1 /* $OpenBSD: monitor.c,v 1.115 2011/06/23 23:35:42 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 "jpake.h"
99 #include "roaming.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 int mm_answer_jpake_get_pwdata(int, Buffer *);
164 int mm_answer_jpake_step1(int, Buffer *);
165 int mm_answer_jpake_step2(int, Buffer *);
166 int mm_answer_jpake_key_confirm(int, Buffer *);
167 int mm_answer_jpake_check_confirm(int, Buffer *);
168
169 #ifdef USE_PAM
170 int mm_answer_pam_start(int, Buffer *);
171 int mm_answer_pam_account(int, Buffer *);
172 int mm_answer_pam_init_ctx(int, Buffer *);
173 int mm_answer_pam_query(int, Buffer *);
174 int mm_answer_pam_respond(int, Buffer *);
175 int mm_answer_pam_free_ctx(int, Buffer *);
176 #endif
177
178 #ifdef GSSAPI
179 int mm_answer_gss_setup_ctx(int, Buffer *);
180 int mm_answer_gss_accept_ctx(int, Buffer *);
181 int mm_answer_gss_userok(int, Buffer *);
182 int mm_answer_gss_checkmic(int, Buffer *);
183 #endif
184
185 #ifdef SSH_AUDIT_EVENTS
186 int mm_answer_audit_event(int, Buffer *);
187 int mm_answer_audit_command(int, Buffer *);
188 #endif
189
190 static int monitor_read_log(struct monitor *);
191
192 static Authctxt *authctxt;
193 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
194
195 /* local state for key verify */
196 static u_char *key_blob = NULL;
197 static u_int key_bloblen = 0;
198 static int key_blobtype = MM_NOKEY;
199 static char *hostbased_cuser = NULL;
200 static char *hostbased_chost = NULL;
201 static char *auth_method = "unknown";
202 static u_int session_id2_len = 0;
203 static u_char *session_id2 = NULL;
204 static pid_t monitor_child_pid;
205
206 struct mon_table {
207 enum monitor_reqtype type;
208 int flags;
209 int (*f)(int, Buffer *);
210 };
211
212 #define MON_ISAUTH 0x0004 /* Required for Authentication */
213 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
214 #define MON_ONCE 0x0010 /* Disable after calling */
215 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
216
217 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
218
219 #define MON_PERMIT 0x1000 /* Request is permitted */
220
221 struct mon_table mon_dispatch_proto20[] = {
222 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
223 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
224 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
225 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
226 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
227 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
228 #ifdef USE_PAM
229 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
230 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
231 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
232 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
233 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
234 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
235 #endif
236 #ifdef SSH_AUDIT_EVENTS
237 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
238 #endif
239 #ifdef BSD_AUTH
240 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
241 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
242 #endif
243 #ifdef SKEY
244 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
245 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
246 #endif
247 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
248 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
249 #ifdef GSSAPI
250 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
251 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
252 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
253 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
254 #endif
255 #ifdef JPAKE
256 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata},
257 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1},
258 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2},
259 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm},
260 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm},
261 #endif
262 {0, 0, NULL}
263 };
264
265 struct mon_table mon_dispatch_postauth20[] = {
266 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
267 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
268 {MONITOR_REQ_PTY, 0, mm_answer_pty},
269 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
270 {MONITOR_REQ_TERM, 0, mm_answer_term},
271 #ifdef SSH_AUDIT_EVENTS
272 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
273 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
274 #endif
275 {0, 0, NULL}
276 };
277
278 struct mon_table mon_dispatch_proto15[] = {
279 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
280 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
281 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
282 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
283 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
284 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
285 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
286 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
287 #ifdef BSD_AUTH
288 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
289 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
290 #endif
291 #ifdef SKEY
292 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
293 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
294 #endif
295 #ifdef USE_PAM
296 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
297 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
298 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
299 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
300 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
301 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
302 #endif
303 #ifdef SSH_AUDIT_EVENTS
304 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
305 #endif
306 {0, 0, NULL}
307 };
308
309 struct mon_table mon_dispatch_postauth15[] = {
310 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
311 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
312 {MONITOR_REQ_TERM, 0, mm_answer_term},
313 #ifdef SSH_AUDIT_EVENTS
314 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
315 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
316 #endif
317 {0, 0, NULL}
318 };
319
320 struct mon_table *mon_dispatch;
321
322 /* Specifies if a certain message is allowed at the moment */
323
324 static void
monitor_permit(struct mon_table * ent,enum monitor_reqtype type,int permit)325 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
326 {
327 while (ent->f != NULL) {
328 if (ent->type == type) {
329 ent->flags &= ~MON_PERMIT;
330 ent->flags |= permit ? MON_PERMIT : 0;
331 return;
332 }
333 ent++;
334 }
335 }
336
337 static void
monitor_permit_authentications(int permit)338 monitor_permit_authentications(int permit)
339 {
340 struct mon_table *ent = mon_dispatch;
341
342 while (ent->f != NULL) {
343 if (ent->flags & MON_AUTH) {
344 ent->flags &= ~MON_PERMIT;
345 ent->flags |= permit ? MON_PERMIT : 0;
346 }
347 ent++;
348 }
349 }
350
351 void
monitor_child_preauth(Authctxt * _authctxt,struct monitor * pmonitor)352 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
353 {
354 struct mon_table *ent;
355 int authenticated = 0;
356
357 debug3("preauth child monitor started");
358
359 close(pmonitor->m_recvfd);
360 close(pmonitor->m_log_sendfd);
361 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
362
363 authctxt = _authctxt;
364 memset(authctxt, 0, sizeof(*authctxt));
365
366 authctxt->loginmsg = &loginmsg;
367
368 if (compat20) {
369 mon_dispatch = mon_dispatch_proto20;
370
371 /* Permit requests for moduli and signatures */
372 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
373 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
374 } else {
375 mon_dispatch = mon_dispatch_proto15;
376
377 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
378 }
379
380 /* The first few requests do not require asynchronous access */
381 while (!authenticated) {
382 auth_method = "unknown";
383 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
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
405 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
406 auth_log(authctxt, authenticated, auth_method,
407 compat20 ? " ssh2" : "");
408 if (!authenticated)
409 authctxt->failures++;
410 }
411 #ifdef JPAKE
412 /* Cleanup JPAKE context after authentication */
413 if (ent->flags & MON_AUTHDECIDE) {
414 if (authctxt->jpake_ctx != NULL) {
415 jpake_free(authctxt->jpake_ctx);
416 authctxt->jpake_ctx = NULL;
417 }
418 }
419 #endif
420 }
421
422 /* Drain any buffered messages from the child */
423 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
424 ;
425
426 if (!authctxt->valid)
427 fatal("%s: authenticated invalid user", __func__);
428 if (strcmp(auth_method, "unknown") == 0)
429 fatal("%s: authentication method name unknown", __func__);
430
431 debug("%s: %s has been authenticated by privileged process",
432 __func__, authctxt->user);
433
434 mm_get_keystate(pmonitor);
435
436 close(pmonitor->m_sendfd);
437 close(pmonitor->m_log_recvfd);
438 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
439 }
440
441 static void
monitor_set_child_handler(pid_t pid)442 monitor_set_child_handler(pid_t pid)
443 {
444 monitor_child_pid = pid;
445 }
446
447 static void
monitor_child_handler(int sig)448 monitor_child_handler(int sig)
449 {
450 kill(monitor_child_pid, sig);
451 }
452
453 void
monitor_child_postauth(struct monitor * pmonitor)454 monitor_child_postauth(struct monitor *pmonitor)
455 {
456 close(pmonitor->m_recvfd);
457 pmonitor->m_recvfd = -1;
458
459 monitor_set_child_handler(pmonitor->m_pid);
460 signal(SIGHUP, &monitor_child_handler);
461 signal(SIGTERM, &monitor_child_handler);
462 signal(SIGINT, &monitor_child_handler);
463
464 if (compat20) {
465 mon_dispatch = mon_dispatch_postauth20;
466
467 /* Permit requests for moduli and signatures */
468 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
469 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
470 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
471 } else {
472 mon_dispatch = mon_dispatch_postauth15;
473 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
474 }
475 if (!no_pty_flag) {
476 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
477 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
478 }
479
480 for (;;)
481 monitor_read(pmonitor, mon_dispatch, NULL);
482
483 close(pmonitor->m_sendfd);
484 pmonitor->m_sendfd = -1;
485 }
486
487 void
monitor_sync(struct monitor * pmonitor)488 monitor_sync(struct monitor *pmonitor)
489 {
490 if (options.compression) {
491 /* The member allocation is not visible, so sync it */
492 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
493 }
494 }
495
496 static int
monitor_read_log(struct monitor * pmonitor)497 monitor_read_log(struct monitor *pmonitor)
498 {
499 Buffer logmsg;
500 u_int len, level;
501 char *msg;
502
503 buffer_init(&logmsg);
504
505 /* Read length */
506 buffer_append_space(&logmsg, 4);
507 if (atomicio(read, pmonitor->m_log_recvfd,
508 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
509 if (errno == EPIPE) {
510 debug("%s: child log fd closed", __func__);
511 close(pmonitor->m_log_recvfd);
512 pmonitor->m_log_recvfd = -1;
513 return -1;
514 }
515 fatal("%s: log fd read: %s", __func__, strerror(errno));
516 }
517 len = buffer_get_int(&logmsg);
518 if (len <= 4 || len > 8192)
519 fatal("%s: invalid log message length %u", __func__, len);
520
521 /* Read severity, message */
522 buffer_clear(&logmsg);
523 buffer_append_space(&logmsg, len);
524 if (atomicio(read, pmonitor->m_log_recvfd,
525 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
526 fatal("%s: log fd read: %s", __func__, strerror(errno));
527
528 /* Log it */
529 level = buffer_get_int(&logmsg);
530 msg = buffer_get_string(&logmsg, NULL);
531 if (log_level_name(level) == NULL)
532 fatal("%s: invalid log level %u (corrupted message?)",
533 __func__, level);
534 do_log2(level, "%s [preauth]", msg);
535
536 buffer_free(&logmsg);
537 xfree(msg);
538
539 return 0;
540 }
541
542 int
monitor_read(struct monitor * pmonitor,struct mon_table * ent,struct mon_table ** pent)543 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
544 struct mon_table **pent)
545 {
546 Buffer m;
547 int ret;
548 u_char type;
549 struct pollfd pfd[2];
550
551 for (;;) {
552 bzero(&pfd, sizeof(pfd));
553 pfd[0].fd = pmonitor->m_sendfd;
554 pfd[0].events = POLLIN;
555 pfd[1].fd = pmonitor->m_log_recvfd;
556 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
557 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
558 if (errno == EINTR || errno == EAGAIN)
559 continue;
560 fatal("%s: poll: %s", __func__, strerror(errno));
561 }
562 if (pfd[1].revents) {
563 /*
564 * Drain all log messages before processing next
565 * monitor request.
566 */
567 monitor_read_log(pmonitor);
568 continue;
569 }
570 if (pfd[0].revents)
571 break; /* Continues below */
572 }
573
574 buffer_init(&m);
575
576 mm_request_receive(pmonitor->m_sendfd, &m);
577 type = buffer_get_char(&m);
578
579 debug3("%s: checking request %d", __func__, type);
580
581 while (ent->f != NULL) {
582 if (ent->type == type)
583 break;
584 ent++;
585 }
586
587 if (ent->f != NULL) {
588 if (!(ent->flags & MON_PERMIT))
589 fatal("%s: unpermitted request %d", __func__,
590 type);
591 ret = (*ent->f)(pmonitor->m_sendfd, &m);
592 buffer_free(&m);
593
594 /* The child may use this request only once, disable it */
595 if (ent->flags & MON_ONCE) {
596 debug2("%s: %d used once, disabling now", __func__,
597 type);
598 ent->flags &= ~MON_PERMIT;
599 }
600
601 if (pent != NULL)
602 *pent = ent;
603
604 return ret;
605 }
606
607 fatal("%s: unsupported request: %d", __func__, type);
608
609 /* NOTREACHED */
610 return (-1);
611 }
612
613 /* allowed key state */
614 static int
monitor_allowed_key(u_char * blob,u_int bloblen)615 monitor_allowed_key(u_char *blob, u_int bloblen)
616 {
617 /* make sure key is allowed */
618 if (key_blob == NULL || key_bloblen != bloblen ||
619 timingsafe_bcmp(key_blob, blob, key_bloblen))
620 return (0);
621 return (1);
622 }
623
624 static void
monitor_reset_key_state(void)625 monitor_reset_key_state(void)
626 {
627 /* reset state */
628 if (key_blob != NULL)
629 xfree(key_blob);
630 if (hostbased_cuser != NULL)
631 xfree(hostbased_cuser);
632 if (hostbased_chost != NULL)
633 xfree(hostbased_chost);
634 key_blob = NULL;
635 key_bloblen = 0;
636 key_blobtype = MM_NOKEY;
637 hostbased_cuser = NULL;
638 hostbased_chost = NULL;
639 }
640
641 int
mm_answer_moduli(int sock,Buffer * m)642 mm_answer_moduli(int sock, Buffer *m)
643 {
644 DH *dh;
645 int min, want, max;
646
647 min = buffer_get_int(m);
648 want = buffer_get_int(m);
649 max = buffer_get_int(m);
650
651 debug3("%s: got parameters: %d %d %d",
652 __func__, min, want, max);
653 /* We need to check here, too, in case the child got corrupted */
654 if (max < min || want < min || max < want)
655 fatal("%s: bad parameters: %d %d %d",
656 __func__, min, want, max);
657
658 buffer_clear(m);
659
660 dh = choose_dh(min, want, max);
661 if (dh == NULL) {
662 buffer_put_char(m, 0);
663 return (0);
664 } else {
665 /* Send first bignum */
666 buffer_put_char(m, 1);
667 buffer_put_bignum2(m, dh->p);
668 buffer_put_bignum2(m, dh->g);
669
670 DH_free(dh);
671 }
672 mm_request_send(sock, MONITOR_ANS_MODULI, m);
673 return (0);
674 }
675
676 int
mm_answer_sign(int sock,Buffer * m)677 mm_answer_sign(int sock, Buffer *m)
678 {
679 Key *key;
680 u_char *p;
681 u_char *signature;
682 u_int siglen, datlen;
683 int keyid;
684
685 debug3("%s", __func__);
686
687 keyid = buffer_get_int(m);
688 p = buffer_get_string(m, &datlen);
689
690 /*
691 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
692 * SHA384 (48 bytes) and SHA512 (64 bytes).
693 */
694 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64)
695 fatal("%s: data length incorrect: %u", __func__, datlen);
696
697 /* save session id, it will be passed on the first call */
698 if (session_id2_len == 0) {
699 session_id2_len = datlen;
700 session_id2 = xmalloc(session_id2_len);
701 memcpy(session_id2, p, session_id2_len);
702 }
703
704 if ((key = get_hostkey_by_index(keyid)) == NULL)
705 fatal("%s: no hostkey from index %d", __func__, keyid);
706 if (key_sign(key, &signature, &siglen, p, datlen) < 0)
707 fatal("%s: key_sign failed", __func__);
708
709 debug3("%s: signature %p(%u)", __func__, signature, siglen);
710
711 buffer_clear(m);
712 buffer_put_string(m, signature, siglen);
713
714 xfree(p);
715 xfree(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 xfree(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_PW_GECOS_IN_PASSWD
765 buffer_put_cstring(m, pwent->pw_gecos);
766 #endif
767 #ifdef HAVE_PW_CLASS_IN_PASSWD
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 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
790 mm_request_send(sock, MONITOR_ANS_PWNAM, m);
791
792 /* For SSHv1 allow authentication now */
793 if (!compat20)
794 monitor_permit_authentications(1);
795 else {
796 /* Allow service/style information on the auth context */
797 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
798 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
799 }
800 #ifdef USE_PAM
801 if (options.use_pam)
802 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
803 #endif
804
805 return (0);
806 }
807
mm_answer_auth2_read_banner(int sock,Buffer * m)808 int mm_answer_auth2_read_banner(int sock, Buffer *m)
809 {
810 char *banner;
811
812 buffer_clear(m);
813 banner = auth2_read_banner();
814 buffer_put_cstring(m, banner != NULL ? banner : "");
815 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
816
817 if (banner != NULL)
818 xfree(banner);
819
820 return (0);
821 }
822
823 int
mm_answer_authserv(int sock,Buffer * m)824 mm_answer_authserv(int sock, Buffer *m)
825 {
826 monitor_permit_authentications(1);
827
828 authctxt->service = buffer_get_string(m, NULL);
829 authctxt->style = buffer_get_string(m, NULL);
830 debug3("%s: service=%s, style=%s",
831 __func__, authctxt->service, authctxt->style);
832
833 if (strlen(authctxt->style) == 0) {
834 xfree(authctxt->style);
835 authctxt->style = NULL;
836 }
837
838 return (0);
839 }
840
841 int
mm_answer_authpassword(int sock,Buffer * m)842 mm_answer_authpassword(int sock, Buffer *m)
843 {
844 static int call_count;
845 char *passwd;
846 int authenticated;
847 u_int plen;
848
849 passwd = buffer_get_string(m, &plen);
850 /* Only authenticate if the context is valid */
851 #ifndef ANDROID
852 /* no password authentication in android */
853 authenticated = options.password_authentication &&
854 auth_password(authctxt, passwd);
855 #else
856 authenticated = 0;
857 #endif
858 memset(passwd, 0, strlen(passwd));
859 xfree(passwd);
860
861 buffer_clear(m);
862 buffer_put_int(m, authenticated);
863
864 debug3("%s: sending result %d", __func__, authenticated);
865 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
866
867 call_count++;
868 if (plen == 0 && call_count == 1)
869 auth_method = "none";
870 else
871 auth_method = "password";
872
873 /* Causes monitor loop to terminate if authenticated */
874 return (authenticated);
875 }
876
877 #ifdef BSD_AUTH
878 int
mm_answer_bsdauthquery(int sock,Buffer * m)879 mm_answer_bsdauthquery(int sock, Buffer *m)
880 {
881 char *name, *infotxt;
882 u_int numprompts;
883 u_int *echo_on;
884 char **prompts;
885 u_int success;
886
887 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
888 &prompts, &echo_on) < 0 ? 0 : 1;
889
890 buffer_clear(m);
891 buffer_put_int(m, success);
892 if (success)
893 buffer_put_cstring(m, prompts[0]);
894
895 debug3("%s: sending challenge success: %u", __func__, success);
896 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
897
898 if (success) {
899 xfree(name);
900 xfree(infotxt);
901 xfree(prompts);
902 xfree(echo_on);
903 }
904
905 return (0);
906 }
907
908 int
mm_answer_bsdauthrespond(int sock,Buffer * m)909 mm_answer_bsdauthrespond(int sock, Buffer *m)
910 {
911 char *response;
912 int authok;
913
914 if (authctxt->as == 0)
915 fatal("%s: no bsd auth session", __func__);
916
917 response = buffer_get_string(m, NULL);
918 authok = options.challenge_response_authentication &&
919 auth_userresponse(authctxt->as, response, 0);
920 authctxt->as = NULL;
921 debug3("%s: <%s> = <%d>", __func__, response, authok);
922 xfree(response);
923
924 buffer_clear(m);
925 buffer_put_int(m, authok);
926
927 debug3("%s: sending authenticated: %d", __func__, authok);
928 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
929
930 auth_method = "bsdauth";
931
932 return (authok != 0);
933 }
934 #endif
935
936 #ifdef SKEY
937 int
mm_answer_skeyquery(int sock,Buffer * m)938 mm_answer_skeyquery(int sock, Buffer *m)
939 {
940 struct skey skey;
941 char challenge[1024];
942 u_int success;
943
944 success = _compat_skeychallenge(&skey, authctxt->user, challenge,
945 sizeof(challenge)) < 0 ? 0 : 1;
946
947 buffer_clear(m);
948 buffer_put_int(m, success);
949 if (success)
950 buffer_put_cstring(m, challenge);
951
952 debug3("%s: sending challenge success: %u", __func__, success);
953 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
954
955 return (0);
956 }
957
958 int
mm_answer_skeyrespond(int sock,Buffer * m)959 mm_answer_skeyrespond(int sock, Buffer *m)
960 {
961 char *response;
962 int authok;
963
964 response = buffer_get_string(m, NULL);
965
966 authok = (options.challenge_response_authentication &&
967 authctxt->valid &&
968 skey_haskey(authctxt->pw->pw_name) == 0 &&
969 skey_passcheck(authctxt->pw->pw_name, response) != -1);
970
971 xfree(response);
972
973 buffer_clear(m);
974 buffer_put_int(m, authok);
975
976 debug3("%s: sending authenticated: %d", __func__, authok);
977 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
978
979 auth_method = "skey";
980
981 return (authok != 0);
982 }
983 #endif
984
985 #ifdef USE_PAM
986 int
mm_answer_pam_start(int sock,Buffer * m)987 mm_answer_pam_start(int sock, Buffer *m)
988 {
989 if (!options.use_pam)
990 fatal("UsePAM not set, but ended up in %s anyway", __func__);
991
992 start_pam(authctxt);
993
994 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
995
996 return (0);
997 }
998
999 int
mm_answer_pam_account(int sock,Buffer * m)1000 mm_answer_pam_account(int sock, Buffer *m)
1001 {
1002 u_int ret;
1003
1004 if (!options.use_pam)
1005 fatal("UsePAM not set, but ended up in %s anyway", __func__);
1006
1007 ret = do_pam_account();
1008
1009 buffer_put_int(m, ret);
1010 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1011
1012 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
1013
1014 return (ret);
1015 }
1016
1017 static void *sshpam_ctxt, *sshpam_authok;
1018 extern KbdintDevice sshpam_device;
1019
1020 int
mm_answer_pam_init_ctx(int sock,Buffer * m)1021 mm_answer_pam_init_ctx(int sock, Buffer *m)
1022 {
1023
1024 debug3("%s", __func__);
1025 authctxt->user = buffer_get_string(m, NULL);
1026 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
1027 sshpam_authok = NULL;
1028 buffer_clear(m);
1029 if (sshpam_ctxt != NULL) {
1030 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
1031 buffer_put_int(m, 1);
1032 } else {
1033 buffer_put_int(m, 0);
1034 }
1035 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
1036 return (0);
1037 }
1038
1039 int
mm_answer_pam_query(int sock,Buffer * m)1040 mm_answer_pam_query(int sock, Buffer *m)
1041 {
1042 char *name = NULL, *info = NULL, **prompts = NULL;
1043 u_int i, num = 0, *echo_on = 0;
1044 int ret;
1045
1046 debug3("%s", __func__);
1047 sshpam_authok = NULL;
1048 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
1049 if (ret == 0 && num == 0)
1050 sshpam_authok = sshpam_ctxt;
1051 if (num > 1 || name == NULL || info == NULL)
1052 ret = -1;
1053 buffer_clear(m);
1054 buffer_put_int(m, ret);
1055 buffer_put_cstring(m, name);
1056 xfree(name);
1057 buffer_put_cstring(m, info);
1058 xfree(info);
1059 buffer_put_int(m, num);
1060 for (i = 0; i < num; ++i) {
1061 buffer_put_cstring(m, prompts[i]);
1062 xfree(prompts[i]);
1063 buffer_put_int(m, echo_on[i]);
1064 }
1065 if (prompts != NULL)
1066 xfree(prompts);
1067 if (echo_on != NULL)
1068 xfree(echo_on);
1069 auth_method = "keyboard-interactive/pam";
1070 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
1071 return (0);
1072 }
1073
1074 int
mm_answer_pam_respond(int sock,Buffer * m)1075 mm_answer_pam_respond(int sock, Buffer *m)
1076 {
1077 char **resp;
1078 u_int i, num;
1079 int ret;
1080
1081 debug3("%s", __func__);
1082 sshpam_authok = NULL;
1083 num = buffer_get_int(m);
1084 if (num > 0) {
1085 resp = xcalloc(num, sizeof(char *));
1086 for (i = 0; i < num; ++i)
1087 resp[i] = buffer_get_string(m, NULL);
1088 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
1089 for (i = 0; i < num; ++i)
1090 xfree(resp[i]);
1091 xfree(resp);
1092 } else {
1093 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
1094 }
1095 buffer_clear(m);
1096 buffer_put_int(m, ret);
1097 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
1098 auth_method = "keyboard-interactive/pam";
1099 if (ret == 0)
1100 sshpam_authok = sshpam_ctxt;
1101 return (0);
1102 }
1103
1104 int
mm_answer_pam_free_ctx(int sock,Buffer * m)1105 mm_answer_pam_free_ctx(int sock, Buffer *m)
1106 {
1107
1108 debug3("%s", __func__);
1109 (sshpam_device.free_ctx)(sshpam_ctxt);
1110 buffer_clear(m);
1111 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
1112 auth_method = "keyboard-interactive/pam";
1113 return (sshpam_authok == sshpam_ctxt);
1114 }
1115 #endif
1116
1117 int
mm_answer_keyallowed(int sock,Buffer * m)1118 mm_answer_keyallowed(int sock, Buffer *m)
1119 {
1120 Key *key;
1121 char *cuser, *chost;
1122 u_char *blob;
1123 u_int bloblen;
1124 enum mm_keytype type = 0;
1125 int allowed = 0;
1126
1127 debug3("%s entering", __func__);
1128
1129 type = buffer_get_int(m);
1130 cuser = buffer_get_string(m, NULL);
1131 chost = buffer_get_string(m, NULL);
1132 blob = buffer_get_string(m, &bloblen);
1133
1134 key = key_from_blob(blob, bloblen);
1135
1136 if ((compat20 && type == MM_RSAHOSTKEY) ||
1137 (!compat20 && type != MM_RSAHOSTKEY))
1138 fatal("%s: key type and protocol mismatch", __func__);
1139
1140 debug3("%s: key_from_blob: %p", __func__, key);
1141
1142 if (key != NULL && authctxt->valid) {
1143 switch (type) {
1144 case MM_USERKEY:
1145 allowed = options.pubkey_authentication &&
1146 user_key_allowed(authctxt->pw, key);
1147 auth_method = "publickey";
1148 if (options.pubkey_authentication && allowed != 1)
1149 auth_clear_options();
1150 break;
1151 case MM_HOSTKEY:
1152 allowed = options.hostbased_authentication &&
1153 hostbased_key_allowed(authctxt->pw,
1154 cuser, chost, key);
1155 auth_method = "hostbased";
1156 break;
1157 case MM_RSAHOSTKEY:
1158 key->type = KEY_RSA1; /* XXX */
1159 allowed = options.rhosts_rsa_authentication &&
1160 auth_rhosts_rsa_key_allowed(authctxt->pw,
1161 cuser, chost, key);
1162 if (options.rhosts_rsa_authentication && allowed != 1)
1163 auth_clear_options();
1164 auth_method = "rsa";
1165 break;
1166 default:
1167 fatal("%s: unknown key type %d", __func__, type);
1168 break;
1169 }
1170 }
1171 if (key != NULL)
1172 key_free(key);
1173
1174 /* clear temporarily storage (used by verify) */
1175 monitor_reset_key_state();
1176
1177 if (allowed) {
1178 /* Save temporarily for comparison in verify */
1179 key_blob = blob;
1180 key_bloblen = bloblen;
1181 key_blobtype = type;
1182 hostbased_cuser = cuser;
1183 hostbased_chost = chost;
1184 } else {
1185 /* Log failed attempt */
1186 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1187 xfree(blob);
1188 xfree(cuser);
1189 xfree(chost);
1190 }
1191
1192 debug3("%s: key %p is %s",
1193 __func__, key, allowed ? "allowed" : "not allowed");
1194
1195 buffer_clear(m);
1196 buffer_put_int(m, allowed);
1197 buffer_put_int(m, forced_command != NULL);
1198
1199 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1200
1201 if (type == MM_RSAHOSTKEY)
1202 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1203
1204 return (0);
1205 }
1206
1207 static int
monitor_valid_userblob(u_char * data,u_int datalen)1208 monitor_valid_userblob(u_char *data, u_int datalen)
1209 {
1210 Buffer b;
1211 char *p;
1212 u_int len;
1213 int fail = 0;
1214
1215 buffer_init(&b);
1216 buffer_append(&b, data, datalen);
1217
1218 if (datafellows & SSH_OLD_SESSIONID) {
1219 p = buffer_ptr(&b);
1220 len = buffer_len(&b);
1221 if ((session_id2 == NULL) ||
1222 (len < session_id2_len) ||
1223 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1224 fail++;
1225 buffer_consume(&b, session_id2_len);
1226 } else {
1227 p = buffer_get_string(&b, &len);
1228 if ((session_id2 == NULL) ||
1229 (len != session_id2_len) ||
1230 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1231 fail++;
1232 xfree(p);
1233 }
1234 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1235 fail++;
1236 p = buffer_get_string(&b, NULL);
1237 if (strcmp(authctxt->user, p) != 0) {
1238 logit("wrong user name passed to monitor: expected %s != %.100s",
1239 authctxt->user, p);
1240 fail++;
1241 }
1242 xfree(p);
1243 buffer_skip_string(&b);
1244 if (datafellows & SSH_BUG_PKAUTH) {
1245 if (!buffer_get_char(&b))
1246 fail++;
1247 } else {
1248 p = buffer_get_string(&b, NULL);
1249 if (strcmp("publickey", p) != 0)
1250 fail++;
1251 xfree(p);
1252 if (!buffer_get_char(&b))
1253 fail++;
1254 buffer_skip_string(&b);
1255 }
1256 buffer_skip_string(&b);
1257 if (buffer_len(&b) != 0)
1258 fail++;
1259 buffer_free(&b);
1260 return (fail == 0);
1261 }
1262
1263 static int
monitor_valid_hostbasedblob(u_char * data,u_int datalen,char * cuser,char * chost)1264 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1265 char *chost)
1266 {
1267 Buffer b;
1268 char *p;
1269 u_int len;
1270 int fail = 0;
1271
1272 buffer_init(&b);
1273 buffer_append(&b, data, datalen);
1274
1275 p = buffer_get_string(&b, &len);
1276 if ((session_id2 == NULL) ||
1277 (len != session_id2_len) ||
1278 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1279 fail++;
1280 xfree(p);
1281
1282 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1283 fail++;
1284 p = buffer_get_string(&b, NULL);
1285 if (strcmp(authctxt->user, p) != 0) {
1286 logit("wrong user name passed to monitor: expected %s != %.100s",
1287 authctxt->user, p);
1288 fail++;
1289 }
1290 xfree(p);
1291 buffer_skip_string(&b); /* service */
1292 p = buffer_get_string(&b, NULL);
1293 if (strcmp(p, "hostbased") != 0)
1294 fail++;
1295 xfree(p);
1296 buffer_skip_string(&b); /* pkalg */
1297 buffer_skip_string(&b); /* pkblob */
1298
1299 /* verify client host, strip trailing dot if necessary */
1300 p = buffer_get_string(&b, NULL);
1301 if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1302 p[len - 1] = '\0';
1303 if (strcmp(p, chost) != 0)
1304 fail++;
1305 xfree(p);
1306
1307 /* verify client user */
1308 p = buffer_get_string(&b, NULL);
1309 if (strcmp(p, cuser) != 0)
1310 fail++;
1311 xfree(p);
1312
1313 if (buffer_len(&b) != 0)
1314 fail++;
1315 buffer_free(&b);
1316 return (fail == 0);
1317 }
1318
1319 int
mm_answer_keyverify(int sock,Buffer * m)1320 mm_answer_keyverify(int sock, Buffer *m)
1321 {
1322 Key *key;
1323 u_char *signature, *data, *blob;
1324 u_int signaturelen, datalen, bloblen;
1325 int verified = 0;
1326 int valid_data = 0;
1327
1328 blob = buffer_get_string(m, &bloblen);
1329 signature = buffer_get_string(m, &signaturelen);
1330 data = buffer_get_string(m, &datalen);
1331
1332 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1333 !monitor_allowed_key(blob, bloblen))
1334 fatal("%s: bad key, not previously allowed", __func__);
1335
1336 key = key_from_blob(blob, bloblen);
1337 if (key == NULL)
1338 fatal("%s: bad public key blob", __func__);
1339
1340 switch (key_blobtype) {
1341 case MM_USERKEY:
1342 valid_data = monitor_valid_userblob(data, datalen);
1343 break;
1344 case MM_HOSTKEY:
1345 valid_data = monitor_valid_hostbasedblob(data, datalen,
1346 hostbased_cuser, hostbased_chost);
1347 break;
1348 default:
1349 valid_data = 0;
1350 break;
1351 }
1352 if (!valid_data)
1353 fatal("%s: bad signature data blob", __func__);
1354
1355 verified = key_verify(key, signature, signaturelen, data, datalen);
1356 debug3("%s: key %p signature %s",
1357 __func__, key, (verified == 1) ? "verified" : "unverified");
1358
1359 key_free(key);
1360 xfree(blob);
1361 xfree(signature);
1362 xfree(data);
1363
1364 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1365
1366 monitor_reset_key_state();
1367
1368 buffer_clear(m);
1369 buffer_put_int(m, verified);
1370 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1371
1372 return (verified == 1);
1373 }
1374
1375 static void
mm_record_login(Session * s,struct passwd * pw)1376 mm_record_login(Session *s, struct passwd *pw)
1377 {
1378 socklen_t fromlen;
1379 struct sockaddr_storage from;
1380
1381 /*
1382 * Get IP address of client. If the connection is not a socket, let
1383 * the address be 0.0.0.0.
1384 */
1385 memset(&from, 0, sizeof(from));
1386 fromlen = sizeof(from);
1387 if (packet_connection_is_on_socket()) {
1388 if (getpeername(packet_get_connection_in(),
1389 (struct sockaddr *)&from, &fromlen) < 0) {
1390 debug("getpeername: %.100s", strerror(errno));
1391 cleanup_exit(255);
1392 }
1393 }
1394 /* Record that there was a login on that tty from the remote host. */
1395 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1396 get_remote_name_or_ip(utmp_len, options.use_dns),
1397 (struct sockaddr *)&from, fromlen);
1398 }
1399
1400 static void
mm_session_close(Session * s)1401 mm_session_close(Session *s)
1402 {
1403 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1404 if (s->ttyfd != -1) {
1405 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1406 session_pty_cleanup2(s);
1407 }
1408 session_unused(s->self);
1409 }
1410
1411 int
mm_answer_pty(int sock,Buffer * m)1412 mm_answer_pty(int sock, Buffer *m)
1413 {
1414 extern struct monitor *pmonitor;
1415 Session *s;
1416 int res, fd0;
1417
1418 debug3("%s entering", __func__);
1419
1420 buffer_clear(m);
1421 s = session_new();
1422 if (s == NULL)
1423 goto error;
1424 s->authctxt = authctxt;
1425 s->pw = authctxt->pw;
1426 s->pid = pmonitor->m_pid;
1427 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1428 if (res == 0)
1429 goto error;
1430 pty_setowner(authctxt->pw, s->tty);
1431
1432 buffer_put_int(m, 1);
1433 buffer_put_cstring(m, s->tty);
1434
1435 /* We need to trick ttyslot */
1436 if (dup2(s->ttyfd, 0) == -1)
1437 fatal("%s: dup2", __func__);
1438
1439 mm_record_login(s, authctxt->pw);
1440
1441 /* Now we can close the file descriptor again */
1442 close(0);
1443
1444 /* send messages generated by record_login */
1445 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1446 buffer_clear(&loginmsg);
1447
1448 mm_request_send(sock, MONITOR_ANS_PTY, m);
1449
1450 if (mm_send_fd(sock, s->ptyfd) == -1 ||
1451 mm_send_fd(sock, s->ttyfd) == -1)
1452 fatal("%s: send fds failed", __func__);
1453
1454 /* make sure nothing uses fd 0 */
1455 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1456 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1457 if (fd0 != 0)
1458 error("%s: fd0 %d != 0", __func__, fd0);
1459
1460 /* slave is not needed */
1461 close(s->ttyfd);
1462 s->ttyfd = s->ptyfd;
1463 /* no need to dup() because nobody closes ptyfd */
1464 s->ptymaster = s->ptyfd;
1465
1466 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1467
1468 return (0);
1469
1470 error:
1471 if (s != NULL)
1472 mm_session_close(s);
1473 buffer_put_int(m, 0);
1474 mm_request_send(sock, MONITOR_ANS_PTY, m);
1475 return (0);
1476 }
1477
1478 int
mm_answer_pty_cleanup(int sock,Buffer * m)1479 mm_answer_pty_cleanup(int sock, Buffer *m)
1480 {
1481 Session *s;
1482 char *tty;
1483
1484 debug3("%s entering", __func__);
1485
1486 tty = buffer_get_string(m, NULL);
1487 if ((s = session_by_tty(tty)) != NULL)
1488 mm_session_close(s);
1489 buffer_clear(m);
1490 xfree(tty);
1491 return (0);
1492 }
1493
1494 int
mm_answer_sesskey(int sock,Buffer * m)1495 mm_answer_sesskey(int sock, Buffer *m)
1496 {
1497 BIGNUM *p;
1498 int rsafail;
1499
1500 /* Turn off permissions */
1501 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1502
1503 if ((p = BN_new()) == NULL)
1504 fatal("%s: BN_new", __func__);
1505
1506 buffer_get_bignum2(m, p);
1507
1508 rsafail = ssh1_session_key(p);
1509
1510 buffer_clear(m);
1511 buffer_put_int(m, rsafail);
1512 buffer_put_bignum2(m, p);
1513
1514 BN_clear_free(p);
1515
1516 mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1517
1518 /* Turn on permissions for sessid passing */
1519 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1520
1521 return (0);
1522 }
1523
1524 int
mm_answer_sessid(int sock,Buffer * m)1525 mm_answer_sessid(int sock, Buffer *m)
1526 {
1527 int i;
1528
1529 debug3("%s entering", __func__);
1530
1531 if (buffer_len(m) != 16)
1532 fatal("%s: bad ssh1 session id", __func__);
1533 for (i = 0; i < 16; i++)
1534 session_id[i] = buffer_get_char(m);
1535
1536 /* Turn on permissions for getpwnam */
1537 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1538
1539 return (0);
1540 }
1541
1542 int
mm_answer_rsa_keyallowed(int sock,Buffer * m)1543 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1544 {
1545 BIGNUM *client_n;
1546 Key *key = NULL;
1547 u_char *blob = NULL;
1548 u_int blen = 0;
1549 int allowed = 0;
1550
1551 debug3("%s entering", __func__);
1552
1553 auth_method = "rsa";
1554 if (options.rsa_authentication && authctxt->valid) {
1555 if ((client_n = BN_new()) == NULL)
1556 fatal("%s: BN_new", __func__);
1557 buffer_get_bignum2(m, client_n);
1558 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1559 BN_clear_free(client_n);
1560 }
1561 buffer_clear(m);
1562 buffer_put_int(m, allowed);
1563 buffer_put_int(m, forced_command != NULL);
1564
1565 /* clear temporarily storage (used by generate challenge) */
1566 monitor_reset_key_state();
1567
1568 if (allowed && key != NULL) {
1569 key->type = KEY_RSA; /* cheat for key_to_blob */
1570 if (key_to_blob(key, &blob, &blen) == 0)
1571 fatal("%s: key_to_blob failed", __func__);
1572 buffer_put_string(m, blob, blen);
1573
1574 /* Save temporarily for comparison in verify */
1575 key_blob = blob;
1576 key_bloblen = blen;
1577 key_blobtype = MM_RSAUSERKEY;
1578 }
1579 if (key != NULL)
1580 key_free(key);
1581
1582 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1583
1584 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1585 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1586 return (0);
1587 }
1588
1589 int
mm_answer_rsa_challenge(int sock,Buffer * m)1590 mm_answer_rsa_challenge(int sock, Buffer *m)
1591 {
1592 Key *key = NULL;
1593 u_char *blob;
1594 u_int blen;
1595
1596 debug3("%s entering", __func__);
1597
1598 if (!authctxt->valid)
1599 fatal("%s: authctxt not valid", __func__);
1600 blob = buffer_get_string(m, &blen);
1601 if (!monitor_allowed_key(blob, blen))
1602 fatal("%s: bad key, not previously allowed", __func__);
1603 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1604 fatal("%s: key type mismatch", __func__);
1605 if ((key = key_from_blob(blob, blen)) == NULL)
1606 fatal("%s: received bad key", __func__);
1607 if (key->type != KEY_RSA)
1608 fatal("%s: received bad key type %d", __func__, key->type);
1609 key->type = KEY_RSA1;
1610 if (ssh1_challenge)
1611 BN_clear_free(ssh1_challenge);
1612 ssh1_challenge = auth_rsa_generate_challenge(key);
1613
1614 buffer_clear(m);
1615 buffer_put_bignum2(m, ssh1_challenge);
1616
1617 debug3("%s sending reply", __func__);
1618 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1619
1620 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1621
1622 xfree(blob);
1623 key_free(key);
1624 return (0);
1625 }
1626
1627 int
mm_answer_rsa_response(int sock,Buffer * m)1628 mm_answer_rsa_response(int sock, Buffer *m)
1629 {
1630 Key *key = NULL;
1631 u_char *blob, *response;
1632 u_int blen, len;
1633 int success;
1634
1635 debug3("%s entering", __func__);
1636
1637 if (!authctxt->valid)
1638 fatal("%s: authctxt not valid", __func__);
1639 if (ssh1_challenge == NULL)
1640 fatal("%s: no ssh1_challenge", __func__);
1641
1642 blob = buffer_get_string(m, &blen);
1643 if (!monitor_allowed_key(blob, blen))
1644 fatal("%s: bad key, not previously allowed", __func__);
1645 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1646 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1647 if ((key = key_from_blob(blob, blen)) == NULL)
1648 fatal("%s: received bad key", __func__);
1649 response = buffer_get_string(m, &len);
1650 if (len != 16)
1651 fatal("%s: received bad response to challenge", __func__);
1652 success = auth_rsa_verify_response(key, ssh1_challenge, response);
1653
1654 xfree(blob);
1655 key_free(key);
1656 xfree(response);
1657
1658 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1659
1660 /* reset state */
1661 BN_clear_free(ssh1_challenge);
1662 ssh1_challenge = NULL;
1663 monitor_reset_key_state();
1664
1665 buffer_clear(m);
1666 buffer_put_int(m, success);
1667 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1668
1669 return (success);
1670 }
1671
1672 int
mm_answer_term(int sock,Buffer * req)1673 mm_answer_term(int sock, Buffer *req)
1674 {
1675 extern struct monitor *pmonitor;
1676 int res, status;
1677
1678 debug3("%s: tearing down sessions", __func__);
1679
1680 /* The child is terminating */
1681 session_destroy_all(&mm_session_close);
1682
1683 #ifdef USE_PAM
1684 if (options.use_pam)
1685 sshpam_cleanup();
1686 #endif
1687
1688 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1689 if (errno != EINTR)
1690 exit(1);
1691
1692 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1693
1694 /* Terminate process */
1695 exit(res);
1696 }
1697
1698 #ifdef SSH_AUDIT_EVENTS
1699 /* Report that an audit event occurred */
1700 int
mm_answer_audit_event(int socket,Buffer * m)1701 mm_answer_audit_event(int socket, Buffer *m)
1702 {
1703 ssh_audit_event_t event;
1704
1705 debug3("%s entering", __func__);
1706
1707 event = buffer_get_int(m);
1708 switch(event) {
1709 case SSH_AUTH_FAIL_PUBKEY:
1710 case SSH_AUTH_FAIL_HOSTBASED:
1711 case SSH_AUTH_FAIL_GSSAPI:
1712 case SSH_LOGIN_EXCEED_MAXTRIES:
1713 case SSH_LOGIN_ROOT_DENIED:
1714 case SSH_CONNECTION_CLOSE:
1715 case SSH_INVALID_USER:
1716 audit_event(event);
1717 break;
1718 default:
1719 fatal("Audit event type %d not permitted", event);
1720 }
1721
1722 return (0);
1723 }
1724
1725 int
mm_answer_audit_command(int socket,Buffer * m)1726 mm_answer_audit_command(int socket, Buffer *m)
1727 {
1728 u_int len;
1729 char *cmd;
1730
1731 debug3("%s entering", __func__);
1732 cmd = buffer_get_string(m, &len);
1733 /* sanity check command, if so how? */
1734 audit_run_command(cmd);
1735 xfree(cmd);
1736 return (0);
1737 }
1738 #endif /* SSH_AUDIT_EVENTS */
1739
1740 void
monitor_apply_keystate(struct monitor * pmonitor)1741 monitor_apply_keystate(struct monitor *pmonitor)
1742 {
1743 if (compat20) {
1744 set_newkeys(MODE_IN);
1745 set_newkeys(MODE_OUT);
1746 } else {
1747 packet_set_protocol_flags(child_state.ssh1protoflags);
1748 packet_set_encryption_key(child_state.ssh1key,
1749 child_state.ssh1keylen, child_state.ssh1cipher);
1750 xfree(child_state.ssh1key);
1751 }
1752
1753 /* for rc4 and other stateful ciphers */
1754 packet_set_keycontext(MODE_OUT, child_state.keyout);
1755 xfree(child_state.keyout);
1756 packet_set_keycontext(MODE_IN, child_state.keyin);
1757 xfree(child_state.keyin);
1758
1759 if (!compat20) {
1760 packet_set_iv(MODE_OUT, child_state.ivout);
1761 xfree(child_state.ivout);
1762 packet_set_iv(MODE_IN, child_state.ivin);
1763 xfree(child_state.ivin);
1764 }
1765
1766 memcpy(&incoming_stream, &child_state.incoming,
1767 sizeof(incoming_stream));
1768 memcpy(&outgoing_stream, &child_state.outgoing,
1769 sizeof(outgoing_stream));
1770
1771 /* Update with new address */
1772 if (options.compression)
1773 mm_init_compression(pmonitor->m_zlib);
1774
1775 /* Network I/O buffers */
1776 /* XXX inefficient for large buffers, need: buffer_init_from_string */
1777 buffer_clear(packet_get_input());
1778 buffer_append(packet_get_input(), child_state.input, child_state.ilen);
1779 memset(child_state.input, 0, child_state.ilen);
1780 xfree(child_state.input);
1781
1782 buffer_clear(packet_get_output());
1783 buffer_append(packet_get_output(), child_state.output,
1784 child_state.olen);
1785 memset(child_state.output, 0, child_state.olen);
1786 xfree(child_state.output);
1787
1788 /* Roaming */
1789 if (compat20)
1790 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes);
1791 }
1792
1793 static Kex *
mm_get_kex(Buffer * m)1794 mm_get_kex(Buffer *m)
1795 {
1796 Kex *kex;
1797 void *blob;
1798 u_int bloblen;
1799
1800 kex = xcalloc(1, sizeof(*kex));
1801 kex->session_id = buffer_get_string(m, &kex->session_id_len);
1802 if (session_id2 == NULL ||
1803 kex->session_id_len != session_id2_len ||
1804 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0)
1805 fatal("mm_get_get: internal error: bad session id");
1806 kex->we_need = buffer_get_int(m);
1807 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1808 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1809 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1810 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1811 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1812 kex->server = 1;
1813 kex->hostkey_type = buffer_get_int(m);
1814 kex->kex_type = buffer_get_int(m);
1815 blob = buffer_get_string(m, &bloblen);
1816 buffer_init(&kex->my);
1817 buffer_append(&kex->my, blob, bloblen);
1818 xfree(blob);
1819 blob = buffer_get_string(m, &bloblen);
1820 buffer_init(&kex->peer);
1821 buffer_append(&kex->peer, blob, bloblen);
1822 xfree(blob);
1823 kex->done = 1;
1824 kex->flags = buffer_get_int(m);
1825 kex->client_version_string = buffer_get_string(m, NULL);
1826 kex->server_version_string = buffer_get_string(m, NULL);
1827 kex->load_host_public_key=&get_hostkey_public_by_type;
1828 kex->load_host_private_key=&get_hostkey_private_by_type;
1829 kex->host_key_index=&get_hostkey_index;
1830
1831 return (kex);
1832 }
1833
1834 /* This function requries careful sanity checking */
1835
1836 void
mm_get_keystate(struct monitor * pmonitor)1837 mm_get_keystate(struct monitor *pmonitor)
1838 {
1839 Buffer m;
1840 u_char *blob, *p;
1841 u_int bloblen, plen;
1842 u_int32_t seqnr, packets;
1843 u_int64_t blocks, bytes;
1844
1845 debug3("%s: Waiting for new keys", __func__);
1846
1847 buffer_init(&m);
1848 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1849 if (!compat20) {
1850 child_state.ssh1protoflags = buffer_get_int(&m);
1851 child_state.ssh1cipher = buffer_get_int(&m);
1852 child_state.ssh1key = buffer_get_string(&m,
1853 &child_state.ssh1keylen);
1854 child_state.ivout = buffer_get_string(&m,
1855 &child_state.ivoutlen);
1856 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1857 goto skip;
1858 } else {
1859 /* Get the Kex for rekeying */
1860 *pmonitor->m_pkex = mm_get_kex(&m);
1861 }
1862
1863 blob = buffer_get_string(&m, &bloblen);
1864 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1865 xfree(blob);
1866
1867 debug3("%s: Waiting for second key", __func__);
1868 blob = buffer_get_string(&m, &bloblen);
1869 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1870 xfree(blob);
1871
1872 /* Now get sequence numbers for the packets */
1873 seqnr = buffer_get_int(&m);
1874 blocks = buffer_get_int64(&m);
1875 packets = buffer_get_int(&m);
1876 bytes = buffer_get_int64(&m);
1877 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1878 seqnr = buffer_get_int(&m);
1879 blocks = buffer_get_int64(&m);
1880 packets = buffer_get_int(&m);
1881 bytes = buffer_get_int64(&m);
1882 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1883
1884 skip:
1885 /* Get the key context */
1886 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1887 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1888
1889 debug3("%s: Getting compression state", __func__);
1890 /* Get compression state */
1891 p = buffer_get_string(&m, &plen);
1892 if (plen != sizeof(child_state.outgoing))
1893 fatal("%s: bad request size", __func__);
1894 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1895 xfree(p);
1896
1897 p = buffer_get_string(&m, &plen);
1898 if (plen != sizeof(child_state.incoming))
1899 fatal("%s: bad request size", __func__);
1900 memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1901 xfree(p);
1902
1903 /* Network I/O buffers */
1904 debug3("%s: Getting Network I/O buffers", __func__);
1905 child_state.input = buffer_get_string(&m, &child_state.ilen);
1906 child_state.output = buffer_get_string(&m, &child_state.olen);
1907
1908 /* Roaming */
1909 if (compat20) {
1910 child_state.sent_bytes = buffer_get_int64(&m);
1911 child_state.recv_bytes = buffer_get_int64(&m);
1912 }
1913
1914 buffer_free(&m);
1915 }
1916
1917
1918 /* Allocation functions for zlib */
1919 void *
mm_zalloc(struct mm_master * mm,u_int ncount,u_int size)1920 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1921 {
1922 size_t len = (size_t) size * ncount;
1923 void *address;
1924
1925 if (len == 0 || ncount > SIZE_T_MAX / size)
1926 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1927
1928 address = mm_malloc(mm, len);
1929
1930 return (address);
1931 }
1932
1933 void
mm_zfree(struct mm_master * mm,void * address)1934 mm_zfree(struct mm_master *mm, void *address)
1935 {
1936 mm_free(mm, address);
1937 }
1938
1939 void
mm_init_compression(struct mm_master * mm)1940 mm_init_compression(struct mm_master *mm)
1941 {
1942 outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1943 outgoing_stream.zfree = (free_func)mm_zfree;
1944 outgoing_stream.opaque = mm;
1945
1946 incoming_stream.zalloc = (alloc_func)mm_zalloc;
1947 incoming_stream.zfree = (free_func)mm_zfree;
1948 incoming_stream.opaque = mm;
1949 }
1950
1951 /* XXX */
1952
1953 #define FD_CLOSEONEXEC(x) do { \
1954 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1955 fatal("fcntl(%d, F_SETFD)", x); \
1956 } while (0)
1957
1958 static void
monitor_openfds(struct monitor * mon,int do_logfds)1959 monitor_openfds(struct monitor *mon, int do_logfds)
1960 {
1961 int pair[2];
1962
1963 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1964 fatal("%s: socketpair: %s", __func__, strerror(errno));
1965 FD_CLOSEONEXEC(pair[0]);
1966 FD_CLOSEONEXEC(pair[1]);
1967 mon->m_recvfd = pair[0];
1968 mon->m_sendfd = pair[1];
1969
1970 if (do_logfds) {
1971 if (pipe(pair) == -1)
1972 fatal("%s: pipe: %s", __func__, strerror(errno));
1973 FD_CLOSEONEXEC(pair[0]);
1974 FD_CLOSEONEXEC(pair[1]);
1975 mon->m_log_recvfd = pair[0];
1976 mon->m_log_sendfd = pair[1];
1977 } else
1978 mon->m_log_recvfd = mon->m_log_sendfd = -1;
1979 }
1980
1981 #define MM_MEMSIZE 65536
1982
1983 struct monitor *
monitor_init(void)1984 monitor_init(void)
1985 {
1986 struct monitor *mon;
1987
1988 mon = xcalloc(1, sizeof(*mon));
1989
1990 monitor_openfds(mon, 1);
1991
1992 /* Used to share zlib space across processes */
1993 if (options.compression) {
1994 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1995 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1996
1997 /* Compression needs to share state across borders */
1998 mm_init_compression(mon->m_zlib);
1999 }
2000
2001 return mon;
2002 }
2003
2004 void
monitor_reinit(struct monitor * mon)2005 monitor_reinit(struct monitor *mon)
2006 {
2007 monitor_openfds(mon, 0);
2008 }
2009
2010 #ifdef GSSAPI
2011 int
mm_answer_gss_setup_ctx(int sock,Buffer * m)2012 mm_answer_gss_setup_ctx(int sock, Buffer *m)
2013 {
2014 gss_OID_desc goid;
2015 OM_uint32 major;
2016 u_int len;
2017
2018 goid.elements = buffer_get_string(m, &len);
2019 goid.length = len;
2020
2021 major = ssh_gssapi_server_ctx(&gsscontext, &goid);
2022
2023 xfree(goid.elements);
2024
2025 buffer_clear(m);
2026 buffer_put_int(m, major);
2027
2028 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
2029
2030 /* Now we have a context, enable the step */
2031 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
2032
2033 return (0);
2034 }
2035
2036 int
mm_answer_gss_accept_ctx(int sock,Buffer * m)2037 mm_answer_gss_accept_ctx(int sock, Buffer *m)
2038 {
2039 gss_buffer_desc in;
2040 gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
2041 OM_uint32 major, minor;
2042 OM_uint32 flags = 0; /* GSI needs this */
2043 u_int len;
2044
2045 in.value = buffer_get_string(m, &len);
2046 in.length = len;
2047 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
2048 xfree(in.value);
2049
2050 buffer_clear(m);
2051 buffer_put_int(m, major);
2052 buffer_put_string(m, out.value, out.length);
2053 buffer_put_int(m, flags);
2054 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
2055
2056 gss_release_buffer(&minor, &out);
2057
2058 if (major == GSS_S_COMPLETE) {
2059 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
2060 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2061 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
2062 }
2063 return (0);
2064 }
2065
2066 int
mm_answer_gss_checkmic(int sock,Buffer * m)2067 mm_answer_gss_checkmic(int sock, Buffer *m)
2068 {
2069 gss_buffer_desc gssbuf, mic;
2070 OM_uint32 ret;
2071 u_int len;
2072
2073 gssbuf.value = buffer_get_string(m, &len);
2074 gssbuf.length = len;
2075 mic.value = buffer_get_string(m, &len);
2076 mic.length = len;
2077
2078 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
2079
2080 xfree(gssbuf.value);
2081 xfree(mic.value);
2082
2083 buffer_clear(m);
2084 buffer_put_int(m, ret);
2085
2086 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
2087
2088 if (!GSS_ERROR(ret))
2089 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2090
2091 return (0);
2092 }
2093
2094 int
mm_answer_gss_userok(int sock,Buffer * m)2095 mm_answer_gss_userok(int sock, Buffer *m)
2096 {
2097 int authenticated;
2098
2099 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2100
2101 buffer_clear(m);
2102 buffer_put_int(m, authenticated);
2103
2104 debug3("%s: sending result %d", __func__, authenticated);
2105 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
2106
2107 auth_method = "gssapi-with-mic";
2108
2109 /* Monitor loop will terminate if authenticated */
2110 return (authenticated);
2111 }
2112 #endif /* GSSAPI */
2113
2114 #ifdef JPAKE
2115 int
mm_answer_jpake_step1(int sock,Buffer * m)2116 mm_answer_jpake_step1(int sock, Buffer *m)
2117 {
2118 struct jpake_ctx *pctx;
2119 u_char *x3_proof, *x4_proof;
2120 u_int x3_proof_len, x4_proof_len;
2121
2122 if (!options.zero_knowledge_password_authentication)
2123 fatal("zero_knowledge_password_authentication disabled");
2124
2125 if (authctxt->jpake_ctx != NULL)
2126 fatal("%s: authctxt->jpake_ctx already set (%p)",
2127 __func__, authctxt->jpake_ctx);
2128 authctxt->jpake_ctx = pctx = jpake_new();
2129
2130 jpake_step1(pctx->grp,
2131 &pctx->server_id, &pctx->server_id_len,
2132 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4,
2133 &x3_proof, &x3_proof_len,
2134 &x4_proof, &x4_proof_len);
2135
2136 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__));
2137
2138 buffer_clear(m);
2139
2140 buffer_put_string(m, pctx->server_id, pctx->server_id_len);
2141 buffer_put_bignum2(m, pctx->g_x3);
2142 buffer_put_bignum2(m, pctx->g_x4);
2143 buffer_put_string(m, x3_proof, x3_proof_len);
2144 buffer_put_string(m, x4_proof, x4_proof_len);
2145
2146 debug3("%s: sending step1", __func__);
2147 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m);
2148
2149 bzero(x3_proof, x3_proof_len);
2150 bzero(x4_proof, x4_proof_len);
2151 xfree(x3_proof);
2152 xfree(x4_proof);
2153
2154 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1);
2155 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0);
2156
2157 return 0;
2158 }
2159
2160 int
mm_answer_jpake_get_pwdata(int sock,Buffer * m)2161 mm_answer_jpake_get_pwdata(int sock, Buffer *m)
2162 {
2163 struct jpake_ctx *pctx = authctxt->jpake_ctx;
2164 char *hash_scheme, *salt;
2165
2166 if (pctx == NULL)
2167 fatal("%s: pctx == NULL", __func__);
2168
2169 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt);
2170
2171 buffer_clear(m);
2172 /* pctx->s is sensitive, not returned to slave */
2173 buffer_put_cstring(m, hash_scheme);
2174 buffer_put_cstring(m, salt);
2175
2176 debug3("%s: sending pwdata", __func__);
2177 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m);
2178
2179 bzero(hash_scheme, strlen(hash_scheme));
2180 bzero(salt, strlen(salt));
2181 xfree(hash_scheme);
2182 xfree(salt);
2183
2184 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1);
2185
2186 return 0;
2187 }
2188
2189 int
mm_answer_jpake_step2(int sock,Buffer * m)2190 mm_answer_jpake_step2(int sock, Buffer *m)
2191 {
2192 struct jpake_ctx *pctx = authctxt->jpake_ctx;
2193 u_char *x1_proof, *x2_proof, *x4_s_proof;
2194 u_int x1_proof_len, x2_proof_len, x4_s_proof_len;
2195
2196 if (pctx == NULL)
2197 fatal("%s: pctx == NULL", __func__);
2198
2199 if ((pctx->g_x1 = BN_new()) == NULL ||
2200 (pctx->g_x2 = BN_new()) == NULL)
2201 fatal("%s: BN_new", __func__);
2202 buffer_get_bignum2(m, pctx->g_x1);
2203 buffer_get_bignum2(m, pctx->g_x2);
2204 pctx->client_id = buffer_get_string(m, &pctx->client_id_len);
2205 x1_proof = buffer_get_string(m, &x1_proof_len);
2206 x2_proof = buffer_get_string(m, &x2_proof_len);
2207
2208 jpake_step2(pctx->grp, pctx->s, pctx->g_x3,
2209 pctx->g_x1, pctx->g_x2, pctx->x4,
2210 pctx->client_id, pctx->client_id_len,
2211 pctx->server_id, pctx->server_id_len,
2212 x1_proof, x1_proof_len,
2213 x2_proof, x2_proof_len,
2214 &pctx->b,
2215 &x4_s_proof, &x4_s_proof_len);
2216
2217 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__));
2218
2219 bzero(x1_proof, x1_proof_len);
2220 bzero(x2_proof, x2_proof_len);
2221 xfree(x1_proof);
2222 xfree(x2_proof);
2223
2224 buffer_clear(m);
2225
2226 buffer_put_bignum2(m, pctx->b);
2227 buffer_put_string(m, x4_s_proof, x4_s_proof_len);
2228
2229 debug3("%s: sending step2", __func__);
2230 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m);
2231
2232 bzero(x4_s_proof, x4_s_proof_len);
2233 xfree(x4_s_proof);
2234
2235 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1);
2236
2237 return 0;
2238 }
2239
2240 int
mm_answer_jpake_key_confirm(int sock,Buffer * m)2241 mm_answer_jpake_key_confirm(int sock, Buffer *m)
2242 {
2243 struct jpake_ctx *pctx = authctxt->jpake_ctx;
2244 u_char *x2_s_proof;
2245 u_int x2_s_proof_len;
2246
2247 if (pctx == NULL)
2248 fatal("%s: pctx == NULL", __func__);
2249
2250 if ((pctx->a = BN_new()) == NULL)
2251 fatal("%s: BN_new", __func__);
2252 buffer_get_bignum2(m, pctx->a);
2253 x2_s_proof = buffer_get_string(m, &x2_s_proof_len);
2254
2255 jpake_key_confirm(pctx->grp, pctx->s, pctx->a,
2256 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2,
2257 pctx->server_id, pctx->server_id_len,
2258 pctx->client_id, pctx->client_id_len,
2259 session_id2, session_id2_len,
2260 x2_s_proof, x2_s_proof_len,
2261 &pctx->k,
2262 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len);
2263
2264 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__));
2265
2266 bzero(x2_s_proof, x2_s_proof_len);
2267 buffer_clear(m);
2268
2269 /* pctx->k is sensitive, not sent */
2270 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len);
2271
2272 debug3("%s: sending confirmation hash", __func__);
2273 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m);
2274
2275 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1);
2276
2277 return 0;
2278 }
2279
2280 int
mm_answer_jpake_check_confirm(int sock,Buffer * m)2281 mm_answer_jpake_check_confirm(int sock, Buffer *m)
2282 {
2283 int authenticated = 0;
2284 u_char *peer_confirm_hash;
2285 u_int peer_confirm_hash_len;
2286 struct jpake_ctx *pctx = authctxt->jpake_ctx;
2287
2288 if (pctx == NULL)
2289 fatal("%s: pctx == NULL", __func__);
2290
2291 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len);
2292
2293 authenticated = jpake_check_confirm(pctx->k,
2294 pctx->client_id, pctx->client_id_len,
2295 session_id2, session_id2_len,
2296 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid;
2297
2298 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__));
2299
2300 bzero(peer_confirm_hash, peer_confirm_hash_len);
2301 xfree(peer_confirm_hash);
2302
2303 buffer_clear(m);
2304 buffer_put_int(m, authenticated);
2305
2306 debug3("%s: sending result %d", __func__, authenticated);
2307 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m);
2308
2309 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1);
2310
2311 auth_method = "jpake-01@openssh.com";
2312 return authenticated;
2313 }
2314
2315 #endif /* JPAKE */
2316