Annotation of src/usr.bin/ssh/monitor.c, Revision 1.46
1.1 provos 1: /*
2: * Copyright 2002 Niels Provos <provos@citi.umich.edu>
3: * Copyright 2002 Markus Friedl <markus@openbsd.org>
4: * All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: #include "includes.h"
1.46 ! markus 28: RCSID("$OpenBSD: monitor.c,v 1.45 2003/07/22 13:35:22 markus Exp $");
1.1 provos 29:
30: #include <openssl/dh.h>
31:
32: #ifdef SKEY
33: #include <skey.h>
34: #endif
35:
36: #include "ssh.h"
37: #include "auth.h"
38: #include "kex.h"
39: #include "dh.h"
40: #include "zlib.h"
41: #include "packet.h"
42: #include "auth-options.h"
43: #include "sshpty.h"
44: #include "channels.h"
45: #include "session.h"
46: #include "sshlogin.h"
47: #include "canohost.h"
48: #include "log.h"
49: #include "servconf.h"
50: #include "monitor.h"
51: #include "monitor_mm.h"
52: #include "monitor_wrap.h"
53: #include "monitor_fdpass.h"
54: #include "xmalloc.h"
55: #include "misc.h"
56: #include "buffer.h"
57: #include "bufaux.h"
58: #include "compat.h"
59: #include "ssh2.h"
60: #include "mpaux.h"
61:
1.46 ! markus 62: #ifdef GSSAPI
! 63: #include "ssh-gss.h"
! 64: static Gssctxt *gsscontext = NULL;
! 65: #endif
! 66:
1.1 provos 67: /* Imports */
68: extern ServerOptions options;
69: extern u_int utmp_len;
70: extern Newkeys *current_keys[];
71: extern z_stream incoming_stream;
72: extern z_stream outgoing_stream;
73: extern u_char session_id[];
74: extern Buffer input, output;
75: extern Buffer auth_debug;
76: extern int auth_debug_init;
77:
78: /* State exported from the child */
79:
80: struct {
81: z_stream incoming;
82: z_stream outgoing;
83: u_char *keyin;
84: u_int keyinlen;
85: u_char *keyout;
86: u_int keyoutlen;
87: u_char *ivin;
88: u_int ivinlen;
89: u_char *ivout;
90: u_int ivoutlen;
1.15 markus 91: u_char *ssh1key;
92: u_int ssh1keylen;
1.1 provos 93: int ssh1cipher;
94: int ssh1protoflags;
95: u_char *input;
96: u_int ilen;
97: u_char *output;
98: u_int olen;
99: } child_state;
100:
1.43 markus 101: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 102:
103: int mm_answer_moduli(int, Buffer *);
104: int mm_answer_sign(int, Buffer *);
105: int mm_answer_pwnamallow(int, Buffer *);
1.10 djm 106: int mm_answer_auth2_read_banner(int, Buffer *);
1.1 provos 107: int mm_answer_authserv(int, Buffer *);
108: int mm_answer_authpassword(int, Buffer *);
109: int mm_answer_bsdauthquery(int, Buffer *);
110: int mm_answer_bsdauthrespond(int, Buffer *);
111: int mm_answer_skeyquery(int, Buffer *);
112: int mm_answer_skeyrespond(int, Buffer *);
113: int mm_answer_keyallowed(int, Buffer *);
114: int mm_answer_keyverify(int, Buffer *);
115: int mm_answer_pty(int, Buffer *);
116: int mm_answer_pty_cleanup(int, Buffer *);
117: int mm_answer_term(int, Buffer *);
118: int mm_answer_rsa_keyallowed(int, Buffer *);
119: int mm_answer_rsa_challenge(int, Buffer *);
120: int mm_answer_rsa_response(int, Buffer *);
121: int mm_answer_sesskey(int, Buffer *);
122: int mm_answer_sessid(int, Buffer *);
123:
1.25 itojun 124: #ifdef KRB5
125: int mm_answer_krb5(int, Buffer *);
126: #endif
1.46 ! markus 127: #ifdef GSSAPI
! 128: int mm_answer_gss_setup_ctx(int, Buffer *);
! 129: int mm_answer_gss_accept_ctx(int, Buffer *);
! 130: int mm_answer_gss_userok(int, Buffer *);
! 131: #endif
1.25 itojun 132:
1.1 provos 133: static Authctxt *authctxt;
134: static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
135:
136: /* local state for key verify */
137: static u_char *key_blob = NULL;
138: static u_int key_bloblen = 0;
139: static int key_blobtype = MM_NOKEY;
1.26 markus 140: static char *hostbased_cuser = NULL;
141: static char *hostbased_chost = NULL;
1.1 provos 142: static char *auth_method = "unknown";
1.44 markus 143: static u_int session_id2_len = 0;
1.13 markus 144: static u_char *session_id2 = NULL;
1.40 markus 145: static pid_t monitor_child_pid;
1.1 provos 146:
147: struct mon_table {
148: enum monitor_reqtype type;
149: int flags;
150: int (*f)(int, Buffer *);
151: };
152:
153: #define MON_ISAUTH 0x0004 /* Required for Authentication */
154: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
155: #define MON_ONCE 0x0010 /* Disable after calling */
156:
157: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
158:
159: #define MON_PERMIT 0x1000 /* Request is permitted */
160:
161: struct mon_table mon_dispatch_proto20[] = {
162: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
163: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
164: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
165: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 166: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 167: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
168: #ifdef BSD_AUTH
169: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
170: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
171: #endif
172: #ifdef SKEY
173: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
174: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
175: #endif
176: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
177: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.39 markus 178: #ifdef KRB5
179: {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5},
180: #endif
1.46 ! markus 181: #ifdef GSSAPI
! 182: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
! 183: {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
! 184: {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
! 185: #endif
1.1 provos 186: {0, 0, NULL}
187: };
188:
189: struct mon_table mon_dispatch_postauth20[] = {
190: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
191: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
192: {MONITOR_REQ_PTY, 0, mm_answer_pty},
193: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
194: {MONITOR_REQ_TERM, 0, mm_answer_term},
195: {0, 0, NULL}
196: };
197:
198: struct mon_table mon_dispatch_proto15[] = {
199: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
200: {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
201: {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
202: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
203: {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
204: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
205: {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
206: {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
207: #ifdef BSD_AUTH
208: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
209: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
210: #endif
211: #ifdef SKEY
212: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
213: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
214: #endif
1.25 itojun 215: #ifdef KRB5
216: {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5},
217: #endif
1.1 provos 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:
259: Authctxt *
1.11 mouring 260: monitor_child_preauth(struct monitor *pmonitor)
1.1 provos 261: {
262: struct mon_table *ent;
263: int authenticated = 0;
264:
265: debug3("preauth child monitor started");
266:
267: if (compat20) {
268: mon_dispatch = mon_dispatch_proto20;
269:
270: /* Permit requests for moduli and signatures */
271: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
272: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
273: } else {
274: mon_dispatch = mon_dispatch_proto15;
275:
276: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
277: }
278:
279: authctxt = authctxt_new();
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: return (authctxt);
310: }
311:
1.40 markus 312: static void
313: monitor_set_child_handler(pid_t pid)
314: {
315: monitor_child_pid = pid;
316: }
317:
318: static void
319: monitor_child_handler(int signal)
320: {
321: kill(monitor_child_pid, signal);
322: }
323:
1.1 provos 324: void
1.11 mouring 325: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 326: {
1.40 markus 327: monitor_set_child_handler(pmonitor->m_pid);
328: signal(SIGHUP, &monitor_child_handler);
329: signal(SIGTERM, &monitor_child_handler);
330:
1.1 provos 331: if (compat20) {
332: mon_dispatch = mon_dispatch_postauth20;
333:
334: /* Permit requests for moduli and signatures */
335: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
336: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
337: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
338: } else {
339: mon_dispatch = mon_dispatch_postauth15;
340: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
341: }
342: if (!no_pty_flag) {
343: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
344: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
345: }
346:
347: for (;;)
1.11 mouring 348: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 349: }
350:
351: void
1.11 mouring 352: monitor_sync(struct monitor *pmonitor)
1.1 provos 353: {
1.16 djm 354: if (options.compression) {
355: /* The member allocation is not visible, so sync it */
356: mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
357: }
1.1 provos 358: }
359:
360: int
1.11 mouring 361: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 362: struct mon_table **pent)
363: {
364: Buffer m;
365: int ret;
366: u_char type;
367:
368: buffer_init(&m);
369:
1.11 mouring 370: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 371: type = buffer_get_char(&m);
372:
1.14 markus 373: debug3("%s: checking request %d", __func__, type);
1.1 provos 374:
375: while (ent->f != NULL) {
376: if (ent->type == type)
377: break;
378: ent++;
379: }
380:
381: if (ent->f != NULL) {
382: if (!(ent->flags & MON_PERMIT))
1.14 markus 383: fatal("%s: unpermitted request %d", __func__,
1.1 provos 384: type);
1.11 mouring 385: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 386: buffer_free(&m);
387:
388: /* The child may use this request only once, disable it */
389: if (ent->flags & MON_ONCE) {
1.14 markus 390: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 391: type);
392: ent->flags &= ~MON_PERMIT;
393: }
394:
395: if (pent != NULL)
396: *pent = ent;
1.3 markus 397:
1.1 provos 398: return ret;
399: }
400:
1.14 markus 401: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 402:
403: /* NOTREACHED */
404: return (-1);
405: }
406:
407: /* allowed key state */
408: static int
409: monitor_allowed_key(u_char *blob, u_int bloblen)
410: {
411: /* make sure key is allowed */
412: if (key_blob == NULL || key_bloblen != bloblen ||
413: memcmp(key_blob, blob, key_bloblen))
414: return (0);
415: return (1);
416: }
417:
418: static void
419: monitor_reset_key_state(void)
420: {
421: /* reset state */
422: if (key_blob != NULL)
423: xfree(key_blob);
424: if (hostbased_cuser != NULL)
425: xfree(hostbased_cuser);
426: if (hostbased_chost != NULL)
427: xfree(hostbased_chost);
428: key_blob = NULL;
429: key_bloblen = 0;
430: key_blobtype = MM_NOKEY;
431: hostbased_cuser = NULL;
432: hostbased_chost = NULL;
433: }
434:
435: int
436: mm_answer_moduli(int socket, Buffer *m)
437: {
438: DH *dh;
439: int min, want, max;
440:
441: min = buffer_get_int(m);
442: want = buffer_get_int(m);
443: max = buffer_get_int(m);
444:
445: debug3("%s: got parameters: %d %d %d",
1.14 markus 446: __func__, min, want, max);
1.1 provos 447: /* We need to check here, too, in case the child got corrupted */
448: if (max < min || want < min || max < want)
449: fatal("%s: bad parameters: %d %d %d",
1.14 markus 450: __func__, min, want, max);
1.1 provos 451:
452: buffer_clear(m);
453:
454: dh = choose_dh(min, want, max);
455: if (dh == NULL) {
456: buffer_put_char(m, 0);
457: return (0);
458: } else {
459: /* Send first bignum */
460: buffer_put_char(m, 1);
461: buffer_put_bignum2(m, dh->p);
462: buffer_put_bignum2(m, dh->g);
1.3 markus 463:
1.1 provos 464: DH_free(dh);
465: }
466: mm_request_send(socket, MONITOR_ANS_MODULI, m);
467: return (0);
468: }
469:
470: int
471: mm_answer_sign(int socket, Buffer *m)
472: {
473: Key *key;
474: u_char *p;
475: u_char *signature;
476: u_int siglen, datlen;
477: int keyid;
1.3 markus 478:
1.14 markus 479: debug3("%s", __func__);
1.1 provos 480:
1.3 markus 481: keyid = buffer_get_int(m);
482: p = buffer_get_string(m, &datlen);
1.1 provos 483:
484: if (datlen != 20)
1.19 deraadt 485: fatal("%s: data length incorrect: %u", __func__, datlen);
1.1 provos 486:
1.13 markus 487: /* save session id, it will be passed on the first call */
488: if (session_id2_len == 0) {
489: session_id2_len = datlen;
490: session_id2 = xmalloc(session_id2_len);
491: memcpy(session_id2, p, session_id2_len);
492: }
493:
1.1 provos 494: if ((key = get_hostkey_by_index(keyid)) == NULL)
1.14 markus 495: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 496: if (key_sign(key, &signature, &siglen, p, datlen) < 0)
1.14 markus 497: fatal("%s: key_sign failed", __func__);
1.1 provos 498:
1.19 deraadt 499: debug3("%s: signature %p(%u)", __func__, signature, siglen);
1.1 provos 500:
501: buffer_clear(m);
502: buffer_put_string(m, signature, siglen);
503:
504: xfree(p);
505: xfree(signature);
506:
507: mm_request_send(socket, MONITOR_ANS_SIGN, m);
508:
509: /* Turn on permissions for getpwnam */
510: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
511:
512: return (0);
513: }
514:
515: /* Retrieves the password entry and also checks if the user is permitted */
516:
517: int
518: mm_answer_pwnamallow(int socket, Buffer *m)
519: {
520: char *login;
521: struct passwd *pwent;
522: int allowed = 0;
1.3 markus 523:
1.14 markus 524: debug3("%s", __func__);
1.1 provos 525:
526: if (authctxt->attempt++ != 0)
1.14 markus 527: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 528:
529: login = buffer_get_string(m, NULL);
530:
531: pwent = getpwnamallow(login);
532:
533: authctxt->user = xstrdup(login);
534: setproctitle("%s [priv]", pwent ? login : "unknown");
535: xfree(login);
536:
537: buffer_clear(m);
538:
539: if (pwent == NULL) {
540: buffer_put_char(m, 0);
541: goto out;
542: }
543:
544: allowed = 1;
1.4 markus 545: authctxt->pw = pwent;
1.1 provos 546: authctxt->valid = 1;
547:
548: buffer_put_char(m, 1);
549: buffer_put_string(m, pwent, sizeof(struct passwd));
550: buffer_put_cstring(m, pwent->pw_name);
551: buffer_put_cstring(m, "*");
552: buffer_put_cstring(m, pwent->pw_gecos);
553: buffer_put_cstring(m, pwent->pw_class);
554: buffer_put_cstring(m, pwent->pw_dir);
555: buffer_put_cstring(m, pwent->pw_shell);
556:
557: out:
1.14 markus 558: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.1 provos 559: mm_request_send(socket, MONITOR_ANS_PWNAM, m);
560:
561: /* For SSHv1 allow authentication now */
562: if (!compat20)
563: monitor_permit_authentications(1);
1.10 djm 564: else {
1.1 provos 565: /* Allow service/style information on the auth context */
566: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
1.10 djm 567: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
568: }
569:
570:
571: return (0);
572: }
573:
574: int mm_answer_auth2_read_banner(int socket, Buffer *m)
575: {
576: char *banner;
577:
578: buffer_clear(m);
579: banner = auth2_read_banner();
580: buffer_put_cstring(m, banner != NULL ? banner : "");
581: mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.1 provos 582:
1.10 djm 583: if (banner != NULL)
1.21 deraadt 584: xfree(banner);
1.1 provos 585:
586: return (0);
587: }
588:
589: int
590: mm_answer_authserv(int socket, Buffer *m)
591: {
592: monitor_permit_authentications(1);
593:
594: authctxt->service = buffer_get_string(m, NULL);
595: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 596: debug3("%s: service=%s, style=%s",
1.14 markus 597: __func__, authctxt->service, authctxt->style);
1.6 stevesk 598:
1.1 provos 599: if (strlen(authctxt->style) == 0) {
600: xfree(authctxt->style);
601: authctxt->style = NULL;
602: }
603:
604: return (0);
605: }
606:
607: int
608: mm_answer_authpassword(int socket, Buffer *m)
609: {
610: static int call_count;
611: char *passwd;
1.22 stevesk 612: int authenticated;
613: u_int plen;
1.1 provos 614:
615: passwd = buffer_get_string(m, &plen);
616: /* Only authenticate if the context is valid */
1.12 markus 617: authenticated = options.password_authentication &&
618: authctxt->valid && auth_password(authctxt, passwd);
1.1 provos 619: memset(passwd, 0, strlen(passwd));
620: xfree(passwd);
621:
622: buffer_clear(m);
623: buffer_put_int(m, authenticated);
624:
1.14 markus 625: debug3("%s: sending result %d", __func__, authenticated);
1.1 provos 626: mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m);
627:
628: call_count++;
629: if (plen == 0 && call_count == 1)
630: auth_method = "none";
631: else
632: auth_method = "password";
633:
634: /* Causes monitor loop to terminate if authenticated */
635: return (authenticated);
636: }
637:
638: #ifdef BSD_AUTH
639: int
640: mm_answer_bsdauthquery(int socket, Buffer *m)
641: {
642: char *name, *infotxt;
643: u_int numprompts;
644: u_int *echo_on;
645: char **prompts;
1.31 markus 646: u_int success;
1.1 provos 647:
1.31 markus 648: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
649: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 650:
651: buffer_clear(m);
1.31 markus 652: buffer_put_int(m, success);
653: if (success)
1.1 provos 654: buffer_put_cstring(m, prompts[0]);
655:
1.31 markus 656: debug3("%s: sending challenge success: %u", __func__, success);
1.1 provos 657: mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m);
658:
1.31 markus 659: if (success) {
1.1 provos 660: xfree(name);
661: xfree(infotxt);
662: xfree(prompts);
663: xfree(echo_on);
664: }
665:
666: return (0);
667: }
668:
669: int
670: mm_answer_bsdauthrespond(int socket, Buffer *m)
671: {
672: char *response;
673: int authok;
674:
675: if (authctxt->as == 0)
1.14 markus 676: fatal("%s: no bsd auth session", __func__);
1.1 provos 677:
678: response = buffer_get_string(m, NULL);
1.12 markus 679: authok = options.challenge_response_authentication &&
680: auth_userresponse(authctxt->as, response, 0);
1.1 provos 681: authctxt->as = NULL;
1.14 markus 682: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.1 provos 683: xfree(response);
684:
685: buffer_clear(m);
686: buffer_put_int(m, authok);
687:
1.14 markus 688: debug3("%s: sending authenticated: %d", __func__, authok);
1.1 provos 689: mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m);
690:
691: auth_method = "bsdauth";
692:
693: return (authok != 0);
694: }
695: #endif
696:
697: #ifdef SKEY
698: int
699: mm_answer_skeyquery(int socket, Buffer *m)
700: {
701: struct skey skey;
702: char challenge[1024];
1.31 markus 703: u_int success;
1.1 provos 704:
1.31 markus 705: success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
1.1 provos 706:
707: buffer_clear(m);
1.31 markus 708: buffer_put_int(m, success);
709: if (success)
1.1 provos 710: buffer_put_cstring(m, challenge);
711:
1.31 markus 712: debug3("%s: sending challenge success: %u", __func__, success);
1.1 provos 713: mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
714:
715: return (0);
716: }
717:
718: int
719: mm_answer_skeyrespond(int socket, Buffer *m)
720: {
721: char *response;
722: int authok;
723:
724: response = buffer_get_string(m, NULL);
725:
1.12 markus 726: authok = (options.challenge_response_authentication &&
727: authctxt->valid &&
1.1 provos 728: skey_haskey(authctxt->pw->pw_name) == 0 &&
729: skey_passcheck(authctxt->pw->pw_name, response) != -1);
730:
731: xfree(response);
732:
733: buffer_clear(m);
734: buffer_put_int(m, authok);
735:
1.14 markus 736: debug3("%s: sending authenticated: %d", __func__, authok);
1.1 provos 737: mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m);
738:
739: auth_method = "skey";
740:
741: return (authok != 0);
742: }
743: #endif
744:
1.2 markus 745: static void
1.1 provos 746: mm_append_debug(Buffer *m)
747: {
748: if (auth_debug_init && buffer_len(&auth_debug)) {
1.14 markus 749: debug3("%s: Appending debug messages for child", __func__);
1.1 provos 750: buffer_append(m, buffer_ptr(&auth_debug),
751: buffer_len(&auth_debug));
752: buffer_clear(&auth_debug);
753: }
754: }
755:
756: int
757: mm_answer_keyallowed(int socket, Buffer *m)
758: {
759: Key *key;
1.26 markus 760: char *cuser, *chost;
761: u_char *blob;
1.1 provos 762: u_int bloblen;
763: enum mm_keytype type = 0;
764: int allowed = 0;
765:
1.14 markus 766: debug3("%s entering", __func__);
1.3 markus 767:
1.1 provos 768: type = buffer_get_int(m);
769: cuser = buffer_get_string(m, NULL);
770: chost = buffer_get_string(m, NULL);
771: blob = buffer_get_string(m, &bloblen);
772:
773: key = key_from_blob(blob, bloblen);
774:
775: if ((compat20 && type == MM_RSAHOSTKEY) ||
776: (!compat20 && type != MM_RSAHOSTKEY))
1.14 markus 777: fatal("%s: key type and protocol mismatch", __func__);
1.1 provos 778:
1.14 markus 779: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 780:
781: if (key != NULL && authctxt->pw != NULL) {
782: switch(type) {
783: case MM_USERKEY:
1.12 markus 784: allowed = options.pubkey_authentication &&
785: user_key_allowed(authctxt->pw, key);
1.1 provos 786: break;
787: case MM_HOSTKEY:
1.12 markus 788: allowed = options.hostbased_authentication &&
789: hostbased_key_allowed(authctxt->pw,
1.1 provos 790: cuser, chost, key);
791: break;
792: case MM_RSAHOSTKEY:
793: key->type = KEY_RSA1; /* XXX */
1.12 markus 794: allowed = options.rhosts_rsa_authentication &&
795: auth_rhosts_rsa_key_allowed(authctxt->pw,
1.1 provos 796: cuser, chost, key);
797: break;
798: default:
1.14 markus 799: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 800: break;
801: }
1.33 markus 802: }
803: if (key != NULL)
1.1 provos 804: key_free(key);
805:
806: /* clear temporarily storage (used by verify) */
807: monitor_reset_key_state();
808:
809: if (allowed) {
810: /* Save temporarily for comparison in verify */
811: key_blob = blob;
812: key_bloblen = bloblen;
813: key_blobtype = type;
814: hostbased_cuser = cuser;
815: hostbased_chost = chost;
816: }
817:
818: debug3("%s: key %p is %s",
1.14 markus 819: __func__, key, allowed ? "allowed" : "disallowed");
1.1 provos 820:
821: buffer_clear(m);
822: buffer_put_int(m, allowed);
1.32 markus 823: buffer_put_int(m, forced_command != NULL);
1.1 provos 824:
825: mm_append_debug(m);
826:
827: mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m);
828:
829: if (type == MM_RSAHOSTKEY)
830: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
831:
832: return (0);
833: }
834:
835: static int
836: monitor_valid_userblob(u_char *data, u_int datalen)
837: {
838: Buffer b;
1.26 markus 839: char *p;
1.1 provos 840: u_int len;
841: int fail = 0;
842:
843: buffer_init(&b);
844: buffer_append(&b, data, datalen);
1.3 markus 845:
1.1 provos 846: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 847: p = buffer_ptr(&b);
848: len = buffer_len(&b);
849: if ((session_id2 == NULL) ||
850: (len < session_id2_len) ||
851: (memcmp(p, session_id2, session_id2_len) != 0))
852: fail++;
1.1 provos 853: buffer_consume(&b, session_id2_len);
854: } else {
1.13 markus 855: p = buffer_get_string(&b, &len);
856: if ((session_id2 == NULL) ||
857: (len != session_id2_len) ||
858: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 859: fail++;
1.13 markus 860: xfree(p);
1.1 provos 861: }
862: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
863: fail++;
864: p = buffer_get_string(&b, NULL);
865: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 866: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 867: authctxt->user, p);
868: fail++;
869: }
870: xfree(p);
871: buffer_skip_string(&b);
872: if (datafellows & SSH_BUG_PKAUTH) {
873: if (!buffer_get_char(&b))
874: fail++;
875: } else {
876: p = buffer_get_string(&b, NULL);
877: if (strcmp("publickey", p) != 0)
878: fail++;
879: xfree(p);
880: if (!buffer_get_char(&b))
881: fail++;
882: buffer_skip_string(&b);
883: }
884: buffer_skip_string(&b);
885: if (buffer_len(&b) != 0)
886: fail++;
887: buffer_free(&b);
888: return (fail == 0);
889: }
890:
891: static int
1.26 markus 892: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
893: char *chost)
1.1 provos 894: {
895: Buffer b;
1.26 markus 896: char *p;
1.1 provos 897: u_int len;
898: int fail = 0;
899:
900: buffer_init(&b);
901: buffer_append(&b, data, datalen);
1.3 markus 902:
1.13 markus 903: p = buffer_get_string(&b, &len);
904: if ((session_id2 == NULL) ||
905: (len != session_id2_len) ||
906: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 907: fail++;
1.13 markus 908: xfree(p);
909:
1.1 provos 910: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
911: fail++;
912: p = buffer_get_string(&b, NULL);
913: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 914: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 915: authctxt->user, p);
916: fail++;
917: }
918: xfree(p);
919: buffer_skip_string(&b); /* service */
920: p = buffer_get_string(&b, NULL);
921: if (strcmp(p, "hostbased") != 0)
922: fail++;
923: xfree(p);
924: buffer_skip_string(&b); /* pkalg */
925: buffer_skip_string(&b); /* pkblob */
926:
927: /* verify client host, strip trailing dot if necessary */
928: p = buffer_get_string(&b, NULL);
929: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
930: p[len - 1] = '\0';
931: if (strcmp(p, chost) != 0)
932: fail++;
933: xfree(p);
934:
935: /* verify client user */
936: p = buffer_get_string(&b, NULL);
937: if (strcmp(p, cuser) != 0)
938: fail++;
939: xfree(p);
940:
941: if (buffer_len(&b) != 0)
942: fail++;
943: buffer_free(&b);
944: return (fail == 0);
945: }
946:
947: int
948: mm_answer_keyverify(int socket, Buffer *m)
949: {
950: Key *key;
951: u_char *signature, *data, *blob;
952: u_int signaturelen, datalen, bloblen;
953: int verified = 0;
954: int valid_data = 0;
955:
956: blob = buffer_get_string(m, &bloblen);
957: signature = buffer_get_string(m, &signaturelen);
958: data = buffer_get_string(m, &datalen);
959:
960: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 961: !monitor_allowed_key(blob, bloblen))
1.14 markus 962: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 963:
964: key = key_from_blob(blob, bloblen);
965: if (key == NULL)
1.14 markus 966: fatal("%s: bad public key blob", __func__);
1.1 provos 967:
968: switch (key_blobtype) {
969: case MM_USERKEY:
970: valid_data = monitor_valid_userblob(data, datalen);
971: break;
972: case MM_HOSTKEY:
973: valid_data = monitor_valid_hostbasedblob(data, datalen,
974: hostbased_cuser, hostbased_chost);
975: break;
976: default:
977: valid_data = 0;
978: break;
979: }
980: if (!valid_data)
1.14 markus 981: fatal("%s: bad signature data blob", __func__);
1.1 provos 982:
983: verified = key_verify(key, signature, signaturelen, data, datalen);
984: debug3("%s: key %p signature %s",
1.14 markus 985: __func__, key, verified ? "verified" : "unverified");
1.1 provos 986:
987: key_free(key);
988: xfree(blob);
989: xfree(signature);
990: xfree(data);
991:
1.17 stevesk 992: auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
993:
1.1 provos 994: monitor_reset_key_state();
1.3 markus 995:
1.1 provos 996: buffer_clear(m);
997: buffer_put_int(m, verified);
998: mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m);
999:
1000: return (verified);
1001: }
1002:
1.2 markus 1003: static void
1.1 provos 1004: mm_record_login(Session *s, struct passwd *pw)
1005: {
1006: socklen_t fromlen;
1007: struct sockaddr_storage from;
1008:
1009: /*
1010: * Get IP address of client. If the connection is not a socket, let
1011: * the address be 0.0.0.0.
1012: */
1013: memset(&from, 0, sizeof(from));
1.24 stevesk 1014: fromlen = sizeof(from);
1.1 provos 1015: if (packet_connection_is_on_socket()) {
1016: if (getpeername(packet_get_connection_in(),
1017: (struct sockaddr *) & from, &fromlen) < 0) {
1018: debug("getpeername: %.100s", strerror(errno));
1019: fatal_cleanup();
1020: }
1021: }
1022: /* Record that there was a login on that tty from the remote host. */
1023: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.42 markus 1024: get_remote_name_or_ip(utmp_len, options.use_dns),
1.24 stevesk 1025: (struct sockaddr *)&from, fromlen);
1.1 provos 1026: }
1027:
1028: static void
1029: mm_session_close(Session *s)
1030: {
1.41 djm 1031: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1032: if (s->ttyfd != -1) {
1.14 markus 1033: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1034: fatal_remove_cleanup(session_pty_cleanup2, (void *)s);
1035: session_pty_cleanup2(s);
1036: }
1037: s->used = 0;
1038: }
1039:
1040: int
1041: mm_answer_pty(int socket, Buffer *m)
1042: {
1.11 mouring 1043: extern struct monitor *pmonitor;
1.1 provos 1044: Session *s;
1045: int res, fd0;
1046:
1.14 markus 1047: debug3("%s entering", __func__);
1.1 provos 1048:
1049: buffer_clear(m);
1050: s = session_new();
1051: if (s == NULL)
1052: goto error;
1053: s->authctxt = authctxt;
1054: s->pw = authctxt->pw;
1.11 mouring 1055: s->pid = pmonitor->m_pid;
1.1 provos 1056: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1057: if (res == 0)
1058: goto error;
1059: fatal_add_cleanup(session_pty_cleanup2, (void *)s);
1060: pty_setowner(authctxt->pw, s->tty);
1061:
1062: buffer_put_int(m, 1);
1063: buffer_put_cstring(m, s->tty);
1064: mm_request_send(socket, MONITOR_ANS_PTY, m);
1065:
1066: mm_send_fd(socket, s->ptyfd);
1067: mm_send_fd(socket, s->ttyfd);
1068:
1069: /* We need to trick ttyslot */
1070: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1071: fatal("%s: dup2", __func__);
1.1 provos 1072:
1073: mm_record_login(s, authctxt->pw);
1074:
1075: /* Now we can close the file descriptor again */
1076: close(0);
1077:
1078: /* make sure nothing uses fd 0 */
1079: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1080: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1081: if (fd0 != 0)
1.14 markus 1082: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1083:
1084: /* slave is not needed */
1085: close(s->ttyfd);
1086: s->ttyfd = s->ptyfd;
1087: /* no need to dup() because nobody closes ptyfd */
1088: s->ptymaster = s->ptyfd;
1089:
1.14 markus 1090: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1091:
1092: return (0);
1093:
1094: error:
1095: if (s != NULL)
1096: mm_session_close(s);
1097: buffer_put_int(m, 0);
1098: mm_request_send(socket, MONITOR_ANS_PTY, m);
1099: return (0);
1100: }
1101:
1102: int
1103: mm_answer_pty_cleanup(int socket, Buffer *m)
1104: {
1105: Session *s;
1106: char *tty;
1107:
1.14 markus 1108: debug3("%s entering", __func__);
1.1 provos 1109:
1110: tty = buffer_get_string(m, NULL);
1111: if ((s = session_by_tty(tty)) != NULL)
1112: mm_session_close(s);
1113: buffer_clear(m);
1114: xfree(tty);
1115: return (0);
1116: }
1117:
1118: int
1119: mm_answer_sesskey(int socket, Buffer *m)
1120: {
1121: BIGNUM *p;
1122: int rsafail;
1123:
1124: /* Turn off permissions */
1125: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
1126:
1127: if ((p = BN_new()) == NULL)
1.14 markus 1128: fatal("%s: BN_new", __func__);
1.1 provos 1129:
1130: buffer_get_bignum2(m, p);
1131:
1132: rsafail = ssh1_session_key(p);
1133:
1134: buffer_clear(m);
1135: buffer_put_int(m, rsafail);
1136: buffer_put_bignum2(m, p);
1137:
1138: BN_clear_free(p);
1139:
1140: mm_request_send(socket, MONITOR_ANS_SESSKEY, m);
1141:
1142: /* Turn on permissions for sessid passing */
1143: monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1144:
1145: return (0);
1146: }
1147:
1148: int
1149: mm_answer_sessid(int socket, Buffer *m)
1150: {
1151: int i;
1152:
1.14 markus 1153: debug3("%s entering", __func__);
1.1 provos 1154:
1155: if (buffer_len(m) != 16)
1.14 markus 1156: fatal("%s: bad ssh1 session id", __func__);
1.1 provos 1157: for (i = 0; i < 16; i++)
1158: session_id[i] = buffer_get_char(m);
1159:
1160: /* Turn on permissions for getpwnam */
1161: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1162:
1163: return (0);
1164: }
1165:
1166: int
1167: mm_answer_rsa_keyallowed(int socket, Buffer *m)
1168: {
1169: BIGNUM *client_n;
1170: Key *key = NULL;
1.3 markus 1171: u_char *blob = NULL;
1172: u_int blen = 0;
1.1 provos 1173: int allowed = 0;
1174:
1.14 markus 1175: debug3("%s entering", __func__);
1.1 provos 1176:
1.12 markus 1177: if (options.rsa_authentication && authctxt->valid) {
1.1 provos 1178: if ((client_n = BN_new()) == NULL)
1.14 markus 1179: fatal("%s: BN_new", __func__);
1.1 provos 1180: buffer_get_bignum2(m, client_n);
1181: allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1182: BN_clear_free(client_n);
1183: }
1184: buffer_clear(m);
1185: buffer_put_int(m, allowed);
1.32 markus 1186: buffer_put_int(m, forced_command != NULL);
1.1 provos 1187:
1188: /* clear temporarily storage (used by generate challenge) */
1189: monitor_reset_key_state();
1190:
1191: if (allowed && key != NULL) {
1192: key->type = KEY_RSA; /* cheat for key_to_blob */
1193: if (key_to_blob(key, &blob, &blen) == 0)
1.14 markus 1194: fatal("%s: key_to_blob failed", __func__);
1.1 provos 1195: buffer_put_string(m, blob, blen);
1196:
1197: /* Save temporarily for comparison in verify */
1198: key_blob = blob;
1199: key_bloblen = blen;
1200: key_blobtype = MM_RSAUSERKEY;
1.33 markus 1201: }
1202: if (key != NULL)
1.1 provos 1203: key_free(key);
1204:
1205: mm_append_debug(m);
1206:
1207: mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m);
1208:
1209: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1210: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1211: return (0);
1212: }
1213:
1214: int
1215: mm_answer_rsa_challenge(int socket, Buffer *m)
1216: {
1217: Key *key = NULL;
1.3 markus 1218: u_char *blob;
1219: u_int blen;
1.1 provos 1220:
1.14 markus 1221: debug3("%s entering", __func__);
1.1 provos 1222:
1223: if (!authctxt->valid)
1.14 markus 1224: fatal("%s: authctxt not valid", __func__);
1.1 provos 1225: blob = buffer_get_string(m, &blen);
1226: if (!monitor_allowed_key(blob, blen))
1.14 markus 1227: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1228: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1229: fatal("%s: key type mismatch", __func__);
1.1 provos 1230: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1231: fatal("%s: received bad key", __func__);
1.1 provos 1232:
1233: if (ssh1_challenge)
1234: BN_clear_free(ssh1_challenge);
1235: ssh1_challenge = auth_rsa_generate_challenge(key);
1236:
1237: buffer_clear(m);
1238: buffer_put_bignum2(m, ssh1_challenge);
1239:
1.14 markus 1240: debug3("%s sending reply", __func__);
1.1 provos 1241: mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m);
1242:
1243: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1.33 markus 1244:
1245: xfree(blob);
1246: key_free(key);
1.1 provos 1247: return (0);
1248: }
1249:
1250: int
1251: mm_answer_rsa_response(int socket, Buffer *m)
1252: {
1253: Key *key = NULL;
1.3 markus 1254: u_char *blob, *response;
1255: u_int blen, len;
1256: int success;
1.1 provos 1257:
1.14 markus 1258: debug3("%s entering", __func__);
1.1 provos 1259:
1260: if (!authctxt->valid)
1.14 markus 1261: fatal("%s: authctxt not valid", __func__);
1.1 provos 1262: if (ssh1_challenge == NULL)
1.14 markus 1263: fatal("%s: no ssh1_challenge", __func__);
1.1 provos 1264:
1265: blob = buffer_get_string(m, &blen);
1266: if (!monitor_allowed_key(blob, blen))
1.14 markus 1267: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1268: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1269: fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1.1 provos 1270: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1271: fatal("%s: received bad key", __func__);
1.1 provos 1272: response = buffer_get_string(m, &len);
1273: if (len != 16)
1.14 markus 1274: fatal("%s: received bad response to challenge", __func__);
1.1 provos 1275: success = auth_rsa_verify_response(key, ssh1_challenge, response);
1276:
1.33 markus 1277: xfree(blob);
1.1 provos 1278: key_free(key);
1279: xfree(response);
1280:
1281: auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1282:
1283: /* reset state */
1284: BN_clear_free(ssh1_challenge);
1285: ssh1_challenge = NULL;
1286: monitor_reset_key_state();
1287:
1288: buffer_clear(m);
1289: buffer_put_int(m, success);
1290: mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m);
1291:
1292: return (success);
1293: }
1.25 itojun 1294:
1295: #ifdef KRB5
1296: int
1297: mm_answer_krb5(int socket, Buffer *m)
1298: {
1299: krb5_data tkt, reply;
1300: char *client_user;
1301: u_int len;
1302: int success;
1303:
1304: /* use temporary var to avoid size issues on 64bit arch */
1305: tkt.data = buffer_get_string(m, &len);
1306: tkt.length = len;
1307:
1.28 markus 1308: success = options.kerberos_authentication &&
1309: authctxt->valid &&
1.27 markus 1310: auth_krb5(authctxt, &tkt, &client_user, &reply);
1.25 itojun 1311:
1312: if (tkt.length)
1313: xfree(tkt.data);
1314:
1315: buffer_clear(m);
1316: buffer_put_int(m, success);
1317:
1318: if (success) {
1319: buffer_put_cstring(m, client_user);
1320: buffer_put_string(m, reply.data, reply.length);
1321: if (client_user)
1322: xfree(client_user);
1323: if (reply.length)
1324: xfree(reply.data);
1325: }
1326: mm_request_send(socket, MONITOR_ANS_KRB5, m);
1.39 markus 1327:
1328: auth_method = "kerberos";
1.25 itojun 1329:
1330: return success;
1331: }
1332: #endif
1.1 provos 1333:
1334: int
1335: mm_answer_term(int socket, Buffer *req)
1336: {
1.11 mouring 1337: extern struct monitor *pmonitor;
1.1 provos 1338: int res, status;
1339:
1.14 markus 1340: debug3("%s: tearing down sessions", __func__);
1.1 provos 1341:
1342: /* The child is terminating */
1343: session_destroy_all(&mm_session_close);
1344:
1.11 mouring 1345: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1346: if (errno != EINTR)
1347: exit(1);
1.1 provos 1348:
1349: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1350:
1351: /* Terminate process */
1352: exit (res);
1353: }
1354:
1355: void
1.11 mouring 1356: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1357: {
1358: if (compat20) {
1359: set_newkeys(MODE_IN);
1360: set_newkeys(MODE_OUT);
1361: } else {
1362: packet_set_protocol_flags(child_state.ssh1protoflags);
1.15 markus 1363: packet_set_encryption_key(child_state.ssh1key,
1364: child_state.ssh1keylen, child_state.ssh1cipher);
1365: xfree(child_state.ssh1key);
1.1 provos 1366: }
1367:
1.15 markus 1368: /* for rc4 and other stateful ciphers */
1.1 provos 1369: packet_set_keycontext(MODE_OUT, child_state.keyout);
1370: xfree(child_state.keyout);
1371: packet_set_keycontext(MODE_IN, child_state.keyin);
1372: xfree(child_state.keyin);
1373:
1374: if (!compat20) {
1375: packet_set_iv(MODE_OUT, child_state.ivout);
1376: xfree(child_state.ivout);
1377: packet_set_iv(MODE_IN, child_state.ivin);
1378: xfree(child_state.ivin);
1379: }
1380:
1381: memcpy(&incoming_stream, &child_state.incoming,
1382: sizeof(incoming_stream));
1383: memcpy(&outgoing_stream, &child_state.outgoing,
1384: sizeof(outgoing_stream));
1.3 markus 1385:
1.1 provos 1386: /* Update with new address */
1.16 djm 1387: if (options.compression)
1388: mm_init_compression(pmonitor->m_zlib);
1.1 provos 1389:
1390: /* Network I/O buffers */
1391: /* XXX inefficient for large buffers, need: buffer_init_from_string */
1392: buffer_clear(&input);
1393: buffer_append(&input, child_state.input, child_state.ilen);
1394: memset(child_state.input, 0, child_state.ilen);
1395: xfree(child_state.input);
1396:
1397: buffer_clear(&output);
1398: buffer_append(&output, child_state.output, child_state.olen);
1399: memset(child_state.output, 0, child_state.olen);
1400: xfree(child_state.output);
1401: }
1402:
1.2 markus 1403: static Kex *
1.1 provos 1404: mm_get_kex(Buffer *m)
1405: {
1406: Kex *kex;
1407: void *blob;
1408: u_int bloblen;
1409:
1410: kex = xmalloc(sizeof(*kex));
1411: memset(kex, 0, sizeof(*kex));
1412: kex->session_id = buffer_get_string(m, &kex->session_id_len);
1.13 markus 1413: if ((session_id2 == NULL) ||
1414: (kex->session_id_len != session_id2_len) ||
1415: (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1416: fatal("mm_get_get: internal error: bad session id");
1.1 provos 1417: kex->we_need = buffer_get_int(m);
1.34 markus 1418: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1419: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.1 provos 1420: kex->server = 1;
1421: kex->hostkey_type = buffer_get_int(m);
1422: kex->kex_type = buffer_get_int(m);
1423: blob = buffer_get_string(m, &bloblen);
1424: buffer_init(&kex->my);
1425: buffer_append(&kex->my, blob, bloblen);
1426: xfree(blob);
1427: blob = buffer_get_string(m, &bloblen);
1428: buffer_init(&kex->peer);
1429: buffer_append(&kex->peer, blob, bloblen);
1430: xfree(blob);
1431: kex->done = 1;
1432: kex->flags = buffer_get_int(m);
1433: kex->client_version_string = buffer_get_string(m, NULL);
1434: kex->server_version_string = buffer_get_string(m, NULL);
1435: kex->load_host_key=&get_hostkey_by_type;
1436: kex->host_key_index=&get_hostkey_index;
1437:
1438: return (kex);
1439: }
1440:
1441: /* This function requries careful sanity checking */
1442:
1443: void
1.11 mouring 1444: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1445: {
1446: Buffer m;
1447: u_char *blob, *p;
1448: u_int bloblen, plen;
1.37 markus 1449: u_int32_t seqnr, packets;
1450: u_int64_t blocks;
1.1 provos 1451:
1.14 markus 1452: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1453:
1454: buffer_init(&m);
1.11 mouring 1455: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1.1 provos 1456: if (!compat20) {
1457: child_state.ssh1protoflags = buffer_get_int(&m);
1458: child_state.ssh1cipher = buffer_get_int(&m);
1.15 markus 1459: child_state.ssh1key = buffer_get_string(&m,
1460: &child_state.ssh1keylen);
1.1 provos 1461: child_state.ivout = buffer_get_string(&m,
1462: &child_state.ivoutlen);
1463: child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1464: goto skip;
1465: } else {
1466: /* Get the Kex for rekeying */
1.11 mouring 1467: *pmonitor->m_pkex = mm_get_kex(&m);
1.1 provos 1468: }
1469:
1470: blob = buffer_get_string(&m, &bloblen);
1471: current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1472: xfree(blob);
1473:
1.14 markus 1474: debug3("%s: Waiting for second key", __func__);
1.1 provos 1475: blob = buffer_get_string(&m, &bloblen);
1476: current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1477: xfree(blob);
1.3 markus 1478:
1.1 provos 1479: /* Now get sequence numbers for the packets */
1.37 markus 1480: seqnr = buffer_get_int(&m);
1481: blocks = buffer_get_int64(&m);
1482: packets = buffer_get_int(&m);
1483: packet_set_state(MODE_OUT, seqnr, blocks, packets);
1484: seqnr = buffer_get_int(&m);
1485: blocks = buffer_get_int64(&m);
1486: packets = buffer_get_int(&m);
1487: packet_set_state(MODE_IN, seqnr, blocks, packets);
1.1 provos 1488:
1489: skip:
1490: /* Get the key context */
1491: child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1492: child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1493:
1.14 markus 1494: debug3("%s: Getting compression state", __func__);
1.1 provos 1495: /* Get compression state */
1496: p = buffer_get_string(&m, &plen);
1497: if (plen != sizeof(child_state.outgoing))
1.14 markus 1498: fatal("%s: bad request size", __func__);
1.1 provos 1499: memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1500: xfree(p);
1501:
1502: p = buffer_get_string(&m, &plen);
1503: if (plen != sizeof(child_state.incoming))
1.14 markus 1504: fatal("%s: bad request size", __func__);
1.1 provos 1505: memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1506: xfree(p);
1507:
1508: /* Network I/O buffers */
1.14 markus 1509: debug3("%s: Getting Network I/O buffers", __func__);
1.1 provos 1510: child_state.input = buffer_get_string(&m, &child_state.ilen);
1511: child_state.output = buffer_get_string(&m, &child_state.olen);
1512:
1513: buffer_free(&m);
1514: }
1515:
1516:
1517: /* Allocation functions for zlib */
1518: void *
1519: mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1520: {
1.30 markus 1521: size_t len = (size_t) size * ncount;
1.1 provos 1522: void *address;
1523:
1.23 millert 1524: if (len == 0 || ncount > SIZE_T_MAX / size)
1.18 deraadt 1525: fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1526:
1527: address = mm_malloc(mm, len);
1.1 provos 1528:
1529: return (address);
1530: }
1531:
1532: void
1533: mm_zfree(struct mm_master *mm, void *address)
1534: {
1535: mm_free(mm, address);
1536: }
1537:
1538: void
1539: mm_init_compression(struct mm_master *mm)
1540: {
1541: outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1542: outgoing_stream.zfree = (free_func)mm_zfree;
1543: outgoing_stream.opaque = mm;
1544:
1545: incoming_stream.zalloc = (alloc_func)mm_zalloc;
1546: incoming_stream.zfree = (free_func)mm_zfree;
1547: incoming_stream.opaque = mm;
1548: }
1549:
1550: /* XXX */
1551:
1552: #define FD_CLOSEONEXEC(x) do { \
1553: if (fcntl(x, F_SETFD, 1) == -1) \
1554: fatal("fcntl(%d, F_SETFD)", x); \
1555: } while (0)
1556:
1.2 markus 1557: static void
1.1 provos 1558: monitor_socketpair(int *pair)
1.3 markus 1559: {
1.1 provos 1560: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.14 markus 1561: fatal("%s: socketpair", __func__);
1.1 provos 1562: FD_CLOSEONEXEC(pair[0]);
1563: FD_CLOSEONEXEC(pair[1]);
1564: }
1565:
1566: #define MM_MEMSIZE 65536
1567:
1568: struct monitor *
1569: monitor_init(void)
1570: {
1571: struct monitor *mon;
1572: int pair[2];
1573:
1574: mon = xmalloc(sizeof(*mon));
1575:
1576: monitor_socketpair(pair);
1577:
1578: mon->m_recvfd = pair[0];
1579: mon->m_sendfd = pair[1];
1580:
1581: /* Used to share zlib space across processes */
1.16 djm 1582: if (options.compression) {
1583: mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1584: mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1.1 provos 1585:
1.16 djm 1586: /* Compression needs to share state across borders */
1587: mm_init_compression(mon->m_zlib);
1588: }
1.1 provos 1589:
1590: return mon;
1591: }
1592:
1593: void
1594: monitor_reinit(struct monitor *mon)
1595: {
1596: int pair[2];
1597:
1598: monitor_socketpair(pair);
1599:
1600: mon->m_recvfd = pair[0];
1601: mon->m_sendfd = pair[1];
1602: }
1.46 ! markus 1603:
! 1604: #ifdef GSSAPI
! 1605: int
! 1606: mm_answer_gss_setup_ctx(int socket, Buffer *m)
! 1607: {
! 1608: gss_OID_desc oid;
! 1609: OM_uint32 major;
! 1610: u_int len;
! 1611:
! 1612: oid.elements = buffer_get_string(m, &len);
! 1613: oid.length = len;
! 1614:
! 1615: major = ssh_gssapi_server_ctx(&gsscontext, &oid);
! 1616:
! 1617: xfree(oid.elements);
! 1618:
! 1619: buffer_clear(m);
! 1620: buffer_put_int(m, major);
! 1621:
! 1622: mm_request_send(socket,MONITOR_ANS_GSSSETUP, m);
! 1623:
! 1624: /* Now we have a context, enable the step */
! 1625: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
! 1626:
! 1627: return (0);
! 1628: }
! 1629:
! 1630: int
! 1631: mm_answer_gss_accept_ctx(int socket, Buffer *m)
! 1632: {
! 1633: gss_buffer_desc in;
! 1634: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
! 1635: OM_uint32 major,minor;
! 1636: OM_uint32 flags = 0; /* GSI needs this */
! 1637:
! 1638: in.value = buffer_get_string(m, &in.length);
! 1639: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
! 1640: xfree(in.value);
! 1641:
! 1642: buffer_clear(m);
! 1643: buffer_put_int(m, major);
! 1644: buffer_put_string(m, out.value, out.length);
! 1645: buffer_put_int(m, flags);
! 1646: mm_request_send(socket, MONITOR_ANS_GSSSTEP, m);
! 1647:
! 1648: gss_release_buffer(&minor, &out);
! 1649:
! 1650: /* Complete - now we can do signing */
! 1651: if (major==GSS_S_COMPLETE) {
! 1652: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
! 1653: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
! 1654: }
! 1655: return (0);
! 1656: }
! 1657:
! 1658: int
! 1659: mm_answer_gss_userok(int socket, Buffer *m)
! 1660: {
! 1661: int authenticated;
! 1662:
! 1663: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
! 1664:
! 1665: buffer_clear(m);
! 1666: buffer_put_int(m, authenticated);
! 1667:
! 1668: debug3("%s: sending result %d", __func__, authenticated);
! 1669: mm_request_send(socket, MONITOR_ANS_GSSUSEROK, m);
! 1670:
! 1671: auth_method="gssapi";
! 1672:
! 1673: /* Monitor loop will terminate if authenticated */
! 1674: return (authenticated);
! 1675: }
! 1676: #endif /* GSSAPI */
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