1 /* $OpenBSD: monitor.c,v 1.131 2014/02/02 03:44:31 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/param.h>
32 #include <sys/socket.h>
33 #include "openbsd-compat/sys-tree.h"
34 #include <sys/wait.h>
35
36 #include <errno.h>
37 #include <fcntl.h>
38 #ifdef HAVE_PATHS_H
39 #include <paths.h>
40 #endif
41 #include <pwd.h>
42 #include <signal.h>
43 #include <stdarg.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #ifdef HAVE_POLL_H
48 #include <poll.h>
49 #else
50 # ifdef HAVE_SYS_POLL_H
51 # include <sys/poll.h>
52 # endif
53 #endif
54
55 #ifdef SKEY
56 #include <skey.h>
57 #endif
58
59 #include <openssl/dh.h>
60
61 #include "openbsd-compat/sys-queue.h"
62 #include "atomicio.h"
63 #include "xmalloc.h"
64 #include "ssh.h"
65 #include "key.h"
66 #include "buffer.h"
67 #include "hostfile.h"
68 #include "auth.h"
69 #include "cipher.h"
70 #include "kex.h"
71 #include "dh.h"
72 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */
73 #undef TARGET_OS_MAC
74 #include "zlib.h"
75 #define TARGET_OS_MAC 1
76 #else
77 #include "zlib.h"
78 #endif
79 #include "packet.h"
80 #include "auth-options.h"
81 #include "sshpty.h"
82 #include "channels.h"
83 #include "session.h"
84 #include "sshlogin.h"
85 #include "canohost.h"
86 #include "log.h"
87 #include "servconf.h"
88 #include "monitor.h"
89 #include "monitor_mm.h"
90 #ifdef GSSAPI
91 #include "ssh-gss.h"
92 #endif
93 #include "monitor_wrap.h"
94 #include "monitor_fdpass.h"
95 #include "misc.h"
96 #include "compat.h"
97 #include "ssh2.h"
98 #include "roaming.h"
99 #include "authfd.h"
100
101 #ifdef GSSAPI
102 static Gssctxt *gsscontext = NULL;
103 #endif
104
105 /* Imports */
106 extern ServerOptions options;
107 extern u_int utmp_len;
108 extern Newkeys *current_keys[];
109 extern z_stream incoming_stream;
110 extern z_stream outgoing_stream;
111 extern u_char session_id[];
112 extern Buffer auth_debug;
113 extern int auth_debug_init;
114 extern Buffer loginmsg;
115
116 /* State exported from the child */
117
118 struct {
119 z_stream incoming;
120 z_stream outgoing;
121 u_char *keyin;
122 u_int keyinlen;
123 u_char *keyout;
124 u_int keyoutlen;
125 u_char *ivin;
126 u_int ivinlen;
127 u_char *ivout;
128 u_int ivoutlen;
129 u_char *ssh1key;
130 u_int ssh1keylen;
131 int ssh1cipher;
132 int ssh1protoflags;
133 u_char *input;
134 u_int ilen;
135 u_char *output;
136 u_int olen;
137 u_int64_t sent_bytes;
138 u_int64_t recv_bytes;
139 } child_state;
140
141 /* Functions on the monitor that answer unprivileged requests */
142
143 int mm_answer_moduli(int, Buffer *);
144 int mm_answer_sign(int, Buffer *);
145 int mm_answer_pwnamallow(int, Buffer *);
146 int mm_answer_auth2_read_banner(int, Buffer *);
147 int mm_answer_authserv(int, Buffer *);
148 int mm_answer_authpassword(int, Buffer *);
149 int mm_answer_bsdauthquery(int, Buffer *);
150 int mm_answer_bsdauthrespond(int, Buffer *);
151 int mm_answer_skeyquery(int, Buffer *);
152 int mm_answer_skeyrespond(int, Buffer *);
153 int mm_answer_keyallowed(int, Buffer *);
154 int mm_answer_keyverify(int, Buffer *);
155 int mm_answer_pty(int, Buffer *);
156 int mm_answer_pty_cleanup(int, Buffer *);
157 int mm_answer_term(int, Buffer *);
158 int mm_answer_rsa_keyallowed(int, Buffer *);
159 int mm_answer_rsa_challenge(int, Buffer *);
160 int mm_answer_rsa_response(int, Buffer *);
161 int mm_answer_sesskey(int, Buffer *);
162 int mm_answer_sessid(int, Buffer *);
163
164 #ifdef USE_PAM
165 int mm_answer_pam_start(int, Buffer *);
166 int mm_answer_pam_account(int, Buffer *);
167 int mm_answer_pam_init_ctx(int, Buffer *);
168 int mm_answer_pam_query(int, Buffer *);
169 int mm_answer_pam_respond(int, Buffer *);
170 int mm_answer_pam_free_ctx(int, Buffer *);
171 #endif
172
173 #ifdef GSSAPI
174 int mm_answer_gss_setup_ctx(int, Buffer *);
175 int mm_answer_gss_accept_ctx(int, Buffer *);
176 int mm_answer_gss_userok(int, Buffer *);
177 int mm_answer_gss_checkmic(int, Buffer *);
178 #endif
179
180 #ifdef SSH_AUDIT_EVENTS
181 int mm_answer_audit_event(int, Buffer *);
182 int mm_answer_audit_command(int, Buffer *);
183 #endif
184
185 static int monitor_read_log(struct monitor *);
186
187 static Authctxt *authctxt;
188 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
189
190 /* local state for key verify */
191 static u_char *key_blob = NULL;
192 static u_int key_bloblen = 0;
193 static int key_blobtype = MM_NOKEY;
194 static char *hostbased_cuser = NULL;
195 static char *hostbased_chost = NULL;
196 static char *auth_method = "unknown";
197 static char *auth_submethod = NULL;
198 static u_int session_id2_len = 0;
199 static u_char *session_id2 = NULL;
200 static pid_t monitor_child_pid;
201
202 struct mon_table {
203 enum monitor_reqtype type;
204 int flags;
205 int (*f)(int, Buffer *);
206 };
207
208 #define MON_ISAUTH 0x0004 /* Required for Authentication */
209 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
210 #define MON_ONCE 0x0010 /* Disable after calling */
211 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
212
213 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
214
215 #define MON_PERMIT 0x1000 /* Request is permitted */
216
217 struct mon_table mon_dispatch_proto20[] = {
218 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
219 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
220 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
221 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
222 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
223 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
224 #ifdef USE_PAM
225 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
226 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
227 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
228 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
229 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
230 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
231 #endif
232 #ifdef SSH_AUDIT_EVENTS
233 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
234 #endif
235 #ifdef BSD_AUTH
236 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
237 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
238 #endif
239 #ifdef SKEY
240 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
241 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
242 #endif
243 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
244 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
245 #ifdef GSSAPI
246 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
247 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
248 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
249 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
250 #endif
251 {0, 0, NULL}
252 };
253
254 struct mon_table mon_dispatch_postauth20[] = {
255 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
256 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
257 {MONITOR_REQ_PTY, 0, mm_answer_pty},
258 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
259 {MONITOR_REQ_TERM, 0, mm_answer_term},
260 #ifdef SSH_AUDIT_EVENTS
261 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
262 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
263 #endif
264 {0, 0, NULL}
265 };
266
267 struct mon_table mon_dispatch_proto15[] = {
268 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
269 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
270 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
271 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
272 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
273 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
274 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
275 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
276 #ifdef BSD_AUTH
277 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
278 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
279 #endif
280 #ifdef SKEY
281 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
282 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
283 #endif
284 #ifdef USE_PAM
285 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
286 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
287 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
288 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
289 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
290 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
291 #endif
292 #ifdef SSH_AUDIT_EVENTS
293 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
294 #endif
295 {0, 0, NULL}
296 };
297
298 struct mon_table mon_dispatch_postauth15[] = {
299 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
300 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
301 {MONITOR_REQ_TERM, 0, mm_answer_term},
302 #ifdef SSH_AUDIT_EVENTS
303 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
304 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
305 #endif
306 {0, 0, NULL}
307 };
308
309 struct mon_table *mon_dispatch;
310
311 /* Specifies if a certain message is allowed at the moment */
312
313 static void
monitor_permit(struct mon_table * ent,enum monitor_reqtype type,int permit)314 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
315 {
316 while (ent->f != NULL) {
317 if (ent->type == type) {
318 ent->flags &= ~MON_PERMIT;
319 ent->flags |= permit ? MON_PERMIT : 0;
320 return;
321 }
322 ent++;
323 }
324 }
325
326 static void
monitor_permit_authentications(int permit)327 monitor_permit_authentications(int permit)
328 {
329 struct mon_table *ent = mon_dispatch;
330
331 while (ent->f != NULL) {
332 if (ent->flags & MON_AUTH) {
333 ent->flags &= ~MON_PERMIT;
334 ent->flags |= permit ? MON_PERMIT : 0;
335 }
336 ent++;
337 }
338 }
339
340 void
monitor_child_preauth(Authctxt * _authctxt,struct monitor * pmonitor)341 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
342 {
343 struct mon_table *ent;
344 int authenticated = 0, partial = 0;
345
346 debug3("preauth child monitor started");
347
348 close(pmonitor->m_recvfd);
349 close(pmonitor->m_log_sendfd);
350 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
351
352 authctxt = _authctxt;
353 memset(authctxt, 0, sizeof(*authctxt));
354
355 authctxt->loginmsg = &loginmsg;
356
357 if (compat20) {
358 mon_dispatch = mon_dispatch_proto20;
359
360 /* Permit requests for moduli and signatures */
361 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
362 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
363 } else {
364 mon_dispatch = mon_dispatch_proto15;
365
366 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
367 }
368
369 /* The first few requests do not require asynchronous access */
370 while (!authenticated) {
371 partial = 0;
372 auth_method = "unknown";
373 auth_submethod = NULL;
374 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
375
376 /* Special handling for multiple required authentications */
377 if (options.num_auth_methods != 0) {
378 if (!compat20)
379 fatal("AuthenticationMethods is not supported"
380 "with SSH protocol 1");
381 if (authenticated &&
382 !auth2_update_methods_lists(authctxt,
383 auth_method, auth_submethod)) {
384 debug3("%s: method %s: partial", __func__,
385 auth_method);
386 authenticated = 0;
387 partial = 1;
388 }
389 }
390
391 if (authenticated) {
392 if (!(ent->flags & MON_AUTHDECIDE))
393 fatal("%s: unexpected authentication from %d",
394 __func__, ent->type);
395 if (authctxt->pw->pw_uid == 0 &&
396 !auth_root_allowed(auth_method))
397 authenticated = 0;
398 #ifdef USE_PAM
399 /* PAM needs to perform account checks after auth */
400 if (options.use_pam && authenticated) {
401 Buffer m;
402
403 buffer_init(&m);
404 mm_request_receive_expect(pmonitor->m_sendfd,
405 MONITOR_REQ_PAM_ACCOUNT, &m);
406 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
407 buffer_free(&m);
408 }
409 #endif
410 }
411 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
412 auth_log(authctxt, authenticated, partial,
413 auth_method, auth_submethod);
414 if (!authenticated)
415 authctxt->failures++;
416 }
417 }
418
419 if (!authctxt->valid)
420 fatal("%s: authenticated invalid user", __func__);
421 if (strcmp(auth_method, "unknown") == 0)
422 fatal("%s: authentication method name unknown", __func__);
423
424 debug("%s: %s has been authenticated by privileged process",
425 __func__, authctxt->user);
426
427 mm_get_keystate(pmonitor);
428
429 /* Drain any buffered messages from the child */
430 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
431 ;
432
433 close(pmonitor->m_sendfd);
434 close(pmonitor->m_log_recvfd);
435 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
436 }
437
438 static void
monitor_set_child_handler(pid_t pid)439 monitor_set_child_handler(pid_t pid)
440 {
441 monitor_child_pid = pid;
442 }
443
444 static void
monitor_child_handler(int sig)445 monitor_child_handler(int sig)
446 {
447 kill(monitor_child_pid, sig);
448 }
449
450 void
monitor_child_postauth(struct monitor * pmonitor)451 monitor_child_postauth(struct monitor *pmonitor)
452 {
453 close(pmonitor->m_recvfd);
454 pmonitor->m_recvfd = -1;
455
456 monitor_set_child_handler(pmonitor->m_pid);
457 signal(SIGHUP, &monitor_child_handler);
458 signal(SIGTERM, &monitor_child_handler);
459 signal(SIGINT, &monitor_child_handler);
460
461 if (compat20) {
462 mon_dispatch = mon_dispatch_postauth20;
463
464 /* Permit requests for moduli and signatures */
465 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
466 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
467 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
468 } else {
469 mon_dispatch = mon_dispatch_postauth15;
470 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
471 }
472 if (!no_pty_flag) {
473 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
474 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
475 }
476
477 for (;;)
478 monitor_read(pmonitor, mon_dispatch, NULL);
479 }
480
481 void
monitor_sync(struct monitor * pmonitor)482 monitor_sync(struct monitor *pmonitor)
483 {
484 if (options.compression) {
485 /* The member allocation is not visible, so sync it */
486 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
487 }
488 }
489
490 static int
monitor_read_log(struct monitor * pmonitor)491 monitor_read_log(struct monitor *pmonitor)
492 {
493 Buffer logmsg;
494 u_int len, level;
495 char *msg;
496
497 buffer_init(&logmsg);
498
499 /* Read length */
500 buffer_append_space(&logmsg, 4);
501 if (atomicio(read, pmonitor->m_log_recvfd,
502 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
503 if (errno == EPIPE) {
504 buffer_free(&logmsg);
505 debug("%s: child log fd closed", __func__);
506 close(pmonitor->m_log_recvfd);
507 pmonitor->m_log_recvfd = -1;
508 return -1;
509 }
510 fatal("%s: log fd read: %s", __func__, strerror(errno));
511 }
512 len = buffer_get_int(&logmsg);
513 if (len <= 4 || len > 8192)
514 fatal("%s: invalid log message length %u", __func__, len);
515
516 /* Read severity, message */
517 buffer_clear(&logmsg);
518 buffer_append_space(&logmsg, len);
519 if (atomicio(read, pmonitor->m_log_recvfd,
520 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
521 fatal("%s: log fd read: %s", __func__, strerror(errno));
522
523 /* Log it */
524 level = buffer_get_int(&logmsg);
525 msg = buffer_get_string(&logmsg, NULL);
526 if (log_level_name(level) == NULL)
527 fatal("%s: invalid log level %u (corrupted message?)",
528 __func__, level);
529 do_log2(level, "%s [preauth]", msg);
530
531 buffer_free(&logmsg);
532 free(msg);
533
534 return 0;
535 }
536
537 int
monitor_read(struct monitor * pmonitor,struct mon_table * ent,struct mon_table ** pent)538 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
539 struct mon_table **pent)
540 {
541 Buffer m;
542 int ret;
543 u_char type;
544 struct pollfd pfd[2];
545
546 for (;;) {
547 memset(&pfd, 0, sizeof(pfd));
548 pfd[0].fd = pmonitor->m_sendfd;
549 pfd[0].events = POLLIN;
550 pfd[1].fd = pmonitor->m_log_recvfd;
551 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
552 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
553 if (errno == EINTR || errno == EAGAIN)
554 continue;
555 fatal("%s: poll: %s", __func__, strerror(errno));
556 }
557 if (pfd[1].revents) {
558 /*
559 * Drain all log messages before processing next
560 * monitor request.
561 */
562 monitor_read_log(pmonitor);
563 continue;
564 }
565 if (pfd[0].revents)
566 break; /* Continues below */
567 }
568
569 buffer_init(&m);
570
571 mm_request_receive(pmonitor->m_sendfd, &m);
572 type = buffer_get_char(&m);
573
574 debug3("%s: checking request %d", __func__, type);
575
576 while (ent->f != NULL) {
577 if (ent->type == type)
578 break;
579 ent++;
580 }
581
582 if (ent->f != NULL) {
583 if (!(ent->flags & MON_PERMIT))
584 fatal("%s: unpermitted request %d", __func__,
585 type);
586 ret = (*ent->f)(pmonitor->m_sendfd, &m);
587 buffer_free(&m);
588
589 /* The child may use this request only once, disable it */
590 if (ent->flags & MON_ONCE) {
591 debug2("%s: %d used once, disabling now", __func__,
592 type);
593 ent->flags &= ~MON_PERMIT;
594 }
595
596 if (pent != NULL)
597 *pent = ent;
598
599 return ret;
600 }
601
602 fatal("%s: unsupported request: %d", __func__, type);
603
604 /* NOTREACHED */
605 return (-1);
606 }
607
608 /* allowed key state */
609 static int
monitor_allowed_key(u_char * blob,u_int bloblen)610 monitor_allowed_key(u_char *blob, u_int bloblen)
611 {
612 /* make sure key is allowed */
613 if (key_blob == NULL || key_bloblen != bloblen ||
614 timingsafe_bcmp(key_blob, blob, key_bloblen))
615 return (0);
616 return (1);
617 }
618
619 static void
monitor_reset_key_state(void)620 monitor_reset_key_state(void)
621 {
622 /* reset state */
623 free(key_blob);
624 free(hostbased_cuser);
625 free(hostbased_chost);
626 key_blob = NULL;
627 key_bloblen = 0;
628 key_blobtype = MM_NOKEY;
629 hostbased_cuser = NULL;
630 hostbased_chost = NULL;
631 }
632
633 int
mm_answer_moduli(int sock,Buffer * m)634 mm_answer_moduli(int sock, Buffer *m)
635 {
636 DH *dh;
637 int min, want, max;
638
639 min = buffer_get_int(m);
640 want = buffer_get_int(m);
641 max = buffer_get_int(m);
642
643 debug3("%s: got parameters: %d %d %d",
644 __func__, min, want, max);
645 /* We need to check here, too, in case the child got corrupted */
646 if (max < min || want < min || max < want)
647 fatal("%s: bad parameters: %d %d %d",
648 __func__, min, want, max);
649
650 buffer_clear(m);
651
652 dh = choose_dh(min, want, max);
653 if (dh == NULL) {
654 buffer_put_char(m, 0);
655 return (0);
656 } else {
657 /* Send first bignum */
658 buffer_put_char(m, 1);
659 buffer_put_bignum2(m, dh->p);
660 buffer_put_bignum2(m, dh->g);
661
662 DH_free(dh);
663 }
664 mm_request_send(sock, MONITOR_ANS_MODULI, m);
665 return (0);
666 }
667
668 extern AuthenticationConnection *auth_conn;
669
670 int
mm_answer_sign(int sock,Buffer * m)671 mm_answer_sign(int sock, Buffer *m)
672 {
673 Key *key;
674 u_char *p;
675 u_char *signature;
676 u_int siglen, datlen;
677 int keyid;
678
679 debug3("%s", __func__);
680
681 keyid = buffer_get_int(m);
682 p = buffer_get_string(m, &datlen);
683
684 /*
685 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
686 * SHA384 (48 bytes) and SHA512 (64 bytes).
687 */
688 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64)
689 fatal("%s: data length incorrect: %u", __func__, datlen);
690
691 /* save session id, it will be passed on the first call */
692 if (session_id2_len == 0) {
693 session_id2_len = datlen;
694 session_id2 = xmalloc(session_id2_len);
695 memcpy(session_id2, p, session_id2_len);
696 }
697
698 if ((key = get_hostkey_by_index(keyid)) != NULL) {
699 if (key_sign(key, &signature, &siglen, p, datlen) < 0)
700 fatal("%s: key_sign failed", __func__);
701 } else if ((key = get_hostkey_public_by_index(keyid)) != NULL &&
702 auth_conn != NULL) {
703 if (ssh_agent_sign(auth_conn, key, &signature, &siglen, p,
704 datlen) < 0)
705 fatal("%s: ssh_agent_sign failed", __func__);
706 } else
707 fatal("%s: no hostkey from index %d", __func__, keyid);
708
709 debug3("%s: signature %p(%u)", __func__, signature, siglen);
710
711 buffer_clear(m);
712 buffer_put_string(m, signature, siglen);
713
714 free(p);
715 free(signature);
716
717 mm_request_send(sock, MONITOR_ANS_SIGN, m);
718
719 /* Turn on permissions for getpwnam */
720 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
721
722 return (0);
723 }
724
725 /* Retrieves the password entry and also checks if the user is permitted */
726
727 int
mm_answer_pwnamallow(int sock,Buffer * m)728 mm_answer_pwnamallow(int sock, Buffer *m)
729 {
730 char *username;
731 struct passwd *pwent;
732 int allowed = 0;
733 u_int i;
734
735 debug3("%s", __func__);
736
737 if (authctxt->attempt++ != 0)
738 fatal("%s: multiple attempts for getpwnam", __func__);
739
740 username = buffer_get_string(m, NULL);
741
742 pwent = getpwnamallow(username);
743
744 authctxt->user = xstrdup(username);
745 setproctitle("%s [priv]", pwent ? username : "unknown");
746 free(username);
747
748 buffer_clear(m);
749
750 if (pwent == NULL) {
751 buffer_put_char(m, 0);
752 authctxt->pw = fakepw();
753 goto out;
754 }
755
756 allowed = 1;
757 authctxt->pw = pwent;
758 authctxt->valid = 1;
759
760 buffer_put_char(m, 1);
761 buffer_put_string(m, pwent, sizeof(struct passwd));
762 buffer_put_cstring(m, pwent->pw_name);
763 buffer_put_cstring(m, "*");
764 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
765 buffer_put_cstring(m, pwent->pw_gecos);
766 #endif
767 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
768 buffer_put_cstring(m, pwent->pw_class);
769 #endif
770 buffer_put_cstring(m, pwent->pw_dir);
771 buffer_put_cstring(m, pwent->pw_shell);
772
773 out:
774 buffer_put_string(m, &options, sizeof(options));
775
776 #define M_CP_STROPT(x) do { \
777 if (options.x != NULL) \
778 buffer_put_cstring(m, options.x); \
779 } while (0)
780 #define M_CP_STRARRAYOPT(x, nx) do { \
781 for (i = 0; i < options.nx; i++) \
782 buffer_put_cstring(m, options.x[i]); \
783 } while (0)
784 /* See comment in servconf.h */
785 COPY_MATCH_STRING_OPTS();
786 #undef M_CP_STROPT
787 #undef M_CP_STRARRAYOPT
788
789 /* Create valid auth method lists */
790 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) {
791 /*
792 * The monitor will continue long enough to let the child
793 * run to it's packet_disconnect(), but it must not allow any
794 * authentication to succeed.
795 */
796 debug("%s: no valid authentication method lists", __func__);
797 }
798
799 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
800 mm_request_send(sock, MONITOR_ANS_PWNAM, m);
801
802 /* For SSHv1 allow authentication now */
803 if (!compat20)
804 monitor_permit_authentications(1);
805 else {
806 /* Allow service/style information on the auth context */
807 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
808 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
809 }
810 #ifdef USE_PAM
811 if (options.use_pam)
812 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
813 #endif
814
815 return (0);
816 }
817
mm_answer_auth2_read_banner(int sock,Buffer * m)818 int mm_answer_auth2_read_banner(int sock, Buffer *m)
819 {
820 char *banner;
821
822 buffer_clear(m);
823 banner = auth2_read_banner();
824 buffer_put_cstring(m, banner != NULL ? banner : "");
825 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
826 free(banner);
827
828 return (0);
829 }
830
831 int
mm_answer_authserv(int sock,Buffer * m)832 mm_answer_authserv(int sock, Buffer *m)
833 {
834 monitor_permit_authentications(1);
835
836 authctxt->service = buffer_get_string(m, NULL);
837 authctxt->style = buffer_get_string(m, NULL);
838 debug3("%s: service=%s, style=%s",
839 __func__, authctxt->service, authctxt->style);
840
841 if (strlen(authctxt->style) == 0) {
842 free(authctxt->style);
843 authctxt->style = NULL;
844 }
845
846 return (0);
847 }
848
849 int
mm_answer_authpassword(int sock,Buffer * m)850 mm_answer_authpassword(int sock, Buffer *m)
851 {
852 static int call_count;
853 char *passwd;
854 int authenticated;
855 u_int plen;
856
857 passwd = buffer_get_string(m, &plen);
858 /* Only authenticate if the context is valid */
859 authenticated = options.password_authentication &&
860 auth_password(authctxt, passwd);
861 explicit_bzero(passwd, strlen(passwd));
862 free(passwd);
863
864 buffer_clear(m);
865 buffer_put_int(m, authenticated);
866
867 debug3("%s: sending result %d", __func__, authenticated);
868 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
869
870 call_count++;
871 if (plen == 0 && call_count == 1)
872 auth_method = "none";
873 else
874 auth_method = "password";
875
876 /* Causes monitor loop to terminate if authenticated */
877 return (authenticated);
878 }
879
880 #ifdef BSD_AUTH
881 int
mm_answer_bsdauthquery(int sock,Buffer * m)882 mm_answer_bsdauthquery(int sock, Buffer *m)
883 {
884 char *name, *infotxt;
885 u_int numprompts;
886 u_int *echo_on;
887 char **prompts;
888 u_int success;
889
890 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
891 &prompts, &echo_on) < 0 ? 0 : 1;
892
893 buffer_clear(m);
894 buffer_put_int(m, success);
895 if (success)
896 buffer_put_cstring(m, prompts[0]);
897
898 debug3("%s: sending challenge success: %u", __func__, success);
899 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
900
901 if (success) {
902 free(name);
903 free(infotxt);
904 free(prompts);
905 free(echo_on);
906 }
907
908 return (0);
909 }
910
911 int
mm_answer_bsdauthrespond(int sock,Buffer * m)912 mm_answer_bsdauthrespond(int sock, Buffer *m)
913 {
914 char *response;
915 int authok;
916
917 if (authctxt->as == 0)
918 fatal("%s: no bsd auth session", __func__);
919
920 response = buffer_get_string(m, NULL);
921 authok = options.challenge_response_authentication &&
922 auth_userresponse(authctxt->as, response, 0);
923 authctxt->as = NULL;
924 debug3("%s: <%s> = <%d>", __func__, response, authok);
925 free(response);
926
927 buffer_clear(m);
928 buffer_put_int(m, authok);
929
930 debug3("%s: sending authenticated: %d", __func__, authok);
931 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
932
933 if (compat20) {
934 auth_method = "keyboard-interactive";
935 auth_submethod = "bsdauth";
936 } else
937 auth_method = "bsdauth";
938
939 return (authok != 0);
940 }
941 #endif
942
943 #ifdef SKEY
944 int
mm_answer_skeyquery(int sock,Buffer * m)945 mm_answer_skeyquery(int sock, Buffer *m)
946 {
947 struct skey skey;
948 char challenge[1024];
949 u_int success;
950
951 success = _compat_skeychallenge(&skey, authctxt->user, challenge,
952 sizeof(challenge)) < 0 ? 0 : 1;
953
954 buffer_clear(m);
955 buffer_put_int(m, success);
956 if (success)
957 buffer_put_cstring(m, challenge);
958
959 debug3("%s: sending challenge success: %u", __func__, success);
960 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
961
962 return (0);
963 }
964
965 int
mm_answer_skeyrespond(int sock,Buffer * m)966 mm_answer_skeyrespond(int sock, Buffer *m)
967 {
968 char *response;
969 int authok;
970
971 response = buffer_get_string(m, NULL);
972
973 authok = (options.challenge_response_authentication &&
974 authctxt->valid &&
975 skey_haskey(authctxt->pw->pw_name) == 0 &&
976 skey_passcheck(authctxt->pw->pw_name, response) != -1);
977
978 free(response);
979
980 buffer_clear(m);
981 buffer_put_int(m, authok);
982
983 debug3("%s: sending authenticated: %d", __func__, authok);
984 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
985
986 auth_method = "skey";
987
988 return (authok != 0);
989 }
990 #endif
991
992 #ifdef USE_PAM
993 int
mm_answer_pam_start(int sock,Buffer * m)994 mm_answer_pam_start(int sock, Buffer *m)
995 {
996 if (!options.use_pam)
997 fatal("UsePAM not set, but ended up in %s anyway", __func__);
998
999 start_pam(authctxt);
1000
1001 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
1002
1003 return (0);
1004 }
1005
1006 int
mm_answer_pam_account(int sock,Buffer * m)1007 mm_answer_pam_account(int sock, Buffer *m)
1008 {
1009 u_int ret;
1010
1011 if (!options.use_pam)
1012 fatal("UsePAM not set, but ended up in %s anyway", __func__);
1013
1014 ret = do_pam_account();
1015
1016 buffer_put_int(m, ret);
1017 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1018
1019 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
1020
1021 return (ret);
1022 }
1023
1024 static void *sshpam_ctxt, *sshpam_authok;
1025 extern KbdintDevice sshpam_device;
1026
1027 int
mm_answer_pam_init_ctx(int sock,Buffer * m)1028 mm_answer_pam_init_ctx(int sock, Buffer *m)
1029 {
1030 debug3("%s", __func__);
1031 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
1032 sshpam_authok = NULL;
1033 buffer_clear(m);
1034 if (sshpam_ctxt != NULL) {
1035 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
1036 buffer_put_int(m, 1);
1037 } else {
1038 buffer_put_int(m, 0);
1039 }
1040 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
1041 return (0);
1042 }
1043
1044 int
mm_answer_pam_query(int sock,Buffer * m)1045 mm_answer_pam_query(int sock, Buffer *m)
1046 {
1047 char *name = NULL, *info = NULL, **prompts = NULL;
1048 u_int i, num = 0, *echo_on = 0;
1049 int ret;
1050
1051 debug3("%s", __func__);
1052 sshpam_authok = NULL;
1053 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
1054 if (ret == 0 && num == 0)
1055 sshpam_authok = sshpam_ctxt;
1056 if (num > 1 || name == NULL || info == NULL)
1057 ret = -1;
1058 buffer_clear(m);
1059 buffer_put_int(m, ret);
1060 buffer_put_cstring(m, name);
1061 free(name);
1062 buffer_put_cstring(m, info);
1063 free(info);
1064 buffer_put_int(m, num);
1065 for (i = 0; i < num; ++i) {
1066 buffer_put_cstring(m, prompts[i]);
1067 free(prompts[i]);
1068 buffer_put_int(m, echo_on[i]);
1069 }
1070 free(prompts);
1071 free(echo_on);
1072 auth_method = "keyboard-interactive";
1073 auth_submethod = "pam";
1074 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
1075 return (0);
1076 }
1077
1078 int
mm_answer_pam_respond(int sock,Buffer * m)1079 mm_answer_pam_respond(int sock, Buffer *m)
1080 {
1081 char **resp;
1082 u_int i, num;
1083 int ret;
1084
1085 debug3("%s", __func__);
1086 sshpam_authok = NULL;
1087 num = buffer_get_int(m);
1088 if (num > 0) {
1089 resp = xcalloc(num, sizeof(char *));
1090 for (i = 0; i < num; ++i)
1091 resp[i] = buffer_get_string(m, NULL);
1092 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
1093 for (i = 0; i < num; ++i)
1094 free(resp[i]);
1095 free(resp);
1096 } else {
1097 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
1098 }
1099 buffer_clear(m);
1100 buffer_put_int(m, ret);
1101 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
1102 auth_method = "keyboard-interactive";
1103 auth_submethod = "pam";
1104 if (ret == 0)
1105 sshpam_authok = sshpam_ctxt;
1106 return (0);
1107 }
1108
1109 int
mm_answer_pam_free_ctx(int sock,Buffer * m)1110 mm_answer_pam_free_ctx(int sock, Buffer *m)
1111 {
1112 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt;
1113
1114 debug3("%s", __func__);
1115 (sshpam_device.free_ctx)(sshpam_ctxt);
1116 sshpam_ctxt = sshpam_authok = NULL;
1117 buffer_clear(m);
1118 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
1119 auth_method = "keyboard-interactive";
1120 auth_submethod = "pam";
1121 return r;
1122 }
1123 #endif
1124
1125 int
mm_answer_keyallowed(int sock,Buffer * m)1126 mm_answer_keyallowed(int sock, Buffer *m)
1127 {
1128 Key *key;
1129 char *cuser, *chost;
1130 u_char *blob;
1131 u_int bloblen;
1132 enum mm_keytype type = 0;
1133 int allowed = 0;
1134
1135 debug3("%s entering", __func__);
1136
1137 type = buffer_get_int(m);
1138 cuser = buffer_get_string(m, NULL);
1139 chost = buffer_get_string(m, NULL);
1140 blob = buffer_get_string(m, &bloblen);
1141
1142 key = key_from_blob(blob, bloblen);
1143
1144 if ((compat20 && type == MM_RSAHOSTKEY) ||
1145 (!compat20 && type != MM_RSAHOSTKEY))
1146 fatal("%s: key type and protocol mismatch", __func__);
1147
1148 debug3("%s: key_from_blob: %p", __func__, key);
1149
1150 if (key != NULL && authctxt->valid) {
1151 switch (type) {
1152 case MM_USERKEY:
1153 allowed = options.pubkey_authentication &&
1154 user_key_allowed(authctxt->pw, key);
1155 pubkey_auth_info(authctxt, key, NULL);
1156 auth_method = "publickey";
1157 if (options.pubkey_authentication && allowed != 1)
1158 auth_clear_options();
1159 break;
1160 case MM_HOSTKEY:
1161 allowed = options.hostbased_authentication &&
1162 hostbased_key_allowed(authctxt->pw,
1163 cuser, chost, key);
1164 pubkey_auth_info(authctxt, key,
1165 "client user \"%.100s\", client host \"%.100s\"",
1166 cuser, chost);
1167 auth_method = "hostbased";
1168 break;
1169 case MM_RSAHOSTKEY:
1170 key->type = KEY_RSA1; /* XXX */
1171 allowed = options.rhosts_rsa_authentication &&
1172 auth_rhosts_rsa_key_allowed(authctxt->pw,
1173 cuser, chost, key);
1174 if (options.rhosts_rsa_authentication && allowed != 1)
1175 auth_clear_options();
1176 auth_method = "rsa";
1177 break;
1178 default:
1179 fatal("%s: unknown key type %d", __func__, type);
1180 break;
1181 }
1182 }
1183 if (key != NULL)
1184 key_free(key);
1185
1186 /* clear temporarily storage (used by verify) */
1187 monitor_reset_key_state();
1188
1189 if (allowed) {
1190 /* Save temporarily for comparison in verify */
1191 key_blob = blob;
1192 key_bloblen = bloblen;
1193 key_blobtype = type;
1194 hostbased_cuser = cuser;
1195 hostbased_chost = chost;
1196 } else {
1197 /* Log failed attempt */
1198 auth_log(authctxt, 0, 0, auth_method, NULL);
1199 free(blob);
1200 free(cuser);
1201 free(chost);
1202 }
1203
1204 debug3("%s: key %p is %s",
1205 __func__, key, allowed ? "allowed" : "not allowed");
1206
1207 buffer_clear(m);
1208 buffer_put_int(m, allowed);
1209 buffer_put_int(m, forced_command != NULL);
1210
1211 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1212
1213 if (type == MM_RSAHOSTKEY)
1214 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1215
1216 return (0);
1217 }
1218
1219 static int
monitor_valid_userblob(u_char * data,u_int datalen)1220 monitor_valid_userblob(u_char *data, u_int datalen)
1221 {
1222 Buffer b;
1223 char *p, *userstyle;
1224 u_int len;
1225 int fail = 0;
1226
1227 buffer_init(&b);
1228 buffer_append(&b, data, datalen);
1229
1230 if (datafellows & SSH_OLD_SESSIONID) {
1231 p = buffer_ptr(&b);
1232 len = buffer_len(&b);
1233 if ((session_id2 == NULL) ||
1234 (len < session_id2_len) ||
1235 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1236 fail++;
1237 buffer_consume(&b, session_id2_len);
1238 } else {
1239 p = buffer_get_string(&b, &len);
1240 if ((session_id2 == NULL) ||
1241 (len != session_id2_len) ||
1242 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1243 fail++;
1244 free(p);
1245 }
1246 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1247 fail++;
1248 p = buffer_get_cstring(&b, NULL);
1249 xasprintf(&userstyle, "%s%s%s", authctxt->user,
1250 authctxt->style ? ":" : "",
1251 authctxt->style ? authctxt->style : "");
1252 if (strcmp(userstyle, p) != 0) {
1253 logit("wrong user name passed to monitor: expected %s != %.100s",
1254 userstyle, p);
1255 fail++;
1256 }
1257 free(userstyle);
1258 free(p);
1259 buffer_skip_string(&b);
1260 if (datafellows & SSH_BUG_PKAUTH) {
1261 if (!buffer_get_char(&b))
1262 fail++;
1263 } else {
1264 p = buffer_get_cstring(&b, NULL);
1265 if (strcmp("publickey", p) != 0)
1266 fail++;
1267 free(p);
1268 if (!buffer_get_char(&b))
1269 fail++;
1270 buffer_skip_string(&b);
1271 }
1272 buffer_skip_string(&b);
1273 if (buffer_len(&b) != 0)
1274 fail++;
1275 buffer_free(&b);
1276 return (fail == 0);
1277 }
1278
1279 static int
monitor_valid_hostbasedblob(u_char * data,u_int datalen,char * cuser,char * chost)1280 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1281 char *chost)
1282 {
1283 Buffer b;
1284 char *p, *userstyle;
1285 u_int len;
1286 int fail = 0;
1287
1288 buffer_init(&b);
1289 buffer_append(&b, data, datalen);
1290
1291 p = buffer_get_string(&b, &len);
1292 if ((session_id2 == NULL) ||
1293 (len != session_id2_len) ||
1294 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1295 fail++;
1296 free(p);
1297
1298 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1299 fail++;
1300 p = buffer_get_cstring(&b, NULL);
1301 xasprintf(&userstyle, "%s%s%s", authctxt->user,
1302 authctxt->style ? ":" : "",
1303 authctxt->style ? authctxt->style : "");
1304 if (strcmp(userstyle, p) != 0) {
1305 logit("wrong user name passed to monitor: expected %s != %.100s",
1306 userstyle, p);
1307 fail++;
1308 }
1309 free(userstyle);
1310 free(p);
1311 buffer_skip_string(&b); /* service */
1312 p = buffer_get_cstring(&b, NULL);
1313 if (strcmp(p, "hostbased") != 0)
1314 fail++;
1315 free(p);
1316 buffer_skip_string(&b); /* pkalg */
1317 buffer_skip_string(&b); /* pkblob */
1318
1319 /* verify client host, strip trailing dot if necessary */
1320 p = buffer_get_string(&b, NULL);
1321 if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1322 p[len - 1] = '\0';
1323 if (strcmp(p, chost) != 0)
1324 fail++;
1325 free(p);
1326
1327 /* verify client user */
1328 p = buffer_get_string(&b, NULL);
1329 if (strcmp(p, cuser) != 0)
1330 fail++;
1331 free(p);
1332
1333 if (buffer_len(&b) != 0)
1334 fail++;
1335 buffer_free(&b);
1336 return (fail == 0);
1337 }
1338
1339 int
mm_answer_keyverify(int sock,Buffer * m)1340 mm_answer_keyverify(int sock, Buffer *m)
1341 {
1342 Key *key;
1343 u_char *signature, *data, *blob;
1344 u_int signaturelen, datalen, bloblen;
1345 int verified = 0;
1346 int valid_data = 0;
1347
1348 blob = buffer_get_string(m, &bloblen);
1349 signature = buffer_get_string(m, &signaturelen);
1350 data = buffer_get_string(m, &datalen);
1351
1352 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1353 !monitor_allowed_key(blob, bloblen))
1354 fatal("%s: bad key, not previously allowed", __func__);
1355
1356 key = key_from_blob(blob, bloblen);
1357 if (key == NULL)
1358 fatal("%s: bad public key blob", __func__);
1359
1360 switch (key_blobtype) {
1361 case MM_USERKEY:
1362 valid_data = monitor_valid_userblob(data, datalen);
1363 break;
1364 case MM_HOSTKEY:
1365 valid_data = monitor_valid_hostbasedblob(data, datalen,
1366 hostbased_cuser, hostbased_chost);
1367 break;
1368 default:
1369 valid_data = 0;
1370 break;
1371 }
1372 if (!valid_data)
1373 fatal("%s: bad signature data blob", __func__);
1374
1375 verified = key_verify(key, signature, signaturelen, data, datalen);
1376 debug3("%s: key %p signature %s",
1377 __func__, key, (verified == 1) ? "verified" : "unverified");
1378
1379 key_free(key);
1380 free(blob);
1381 free(signature);
1382 free(data);
1383
1384 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1385
1386 monitor_reset_key_state();
1387
1388 buffer_clear(m);
1389 buffer_put_int(m, verified);
1390 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1391
1392 return (verified == 1);
1393 }
1394
1395 static void
mm_record_login(Session * s,struct passwd * pw)1396 mm_record_login(Session *s, struct passwd *pw)
1397 {
1398 socklen_t fromlen;
1399 struct sockaddr_storage from;
1400
1401 /*
1402 * Get IP address of client. If the connection is not a socket, let
1403 * the address be 0.0.0.0.
1404 */
1405 memset(&from, 0, sizeof(from));
1406 fromlen = sizeof(from);
1407 if (packet_connection_is_on_socket()) {
1408 if (getpeername(packet_get_connection_in(),
1409 (struct sockaddr *)&from, &fromlen) < 0) {
1410 debug("getpeername: %.100s", strerror(errno));
1411 cleanup_exit(255);
1412 }
1413 }
1414 /* Record that there was a login on that tty from the remote host. */
1415 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1416 get_remote_name_or_ip(utmp_len, options.use_dns),
1417 (struct sockaddr *)&from, fromlen);
1418 }
1419
1420 static void
mm_session_close(Session * s)1421 mm_session_close(Session *s)
1422 {
1423 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1424 if (s->ttyfd != -1) {
1425 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1426 session_pty_cleanup2(s);
1427 }
1428 session_unused(s->self);
1429 }
1430
1431 int
mm_answer_pty(int sock,Buffer * m)1432 mm_answer_pty(int sock, Buffer *m)
1433 {
1434 extern struct monitor *pmonitor;
1435 Session *s;
1436 int res, fd0;
1437
1438 debug3("%s entering", __func__);
1439
1440 buffer_clear(m);
1441 s = session_new();
1442 if (s == NULL)
1443 goto error;
1444 s->authctxt = authctxt;
1445 s->pw = authctxt->pw;
1446 s->pid = pmonitor->m_pid;
1447 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1448 if (res == 0)
1449 goto error;
1450 pty_setowner(authctxt->pw, s->tty);
1451
1452 buffer_put_int(m, 1);
1453 buffer_put_cstring(m, s->tty);
1454
1455 /* We need to trick ttyslot */
1456 if (dup2(s->ttyfd, 0) == -1)
1457 fatal("%s: dup2", __func__);
1458
1459 mm_record_login(s, authctxt->pw);
1460
1461 /* Now we can close the file descriptor again */
1462 close(0);
1463
1464 /* send messages generated by record_login */
1465 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1466 buffer_clear(&loginmsg);
1467
1468 mm_request_send(sock, MONITOR_ANS_PTY, m);
1469
1470 if (mm_send_fd(sock, s->ptyfd) == -1 ||
1471 mm_send_fd(sock, s->ttyfd) == -1)
1472 fatal("%s: send fds failed", __func__);
1473
1474 /* make sure nothing uses fd 0 */
1475 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1476 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1477 if (fd0 != 0)
1478 error("%s: fd0 %d != 0", __func__, fd0);
1479
1480 /* slave is not needed */
1481 close(s->ttyfd);
1482 s->ttyfd = s->ptyfd;
1483 /* no need to dup() because nobody closes ptyfd */
1484 s->ptymaster = s->ptyfd;
1485
1486 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1487
1488 return (0);
1489
1490 error:
1491 if (s != NULL)
1492 mm_session_close(s);
1493 buffer_put_int(m, 0);
1494 mm_request_send(sock, MONITOR_ANS_PTY, m);
1495 return (0);
1496 }
1497
1498 int
mm_answer_pty_cleanup(int sock,Buffer * m)1499 mm_answer_pty_cleanup(int sock, Buffer *m)
1500 {
1501 Session *s;
1502 char *tty;
1503
1504 debug3("%s entering", __func__);
1505
1506 tty = buffer_get_string(m, NULL);
1507 if ((s = session_by_tty(tty)) != NULL)
1508 mm_session_close(s);
1509 buffer_clear(m);
1510 free(tty);
1511 return (0);
1512 }
1513
1514 int
mm_answer_sesskey(int sock,Buffer * m)1515 mm_answer_sesskey(int sock, Buffer *m)
1516 {
1517 BIGNUM *p;
1518 int rsafail;
1519
1520 /* Turn off permissions */
1521 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1522
1523 if ((p = BN_new()) == NULL)
1524 fatal("%s: BN_new", __func__);
1525
1526 buffer_get_bignum2(m, p);
1527
1528 rsafail = ssh1_session_key(p);
1529
1530 buffer_clear(m);
1531 buffer_put_int(m, rsafail);
1532 buffer_put_bignum2(m, p);
1533
1534 BN_clear_free(p);
1535
1536 mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1537
1538 /* Turn on permissions for sessid passing */
1539 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1540
1541 return (0);
1542 }
1543
1544 int
mm_answer_sessid(int sock,Buffer * m)1545 mm_answer_sessid(int sock, Buffer *m)
1546 {
1547 int i;
1548
1549 debug3("%s entering", __func__);
1550
1551 if (buffer_len(m) != 16)
1552 fatal("%s: bad ssh1 session id", __func__);
1553 for (i = 0; i < 16; i++)
1554 session_id[i] = buffer_get_char(m);
1555
1556 /* Turn on permissions for getpwnam */
1557 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1558
1559 return (0);
1560 }
1561
1562 int
mm_answer_rsa_keyallowed(int sock,Buffer * m)1563 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1564 {
1565 BIGNUM *client_n;
1566 Key *key = NULL;
1567 u_char *blob = NULL;
1568 u_int blen = 0;
1569 int allowed = 0;
1570
1571 debug3("%s entering", __func__);
1572
1573 auth_method = "rsa";
1574 if (options.rsa_authentication && authctxt->valid) {
1575 if ((client_n = BN_new()) == NULL)
1576 fatal("%s: BN_new", __func__);
1577 buffer_get_bignum2(m, client_n);
1578 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1579 BN_clear_free(client_n);
1580 }
1581 buffer_clear(m);
1582 buffer_put_int(m, allowed);
1583 buffer_put_int(m, forced_command != NULL);
1584
1585 /* clear temporarily storage (used by generate challenge) */
1586 monitor_reset_key_state();
1587
1588 if (allowed && key != NULL) {
1589 key->type = KEY_RSA; /* cheat for key_to_blob */
1590 if (key_to_blob(key, &blob, &blen) == 0)
1591 fatal("%s: key_to_blob failed", __func__);
1592 buffer_put_string(m, blob, blen);
1593
1594 /* Save temporarily for comparison in verify */
1595 key_blob = blob;
1596 key_bloblen = blen;
1597 key_blobtype = MM_RSAUSERKEY;
1598 }
1599 if (key != NULL)
1600 key_free(key);
1601
1602 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1603
1604 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1605 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1606 return (0);
1607 }
1608
1609 int
mm_answer_rsa_challenge(int sock,Buffer * m)1610 mm_answer_rsa_challenge(int sock, Buffer *m)
1611 {
1612 Key *key = NULL;
1613 u_char *blob;
1614 u_int blen;
1615
1616 debug3("%s entering", __func__);
1617
1618 if (!authctxt->valid)
1619 fatal("%s: authctxt not valid", __func__);
1620 blob = buffer_get_string(m, &blen);
1621 if (!monitor_allowed_key(blob, blen))
1622 fatal("%s: bad key, not previously allowed", __func__);
1623 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1624 fatal("%s: key type mismatch", __func__);
1625 if ((key = key_from_blob(blob, blen)) == NULL)
1626 fatal("%s: received bad key", __func__);
1627 if (key->type != KEY_RSA)
1628 fatal("%s: received bad key type %d", __func__, key->type);
1629 key->type = KEY_RSA1;
1630 if (ssh1_challenge)
1631 BN_clear_free(ssh1_challenge);
1632 ssh1_challenge = auth_rsa_generate_challenge(key);
1633
1634 buffer_clear(m);
1635 buffer_put_bignum2(m, ssh1_challenge);
1636
1637 debug3("%s sending reply", __func__);
1638 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1639
1640 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1641
1642 free(blob);
1643 key_free(key);
1644 return (0);
1645 }
1646
1647 int
mm_answer_rsa_response(int sock,Buffer * m)1648 mm_answer_rsa_response(int sock, Buffer *m)
1649 {
1650 Key *key = NULL;
1651 u_char *blob, *response;
1652 u_int blen, len;
1653 int success;
1654
1655 debug3("%s entering", __func__);
1656
1657 if (!authctxt->valid)
1658 fatal("%s: authctxt not valid", __func__);
1659 if (ssh1_challenge == NULL)
1660 fatal("%s: no ssh1_challenge", __func__);
1661
1662 blob = buffer_get_string(m, &blen);
1663 if (!monitor_allowed_key(blob, blen))
1664 fatal("%s: bad key, not previously allowed", __func__);
1665 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1666 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1667 if ((key = key_from_blob(blob, blen)) == NULL)
1668 fatal("%s: received bad key", __func__);
1669 response = buffer_get_string(m, &len);
1670 if (len != 16)
1671 fatal("%s: received bad response to challenge", __func__);
1672 success = auth_rsa_verify_response(key, ssh1_challenge, response);
1673
1674 free(blob);
1675 key_free(key);
1676 free(response);
1677
1678 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1679
1680 /* reset state */
1681 BN_clear_free(ssh1_challenge);
1682 ssh1_challenge = NULL;
1683 monitor_reset_key_state();
1684
1685 buffer_clear(m);
1686 buffer_put_int(m, success);
1687 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1688
1689 return (success);
1690 }
1691
1692 int
mm_answer_term(int sock,Buffer * req)1693 mm_answer_term(int sock, Buffer *req)
1694 {
1695 extern struct monitor *pmonitor;
1696 int res, status;
1697
1698 debug3("%s: tearing down sessions", __func__);
1699
1700 /* The child is terminating */
1701 session_destroy_all(&mm_session_close);
1702
1703 #ifdef USE_PAM
1704 if (options.use_pam)
1705 sshpam_cleanup();
1706 #endif
1707
1708 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1709 if (errno != EINTR)
1710 exit(1);
1711
1712 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1713
1714 /* Terminate process */
1715 exit(res);
1716 }
1717
1718 #ifdef SSH_AUDIT_EVENTS
1719 /* Report that an audit event occurred */
1720 int
mm_answer_audit_event(int socket,Buffer * m)1721 mm_answer_audit_event(int socket, Buffer *m)
1722 {
1723 ssh_audit_event_t event;
1724
1725 debug3("%s entering", __func__);
1726
1727 event = buffer_get_int(m);
1728 switch(event) {
1729 case SSH_AUTH_FAIL_PUBKEY:
1730 case SSH_AUTH_FAIL_HOSTBASED:
1731 case SSH_AUTH_FAIL_GSSAPI:
1732 case SSH_LOGIN_EXCEED_MAXTRIES:
1733 case SSH_LOGIN_ROOT_DENIED:
1734 case SSH_CONNECTION_CLOSE:
1735 case SSH_INVALID_USER:
1736 audit_event(event);
1737 break;
1738 default:
1739 fatal("Audit event type %d not permitted", event);
1740 }
1741
1742 return (0);
1743 }
1744
1745 int
mm_answer_audit_command(int socket,Buffer * m)1746 mm_answer_audit_command(int socket, Buffer *m)
1747 {
1748 u_int len;
1749 char *cmd;
1750
1751 debug3("%s entering", __func__);
1752 cmd = buffer_get_string(m, &len);
1753 /* sanity check command, if so how? */
1754 audit_run_command(cmd);
1755 free(cmd);
1756 return (0);
1757 }
1758 #endif /* SSH_AUDIT_EVENTS */
1759
1760 void
monitor_apply_keystate(struct monitor * pmonitor)1761 monitor_apply_keystate(struct monitor *pmonitor)
1762 {
1763 if (compat20) {
1764 set_newkeys(MODE_IN);
1765 set_newkeys(MODE_OUT);
1766 } else {
1767 packet_set_protocol_flags(child_state.ssh1protoflags);
1768 packet_set_encryption_key(child_state.ssh1key,
1769 child_state.ssh1keylen, child_state.ssh1cipher);
1770 free(child_state.ssh1key);
1771 }
1772
1773 /* for rc4 and other stateful ciphers */
1774 packet_set_keycontext(MODE_OUT, child_state.keyout);
1775 free(child_state.keyout);
1776 packet_set_keycontext(MODE_IN, child_state.keyin);
1777 free(child_state.keyin);
1778
1779 if (!compat20) {
1780 packet_set_iv(MODE_OUT, child_state.ivout);
1781 free(child_state.ivout);
1782 packet_set_iv(MODE_IN, child_state.ivin);
1783 free(child_state.ivin);
1784 }
1785
1786 memcpy(&incoming_stream, &child_state.incoming,
1787 sizeof(incoming_stream));
1788 memcpy(&outgoing_stream, &child_state.outgoing,
1789 sizeof(outgoing_stream));
1790
1791 /* Update with new address */
1792 if (options.compression)
1793 mm_init_compression(pmonitor->m_zlib);
1794
1795 if (options.rekey_limit || options.rekey_interval)
1796 packet_set_rekey_limits((u_int32_t)options.rekey_limit,
1797 (time_t)options.rekey_interval);
1798
1799 /* Network I/O buffers */
1800 /* XXX inefficient for large buffers, need: buffer_init_from_string */
1801 buffer_clear(packet_get_input());
1802 buffer_append(packet_get_input(), child_state.input, child_state.ilen);
1803 explicit_bzero(child_state.input, child_state.ilen);
1804 free(child_state.input);
1805
1806 buffer_clear(packet_get_output());
1807 buffer_append(packet_get_output(), child_state.output,
1808 child_state.olen);
1809 explicit_bzero(child_state.output, child_state.olen);
1810 free(child_state.output);
1811
1812 /* Roaming */
1813 if (compat20)
1814 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes);
1815 }
1816
1817 static Kex *
mm_get_kex(Buffer * m)1818 mm_get_kex(Buffer *m)
1819 {
1820 Kex *kex;
1821 void *blob;
1822 u_int bloblen;
1823
1824 kex = xcalloc(1, sizeof(*kex));
1825 kex->session_id = buffer_get_string(m, &kex->session_id_len);
1826 if (session_id2 == NULL ||
1827 kex->session_id_len != session_id2_len ||
1828 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0)
1829 fatal("mm_get_get: internal error: bad session id");
1830 kex->we_need = buffer_get_int(m);
1831 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1832 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1833 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1834 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1835 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1836 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
1837 kex->server = 1;
1838 kex->hostkey_type = buffer_get_int(m);
1839 kex->kex_type = buffer_get_int(m);
1840 blob = buffer_get_string(m, &bloblen);
1841 buffer_init(&kex->my);
1842 buffer_append(&kex->my, blob, bloblen);
1843 free(blob);
1844 blob = buffer_get_string(m, &bloblen);
1845 buffer_init(&kex->peer);
1846 buffer_append(&kex->peer, blob, bloblen);
1847 free(blob);
1848 kex->done = 1;
1849 kex->flags = buffer_get_int(m);
1850 kex->client_version_string = buffer_get_string(m, NULL);
1851 kex->server_version_string = buffer_get_string(m, NULL);
1852 kex->load_host_public_key=&get_hostkey_public_by_type;
1853 kex->load_host_private_key=&get_hostkey_private_by_type;
1854 kex->host_key_index=&get_hostkey_index;
1855 kex->sign = sshd_hostkey_sign;
1856
1857 return (kex);
1858 }
1859
1860 /* This function requries careful sanity checking */
1861
1862 void
mm_get_keystate(struct monitor * pmonitor)1863 mm_get_keystate(struct monitor *pmonitor)
1864 {
1865 Buffer m;
1866 u_char *blob, *p;
1867 u_int bloblen, plen;
1868 u_int32_t seqnr, packets;
1869 u_int64_t blocks, bytes;
1870
1871 debug3("%s: Waiting for new keys", __func__);
1872
1873 buffer_init(&m);
1874 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1875 if (!compat20) {
1876 child_state.ssh1protoflags = buffer_get_int(&m);
1877 child_state.ssh1cipher = buffer_get_int(&m);
1878 child_state.ssh1key = buffer_get_string(&m,
1879 &child_state.ssh1keylen);
1880 child_state.ivout = buffer_get_string(&m,
1881 &child_state.ivoutlen);
1882 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1883 goto skip;
1884 } else {
1885 /* Get the Kex for rekeying */
1886 *pmonitor->m_pkex = mm_get_kex(&m);
1887 }
1888
1889 blob = buffer_get_string(&m, &bloblen);
1890 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1891 free(blob);
1892
1893 debug3("%s: Waiting for second key", __func__);
1894 blob = buffer_get_string(&m, &bloblen);
1895 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1896 free(blob);
1897
1898 /* Now get sequence numbers for the packets */
1899 seqnr = buffer_get_int(&m);
1900 blocks = buffer_get_int64(&m);
1901 packets = buffer_get_int(&m);
1902 bytes = buffer_get_int64(&m);
1903 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1904 seqnr = buffer_get_int(&m);
1905 blocks = buffer_get_int64(&m);
1906 packets = buffer_get_int(&m);
1907 bytes = buffer_get_int64(&m);
1908 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1909
1910 skip:
1911 /* Get the key context */
1912 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1913 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1914
1915 debug3("%s: Getting compression state", __func__);
1916 /* Get compression state */
1917 p = buffer_get_string(&m, &plen);
1918 if (plen != sizeof(child_state.outgoing))
1919 fatal("%s: bad request size", __func__);
1920 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1921 free(p);
1922
1923 p = buffer_get_string(&m, &plen);
1924 if (plen != sizeof(child_state.incoming))
1925 fatal("%s: bad request size", __func__);
1926 memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1927 free(p);
1928
1929 /* Network I/O buffers */
1930 debug3("%s: Getting Network I/O buffers", __func__);
1931 child_state.input = buffer_get_string(&m, &child_state.ilen);
1932 child_state.output = buffer_get_string(&m, &child_state.olen);
1933
1934 /* Roaming */
1935 if (compat20) {
1936 child_state.sent_bytes = buffer_get_int64(&m);
1937 child_state.recv_bytes = buffer_get_int64(&m);
1938 }
1939
1940 buffer_free(&m);
1941 }
1942
1943
1944 /* Allocation functions for zlib */
1945 void *
mm_zalloc(struct mm_master * mm,u_int ncount,u_int size)1946 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1947 {
1948 size_t len = (size_t) size * ncount;
1949 void *address;
1950
1951 if (len == 0 || ncount > SIZE_T_MAX / size)
1952 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1953
1954 address = mm_malloc(mm, len);
1955
1956 return (address);
1957 }
1958
1959 void
mm_zfree(struct mm_master * mm,void * address)1960 mm_zfree(struct mm_master *mm, void *address)
1961 {
1962 mm_free(mm, address);
1963 }
1964
1965 void
mm_init_compression(struct mm_master * mm)1966 mm_init_compression(struct mm_master *mm)
1967 {
1968 outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1969 outgoing_stream.zfree = (free_func)mm_zfree;
1970 outgoing_stream.opaque = mm;
1971
1972 incoming_stream.zalloc = (alloc_func)mm_zalloc;
1973 incoming_stream.zfree = (free_func)mm_zfree;
1974 incoming_stream.opaque = mm;
1975 }
1976
1977 /* XXX */
1978
1979 #define FD_CLOSEONEXEC(x) do { \
1980 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1981 fatal("fcntl(%d, F_SETFD)", x); \
1982 } while (0)
1983
1984 static void
monitor_openfds(struct monitor * mon,int do_logfds)1985 monitor_openfds(struct monitor *mon, int do_logfds)
1986 {
1987 int pair[2];
1988
1989 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1990 fatal("%s: socketpair: %s", __func__, strerror(errno));
1991 FD_CLOSEONEXEC(pair[0]);
1992 FD_CLOSEONEXEC(pair[1]);
1993 mon->m_recvfd = pair[0];
1994 mon->m_sendfd = pair[1];
1995
1996 if (do_logfds) {
1997 if (pipe(pair) == -1)
1998 fatal("%s: pipe: %s", __func__, strerror(errno));
1999 FD_CLOSEONEXEC(pair[0]);
2000 FD_CLOSEONEXEC(pair[1]);
2001 mon->m_log_recvfd = pair[0];
2002 mon->m_log_sendfd = pair[1];
2003 } else
2004 mon->m_log_recvfd = mon->m_log_sendfd = -1;
2005 }
2006
2007 #define MM_MEMSIZE 65536
2008
2009 struct monitor *
monitor_init(void)2010 monitor_init(void)
2011 {
2012 struct monitor *mon;
2013
2014 mon = xcalloc(1, sizeof(*mon));
2015
2016 monitor_openfds(mon, 1);
2017
2018 /* Used to share zlib space across processes */
2019 if (options.compression) {
2020 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
2021 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
2022
2023 /* Compression needs to share state across borders */
2024 mm_init_compression(mon->m_zlib);
2025 }
2026
2027 return mon;
2028 }
2029
2030 void
monitor_reinit(struct monitor * mon)2031 monitor_reinit(struct monitor *mon)
2032 {
2033 monitor_openfds(mon, 0);
2034 }
2035
2036 #ifdef GSSAPI
2037 int
mm_answer_gss_setup_ctx(int sock,Buffer * m)2038 mm_answer_gss_setup_ctx(int sock, Buffer *m)
2039 {
2040 gss_OID_desc goid;
2041 OM_uint32 major;
2042 u_int len;
2043
2044 goid.elements = buffer_get_string(m, &len);
2045 goid.length = len;
2046
2047 major = ssh_gssapi_server_ctx(&gsscontext, &goid);
2048
2049 free(goid.elements);
2050
2051 buffer_clear(m);
2052 buffer_put_int(m, major);
2053
2054 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
2055
2056 /* Now we have a context, enable the step */
2057 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
2058
2059 return (0);
2060 }
2061
2062 int
mm_answer_gss_accept_ctx(int sock,Buffer * m)2063 mm_answer_gss_accept_ctx(int sock, Buffer *m)
2064 {
2065 gss_buffer_desc in;
2066 gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
2067 OM_uint32 major, minor;
2068 OM_uint32 flags = 0; /* GSI needs this */
2069 u_int len;
2070
2071 in.value = buffer_get_string(m, &len);
2072 in.length = len;
2073 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
2074 free(in.value);
2075
2076 buffer_clear(m);
2077 buffer_put_int(m, major);
2078 buffer_put_string(m, out.value, out.length);
2079 buffer_put_int(m, flags);
2080 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
2081
2082 gss_release_buffer(&minor, &out);
2083
2084 if (major == GSS_S_COMPLETE) {
2085 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
2086 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2087 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
2088 }
2089 return (0);
2090 }
2091
2092 int
mm_answer_gss_checkmic(int sock,Buffer * m)2093 mm_answer_gss_checkmic(int sock, Buffer *m)
2094 {
2095 gss_buffer_desc gssbuf, mic;
2096 OM_uint32 ret;
2097 u_int len;
2098
2099 gssbuf.value = buffer_get_string(m, &len);
2100 gssbuf.length = len;
2101 mic.value = buffer_get_string(m, &len);
2102 mic.length = len;
2103
2104 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
2105
2106 free(gssbuf.value);
2107 free(mic.value);
2108
2109 buffer_clear(m);
2110 buffer_put_int(m, ret);
2111
2112 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
2113
2114 if (!GSS_ERROR(ret))
2115 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2116
2117 return (0);
2118 }
2119
2120 int
mm_answer_gss_userok(int sock,Buffer * m)2121 mm_answer_gss_userok(int sock, Buffer *m)
2122 {
2123 int authenticated;
2124
2125 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2126
2127 buffer_clear(m);
2128 buffer_put_int(m, authenticated);
2129
2130 debug3("%s: sending result %d", __func__, authenticated);
2131 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
2132
2133 auth_method = "gssapi-with-mic";
2134
2135 /* Monitor loop will terminate if authenticated */
2136 return (authenticated);
2137 }
2138 #endif /* GSSAPI */
2139
2140