xref: /openssh-portable/monitor_wrap.c (revision 9b8ad938)
1 /* $OpenBSD: monitor_wrap.c,v 1.118 2020/08/27 01:06:18 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 ((r = sshbuf_get_bignum2(m, &p)) != 0 ||
206 	    (r = sshbuf_get_bignum2(m, &g)) != 0)
207 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
208 
209 	debug3("%s: remaining %zu", __func__, sshbuf_len(m));
210 	sshbuf_free(m);
211 
212 	return (dh_new_group(g, p));
213 }
214 #endif
215 
216 int
217 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
218     const u_char *data, size_t datalen, const char *hostkey_alg,
219     const char *sk_provider, const char *sk_pin, u_int compat)
220 {
221 	struct kex *kex = *pmonitor->m_pkex;
222 	struct sshbuf *m;
223 	u_int ndx = kex->host_key_index(key, 0, ssh);
224 	int r;
225 
226 	debug3("%s entering", __func__);
227 	if ((m = sshbuf_new()) == NULL)
228 		fatal("%s: sshbuf_new failed", __func__);
229 	if ((r = sshbuf_put_u32(m, ndx)) != 0 ||
230 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
231 	    (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 ||
232 	    (r = sshbuf_put_u32(m, compat)) != 0)
233 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
234 
235 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m);
236 
237 	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
238 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m);
239 	if ((r = sshbuf_get_string(m, sigp, lenp)) != 0)
240 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
241 	sshbuf_free(m);
242 
243 	return (0);
244 }
245 
246 struct passwd *
247 mm_getpwnamallow(struct ssh *ssh, const char *username)
248 {
249 	struct sshbuf *m;
250 	struct passwd *pw;
251 	size_t len;
252 	u_int i;
253 	ServerOptions *newopts;
254 	int r;
255 	u_char ok;
256 	const u_char *p;
257 
258 	debug3("%s entering", __func__);
259 
260 	if ((m = sshbuf_new()) == NULL)
261 		fatal("%s: sshbuf_new failed", __func__);
262 	if ((r = sshbuf_put_cstring(m, username)) != 0)
263 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
264 
265 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m);
266 
267 	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
268 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m);
269 
270 	if ((r = sshbuf_get_u8(m, &ok)) != 0)
271 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
272 	if (ok == 0) {
273 		pw = NULL;
274 		goto out;
275 	}
276 
277 	/* XXX don't like passing struct passwd like this */
278 	pw = xcalloc(sizeof(*pw), 1);
279 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
280 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
281 	if (len != sizeof(*pw))
282 		fatal("%s: struct passwd size mismatch", __func__);
283 	memcpy(pw, p, sizeof(*pw));
284 
285 	if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 ||
286 	    (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 ||
287 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
288 	    (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 ||
289 #endif
290 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
291 	    (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 ||
292 #endif
293 	    (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 ||
294 	    (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0)
295 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
296 
297 out:
298 	/* copy options block as a Match directive may have changed some */
299 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
300 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
301 	if (len != sizeof(*newopts))
302 		fatal("%s: option block size mismatch", __func__);
303 	newopts = xcalloc(sizeof(*newopts), 1);
304 	memcpy(newopts, p, sizeof(*newopts));
305 
306 #define M_CP_STROPT(x) do { \
307 		if (newopts->x != NULL) { \
308 			if ((r = sshbuf_get_cstring(m, \
309 			    &newopts->x, NULL)) != 0) \
310 				fatal("%s: buffer error: %s", \
311 				    __func__, ssh_err(r)); \
312 		} \
313 	} while (0)
314 #define M_CP_STRARRAYOPT(x, nx) do { \
315 		newopts->x = newopts->nx == 0 ? \
316 		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
317 		for (i = 0; i < newopts->nx; i++) { \
318 			if ((r = sshbuf_get_cstring(m, \
319 			    &newopts->x[i], NULL)) != 0) \
320 				fatal("%s: buffer error: %s", \
321 				    __func__, ssh_err(r)); \
322 		} \
323 	} while (0)
324 	/* See comment in servconf.h */
325 	COPY_MATCH_STRING_OPTS();
326 #undef M_CP_STROPT
327 #undef M_CP_STRARRAYOPT
328 
329 	copy_set_server_options(&options, newopts, 1);
330 	log_change_level(options.log_level);
331 	process_permitopen(ssh, &options);
332 	free(newopts);
333 
334 	sshbuf_free(m);
335 
336 	return (pw);
337 }
338 
339 char *
340 mm_auth2_read_banner(void)
341 {
342 	struct sshbuf *m;
343 	char *banner;
344 	int r;
345 
346 	debug3("%s entering", __func__);
347 
348 	if ((m = sshbuf_new()) == NULL)
349 		fatal("%s: sshbuf_new failed", __func__);
350 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m);
351 	sshbuf_reset(m);
352 
353 	mm_request_receive_expect(pmonitor->m_recvfd,
354 	    MONITOR_ANS_AUTH2_READ_BANNER, m);
355 	if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0)
356 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
357 	sshbuf_free(m);
358 
359 	/* treat empty banner as missing banner */
360 	if (strlen(banner) == 0) {
361 		free(banner);
362 		banner = NULL;
363 	}
364 	return (banner);
365 }
366 
367 /* Inform the privileged process about service and style */
368 
369 void
370 mm_inform_authserv(char *service, char *style)
371 {
372 	struct sshbuf *m;
373 	int r;
374 
375 	debug3("%s entering", __func__);
376 
377 	if ((m = sshbuf_new()) == NULL)
378 		fatal("%s: sshbuf_new failed", __func__);
379 	if ((r = sshbuf_put_cstring(m, service)) != 0 ||
380 	    (r = sshbuf_put_cstring(m, style ? style : "")) != 0)
381 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
382 
383 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m);
384 
385 	sshbuf_free(m);
386 }
387 
388 /* Do the password authentication */
389 int
390 mm_auth_password(struct ssh *ssh, char *password)
391 {
392 	struct sshbuf *m;
393 	int r, authenticated = 0;
394 #ifdef USE_PAM
395 	u_int maxtries = 0;
396 #endif
397 
398 	debug3("%s entering", __func__);
399 
400 	if ((m = sshbuf_new()) == NULL)
401 		fatal("%s: sshbuf_new failed", __func__);
402 	if ((r = sshbuf_put_cstring(m, password)) != 0)
403 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
404 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m);
405 
406 	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
407 	mm_request_receive_expect(pmonitor->m_recvfd,
408 	    MONITOR_ANS_AUTHPASSWORD, m);
409 
410 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
411 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
412 #ifdef USE_PAM
413 	if ((r = sshbuf_get_u32(m, &maxtries)) != 0)
414 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
415 	if (maxtries > INT_MAX)
416 		fatal("%s: bad maxtries %u", __func__, maxtries);
417 	sshpam_set_maxtries_reached(maxtries);
418 #endif
419 
420 	sshbuf_free(m);
421 
422 	debug3("%s: user %sauthenticated",
423 	    __func__, authenticated ? "" : "not ");
424 	return (authenticated);
425 }
426 
427 int
428 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key,
429     int pubkey_auth_attempt, struct sshauthopt **authoptp)
430 {
431 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
432 	    pubkey_auth_attempt, authoptp));
433 }
434 
435 int
436 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw,
437     const char *user, const char *host, struct sshkey *key)
438 {
439 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL));
440 }
441 
442 int
443 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
444     struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp)
445 {
446 	struct sshbuf *m;
447 	int r, allowed = 0;
448 	struct sshauthopt *opts = NULL;
449 
450 	debug3("%s entering", __func__);
451 
452 	if (authoptp != NULL)
453 		*authoptp = NULL;
454 
455 	if ((m = sshbuf_new()) == NULL)
456 		fatal("%s: sshbuf_new failed", __func__);
457 	if ((r = sshbuf_put_u32(m, type)) != 0 ||
458 	    (r = sshbuf_put_cstring(m, user ? user : "")) != 0 ||
459 	    (r = sshbuf_put_cstring(m, host ? host : "")) != 0 ||
460 	    (r = sshkey_puts(key, m)) != 0 ||
461 	    (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0)
462 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
463 
464 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m);
465 
466 	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
467 	mm_request_receive_expect(pmonitor->m_recvfd,
468 	    MONITOR_ANS_KEYALLOWED, m);
469 
470 	if ((r = sshbuf_get_u32(m, &allowed)) != 0)
471 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
472 	if (allowed && type == MM_USERKEY) {
473 		if ((r = sshauthopt_deserialise(m, &opts)) != 0)
474 			fatal("%s: sshauthopt_deserialise: %s",
475 			    __func__, ssh_err(r));
476 	}
477 	sshbuf_free(m);
478 
479 	if (authoptp != NULL) {
480 		*authoptp = opts;
481 		opts = NULL;
482 	}
483 	sshauthopt_free(opts);
484 
485 	return allowed;
486 }
487 
488 /*
489  * This key verify needs to send the key type along, because the
490  * privileged parent makes the decision if the key is allowed
491  * for authentication.
492  */
493 
494 int
495 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
496     const u_char *data, size_t datalen, const char *sigalg, u_int compat,
497     struct sshkey_sig_details **sig_detailsp)
498 {
499 	struct sshbuf *m;
500 	u_int encoded_ret = 0;
501 	int r;
502 	u_char sig_details_present, flags;
503 	u_int counter;
504 
505 	debug3("%s entering", __func__);
506 
507 	if (sig_detailsp != NULL)
508 		*sig_detailsp = NULL;
509 	if ((m = sshbuf_new()) == NULL)
510 		fatal("%s: sshbuf_new failed", __func__);
511 	if ((r = sshkey_puts(key, m)) != 0 ||
512 	    (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
513 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
514 	    (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
515 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
516 
517 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
518 
519 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
520 	mm_request_receive_expect(pmonitor->m_recvfd,
521 	    MONITOR_ANS_KEYVERIFY, m);
522 
523 	if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 ||
524 	    (r = sshbuf_get_u8(m, &sig_details_present)) != 0)
525 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
526 	if (sig_details_present && encoded_ret == 0) {
527 		if ((r = sshbuf_get_u32(m, &counter)) != 0 ||
528 		    (r = sshbuf_get_u8(m, &flags)) != 0)
529 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
530 		if (sig_detailsp != NULL) {
531 			*sig_detailsp = xcalloc(1, sizeof(**sig_detailsp));
532 			(*sig_detailsp)->sk_counter = counter;
533 			(*sig_detailsp)->sk_flags = flags;
534 		}
535 	}
536 
537 	sshbuf_free(m);
538 
539 	if (encoded_ret != 0)
540 		return SSH_ERR_SIGNATURE_INVALID;
541 	return 0;
542 }
543 
544 void
545 mm_send_keystate(struct ssh *ssh, struct monitor *monitor)
546 {
547 	struct sshbuf *m;
548 	int r;
549 
550 	if ((m = sshbuf_new()) == NULL)
551 		fatal("%s: sshbuf_new failed", __func__);
552 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
553 		fatal("%s: get_state failed: %s",
554 		    __func__, ssh_err(r));
555 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
556 	debug3("%s: Finished sending state", __func__);
557 	sshbuf_free(m);
558 }
559 
560 int
561 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
562 {
563 	struct sshbuf *m;
564 	char *p, *msg;
565 	int success = 0, tmp1 = -1, tmp2 = -1, r;
566 
567 	/* Kludge: ensure there are fds free to receive the pty/tty */
568 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
569 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
570 		error("%s: cannot allocate fds for pty", __func__);
571 		if (tmp1 > 0)
572 			close(tmp1);
573 		if (tmp2 > 0)
574 			close(tmp2);
575 		return 0;
576 	}
577 	close(tmp1);
578 	close(tmp2);
579 
580 	if ((m = sshbuf_new()) == NULL)
581 		fatal("%s: sshbuf_new failed", __func__);
582 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
583 
584 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
585 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
586 
587 	if ((r = sshbuf_get_u32(m, &success)) != 0)
588 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
589 	if (success == 0) {
590 		debug3("%s: pty alloc failed", __func__);
591 		sshbuf_free(m);
592 		return (0);
593 	}
594 	if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
595 	    (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
596 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
597 	sshbuf_free(m);
598 
599 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
600 	free(p);
601 
602 	if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
603 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
604 	free(msg);
605 
606 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
607 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
608 		fatal("%s: receive fds failed", __func__);
609 
610 	/* Success */
611 	return (1);
612 }
613 
614 void
615 mm_session_pty_cleanup2(Session *s)
616 {
617 	struct sshbuf *m;
618 	int r;
619 
620 	if (s->ttyfd == -1)
621 		return;
622 	if ((m = sshbuf_new()) == NULL)
623 		fatal("%s: sshbuf_new failed", __func__);
624 	if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
625 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
626 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
627 	sshbuf_free(m);
628 
629 	/* closed dup'ed master */
630 	if (s->ptymaster != -1 && close(s->ptymaster) == -1)
631 		error("close(s->ptymaster/%d): %s",
632 		    s->ptymaster, strerror(errno));
633 
634 	/* unlink pty from session */
635 	s->ttyfd = -1;
636 }
637 
638 #ifdef USE_PAM
639 void
640 mm_start_pam(struct ssh *ssh)
641 {
642 	struct sshbuf *m;
643 
644 	debug3("%s entering", __func__);
645 	if (!options.use_pam)
646 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
647 	if ((m = sshbuf_new()) == NULL)
648 		fatal("%s: sshbuf_new failed", __func__);
649 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m);
650 
651 	sshbuf_free(m);
652 }
653 
654 u_int
655 mm_do_pam_account(void)
656 {
657 	struct sshbuf *m;
658 	u_int ret;
659 	char *msg;
660 	size_t msglen;
661 	int r;
662 
663 	debug3("%s entering", __func__);
664 	if (!options.use_pam)
665 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
666 
667 	if ((m = sshbuf_new()) == NULL)
668 		fatal("%s: sshbuf_new failed", __func__);
669 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m);
670 
671 	mm_request_receive_expect(pmonitor->m_recvfd,
672 	    MONITOR_ANS_PAM_ACCOUNT, m);
673 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
674 	    (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 ||
675 	    (r = sshbuf_put(loginmsg, msg, msglen)) != 0)
676 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
677 
678 	free(msg);
679 	sshbuf_free(m);
680 
681 	debug3("%s returning %d", __func__, ret);
682 
683 	return (ret);
684 }
685 
686 void *
687 mm_sshpam_init_ctx(Authctxt *authctxt)
688 {
689 	struct sshbuf *m;
690 	int r, success;
691 
692 	debug3("%s", __func__);
693 	if ((m = sshbuf_new()) == NULL)
694 		fatal("%s: sshbuf_new failed", __func__);
695 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m);
696 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
697 	mm_request_receive_expect(pmonitor->m_recvfd,
698 	    MONITOR_ANS_PAM_INIT_CTX, m);
699 	if ((r = sshbuf_get_u32(m, &success)) != 0)
700 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
701 	if (success == 0) {
702 		debug3("%s: pam_init_ctx failed", __func__);
703 		sshbuf_free(m);
704 		return (NULL);
705 	}
706 	sshbuf_free(m);
707 	return (authctxt);
708 }
709 
710 int
711 mm_sshpam_query(void *ctx, char **name, char **info,
712     u_int *num, char ***prompts, u_int **echo_on)
713 {
714 	struct sshbuf *m;
715 	u_int i, n;
716 	int r, ret;
717 
718 	debug3("%s", __func__);
719 	if ((m = sshbuf_new()) == NULL)
720 		fatal("%s: sshbuf_new failed", __func__);
721 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m);
722 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
723 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m);
724 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
725 	    (r = sshbuf_get_cstring(m, name, NULL)) != 0 ||
726 	    (r = sshbuf_get_cstring(m, info, NULL)) != 0 ||
727 	    (r = sshbuf_get_u32(m, &n)) != 0 ||
728 	    (r = sshbuf_get_u32(m, num)) != 0)
729 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
730 	debug3("%s: pam_query returned %d", __func__, ret);
731 	sshpam_set_maxtries_reached(n);
732 	if (*num > PAM_MAX_NUM_MSG)
733 		fatal("%s: received %u PAM messages, expected <= %u",
734 		    __func__, *num, PAM_MAX_NUM_MSG);
735 	*prompts = xcalloc((*num + 1), sizeof(char *));
736 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
737 	for (i = 0; i < *num; ++i) {
738 		if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 ||
739 		    (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0)
740 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
741 	}
742 	sshbuf_free(m);
743 	return (ret);
744 }
745 
746 int
747 mm_sshpam_respond(void *ctx, u_int num, char **resp)
748 {
749 	struct sshbuf *m;
750 	u_int n, i;
751 	int r, ret;
752 
753 	debug3("%s", __func__);
754 	if ((m = sshbuf_new()) == NULL)
755 		fatal("%s: sshbuf_new failed", __func__);
756 	if ((r = sshbuf_put_u32(m, num)) != 0)
757 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
758 	for (i = 0; i < num; ++i) {
759 		if ((r = sshbuf_put_cstring(m, resp[i])) != 0)
760 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
761 	}
762 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m);
763 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
764 	mm_request_receive_expect(pmonitor->m_recvfd,
765 	    MONITOR_ANS_PAM_RESPOND, m);
766 	if ((r = sshbuf_get_u32(m, &n)) != 0)
767 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
768 	ret = (int)n; /* XXX */
769 	debug3("%s: pam_respond returned %d", __func__, ret);
770 	sshbuf_free(m);
771 	return (ret);
772 }
773 
774 void
775 mm_sshpam_free_ctx(void *ctxtp)
776 {
777 	struct sshbuf *m;
778 
779 	debug3("%s", __func__);
780 	if ((m = sshbuf_new()) == NULL)
781 		fatal("%s: sshbuf_new failed", __func__);
782 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m);
783 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
784 	mm_request_receive_expect(pmonitor->m_recvfd,
785 	    MONITOR_ANS_PAM_FREE_CTX, m);
786 	sshbuf_free(m);
787 }
788 #endif /* USE_PAM */
789 
790 /* Request process termination */
791 
792 void
793 mm_terminate(void)
794 {
795 	struct sshbuf *m;
796 
797 	if ((m = sshbuf_new()) == NULL)
798 		fatal("%s: sshbuf_new failed", __func__);
799 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
800 	sshbuf_free(m);
801 }
802 
803 static void
804 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
805     char ***prompts, u_int **echo_on)
806 {
807 	*name = xstrdup("");
808 	*infotxt = xstrdup("");
809 	*numprompts = 1;
810 	*prompts = xcalloc(*numprompts, sizeof(char *));
811 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
812 	(*echo_on)[0] = 0;
813 }
814 
815 int
816 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
817    u_int *numprompts, char ***prompts, u_int **echo_on)
818 {
819 	struct sshbuf *m;
820 	u_int success;
821 	char *challenge;
822 	int r;
823 
824 	debug3("%s: entering", __func__);
825 
826 	if ((m = sshbuf_new()) == NULL)
827 		fatal("%s: sshbuf_new failed", __func__);
828 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
829 
830 	mm_request_receive_expect(pmonitor->m_recvfd,
831 	    MONITOR_ANS_BSDAUTHQUERY, m);
832 	if ((r = sshbuf_get_u32(m, &success)) != 0)
833 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
834 	if (success == 0) {
835 		debug3("%s: no challenge", __func__);
836 		sshbuf_free(m);
837 		return (-1);
838 	}
839 
840 	/* Get the challenge, and format the response */
841 	if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
842 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
843 	sshbuf_free(m);
844 
845 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
846 	(*prompts)[0] = challenge;
847 
848 	debug3("%s: received challenge: %s", __func__, challenge);
849 
850 	return (0);
851 }
852 
853 int
854 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
855 {
856 	struct sshbuf *m;
857 	int r, authok;
858 
859 	debug3("%s: entering", __func__);
860 	if (numresponses != 1)
861 		return (-1);
862 
863 	if ((m = sshbuf_new()) == NULL)
864 		fatal("%s: sshbuf_new failed", __func__);
865 	if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
866 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
867 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
868 
869 	mm_request_receive_expect(pmonitor->m_recvfd,
870 	    MONITOR_ANS_BSDAUTHRESPOND, m);
871 
872 	if ((r = sshbuf_get_u32(m, &authok)) != 0)
873 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
874 	sshbuf_free(m);
875 
876 	return ((authok == 0) ? -1 : 0);
877 }
878 
879 #ifdef SSH_AUDIT_EVENTS
880 void
881 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event)
882 {
883 	struct sshbuf *m;
884 	int r;
885 
886 	debug3("%s entering", __func__);
887 
888 	if ((m = sshbuf_new()) == NULL)
889 		fatal("%s: sshbuf_new failed", __func__);
890 	if ((r = sshbuf_put_u32(m, event)) != 0)
891 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
892 
893 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m);
894 	sshbuf_free(m);
895 }
896 
897 void
898 mm_audit_run_command(const char *command)
899 {
900 	struct sshbuf *m;
901 	int r;
902 
903 	debug3("%s entering command %s", __func__, command);
904 
905 	if ((m = sshbuf_new()) == NULL)
906 		fatal("%s: sshbuf_new failed", __func__);
907 	if ((r = sshbuf_put_cstring(m, command)) != 0)
908 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
909 
910 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m);
911 	sshbuf_free(m);
912 }
913 #endif /* SSH_AUDIT_EVENTS */
914 
915 #ifdef GSSAPI
916 OM_uint32
917 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
918 {
919 	struct sshbuf *m;
920 	OM_uint32 major;
921 	int r;
922 
923 	/* Client doesn't get to see the context */
924 	*ctx = NULL;
925 
926 	if ((m = sshbuf_new()) == NULL)
927 		fatal("%s: sshbuf_new failed", __func__);
928 	if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
929 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
930 
931 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
932 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
933 
934 	if ((r = sshbuf_get_u32(m, &major)) != 0)
935 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
936 
937 	sshbuf_free(m);
938 	return (major);
939 }
940 
941 OM_uint32
942 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
943     gss_buffer_desc *out, OM_uint32 *flagsp)
944 {
945 	struct sshbuf *m;
946 	OM_uint32 major;
947 	u_int flags;
948 	int r;
949 
950 	if ((m = sshbuf_new()) == NULL)
951 		fatal("%s: sshbuf_new failed", __func__);
952 	if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
953 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
954 
955 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
956 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
957 
958 	if ((r = sshbuf_get_u32(m, &major)) != 0 ||
959 	    (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
960 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
961 	if (flagsp != NULL) {
962 		if ((r = sshbuf_get_u32(m, &flags)) != 0)
963 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
964 		*flagsp = flags;
965 	}
966 
967 	sshbuf_free(m);
968 
969 	return (major);
970 }
971 
972 OM_uint32
973 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
974 {
975 	struct sshbuf *m;
976 	OM_uint32 major;
977 	int r;
978 
979 	if ((m = sshbuf_new()) == NULL)
980 		fatal("%s: sshbuf_new failed", __func__);
981 	if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
982 	    (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
983 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
984 
985 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
986 	mm_request_receive_expect(pmonitor->m_recvfd,
987 	    MONITOR_ANS_GSSCHECKMIC, m);
988 
989 	if ((r = sshbuf_get_u32(m, &major)) != 0)
990 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
991 	sshbuf_free(m);
992 	return(major);
993 }
994 
995 int
996 mm_ssh_gssapi_userok(char *user)
997 {
998 	struct sshbuf *m;
999 	int r, authenticated = 0;
1000 
1001 	if ((m = sshbuf_new()) == NULL)
1002 		fatal("%s: sshbuf_new failed", __func__);
1003 
1004 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
1005 	mm_request_receive_expect(pmonitor->m_recvfd,
1006 	    MONITOR_ANS_GSSUSEROK, m);
1007 
1008 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
1009 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
1010 
1011 	sshbuf_free(m);
1012 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
1013 	return (authenticated);
1014 }
1015 #endif /* GSSAPI */
1016