xref: /openbsd-src/usr.bin/ssh/monitor.c (revision 48950c12d106c85f315112191a0228d7b83b9510)
1 /* $OpenBSD: monitor.c,v 1.122 2013/03/07 19:27:25 markus 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 <sys/types.h>
29 #include <sys/wait.h>
30 #include <sys/socket.h>
31 #include <sys/tree.h>
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 
35 #include <openssl/dh.h>
36 
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <paths.h>
40 #include <poll.h>
41 #include <pwd.h>
42 #include <signal.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "atomicio.h"
47 #include "xmalloc.h"
48 #include "ssh.h"
49 #include "key.h"
50 #include "buffer.h"
51 #include "hostfile.h"
52 #include "auth.h"
53 #include "cipher.h"
54 #include "kex.h"
55 #include "dh.h"
56 #include <zlib.h>
57 #include "packet.h"
58 #include "auth-options.h"
59 #include "sshpty.h"
60 #include "channels.h"
61 #include "session.h"
62 #include "sshlogin.h"
63 #include "canohost.h"
64 #include "log.h"
65 #include "servconf.h"
66 #include "monitor.h"
67 #include "monitor_mm.h"
68 #ifdef GSSAPI
69 #include "ssh-gss.h"
70 #endif
71 #include "monitor_wrap.h"
72 #include "monitor_fdpass.h"
73 #include "misc.h"
74 #include "compat.h"
75 #include "ssh2.h"
76 #include "jpake.h"
77 #include "roaming.h"
78 
79 #ifdef GSSAPI
80 static Gssctxt *gsscontext = NULL;
81 #endif
82 
83 /* Imports */
84 extern ServerOptions options;
85 extern u_int utmp_len;
86 extern Newkeys *current_keys[];
87 extern z_stream incoming_stream;
88 extern z_stream outgoing_stream;
89 extern u_char session_id[];
90 extern Buffer auth_debug;
91 extern int auth_debug_init;
92 extern Buffer loginmsg;
93 
94 /* State exported from the child */
95 
96 struct {
97 	z_stream incoming;
98 	z_stream outgoing;
99 	u_char *keyin;
100 	u_int keyinlen;
101 	u_char *keyout;
102 	u_int keyoutlen;
103 	u_char *ivin;
104 	u_int ivinlen;
105 	u_char *ivout;
106 	u_int ivoutlen;
107 	u_char *ssh1key;
108 	u_int ssh1keylen;
109 	int ssh1cipher;
110 	int ssh1protoflags;
111 	u_char *input;
112 	u_int ilen;
113 	u_char *output;
114 	u_int olen;
115 	u_int64_t sent_bytes;
116 	u_int64_t recv_bytes;
117 } child_state;
118 
119 /* Functions on the monitor that answer unprivileged requests */
120 
121 int mm_answer_moduli(int, Buffer *);
122 int mm_answer_sign(int, Buffer *);
123 int mm_answer_pwnamallow(int, Buffer *);
124 int mm_answer_auth2_read_banner(int, Buffer *);
125 int mm_answer_authserv(int, Buffer *);
126 int mm_answer_authpassword(int, Buffer *);
127 int mm_answer_bsdauthquery(int, Buffer *);
128 int mm_answer_bsdauthrespond(int, Buffer *);
129 int mm_answer_skeyquery(int, Buffer *);
130 int mm_answer_skeyrespond(int, Buffer *);
131 int mm_answer_keyallowed(int, Buffer *);
132 int mm_answer_keyverify(int, Buffer *);
133 int mm_answer_pty(int, Buffer *);
134 int mm_answer_pty_cleanup(int, Buffer *);
135 int mm_answer_term(int, Buffer *);
136 int mm_answer_rsa_keyallowed(int, Buffer *);
137 int mm_answer_rsa_challenge(int, Buffer *);
138 int mm_answer_rsa_response(int, Buffer *);
139 int mm_answer_sesskey(int, Buffer *);
140 int mm_answer_sessid(int, Buffer *);
141 int mm_answer_jpake_get_pwdata(int, Buffer *);
142 int mm_answer_jpake_step1(int, Buffer *);
143 int mm_answer_jpake_step2(int, Buffer *);
144 int mm_answer_jpake_key_confirm(int, Buffer *);
145 int mm_answer_jpake_check_confirm(int, Buffer *);
146 
147 #ifdef GSSAPI
148 int mm_answer_gss_setup_ctx(int, Buffer *);
149 int mm_answer_gss_accept_ctx(int, Buffer *);
150 int mm_answer_gss_userok(int, Buffer *);
151 int mm_answer_gss_checkmic(int, Buffer *);
152 #endif
153 
154 static int monitor_read_log(struct monitor *);
155 
156 static Authctxt *authctxt;
157 static BIGNUM *ssh1_challenge = NULL;	/* used for ssh1 rsa auth */
158 
159 /* local state for key verify */
160 static u_char *key_blob = NULL;
161 static u_int key_bloblen = 0;
162 static int key_blobtype = MM_NOKEY;
163 static char *hostbased_cuser = NULL;
164 static char *hostbased_chost = NULL;
165 static char *auth_method = "unknown";
166 static char *auth_submethod = NULL;
167 static u_int session_id2_len = 0;
168 static u_char *session_id2 = NULL;
169 static pid_t monitor_child_pid;
170 
171 struct mon_table {
172 	enum monitor_reqtype type;
173 	int flags;
174 	int (*f)(int, Buffer *);
175 };
176 
177 #define MON_ISAUTH	0x0004	/* Required for Authentication */
178 #define MON_AUTHDECIDE	0x0008	/* Decides Authentication */
179 #define MON_ONCE	0x0010	/* Disable after calling */
180 #define MON_ALOG	0x0020	/* Log auth attempt without authenticating */
181 
182 #define MON_AUTH	(MON_ISAUTH|MON_AUTHDECIDE)
183 
184 #define MON_PERMIT	0x1000	/* Request is permitted */
185 
186 struct mon_table mon_dispatch_proto20[] = {
187     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
188     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
189     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
190     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
191     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
192     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
193     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
194     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
195     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
196     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
197 #ifdef GSSAPI
198     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
199     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
200     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
201     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
202 #endif
203 #ifdef JPAKE
204     {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata},
205     {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1},
206     {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2},
207     {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm},
208     {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm},
209 #endif
210     {0, 0, NULL}
211 };
212 
213 struct mon_table mon_dispatch_postauth20[] = {
214     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
215     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
216     {MONITOR_REQ_PTY, 0, mm_answer_pty},
217     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
218     {MONITOR_REQ_TERM, 0, mm_answer_term},
219     {0, 0, NULL}
220 };
221 
222 struct mon_table mon_dispatch_proto15[] = {
223     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
224     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
225     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
226     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
227     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
228     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
229     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
230     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
231     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
232     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
233     {0, 0, NULL}
234 };
235 
236 struct mon_table mon_dispatch_postauth15[] = {
237     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
238     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
239     {MONITOR_REQ_TERM, 0, mm_answer_term},
240     {0, 0, NULL}
241 };
242 
243 struct mon_table *mon_dispatch;
244 
245 /* Specifies if a certain message is allowed at the moment */
246 
247 static void
248 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
249 {
250 	while (ent->f != NULL) {
251 		if (ent->type == type) {
252 			ent->flags &= ~MON_PERMIT;
253 			ent->flags |= permit ? MON_PERMIT : 0;
254 			return;
255 		}
256 		ent++;
257 	}
258 }
259 
260 static void
261 monitor_permit_authentications(int permit)
262 {
263 	struct mon_table *ent = mon_dispatch;
264 
265 	while (ent->f != NULL) {
266 		if (ent->flags & MON_AUTH) {
267 			ent->flags &= ~MON_PERMIT;
268 			ent->flags |= permit ? MON_PERMIT : 0;
269 		}
270 		ent++;
271 	}
272 }
273 
274 void
275 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
276 {
277 	struct mon_table *ent;
278 	int authenticated = 0, partial = 0;
279 
280 	debug3("preauth child monitor started");
281 
282 	close(pmonitor->m_recvfd);
283 	close(pmonitor->m_log_sendfd);
284 	pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
285 
286 	authctxt = _authctxt;
287 	memset(authctxt, 0, sizeof(*authctxt));
288 
289 	if (compat20) {
290 		mon_dispatch = mon_dispatch_proto20;
291 
292 		/* Permit requests for moduli and signatures */
293 		monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
294 		monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
295 	} else {
296 		mon_dispatch = mon_dispatch_proto15;
297 
298 		monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
299 	}
300 
301 	/* The first few requests do not require asynchronous access */
302 	while (!authenticated) {
303 		partial = 0;
304 		auth_method = "unknown";
305 		auth_submethod = NULL;
306 		authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
307 
308 		/* Special handling for multiple required authentications */
309 		if (options.num_auth_methods != 0) {
310 			if (!compat20)
311 				fatal("AuthenticationMethods is not supported"
312 				    "with SSH protocol 1");
313 			if (authenticated &&
314 			    !auth2_update_methods_lists(authctxt,
315 			    auth_method, auth_submethod)) {
316 				debug3("%s: method %s: partial", __func__,
317 				    auth_method);
318 				authenticated = 0;
319 				partial = 1;
320 			}
321 		}
322 
323 		if (authenticated) {
324 			if (!(ent->flags & MON_AUTHDECIDE))
325 				fatal("%s: unexpected authentication from %d",
326 				    __func__, ent->type);
327 			if (authctxt->pw->pw_uid == 0 &&
328 			    !auth_root_allowed(auth_method))
329 				authenticated = 0;
330 		}
331 		if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
332 			auth_log(authctxt, authenticated, partial,
333 			    auth_method, auth_submethod,
334 			    compat20 ? " ssh2" : "");
335 			if (!authenticated)
336 				authctxt->failures++;
337 		}
338 #ifdef JPAKE
339 		/* Cleanup JPAKE context after authentication */
340 		if (ent->flags & MON_AUTHDECIDE) {
341 			if (authctxt->jpake_ctx != NULL) {
342 				jpake_free(authctxt->jpake_ctx);
343 				authctxt->jpake_ctx = NULL;
344 			}
345 		}
346 #endif
347 	}
348 
349 	if (!authctxt->valid)
350 		fatal("%s: authenticated invalid user", __func__);
351 	if (strcmp(auth_method, "unknown") == 0)
352 		fatal("%s: authentication method name unknown", __func__);
353 
354 	debug("%s: %s has been authenticated by privileged process",
355 	    __func__, authctxt->user);
356 
357 	mm_get_keystate(pmonitor);
358 
359 	/* Drain any buffered messages from the child */
360 	while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
361 		;
362 
363 	close(pmonitor->m_sendfd);
364 	close(pmonitor->m_log_recvfd);
365 	pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
366 }
367 
368 static void
369 monitor_set_child_handler(pid_t pid)
370 {
371 	monitor_child_pid = pid;
372 }
373 
374 static void
375 monitor_child_handler(int sig)
376 {
377 	kill(monitor_child_pid, sig);
378 }
379 
380 void
381 monitor_child_postauth(struct monitor *pmonitor)
382 {
383 	close(pmonitor->m_recvfd);
384 	pmonitor->m_recvfd = -1;
385 
386 	monitor_set_child_handler(pmonitor->m_pid);
387 	signal(SIGHUP, &monitor_child_handler);
388 	signal(SIGTERM, &monitor_child_handler);
389 	signal(SIGINT, &monitor_child_handler);
390 
391 	if (compat20) {
392 		mon_dispatch = mon_dispatch_postauth20;
393 
394 		/* Permit requests for moduli and signatures */
395 		monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
396 		monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
397 		monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
398 	} else {
399 		mon_dispatch = mon_dispatch_postauth15;
400 		monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
401 	}
402 	if (!no_pty_flag) {
403 		monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
404 		monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
405 	}
406 
407 	for (;;)
408 		monitor_read(pmonitor, mon_dispatch, NULL);
409 }
410 
411 void
412 monitor_sync(struct monitor *pmonitor)
413 {
414 	if (options.compression) {
415 		/* The member allocation is not visible, so sync it */
416 		mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
417 	}
418 }
419 
420 static int
421 monitor_read_log(struct monitor *pmonitor)
422 {
423 	Buffer logmsg;
424 	u_int len, level;
425 	char *msg;
426 
427 	buffer_init(&logmsg);
428 
429 	/* Read length */
430 	buffer_append_space(&logmsg, 4);
431 	if (atomicio(read, pmonitor->m_log_recvfd,
432 	    buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
433 		if (errno == EPIPE) {
434 			buffer_free(&logmsg);
435 			debug("%s: child log fd closed", __func__);
436 			close(pmonitor->m_log_recvfd);
437 			pmonitor->m_log_recvfd = -1;
438 			return -1;
439 		}
440 		fatal("%s: log fd read: %s", __func__, strerror(errno));
441 	}
442 	len = buffer_get_int(&logmsg);
443 	if (len <= 4 || len > 8192)
444 		fatal("%s: invalid log message length %u", __func__, len);
445 
446 	/* Read severity, message */
447 	buffer_clear(&logmsg);
448 	buffer_append_space(&logmsg, len);
449 	if (atomicio(read, pmonitor->m_log_recvfd,
450 	    buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
451 		fatal("%s: log fd read: %s", __func__, strerror(errno));
452 
453 	/* Log it */
454 	level = buffer_get_int(&logmsg);
455 	msg = buffer_get_string(&logmsg, NULL);
456 	if (log_level_name(level) == NULL)
457 		fatal("%s: invalid log level %u (corrupted message?)",
458 		    __func__, level);
459 	do_log2(level, "%s [preauth]", msg);
460 
461 	buffer_free(&logmsg);
462 	xfree(msg);
463 
464 	return 0;
465 }
466 
467 int
468 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
469     struct mon_table **pent)
470 {
471 	Buffer m;
472 	int ret;
473 	u_char type;
474 	struct pollfd pfd[2];
475 
476 	for (;;) {
477 		bzero(&pfd, sizeof(pfd));
478 		pfd[0].fd = pmonitor->m_sendfd;
479 		pfd[0].events = POLLIN;
480 		pfd[1].fd = pmonitor->m_log_recvfd;
481 		pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
482 		if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
483 			if (errno == EINTR || errno == EAGAIN)
484 				continue;
485 			fatal("%s: poll: %s", __func__, strerror(errno));
486 		}
487 		if (pfd[1].revents) {
488 			/*
489 			 * Drain all log messages before processing next
490 			 * monitor request.
491 			 */
492 			monitor_read_log(pmonitor);
493 			continue;
494 		}
495 		if (pfd[0].revents)
496 			break;  /* Continues below */
497 	}
498 
499 	buffer_init(&m);
500 
501 	mm_request_receive(pmonitor->m_sendfd, &m);
502 	type = buffer_get_char(&m);
503 
504 	debug3("%s: checking request %d", __func__, type);
505 
506 	while (ent->f != NULL) {
507 		if (ent->type == type)
508 			break;
509 		ent++;
510 	}
511 
512 	if (ent->f != NULL) {
513 		if (!(ent->flags & MON_PERMIT))
514 			fatal("%s: unpermitted request %d", __func__,
515 			    type);
516 		ret = (*ent->f)(pmonitor->m_sendfd, &m);
517 		buffer_free(&m);
518 
519 		/* The child may use this request only once, disable it */
520 		if (ent->flags & MON_ONCE) {
521 			debug2("%s: %d used once, disabling now", __func__,
522 			    type);
523 			ent->flags &= ~MON_PERMIT;
524 		}
525 
526 		if (pent != NULL)
527 			*pent = ent;
528 
529 		return ret;
530 	}
531 
532 	fatal("%s: unsupported request: %d", __func__, type);
533 
534 	/* NOTREACHED */
535 	return (-1);
536 }
537 
538 /* allowed key state */
539 static int
540 monitor_allowed_key(u_char *blob, u_int bloblen)
541 {
542 	/* make sure key is allowed */
543 	if (key_blob == NULL || key_bloblen != bloblen ||
544 	    timingsafe_bcmp(key_blob, blob, key_bloblen))
545 		return (0);
546 	return (1);
547 }
548 
549 static void
550 monitor_reset_key_state(void)
551 {
552 	/* reset state */
553 	if (key_blob != NULL)
554 		xfree(key_blob);
555 	if (hostbased_cuser != NULL)
556 		xfree(hostbased_cuser);
557 	if (hostbased_chost != NULL)
558 		xfree(hostbased_chost);
559 	key_blob = NULL;
560 	key_bloblen = 0;
561 	key_blobtype = MM_NOKEY;
562 	hostbased_cuser = NULL;
563 	hostbased_chost = NULL;
564 }
565 
566 int
567 mm_answer_moduli(int sock, Buffer *m)
568 {
569 	DH *dh;
570 	int min, want, max;
571 
572 	min = buffer_get_int(m);
573 	want = buffer_get_int(m);
574 	max = buffer_get_int(m);
575 
576 	debug3("%s: got parameters: %d %d %d",
577 	    __func__, min, want, max);
578 	/* We need to check here, too, in case the child got corrupted */
579 	if (max < min || want < min || max < want)
580 		fatal("%s: bad parameters: %d %d %d",
581 		    __func__, min, want, max);
582 
583 	buffer_clear(m);
584 
585 	dh = choose_dh(min, want, max);
586 	if (dh == NULL) {
587 		buffer_put_char(m, 0);
588 		return (0);
589 	} else {
590 		/* Send first bignum */
591 		buffer_put_char(m, 1);
592 		buffer_put_bignum2(m, dh->p);
593 		buffer_put_bignum2(m, dh->g);
594 
595 		DH_free(dh);
596 	}
597 	mm_request_send(sock, MONITOR_ANS_MODULI, m);
598 	return (0);
599 }
600 
601 int
602 mm_answer_sign(int sock, Buffer *m)
603 {
604 	Key *key;
605 	u_char *p;
606 	u_char *signature;
607 	u_int siglen, datlen;
608 	int keyid;
609 
610 	debug3("%s", __func__);
611 
612 	keyid = buffer_get_int(m);
613 	p = buffer_get_string(m, &datlen);
614 
615 	/*
616 	 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
617 	 * SHA384 (48 bytes) and SHA512 (64 bytes).
618 	 */
619 	if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64)
620 		fatal("%s: data length incorrect: %u", __func__, datlen);
621 
622 	/* save session id, it will be passed on the first call */
623 	if (session_id2_len == 0) {
624 		session_id2_len = datlen;
625 		session_id2 = xmalloc(session_id2_len);
626 		memcpy(session_id2, p, session_id2_len);
627 	}
628 
629 	if ((key = get_hostkey_by_index(keyid)) == NULL)
630 		fatal("%s: no hostkey from index %d", __func__, keyid);
631 	if (key_sign(key, &signature, &siglen, p, datlen) < 0)
632 		fatal("%s: key_sign failed", __func__);
633 
634 	debug3("%s: signature %p(%u)", __func__, signature, siglen);
635 
636 	buffer_clear(m);
637 	buffer_put_string(m, signature, siglen);
638 
639 	xfree(p);
640 	xfree(signature);
641 
642 	mm_request_send(sock, MONITOR_ANS_SIGN, m);
643 
644 	/* Turn on permissions for getpwnam */
645 	monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
646 
647 	return (0);
648 }
649 
650 /* Retrieves the password entry and also checks if the user is permitted */
651 
652 int
653 mm_answer_pwnamallow(int sock, Buffer *m)
654 {
655 	char *username;
656 	struct passwd *pwent;
657 	int allowed = 0;
658 	u_int i;
659 
660 	debug3("%s", __func__);
661 
662 	if (authctxt->attempt++ != 0)
663 		fatal("%s: multiple attempts for getpwnam", __func__);
664 
665 	username = buffer_get_string(m, NULL);
666 
667 	pwent = getpwnamallow(username);
668 
669 	authctxt->user = xstrdup(username);
670 	setproctitle("%s [priv]", pwent ? username : "unknown");
671 	xfree(username);
672 
673 	buffer_clear(m);
674 
675 	if (pwent == NULL) {
676 		buffer_put_char(m, 0);
677 		authctxt->pw = fakepw();
678 		goto out;
679 	}
680 
681 	allowed = 1;
682 	authctxt->pw = pwent;
683 	authctxt->valid = 1;
684 
685 	buffer_put_char(m, 1);
686 	buffer_put_string(m, pwent, sizeof(struct passwd));
687 	buffer_put_cstring(m, pwent->pw_name);
688 	buffer_put_cstring(m, "*");
689 	buffer_put_cstring(m, pwent->pw_gecos);
690 	buffer_put_cstring(m, pwent->pw_class);
691 	buffer_put_cstring(m, pwent->pw_dir);
692 	buffer_put_cstring(m, pwent->pw_shell);
693 
694  out:
695 	buffer_put_string(m, &options, sizeof(options));
696 
697 #define M_CP_STROPT(x) do { \
698 		if (options.x != NULL) \
699 			buffer_put_cstring(m, options.x); \
700 	} while (0)
701 #define M_CP_STRARRAYOPT(x, nx) do { \
702 		for (i = 0; i < options.nx; i++) \
703 			buffer_put_cstring(m, options.x[i]); \
704 	} while (0)
705 	/* See comment in servconf.h */
706 	COPY_MATCH_STRING_OPTS();
707 #undef M_CP_STROPT
708 #undef M_CP_STRARRAYOPT
709 
710 	/* Create valid auth method lists */
711 	if (compat20 && auth2_setup_methods_lists(authctxt) != 0) {
712 		/*
713 		 * The monitor will continue long enough to let the child
714 		 * run to it's packet_disconnect(), but it must not allow any
715 		 * authentication to succeed.
716 		 */
717 		debug("%s: no valid authentication method lists", __func__);
718 	}
719 
720 	debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
721 	mm_request_send(sock, MONITOR_ANS_PWNAM, m);
722 
723 	/* For SSHv1 allow authentication now */
724 	if (!compat20)
725 		monitor_permit_authentications(1);
726 	else {
727 		/* Allow service/style information on the auth context */
728 		monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
729 		monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
730 	}
731 
732 	return (0);
733 }
734 
735 int mm_answer_auth2_read_banner(int sock, Buffer *m)
736 {
737 	char *banner;
738 
739 	buffer_clear(m);
740 	banner = auth2_read_banner();
741 	buffer_put_cstring(m, banner != NULL ? banner : "");
742 	mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
743 
744 	if (banner != NULL)
745 		xfree(banner);
746 
747 	return (0);
748 }
749 
750 int
751 mm_answer_authserv(int sock, Buffer *m)
752 {
753 	monitor_permit_authentications(1);
754 
755 	authctxt->service = buffer_get_string(m, NULL);
756 	authctxt->style = buffer_get_string(m, NULL);
757 	debug3("%s: service=%s, style=%s",
758 	    __func__, authctxt->service, authctxt->style);
759 
760 	if (strlen(authctxt->style) == 0) {
761 		xfree(authctxt->style);
762 		authctxt->style = NULL;
763 	}
764 
765 	return (0);
766 }
767 
768 int
769 mm_answer_authpassword(int sock, Buffer *m)
770 {
771 	static int call_count;
772 	char *passwd;
773 	int authenticated;
774 	u_int plen;
775 
776 	passwd = buffer_get_string(m, &plen);
777 	/* Only authenticate if the context is valid */
778 	authenticated = options.password_authentication &&
779 	    auth_password(authctxt, passwd);
780 	memset(passwd, 0, strlen(passwd));
781 	xfree(passwd);
782 
783 	buffer_clear(m);
784 	buffer_put_int(m, authenticated);
785 
786 	debug3("%s: sending result %d", __func__, authenticated);
787 	mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
788 
789 	call_count++;
790 	if (plen == 0 && call_count == 1)
791 		auth_method = "none";
792 	else
793 		auth_method = "password";
794 
795 	/* Causes monitor loop to terminate if authenticated */
796 	return (authenticated);
797 }
798 
799 int
800 mm_answer_bsdauthquery(int sock, Buffer *m)
801 {
802 	char *name, *infotxt;
803 	u_int numprompts;
804 	u_int *echo_on;
805 	char **prompts;
806 	u_int success;
807 
808 	success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
809 	    &prompts, &echo_on) < 0 ? 0 : 1;
810 
811 	buffer_clear(m);
812 	buffer_put_int(m, success);
813 	if (success)
814 		buffer_put_cstring(m, prompts[0]);
815 
816 	debug3("%s: sending challenge success: %u", __func__, success);
817 	mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
818 
819 	if (success) {
820 		xfree(name);
821 		xfree(infotxt);
822 		xfree(prompts);
823 		xfree(echo_on);
824 	}
825 
826 	return (0);
827 }
828 
829 int
830 mm_answer_bsdauthrespond(int sock, Buffer *m)
831 {
832 	char *response;
833 	int authok;
834 
835 	if (authctxt->as == 0)
836 		fatal("%s: no bsd auth session", __func__);
837 
838 	response = buffer_get_string(m, NULL);
839 	authok = options.challenge_response_authentication &&
840 	    auth_userresponse(authctxt->as, response, 0);
841 	authctxt->as = NULL;
842 	debug3("%s: <%s> = <%d>", __func__, response, authok);
843 	xfree(response);
844 
845 	buffer_clear(m);
846 	buffer_put_int(m, authok);
847 
848 	debug3("%s: sending authenticated: %d", __func__, authok);
849 	mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
850 
851 	if (compat20) {
852 		auth_method = "keyboard-interactive";
853 		auth_submethod = "bsdauth";
854 	} else
855 		auth_method = "bsdauth";
856 
857 	return (authok != 0);
858 }
859 
860 int
861 mm_answer_keyallowed(int sock, Buffer *m)
862 {
863 	Key *key;
864 	char *cuser, *chost;
865 	u_char *blob;
866 	u_int bloblen;
867 	enum mm_keytype type = 0;
868 	int allowed = 0;
869 
870 	debug3("%s entering", __func__);
871 
872 	type = buffer_get_int(m);
873 	cuser = buffer_get_string(m, NULL);
874 	chost = buffer_get_string(m, NULL);
875 	blob = buffer_get_string(m, &bloblen);
876 
877 	key = key_from_blob(blob, bloblen);
878 
879 	if ((compat20 && type == MM_RSAHOSTKEY) ||
880 	    (!compat20 && type != MM_RSAHOSTKEY))
881 		fatal("%s: key type and protocol mismatch", __func__);
882 
883 	debug3("%s: key_from_blob: %p", __func__, key);
884 
885 	if (key != NULL && authctxt->valid) {
886 		switch (type) {
887 		case MM_USERKEY:
888 			allowed = options.pubkey_authentication &&
889 			    user_key_allowed(authctxt->pw, key);
890 			auth_method = "publickey";
891 			if (options.pubkey_authentication && allowed != 1)
892 				auth_clear_options();
893 			break;
894 		case MM_HOSTKEY:
895 			allowed = options.hostbased_authentication &&
896 			    hostbased_key_allowed(authctxt->pw,
897 			    cuser, chost, key);
898 			auth_method = "hostbased";
899 			break;
900 		case MM_RSAHOSTKEY:
901 			key->type = KEY_RSA1; /* XXX */
902 			allowed = options.rhosts_rsa_authentication &&
903 			    auth_rhosts_rsa_key_allowed(authctxt->pw,
904 			    cuser, chost, key);
905 			if (options.rhosts_rsa_authentication && allowed != 1)
906 				auth_clear_options();
907 			auth_method = "rsa";
908 			break;
909 		default:
910 			fatal("%s: unknown key type %d", __func__, type);
911 			break;
912 		}
913 	}
914 	if (key != NULL)
915 		key_free(key);
916 
917 	/* clear temporarily storage (used by verify) */
918 	monitor_reset_key_state();
919 
920 	if (allowed) {
921 		/* Save temporarily for comparison in verify */
922 		key_blob = blob;
923 		key_bloblen = bloblen;
924 		key_blobtype = type;
925 		hostbased_cuser = cuser;
926 		hostbased_chost = chost;
927 	} else {
928 		/* Log failed attempt */
929 		auth_log(authctxt, 0, 0, auth_method, NULL,
930 		    compat20 ? " ssh2" : "");
931 		xfree(blob);
932 		xfree(cuser);
933 		xfree(chost);
934 	}
935 
936 	debug3("%s: key %p is %s",
937 	    __func__, key, allowed ? "allowed" : "not allowed");
938 
939 	buffer_clear(m);
940 	buffer_put_int(m, allowed);
941 	buffer_put_int(m, forced_command != NULL);
942 
943 	mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
944 
945 	if (type == MM_RSAHOSTKEY)
946 		monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
947 
948 	return (0);
949 }
950 
951 static int
952 monitor_valid_userblob(u_char *data, u_int datalen)
953 {
954 	Buffer b;
955 	char *p, *userstyle;
956 	u_int len;
957 	int fail = 0;
958 
959 	buffer_init(&b);
960 	buffer_append(&b, data, datalen);
961 
962 	if (datafellows & SSH_OLD_SESSIONID) {
963 		p = buffer_ptr(&b);
964 		len = buffer_len(&b);
965 		if ((session_id2 == NULL) ||
966 		    (len < session_id2_len) ||
967 		    (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
968 			fail++;
969 		buffer_consume(&b, session_id2_len);
970 	} else {
971 		p = buffer_get_string(&b, &len);
972 		if ((session_id2 == NULL) ||
973 		    (len != session_id2_len) ||
974 		    (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
975 			fail++;
976 		xfree(p);
977 	}
978 	if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
979 		fail++;
980 	p = buffer_get_cstring(&b, NULL);
981 	xasprintf(&userstyle, "%s%s%s", authctxt->user,
982 	    authctxt->style ? ":" : "",
983 	    authctxt->style ? authctxt->style : "");
984 	if (strcmp(userstyle, p) != 0) {
985 		logit("wrong user name passed to monitor: expected %s != %.100s",
986 		    userstyle, p);
987 		fail++;
988 	}
989 	xfree(userstyle);
990 	xfree(p);
991 	buffer_skip_string(&b);
992 	if (datafellows & SSH_BUG_PKAUTH) {
993 		if (!buffer_get_char(&b))
994 			fail++;
995 	} else {
996 		p = buffer_get_cstring(&b, NULL);
997 		if (strcmp("publickey", p) != 0)
998 			fail++;
999 		xfree(p);
1000 		if (!buffer_get_char(&b))
1001 			fail++;
1002 		buffer_skip_string(&b);
1003 	}
1004 	buffer_skip_string(&b);
1005 	if (buffer_len(&b) != 0)
1006 		fail++;
1007 	buffer_free(&b);
1008 	return (fail == 0);
1009 }
1010 
1011 static int
1012 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1013     char *chost)
1014 {
1015 	Buffer b;
1016 	char *p, *userstyle;
1017 	u_int len;
1018 	int fail = 0;
1019 
1020 	buffer_init(&b);
1021 	buffer_append(&b, data, datalen);
1022 
1023 	p = buffer_get_string(&b, &len);
1024 	if ((session_id2 == NULL) ||
1025 	    (len != session_id2_len) ||
1026 	    (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1027 		fail++;
1028 	xfree(p);
1029 
1030 	if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1031 		fail++;
1032 	p = buffer_get_cstring(&b, NULL);
1033 	xasprintf(&userstyle, "%s%s%s", authctxt->user,
1034 	    authctxt->style ? ":" : "",
1035 	    authctxt->style ? authctxt->style : "");
1036 	if (strcmp(userstyle, p) != 0) {
1037 		logit("wrong user name passed to monitor: expected %s != %.100s",
1038 		    userstyle, p);
1039 		fail++;
1040 	}
1041 	free(userstyle);
1042 	xfree(p);
1043 	buffer_skip_string(&b);	/* service */
1044 	p = buffer_get_cstring(&b, NULL);
1045 	if (strcmp(p, "hostbased") != 0)
1046 		fail++;
1047 	xfree(p);
1048 	buffer_skip_string(&b);	/* pkalg */
1049 	buffer_skip_string(&b);	/* pkblob */
1050 
1051 	/* verify client host, strip trailing dot if necessary */
1052 	p = buffer_get_string(&b, NULL);
1053 	if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1054 		p[len - 1] = '\0';
1055 	if (strcmp(p, chost) != 0)
1056 		fail++;
1057 	xfree(p);
1058 
1059 	/* verify client user */
1060 	p = buffer_get_string(&b, NULL);
1061 	if (strcmp(p, cuser) != 0)
1062 		fail++;
1063 	xfree(p);
1064 
1065 	if (buffer_len(&b) != 0)
1066 		fail++;
1067 	buffer_free(&b);
1068 	return (fail == 0);
1069 }
1070 
1071 int
1072 mm_answer_keyverify(int sock, Buffer *m)
1073 {
1074 	Key *key;
1075 	u_char *signature, *data, *blob;
1076 	u_int signaturelen, datalen, bloblen;
1077 	int verified = 0;
1078 	int valid_data = 0;
1079 
1080 	blob = buffer_get_string(m, &bloblen);
1081 	signature = buffer_get_string(m, &signaturelen);
1082 	data = buffer_get_string(m, &datalen);
1083 
1084 	if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1085 	  !monitor_allowed_key(blob, bloblen))
1086 		fatal("%s: bad key, not previously allowed", __func__);
1087 
1088 	key = key_from_blob(blob, bloblen);
1089 	if (key == NULL)
1090 		fatal("%s: bad public key blob", __func__);
1091 
1092 	switch (key_blobtype) {
1093 	case MM_USERKEY:
1094 		valid_data = monitor_valid_userblob(data, datalen);
1095 		break;
1096 	case MM_HOSTKEY:
1097 		valid_data = monitor_valid_hostbasedblob(data, datalen,
1098 		    hostbased_cuser, hostbased_chost);
1099 		break;
1100 	default:
1101 		valid_data = 0;
1102 		break;
1103 	}
1104 	if (!valid_data)
1105 		fatal("%s: bad signature data blob", __func__);
1106 
1107 	verified = key_verify(key, signature, signaturelen, data, datalen);
1108 	debug3("%s: key %p signature %s",
1109 	    __func__, key, (verified == 1) ? "verified" : "unverified");
1110 
1111 	key_free(key);
1112 	xfree(blob);
1113 	xfree(signature);
1114 	xfree(data);
1115 
1116 	auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1117 
1118 	monitor_reset_key_state();
1119 
1120 	buffer_clear(m);
1121 	buffer_put_int(m, verified);
1122 	mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1123 
1124 	return (verified == 1);
1125 }
1126 
1127 static void
1128 mm_record_login(Session *s, struct passwd *pw)
1129 {
1130 	socklen_t fromlen;
1131 	struct sockaddr_storage from;
1132 
1133 	/*
1134 	 * Get IP address of client. If the connection is not a socket, let
1135 	 * the address be 0.0.0.0.
1136 	 */
1137 	memset(&from, 0, sizeof(from));
1138 	fromlen = sizeof(from);
1139 	if (packet_connection_is_on_socket()) {
1140 		if (getpeername(packet_get_connection_in(),
1141 		    (struct sockaddr *)&from, &fromlen) < 0) {
1142 			debug("getpeername: %.100s", strerror(errno));
1143 			cleanup_exit(255);
1144 		}
1145 	}
1146 	/* Record that there was a login on that tty from the remote host. */
1147 	record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1148 	    get_remote_name_or_ip(utmp_len, options.use_dns),
1149 	    (struct sockaddr *)&from, fromlen);
1150 }
1151 
1152 static void
1153 mm_session_close(Session *s)
1154 {
1155 	debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1156 	if (s->ttyfd != -1) {
1157 		debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1158 		session_pty_cleanup2(s);
1159 	}
1160 	session_unused(s->self);
1161 }
1162 
1163 int
1164 mm_answer_pty(int sock, Buffer *m)
1165 {
1166 	extern struct monitor *pmonitor;
1167 	Session *s;
1168 	int res, fd0;
1169 
1170 	debug3("%s entering", __func__);
1171 
1172 	buffer_clear(m);
1173 	s = session_new();
1174 	if (s == NULL)
1175 		goto error;
1176 	s->authctxt = authctxt;
1177 	s->pw = authctxt->pw;
1178 	s->pid = pmonitor->m_pid;
1179 	res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1180 	if (res == 0)
1181 		goto error;
1182 	pty_setowner(authctxt->pw, s->tty);
1183 
1184 	buffer_put_int(m, 1);
1185 	buffer_put_cstring(m, s->tty);
1186 
1187 	/* We need to trick ttyslot */
1188 	if (dup2(s->ttyfd, 0) == -1)
1189 		fatal("%s: dup2", __func__);
1190 
1191 	mm_record_login(s, authctxt->pw);
1192 
1193 	/* Now we can close the file descriptor again */
1194 	close(0);
1195 
1196 	/* send messages generated by record_login */
1197 	buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1198 	buffer_clear(&loginmsg);
1199 
1200 	mm_request_send(sock, MONITOR_ANS_PTY, m);
1201 
1202 	if (mm_send_fd(sock, s->ptyfd) == -1 ||
1203 	    mm_send_fd(sock, s->ttyfd) == -1)
1204 		fatal("%s: send fds failed", __func__);
1205 
1206 	/* make sure nothing uses fd 0 */
1207 	if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1208 		fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1209 	if (fd0 != 0)
1210 		error("%s: fd0 %d != 0", __func__, fd0);
1211 
1212 	/* slave is not needed */
1213 	close(s->ttyfd);
1214 	s->ttyfd = s->ptyfd;
1215 	/* no need to dup() because nobody closes ptyfd */
1216 	s->ptymaster = s->ptyfd;
1217 
1218 	debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1219 
1220 	return (0);
1221 
1222  error:
1223 	if (s != NULL)
1224 		mm_session_close(s);
1225 	buffer_put_int(m, 0);
1226 	mm_request_send(sock, MONITOR_ANS_PTY, m);
1227 	return (0);
1228 }
1229 
1230 int
1231 mm_answer_pty_cleanup(int sock, Buffer *m)
1232 {
1233 	Session *s;
1234 	char *tty;
1235 
1236 	debug3("%s entering", __func__);
1237 
1238 	tty = buffer_get_string(m, NULL);
1239 	if ((s = session_by_tty(tty)) != NULL)
1240 		mm_session_close(s);
1241 	buffer_clear(m);
1242 	xfree(tty);
1243 	return (0);
1244 }
1245 
1246 int
1247 mm_answer_sesskey(int sock, Buffer *m)
1248 {
1249 	BIGNUM *p;
1250 	int rsafail;
1251 
1252 	/* Turn off permissions */
1253 	monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1254 
1255 	if ((p = BN_new()) == NULL)
1256 		fatal("%s: BN_new", __func__);
1257 
1258 	buffer_get_bignum2(m, p);
1259 
1260 	rsafail = ssh1_session_key(p);
1261 
1262 	buffer_clear(m);
1263 	buffer_put_int(m, rsafail);
1264 	buffer_put_bignum2(m, p);
1265 
1266 	BN_clear_free(p);
1267 
1268 	mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1269 
1270 	/* Turn on permissions for sessid passing */
1271 	monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1272 
1273 	return (0);
1274 }
1275 
1276 int
1277 mm_answer_sessid(int sock, Buffer *m)
1278 {
1279 	int i;
1280 
1281 	debug3("%s entering", __func__);
1282 
1283 	if (buffer_len(m) != 16)
1284 		fatal("%s: bad ssh1 session id", __func__);
1285 	for (i = 0; i < 16; i++)
1286 		session_id[i] = buffer_get_char(m);
1287 
1288 	/* Turn on permissions for getpwnam */
1289 	monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1290 
1291 	return (0);
1292 }
1293 
1294 int
1295 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1296 {
1297 	BIGNUM *client_n;
1298 	Key *key = NULL;
1299 	u_char *blob = NULL;
1300 	u_int blen = 0;
1301 	int allowed = 0;
1302 
1303 	debug3("%s entering", __func__);
1304 
1305 	auth_method = "rsa";
1306 	if (options.rsa_authentication && authctxt->valid) {
1307 		if ((client_n = BN_new()) == NULL)
1308 			fatal("%s: BN_new", __func__);
1309 		buffer_get_bignum2(m, client_n);
1310 		allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1311 		BN_clear_free(client_n);
1312 	}
1313 	buffer_clear(m);
1314 	buffer_put_int(m, allowed);
1315 	buffer_put_int(m, forced_command != NULL);
1316 
1317 	/* clear temporarily storage (used by generate challenge) */
1318 	monitor_reset_key_state();
1319 
1320 	if (allowed && key != NULL) {
1321 		key->type = KEY_RSA;	/* cheat for key_to_blob */
1322 		if (key_to_blob(key, &blob, &blen) == 0)
1323 			fatal("%s: key_to_blob failed", __func__);
1324 		buffer_put_string(m, blob, blen);
1325 
1326 		/* Save temporarily for comparison in verify */
1327 		key_blob = blob;
1328 		key_bloblen = blen;
1329 		key_blobtype = MM_RSAUSERKEY;
1330 	}
1331 	if (key != NULL)
1332 		key_free(key);
1333 
1334 	mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1335 
1336 	monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1337 	monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1338 	return (0);
1339 }
1340 
1341 int
1342 mm_answer_rsa_challenge(int sock, Buffer *m)
1343 {
1344 	Key *key = NULL;
1345 	u_char *blob;
1346 	u_int blen;
1347 
1348 	debug3("%s entering", __func__);
1349 
1350 	if (!authctxt->valid)
1351 		fatal("%s: authctxt not valid", __func__);
1352 	blob = buffer_get_string(m, &blen);
1353 	if (!monitor_allowed_key(blob, blen))
1354 		fatal("%s: bad key, not previously allowed", __func__);
1355 	if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1356 		fatal("%s: key type mismatch", __func__);
1357 	if ((key = key_from_blob(blob, blen)) == NULL)
1358 		fatal("%s: received bad key", __func__);
1359 	if (key->type != KEY_RSA)
1360 		fatal("%s: received bad key type %d", __func__, key->type);
1361 	key->type = KEY_RSA1;
1362 	if (ssh1_challenge)
1363 		BN_clear_free(ssh1_challenge);
1364 	ssh1_challenge = auth_rsa_generate_challenge(key);
1365 
1366 	buffer_clear(m);
1367 	buffer_put_bignum2(m, ssh1_challenge);
1368 
1369 	debug3("%s sending reply", __func__);
1370 	mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1371 
1372 	monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1373 
1374 	xfree(blob);
1375 	key_free(key);
1376 	return (0);
1377 }
1378 
1379 int
1380 mm_answer_rsa_response(int sock, Buffer *m)
1381 {
1382 	Key *key = NULL;
1383 	u_char *blob, *response;
1384 	u_int blen, len;
1385 	int success;
1386 
1387 	debug3("%s entering", __func__);
1388 
1389 	if (!authctxt->valid)
1390 		fatal("%s: authctxt not valid", __func__);
1391 	if (ssh1_challenge == NULL)
1392 		fatal("%s: no ssh1_challenge", __func__);
1393 
1394 	blob = buffer_get_string(m, &blen);
1395 	if (!monitor_allowed_key(blob, blen))
1396 		fatal("%s: bad key, not previously allowed", __func__);
1397 	if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1398 		fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1399 	if ((key = key_from_blob(blob, blen)) == NULL)
1400 		fatal("%s: received bad key", __func__);
1401 	response = buffer_get_string(m, &len);
1402 	if (len != 16)
1403 		fatal("%s: received bad response to challenge", __func__);
1404 	success = auth_rsa_verify_response(key, ssh1_challenge, response);
1405 
1406 	xfree(blob);
1407 	key_free(key);
1408 	xfree(response);
1409 
1410 	auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1411 
1412 	/* reset state */
1413 	BN_clear_free(ssh1_challenge);
1414 	ssh1_challenge = NULL;
1415 	monitor_reset_key_state();
1416 
1417 	buffer_clear(m);
1418 	buffer_put_int(m, success);
1419 	mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1420 
1421 	return (success);
1422 }
1423 
1424 int
1425 mm_answer_term(int sock, Buffer *req)
1426 {
1427 	extern struct monitor *pmonitor;
1428 	int res, status;
1429 
1430 	debug3("%s: tearing down sessions", __func__);
1431 
1432 	/* The child is terminating */
1433 	session_destroy_all(&mm_session_close);
1434 
1435 	while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1436 		if (errno != EINTR)
1437 			exit(1);
1438 
1439 	res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1440 
1441 	/* Terminate process */
1442 	exit(res);
1443 }
1444 
1445 void
1446 monitor_apply_keystate(struct monitor *pmonitor)
1447 {
1448 	if (compat20) {
1449 		set_newkeys(MODE_IN);
1450 		set_newkeys(MODE_OUT);
1451 	} else {
1452 		packet_set_protocol_flags(child_state.ssh1protoflags);
1453 		packet_set_encryption_key(child_state.ssh1key,
1454 		    child_state.ssh1keylen, child_state.ssh1cipher);
1455 		xfree(child_state.ssh1key);
1456 	}
1457 
1458 	/* for rc4 and other stateful ciphers */
1459 	packet_set_keycontext(MODE_OUT, child_state.keyout);
1460 	xfree(child_state.keyout);
1461 	packet_set_keycontext(MODE_IN, child_state.keyin);
1462 	xfree(child_state.keyin);
1463 
1464 	if (!compat20) {
1465 		packet_set_iv(MODE_OUT, child_state.ivout);
1466 		xfree(child_state.ivout);
1467 		packet_set_iv(MODE_IN, child_state.ivin);
1468 		xfree(child_state.ivin);
1469 	}
1470 
1471 	memcpy(&incoming_stream, &child_state.incoming,
1472 	    sizeof(incoming_stream));
1473 	memcpy(&outgoing_stream, &child_state.outgoing,
1474 	    sizeof(outgoing_stream));
1475 
1476 	/* Update with new address */
1477 	if (options.compression)
1478 		mm_init_compression(pmonitor->m_zlib);
1479 
1480 	/* Network I/O buffers */
1481 	/* XXX inefficient for large buffers, need: buffer_init_from_string */
1482 	buffer_clear(packet_get_input());
1483 	buffer_append(packet_get_input(), child_state.input, child_state.ilen);
1484 	memset(child_state.input, 0, child_state.ilen);
1485 	xfree(child_state.input);
1486 
1487 	buffer_clear(packet_get_output());
1488 	buffer_append(packet_get_output(), child_state.output,
1489 		      child_state.olen);
1490 	memset(child_state.output, 0, child_state.olen);
1491 	xfree(child_state.output);
1492 
1493 	/* Roaming */
1494 	if (compat20)
1495 		roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes);
1496 }
1497 
1498 static Kex *
1499 mm_get_kex(Buffer *m)
1500 {
1501 	Kex *kex;
1502 	void *blob;
1503 	u_int bloblen;
1504 
1505 	kex = xcalloc(1, sizeof(*kex));
1506 	kex->session_id = buffer_get_string(m, &kex->session_id_len);
1507 	if (session_id2 == NULL ||
1508 	    kex->session_id_len != session_id2_len ||
1509 	    timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0)
1510 		fatal("mm_get_get: internal error: bad session id");
1511 	kex->we_need = buffer_get_int(m);
1512 	kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1513 	kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1514 	kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1515 	kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1516 	kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1517 	kex->server = 1;
1518 	kex->hostkey_type = buffer_get_int(m);
1519 	kex->kex_type = buffer_get_int(m);
1520 	blob = buffer_get_string(m, &bloblen);
1521 	buffer_init(&kex->my);
1522 	buffer_append(&kex->my, blob, bloblen);
1523 	xfree(blob);
1524 	blob = buffer_get_string(m, &bloblen);
1525 	buffer_init(&kex->peer);
1526 	buffer_append(&kex->peer, blob, bloblen);
1527 	xfree(blob);
1528 	kex->done = 1;
1529 	kex->flags = buffer_get_int(m);
1530 	kex->client_version_string = buffer_get_string(m, NULL);
1531 	kex->server_version_string = buffer_get_string(m, NULL);
1532 	kex->load_host_public_key=&get_hostkey_public_by_type;
1533 	kex->load_host_private_key=&get_hostkey_private_by_type;
1534 	kex->host_key_index=&get_hostkey_index;
1535 
1536 	return (kex);
1537 }
1538 
1539 /* This function requries careful sanity checking */
1540 
1541 void
1542 mm_get_keystate(struct monitor *pmonitor)
1543 {
1544 	Buffer m;
1545 	u_char *blob, *p;
1546 	u_int bloblen, plen;
1547 	u_int32_t seqnr, packets;
1548 	u_int64_t blocks, bytes;
1549 
1550 	debug3("%s: Waiting for new keys", __func__);
1551 
1552 	buffer_init(&m);
1553 	mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1554 	if (!compat20) {
1555 		child_state.ssh1protoflags = buffer_get_int(&m);
1556 		child_state.ssh1cipher = buffer_get_int(&m);
1557 		child_state.ssh1key = buffer_get_string(&m,
1558 		    &child_state.ssh1keylen);
1559 		child_state.ivout = buffer_get_string(&m,
1560 		    &child_state.ivoutlen);
1561 		child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1562 		goto skip;
1563 	} else {
1564 		/* Get the Kex for rekeying */
1565 		*pmonitor->m_pkex = mm_get_kex(&m);
1566 	}
1567 
1568 	blob = buffer_get_string(&m, &bloblen);
1569 	current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1570 	xfree(blob);
1571 
1572 	debug3("%s: Waiting for second key", __func__);
1573 	blob = buffer_get_string(&m, &bloblen);
1574 	current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1575 	xfree(blob);
1576 
1577 	/* Now get sequence numbers for the packets */
1578 	seqnr = buffer_get_int(&m);
1579 	blocks = buffer_get_int64(&m);
1580 	packets = buffer_get_int(&m);
1581 	bytes = buffer_get_int64(&m);
1582 	packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1583 	seqnr = buffer_get_int(&m);
1584 	blocks = buffer_get_int64(&m);
1585 	packets = buffer_get_int(&m);
1586 	bytes = buffer_get_int64(&m);
1587 	packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1588 
1589  skip:
1590 	/* Get the key context */
1591 	child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1592 	child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1593 
1594 	debug3("%s: Getting compression state", __func__);
1595 	/* Get compression state */
1596 	p = buffer_get_string(&m, &plen);
1597 	if (plen != sizeof(child_state.outgoing))
1598 		fatal("%s: bad request size", __func__);
1599 	memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1600 	xfree(p);
1601 
1602 	p = buffer_get_string(&m, &plen);
1603 	if (plen != sizeof(child_state.incoming))
1604 		fatal("%s: bad request size", __func__);
1605 	memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1606 	xfree(p);
1607 
1608 	/* Network I/O buffers */
1609 	debug3("%s: Getting Network I/O buffers", __func__);
1610 	child_state.input = buffer_get_string(&m, &child_state.ilen);
1611 	child_state.output = buffer_get_string(&m, &child_state.olen);
1612 
1613 	/* Roaming */
1614 	if (compat20) {
1615 		child_state.sent_bytes = buffer_get_int64(&m);
1616 		child_state.recv_bytes = buffer_get_int64(&m);
1617 	}
1618 
1619 	buffer_free(&m);
1620 }
1621 
1622 
1623 /* Allocation functions for zlib */
1624 void *
1625 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1626 {
1627 	size_t len = (size_t) size * ncount;
1628 	void *address;
1629 
1630 	if (len == 0 || ncount > SIZE_T_MAX / size)
1631 		fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1632 
1633 	address = mm_malloc(mm, len);
1634 
1635 	return (address);
1636 }
1637 
1638 void
1639 mm_zfree(struct mm_master *mm, void *address)
1640 {
1641 	mm_free(mm, address);
1642 }
1643 
1644 void
1645 mm_init_compression(struct mm_master *mm)
1646 {
1647 	outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1648 	outgoing_stream.zfree = (free_func)mm_zfree;
1649 	outgoing_stream.opaque = mm;
1650 
1651 	incoming_stream.zalloc = (alloc_func)mm_zalloc;
1652 	incoming_stream.zfree = (free_func)mm_zfree;
1653 	incoming_stream.opaque = mm;
1654 }
1655 
1656 /* XXX */
1657 
1658 #define FD_CLOSEONEXEC(x) do { \
1659 	if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1660 		fatal("fcntl(%d, F_SETFD)", x); \
1661 } while (0)
1662 
1663 static void
1664 monitor_openfds(struct monitor *mon, int do_logfds)
1665 {
1666 	int pair[2];
1667 
1668 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1669 		fatal("%s: socketpair: %s", __func__, strerror(errno));
1670 	FD_CLOSEONEXEC(pair[0]);
1671 	FD_CLOSEONEXEC(pair[1]);
1672 	mon->m_recvfd = pair[0];
1673 	mon->m_sendfd = pair[1];
1674 
1675 	if (do_logfds) {
1676 		if (pipe(pair) == -1)
1677 			fatal("%s: pipe: %s", __func__, strerror(errno));
1678 		FD_CLOSEONEXEC(pair[0]);
1679 		FD_CLOSEONEXEC(pair[1]);
1680 		mon->m_log_recvfd = pair[0];
1681 		mon->m_log_sendfd = pair[1];
1682 	} else
1683 		mon->m_log_recvfd = mon->m_log_sendfd = -1;
1684 }
1685 
1686 #define MM_MEMSIZE	65536
1687 
1688 struct monitor *
1689 monitor_init(void)
1690 {
1691 	struct monitor *mon;
1692 
1693 	mon = xcalloc(1, sizeof(*mon));
1694 
1695 	monitor_openfds(mon, 1);
1696 
1697 	/* Used to share zlib space across processes */
1698 	if (options.compression) {
1699 		mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1700 		mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1701 
1702 		/* Compression needs to share state across borders */
1703 		mm_init_compression(mon->m_zlib);
1704 	}
1705 
1706 	return mon;
1707 }
1708 
1709 void
1710 monitor_reinit(struct monitor *mon)
1711 {
1712 	monitor_openfds(mon, 0);
1713 }
1714 
1715 #ifdef GSSAPI
1716 int
1717 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1718 {
1719 	gss_OID_desc goid;
1720 	OM_uint32 major;
1721 	u_int len;
1722 
1723 	goid.elements = buffer_get_string(m, &len);
1724 	goid.length = len;
1725 
1726 	major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1727 
1728 	xfree(goid.elements);
1729 
1730 	buffer_clear(m);
1731 	buffer_put_int(m, major);
1732 
1733 	mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1734 
1735 	/* Now we have a context, enable the step */
1736 	monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1737 
1738 	return (0);
1739 }
1740 
1741 int
1742 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1743 {
1744 	gss_buffer_desc in;
1745 	gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1746 	OM_uint32 major, minor;
1747 	OM_uint32 flags = 0; /* GSI needs this */
1748 	u_int len;
1749 
1750 	in.value = buffer_get_string(m, &len);
1751 	in.length = len;
1752 	major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1753 	xfree(in.value);
1754 
1755 	buffer_clear(m);
1756 	buffer_put_int(m, major);
1757 	buffer_put_string(m, out.value, out.length);
1758 	buffer_put_int(m, flags);
1759 	mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1760 
1761 	gss_release_buffer(&minor, &out);
1762 
1763 	if (major == GSS_S_COMPLETE) {
1764 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1765 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1766 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1767 	}
1768 	return (0);
1769 }
1770 
1771 int
1772 mm_answer_gss_checkmic(int sock, Buffer *m)
1773 {
1774 	gss_buffer_desc gssbuf, mic;
1775 	OM_uint32 ret;
1776 	u_int len;
1777 
1778 	gssbuf.value = buffer_get_string(m, &len);
1779 	gssbuf.length = len;
1780 	mic.value = buffer_get_string(m, &len);
1781 	mic.length = len;
1782 
1783 	ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1784 
1785 	xfree(gssbuf.value);
1786 	xfree(mic.value);
1787 
1788 	buffer_clear(m);
1789 	buffer_put_int(m, ret);
1790 
1791 	mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1792 
1793 	if (!GSS_ERROR(ret))
1794 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1795 
1796 	return (0);
1797 }
1798 
1799 int
1800 mm_answer_gss_userok(int sock, Buffer *m)
1801 {
1802 	int authenticated;
1803 
1804 	authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1805 
1806 	buffer_clear(m);
1807 	buffer_put_int(m, authenticated);
1808 
1809 	debug3("%s: sending result %d", __func__, authenticated);
1810 	mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1811 
1812 	auth_method = "gssapi-with-mic";
1813 
1814 	/* Monitor loop will terminate if authenticated */
1815 	return (authenticated);
1816 }
1817 #endif /* GSSAPI */
1818 
1819 #ifdef JPAKE
1820 int
1821 mm_answer_jpake_step1(int sock, Buffer *m)
1822 {
1823 	struct jpake_ctx *pctx;
1824 	u_char *x3_proof, *x4_proof;
1825 	u_int x3_proof_len, x4_proof_len;
1826 
1827 	if (!options.zero_knowledge_password_authentication)
1828 		fatal("zero_knowledge_password_authentication disabled");
1829 
1830 	if (authctxt->jpake_ctx != NULL)
1831 		fatal("%s: authctxt->jpake_ctx already set (%p)",
1832 		    __func__, authctxt->jpake_ctx);
1833 	authctxt->jpake_ctx = pctx = jpake_new();
1834 
1835 	jpake_step1(pctx->grp,
1836 	    &pctx->server_id, &pctx->server_id_len,
1837 	    &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4,
1838 	    &x3_proof, &x3_proof_len,
1839 	    &x4_proof, &x4_proof_len);
1840 
1841 	JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__));
1842 
1843 	buffer_clear(m);
1844 
1845 	buffer_put_string(m, pctx->server_id, pctx->server_id_len);
1846 	buffer_put_bignum2(m, pctx->g_x3);
1847 	buffer_put_bignum2(m, pctx->g_x4);
1848 	buffer_put_string(m, x3_proof, x3_proof_len);
1849 	buffer_put_string(m, x4_proof, x4_proof_len);
1850 
1851 	debug3("%s: sending step1", __func__);
1852 	mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m);
1853 
1854 	bzero(x3_proof, x3_proof_len);
1855 	bzero(x4_proof, x4_proof_len);
1856 	xfree(x3_proof);
1857 	xfree(x4_proof);
1858 
1859 	monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1);
1860 	monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0);
1861 
1862 	return 0;
1863 }
1864 
1865 int
1866 mm_answer_jpake_get_pwdata(int sock, Buffer *m)
1867 {
1868 	struct jpake_ctx *pctx = authctxt->jpake_ctx;
1869 	char *hash_scheme, *salt;
1870 
1871 	if (pctx == NULL)
1872 		fatal("%s: pctx == NULL", __func__);
1873 
1874 	auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt);
1875 
1876 	buffer_clear(m);
1877 	/* pctx->s is sensitive, not returned to slave */
1878 	buffer_put_cstring(m, hash_scheme);
1879 	buffer_put_cstring(m, salt);
1880 
1881 	debug3("%s: sending pwdata", __func__);
1882 	mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m);
1883 
1884 	bzero(hash_scheme, strlen(hash_scheme));
1885 	bzero(salt, strlen(salt));
1886 	xfree(hash_scheme);
1887 	xfree(salt);
1888 
1889 	monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1);
1890 
1891 	return 0;
1892 }
1893 
1894 int
1895 mm_answer_jpake_step2(int sock, Buffer *m)
1896 {
1897 	struct jpake_ctx *pctx = authctxt->jpake_ctx;
1898 	u_char *x1_proof, *x2_proof, *x4_s_proof;
1899 	u_int x1_proof_len, x2_proof_len, x4_s_proof_len;
1900 
1901 	if (pctx == NULL)
1902 		fatal("%s: pctx == NULL", __func__);
1903 
1904 	if ((pctx->g_x1 = BN_new()) == NULL ||
1905 	    (pctx->g_x2 = BN_new()) == NULL)
1906 		fatal("%s: BN_new", __func__);
1907 	buffer_get_bignum2(m, pctx->g_x1);
1908 	buffer_get_bignum2(m, pctx->g_x2);
1909 	pctx->client_id = buffer_get_string(m, &pctx->client_id_len);
1910 	x1_proof = buffer_get_string(m, &x1_proof_len);
1911 	x2_proof = buffer_get_string(m, &x2_proof_len);
1912 
1913 	jpake_step2(pctx->grp, pctx->s, pctx->g_x3,
1914 	    pctx->g_x1, pctx->g_x2, pctx->x4,
1915 	    pctx->client_id, pctx->client_id_len,
1916 	    pctx->server_id, pctx->server_id_len,
1917 	    x1_proof, x1_proof_len,
1918 	    x2_proof, x2_proof_len,
1919 	    &pctx->b,
1920 	    &x4_s_proof, &x4_s_proof_len);
1921 
1922 	JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__));
1923 
1924 	bzero(x1_proof, x1_proof_len);
1925 	bzero(x2_proof, x2_proof_len);
1926 	xfree(x1_proof);
1927 	xfree(x2_proof);
1928 
1929 	buffer_clear(m);
1930 
1931 	buffer_put_bignum2(m, pctx->b);
1932 	buffer_put_string(m, x4_s_proof, x4_s_proof_len);
1933 
1934 	debug3("%s: sending step2", __func__);
1935 	mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m);
1936 
1937 	bzero(x4_s_proof, x4_s_proof_len);
1938 	xfree(x4_s_proof);
1939 
1940 	monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1);
1941 
1942 	return 0;
1943 }
1944 
1945 int
1946 mm_answer_jpake_key_confirm(int sock, Buffer *m)
1947 {
1948 	struct jpake_ctx *pctx = authctxt->jpake_ctx;
1949 	u_char *x2_s_proof;
1950 	u_int x2_s_proof_len;
1951 
1952 	if (pctx == NULL)
1953 		fatal("%s: pctx == NULL", __func__);
1954 
1955 	if ((pctx->a = BN_new()) == NULL)
1956 		fatal("%s: BN_new", __func__);
1957 	buffer_get_bignum2(m, pctx->a);
1958 	x2_s_proof = buffer_get_string(m, &x2_s_proof_len);
1959 
1960 	jpake_key_confirm(pctx->grp, pctx->s, pctx->a,
1961 	    pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2,
1962 	    pctx->server_id, pctx->server_id_len,
1963 	    pctx->client_id, pctx->client_id_len,
1964 	    session_id2, session_id2_len,
1965 	    x2_s_proof, x2_s_proof_len,
1966 	    &pctx->k,
1967 	    &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len);
1968 
1969 	JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__));
1970 
1971 	bzero(x2_s_proof, x2_s_proof_len);
1972 	buffer_clear(m);
1973 
1974 	/* pctx->k is sensitive, not sent */
1975 	buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len);
1976 
1977 	debug3("%s: sending confirmation hash", __func__);
1978 	mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m);
1979 
1980 	monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1);
1981 
1982 	return 0;
1983 }
1984 
1985 int
1986 mm_answer_jpake_check_confirm(int sock, Buffer *m)
1987 {
1988 	int authenticated = 0;
1989 	u_char *peer_confirm_hash;
1990 	u_int peer_confirm_hash_len;
1991 	struct jpake_ctx *pctx = authctxt->jpake_ctx;
1992 
1993 	if (pctx == NULL)
1994 		fatal("%s: pctx == NULL", __func__);
1995 
1996 	peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len);
1997 
1998 	authenticated = jpake_check_confirm(pctx->k,
1999 	    pctx->client_id, pctx->client_id_len,
2000 	    session_id2, session_id2_len,
2001 	    peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid;
2002 
2003 	JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__));
2004 
2005 	bzero(peer_confirm_hash, peer_confirm_hash_len);
2006 	xfree(peer_confirm_hash);
2007 
2008 	buffer_clear(m);
2009 	buffer_put_int(m, authenticated);
2010 
2011 	debug3("%s: sending result %d", __func__, authenticated);
2012 	mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m);
2013 
2014 	monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1);
2015 
2016 	auth_method = "jpake-01@openssh.com";
2017 	return authenticated;
2018 }
2019 
2020 #endif /* JPAKE */
2021