xref: /freebsd/crypto/openssh/monitor_wrap.c (revision 058ac3e8063366dafa634d9107642e12b038bf09)
1 /* $OpenBSD: monitor_wrap.c,v 1.125 2022/06/15 16:08:25 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, int forced, 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_f("no log channel");
94 
95 	if ((log_msg = sshbuf_new()) == NULL)
96 		fatal_f("sshbuf_new failed");
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_u32(log_msg, forced)) != 0 ||
101 	    (r = sshbuf_put_cstring(log_msg, msg)) != 0)
102 		fatal_fr(r, "assemble");
103 	if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff)
104 		fatal_f("bad length %zu", len);
105 	POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4);
106 	if (atomicio(vwrite, mon->m_log_sendfd,
107 	    sshbuf_mutable_ptr(log_msg), len) != len)
108 		fatal_f("write: %s", strerror(errno));
109 	sshbuf_free(log_msg);
110 }
111 
112 int
113 mm_is_monitor(void)
114 {
115 	/*
116 	 * m_pid is only set in the privileged part, and
117 	 * points to the unprivileged child.
118 	 */
119 	return (pmonitor && pmonitor->m_pid > 0);
120 }
121 
122 void
123 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m)
124 {
125 	size_t mlen = sshbuf_len(m);
126 	u_char buf[5];
127 
128 	debug3_f("entering, type %d", type);
129 
130 	if (mlen >= 0xffffffff)
131 		fatal_f("bad length %zu", mlen);
132 	POKE_U32(buf, mlen + 1);
133 	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
134 	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
135 		fatal_f("write: %s", strerror(errno));
136 	if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen)
137 		fatal_f("write: %s", strerror(errno));
138 }
139 
140 void
141 mm_request_receive(int sock, struct sshbuf *m)
142 {
143 	u_char buf[4], *p = NULL;
144 	u_int msg_len;
145 	int r;
146 
147 	debug3_f("entering");
148 
149 	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
150 		if (errno == EPIPE)
151 			cleanup_exit(255);
152 		fatal_f("read: %s", strerror(errno));
153 	}
154 	msg_len = PEEK_U32(buf);
155 	if (msg_len > 256 * 1024)
156 		fatal_f("read: bad msg_len %d", msg_len);
157 	sshbuf_reset(m);
158 	if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
159 		fatal_fr(r, "reserve");
160 	if (atomicio(read, sock, p, msg_len) != msg_len)
161 		fatal_f("read: %s", strerror(errno));
162 }
163 
164 void
165 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m)
166 {
167 	u_char rtype;
168 	int r;
169 
170 	debug3_f("entering, type %d", type);
171 
172 	mm_request_receive(sock, m);
173 	if ((r = sshbuf_get_u8(m, &rtype)) != 0)
174 		fatal_fr(r, "parse");
175 	if (rtype != type)
176 		fatal_f("read: rtype %d != type %d", 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_f("sshbuf_new failed");
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_fr(r, "assemble");
194 
195 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m);
196 
197 	debug3_f("waiting for MONITOR_ANS_MODULI");
198 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m);
199 
200 	if ((r = sshbuf_get_u8(m, &success)) != 0)
201 		fatal_fr(r, "parse success");
202 	if (success == 0)
203 		fatal_f("MONITOR_ANS_MODULI failed");
204 
205 	if ((r = sshbuf_get_bignum2(m, &p)) != 0 ||
206 	    (r = sshbuf_get_bignum2(m, &g)) != 0)
207 		fatal_fr(r, "parse group");
208 
209 	debug3_f("remaining %zu", 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_f("entering");
227 	if ((m = sshbuf_new()) == NULL)
228 		fatal_f("sshbuf_new failed");
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_fr(r, "assemble");
234 
235 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m);
236 
237 	debug3_f("waiting for MONITOR_ANS_SIGN");
238 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m);
239 	if ((r = sshbuf_get_string(m, sigp, lenp)) != 0)
240 		fatal_fr(r, "parse");
241 	sshbuf_free(m);
242 
243 	return (0);
244 }
245 
246 #define GETPW(b, id) \
247 	do { \
248 		if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \
249 			fatal_fr(r, "parse pw %s", #id); \
250 		if (len != sizeof(pw->id)) \
251 			fatal_fr(r, "bad length for %s", #id); \
252 		memcpy(&pw->id, p, len); \
253 	} while (0)
254 
255 struct passwd *
256 mm_getpwnamallow(struct ssh *ssh, const char *username)
257 {
258 	struct sshbuf *m;
259 	struct passwd *pw;
260 	size_t len;
261 	u_int i;
262 	ServerOptions *newopts;
263 	int r;
264 	u_char ok;
265 	const u_char *p;
266 
267 	debug3_f("entering");
268 
269 	if ((m = sshbuf_new()) == NULL)
270 		fatal_f("sshbuf_new failed");
271 	if ((r = sshbuf_put_cstring(m, username)) != 0)
272 		fatal_fr(r, "assemble");
273 
274 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m);
275 
276 	debug3_f("waiting for MONITOR_ANS_PWNAM");
277 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m);
278 
279 	if ((r = sshbuf_get_u8(m, &ok)) != 0)
280 		fatal_fr(r, "parse success");
281 	if (ok == 0) {
282 		pw = NULL;
283 		goto out;
284 	}
285 
286 	/* XXX don't like passing struct passwd like this */
287 	pw = xcalloc(sizeof(*pw), 1);
288 	GETPW(m, pw_uid);
289 	GETPW(m, pw_gid);
290 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
291 	GETPW(m, pw_change);
292 #endif
293 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
294 	GETPW(m, pw_expire);
295 #endif
296 	if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 ||
297 	    (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 ||
298 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
299 	    (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 ||
300 #endif
301 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
302 	    (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 ||
303 #endif
304 	    (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 ||
305 	    (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0)
306 		fatal_fr(r, "parse pw");
307 
308 out:
309 	/* copy options block as a Match directive may have changed some */
310 	if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
311 		fatal_fr(r, "parse opts");
312 	if (len != sizeof(*newopts))
313 		fatal_f("option block size mismatch");
314 	newopts = xcalloc(sizeof(*newopts), 1);
315 	memcpy(newopts, p, sizeof(*newopts));
316 
317 #define M_CP_STROPT(x) do { \
318 		if (newopts->x != NULL && \
319 		    (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \
320 			fatal_fr(r, "parse %s", #x); \
321 	} while (0)
322 #define M_CP_STRARRAYOPT(x, nx) do { \
323 		newopts->x = newopts->nx == 0 ? \
324 		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
325 		for (i = 0; i < newopts->nx; i++) { \
326 			if ((r = sshbuf_get_cstring(m, \
327 			    &newopts->x[i], NULL)) != 0) \
328 				fatal_fr(r, "parse %s", #x); \
329 		} \
330 	} while (0)
331 	/* See comment in servconf.h */
332 	COPY_MATCH_STRING_OPTS();
333 #undef M_CP_STROPT
334 #undef M_CP_STRARRAYOPT
335 
336 	copy_set_server_options(&options, newopts, 1);
337 	log_change_level(options.log_level);
338 	log_verbose_reset();
339 	for (i = 0; i < options.num_log_verbose; i++)
340 		log_verbose_add(options.log_verbose[i]);
341 	process_permitopen(ssh, &options);
342 	free(newopts);
343 
344 	sshbuf_free(m);
345 
346 	return (pw);
347 }
348 
349 char *
350 mm_auth2_read_banner(void)
351 {
352 	struct sshbuf *m;
353 	char *banner;
354 	int r;
355 
356 	debug3_f("entering");
357 
358 	if ((m = sshbuf_new()) == NULL)
359 		fatal_f("sshbuf_new failed");
360 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m);
361 	sshbuf_reset(m);
362 
363 	mm_request_receive_expect(pmonitor->m_recvfd,
364 	    MONITOR_ANS_AUTH2_READ_BANNER, m);
365 	if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0)
366 		fatal_fr(r, "parse");
367 	sshbuf_free(m);
368 
369 	/* treat empty banner as missing banner */
370 	if (strlen(banner) == 0) {
371 		free(banner);
372 		banner = NULL;
373 	}
374 	return (banner);
375 }
376 
377 /* Inform the privileged process about service and style */
378 
379 void
380 mm_inform_authserv(char *service, char *style)
381 {
382 	struct sshbuf *m;
383 	int r;
384 
385 	debug3_f("entering");
386 
387 	if ((m = sshbuf_new()) == NULL)
388 		fatal_f("sshbuf_new failed");
389 	if ((r = sshbuf_put_cstring(m, service)) != 0 ||
390 	    (r = sshbuf_put_cstring(m, style ? style : "")) != 0)
391 		fatal_fr(r, "assemble");
392 
393 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m);
394 
395 	sshbuf_free(m);
396 }
397 
398 /* Do the password authentication */
399 int
400 mm_auth_password(struct ssh *ssh, char *password)
401 {
402 	struct sshbuf *m;
403 	int r, authenticated = 0;
404 #ifdef USE_PAM
405 	u_int maxtries = 0;
406 #endif
407 
408 	debug3_f("entering");
409 
410 	if ((m = sshbuf_new()) == NULL)
411 		fatal_f("sshbuf_new failed");
412 	if ((r = sshbuf_put_cstring(m, password)) != 0)
413 		fatal_fr(r, "assemble");
414 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m);
415 
416 	debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD");
417 	mm_request_receive_expect(pmonitor->m_recvfd,
418 	    MONITOR_ANS_AUTHPASSWORD, m);
419 
420 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
421 		fatal_fr(r, "parse");
422 #ifdef USE_PAM
423 	if ((r = sshbuf_get_u32(m, &maxtries)) != 0)
424 		fatal_fr(r, "parse PAM");
425 	if (maxtries > INT_MAX)
426 		fatal_fr(r, "bad maxtries");
427 	sshpam_set_maxtries_reached(maxtries);
428 #endif
429 
430 	sshbuf_free(m);
431 
432 	debug3_f("user %sauthenticated", authenticated ? "" : "not ");
433 	return (authenticated);
434 }
435 
436 int
437 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key,
438     int pubkey_auth_attempt, struct sshauthopt **authoptp)
439 {
440 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
441 	    pubkey_auth_attempt, authoptp));
442 }
443 
444 int
445 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw,
446     const char *user, const char *host, struct sshkey *key)
447 {
448 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL));
449 }
450 
451 int
452 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
453     struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp)
454 {
455 	struct sshbuf *m;
456 	int r, allowed = 0;
457 	struct sshauthopt *opts = NULL;
458 
459 	debug3_f("entering");
460 
461 	if (authoptp != NULL)
462 		*authoptp = NULL;
463 
464 	if ((m = sshbuf_new()) == NULL)
465 		fatal_f("sshbuf_new failed");
466 	if ((r = sshbuf_put_u32(m, type)) != 0 ||
467 	    (r = sshbuf_put_cstring(m, user ? user : "")) != 0 ||
468 	    (r = sshbuf_put_cstring(m, host ? host : "")) != 0 ||
469 	    (r = sshkey_puts(key, m)) != 0 ||
470 	    (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0)
471 		fatal_fr(r, "assemble");
472 
473 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m);
474 
475 	debug3_f("waiting for MONITOR_ANS_KEYALLOWED");
476 	mm_request_receive_expect(pmonitor->m_recvfd,
477 	    MONITOR_ANS_KEYALLOWED, m);
478 
479 	if ((r = sshbuf_get_u32(m, &allowed)) != 0)
480 		fatal_fr(r, "parse");
481 	if (allowed && type == MM_USERKEY &&
482 	    (r = sshauthopt_deserialise(m, &opts)) != 0)
483 		fatal_fr(r, "sshauthopt_deserialise");
484 	sshbuf_free(m);
485 
486 	if (authoptp != NULL) {
487 		*authoptp = opts;
488 		opts = NULL;
489 	}
490 	sshauthopt_free(opts);
491 
492 	return allowed;
493 }
494 
495 /*
496  * This key verify needs to send the key type along, because the
497  * privileged parent makes the decision if the key is allowed
498  * for authentication.
499  */
500 
501 int
502 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
503     const u_char *data, size_t datalen, const char *sigalg, u_int compat,
504     struct sshkey_sig_details **sig_detailsp)
505 {
506 	struct sshbuf *m;
507 	u_int encoded_ret = 0;
508 	int r;
509 	u_char sig_details_present, flags;
510 	u_int counter;
511 
512 	debug3_f("entering");
513 
514 	if (sig_detailsp != NULL)
515 		*sig_detailsp = NULL;
516 	if ((m = sshbuf_new()) == NULL)
517 		fatal_f("sshbuf_new failed");
518 	if ((r = sshkey_puts(key, m)) != 0 ||
519 	    (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
520 	    (r = sshbuf_put_string(m, data, datalen)) != 0 ||
521 	    (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
522 		fatal_fr(r, "assemble");
523 
524 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
525 
526 	debug3_f("waiting for MONITOR_ANS_KEYVERIFY");
527 	mm_request_receive_expect(pmonitor->m_recvfd,
528 	    MONITOR_ANS_KEYVERIFY, m);
529 
530 	if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 ||
531 	    (r = sshbuf_get_u8(m, &sig_details_present)) != 0)
532 		fatal_fr(r, "parse");
533 	if (sig_details_present && encoded_ret == 0) {
534 		if ((r = sshbuf_get_u32(m, &counter)) != 0 ||
535 		    (r = sshbuf_get_u8(m, &flags)) != 0)
536 			fatal_fr(r, "parse sig_details");
537 		if (sig_detailsp != NULL) {
538 			*sig_detailsp = xcalloc(1, sizeof(**sig_detailsp));
539 			(*sig_detailsp)->sk_counter = counter;
540 			(*sig_detailsp)->sk_flags = flags;
541 		}
542 	}
543 
544 	sshbuf_free(m);
545 
546 	if (encoded_ret != 0)
547 		return SSH_ERR_SIGNATURE_INVALID;
548 	return 0;
549 }
550 
551 void
552 mm_send_keystate(struct ssh *ssh, struct monitor *monitor)
553 {
554 	struct sshbuf *m;
555 	int r;
556 
557 	if ((m = sshbuf_new()) == NULL)
558 		fatal_f("sshbuf_new failed");
559 	if ((r = ssh_packet_get_state(ssh, m)) != 0)
560 		fatal_fr(r, "ssh_packet_get_state");
561 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
562 	debug3_f("Finished sending state");
563 	sshbuf_free(m);
564 }
565 
566 int
567 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
568 {
569 	struct sshbuf *m;
570 	char *p, *msg;
571 	int success = 0, tmp1 = -1, tmp2 = -1, r;
572 
573 	/* Kludge: ensure there are fds free to receive the pty/tty */
574 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
575 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
576 		error_f("cannot allocate fds for pty");
577 		if (tmp1 > 0)
578 			close(tmp1);
579 		if (tmp2 > 0)
580 			close(tmp2);
581 		return 0;
582 	}
583 	close(tmp1);
584 	close(tmp2);
585 
586 	if ((m = sshbuf_new()) == NULL)
587 		fatal_f("sshbuf_new failed");
588 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
589 
590 	debug3_f("waiting for MONITOR_ANS_PTY");
591 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
592 
593 	if ((r = sshbuf_get_u32(m, &success)) != 0)
594 		fatal_fr(r, "parse success");
595 	if (success == 0) {
596 		debug3_f("pty alloc failed");
597 		sshbuf_free(m);
598 		return (0);
599 	}
600 	if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
601 	    (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
602 		fatal_fr(r, "parse");
603 	sshbuf_free(m);
604 
605 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
606 	free(p);
607 
608 	if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
609 		fatal_fr(r, "put loginmsg");
610 	free(msg);
611 
612 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
613 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
614 		fatal_f("receive fds failed");
615 
616 	/* Success */
617 	return (1);
618 }
619 
620 void
621 mm_session_pty_cleanup2(Session *s)
622 {
623 	struct sshbuf *m;
624 	int r;
625 
626 	if (s->ttyfd == -1)
627 		return;
628 	if ((m = sshbuf_new()) == NULL)
629 		fatal_f("sshbuf_new failed");
630 	if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
631 		fatal_fr(r, "assmble");
632 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
633 	sshbuf_free(m);
634 
635 	/* closed dup'ed master */
636 	if (s->ptymaster != -1 && close(s->ptymaster) == -1)
637 		error("close(s->ptymaster/%d): %s",
638 		    s->ptymaster, strerror(errno));
639 
640 	/* unlink pty from session */
641 	s->ttyfd = -1;
642 }
643 
644 #ifdef USE_PAM
645 void
646 mm_start_pam(struct ssh *ssh)
647 {
648 	struct sshbuf *m;
649 
650 	debug3("%s entering", __func__);
651 	if (!options.use_pam)
652 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
653 	if ((m = sshbuf_new()) == NULL)
654 		fatal("%s: sshbuf_new failed", __func__);
655 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m);
656 
657 	sshbuf_free(m);
658 }
659 
660 u_int
661 mm_do_pam_account(void)
662 {
663 	struct sshbuf *m;
664 	u_int ret;
665 	char *msg;
666 	size_t msglen;
667 	int r;
668 
669 	debug3("%s entering", __func__);
670 	if (!options.use_pam)
671 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
672 
673 	if ((m = sshbuf_new()) == NULL)
674 		fatal("%s: sshbuf_new failed", __func__);
675 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m);
676 
677 	mm_request_receive_expect(pmonitor->m_recvfd,
678 	    MONITOR_ANS_PAM_ACCOUNT, m);
679 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
680 	    (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 ||
681 	    (r = sshbuf_put(loginmsg, msg, msglen)) != 0)
682 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
683 
684 	free(msg);
685 	sshbuf_free(m);
686 
687 	debug3("%s returning %d", __func__, ret);
688 
689 	return (ret);
690 }
691 
692 void *
693 mm_sshpam_init_ctx(Authctxt *authctxt)
694 {
695 	struct sshbuf *m;
696 	int r, success;
697 
698 	debug3("%s", __func__);
699 	if ((m = sshbuf_new()) == NULL)
700 		fatal("%s: sshbuf_new failed", __func__);
701 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m);
702 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
703 	mm_request_receive_expect(pmonitor->m_recvfd,
704 	    MONITOR_ANS_PAM_INIT_CTX, m);
705 	if ((r = sshbuf_get_u32(m, &success)) != 0)
706 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
707 	if (success == 0) {
708 		debug3("%s: pam_init_ctx failed", __func__);
709 		sshbuf_free(m);
710 		return (NULL);
711 	}
712 	sshbuf_free(m);
713 	return (authctxt);
714 }
715 
716 int
717 mm_sshpam_query(void *ctx, char **name, char **info,
718     u_int *num, char ***prompts, u_int **echo_on)
719 {
720 	struct sshbuf *m;
721 	u_int i, n;
722 	int r, ret;
723 
724 	debug3("%s", __func__);
725 	if ((m = sshbuf_new()) == NULL)
726 		fatal("%s: sshbuf_new failed", __func__);
727 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m);
728 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
729 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m);
730 	if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
731 	    (r = sshbuf_get_cstring(m, name, NULL)) != 0 ||
732 	    (r = sshbuf_get_cstring(m, info, NULL)) != 0 ||
733 	    (r = sshbuf_get_u32(m, &n)) != 0 ||
734 	    (r = sshbuf_get_u32(m, num)) != 0)
735 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
736 	debug3("%s: pam_query returned %d", __func__, ret);
737 	sshpam_set_maxtries_reached(n);
738 	if (*num > PAM_MAX_NUM_MSG)
739 		fatal("%s: received %u PAM messages, expected <= %u",
740 		    __func__, *num, PAM_MAX_NUM_MSG);
741 	*prompts = xcalloc((*num + 1), sizeof(char *));
742 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
743 	for (i = 0; i < *num; ++i) {
744 		if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 ||
745 		    (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0)
746 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
747 	}
748 	sshbuf_free(m);
749 	return (ret);
750 }
751 
752 int
753 mm_sshpam_respond(void *ctx, u_int num, char **resp)
754 {
755 	struct sshbuf *m;
756 	u_int n, i;
757 	int r, ret;
758 
759 	debug3("%s", __func__);
760 	if ((m = sshbuf_new()) == NULL)
761 		fatal("%s: sshbuf_new failed", __func__);
762 	if ((r = sshbuf_put_u32(m, num)) != 0)
763 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
764 	for (i = 0; i < num; ++i) {
765 		if ((r = sshbuf_put_cstring(m, resp[i])) != 0)
766 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
767 	}
768 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m);
769 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
770 	mm_request_receive_expect(pmonitor->m_recvfd,
771 	    MONITOR_ANS_PAM_RESPOND, m);
772 	if ((r = sshbuf_get_u32(m, &n)) != 0)
773 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
774 	ret = (int)n; /* XXX */
775 	debug3("%s: pam_respond returned %d", __func__, ret);
776 	sshbuf_free(m);
777 	return (ret);
778 }
779 
780 void
781 mm_sshpam_free_ctx(void *ctxtp)
782 {
783 	struct sshbuf *m;
784 
785 	debug3("%s", __func__);
786 	if ((m = sshbuf_new()) == NULL)
787 		fatal("%s: sshbuf_new failed", __func__);
788 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m);
789 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
790 	mm_request_receive_expect(pmonitor->m_recvfd,
791 	    MONITOR_ANS_PAM_FREE_CTX, m);
792 	sshbuf_free(m);
793 }
794 #endif /* USE_PAM */
795 
796 /* Request process termination */
797 
798 void
799 mm_terminate(void)
800 {
801 	struct sshbuf *m;
802 
803 	if ((m = sshbuf_new()) == NULL)
804 		fatal_f("sshbuf_new failed");
805 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
806 	sshbuf_free(m);
807 }
808 
809 static void
810 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
811     char ***prompts, u_int **echo_on)
812 {
813 	*name = xstrdup("");
814 	*infotxt = xstrdup("");
815 	*numprompts = 1;
816 	*prompts = xcalloc(*numprompts, sizeof(char *));
817 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
818 	(*echo_on)[0] = 0;
819 }
820 
821 int
822 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
823    u_int *numprompts, char ***prompts, u_int **echo_on)
824 {
825 	struct sshbuf *m;
826 	u_int success;
827 	char *challenge;
828 	int r;
829 
830 	debug3_f("entering");
831 
832 	if ((m = sshbuf_new()) == NULL)
833 		fatal_f("sshbuf_new failed");
834 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
835 
836 	mm_request_receive_expect(pmonitor->m_recvfd,
837 	    MONITOR_ANS_BSDAUTHQUERY, m);
838 	if ((r = sshbuf_get_u32(m, &success)) != 0)
839 		fatal_fr(r, "parse success");
840 	if (success == 0) {
841 		debug3_f("no challenge");
842 		sshbuf_free(m);
843 		return (-1);
844 	}
845 
846 	/* Get the challenge, and format the response */
847 	if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
848 		fatal_fr(r, "parse challenge");
849 	sshbuf_free(m);
850 
851 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
852 	(*prompts)[0] = challenge;
853 
854 	debug3_f("received challenge: %s", challenge);
855 
856 	return (0);
857 }
858 
859 int
860 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
861 {
862 	struct sshbuf *m;
863 	int r, authok;
864 
865 	debug3_f("entering");
866 	if (numresponses != 1)
867 		return (-1);
868 
869 	if ((m = sshbuf_new()) == NULL)
870 		fatal_f("sshbuf_new failed");
871 	if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
872 		fatal_fr(r, "assemble");
873 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
874 
875 	mm_request_receive_expect(pmonitor->m_recvfd,
876 	    MONITOR_ANS_BSDAUTHRESPOND, m);
877 
878 	if ((r = sshbuf_get_u32(m, &authok)) != 0)
879 		fatal_fr(r, "parse");
880 	sshbuf_free(m);
881 
882 	return ((authok == 0) ? -1 : 0);
883 }
884 
885 #ifdef SSH_AUDIT_EVENTS
886 void
887 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event)
888 {
889 	struct sshbuf *m;
890 	int r;
891 
892 	debug3("%s entering", __func__);
893 
894 	if ((m = sshbuf_new()) == NULL)
895 		fatal("%s: sshbuf_new failed", __func__);
896 	if ((r = sshbuf_put_u32(m, event)) != 0)
897 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
898 
899 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m);
900 	sshbuf_free(m);
901 }
902 
903 void
904 mm_audit_run_command(const char *command)
905 {
906 	struct sshbuf *m;
907 	int r;
908 
909 	debug3("%s entering command %s", __func__, command);
910 
911 	if ((m = sshbuf_new()) == NULL)
912 		fatal("%s: sshbuf_new failed", __func__);
913 	if ((r = sshbuf_put_cstring(m, command)) != 0)
914 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
915 
916 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m);
917 	sshbuf_free(m);
918 }
919 #endif /* SSH_AUDIT_EVENTS */
920 
921 #ifdef GSSAPI
922 OM_uint32
923 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
924 {
925 	struct sshbuf *m;
926 	OM_uint32 major;
927 	int r;
928 
929 	/* Client doesn't get to see the context */
930 	*ctx = NULL;
931 
932 	if ((m = sshbuf_new()) == NULL)
933 		fatal_f("sshbuf_new failed");
934 	if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
935 		fatal_fr(r, "assemble");
936 
937 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
938 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
939 
940 	if ((r = sshbuf_get_u32(m, &major)) != 0)
941 		fatal_fr(r, "parse");
942 
943 	sshbuf_free(m);
944 	return (major);
945 }
946 
947 OM_uint32
948 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
949     gss_buffer_desc *out, OM_uint32 *flagsp)
950 {
951 	struct sshbuf *m;
952 	OM_uint32 major;
953 	u_int flags;
954 	int r;
955 
956 	if ((m = sshbuf_new()) == NULL)
957 		fatal_f("sshbuf_new failed");
958 	if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
959 		fatal_fr(r, "assemble");
960 
961 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
962 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
963 
964 	if ((r = sshbuf_get_u32(m, &major)) != 0 ||
965 	    (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
966 		fatal_fr(r, "parse");
967 	if (flagsp != NULL) {
968 		if ((r = sshbuf_get_u32(m, &flags)) != 0)
969 			fatal_fr(r, "parse flags");
970 		*flagsp = flags;
971 	}
972 
973 	sshbuf_free(m);
974 
975 	return (major);
976 }
977 
978 OM_uint32
979 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
980 {
981 	struct sshbuf *m;
982 	OM_uint32 major;
983 	int r;
984 
985 	if ((m = sshbuf_new()) == NULL)
986 		fatal_f("sshbuf_new failed");
987 	if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
988 	    (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
989 		fatal_fr(r, "assemble");
990 
991 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
992 	mm_request_receive_expect(pmonitor->m_recvfd,
993 	    MONITOR_ANS_GSSCHECKMIC, m);
994 
995 	if ((r = sshbuf_get_u32(m, &major)) != 0)
996 		fatal_fr(r, "parse");
997 	sshbuf_free(m);
998 	return(major);
999 }
1000 
1001 int
1002 mm_ssh_gssapi_userok(char *user)
1003 {
1004 	struct sshbuf *m;
1005 	int r, authenticated = 0;
1006 
1007 	if ((m = sshbuf_new()) == NULL)
1008 		fatal_f("sshbuf_new failed");
1009 
1010 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
1011 	mm_request_receive_expect(pmonitor->m_recvfd,
1012 	    MONITOR_ANS_GSSUSEROK, m);
1013 
1014 	if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
1015 		fatal_fr(r, "parse");
1016 
1017 	sshbuf_free(m);
1018 	debug3_f("user %sauthenticated", authenticated ? "" : "not ");
1019 	return (authenticated);
1020 }
1021 #endif /* GSSAPI */
1022