Annotation of src/usr.bin/ssh/monitor.c, Revision 1.76
1.76 ! djm 1: /* $OpenBSD$ */
1.1 provos 2: /*
3: * Copyright 2002 Niels Provos <provos@citi.umich.edu>
4: * Copyright 2002 Markus Friedl <markus@openbsd.org>
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26: */
27:
28: #include "includes.h"
1.67 stevesk 29:
30: #include <sys/types.h>
31: #include <sys/wait.h>
1.1 provos 32:
1.65 stevesk 33: #include <paths.h>
1.68 stevesk 34: #include <signal.h>
1.1 provos 35:
36: #ifdef SKEY
37: #include <skey.h>
38: #endif
1.65 stevesk 39:
40: #include <openssl/dh.h>
1.1 provos 41:
42: #include "ssh.h"
43: #include "auth.h"
44: #include "kex.h"
45: #include "dh.h"
46: #include "zlib.h"
47: #include "packet.h"
48: #include "auth-options.h"
49: #include "sshpty.h"
50: #include "channels.h"
51: #include "session.h"
52: #include "sshlogin.h"
53: #include "canohost.h"
54: #include "log.h"
55: #include "servconf.h"
56: #include "monitor.h"
57: #include "monitor_mm.h"
58: #include "monitor_wrap.h"
59: #include "monitor_fdpass.h"
60: #include "xmalloc.h"
61: #include "misc.h"
62: #include "buffer.h"
63: #include "bufaux.h"
64: #include "compat.h"
65: #include "ssh2.h"
66:
1.46 markus 67: #ifdef GSSAPI
68: #include "ssh-gss.h"
69: static Gssctxt *gsscontext = NULL;
70: #endif
71:
1.1 provos 72: /* Imports */
73: extern ServerOptions options;
74: extern u_int utmp_len;
75: extern Newkeys *current_keys[];
76: extern z_stream incoming_stream;
77: extern z_stream outgoing_stream;
78: extern u_char session_id[];
79: extern Buffer input, output;
80: extern Buffer auth_debug;
81: extern int auth_debug_init;
1.61 dtucker 82: extern Buffer loginmsg;
1.1 provos 83:
84: /* State exported from the child */
85:
86: struct {
87: z_stream incoming;
88: z_stream outgoing;
89: u_char *keyin;
90: u_int keyinlen;
91: u_char *keyout;
92: u_int keyoutlen;
93: u_char *ivin;
94: u_int ivinlen;
95: u_char *ivout;
96: u_int ivoutlen;
1.15 markus 97: u_char *ssh1key;
98: u_int ssh1keylen;
1.1 provos 99: int ssh1cipher;
100: int ssh1protoflags;
101: u_char *input;
102: u_int ilen;
103: u_char *output;
104: u_int olen;
105: } child_state;
106:
1.43 markus 107: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 108:
109: int mm_answer_moduli(int, Buffer *);
110: int mm_answer_sign(int, Buffer *);
111: int mm_answer_pwnamallow(int, Buffer *);
1.10 djm 112: int mm_answer_auth2_read_banner(int, Buffer *);
1.1 provos 113: int mm_answer_authserv(int, Buffer *);
114: int mm_answer_authpassword(int, Buffer *);
115: int mm_answer_bsdauthquery(int, Buffer *);
116: int mm_answer_bsdauthrespond(int, Buffer *);
117: int mm_answer_skeyquery(int, Buffer *);
118: int mm_answer_skeyrespond(int, Buffer *);
119: int mm_answer_keyallowed(int, Buffer *);
120: int mm_answer_keyverify(int, Buffer *);
121: int mm_answer_pty(int, Buffer *);
122: int mm_answer_pty_cleanup(int, Buffer *);
123: int mm_answer_term(int, Buffer *);
124: int mm_answer_rsa_keyallowed(int, Buffer *);
125: int mm_answer_rsa_challenge(int, Buffer *);
126: int mm_answer_rsa_response(int, Buffer *);
127: int mm_answer_sesskey(int, Buffer *);
128: int mm_answer_sessid(int, Buffer *);
129:
1.46 markus 130: #ifdef GSSAPI
131: int mm_answer_gss_setup_ctx(int, Buffer *);
132: int mm_answer_gss_accept_ctx(int, Buffer *);
133: int mm_answer_gss_userok(int, Buffer *);
1.52 markus 134: int mm_answer_gss_checkmic(int, Buffer *);
1.46 markus 135: #endif
1.25 itojun 136:
1.1 provos 137: static Authctxt *authctxt;
138: static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
139:
140: /* local state for key verify */
141: static u_char *key_blob = NULL;
142: static u_int key_bloblen = 0;
143: static int key_blobtype = MM_NOKEY;
1.26 markus 144: static char *hostbased_cuser = NULL;
145: static char *hostbased_chost = NULL;
1.1 provos 146: static char *auth_method = "unknown";
1.44 markus 147: static u_int session_id2_len = 0;
1.13 markus 148: static u_char *session_id2 = NULL;
1.40 markus 149: static pid_t monitor_child_pid;
1.1 provos 150:
151: struct mon_table {
152: enum monitor_reqtype type;
153: int flags;
154: int (*f)(int, Buffer *);
155: };
156:
157: #define MON_ISAUTH 0x0004 /* Required for Authentication */
158: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
159: #define MON_ONCE 0x0010 /* Disable after calling */
160:
161: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
162:
163: #define MON_PERMIT 0x1000 /* Request is permitted */
164:
165: struct mon_table mon_dispatch_proto20[] = {
166: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
167: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
168: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
169: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 170: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 171: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
172: #ifdef BSD_AUTH
173: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 174: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 175: #endif
176: #ifdef SKEY
177: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
178: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
179: #endif
180: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
181: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 182: #ifdef GSSAPI
183: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
184: {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
185: {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
1.52 markus 186: {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
1.46 markus 187: #endif
1.1 provos 188: {0, 0, NULL}
189: };
190:
191: struct mon_table mon_dispatch_postauth20[] = {
192: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
193: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
194: {MONITOR_REQ_PTY, 0, mm_answer_pty},
195: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
196: {MONITOR_REQ_TERM, 0, mm_answer_term},
197: {0, 0, NULL}
198: };
199:
200: struct mon_table mon_dispatch_proto15[] = {
201: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
202: {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
203: {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
204: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
205: {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
206: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
207: {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
208: {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
209: #ifdef BSD_AUTH
210: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 211: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 212: #endif
213: #ifdef SKEY
214: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
215: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
216: #endif
217: {0, 0, NULL}
218: };
219:
220: struct mon_table mon_dispatch_postauth15[] = {
221: {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
222: {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
223: {MONITOR_REQ_TERM, 0, mm_answer_term},
224: {0, 0, NULL}
225: };
226:
227: struct mon_table *mon_dispatch;
228:
229: /* Specifies if a certain message is allowed at the moment */
230:
231: static void
232: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
233: {
234: while (ent->f != NULL) {
235: if (ent->type == type) {
236: ent->flags &= ~MON_PERMIT;
237: ent->flags |= permit ? MON_PERMIT : 0;
238: return;
239: }
240: ent++;
241: }
242: }
243:
244: static void
245: monitor_permit_authentications(int permit)
246: {
247: struct mon_table *ent = mon_dispatch;
248:
249: while (ent->f != NULL) {
250: if (ent->flags & MON_AUTH) {
251: ent->flags &= ~MON_PERMIT;
252: ent->flags |= permit ? MON_PERMIT : 0;
253: }
254: ent++;
255: }
256: }
257:
1.50 markus 258: void
259: monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
1.1 provos 260: {
261: struct mon_table *ent;
262: int authenticated = 0;
263:
264: debug3("preauth child monitor started");
265:
1.50 markus 266: authctxt = _authctxt;
267: memset(authctxt, 0, sizeof(*authctxt));
268:
1.1 provos 269: if (compat20) {
270: mon_dispatch = mon_dispatch_proto20;
271:
272: /* Permit requests for moduli and signatures */
273: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
274: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
275: } else {
276: mon_dispatch = mon_dispatch_proto15;
277:
278: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
279: }
280:
281: /* The first few requests do not require asynchronous access */
282: while (!authenticated) {
1.11 mouring 283: authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
1.1 provos 284: if (authenticated) {
285: if (!(ent->flags & MON_AUTHDECIDE))
286: fatal("%s: unexpected authentication from %d",
1.14 markus 287: __func__, ent->type);
1.1 provos 288: if (authctxt->pw->pw_uid == 0 &&
289: !auth_root_allowed(auth_method))
290: authenticated = 0;
291: }
292:
293: if (ent->flags & MON_AUTHDECIDE) {
294: auth_log(authctxt, authenticated, auth_method,
295: compat20 ? " ssh2" : "");
296: if (!authenticated)
297: authctxt->failures++;
298: }
299: }
300:
301: if (!authctxt->valid)
1.14 markus 302: fatal("%s: authenticated invalid user", __func__);
1.1 provos 303:
304: debug("%s: %s has been authenticated by privileged process",
1.14 markus 305: __func__, authctxt->user);
1.1 provos 306:
1.11 mouring 307: mm_get_keystate(pmonitor);
1.1 provos 308: }
309:
1.40 markus 310: static void
311: monitor_set_child_handler(pid_t pid)
312: {
313: monitor_child_pid = pid;
314: }
315:
316: static void
1.59 avsm 317: monitor_child_handler(int sig)
1.40 markus 318: {
1.59 avsm 319: kill(monitor_child_pid, sig);
1.40 markus 320: }
321:
1.1 provos 322: void
1.11 mouring 323: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 324: {
1.40 markus 325: monitor_set_child_handler(pmonitor->m_pid);
326: signal(SIGHUP, &monitor_child_handler);
327: signal(SIGTERM, &monitor_child_handler);
328:
1.1 provos 329: if (compat20) {
330: mon_dispatch = mon_dispatch_postauth20;
331:
332: /* Permit requests for moduli and signatures */
333: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
334: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
335: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
336: } else {
337: mon_dispatch = mon_dispatch_postauth15;
338: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
339: }
340: if (!no_pty_flag) {
341: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
342: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
343: }
344:
345: for (;;)
1.11 mouring 346: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 347: }
348:
349: void
1.11 mouring 350: monitor_sync(struct monitor *pmonitor)
1.1 provos 351: {
1.16 djm 352: if (options.compression) {
353: /* The member allocation is not visible, so sync it */
354: mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
355: }
1.1 provos 356: }
357:
358: int
1.11 mouring 359: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 360: struct mon_table **pent)
361: {
362: Buffer m;
363: int ret;
364: u_char type;
365:
366: buffer_init(&m);
367:
1.11 mouring 368: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 369: type = buffer_get_char(&m);
370:
1.14 markus 371: debug3("%s: checking request %d", __func__, type);
1.1 provos 372:
373: while (ent->f != NULL) {
374: if (ent->type == type)
375: break;
376: ent++;
377: }
378:
379: if (ent->f != NULL) {
380: if (!(ent->flags & MON_PERMIT))
1.14 markus 381: fatal("%s: unpermitted request %d", __func__,
1.1 provos 382: type);
1.11 mouring 383: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 384: buffer_free(&m);
385:
386: /* The child may use this request only once, disable it */
387: if (ent->flags & MON_ONCE) {
1.14 markus 388: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 389: type);
390: ent->flags &= ~MON_PERMIT;
391: }
392:
393: if (pent != NULL)
394: *pent = ent;
1.3 markus 395:
1.1 provos 396: return ret;
397: }
398:
1.14 markus 399: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 400:
401: /* NOTREACHED */
402: return (-1);
403: }
404:
405: /* allowed key state */
406: static int
407: monitor_allowed_key(u_char *blob, u_int bloblen)
408: {
409: /* make sure key is allowed */
410: if (key_blob == NULL || key_bloblen != bloblen ||
411: memcmp(key_blob, blob, key_bloblen))
412: return (0);
413: return (1);
414: }
415:
416: static void
417: monitor_reset_key_state(void)
418: {
419: /* reset state */
420: if (key_blob != NULL)
421: xfree(key_blob);
422: if (hostbased_cuser != NULL)
423: xfree(hostbased_cuser);
424: if (hostbased_chost != NULL)
425: xfree(hostbased_chost);
426: key_blob = NULL;
427: key_bloblen = 0;
428: key_blobtype = MM_NOKEY;
429: hostbased_cuser = NULL;
430: hostbased_chost = NULL;
431: }
432:
433: int
1.59 avsm 434: mm_answer_moduli(int sock, Buffer *m)
1.1 provos 435: {
436: DH *dh;
437: int min, want, max;
438:
439: min = buffer_get_int(m);
440: want = buffer_get_int(m);
441: max = buffer_get_int(m);
442:
443: debug3("%s: got parameters: %d %d %d",
1.14 markus 444: __func__, min, want, max);
1.1 provos 445: /* We need to check here, too, in case the child got corrupted */
446: if (max < min || want < min || max < want)
447: fatal("%s: bad parameters: %d %d %d",
1.14 markus 448: __func__, min, want, max);
1.1 provos 449:
450: buffer_clear(m);
451:
452: dh = choose_dh(min, want, max);
453: if (dh == NULL) {
454: buffer_put_char(m, 0);
455: return (0);
456: } else {
457: /* Send first bignum */
458: buffer_put_char(m, 1);
459: buffer_put_bignum2(m, dh->p);
460: buffer_put_bignum2(m, dh->g);
1.3 markus 461:
1.1 provos 462: DH_free(dh);
463: }
1.59 avsm 464: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 465: return (0);
466: }
467:
468: int
1.59 avsm 469: mm_answer_sign(int sock, Buffer *m)
1.1 provos 470: {
471: Key *key;
472: u_char *p;
473: u_char *signature;
474: u_int siglen, datlen;
475: int keyid;
1.3 markus 476:
1.14 markus 477: debug3("%s", __func__);
1.1 provos 478:
1.3 markus 479: keyid = buffer_get_int(m);
480: p = buffer_get_string(m, &datlen);
1.1 provos 481:
1.69 djm 482: /*
1.71 deraadt 483: * Supported KEX types will only return SHA1 (20 byte) or
1.69 djm 484: * SHA256 (32 byte) hashes
485: */
486: if (datlen != 20 && datlen != 32)
1.19 deraadt 487: fatal("%s: data length incorrect: %u", __func__, datlen);
1.1 provos 488:
1.13 markus 489: /* save session id, it will be passed on the first call */
490: if (session_id2_len == 0) {
491: session_id2_len = datlen;
492: session_id2 = xmalloc(session_id2_len);
493: memcpy(session_id2, p, session_id2_len);
494: }
495:
1.1 provos 496: if ((key = get_hostkey_by_index(keyid)) == NULL)
1.14 markus 497: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 498: if (key_sign(key, &signature, &siglen, p, datlen) < 0)
1.14 markus 499: fatal("%s: key_sign failed", __func__);
1.1 provos 500:
1.19 deraadt 501: debug3("%s: signature %p(%u)", __func__, signature, siglen);
1.1 provos 502:
503: buffer_clear(m);
504: buffer_put_string(m, signature, siglen);
505:
506: xfree(p);
507: xfree(signature);
508:
1.59 avsm 509: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 510:
511: /* Turn on permissions for getpwnam */
512: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
513:
514: return (0);
515: }
516:
517: /* Retrieves the password entry and also checks if the user is permitted */
518:
519: int
1.59 avsm 520: mm_answer_pwnamallow(int sock, Buffer *m)
1.1 provos 521: {
1.60 dtucker 522: char *username;
1.1 provos 523: struct passwd *pwent;
524: int allowed = 0;
1.3 markus 525:
1.14 markus 526: debug3("%s", __func__);
1.1 provos 527:
528: if (authctxt->attempt++ != 0)
1.14 markus 529: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 530:
1.60 dtucker 531: username = buffer_get_string(m, NULL);
1.1 provos 532:
1.60 dtucker 533: pwent = getpwnamallow(username);
1.1 provos 534:
1.60 dtucker 535: authctxt->user = xstrdup(username);
536: setproctitle("%s [priv]", pwent ? username : "unknown");
537: xfree(username);
1.1 provos 538:
539: buffer_clear(m);
540:
541: if (pwent == NULL) {
542: buffer_put_char(m, 0);
1.53 djm 543: authctxt->pw = fakepw();
1.1 provos 544: goto out;
545: }
546:
547: allowed = 1;
1.4 markus 548: authctxt->pw = pwent;
1.1 provos 549: authctxt->valid = 1;
550:
551: buffer_put_char(m, 1);
552: buffer_put_string(m, pwent, sizeof(struct passwd));
553: buffer_put_cstring(m, pwent->pw_name);
554: buffer_put_cstring(m, "*");
555: buffer_put_cstring(m, pwent->pw_gecos);
556: buffer_put_cstring(m, pwent->pw_class);
557: buffer_put_cstring(m, pwent->pw_dir);
558: buffer_put_cstring(m, pwent->pw_shell);
559:
560: out:
1.14 markus 561: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 562: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 563:
564: /* For SSHv1 allow authentication now */
565: if (!compat20)
566: monitor_permit_authentications(1);
1.10 djm 567: else {
1.1 provos 568: /* Allow service/style information on the auth context */
569: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
1.10 djm 570: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
571: }
572:
573:
574: return (0);
575: }
576:
1.59 avsm 577: int mm_answer_auth2_read_banner(int sock, Buffer *m)
1.10 djm 578: {
579: char *banner;
580:
581: buffer_clear(m);
582: banner = auth2_read_banner();
583: buffer_put_cstring(m, banner != NULL ? banner : "");
1.59 avsm 584: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.1 provos 585:
1.10 djm 586: if (banner != NULL)
1.21 deraadt 587: xfree(banner);
1.1 provos 588:
589: return (0);
590: }
591:
592: int
1.59 avsm 593: mm_answer_authserv(int sock, Buffer *m)
1.1 provos 594: {
595: monitor_permit_authentications(1);
596:
597: authctxt->service = buffer_get_string(m, NULL);
598: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 599: debug3("%s: service=%s, style=%s",
1.14 markus 600: __func__, authctxt->service, authctxt->style);
1.6 stevesk 601:
1.1 provos 602: if (strlen(authctxt->style) == 0) {
603: xfree(authctxt->style);
604: authctxt->style = NULL;
605: }
606:
607: return (0);
608: }
609:
610: int
1.59 avsm 611: mm_answer_authpassword(int sock, Buffer *m)
1.1 provos 612: {
613: static int call_count;
614: char *passwd;
1.22 stevesk 615: int authenticated;
616: u_int plen;
1.1 provos 617:
618: passwd = buffer_get_string(m, &plen);
619: /* Only authenticate if the context is valid */
1.12 markus 620: authenticated = options.password_authentication &&
1.48 markus 621: auth_password(authctxt, passwd);
1.1 provos 622: memset(passwd, 0, strlen(passwd));
623: xfree(passwd);
624:
625: buffer_clear(m);
626: buffer_put_int(m, authenticated);
627:
1.14 markus 628: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 629: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 630:
631: call_count++;
632: if (plen == 0 && call_count == 1)
633: auth_method = "none";
634: else
635: auth_method = "password";
636:
637: /* Causes monitor loop to terminate if authenticated */
638: return (authenticated);
639: }
640:
641: #ifdef BSD_AUTH
642: int
1.59 avsm 643: mm_answer_bsdauthquery(int sock, Buffer *m)
1.1 provos 644: {
645: char *name, *infotxt;
646: u_int numprompts;
647: u_int *echo_on;
648: char **prompts;
1.31 markus 649: u_int success;
1.1 provos 650:
1.31 markus 651: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
652: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 653:
654: buffer_clear(m);
1.31 markus 655: buffer_put_int(m, success);
656: if (success)
1.1 provos 657: buffer_put_cstring(m, prompts[0]);
658:
1.31 markus 659: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 660: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 661:
1.31 markus 662: if (success) {
1.1 provos 663: xfree(name);
664: xfree(infotxt);
665: xfree(prompts);
666: xfree(echo_on);
667: }
668:
669: return (0);
670: }
671:
672: int
1.59 avsm 673: mm_answer_bsdauthrespond(int sock, Buffer *m)
1.1 provos 674: {
675: char *response;
676: int authok;
677:
678: if (authctxt->as == 0)
1.14 markus 679: fatal("%s: no bsd auth session", __func__);
1.1 provos 680:
681: response = buffer_get_string(m, NULL);
1.12 markus 682: authok = options.challenge_response_authentication &&
683: auth_userresponse(authctxt->as, response, 0);
1.1 provos 684: authctxt->as = NULL;
1.14 markus 685: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.1 provos 686: xfree(response);
687:
688: buffer_clear(m);
689: buffer_put_int(m, authok);
690:
1.14 markus 691: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 692: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 693:
694: auth_method = "bsdauth";
695:
696: return (authok != 0);
697: }
698: #endif
699:
700: #ifdef SKEY
701: int
1.59 avsm 702: mm_answer_skeyquery(int sock, Buffer *m)
1.1 provos 703: {
704: struct skey skey;
705: char challenge[1024];
1.31 markus 706: u_int success;
1.1 provos 707:
1.31 markus 708: success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
1.1 provos 709:
710: buffer_clear(m);
1.31 markus 711: buffer_put_int(m, success);
712: if (success)
1.1 provos 713: buffer_put_cstring(m, challenge);
714:
1.31 markus 715: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 716: mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
1.1 provos 717:
718: return (0);
719: }
720:
721: int
1.59 avsm 722: mm_answer_skeyrespond(int sock, Buffer *m)
1.1 provos 723: {
724: char *response;
725: int authok;
726:
727: response = buffer_get_string(m, NULL);
728:
1.12 markus 729: authok = (options.challenge_response_authentication &&
730: authctxt->valid &&
1.1 provos 731: skey_haskey(authctxt->pw->pw_name) == 0 &&
732: skey_passcheck(authctxt->pw->pw_name, response) != -1);
733:
734: xfree(response);
735:
736: buffer_clear(m);
737: buffer_put_int(m, authok);
738:
1.14 markus 739: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 740: mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
1.1 provos 741:
742: auth_method = "skey";
743:
744: return (authok != 0);
745: }
746: #endif
747:
1.2 markus 748: static void
1.1 provos 749: mm_append_debug(Buffer *m)
750: {
751: if (auth_debug_init && buffer_len(&auth_debug)) {
1.14 markus 752: debug3("%s: Appending debug messages for child", __func__);
1.1 provos 753: buffer_append(m, buffer_ptr(&auth_debug),
754: buffer_len(&auth_debug));
755: buffer_clear(&auth_debug);
756: }
757: }
758:
759: int
1.59 avsm 760: mm_answer_keyallowed(int sock, Buffer *m)
1.1 provos 761: {
762: Key *key;
1.26 markus 763: char *cuser, *chost;
764: u_char *blob;
1.1 provos 765: u_int bloblen;
766: enum mm_keytype type = 0;
767: int allowed = 0;
768:
1.14 markus 769: debug3("%s entering", __func__);
1.3 markus 770:
1.1 provos 771: type = buffer_get_int(m);
772: cuser = buffer_get_string(m, NULL);
773: chost = buffer_get_string(m, NULL);
774: blob = buffer_get_string(m, &bloblen);
775:
776: key = key_from_blob(blob, bloblen);
777:
778: if ((compat20 && type == MM_RSAHOSTKEY) ||
779: (!compat20 && type != MM_RSAHOSTKEY))
1.14 markus 780: fatal("%s: key type and protocol mismatch", __func__);
1.1 provos 781:
1.14 markus 782: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 783:
1.51 djm 784: if (key != NULL && authctxt->valid) {
1.63 deraadt 785: switch (type) {
1.1 provos 786: case MM_USERKEY:
1.12 markus 787: allowed = options.pubkey_authentication &&
788: user_key_allowed(authctxt->pw, key);
1.1 provos 789: break;
790: case MM_HOSTKEY:
1.12 markus 791: allowed = options.hostbased_authentication &&
792: hostbased_key_allowed(authctxt->pw,
1.1 provos 793: cuser, chost, key);
794: break;
795: case MM_RSAHOSTKEY:
796: key->type = KEY_RSA1; /* XXX */
1.12 markus 797: allowed = options.rhosts_rsa_authentication &&
798: auth_rhosts_rsa_key_allowed(authctxt->pw,
1.1 provos 799: cuser, chost, key);
800: break;
801: default:
1.14 markus 802: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 803: break;
804: }
1.33 markus 805: }
806: if (key != NULL)
1.1 provos 807: key_free(key);
808:
809: /* clear temporarily storage (used by verify) */
810: monitor_reset_key_state();
811:
812: if (allowed) {
813: /* Save temporarily for comparison in verify */
814: key_blob = blob;
815: key_bloblen = bloblen;
816: key_blobtype = type;
817: hostbased_cuser = cuser;
818: hostbased_chost = chost;
1.72 djm 819: } else {
820: xfree(blob);
821: xfree(cuser);
822: xfree(chost);
1.1 provos 823: }
824:
825: debug3("%s: key %p is %s",
1.14 markus 826: __func__, key, allowed ? "allowed" : "disallowed");
1.1 provos 827:
828: buffer_clear(m);
829: buffer_put_int(m, allowed);
1.32 markus 830: buffer_put_int(m, forced_command != NULL);
1.1 provos 831:
832: mm_append_debug(m);
833:
1.59 avsm 834: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 835:
836: if (type == MM_RSAHOSTKEY)
837: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
838:
839: return (0);
840: }
841:
842: static int
843: monitor_valid_userblob(u_char *data, u_int datalen)
844: {
845: Buffer b;
1.26 markus 846: char *p;
1.1 provos 847: u_int len;
848: int fail = 0;
849:
850: buffer_init(&b);
851: buffer_append(&b, data, datalen);
1.3 markus 852:
1.1 provos 853: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 854: p = buffer_ptr(&b);
855: len = buffer_len(&b);
856: if ((session_id2 == NULL) ||
857: (len < session_id2_len) ||
858: (memcmp(p, session_id2, session_id2_len) != 0))
859: fail++;
1.1 provos 860: buffer_consume(&b, session_id2_len);
861: } else {
1.13 markus 862: p = buffer_get_string(&b, &len);
863: if ((session_id2 == NULL) ||
864: (len != session_id2_len) ||
865: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 866: fail++;
1.13 markus 867: xfree(p);
1.1 provos 868: }
869: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
870: fail++;
871: p = buffer_get_string(&b, NULL);
872: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 873: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 874: authctxt->user, p);
875: fail++;
876: }
877: xfree(p);
878: buffer_skip_string(&b);
879: if (datafellows & SSH_BUG_PKAUTH) {
880: if (!buffer_get_char(&b))
881: fail++;
882: } else {
883: p = buffer_get_string(&b, NULL);
884: if (strcmp("publickey", p) != 0)
885: fail++;
886: xfree(p);
887: if (!buffer_get_char(&b))
888: fail++;
889: buffer_skip_string(&b);
890: }
891: buffer_skip_string(&b);
892: if (buffer_len(&b) != 0)
893: fail++;
894: buffer_free(&b);
895: return (fail == 0);
896: }
897:
898: static int
1.26 markus 899: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
900: char *chost)
1.1 provos 901: {
902: Buffer b;
1.26 markus 903: char *p;
1.1 provos 904: u_int len;
905: int fail = 0;
906:
907: buffer_init(&b);
908: buffer_append(&b, data, datalen);
1.3 markus 909:
1.13 markus 910: p = buffer_get_string(&b, &len);
911: if ((session_id2 == NULL) ||
912: (len != session_id2_len) ||
913: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 914: fail++;
1.13 markus 915: xfree(p);
916:
1.1 provos 917: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
918: fail++;
919: p = buffer_get_string(&b, NULL);
920: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 921: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 922: authctxt->user, p);
923: fail++;
924: }
925: xfree(p);
926: buffer_skip_string(&b); /* service */
927: p = buffer_get_string(&b, NULL);
928: if (strcmp(p, "hostbased") != 0)
929: fail++;
930: xfree(p);
931: buffer_skip_string(&b); /* pkalg */
932: buffer_skip_string(&b); /* pkblob */
933:
934: /* verify client host, strip trailing dot if necessary */
935: p = buffer_get_string(&b, NULL);
936: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
937: p[len - 1] = '\0';
938: if (strcmp(p, chost) != 0)
939: fail++;
940: xfree(p);
941:
942: /* verify client user */
943: p = buffer_get_string(&b, NULL);
944: if (strcmp(p, cuser) != 0)
945: fail++;
946: xfree(p);
947:
948: if (buffer_len(&b) != 0)
949: fail++;
950: buffer_free(&b);
951: return (fail == 0);
952: }
953:
954: int
1.59 avsm 955: mm_answer_keyverify(int sock, Buffer *m)
1.1 provos 956: {
957: Key *key;
958: u_char *signature, *data, *blob;
959: u_int signaturelen, datalen, bloblen;
960: int verified = 0;
961: int valid_data = 0;
962:
963: blob = buffer_get_string(m, &bloblen);
964: signature = buffer_get_string(m, &signaturelen);
965: data = buffer_get_string(m, &datalen);
966:
967: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 968: !monitor_allowed_key(blob, bloblen))
1.14 markus 969: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 970:
971: key = key_from_blob(blob, bloblen);
972: if (key == NULL)
1.14 markus 973: fatal("%s: bad public key blob", __func__);
1.1 provos 974:
975: switch (key_blobtype) {
976: case MM_USERKEY:
977: valid_data = monitor_valid_userblob(data, datalen);
978: break;
979: case MM_HOSTKEY:
980: valid_data = monitor_valid_hostbasedblob(data, datalen,
981: hostbased_cuser, hostbased_chost);
982: break;
983: default:
984: valid_data = 0;
985: break;
986: }
987: if (!valid_data)
1.14 markus 988: fatal("%s: bad signature data blob", __func__);
1.1 provos 989:
990: verified = key_verify(key, signature, signaturelen, data, datalen);
991: debug3("%s: key %p signature %s",
1.14 markus 992: __func__, key, verified ? "verified" : "unverified");
1.1 provos 993:
994: key_free(key);
995: xfree(blob);
996: xfree(signature);
997: xfree(data);
998:
1.17 stevesk 999: auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1000:
1.1 provos 1001: monitor_reset_key_state();
1.3 markus 1002:
1.1 provos 1003: buffer_clear(m);
1004: buffer_put_int(m, verified);
1.59 avsm 1005: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.1 provos 1006:
1007: return (verified);
1008: }
1009:
1.2 markus 1010: static void
1.1 provos 1011: mm_record_login(Session *s, struct passwd *pw)
1012: {
1013: socklen_t fromlen;
1014: struct sockaddr_storage from;
1015:
1016: /*
1017: * Get IP address of client. If the connection is not a socket, let
1018: * the address be 0.0.0.0.
1019: */
1020: memset(&from, 0, sizeof(from));
1.24 stevesk 1021: fromlen = sizeof(from);
1.1 provos 1022: if (packet_connection_is_on_socket()) {
1023: if (getpeername(packet_get_connection_in(),
1.74 deraadt 1024: (struct sockaddr *)&from, &fromlen) < 0) {
1.1 provos 1025: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1026: cleanup_exit(255);
1.1 provos 1027: }
1028: }
1029: /* Record that there was a login on that tty from the remote host. */
1030: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.42 markus 1031: get_remote_name_or_ip(utmp_len, options.use_dns),
1.24 stevesk 1032: (struct sockaddr *)&from, fromlen);
1.1 provos 1033: }
1034:
1035: static void
1036: mm_session_close(Session *s)
1037: {
1.41 djm 1038: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1039: if (s->ttyfd != -1) {
1.14 markus 1040: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1041: session_pty_cleanup2(s);
1042: }
1043: s->used = 0;
1044: }
1045:
1046: int
1.59 avsm 1047: mm_answer_pty(int sock, Buffer *m)
1.1 provos 1048: {
1.11 mouring 1049: extern struct monitor *pmonitor;
1.1 provos 1050: Session *s;
1051: int res, fd0;
1052:
1.14 markus 1053: debug3("%s entering", __func__);
1.1 provos 1054:
1055: buffer_clear(m);
1056: s = session_new();
1057: if (s == NULL)
1058: goto error;
1059: s->authctxt = authctxt;
1060: s->pw = authctxt->pw;
1.11 mouring 1061: s->pid = pmonitor->m_pid;
1.1 provos 1062: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1063: if (res == 0)
1064: goto error;
1065: pty_setowner(authctxt->pw, s->tty);
1066:
1067: buffer_put_int(m, 1);
1068: buffer_put_cstring(m, s->tty);
1069:
1070: /* We need to trick ttyslot */
1071: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1072: fatal("%s: dup2", __func__);
1.1 provos 1073:
1074: mm_record_login(s, authctxt->pw);
1075:
1076: /* Now we can close the file descriptor again */
1077: close(0);
1.61 dtucker 1078:
1079: /* send messages generated by record_login */
1080: buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1081: buffer_clear(&loginmsg);
1082:
1083: mm_request_send(sock, MONITOR_ANS_PTY, m);
1084:
1085: mm_send_fd(sock, s->ptyfd);
1086: mm_send_fd(sock, s->ttyfd);
1.1 provos 1087:
1088: /* make sure nothing uses fd 0 */
1089: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1090: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1091: if (fd0 != 0)
1.14 markus 1092: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1093:
1094: /* slave is not needed */
1095: close(s->ttyfd);
1096: s->ttyfd = s->ptyfd;
1097: /* no need to dup() because nobody closes ptyfd */
1098: s->ptymaster = s->ptyfd;
1099:
1.14 markus 1100: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1101:
1102: return (0);
1103:
1104: error:
1105: if (s != NULL)
1106: mm_session_close(s);
1107: buffer_put_int(m, 0);
1.59 avsm 1108: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1109: return (0);
1110: }
1111:
1112: int
1.59 avsm 1113: mm_answer_pty_cleanup(int sock, Buffer *m)
1.1 provos 1114: {
1115: Session *s;
1116: char *tty;
1117:
1.14 markus 1118: debug3("%s entering", __func__);
1.1 provos 1119:
1120: tty = buffer_get_string(m, NULL);
1121: if ((s = session_by_tty(tty)) != NULL)
1122: mm_session_close(s);
1123: buffer_clear(m);
1124: xfree(tty);
1125: return (0);
1126: }
1127:
1128: int
1.59 avsm 1129: mm_answer_sesskey(int sock, Buffer *m)
1.1 provos 1130: {
1131: BIGNUM *p;
1132: int rsafail;
1133:
1134: /* Turn off permissions */
1.62 dtucker 1135: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1.1 provos 1136:
1137: if ((p = BN_new()) == NULL)
1.14 markus 1138: fatal("%s: BN_new", __func__);
1.1 provos 1139:
1140: buffer_get_bignum2(m, p);
1141:
1142: rsafail = ssh1_session_key(p);
1143:
1144: buffer_clear(m);
1145: buffer_put_int(m, rsafail);
1146: buffer_put_bignum2(m, p);
1147:
1148: BN_clear_free(p);
1149:
1.59 avsm 1150: mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1.1 provos 1151:
1152: /* Turn on permissions for sessid passing */
1153: monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1154:
1155: return (0);
1156: }
1157:
1158: int
1.59 avsm 1159: mm_answer_sessid(int sock, Buffer *m)
1.1 provos 1160: {
1161: int i;
1162:
1.14 markus 1163: debug3("%s entering", __func__);
1.1 provos 1164:
1165: if (buffer_len(m) != 16)
1.14 markus 1166: fatal("%s: bad ssh1 session id", __func__);
1.1 provos 1167: for (i = 0; i < 16; i++)
1168: session_id[i] = buffer_get_char(m);
1169:
1170: /* Turn on permissions for getpwnam */
1171: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1172:
1173: return (0);
1174: }
1175:
1176: int
1.59 avsm 1177: mm_answer_rsa_keyallowed(int sock, Buffer *m)
1.1 provos 1178: {
1179: BIGNUM *client_n;
1180: Key *key = NULL;
1.3 markus 1181: u_char *blob = NULL;
1182: u_int blen = 0;
1.1 provos 1183: int allowed = 0;
1184:
1.14 markus 1185: debug3("%s entering", __func__);
1.1 provos 1186:
1.12 markus 1187: if (options.rsa_authentication && authctxt->valid) {
1.1 provos 1188: if ((client_n = BN_new()) == NULL)
1.14 markus 1189: fatal("%s: BN_new", __func__);
1.1 provos 1190: buffer_get_bignum2(m, client_n);
1191: allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1192: BN_clear_free(client_n);
1193: }
1194: buffer_clear(m);
1195: buffer_put_int(m, allowed);
1.32 markus 1196: buffer_put_int(m, forced_command != NULL);
1.1 provos 1197:
1198: /* clear temporarily storage (used by generate challenge) */
1199: monitor_reset_key_state();
1200:
1201: if (allowed && key != NULL) {
1202: key->type = KEY_RSA; /* cheat for key_to_blob */
1203: if (key_to_blob(key, &blob, &blen) == 0)
1.14 markus 1204: fatal("%s: key_to_blob failed", __func__);
1.1 provos 1205: buffer_put_string(m, blob, blen);
1206:
1207: /* Save temporarily for comparison in verify */
1208: key_blob = blob;
1209: key_bloblen = blen;
1210: key_blobtype = MM_RSAUSERKEY;
1.33 markus 1211: }
1212: if (key != NULL)
1.1 provos 1213: key_free(key);
1214:
1215: mm_append_debug(m);
1216:
1.59 avsm 1217: mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1.1 provos 1218:
1219: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1220: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1221: return (0);
1222: }
1223:
1224: int
1.59 avsm 1225: mm_answer_rsa_challenge(int sock, Buffer *m)
1.1 provos 1226: {
1227: Key *key = NULL;
1.3 markus 1228: u_char *blob;
1229: u_int blen;
1.1 provos 1230:
1.14 markus 1231: debug3("%s entering", __func__);
1.1 provos 1232:
1233: if (!authctxt->valid)
1.14 markus 1234: fatal("%s: authctxt not valid", __func__);
1.1 provos 1235: blob = buffer_get_string(m, &blen);
1236: if (!monitor_allowed_key(blob, blen))
1.14 markus 1237: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1238: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1239: fatal("%s: key type mismatch", __func__);
1.1 provos 1240: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1241: fatal("%s: received bad key", __func__);
1.1 provos 1242:
1243: if (ssh1_challenge)
1244: BN_clear_free(ssh1_challenge);
1245: ssh1_challenge = auth_rsa_generate_challenge(key);
1246:
1247: buffer_clear(m);
1248: buffer_put_bignum2(m, ssh1_challenge);
1249:
1.14 markus 1250: debug3("%s sending reply", __func__);
1.59 avsm 1251: mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1.1 provos 1252:
1253: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1.33 markus 1254:
1255: xfree(blob);
1256: key_free(key);
1.1 provos 1257: return (0);
1258: }
1259:
1260: int
1.59 avsm 1261: mm_answer_rsa_response(int sock, Buffer *m)
1.1 provos 1262: {
1263: Key *key = NULL;
1.3 markus 1264: u_char *blob, *response;
1265: u_int blen, len;
1266: int success;
1.1 provos 1267:
1.14 markus 1268: debug3("%s entering", __func__);
1.1 provos 1269:
1270: if (!authctxt->valid)
1.14 markus 1271: fatal("%s: authctxt not valid", __func__);
1.1 provos 1272: if (ssh1_challenge == NULL)
1.14 markus 1273: fatal("%s: no ssh1_challenge", __func__);
1.1 provos 1274:
1275: blob = buffer_get_string(m, &blen);
1276: if (!monitor_allowed_key(blob, blen))
1.14 markus 1277: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1278: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1279: fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1.1 provos 1280: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1281: fatal("%s: received bad key", __func__);
1.1 provos 1282: response = buffer_get_string(m, &len);
1283: if (len != 16)
1.14 markus 1284: fatal("%s: received bad response to challenge", __func__);
1.1 provos 1285: success = auth_rsa_verify_response(key, ssh1_challenge, response);
1286:
1.33 markus 1287: xfree(blob);
1.1 provos 1288: key_free(key);
1289: xfree(response);
1290:
1291: auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1292:
1293: /* reset state */
1294: BN_clear_free(ssh1_challenge);
1295: ssh1_challenge = NULL;
1296: monitor_reset_key_state();
1297:
1298: buffer_clear(m);
1299: buffer_put_int(m, success);
1.59 avsm 1300: mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1.1 provos 1301:
1302: return (success);
1303: }
1304:
1305: int
1.59 avsm 1306: mm_answer_term(int sock, Buffer *req)
1.1 provos 1307: {
1.11 mouring 1308: extern struct monitor *pmonitor;
1.1 provos 1309: int res, status;
1310:
1.14 markus 1311: debug3("%s: tearing down sessions", __func__);
1.1 provos 1312:
1313: /* The child is terminating */
1314: session_destroy_all(&mm_session_close);
1315:
1.11 mouring 1316: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1317: if (errno != EINTR)
1318: exit(1);
1.1 provos 1319:
1320: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1321:
1322: /* Terminate process */
1.57 deraadt 1323: exit(res);
1.1 provos 1324: }
1325:
1326: void
1.11 mouring 1327: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1328: {
1329: if (compat20) {
1330: set_newkeys(MODE_IN);
1331: set_newkeys(MODE_OUT);
1332: } else {
1333: packet_set_protocol_flags(child_state.ssh1protoflags);
1.15 markus 1334: packet_set_encryption_key(child_state.ssh1key,
1335: child_state.ssh1keylen, child_state.ssh1cipher);
1336: xfree(child_state.ssh1key);
1.1 provos 1337: }
1338:
1.15 markus 1339: /* for rc4 and other stateful ciphers */
1.1 provos 1340: packet_set_keycontext(MODE_OUT, child_state.keyout);
1341: xfree(child_state.keyout);
1342: packet_set_keycontext(MODE_IN, child_state.keyin);
1343: xfree(child_state.keyin);
1344:
1345: if (!compat20) {
1346: packet_set_iv(MODE_OUT, child_state.ivout);
1347: xfree(child_state.ivout);
1348: packet_set_iv(MODE_IN, child_state.ivin);
1349: xfree(child_state.ivin);
1350: }
1351:
1352: memcpy(&incoming_stream, &child_state.incoming,
1353: sizeof(incoming_stream));
1354: memcpy(&outgoing_stream, &child_state.outgoing,
1355: sizeof(outgoing_stream));
1.3 markus 1356:
1.1 provos 1357: /* Update with new address */
1.16 djm 1358: if (options.compression)
1359: mm_init_compression(pmonitor->m_zlib);
1.1 provos 1360:
1361: /* Network I/O buffers */
1362: /* XXX inefficient for large buffers, need: buffer_init_from_string */
1363: buffer_clear(&input);
1364: buffer_append(&input, child_state.input, child_state.ilen);
1365: memset(child_state.input, 0, child_state.ilen);
1366: xfree(child_state.input);
1367:
1368: buffer_clear(&output);
1369: buffer_append(&output, child_state.output, child_state.olen);
1370: memset(child_state.output, 0, child_state.olen);
1371: xfree(child_state.output);
1372: }
1373:
1.2 markus 1374: static Kex *
1.1 provos 1375: mm_get_kex(Buffer *m)
1376: {
1377: Kex *kex;
1378: void *blob;
1379: u_int bloblen;
1380:
1.75 djm 1381: kex = xcalloc(1, sizeof(*kex));
1.1 provos 1382: kex->session_id = buffer_get_string(m, &kex->session_id_len);
1.13 markus 1383: if ((session_id2 == NULL) ||
1384: (kex->session_id_len != session_id2_len) ||
1385: (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1386: fatal("mm_get_get: internal error: bad session id");
1.1 provos 1387: kex->we_need = buffer_get_int(m);
1.34 markus 1388: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1.58 djm 1389: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1.34 markus 1390: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.69 djm 1391: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.1 provos 1392: kex->server = 1;
1393: kex->hostkey_type = buffer_get_int(m);
1394: kex->kex_type = buffer_get_int(m);
1395: blob = buffer_get_string(m, &bloblen);
1396: buffer_init(&kex->my);
1397: buffer_append(&kex->my, blob, bloblen);
1398: xfree(blob);
1399: blob = buffer_get_string(m, &bloblen);
1400: buffer_init(&kex->peer);
1401: buffer_append(&kex->peer, blob, bloblen);
1402: xfree(blob);
1403: kex->done = 1;
1404: kex->flags = buffer_get_int(m);
1405: kex->client_version_string = buffer_get_string(m, NULL);
1406: kex->server_version_string = buffer_get_string(m, NULL);
1407: kex->load_host_key=&get_hostkey_by_type;
1408: kex->host_key_index=&get_hostkey_index;
1409:
1410: return (kex);
1411: }
1412:
1413: /* This function requries careful sanity checking */
1414:
1415: void
1.11 mouring 1416: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1417: {
1418: Buffer m;
1419: u_char *blob, *p;
1420: u_int bloblen, plen;
1.37 markus 1421: u_int32_t seqnr, packets;
1422: u_int64_t blocks;
1.1 provos 1423:
1.14 markus 1424: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1425:
1426: buffer_init(&m);
1.11 mouring 1427: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1.1 provos 1428: if (!compat20) {
1429: child_state.ssh1protoflags = buffer_get_int(&m);
1430: child_state.ssh1cipher = buffer_get_int(&m);
1.15 markus 1431: child_state.ssh1key = buffer_get_string(&m,
1432: &child_state.ssh1keylen);
1.1 provos 1433: child_state.ivout = buffer_get_string(&m,
1434: &child_state.ivoutlen);
1435: child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1436: goto skip;
1437: } else {
1438: /* Get the Kex for rekeying */
1.11 mouring 1439: *pmonitor->m_pkex = mm_get_kex(&m);
1.1 provos 1440: }
1441:
1442: blob = buffer_get_string(&m, &bloblen);
1443: current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1444: xfree(blob);
1445:
1.14 markus 1446: debug3("%s: Waiting for second key", __func__);
1.1 provos 1447: blob = buffer_get_string(&m, &bloblen);
1448: current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1449: xfree(blob);
1.3 markus 1450:
1.1 provos 1451: /* Now get sequence numbers for the packets */
1.37 markus 1452: seqnr = buffer_get_int(&m);
1453: blocks = buffer_get_int64(&m);
1454: packets = buffer_get_int(&m);
1455: packet_set_state(MODE_OUT, seqnr, blocks, packets);
1456: seqnr = buffer_get_int(&m);
1457: blocks = buffer_get_int64(&m);
1458: packets = buffer_get_int(&m);
1459: packet_set_state(MODE_IN, seqnr, blocks, packets);
1.1 provos 1460:
1461: skip:
1462: /* Get the key context */
1463: child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1464: child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1465:
1.14 markus 1466: debug3("%s: Getting compression state", __func__);
1.1 provos 1467: /* Get compression state */
1468: p = buffer_get_string(&m, &plen);
1469: if (plen != sizeof(child_state.outgoing))
1.14 markus 1470: fatal("%s: bad request size", __func__);
1.1 provos 1471: memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1472: xfree(p);
1473:
1474: p = buffer_get_string(&m, &plen);
1475: if (plen != sizeof(child_state.incoming))
1.14 markus 1476: fatal("%s: bad request size", __func__);
1.1 provos 1477: memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1478: xfree(p);
1479:
1480: /* Network I/O buffers */
1.14 markus 1481: debug3("%s: Getting Network I/O buffers", __func__);
1.1 provos 1482: child_state.input = buffer_get_string(&m, &child_state.ilen);
1483: child_state.output = buffer_get_string(&m, &child_state.olen);
1484:
1485: buffer_free(&m);
1486: }
1487:
1488:
1489: /* Allocation functions for zlib */
1490: void *
1491: mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1492: {
1.30 markus 1493: size_t len = (size_t) size * ncount;
1.1 provos 1494: void *address;
1495:
1.23 millert 1496: if (len == 0 || ncount > SIZE_T_MAX / size)
1.18 deraadt 1497: fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1498:
1499: address = mm_malloc(mm, len);
1.1 provos 1500:
1501: return (address);
1502: }
1503:
1504: void
1505: mm_zfree(struct mm_master *mm, void *address)
1506: {
1507: mm_free(mm, address);
1508: }
1509:
1510: void
1511: mm_init_compression(struct mm_master *mm)
1512: {
1513: outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1514: outgoing_stream.zfree = (free_func)mm_zfree;
1515: outgoing_stream.opaque = mm;
1516:
1517: incoming_stream.zalloc = (alloc_func)mm_zalloc;
1518: incoming_stream.zfree = (free_func)mm_zfree;
1519: incoming_stream.opaque = mm;
1520: }
1521:
1522: /* XXX */
1523:
1524: #define FD_CLOSEONEXEC(x) do { \
1525: if (fcntl(x, F_SETFD, 1) == -1) \
1526: fatal("fcntl(%d, F_SETFD)", x); \
1527: } while (0)
1528:
1.2 markus 1529: static void
1.1 provos 1530: monitor_socketpair(int *pair)
1.3 markus 1531: {
1.1 provos 1532: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.14 markus 1533: fatal("%s: socketpair", __func__);
1.1 provos 1534: FD_CLOSEONEXEC(pair[0]);
1535: FD_CLOSEONEXEC(pair[1]);
1536: }
1537:
1538: #define MM_MEMSIZE 65536
1539:
1540: struct monitor *
1541: monitor_init(void)
1542: {
1543: struct monitor *mon;
1544: int pair[2];
1545:
1.75 djm 1546: mon = xcalloc(1, sizeof(*mon));
1.1 provos 1547:
1548: monitor_socketpair(pair);
1549:
1550: mon->m_recvfd = pair[0];
1551: mon->m_sendfd = pair[1];
1552:
1553: /* Used to share zlib space across processes */
1.16 djm 1554: if (options.compression) {
1555: mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1556: mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1.1 provos 1557:
1.16 djm 1558: /* Compression needs to share state across borders */
1559: mm_init_compression(mon->m_zlib);
1560: }
1.1 provos 1561:
1562: return mon;
1563: }
1564:
1565: void
1566: monitor_reinit(struct monitor *mon)
1567: {
1568: int pair[2];
1569:
1570: monitor_socketpair(pair);
1571:
1572: mon->m_recvfd = pair[0];
1573: mon->m_sendfd = pair[1];
1574: }
1.46 markus 1575:
1576: #ifdef GSSAPI
1577: int
1.59 avsm 1578: mm_answer_gss_setup_ctx(int sock, Buffer *m)
1.46 markus 1579: {
1.59 avsm 1580: gss_OID_desc goid;
1.46 markus 1581: OM_uint32 major;
1582: u_int len;
1583:
1.59 avsm 1584: goid.elements = buffer_get_string(m, &len);
1585: goid.length = len;
1.46 markus 1586:
1.59 avsm 1587: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1588:
1.59 avsm 1589: xfree(goid.elements);
1.46 markus 1590:
1591: buffer_clear(m);
1592: buffer_put_int(m, major);
1593:
1.64 stevesk 1594: mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1.46 markus 1595:
1596: /* Now we have a context, enable the step */
1597: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1598:
1599: return (0);
1600: }
1601:
1602: int
1.59 avsm 1603: mm_answer_gss_accept_ctx(int sock, Buffer *m)
1.46 markus 1604: {
1605: gss_buffer_desc in;
1606: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1.64 stevesk 1607: OM_uint32 major, minor;
1.46 markus 1608: OM_uint32 flags = 0; /* GSI needs this */
1.47 deraadt 1609: u_int len;
1.46 markus 1610:
1.47 deraadt 1611: in.value = buffer_get_string(m, &len);
1612: in.length = len;
1.46 markus 1613: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1614: xfree(in.value);
1615:
1616: buffer_clear(m);
1617: buffer_put_int(m, major);
1618: buffer_put_string(m, out.value, out.length);
1619: buffer_put_int(m, flags);
1.59 avsm 1620: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1621:
1622: gss_release_buffer(&minor, &out);
1623:
1.64 stevesk 1624: if (major == GSS_S_COMPLETE) {
1.46 markus 1625: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1626: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1627: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1628: }
1629: return (0);
1630: }
1631:
1632: int
1.59 avsm 1633: mm_answer_gss_checkmic(int sock, Buffer *m)
1.52 markus 1634: {
1635: gss_buffer_desc gssbuf, mic;
1636: OM_uint32 ret;
1637: u_int len;
1.54 djm 1638:
1.52 markus 1639: gssbuf.value = buffer_get_string(m, &len);
1640: gssbuf.length = len;
1641: mic.value = buffer_get_string(m, &len);
1642: mic.length = len;
1.54 djm 1643:
1.52 markus 1644: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1645:
1.52 markus 1646: xfree(gssbuf.value);
1647: xfree(mic.value);
1.54 djm 1648:
1.52 markus 1649: buffer_clear(m);
1650: buffer_put_int(m, ret);
1.54 djm 1651:
1.59 avsm 1652: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1653:
1.52 markus 1654: if (!GSS_ERROR(ret))
1655: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1656:
1.52 markus 1657: return (0);
1658: }
1659:
1660: int
1.59 avsm 1661: mm_answer_gss_userok(int sock, Buffer *m)
1.46 markus 1662: {
1663: int authenticated;
1664:
1665: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1666:
1667: buffer_clear(m);
1668: buffer_put_int(m, authenticated);
1669:
1670: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1671: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1672:
1.64 stevesk 1673: auth_method = "gssapi-with-mic";
1.46 markus 1674:
1675: /* Monitor loop will terminate if authenticated */
1676: return (authenticated);
1677: }
1678: #endif /* GSSAPI */
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