3("%s sending reply", __func__);
1720 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1721
1722 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1723
1724 free(blob);
1725 key_free(key);
1726 return (0);
1727 }
1728
1729 int
mm_answer_rsa_response(int sock,Buffer * m)1730 mm_answer_rsa_response(int sock, Buffer *m)
1731 {
1732 Key *key = NULL;
1733 u_char *blob, *response;
1734 u_int blen, len;
1735 int success;
1736
1737 debug3("%s entering", __func__);
1738
1739 if (!authctxt->valid)
1740 fatal("%s: authctxt not valid", __func__);
1741 if (ssh1_challenge == NULL)
1742 fatal("%s: no ssh1_challenge", __func__);
1743
1744 blob = buffer_get_string(m, &blen);
1745 if (!monitor_allowed_key(blob, blen))
1746 fatal("%s: bad key, not previously allowed", __func__);
1747 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1748 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1749 if ((key = key_from_blob(blob, blen)) == NULL)
1750 fatal("%s: received bad key", __func__);
1751 response = buffer_get_string(m, &len);
1752 if (len != 16)
1753 fatal("%s: received bad response to challenge", __func__);
1754 success = auth_rsa_verify_response(key, ssh1_challenge, response);
1755
1756 free(blob);
1757 key_free(key);
1758 free(response);
1759
1760 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1761
1762 /* reset state */
1763 BN_clear_free(ssh1_challenge);
1764 ssh1_challenge = NULL;
1765 monitor_reset_key_state();
1766
1767 buffer_clear(m);
1768 buffer_put_int(m, success);
1769 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1770
1771 return (success);
1772 }
1773 #endif
1774
1775 int
mm_answer_term(int sock,Buffer * req)1776 mm_answer_term(int sock, Buffer *req)
1777 {
1778 extern struct monitor *pmonitor;
1779 int res, status;
1780
1781 debug3("%s: tearing down sessions", __func__);
1782
1783 /* The child is terminating */
1784 session_destroy_all(&mm_session_close);
1785
1786 #ifdef USE_PAM
1787 if (options.use_pam)
1788 sshpam_cleanup();
1789 #endif
1790
1791 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1792 if (errno != EINTR)
1793 exit(1);
1794
1795 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1796
1797 /* Terminate process */
1798 exit(res);
1799 }
1800
1801 #ifdef SSH_AUDIT_EVENTS
1802 /* Report that an audit event occurred */
1803 int
mm_answer_audit_event(int socket,Buffer * m)1804 mm_answer_audit_event(int socket, Buffer *m)
1805 {
1806 ssh_audit_event_t event;
1807
1808 debug3("%s entering", __func__);
1809
1810 event = buffer_get_int(m);
1811 switch(event) {
1812 case SSH_AUTH_FAIL_PUBKEY:
1813 case SSH_AUTH_FAIL_HOSTBASED:
1814 case SSH_AUTH_FAIL_GSSAPI:
1815 case SSH_LOGIN_EXCEED_MAXTRIES:
1816 case SSH_LOGIN_ROOT_DENIED:
1817 case SSH_CONNECTION_CLOSE:
1818 case SSH_INVALID_USER:
1819 audit_event(event);
1820 break;
1821 default:
1822 fatal("Audit event type %d not permitted", event);
1823 }
1824
1825 return (0);
1826 }
1827
1828 int
mm_answer_audit_command(int socket,Buffer * m)1829 mm_answer_audit_command(int socket, Buffer *m)
1830 {
1831 u_int len;
1832 char *cmd;
1833
1834 debug3("%s entering", __func__);
1835 cmd = buffer_get_string(m, &len);
1836 /* sanity check command, if so how? */
1837 audit_run_command(cmd);
1838 free(cmd);
1839 return (0);
1840 }
1841 #endif /* SSH_AUDIT_EVENTS */
1842
1843 void
monitor_apply_keystate(struct monitor * pmonitor)1844 monitor_apply_keystate(struct monitor *pmonitor)
1845 {
1846 struct ssh *ssh = active_state; /* XXX */
1847 struct kex *kex;
1848 int r;
1849
1850 debug3("%s: packet_set_state", __func__);
1851 if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
1852 fatal("%s: packet_set_state: %s", __func__, ssh_err(r));
1853 sshbuf_free(child_state);
1854 child_state = NULL;
1855
1856 if ((kex = ssh->kex) != 0) {
1857 /* XXX set callbacks */
1858 #ifdef WITH_OPENSSL
1859 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1860 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1861 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1862 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1863 # ifdef OPENSSL_HAS_ECC
1864 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1865 # endif
1866 #endif /* WITH_OPENSSL */
1867 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
1868 kex->load_host_public_key=&get_hostkey_public_by_type;
1869 kex->load_host_private_key=&get_hostkey_private_by_type;
1870 kex->host_key_index=&get_hostkey_index;
1871 kex->sign = sshd_hostkey_sign;
1872 }
1873
1874 /* Update with new address */
1875 if (options.compression) {
1876 ssh_packet_set_compress_hooks(ssh, pmonitor->m_zlib,
1877 (ssh_packet_comp_alloc_func *)mm_zalloc,
1878 (ssh_packet_comp_free_func *)mm_zfree);
1879 }
1880 }
1881
1882 /* This function requries careful sanity checking */
1883
1884 void
mm_get_keystate(struct monitor * pmonitor)1885 mm_get_keystate(struct monitor *pmonitor)
1886 {
1887 debug3("%s: Waiting for new keys", __func__);
1888
1889 if ((child_state = sshbuf_new()) == NULL)
1890 fatal("%s: sshbuf_new failed", __func__);
1891 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
1892 child_state);
1893 debug3("%s: GOT new keys", __func__);
1894 }
1895
1896
1897 /* XXX */
1898
1899 #define FD_CLOSEONEXEC(x) do { \
1900 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1901 fatal("fcntl(%d, F_SETFD)", x); \
1902 } while (0)
1903
1904 static void
monitor_openfds(struct monitor * mon,int do_logfds)1905 monitor_openfds(struct monitor *mon, int do_logfds)
1906 {
1907 int pair[2];
1908
1909 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1910 fatal("%s: socketpair: %s", __func__, strerror(errno));
1911 FD_CLOSEONEXEC(pair[0]);
1912 FD_CLOSEONEXEC(pair[1]);
1913 mon->m_recvfd = pair[0];
1914 mon->m_sendfd = pair[1];
1915
1916 if (do_logfds) {
1917 if (pipe(pair) == -1)
1918 fatal("%s: pipe: %s", __func__, strerror(errno));
1919 FD_CLOSEONEXEC(pair[0]);
1920 FD_CLOSEONEXEC(pair[1]);
1921 mon->m_log_recvfd = pair[0];
1922 mon->m_log_sendfd = pair[1];
1923 } else
1924 mon->m_log_recvfd = mon->m_log_sendfd = -1;
1925 }
1926
1927 #define MM_MEMSIZE 65536
1928
1929 struct monitor *
monitor_init(void)1930 monitor_init(void)
1931 {
1932 struct ssh *ssh = active_state; /* XXX */
1933 struct monitor *mon;
1934
1935 mon = xcalloc(1, sizeof(*mon));
1936
1937 monitor_openfds(mon, 1);
1938
1939 /* Used to share zlib space across processes */
1940 if (options.compression) {
1941 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1942 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1943
1944 /* Compression needs to share state across borders */
1945 ssh_packet_set_compress_hooks(ssh, mon->m_zlib,
1946 (ssh_packet_comp_alloc_func *)mm_zalloc,
1947 (ssh_packet_comp_free_func *)mm_zfree);
1948 }
1949
1950 return mon;
1951 }
1952
1953 void
monitor_reinit(struct monitor * mon)1954 monitor_reinit(struct monitor *mon)
1955 {
1956 monitor_openfds(mon, 0);
1957 }
1958
1959 #ifdef GSSAPI
1960 int
mm_answer_gss_setup_ctx(int sock,Buffer * m)1961 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1962 {
1963 gss_OID_desc goid;
1964 OM_uint32 major;
1965 u_int len;
1966
1967 goid.elements = buffer_get_string(m, &len);
1968 goid.length = len;
1969
1970 major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1971
1972 free(goid.elements);
1973
1974 buffer_clear(m);
1975 buffer_put_int(m, major);
1976
1977 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1978
1979 /* Now we have a context, enable the step */
1980 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1981
1982 return (0);
1983 }
1984
1985 int
mm_answer_gss_accept_ctx(int sock,Buffer * m)1986 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1987 {
1988 gss_buffer_desc in;
1989 gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1990 OM_uint32 major, minor;
1991 OM_uint32 flags = 0; /* GSI needs this */
1992 u_int len;
1993
1994 in.value = buffer_get_string(m, &len);
1995 in.length = len;
1996 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1997 free(in.value);
1998
1999 buffer_clear(m);
2000 buffer_put_int(m, major);
2001 buffer_put_string(m, out.value, out.length);
2002 buffer_put_int(m, flags);
2003 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
2004
2005 gss_release_buffer(&minor, &out);
2006
2007 if (major == GSS_S_COMPLETE) {
2008 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
2009 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2010 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
2011 }
2012 return (0);
2013 }
2014
2015 int
mm_answer_gss_checkmic(int sock,Buffer * m)2016 mm_answer_gss_checkmic(int sock, Buffer *m)
2017 {
2018 gss_buffer_desc gssbuf, mic;
2019 OM_uint32 ret;
2020 u_int len;
2021
2022 gssbuf.value = buffer_get_string(m, &len);
2023 gssbuf.length = len;
2024 mic.value = buffer_get_string(m, &len);
2025 mic.length = len;
2026
2027 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
2028
2029 free(gssbuf.value);
2030 free(mic.value);
2031
2032 buffer_clear(m);
2033 buffer_put_int(m, ret);
2034
2035 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
2036
2037 if (!GSS_ERROR(ret))
2038 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2039
2040 return (0);
2041 }
2042
2043 int
mm_answer_gss_userok(int sock,Buffer * m)2044 mm_answer_gss_userok(int sock, Buffer *m)
2045 {
2046 int authenticated;
2047
2048 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2049
2050 buffer_clear(m);
2051 buffer_put_int(m, authenticated);
2052
2053 debug3("%s: sending result %d", __func__, authenticated);
2054 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
2055
2056 auth_method = "gssapi-with-mic";
2057
2058 /* Monitor loop will terminate if authenticated */
2059 return (authenticated);
2060 }
2061 #endif /* GSSAPI */
2062
2063