xref: /freebsd/crypto/openssh/monitor_wrap.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /* $OpenBSD: monitor_wrap.c,v 1.63 2008/07/10 18:08:11 markus 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 #include <openssl/bn.h>
42 #include <openssl/dh.h>
43 
44 #include "openbsd-compat/sys-queue.h"
45 #include "xmalloc.h"
46 #include "ssh.h"
47 #include "dh.h"
48 #include "buffer.h"
49 #include "key.h"
50 #include "cipher.h"
51 #include "kex.h"
52 #include "hostfile.h"
53 #include "auth.h"
54 #include "auth-options.h"
55 #include "packet.h"
56 #include "mac.h"
57 #include "log.h"
58 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
59 #undef TARGET_OS_MAC
60 #include "zlib.h"
61 #define TARGET_OS_MAC 1
62 #else
63 #include "zlib.h"
64 #endif
65 #include "monitor.h"
66 #ifdef GSSAPI
67 #include "ssh-gss.h"
68 #endif
69 #include "monitor_wrap.h"
70 #include "atomicio.h"
71 #include "monitor_fdpass.h"
72 #include "misc.h"
73 #include "servconf.h"
74 
75 #include "channels.h"
76 #include "session.h"
77 #include "servconf.h"
78 
79 /* Imports */
80 extern int compat20;
81 extern Newkeys *newkeys[];
82 extern z_stream incoming_stream;
83 extern z_stream outgoing_stream;
84 extern struct monitor *pmonitor;
85 extern Buffer input, output;
86 extern Buffer loginmsg;
87 extern ServerOptions options;
88 
89 int
90 mm_is_monitor(void)
91 {
92 	/*
93 	 * m_pid is only set in the privileged part, and
94 	 * points to the unprivileged child.
95 	 */
96 	return (pmonitor && pmonitor->m_pid > 0);
97 }
98 
99 void
100 mm_request_send(int sock, enum monitor_reqtype type, Buffer *m)
101 {
102 	u_int mlen = buffer_len(m);
103 	u_char buf[5];
104 
105 	debug3("%s entering: type %d", __func__, type);
106 
107 	put_u32(buf, mlen + 1);
108 	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
109 	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
110 		fatal("%s: write: %s", __func__, strerror(errno));
111 	if (atomicio(vwrite, sock, buffer_ptr(m), mlen) != mlen)
112 		fatal("%s: write: %s", __func__, strerror(errno));
113 }
114 
115 void
116 mm_request_receive(int sock, Buffer *m)
117 {
118 	u_char buf[4];
119 	u_int msg_len;
120 
121 	debug3("%s entering", __func__);
122 
123 	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
124 		if (errno == EPIPE)
125 			cleanup_exit(255);
126 		fatal("%s: read: %s", __func__, strerror(errno));
127 	}
128 	msg_len = get_u32(buf);
129 	if (msg_len > 256 * 1024)
130 		fatal("%s: read: bad msg_len %d", __func__, msg_len);
131 	buffer_clear(m);
132 	buffer_append_space(m, msg_len);
133 	if (atomicio(read, sock, buffer_ptr(m), msg_len) != msg_len)
134 		fatal("%s: read: %s", __func__, strerror(errno));
135 }
136 
137 void
138 mm_request_receive_expect(int sock, enum monitor_reqtype type, Buffer *m)
139 {
140 	u_char rtype;
141 
142 	debug3("%s entering: type %d", __func__, type);
143 
144 	mm_request_receive(sock, m);
145 	rtype = buffer_get_char(m);
146 	if (rtype != type)
147 		fatal("%s: read: rtype %d != type %d", __func__,
148 		    rtype, type);
149 }
150 
151 DH *
152 mm_choose_dh(int min, int nbits, int max)
153 {
154 	BIGNUM *p, *g;
155 	int success = 0;
156 	Buffer m;
157 
158 	buffer_init(&m);
159 	buffer_put_int(&m, min);
160 	buffer_put_int(&m, nbits);
161 	buffer_put_int(&m, max);
162 
163 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, &m);
164 
165 	debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
166 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, &m);
167 
168 	success = buffer_get_char(&m);
169 	if (success == 0)
170 		fatal("%s: MONITOR_ANS_MODULI failed", __func__);
171 
172 	if ((p = BN_new()) == NULL)
173 		fatal("%s: BN_new failed", __func__);
174 	if ((g = BN_new()) == NULL)
175 		fatal("%s: BN_new failed", __func__);
176 	buffer_get_bignum2(&m, p);
177 	buffer_get_bignum2(&m, g);
178 
179 	debug3("%s: remaining %d", __func__, buffer_len(&m));
180 	buffer_free(&m);
181 
182 	return (dh_new_group(g, p));
183 }
184 
185 int
186 mm_key_sign(Key *key, u_char **sigp, u_int *lenp, u_char *data, u_int datalen)
187 {
188 	Kex *kex = *pmonitor->m_pkex;
189 	Buffer m;
190 
191 	debug3("%s entering", __func__);
192 
193 	buffer_init(&m);
194 	buffer_put_int(&m, kex->host_key_index(key));
195 	buffer_put_string(&m, data, datalen);
196 
197 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m);
198 
199 	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
200 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m);
201 	*sigp  = buffer_get_string(&m, lenp);
202 	buffer_free(&m);
203 
204 	return (0);
205 }
206 
207 struct passwd *
208 mm_getpwnamallow(const char *username)
209 {
210 	Buffer m;
211 	struct passwd *pw;
212 	u_int len;
213 	ServerOptions *newopts;
214 
215 	debug3("%s entering", __func__);
216 
217 	buffer_init(&m);
218 	buffer_put_cstring(&m, username);
219 
220 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, &m);
221 
222 	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
223 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, &m);
224 
225 	if (buffer_get_char(&m) == 0) {
226 		pw = NULL;
227 		goto out;
228 	}
229 	pw = buffer_get_string(&m, &len);
230 	if (len != sizeof(struct passwd))
231 		fatal("%s: struct passwd size mismatch", __func__);
232 	pw->pw_name = buffer_get_string(&m, NULL);
233 	pw->pw_passwd = buffer_get_string(&m, NULL);
234 	pw->pw_gecos = buffer_get_string(&m, NULL);
235 #ifdef HAVE_PW_CLASS_IN_PASSWD
236 	pw->pw_class = buffer_get_string(&m, NULL);
237 #endif
238 	pw->pw_dir = buffer_get_string(&m, NULL);
239 	pw->pw_shell = buffer_get_string(&m, NULL);
240 
241 out:
242 	/* copy options block as a Match directive may have changed some */
243 	newopts = buffer_get_string(&m, &len);
244 	if (len != sizeof(*newopts))
245 		fatal("%s: option block size mismatch", __func__);
246 	if (newopts->banner != NULL)
247 		newopts->banner = buffer_get_string(&m, NULL);
248 	copy_set_server_options(&options, newopts, 1);
249 	xfree(newopts);
250 
251 	buffer_free(&m);
252 
253 	return (pw);
254 }
255 
256 char *
257 mm_auth2_read_banner(void)
258 {
259 	Buffer m;
260 	char *banner;
261 
262 	debug3("%s entering", __func__);
263 
264 	buffer_init(&m);
265 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
266 	buffer_clear(&m);
267 
268 	mm_request_receive_expect(pmonitor->m_recvfd,
269 	    MONITOR_ANS_AUTH2_READ_BANNER, &m);
270 	banner = buffer_get_string(&m, NULL);
271 	buffer_free(&m);
272 
273 	/* treat empty banner as missing banner */
274 	if (strlen(banner) == 0) {
275 		xfree(banner);
276 		banner = NULL;
277 	}
278 	return (banner);
279 }
280 
281 /* Inform the privileged process about service and style */
282 
283 void
284 mm_inform_authserv(char *service, char *style)
285 {
286 	Buffer m;
287 
288 	debug3("%s entering", __func__);
289 
290 	buffer_init(&m);
291 	buffer_put_cstring(&m, service);
292 	buffer_put_cstring(&m, style ? style : "");
293 
294 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m);
295 
296 	buffer_free(&m);
297 }
298 
299 /* Do the password authentication */
300 int
301 mm_auth_password(Authctxt *authctxt, char *password)
302 {
303 	Buffer m;
304 	int authenticated = 0;
305 
306 	debug3("%s entering", __func__);
307 
308 	buffer_init(&m);
309 	buffer_put_cstring(&m, password);
310 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m);
311 
312 	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
313 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m);
314 
315 	authenticated = buffer_get_int(&m);
316 
317 	buffer_free(&m);
318 
319 	debug3("%s: user %sauthenticated",
320 	    __func__, authenticated ? "" : "not ");
321 	return (authenticated);
322 }
323 
324 int
325 mm_user_key_allowed(struct passwd *pw, Key *key)
326 {
327 	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key));
328 }
329 
330 int
331 mm_hostbased_key_allowed(struct passwd *pw, char *user, char *host,
332     Key *key)
333 {
334 	return (mm_key_allowed(MM_HOSTKEY, user, host, key));
335 }
336 
337 int
338 mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, char *user,
339     char *host, Key *key)
340 {
341 	int ret;
342 
343 	key->type = KEY_RSA; /* XXX hack for key_to_blob */
344 	ret = mm_key_allowed(MM_RSAHOSTKEY, user, host, key);
345 	key->type = KEY_RSA1;
346 	return (ret);
347 }
348 
349 static void
350 mm_send_debug(Buffer *m)
351 {
352 	char *msg;
353 
354 	while (buffer_len(m)) {
355 		msg = buffer_get_string(m, NULL);
356 		debug3("%s: Sending debug: %s", __func__, msg);
357 		packet_send_debug("%s", msg);
358 		xfree(msg);
359 	}
360 }
361 
362 int
363 mm_key_allowed(enum mm_keytype type, char *user, char *host, Key *key)
364 {
365 	Buffer m;
366 	u_char *blob;
367 	u_int len;
368 	int allowed = 0, have_forced = 0;
369 
370 	debug3("%s entering", __func__);
371 
372 	/* Convert the key to a blob and the pass it over */
373 	if (!key_to_blob(key, &blob, &len))
374 		return (0);
375 
376 	buffer_init(&m);
377 	buffer_put_int(&m, type);
378 	buffer_put_cstring(&m, user ? user : "");
379 	buffer_put_cstring(&m, host ? host : "");
380 	buffer_put_string(&m, blob, len);
381 	xfree(blob);
382 
383 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);
384 
385 	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
386 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);
387 
388 	allowed = buffer_get_int(&m);
389 
390 	/* fake forced command */
391 	auth_clear_options();
392 	have_forced = buffer_get_int(&m);
393 	forced_command = have_forced ? xstrdup("true") : NULL;
394 
395 	/* Send potential debug messages */
396 	mm_send_debug(&m);
397 
398 	buffer_free(&m);
399 
400 	return (allowed);
401 }
402 
403 /*
404  * This key verify needs to send the key type along, because the
405  * privileged parent makes the decision if the key is allowed
406  * for authentication.
407  */
408 
409 int
410 mm_key_verify(Key *key, u_char *sig, u_int siglen, u_char *data, u_int datalen)
411 {
412 	Buffer m;
413 	u_char *blob;
414 	u_int len;
415 	int verified = 0;
416 
417 	debug3("%s entering", __func__);
418 
419 	/* Convert the key to a blob and the pass it over */
420 	if (!key_to_blob(key, &blob, &len))
421 		return (0);
422 
423 	buffer_init(&m);
424 	buffer_put_string(&m, blob, len);
425 	buffer_put_string(&m, sig, siglen);
426 	buffer_put_string(&m, data, datalen);
427 	xfree(blob);
428 
429 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);
430 
431 	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
432 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m);
433 
434 	verified = buffer_get_int(&m);
435 
436 	buffer_free(&m);
437 
438 	return (verified);
439 }
440 
441 /* Export key state after authentication */
442 Newkeys *
443 mm_newkeys_from_blob(u_char *blob, int blen)
444 {
445 	Buffer b;
446 	u_int len;
447 	Newkeys *newkey = NULL;
448 	Enc *enc;
449 	Mac *mac;
450 	Comp *comp;
451 
452 	debug3("%s: %p(%d)", __func__, blob, blen);
453 #ifdef DEBUG_PK
454 	dump_base64(stderr, blob, blen);
455 #endif
456 	buffer_init(&b);
457 	buffer_append(&b, blob, blen);
458 
459 	newkey = xmalloc(sizeof(*newkey));
460 	enc = &newkey->enc;
461 	mac = &newkey->mac;
462 	comp = &newkey->comp;
463 
464 	/* Enc structure */
465 	enc->name = buffer_get_string(&b, NULL);
466 	buffer_get(&b, &enc->cipher, sizeof(enc->cipher));
467 	enc->enabled = buffer_get_int(&b);
468 	enc->block_size = buffer_get_int(&b);
469 	enc->key = buffer_get_string(&b, &enc->key_len);
470 	enc->iv = buffer_get_string(&b, &len);
471 	if (len != enc->block_size)
472 		fatal("%s: bad ivlen: expected %u != %u", __func__,
473 		    enc->block_size, len);
474 
475 	if (enc->name == NULL || cipher_by_name(enc->name) != enc->cipher)
476 		fatal("%s: bad cipher name %s or pointer %p", __func__,
477 		    enc->name, enc->cipher);
478 
479 	/* Mac structure */
480 	mac->name = buffer_get_string(&b, NULL);
481 	if (mac->name == NULL || mac_setup(mac, mac->name) == -1)
482 		fatal("%s: can not setup mac %s", __func__, mac->name);
483 	mac->enabled = buffer_get_int(&b);
484 	mac->key = buffer_get_string(&b, &len);
485 	if (len > mac->key_len)
486 		fatal("%s: bad mac key length: %u > %d", __func__, len,
487 		    mac->key_len);
488 	mac->key_len = len;
489 
490 	/* Comp structure */
491 	comp->type = buffer_get_int(&b);
492 	comp->enabled = buffer_get_int(&b);
493 	comp->name = buffer_get_string(&b, NULL);
494 
495 	len = buffer_len(&b);
496 	if (len != 0)
497 		error("newkeys_from_blob: remaining bytes in blob %u", len);
498 	buffer_free(&b);
499 	return (newkey);
500 }
501 
502 int
503 mm_newkeys_to_blob(int mode, u_char **blobp, u_int *lenp)
504 {
505 	Buffer b;
506 	int len;
507 	Enc *enc;
508 	Mac *mac;
509 	Comp *comp;
510 	Newkeys *newkey = newkeys[mode];
511 
512 	debug3("%s: converting %p", __func__, newkey);
513 
514 	if (newkey == NULL) {
515 		error("%s: newkey == NULL", __func__);
516 		return 0;
517 	}
518 	enc = &newkey->enc;
519 	mac = &newkey->mac;
520 	comp = &newkey->comp;
521 
522 	buffer_init(&b);
523 	/* Enc structure */
524 	buffer_put_cstring(&b, enc->name);
525 	/* The cipher struct is constant and shared, you export pointer */
526 	buffer_append(&b, &enc->cipher, sizeof(enc->cipher));
527 	buffer_put_int(&b, enc->enabled);
528 	buffer_put_int(&b, enc->block_size);
529 	buffer_put_string(&b, enc->key, enc->key_len);
530 	packet_get_keyiv(mode, enc->iv, enc->block_size);
531 	buffer_put_string(&b, enc->iv, enc->block_size);
532 
533 	/* Mac structure */
534 	buffer_put_cstring(&b, mac->name);
535 	buffer_put_int(&b, mac->enabled);
536 	buffer_put_string(&b, mac->key, mac->key_len);
537 
538 	/* Comp structure */
539 	buffer_put_int(&b, comp->type);
540 	buffer_put_int(&b, comp->enabled);
541 	buffer_put_cstring(&b, comp->name);
542 
543 	len = buffer_len(&b);
544 	if (lenp != NULL)
545 		*lenp = len;
546 	if (blobp != NULL) {
547 		*blobp = xmalloc(len);
548 		memcpy(*blobp, buffer_ptr(&b), len);
549 	}
550 	memset(buffer_ptr(&b), 0, len);
551 	buffer_free(&b);
552 	return len;
553 }
554 
555 static void
556 mm_send_kex(Buffer *m, Kex *kex)
557 {
558 	buffer_put_string(m, kex->session_id, kex->session_id_len);
559 	buffer_put_int(m, kex->we_need);
560 	buffer_put_int(m, kex->hostkey_type);
561 	buffer_put_int(m, kex->kex_type);
562 	buffer_put_string(m, buffer_ptr(&kex->my), buffer_len(&kex->my));
563 	buffer_put_string(m, buffer_ptr(&kex->peer), buffer_len(&kex->peer));
564 	buffer_put_int(m, kex->flags);
565 	buffer_put_cstring(m, kex->client_version_string);
566 	buffer_put_cstring(m, kex->server_version_string);
567 }
568 
569 void
570 mm_send_keystate(struct monitor *monitor)
571 {
572 	Buffer m;
573 	u_char *blob, *p;
574 	u_int bloblen, plen;
575 	u_int32_t seqnr, packets;
576 	u_int64_t blocks, bytes;
577 
578 	buffer_init(&m);
579 
580 	if (!compat20) {
581 		u_char iv[24];
582 		u_char *key;
583 		u_int ivlen, keylen;
584 
585 		buffer_put_int(&m, packet_get_protocol_flags());
586 
587 		buffer_put_int(&m, packet_get_ssh1_cipher());
588 
589 		debug3("%s: Sending ssh1 KEY+IV", __func__);
590 		keylen = packet_get_encryption_key(NULL);
591 		key = xmalloc(keylen+1);	/* add 1 if keylen == 0 */
592 		keylen = packet_get_encryption_key(key);
593 		buffer_put_string(&m, key, keylen);
594 		memset(key, 0, keylen);
595 		xfree(key);
596 
597 		ivlen = packet_get_keyiv_len(MODE_OUT);
598 		packet_get_keyiv(MODE_OUT, iv, ivlen);
599 		buffer_put_string(&m, iv, ivlen);
600 		ivlen = packet_get_keyiv_len(MODE_OUT);
601 		packet_get_keyiv(MODE_IN, iv, ivlen);
602 		buffer_put_string(&m, iv, ivlen);
603 		goto skip;
604 	} else {
605 		/* Kex for rekeying */
606 		mm_send_kex(&m, *monitor->m_pkex);
607 	}
608 
609 	debug3("%s: Sending new keys: %p %p",
610 	    __func__, newkeys[MODE_OUT], newkeys[MODE_IN]);
611 
612 	/* Keys from Kex */
613 	if (!mm_newkeys_to_blob(MODE_OUT, &blob, &bloblen))
614 		fatal("%s: conversion of newkeys failed", __func__);
615 
616 	buffer_put_string(&m, blob, bloblen);
617 	xfree(blob);
618 
619 	if (!mm_newkeys_to_blob(MODE_IN, &blob, &bloblen))
620 		fatal("%s: conversion of newkeys failed", __func__);
621 
622 	buffer_put_string(&m, blob, bloblen);
623 	xfree(blob);
624 
625 	packet_get_state(MODE_OUT, &seqnr, &blocks, &packets, &bytes);
626 	buffer_put_int(&m, seqnr);
627 	buffer_put_int64(&m, blocks);
628 	buffer_put_int(&m, packets);
629 	buffer_put_int64(&m, bytes);
630 	packet_get_state(MODE_IN, &seqnr, &blocks, &packets, &bytes);
631 	buffer_put_int(&m, seqnr);
632 	buffer_put_int64(&m, blocks);
633 	buffer_put_int(&m, packets);
634 	buffer_put_int64(&m, bytes);
635 
636 	debug3("%s: New keys have been sent", __func__);
637  skip:
638 	/* More key context */
639 	plen = packet_get_keycontext(MODE_OUT, NULL);
640 	p = xmalloc(plen+1);
641 	packet_get_keycontext(MODE_OUT, p);
642 	buffer_put_string(&m, p, plen);
643 	xfree(p);
644 
645 	plen = packet_get_keycontext(MODE_IN, NULL);
646 	p = xmalloc(plen+1);
647 	packet_get_keycontext(MODE_IN, p);
648 	buffer_put_string(&m, p, plen);
649 	xfree(p);
650 
651 	/* Compression state */
652 	debug3("%s: Sending compression state", __func__);
653 	buffer_put_string(&m, &outgoing_stream, sizeof(outgoing_stream));
654 	buffer_put_string(&m, &incoming_stream, sizeof(incoming_stream));
655 
656 	/* Network I/O buffers */
657 	buffer_put_string(&m, buffer_ptr(&input), buffer_len(&input));
658 	buffer_put_string(&m, buffer_ptr(&output), buffer_len(&output));
659 
660 	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, &m);
661 	debug3("%s: Finished sending state", __func__);
662 
663 	buffer_free(&m);
664 }
665 
666 int
667 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
668 {
669 	Buffer m;
670 	char *p, *msg;
671 	int success = 0, tmp1 = -1, tmp2 = -1;
672 
673 	/* Kludge: ensure there are fds free to receive the pty/tty */
674 	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
675 	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
676 		error("%s: cannot allocate fds for pty", __func__);
677 		if (tmp1 > 0)
678 			close(tmp1);
679 		if (tmp2 > 0)
680 			close(tmp2);
681 		return 0;
682 	}
683 	close(tmp1);
684 	close(tmp2);
685 
686 	buffer_init(&m);
687 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);
688 
689 	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
690 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);
691 
692 	success = buffer_get_int(&m);
693 	if (success == 0) {
694 		debug3("%s: pty alloc failed", __func__);
695 		buffer_free(&m);
696 		return (0);
697 	}
698 	p = buffer_get_string(&m, NULL);
699 	msg = buffer_get_string(&m, NULL);
700 	buffer_free(&m);
701 
702 	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
703 	xfree(p);
704 
705 	buffer_append(&loginmsg, msg, strlen(msg));
706 	xfree(msg);
707 
708 	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
709 	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
710 		fatal("%s: receive fds failed", __func__);
711 
712 	/* Success */
713 	return (1);
714 }
715 
716 void
717 mm_session_pty_cleanup2(Session *s)
718 {
719 	Buffer m;
720 
721 	if (s->ttyfd == -1)
722 		return;
723 	buffer_init(&m);
724 	buffer_put_cstring(&m, s->tty);
725 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
726 	buffer_free(&m);
727 
728 	/* closed dup'ed master */
729 	if (s->ptymaster != -1 && close(s->ptymaster) < 0)
730 		error("close(s->ptymaster/%d): %s",
731 		    s->ptymaster, strerror(errno));
732 
733 	/* unlink pty from session */
734 	s->ttyfd = -1;
735 }
736 
737 #ifdef USE_PAM
738 void
739 mm_start_pam(Authctxt *authctxt)
740 {
741 	Buffer m;
742 
743 	debug3("%s entering", __func__);
744 	if (!options.use_pam)
745 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
746 
747 	buffer_init(&m);
748 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, &m);
749 
750 	buffer_free(&m);
751 }
752 
753 u_int
754 mm_do_pam_account(void)
755 {
756 	Buffer m;
757 	u_int ret;
758 	char *msg;
759 
760 	debug3("%s entering", __func__);
761 	if (!options.use_pam)
762 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
763 
764 	buffer_init(&m);
765 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, &m);
766 
767 	mm_request_receive_expect(pmonitor->m_recvfd,
768 	    MONITOR_ANS_PAM_ACCOUNT, &m);
769 	ret = buffer_get_int(&m);
770 	msg = buffer_get_string(&m, NULL);
771 	buffer_append(&loginmsg, msg, strlen(msg));
772 	xfree(msg);
773 
774 	buffer_free(&m);
775 
776 	debug3("%s returning %d", __func__, ret);
777 
778 	return (ret);
779 }
780 
781 void *
782 mm_sshpam_init_ctx(Authctxt *authctxt)
783 {
784 	Buffer m;
785 	int success;
786 
787 	debug3("%s", __func__);
788 	buffer_init(&m);
789 	buffer_put_cstring(&m, authctxt->user);
790 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, &m);
791 	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
792 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, &m);
793 	success = buffer_get_int(&m);
794 	if (success == 0) {
795 		debug3("%s: pam_init_ctx failed", __func__);
796 		buffer_free(&m);
797 		return (NULL);
798 	}
799 	buffer_free(&m);
800 	return (authctxt);
801 }
802 
803 int
804 mm_sshpam_query(void *ctx, char **name, char **info,
805     u_int *num, char ***prompts, u_int **echo_on)
806 {
807 	Buffer m;
808 	u_int i;
809 	int ret;
810 
811 	debug3("%s", __func__);
812 	buffer_init(&m);
813 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, &m);
814 	debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
815 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, &m);
816 	ret = buffer_get_int(&m);
817 	debug3("%s: pam_query returned %d", __func__, ret);
818 	*name = buffer_get_string(&m, NULL);
819 	*info = buffer_get_string(&m, NULL);
820 	*num = buffer_get_int(&m);
821 	if (*num > PAM_MAX_NUM_MSG)
822 		fatal("%s: recieved %u PAM messages, expected <= %u",
823 		    __func__, *num, PAM_MAX_NUM_MSG);
824 	*prompts = xcalloc((*num + 1), sizeof(char *));
825 	*echo_on = xcalloc((*num + 1), sizeof(u_int));
826 	for (i = 0; i < *num; ++i) {
827 		(*prompts)[i] = buffer_get_string(&m, NULL);
828 		(*echo_on)[i] = buffer_get_int(&m);
829 	}
830 	buffer_free(&m);
831 	return (ret);
832 }
833 
834 int
835 mm_sshpam_respond(void *ctx, u_int num, char **resp)
836 {
837 	Buffer m;
838 	u_int i;
839 	int ret;
840 
841 	debug3("%s", __func__);
842 	buffer_init(&m);
843 	buffer_put_int(&m, num);
844 	for (i = 0; i < num; ++i)
845 		buffer_put_cstring(&m, resp[i]);
846 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, &m);
847 	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
848 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, &m);
849 	ret = buffer_get_int(&m);
850 	debug3("%s: pam_respond returned %d", __func__, ret);
851 	buffer_free(&m);
852 	return (ret);
853 }
854 
855 void
856 mm_sshpam_free_ctx(void *ctxtp)
857 {
858 	Buffer m;
859 
860 	debug3("%s", __func__);
861 	buffer_init(&m);
862 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, &m);
863 	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
864 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, &m);
865 	buffer_free(&m);
866 }
867 #endif /* USE_PAM */
868 
869 /* Request process termination */
870 
871 void
872 mm_terminate(void)
873 {
874 	Buffer m;
875 
876 	buffer_init(&m);
877 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
878 	buffer_free(&m);
879 }
880 
881 int
882 mm_ssh1_session_key(BIGNUM *num)
883 {
884 	int rsafail;
885 	Buffer m;
886 
887 	buffer_init(&m);
888 	buffer_put_bignum2(&m, num);
889 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSKEY, &m);
890 
891 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SESSKEY, &m);
892 
893 	rsafail = buffer_get_int(&m);
894 	buffer_get_bignum2(&m, num);
895 
896 	buffer_free(&m);
897 
898 	return (rsafail);
899 }
900 
901 static void
902 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
903     char ***prompts, u_int **echo_on)
904 {
905 	*name = xstrdup("");
906 	*infotxt = xstrdup("");
907 	*numprompts = 1;
908 	*prompts = xcalloc(*numprompts, sizeof(char *));
909 	*echo_on = xcalloc(*numprompts, sizeof(u_int));
910 	(*echo_on)[0] = 0;
911 }
912 
913 int
914 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
915    u_int *numprompts, char ***prompts, u_int **echo_on)
916 {
917 	Buffer m;
918 	u_int success;
919 	char *challenge;
920 
921 	debug3("%s: entering", __func__);
922 
923 	buffer_init(&m);
924 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);
925 
926 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
927 	    &m);
928 	success = buffer_get_int(&m);
929 	if (success == 0) {
930 		debug3("%s: no challenge", __func__);
931 		buffer_free(&m);
932 		return (-1);
933 	}
934 
935 	/* Get the challenge, and format the response */
936 	challenge  = buffer_get_string(&m, NULL);
937 	buffer_free(&m);
938 
939 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
940 	(*prompts)[0] = challenge;
941 
942 	debug3("%s: received challenge: %s", __func__, challenge);
943 
944 	return (0);
945 }
946 
947 int
948 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
949 {
950 	Buffer m;
951 	int authok;
952 
953 	debug3("%s: entering", __func__);
954 	if (numresponses != 1)
955 		return (-1);
956 
957 	buffer_init(&m);
958 	buffer_put_cstring(&m, responses[0]);
959 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);
960 
961 	mm_request_receive_expect(pmonitor->m_recvfd,
962 	    MONITOR_ANS_BSDAUTHRESPOND, &m);
963 
964 	authok = buffer_get_int(&m);
965 	buffer_free(&m);
966 
967 	return ((authok == 0) ? -1 : 0);
968 }
969 
970 #ifdef SKEY
971 int
972 mm_skey_query(void *ctx, char **name, char **infotxt,
973    u_int *numprompts, char ***prompts, u_int **echo_on)
974 {
975 	Buffer m;
976 	u_int success;
977 	char *challenge;
978 
979 	debug3("%s: entering", __func__);
980 
981 	buffer_init(&m);
982 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m);
983 
984 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY,
985 	    &m);
986 	success = buffer_get_int(&m);
987 	if (success == 0) {
988 		debug3("%s: no challenge", __func__);
989 		buffer_free(&m);
990 		return (-1);
991 	}
992 
993 	/* Get the challenge, and format the response */
994 	challenge  = buffer_get_string(&m, NULL);
995 	buffer_free(&m);
996 
997 	debug3("%s: received challenge: %s", __func__, challenge);
998 
999 	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
1000 
1001 	xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT);
1002 	xfree(challenge);
1003 
1004 	return (0);
1005 }
1006 
1007 int
1008 mm_skey_respond(void *ctx, u_int numresponses, char **responses)
1009 {
1010 	Buffer m;
1011 	int authok;
1012 
1013 	debug3("%s: entering", __func__);
1014 	if (numresponses != 1)
1015 		return (-1);
1016 
1017 	buffer_init(&m);
1018 	buffer_put_cstring(&m, responses[0]);
1019 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m);
1020 
1021 	mm_request_receive_expect(pmonitor->m_recvfd,
1022 	    MONITOR_ANS_SKEYRESPOND, &m);
1023 
1024 	authok = buffer_get_int(&m);
1025 	buffer_free(&m);
1026 
1027 	return ((authok == 0) ? -1 : 0);
1028 }
1029 #endif /* SKEY */
1030 
1031 void
1032 mm_ssh1_session_id(u_char session_id[16])
1033 {
1034 	Buffer m;
1035 	int i;
1036 
1037 	debug3("%s entering", __func__);
1038 
1039 	buffer_init(&m);
1040 	for (i = 0; i < 16; i++)
1041 		buffer_put_char(&m, session_id[i]);
1042 
1043 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSID, &m);
1044 	buffer_free(&m);
1045 }
1046 
1047 int
1048 mm_auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
1049 {
1050 	Buffer m;
1051 	Key *key;
1052 	u_char *blob;
1053 	u_int blen;
1054 	int allowed = 0, have_forced = 0;
1055 
1056 	debug3("%s entering", __func__);
1057 
1058 	buffer_init(&m);
1059 	buffer_put_bignum2(&m, client_n);
1060 
1061 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSAKEYALLOWED, &m);
1062 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSAKEYALLOWED, &m);
1063 
1064 	allowed = buffer_get_int(&m);
1065 
1066 	/* fake forced command */
1067 	auth_clear_options();
1068 	have_forced = buffer_get_int(&m);
1069 	forced_command = have_forced ? xstrdup("true") : NULL;
1070 
1071 	if (allowed && rkey != NULL) {
1072 		blob = buffer_get_string(&m, &blen);
1073 		if ((key = key_from_blob(blob, blen)) == NULL)
1074 			fatal("%s: key_from_blob failed", __func__);
1075 		*rkey = key;
1076 		xfree(blob);
1077 	}
1078 	mm_send_debug(&m);
1079 	buffer_free(&m);
1080 
1081 	return (allowed);
1082 }
1083 
1084 BIGNUM *
1085 mm_auth_rsa_generate_challenge(Key *key)
1086 {
1087 	Buffer m;
1088 	BIGNUM *challenge;
1089 	u_char *blob;
1090 	u_int blen;
1091 
1092 	debug3("%s entering", __func__);
1093 
1094 	if ((challenge = BN_new()) == NULL)
1095 		fatal("%s: BN_new failed", __func__);
1096 
1097 	key->type = KEY_RSA;    /* XXX cheat for key_to_blob */
1098 	if (key_to_blob(key, &blob, &blen) == 0)
1099 		fatal("%s: key_to_blob failed", __func__);
1100 	key->type = KEY_RSA1;
1101 
1102 	buffer_init(&m);
1103 	buffer_put_string(&m, blob, blen);
1104 	xfree(blob);
1105 
1106 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSACHALLENGE, &m);
1107 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSACHALLENGE, &m);
1108 
1109 	buffer_get_bignum2(&m, challenge);
1110 	buffer_free(&m);
1111 
1112 	return (challenge);
1113 }
1114 
1115 int
1116 mm_auth_rsa_verify_response(Key *key, BIGNUM *p, u_char response[16])
1117 {
1118 	Buffer m;
1119 	u_char *blob;
1120 	u_int blen;
1121 	int success = 0;
1122 
1123 	debug3("%s entering", __func__);
1124 
1125 	key->type = KEY_RSA;    /* XXX cheat for key_to_blob */
1126 	if (key_to_blob(key, &blob, &blen) == 0)
1127 		fatal("%s: key_to_blob failed", __func__);
1128 	key->type = KEY_RSA1;
1129 
1130 	buffer_init(&m);
1131 	buffer_put_string(&m, blob, blen);
1132 	buffer_put_string(&m, response, 16);
1133 	xfree(blob);
1134 
1135 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSARESPONSE, &m);
1136 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSARESPONSE, &m);
1137 
1138 	success = buffer_get_int(&m);
1139 	buffer_free(&m);
1140 
1141 	return (success);
1142 }
1143 
1144 #ifdef SSH_AUDIT_EVENTS
1145 void
1146 mm_audit_event(ssh_audit_event_t event)
1147 {
1148 	Buffer m;
1149 
1150 	debug3("%s entering", __func__);
1151 
1152 	buffer_init(&m);
1153 	buffer_put_int(&m, event);
1154 
1155 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, &m);
1156 	buffer_free(&m);
1157 }
1158 
1159 void
1160 mm_audit_run_command(const char *command)
1161 {
1162 	Buffer m;
1163 
1164 	debug3("%s entering command %s", __func__, command);
1165 
1166 	buffer_init(&m);
1167 	buffer_put_cstring(&m, command);
1168 
1169 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, &m);
1170 	buffer_free(&m);
1171 }
1172 #endif /* SSH_AUDIT_EVENTS */
1173 
1174 #ifdef GSSAPI
1175 OM_uint32
1176 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
1177 {
1178 	Buffer m;
1179 	OM_uint32 major;
1180 
1181 	/* Client doesn't get to see the context */
1182 	*ctx = NULL;
1183 
1184 	buffer_init(&m);
1185 	buffer_put_string(&m, goid->elements, goid->length);
1186 
1187 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
1188 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);
1189 
1190 	major = buffer_get_int(&m);
1191 
1192 	buffer_free(&m);
1193 	return (major);
1194 }
1195 
1196 OM_uint32
1197 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
1198     gss_buffer_desc *out, OM_uint32 *flags)
1199 {
1200 	Buffer m;
1201 	OM_uint32 major;
1202 	u_int len;
1203 
1204 	buffer_init(&m);
1205 	buffer_put_string(&m, in->value, in->length);
1206 
1207 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
1208 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);
1209 
1210 	major = buffer_get_int(&m);
1211 	out->value = buffer_get_string(&m, &len);
1212 	out->length = len;
1213 	if (flags)
1214 		*flags = buffer_get_int(&m);
1215 
1216 	buffer_free(&m);
1217 
1218 	return (major);
1219 }
1220 
1221 OM_uint32
1222 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
1223 {
1224 	Buffer m;
1225 	OM_uint32 major;
1226 
1227 	buffer_init(&m);
1228 	buffer_put_string(&m, gssbuf->value, gssbuf->length);
1229 	buffer_put_string(&m, gssmic->value, gssmic->length);
1230 
1231 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
1232 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
1233 	    &m);
1234 
1235 	major = buffer_get_int(&m);
1236 	buffer_free(&m);
1237 	return(major);
1238 }
1239 
1240 int
1241 mm_ssh_gssapi_userok(char *user)
1242 {
1243 	Buffer m;
1244 	int authenticated = 0;
1245 
1246 	buffer_init(&m);
1247 
1248 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
1249 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
1250 				  &m);
1251 
1252 	authenticated = buffer_get_int(&m);
1253 
1254 	buffer_free(&m);
1255 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
1256 	return (authenticated);
1257 }
1258 #endif /* GSSAPI */
1259