xref: /netbsd-src/crypto/external/bsd/openssh/dist/monitor_wrap.c (revision 796c32c94f6e154afc9de0f63da35c91bb739b45)
1 /*	$NetBSD: monitor_wrap.c,v 1.18 2017/10/07 19:39:19 christos Exp $	*/
2 /* $OpenBSD: monitor_wrap.c,v 1.94 2017/10/02 19:33:20 djm Exp $ */
3 /*
4  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
5  * Copyright 2002 Markus Friedl <markus@openbsd.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "includes.h"
30 __RCSID("$NetBSD: monitor_wrap.c,v 1.18 2017/10/07 19:39:19 christos Exp $");
31 #include <sys/types.h>
32 #include <sys/uio.h>
33 #include <sys/queue.h>
34 
35 #include <errno.h>
36 #include <pwd.h>
37 #include <signal.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <unistd.h>
41 
42 #ifdef WITH_OPENSSL
43 #include <openssl/bn.h>
44 #include <openssl/dh.h>
45 #endif
46 
47 #include "xmalloc.h"
48 #include "ssh.h"
49 #ifdef WITH_OPENSSL
50 #include "dh.h"
51 #endif
52 #include "buffer.h"
53 #include "key.h"
54 #include "cipher.h"
55 #include "kex.h"
56 #include "hostfile.h"
57 #include "auth.h"
58 #include "auth-options.h"
59 #include "packet.h"
60 #include "mac.h"
61 #include "log.h"
62 #include <zlib.h>
63 #include "monitor.h"
64 #ifdef GSSAPI
65 #include "ssh-gss.h"
66 #endif
67 #include "monitor_wrap.h"
68 #include "atomicio.h"
69 #include "monitor_fdpass.h"
70 #ifdef USE_PAM
71 #include "misc.h"
72 #include "servconf.h"
73 #include <security/pam_appl.h>
74 #endif
75 #include "misc.h"
76 #include "uuencode.h"
77 
78 #include "channels.h"
79 #include "session.h"
80 #include "servconf.h"
81 
82 #include "ssherr.h"
83 
84 /* Imports */
85 extern z_stream incoming_stream;
86 extern z_stream outgoing_stream;
87 extern struct monitor *pmonitor;
88 extern Buffer loginmsg;
89 extern ServerOptions options;
90 
91 void
92 mm_log_handler(LogLevel level, const char *msg, void *ctx)
93 {
94 	Buffer log_msg;
95 	struct monitor *mon = (struct monitor *)ctx;
96 
97 	if (mon->m_log_sendfd == -1)
98 		fatal("%s: no log channel", __func__);
99 
100 	buffer_init(&log_msg);
101 	/*
102 	 * Placeholder for packet length. Will be filled in with the actual
103 	 * packet length once the packet has been constucted. This saves
104 	 * fragile math.
105 	 */
106 	buffer_put_int(&log_msg, 0);
107 
108 	buffer_put_int(&log_msg, level);
109 	buffer_put_cstring(&log_msg, msg);
110 	put_u32(buffer_ptr(&log_msg), buffer_len(&log_msg) - 4);
111 	if (atomicio(vwrite, mon->m_log_sendfd, buffer_ptr(&log_msg),
112 	    buffer_len(&log_msg)) != buffer_len(&log_msg))
113 		fatal("%s: write: %s", __func__, strerror(errno));
114 	buffer_free(&log_msg);
115 }
116 
117 int
118 mm_is_monitor(void)
119 {
120 	/*
121 	 * m_pid is only set in the privileged part, and
122 	 * points to the unprivileged child.
123 	 */
124 	return (pmonitor && pmonitor->m_pid > 0);
125 }
126 
127 void
128 mm_request_send(int sock, enum monitor_reqtype type, Buffer *m)
129 {
130 	u_int mlen = buffer_len(m);
131 	u_char buf[5];
132 
133 	debug3("%s entering: type %d", __func__, type);
134 
135 	put_u32(buf, mlen + 1);
136 	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
137 	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
138 		fatal("%s: write: %s", __func__, strerror(errno));
139 	if (atomicio(vwrite, sock, buffer_ptr(m), mlen) != mlen)
140 		fatal("%s: write: %s", __func__, strerror(errno));
141 }
142 
143 void
144 mm_request_receive(int sock, Buffer *m)
145 {
146 	u_char buf[4];
147 	u_int msg_len;
148 
149 	debug3("%s entering", __func__);
150 
151 	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
152 		if (errno == EPIPE)
153 			cleanup_exit(255);
154 		fatal("%s: read: %s", __func__, strerror(errno));
155 	}
156 	msg_len = get_u32(buf);
157 	if (msg_len > 256 * 1024)
158 		fatal("%s: read: bad msg_len %d", __func__, msg_len);
159 	buffer_clear(m);
160 	buffer_append_space(m, msg_len);
161 	if (atomicio(read, sock, buffer_ptr(m), msg_len) != msg_len)
162 		fatal("%s: read: %s", __func__, strerror(errno));
163 }
164 
165 void
166 mm_request_receive_expect(int sock, enum monitor_reqtype type, Buffer *m)
167 {
168 	u_char rtype;
169 
170 	debug3("%s entering: type %d", __func__, type);
171 
172 	mm_request_receive(sock, m);
173 	rtype = buffer_get_char(m);
174 	if (rtype != type)
175 		fatal("%s: read: rtype %d != type %d", __func__,
176 		    rtype, type);
177 }
178 
179 #ifdef WITH_OPENSSL
180 DH *
181 mm_choose_dh(int min, int nbits, int max)
182 {
183 	BIGNUM *p, *g;
184 	int success = 0;
185 	Buffer m;
186 
187 	buffer_init(&m);
188 	buffer_put_int(&m, min);
189 	buffer_put_int(&m, nbits);
190 	buffer_put_int(&m, max);
191 
192 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, &m);
193 
194 	debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
195 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, &m);
196 
197 	success = buffer_get_char(&m);
198 	if (success == 0)
199 		fatal("%s: MONITOR_ANS_MODULI failed", __func__);
200 
201 	if ((p = BN_new()) == NULL)
202 		fatal("%s: BN_new failed", __func__);
203 	if ((g = BN_new()) == NULL)
204 		fatal("%s: BN_new failed", __func__);
205 	buffer_get_bignum2(&m, p);
206 	buffer_get_bignum2(&m, g);
207 
208 	debug3("%s: remaining %d", __func__, buffer_len(&m));
209 	buffer_free(&m);
210 
211 	return (dh_new_group(g, p));
212 }
213 #endif
214 
215 int
216 mm_key_sign(struct sshkey *key, u_char **sigp, u_int *lenp,
217     const u_char *data, u_int datalen, const char *hostkey_alg)
218 {
219 	struct kex *kex = *pmonitor->m_pkex;
220 	Buffer m;
221 
222 	debug3("%s entering", __func__);
223 
224 	buffer_init(&m);
225 	buffer_put_int(&m, kex->host_key_index(key, 0, active_state));
226 	buffer_put_string(&m, data, datalen);
227 	buffer_put_cstring(&m, hostkey_alg);
228 
229 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m);
230 
231 	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
232 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m);
233 	*sigp  = buffer_get_string(&m, lenp);
234 	buffer_free(&m);
235 
236 	return (0);
237 }
238 
239 struct passwd *
240 mm_getpwnamallow(const char *username)
241 {
242 	struct ssh *ssh = active_state;		/* XXX */
243 	Buffer m;
244 	struct passwd *pw;
245 	u_int len, i;
246 	ServerOptions *newopts;
247 
248 	debug3("%s entering", __func__);
249 
250 	buffer_init(&m);
251 	buffer_put_cstring(&m, username);
252 
253 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, &m);
254 
255 	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
256 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, &m);
257 
258 	if (buffer_get_char(&m) == 0) {
259 		pw = NULL;
260 		goto out;
261 	}
262 	pw = buffer_get_string(&m, &len);
263 	if (len != sizeof(struct passwd))
264 		fatal("%s: struct passwd size mismatch", __func__);
265 	pw->pw_name = buffer_get_string(&m, NULL);
266 	pw->pw_passwd = buffer_get_string(&m, NULL);
267 	pw->pw_gecos = buffer_get_string(&m, NULL);
268 	pw->pw_class = buffer_get_string(&m, NULL);
269 	pw->pw_dir = buffer_get_string(&m, NULL);
270 	pw->pw_shell = buffer_get_string(&m, NULL);
271 
272 out:
273 	/* copy options block as a Match directive may have changed some */
274 	newopts = buffer_get_string(&m, &len);
275 	if (len != sizeof(*newopts))
276 		fatal("%s: option block size mismatch", __func__);
277 
278 #define M_CP_STROPT(x) do { \
279 		if (newopts->x != NULL) \
280 			newopts->x = buffer_get_string(&m, NULL); \
281 	} while (0)
282 #define M_CP_STRARRAYOPT(x, nx) do { \
283 		for (i = 0; i < newopts->nx; i++) \
284 			newopts->x[i] = buffer_get_string(&m, NULL); \
285 	} while (0)
286 #define M_CP_STRARRAYOPT_ALLOC(x, nx) do { \
287 		newopts->x = newopts->nx == 0 ? \
288 		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
289 		M_CP_STRARRAYOPT(x, nx); \
290 	} while (0)
291 	/* See comment in servconf.h */
292 	COPY_MATCH_STRING_OPTS();
293 #undef M_CP_STROPT
294 #undef M_CP_STRARRAYOPT
295 #undef M_CP_STRARRAYOPT_ALLOC
296 
297 	copy_set_server_options(&options, newopts, 1);
298 	log_change_level(options.log_level);
299 	process_permitopen(ssh, &options);
300 	free(newopts);
301 
302 	buffer_free(&m);
303 
304 	return (pw);
305 }
306 
307 char *
308 mm_auth2_read_banner(void)
309 {
310 	Buffer m;
311 	char *banner;
312 
313 	debug3("%s entering", __func__);
314 
315 	buffer_init(&m);
316 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
317 	buffer_clear(&m);
318 
319 	mm_request_receive_expect(pmonitor->m_recvfd,
320 	    MONITOR_ANS_AUTH2_READ_BANNER, &m);
321 	banner = buffer_get_string(&m, NULL);
322 	buffer_free(&m);
323 
324 	/* treat empty banner as missing banner */
325 	if (strlen(banner) == 0) {
326 		free(banner);
327 		banner = NULL;
328 	}
329 	return (banner);
330 }
331 
332 /* Inform the privileged process about service and style */
333 
334 void
335 mm_inform_authserv(char *service, char *style)
336 {
337 	Buffer m;
338 
339 	debug3("%s entering", __func__);
340 
341 	buffer_init(&m);
342 	buffer_put_cstring(&m, service);
343 	buffer_put_cstring(&m, style ? style : "");
344 
345 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m);
346 
347 	buffer_free(&m);
348 }
349 
350 /* Do the password authentication */
351 int
352 mm_auth_password(Authctxt *authctxt, const char *password)
353 {
354 	Buffer m;
355 	int authenticated = 0;
356 
357 	debug3("%s entering", __func__);
358 
359 	buffer_init(&m);
360 	buffer_put_cstring(&m, password);
361 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m);
362 
363 	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
364 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m);
365 
366 	authenticated = buffer_get_int(&m);
367 
368 	buffer_free(&m);
369 
370 	debug3("%s: user %sauthenticated",
371 	    __func__, authenticated ? "" : "not ");
372 	return (authenticated);
373 }
374 
375 int
376 mm_user_key_allowed(struct passwd *pw, struct sshkey *key,
377     int pubkey_auth_attempt)
378 {
379 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
380 	    pubkey_auth_attempt));
381 }
382 
383 int
384 mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host,
385     struct sshkey *key)
386 {
387 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
388 }
389 
390 int
391 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
392     struct sshkey *key, int pubkey_auth_attempt)
393 {
394 	Buffer m;
395 	u_char *blob;
396 	u_int len;
397 	int allowed = 0, have_forced = 0;
398 
399 	debug3("%s entering", __func__);
400 
401 	/* Convert the key to a blob and the pass it over */
402 	if (!key_to_blob(key, &blob, &len))
403 		return (0);
404 
405 	buffer_init(&m);
406 	buffer_put_int(&m, type);
407 	buffer_put_cstring(&m, user ? user : "");
408 	buffer_put_cstring(&m, host ? host : "");
409 	buffer_put_string(&m, blob, len);
410 	buffer_put_int(&m, pubkey_auth_attempt);
411 	free(blob);
412 
413 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);
414 
415 	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
416 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);
417 
418 	allowed = buffer_get_int(&m);
419 
420 	/* fake forced command */
421 	auth_clear_options();
422 	have_forced = buffer_get_int(&m);
423 	forced_command = have_forced ? xstrdup("true") : NULL;
424 
425 	buffer_free(&m);
426 
427 	return (allowed);
428 }
429 
430 /*
431  * This key verify needs to send the key type along, because the
432  * privileged parent makes the decision if the key is allowed
433  * for authentication.
434  */
435 
436 int
437 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
438     const u_char *data, size_t datalen, u_int compat)
439 {
440 	Buffer m;
441 	u_char *blob;
442 	u_int len;
443 	u_int encoded_ret = 0;
444 
445 	debug3("%s entering", __func__);
446 
447 	/* Convert the key to a blob and the pass it over */
448 	if (!key_to_blob(key, &blob, &len))
449 		return (0);
450 
451 	buffer_init(&m);
452 	buffer_put_string(&m, blob, len);
453 	buffer_put_string(&m, sig, siglen);
454 	buffer_put_string(&m, data, datalen);
455 	free(blob);
456 
457 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);
458 
459 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
460 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m);
461 
462 	encoded_ret = buffer_get_int(&m);
463 
464 	buffer_free(&m);
465 
466 	if (encoded_ret != 0)
467 		return SSH_ERR_SIGNATURE_INVALID;
468 	return 0;
469 }
470 
471 void
472 mm_send_keystate(struct monitor *monitor)
473 {
474 	struct ssh *ssh = active_state;		/* XXX */
475 	struct sshbuf *m;
476 	int r;
477 
478 	if ((m = sshbuf_new()) == NULL)
479 		fatal("%s: sshbuf_new failed", __func__);
480 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
481 		fatal("%s: get_state failed: %s",
482 		    __func__, ssh_err(r));
483 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
484 	debug3("%s: Finished sending state", __func__);
485 	sshbuf_free(m);
486 }
487 
488 int
489 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
490 {
491 	Buffer m;
492 	char *p, *msg;
493 	int success = 0, tmp1 = -1, tmp2 = -1;
494 
495 	/* Kludge: ensure there are fds free to receive the pty/tty */
496 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
497 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
498 		error("%s: cannot allocate fds for pty", __func__);
499 		if (tmp1 > 0)
500 			close(tmp1);
501 		if (tmp2 > 0)
502 			close(tmp2);
503 		return 0;
504 	}
505 	close(tmp1);
506 	close(tmp2);
507 
508 	buffer_init(&m);
509 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);
510 
511 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
512 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);
513 
514 	success = buffer_get_int(&m);
515 	if (success == 0) {
516 		debug3("%s: pty alloc failed", __func__);
517 		buffer_free(&m);
518 		return (0);
519 	}
520 	p = buffer_get_string(&m, NULL);
521 	msg = buffer_get_string(&m, NULL);
522 	buffer_free(&m);
523 
524 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
525 	free(p);
526 
527 	buffer_append(&loginmsg, msg, strlen(msg));
528 	free(msg);
529 
530 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
531 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
532 		fatal("%s: receive fds failed", __func__);
533 
534 	/* Success */
535 	return (1);
536 }
537 
538 void
539 mm_session_pty_cleanup2(Session *s)
540 {
541 	Buffer m;
542 
543 	if (s->ttyfd == -1)
544 		return;
545 	buffer_init(&m);
546 	buffer_put_cstring(&m, s->tty);
547 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
548 	buffer_free(&m);
549 
550 	/* closed dup'ed master */
551 	if (s->ptymaster != -1 && close(s->ptymaster) < 0)
552 		error("close(s->ptymaster/%d): %s",
553 		    s->ptymaster, strerror(errno));
554 
555 	/* unlink pty from session */
556 	s->ttyfd = -1;
557 }
558 
559 #ifdef USE_PAM
560 void
561 mm_start_pam(Authctxt *authctxt)
562 {
563 	Buffer m;
564 
565 	debug3("%s entering", __func__);
566 	if (!options.use_pam)
567 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
568 
569 	buffer_init(&m);
570 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, &m);
571 
572 	buffer_free(&m);
573 }
574 
575 u_int
576 mm_do_pam_account(void)
577 {
578 	Buffer m;
579 	u_int ret;
580 	char *msg;
581 
582 	debug3("%s entering", __func__);
583 	if (!options.use_pam)
584 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
585 
586 	buffer_init(&m);
587 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, &m);
588 
589 	mm_request_receive_expect(pmonitor->m_recvfd,
590 	    MONITOR_ANS_PAM_ACCOUNT, &m);
591 	ret = buffer_get_int(&m);
592 	msg = buffer_get_string(&m, NULL);
593 	buffer_append(&loginmsg, msg, strlen(msg));
594 	free(msg);
595 
596 	buffer_free(&m);
597 
598 	debug3("%s returning %d", __func__, ret);
599 
600 	return (ret);
601 }
602 
603 void *
604 mm_sshpam_init_ctx(Authctxt *authctxt)
605 {
606 	Buffer m;
607 	int success;
608 
609 	debug3("%s", __func__);
610 	buffer_init(&m);
611 	buffer_put_cstring(&m, authctxt->user);
612 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, &m);
613 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
614 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, &m);
615 	success = buffer_get_int(&m);
616 	if (success == 0) {
617 		debug3("%s: pam_init_ctx failed", __func__);
618 		buffer_free(&m);
619 		return (NULL);
620 	}
621 	buffer_free(&m);
622 	return (authctxt);
623 }
624 
625 int
626 mm_sshpam_query(void *ctx, char **name, char **info,
627     u_int *num, char ***prompts, u_int **echo_on)
628 {
629 	Buffer m;
630 	u_int i;
631 	int ret;
632 
633 	debug3("%s", __func__);
634 	buffer_init(&m);
635 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, &m);
636 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
637 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, &m);
638 	ret = buffer_get_int(&m);
639 	debug3("%s: pam_query returned %d", __func__, ret);
640 	*name = buffer_get_string(&m, NULL);
641 	*info = buffer_get_string(&m, NULL);
642 	*num = buffer_get_int(&m);
643 	if (*num > PAM_MAX_NUM_MSG)
644 		fatal("%s: received %u PAM messages, expected <= %u",
645 		    __func__, *num, PAM_MAX_NUM_MSG);
646 	*prompts = xcalloc((*num + 1), sizeof(char *));
647 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
648 	for (i = 0; i < *num; ++i) {
649 		(*prompts)[i] = buffer_get_string(&m, NULL);
650 		(*echo_on)[i] = buffer_get_int(&m);
651 	}
652 	buffer_free(&m);
653 	return (ret);
654 }
655 
656 int
657 mm_sshpam_respond(void *ctx, u_int num, char **resp)
658 {
659 	Buffer m;
660 	u_int i;
661 	int ret;
662 
663 	debug3("%s", __func__);
664 	buffer_init(&m);
665 	buffer_put_int(&m, num);
666 	for (i = 0; i < num; ++i)
667 		buffer_put_cstring(&m, resp[i]);
668 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, &m);
669 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
670 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, &m);
671 	ret = buffer_get_int(&m);
672 	debug3("%s: pam_respond returned %d", __func__, ret);
673 	buffer_free(&m);
674 	return (ret);
675 }
676 
677 void
678 mm_sshpam_free_ctx(void *ctxtp)
679 {
680 	Buffer m;
681 
682 	debug3("%s", __func__);
683 	buffer_init(&m);
684 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, &m);
685 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
686 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, &m);
687 	buffer_free(&m);
688 }
689 #endif /* USE_PAM */
690 
691 /* Request process termination */
692 
693 void
694 mm_terminate(void)
695 {
696 	Buffer m;
697 
698 	buffer_init(&m);
699 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
700 	buffer_free(&m);
701 }
702 
703 #if defined(BSD_AUTH) || defined(SKEY)
704 static void
705 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
706     char ***prompts, u_int **echo_on)
707 {
708 	*name = xstrdup("");
709 	*infotxt = xstrdup("");
710 	*numprompts = 1;
711 	*prompts = xcalloc(*numprompts, sizeof(char *));
712 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
713 	(*echo_on)[0] = 0;
714 }
715 
716 #ifdef BSD_AUTH
717 int
718 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
719    u_int *numprompts, char ***prompts, u_int **echo_on)
720 {
721 	Buffer m;
722 	u_int success;
723 	char *challenge;
724 
725 	debug3("%s: entering", __func__);
726 
727 	buffer_init(&m);
728 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);
729 
730 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
731 	    &m);
732 	success = buffer_get_int(&m);
733 	if (success == 0) {
734 		debug3("%s: no challenge", __func__);
735 		buffer_free(&m);
736 		return (-1);
737 	}
738 
739 	/* Get the challenge, and format the response */
740 	challenge  = buffer_get_string(&m, NULL);
741 	buffer_free(&m);
742 
743 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
744 	(*prompts)[0] = challenge;
745 
746 	debug3("%s: received challenge: %s", __func__, challenge);
747 
748 	return (0);
749 }
750 
751 int
752 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
753 {
754 	Buffer m;
755 	int authok;
756 
757 	debug3("%s: entering", __func__);
758 	if (numresponses != 1)
759 		return (-1);
760 
761 	buffer_init(&m);
762 	buffer_put_cstring(&m, responses[0]);
763 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);
764 
765 	mm_request_receive_expect(pmonitor->m_recvfd,
766 	    MONITOR_ANS_BSDAUTHRESPOND, &m);
767 
768 	authok = buffer_get_int(&m);
769 	buffer_free(&m);
770 
771 	return ((authok == 0) ? -1 : 0);
772 }
773 #endif
774 
775 #ifdef SKEY
776 int
777 mm_skey_query(void *ctx, char **name, char **infotxt,
778    u_int *numprompts, char ***prompts, u_int **echo_on)
779 {
780 	Buffer m;
781 	u_int success;
782 	char *challenge;
783 
784 	debug3("%s: entering", __func__);
785 
786 	buffer_init(&m);
787 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m);
788 
789 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY,
790 	    &m);
791 	success = buffer_get_int(&m);
792 	if (success == 0) {
793 		debug3("%s: no challenge", __func__);
794 		buffer_free(&m);
795 		return (-1);
796 	}
797 
798 	/* Get the challenge, and format the response */
799 	challenge  = buffer_get_string(&m, NULL);
800 	buffer_free(&m);
801 
802 	debug3("%s: received challenge: %s", __func__, challenge);
803 
804 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
805 
806 	xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT);
807 	free(challenge);
808 
809 	return (0);
810 }
811 
812 int
813 mm_skey_respond(void *ctx, u_int numresponses, char **responses)
814 {
815 	Buffer m;
816 	int authok;
817 
818 	debug3("%s: entering", __func__);
819 	if (numresponses != 1)
820 		return (-1);
821 
822 	buffer_init(&m);
823 	buffer_put_cstring(&m, responses[0]);
824 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m);
825 
826 	mm_request_receive_expect(pmonitor->m_recvfd,
827 	    MONITOR_ANS_SKEYRESPOND, &m);
828 
829 	authok = buffer_get_int(&m);
830 	buffer_free(&m);
831 
832 	return ((authok == 0) ? -1 : 0);
833 }
834 #endif /* SKEY */
835 #endif /* BSDAUTH || SKEY */
836 
837 #ifdef GSSAPI
838 OM_uint32
839 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
840 {
841 	Buffer m;
842 	OM_uint32 major;
843 
844 	/* Client doesn't get to see the context */
845 	*ctx = NULL;
846 
847 	buffer_init(&m);
848 	buffer_put_string(&m, goid->elements, goid->length);
849 
850 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
851 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);
852 
853 	major = buffer_get_int(&m);
854 
855 	buffer_free(&m);
856 	return (major);
857 }
858 
859 OM_uint32
860 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
861     gss_buffer_desc *out, OM_uint32 *flags)
862 {
863 	Buffer m;
864 	OM_uint32 major;
865 	u_int len;
866 
867 	buffer_init(&m);
868 	buffer_put_string(&m, in->value, in->length);
869 
870 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
871 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);
872 
873 	major = buffer_get_int(&m);
874 	out->value = buffer_get_string(&m, &len);
875 	out->length = len;
876 	if (flags)
877 		*flags = buffer_get_int(&m);
878 
879 	buffer_free(&m);
880 
881 	return (major);
882 }
883 
884 OM_uint32
885 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
886 {
887 	Buffer m;
888 	OM_uint32 major;
889 
890 	buffer_init(&m);
891 	buffer_put_string(&m, gssbuf->value, gssbuf->length);
892 	buffer_put_string(&m, gssmic->value, gssmic->length);
893 
894 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
895 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
896 	    &m);
897 
898 	major = buffer_get_int(&m);
899 	buffer_free(&m);
900 	return(major);
901 }
902 
903 int
904 mm_ssh_gssapi_userok(char *user)
905 {
906 	Buffer m;
907 	int authenticated = 0;
908 
909 	buffer_init(&m);
910 
911 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
912 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
913 				  &m);
914 
915 	authenticated = buffer_get_int(&m);
916 
917 	buffer_free(&m);
918 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
919 	return (authenticated);
920 }
921 #endif /* GSSAPI */
922 
923 #ifdef KRB5
924 int
925 mm_auth_krb5(void *ctx, void *argp, char **userp, void *resp)
926 {
927 	krb5_data *tkt, *reply;
928 	Buffer m;
929 	int success;
930 
931 	debug3("%s entering", __func__);
932 	tkt = (krb5_data *) argp;
933 	reply = (krb5_data *) resp;
934 
935 	buffer_init(&m);
936 	buffer_put_string(&m, tkt->data, tkt->length);
937 
938 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KRB5, &m);
939 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KRB5, &m);
940 
941 	success = buffer_get_int(&m);
942 	if (success) {
943 		u_int len;
944 
945 		*userp = buffer_get_string(&m, NULL);
946 		reply->data = buffer_get_string(&m, &len);
947 		reply->length = len;
948 	} else {
949 		memset(reply, 0, sizeof(*reply));
950 		*userp = NULL;
951 	}
952 
953 	buffer_free(&m);
954 	return (success);
955 }
956 #endif
957