xref: /openssh-portable/monitor_wrap.c (revision 4d28fa78)
1 /* $OpenBSD: monitor_wrap.c,v 1.113 2019/06/28 13:35:04 deraadt 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, u_int compat)
219 {
220 	struct kex *kex = *pmonitor->m_pkex;
221 	struct sshbuf *m;
222 	u_int ndx = kex->host_key_index(key, 0, ssh);
223 	int r;
224 
225 	debug3("%s entering", __func__);
226 
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 {
498 	struct sshbuf *m;
499 	u_int encoded_ret = 0;
500 	int r;
501 
502 	debug3("%s entering", __func__);
503 
504 
505 	if ((m = sshbuf_new()) == NULL)
506 		fatal("%s: sshbuf_new failed", __func__);
507 	if ((r = sshkey_puts(key, m)) != 0 ||
508 	    (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
509 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
510 	    (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
511 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
512 
513 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
514 
515 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
516 	mm_request_receive_expect(pmonitor->m_recvfd,
517 	    MONITOR_ANS_KEYVERIFY, m);
518 
519 	if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0)
520 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
521 
522 	sshbuf_free(m);
523 
524 	if (encoded_ret != 0)
525 		return SSH_ERR_SIGNATURE_INVALID;
526 	return 0;
527 }
528 
529 void
530 mm_send_keystate(struct ssh *ssh, struct monitor *monitor)
531 {
532 	struct sshbuf *m;
533 	int r;
534 
535 	if ((m = sshbuf_new()) == NULL)
536 		fatal("%s: sshbuf_new failed", __func__);
537 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
538 		fatal("%s: get_state failed: %s",
539 		    __func__, ssh_err(r));
540 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
541 	debug3("%s: Finished sending state", __func__);
542 	sshbuf_free(m);
543 }
544 
545 int
546 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
547 {
548 	struct sshbuf *m;
549 	char *p, *msg;
550 	int success = 0, tmp1 = -1, tmp2 = -1, r;
551 
552 	/* Kludge: ensure there are fds free to receive the pty/tty */
553 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
554 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
555 		error("%s: cannot allocate fds for pty", __func__);
556 		if (tmp1 > 0)
557 			close(tmp1);
558 		if (tmp2 > 0)
559 			close(tmp2);
560 		return 0;
561 	}
562 	close(tmp1);
563 	close(tmp2);
564 
565 	if ((m = sshbuf_new()) == NULL)
566 		fatal("%s: sshbuf_new failed", __func__);
567 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
568 
569 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
570 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
571 
572 	if ((r = sshbuf_get_u32(m, &success)) != 0)
573 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
574 	if (success == 0) {
575 		debug3("%s: pty alloc failed", __func__);
576 		sshbuf_free(m);
577 		return (0);
578 	}
579 	if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
580 	    (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
581 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
582 	sshbuf_free(m);
583 
584 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
585 	free(p);
586 
587 	if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
588 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
589 	free(msg);
590 
591 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
592 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
593 		fatal("%s: receive fds failed", __func__);
594 
595 	/* Success */
596 	return (1);
597 }
598 
599 void
600 mm_session_pty_cleanup2(Session *s)
601 {
602 	struct sshbuf *m;
603 	int r;
604 
605 	if (s->ttyfd == -1)
606 		return;
607 	if ((m = sshbuf_new()) == NULL)
608 		fatal("%s: sshbuf_new failed", __func__);
609 	if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
610 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
611 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
612 	sshbuf_free(m);
613 
614 	/* closed dup'ed master */
615 	if (s->ptymaster != -1 && close(s->ptymaster) == -1)
616 		error("close(s->ptymaster/%d): %s",
617 		    s->ptymaster, strerror(errno));
618 
619 	/* unlink pty from session */
620 	s->ttyfd = -1;
621 }
622 
623 #ifdef USE_PAM
624 void
625 mm_start_pam(struct ssh *ssh)
626 {
627 	struct sshbuf *m;
628 
629 	debug3("%s entering", __func__);
630 	if (!options.use_pam)
631 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
632 	if ((m = sshbuf_new()) == NULL)
633 		fatal("%s: sshbuf_new failed", __func__);
634 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m);
635 
636 	sshbuf_free(m);
637 }
638 
639 u_int
640 mm_do_pam_account(void)
641 {
642 	struct sshbuf *m;
643 	u_int ret;
644 	char *msg;
645 	size_t msglen;
646 	int r;
647 
648 	debug3("%s entering", __func__);
649 	if (!options.use_pam)
650 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
651 
652 	if ((m = sshbuf_new()) == NULL)
653 		fatal("%s: sshbuf_new failed", __func__);
654 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m);
655 
656 	mm_request_receive_expect(pmonitor->m_recvfd,
657 	    MONITOR_ANS_PAM_ACCOUNT, m);
658 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
659 	    (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 ||
660 	    (r = sshbuf_put(loginmsg, msg, msglen)) != 0)
661 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
662 
663 	free(msg);
664 	sshbuf_free(m);
665 
666 	debug3("%s returning %d", __func__, ret);
667 
668 	return (ret);
669 }
670 
671 void *
672 mm_sshpam_init_ctx(Authctxt *authctxt)
673 {
674 	struct sshbuf *m;
675 	int r, success;
676 
677 	debug3("%s", __func__);
678 	if ((m = sshbuf_new()) == NULL)
679 		fatal("%s: sshbuf_new failed", __func__);
680 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m);
681 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
682 	mm_request_receive_expect(pmonitor->m_recvfd,
683 	    MONITOR_ANS_PAM_INIT_CTX, m);
684 	if ((r = sshbuf_get_u32(m, &success)) != 0)
685 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
686 	if (success == 0) {
687 		debug3("%s: pam_init_ctx failed", __func__);
688 		sshbuf_free(m);
689 		return (NULL);
690 	}
691 	sshbuf_free(m);
692 	return (authctxt);
693 }
694 
695 int
696 mm_sshpam_query(void *ctx, char **name, char **info,
697     u_int *num, char ***prompts, u_int **echo_on)
698 {
699 	struct sshbuf *m;
700 	u_int i, n;
701 	int r, ret;
702 
703 	debug3("%s", __func__);
704 	if ((m = sshbuf_new()) == NULL)
705 		fatal("%s: sshbuf_new failed", __func__);
706 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m);
707 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
708 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m);
709 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
710 	    (r = sshbuf_get_cstring(m, name, NULL)) != 0 ||
711 	    (r = sshbuf_get_cstring(m, info, NULL)) != 0 ||
712 	    (r = sshbuf_get_u32(m, &n)) != 0 ||
713 	    (r = sshbuf_get_u32(m, num)) != 0)
714 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
715 	debug3("%s: pam_query returned %d", __func__, ret);
716 	sshpam_set_maxtries_reached(n);
717 	if (*num > PAM_MAX_NUM_MSG)
718 		fatal("%s: received %u PAM messages, expected <= %u",
719 		    __func__, *num, PAM_MAX_NUM_MSG);
720 	*prompts = xcalloc((*num + 1), sizeof(char *));
721 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
722 	for (i = 0; i < *num; ++i) {
723 		if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 ||
724 		    (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0)
725 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
726 	}
727 	sshbuf_free(m);
728 	return (ret);
729 }
730 
731 int
732 mm_sshpam_respond(void *ctx, u_int num, char **resp)
733 {
734 	struct sshbuf *m;
735 	u_int n, i;
736 	int r, ret;
737 
738 	debug3("%s", __func__);
739 	if ((m = sshbuf_new()) == NULL)
740 		fatal("%s: sshbuf_new failed", __func__);
741 	if ((r = sshbuf_put_u32(m, num)) != 0)
742 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
743 	for (i = 0; i < num; ++i) {
744 		if ((r = sshbuf_put_cstring(m, resp[i])) != 0)
745 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
746 	}
747 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m);
748 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
749 	mm_request_receive_expect(pmonitor->m_recvfd,
750 	    MONITOR_ANS_PAM_RESPOND, m);
751 	if ((r = sshbuf_get_u32(m, &n)) != 0)
752 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
753 	ret = (int)n; /* XXX */
754 	debug3("%s: pam_respond returned %d", __func__, ret);
755 	sshbuf_free(m);
756 	return (ret);
757 }
758 
759 void
760 mm_sshpam_free_ctx(void *ctxtp)
761 {
762 	struct sshbuf *m;
763 
764 	debug3("%s", __func__);
765 	if ((m = sshbuf_new()) == NULL)
766 		fatal("%s: sshbuf_new failed", __func__);
767 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m);
768 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
769 	mm_request_receive_expect(pmonitor->m_recvfd,
770 	    MONITOR_ANS_PAM_FREE_CTX, m);
771 	sshbuf_free(m);
772 }
773 #endif /* USE_PAM */
774 
775 /* Request process termination */
776 
777 void
778 mm_terminate(void)
779 {
780 	struct sshbuf *m;
781 
782 	if ((m = sshbuf_new()) == NULL)
783 		fatal("%s: sshbuf_new failed", __func__);
784 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
785 	sshbuf_free(m);
786 }
787 
788 static void
789 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
790     char ***prompts, u_int **echo_on)
791 {
792 	*name = xstrdup("");
793 	*infotxt = xstrdup("");
794 	*numprompts = 1;
795 	*prompts = xcalloc(*numprompts, sizeof(char *));
796 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
797 	(*echo_on)[0] = 0;
798 }
799 
800 int
801 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
802    u_int *numprompts, char ***prompts, u_int **echo_on)
803 {
804 	struct sshbuf *m;
805 	u_int success;
806 	char *challenge;
807 	int r;
808 
809 	debug3("%s: entering", __func__);
810 
811 	if ((m = sshbuf_new()) == NULL)
812 		fatal("%s: sshbuf_new failed", __func__);
813 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
814 
815 	mm_request_receive_expect(pmonitor->m_recvfd,
816 	    MONITOR_ANS_BSDAUTHQUERY, m);
817 	if ((r = sshbuf_get_u32(m, &success)) != 0)
818 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
819 	if (success == 0) {
820 		debug3("%s: no challenge", __func__);
821 		sshbuf_free(m);
822 		return (-1);
823 	}
824 
825 	/* Get the challenge, and format the response */
826 	if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
827 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
828 	sshbuf_free(m);
829 
830 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
831 	(*prompts)[0] = challenge;
832 
833 	debug3("%s: received challenge: %s", __func__, challenge);
834 
835 	return (0);
836 }
837 
838 int
839 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
840 {
841 	struct sshbuf *m;
842 	int r, authok;
843 
844 	debug3("%s: entering", __func__);
845 	if (numresponses != 1)
846 		return (-1);
847 
848 	if ((m = sshbuf_new()) == NULL)
849 		fatal("%s: sshbuf_new failed", __func__);
850 	if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
851 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
852 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
853 
854 	mm_request_receive_expect(pmonitor->m_recvfd,
855 	    MONITOR_ANS_BSDAUTHRESPOND, m);
856 
857 	if ((r = sshbuf_get_u32(m, &authok)) != 0)
858 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
859 	sshbuf_free(m);
860 
861 	return ((authok == 0) ? -1 : 0);
862 }
863 
864 #ifdef SSH_AUDIT_EVENTS
865 void
866 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event)
867 {
868 	struct sshbuf *m;
869 	int r;
870 
871 	debug3("%s entering", __func__);
872 
873 	if ((m = sshbuf_new()) == NULL)
874 		fatal("%s: sshbuf_new failed", __func__);
875 	if ((r = sshbuf_put_u32(m, event)) != 0)
876 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
877 
878 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m);
879 	sshbuf_free(m);
880 }
881 
882 void
883 mm_audit_run_command(const char *command)
884 {
885 	struct sshbuf *m;
886 	int r;
887 
888 	debug3("%s entering command %s", __func__, command);
889 
890 	if ((m = sshbuf_new()) == NULL)
891 		fatal("%s: sshbuf_new failed", __func__);
892 	if ((r = sshbuf_put_cstring(m, command)) != 0)
893 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
894 
895 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m);
896 	sshbuf_free(m);
897 }
898 #endif /* SSH_AUDIT_EVENTS */
899 
900 #ifdef GSSAPI
901 OM_uint32
902 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
903 {
904 	struct sshbuf *m;
905 	OM_uint32 major;
906 	int r;
907 
908 	/* Client doesn't get to see the context */
909 	*ctx = NULL;
910 
911 	if ((m = sshbuf_new()) == NULL)
912 		fatal("%s: sshbuf_new failed", __func__);
913 	if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
914 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
915 
916 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
917 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
918 
919 	if ((r = sshbuf_get_u32(m, &major)) != 0)
920 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
921 
922 	sshbuf_free(m);
923 	return (major);
924 }
925 
926 OM_uint32
927 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
928     gss_buffer_desc *out, OM_uint32 *flagsp)
929 {
930 	struct sshbuf *m;
931 	OM_uint32 major;
932 	u_int flags;
933 	int r;
934 
935 	if ((m = sshbuf_new()) == NULL)
936 		fatal("%s: sshbuf_new failed", __func__);
937 	if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
938 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
939 
940 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
941 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
942 
943 	if ((r = sshbuf_get_u32(m, &major)) != 0 ||
944 	    (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
945 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
946 	if (flagsp != NULL) {
947 		if ((r = sshbuf_get_u32(m, &flags)) != 0)
948 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
949 		*flagsp = flags;
950 	}
951 
952 	sshbuf_free(m);
953 
954 	return (major);
955 }
956 
957 OM_uint32
958 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
959 {
960 	struct sshbuf *m;
961 	OM_uint32 major;
962 	int r;
963 
964 	if ((m = sshbuf_new()) == NULL)
965 		fatal("%s: sshbuf_new failed", __func__);
966 	if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
967 	    (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
968 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
969 
970 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
971 	mm_request_receive_expect(pmonitor->m_recvfd,
972 	    MONITOR_ANS_GSSCHECKMIC, m);
973 
974 	if ((r = sshbuf_get_u32(m, &major)) != 0)
975 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
976 	sshbuf_free(m);
977 	return(major);
978 }
979 
980 int
981 mm_ssh_gssapi_userok(char *user)
982 {
983 	struct sshbuf *m;
984 	int r, authenticated = 0;
985 
986 	if ((m = sshbuf_new()) == NULL)
987 		fatal("%s: sshbuf_new failed", __func__);
988 
989 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
990 	mm_request_receive_expect(pmonitor->m_recvfd,
991 	    MONITOR_ANS_GSSUSEROK, m);
992 
993 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
994 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
995 
996 	sshbuf_free(m);
997 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
998 	return (authenticated);
999 }
1000 #endif /* GSSAPI */
1001