xref: /openbsd/usr.bin/ssh/monitor_wrap.c (revision 09467b48)
1 /* $OpenBSD: monitor_wrap.c,v 1.117 2019/12/15 18:57:30 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 <sys/types.h>
29 #include <sys/uio.h>
30 #include <sys/queue.h>
31 
32 #include <errno.h>
33 #include <pwd.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <stdarg.h>
38 #include <unistd.h>
39 
40 #ifdef WITH_OPENSSL
41 #include <openssl/bn.h>
42 #include <openssl/dh.h>
43 #endif
44 
45 #include "xmalloc.h"
46 #include "ssh.h"
47 #ifdef WITH_OPENSSL
48 #include "dh.h"
49 #endif
50 #include "sshbuf.h"
51 #include "sshkey.h"
52 #include "cipher.h"
53 #include "kex.h"
54 #include "hostfile.h"
55 #include "auth.h"
56 #include "auth-options.h"
57 #include "packet.h"
58 #include "mac.h"
59 #include "log.h"
60 #include "monitor.h"
61 #ifdef GSSAPI
62 #include "ssh-gss.h"
63 #endif
64 #include "monitor_wrap.h"
65 #include "atomicio.h"
66 #include "monitor_fdpass.h"
67 #include "misc.h"
68 
69 #include "channels.h"
70 #include "session.h"
71 #include "servconf.h"
72 
73 #include "ssherr.h"
74 
75 /* Imports */
76 extern struct monitor *pmonitor;
77 extern struct sshbuf *loginmsg;
78 extern ServerOptions options;
79 
80 void
81 mm_log_handler(LogLevel level, const char *msg, void *ctx)
82 {
83 	struct sshbuf *log_msg;
84 	struct monitor *mon = (struct monitor *)ctx;
85 	int r;
86 	size_t len;
87 
88 	if (mon->m_log_sendfd == -1)
89 		fatal("%s: no log channel", __func__);
90 
91 	if ((log_msg = sshbuf_new()) == NULL)
92 		fatal("%s: sshbuf_new failed", __func__);
93 
94 	if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */
95 	    (r = sshbuf_put_u32(log_msg, level)) != 0 ||
96 	    (r = sshbuf_put_cstring(log_msg, msg)) != 0)
97 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
98 	if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff)
99 		fatal("%s: bad length %zu", __func__, len);
100 	POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4);
101 	if (atomicio(vwrite, mon->m_log_sendfd,
102 	    sshbuf_mutable_ptr(log_msg), len) != len)
103 		fatal("%s: write: %s", __func__, strerror(errno));
104 	sshbuf_free(log_msg);
105 }
106 
107 int
108 mm_is_monitor(void)
109 {
110 	/*
111 	 * m_pid is only set in the privileged part, and
112 	 * points to the unprivileged child.
113 	 */
114 	return (pmonitor && pmonitor->m_pid > 0);
115 }
116 
117 void
118 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m)
119 {
120 	size_t mlen = sshbuf_len(m);
121 	u_char buf[5];
122 
123 	debug3("%s entering: type %d", __func__, type);
124 
125 	if (mlen >= 0xffffffff)
126 		fatal("%s: bad length %zu", __func__, mlen);
127 	POKE_U32(buf, mlen + 1);
128 	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
129 	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
130 		fatal("%s: write: %s", __func__, strerror(errno));
131 	if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen)
132 		fatal("%s: write: %s", __func__, strerror(errno));
133 }
134 
135 void
136 mm_request_receive(int sock, struct sshbuf *m)
137 {
138 	u_char buf[4], *p = NULL;
139 	u_int msg_len;
140 	int r;
141 
142 	debug3("%s entering", __func__);
143 
144 	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
145 		if (errno == EPIPE)
146 			cleanup_exit(255);
147 		fatal("%s: read: %s", __func__, strerror(errno));
148 	}
149 	msg_len = PEEK_U32(buf);
150 	if (msg_len > 256 * 1024)
151 		fatal("%s: read: bad msg_len %d", __func__, msg_len);
152 	sshbuf_reset(m);
153 	if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
154 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
155 	if (atomicio(read, sock, p, msg_len) != msg_len)
156 		fatal("%s: read: %s", __func__, strerror(errno));
157 }
158 
159 void
160 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m)
161 {
162 	u_char rtype;
163 	int r;
164 
165 	debug3("%s entering: type %d", __func__, type);
166 
167 	mm_request_receive(sock, m);
168 	if ((r = sshbuf_get_u8(m, &rtype)) != 0)
169 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
170 	if (rtype != type)
171 		fatal("%s: read: rtype %d != type %d", __func__,
172 		    rtype, type);
173 }
174 
175 #ifdef WITH_OPENSSL
176 DH *
177 mm_choose_dh(int min, int nbits, int max)
178 {
179 	BIGNUM *p, *g;
180 	int r;
181 	u_char success = 0;
182 	struct sshbuf *m;
183 
184 	if ((m = sshbuf_new()) == NULL)
185 		fatal("%s: sshbuf_new failed", __func__);
186 	if ((r = sshbuf_put_u32(m, min)) != 0 ||
187 	    (r = sshbuf_put_u32(m, nbits)) != 0 ||
188 	    (r = sshbuf_put_u32(m, max)) != 0)
189 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
190 
191 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m);
192 
193 	debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
194 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m);
195 
196 	if ((r = sshbuf_get_u8(m, &success)) != 0)
197 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
198 	if (success == 0)
199 		fatal("%s: MONITOR_ANS_MODULI failed", __func__);
200 
201 	if ((r = sshbuf_get_bignum2(m, &p)) != 0 ||
202 	    (r = sshbuf_get_bignum2(m, &g)) != 0)
203 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
204 
205 	debug3("%s: remaining %zu", __func__, sshbuf_len(m));
206 	sshbuf_free(m);
207 
208 	return (dh_new_group(g, p));
209 }
210 #endif
211 
212 int
213 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
214     const u_char *data, size_t datalen, const char *hostkey_alg,
215     const char *sk_provider, u_int compat)
216 {
217 	struct kex *kex = *pmonitor->m_pkex;
218 	struct sshbuf *m;
219 	u_int ndx = kex->host_key_index(key, 0, ssh);
220 	int r;
221 
222 	debug3("%s entering", __func__);
223 	if ((m = sshbuf_new()) == NULL)
224 		fatal("%s: sshbuf_new failed", __func__);
225 	if ((r = sshbuf_put_u32(m, ndx)) != 0 ||
226 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
227 	    (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 ||
228 	    (r = sshbuf_put_u32(m, compat)) != 0)
229 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
230 
231 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m);
232 
233 	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
234 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m);
235 	if ((r = sshbuf_get_string(m, sigp, lenp)) != 0)
236 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
237 	sshbuf_free(m);
238 
239 	return (0);
240 }
241 
242 struct passwd *
243 mm_getpwnamallow(struct ssh *ssh, const char *username)
244 {
245 	struct sshbuf *m;
246 	struct passwd *pw;
247 	size_t len;
248 	u_int i;
249 	ServerOptions *newopts;
250 	int r;
251 	u_char ok;
252 	const u_char *p;
253 
254 	debug3("%s entering", __func__);
255 
256 	if ((m = sshbuf_new()) == NULL)
257 		fatal("%s: sshbuf_new failed", __func__);
258 	if ((r = sshbuf_put_cstring(m, username)) != 0)
259 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
260 
261 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m);
262 
263 	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
264 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m);
265 
266 	if ((r = sshbuf_get_u8(m, &ok)) != 0)
267 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
268 	if (ok == 0) {
269 		pw = NULL;
270 		goto out;
271 	}
272 
273 	/* XXX don't like passing struct passwd like this */
274 	pw = xcalloc(sizeof(*pw), 1);
275 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
276 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
277 	if (len != sizeof(*pw))
278 		fatal("%s: struct passwd size mismatch", __func__);
279 	memcpy(pw, p, sizeof(*pw));
280 
281 	if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 ||
282 	    (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 ||
283 	    (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 ||
284 	    (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 ||
285 	    (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 ||
286 	    (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0)
287 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
288 
289 out:
290 	/* copy options block as a Match directive may have changed some */
291 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
292 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
293 	if (len != sizeof(*newopts))
294 		fatal("%s: option block size mismatch", __func__);
295 	newopts = xcalloc(sizeof(*newopts), 1);
296 	memcpy(newopts, p, sizeof(*newopts));
297 
298 #define M_CP_STROPT(x) do { \
299 		if (newopts->x != NULL) { \
300 			if ((r = sshbuf_get_cstring(m, \
301 			    &newopts->x, NULL)) != 0) \
302 				fatal("%s: buffer error: %s", \
303 				    __func__, ssh_err(r)); \
304 		} \
305 	} while (0)
306 #define M_CP_STRARRAYOPT(x, nx) do { \
307 		newopts->x = newopts->nx == 0 ? \
308 		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
309 		for (i = 0; i < newopts->nx; i++) { \
310 			if ((r = sshbuf_get_cstring(m, \
311 			    &newopts->x[i], NULL)) != 0) \
312 				fatal("%s: buffer error: %s", \
313 				    __func__, ssh_err(r)); \
314 		} \
315 	} while (0)
316 	/* See comment in servconf.h */
317 	COPY_MATCH_STRING_OPTS();
318 #undef M_CP_STROPT
319 #undef M_CP_STRARRAYOPT
320 
321 	copy_set_server_options(&options, newopts, 1);
322 	log_change_level(options.log_level);
323 	process_permitopen(ssh, &options);
324 	free(newopts);
325 
326 	sshbuf_free(m);
327 
328 	return (pw);
329 }
330 
331 char *
332 mm_auth2_read_banner(void)
333 {
334 	struct sshbuf *m;
335 	char *banner;
336 	int r;
337 
338 	debug3("%s entering", __func__);
339 
340 	if ((m = sshbuf_new()) == NULL)
341 		fatal("%s: sshbuf_new failed", __func__);
342 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m);
343 	sshbuf_reset(m);
344 
345 	mm_request_receive_expect(pmonitor->m_recvfd,
346 	    MONITOR_ANS_AUTH2_READ_BANNER, m);
347 	if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0)
348 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
349 	sshbuf_free(m);
350 
351 	/* treat empty banner as missing banner */
352 	if (strlen(banner) == 0) {
353 		free(banner);
354 		banner = NULL;
355 	}
356 	return (banner);
357 }
358 
359 /* Inform the privileged process about service and style */
360 
361 void
362 mm_inform_authserv(char *service, char *style)
363 {
364 	struct sshbuf *m;
365 	int r;
366 
367 	debug3("%s entering", __func__);
368 
369 	if ((m = sshbuf_new()) == NULL)
370 		fatal("%s: sshbuf_new failed", __func__);
371 	if ((r = sshbuf_put_cstring(m, service)) != 0 ||
372 	    (r = sshbuf_put_cstring(m, style ? style : "")) != 0)
373 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
374 
375 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m);
376 
377 	sshbuf_free(m);
378 }
379 
380 /* Do the password authentication */
381 int
382 mm_auth_password(struct ssh *ssh, char *password)
383 {
384 	struct sshbuf *m;
385 	int r, authenticated = 0;
386 
387 	debug3("%s entering", __func__);
388 
389 	if ((m = sshbuf_new()) == NULL)
390 		fatal("%s: sshbuf_new failed", __func__);
391 	if ((r = sshbuf_put_cstring(m, password)) != 0)
392 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
393 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m);
394 
395 	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
396 	mm_request_receive_expect(pmonitor->m_recvfd,
397 	    MONITOR_ANS_AUTHPASSWORD, m);
398 
399 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
400 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
401 
402 	sshbuf_free(m);
403 
404 	debug3("%s: user %sauthenticated",
405 	    __func__, authenticated ? "" : "not ");
406 	return (authenticated);
407 }
408 
409 int
410 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key,
411     int pubkey_auth_attempt, struct sshauthopt **authoptp)
412 {
413 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
414 	    pubkey_auth_attempt, authoptp));
415 }
416 
417 int
418 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw,
419     const char *user, const char *host, struct sshkey *key)
420 {
421 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL));
422 }
423 
424 int
425 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
426     struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp)
427 {
428 	struct sshbuf *m;
429 	int r, allowed = 0;
430 	struct sshauthopt *opts = NULL;
431 
432 	debug3("%s entering", __func__);
433 
434 	if (authoptp != NULL)
435 		*authoptp = NULL;
436 
437 	if ((m = sshbuf_new()) == NULL)
438 		fatal("%s: sshbuf_new failed", __func__);
439 	if ((r = sshbuf_put_u32(m, type)) != 0 ||
440 	    (r = sshbuf_put_cstring(m, user ? user : "")) != 0 ||
441 	    (r = sshbuf_put_cstring(m, host ? host : "")) != 0 ||
442 	    (r = sshkey_puts(key, m)) != 0 ||
443 	    (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0)
444 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
445 
446 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m);
447 
448 	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
449 	mm_request_receive_expect(pmonitor->m_recvfd,
450 	    MONITOR_ANS_KEYALLOWED, m);
451 
452 	if ((r = sshbuf_get_u32(m, &allowed)) != 0)
453 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
454 	if (allowed && type == MM_USERKEY) {
455 		if ((r = sshauthopt_deserialise(m, &opts)) != 0)
456 			fatal("%s: sshauthopt_deserialise: %s",
457 			    __func__, ssh_err(r));
458 	}
459 	sshbuf_free(m);
460 
461 	if (authoptp != NULL) {
462 		*authoptp = opts;
463 		opts = NULL;
464 	}
465 	sshauthopt_free(opts);
466 
467 	return allowed;
468 }
469 
470 /*
471  * This key verify needs to send the key type along, because the
472  * privileged parent makes the decision if the key is allowed
473  * for authentication.
474  */
475 
476 int
477 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
478     const u_char *data, size_t datalen, const char *sigalg, u_int compat,
479     struct sshkey_sig_details **sig_detailsp)
480 {
481 	struct sshbuf *m;
482 	u_int encoded_ret = 0;
483 	int r;
484 	u_char sig_details_present, flags;
485 	u_int counter;
486 
487 	debug3("%s entering", __func__);
488 
489 	if (sig_detailsp != NULL)
490 		*sig_detailsp = NULL;
491 	if ((m = sshbuf_new()) == NULL)
492 		fatal("%s: sshbuf_new failed", __func__);
493 	if ((r = sshkey_puts(key, m)) != 0 ||
494 	    (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
495 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
496 	    (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
497 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
498 
499 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
500 
501 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
502 	mm_request_receive_expect(pmonitor->m_recvfd,
503 	    MONITOR_ANS_KEYVERIFY, m);
504 
505 	if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 ||
506 	    (r = sshbuf_get_u8(m, &sig_details_present)) != 0)
507 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
508 	if (sig_details_present && encoded_ret == 0) {
509 		if ((r = sshbuf_get_u32(m, &counter)) != 0 ||
510 		    (r = sshbuf_get_u8(m, &flags)) != 0)
511 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
512 		if (sig_detailsp != NULL) {
513 			*sig_detailsp = xcalloc(1, sizeof(**sig_detailsp));
514 			(*sig_detailsp)->sk_counter = counter;
515 			(*sig_detailsp)->sk_flags = flags;
516 		}
517 	}
518 
519 	sshbuf_free(m);
520 
521 	if (encoded_ret != 0)
522 		return SSH_ERR_SIGNATURE_INVALID;
523 	return 0;
524 }
525 
526 void
527 mm_send_keystate(struct ssh *ssh, struct monitor *monitor)
528 {
529 	struct sshbuf *m;
530 	int r;
531 
532 	if ((m = sshbuf_new()) == NULL)
533 		fatal("%s: sshbuf_new failed", __func__);
534 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
535 		fatal("%s: get_state failed: %s",
536 		    __func__, ssh_err(r));
537 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
538 	debug3("%s: Finished sending state", __func__);
539 	sshbuf_free(m);
540 }
541 
542 int
543 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
544 {
545 	struct sshbuf *m;
546 	char *p, *msg;
547 	int success = 0, tmp1 = -1, tmp2 = -1, r;
548 
549 	/* Kludge: ensure there are fds free to receive the pty/tty */
550 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
551 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
552 		error("%s: cannot allocate fds for pty", __func__);
553 		if (tmp1 > 0)
554 			close(tmp1);
555 		if (tmp2 > 0)
556 			close(tmp2);
557 		return 0;
558 	}
559 	close(tmp1);
560 	close(tmp2);
561 
562 	if ((m = sshbuf_new()) == NULL)
563 		fatal("%s: sshbuf_new failed", __func__);
564 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
565 
566 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
567 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
568 
569 	if ((r = sshbuf_get_u32(m, &success)) != 0)
570 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
571 	if (success == 0) {
572 		debug3("%s: pty alloc failed", __func__);
573 		sshbuf_free(m);
574 		return (0);
575 	}
576 	if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
577 	    (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
578 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
579 	sshbuf_free(m);
580 
581 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
582 	free(p);
583 
584 	if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
585 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
586 	free(msg);
587 
588 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
589 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
590 		fatal("%s: receive fds failed", __func__);
591 
592 	/* Success */
593 	return (1);
594 }
595 
596 void
597 mm_session_pty_cleanup2(Session *s)
598 {
599 	struct sshbuf *m;
600 	int r;
601 
602 	if (s->ttyfd == -1)
603 		return;
604 	if ((m = sshbuf_new()) == NULL)
605 		fatal("%s: sshbuf_new failed", __func__);
606 	if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
607 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
608 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
609 	sshbuf_free(m);
610 
611 	/* closed dup'ed master */
612 	if (s->ptymaster != -1 && close(s->ptymaster) == -1)
613 		error("close(s->ptymaster/%d): %s",
614 		    s->ptymaster, strerror(errno));
615 
616 	/* unlink pty from session */
617 	s->ttyfd = -1;
618 }
619 
620 /* Request process termination */
621 
622 void
623 mm_terminate(void)
624 {
625 	struct sshbuf *m;
626 
627 	if ((m = sshbuf_new()) == NULL)
628 		fatal("%s: sshbuf_new failed", __func__);
629 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
630 	sshbuf_free(m);
631 }
632 
633 static void
634 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
635     char ***prompts, u_int **echo_on)
636 {
637 	*name = xstrdup("");
638 	*infotxt = xstrdup("");
639 	*numprompts = 1;
640 	*prompts = xcalloc(*numprompts, sizeof(char *));
641 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
642 	(*echo_on)[0] = 0;
643 }
644 
645 int
646 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
647    u_int *numprompts, char ***prompts, u_int **echo_on)
648 {
649 	struct sshbuf *m;
650 	u_int success;
651 	char *challenge;
652 	int r;
653 
654 	debug3("%s: entering", __func__);
655 
656 	if ((m = sshbuf_new()) == NULL)
657 		fatal("%s: sshbuf_new failed", __func__);
658 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
659 
660 	mm_request_receive_expect(pmonitor->m_recvfd,
661 	    MONITOR_ANS_BSDAUTHQUERY, m);
662 	if ((r = sshbuf_get_u32(m, &success)) != 0)
663 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
664 	if (success == 0) {
665 		debug3("%s: no challenge", __func__);
666 		sshbuf_free(m);
667 		return (-1);
668 	}
669 
670 	/* Get the challenge, and format the response */
671 	if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
672 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
673 	sshbuf_free(m);
674 
675 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
676 	(*prompts)[0] = challenge;
677 
678 	debug3("%s: received challenge: %s", __func__, challenge);
679 
680 	return (0);
681 }
682 
683 int
684 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
685 {
686 	struct sshbuf *m;
687 	int r, authok;
688 
689 	debug3("%s: entering", __func__);
690 	if (numresponses != 1)
691 		return (-1);
692 
693 	if ((m = sshbuf_new()) == NULL)
694 		fatal("%s: sshbuf_new failed", __func__);
695 	if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
696 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
697 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
698 
699 	mm_request_receive_expect(pmonitor->m_recvfd,
700 	    MONITOR_ANS_BSDAUTHRESPOND, m);
701 
702 	if ((r = sshbuf_get_u32(m, &authok)) != 0)
703 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
704 	sshbuf_free(m);
705 
706 	return ((authok == 0) ? -1 : 0);
707 }
708 
709 #ifdef GSSAPI
710 OM_uint32
711 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
712 {
713 	struct sshbuf *m;
714 	OM_uint32 major;
715 	int r;
716 
717 	/* Client doesn't get to see the context */
718 	*ctx = NULL;
719 
720 	if ((m = sshbuf_new()) == NULL)
721 		fatal("%s: sshbuf_new failed", __func__);
722 	if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
723 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
724 
725 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
726 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
727 
728 	if ((r = sshbuf_get_u32(m, &major)) != 0)
729 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
730 
731 	sshbuf_free(m);
732 	return (major);
733 }
734 
735 OM_uint32
736 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
737     gss_buffer_desc *out, OM_uint32 *flagsp)
738 {
739 	struct sshbuf *m;
740 	OM_uint32 major;
741 	u_int flags;
742 	int r;
743 
744 	if ((m = sshbuf_new()) == NULL)
745 		fatal("%s: sshbuf_new failed", __func__);
746 	if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
747 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
748 
749 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
750 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
751 
752 	if ((r = sshbuf_get_u32(m, &major)) != 0 ||
753 	    (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
754 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
755 	if (flagsp != NULL) {
756 		if ((r = sshbuf_get_u32(m, &flags)) != 0)
757 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
758 		*flagsp = flags;
759 	}
760 
761 	sshbuf_free(m);
762 
763 	return (major);
764 }
765 
766 OM_uint32
767 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
768 {
769 	struct sshbuf *m;
770 	OM_uint32 major;
771 	int r;
772 
773 	if ((m = sshbuf_new()) == NULL)
774 		fatal("%s: sshbuf_new failed", __func__);
775 	if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
776 	    (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
777 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
778 
779 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
780 	mm_request_receive_expect(pmonitor->m_recvfd,
781 	    MONITOR_ANS_GSSCHECKMIC, m);
782 
783 	if ((r = sshbuf_get_u32(m, &major)) != 0)
784 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
785 	sshbuf_free(m);
786 	return(major);
787 }
788 
789 int
790 mm_ssh_gssapi_userok(char *user)
791 {
792 	struct sshbuf *m;
793 	int r, authenticated = 0;
794 
795 	if ((m = sshbuf_new()) == NULL)
796 		fatal("%s: sshbuf_new failed", __func__);
797 
798 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
799 	mm_request_receive_expect(pmonitor->m_recvfd,
800 	    MONITOR_ANS_GSSUSEROK, m);
801 
802 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
803 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
804 
805 	sshbuf_free(m);
806 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
807 	return (authenticated);
808 }
809 #endif /* GSSAPI */
810