Annotation of src/usr.bin/ssh/monitor.c, Revision 1.77
1.77 ! dtucker 1: /* $OpenBSD: monitor.c,v 1.76 2006/03/25 13:17:02 djm Exp $ */
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 */
1.77 ! dtucker 160: #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
1.1 provos 161:
162: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
163:
164: #define MON_PERMIT 0x1000 /* Request is permitted */
165:
166: struct mon_table mon_dispatch_proto20[] = {
167: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
168: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
169: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
170: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 171: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 172: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
173: #ifdef BSD_AUTH
174: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 175: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 176: #endif
177: #ifdef SKEY
178: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
179: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
180: #endif
181: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
182: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 183: #ifdef GSSAPI
184: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
185: {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
186: {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
1.52 markus 187: {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
1.46 markus 188: #endif
1.1 provos 189: {0, 0, NULL}
190: };
191:
192: struct mon_table mon_dispatch_postauth20[] = {
193: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
194: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
195: {MONITOR_REQ_PTY, 0, mm_answer_pty},
196: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
197: {MONITOR_REQ_TERM, 0, mm_answer_term},
198: {0, 0, NULL}
199: };
200:
201: struct mon_table mon_dispatch_proto15[] = {
202: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
203: {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
204: {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
205: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
1.77 ! dtucker 206: {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
! 207: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
1.1 provos 208: {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
209: {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
210: #ifdef BSD_AUTH
211: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 212: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 213: #endif
214: #ifdef SKEY
215: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
216: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
217: #endif
218: {0, 0, NULL}
219: };
220:
221: struct mon_table mon_dispatch_postauth15[] = {
222: {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
223: {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
224: {MONITOR_REQ_TERM, 0, mm_answer_term},
225: {0, 0, NULL}
226: };
227:
228: struct mon_table *mon_dispatch;
229:
230: /* Specifies if a certain message is allowed at the moment */
231:
232: static void
233: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
234: {
235: while (ent->f != NULL) {
236: if (ent->type == type) {
237: ent->flags &= ~MON_PERMIT;
238: ent->flags |= permit ? MON_PERMIT : 0;
239: return;
240: }
241: ent++;
242: }
243: }
244:
245: static void
246: monitor_permit_authentications(int permit)
247: {
248: struct mon_table *ent = mon_dispatch;
249:
250: while (ent->f != NULL) {
251: if (ent->flags & MON_AUTH) {
252: ent->flags &= ~MON_PERMIT;
253: ent->flags |= permit ? MON_PERMIT : 0;
254: }
255: ent++;
256: }
257: }
258:
1.50 markus 259: void
260: monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
1.1 provos 261: {
262: struct mon_table *ent;
263: int authenticated = 0;
264:
265: debug3("preauth child monitor started");
266:
1.50 markus 267: authctxt = _authctxt;
268: memset(authctxt, 0, sizeof(*authctxt));
269:
1.1 provos 270: if (compat20) {
271: mon_dispatch = mon_dispatch_proto20;
272:
273: /* Permit requests for moduli and signatures */
274: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
275: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
276: } else {
277: mon_dispatch = mon_dispatch_proto15;
278:
279: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
280: }
281:
282: /* The first few requests do not require asynchronous access */
283: while (!authenticated) {
1.77 ! dtucker 284: auth_method = "unknown";
1.11 mouring 285: authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
1.1 provos 286: if (authenticated) {
287: if (!(ent->flags & MON_AUTHDECIDE))
288: fatal("%s: unexpected authentication from %d",
1.14 markus 289: __func__, ent->type);
1.1 provos 290: if (authctxt->pw->pw_uid == 0 &&
291: !auth_root_allowed(auth_method))
292: authenticated = 0;
293: }
294:
1.77 ! dtucker 295: if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
1.1 provos 296: auth_log(authctxt, authenticated, auth_method,
297: compat20 ? " ssh2" : "");
298: if (!authenticated)
299: authctxt->failures++;
300: }
301: }
302:
303: if (!authctxt->valid)
1.14 markus 304: fatal("%s: authenticated invalid user", __func__);
1.77 ! dtucker 305: if (strcmp(auth_method, "unknown") == 0)
! 306: fatal("%s: authentication method name unknown", __func__);
1.1 provos 307:
308: debug("%s: %s has been authenticated by privileged process",
1.14 markus 309: __func__, authctxt->user);
1.1 provos 310:
1.11 mouring 311: mm_get_keystate(pmonitor);
1.1 provos 312: }
313:
1.40 markus 314: static void
315: monitor_set_child_handler(pid_t pid)
316: {
317: monitor_child_pid = pid;
318: }
319:
320: static void
1.59 avsm 321: monitor_child_handler(int sig)
1.40 markus 322: {
1.59 avsm 323: kill(monitor_child_pid, sig);
1.40 markus 324: }
325:
1.1 provos 326: void
1.11 mouring 327: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 328: {
1.40 markus 329: monitor_set_child_handler(pmonitor->m_pid);
330: signal(SIGHUP, &monitor_child_handler);
331: signal(SIGTERM, &monitor_child_handler);
332:
1.1 provos 333: if (compat20) {
334: mon_dispatch = mon_dispatch_postauth20;
335:
336: /* Permit requests for moduli and signatures */
337: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
338: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
339: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
340: } else {
341: mon_dispatch = mon_dispatch_postauth15;
342: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
343: }
344: if (!no_pty_flag) {
345: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
346: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
347: }
348:
349: for (;;)
1.11 mouring 350: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 351: }
352:
353: void
1.11 mouring 354: monitor_sync(struct monitor *pmonitor)
1.1 provos 355: {
1.16 djm 356: if (options.compression) {
357: /* The member allocation is not visible, so sync it */
358: mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
359: }
1.1 provos 360: }
361:
362: int
1.11 mouring 363: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 364: struct mon_table **pent)
365: {
366: Buffer m;
367: int ret;
368: u_char type;
369:
370: buffer_init(&m);
371:
1.11 mouring 372: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 373: type = buffer_get_char(&m);
374:
1.14 markus 375: debug3("%s: checking request %d", __func__, type);
1.1 provos 376:
377: while (ent->f != NULL) {
378: if (ent->type == type)
379: break;
380: ent++;
381: }
382:
383: if (ent->f != NULL) {
384: if (!(ent->flags & MON_PERMIT))
1.14 markus 385: fatal("%s: unpermitted request %d", __func__,
1.1 provos 386: type);
1.11 mouring 387: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 388: buffer_free(&m);
389:
390: /* The child may use this request only once, disable it */
391: if (ent->flags & MON_ONCE) {
1.14 markus 392: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 393: type);
394: ent->flags &= ~MON_PERMIT;
395: }
396:
397: if (pent != NULL)
398: *pent = ent;
1.3 markus 399:
1.1 provos 400: return ret;
401: }
402:
1.14 markus 403: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 404:
405: /* NOTREACHED */
406: return (-1);
407: }
408:
409: /* allowed key state */
410: static int
411: monitor_allowed_key(u_char *blob, u_int bloblen)
412: {
413: /* make sure key is allowed */
414: if (key_blob == NULL || key_bloblen != bloblen ||
415: memcmp(key_blob, blob, key_bloblen))
416: return (0);
417: return (1);
418: }
419:
420: static void
421: monitor_reset_key_state(void)
422: {
423: /* reset state */
424: if (key_blob != NULL)
425: xfree(key_blob);
426: if (hostbased_cuser != NULL)
427: xfree(hostbased_cuser);
428: if (hostbased_chost != NULL)
429: xfree(hostbased_chost);
430: key_blob = NULL;
431: key_bloblen = 0;
432: key_blobtype = MM_NOKEY;
433: hostbased_cuser = NULL;
434: hostbased_chost = NULL;
435: }
436:
437: int
1.59 avsm 438: mm_answer_moduli(int sock, Buffer *m)
1.1 provos 439: {
440: DH *dh;
441: int min, want, max;
442:
443: min = buffer_get_int(m);
444: want = buffer_get_int(m);
445: max = buffer_get_int(m);
446:
447: debug3("%s: got parameters: %d %d %d",
1.14 markus 448: __func__, min, want, max);
1.1 provos 449: /* We need to check here, too, in case the child got corrupted */
450: if (max < min || want < min || max < want)
451: fatal("%s: bad parameters: %d %d %d",
1.14 markus 452: __func__, min, want, max);
1.1 provos 453:
454: buffer_clear(m);
455:
456: dh = choose_dh(min, want, max);
457: if (dh == NULL) {
458: buffer_put_char(m, 0);
459: return (0);
460: } else {
461: /* Send first bignum */
462: buffer_put_char(m, 1);
463: buffer_put_bignum2(m, dh->p);
464: buffer_put_bignum2(m, dh->g);
1.3 markus 465:
1.1 provos 466: DH_free(dh);
467: }
1.59 avsm 468: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 469: return (0);
470: }
471:
472: int
1.59 avsm 473: mm_answer_sign(int sock, Buffer *m)
1.1 provos 474: {
475: Key *key;
476: u_char *p;
477: u_char *signature;
478: u_int siglen, datlen;
479: int keyid;
1.3 markus 480:
1.14 markus 481: debug3("%s", __func__);
1.1 provos 482:
1.3 markus 483: keyid = buffer_get_int(m);
484: p = buffer_get_string(m, &datlen);
1.1 provos 485:
1.69 djm 486: /*
1.71 deraadt 487: * Supported KEX types will only return SHA1 (20 byte) or
1.69 djm 488: * SHA256 (32 byte) hashes
489: */
490: if (datlen != 20 && datlen != 32)
1.19 deraadt 491: fatal("%s: data length incorrect: %u", __func__, datlen);
1.1 provos 492:
1.13 markus 493: /* save session id, it will be passed on the first call */
494: if (session_id2_len == 0) {
495: session_id2_len = datlen;
496: session_id2 = xmalloc(session_id2_len);
497: memcpy(session_id2, p, session_id2_len);
498: }
499:
1.1 provos 500: if ((key = get_hostkey_by_index(keyid)) == NULL)
1.14 markus 501: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 502: if (key_sign(key, &signature, &siglen, p, datlen) < 0)
1.14 markus 503: fatal("%s: key_sign failed", __func__);
1.1 provos 504:
1.19 deraadt 505: debug3("%s: signature %p(%u)", __func__, signature, siglen);
1.1 provos 506:
507: buffer_clear(m);
508: buffer_put_string(m, signature, siglen);
509:
510: xfree(p);
511: xfree(signature);
512:
1.59 avsm 513: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 514:
515: /* Turn on permissions for getpwnam */
516: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
517:
518: return (0);
519: }
520:
521: /* Retrieves the password entry and also checks if the user is permitted */
522:
523: int
1.59 avsm 524: mm_answer_pwnamallow(int sock, Buffer *m)
1.1 provos 525: {
1.60 dtucker 526: char *username;
1.1 provos 527: struct passwd *pwent;
528: int allowed = 0;
1.3 markus 529:
1.14 markus 530: debug3("%s", __func__);
1.1 provos 531:
532: if (authctxt->attempt++ != 0)
1.14 markus 533: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 534:
1.60 dtucker 535: username = buffer_get_string(m, NULL);
1.1 provos 536:
1.60 dtucker 537: pwent = getpwnamallow(username);
1.1 provos 538:
1.60 dtucker 539: authctxt->user = xstrdup(username);
540: setproctitle("%s [priv]", pwent ? username : "unknown");
541: xfree(username);
1.1 provos 542:
543: buffer_clear(m);
544:
545: if (pwent == NULL) {
546: buffer_put_char(m, 0);
1.53 djm 547: authctxt->pw = fakepw();
1.1 provos 548: goto out;
549: }
550:
551: allowed = 1;
1.4 markus 552: authctxt->pw = pwent;
1.1 provos 553: authctxt->valid = 1;
554:
555: buffer_put_char(m, 1);
556: buffer_put_string(m, pwent, sizeof(struct passwd));
557: buffer_put_cstring(m, pwent->pw_name);
558: buffer_put_cstring(m, "*");
559: buffer_put_cstring(m, pwent->pw_gecos);
560: buffer_put_cstring(m, pwent->pw_class);
561: buffer_put_cstring(m, pwent->pw_dir);
562: buffer_put_cstring(m, pwent->pw_shell);
563:
564: out:
1.14 markus 565: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 566: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 567:
568: /* For SSHv1 allow authentication now */
569: if (!compat20)
570: monitor_permit_authentications(1);
1.10 djm 571: else {
1.1 provos 572: /* Allow service/style information on the auth context */
573: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
1.10 djm 574: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
575: }
576:
577:
578: return (0);
579: }
580:
1.59 avsm 581: int mm_answer_auth2_read_banner(int sock, Buffer *m)
1.10 djm 582: {
583: char *banner;
584:
585: buffer_clear(m);
586: banner = auth2_read_banner();
587: buffer_put_cstring(m, banner != NULL ? banner : "");
1.59 avsm 588: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.1 provos 589:
1.10 djm 590: if (banner != NULL)
1.21 deraadt 591: xfree(banner);
1.1 provos 592:
593: return (0);
594: }
595:
596: int
1.59 avsm 597: mm_answer_authserv(int sock, Buffer *m)
1.1 provos 598: {
599: monitor_permit_authentications(1);
600:
601: authctxt->service = buffer_get_string(m, NULL);
602: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 603: debug3("%s: service=%s, style=%s",
1.14 markus 604: __func__, authctxt->service, authctxt->style);
1.6 stevesk 605:
1.1 provos 606: if (strlen(authctxt->style) == 0) {
607: xfree(authctxt->style);
608: authctxt->style = NULL;
609: }
610:
611: return (0);
612: }
613:
614: int
1.59 avsm 615: mm_answer_authpassword(int sock, Buffer *m)
1.1 provos 616: {
617: static int call_count;
618: char *passwd;
1.22 stevesk 619: int authenticated;
620: u_int plen;
1.1 provos 621:
622: passwd = buffer_get_string(m, &plen);
623: /* Only authenticate if the context is valid */
1.12 markus 624: authenticated = options.password_authentication &&
1.48 markus 625: auth_password(authctxt, passwd);
1.1 provos 626: memset(passwd, 0, strlen(passwd));
627: xfree(passwd);
628:
629: buffer_clear(m);
630: buffer_put_int(m, authenticated);
631:
1.14 markus 632: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 633: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 634:
635: call_count++;
636: if (plen == 0 && call_count == 1)
637: auth_method = "none";
638: else
639: auth_method = "password";
640:
641: /* Causes monitor loop to terminate if authenticated */
642: return (authenticated);
643: }
644:
645: #ifdef BSD_AUTH
646: int
1.59 avsm 647: mm_answer_bsdauthquery(int sock, Buffer *m)
1.1 provos 648: {
649: char *name, *infotxt;
650: u_int numprompts;
651: u_int *echo_on;
652: char **prompts;
1.31 markus 653: u_int success;
1.1 provos 654:
1.31 markus 655: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
656: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 657:
658: buffer_clear(m);
1.31 markus 659: buffer_put_int(m, success);
660: if (success)
1.1 provos 661: buffer_put_cstring(m, prompts[0]);
662:
1.31 markus 663: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 664: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 665:
1.31 markus 666: if (success) {
1.1 provos 667: xfree(name);
668: xfree(infotxt);
669: xfree(prompts);
670: xfree(echo_on);
671: }
672:
673: return (0);
674: }
675:
676: int
1.59 avsm 677: mm_answer_bsdauthrespond(int sock, Buffer *m)
1.1 provos 678: {
679: char *response;
680: int authok;
681:
682: if (authctxt->as == 0)
1.14 markus 683: fatal("%s: no bsd auth session", __func__);
1.1 provos 684:
685: response = buffer_get_string(m, NULL);
1.12 markus 686: authok = options.challenge_response_authentication &&
687: auth_userresponse(authctxt->as, response, 0);
1.1 provos 688: authctxt->as = NULL;
1.14 markus 689: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.1 provos 690: xfree(response);
691:
692: buffer_clear(m);
693: buffer_put_int(m, authok);
694:
1.14 markus 695: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 696: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 697:
698: auth_method = "bsdauth";
699:
700: return (authok != 0);
701: }
702: #endif
703:
704: #ifdef SKEY
705: int
1.59 avsm 706: mm_answer_skeyquery(int sock, Buffer *m)
1.1 provos 707: {
708: struct skey skey;
709: char challenge[1024];
1.31 markus 710: u_int success;
1.1 provos 711:
1.31 markus 712: success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
1.1 provos 713:
714: buffer_clear(m);
1.31 markus 715: buffer_put_int(m, success);
716: if (success)
1.1 provos 717: buffer_put_cstring(m, challenge);
718:
1.31 markus 719: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 720: mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
1.1 provos 721:
722: return (0);
723: }
724:
725: int
1.59 avsm 726: mm_answer_skeyrespond(int sock, Buffer *m)
1.1 provos 727: {
728: char *response;
729: int authok;
730:
731: response = buffer_get_string(m, NULL);
732:
1.12 markus 733: authok = (options.challenge_response_authentication &&
734: authctxt->valid &&
1.1 provos 735: skey_haskey(authctxt->pw->pw_name) == 0 &&
736: skey_passcheck(authctxt->pw->pw_name, response) != -1);
737:
738: xfree(response);
739:
740: buffer_clear(m);
741: buffer_put_int(m, authok);
742:
1.14 markus 743: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 744: mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
1.1 provos 745:
746: auth_method = "skey";
747:
748: return (authok != 0);
749: }
750: #endif
751:
1.2 markus 752: static void
1.1 provos 753: mm_append_debug(Buffer *m)
754: {
755: if (auth_debug_init && buffer_len(&auth_debug)) {
1.14 markus 756: debug3("%s: Appending debug messages for child", __func__);
1.1 provos 757: buffer_append(m, buffer_ptr(&auth_debug),
758: buffer_len(&auth_debug));
759: buffer_clear(&auth_debug);
760: }
761: }
762:
763: int
1.59 avsm 764: mm_answer_keyallowed(int sock, Buffer *m)
1.1 provos 765: {
766: Key *key;
1.26 markus 767: char *cuser, *chost;
768: u_char *blob;
1.1 provos 769: u_int bloblen;
770: enum mm_keytype type = 0;
771: int allowed = 0;
772:
1.14 markus 773: debug3("%s entering", __func__);
1.3 markus 774:
1.1 provos 775: type = buffer_get_int(m);
776: cuser = buffer_get_string(m, NULL);
777: chost = buffer_get_string(m, NULL);
778: blob = buffer_get_string(m, &bloblen);
779:
780: key = key_from_blob(blob, bloblen);
781:
782: if ((compat20 && type == MM_RSAHOSTKEY) ||
783: (!compat20 && type != MM_RSAHOSTKEY))
1.14 markus 784: fatal("%s: key type and protocol mismatch", __func__);
1.1 provos 785:
1.14 markus 786: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 787:
1.51 djm 788: if (key != NULL && authctxt->valid) {
1.63 deraadt 789: switch (type) {
1.1 provos 790: case MM_USERKEY:
1.12 markus 791: allowed = options.pubkey_authentication &&
792: user_key_allowed(authctxt->pw, key);
1.77 ! dtucker 793: auth_method = "publickey";
1.1 provos 794: break;
795: case MM_HOSTKEY:
1.12 markus 796: allowed = options.hostbased_authentication &&
797: hostbased_key_allowed(authctxt->pw,
1.1 provos 798: cuser, chost, key);
1.77 ! dtucker 799: auth_method = "hostbased";
1.1 provos 800: break;
801: case MM_RSAHOSTKEY:
802: key->type = KEY_RSA1; /* XXX */
1.12 markus 803: allowed = options.rhosts_rsa_authentication &&
804: auth_rhosts_rsa_key_allowed(authctxt->pw,
1.1 provos 805: cuser, chost, key);
1.77 ! dtucker 806: auth_method = "rsa";
1.1 provos 807: break;
808: default:
1.14 markus 809: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 810: break;
811: }
1.33 markus 812: }
813: if (key != NULL)
1.1 provos 814: key_free(key);
815:
816: /* clear temporarily storage (used by verify) */
817: monitor_reset_key_state();
818:
819: if (allowed) {
820: /* Save temporarily for comparison in verify */
821: key_blob = blob;
822: key_bloblen = bloblen;
823: key_blobtype = type;
824: hostbased_cuser = cuser;
825: hostbased_chost = chost;
1.72 djm 826: } else {
1.77 ! dtucker 827: /* Log failed attempt */
! 828: auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1.72 djm 829: xfree(blob);
830: xfree(cuser);
831: xfree(chost);
1.1 provos 832: }
833:
834: debug3("%s: key %p is %s",
1.14 markus 835: __func__, key, allowed ? "allowed" : "disallowed");
1.1 provos 836:
837: buffer_clear(m);
838: buffer_put_int(m, allowed);
1.32 markus 839: buffer_put_int(m, forced_command != NULL);
1.1 provos 840:
841: mm_append_debug(m);
842:
1.59 avsm 843: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 844:
845: if (type == MM_RSAHOSTKEY)
846: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
847:
848: return (0);
849: }
850:
851: static int
852: monitor_valid_userblob(u_char *data, u_int datalen)
853: {
854: Buffer b;
1.26 markus 855: char *p;
1.1 provos 856: u_int len;
857: int fail = 0;
858:
859: buffer_init(&b);
860: buffer_append(&b, data, datalen);
1.3 markus 861:
1.1 provos 862: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 863: p = buffer_ptr(&b);
864: len = buffer_len(&b);
865: if ((session_id2 == NULL) ||
866: (len < session_id2_len) ||
867: (memcmp(p, session_id2, session_id2_len) != 0))
868: fail++;
1.1 provos 869: buffer_consume(&b, session_id2_len);
870: } else {
1.13 markus 871: p = buffer_get_string(&b, &len);
872: if ((session_id2 == NULL) ||
873: (len != session_id2_len) ||
874: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 875: fail++;
1.13 markus 876: xfree(p);
1.1 provos 877: }
878: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
879: fail++;
880: p = buffer_get_string(&b, NULL);
881: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 882: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 883: authctxt->user, p);
884: fail++;
885: }
886: xfree(p);
887: buffer_skip_string(&b);
888: if (datafellows & SSH_BUG_PKAUTH) {
889: if (!buffer_get_char(&b))
890: fail++;
891: } else {
892: p = buffer_get_string(&b, NULL);
893: if (strcmp("publickey", p) != 0)
894: fail++;
895: xfree(p);
896: if (!buffer_get_char(&b))
897: fail++;
898: buffer_skip_string(&b);
899: }
900: buffer_skip_string(&b);
901: if (buffer_len(&b) != 0)
902: fail++;
903: buffer_free(&b);
904: return (fail == 0);
905: }
906:
907: static int
1.26 markus 908: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
909: char *chost)
1.1 provos 910: {
911: Buffer b;
1.26 markus 912: char *p;
1.1 provos 913: u_int len;
914: int fail = 0;
915:
916: buffer_init(&b);
917: buffer_append(&b, data, datalen);
1.3 markus 918:
1.13 markus 919: p = buffer_get_string(&b, &len);
920: if ((session_id2 == NULL) ||
921: (len != session_id2_len) ||
922: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 923: fail++;
1.13 markus 924: xfree(p);
925:
1.1 provos 926: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
927: fail++;
928: p = buffer_get_string(&b, NULL);
929: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 930: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 931: authctxt->user, p);
932: fail++;
933: }
934: xfree(p);
935: buffer_skip_string(&b); /* service */
936: p = buffer_get_string(&b, NULL);
937: if (strcmp(p, "hostbased") != 0)
938: fail++;
939: xfree(p);
940: buffer_skip_string(&b); /* pkalg */
941: buffer_skip_string(&b); /* pkblob */
942:
943: /* verify client host, strip trailing dot if necessary */
944: p = buffer_get_string(&b, NULL);
945: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
946: p[len - 1] = '\0';
947: if (strcmp(p, chost) != 0)
948: fail++;
949: xfree(p);
950:
951: /* verify client user */
952: p = buffer_get_string(&b, NULL);
953: if (strcmp(p, cuser) != 0)
954: fail++;
955: xfree(p);
956:
957: if (buffer_len(&b) != 0)
958: fail++;
959: buffer_free(&b);
960: return (fail == 0);
961: }
962:
963: int
1.59 avsm 964: mm_answer_keyverify(int sock, Buffer *m)
1.1 provos 965: {
966: Key *key;
967: u_char *signature, *data, *blob;
968: u_int signaturelen, datalen, bloblen;
969: int verified = 0;
970: int valid_data = 0;
971:
972: blob = buffer_get_string(m, &bloblen);
973: signature = buffer_get_string(m, &signaturelen);
974: data = buffer_get_string(m, &datalen);
975:
976: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 977: !monitor_allowed_key(blob, bloblen))
1.14 markus 978: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 979:
980: key = key_from_blob(blob, bloblen);
981: if (key == NULL)
1.14 markus 982: fatal("%s: bad public key blob", __func__);
1.1 provos 983:
984: switch (key_blobtype) {
985: case MM_USERKEY:
986: valid_data = monitor_valid_userblob(data, datalen);
987: break;
988: case MM_HOSTKEY:
989: valid_data = monitor_valid_hostbasedblob(data, datalen,
990: hostbased_cuser, hostbased_chost);
991: break;
992: default:
993: valid_data = 0;
994: break;
995: }
996: if (!valid_data)
1.14 markus 997: fatal("%s: bad signature data blob", __func__);
1.1 provos 998:
999: verified = key_verify(key, signature, signaturelen, data, datalen);
1000: debug3("%s: key %p signature %s",
1.14 markus 1001: __func__, key, verified ? "verified" : "unverified");
1.1 provos 1002:
1003: key_free(key);
1004: xfree(blob);
1005: xfree(signature);
1006: xfree(data);
1007:
1.17 stevesk 1008: auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1009:
1.1 provos 1010: monitor_reset_key_state();
1.3 markus 1011:
1.1 provos 1012: buffer_clear(m);
1013: buffer_put_int(m, verified);
1.59 avsm 1014: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.1 provos 1015:
1016: return (verified);
1017: }
1018:
1.2 markus 1019: static void
1.1 provos 1020: mm_record_login(Session *s, struct passwd *pw)
1021: {
1022: socklen_t fromlen;
1023: struct sockaddr_storage from;
1024:
1025: /*
1026: * Get IP address of client. If the connection is not a socket, let
1027: * the address be 0.0.0.0.
1028: */
1029: memset(&from, 0, sizeof(from));
1.24 stevesk 1030: fromlen = sizeof(from);
1.1 provos 1031: if (packet_connection_is_on_socket()) {
1032: if (getpeername(packet_get_connection_in(),
1.74 deraadt 1033: (struct sockaddr *)&from, &fromlen) < 0) {
1.1 provos 1034: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1035: cleanup_exit(255);
1.1 provos 1036: }
1037: }
1038: /* Record that there was a login on that tty from the remote host. */
1039: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.42 markus 1040: get_remote_name_or_ip(utmp_len, options.use_dns),
1.24 stevesk 1041: (struct sockaddr *)&from, fromlen);
1.1 provos 1042: }
1043:
1044: static void
1045: mm_session_close(Session *s)
1046: {
1.41 djm 1047: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1048: if (s->ttyfd != -1) {
1.14 markus 1049: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1050: session_pty_cleanup2(s);
1051: }
1052: s->used = 0;
1053: }
1054:
1055: int
1.59 avsm 1056: mm_answer_pty(int sock, Buffer *m)
1.1 provos 1057: {
1.11 mouring 1058: extern struct monitor *pmonitor;
1.1 provos 1059: Session *s;
1060: int res, fd0;
1061:
1.14 markus 1062: debug3("%s entering", __func__);
1.1 provos 1063:
1064: buffer_clear(m);
1065: s = session_new();
1066: if (s == NULL)
1067: goto error;
1068: s->authctxt = authctxt;
1069: s->pw = authctxt->pw;
1.11 mouring 1070: s->pid = pmonitor->m_pid;
1.1 provos 1071: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1072: if (res == 0)
1073: goto error;
1074: pty_setowner(authctxt->pw, s->tty);
1075:
1076: buffer_put_int(m, 1);
1077: buffer_put_cstring(m, s->tty);
1078:
1079: /* We need to trick ttyslot */
1080: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1081: fatal("%s: dup2", __func__);
1.1 provos 1082:
1083: mm_record_login(s, authctxt->pw);
1084:
1085: /* Now we can close the file descriptor again */
1086: close(0);
1.61 dtucker 1087:
1088: /* send messages generated by record_login */
1089: buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1090: buffer_clear(&loginmsg);
1091:
1092: mm_request_send(sock, MONITOR_ANS_PTY, m);
1093:
1094: mm_send_fd(sock, s->ptyfd);
1095: mm_send_fd(sock, s->ttyfd);
1.1 provos 1096:
1097: /* make sure nothing uses fd 0 */
1098: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1099: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1100: if (fd0 != 0)
1.14 markus 1101: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1102:
1103: /* slave is not needed */
1104: close(s->ttyfd);
1105: s->ttyfd = s->ptyfd;
1106: /* no need to dup() because nobody closes ptyfd */
1107: s->ptymaster = s->ptyfd;
1108:
1.14 markus 1109: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1110:
1111: return (0);
1112:
1113: error:
1114: if (s != NULL)
1115: mm_session_close(s);
1116: buffer_put_int(m, 0);
1.59 avsm 1117: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1118: return (0);
1119: }
1120:
1121: int
1.59 avsm 1122: mm_answer_pty_cleanup(int sock, Buffer *m)
1.1 provos 1123: {
1124: Session *s;
1125: char *tty;
1126:
1.14 markus 1127: debug3("%s entering", __func__);
1.1 provos 1128:
1129: tty = buffer_get_string(m, NULL);
1130: if ((s = session_by_tty(tty)) != NULL)
1131: mm_session_close(s);
1132: buffer_clear(m);
1133: xfree(tty);
1134: return (0);
1135: }
1136:
1137: int
1.59 avsm 1138: mm_answer_sesskey(int sock, Buffer *m)
1.1 provos 1139: {
1140: BIGNUM *p;
1141: int rsafail;
1142:
1143: /* Turn off permissions */
1.62 dtucker 1144: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1.1 provos 1145:
1146: if ((p = BN_new()) == NULL)
1.14 markus 1147: fatal("%s: BN_new", __func__);
1.1 provos 1148:
1149: buffer_get_bignum2(m, p);
1150:
1151: rsafail = ssh1_session_key(p);
1152:
1153: buffer_clear(m);
1154: buffer_put_int(m, rsafail);
1155: buffer_put_bignum2(m, p);
1156:
1157: BN_clear_free(p);
1158:
1.59 avsm 1159: mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1.1 provos 1160:
1161: /* Turn on permissions for sessid passing */
1162: monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1163:
1164: return (0);
1165: }
1166:
1167: int
1.59 avsm 1168: mm_answer_sessid(int sock, Buffer *m)
1.1 provos 1169: {
1170: int i;
1171:
1.14 markus 1172: debug3("%s entering", __func__);
1.1 provos 1173:
1174: if (buffer_len(m) != 16)
1.14 markus 1175: fatal("%s: bad ssh1 session id", __func__);
1.1 provos 1176: for (i = 0; i < 16; i++)
1177: session_id[i] = buffer_get_char(m);
1178:
1179: /* Turn on permissions for getpwnam */
1180: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1181:
1182: return (0);
1183: }
1184:
1185: int
1.59 avsm 1186: mm_answer_rsa_keyallowed(int sock, Buffer *m)
1.1 provos 1187: {
1188: BIGNUM *client_n;
1189: Key *key = NULL;
1.3 markus 1190: u_char *blob = NULL;
1191: u_int blen = 0;
1.1 provos 1192: int allowed = 0;
1193:
1.14 markus 1194: debug3("%s entering", __func__);
1.1 provos 1195:
1.77 ! dtucker 1196: auth_method = "rsa";
1.12 markus 1197: if (options.rsa_authentication && authctxt->valid) {
1.1 provos 1198: if ((client_n = BN_new()) == NULL)
1.14 markus 1199: fatal("%s: BN_new", __func__);
1.1 provos 1200: buffer_get_bignum2(m, client_n);
1201: allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1202: BN_clear_free(client_n);
1203: }
1204: buffer_clear(m);
1205: buffer_put_int(m, allowed);
1.32 markus 1206: buffer_put_int(m, forced_command != NULL);
1.1 provos 1207:
1208: /* clear temporarily storage (used by generate challenge) */
1209: monitor_reset_key_state();
1210:
1211: if (allowed && key != NULL) {
1212: key->type = KEY_RSA; /* cheat for key_to_blob */
1213: if (key_to_blob(key, &blob, &blen) == 0)
1.14 markus 1214: fatal("%s: key_to_blob failed", __func__);
1.1 provos 1215: buffer_put_string(m, blob, blen);
1216:
1217: /* Save temporarily for comparison in verify */
1218: key_blob = blob;
1219: key_bloblen = blen;
1220: key_blobtype = MM_RSAUSERKEY;
1.33 markus 1221: }
1222: if (key != NULL)
1.1 provos 1223: key_free(key);
1224:
1225: mm_append_debug(m);
1226:
1.59 avsm 1227: mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1.1 provos 1228:
1229: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1230: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1231: return (0);
1232: }
1233:
1234: int
1.59 avsm 1235: mm_answer_rsa_challenge(int sock, Buffer *m)
1.1 provos 1236: {
1237: Key *key = NULL;
1.3 markus 1238: u_char *blob;
1239: u_int blen;
1.1 provos 1240:
1.14 markus 1241: debug3("%s entering", __func__);
1.1 provos 1242:
1243: if (!authctxt->valid)
1.14 markus 1244: fatal("%s: authctxt not valid", __func__);
1.1 provos 1245: blob = buffer_get_string(m, &blen);
1246: if (!monitor_allowed_key(blob, blen))
1.14 markus 1247: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1248: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1249: fatal("%s: key type mismatch", __func__);
1.1 provos 1250: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1251: fatal("%s: received bad key", __func__);
1.1 provos 1252:
1253: if (ssh1_challenge)
1254: BN_clear_free(ssh1_challenge);
1255: ssh1_challenge = auth_rsa_generate_challenge(key);
1256:
1257: buffer_clear(m);
1258: buffer_put_bignum2(m, ssh1_challenge);
1259:
1.14 markus 1260: debug3("%s sending reply", __func__);
1.59 avsm 1261: mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1.1 provos 1262:
1263: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1.33 markus 1264:
1265: xfree(blob);
1266: key_free(key);
1.1 provos 1267: return (0);
1268: }
1269:
1270: int
1.59 avsm 1271: mm_answer_rsa_response(int sock, Buffer *m)
1.1 provos 1272: {
1273: Key *key = NULL;
1.3 markus 1274: u_char *blob, *response;
1275: u_int blen, len;
1276: int success;
1.1 provos 1277:
1.14 markus 1278: debug3("%s entering", __func__);
1.1 provos 1279:
1280: if (!authctxt->valid)
1.14 markus 1281: fatal("%s: authctxt not valid", __func__);
1.1 provos 1282: if (ssh1_challenge == NULL)
1.14 markus 1283: fatal("%s: no ssh1_challenge", __func__);
1.1 provos 1284:
1285: blob = buffer_get_string(m, &blen);
1286: if (!monitor_allowed_key(blob, blen))
1.14 markus 1287: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1288: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1289: fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1.1 provos 1290: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1291: fatal("%s: received bad key", __func__);
1.1 provos 1292: response = buffer_get_string(m, &len);
1293: if (len != 16)
1.14 markus 1294: fatal("%s: received bad response to challenge", __func__);
1.1 provos 1295: success = auth_rsa_verify_response(key, ssh1_challenge, response);
1296:
1.33 markus 1297: xfree(blob);
1.1 provos 1298: key_free(key);
1299: xfree(response);
1300:
1301: auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1302:
1303: /* reset state */
1304: BN_clear_free(ssh1_challenge);
1305: ssh1_challenge = NULL;
1306: monitor_reset_key_state();
1307:
1308: buffer_clear(m);
1309: buffer_put_int(m, success);
1.59 avsm 1310: mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1.1 provos 1311:
1312: return (success);
1313: }
1314:
1315: int
1.59 avsm 1316: mm_answer_term(int sock, Buffer *req)
1.1 provos 1317: {
1.11 mouring 1318: extern struct monitor *pmonitor;
1.1 provos 1319: int res, status;
1320:
1.14 markus 1321: debug3("%s: tearing down sessions", __func__);
1.1 provos 1322:
1323: /* The child is terminating */
1324: session_destroy_all(&mm_session_close);
1325:
1.11 mouring 1326: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1327: if (errno != EINTR)
1328: exit(1);
1.1 provos 1329:
1330: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1331:
1332: /* Terminate process */
1.57 deraadt 1333: exit(res);
1.1 provos 1334: }
1335:
1336: void
1.11 mouring 1337: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1338: {
1339: if (compat20) {
1340: set_newkeys(MODE_IN);
1341: set_newkeys(MODE_OUT);
1342: } else {
1343: packet_set_protocol_flags(child_state.ssh1protoflags);
1.15 markus 1344: packet_set_encryption_key(child_state.ssh1key,
1345: child_state.ssh1keylen, child_state.ssh1cipher);
1346: xfree(child_state.ssh1key);
1.1 provos 1347: }
1348:
1.15 markus 1349: /* for rc4 and other stateful ciphers */
1.1 provos 1350: packet_set_keycontext(MODE_OUT, child_state.keyout);
1351: xfree(child_state.keyout);
1352: packet_set_keycontext(MODE_IN, child_state.keyin);
1353: xfree(child_state.keyin);
1354:
1355: if (!compat20) {
1356: packet_set_iv(MODE_OUT, child_state.ivout);
1357: xfree(child_state.ivout);
1358: packet_set_iv(MODE_IN, child_state.ivin);
1359: xfree(child_state.ivin);
1360: }
1361:
1362: memcpy(&incoming_stream, &child_state.incoming,
1363: sizeof(incoming_stream));
1364: memcpy(&outgoing_stream, &child_state.outgoing,
1365: sizeof(outgoing_stream));
1.3 markus 1366:
1.1 provos 1367: /* Update with new address */
1.16 djm 1368: if (options.compression)
1369: mm_init_compression(pmonitor->m_zlib);
1.1 provos 1370:
1371: /* Network I/O buffers */
1372: /* XXX inefficient for large buffers, need: buffer_init_from_string */
1373: buffer_clear(&input);
1374: buffer_append(&input, child_state.input, child_state.ilen);
1375: memset(child_state.input, 0, child_state.ilen);
1376: xfree(child_state.input);
1377:
1378: buffer_clear(&output);
1379: buffer_append(&output, child_state.output, child_state.olen);
1380: memset(child_state.output, 0, child_state.olen);
1381: xfree(child_state.output);
1382: }
1383:
1.2 markus 1384: static Kex *
1.1 provos 1385: mm_get_kex(Buffer *m)
1386: {
1387: Kex *kex;
1388: void *blob;
1389: u_int bloblen;
1390:
1.75 djm 1391: kex = xcalloc(1, sizeof(*kex));
1.1 provos 1392: kex->session_id = buffer_get_string(m, &kex->session_id_len);
1.13 markus 1393: if ((session_id2 == NULL) ||
1394: (kex->session_id_len != session_id2_len) ||
1395: (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1396: fatal("mm_get_get: internal error: bad session id");
1.1 provos 1397: kex->we_need = buffer_get_int(m);
1.34 markus 1398: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1.58 djm 1399: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1.34 markus 1400: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.69 djm 1401: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.1 provos 1402: kex->server = 1;
1403: kex->hostkey_type = buffer_get_int(m);
1404: kex->kex_type = buffer_get_int(m);
1405: blob = buffer_get_string(m, &bloblen);
1406: buffer_init(&kex->my);
1407: buffer_append(&kex->my, blob, bloblen);
1408: xfree(blob);
1409: blob = buffer_get_string(m, &bloblen);
1410: buffer_init(&kex->peer);
1411: buffer_append(&kex->peer, blob, bloblen);
1412: xfree(blob);
1413: kex->done = 1;
1414: kex->flags = buffer_get_int(m);
1415: kex->client_version_string = buffer_get_string(m, NULL);
1416: kex->server_version_string = buffer_get_string(m, NULL);
1417: kex->load_host_key=&get_hostkey_by_type;
1418: kex->host_key_index=&get_hostkey_index;
1419:
1420: return (kex);
1421: }
1422:
1423: /* This function requries careful sanity checking */
1424:
1425: void
1.11 mouring 1426: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1427: {
1428: Buffer m;
1429: u_char *blob, *p;
1430: u_int bloblen, plen;
1.37 markus 1431: u_int32_t seqnr, packets;
1432: u_int64_t blocks;
1.1 provos 1433:
1.14 markus 1434: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1435:
1436: buffer_init(&m);
1.11 mouring 1437: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1.1 provos 1438: if (!compat20) {
1439: child_state.ssh1protoflags = buffer_get_int(&m);
1440: child_state.ssh1cipher = buffer_get_int(&m);
1.15 markus 1441: child_state.ssh1key = buffer_get_string(&m,
1442: &child_state.ssh1keylen);
1.1 provos 1443: child_state.ivout = buffer_get_string(&m,
1444: &child_state.ivoutlen);
1445: child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1446: goto skip;
1447: } else {
1448: /* Get the Kex for rekeying */
1.11 mouring 1449: *pmonitor->m_pkex = mm_get_kex(&m);
1.1 provos 1450: }
1451:
1452: blob = buffer_get_string(&m, &bloblen);
1453: current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1454: xfree(blob);
1455:
1.14 markus 1456: debug3("%s: Waiting for second key", __func__);
1.1 provos 1457: blob = buffer_get_string(&m, &bloblen);
1458: current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1459: xfree(blob);
1.3 markus 1460:
1.1 provos 1461: /* Now get sequence numbers for the packets */
1.37 markus 1462: seqnr = buffer_get_int(&m);
1463: blocks = buffer_get_int64(&m);
1464: packets = buffer_get_int(&m);
1465: packet_set_state(MODE_OUT, seqnr, blocks, packets);
1466: seqnr = buffer_get_int(&m);
1467: blocks = buffer_get_int64(&m);
1468: packets = buffer_get_int(&m);
1469: packet_set_state(MODE_IN, seqnr, blocks, packets);
1.1 provos 1470:
1471: skip:
1472: /* Get the key context */
1473: child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1474: child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1475:
1.14 markus 1476: debug3("%s: Getting compression state", __func__);
1.1 provos 1477: /* Get compression state */
1478: p = buffer_get_string(&m, &plen);
1479: if (plen != sizeof(child_state.outgoing))
1.14 markus 1480: fatal("%s: bad request size", __func__);
1.1 provos 1481: memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1482: xfree(p);
1483:
1484: p = buffer_get_string(&m, &plen);
1485: if (plen != sizeof(child_state.incoming))
1.14 markus 1486: fatal("%s: bad request size", __func__);
1.1 provos 1487: memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1488: xfree(p);
1489:
1490: /* Network I/O buffers */
1.14 markus 1491: debug3("%s: Getting Network I/O buffers", __func__);
1.1 provos 1492: child_state.input = buffer_get_string(&m, &child_state.ilen);
1493: child_state.output = buffer_get_string(&m, &child_state.olen);
1494:
1495: buffer_free(&m);
1496: }
1497:
1498:
1499: /* Allocation functions for zlib */
1500: void *
1501: mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1502: {
1.30 markus 1503: size_t len = (size_t) size * ncount;
1.1 provos 1504: void *address;
1505:
1.23 millert 1506: if (len == 0 || ncount > SIZE_T_MAX / size)
1.18 deraadt 1507: fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1508:
1509: address = mm_malloc(mm, len);
1.1 provos 1510:
1511: return (address);
1512: }
1513:
1514: void
1515: mm_zfree(struct mm_master *mm, void *address)
1516: {
1517: mm_free(mm, address);
1518: }
1519:
1520: void
1521: mm_init_compression(struct mm_master *mm)
1522: {
1523: outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1524: outgoing_stream.zfree = (free_func)mm_zfree;
1525: outgoing_stream.opaque = mm;
1526:
1527: incoming_stream.zalloc = (alloc_func)mm_zalloc;
1528: incoming_stream.zfree = (free_func)mm_zfree;
1529: incoming_stream.opaque = mm;
1530: }
1531:
1532: /* XXX */
1533:
1534: #define FD_CLOSEONEXEC(x) do { \
1535: if (fcntl(x, F_SETFD, 1) == -1) \
1536: fatal("fcntl(%d, F_SETFD)", x); \
1537: } while (0)
1538:
1.2 markus 1539: static void
1.1 provos 1540: monitor_socketpair(int *pair)
1.3 markus 1541: {
1.1 provos 1542: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.14 markus 1543: fatal("%s: socketpair", __func__);
1.1 provos 1544: FD_CLOSEONEXEC(pair[0]);
1545: FD_CLOSEONEXEC(pair[1]);
1546: }
1547:
1548: #define MM_MEMSIZE 65536
1549:
1550: struct monitor *
1551: monitor_init(void)
1552: {
1553: struct monitor *mon;
1554: int pair[2];
1555:
1.75 djm 1556: mon = xcalloc(1, sizeof(*mon));
1.1 provos 1557:
1558: monitor_socketpair(pair);
1559:
1560: mon->m_recvfd = pair[0];
1561: mon->m_sendfd = pair[1];
1562:
1563: /* Used to share zlib space across processes */
1.16 djm 1564: if (options.compression) {
1565: mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1566: mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1.1 provos 1567:
1.16 djm 1568: /* Compression needs to share state across borders */
1569: mm_init_compression(mon->m_zlib);
1570: }
1.1 provos 1571:
1572: return mon;
1573: }
1574:
1575: void
1576: monitor_reinit(struct monitor *mon)
1577: {
1578: int pair[2];
1579:
1580: monitor_socketpair(pair);
1581:
1582: mon->m_recvfd = pair[0];
1583: mon->m_sendfd = pair[1];
1584: }
1.46 markus 1585:
1586: #ifdef GSSAPI
1587: int
1.59 avsm 1588: mm_answer_gss_setup_ctx(int sock, Buffer *m)
1.46 markus 1589: {
1.59 avsm 1590: gss_OID_desc goid;
1.46 markus 1591: OM_uint32 major;
1592: u_int len;
1593:
1.59 avsm 1594: goid.elements = buffer_get_string(m, &len);
1595: goid.length = len;
1.46 markus 1596:
1.59 avsm 1597: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1598:
1.59 avsm 1599: xfree(goid.elements);
1.46 markus 1600:
1601: buffer_clear(m);
1602: buffer_put_int(m, major);
1603:
1.64 stevesk 1604: mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1.46 markus 1605:
1606: /* Now we have a context, enable the step */
1607: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1608:
1609: return (0);
1610: }
1611:
1612: int
1.59 avsm 1613: mm_answer_gss_accept_ctx(int sock, Buffer *m)
1.46 markus 1614: {
1615: gss_buffer_desc in;
1616: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1.64 stevesk 1617: OM_uint32 major, minor;
1.46 markus 1618: OM_uint32 flags = 0; /* GSI needs this */
1.47 deraadt 1619: u_int len;
1.46 markus 1620:
1.47 deraadt 1621: in.value = buffer_get_string(m, &len);
1622: in.length = len;
1.46 markus 1623: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1624: xfree(in.value);
1625:
1626: buffer_clear(m);
1627: buffer_put_int(m, major);
1628: buffer_put_string(m, out.value, out.length);
1629: buffer_put_int(m, flags);
1.59 avsm 1630: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1631:
1632: gss_release_buffer(&minor, &out);
1633:
1.64 stevesk 1634: if (major == GSS_S_COMPLETE) {
1.46 markus 1635: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1636: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1637: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1638: }
1639: return (0);
1640: }
1641:
1642: int
1.59 avsm 1643: mm_answer_gss_checkmic(int sock, Buffer *m)
1.52 markus 1644: {
1645: gss_buffer_desc gssbuf, mic;
1646: OM_uint32 ret;
1647: u_int len;
1.54 djm 1648:
1.52 markus 1649: gssbuf.value = buffer_get_string(m, &len);
1650: gssbuf.length = len;
1651: mic.value = buffer_get_string(m, &len);
1652: mic.length = len;
1.54 djm 1653:
1.52 markus 1654: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1655:
1.52 markus 1656: xfree(gssbuf.value);
1657: xfree(mic.value);
1.54 djm 1658:
1.52 markus 1659: buffer_clear(m);
1660: buffer_put_int(m, ret);
1.54 djm 1661:
1.59 avsm 1662: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1663:
1.52 markus 1664: if (!GSS_ERROR(ret))
1665: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1666:
1.52 markus 1667: return (0);
1668: }
1669:
1670: int
1.59 avsm 1671: mm_answer_gss_userok(int sock, Buffer *m)
1.46 markus 1672: {
1673: int authenticated;
1674:
1675: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1676:
1677: buffer_clear(m);
1678: buffer_put_int(m, authenticated);
1679:
1680: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1681: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1682:
1.64 stevesk 1683: auth_method = "gssapi-with-mic";
1.46 markus 1684:
1685: /* Monitor loop will terminate if authenticated */
1686: return (authenticated);
1687: }
1688: #endif /* GSSAPI */
![[BACK]](/icons/back.gif){kind=icon}
Return to monitor.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh