Annotation of src/usr.bin/ssh/monitor.c, Revision 1.63
1.1 provos 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"
1.63 ! deraadt 28: RCSID("$OpenBSD: monitor.c,v 1.62 2005/01/30 11:18:08 dtucker Exp $");
1.1 provos 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:
1.46 markus 61: #ifdef GSSAPI
62: #include "ssh-gss.h"
63: static Gssctxt *gsscontext = NULL;
64: #endif
65:
1.1 provos 66: /* Imports */
67: extern ServerOptions options;
68: extern u_int utmp_len;
69: extern Newkeys *current_keys[];
70: extern z_stream incoming_stream;
71: extern z_stream outgoing_stream;
72: extern u_char session_id[];
73: extern Buffer input, output;
74: extern Buffer auth_debug;
75: extern int auth_debug_init;
1.61 dtucker 76: extern Buffer loginmsg;
1.1 provos 77:
78: /* State exported from the child */
79:
80: struct {
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;
1.15 markus 91: u_char *ssh1key;
92: u_int ssh1keylen;
1.1 provos 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:
1.43 markus 101: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 102:
103: int mm_answer_moduli(int, Buffer *);
104: int mm_answer_sign(int, Buffer *);
105: int mm_answer_pwnamallow(int, Buffer *);
1.10 djm 106: int mm_answer_auth2_read_banner(int, Buffer *);
1.1 provos 107: int mm_answer_authserv(int, Buffer *);
108: int mm_answer_authpassword(int, Buffer *);
109: int mm_answer_bsdauthquery(int, Buffer *);
110: int mm_answer_bsdauthrespond(int, Buffer *);
111: int mm_answer_skeyquery(int, Buffer *);
112: int mm_answer_skeyrespond(int, Buffer *);
113: int mm_answer_keyallowed(int, Buffer *);
114: int mm_answer_keyverify(int, Buffer *);
115: int mm_answer_pty(int, Buffer *);
116: int mm_answer_pty_cleanup(int, Buffer *);
117: int mm_answer_term(int, Buffer *);
118: int mm_answer_rsa_keyallowed(int, Buffer *);
119: int mm_answer_rsa_challenge(int, Buffer *);
120: int mm_answer_rsa_response(int, Buffer *);
121: int mm_answer_sesskey(int, Buffer *);
122: int mm_answer_sessid(int, Buffer *);
123:
1.46 markus 124: #ifdef GSSAPI
125: int mm_answer_gss_setup_ctx(int, Buffer *);
126: int mm_answer_gss_accept_ctx(int, Buffer *);
127: int mm_answer_gss_userok(int, Buffer *);
1.52 markus 128: int mm_answer_gss_checkmic(int, Buffer *);
1.46 markus 129: #endif
1.25 itojun 130:
1.1 provos 131: static Authctxt *authctxt;
132: static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
133:
134: /* local state for key verify */
135: static u_char *key_blob = NULL;
136: static u_int key_bloblen = 0;
137: static int key_blobtype = MM_NOKEY;
1.26 markus 138: static char *hostbased_cuser = NULL;
139: static char *hostbased_chost = NULL;
1.1 provos 140: static char *auth_method = "unknown";
1.44 markus 141: static u_int session_id2_len = 0;
1.13 markus 142: static u_char *session_id2 = NULL;
1.40 markus 143: static pid_t monitor_child_pid;
1.1 provos 144:
145: struct mon_table {
146: enum monitor_reqtype type;
147: int flags;
148: int (*f)(int, Buffer *);
149: };
150:
151: #define MON_ISAUTH 0x0004 /* Required for Authentication */
152: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
153: #define MON_ONCE 0x0010 /* Disable after calling */
154:
155: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
156:
157: #define MON_PERMIT 0x1000 /* Request is permitted */
158:
159: struct mon_table mon_dispatch_proto20[] = {
160: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
161: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
162: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
163: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 164: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 165: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
166: #ifdef BSD_AUTH
167: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
168: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
169: #endif
170: #ifdef SKEY
171: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
172: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
173: #endif
174: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
175: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 176: #ifdef GSSAPI
177: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
178: {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
179: {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
1.52 markus 180: {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
1.46 markus 181: #endif
1.1 provos 182: {0, 0, NULL}
183: };
184:
185: struct mon_table mon_dispatch_postauth20[] = {
186: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
187: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
188: {MONITOR_REQ_PTY, 0, mm_answer_pty},
189: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
190: {MONITOR_REQ_TERM, 0, mm_answer_term},
191: {0, 0, NULL}
192: };
193:
194: struct mon_table mon_dispatch_proto15[] = {
195: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
196: {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
197: {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
198: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
199: {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
200: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
201: {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
202: {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
203: #ifdef BSD_AUTH
204: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
205: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
206: #endif
207: #ifdef SKEY
208: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
209: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
210: #endif
211: {0, 0, NULL}
212: };
213:
214: struct mon_table mon_dispatch_postauth15[] = {
215: {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
216: {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
217: {MONITOR_REQ_TERM, 0, mm_answer_term},
218: {0, 0, NULL}
219: };
220:
221: struct mon_table *mon_dispatch;
222:
223: /* Specifies if a certain message is allowed at the moment */
224:
225: static void
226: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
227: {
228: while (ent->f != NULL) {
229: if (ent->type == type) {
230: ent->flags &= ~MON_PERMIT;
231: ent->flags |= permit ? MON_PERMIT : 0;
232: return;
233: }
234: ent++;
235: }
236: }
237:
238: static void
239: monitor_permit_authentications(int permit)
240: {
241: struct mon_table *ent = mon_dispatch;
242:
243: while (ent->f != NULL) {
244: if (ent->flags & MON_AUTH) {
245: ent->flags &= ~MON_PERMIT;
246: ent->flags |= permit ? MON_PERMIT : 0;
247: }
248: ent++;
249: }
250: }
251:
1.50 markus 252: void
253: monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
1.1 provos 254: {
255: struct mon_table *ent;
256: int authenticated = 0;
257:
258: debug3("preauth child monitor started");
259:
1.50 markus 260: authctxt = _authctxt;
261: memset(authctxt, 0, sizeof(*authctxt));
262:
1.1 provos 263: if (compat20) {
264: mon_dispatch = mon_dispatch_proto20;
265:
266: /* Permit requests for moduli and signatures */
267: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
268: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
269: } else {
270: mon_dispatch = mon_dispatch_proto15;
271:
272: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
273: }
274:
275: /* The first few requests do not require asynchronous access */
276: while (!authenticated) {
1.11 mouring 277: authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
1.1 provos 278: if (authenticated) {
279: if (!(ent->flags & MON_AUTHDECIDE))
280: fatal("%s: unexpected authentication from %d",
1.14 markus 281: __func__, ent->type);
1.1 provos 282: if (authctxt->pw->pw_uid == 0 &&
283: !auth_root_allowed(auth_method))
284: authenticated = 0;
285: }
286:
287: if (ent->flags & MON_AUTHDECIDE) {
288: auth_log(authctxt, authenticated, auth_method,
289: compat20 ? " ssh2" : "");
290: if (!authenticated)
291: authctxt->failures++;
292: }
293: }
294:
295: if (!authctxt->valid)
1.14 markus 296: fatal("%s: authenticated invalid user", __func__);
1.1 provos 297:
298: debug("%s: %s has been authenticated by privileged process",
1.14 markus 299: __func__, authctxt->user);
1.1 provos 300:
1.11 mouring 301: mm_get_keystate(pmonitor);
1.1 provos 302: }
303:
1.40 markus 304: static void
305: monitor_set_child_handler(pid_t pid)
306: {
307: monitor_child_pid = pid;
308: }
309:
310: static void
1.59 avsm 311: monitor_child_handler(int sig)
1.40 markus 312: {
1.59 avsm 313: kill(monitor_child_pid, sig);
1.40 markus 314: }
315:
1.1 provos 316: void
1.11 mouring 317: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 318: {
1.40 markus 319: monitor_set_child_handler(pmonitor->m_pid);
320: signal(SIGHUP, &monitor_child_handler);
321: signal(SIGTERM, &monitor_child_handler);
322:
1.1 provos 323: if (compat20) {
324: mon_dispatch = mon_dispatch_postauth20;
325:
326: /* Permit requests for moduli and signatures */
327: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
328: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
329: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
330: } else {
331: mon_dispatch = mon_dispatch_postauth15;
332: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
333: }
334: if (!no_pty_flag) {
335: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
336: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
337: }
338:
339: for (;;)
1.11 mouring 340: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 341: }
342:
343: void
1.11 mouring 344: monitor_sync(struct monitor *pmonitor)
1.1 provos 345: {
1.16 djm 346: if (options.compression) {
347: /* The member allocation is not visible, so sync it */
348: mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
349: }
1.1 provos 350: }
351:
352: int
1.11 mouring 353: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 354: struct mon_table **pent)
355: {
356: Buffer m;
357: int ret;
358: u_char type;
359:
360: buffer_init(&m);
361:
1.11 mouring 362: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 363: type = buffer_get_char(&m);
364:
1.14 markus 365: debug3("%s: checking request %d", __func__, type);
1.1 provos 366:
367: while (ent->f != NULL) {
368: if (ent->type == type)
369: break;
370: ent++;
371: }
372:
373: if (ent->f != NULL) {
374: if (!(ent->flags & MON_PERMIT))
1.14 markus 375: fatal("%s: unpermitted request %d", __func__,
1.1 provos 376: type);
1.11 mouring 377: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 378: buffer_free(&m);
379:
380: /* The child may use this request only once, disable it */
381: if (ent->flags & MON_ONCE) {
1.14 markus 382: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 383: type);
384: ent->flags &= ~MON_PERMIT;
385: }
386:
387: if (pent != NULL)
388: *pent = ent;
1.3 markus 389:
1.1 provos 390: return ret;
391: }
392:
1.14 markus 393: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 394:
395: /* NOTREACHED */
396: return (-1);
397: }
398:
399: /* allowed key state */
400: static int
401: monitor_allowed_key(u_char *blob, u_int bloblen)
402: {
403: /* make sure key is allowed */
404: if (key_blob == NULL || key_bloblen != bloblen ||
405: memcmp(key_blob, blob, key_bloblen))
406: return (0);
407: return (1);
408: }
409:
410: static void
411: monitor_reset_key_state(void)
412: {
413: /* reset state */
414: if (key_blob != NULL)
415: xfree(key_blob);
416: if (hostbased_cuser != NULL)
417: xfree(hostbased_cuser);
418: if (hostbased_chost != NULL)
419: xfree(hostbased_chost);
420: key_blob = NULL;
421: key_bloblen = 0;
422: key_blobtype = MM_NOKEY;
423: hostbased_cuser = NULL;
424: hostbased_chost = NULL;
425: }
426:
427: int
1.59 avsm 428: mm_answer_moduli(int sock, Buffer *m)
1.1 provos 429: {
430: DH *dh;
431: int min, want, max;
432:
433: min = buffer_get_int(m);
434: want = buffer_get_int(m);
435: max = buffer_get_int(m);
436:
437: debug3("%s: got parameters: %d %d %d",
1.14 markus 438: __func__, min, want, max);
1.1 provos 439: /* We need to check here, too, in case the child got corrupted */
440: if (max < min || want < min || max < want)
441: fatal("%s: bad parameters: %d %d %d",
1.14 markus 442: __func__, min, want, max);
1.1 provos 443:
444: buffer_clear(m);
445:
446: dh = choose_dh(min, want, max);
447: if (dh == NULL) {
448: buffer_put_char(m, 0);
449: return (0);
450: } else {
451: /* Send first bignum */
452: buffer_put_char(m, 1);
453: buffer_put_bignum2(m, dh->p);
454: buffer_put_bignum2(m, dh->g);
1.3 markus 455:
1.1 provos 456: DH_free(dh);
457: }
1.59 avsm 458: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 459: return (0);
460: }
461:
462: int
1.59 avsm 463: mm_answer_sign(int sock, Buffer *m)
1.1 provos 464: {
465: Key *key;
466: u_char *p;
467: u_char *signature;
468: u_int siglen, datlen;
469: int keyid;
1.3 markus 470:
1.14 markus 471: debug3("%s", __func__);
1.1 provos 472:
1.3 markus 473: keyid = buffer_get_int(m);
474: p = buffer_get_string(m, &datlen);
1.1 provos 475:
476: if (datlen != 20)
1.19 deraadt 477: fatal("%s: data length incorrect: %u", __func__, datlen);
1.1 provos 478:
1.13 markus 479: /* save session id, it will be passed on the first call */
480: if (session_id2_len == 0) {
481: session_id2_len = datlen;
482: session_id2 = xmalloc(session_id2_len);
483: memcpy(session_id2, p, session_id2_len);
484: }
485:
1.1 provos 486: if ((key = get_hostkey_by_index(keyid)) == NULL)
1.14 markus 487: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 488: if (key_sign(key, &signature, &siglen, p, datlen) < 0)
1.14 markus 489: fatal("%s: key_sign failed", __func__);
1.1 provos 490:
1.19 deraadt 491: debug3("%s: signature %p(%u)", __func__, signature, siglen);
1.1 provos 492:
493: buffer_clear(m);
494: buffer_put_string(m, signature, siglen);
495:
496: xfree(p);
497: xfree(signature);
498:
1.59 avsm 499: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 500:
501: /* Turn on permissions for getpwnam */
502: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
503:
504: return (0);
505: }
506:
507: /* Retrieves the password entry and also checks if the user is permitted */
508:
509: int
1.59 avsm 510: mm_answer_pwnamallow(int sock, Buffer *m)
1.1 provos 511: {
1.60 dtucker 512: char *username;
1.1 provos 513: struct passwd *pwent;
514: int allowed = 0;
1.3 markus 515:
1.14 markus 516: debug3("%s", __func__);
1.1 provos 517:
518: if (authctxt->attempt++ != 0)
1.14 markus 519: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 520:
1.60 dtucker 521: username = buffer_get_string(m, NULL);
1.1 provos 522:
1.60 dtucker 523: pwent = getpwnamallow(username);
1.1 provos 524:
1.60 dtucker 525: authctxt->user = xstrdup(username);
526: setproctitle("%s [priv]", pwent ? username : "unknown");
527: xfree(username);
1.1 provos 528:
529: buffer_clear(m);
530:
531: if (pwent == NULL) {
532: buffer_put_char(m, 0);
1.53 djm 533: authctxt->pw = fakepw();
1.1 provos 534: goto out;
535: }
536:
537: allowed = 1;
1.4 markus 538: authctxt->pw = pwent;
1.1 provos 539: authctxt->valid = 1;
540:
541: buffer_put_char(m, 1);
542: buffer_put_string(m, pwent, sizeof(struct passwd));
543: buffer_put_cstring(m, pwent->pw_name);
544: buffer_put_cstring(m, "*");
545: buffer_put_cstring(m, pwent->pw_gecos);
546: buffer_put_cstring(m, pwent->pw_class);
547: buffer_put_cstring(m, pwent->pw_dir);
548: buffer_put_cstring(m, pwent->pw_shell);
549:
550: out:
1.14 markus 551: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 552: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 553:
554: /* For SSHv1 allow authentication now */
555: if (!compat20)
556: monitor_permit_authentications(1);
1.10 djm 557: else {
1.1 provos 558: /* Allow service/style information on the auth context */
559: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
1.10 djm 560: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
561: }
562:
563:
564: return (0);
565: }
566:
1.59 avsm 567: int mm_answer_auth2_read_banner(int sock, Buffer *m)
1.10 djm 568: {
569: char *banner;
570:
571: buffer_clear(m);
572: banner = auth2_read_banner();
573: buffer_put_cstring(m, banner != NULL ? banner : "");
1.59 avsm 574: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.1 provos 575:
1.10 djm 576: if (banner != NULL)
1.21 deraadt 577: xfree(banner);
1.1 provos 578:
579: return (0);
580: }
581:
582: int
1.59 avsm 583: mm_answer_authserv(int sock, Buffer *m)
1.1 provos 584: {
585: monitor_permit_authentications(1);
586:
587: authctxt->service = buffer_get_string(m, NULL);
588: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 589: debug3("%s: service=%s, style=%s",
1.14 markus 590: __func__, authctxt->service, authctxt->style);
1.6 stevesk 591:
1.1 provos 592: if (strlen(authctxt->style) == 0) {
593: xfree(authctxt->style);
594: authctxt->style = NULL;
595: }
596:
597: return (0);
598: }
599:
600: int
1.59 avsm 601: mm_answer_authpassword(int sock, Buffer *m)
1.1 provos 602: {
603: static int call_count;
604: char *passwd;
1.22 stevesk 605: int authenticated;
606: u_int plen;
1.1 provos 607:
608: passwd = buffer_get_string(m, &plen);
609: /* Only authenticate if the context is valid */
1.12 markus 610: authenticated = options.password_authentication &&
1.48 markus 611: auth_password(authctxt, passwd);
1.1 provos 612: memset(passwd, 0, strlen(passwd));
613: xfree(passwd);
614:
615: buffer_clear(m);
616: buffer_put_int(m, authenticated);
617:
1.14 markus 618: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 619: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 620:
621: call_count++;
622: if (plen == 0 && call_count == 1)
623: auth_method = "none";
624: else
625: auth_method = "password";
626:
627: /* Causes monitor loop to terminate if authenticated */
628: return (authenticated);
629: }
630:
631: #ifdef BSD_AUTH
632: int
1.59 avsm 633: mm_answer_bsdauthquery(int sock, Buffer *m)
1.1 provos 634: {
635: char *name, *infotxt;
636: u_int numprompts;
637: u_int *echo_on;
638: char **prompts;
1.31 markus 639: u_int success;
1.1 provos 640:
1.31 markus 641: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
642: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 643:
644: buffer_clear(m);
1.31 markus 645: buffer_put_int(m, success);
646: if (success)
1.1 provos 647: buffer_put_cstring(m, prompts[0]);
648:
1.31 markus 649: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 650: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 651:
1.31 markus 652: if (success) {
1.1 provos 653: xfree(name);
654: xfree(infotxt);
655: xfree(prompts);
656: xfree(echo_on);
657: }
658:
659: return (0);
660: }
661:
662: int
1.59 avsm 663: mm_answer_bsdauthrespond(int sock, Buffer *m)
1.1 provos 664: {
665: char *response;
666: int authok;
667:
668: if (authctxt->as == 0)
1.14 markus 669: fatal("%s: no bsd auth session", __func__);
1.1 provos 670:
671: response = buffer_get_string(m, NULL);
1.12 markus 672: authok = options.challenge_response_authentication &&
673: auth_userresponse(authctxt->as, response, 0);
1.1 provos 674: authctxt->as = NULL;
1.14 markus 675: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.1 provos 676: xfree(response);
677:
678: buffer_clear(m);
679: buffer_put_int(m, authok);
680:
1.14 markus 681: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 682: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 683:
684: auth_method = "bsdauth";
685:
686: return (authok != 0);
687: }
688: #endif
689:
690: #ifdef SKEY
691: int
1.59 avsm 692: mm_answer_skeyquery(int sock, Buffer *m)
1.1 provos 693: {
694: struct skey skey;
695: char challenge[1024];
1.31 markus 696: u_int success;
1.1 provos 697:
1.31 markus 698: success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
1.1 provos 699:
700: buffer_clear(m);
1.31 markus 701: buffer_put_int(m, success);
702: if (success)
1.1 provos 703: buffer_put_cstring(m, challenge);
704:
1.31 markus 705: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 706: mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
1.1 provos 707:
708: return (0);
709: }
710:
711: int
1.59 avsm 712: mm_answer_skeyrespond(int sock, Buffer *m)
1.1 provos 713: {
714: char *response;
715: int authok;
716:
717: response = buffer_get_string(m, NULL);
718:
1.12 markus 719: authok = (options.challenge_response_authentication &&
720: authctxt->valid &&
1.1 provos 721: skey_haskey(authctxt->pw->pw_name) == 0 &&
722: skey_passcheck(authctxt->pw->pw_name, response) != -1);
723:
724: xfree(response);
725:
726: buffer_clear(m);
727: buffer_put_int(m, authok);
728:
1.14 markus 729: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 730: mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
1.1 provos 731:
732: auth_method = "skey";
733:
734: return (authok != 0);
735: }
736: #endif
737:
1.2 markus 738: static void
1.1 provos 739: mm_append_debug(Buffer *m)
740: {
741: if (auth_debug_init && buffer_len(&auth_debug)) {
1.14 markus 742: debug3("%s: Appending debug messages for child", __func__);
1.1 provos 743: buffer_append(m, buffer_ptr(&auth_debug),
744: buffer_len(&auth_debug));
745: buffer_clear(&auth_debug);
746: }
747: }
748:
749: int
1.59 avsm 750: mm_answer_keyallowed(int sock, Buffer *m)
1.1 provos 751: {
752: Key *key;
1.26 markus 753: char *cuser, *chost;
754: u_char *blob;
1.1 provos 755: u_int bloblen;
756: enum mm_keytype type = 0;
757: int allowed = 0;
758:
1.14 markus 759: debug3("%s entering", __func__);
1.3 markus 760:
1.1 provos 761: type = buffer_get_int(m);
762: cuser = buffer_get_string(m, NULL);
763: chost = buffer_get_string(m, NULL);
764: blob = buffer_get_string(m, &bloblen);
765:
766: key = key_from_blob(blob, bloblen);
767:
768: if ((compat20 && type == MM_RSAHOSTKEY) ||
769: (!compat20 && type != MM_RSAHOSTKEY))
1.14 markus 770: fatal("%s: key type and protocol mismatch", __func__);
1.1 provos 771:
1.14 markus 772: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 773:
1.51 djm 774: if (key != NULL && authctxt->valid) {
1.63 ! deraadt 775: switch (type) {
1.1 provos 776: case MM_USERKEY:
1.12 markus 777: allowed = options.pubkey_authentication &&
778: user_key_allowed(authctxt->pw, key);
1.1 provos 779: break;
780: case MM_HOSTKEY:
1.12 markus 781: allowed = options.hostbased_authentication &&
782: hostbased_key_allowed(authctxt->pw,
1.1 provos 783: cuser, chost, key);
784: break;
785: case MM_RSAHOSTKEY:
786: key->type = KEY_RSA1; /* XXX */
1.12 markus 787: allowed = options.rhosts_rsa_authentication &&
788: auth_rhosts_rsa_key_allowed(authctxt->pw,
1.1 provos 789: cuser, chost, key);
790: break;
791: default:
1.14 markus 792: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 793: break;
794: }
1.33 markus 795: }
796: if (key != NULL)
1.1 provos 797: key_free(key);
798:
799: /* clear temporarily storage (used by verify) */
800: monitor_reset_key_state();
801:
802: if (allowed) {
803: /* Save temporarily for comparison in verify */
804: key_blob = blob;
805: key_bloblen = bloblen;
806: key_blobtype = type;
807: hostbased_cuser = cuser;
808: hostbased_chost = chost;
809: }
810:
811: debug3("%s: key %p is %s",
1.14 markus 812: __func__, key, allowed ? "allowed" : "disallowed");
1.1 provos 813:
814: buffer_clear(m);
815: buffer_put_int(m, allowed);
1.32 markus 816: buffer_put_int(m, forced_command != NULL);
1.1 provos 817:
818: mm_append_debug(m);
819:
1.59 avsm 820: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 821:
822: if (type == MM_RSAHOSTKEY)
823: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
824:
825: return (0);
826: }
827:
828: static int
829: monitor_valid_userblob(u_char *data, u_int datalen)
830: {
831: Buffer b;
1.26 markus 832: char *p;
1.1 provos 833: u_int len;
834: int fail = 0;
835:
836: buffer_init(&b);
837: buffer_append(&b, data, datalen);
1.3 markus 838:
1.1 provos 839: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 840: p = buffer_ptr(&b);
841: len = buffer_len(&b);
842: if ((session_id2 == NULL) ||
843: (len < session_id2_len) ||
844: (memcmp(p, session_id2, session_id2_len) != 0))
845: fail++;
1.1 provos 846: buffer_consume(&b, session_id2_len);
847: } else {
1.13 markus 848: p = buffer_get_string(&b, &len);
849: if ((session_id2 == NULL) ||
850: (len != session_id2_len) ||
851: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 852: fail++;
1.13 markus 853: xfree(p);
1.1 provos 854: }
855: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
856: fail++;
857: p = buffer_get_string(&b, NULL);
858: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 859: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 860: authctxt->user, p);
861: fail++;
862: }
863: xfree(p);
864: buffer_skip_string(&b);
865: if (datafellows & SSH_BUG_PKAUTH) {
866: if (!buffer_get_char(&b))
867: fail++;
868: } else {
869: p = buffer_get_string(&b, NULL);
870: if (strcmp("publickey", p) != 0)
871: fail++;
872: xfree(p);
873: if (!buffer_get_char(&b))
874: fail++;
875: buffer_skip_string(&b);
876: }
877: buffer_skip_string(&b);
878: if (buffer_len(&b) != 0)
879: fail++;
880: buffer_free(&b);
881: return (fail == 0);
882: }
883:
884: static int
1.26 markus 885: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
886: char *chost)
1.1 provos 887: {
888: Buffer b;
1.26 markus 889: char *p;
1.1 provos 890: u_int len;
891: int fail = 0;
892:
893: buffer_init(&b);
894: buffer_append(&b, data, datalen);
1.3 markus 895:
1.13 markus 896: p = buffer_get_string(&b, &len);
897: if ((session_id2 == NULL) ||
898: (len != session_id2_len) ||
899: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 900: fail++;
1.13 markus 901: xfree(p);
902:
1.1 provos 903: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
904: fail++;
905: p = buffer_get_string(&b, NULL);
906: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 907: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 908: authctxt->user, p);
909: fail++;
910: }
911: xfree(p);
912: buffer_skip_string(&b); /* service */
913: p = buffer_get_string(&b, NULL);
914: if (strcmp(p, "hostbased") != 0)
915: fail++;
916: xfree(p);
917: buffer_skip_string(&b); /* pkalg */
918: buffer_skip_string(&b); /* pkblob */
919:
920: /* verify client host, strip trailing dot if necessary */
921: p = buffer_get_string(&b, NULL);
922: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
923: p[len - 1] = '\0';
924: if (strcmp(p, chost) != 0)
925: fail++;
926: xfree(p);
927:
928: /* verify client user */
929: p = buffer_get_string(&b, NULL);
930: if (strcmp(p, cuser) != 0)
931: fail++;
932: xfree(p);
933:
934: if (buffer_len(&b) != 0)
935: fail++;
936: buffer_free(&b);
937: return (fail == 0);
938: }
939:
940: int
1.59 avsm 941: mm_answer_keyverify(int sock, Buffer *m)
1.1 provos 942: {
943: Key *key;
944: u_char *signature, *data, *blob;
945: u_int signaturelen, datalen, bloblen;
946: int verified = 0;
947: int valid_data = 0;
948:
949: blob = buffer_get_string(m, &bloblen);
950: signature = buffer_get_string(m, &signaturelen);
951: data = buffer_get_string(m, &datalen);
952:
953: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 954: !monitor_allowed_key(blob, bloblen))
1.14 markus 955: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 956:
957: key = key_from_blob(blob, bloblen);
958: if (key == NULL)
1.14 markus 959: fatal("%s: bad public key blob", __func__);
1.1 provos 960:
961: switch (key_blobtype) {
962: case MM_USERKEY:
963: valid_data = monitor_valid_userblob(data, datalen);
964: break;
965: case MM_HOSTKEY:
966: valid_data = monitor_valid_hostbasedblob(data, datalen,
967: hostbased_cuser, hostbased_chost);
968: break;
969: default:
970: valid_data = 0;
971: break;
972: }
973: if (!valid_data)
1.14 markus 974: fatal("%s: bad signature data blob", __func__);
1.1 provos 975:
976: verified = key_verify(key, signature, signaturelen, data, datalen);
977: debug3("%s: key %p signature %s",
1.14 markus 978: __func__, key, verified ? "verified" : "unverified");
1.1 provos 979:
980: key_free(key);
981: xfree(blob);
982: xfree(signature);
983: xfree(data);
984:
1.17 stevesk 985: auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
986:
1.1 provos 987: monitor_reset_key_state();
1.3 markus 988:
1.1 provos 989: buffer_clear(m);
990: buffer_put_int(m, verified);
1.59 avsm 991: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.1 provos 992:
993: return (verified);
994: }
995:
1.2 markus 996: static void
1.1 provos 997: mm_record_login(Session *s, struct passwd *pw)
998: {
999: socklen_t fromlen;
1000: struct sockaddr_storage from;
1001:
1002: /*
1003: * Get IP address of client. If the connection is not a socket, let
1004: * the address be 0.0.0.0.
1005: */
1006: memset(&from, 0, sizeof(from));
1.24 stevesk 1007: fromlen = sizeof(from);
1.1 provos 1008: if (packet_connection_is_on_socket()) {
1009: if (getpeername(packet_get_connection_in(),
1010: (struct sockaddr *) & from, &fromlen) < 0) {
1011: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1012: cleanup_exit(255);
1.1 provos 1013: }
1014: }
1015: /* Record that there was a login on that tty from the remote host. */
1016: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.42 markus 1017: get_remote_name_or_ip(utmp_len, options.use_dns),
1.24 stevesk 1018: (struct sockaddr *)&from, fromlen);
1.1 provos 1019: }
1020:
1021: static void
1022: mm_session_close(Session *s)
1023: {
1.41 djm 1024: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1025: if (s->ttyfd != -1) {
1.14 markus 1026: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1027: session_pty_cleanup2(s);
1028: }
1029: s->used = 0;
1030: }
1031:
1032: int
1.59 avsm 1033: mm_answer_pty(int sock, Buffer *m)
1.1 provos 1034: {
1.11 mouring 1035: extern struct monitor *pmonitor;
1.1 provos 1036: Session *s;
1037: int res, fd0;
1038:
1.14 markus 1039: debug3("%s entering", __func__);
1.1 provos 1040:
1041: buffer_clear(m);
1042: s = session_new();
1043: if (s == NULL)
1044: goto error;
1045: s->authctxt = authctxt;
1046: s->pw = authctxt->pw;
1.11 mouring 1047: s->pid = pmonitor->m_pid;
1.1 provos 1048: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1049: if (res == 0)
1050: goto error;
1051: pty_setowner(authctxt->pw, s->tty);
1052:
1053: buffer_put_int(m, 1);
1054: buffer_put_cstring(m, s->tty);
1055:
1056: /* We need to trick ttyslot */
1057: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1058: fatal("%s: dup2", __func__);
1.1 provos 1059:
1060: mm_record_login(s, authctxt->pw);
1061:
1062: /* Now we can close the file descriptor again */
1063: close(0);
1.61 dtucker 1064:
1065: /* send messages generated by record_login */
1066: buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1067: buffer_clear(&loginmsg);
1068:
1069: mm_request_send(sock, MONITOR_ANS_PTY, m);
1070:
1071: mm_send_fd(sock, s->ptyfd);
1072: mm_send_fd(sock, s->ttyfd);
1.1 provos 1073:
1074: /* make sure nothing uses fd 0 */
1075: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1076: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1077: if (fd0 != 0)
1.14 markus 1078: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1079:
1080: /* slave is not needed */
1081: close(s->ttyfd);
1082: s->ttyfd = s->ptyfd;
1083: /* no need to dup() because nobody closes ptyfd */
1084: s->ptymaster = s->ptyfd;
1085:
1.14 markus 1086: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1087:
1088: return (0);
1089:
1090: error:
1091: if (s != NULL)
1092: mm_session_close(s);
1093: buffer_put_int(m, 0);
1.59 avsm 1094: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1095: return (0);
1096: }
1097:
1098: int
1.59 avsm 1099: mm_answer_pty_cleanup(int sock, Buffer *m)
1.1 provos 1100: {
1101: Session *s;
1102: char *tty;
1103:
1.14 markus 1104: debug3("%s entering", __func__);
1.1 provos 1105:
1106: tty = buffer_get_string(m, NULL);
1107: if ((s = session_by_tty(tty)) != NULL)
1108: mm_session_close(s);
1109: buffer_clear(m);
1110: xfree(tty);
1111: return (0);
1112: }
1113:
1114: int
1.59 avsm 1115: mm_answer_sesskey(int sock, Buffer *m)
1.1 provos 1116: {
1117: BIGNUM *p;
1118: int rsafail;
1119:
1120: /* Turn off permissions */
1.62 dtucker 1121: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1.1 provos 1122:
1123: if ((p = BN_new()) == NULL)
1.14 markus 1124: fatal("%s: BN_new", __func__);
1.1 provos 1125:
1126: buffer_get_bignum2(m, p);
1127:
1128: rsafail = ssh1_session_key(p);
1129:
1130: buffer_clear(m);
1131: buffer_put_int(m, rsafail);
1132: buffer_put_bignum2(m, p);
1133:
1134: BN_clear_free(p);
1135:
1.59 avsm 1136: mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1.1 provos 1137:
1138: /* Turn on permissions for sessid passing */
1139: monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1140:
1141: return (0);
1142: }
1143:
1144: int
1.59 avsm 1145: mm_answer_sessid(int sock, Buffer *m)
1.1 provos 1146: {
1147: int i;
1148:
1.14 markus 1149: debug3("%s entering", __func__);
1.1 provos 1150:
1151: if (buffer_len(m) != 16)
1.14 markus 1152: fatal("%s: bad ssh1 session id", __func__);
1.1 provos 1153: for (i = 0; i < 16; i++)
1154: session_id[i] = buffer_get_char(m);
1155:
1156: /* Turn on permissions for getpwnam */
1157: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1158:
1159: return (0);
1160: }
1161:
1162: int
1.59 avsm 1163: mm_answer_rsa_keyallowed(int sock, Buffer *m)
1.1 provos 1164: {
1165: BIGNUM *client_n;
1166: Key *key = NULL;
1.3 markus 1167: u_char *blob = NULL;
1168: u_int blen = 0;
1.1 provos 1169: int allowed = 0;
1170:
1.14 markus 1171: debug3("%s entering", __func__);
1.1 provos 1172:
1.12 markus 1173: if (options.rsa_authentication && authctxt->valid) {
1.1 provos 1174: if ((client_n = BN_new()) == NULL)
1.14 markus 1175: fatal("%s: BN_new", __func__);
1.1 provos 1176: buffer_get_bignum2(m, client_n);
1177: allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1178: BN_clear_free(client_n);
1179: }
1180: buffer_clear(m);
1181: buffer_put_int(m, allowed);
1.32 markus 1182: buffer_put_int(m, forced_command != NULL);
1.1 provos 1183:
1184: /* clear temporarily storage (used by generate challenge) */
1185: monitor_reset_key_state();
1186:
1187: if (allowed && key != NULL) {
1188: key->type = KEY_RSA; /* cheat for key_to_blob */
1189: if (key_to_blob(key, &blob, &blen) == 0)
1.14 markus 1190: fatal("%s: key_to_blob failed", __func__);
1.1 provos 1191: buffer_put_string(m, blob, blen);
1192:
1193: /* Save temporarily for comparison in verify */
1194: key_blob = blob;
1195: key_bloblen = blen;
1196: key_blobtype = MM_RSAUSERKEY;
1.33 markus 1197: }
1198: if (key != NULL)
1.1 provos 1199: key_free(key);
1200:
1201: mm_append_debug(m);
1202:
1.59 avsm 1203: mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1.1 provos 1204:
1205: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1206: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1207: return (0);
1208: }
1209:
1210: int
1.59 avsm 1211: mm_answer_rsa_challenge(int sock, Buffer *m)
1.1 provos 1212: {
1213: Key *key = NULL;
1.3 markus 1214: u_char *blob;
1215: u_int blen;
1.1 provos 1216:
1.14 markus 1217: debug3("%s entering", __func__);
1.1 provos 1218:
1219: if (!authctxt->valid)
1.14 markus 1220: fatal("%s: authctxt not valid", __func__);
1.1 provos 1221: blob = buffer_get_string(m, &blen);
1222: if (!monitor_allowed_key(blob, blen))
1.14 markus 1223: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1224: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1225: fatal("%s: key type mismatch", __func__);
1.1 provos 1226: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1227: fatal("%s: received bad key", __func__);
1.1 provos 1228:
1229: if (ssh1_challenge)
1230: BN_clear_free(ssh1_challenge);
1231: ssh1_challenge = auth_rsa_generate_challenge(key);
1232:
1233: buffer_clear(m);
1234: buffer_put_bignum2(m, ssh1_challenge);
1235:
1.14 markus 1236: debug3("%s sending reply", __func__);
1.59 avsm 1237: mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1.1 provos 1238:
1239: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1.33 markus 1240:
1241: xfree(blob);
1242: key_free(key);
1.1 provos 1243: return (0);
1244: }
1245:
1246: int
1.59 avsm 1247: mm_answer_rsa_response(int sock, Buffer *m)
1.1 provos 1248: {
1249: Key *key = NULL;
1.3 markus 1250: u_char *blob, *response;
1251: u_int blen, len;
1252: int success;
1.1 provos 1253:
1.14 markus 1254: debug3("%s entering", __func__);
1.1 provos 1255:
1256: if (!authctxt->valid)
1.14 markus 1257: fatal("%s: authctxt not valid", __func__);
1.1 provos 1258: if (ssh1_challenge == NULL)
1.14 markus 1259: fatal("%s: no ssh1_challenge", __func__);
1.1 provos 1260:
1261: blob = buffer_get_string(m, &blen);
1262: if (!monitor_allowed_key(blob, blen))
1.14 markus 1263: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1264: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1265: fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1.1 provos 1266: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1267: fatal("%s: received bad key", __func__);
1.1 provos 1268: response = buffer_get_string(m, &len);
1269: if (len != 16)
1.14 markus 1270: fatal("%s: received bad response to challenge", __func__);
1.1 provos 1271: success = auth_rsa_verify_response(key, ssh1_challenge, response);
1272:
1.33 markus 1273: xfree(blob);
1.1 provos 1274: key_free(key);
1275: xfree(response);
1276:
1277: auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1278:
1279: /* reset state */
1280: BN_clear_free(ssh1_challenge);
1281: ssh1_challenge = NULL;
1282: monitor_reset_key_state();
1283:
1284: buffer_clear(m);
1285: buffer_put_int(m, success);
1.59 avsm 1286: mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1.1 provos 1287:
1288: return (success);
1289: }
1290:
1291: int
1.59 avsm 1292: mm_answer_term(int sock, Buffer *req)
1.1 provos 1293: {
1.11 mouring 1294: extern struct monitor *pmonitor;
1.1 provos 1295: int res, status;
1296:
1.14 markus 1297: debug3("%s: tearing down sessions", __func__);
1.1 provos 1298:
1299: /* The child is terminating */
1300: session_destroy_all(&mm_session_close);
1301:
1.11 mouring 1302: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1303: if (errno != EINTR)
1304: exit(1);
1.1 provos 1305:
1306: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1307:
1308: /* Terminate process */
1.57 deraadt 1309: exit(res);
1.1 provos 1310: }
1311:
1312: void
1.11 mouring 1313: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1314: {
1315: if (compat20) {
1316: set_newkeys(MODE_IN);
1317: set_newkeys(MODE_OUT);
1318: } else {
1319: packet_set_protocol_flags(child_state.ssh1protoflags);
1.15 markus 1320: packet_set_encryption_key(child_state.ssh1key,
1321: child_state.ssh1keylen, child_state.ssh1cipher);
1322: xfree(child_state.ssh1key);
1.1 provos 1323: }
1324:
1.15 markus 1325: /* for rc4 and other stateful ciphers */
1.1 provos 1326: packet_set_keycontext(MODE_OUT, child_state.keyout);
1327: xfree(child_state.keyout);
1328: packet_set_keycontext(MODE_IN, child_state.keyin);
1329: xfree(child_state.keyin);
1330:
1331: if (!compat20) {
1332: packet_set_iv(MODE_OUT, child_state.ivout);
1333: xfree(child_state.ivout);
1334: packet_set_iv(MODE_IN, child_state.ivin);
1335: xfree(child_state.ivin);
1336: }
1337:
1338: memcpy(&incoming_stream, &child_state.incoming,
1339: sizeof(incoming_stream));
1340: memcpy(&outgoing_stream, &child_state.outgoing,
1341: sizeof(outgoing_stream));
1.3 markus 1342:
1.1 provos 1343: /* Update with new address */
1.16 djm 1344: if (options.compression)
1345: mm_init_compression(pmonitor->m_zlib);
1.1 provos 1346:
1347: /* Network I/O buffers */
1348: /* XXX inefficient for large buffers, need: buffer_init_from_string */
1349: buffer_clear(&input);
1350: buffer_append(&input, child_state.input, child_state.ilen);
1351: memset(child_state.input, 0, child_state.ilen);
1352: xfree(child_state.input);
1353:
1354: buffer_clear(&output);
1355: buffer_append(&output, child_state.output, child_state.olen);
1356: memset(child_state.output, 0, child_state.olen);
1357: xfree(child_state.output);
1358: }
1359:
1.2 markus 1360: static Kex *
1.1 provos 1361: mm_get_kex(Buffer *m)
1362: {
1363: Kex *kex;
1364: void *blob;
1365: u_int bloblen;
1366:
1367: kex = xmalloc(sizeof(*kex));
1368: memset(kex, 0, sizeof(*kex));
1369: kex->session_id = buffer_get_string(m, &kex->session_id_len);
1.13 markus 1370: if ((session_id2 == NULL) ||
1371: (kex->session_id_len != session_id2_len) ||
1372: (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1373: fatal("mm_get_get: internal error: bad session id");
1.1 provos 1374: kex->we_need = buffer_get_int(m);
1.34 markus 1375: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1.58 djm 1376: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1.34 markus 1377: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.1 provos 1378: kex->server = 1;
1379: kex->hostkey_type = buffer_get_int(m);
1380: kex->kex_type = buffer_get_int(m);
1381: blob = buffer_get_string(m, &bloblen);
1382: buffer_init(&kex->my);
1383: buffer_append(&kex->my, blob, bloblen);
1384: xfree(blob);
1385: blob = buffer_get_string(m, &bloblen);
1386: buffer_init(&kex->peer);
1387: buffer_append(&kex->peer, blob, bloblen);
1388: xfree(blob);
1389: kex->done = 1;
1390: kex->flags = buffer_get_int(m);
1391: kex->client_version_string = buffer_get_string(m, NULL);
1392: kex->server_version_string = buffer_get_string(m, NULL);
1393: kex->load_host_key=&get_hostkey_by_type;
1394: kex->host_key_index=&get_hostkey_index;
1395:
1396: return (kex);
1397: }
1398:
1399: /* This function requries careful sanity checking */
1400:
1401: void
1.11 mouring 1402: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1403: {
1404: Buffer m;
1405: u_char *blob, *p;
1406: u_int bloblen, plen;
1.37 markus 1407: u_int32_t seqnr, packets;
1408: u_int64_t blocks;
1.1 provos 1409:
1.14 markus 1410: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1411:
1412: buffer_init(&m);
1.11 mouring 1413: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1.1 provos 1414: if (!compat20) {
1415: child_state.ssh1protoflags = buffer_get_int(&m);
1416: child_state.ssh1cipher = buffer_get_int(&m);
1.15 markus 1417: child_state.ssh1key = buffer_get_string(&m,
1418: &child_state.ssh1keylen);
1.1 provos 1419: child_state.ivout = buffer_get_string(&m,
1420: &child_state.ivoutlen);
1421: child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1422: goto skip;
1423: } else {
1424: /* Get the Kex for rekeying */
1.11 mouring 1425: *pmonitor->m_pkex = mm_get_kex(&m);
1.1 provos 1426: }
1427:
1428: blob = buffer_get_string(&m, &bloblen);
1429: current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1430: xfree(blob);
1431:
1.14 markus 1432: debug3("%s: Waiting for second key", __func__);
1.1 provos 1433: blob = buffer_get_string(&m, &bloblen);
1434: current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1435: xfree(blob);
1.3 markus 1436:
1.1 provos 1437: /* Now get sequence numbers for the packets */
1.37 markus 1438: seqnr = buffer_get_int(&m);
1439: blocks = buffer_get_int64(&m);
1440: packets = buffer_get_int(&m);
1441: packet_set_state(MODE_OUT, seqnr, blocks, packets);
1442: seqnr = buffer_get_int(&m);
1443: blocks = buffer_get_int64(&m);
1444: packets = buffer_get_int(&m);
1445: packet_set_state(MODE_IN, seqnr, blocks, packets);
1.1 provos 1446:
1447: skip:
1448: /* Get the key context */
1449: child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1450: child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1451:
1.14 markus 1452: debug3("%s: Getting compression state", __func__);
1.1 provos 1453: /* Get compression state */
1454: p = buffer_get_string(&m, &plen);
1455: if (plen != sizeof(child_state.outgoing))
1.14 markus 1456: fatal("%s: bad request size", __func__);
1.1 provos 1457: memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1458: xfree(p);
1459:
1460: p = buffer_get_string(&m, &plen);
1461: if (plen != sizeof(child_state.incoming))
1.14 markus 1462: fatal("%s: bad request size", __func__);
1.1 provos 1463: memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1464: xfree(p);
1465:
1466: /* Network I/O buffers */
1.14 markus 1467: debug3("%s: Getting Network I/O buffers", __func__);
1.1 provos 1468: child_state.input = buffer_get_string(&m, &child_state.ilen);
1469: child_state.output = buffer_get_string(&m, &child_state.olen);
1470:
1471: buffer_free(&m);
1472: }
1473:
1474:
1475: /* Allocation functions for zlib */
1476: void *
1477: mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1478: {
1.30 markus 1479: size_t len = (size_t) size * ncount;
1.1 provos 1480: void *address;
1481:
1.23 millert 1482: if (len == 0 || ncount > SIZE_T_MAX / size)
1.18 deraadt 1483: fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1484:
1485: address = mm_malloc(mm, len);
1.1 provos 1486:
1487: return (address);
1488: }
1489:
1490: void
1491: mm_zfree(struct mm_master *mm, void *address)
1492: {
1493: mm_free(mm, address);
1494: }
1495:
1496: void
1497: mm_init_compression(struct mm_master *mm)
1498: {
1499: outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1500: outgoing_stream.zfree = (free_func)mm_zfree;
1501: outgoing_stream.opaque = mm;
1502:
1503: incoming_stream.zalloc = (alloc_func)mm_zalloc;
1504: incoming_stream.zfree = (free_func)mm_zfree;
1505: incoming_stream.opaque = mm;
1506: }
1507:
1508: /* XXX */
1509:
1510: #define FD_CLOSEONEXEC(x) do { \
1511: if (fcntl(x, F_SETFD, 1) == -1) \
1512: fatal("fcntl(%d, F_SETFD)", x); \
1513: } while (0)
1514:
1.2 markus 1515: static void
1.1 provos 1516: monitor_socketpair(int *pair)
1.3 markus 1517: {
1.1 provos 1518: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.14 markus 1519: fatal("%s: socketpair", __func__);
1.1 provos 1520: FD_CLOSEONEXEC(pair[0]);
1521: FD_CLOSEONEXEC(pair[1]);
1522: }
1523:
1524: #define MM_MEMSIZE 65536
1525:
1526: struct monitor *
1527: monitor_init(void)
1528: {
1529: struct monitor *mon;
1530: int pair[2];
1531:
1532: mon = xmalloc(sizeof(*mon));
1533:
1.55 dtucker 1534: mon->m_pid = 0;
1.1 provos 1535: monitor_socketpair(pair);
1536:
1537: mon->m_recvfd = pair[0];
1538: mon->m_sendfd = pair[1];
1539:
1540: /* Used to share zlib space across processes */
1.16 djm 1541: if (options.compression) {
1542: mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1543: mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1.1 provos 1544:
1.16 djm 1545: /* Compression needs to share state across borders */
1546: mm_init_compression(mon->m_zlib);
1547: }
1.1 provos 1548:
1549: return mon;
1550: }
1551:
1552: void
1553: monitor_reinit(struct monitor *mon)
1554: {
1555: int pair[2];
1556:
1557: monitor_socketpair(pair);
1558:
1559: mon->m_recvfd = pair[0];
1560: mon->m_sendfd = pair[1];
1561: }
1.46 markus 1562:
1563: #ifdef GSSAPI
1564: int
1.59 avsm 1565: mm_answer_gss_setup_ctx(int sock, Buffer *m)
1.46 markus 1566: {
1.59 avsm 1567: gss_OID_desc goid;
1.46 markus 1568: OM_uint32 major;
1569: u_int len;
1570:
1.59 avsm 1571: goid.elements = buffer_get_string(m, &len);
1572: goid.length = len;
1.46 markus 1573:
1.59 avsm 1574: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1575:
1.59 avsm 1576: xfree(goid.elements);
1.46 markus 1577:
1578: buffer_clear(m);
1579: buffer_put_int(m, major);
1580:
1.59 avsm 1581: mm_request_send(sock,MONITOR_ANS_GSSSETUP, m);
1.46 markus 1582:
1583: /* Now we have a context, enable the step */
1584: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1585:
1586: return (0);
1587: }
1588:
1589: int
1.59 avsm 1590: mm_answer_gss_accept_ctx(int sock, Buffer *m)
1.46 markus 1591: {
1592: gss_buffer_desc in;
1593: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1594: OM_uint32 major,minor;
1595: OM_uint32 flags = 0; /* GSI needs this */
1.47 deraadt 1596: u_int len;
1.46 markus 1597:
1.47 deraadt 1598: in.value = buffer_get_string(m, &len);
1599: in.length = len;
1.46 markus 1600: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1601: xfree(in.value);
1602:
1603: buffer_clear(m);
1604: buffer_put_int(m, major);
1605: buffer_put_string(m, out.value, out.length);
1606: buffer_put_int(m, flags);
1.59 avsm 1607: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1608:
1609: gss_release_buffer(&minor, &out);
1610:
1611: if (major==GSS_S_COMPLETE) {
1612: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1613: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1614: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1615: }
1616: return (0);
1617: }
1618:
1619: int
1.59 avsm 1620: mm_answer_gss_checkmic(int sock, Buffer *m)
1.52 markus 1621: {
1622: gss_buffer_desc gssbuf, mic;
1623: OM_uint32 ret;
1624: u_int len;
1.54 djm 1625:
1.52 markus 1626: gssbuf.value = buffer_get_string(m, &len);
1627: gssbuf.length = len;
1628: mic.value = buffer_get_string(m, &len);
1629: mic.length = len;
1.54 djm 1630:
1.52 markus 1631: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1632:
1.52 markus 1633: xfree(gssbuf.value);
1634: xfree(mic.value);
1.54 djm 1635:
1.52 markus 1636: buffer_clear(m);
1637: buffer_put_int(m, ret);
1.54 djm 1638:
1.59 avsm 1639: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1640:
1.52 markus 1641: if (!GSS_ERROR(ret))
1642: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1643:
1.52 markus 1644: return (0);
1645: }
1646:
1647: int
1.59 avsm 1648: mm_answer_gss_userok(int sock, Buffer *m)
1.46 markus 1649: {
1650: int authenticated;
1651:
1652: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1653:
1654: buffer_clear(m);
1655: buffer_put_int(m, authenticated);
1656:
1657: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1658: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1659:
1.52 markus 1660: auth_method="gssapi-with-mic";
1.46 markus 1661:
1662: /* Monitor loop will terminate if authenticated */
1663: return (authenticated);
1664: }
1665: #endif /* GSSAPI */
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