xref: /freebsd/crypto/openssh/monitor_wrap.c (revision 642870485c089b57000fe538d3485e272b038d59)
1 /* $OpenBSD: monitor_wrap.c,v 1.88 2016/03/07 19:02:43 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/uio.h>
32 
33 #include <errno.h>
34 #include <pwd.h>
35 #include <signal.h>
36 #include <stdarg.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <unistd.h>
40 
41 #ifdef WITH_OPENSSL
42 #include <openssl/bn.h>
43 #include <openssl/dh.h>
44 #include <openssl/evp.h>
45 #endif
46 
47 #include "openbsd-compat/sys-queue.h"
48 #include "xmalloc.h"
49 #include "ssh.h"
50 #ifdef WITH_OPENSSL
51 #include "dh.h"
52 #endif
53 #include "buffer.h"
54 #include "key.h"
55 #include "cipher.h"
56 #include "kex.h"
57 #include "hostfile.h"
58 #include "auth.h"
59 #include "auth-options.h"
60 #include "packet.h"
61 #include "mac.h"
62 #include "log.h"
63 #include "auth-pam.h"
64 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
65 #undef TARGET_OS_MAC
66 #include "zlib.h"
67 #define TARGET_OS_MAC 1
68 #else
69 #include "zlib.h"
70 #endif
71 #include "monitor.h"
72 #ifdef GSSAPI
73 #include "ssh-gss.h"
74 #endif
75 #include "monitor_wrap.h"
76 #include "atomicio.h"
77 #include "monitor_fdpass.h"
78 #include "misc.h"
79 #include "uuencode.h"
80 
81 #include "channels.h"
82 #include "session.h"
83 #include "servconf.h"
84 
85 #include "ssherr.h"
86 
87 /* Imports */
88 extern int compat20;
89 extern z_stream incoming_stream;
90 extern z_stream outgoing_stream;
91 extern struct monitor *pmonitor;
92 extern Buffer loginmsg;
93 extern ServerOptions options;
94 
95 void
96 mm_log_handler(LogLevel level, const char *msg, void *ctx)
97 {
98 	Buffer log_msg;
99 	struct monitor *mon = (struct monitor *)ctx;
100 
101 	if (mon->m_log_sendfd == -1)
102 		fatal("%s: no log channel", __func__);
103 
104 	buffer_init(&log_msg);
105 	/*
106 	 * Placeholder for packet length. Will be filled in with the actual
107 	 * packet length once the packet has been constucted. This saves
108 	 * fragile math.
109 	 */
110 	buffer_put_int(&log_msg, 0);
111 
112 	buffer_put_int(&log_msg, level);
113 	buffer_put_cstring(&log_msg, msg);
114 	put_u32(buffer_ptr(&log_msg), buffer_len(&log_msg) - 4);
115 	if (atomicio(vwrite, mon->m_log_sendfd, buffer_ptr(&log_msg),
116 	    buffer_len(&log_msg)) != buffer_len(&log_msg))
117 		fatal("%s: write: %s", __func__, strerror(errno));
118 	buffer_free(&log_msg);
119 }
120 
121 int
122 mm_is_monitor(void)
123 {
124 	/*
125 	 * m_pid is only set in the privileged part, and
126 	 * points to the unprivileged child.
127 	 */
128 	return (pmonitor && pmonitor->m_pid > 0);
129 }
130 
131 void
132 mm_request_send(int sock, enum monitor_reqtype type, Buffer *m)
133 {
134 	u_int mlen = buffer_len(m);
135 	u_char buf[5];
136 
137 	debug3("%s entering: type %d", __func__, type);
138 
139 	put_u32(buf, mlen + 1);
140 	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
141 	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
142 		fatal("%s: write: %s", __func__, strerror(errno));
143 	if (atomicio(vwrite, sock, buffer_ptr(m), mlen) != mlen)
144 		fatal("%s: write: %s", __func__, strerror(errno));
145 }
146 
147 void
148 mm_request_receive(int sock, Buffer *m)
149 {
150 	u_char buf[4];
151 	u_int msg_len;
152 
153 	debug3("%s entering", __func__);
154 
155 	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
156 		if (errno == EPIPE)
157 			cleanup_exit(255);
158 		fatal("%s: read: %s", __func__, strerror(errno));
159 	}
160 	msg_len = get_u32(buf);
161 	if (msg_len > 256 * 1024)
162 		fatal("%s: read: bad msg_len %d", __func__, msg_len);
163 	buffer_clear(m);
164 	buffer_append_space(m, msg_len);
165 	if (atomicio(read, sock, buffer_ptr(m), msg_len) != msg_len)
166 		fatal("%s: read: %s", __func__, strerror(errno));
167 }
168 
169 void
170 mm_request_receive_expect(int sock, enum monitor_reqtype type, Buffer *m)
171 {
172 	u_char rtype;
173 
174 	debug3("%s entering: type %d", __func__, type);
175 
176 	mm_request_receive(sock, m);
177 	rtype = buffer_get_char(m);
178 	if (rtype != type)
179 		fatal("%s: read: rtype %d != type %d", __func__,
180 		    rtype, type);
181 }
182 
183 #ifdef WITH_OPENSSL
184 DH *
185 mm_choose_dh(int min, int nbits, int max)
186 {
187 	BIGNUM *p, *g;
188 	int success = 0;
189 	Buffer m;
190 
191 	buffer_init(&m);
192 	buffer_put_int(&m, min);
193 	buffer_put_int(&m, nbits);
194 	buffer_put_int(&m, max);
195 
196 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, &m);
197 
198 	debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
199 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, &m);
200 
201 	success = buffer_get_char(&m);
202 	if (success == 0)
203 		fatal("%s: MONITOR_ANS_MODULI failed", __func__);
204 
205 	if ((p = BN_new()) == NULL)
206 		fatal("%s: BN_new failed", __func__);
207 	if ((g = BN_new()) == NULL)
208 		fatal("%s: BN_new failed", __func__);
209 	buffer_get_bignum2(&m, p);
210 	buffer_get_bignum2(&m, g);
211 
212 	debug3("%s: remaining %d", __func__, buffer_len(&m));
213 	buffer_free(&m);
214 
215 	return (dh_new_group(g, p));
216 }
217 #endif
218 
219 int
220 mm_key_sign(Key *key, u_char **sigp, u_int *lenp,
221     const u_char *data, u_int datalen, const char *hostkey_alg)
222 {
223 	struct kex *kex = *pmonitor->m_pkex;
224 	Buffer m;
225 
226 	debug3("%s entering", __func__);
227 
228 	buffer_init(&m);
229 	buffer_put_int(&m, kex->host_key_index(key, 0, active_state));
230 	buffer_put_string(&m, data, datalen);
231 	buffer_put_cstring(&m, hostkey_alg);
232 
233 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m);
234 
235 	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
236 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m);
237 	*sigp  = buffer_get_string(&m, lenp);
238 	buffer_free(&m);
239 
240 	return (0);
241 }
242 
243 struct passwd *
244 mm_getpwnamallow(const char *username)
245 {
246 	Buffer m;
247 	struct passwd *pw;
248 	u_int len, i;
249 	ServerOptions *newopts;
250 
251 	debug3("%s entering", __func__);
252 
253 	buffer_init(&m);
254 	buffer_put_cstring(&m, username);
255 
256 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, &m);
257 
258 	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
259 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, &m);
260 
261 	if (buffer_get_char(&m) == 0) {
262 		pw = NULL;
263 		goto out;
264 	}
265 	pw = buffer_get_string(&m, &len);
266 	if (len != sizeof(struct passwd))
267 		fatal("%s: struct passwd size mismatch", __func__);
268 	pw->pw_name = buffer_get_string(&m, NULL);
269 	pw->pw_passwd = buffer_get_string(&m, NULL);
270 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
271 	pw->pw_gecos = buffer_get_string(&m, NULL);
272 #endif
273 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
274 	pw->pw_class = buffer_get_string(&m, NULL);
275 #endif
276 	pw->pw_dir = buffer_get_string(&m, NULL);
277 	pw->pw_shell = buffer_get_string(&m, NULL);
278 
279 out:
280 	/* copy options block as a Match directive may have changed some */
281 	newopts = buffer_get_string(&m, &len);
282 	if (len != sizeof(*newopts))
283 		fatal("%s: option block size mismatch", __func__);
284 
285 #define M_CP_STROPT(x) do { \
286 		if (newopts->x != NULL) \
287 			newopts->x = buffer_get_string(&m, NULL); \
288 	} while (0)
289 #define M_CP_STRARRAYOPT(x, nx) do { \
290 		for (i = 0; i < newopts->nx; i++) \
291 			newopts->x[i] = buffer_get_string(&m, NULL); \
292 	} while (0)
293 	/* See comment in servconf.h */
294 	COPY_MATCH_STRING_OPTS();
295 #undef M_CP_STROPT
296 #undef M_CP_STRARRAYOPT
297 
298 	copy_set_server_options(&options, newopts, 1);
299 	free(newopts);
300 
301 	buffer_free(&m);
302 
303 	return (pw);
304 }
305 
306 char *
307 mm_auth2_read_banner(void)
308 {
309 	Buffer m;
310 	char *banner;
311 
312 	debug3("%s entering", __func__);
313 
314 	buffer_init(&m);
315 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
316 	buffer_clear(&m);
317 
318 	mm_request_receive_expect(pmonitor->m_recvfd,
319 	    MONITOR_ANS_AUTH2_READ_BANNER, &m);
320 	banner = buffer_get_string(&m, NULL);
321 	buffer_free(&m);
322 
323 	/* treat empty banner as missing banner */
324 	if (strlen(banner) == 0) {
325 		free(banner);
326 		banner = NULL;
327 	}
328 	return (banner);
329 }
330 
331 /* Inform the privileged process about service and style */
332 
333 void
334 mm_inform_authserv(char *service, char *style)
335 {
336 	Buffer m;
337 
338 	debug3("%s entering", __func__);
339 
340 	buffer_init(&m);
341 	buffer_put_cstring(&m, service);
342 	buffer_put_cstring(&m, style ? style : "");
343 
344 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m);
345 
346 	buffer_free(&m);
347 }
348 
349 /* Do the password authentication */
350 int
351 mm_auth_password(Authctxt *authctxt, char *password)
352 {
353 	Buffer m;
354 	int authenticated = 0;
355 
356 	debug3("%s entering", __func__);
357 
358 	buffer_init(&m);
359 	buffer_put_cstring(&m, password);
360 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m);
361 
362 	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
363 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m);
364 
365 	authenticated = buffer_get_int(&m);
366 #ifdef USE_PAM
367 	sshpam_set_maxtries_reached(buffer_get_int(&m));
368 #endif
369 
370 	buffer_free(&m);
371 
372 	debug3("%s: user %sauthenticated",
373 	    __func__, authenticated ? "" : "not ");
374 	return (authenticated);
375 }
376 
377 int
378 mm_user_key_allowed(struct passwd *pw, Key *key, int pubkey_auth_attempt)
379 {
380 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
381 	    pubkey_auth_attempt));
382 }
383 
384 int
385 mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host,
386     Key *key)
387 {
388 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
389 }
390 
391 int
392 mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, const char *user,
393     const char *host, Key *key)
394 {
395 	int ret;
396 
397 	key->type = KEY_RSA; /* XXX hack for key_to_blob */
398 	ret = mm_key_allowed(MM_RSAHOSTKEY, user, host, key, 0);
399 	key->type = KEY_RSA1;
400 	return (ret);
401 }
402 
403 int
404 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
405     Key *key, int pubkey_auth_attempt)
406 {
407 	Buffer m;
408 	u_char *blob;
409 	u_int len;
410 	int allowed = 0, have_forced = 0;
411 
412 	debug3("%s entering", __func__);
413 
414 	/* Convert the key to a blob and the pass it over */
415 	if (!key_to_blob(key, &blob, &len))
416 		return (0);
417 
418 	buffer_init(&m);
419 	buffer_put_int(&m, type);
420 	buffer_put_cstring(&m, user ? user : "");
421 	buffer_put_cstring(&m, host ? host : "");
422 	buffer_put_string(&m, blob, len);
423 	buffer_put_int(&m, pubkey_auth_attempt);
424 	free(blob);
425 
426 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);
427 
428 	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
429 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);
430 
431 	allowed = buffer_get_int(&m);
432 
433 	/* fake forced command */
434 	auth_clear_options();
435 	have_forced = buffer_get_int(&m);
436 	forced_command = have_forced ? xstrdup("true") : NULL;
437 
438 	buffer_free(&m);
439 
440 	return (allowed);
441 }
442 
443 /*
444  * This key verify needs to send the key type along, because the
445  * privileged parent makes the decision if the key is allowed
446  * for authentication.
447  */
448 
449 int
450 mm_key_verify(Key *key, u_char *sig, u_int siglen, u_char *data, u_int datalen)
451 {
452 	Buffer m;
453 	u_char *blob;
454 	u_int len;
455 	int verified = 0;
456 
457 	debug3("%s entering", __func__);
458 
459 	/* Convert the key to a blob and the pass it over */
460 	if (!key_to_blob(key, &blob, &len))
461 		return (0);
462 
463 	buffer_init(&m);
464 	buffer_put_string(&m, blob, len);
465 	buffer_put_string(&m, sig, siglen);
466 	buffer_put_string(&m, data, datalen);
467 	free(blob);
468 
469 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);
470 
471 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
472 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m);
473 
474 	verified = buffer_get_int(&m);
475 
476 	buffer_free(&m);
477 
478 	return (verified);
479 }
480 
481 void
482 mm_send_keystate(struct monitor *monitor)
483 {
484 	struct ssh *ssh = active_state;		/* XXX */
485 	struct sshbuf *m;
486 	int r;
487 
488 	if ((m = sshbuf_new()) == NULL)
489 		fatal("%s: sshbuf_new failed", __func__);
490 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
491 		fatal("%s: get_state failed: %s",
492 		    __func__, ssh_err(r));
493 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
494 	debug3("%s: Finished sending state", __func__);
495 	sshbuf_free(m);
496 }
497 
498 int
499 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
500 {
501 	Buffer m;
502 	char *p, *msg;
503 	int success = 0, tmp1 = -1, tmp2 = -1;
504 
505 	/* Kludge: ensure there are fds free to receive the pty/tty */
506 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
507 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
508 		error("%s: cannot allocate fds for pty", __func__);
509 		if (tmp1 > 0)
510 			close(tmp1);
511 		if (tmp2 > 0)
512 			close(tmp2);
513 		return 0;
514 	}
515 	close(tmp1);
516 	close(tmp2);
517 
518 	buffer_init(&m);
519 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);
520 
521 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
522 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);
523 
524 	success = buffer_get_int(&m);
525 	if (success == 0) {
526 		debug3("%s: pty alloc failed", __func__);
527 		buffer_free(&m);
528 		return (0);
529 	}
530 	p = buffer_get_string(&m, NULL);
531 	msg = buffer_get_string(&m, NULL);
532 	buffer_free(&m);
533 
534 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
535 	free(p);
536 
537 	buffer_append(&loginmsg, msg, strlen(msg));
538 	free(msg);
539 
540 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
541 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
542 		fatal("%s: receive fds failed", __func__);
543 
544 	/* Success */
545 	return (1);
546 }
547 
548 void
549 mm_session_pty_cleanup2(Session *s)
550 {
551 	Buffer m;
552 
553 	if (s->ttyfd == -1)
554 		return;
555 	buffer_init(&m);
556 	buffer_put_cstring(&m, s->tty);
557 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
558 	buffer_free(&m);
559 
560 	/* closed dup'ed master */
561 	if (s->ptymaster != -1 && close(s->ptymaster) < 0)
562 		error("close(s->ptymaster/%d): %s",
563 		    s->ptymaster, strerror(errno));
564 
565 	/* unlink pty from session */
566 	s->ttyfd = -1;
567 }
568 
569 #ifdef USE_PAM
570 void
571 mm_start_pam(Authctxt *authctxt)
572 {
573 	Buffer m;
574 
575 	debug3("%s entering", __func__);
576 	if (!options.use_pam)
577 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
578 
579 	buffer_init(&m);
580 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, &m);
581 
582 	buffer_free(&m);
583 }
584 
585 u_int
586 mm_do_pam_account(void)
587 {
588 	Buffer m;
589 	u_int ret;
590 	char *msg;
591 
592 	debug3("%s entering", __func__);
593 	if (!options.use_pam)
594 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
595 
596 	buffer_init(&m);
597 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, &m);
598 
599 	mm_request_receive_expect(pmonitor->m_recvfd,
600 	    MONITOR_ANS_PAM_ACCOUNT, &m);
601 	ret = buffer_get_int(&m);
602 	msg = buffer_get_string(&m, NULL);
603 	buffer_append(&loginmsg, msg, strlen(msg));
604 	free(msg);
605 
606 	buffer_free(&m);
607 
608 	debug3("%s returning %d", __func__, ret);
609 
610 	return (ret);
611 }
612 
613 void *
614 mm_sshpam_init_ctx(Authctxt *authctxt)
615 {
616 	Buffer m;
617 	int success;
618 
619 	debug3("%s", __func__);
620 	buffer_init(&m);
621 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, &m);
622 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
623 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, &m);
624 	success = buffer_get_int(&m);
625 	if (success == 0) {
626 		debug3("%s: pam_init_ctx failed", __func__);
627 		buffer_free(&m);
628 		return (NULL);
629 	}
630 	buffer_free(&m);
631 	return (authctxt);
632 }
633 
634 int
635 mm_sshpam_query(void *ctx, char **name, char **info,
636     u_int *num, char ***prompts, u_int **echo_on)
637 {
638 	Buffer m;
639 	u_int i;
640 	int ret;
641 
642 	debug3("%s", __func__);
643 	buffer_init(&m);
644 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, &m);
645 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
646 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, &m);
647 	ret = buffer_get_int(&m);
648 	debug3("%s: pam_query returned %d", __func__, ret);
649 	*name = buffer_get_string(&m, NULL);
650 	*info = buffer_get_string(&m, NULL);
651 	sshpam_set_maxtries_reached(buffer_get_int(&m));
652 	*num = buffer_get_int(&m);
653 	if (*num > PAM_MAX_NUM_MSG)
654 		fatal("%s: recieved %u PAM messages, expected <= %u",
655 		    __func__, *num, PAM_MAX_NUM_MSG);
656 	*prompts = xcalloc((*num + 1), sizeof(char *));
657 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
658 	for (i = 0; i < *num; ++i) {
659 		(*prompts)[i] = buffer_get_string(&m, NULL);
660 		(*echo_on)[i] = buffer_get_int(&m);
661 	}
662 	buffer_free(&m);
663 	return (ret);
664 }
665 
666 int
667 mm_sshpam_respond(void *ctx, u_int num, char **resp)
668 {
669 	Buffer m;
670 	u_int i;
671 	int ret;
672 
673 	debug3("%s", __func__);
674 	buffer_init(&m);
675 	buffer_put_int(&m, num);
676 	for (i = 0; i < num; ++i)
677 		buffer_put_cstring(&m, resp[i]);
678 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, &m);
679 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
680 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, &m);
681 	ret = buffer_get_int(&m);
682 	debug3("%s: pam_respond returned %d", __func__, ret);
683 	buffer_free(&m);
684 	return (ret);
685 }
686 
687 void
688 mm_sshpam_free_ctx(void *ctxtp)
689 {
690 	Buffer m;
691 
692 	debug3("%s", __func__);
693 	buffer_init(&m);
694 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, &m);
695 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
696 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, &m);
697 	buffer_free(&m);
698 }
699 #endif /* USE_PAM */
700 
701 /* Request process termination */
702 
703 void
704 mm_terminate(void)
705 {
706 	Buffer m;
707 
708 	buffer_init(&m);
709 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
710 	buffer_free(&m);
711 }
712 
713 #ifdef WITH_SSH1
714 int
715 mm_ssh1_session_key(BIGNUM *num)
716 {
717 	int rsafail;
718 	Buffer m;
719 
720 	buffer_init(&m);
721 	buffer_put_bignum2(&m, num);
722 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSKEY, &m);
723 
724 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SESSKEY, &m);
725 
726 	rsafail = buffer_get_int(&m);
727 	buffer_get_bignum2(&m, num);
728 
729 	buffer_free(&m);
730 
731 	return (rsafail);
732 }
733 #endif
734 
735 static void
736 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
737     char ***prompts, u_int **echo_on)
738 {
739 	*name = xstrdup("");
740 	*infotxt = xstrdup("");
741 	*numprompts = 1;
742 	*prompts = xcalloc(*numprompts, sizeof(char *));
743 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
744 	(*echo_on)[0] = 0;
745 }
746 
747 int
748 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
749    u_int *numprompts, char ***prompts, u_int **echo_on)
750 {
751 	Buffer m;
752 	u_int success;
753 	char *challenge;
754 
755 	debug3("%s: entering", __func__);
756 
757 	buffer_init(&m);
758 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);
759 
760 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
761 	    &m);
762 	success = buffer_get_int(&m);
763 	if (success == 0) {
764 		debug3("%s: no challenge", __func__);
765 		buffer_free(&m);
766 		return (-1);
767 	}
768 
769 	/* Get the challenge, and format the response */
770 	challenge  = buffer_get_string(&m, NULL);
771 	buffer_free(&m);
772 
773 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
774 	(*prompts)[0] = challenge;
775 
776 	debug3("%s: received challenge: %s", __func__, challenge);
777 
778 	return (0);
779 }
780 
781 int
782 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
783 {
784 	Buffer m;
785 	int authok;
786 
787 	debug3("%s: entering", __func__);
788 	if (numresponses != 1)
789 		return (-1);
790 
791 	buffer_init(&m);
792 	buffer_put_cstring(&m, responses[0]);
793 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);
794 
795 	mm_request_receive_expect(pmonitor->m_recvfd,
796 	    MONITOR_ANS_BSDAUTHRESPOND, &m);
797 
798 	authok = buffer_get_int(&m);
799 	buffer_free(&m);
800 
801 	return ((authok == 0) ? -1 : 0);
802 }
803 
804 #ifdef SKEY
805 int
806 mm_skey_query(void *ctx, char **name, char **infotxt,
807    u_int *numprompts, char ***prompts, u_int **echo_on)
808 {
809 	Buffer m;
810 	u_int success;
811 	char *challenge;
812 
813 	debug3("%s: entering", __func__);
814 
815 	buffer_init(&m);
816 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m);
817 
818 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY,
819 	    &m);
820 	success = buffer_get_int(&m);
821 	if (success == 0) {
822 		debug3("%s: no challenge", __func__);
823 		buffer_free(&m);
824 		return (-1);
825 	}
826 
827 	/* Get the challenge, and format the response */
828 	challenge  = buffer_get_string(&m, NULL);
829 	buffer_free(&m);
830 
831 	debug3("%s: received challenge: %s", __func__, challenge);
832 
833 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
834 
835 	xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT);
836 	free(challenge);
837 
838 	return (0);
839 }
840 
841 int
842 mm_skey_respond(void *ctx, u_int numresponses, char **responses)
843 {
844 	Buffer m;
845 	int authok;
846 
847 	debug3("%s: entering", __func__);
848 	if (numresponses != 1)
849 		return (-1);
850 
851 	buffer_init(&m);
852 	buffer_put_cstring(&m, responses[0]);
853 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m);
854 
855 	mm_request_receive_expect(pmonitor->m_recvfd,
856 	    MONITOR_ANS_SKEYRESPOND, &m);
857 
858 	authok = buffer_get_int(&m);
859 	buffer_free(&m);
860 
861 	return ((authok == 0) ? -1 : 0);
862 }
863 #endif /* SKEY */
864 
865 void
866 mm_ssh1_session_id(u_char session_id[16])
867 {
868 	Buffer m;
869 	int i;
870 
871 	debug3("%s entering", __func__);
872 
873 	buffer_init(&m);
874 	for (i = 0; i < 16; i++)
875 		buffer_put_char(&m, session_id[i]);
876 
877 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSID, &m);
878 	buffer_free(&m);
879 }
880 
881 #ifdef WITH_SSH1
882 int
883 mm_auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
884 {
885 	Buffer m;
886 	Key *key;
887 	u_char *blob;
888 	u_int blen;
889 	int allowed = 0, have_forced = 0;
890 
891 	debug3("%s entering", __func__);
892 
893 	buffer_init(&m);
894 	buffer_put_bignum2(&m, client_n);
895 
896 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSAKEYALLOWED, &m);
897 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSAKEYALLOWED, &m);
898 
899 	allowed = buffer_get_int(&m);
900 
901 	/* fake forced command */
902 	auth_clear_options();
903 	have_forced = buffer_get_int(&m);
904 	forced_command = have_forced ? xstrdup("true") : NULL;
905 
906 	if (allowed && rkey != NULL) {
907 		blob = buffer_get_string(&m, &blen);
908 		if ((key = key_from_blob(blob, blen)) == NULL)
909 			fatal("%s: key_from_blob failed", __func__);
910 		*rkey = key;
911 		free(blob);
912 	}
913 	buffer_free(&m);
914 
915 	return (allowed);
916 }
917 
918 BIGNUM *
919 mm_auth_rsa_generate_challenge(Key *key)
920 {
921 	Buffer m;
922 	BIGNUM *challenge;
923 	u_char *blob;
924 	u_int blen;
925 
926 	debug3("%s entering", __func__);
927 
928 	if ((challenge = BN_new()) == NULL)
929 		fatal("%s: BN_new failed", __func__);
930 
931 	key->type = KEY_RSA;    /* XXX cheat for key_to_blob */
932 	if (key_to_blob(key, &blob, &blen) == 0)
933 		fatal("%s: key_to_blob failed", __func__);
934 	key->type = KEY_RSA1;
935 
936 	buffer_init(&m);
937 	buffer_put_string(&m, blob, blen);
938 	free(blob);
939 
940 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSACHALLENGE, &m);
941 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSACHALLENGE, &m);
942 
943 	buffer_get_bignum2(&m, challenge);
944 	buffer_free(&m);
945 
946 	return (challenge);
947 }
948 
949 int
950 mm_auth_rsa_verify_response(Key *key, BIGNUM *p, u_char response[16])
951 {
952 	Buffer m;
953 	u_char *blob;
954 	u_int blen;
955 	int success = 0;
956 
957 	debug3("%s entering", __func__);
958 
959 	key->type = KEY_RSA;    /* XXX cheat for key_to_blob */
960 	if (key_to_blob(key, &blob, &blen) == 0)
961 		fatal("%s: key_to_blob failed", __func__);
962 	key->type = KEY_RSA1;
963 
964 	buffer_init(&m);
965 	buffer_put_string(&m, blob, blen);
966 	buffer_put_string(&m, response, 16);
967 	free(blob);
968 
969 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSARESPONSE, &m);
970 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSARESPONSE, &m);
971 
972 	success = buffer_get_int(&m);
973 	buffer_free(&m);
974 
975 	return (success);
976 }
977 #endif
978 
979 #ifdef SSH_AUDIT_EVENTS
980 void
981 mm_audit_event(ssh_audit_event_t event)
982 {
983 	Buffer m;
984 
985 	debug3("%s entering", __func__);
986 
987 	buffer_init(&m);
988 	buffer_put_int(&m, event);
989 
990 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, &m);
991 	buffer_free(&m);
992 }
993 
994 void
995 mm_audit_run_command(const char *command)
996 {
997 	Buffer m;
998 
999 	debug3("%s entering command %s", __func__, command);
1000 
1001 	buffer_init(&m);
1002 	buffer_put_cstring(&m, command);
1003 
1004 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, &m);
1005 	buffer_free(&m);
1006 }
1007 #endif /* SSH_AUDIT_EVENTS */
1008 
1009 #ifdef GSSAPI
1010 OM_uint32
1011 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
1012 {
1013 	Buffer m;
1014 	OM_uint32 major;
1015 
1016 	/* Client doesn't get to see the context */
1017 	*ctx = NULL;
1018 
1019 	buffer_init(&m);
1020 	buffer_put_string(&m, goid->elements, goid->length);
1021 
1022 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
1023 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);
1024 
1025 	major = buffer_get_int(&m);
1026 
1027 	buffer_free(&m);
1028 	return (major);
1029 }
1030 
1031 OM_uint32
1032 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
1033     gss_buffer_desc *out, OM_uint32 *flags)
1034 {
1035 	Buffer m;
1036 	OM_uint32 major;
1037 	u_int len;
1038 
1039 	buffer_init(&m);
1040 	buffer_put_string(&m, in->value, in->length);
1041 
1042 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
1043 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);
1044 
1045 	major = buffer_get_int(&m);
1046 	out->value = buffer_get_string(&m, &len);
1047 	out->length = len;
1048 	if (flags)
1049 		*flags = buffer_get_int(&m);
1050 
1051 	buffer_free(&m);
1052 
1053 	return (major);
1054 }
1055 
1056 OM_uint32
1057 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
1058 {
1059 	Buffer m;
1060 	OM_uint32 major;
1061 
1062 	buffer_init(&m);
1063 	buffer_put_string(&m, gssbuf->value, gssbuf->length);
1064 	buffer_put_string(&m, gssmic->value, gssmic->length);
1065 
1066 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
1067 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
1068 	    &m);
1069 
1070 	major = buffer_get_int(&m);
1071 	buffer_free(&m);
1072 	return(major);
1073 }
1074 
1075 int
1076 mm_ssh_gssapi_userok(char *user)
1077 {
1078 	Buffer m;
1079 	int authenticated = 0;
1080 
1081 	buffer_init(&m);
1082 
1083 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
1084 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
1085 				  &m);
1086 
1087 	authenticated = buffer_get_int(&m);
1088 
1089 	buffer_free(&m);
1090 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
1091 	return (authenticated);
1092 }
1093 #endif /* GSSAPI */
1094 
1095