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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"
6a9b3198 28RCSID("$OpenBSD: monitor.c,v 1.36 2003/04/01 10:22:21 markus 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"
40#include "zlib.h"
41#include "packet.h"
42#include "auth-options.h"
43#include "sshpty.h"
44#include "channels.h"
45#include "session.h"
46#include "sshlogin.h"
47#include "canohost.h"
48#include "log.h"
49#include "servconf.h"
50#include "monitor.h"
51#include "monitor_mm.h"
52#include "monitor_wrap.h"
53#include "monitor_fdpass.h"
54#include "xmalloc.h"
55#include "misc.h"
56#include "buffer.h"
57#include "bufaux.h"
58#include "compat.h"
59#include "ssh2.h"
60#include "mpaux.h"
61
c0fc5818 62#ifdef GSSAPI
63#include "ssh-gss.h"
64static Gssctxt *gsscontext = NULL;
65#endif
66
700318f3 67/* Imports */
68extern ServerOptions options;
69extern u_int utmp_len;
70extern Newkeys *current_keys[];
71extern z_stream incoming_stream;
72extern z_stream outgoing_stream;
73extern u_char session_id[];
74extern Buffer input, output;
75extern Buffer auth_debug;
76extern int auth_debug_init;
77
78/* State exported from the child */
79
80struct {
81 z_stream incoming;
82 z_stream outgoing;
83 u_char *keyin;
84 u_int keyinlen;
85 u_char *keyout;
86 u_int keyoutlen;
87 u_char *ivin;
88 u_int ivinlen;
89 u_char *ivout;
90 u_int ivoutlen;
f5799ae1 91 u_char *ssh1key;
92 u_int ssh1keylen;
700318f3 93 int ssh1cipher;
94 int ssh1protoflags;
95 u_char *input;
96 u_int ilen;
97 u_char *output;
98 u_int olen;
99} child_state;
100
101/* Functions on the montior that answer unprivileged requests */
102
103int mm_answer_moduli(int, Buffer *);
104int mm_answer_sign(int, Buffer *);
105int mm_answer_pwnamallow(int, Buffer *);
106int mm_answer_auth2_read_banner(int, Buffer *);
107int mm_answer_authserv(int, Buffer *);
108int mm_answer_authpassword(int, Buffer *);
109int mm_answer_bsdauthquery(int, Buffer *);
110int mm_answer_bsdauthrespond(int, Buffer *);
111int mm_answer_skeyquery(int, Buffer *);
112int mm_answer_skeyrespond(int, Buffer *);
113int mm_answer_keyallowed(int, Buffer *);
114int mm_answer_keyverify(int, Buffer *);
115int mm_answer_pty(int, Buffer *);
116int mm_answer_pty_cleanup(int, Buffer *);
117int mm_answer_term(int, Buffer *);
118int mm_answer_rsa_keyallowed(int, Buffer *);
119int mm_answer_rsa_challenge(int, Buffer *);
120int mm_answer_rsa_response(int, Buffer *);
121int mm_answer_sesskey(int, Buffer *);
122int mm_answer_sessid(int, Buffer *);
123
124#ifdef USE_PAM
125int mm_answer_pam_start(int, Buffer *);
126#endif
127
41b2f314 128#ifdef KRB4
129int mm_answer_krb4(int, Buffer *);
130#endif
131#ifdef KRB5
132int mm_answer_krb5(int, Buffer *);
133#endif
134
c0fc5818 135#ifdef GSSAPI
136int mm_answer_gss_setup_ctx(int, Buffer *);
137int mm_answer_gss_accept_ctx(int, Buffer *);
138int mm_answer_gss_userok(int, Buffer *);
139int mm_answer_gss_sign(int, Buffer *);
140int mm_answer_gss_error(int, Buffer *);
141int mm_answer_gss_indicate_mechs(int, Buffer *);
142int mm_answer_gss_localname(int, Buffer *);
143#endif
144
700318f3 145static Authctxt *authctxt;
146static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
147
148/* local state for key verify */
149static u_char *key_blob = NULL;
150static u_int key_bloblen = 0;
151static int key_blobtype = MM_NOKEY;
41b2f314 152static char *hostbased_cuser = NULL;
153static char *hostbased_chost = NULL;
700318f3 154static char *auth_method = "unknown";
f5799ae1 155static int session_id2_len = 0;
156static u_char *session_id2 = NULL;
700318f3 157
158struct mon_table {
159 enum monitor_reqtype type;
160 int flags;
161 int (*f)(int, Buffer *);
162};
163
164#define MON_ISAUTH 0x0004 /* Required for Authentication */
165#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
166#define MON_ONCE 0x0010 /* Disable after calling */
167
168#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
169
170#define MON_PERMIT 0x1000 /* Request is permitted */
171
172struct mon_table mon_dispatch_proto20[] = {
173 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
174 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
175 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
176 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
177 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
178 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
179#ifdef USE_PAM
180 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
181#endif
182#ifdef BSD_AUTH
183 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
184 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
185#endif
186#ifdef SKEY
187 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
188 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
c0fc5818 189#endif
190#ifdef GSSAPI
191 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
192 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
193 {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign},
194 {MONITOR_REQ_GSSERR, MON_ISAUTH | MON_ONCE, mm_answer_gss_error},
195 {MONITOR_REQ_GSSMECHS, MON_ISAUTH, mm_answer_gss_indicate_mechs},
196 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
197/* Turn this off until we use it */
198#if 0
199 {MONITOR_REQ_GSSLOCALNAME, MON_ISAUTH, mm_answer_gss_localname},
200#endif
700318f3 201#endif
202 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
203 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
204 {0, 0, NULL}
205};
206
207struct mon_table mon_dispatch_postauth20[] = {
c0fc5818 208#ifdef GSSAPI
209 {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx},
210 {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
211 {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign},
212 {MONITOR_REQ_GSSERR, 0, mm_answer_gss_error},
213 {MONITOR_REQ_GSSMECHS, 0, mm_answer_gss_indicate_mechs},
214#endif
700318f3 215 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
216 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
217 {MONITOR_REQ_PTY, 0, mm_answer_pty},
218 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
219 {MONITOR_REQ_TERM, 0, mm_answer_term},
220 {0, 0, NULL}
221};
222
223struct mon_table mon_dispatch_proto15[] = {
224 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
225 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
226 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
227 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
228 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
229 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
230 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
231 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
700318f3 232#ifdef BSD_AUTH
233 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
234 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
235#endif
236#ifdef SKEY
237 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
238 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
239#endif
240#ifdef USE_PAM
241 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
41b2f314 242#endif
243#ifdef KRB4
244 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4},
245#endif
246#ifdef KRB5
247 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5},
700318f3 248#endif
249 {0, 0, NULL}
250};
251
252struct mon_table mon_dispatch_postauth15[] = {
253 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
254 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
255 {MONITOR_REQ_TERM, 0, mm_answer_term},
256 {0, 0, NULL}
257};
258
259struct mon_table *mon_dispatch;
260
261/* Specifies if a certain message is allowed at the moment */
262
263static void
264monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
265{
266 while (ent->f != NULL) {
267 if (ent->type == type) {
268 ent->flags &= ~MON_PERMIT;
269 ent->flags |= permit ? MON_PERMIT : 0;
270 return;
271 }
272 ent++;
273 }
274}
275
276static void
277monitor_permit_authentications(int permit)
278{
279 struct mon_table *ent = mon_dispatch;
280
281 while (ent->f != NULL) {
282 if (ent->flags & MON_AUTH) {
283 ent->flags &= ~MON_PERMIT;
284 ent->flags |= permit ? MON_PERMIT : 0;
285 }
286 ent++;
287 }
288}
289
290Authctxt *
291monitor_child_preauth(struct monitor *pmonitor)
292{
293 struct mon_table *ent;
294 int authenticated = 0;
295
296 debug3("preauth child monitor started");
297
298 if (compat20) {
299 mon_dispatch = mon_dispatch_proto20;
300
301 /* Permit requests for moduli and signatures */
302 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
303 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
c0fc5818 304#ifdef GSSAPI
305 /* and for the GSSAPI key exchange */
306 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
307 monitor_permit(mon_dispatch, MONITOR_REQ_GSSERR, 1);
308 monitor_permit(mon_dispatch, MONITOR_REQ_GSSMECHS, 1);
309#endif
700318f3 310 } else {
311 mon_dispatch = mon_dispatch_proto15;
312
313 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
314 }
315
316 authctxt = authctxt_new();
317
318 /* The first few requests do not require asynchronous access */
319 while (!authenticated) {
320 authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
321 if (authenticated) {
322 if (!(ent->flags & MON_AUTHDECIDE))
323 fatal("%s: unexpected authentication from %d",
f5799ae1 324 __func__, ent->type);
700318f3 325 if (authctxt->pw->pw_uid == 0 &&
326 !auth_root_allowed(auth_method))
327 authenticated = 0;
328#ifdef USE_PAM
329 if (!do_pam_account(authctxt->pw->pw_name, NULL))
330 authenticated = 0;
331#endif
332 }
333
334 if (ent->flags & MON_AUTHDECIDE) {
335 auth_log(authctxt, authenticated, auth_method,
336 compat20 ? " ssh2" : "");
337 if (!authenticated)
338 authctxt->failures++;
339 }
340 }
341
342 if (!authctxt->valid)
f5799ae1 343 fatal("%s: authenticated invalid user", __func__);
700318f3 344
345 debug("%s: %s has been authenticated by privileged process",
f5799ae1 346 __func__, authctxt->user);
700318f3 347
348 mm_get_keystate(pmonitor);
349
350 return (authctxt);
351}
352
353void
354monitor_child_postauth(struct monitor *pmonitor)
355{
356 if (compat20) {
357 mon_dispatch = mon_dispatch_postauth20;
358
359 /* Permit requests for moduli and signatures */
360 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
361 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
362 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
363
c0fc5818 364#ifdef GSSAPI
365 /* and for the GSSAPI key exchange */
366 monitor_permit(mon_dispatch, MONITOR_REQ_GSSMECHS,1);
367 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP,1);
368 monitor_permit(mon_dispatch, MONITOR_REQ_GSSERR,1);
369#endif
370
700318f3 371 } else {
372 mon_dispatch = mon_dispatch_postauth15;
373 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
374 }
375 if (!no_pty_flag) {
376 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
377 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
378 }
379
380 for (;;)
381 monitor_read(pmonitor, mon_dispatch, NULL);
382}
383
384void
385monitor_sync(struct monitor *pmonitor)
386{
f5799ae1 387 if (options.compression) {
388 /* The member allocation is not visible, so sync it */
389 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
390 }
700318f3 391}
392
393int
394monitor_read(struct monitor *pmonitor, struct mon_table *ent,
395 struct mon_table **pent)
396{
397 Buffer m;
398 int ret;
399 u_char type;
400
401 buffer_init(&m);
402
403 mm_request_receive(pmonitor->m_sendfd, &m);
404 type = buffer_get_char(&m);
405
f5799ae1 406 debug3("%s: checking request %d", __func__, type);
700318f3 407
408 while (ent->f != NULL) {
409 if (ent->type == type)
410 break;
411 ent++;
412 }
413
414 if (ent->f != NULL) {
415 if (!(ent->flags & MON_PERMIT))
f5799ae1 416 fatal("%s: unpermitted request %d", __func__,
700318f3 417 type);
418 ret = (*ent->f)(pmonitor->m_sendfd, &m);
419 buffer_free(&m);
420
421 /* The child may use this request only once, disable it */
422 if (ent->flags & MON_ONCE) {
f5799ae1 423 debug2("%s: %d used once, disabling now", __func__,
700318f3 424 type);
425 ent->flags &= ~MON_PERMIT;
426 }
427
428 if (pent != NULL)
429 *pent = ent;
430
431 return ret;
432 }
433
f5799ae1 434 fatal("%s: unsupported request: %d", __func__, type);
700318f3 435
436 /* NOTREACHED */
437 return (-1);
438}
439
440/* allowed key state */
441static int
442monitor_allowed_key(u_char *blob, u_int bloblen)
443{
444 /* make sure key is allowed */
445 if (key_blob == NULL || key_bloblen != bloblen ||
446 memcmp(key_blob, blob, key_bloblen))
447 return (0);
448 return (1);
449}
450
451static void
452monitor_reset_key_state(void)
453{
454 /* reset state */
455 if (key_blob != NULL)
456 xfree(key_blob);
457 if (hostbased_cuser != NULL)
458 xfree(hostbased_cuser);
459 if (hostbased_chost != NULL)
460 xfree(hostbased_chost);
461 key_blob = NULL;
462 key_bloblen = 0;
463 key_blobtype = MM_NOKEY;
464 hostbased_cuser = NULL;
465 hostbased_chost = NULL;
466}
467
468int
469mm_answer_moduli(int socket, Buffer *m)
470{
471 DH *dh;
472 int min, want, max;
473
474 min = buffer_get_int(m);
475 want = buffer_get_int(m);
476 max = buffer_get_int(m);
477
478 debug3("%s: got parameters: %d %d %d",
f5799ae1 479 __func__, min, want, max);
700318f3 480 /* We need to check here, too, in case the child got corrupted */
481 if (max < min || want < min || max < want)
482 fatal("%s: bad parameters: %d %d %d",
f5799ae1 483 __func__, min, want, max);
700318f3 484
485 buffer_clear(m);
486
487 dh = choose_dh(min, want, max);
488 if (dh == NULL) {
489 buffer_put_char(m, 0);
490 return (0);
491 } else {
492 /* Send first bignum */
493 buffer_put_char(m, 1);
494 buffer_put_bignum2(m, dh->p);
495 buffer_put_bignum2(m, dh->g);
496
497 DH_free(dh);
498 }
499 mm_request_send(socket, MONITOR_ANS_MODULI, m);
500 return (0);
501}
502
503int
504mm_answer_sign(int socket, Buffer *m)
505{
506 Key *key;
507 u_char *p;
508 u_char *signature;
509 u_int siglen, datlen;
510 int keyid;
511
f5799ae1 512 debug3("%s", __func__);
700318f3 513
514 keyid = buffer_get_int(m);
515 p = buffer_get_string(m, &datlen);
516
517 if (datlen != 20)
41b2f314 518 fatal("%s: data length incorrect: %u", __func__, datlen);
f5799ae1 519
520 /* save session id, it will be passed on the first call */
521 if (session_id2_len == 0) {
522 session_id2_len = datlen;
523 session_id2 = xmalloc(session_id2_len);
524 memcpy(session_id2, p, session_id2_len);
525 }
700318f3 526
527 if ((key = get_hostkey_by_index(keyid)) == NULL)
f5799ae1 528 fatal("%s: no hostkey from index %d", __func__, keyid);
700318f3 529 if (key_sign(key, &signature, &siglen, p, datlen) < 0)
f5799ae1 530 fatal("%s: key_sign failed", __func__);
700318f3 531
41b2f314 532 debug3("%s: signature %p(%u)", __func__, signature, siglen);
700318f3 533
534 buffer_clear(m);
535 buffer_put_string(m, signature, siglen);
536
537 xfree(p);
538 xfree(signature);
539
540 mm_request_send(socket, MONITOR_ANS_SIGN, m);
541
542 /* Turn on permissions for getpwnam */
543 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
544
545 return (0);
546}
547
548/* Retrieves the password entry and also checks if the user is permitted */
549
550int
551mm_answer_pwnamallow(int socket, Buffer *m)
552{
553 char *login;
554 struct passwd *pwent;
555 int allowed = 0;
556
f5799ae1 557 debug3("%s", __func__);
700318f3 558
559 if (authctxt->attempt++ != 0)
f5799ae1 560 fatal("%s: multiple attempts for getpwnam", __func__);
700318f3 561
562 login = buffer_get_string(m, NULL);
563
564 pwent = getpwnamallow(login);
565
566 authctxt->user = xstrdup(login);
567 setproctitle("%s [priv]", pwent ? login : "unknown");
568 xfree(login);
569
570 buffer_clear(m);
571
572 if (pwent == NULL) {
573 buffer_put_char(m, 0);
574 goto out;
575 }
576
577 allowed = 1;
578 authctxt->pw = pwent;
579 authctxt->valid = 1;
580
581 buffer_put_char(m, 1);
582 buffer_put_string(m, pwent, sizeof(struct passwd));
583 buffer_put_cstring(m, pwent->pw_name);
584 buffer_put_cstring(m, "*");
585 buffer_put_cstring(m, pwent->pw_gecos);
586#ifdef HAVE_PW_CLASS_IN_PASSWD
587 buffer_put_cstring(m, pwent->pw_class);
588#endif
589 buffer_put_cstring(m, pwent->pw_dir);
590 buffer_put_cstring(m, pwent->pw_shell);
591
592 out:
f5799ae1 593 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
700318f3 594 mm_request_send(socket, MONITOR_ANS_PWNAM, m);
595
596 /* For SSHv1 allow authentication now */
597 if (!compat20)
598 monitor_permit_authentications(1);
599 else {
600 /* Allow service/style information on the auth context */
601 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
602 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
603 }
604
605#ifdef USE_PAM
606 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
607#endif
608
609 return (0);
610}
611
612int mm_answer_auth2_read_banner(int socket, Buffer *m)
613{
614 char *banner;
615
616 buffer_clear(m);
617 banner = auth2_read_banner();
618 buffer_put_cstring(m, banner != NULL ? banner : "");
619 mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m);
620
621 if (banner != NULL)
41b2f314 622 xfree(banner);
700318f3 623
624 return (0);
625}
626
627int
628mm_answer_authserv(int socket, Buffer *m)
629{
630 monitor_permit_authentications(1);
631
632 authctxt->service = buffer_get_string(m, NULL);
633 authctxt->style = buffer_get_string(m, NULL);
634 debug3("%s: service=%s, style=%s",
f5799ae1 635 __func__, authctxt->service, authctxt->style);
700318f3 636
637 if (strlen(authctxt->style) == 0) {
638 xfree(authctxt->style);
639 authctxt->style = NULL;
640 }
641
642 return (0);
643}
644
645int
646mm_answer_authpassword(int socket, Buffer *m)
647{
648 static int call_count;
649 char *passwd;
41b2f314 650 int authenticated;
651 u_int plen;
700318f3 652
653 passwd = buffer_get_string(m, &plen);
654 /* Only authenticate if the context is valid */
f5799ae1 655 authenticated = options.password_authentication &&
7e772e1f 656 auth_password(authctxt, passwd) && authctxt->valid;
700318f3 657 memset(passwd, 0, strlen(passwd));
658 xfree(passwd);
659
660 buffer_clear(m);
661 buffer_put_int(m, authenticated);
662
f5799ae1 663 debug3("%s: sending result %d", __func__, authenticated);
700318f3 664 mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m);
665
666 call_count++;
667 if (plen == 0 && call_count == 1)
668 auth_method = "none";
669 else
670 auth_method = "password";
671
672 /* Causes monitor loop to terminate if authenticated */
673 return (authenticated);
674}
675
676#ifdef BSD_AUTH
677int
678mm_answer_bsdauthquery(int socket, Buffer *m)
679{
680 char *name, *infotxt;
681 u_int numprompts;
682 u_int *echo_on;
683 char **prompts;
6a9b3198 684 u_int success;
700318f3 685
6a9b3198 686 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
687 &prompts, &echo_on) < 0 ? 0 : 1;
700318f3 688
689 buffer_clear(m);
6a9b3198 690 buffer_put_int(m, success);
691 if (success)
700318f3 692 buffer_put_cstring(m, prompts[0]);
693
6a9b3198 694 debug3("%s: sending challenge success: %u", __func__, success);
700318f3 695 mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m);
696
6a9b3198 697 if (success) {
700318f3 698 xfree(name);
699 xfree(infotxt);
700 xfree(prompts);
701 xfree(echo_on);
702 }
703
704 return (0);
705}
706
707int
708mm_answer_bsdauthrespond(int socket, Buffer *m)
709{
710 char *response;
711 int authok;
712
713 if (authctxt->as == 0)
f5799ae1 714 fatal("%s: no bsd auth session", __func__);
700318f3 715
716 response = buffer_get_string(m, NULL);
f5799ae1 717 authok = options.challenge_response_authentication &&
718 auth_userresponse(authctxt->as, response, 0);
700318f3 719 authctxt->as = NULL;
f5799ae1 720 debug3("%s: <%s> = <%d>", __func__, response, authok);
700318f3 721 xfree(response);
722
723 buffer_clear(m);
724 buffer_put_int(m, authok);
725
f5799ae1 726 debug3("%s: sending authenticated: %d", __func__, authok);
700318f3 727 mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m);
728
729 auth_method = "bsdauth";
730
731 return (authok != 0);
732}
733#endif
734
735#ifdef SKEY
736int
737mm_answer_skeyquery(int socket, Buffer *m)
738{
739 struct skey skey;
740 char challenge[1024];
6a9b3198 741 u_int success;
700318f3 742
6a9b3198 743 success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
700318f3 744
745 buffer_clear(m);
6a9b3198 746 buffer_put_int(m, success);
747 if (success)
700318f3 748 buffer_put_cstring(m, challenge);
749
6a9b3198 750 debug3("%s: sending challenge success: %u", __func__, success);
700318f3 751 mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
752
753 return (0);
754}
755
756int
757mm_answer_skeyrespond(int socket, Buffer *m)
758{
759 char *response;
760 int authok;
761
762 response = buffer_get_string(m, NULL);
763
f5799ae1 764 authok = (options.challenge_response_authentication &&
765 authctxt->valid &&
700318f3 766 skey_haskey(authctxt->pw->pw_name) == 0 &&
767 skey_passcheck(authctxt->pw->pw_name, response) != -1);
768
769 xfree(response);
770
771 buffer_clear(m);
772 buffer_put_int(m, authok);
773
f5799ae1 774 debug3("%s: sending authenticated: %d", __func__, authok);
700318f3 775 mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m);
776
777 auth_method = "skey";
778
779 return (authok != 0);
780}
781#endif
782
783#ifdef USE_PAM
784int
785mm_answer_pam_start(int socket, Buffer *m)
786{
787 char *user;
788
789 user = buffer_get_string(m, NULL);
790
791 start_pam(user);
792
793 xfree(user);
794
795 return (0);
796}
797#endif
798
799static void
800mm_append_debug(Buffer *m)
801{
802 if (auth_debug_init && buffer_len(&auth_debug)) {
f5799ae1 803 debug3("%s: Appending debug messages for child", __func__);
700318f3 804 buffer_append(m, buffer_ptr(&auth_debug),
805 buffer_len(&auth_debug));
806 buffer_clear(&auth_debug);
807 }
808}
809
810int
811mm_answer_keyallowed(int socket, Buffer *m)
812{
813 Key *key;
41b2f314 814 char *cuser, *chost;
815 u_char *blob;
700318f3 816 u_int bloblen;
817 enum mm_keytype type = 0;
818 int allowed = 0;
819
f5799ae1 820 debug3("%s entering", __func__);
700318f3 821
822 type = buffer_get_int(m);
823 cuser = buffer_get_string(m, NULL);
824 chost = buffer_get_string(m, NULL);
825 blob = buffer_get_string(m, &bloblen);
826
827 key = key_from_blob(blob, bloblen);
828
829 if ((compat20 && type == MM_RSAHOSTKEY) ||
830 (!compat20 && type != MM_RSAHOSTKEY))
f5799ae1 831 fatal("%s: key type and protocol mismatch", __func__);
700318f3 832
f5799ae1 833 debug3("%s: key_from_blob: %p", __func__, key);
700318f3 834
835 if (key != NULL && authctxt->pw != NULL) {
836 switch(type) {
837 case MM_USERKEY:
f5799ae1 838 allowed = options.pubkey_authentication &&
839 user_key_allowed(authctxt->pw, key);
700318f3 840 break;
841 case MM_HOSTKEY:
f5799ae1 842 allowed = options.hostbased_authentication &&
843 hostbased_key_allowed(authctxt->pw,
700318f3 844 cuser, chost, key);
845 break;
846 case MM_RSAHOSTKEY:
847 key->type = KEY_RSA1; /* XXX */
f5799ae1 848 allowed = options.rhosts_rsa_authentication &&
849 auth_rhosts_rsa_key_allowed(authctxt->pw,
700318f3 850 cuser, chost, key);
851 break;
852 default:
f5799ae1 853 fatal("%s: unknown key type %d", __func__, type);
700318f3 854 break;
855 }
700318f3 856 }
6a9b3198 857 if (key != NULL)
858 key_free(key);
700318f3 859
860 /* clear temporarily storage (used by verify) */
861 monitor_reset_key_state();
862
863 if (allowed) {
864 /* Save temporarily for comparison in verify */
865 key_blob = blob;
866 key_bloblen = bloblen;
867 key_blobtype = type;
868 hostbased_cuser = cuser;
869 hostbased_chost = chost;
870 }
871
872 debug3("%s: key %p is %s",
f5799ae1 873 __func__, key, allowed ? "allowed" : "disallowed");
700318f3 874
875 buffer_clear(m);
876 buffer_put_int(m, allowed);
6a9b3198 877 buffer_put_int(m, forced_command != NULL);
700318f3 878
879 mm_append_debug(m);
880
881 mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m);
882
883 if (type == MM_RSAHOSTKEY)
884 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
885
886 return (0);
887}
888
889static int
890monitor_valid_userblob(u_char *data, u_int datalen)
891{
892 Buffer b;
41b2f314 893 char *p;
700318f3 894 u_int len;
895 int fail = 0;
700318f3 896
897 buffer_init(&b);
898 buffer_append(&b, data, datalen);
899
900 if (datafellows & SSH_OLD_SESSIONID) {
f5799ae1 901 p = buffer_ptr(&b);
902 len = buffer_len(&b);
903 if ((session_id2 == NULL) ||
904 (len < session_id2_len) ||
905 (memcmp(p, session_id2, session_id2_len) != 0))
906 fail++;
700318f3 907 buffer_consume(&b, session_id2_len);
908 } else {
f5799ae1 909 p = buffer_get_string(&b, &len);
910 if ((session_id2 == NULL) ||
911 (len != session_id2_len) ||
912 (memcmp(p, session_id2, session_id2_len) != 0))
700318f3 913 fail++;
f5799ae1 914 xfree(p);
700318f3 915 }
916 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
917 fail++;
918 p = buffer_get_string(&b, NULL);
919 if (strcmp(authctxt->user, p) != 0) {
920 log("wrong user name passed to monitor: expected %s != %.100s",
921 authctxt->user, p);
922 fail++;
923 }
924 xfree(p);
925 buffer_skip_string(&b);
926 if (datafellows & SSH_BUG_PKAUTH) {
927 if (!buffer_get_char(&b))
928 fail++;
929 } else {
930 p = buffer_get_string(&b, NULL);
931 if (strcmp("publickey", p) != 0)
932 fail++;
933 xfree(p);
934 if (!buffer_get_char(&b))
935 fail++;
936 buffer_skip_string(&b);
937 }
938 buffer_skip_string(&b);
939 if (buffer_len(&b) != 0)
940 fail++;
941 buffer_free(&b);
942 return (fail == 0);
943}
944
945static int
41b2f314 946monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
947 char *chost)
700318f3 948{
949 Buffer b;
41b2f314 950 char *p;
700318f3 951 u_int len;
952 int fail = 0;
700318f3 953
954 buffer_init(&b);
955 buffer_append(&b, data, datalen);
956
f5799ae1 957 p = buffer_get_string(&b, &len);
958 if ((session_id2 == NULL) ||
959 (len != session_id2_len) ||
960 (memcmp(p, session_id2, session_id2_len) != 0))
700318f3 961 fail++;
f5799ae1 962 xfree(p);
963
700318f3 964 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
965 fail++;
966 p = buffer_get_string(&b, NULL);
967 if (strcmp(authctxt->user, p) != 0) {
968 log("wrong user name passed to monitor: expected %s != %.100s",
969 authctxt->user, p);
970 fail++;
971 }
972 xfree(p);
973 buffer_skip_string(&b); /* service */
974 p = buffer_get_string(&b, NULL);
975 if (strcmp(p, "hostbased") != 0)
976 fail++;
977 xfree(p);
978 buffer_skip_string(&b); /* pkalg */
979 buffer_skip_string(&b); /* pkblob */
980
981 /* verify client host, strip trailing dot if necessary */
982 p = buffer_get_string(&b, NULL);
983 if (((len = strlen(p)) > 0) && p[len - 1] == '.')
984 p[len - 1] = '\0';
985 if (strcmp(p, chost) != 0)
986 fail++;
987 xfree(p);
988
989 /* verify client user */
990 p = buffer_get_string(&b, NULL);
991 if (strcmp(p, cuser) != 0)
992 fail++;
993 xfree(p);
994
995 if (buffer_len(&b) != 0)
996 fail++;
997 buffer_free(&b);
998 return (fail == 0);
999}
1000
1001int
1002mm_answer_keyverify(int socket, Buffer *m)
1003{
1004 Key *key;
1005 u_char *signature, *data, *blob;
1006 u_int signaturelen, datalen, bloblen;
1007 int verified = 0;
1008 int valid_data = 0;
1009
1010 blob = buffer_get_string(m, &bloblen);
1011 signature = buffer_get_string(m, &signaturelen);
1012 data = buffer_get_string(m, &datalen);
1013
1014 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1015 !monitor_allowed_key(blob, bloblen))
f5799ae1 1016 fatal("%s: bad key, not previously allowed", __func__);
700318f3 1017
1018 key = key_from_blob(blob, bloblen);
1019 if (key == NULL)
f5799ae1 1020 fatal("%s: bad public key blob", __func__);
700318f3 1021
1022 switch (key_blobtype) {
1023 case MM_USERKEY:
1024 valid_data = monitor_valid_userblob(data, datalen);
1025 break;
1026 case MM_HOSTKEY:
1027 valid_data = monitor_valid_hostbasedblob(data, datalen,
1028 hostbased_cuser, hostbased_chost);
1029 break;
1030 default:
1031 valid_data = 0;
1032 break;
1033 }
1034 if (!valid_data)
f5799ae1 1035 fatal("%s: bad signature data blob", __func__);
700318f3 1036
1037 verified = key_verify(key, signature, signaturelen, data, datalen);
1038 debug3("%s: key %p signature %s",
f5799ae1 1039 __func__, key, verified ? "verified" : "unverified");
700318f3 1040
1041 key_free(key);
1042 xfree(blob);
1043 xfree(signature);
1044 xfree(data);
1045
680cee3b 1046 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1047
700318f3 1048 monitor_reset_key_state();
1049
1050 buffer_clear(m);
1051 buffer_put_int(m, verified);
1052 mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m);
1053
700318f3 1054 return (verified);
1055}
1056
1057static void
1058mm_record_login(Session *s, struct passwd *pw)
1059{
1060 socklen_t fromlen;
1061 struct sockaddr_storage from;
1062
1063 /*
1064 * Get IP address of client. If the connection is not a socket, let
1065 * the address be 0.0.0.0.
1066 */
1067 memset(&from, 0, sizeof(from));
41b2f314 1068 fromlen = sizeof(from);
700318f3 1069 if (packet_connection_is_on_socket()) {
700318f3 1070 if (getpeername(packet_get_connection_in(),
1071 (struct sockaddr *) & from, &fromlen) < 0) {
1072 debug("getpeername: %.100s", strerror(errno));
1073 fatal_cleanup();
1074 }
1075 }
1076 /* Record that there was a login on that tty from the remote host. */
1077 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1078 get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping),
41b2f314 1079 (struct sockaddr *)&from, fromlen);
700318f3 1080}
1081
1082static void
1083mm_session_close(Session *s)
1084{
f5799ae1 1085 debug3("%s: session %d pid %d", __func__, s->self, s->pid);
700318f3 1086 if (s->ttyfd != -1) {
f5799ae1 1087 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
700318f3 1088 fatal_remove_cleanup(session_pty_cleanup2, (void *)s);
1089 session_pty_cleanup2(s);
1090 }
1091 s->used = 0;
1092}
1093
1094int
1095mm_answer_pty(int socket, Buffer *m)
1096{
1097 extern struct monitor *pmonitor;
1098 Session *s;
1099 int res, fd0;
1100
f5799ae1 1101 debug3("%s entering", __func__);
700318f3 1102
1103 buffer_clear(m);
1104 s = session_new();
1105 if (s == NULL)
1106 goto error;
1107 s->authctxt = authctxt;
1108 s->pw = authctxt->pw;
1109 s->pid = pmonitor->m_pid;
1110 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1111 if (res == 0)
1112 goto error;
1113 fatal_add_cleanup(session_pty_cleanup2, (void *)s);
1114 pty_setowner(authctxt->pw, s->tty);
1115
1116 buffer_put_int(m, 1);
1117 buffer_put_cstring(m, s->tty);
1118 mm_request_send(socket, MONITOR_ANS_PTY, m);
1119
1120 mm_send_fd(socket, s->ptyfd);
1121 mm_send_fd(socket, s->ttyfd);
1122
1123 /* We need to trick ttyslot */
1124 if (dup2(s->ttyfd, 0) == -1)
f5799ae1 1125 fatal("%s: dup2", __func__);
700318f3 1126
1127 mm_record_login(s, authctxt->pw);
1128
1129 /* Now we can close the file descriptor again */
1130 close(0);
1131
1132 /* make sure nothing uses fd 0 */
1133 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
f5799ae1 1134 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
700318f3 1135 if (fd0 != 0)
f5799ae1 1136 error("%s: fd0 %d != 0", __func__, fd0);
700318f3 1137
1138 /* slave is not needed */
1139 close(s->ttyfd);
1140 s->ttyfd = s->ptyfd;
1141 /* no need to dup() because nobody closes ptyfd */
1142 s->ptymaster = s->ptyfd;
1143
f5799ae1 1144 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
700318f3 1145
1146 return (0);
1147
1148 error:
1149 if (s != NULL)
1150 mm_session_close(s);
1151 buffer_put_int(m, 0);
1152 mm_request_send(socket, MONITOR_ANS_PTY, m);
1153 return (0);
1154}
1155
1156int
1157mm_answer_pty_cleanup(int socket, Buffer *m)
1158{
1159 Session *s;
1160 char *tty;
1161
f5799ae1 1162 debug3("%s entering", __func__);
700318f3 1163
1164 tty = buffer_get_string(m, NULL);
1165 if ((s = session_by_tty(tty)) != NULL)
1166 mm_session_close(s);
1167 buffer_clear(m);
1168 xfree(tty);
1169 return (0);
1170}
1171
1172int
1173mm_answer_sesskey(int socket, Buffer *m)
1174{
1175 BIGNUM *p;
1176 int rsafail;
1177
1178 /* Turn off permissions */
1179 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
1180
1181 if ((p = BN_new()) == NULL)
f5799ae1 1182 fatal("%s: BN_new", __func__);
700318f3 1183
1184 buffer_get_bignum2(m, p);
1185
1186 rsafail = ssh1_session_key(p);
1187
1188 buffer_clear(m);
1189 buffer_put_int(m, rsafail);
1190 buffer_put_bignum2(m, p);
1191
1192 BN_clear_free(p);
1193
1194 mm_request_send(socket, MONITOR_ANS_SESSKEY, m);
1195
1196 /* Turn on permissions for sessid passing */
1197 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1198
1199 return (0);
1200}
1201
1202int
1203mm_answer_sessid(int socket, Buffer *m)
1204{
1205 int i;
1206
f5799ae1 1207 debug3("%s entering", __func__);
700318f3 1208
1209 if (buffer_len(m) != 16)
f5799ae1 1210 fatal("%s: bad ssh1 session id", __func__);
700318f3 1211 for (i = 0; i < 16; i++)
1212 session_id[i] = buffer_get_char(m);
1213
1214 /* Turn on permissions for getpwnam */
1215 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1216
1217 return (0);
1218}
1219
1220int
1221mm_answer_rsa_keyallowed(int socket, Buffer *m)
1222{
1223 BIGNUM *client_n;
1224 Key *key = NULL;
1225 u_char *blob = NULL;
1226 u_int blen = 0;
1227 int allowed = 0;
1228
f5799ae1 1229 debug3("%s entering", __func__);
700318f3 1230
f5799ae1 1231 if (options.rsa_authentication && authctxt->valid) {
700318f3 1232 if ((client_n = BN_new()) == NULL)
f5799ae1 1233 fatal("%s: BN_new", __func__);
700318f3 1234 buffer_get_bignum2(m, client_n);
1235 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1236 BN_clear_free(client_n);
1237 }
1238 buffer_clear(m);
1239 buffer_put_int(m, allowed);
6a9b3198 1240 buffer_put_int(m, forced_command != NULL);
700318f3 1241
1242 /* clear temporarily storage (used by generate challenge) */
1243 monitor_reset_key_state();
1244
1245 if (allowed && key != NULL) {
1246 key->type = KEY_RSA; /* cheat for key_to_blob */
1247 if (key_to_blob(key, &blob, &blen) == 0)
f5799ae1 1248 fatal("%s: key_to_blob failed", __func__);
700318f3 1249 buffer_put_string(m, blob, blen);
1250
1251 /* Save temporarily for comparison in verify */
1252 key_blob = blob;
1253 key_bloblen = blen;
1254 key_blobtype = MM_RSAUSERKEY;
700318f3 1255 }
6a9b3198 1256 if (key != NULL)
1257 key_free(key);
700318f3 1258
1259 mm_append_debug(m);
1260
1261 mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m);
1262
1263 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1264 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1265 return (0);
1266}
1267
1268int
1269mm_answer_rsa_challenge(int socket, Buffer *m)
1270{
1271 Key *key = NULL;
1272 u_char *blob;
1273 u_int blen;
1274
f5799ae1 1275 debug3("%s entering", __func__);
700318f3 1276
1277 if (!authctxt->valid)
f5799ae1 1278 fatal("%s: authctxt not valid", __func__);
700318f3 1279 blob = buffer_get_string(m, &blen);
1280 if (!monitor_allowed_key(blob, blen))
f5799ae1 1281 fatal("%s: bad key, not previously allowed", __func__);
700318f3 1282 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
f5799ae1 1283 fatal("%s: key type mismatch", __func__);
700318f3 1284 if ((key = key_from_blob(blob, blen)) == NULL)
f5799ae1 1285 fatal("%s: received bad key", __func__);
700318f3 1286
1287 if (ssh1_challenge)
1288 BN_clear_free(ssh1_challenge);
1289 ssh1_challenge = auth_rsa_generate_challenge(key);
1290
1291 buffer_clear(m);
1292 buffer_put_bignum2(m, ssh1_challenge);
1293
f5799ae1 1294 debug3("%s sending reply", __func__);
700318f3 1295 mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m);
1296
1297 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
6a9b3198 1298
1299 xfree(blob);
1300 key_free(key);
700318f3 1301 return (0);
1302}
1303
1304int
1305mm_answer_rsa_response(int socket, Buffer *m)
1306{
1307 Key *key = NULL;
1308 u_char *blob, *response;
1309 u_int blen, len;
1310 int success;
1311
f5799ae1 1312 debug3("%s entering", __func__);
700318f3 1313
1314 if (!authctxt->valid)
f5799ae1 1315 fatal("%s: authctxt not valid", __func__);
700318f3 1316 if (ssh1_challenge == NULL)
f5799ae1 1317 fatal("%s: no ssh1_challenge", __func__);
700318f3 1318
1319 blob = buffer_get_string(m, &blen);
1320 if (!monitor_allowed_key(blob, blen))
f5799ae1 1321 fatal("%s: bad key, not previously allowed", __func__);
700318f3 1322 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
f5799ae1 1323 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
700318f3 1324 if ((key = key_from_blob(blob, blen)) == NULL)
f5799ae1 1325 fatal("%s: received bad key", __func__);
700318f3 1326 response = buffer_get_string(m, &len);
1327 if (len != 16)
f5799ae1 1328 fatal("%s: received bad response to challenge", __func__);
700318f3 1329 success = auth_rsa_verify_response(key, ssh1_challenge, response);
1330
6a9b3198 1331 xfree(blob);
700318f3 1332 key_free(key);
1333 xfree(response);
1334
1335 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1336
1337 /* reset state */
1338 BN_clear_free(ssh1_challenge);
1339 ssh1_challenge = NULL;
1340 monitor_reset_key_state();
1341
1342 buffer_clear(m);
1343 buffer_put_int(m, success);
1344 mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m);
1345
1346 return (success);
1347}
1348
41b2f314 1349#ifdef KRB4
1350int
1351mm_answer_krb4(int socket, Buffer *m)
1352{
1353 KTEXT_ST auth, reply;
1354 char *client, *p;
1355 int success;
1356 u_int alen;
1357
1358 reply.length = auth.length = 0;
1359
1360 p = buffer_get_string(m, &alen);
1361 if (alen >= MAX_KTXT_LEN)
1362 fatal("%s: auth too large", __func__);
1363 memcpy(auth.dat, p, alen);
1364 auth.length = alen;
1365 memset(p, 0, alen);
1366 xfree(p);
1367
1368 success = options.kerberos_authentication &&
1369 authctxt->valid &&
1370 auth_krb4(authctxt, &auth, &client, &reply);
1371
1372 memset(auth.dat, 0, alen);
1373 buffer_clear(m);
1374 buffer_put_int(m, success);
1375
1376 if (success) {
1377 buffer_put_cstring(m, client);
1378 buffer_put_string(m, reply.dat, reply.length);
1379 if (client)
1380 xfree(client);
1381 if (reply.length)
1382 memset(reply.dat, 0, reply.length);
1383 }
1384
1385 debug3("%s: sending result %d", __func__, success);
1386 mm_request_send(socket, MONITOR_ANS_KRB4, m);
1387
1388 auth_method = "kerberos";
1389
1390 /* Causes monitor loop to terminate if authenticated */
1391 return (success);
1392}
1393#endif
1394
1395#ifdef KRB5
1396int
1397mm_answer_krb5(int socket, Buffer *m)
1398{
1399 krb5_data tkt, reply;
1400 char *client_user;
1401 u_int len;
1402 int success;
1403
1404 /* use temporary var to avoid size issues on 64bit arch */
1405 tkt.data = buffer_get_string(m, &len);
1406 tkt.length = len;
1407
1408 success = options.kerberos_authentication &&
1409 authctxt->valid &&
1410 auth_krb5(authctxt, &tkt, &client_user, &reply);
1411
1412 if (tkt.length)
1413 xfree(tkt.data);
1414
1415 buffer_clear(m);
1416 buffer_put_int(m, success);
1417
1418 if (success) {
1419 buffer_put_cstring(m, client_user);
1420 buffer_put_string(m, reply.data, reply.length);
1421 if (client_user)
1422 xfree(client_user);
1423 if (reply.length)
1424 xfree(reply.data);
1425 }
1426 mm_request_send(socket, MONITOR_ANS_KRB5, m);
1427
1428 return success;
1429}
1430#endif
1431
700318f3 1432int
1433mm_answer_term(int socket, Buffer *req)
1434{
1435 extern struct monitor *pmonitor;
1436 int res, status;
1437
f5799ae1 1438 debug3("%s: tearing down sessions", __func__);
700318f3 1439
1440 /* The child is terminating */
1441 session_destroy_all(&mm_session_close);
1442
1443 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1444 if (errno != EINTR)
1445 exit(1);
1446
1447 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1448
1449 /* Terminate process */
1450 exit (res);
1451}
1452
1453void
1454monitor_apply_keystate(struct monitor *pmonitor)
1455{
1456 if (compat20) {
1457 set_newkeys(MODE_IN);
1458 set_newkeys(MODE_OUT);
1459 } else {
700318f3 1460 packet_set_protocol_flags(child_state.ssh1protoflags);
f5799ae1 1461 packet_set_encryption_key(child_state.ssh1key,
1462 child_state.ssh1keylen, child_state.ssh1cipher);
1463 xfree(child_state.ssh1key);
700318f3 1464 }
1465
f5799ae1 1466 /* for rc4 and other stateful ciphers */
700318f3 1467 packet_set_keycontext(MODE_OUT, child_state.keyout);
1468 xfree(child_state.keyout);
1469 packet_set_keycontext(MODE_IN, child_state.keyin);
1470 xfree(child_state.keyin);
1471
1472 if (!compat20) {
1473 packet_set_iv(MODE_OUT, child_state.ivout);
1474 xfree(child_state.ivout);
1475 packet_set_iv(MODE_IN, child_state.ivin);
1476 xfree(child_state.ivin);
1477 }
1478
1479 memcpy(&incoming_stream, &child_state.incoming,
1480 sizeof(incoming_stream));
1481 memcpy(&outgoing_stream, &child_state.outgoing,
1482 sizeof(outgoing_stream));
1483
1484 /* Update with new address */
f5799ae1 1485 if (options.compression)
1486 mm_init_compression(pmonitor->m_zlib);
700318f3 1487
1488 /* Network I/O buffers */
1489 /* XXX inefficient for large buffers, need: buffer_init_from_string */
1490 buffer_clear(&input);
1491 buffer_append(&input, child_state.input, child_state.ilen);
1492 memset(child_state.input, 0, child_state.ilen);
1493 xfree(child_state.input);
1494
1495 buffer_clear(&output);
1496 buffer_append(&output, child_state.output, child_state.olen);
1497 memset(child_state.output, 0, child_state.olen);
1498 xfree(child_state.output);
1499}
1500
1501static Kex *
1502mm_get_kex(Buffer *m)
1503{
1504 Kex *kex;
1505 void *blob;
1506 u_int bloblen;
1507
1508 kex = xmalloc(sizeof(*kex));
1509 memset(kex, 0, sizeof(*kex));
1510 kex->session_id = buffer_get_string(m, &kex->session_id_len);
f5799ae1 1511 if ((session_id2 == NULL) ||
1512 (kex->session_id_len != session_id2_len) ||
1513 (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1514 fatal("mm_get_get: internal error: bad session id");
700318f3 1515 kex->we_need = buffer_get_int(m);
6a9b3198 1516 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1517 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
c0fc5818 1518#ifdef GSSAPI
1519 kex->kex[KEX_GSS_GRP1_SHA1] =kexgss_server;
1520#endif
700318f3 1521 kex->server = 1;
1522 kex->hostkey_type = buffer_get_int(m);
1523 kex->kex_type = buffer_get_int(m);
1524 blob = buffer_get_string(m, &bloblen);
1525 buffer_init(&kex->my);
1526 buffer_append(&kex->my, blob, bloblen);
1527 xfree(blob);
1528 blob = buffer_get_string(m, &bloblen);
1529 buffer_init(&kex->peer);
1530 buffer_append(&kex->peer, blob, bloblen);
1531 xfree(blob);
1532 kex->done = 1;
1533 kex->flags = buffer_get_int(m);
1534 kex->client_version_string = buffer_get_string(m, NULL);
1535 kex->server_version_string = buffer_get_string(m, NULL);
1536 kex->load_host_key=&get_hostkey_by_type;
1537 kex->host_key_index=&get_hostkey_index;
1538
1539 return (kex);
1540}
1541
1542/* This function requries careful sanity checking */
1543
1544void
1545mm_get_keystate(struct monitor *pmonitor)
1546{
1547 Buffer m;
1548 u_char *blob, *p;
1549 u_int bloblen, plen;
1550
f5799ae1 1551 debug3("%s: Waiting for new keys", __func__);
700318f3 1552
1553 buffer_init(&m);
1554 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1555 if (!compat20) {
1556 child_state.ssh1protoflags = buffer_get_int(&m);
1557 child_state.ssh1cipher = buffer_get_int(&m);
f5799ae1 1558 child_state.ssh1key = buffer_get_string(&m,
1559 &child_state.ssh1keylen);
700318f3 1560 child_state.ivout = buffer_get_string(&m,
1561 &child_state.ivoutlen);
1562 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1563 goto skip;
1564 } else {
1565 /* Get the Kex for rekeying */
1566 *pmonitor->m_pkex = mm_get_kex(&m);
1567 }
1568
1569 blob = buffer_get_string(&m, &bloblen);
1570 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1571 xfree(blob);
1572
f5799ae1 1573 debug3("%s: Waiting for second key", __func__);
700318f3 1574 blob = buffer_get_string(&m, &bloblen);
1575 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1576 xfree(blob);
1577
1578 /* Now get sequence numbers for the packets */
1579 packet_set_seqnr(MODE_OUT, buffer_get_int(&m));
1580 packet_set_seqnr(MODE_IN, buffer_get_int(&m));
1581
1582 skip:
1583 /* Get the key context */
1584 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1585 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1586
f5799ae1 1587 debug3("%s: Getting compression state", __func__);
700318f3 1588 /* Get compression state */
1589 p = buffer_get_string(&m, &plen);
1590 if (plen != sizeof(child_state.outgoing))
f5799ae1 1591 fatal("%s: bad request size", __func__);
700318f3 1592 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1593 xfree(p);
1594
1595 p = buffer_get_string(&m, &plen);
1596 if (plen != sizeof(child_state.incoming))
f5799ae1 1597 fatal("%s: bad request size", __func__);
700318f3 1598 memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1599 xfree(p);
1600
1601 /* Network I/O buffers */
f5799ae1 1602 debug3("%s: Getting Network I/O buffers", __func__);
700318f3 1603 child_state.input = buffer_get_string(&m, &child_state.ilen);
1604 child_state.output = buffer_get_string(&m, &child_state.olen);
1605
1606 buffer_free(&m);
1607}
1608
1609
1610/* Allocation functions for zlib */
1611void *
1612mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1613{
6a9b3198 1614 size_t len = (size_t) size * ncount;
700318f3 1615 void *address;
1616
41b2f314 1617 if (len == 0 || ncount > SIZE_T_MAX / size)
680cee3b 1618 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1619
1620 address = mm_malloc(mm, len);
700318f3 1621
1622 return (address);
1623}
1624
1625void
1626mm_zfree(struct mm_master *mm, void *address)
1627{
1628 mm_free(mm, address);
1629}
1630
1631void
1632mm_init_compression(struct mm_master *mm)
1633{
1634 outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1635 outgoing_stream.zfree = (free_func)mm_zfree;
1636 outgoing_stream.opaque = mm;
1637
1638 incoming_stream.zalloc = (alloc_func)mm_zalloc;
1639 incoming_stream.zfree = (free_func)mm_zfree;
1640 incoming_stream.opaque = mm;
1641}
1642
1643/* XXX */
1644
1645#define FD_CLOSEONEXEC(x) do { \
1646 if (fcntl(x, F_SETFD, 1) == -1) \
1647 fatal("fcntl(%d, F_SETFD)", x); \
1648} while (0)
1649
1650static void
1651monitor_socketpair(int *pair)
1652{
1653#ifdef HAVE_SOCKETPAIR
1654 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
f5799ae1 1655 fatal("%s: socketpair", __func__);
700318f3 1656#else
1657 fatal("%s: UsePrivilegeSeparation=yes not supported",
f5799ae1 1658 __func__);
700318f3 1659#endif
1660 FD_CLOSEONEXEC(pair[0]);
1661 FD_CLOSEONEXEC(pair[1]);
1662}
1663
1664#define MM_MEMSIZE 65536
1665
1666struct monitor *
1667monitor_init(void)
1668{
1669 struct monitor *mon;
1670 int pair[2];
1671
1672 mon = xmalloc(sizeof(*mon));
1673
1674 monitor_socketpair(pair);
1675
1676 mon->m_recvfd = pair[0];
1677 mon->m_sendfd = pair[1];
1678
1679 /* Used to share zlib space across processes */
f5799ae1 1680 if (options.compression) {
1681 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1682 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
700318f3 1683
f5799ae1 1684 /* Compression needs to share state across borders */
1685 mm_init_compression(mon->m_zlib);
1686 }
700318f3 1687
1688 return mon;
1689}
1690
1691void
1692monitor_reinit(struct monitor *mon)
1693{
1694 int pair[2];
1695
1696 monitor_socketpair(pair);
1697
1698 mon->m_recvfd = pair[0];
1699 mon->m_sendfd = pair[1];
1700}
c0fc5818 1701
1702#ifdef GSSAPI
1703
1704int
1705mm_answer_gss_setup_ctx(int socket, Buffer *m) {
1706 gss_OID_desc oid;
1707 OM_uint32 major;
1708 u_int len;
1709
1710 oid.elements=buffer_get_string(m,&len);
1711 oid.length=len;
1712
1713 major=ssh_gssapi_server_ctx(&gsscontext,&oid);
1714
1715 xfree(oid.elements);
1716
1717 buffer_clear(m);
1718 buffer_put_int(m,major);
1719
1720 mm_request_send(socket,MONITOR_ANS_GSSSETUP,m);
1721
1722 /* Now we have a context, enable the step and sign */
1723 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP,1);
1724
1725 return(0);
1726}
1727
1728int
1729mm_answer_gss_accept_ctx(int socket, Buffer *m) {
1730 gss_buffer_desc in,out;
1731 OM_uint32 major,minor;
1732 OM_uint32 flags = 0; /* GSI needs this */
1733
1734 in.value = buffer_get_string(m,&in.length);
1735 major=ssh_gssapi_accept_ctx(gsscontext,&in,&out,&flags);
1736 xfree(in.value);
1737
1738 buffer_clear(m);
1739 buffer_put_int(m, major);
1740 buffer_put_string(m, out.value, out.length);
1741 buffer_put_int(m, flags);
1742 mm_request_send(socket,MONITOR_ANS_GSSSTEP,m);
1743
1744 gss_release_buffer(&minor, &out);
1745
1746 /* Complete - now we can do signing */
1747 if (major==GSS_S_COMPLETE) {
1748 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP,0);
1749 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN,1);
1750 }
1751 return(0);
1752}
1753
1754int
1755mm_answer_gss_userok(int socket, Buffer *m) {
1756 int authenticated;
1757
1758 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1759
1760 buffer_clear(m);
1761 buffer_put_int(m, authenticated);
1762
1763 debug3("%s: sending result %d", __func__, authenticated);
1764 mm_request_send(socket, MONITOR_ANS_GSSUSEROK, m);
1765
1766 /* XXX - auth method could also be 'external' */
1767 auth_method="gssapi";
1768
1769 /* Monitor loop will terminate if authenticated */
1770 return(authenticated);
1771}
1772
1773int
1774mm_answer_gss_sign(int socket, Buffer *m) {
1775 gss_buffer_desc data,hash;
1776 OM_uint32 major,minor;
1777
1778 data.value = buffer_get_string(m,&data.length);
1779 if (data.length != 20)
1780 fatal("%s: data length incorrect: %d", __func__, data.length);
1781
1782 /* Save the session ID - only first time round */
1783 if (session_id2_len == 0) {
1784 session_id2_len=data.length;
1785 session_id2 = xmalloc(session_id2_len);
1786 memcpy(session_id2, data.value, session_id2_len);
1787 }
1788 major=ssh_gssapi_sign(gsscontext, &data, &hash);
1789
1790 xfree(data.value);
1791
1792 buffer_clear(m);
1793 buffer_put_int(m, major);
1794 buffer_put_string(m, hash.value, hash.length);
1795
1796 mm_request_send(socket,MONITOR_ANS_GSSSIGN,m);
1797
1798 gss_release_buffer(&minor,&hash);
1799
1800 /* Turn on permissions for getpwnam */
1801 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1802
1803 return(0);
1804}
1805
1806int
1807mm_answer_gss_error(int socket, Buffer *m) {
1808 OM_uint32 major,minor;
1809 char *msg;
1810
1811 msg=ssh_gssapi_last_error(gsscontext,&major,&minor);
1812 buffer_clear(m);
1813 buffer_put_int(m,major);
1814 buffer_put_int(m,minor);
1815 buffer_put_cstring(m,msg);
1816
1817 mm_request_send(socket,MONITOR_ANS_GSSERR,m);
1818
1819 xfree(msg);
1820
1821 return(0);
1822}
1823
1824int
1825mm_answer_gss_indicate_mechs(int socket, Buffer *m) {
1826 OM_uint32 major,minor;
1827 gss_OID_set mech_set;
1828 int i;
1829
1830 major=gss_indicate_mechs(&minor, &mech_set);
1831
1832 buffer_clear(m);
1833 buffer_put_int(m, major);
1834 buffer_put_int(m, mech_set->count);
1835 for (i=0; i < mech_set->count; i++) {
1836 buffer_put_string(m, mech_set->elements[i].elements,
1837 mech_set->elements[i].length);
1838 }
1839
1840 gss_release_oid_set(&minor,&mech_set);
1841
1842 mm_request_send(socket,MONITOR_ANS_GSSMECHS,m);
1843
1844 return(0);
1845}
1846
1847int
1848mm_answer_gss_localname(int socket, Buffer *m) {
1849 char *name;
1850
1851 ssh_gssapi_localname(&name);
1852
1853 buffer_clear(m);
1854 if (name) {
1855 buffer_put_cstring(m, name);
1856 debug3("%s: sending result %s", __func__, name);
1857 xfree(name);
1858 } else {
1859 buffer_put_cstring(m, "");
1860 debug3("%s: sending result \"\"", __func__);
1861 }
1862
1863 mm_request_send(socket, MONITOR_ANS_GSSLOCALNAME, m);
1864
1865 return(0);
1866}
1867#endif /* GSSAPI */
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