xref: /openssh-portable/monitor_wrap.c (revision 6ad8648e)
1 /* $OpenBSD: monitor_wrap.c,v 1.107 2018/07/20 03:46:34 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 "sshbuf.h"
54 #include "sshkey.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 #include "monitor.h"
65 #ifdef GSSAPI
66 #include "ssh-gss.h"
67 #endif
68 #include "monitor_wrap.h"
69 #include "atomicio.h"
70 #include "monitor_fdpass.h"
71 #include "misc.h"
72 
73 #include "channels.h"
74 #include "session.h"
75 #include "servconf.h"
76 
77 #include "ssherr.h"
78 
79 /* Imports */
80 extern struct monitor *pmonitor;
81 extern struct sshbuf *loginmsg;
82 extern ServerOptions options;
83 
84 void
85 mm_log_handler(LogLevel level, const char *msg, void *ctx)
86 {
87 	struct sshbuf *log_msg;
88 	struct monitor *mon = (struct monitor *)ctx;
89 	int r;
90 	size_t len;
91 
92 	if (mon->m_log_sendfd == -1)
93 		fatal("%s: no log channel", __func__);
94 
95 	if ((log_msg = sshbuf_new()) == NULL)
96 		fatal("%s: sshbuf_new failed", __func__);
97 
98 	if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */
99 	    (r = sshbuf_put_u32(log_msg, level)) != 0 ||
100 	    (r = sshbuf_put_cstring(log_msg, msg)) != 0)
101 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
102 	if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff)
103 		fatal("%s: bad length %zu", __func__, len);
104 	POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4);
105 	if (atomicio(vwrite, mon->m_log_sendfd,
106 	    sshbuf_mutable_ptr(log_msg), len) != len)
107 		fatal("%s: write: %s", __func__, strerror(errno));
108 	sshbuf_free(log_msg);
109 }
110 
111 int
112 mm_is_monitor(void)
113 {
114 	/*
115 	 * m_pid is only set in the privileged part, and
116 	 * points to the unprivileged child.
117 	 */
118 	return (pmonitor && pmonitor->m_pid > 0);
119 }
120 
121 void
122 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m)
123 {
124 	size_t mlen = sshbuf_len(m);
125 	u_char buf[5];
126 
127 	debug3("%s entering: type %d", __func__, type);
128 
129 	if (mlen >= 0xffffffff)
130 		fatal("%s: bad length %zu", __func__, mlen);
131 	POKE_U32(buf, mlen + 1);
132 	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
133 	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
134 		fatal("%s: write: %s", __func__, strerror(errno));
135 	if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen)
136 		fatal("%s: write: %s", __func__, strerror(errno));
137 }
138 
139 void
140 mm_request_receive(int sock, struct sshbuf *m)
141 {
142 	u_char buf[4], *p = NULL;
143 	u_int msg_len;
144 	int r;
145 
146 	debug3("%s entering", __func__);
147 
148 	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
149 		if (errno == EPIPE)
150 			cleanup_exit(255);
151 		fatal("%s: read: %s", __func__, strerror(errno));
152 	}
153 	msg_len = PEEK_U32(buf);
154 	if (msg_len > 256 * 1024)
155 		fatal("%s: read: bad msg_len %d", __func__, msg_len);
156 	sshbuf_reset(m);
157 	if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
158 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
159 	if (atomicio(read, sock, p, msg_len) != msg_len)
160 		fatal("%s: read: %s", __func__, strerror(errno));
161 }
162 
163 void
164 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m)
165 {
166 	u_char rtype;
167 	int r;
168 
169 	debug3("%s entering: type %d", __func__, type);
170 
171 	mm_request_receive(sock, m);
172 	if ((r = sshbuf_get_u8(m, &rtype)) != 0)
173 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
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 r;
185 	u_char success = 0;
186 	struct sshbuf *m;
187 
188 	if ((m = sshbuf_new()) == NULL)
189 		fatal("%s: sshbuf_new failed", __func__);
190 	if ((r = sshbuf_put_u32(m, min)) != 0 ||
191 	    (r = sshbuf_put_u32(m, nbits)) != 0 ||
192 	    (r = sshbuf_put_u32(m, max)) != 0)
193 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
194 
195 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m);
196 
197 	debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
198 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m);
199 
200 	if ((r = sshbuf_get_u8(m, &success)) != 0)
201 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
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 	if ((r = sshbuf_get_bignum2(m, p)) != 0 ||
210 	    (r = sshbuf_get_bignum2(m, g)) != 0)
211 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
212 
213 	debug3("%s: remaining %zu", __func__, sshbuf_len(m));
214 	sshbuf_free(m);
215 
216 	return (dh_new_group(g, p));
217 }
218 #endif
219 
220 int
221 mm_sshkey_sign(struct sshkey *key, u_char **sigp, size_t *lenp,
222     const u_char *data, size_t datalen, const char *hostkey_alg, u_int compat)
223 {
224 	struct kex *kex = *pmonitor->m_pkex;
225 	struct sshbuf *m;
226 	u_int ndx = kex->host_key_index(key, 0, active_state);
227 	int r;
228 
229 	debug3("%s entering", __func__);
230 
231 	if ((m = sshbuf_new()) == NULL)
232 		fatal("%s: sshbuf_new failed", __func__);
233 	if ((r = sshbuf_put_u32(m, ndx)) != 0 ||
234 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
235 	    (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 ||
236 	    (r = sshbuf_put_u32(m, compat)) != 0)
237 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
238 
239 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m);
240 
241 	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
242 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m);
243 	if ((r = sshbuf_get_string(m, sigp, lenp)) != 0)
244 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
245 	sshbuf_free(m);
246 
247 	return (0);
248 }
249 
250 struct passwd *
251 mm_getpwnamallow(const char *username)
252 {
253 	struct ssh *ssh = active_state;		/* XXX */
254 	struct sshbuf *m;
255 	struct passwd *pw;
256 	size_t len;
257 	u_int i;
258 	ServerOptions *newopts;
259 	int r;
260 	u_char ok;
261 	const u_char *p;
262 
263 	debug3("%s entering", __func__);
264 
265 	if ((m = sshbuf_new()) == NULL)
266 		fatal("%s: sshbuf_new failed", __func__);
267 	if ((r = sshbuf_put_cstring(m, username)) != 0)
268 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
269 
270 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m);
271 
272 	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
273 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m);
274 
275 	if ((r = sshbuf_get_u8(m, &ok)) != 0)
276 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
277 	if (ok == 0) {
278 		pw = NULL;
279 		goto out;
280 	}
281 
282 	/* XXX don't like passing struct passwd like this */
283 	pw = xcalloc(sizeof(*pw), 1);
284 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
285 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
286 	if (len != sizeof(*pw))
287 		fatal("%s: struct passwd size mismatch", __func__);
288 	memcpy(pw, p, sizeof(*pw));
289 
290 	if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 ||
291 	    (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 ||
292 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
293 	    (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 ||
294 #endif
295 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
296 	    (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 ||
297 #endif
298 	    (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 ||
299 	    (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0)
300 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
301 
302 out:
303 	/* copy options block as a Match directive may have changed some */
304 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
305 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
306 	if (len != sizeof(*newopts))
307 		fatal("%s: option block size mismatch", __func__);
308 	newopts = xcalloc(sizeof(*newopts), 1);
309 	memcpy(newopts, p, sizeof(*newopts));
310 
311 #define M_CP_STROPT(x) do { \
312 		if (newopts->x != NULL) { \
313 			if ((r = sshbuf_get_cstring(m, \
314 			    &newopts->x, NULL)) != 0) \
315 				fatal("%s: buffer error: %s", \
316 				    __func__, ssh_err(r)); \
317 		} \
318 	} while (0)
319 #define M_CP_STRARRAYOPT(x, nx) do { \
320 		newopts->x = newopts->nx == 0 ? \
321 		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
322 		for (i = 0; i < newopts->nx; i++) { \
323 			if ((r = sshbuf_get_cstring(m, \
324 			    &newopts->x[i], NULL)) != 0) \
325 				fatal("%s: buffer error: %s", \
326 				    __func__, ssh_err(r)); \
327 		} \
328 	} while (0)
329 	/* See comment in servconf.h */
330 	COPY_MATCH_STRING_OPTS();
331 #undef M_CP_STROPT
332 #undef M_CP_STRARRAYOPT
333 
334 	copy_set_server_options(&options, newopts, 1);
335 	log_change_level(options.log_level);
336 	process_permitopen(ssh, &options);
337 	free(newopts);
338 
339 	sshbuf_free(m);
340 
341 	return (pw);
342 }
343 
344 char *
345 mm_auth2_read_banner(void)
346 {
347 	struct sshbuf *m;
348 	char *banner;
349 	int r;
350 
351 	debug3("%s entering", __func__);
352 
353 	if ((m = sshbuf_new()) == NULL)
354 		fatal("%s: sshbuf_new failed", __func__);
355 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m);
356 	sshbuf_reset(m);
357 
358 	mm_request_receive_expect(pmonitor->m_recvfd,
359 	    MONITOR_ANS_AUTH2_READ_BANNER, m);
360 	if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0)
361 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
362 	sshbuf_free(m);
363 
364 	/* treat empty banner as missing banner */
365 	if (strlen(banner) == 0) {
366 		free(banner);
367 		banner = NULL;
368 	}
369 	return (banner);
370 }
371 
372 /* Inform the privileged process about service and style */
373 
374 void
375 mm_inform_authserv(char *service, char *style)
376 {
377 	struct sshbuf *m;
378 	int r;
379 
380 	debug3("%s entering", __func__);
381 
382 	if ((m = sshbuf_new()) == NULL)
383 		fatal("%s: sshbuf_new failed", __func__);
384 	if ((r = sshbuf_put_cstring(m, service)) != 0 ||
385 	    (r = sshbuf_put_cstring(m, style ? style : "")) != 0)
386 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
387 
388 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m);
389 
390 	sshbuf_free(m);
391 }
392 
393 /* Do the password authentication */
394 int
395 mm_auth_password(struct ssh *ssh, char *password)
396 {
397 	struct sshbuf *m;
398 	int r, authenticated = 0;
399 #ifdef USE_PAM
400 	u_int maxtries = 0;
401 #endif
402 
403 	debug3("%s entering", __func__);
404 
405 	if ((m = sshbuf_new()) == NULL)
406 		fatal("%s: sshbuf_new failed", __func__);
407 	if ((r = sshbuf_put_cstring(m, password)) != 0)
408 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
409 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m);
410 
411 	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
412 	mm_request_receive_expect(pmonitor->m_recvfd,
413 	    MONITOR_ANS_AUTHPASSWORD, m);
414 
415 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
416 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
417 #ifdef USE_PAM
418 	if ((r = sshbuf_get_u32(m, &maxtries)) != 0)
419 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
420 	if (maxtries > INT_MAX)
421 		fatal("%s: bad maxtries %u", __func__, maxtries);
422 	sshpam_set_maxtries_reached(maxtries);
423 #endif
424 
425 	sshbuf_free(m);
426 
427 	debug3("%s: user %sauthenticated",
428 	    __func__, authenticated ? "" : "not ");
429 	return (authenticated);
430 }
431 
432 int
433 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key,
434     int pubkey_auth_attempt, struct sshauthopt **authoptp)
435 {
436 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
437 	    pubkey_auth_attempt, authoptp));
438 }
439 
440 int
441 mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host,
442     struct sshkey *key)
443 {
444 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL));
445 }
446 
447 int
448 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
449     struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp)
450 {
451 	struct sshbuf *m;
452 	int r, allowed = 0;
453 	struct sshauthopt *opts = NULL;
454 
455 	debug3("%s entering", __func__);
456 
457 	if (authoptp != NULL)
458 		*authoptp = NULL;
459 
460 	if ((m = sshbuf_new()) == NULL)
461 		fatal("%s: sshbuf_new failed", __func__);
462 	if ((r = sshbuf_put_u32(m, type)) != 0 ||
463 	    (r = sshbuf_put_cstring(m, user ? user : "")) != 0 ||
464 	    (r = sshbuf_put_cstring(m, host ? host : "")) != 0 ||
465 	    (r = sshkey_puts(key, m)) != 0 ||
466 	    (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0)
467 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
468 
469 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m);
470 
471 	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
472 	mm_request_receive_expect(pmonitor->m_recvfd,
473 	    MONITOR_ANS_KEYALLOWED, m);
474 
475 	if ((r = sshbuf_get_u32(m, &allowed)) != 0)
476 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
477 	if (allowed && type == MM_USERKEY) {
478 		if ((r = sshauthopt_deserialise(m, &opts)) != 0)
479 			fatal("%s: sshauthopt_deserialise: %s",
480 			    __func__, ssh_err(r));
481 	}
482 	sshbuf_free(m);
483 
484 	if (authoptp != NULL) {
485 		*authoptp = opts;
486 		opts = NULL;
487 	}
488 	sshauthopt_free(opts);
489 
490 	return allowed;
491 }
492 
493 /*
494  * This key verify needs to send the key type along, because the
495  * privileged parent makes the decision if the key is allowed
496  * for authentication.
497  */
498 
499 int
500 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
501     const u_char *data, size_t datalen, const char *sigalg, u_int compat)
502 {
503 	struct sshbuf *m;
504 	u_int encoded_ret = 0;
505 	int r;
506 
507 	debug3("%s entering", __func__);
508 
509 
510 	if ((m = sshbuf_new()) == NULL)
511 		fatal("%s: sshbuf_new failed", __func__);
512 	if ((r = sshkey_puts(key, m)) != 0 ||
513 	    (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
514 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
515 	    (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
516 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
517 
518 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
519 
520 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
521 	mm_request_receive_expect(pmonitor->m_recvfd,
522 	    MONITOR_ANS_KEYVERIFY, m);
523 
524 	if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0)
525 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
526 
527 	sshbuf_free(m);
528 
529 	if (encoded_ret != 0)
530 		return SSH_ERR_SIGNATURE_INVALID;
531 	return 0;
532 }
533 
534 void
535 mm_send_keystate(struct monitor *monitor)
536 {
537 	struct ssh *ssh = active_state;		/* XXX */
538 	struct sshbuf *m;
539 	int r;
540 
541 	if ((m = sshbuf_new()) == NULL)
542 		fatal("%s: sshbuf_new failed", __func__);
543 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
544 		fatal("%s: get_state failed: %s",
545 		    __func__, ssh_err(r));
546 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
547 	debug3("%s: Finished sending state", __func__);
548 	sshbuf_free(m);
549 }
550 
551 int
552 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
553 {
554 	struct sshbuf *m;
555 	char *p, *msg;
556 	int success = 0, tmp1 = -1, tmp2 = -1, r;
557 
558 	/* Kludge: ensure there are fds free to receive the pty/tty */
559 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
560 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
561 		error("%s: cannot allocate fds for pty", __func__);
562 		if (tmp1 > 0)
563 			close(tmp1);
564 		if (tmp2 > 0)
565 			close(tmp2);
566 		return 0;
567 	}
568 	close(tmp1);
569 	close(tmp2);
570 
571 	if ((m = sshbuf_new()) == NULL)
572 		fatal("%s: sshbuf_new failed", __func__);
573 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
574 
575 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
576 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
577 
578 	if ((r = sshbuf_get_u32(m, &success)) != 0)
579 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
580 	if (success == 0) {
581 		debug3("%s: pty alloc failed", __func__);
582 		sshbuf_free(m);
583 		return (0);
584 	}
585 	if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
586 	    (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
587 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
588 	sshbuf_free(m);
589 
590 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
591 	free(p);
592 
593 	if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
594 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
595 	free(msg);
596 
597 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
598 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
599 		fatal("%s: receive fds failed", __func__);
600 
601 	/* Success */
602 	return (1);
603 }
604 
605 void
606 mm_session_pty_cleanup2(Session *s)
607 {
608 	struct sshbuf *m;
609 	int r;
610 
611 	if (s->ttyfd == -1)
612 		return;
613 	if ((m = sshbuf_new()) == NULL)
614 		fatal("%s: sshbuf_new failed", __func__);
615 	if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
616 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
617 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
618 	sshbuf_free(m);
619 
620 	/* closed dup'ed master */
621 	if (s->ptymaster != -1 && close(s->ptymaster) < 0)
622 		error("close(s->ptymaster/%d): %s",
623 		    s->ptymaster, strerror(errno));
624 
625 	/* unlink pty from session */
626 	s->ttyfd = -1;
627 }
628 
629 #ifdef USE_PAM
630 void
631 mm_start_pam(Authctxt *authctxt)
632 {
633 	struct sshbuf *m;
634 
635 	debug3("%s entering", __func__);
636 	if (!options.use_pam)
637 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
638 	if ((m = sshbuf_new()) == NULL)
639 		fatal("%s: sshbuf_new failed", __func__);
640 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m);
641 
642 	sshbuf_free(m);
643 }
644 
645 u_int
646 mm_do_pam_account(void)
647 {
648 	struct sshbuf *m;
649 	u_int ret;
650 	char *msg;
651 	size_t msglen;
652 	int r;
653 
654 	debug3("%s entering", __func__);
655 	if (!options.use_pam)
656 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
657 
658 	if ((m = sshbuf_new()) == NULL)
659 		fatal("%s: sshbuf_new failed", __func__);
660 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m);
661 
662 	mm_request_receive_expect(pmonitor->m_recvfd,
663 	    MONITOR_ANS_PAM_ACCOUNT, m);
664 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
665 	    (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 ||
666 	    (r = sshbuf_put(loginmsg, msg, msglen)) != 0)
667 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
668 
669 	free(msg);
670 	sshbuf_free(m);
671 
672 	debug3("%s returning %d", __func__, ret);
673 
674 	return (ret);
675 }
676 
677 void *
678 mm_sshpam_init_ctx(Authctxt *authctxt)
679 {
680 	struct sshbuf *m;
681 	int r, success;
682 
683 	debug3("%s", __func__);
684 	if ((m = sshbuf_new()) == NULL)
685 		fatal("%s: sshbuf_new failed", __func__);
686 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m);
687 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
688 	mm_request_receive_expect(pmonitor->m_recvfd,
689 	    MONITOR_ANS_PAM_INIT_CTX, m);
690 	if ((r = sshbuf_get_u32(m, &success)) != 0)
691 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
692 	if (success == 0) {
693 		debug3("%s: pam_init_ctx failed", __func__);
694 		sshbuf_free(m);
695 		return (NULL);
696 	}
697 	sshbuf_free(m);
698 	return (authctxt);
699 }
700 
701 int
702 mm_sshpam_query(void *ctx, char **name, char **info,
703     u_int *num, char ***prompts, u_int **echo_on)
704 {
705 	struct sshbuf *m;
706 	u_int i, n;
707 	int r, ret;
708 
709 	debug3("%s", __func__);
710 	if ((m = sshbuf_new()) == NULL)
711 		fatal("%s: sshbuf_new failed", __func__);
712 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m);
713 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
714 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m);
715 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
716 	    (r = sshbuf_get_cstring(m, name, NULL)) != 0 ||
717 	    (r = sshbuf_get_cstring(m, info, NULL)) != 0 ||
718 	    (r = sshbuf_get_u32(m, &n)) != 0 ||
719 	    (r = sshbuf_get_u32(m, num)) != 0)
720 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
721 	debug3("%s: pam_query returned %d", __func__, ret);
722 	sshpam_set_maxtries_reached(n);
723 	if (*num > PAM_MAX_NUM_MSG)
724 		fatal("%s: received %u PAM messages, expected <= %u",
725 		    __func__, *num, PAM_MAX_NUM_MSG);
726 	*prompts = xcalloc((*num + 1), sizeof(char *));
727 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
728 	for (i = 0; i < *num; ++i) {
729 		if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 ||
730 		    (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0)
731 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
732 	}
733 	sshbuf_free(m);
734 	return (ret);
735 }
736 
737 int
738 mm_sshpam_respond(void *ctx, u_int num, char **resp)
739 {
740 	struct sshbuf *m;
741 	u_int n, i;
742 	int r, ret;
743 
744 	debug3("%s", __func__);
745 	if ((m = sshbuf_new()) == NULL)
746 		fatal("%s: sshbuf_new failed", __func__);
747 	if ((r = sshbuf_put_u32(m, num)) != 0)
748 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
749 	for (i = 0; i < num; ++i) {
750 		if ((r = sshbuf_put_cstring(m, resp[i])) != 0)
751 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
752 	}
753 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m);
754 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
755 	mm_request_receive_expect(pmonitor->m_recvfd,
756 	    MONITOR_ANS_PAM_RESPOND, m);
757 	if ((r = sshbuf_get_u32(m, &n)) != 0)
758 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
759 	ret = (int)n; /* XXX */
760 	debug3("%s: pam_respond returned %d", __func__, ret);
761 	sshbuf_free(m);
762 	return (ret);
763 }
764 
765 void
766 mm_sshpam_free_ctx(void *ctxtp)
767 {
768 	struct sshbuf *m;
769 
770 	debug3("%s", __func__);
771 	if ((m = sshbuf_new()) == NULL)
772 		fatal("%s: sshbuf_new failed", __func__);
773 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m);
774 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
775 	mm_request_receive_expect(pmonitor->m_recvfd,
776 	    MONITOR_ANS_PAM_FREE_CTX, m);
777 	sshbuf_free(m);
778 }
779 #endif /* USE_PAM */
780 
781 /* Request process termination */
782 
783 void
784 mm_terminate(void)
785 {
786 	struct sshbuf *m;
787 
788 	if ((m = sshbuf_new()) == NULL)
789 		fatal("%s: sshbuf_new failed", __func__);
790 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
791 	sshbuf_free(m);
792 }
793 
794 static void
795 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
796     char ***prompts, u_int **echo_on)
797 {
798 	*name = xstrdup("");
799 	*infotxt = xstrdup("");
800 	*numprompts = 1;
801 	*prompts = xcalloc(*numprompts, sizeof(char *));
802 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
803 	(*echo_on)[0] = 0;
804 }
805 
806 int
807 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
808    u_int *numprompts, char ***prompts, u_int **echo_on)
809 {
810 	struct sshbuf *m;
811 	u_int success;
812 	char *challenge;
813 	int r;
814 
815 	debug3("%s: entering", __func__);
816 
817 	if ((m = sshbuf_new()) == NULL)
818 		fatal("%s: sshbuf_new failed", __func__);
819 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
820 
821 	mm_request_receive_expect(pmonitor->m_recvfd,
822 	    MONITOR_ANS_BSDAUTHQUERY, m);
823 	if ((r = sshbuf_get_u32(m, &success)) != 0)
824 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
825 	if (success == 0) {
826 		debug3("%s: no challenge", __func__);
827 		sshbuf_free(m);
828 		return (-1);
829 	}
830 
831 	/* Get the challenge, and format the response */
832 	if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
833 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
834 	sshbuf_free(m);
835 
836 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
837 	(*prompts)[0] = challenge;
838 
839 	debug3("%s: received challenge: %s", __func__, challenge);
840 
841 	return (0);
842 }
843 
844 int
845 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
846 {
847 	struct sshbuf *m;
848 	int r, authok;
849 
850 	debug3("%s: entering", __func__);
851 	if (numresponses != 1)
852 		return (-1);
853 
854 	if ((m = sshbuf_new()) == NULL)
855 		fatal("%s: sshbuf_new failed", __func__);
856 	if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
857 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
858 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
859 
860 	mm_request_receive_expect(pmonitor->m_recvfd,
861 	    MONITOR_ANS_BSDAUTHRESPOND, m);
862 
863 	if ((r = sshbuf_get_u32(m, &authok)) != 0)
864 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
865 	sshbuf_free(m);
866 
867 	return ((authok == 0) ? -1 : 0);
868 }
869 
870 #ifdef SKEY
871 int
872 mm_skey_query(void *ctx, char **name, char **infotxt,
873    u_int *numprompts, char ***prompts, u_int **echo_on)
874 {
875 	struct sshbuf *m;
876 	u_int success;
877 	char *challenge;
878 	int r;
879 
880 	debug3("%s: entering", __func__);
881 
882 	if ((m = sshbuf_new()) == NULL)
883 		fatal("%s: sshbuf_new failed", __func__);
884 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, m);
885 
886 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY, m);
887 	if ((r = sshbuf_get_u32(m, &success)) != 0)
888 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
889 	if (success == 0) {
890 		debug3("%s: no challenge", __func__);
891 		sshbuf_free(m);
892 		return (-1);
893 	}
894 
895 	/* Get the challenge, and format the response */
896 	if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
897 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
898 	sshbuf_free(m);
899 
900 	debug3("%s: received challenge: %s", __func__, challenge);
901 
902 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
903 
904 	xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT);
905 	free(challenge);
906 
907 	return (0);
908 }
909 
910 int
911 mm_skey_respond(void *ctx, u_int numresponses, char **responses)
912 {
913 	struct sshbuf *m;
914 	int authok, r;
915 
916 	debug3("%s: entering", __func__);
917 	if (numresponses != 1)
918 		return (-1);
919 
920 	if ((m = sshbuf_new()) == NULL)
921 		fatal("%s: sshbuf_new failed", __func__);
922 	if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
923 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
924 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, m);
925 
926 	mm_request_receive_expect(pmonitor->m_recvfd,
927 	    MONITOR_ANS_SKEYRESPOND, m);
928 
929 	if ((r = sshbuf_get_u32(m, &authok)) != 0)
930 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
931 	sshbuf_free(m);
932 
933 	return ((authok == 0) ? -1 : 0);
934 }
935 #endif /* SKEY */
936 
937 #ifdef SSH_AUDIT_EVENTS
938 void
939 mm_audit_event(ssh_audit_event_t event)
940 {
941 	struct sshbuf *m;
942 	int r;
943 
944 	debug3("%s entering", __func__);
945 
946 	if ((m = sshbuf_new()) == NULL)
947 		fatal("%s: sshbuf_new failed", __func__);
948 	if ((r = sshbuf_put_u32(m, event)) != 0)
949 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
950 
951 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m);
952 	sshbuf_free(m);
953 }
954 
955 void
956 mm_audit_run_command(const char *command)
957 {
958 	struct sshbuf *m;
959 	int r;
960 
961 	debug3("%s entering command %s", __func__, command);
962 
963 	if ((m = sshbuf_new()) == NULL)
964 		fatal("%s: sshbuf_new failed", __func__);
965 	if ((r = sshbuf_put_cstring(m, command)) != 0)
966 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
967 
968 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m);
969 	sshbuf_free(m);
970 }
971 #endif /* SSH_AUDIT_EVENTS */
972 
973 #ifdef GSSAPI
974 OM_uint32
975 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
976 {
977 	struct sshbuf *m;
978 	OM_uint32 major;
979 	int r;
980 
981 	/* Client doesn't get to see the context */
982 	*ctx = NULL;
983 
984 	if ((m = sshbuf_new()) == NULL)
985 		fatal("%s: sshbuf_new failed", __func__);
986 	if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
987 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
988 
989 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
990 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
991 
992 	if ((r = sshbuf_get_u32(m, &major)) != 0)
993 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
994 
995 	sshbuf_free(m);
996 	return (major);
997 }
998 
999 OM_uint32
1000 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
1001     gss_buffer_desc *out, OM_uint32 *flagsp)
1002 {
1003 	struct sshbuf *m;
1004 	OM_uint32 major;
1005 	u_int flags;
1006 	int r;
1007 
1008 	if ((m = sshbuf_new()) == NULL)
1009 		fatal("%s: sshbuf_new failed", __func__);
1010 	if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
1011 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
1012 
1013 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
1014 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
1015 
1016 	if ((r = sshbuf_get_u32(m, &major)) != 0 ||
1017 	    (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
1018 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
1019 	if (flagsp != NULL) {
1020 		if ((r = sshbuf_get_u32(m, &flags)) != 0)
1021 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
1022 		*flagsp = flags;
1023 	}
1024 
1025 	sshbuf_free(m);
1026 
1027 	return (major);
1028 }
1029 
1030 OM_uint32
1031 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
1032 {
1033 	struct sshbuf *m;
1034 	OM_uint32 major;
1035 	int r;
1036 
1037 	if ((m = sshbuf_new()) == NULL)
1038 		fatal("%s: sshbuf_new failed", __func__);
1039 	if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
1040 	    (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
1041 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
1042 
1043 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
1044 	mm_request_receive_expect(pmonitor->m_recvfd,
1045 	    MONITOR_ANS_GSSCHECKMIC, m);
1046 
1047 	if ((r = sshbuf_get_u32(m, &major)) != 0)
1048 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
1049 	sshbuf_free(m);
1050 	return(major);
1051 }
1052 
1053 int
1054 mm_ssh_gssapi_userok(char *user)
1055 {
1056 	struct sshbuf *m;
1057 	int r, authenticated = 0;
1058 
1059 	if ((m = sshbuf_new()) == NULL)
1060 		fatal("%s: sshbuf_new failed", __func__);
1061 
1062 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
1063 	mm_request_receive_expect(pmonitor->m_recvfd,
1064 	    MONITOR_ANS_GSSUSEROK, m);
1065 
1066 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
1067 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
1068 
1069 	sshbuf_free(m);
1070 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
1071 	return (authenticated);
1072 }
1073 #endif /* GSSAPI */
1074