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700318f3 1/*
2 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
3 * Copyright 2002 Markus Friedl <markus@openbsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
cdd66111 28RCSID("$OpenBSD: monitor.c,v 1.55 2004/02/05 05:37:17 dtucker Exp $");
700318f3 29
30#include <openssl/dh.h>
31
32#ifdef SKEY
33#include <skey.h>
34#endif
35
36#include "ssh.h"
37#include "auth.h"
38#include "kex.h"
39#include "dh.h"
99be0775 40#ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */
41#undef TARGET_OS_MAC
700318f3 42#include "zlib.h"
99be0775 43#define TARGET_OS_MAC 1
44#else
45#include "zlib.h"
46#endif
700318f3 47#include "packet.h"
48#include "auth-options.h"
49#include "sshpty.h"
50#include "channels.h"
51#include "session.h"
52#include "sshlogin.h"
53#include "canohost.h"
54#include "log.h"
55#include "servconf.h"
56#include "monitor.h"
57#include "monitor_mm.h"
58#include "monitor_wrap.h"
59#include "monitor_fdpass.h"
60#include "xmalloc.h"
61#include "misc.h"
62#include "buffer.h"
63#include "bufaux.h"
64#include "compat.h"
65#include "ssh2.h"
66#include "mpaux.h"
67
0fff78ff 68#ifdef GSSAPI
69#include "ssh-gss.h"
70static Gssctxt *gsscontext = NULL;
71#endif
72
700318f3 73/* Imports */
74extern ServerOptions options;
75extern u_int utmp_len;
76extern Newkeys *current_keys[];
77extern z_stream incoming_stream;
78extern z_stream outgoing_stream;
79extern u_char session_id[];
80extern Buffer input, output;
81extern Buffer auth_debug;
82extern int auth_debug_init;
83
84/* State exported from the child */
85
86struct {
87 z_stream incoming;
88 z_stream outgoing;
89 u_char *keyin;
90 u_int keyinlen;
91 u_char *keyout;
92 u_int keyoutlen;
93 u_char *ivin;
94 u_int ivinlen;
95 u_char *ivout;
96 u_int ivoutlen;
f5799ae1 97 u_char *ssh1key;
98 u_int ssh1keylen;
700318f3 99 int ssh1cipher;
100 int ssh1protoflags;
101 u_char *input;
102 u_int ilen;
103 u_char *output;
104 u_int olen;
105} child_state;
106
0fff78ff 107/* Functions on the monitor that answer unprivileged requests */
700318f3 108
109int mm_answer_moduli(int, Buffer *);
110int mm_answer_sign(int, Buffer *);
111int mm_answer_pwnamallow(int, Buffer *);
112int mm_answer_auth2_read_banner(int, Buffer *);
113int mm_answer_authserv(int, Buffer *);
114int mm_answer_authpassword(int, Buffer *);
115int mm_answer_bsdauthquery(int, Buffer *);
116int mm_answer_bsdauthrespond(int, Buffer *);
117int mm_answer_skeyquery(int, Buffer *);
118int mm_answer_skeyrespond(int, Buffer *);
119int mm_answer_keyallowed(int, Buffer *);
120int mm_answer_keyverify(int, Buffer *);
121int mm_answer_pty(int, Buffer *);
122int mm_answer_pty_cleanup(int, Buffer *);
123int mm_answer_term(int, Buffer *);
124int mm_answer_rsa_keyallowed(int, Buffer *);
125int mm_answer_rsa_challenge(int, Buffer *);
126int mm_answer_rsa_response(int, Buffer *);
127int mm_answer_sesskey(int, Buffer *);
128int mm_answer_sessid(int, Buffer *);
129
130#ifdef USE_PAM
131int mm_answer_pam_start(int, Buffer *);
0fff78ff 132int mm_answer_pam_account(int, Buffer *);
133int mm_answer_pam_init_ctx(int, Buffer *);
134int mm_answer_pam_query(int, Buffer *);
135int mm_answer_pam_respond(int, Buffer *);
136int mm_answer_pam_free_ctx(int, Buffer *);
700318f3 137#endif
138
0fff78ff 139#ifdef GSSAPI
140int mm_answer_gss_setup_ctx(int, Buffer *);
141int mm_answer_gss_accept_ctx(int, Buffer *);
142int mm_answer_gss_userok(int, Buffer *);
cdd66111 143int mm_answer_gss_checkmic(int, Buffer *);
41b2f314 144#endif
145
700318f3 146static Authctxt *authctxt;
147static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
148
149/* local state for key verify */
150static u_char *key_blob = NULL;
151static u_int key_bloblen = 0;
152static int key_blobtype = MM_NOKEY;
41b2f314 153static char *hostbased_cuser = NULL;
154static char *hostbased_chost = NULL;
700318f3 155static char *auth_method = "unknown";
0fff78ff 156static u_int session_id2_len = 0;
f5799ae1 157static u_char *session_id2 = NULL;
0fff78ff 158static pid_t monitor_child_pid;
700318f3 159
160struct mon_table {
161 enum monitor_reqtype type;
162 int flags;
163 int (*f)(int, Buffer *);
164};
165
166#define MON_ISAUTH 0x0004 /* Required for Authentication */
167#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
168#define MON_ONCE 0x0010 /* Disable after calling */
169
170#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
171
172#define MON_PERMIT 0x1000 /* Request is permitted */
173
174struct mon_table mon_dispatch_proto20[] = {
175 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
176 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
177 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
178 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
179 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
180 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
181#ifdef USE_PAM
182 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
0fff78ff 183 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
184 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
185 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
186 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
187 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
700318f3 188#endif
189#ifdef BSD_AUTH
190 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
191 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
192#endif
193#ifdef SKEY
194 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
195 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
196#endif
197 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
198 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
0fff78ff 199#ifdef GSSAPI
200 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
201 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
202 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
cdd66111 203 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
0fff78ff 204#endif
700318f3 205 {0, 0, NULL}
206};
207
208struct mon_table mon_dispatch_postauth20[] = {
209 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
210 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
211 {MONITOR_REQ_PTY, 0, mm_answer_pty},
212 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
213 {MONITOR_REQ_TERM, 0, mm_answer_term},
214 {0, 0, NULL}
215};
216
217struct mon_table mon_dispatch_proto15[] = {
218 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
219 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
220 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
221 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
222 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
223 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
224 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
225 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
700318f3 226#ifdef BSD_AUTH
227 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
228 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
229#endif
230#ifdef SKEY
231 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
232 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
233#endif
234#ifdef USE_PAM
235 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
0fff78ff 236 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
237 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
238 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
239 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
240 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
700318f3 241#endif
242 {0, 0, NULL}
243};
244
245struct mon_table mon_dispatch_postauth15[] = {
246 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
247 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
248 {MONITOR_REQ_TERM, 0, mm_answer_term},
249 {0, 0, NULL}
250};
251
252struct mon_table *mon_dispatch;
253
254/* Specifies if a certain message is allowed at the moment */
255
256static void
257monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
258{
259 while (ent->f != NULL) {
260 if (ent->type == type) {
261 ent->flags &= ~MON_PERMIT;
262 ent->flags |= permit ? MON_PERMIT : 0;
263 return;
264 }
265 ent++;
266 }
267}
268
269static void
270monitor_permit_authentications(int permit)
271{
272 struct mon_table *ent = mon_dispatch;
273
274 while (ent->f != NULL) {
275 if (ent->flags & MON_AUTH) {
276 ent->flags &= ~MON_PERMIT;
277 ent->flags |= permit ? MON_PERMIT : 0;
278 }
279 ent++;
280 }
281}
282
cdd66111 283void
284monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
700318f3 285{
286 struct mon_table *ent;
287 int authenticated = 0;
288
289 debug3("preauth child monitor started");
290
cdd66111 291 authctxt = _authctxt;
292 memset(authctxt, 0, sizeof(*authctxt));
293
700318f3 294 if (compat20) {
295 mon_dispatch = mon_dispatch_proto20;
296
297 /* Permit requests for moduli and signatures */
298 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
299 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
300 } else {
301 mon_dispatch = mon_dispatch_proto15;
302
303 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
304 }
305
700318f3 306 /* The first few requests do not require asynchronous access */
307 while (!authenticated) {
308 authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
309 if (authenticated) {
310 if (!(ent->flags & MON_AUTHDECIDE))
311 fatal("%s: unexpected authentication from %d",
f5799ae1 312 __func__, ent->type);
700318f3 313 if (authctxt->pw->pw_uid == 0 &&
314 !auth_root_allowed(auth_method))
315 authenticated = 0;
316#ifdef USE_PAM
0fff78ff 317 /* PAM needs to perform account checks after auth */
cdd66111 318 if (options.use_pam && authenticated) {
0fff78ff 319 Buffer m;
320
321 buffer_init(&m);
cdd66111 322 mm_request_receive_expect(pmonitor->m_sendfd,
0fff78ff 323 MONITOR_REQ_PAM_ACCOUNT, &m);
324 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
325 buffer_free(&m);
326 }
700318f3 327#endif
328 }
329
330 if (ent->flags & MON_AUTHDECIDE) {
331 auth_log(authctxt, authenticated, auth_method,
332 compat20 ? " ssh2" : "");
333 if (!authenticated)
334 authctxt->failures++;
335 }
336 }
337
338 if (!authctxt->valid)
f5799ae1 339 fatal("%s: authenticated invalid user", __func__);
700318f3 340
341 debug("%s: %s has been authenticated by privileged process",
f5799ae1 342 __func__, authctxt->user);
700318f3 343
344 mm_get_keystate(pmonitor);
700318f3 345}
346
0fff78ff 347static void
348monitor_set_child_handler(pid_t pid)
349{
350 monitor_child_pid = pid;
351}
352
353static void
354monitor_child_handler(int signal)
355{
356 kill(monitor_child_pid, signal);
357}
358
700318f3 359void
360monitor_child_postauth(struct monitor *pmonitor)
361{
0fff78ff 362 monitor_set_child_handler(pmonitor->m_pid);
363 signal(SIGHUP, &monitor_child_handler);
364 signal(SIGTERM, &monitor_child_handler);
365
700318f3 366 if (compat20) {
367 mon_dispatch = mon_dispatch_postauth20;
368
369 /* Permit requests for moduli and signatures */
370 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
371 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
372 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
700318f3 373 } else {
374 mon_dispatch = mon_dispatch_postauth15;
375 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
376 }
377 if (!no_pty_flag) {
378 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
379 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
380 }
381
382 for (;;)
383 monitor_read(pmonitor, mon_dispatch, NULL);
384}
385
386void
387monitor_sync(struct monitor *pmonitor)
388{
f5799ae1 389 if (options.compression) {
390 /* The member allocation is not visible, so sync it */
391 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
392 }
700318f3 393}
394
395int
396monitor_read(struct monitor *pmonitor, struct mon_table *ent,
397 struct mon_table **pent)
398{
399 Buffer m;
400 int ret;
401 u_char type;
402
403 buffer_init(&m);
404
405 mm_request_receive(pmonitor->m_sendfd, &m);
406 type = buffer_get_char(&m);
407
f5799ae1 408 debug3("%s: checking request %d", __func__, type);
700318f3 409
410 while (ent->f != NULL) {
411 if (ent->type == type)
412 break;
413 ent++;
414 }
415
416 if (ent->f != NULL) {
417 if (!(ent->flags & MON_PERMIT))
f5799ae1 418 fatal("%s: unpermitted request %d", __func__,
700318f3 419 type);
420 ret = (*ent->f)(pmonitor->m_sendfd, &m);
421 buffer_free(&m);
422
423 /* The child may use this request only once, disable it */
424 if (ent->flags & MON_ONCE) {
f5799ae1 425 debug2("%s: %d used once, disabling now", __func__,
700318f3 426 type);
427 ent->flags &= ~MON_PERMIT;
428 }
429
430 if (pent != NULL)
431 *pent = ent;
432
433 return ret;
434 }
435
f5799ae1 436 fatal("%s: unsupported request: %d", __func__, type);
700318f3 437
438 /* NOTREACHED */
439 return (-1);
440}
441
442/* allowed key state */
443static int
444monitor_allowed_key(u_char *blob, u_int bloblen)
445{
446 /* make sure key is allowed */
447 if (key_blob == NULL || key_bloblen != bloblen ||
448 memcmp(key_blob, blob, key_bloblen))
449 return (0);
450 return (1);
451}
452
453static void
454monitor_reset_key_state(void)
455{
456 /* reset state */
457 if (key_blob != NULL)
458 xfree(key_blob);
459 if (hostbased_cuser != NULL)
460 xfree(hostbased_cuser);
461 if (hostbased_chost != NULL)
462 xfree(hostbased_chost);
463 key_blob = NULL;
464 key_bloblen = 0;
465 key_blobtype = MM_NOKEY;
466 hostbased_cuser = NULL;
467 hostbased_chost = NULL;
468}
469
470int
471mm_answer_moduli(int socket, Buffer *m)
472{
473 DH *dh;
474 int min, want, max;
475
476 min = buffer_get_int(m);
477 want = buffer_get_int(m);
478 max = buffer_get_int(m);
479
480 debug3("%s: got parameters: %d %d %d",
f5799ae1 481 __func__, min, want, max);
700318f3 482 /* We need to check here, too, in case the child got corrupted */
483 if (max < min || want < min || max < want)
484 fatal("%s: bad parameters: %d %d %d",
f5799ae1 485 __func__, min, want, max);
700318f3 486
487 buffer_clear(m);
488
489 dh = choose_dh(min, want, max);
490 if (dh == NULL) {
491 buffer_put_char(m, 0);
492 return (0);
493 } else {
494 /* Send first bignum */
495 buffer_put_char(m, 1);
496 buffer_put_bignum2(m, dh->p);
497 buffer_put_bignum2(m, dh->g);
498
499 DH_free(dh);
500 }
501 mm_request_send(socket, MONITOR_ANS_MODULI, m);
502 return (0);
503}
504
505int
506mm_answer_sign(int socket, Buffer *m)
507{
508 Key *key;
509 u_char *p;
510 u_char *signature;
511 u_int siglen, datlen;
512 int keyid;
513
f5799ae1 514 debug3("%s", __func__);
700318f3 515
516 keyid = buffer_get_int(m);
517 p = buffer_get_string(m, &datlen);
518
519 if (datlen != 20)
41b2f314 520 fatal("%s: data length incorrect: %u", __func__, datlen);
f5799ae1 521
522 /* save session id, it will be passed on the first call */
523 if (session_id2_len == 0) {
524 session_id2_len = datlen;
525 session_id2 = xmalloc(session_id2_len);
526 memcpy(session_id2, p, session_id2_len);
527 }
700318f3 528
529 if ((key = get_hostkey_by_index(keyid)) == NULL)
f5799ae1 530 fatal("%s: no hostkey from index %d", __func__, keyid);
700318f3 531 if (key_sign(key, &signature, &siglen, p, datlen) < 0)
f5799ae1 532 fatal("%s: key_sign failed", __func__);
700318f3 533
41b2f314 534 debug3("%s: signature %p(%u)", __func__, signature, siglen);
700318f3 535
536 buffer_clear(m);
537 buffer_put_string(m, signature, siglen);
538
539 xfree(p);
540 xfree(signature);
541
542 mm_request_send(socket, MONITOR_ANS_SIGN, m);
543
544 /* Turn on permissions for getpwnam */
545 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
546
547 return (0);
548}
549
550/* Retrieves the password entry and also checks if the user is permitted */
551
552int
553mm_answer_pwnamallow(int socket, Buffer *m)
554{
555 char *login;
556 struct passwd *pwent;
557 int allowed = 0;
558
f5799ae1 559 debug3("%s", __func__);
700318f3 560
561 if (authctxt->attempt++ != 0)
f5799ae1 562 fatal("%s: multiple attempts for getpwnam", __func__);
700318f3 563
564 login = buffer_get_string(m, NULL);
565
566 pwent = getpwnamallow(login);
567
568 authctxt->user = xstrdup(login);
569 setproctitle("%s [priv]", pwent ? login : "unknown");
570 xfree(login);
571
572 buffer_clear(m);
573
574 if (pwent == NULL) {
575 buffer_put_char(m, 0);
cdd66111 576 authctxt->pw = fakepw();
700318f3 577 goto out;
578 }
579
580 allowed = 1;
581 authctxt->pw = pwent;
582 authctxt->valid = 1;
583
584 buffer_put_char(m, 1);
585 buffer_put_string(m, pwent, sizeof(struct passwd));
586 buffer_put_cstring(m, pwent->pw_name);
587 buffer_put_cstring(m, "*");
588 buffer_put_cstring(m, pwent->pw_gecos);
589#ifdef HAVE_PW_CLASS_IN_PASSWD
590 buffer_put_cstring(m, pwent->pw_class);
591#endif
592 buffer_put_cstring(m, pwent->pw_dir);
593 buffer_put_cstring(m, pwent->pw_shell);
594
595 out:
f5799ae1 596 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
700318f3 597 mm_request_send(socket, MONITOR_ANS_PWNAM, m);
598
599 /* For SSHv1 allow authentication now */
600 if (!compat20)
601 monitor_permit_authentications(1);
602 else {
603 /* Allow service/style information on the auth context */
604 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
605 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
606 }
607
608#ifdef USE_PAM
0fff78ff 609 if (options.use_pam)
610 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
700318f3 611#endif
612
613 return (0);
614}
615
616int mm_answer_auth2_read_banner(int socket, Buffer *m)
617{
618 char *banner;
619
620 buffer_clear(m);
621 banner = auth2_read_banner();
622 buffer_put_cstring(m, banner != NULL ? banner : "");
623 mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m);
624
625 if (banner != NULL)
41b2f314 626 xfree(banner);
700318f3 627
628 return (0);
629}
630
631int
632mm_answer_authserv(int socket, Buffer *m)
633{
634 monitor_permit_authentications(1);
635
636 authctxt->service = buffer_get_string(m, NULL);
637 authctxt->style = buffer_get_string(m, NULL);
638 debug3("%s: service=%s, style=%s",
f5799ae1 639 __func__, authctxt->service, authctxt->style);
700318f3 640
641 if (strlen(authctxt->style) == 0) {
642 xfree(authctxt->style);
643 authctxt->style = NULL;
644 }
645
646 return (0);
647}
648
649int
650mm_answer_authpassword(int socket, Buffer *m)
651{
652 static int call_count;
653 char *passwd;
41b2f314 654 int authenticated;
655 u_int plen;
700318f3 656
657 passwd = buffer_get_string(m, &plen);
658 /* Only authenticate if the context is valid */
f5799ae1 659 authenticated = options.password_authentication &&
0fff78ff 660 auth_password(authctxt, passwd);
700318f3 661 memset(passwd, 0, strlen(passwd));
662 xfree(passwd);
663
664 buffer_clear(m);
665 buffer_put_int(m, authenticated);
666
f5799ae1 667 debug3("%s: sending result %d", __func__, authenticated);
700318f3 668 mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m);
669
670 call_count++;
671 if (plen == 0 && call_count == 1)
672 auth_method = "none";
673 else
674 auth_method = "password";
675
676 /* Causes monitor loop to terminate if authenticated */
677 return (authenticated);
678}
679
680#ifdef BSD_AUTH
681int
682mm_answer_bsdauthquery(int socket, Buffer *m)
683{
684 char *name, *infotxt;
685 u_int numprompts;
686 u_int *echo_on;
687 char **prompts;
6a9b3198 688 u_int success;
700318f3 689
6a9b3198 690 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
691 &prompts, &echo_on) < 0 ? 0 : 1;
700318f3 692
693 buffer_clear(m);
6a9b3198 694 buffer_put_int(m, success);
695 if (success)
700318f3 696 buffer_put_cstring(m, prompts[0]);
697
6a9b3198 698 debug3("%s: sending challenge success: %u", __func__, success);
700318f3 699 mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m);
700
6a9b3198 701 if (success) {
700318f3 702 xfree(name);
703 xfree(infotxt);
704 xfree(prompts);
705 xfree(echo_on);
706 }
707
708 return (0);
709}
710
711int
712mm_answer_bsdauthrespond(int socket, Buffer *m)
713{
714 char *response;
715 int authok;
716
717 if (authctxt->as == 0)
f5799ae1 718 fatal("%s: no bsd auth session", __func__);
700318f3 719
720 response = buffer_get_string(m, NULL);
f5799ae1 721 authok = options.challenge_response_authentication &&
722 auth_userresponse(authctxt->as, response, 0);
700318f3 723 authctxt->as = NULL;
f5799ae1 724 debug3("%s: <%s> = <%d>", __func__, response, authok);
700318f3 725 xfree(response);
726
727 buffer_clear(m);
728 buffer_put_int(m, authok);
729
f5799ae1 730 debug3("%s: sending authenticated: %d", __func__, authok);
700318f3 731 mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m);
732
733 auth_method = "bsdauth";
734
735 return (authok != 0);
736}
737#endif
738
739#ifdef SKEY
740int
741mm_answer_skeyquery(int socket, Buffer *m)
742{
743 struct skey skey;
744 char challenge[1024];
6a9b3198 745 u_int success;
700318f3 746
99be0775 747 success = _compat_skeychallenge(&skey, authctxt->user, challenge,
748 sizeof(challenge)) < 0 ? 0 : 1;
700318f3 749
750 buffer_clear(m);
6a9b3198 751 buffer_put_int(m, success);
752 if (success)
700318f3 753 buffer_put_cstring(m, challenge);
754
6a9b3198 755 debug3("%s: sending challenge success: %u", __func__, success);
700318f3 756 mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
757
758 return (0);
759}
760
761int
762mm_answer_skeyrespond(int socket, Buffer *m)
763{
764 char *response;
765 int authok;
766
767 response = buffer_get_string(m, NULL);
768
f5799ae1 769 authok = (options.challenge_response_authentication &&
770 authctxt->valid &&
700318f3 771 skey_haskey(authctxt->pw->pw_name) == 0 &&
772 skey_passcheck(authctxt->pw->pw_name, response) != -1);
773
774 xfree(response);
775
776 buffer_clear(m);
777 buffer_put_int(m, authok);
778
f5799ae1 779 debug3("%s: sending authenticated: %d", __func__, authok);
700318f3 780 mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m);
781
782 auth_method = "skey";
783
784 return (authok != 0);
785}
786#endif
787
788#ifdef USE_PAM
789int
790mm_answer_pam_start(int socket, Buffer *m)
791{
0fff78ff 792 if (!options.use_pam)
793 fatal("UsePAM not set, but ended up in %s anyway", __func__);
794
99be0775 795 start_pam(authctxt);
700318f3 796
0fff78ff 797 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
798
700318f3 799 return (0);
800}
0fff78ff 801
802int
803mm_answer_pam_account(int socket, Buffer *m)
804{
805 u_int ret;
cdd66111 806
0fff78ff 807 if (!options.use_pam)
808 fatal("UsePAM not set, but ended up in %s anyway", __func__);
809
810 ret = do_pam_account();
811
812 buffer_put_int(m, ret);
813
814 mm_request_send(socket, MONITOR_ANS_PAM_ACCOUNT, m);
815
816 return (ret);
817}
818
819static void *sshpam_ctxt, *sshpam_authok;
820extern KbdintDevice sshpam_device;
821
822int
823mm_answer_pam_init_ctx(int socket, Buffer *m)
824{
825
826 debug3("%s", __func__);
827 authctxt->user = buffer_get_string(m, NULL);
828 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
829 sshpam_authok = NULL;
830 buffer_clear(m);
831 if (sshpam_ctxt != NULL) {
832 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
833 buffer_put_int(m, 1);
834 } else {
835 buffer_put_int(m, 0);
836 }
837 mm_request_send(socket, MONITOR_ANS_PAM_INIT_CTX, m);
838 return (0);
839}
840
841int
842mm_answer_pam_query(int socket, Buffer *m)
843{
844 char *name, *info, **prompts;
845 u_int num, *echo_on;
846 int i, ret;
847
848 debug3("%s", __func__);
849 sshpam_authok = NULL;
850 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
851 if (ret == 0 && num == 0)
852 sshpam_authok = sshpam_ctxt;
853 if (num > 1 || name == NULL || info == NULL)
854 ret = -1;
855 buffer_clear(m);
856 buffer_put_int(m, ret);
857 buffer_put_cstring(m, name);
858 xfree(name);
859 buffer_put_cstring(m, info);
860 xfree(info);
861 buffer_put_int(m, num);
862 for (i = 0; i < num; ++i) {
863 buffer_put_cstring(m, prompts[i]);
864 xfree(prompts[i]);
865 buffer_put_int(m, echo_on[i]);
866 }
867 if (prompts != NULL)
868 xfree(prompts);
869 if (echo_on != NULL)
870 xfree(echo_on);
871 mm_request_send(socket, MONITOR_ANS_PAM_QUERY, m);
872 return (0);
873}
874
875int
876mm_answer_pam_respond(int socket, Buffer *m)
877{
878 char **resp;
879 u_int num;
880 int i, ret;
881
882 debug3("%s", __func__);
883 sshpam_authok = NULL;
884 num = buffer_get_int(m);
885 if (num > 0) {
886 resp = xmalloc(num * sizeof(char *));
887 for (i = 0; i < num; ++i)
888 resp[i] = buffer_get_string(m, NULL);
889 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
890 for (i = 0; i < num; ++i)
891 xfree(resp[i]);
892 xfree(resp);
893 } else {
894 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
895 }
896 buffer_clear(m);
897 buffer_put_int(m, ret);
898 mm_request_send(socket, MONITOR_ANS_PAM_RESPOND, m);
899 auth_method = "keyboard-interactive/pam";
900 if (ret == 0)
901 sshpam_authok = sshpam_ctxt;
902 return (0);
903}
904
905int
906mm_answer_pam_free_ctx(int socket, Buffer *m)
907{
908
909 debug3("%s", __func__);
910 (sshpam_device.free_ctx)(sshpam_ctxt);
911 buffer_clear(m);
912 mm_request_send(socket, MONITOR_ANS_PAM_FREE_CTX, m);
913 return (sshpam_authok == sshpam_ctxt);
914}
700318f3 915#endif
916
917static void
918mm_append_debug(Buffer *m)
919{
920 if (auth_debug_init && buffer_len(&auth_debug)) {
f5799ae1 921 debug3("%s: Appending debug messages for child", __func__);
700318f3 922 buffer_append(m, buffer_ptr(&auth_debug),
923 buffer_len(&auth_debug));
924 buffer_clear(&auth_debug);
925 }
926}
927
928int
929mm_answer_keyallowed(int socket, Buffer *m)
930{
931 Key *key;
41b2f314 932 char *cuser, *chost;
933 u_char *blob;
700318f3 934 u_int bloblen;
935 enum mm_keytype type = 0;
936 int allowed = 0;
937
f5799ae1 938 debug3("%s entering", __func__);
700318f3 939
940 type = buffer_get_int(m);
941 cuser = buffer_get_string(m, NULL);
942 chost = buffer_get_string(m, NULL);
943 blob = buffer_get_string(m, &bloblen);
944
945 key = key_from_blob(blob, bloblen);
946
947 if ((compat20 && type == MM_RSAHOSTKEY) ||
948 (!compat20 && type != MM_RSAHOSTKEY))
f5799ae1 949 fatal("%s: key type and protocol mismatch", __func__);
700318f3 950
f5799ae1 951 debug3("%s: key_from_blob: %p", __func__, key);
700318f3 952
cdd66111 953 if (key != NULL && authctxt->valid) {
700318f3 954 switch(type) {
955 case MM_USERKEY:
f5799ae1 956 allowed = options.pubkey_authentication &&
957 user_key_allowed(authctxt->pw, key);
700318f3 958 break;
959 case MM_HOSTKEY:
f5799ae1 960 allowed = options.hostbased_authentication &&
961 hostbased_key_allowed(authctxt->pw,
700318f3 962 cuser, chost, key);
963 break;
964 case MM_RSAHOSTKEY:
965 key->type = KEY_RSA1; /* XXX */
f5799ae1 966 allowed = options.rhosts_rsa_authentication &&
967 auth_rhosts_rsa_key_allowed(authctxt->pw,
700318f3 968 cuser, chost, key);
969 break;
970 default:
f5799ae1 971 fatal("%s: unknown key type %d", __func__, type);
700318f3 972 break;
973 }
700318f3 974 }
6a9b3198 975 if (key != NULL)
976 key_free(key);
700318f3 977
978 /* clear temporarily storage (used by verify) */
979 monitor_reset_key_state();
980
981 if (allowed) {
982 /* Save temporarily for comparison in verify */
983 key_blob = blob;
984 key_bloblen = bloblen;
985 key_blobtype = type;
986 hostbased_cuser = cuser;
987 hostbased_chost = chost;
988 }
989
990 debug3("%s: key %p is %s",
f5799ae1 991 __func__, key, allowed ? "allowed" : "disallowed");
700318f3 992
993 buffer_clear(m);
994 buffer_put_int(m, allowed);
6a9b3198 995 buffer_put_int(m, forced_command != NULL);
700318f3 996
997 mm_append_debug(m);
998
999 mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m);
1000
1001 if (type == MM_RSAHOSTKEY)
1002 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1003
1004 return (0);
1005}
1006
1007static int
1008monitor_valid_userblob(u_char *data, u_int datalen)
1009{
1010 Buffer b;
41b2f314 1011 char *p;
700318f3 1012 u_int len;
1013 int fail = 0;
700318f3 1014
1015 buffer_init(&b);
1016 buffer_append(&b, data, datalen);
1017
1018 if (datafellows & SSH_OLD_SESSIONID) {
f5799ae1 1019 p = buffer_ptr(&b);
1020 len = buffer_len(&b);
1021 if ((session_id2 == NULL) ||
1022 (len < session_id2_len) ||
1023 (memcmp(p, session_id2, session_id2_len) != 0))
1024 fail++;
700318f3 1025 buffer_consume(&b, session_id2_len);
1026 } else {
f5799ae1 1027 p = buffer_get_string(&b, &len);
1028 if ((session_id2 == NULL) ||
1029 (len != session_id2_len) ||
1030 (memcmp(p, session_id2, session_id2_len) != 0))
700318f3 1031 fail++;
f5799ae1 1032 xfree(p);
700318f3 1033 }
1034 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1035 fail++;
1036 p = buffer_get_string(&b, NULL);
1037 if (strcmp(authctxt->user, p) != 0) {
0fff78ff 1038 logit("wrong user name passed to monitor: expected %s != %.100s",
700318f3 1039 authctxt->user, p);
1040 fail++;
1041 }
1042 xfree(p);
1043 buffer_skip_string(&b);
1044 if (datafellows & SSH_BUG_PKAUTH) {
1045 if (!buffer_get_char(&b))
1046 fail++;
1047 } else {
1048 p = buffer_get_string(&b, NULL);
1049 if (strcmp("publickey", p) != 0)
1050 fail++;
1051 xfree(p);
1052 if (!buffer_get_char(&b))
1053 fail++;
1054 buffer_skip_string(&b);
1055 }
1056 buffer_skip_string(&b);
1057 if (buffer_len(&b) != 0)
1058 fail++;
1059 buffer_free(&b);
1060 return (fail == 0);
1061}
1062
1063static int
41b2f314 1064monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1065 char *chost)
700318f3 1066{
1067 Buffer b;
41b2f314 1068 char *p;
700318f3 1069 u_int len;
1070 int fail = 0;
700318f3 1071
1072 buffer_init(&b);
1073 buffer_append(&b, data, datalen);
1074
f5799ae1 1075 p = buffer_get_string(&b, &len);
1076 if ((session_id2 == NULL) ||
1077 (len != session_id2_len) ||
1078 (memcmp(p, session_id2, session_id2_len) != 0))
700318f3 1079 fail++;
f5799ae1 1080 xfree(p);
1081
700318f3 1082 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1083 fail++;
1084 p = buffer_get_string(&b, NULL);
1085 if (strcmp(authctxt->user, p) != 0) {
0fff78ff 1086 logit("wrong user name passed to monitor: expected %s != %.100s",
700318f3 1087 authctxt->user, p);
1088 fail++;
1089 }
1090 xfree(p);
1091 buffer_skip_string(&b); /* service */
1092 p = buffer_get_string(&b, NULL);
1093 if (strcmp(p, "hostbased") != 0)
1094 fail++;
1095 xfree(p);
1096 buffer_skip_string(&b); /* pkalg */
1097 buffer_skip_string(&b); /* pkblob */
1098
1099 /* verify client host, strip trailing dot if necessary */
1100 p = buffer_get_string(&b, NULL);
1101 if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1102 p[len - 1] = '\0';
1103 if (strcmp(p, chost) != 0)
1104 fail++;
1105 xfree(p);
1106
1107 /* verify client user */
1108 p = buffer_get_string(&b, NULL);
1109 if (strcmp(p, cuser) != 0)
1110 fail++;
1111 xfree(p);
1112
1113 if (buffer_len(&b) != 0)
1114 fail++;
1115 buffer_free(&b);
1116 return (fail == 0);
1117}
1118
1119int
1120mm_answer_keyverify(int socket, Buffer *m)
1121{
1122 Key *key;
1123 u_char *signature, *data, *blob;
1124 u_int signaturelen, datalen, bloblen;
1125 int verified = 0;
1126 int valid_data = 0;
1127
1128 blob = buffer_get_string(m, &bloblen);
1129 signature = buffer_get_string(m, &signaturelen);
1130 data = buffer_get_string(m, &datalen);
1131
1132 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1133 !monitor_allowed_key(blob, bloblen))
f5799ae1 1134 fatal("%s: bad key, not previously allowed", __func__);
700318f3 1135
1136 key = key_from_blob(blob, bloblen);
1137 if (key == NULL)
f5799ae1 1138 fatal("%s: bad public key blob", __func__);
700318f3 1139
1140 switch (key_blobtype) {
1141 case MM_USERKEY:
1142 valid_data = monitor_valid_userblob(data, datalen);
1143 break;
1144 case MM_HOSTKEY:
1145 valid_data = monitor_valid_hostbasedblob(data, datalen,
1146 hostbased_cuser, hostbased_chost);
1147 break;
1148 default:
1149 valid_data = 0;
1150 break;
1151 }
1152 if (!valid_data)
f5799ae1 1153 fatal("%s: bad signature data blob", __func__);
700318f3 1154
1155 verified = key_verify(key, signature, signaturelen, data, datalen);
1156 debug3("%s: key %p signature %s",
f5799ae1 1157 __func__, key, verified ? "verified" : "unverified");
700318f3 1158
1159 key_free(key);
1160 xfree(blob);
1161 xfree(signature);
1162 xfree(data);
1163
680cee3b 1164 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1165
700318f3 1166 monitor_reset_key_state();
1167
1168 buffer_clear(m);
1169 buffer_put_int(m, verified);
1170 mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m);
1171
700318f3 1172 return (verified);
1173}
1174
1175static void
1176mm_record_login(Session *s, struct passwd *pw)
1177{
1178 socklen_t fromlen;
1179 struct sockaddr_storage from;
1180
1181 /*
1182 * Get IP address of client. If the connection is not a socket, let
1183 * the address be 0.0.0.0.
1184 */
1185 memset(&from, 0, sizeof(from));
41b2f314 1186 fromlen = sizeof(from);
700318f3 1187 if (packet_connection_is_on_socket()) {
700318f3 1188 if (getpeername(packet_get_connection_in(),
1189 (struct sockaddr *) & from, &fromlen) < 0) {
1190 debug("getpeername: %.100s", strerror(errno));
cdd66111 1191 cleanup_exit(255);
700318f3 1192 }
1193 }
1194 /* Record that there was a login on that tty from the remote host. */
1195 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
0fff78ff 1196 get_remote_name_or_ip(utmp_len, options.use_dns),
41b2f314 1197 (struct sockaddr *)&from, fromlen);
700318f3 1198}
1199
1200static void
1201mm_session_close(Session *s)
1202{
0fff78ff 1203 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
700318f3 1204 if (s->ttyfd != -1) {
f5799ae1 1205 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
700318f3 1206 session_pty_cleanup2(s);
1207 }
1208 s->used = 0;
1209}
1210
1211int
1212mm_answer_pty(int socket, Buffer *m)
1213{
1214 extern struct monitor *pmonitor;
1215 Session *s;
1216 int res, fd0;
1217
f5799ae1 1218 debug3("%s entering", __func__);
700318f3 1219
1220 buffer_clear(m);
1221 s = session_new();
1222 if (s == NULL)
1223 goto error;
1224 s->authctxt = authctxt;
1225 s->pw = authctxt->pw;
1226 s->pid = pmonitor->m_pid;
1227 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1228 if (res == 0)
1229 goto error;
700318f3 1230 pty_setowner(authctxt->pw, s->tty);
1231
1232 buffer_put_int(m, 1);
1233 buffer_put_cstring(m, s->tty);
1234 mm_request_send(socket, MONITOR_ANS_PTY, m);
1235
1236 mm_send_fd(socket, s->ptyfd);
1237 mm_send_fd(socket, s->ttyfd);
1238
1239 /* We need to trick ttyslot */
1240 if (dup2(s->ttyfd, 0) == -1)
f5799ae1 1241 fatal("%s: dup2", __func__);
700318f3 1242
1243 mm_record_login(s, authctxt->pw);
1244
1245 /* Now we can close the file descriptor again */
1246 close(0);
1247
1248 /* make sure nothing uses fd 0 */
1249 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
f5799ae1 1250 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
700318f3 1251 if (fd0 != 0)
f5799ae1 1252 error("%s: fd0 %d != 0", __func__, fd0);
700318f3 1253
1254 /* slave is not needed */
1255 close(s->ttyfd);
1256 s->ttyfd = s->ptyfd;
1257 /* no need to dup() because nobody closes ptyfd */
1258 s->ptymaster = s->ptyfd;
1259
f5799ae1 1260 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
700318f3 1261
1262 return (0);
1263
1264 error:
1265 if (s != NULL)
1266 mm_session_close(s);
1267 buffer_put_int(m, 0);
1268 mm_request_send(socket, MONITOR_ANS_PTY, m);
1269 return (0);
1270}
1271
1272int
1273mm_answer_pty_cleanup(int socket, Buffer *m)
1274{
1275 Session *s;
1276 char *tty;
1277
f5799ae1 1278 debug3("%s entering", __func__);
700318f3 1279
1280 tty = buffer_get_string(m, NULL);
1281 if ((s = session_by_tty(tty)) != NULL)
1282 mm_session_close(s);
1283 buffer_clear(m);
1284 xfree(tty);
1285 return (0);
1286}
1287
1288int
1289mm_answer_sesskey(int socket, Buffer *m)
1290{
1291 BIGNUM *p;
1292 int rsafail;
1293
1294 /* Turn off permissions */
1295 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
1296
1297 if ((p = BN_new()) == NULL)
f5799ae1 1298 fatal("%s: BN_new", __func__);
700318f3 1299
1300 buffer_get_bignum2(m, p);
1301
1302 rsafail = ssh1_session_key(p);
1303
1304 buffer_clear(m);
1305 buffer_put_int(m, rsafail);
1306 buffer_put_bignum2(m, p);
1307
1308 BN_clear_free(p);
1309
1310 mm_request_send(socket, MONITOR_ANS_SESSKEY, m);
1311
1312 /* Turn on permissions for sessid passing */
1313 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1314
1315 return (0);
1316}
1317
1318int
1319mm_answer_sessid(int socket, Buffer *m)
1320{
1321 int i;
1322
f5799ae1 1323 debug3("%s entering", __func__);
700318f3 1324
1325 if (buffer_len(m) != 16)
f5799ae1 1326 fatal("%s: bad ssh1 session id", __func__);
700318f3 1327 for (i = 0; i < 16; i++)
1328 session_id[i] = buffer_get_char(m);
1329
1330 /* Turn on permissions for getpwnam */
1331 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1332
1333 return (0);
1334}
1335
1336int
1337mm_answer_rsa_keyallowed(int socket, Buffer *m)
1338{
1339 BIGNUM *client_n;
1340 Key *key = NULL;
1341 u_char *blob = NULL;
1342 u_int blen = 0;
1343 int allowed = 0;
1344
f5799ae1 1345 debug3("%s entering", __func__);
700318f3 1346
f5799ae1 1347 if (options.rsa_authentication && authctxt->valid) {
700318f3 1348 if ((client_n = BN_new()) == NULL)
f5799ae1 1349 fatal("%s: BN_new", __func__);
700318f3 1350 buffer_get_bignum2(m, client_n);
1351 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1352 BN_clear_free(client_n);
1353 }
1354 buffer_clear(m);
1355 buffer_put_int(m, allowed);
6a9b3198 1356 buffer_put_int(m, forced_command != NULL);
700318f3 1357
1358 /* clear temporarily storage (used by generate challenge) */
1359 monitor_reset_key_state();
1360
1361 if (allowed && key != NULL) {
1362 key->type = KEY_RSA; /* cheat for key_to_blob */
1363 if (key_to_blob(key, &blob, &blen) == 0)
f5799ae1 1364 fatal("%s: key_to_blob failed", __func__);
700318f3 1365 buffer_put_string(m, blob, blen);
1366
1367 /* Save temporarily for comparison in verify */
1368 key_blob = blob;
1369 key_bloblen = blen;
1370 key_blobtype = MM_RSAUSERKEY;
700318f3 1371 }
6a9b3198 1372 if (key != NULL)
1373 key_free(key);
700318f3 1374
1375 mm_append_debug(m);
1376
1377 mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m);
1378
1379 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1380 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1381 return (0);
1382}
1383
1384int
1385mm_answer_rsa_challenge(int socket, Buffer *m)
1386{
1387 Key *key = NULL;
1388 u_char *blob;
1389 u_int blen;
1390
f5799ae1 1391 debug3("%s entering", __func__);
700318f3 1392
1393 if (!authctxt->valid)
f5799ae1 1394 fatal("%s: authctxt not valid", __func__);
700318f3 1395 blob = buffer_get_string(m, &blen);
1396 if (!monitor_allowed_key(blob, blen))
f5799ae1 1397 fatal("%s: bad key, not previously allowed", __func__);
700318f3 1398 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
f5799ae1 1399 fatal("%s: key type mismatch", __func__);
700318f3 1400 if ((key = key_from_blob(blob, blen)) == NULL)
f5799ae1 1401 fatal("%s: received bad key", __func__);
700318f3 1402
1403 if (ssh1_challenge)
1404 BN_clear_free(ssh1_challenge);
1405 ssh1_challenge = auth_rsa_generate_challenge(key);
1406
1407 buffer_clear(m);
1408 buffer_put_bignum2(m, ssh1_challenge);
1409
f5799ae1 1410 debug3("%s sending reply", __func__);
700318f3 1411 mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m);
1412
1413 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
6a9b3198 1414
1415 xfree(blob);
1416 key_free(key);
700318f3 1417 return (0);
1418}
1419
1420int
1421mm_answer_rsa_response(int socket, Buffer *m)
1422{
1423 Key *key = NULL;
1424 u_char *blob, *response;
1425 u_int blen, len;
1426 int success;
1427
f5799ae1 1428 debug3("%s entering", __func__);
700318f3 1429
1430 if (!authctxt->valid)
f5799ae1 1431 fatal("%s: authctxt not valid", __func__);
700318f3 1432 if (ssh1_challenge == NULL)
f5799ae1 1433 fatal("%s: no ssh1_challenge", __func__);
700318f3 1434
1435 blob = buffer_get_string(m, &blen);
1436 if (!monitor_allowed_key(blob, blen))
f5799ae1 1437 fatal("%s: bad key, not previously allowed", __func__);
700318f3 1438 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
f5799ae1 1439 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
700318f3 1440 if ((key = key_from_blob(blob, blen)) == NULL)
f5799ae1 1441 fatal("%s: received bad key", __func__);
700318f3 1442 response = buffer_get_string(m, &len);
1443 if (len != 16)
f5799ae1 1444 fatal("%s: received bad response to challenge", __func__);
700318f3 1445 success = auth_rsa_verify_response(key, ssh1_challenge, response);
1446
6a9b3198 1447 xfree(blob);
700318f3 1448 key_free(key);
1449 xfree(response);
1450
1451 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1452
1453 /* reset state */
1454 BN_clear_free(ssh1_challenge);
1455 ssh1_challenge = NULL;
1456 monitor_reset_key_state();
1457
1458 buffer_clear(m);
1459 buffer_put_int(m, success);
1460 mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m);
1461
1462 return (success);
1463}
1464
1465int
1466mm_answer_term(int socket, Buffer *req)
1467{
1468 extern struct monitor *pmonitor;
1469 int res, status;
1470
f5799ae1 1471 debug3("%s: tearing down sessions", __func__);
700318f3 1472
1473 /* The child is terminating */
1474 session_destroy_all(&mm_session_close);
1475
1476 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1477 if (errno != EINTR)
1478 exit(1);
1479
1480 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1481
1482 /* Terminate process */
1483 exit (res);
1484}
1485
1486void
1487monitor_apply_keystate(struct monitor *pmonitor)
1488{
1489 if (compat20) {
1490 set_newkeys(MODE_IN);
1491 set_newkeys(MODE_OUT);
1492 } else {
700318f3 1493 packet_set_protocol_flags(child_state.ssh1protoflags);
f5799ae1 1494 packet_set_encryption_key(child_state.ssh1key,
1495 child_state.ssh1keylen, child_state.ssh1cipher);
1496 xfree(child_state.ssh1key);
700318f3 1497 }
1498
f5799ae1 1499 /* for rc4 and other stateful ciphers */
700318f3 1500 packet_set_keycontext(MODE_OUT, child_state.keyout);
1501 xfree(child_state.keyout);
1502 packet_set_keycontext(MODE_IN, child_state.keyin);
1503 xfree(child_state.keyin);
1504
1505 if (!compat20) {
1506 packet_set_iv(MODE_OUT, child_state.ivout);
1507 xfree(child_state.ivout);
1508 packet_set_iv(MODE_IN, child_state.ivin);
1509 xfree(child_state.ivin);
1510 }
1511
1512 memcpy(&incoming_stream, &child_state.incoming,
1513 sizeof(incoming_stream));
1514 memcpy(&outgoing_stream, &child_state.outgoing,
1515 sizeof(outgoing_stream));
1516
1517 /* Update with new address */
f5799ae1 1518 if (options.compression)
1519 mm_init_compression(pmonitor->m_zlib);
700318f3 1520
1521 /* Network I/O buffers */
1522 /* XXX inefficient for large buffers, need: buffer_init_from_string */
1523 buffer_clear(&input);
1524 buffer_append(&input, child_state.input, child_state.ilen);
1525 memset(child_state.input, 0, child_state.ilen);
1526 xfree(child_state.input);
1527
1528 buffer_clear(&output);
1529 buffer_append(&output, child_state.output, child_state.olen);
1530 memset(child_state.output, 0, child_state.olen);
1531 xfree(child_state.output);
1532}
1533
1534static Kex *
1535mm_get_kex(Buffer *m)
1536{
1537 Kex *kex;
1538 void *blob;
1539 u_int bloblen;
1540
1541 kex = xmalloc(sizeof(*kex));
1542 memset(kex, 0, sizeof(*kex));
1543 kex->session_id = buffer_get_string(m, &kex->session_id_len);
f5799ae1 1544 if ((session_id2 == NULL) ||
1545 (kex->session_id_len != session_id2_len) ||
1546 (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1547 fatal("mm_get_get: internal error: bad session id");
700318f3 1548 kex->we_need = buffer_get_int(m);
6a9b3198 1549 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1550 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
700318f3 1551 kex->server = 1;
1552 kex->hostkey_type = buffer_get_int(m);
1553 kex->kex_type = buffer_get_int(m);
1554 blob = buffer_get_string(m, &bloblen);
1555 buffer_init(&kex->my);
1556 buffer_append(&kex->my, blob, bloblen);
1557 xfree(blob);
1558 blob = buffer_get_string(m, &bloblen);
1559 buffer_init(&kex->peer);
1560 buffer_append(&kex->peer, blob, bloblen);
1561 xfree(blob);
1562 kex->done = 1;
1563 kex->flags = buffer_get_int(m);
1564 kex->client_version_string = buffer_get_string(m, NULL);
1565 kex->server_version_string = buffer_get_string(m, NULL);
1566 kex->load_host_key=&get_hostkey_by_type;
1567 kex->host_key_index=&get_hostkey_index;
1568
1569 return (kex);
1570}
1571
1572/* This function requries careful sanity checking */
1573
1574void
1575mm_get_keystate(struct monitor *pmonitor)
1576{
1577 Buffer m;
1578 u_char *blob, *p;
1579 u_int bloblen, plen;
0fff78ff 1580 u_int32_t seqnr, packets;
1581 u_int64_t blocks;
700318f3 1582
f5799ae1 1583 debug3("%s: Waiting for new keys", __func__);
700318f3 1584
1585 buffer_init(&m);
1586 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1587 if (!compat20) {
1588 child_state.ssh1protoflags = buffer_get_int(&m);
1589 child_state.ssh1cipher = buffer_get_int(&m);
f5799ae1 1590 child_state.ssh1key = buffer_get_string(&m,
1591 &child_state.ssh1keylen);
700318f3 1592 child_state.ivout = buffer_get_string(&m,
1593 &child_state.ivoutlen);
1594 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1595 goto skip;
1596 } else {
1597 /* Get the Kex for rekeying */
1598 *pmonitor->m_pkex = mm_get_kex(&m);
1599 }
1600
1601 blob = buffer_get_string(&m, &bloblen);
1602 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1603 xfree(blob);
1604
f5799ae1 1605 debug3("%s: Waiting for second key", __func__);
700318f3 1606 blob = buffer_get_string(&m, &bloblen);
1607 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1608 xfree(blob);
1609
1610 /* Now get sequence numbers for the packets */
0fff78ff 1611 seqnr = buffer_get_int(&m);
1612 blocks = buffer_get_int64(&m);
1613 packets = buffer_get_int(&m);
1614 packet_set_state(MODE_OUT, seqnr, blocks, packets);
1615 seqnr = buffer_get_int(&m);
1616 blocks = buffer_get_int64(&m);
1617 packets = buffer_get_int(&m);
1618 packet_set_state(MODE_IN, seqnr, blocks, packets);
700318f3 1619
1620 skip:
1621 /* Get the key context */
1622 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1623 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1624
f5799ae1 1625 debug3("%s: Getting compression state", __func__);
700318f3 1626 /* Get compression state */
1627 p = buffer_get_string(&m, &plen);
1628 if (plen != sizeof(child_state.outgoing))
f5799ae1 1629 fatal("%s: bad request size", __func__);
700318f3 1630 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1631 xfree(p);
1632
1633 p = buffer_get_string(&m, &plen);
1634 if (plen != sizeof(child_state.incoming))
f5799ae1 1635 fatal("%s: bad request size", __func__);
700318f3 1636 memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1637 xfree(p);
1638
1639 /* Network I/O buffers */
f5799ae1 1640 debug3("%s: Getting Network I/O buffers", __func__);
700318f3 1641 child_state.input = buffer_get_string(&m, &child_state.ilen);
1642 child_state.output = buffer_get_string(&m, &child_state.olen);
1643
1644 buffer_free(&m);
1645}
1646
1647
1648/* Allocation functions for zlib */
1649void *
1650mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1651{
6a9b3198 1652 size_t len = (size_t) size * ncount;
700318f3 1653 void *address;
1654
41b2f314 1655 if (len == 0 || ncount > SIZE_T_MAX / size)
680cee3b 1656 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1657
1658 address = mm_malloc(mm, len);
700318f3 1659
1660 return (address);
1661}
1662
1663void
1664mm_zfree(struct mm_master *mm, void *address)
1665{
1666 mm_free(mm, address);
1667}
1668
1669void
1670mm_init_compression(struct mm_master *mm)
1671{
1672 outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1673 outgoing_stream.zfree = (free_func)mm_zfree;
1674 outgoing_stream.opaque = mm;
1675
1676 incoming_stream.zalloc = (alloc_func)mm_zalloc;
1677 incoming_stream.zfree = (free_func)mm_zfree;
1678 incoming_stream.opaque = mm;
1679}
1680
1681/* XXX */
1682
1683#define FD_CLOSEONEXEC(x) do { \
1684 if (fcntl(x, F_SETFD, 1) == -1) \
1685 fatal("fcntl(%d, F_SETFD)", x); \
1686} while (0)
1687
1688static void
1689monitor_socketpair(int *pair)
1690{
1691#ifdef HAVE_SOCKETPAIR
1692 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
f5799ae1 1693 fatal("%s: socketpair", __func__);
700318f3 1694#else
1695 fatal("%s: UsePrivilegeSeparation=yes not supported",
f5799ae1 1696 __func__);
700318f3 1697#endif
1698 FD_CLOSEONEXEC(pair[0]);
1699 FD_CLOSEONEXEC(pair[1]);
1700}
1701
1702#define MM_MEMSIZE 65536
1703
1704struct monitor *
1705monitor_init(void)
1706{
1707 struct monitor *mon;
1708 int pair[2];
1709
1710 mon = xmalloc(sizeof(*mon));
1711
cdd66111 1712 mon->m_pid = 0;
700318f3 1713 monitor_socketpair(pair);
1714
1715 mon->m_recvfd = pair[0];
1716 mon->m_sendfd = pair[1];
1717
1718 /* Used to share zlib space across processes */
f5799ae1 1719 if (options.compression) {
1720 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1721 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
700318f3 1722
f5799ae1 1723 /* Compression needs to share state across borders */
1724 mm_init_compression(mon->m_zlib);
1725 }
700318f3 1726
1727 return mon;
1728}
1729
1730void
1731monitor_reinit(struct monitor *mon)
1732{
1733 int pair[2];
1734
1735 monitor_socketpair(pair);
1736
1737 mon->m_recvfd = pair[0];
1738 mon->m_sendfd = pair[1];
1739}
0fff78ff 1740
1741#ifdef GSSAPI
1742int
1743mm_answer_gss_setup_ctx(int socket, Buffer *m)
1744{
1745 gss_OID_desc oid;
1746 OM_uint32 major;
1747 u_int len;
1748
1749 oid.elements = buffer_get_string(m, &len);
1750 oid.length = len;
1751
1752 major = ssh_gssapi_server_ctx(&gsscontext, &oid);
1753
1754 xfree(oid.elements);
1755
1756 buffer_clear(m);
1757 buffer_put_int(m, major);
1758
1759 mm_request_send(socket,MONITOR_ANS_GSSSETUP, m);
1760
1761 /* Now we have a context, enable the step */
1762 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1763
1764 return (0);
1765}
1766
1767int
1768mm_answer_gss_accept_ctx(int socket, Buffer *m)
1769{
1770 gss_buffer_desc in;
1771 gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1772 OM_uint32 major,minor;
1773 OM_uint32 flags = 0; /* GSI needs this */
1774 u_int len;
1775
1776 in.value = buffer_get_string(m, &len);
1777 in.length = len;
1778 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1779 xfree(in.value);
1780
1781 buffer_clear(m);
1782 buffer_put_int(m, major);
1783 buffer_put_string(m, out.value, out.length);
1784 buffer_put_int(m, flags);
1785 mm_request_send(socket, MONITOR_ANS_GSSSTEP, m);
1786
1787 gss_release_buffer(&minor, &out);
1788
0fff78ff 1789 if (major==GSS_S_COMPLETE) {
1790 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1791 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
cdd66111 1792 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
0fff78ff 1793 }
1794 return (0);
1795}
1796
cdd66111 1797int
1798mm_answer_gss_checkmic(int socket, Buffer *m)
1799{
1800 gss_buffer_desc gssbuf, mic;
1801 OM_uint32 ret;
1802 u_int len;
1803
1804 gssbuf.value = buffer_get_string(m, &len);
1805 gssbuf.length = len;
1806 mic.value = buffer_get_string(m, &len);
1807 mic.length = len;
1808
1809 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1810
1811 xfree(gssbuf.value);
1812 xfree(mic.value);
1813
1814 buffer_clear(m);
1815 buffer_put_int(m, ret);
1816
1817 mm_request_send(socket, MONITOR_ANS_GSSCHECKMIC, m);
1818
1819 if (!GSS_ERROR(ret))
1820 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1821
1822 return (0);
1823}
1824
0fff78ff 1825int
1826mm_answer_gss_userok(int socket, Buffer *m)
1827{
1828 int authenticated;
1829
1830 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1831
1832 buffer_clear(m);
1833 buffer_put_int(m, authenticated);
1834
1835 debug3("%s: sending result %d", __func__, authenticated);
1836 mm_request_send(socket, MONITOR_ANS_GSSUSEROK, m);
1837
cdd66111 1838 auth_method="gssapi-with-mic";
0fff78ff 1839
1840 /* Monitor loop will terminate if authenticated */
1841 return (authenticated);
1842}
1843#endif /* GSSAPI */
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