Annotation of src/usr.bin/ssh/monitor.c, Revision 1.83
1.83 ! stevesk 1: /* $OpenBSD: monitor.c,v 1.82 2006/07/22 20:48:23 stevesk 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>
1.79 stevesk 32: #include <sys/socket.h>
1.83 ! stevesk 33: #include <sys/param.h>
1.1 provos 34:
1.78 stevesk 35: #include <openssl/dh.h>
36:
1.81 stevesk 37: #include <errno.h>
1.80 stevesk 38: #include <fcntl.h>
1.65 stevesk 39: #include <paths.h>
1.78 stevesk 40: #include <pwd.h>
1.68 stevesk 41: #include <signal.h>
1.82 stevesk 42: #include <string.h>
1.1 provos 43:
44: #ifdef SKEY
45: #include <skey.h>
46: #endif
47:
48: #include "ssh.h"
49: #include "auth.h"
50: #include "kex.h"
51: #include "dh.h"
52: #include "zlib.h"
53: #include "packet.h"
54: #include "auth-options.h"
55: #include "sshpty.h"
56: #include "channels.h"
57: #include "session.h"
58: #include "sshlogin.h"
59: #include "canohost.h"
60: #include "log.h"
61: #include "servconf.h"
62: #include "monitor.h"
63: #include "monitor_mm.h"
64: #include "monitor_wrap.h"
65: #include "monitor_fdpass.h"
66: #include "xmalloc.h"
67: #include "misc.h"
68: #include "buffer.h"
69: #include "bufaux.h"
70: #include "compat.h"
71: #include "ssh2.h"
72:
1.46 markus 73: #ifdef GSSAPI
74: #include "ssh-gss.h"
75: static Gssctxt *gsscontext = NULL;
76: #endif
77:
1.1 provos 78: /* Imports */
79: extern ServerOptions options;
80: extern u_int utmp_len;
81: extern Newkeys *current_keys[];
82: extern z_stream incoming_stream;
83: extern z_stream outgoing_stream;
84: extern u_char session_id[];
85: extern Buffer input, output;
86: extern Buffer auth_debug;
87: extern int auth_debug_init;
1.61 dtucker 88: extern Buffer loginmsg;
1.1 provos 89:
90: /* State exported from the child */
91:
92: struct {
93: z_stream incoming;
94: z_stream outgoing;
95: u_char *keyin;
96: u_int keyinlen;
97: u_char *keyout;
98: u_int keyoutlen;
99: u_char *ivin;
100: u_int ivinlen;
101: u_char *ivout;
102: u_int ivoutlen;
1.15 markus 103: u_char *ssh1key;
104: u_int ssh1keylen;
1.1 provos 105: int ssh1cipher;
106: int ssh1protoflags;
107: u_char *input;
108: u_int ilen;
109: u_char *output;
110: u_int olen;
111: } child_state;
112:
1.43 markus 113: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 114:
115: int mm_answer_moduli(int, Buffer *);
116: int mm_answer_sign(int, Buffer *);
117: int mm_answer_pwnamallow(int, Buffer *);
1.10 djm 118: int mm_answer_auth2_read_banner(int, Buffer *);
1.1 provos 119: int mm_answer_authserv(int, Buffer *);
120: int mm_answer_authpassword(int, Buffer *);
121: int mm_answer_bsdauthquery(int, Buffer *);
122: int mm_answer_bsdauthrespond(int, Buffer *);
123: int mm_answer_skeyquery(int, Buffer *);
124: int mm_answer_skeyrespond(int, Buffer *);
125: int mm_answer_keyallowed(int, Buffer *);
126: int mm_answer_keyverify(int, Buffer *);
127: int mm_answer_pty(int, Buffer *);
128: int mm_answer_pty_cleanup(int, Buffer *);
129: int mm_answer_term(int, Buffer *);
130: int mm_answer_rsa_keyallowed(int, Buffer *);
131: int mm_answer_rsa_challenge(int, Buffer *);
132: int mm_answer_rsa_response(int, Buffer *);
133: int mm_answer_sesskey(int, Buffer *);
134: int mm_answer_sessid(int, Buffer *);
135:
1.46 markus 136: #ifdef GSSAPI
137: int mm_answer_gss_setup_ctx(int, Buffer *);
138: int mm_answer_gss_accept_ctx(int, Buffer *);
139: int mm_answer_gss_userok(int, Buffer *);
1.52 markus 140: int mm_answer_gss_checkmic(int, Buffer *);
1.46 markus 141: #endif
1.25 itojun 142:
1.1 provos 143: static Authctxt *authctxt;
144: static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
145:
146: /* local state for key verify */
147: static u_char *key_blob = NULL;
148: static u_int key_bloblen = 0;
149: static int key_blobtype = MM_NOKEY;
1.26 markus 150: static char *hostbased_cuser = NULL;
151: static char *hostbased_chost = NULL;
1.1 provos 152: static char *auth_method = "unknown";
1.44 markus 153: static u_int session_id2_len = 0;
1.13 markus 154: static u_char *session_id2 = NULL;
1.40 markus 155: static pid_t monitor_child_pid;
1.1 provos 156:
157: struct mon_table {
158: enum monitor_reqtype type;
159: int flags;
160: int (*f)(int, Buffer *);
161: };
162:
163: #define MON_ISAUTH 0x0004 /* Required for Authentication */
164: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
165: #define MON_ONCE 0x0010 /* Disable after calling */
1.77 dtucker 166: #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
1.1 provos 167:
168: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
169:
170: #define MON_PERMIT 0x1000 /* Request is permitted */
171:
172: struct mon_table mon_dispatch_proto20[] = {
173: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
174: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
175: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
176: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 177: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 178: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
179: #ifdef BSD_AUTH
180: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 181: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 182: #endif
183: #ifdef SKEY
184: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
185: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
186: #endif
187: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
188: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 189: #ifdef GSSAPI
190: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
191: {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
192: {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
1.52 markus 193: {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
1.46 markus 194: #endif
1.1 provos 195: {0, 0, NULL}
196: };
197:
198: struct mon_table mon_dispatch_postauth20[] = {
199: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
200: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
201: {MONITOR_REQ_PTY, 0, mm_answer_pty},
202: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
203: {MONITOR_REQ_TERM, 0, mm_answer_term},
204: {0, 0, NULL}
205: };
206:
207: struct mon_table mon_dispatch_proto15[] = {
208: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
209: {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
210: {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
211: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
1.77 dtucker 212: {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
213: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
1.1 provos 214: {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
215: {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
216: #ifdef BSD_AUTH
217: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 218: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 219: #endif
220: #ifdef SKEY
221: {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
222: {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
223: #endif
224: {0, 0, NULL}
225: };
226:
227: struct mon_table mon_dispatch_postauth15[] = {
228: {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
229: {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
230: {MONITOR_REQ_TERM, 0, mm_answer_term},
231: {0, 0, NULL}
232: };
233:
234: struct mon_table *mon_dispatch;
235:
236: /* Specifies if a certain message is allowed at the moment */
237:
238: static void
239: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
240: {
241: while (ent->f != NULL) {
242: if (ent->type == type) {
243: ent->flags &= ~MON_PERMIT;
244: ent->flags |= permit ? MON_PERMIT : 0;
245: return;
246: }
247: ent++;
248: }
249: }
250:
251: static void
252: monitor_permit_authentications(int permit)
253: {
254: struct mon_table *ent = mon_dispatch;
255:
256: while (ent->f != NULL) {
257: if (ent->flags & MON_AUTH) {
258: ent->flags &= ~MON_PERMIT;
259: ent->flags |= permit ? MON_PERMIT : 0;
260: }
261: ent++;
262: }
263: }
264:
1.50 markus 265: void
266: monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
1.1 provos 267: {
268: struct mon_table *ent;
269: int authenticated = 0;
270:
271: debug3("preauth child monitor started");
272:
1.50 markus 273: authctxt = _authctxt;
274: memset(authctxt, 0, sizeof(*authctxt));
275:
1.1 provos 276: if (compat20) {
277: mon_dispatch = mon_dispatch_proto20;
278:
279: /* Permit requests for moduli and signatures */
280: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
281: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
282: } else {
283: mon_dispatch = mon_dispatch_proto15;
284:
285: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
286: }
287:
288: /* The first few requests do not require asynchronous access */
289: while (!authenticated) {
1.77 dtucker 290: auth_method = "unknown";
1.11 mouring 291: authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
1.1 provos 292: if (authenticated) {
293: if (!(ent->flags & MON_AUTHDECIDE))
294: fatal("%s: unexpected authentication from %d",
1.14 markus 295: __func__, ent->type);
1.1 provos 296: if (authctxt->pw->pw_uid == 0 &&
297: !auth_root_allowed(auth_method))
298: authenticated = 0;
299: }
300:
1.77 dtucker 301: if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
1.1 provos 302: auth_log(authctxt, authenticated, auth_method,
303: compat20 ? " ssh2" : "");
304: if (!authenticated)
305: authctxt->failures++;
306: }
307: }
308:
309: if (!authctxt->valid)
1.14 markus 310: fatal("%s: authenticated invalid user", __func__);
1.77 dtucker 311: if (strcmp(auth_method, "unknown") == 0)
312: fatal("%s: authentication method name unknown", __func__);
1.1 provos 313:
314: debug("%s: %s has been authenticated by privileged process",
1.14 markus 315: __func__, authctxt->user);
1.1 provos 316:
1.11 mouring 317: mm_get_keystate(pmonitor);
1.1 provos 318: }
319:
1.40 markus 320: static void
321: monitor_set_child_handler(pid_t pid)
322: {
323: monitor_child_pid = pid;
324: }
325:
326: static void
1.59 avsm 327: monitor_child_handler(int sig)
1.40 markus 328: {
1.59 avsm 329: kill(monitor_child_pid, sig);
1.40 markus 330: }
331:
1.1 provos 332: void
1.11 mouring 333: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 334: {
1.40 markus 335: monitor_set_child_handler(pmonitor->m_pid);
336: signal(SIGHUP, &monitor_child_handler);
337: signal(SIGTERM, &monitor_child_handler);
338:
1.1 provos 339: if (compat20) {
340: mon_dispatch = mon_dispatch_postauth20;
341:
342: /* Permit requests for moduli and signatures */
343: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
344: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
345: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
346: } else {
347: mon_dispatch = mon_dispatch_postauth15;
348: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
349: }
350: if (!no_pty_flag) {
351: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
352: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
353: }
354:
355: for (;;)
1.11 mouring 356: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 357: }
358:
359: void
1.11 mouring 360: monitor_sync(struct monitor *pmonitor)
1.1 provos 361: {
1.16 djm 362: if (options.compression) {
363: /* The member allocation is not visible, so sync it */
364: mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
365: }
1.1 provos 366: }
367:
368: int
1.11 mouring 369: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 370: struct mon_table **pent)
371: {
372: Buffer m;
373: int ret;
374: u_char type;
375:
376: buffer_init(&m);
377:
1.11 mouring 378: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 379: type = buffer_get_char(&m);
380:
1.14 markus 381: debug3("%s: checking request %d", __func__, type);
1.1 provos 382:
383: while (ent->f != NULL) {
384: if (ent->type == type)
385: break;
386: ent++;
387: }
388:
389: if (ent->f != NULL) {
390: if (!(ent->flags & MON_PERMIT))
1.14 markus 391: fatal("%s: unpermitted request %d", __func__,
1.1 provos 392: type);
1.11 mouring 393: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 394: buffer_free(&m);
395:
396: /* The child may use this request only once, disable it */
397: if (ent->flags & MON_ONCE) {
1.14 markus 398: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 399: type);
400: ent->flags &= ~MON_PERMIT;
401: }
402:
403: if (pent != NULL)
404: *pent = ent;
1.3 markus 405:
1.1 provos 406: return ret;
407: }
408:
1.14 markus 409: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 410:
411: /* NOTREACHED */
412: return (-1);
413: }
414:
415: /* allowed key state */
416: static int
417: monitor_allowed_key(u_char *blob, u_int bloblen)
418: {
419: /* make sure key is allowed */
420: if (key_blob == NULL || key_bloblen != bloblen ||
421: memcmp(key_blob, blob, key_bloblen))
422: return (0);
423: return (1);
424: }
425:
426: static void
427: monitor_reset_key_state(void)
428: {
429: /* reset state */
430: if (key_blob != NULL)
431: xfree(key_blob);
432: if (hostbased_cuser != NULL)
433: xfree(hostbased_cuser);
434: if (hostbased_chost != NULL)
435: xfree(hostbased_chost);
436: key_blob = NULL;
437: key_bloblen = 0;
438: key_blobtype = MM_NOKEY;
439: hostbased_cuser = NULL;
440: hostbased_chost = NULL;
441: }
442:
443: int
1.59 avsm 444: mm_answer_moduli(int sock, Buffer *m)
1.1 provos 445: {
446: DH *dh;
447: int min, want, max;
448:
449: min = buffer_get_int(m);
450: want = buffer_get_int(m);
451: max = buffer_get_int(m);
452:
453: debug3("%s: got parameters: %d %d %d",
1.14 markus 454: __func__, min, want, max);
1.1 provos 455: /* We need to check here, too, in case the child got corrupted */
456: if (max < min || want < min || max < want)
457: fatal("%s: bad parameters: %d %d %d",
1.14 markus 458: __func__, min, want, max);
1.1 provos 459:
460: buffer_clear(m);
461:
462: dh = choose_dh(min, want, max);
463: if (dh == NULL) {
464: buffer_put_char(m, 0);
465: return (0);
466: } else {
467: /* Send first bignum */
468: buffer_put_char(m, 1);
469: buffer_put_bignum2(m, dh->p);
470: buffer_put_bignum2(m, dh->g);
1.3 markus 471:
1.1 provos 472: DH_free(dh);
473: }
1.59 avsm 474: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 475: return (0);
476: }
477:
478: int
1.59 avsm 479: mm_answer_sign(int sock, Buffer *m)
1.1 provos 480: {
481: Key *key;
482: u_char *p;
483: u_char *signature;
484: u_int siglen, datlen;
485: int keyid;
1.3 markus 486:
1.14 markus 487: debug3("%s", __func__);
1.1 provos 488:
1.3 markus 489: keyid = buffer_get_int(m);
490: p = buffer_get_string(m, &datlen);
1.1 provos 491:
1.69 djm 492: /*
1.71 deraadt 493: * Supported KEX types will only return SHA1 (20 byte) or
1.69 djm 494: * SHA256 (32 byte) hashes
495: */
496: if (datlen != 20 && datlen != 32)
1.19 deraadt 497: fatal("%s: data length incorrect: %u", __func__, datlen);
1.1 provos 498:
1.13 markus 499: /* save session id, it will be passed on the first call */
500: if (session_id2_len == 0) {
501: session_id2_len = datlen;
502: session_id2 = xmalloc(session_id2_len);
503: memcpy(session_id2, p, session_id2_len);
504: }
505:
1.1 provos 506: if ((key = get_hostkey_by_index(keyid)) == NULL)
1.14 markus 507: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 508: if (key_sign(key, &signature, &siglen, p, datlen) < 0)
1.14 markus 509: fatal("%s: key_sign failed", __func__);
1.1 provos 510:
1.19 deraadt 511: debug3("%s: signature %p(%u)", __func__, signature, siglen);
1.1 provos 512:
513: buffer_clear(m);
514: buffer_put_string(m, signature, siglen);
515:
516: xfree(p);
517: xfree(signature);
518:
1.59 avsm 519: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 520:
521: /* Turn on permissions for getpwnam */
522: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
523:
524: return (0);
525: }
526:
527: /* Retrieves the password entry and also checks if the user is permitted */
528:
529: int
1.59 avsm 530: mm_answer_pwnamallow(int sock, Buffer *m)
1.1 provos 531: {
1.60 dtucker 532: char *username;
1.1 provos 533: struct passwd *pwent;
534: int allowed = 0;
1.3 markus 535:
1.14 markus 536: debug3("%s", __func__);
1.1 provos 537:
538: if (authctxt->attempt++ != 0)
1.14 markus 539: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 540:
1.60 dtucker 541: username = buffer_get_string(m, NULL);
1.1 provos 542:
1.60 dtucker 543: pwent = getpwnamallow(username);
1.1 provos 544:
1.60 dtucker 545: authctxt->user = xstrdup(username);
546: setproctitle("%s [priv]", pwent ? username : "unknown");
547: xfree(username);
1.1 provos 548:
549: buffer_clear(m);
550:
551: if (pwent == NULL) {
552: buffer_put_char(m, 0);
1.53 djm 553: authctxt->pw = fakepw();
1.1 provos 554: goto out;
555: }
556:
557: allowed = 1;
1.4 markus 558: authctxt->pw = pwent;
1.1 provos 559: authctxt->valid = 1;
560:
561: buffer_put_char(m, 1);
562: buffer_put_string(m, pwent, sizeof(struct passwd));
563: buffer_put_cstring(m, pwent->pw_name);
564: buffer_put_cstring(m, "*");
565: buffer_put_cstring(m, pwent->pw_gecos);
566: buffer_put_cstring(m, pwent->pw_class);
567: buffer_put_cstring(m, pwent->pw_dir);
568: buffer_put_cstring(m, pwent->pw_shell);
569:
570: out:
1.14 markus 571: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 572: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 573:
574: /* For SSHv1 allow authentication now */
575: if (!compat20)
576: monitor_permit_authentications(1);
1.10 djm 577: else {
1.1 provos 578: /* Allow service/style information on the auth context */
579: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
1.10 djm 580: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
581: }
582:
583:
584: return (0);
585: }
586:
1.59 avsm 587: int mm_answer_auth2_read_banner(int sock, Buffer *m)
1.10 djm 588: {
589: char *banner;
590:
591: buffer_clear(m);
592: banner = auth2_read_banner();
593: buffer_put_cstring(m, banner != NULL ? banner : "");
1.59 avsm 594: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.1 provos 595:
1.10 djm 596: if (banner != NULL)
1.21 deraadt 597: xfree(banner);
1.1 provos 598:
599: return (0);
600: }
601:
602: int
1.59 avsm 603: mm_answer_authserv(int sock, Buffer *m)
1.1 provos 604: {
605: monitor_permit_authentications(1);
606:
607: authctxt->service = buffer_get_string(m, NULL);
608: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 609: debug3("%s: service=%s, style=%s",
1.14 markus 610: __func__, authctxt->service, authctxt->style);
1.6 stevesk 611:
1.1 provos 612: if (strlen(authctxt->style) == 0) {
613: xfree(authctxt->style);
614: authctxt->style = NULL;
615: }
616:
617: return (0);
618: }
619:
620: int
1.59 avsm 621: mm_answer_authpassword(int sock, Buffer *m)
1.1 provos 622: {
623: static int call_count;
624: char *passwd;
1.22 stevesk 625: int authenticated;
626: u_int plen;
1.1 provos 627:
628: passwd = buffer_get_string(m, &plen);
629: /* Only authenticate if the context is valid */
1.12 markus 630: authenticated = options.password_authentication &&
1.48 markus 631: auth_password(authctxt, passwd);
1.1 provos 632: memset(passwd, 0, strlen(passwd));
633: xfree(passwd);
634:
635: buffer_clear(m);
636: buffer_put_int(m, authenticated);
637:
1.14 markus 638: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 639: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 640:
641: call_count++;
642: if (plen == 0 && call_count == 1)
643: auth_method = "none";
644: else
645: auth_method = "password";
646:
647: /* Causes monitor loop to terminate if authenticated */
648: return (authenticated);
649: }
650:
651: #ifdef BSD_AUTH
652: int
1.59 avsm 653: mm_answer_bsdauthquery(int sock, Buffer *m)
1.1 provos 654: {
655: char *name, *infotxt;
656: u_int numprompts;
657: u_int *echo_on;
658: char **prompts;
1.31 markus 659: u_int success;
1.1 provos 660:
1.31 markus 661: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
662: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 663:
664: buffer_clear(m);
1.31 markus 665: buffer_put_int(m, success);
666: if (success)
1.1 provos 667: buffer_put_cstring(m, prompts[0]);
668:
1.31 markus 669: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 670: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 671:
1.31 markus 672: if (success) {
1.1 provos 673: xfree(name);
674: xfree(infotxt);
675: xfree(prompts);
676: xfree(echo_on);
677: }
678:
679: return (0);
680: }
681:
682: int
1.59 avsm 683: mm_answer_bsdauthrespond(int sock, Buffer *m)
1.1 provos 684: {
685: char *response;
686: int authok;
687:
688: if (authctxt->as == 0)
1.14 markus 689: fatal("%s: no bsd auth session", __func__);
1.1 provos 690:
691: response = buffer_get_string(m, NULL);
1.12 markus 692: authok = options.challenge_response_authentication &&
693: auth_userresponse(authctxt->as, response, 0);
1.1 provos 694: authctxt->as = NULL;
1.14 markus 695: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.1 provos 696: xfree(response);
697:
698: buffer_clear(m);
699: buffer_put_int(m, authok);
700:
1.14 markus 701: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 702: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 703:
704: auth_method = "bsdauth";
705:
706: return (authok != 0);
707: }
708: #endif
709:
710: #ifdef SKEY
711: int
1.59 avsm 712: mm_answer_skeyquery(int sock, Buffer *m)
1.1 provos 713: {
714: struct skey skey;
715: char challenge[1024];
1.31 markus 716: u_int success;
1.1 provos 717:
1.31 markus 718: success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
1.1 provos 719:
720: buffer_clear(m);
1.31 markus 721: buffer_put_int(m, success);
722: if (success)
1.1 provos 723: buffer_put_cstring(m, challenge);
724:
1.31 markus 725: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 726: mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
1.1 provos 727:
728: return (0);
729: }
730:
731: int
1.59 avsm 732: mm_answer_skeyrespond(int sock, Buffer *m)
1.1 provos 733: {
734: char *response;
735: int authok;
736:
737: response = buffer_get_string(m, NULL);
738:
1.12 markus 739: authok = (options.challenge_response_authentication &&
740: authctxt->valid &&
1.1 provos 741: skey_haskey(authctxt->pw->pw_name) == 0 &&
742: skey_passcheck(authctxt->pw->pw_name, response) != -1);
743:
744: xfree(response);
745:
746: buffer_clear(m);
747: buffer_put_int(m, authok);
748:
1.14 markus 749: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 750: mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
1.1 provos 751:
752: auth_method = "skey";
753:
754: return (authok != 0);
755: }
756: #endif
757:
1.2 markus 758: static void
1.1 provos 759: mm_append_debug(Buffer *m)
760: {
761: if (auth_debug_init && buffer_len(&auth_debug)) {
1.14 markus 762: debug3("%s: Appending debug messages for child", __func__);
1.1 provos 763: buffer_append(m, buffer_ptr(&auth_debug),
764: buffer_len(&auth_debug));
765: buffer_clear(&auth_debug);
766: }
767: }
768:
769: int
1.59 avsm 770: mm_answer_keyallowed(int sock, Buffer *m)
1.1 provos 771: {
772: Key *key;
1.26 markus 773: char *cuser, *chost;
774: u_char *blob;
1.1 provos 775: u_int bloblen;
776: enum mm_keytype type = 0;
777: int allowed = 0;
778:
1.14 markus 779: debug3("%s entering", __func__);
1.3 markus 780:
1.1 provos 781: type = buffer_get_int(m);
782: cuser = buffer_get_string(m, NULL);
783: chost = buffer_get_string(m, NULL);
784: blob = buffer_get_string(m, &bloblen);
785:
786: key = key_from_blob(blob, bloblen);
787:
788: if ((compat20 && type == MM_RSAHOSTKEY) ||
789: (!compat20 && type != MM_RSAHOSTKEY))
1.14 markus 790: fatal("%s: key type and protocol mismatch", __func__);
1.1 provos 791:
1.14 markus 792: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 793:
1.51 djm 794: if (key != NULL && authctxt->valid) {
1.63 deraadt 795: switch (type) {
1.1 provos 796: case MM_USERKEY:
1.12 markus 797: allowed = options.pubkey_authentication &&
798: user_key_allowed(authctxt->pw, key);
1.77 dtucker 799: auth_method = "publickey";
1.1 provos 800: break;
801: case MM_HOSTKEY:
1.12 markus 802: allowed = options.hostbased_authentication &&
803: hostbased_key_allowed(authctxt->pw,
1.1 provos 804: cuser, chost, key);
1.77 dtucker 805: auth_method = "hostbased";
1.1 provos 806: break;
807: case MM_RSAHOSTKEY:
808: key->type = KEY_RSA1; /* XXX */
1.12 markus 809: allowed = options.rhosts_rsa_authentication &&
810: auth_rhosts_rsa_key_allowed(authctxt->pw,
1.1 provos 811: cuser, chost, key);
1.77 dtucker 812: auth_method = "rsa";
1.1 provos 813: break;
814: default:
1.14 markus 815: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 816: break;
817: }
1.33 markus 818: }
819: if (key != NULL)
1.1 provos 820: key_free(key);
821:
822: /* clear temporarily storage (used by verify) */
823: monitor_reset_key_state();
824:
825: if (allowed) {
826: /* Save temporarily for comparison in verify */
827: key_blob = blob;
828: key_bloblen = bloblen;
829: key_blobtype = type;
830: hostbased_cuser = cuser;
831: hostbased_chost = chost;
1.72 djm 832: } else {
1.77 dtucker 833: /* Log failed attempt */
834: auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1.72 djm 835: xfree(blob);
836: xfree(cuser);
837: xfree(chost);
1.1 provos 838: }
839:
840: debug3("%s: key %p is %s",
1.14 markus 841: __func__, key, allowed ? "allowed" : "disallowed");
1.1 provos 842:
843: buffer_clear(m);
844: buffer_put_int(m, allowed);
1.32 markus 845: buffer_put_int(m, forced_command != NULL);
1.1 provos 846:
847: mm_append_debug(m);
848:
1.59 avsm 849: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 850:
851: if (type == MM_RSAHOSTKEY)
852: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
853:
854: return (0);
855: }
856:
857: static int
858: monitor_valid_userblob(u_char *data, u_int datalen)
859: {
860: Buffer b;
1.26 markus 861: char *p;
1.1 provos 862: u_int len;
863: int fail = 0;
864:
865: buffer_init(&b);
866: buffer_append(&b, data, datalen);
1.3 markus 867:
1.1 provos 868: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 869: p = buffer_ptr(&b);
870: len = buffer_len(&b);
871: if ((session_id2 == NULL) ||
872: (len < session_id2_len) ||
873: (memcmp(p, session_id2, session_id2_len) != 0))
874: fail++;
1.1 provos 875: buffer_consume(&b, session_id2_len);
876: } else {
1.13 markus 877: p = buffer_get_string(&b, &len);
878: if ((session_id2 == NULL) ||
879: (len != session_id2_len) ||
880: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 881: fail++;
1.13 markus 882: xfree(p);
1.1 provos 883: }
884: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
885: fail++;
886: p = buffer_get_string(&b, NULL);
887: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 888: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 889: authctxt->user, p);
890: fail++;
891: }
892: xfree(p);
893: buffer_skip_string(&b);
894: if (datafellows & SSH_BUG_PKAUTH) {
895: if (!buffer_get_char(&b))
896: fail++;
897: } else {
898: p = buffer_get_string(&b, NULL);
899: if (strcmp("publickey", p) != 0)
900: fail++;
901: xfree(p);
902: if (!buffer_get_char(&b))
903: fail++;
904: buffer_skip_string(&b);
905: }
906: buffer_skip_string(&b);
907: if (buffer_len(&b) != 0)
908: fail++;
909: buffer_free(&b);
910: return (fail == 0);
911: }
912:
913: static int
1.26 markus 914: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
915: char *chost)
1.1 provos 916: {
917: Buffer b;
1.26 markus 918: char *p;
1.1 provos 919: u_int len;
920: int fail = 0;
921:
922: buffer_init(&b);
923: buffer_append(&b, data, datalen);
1.3 markus 924:
1.13 markus 925: p = buffer_get_string(&b, &len);
926: if ((session_id2 == NULL) ||
927: (len != session_id2_len) ||
928: (memcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 929: fail++;
1.13 markus 930: xfree(p);
931:
1.1 provos 932: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
933: fail++;
934: p = buffer_get_string(&b, NULL);
935: if (strcmp(authctxt->user, p) != 0) {
1.38 itojun 936: logit("wrong user name passed to monitor: expected %s != %.100s",
1.1 provos 937: authctxt->user, p);
938: fail++;
939: }
940: xfree(p);
941: buffer_skip_string(&b); /* service */
942: p = buffer_get_string(&b, NULL);
943: if (strcmp(p, "hostbased") != 0)
944: fail++;
945: xfree(p);
946: buffer_skip_string(&b); /* pkalg */
947: buffer_skip_string(&b); /* pkblob */
948:
949: /* verify client host, strip trailing dot if necessary */
950: p = buffer_get_string(&b, NULL);
951: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
952: p[len - 1] = '\0';
953: if (strcmp(p, chost) != 0)
954: fail++;
955: xfree(p);
956:
957: /* verify client user */
958: p = buffer_get_string(&b, NULL);
959: if (strcmp(p, cuser) != 0)
960: fail++;
961: xfree(p);
962:
963: if (buffer_len(&b) != 0)
964: fail++;
965: buffer_free(&b);
966: return (fail == 0);
967: }
968:
969: int
1.59 avsm 970: mm_answer_keyverify(int sock, Buffer *m)
1.1 provos 971: {
972: Key *key;
973: u_char *signature, *data, *blob;
974: u_int signaturelen, datalen, bloblen;
975: int verified = 0;
976: int valid_data = 0;
977:
978: blob = buffer_get_string(m, &bloblen);
979: signature = buffer_get_string(m, &signaturelen);
980: data = buffer_get_string(m, &datalen);
981:
982: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 983: !monitor_allowed_key(blob, bloblen))
1.14 markus 984: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 985:
986: key = key_from_blob(blob, bloblen);
987: if (key == NULL)
1.14 markus 988: fatal("%s: bad public key blob", __func__);
1.1 provos 989:
990: switch (key_blobtype) {
991: case MM_USERKEY:
992: valid_data = monitor_valid_userblob(data, datalen);
993: break;
994: case MM_HOSTKEY:
995: valid_data = monitor_valid_hostbasedblob(data, datalen,
996: hostbased_cuser, hostbased_chost);
997: break;
998: default:
999: valid_data = 0;
1000: break;
1001: }
1002: if (!valid_data)
1.14 markus 1003: fatal("%s: bad signature data blob", __func__);
1.1 provos 1004:
1005: verified = key_verify(key, signature, signaturelen, data, datalen);
1006: debug3("%s: key %p signature %s",
1.14 markus 1007: __func__, key, verified ? "verified" : "unverified");
1.1 provos 1008:
1009: key_free(key);
1010: xfree(blob);
1011: xfree(signature);
1012: xfree(data);
1013:
1.17 stevesk 1014: auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1015:
1.1 provos 1016: monitor_reset_key_state();
1.3 markus 1017:
1.1 provos 1018: buffer_clear(m);
1019: buffer_put_int(m, verified);
1.59 avsm 1020: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.1 provos 1021:
1022: return (verified);
1023: }
1024:
1.2 markus 1025: static void
1.1 provos 1026: mm_record_login(Session *s, struct passwd *pw)
1027: {
1028: socklen_t fromlen;
1029: struct sockaddr_storage from;
1030:
1031: /*
1032: * Get IP address of client. If the connection is not a socket, let
1033: * the address be 0.0.0.0.
1034: */
1035: memset(&from, 0, sizeof(from));
1.24 stevesk 1036: fromlen = sizeof(from);
1.1 provos 1037: if (packet_connection_is_on_socket()) {
1038: if (getpeername(packet_get_connection_in(),
1.74 deraadt 1039: (struct sockaddr *)&from, &fromlen) < 0) {
1.1 provos 1040: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1041: cleanup_exit(255);
1.1 provos 1042: }
1043: }
1044: /* Record that there was a login on that tty from the remote host. */
1045: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.42 markus 1046: get_remote_name_or_ip(utmp_len, options.use_dns),
1.24 stevesk 1047: (struct sockaddr *)&from, fromlen);
1.1 provos 1048: }
1049:
1050: static void
1051: mm_session_close(Session *s)
1052: {
1.41 djm 1053: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1054: if (s->ttyfd != -1) {
1.14 markus 1055: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1056: session_pty_cleanup2(s);
1057: }
1058: s->used = 0;
1059: }
1060:
1061: int
1.59 avsm 1062: mm_answer_pty(int sock, Buffer *m)
1.1 provos 1063: {
1.11 mouring 1064: extern struct monitor *pmonitor;
1.1 provos 1065: Session *s;
1066: int res, fd0;
1067:
1.14 markus 1068: debug3("%s entering", __func__);
1.1 provos 1069:
1070: buffer_clear(m);
1071: s = session_new();
1072: if (s == NULL)
1073: goto error;
1074: s->authctxt = authctxt;
1075: s->pw = authctxt->pw;
1.11 mouring 1076: s->pid = pmonitor->m_pid;
1.1 provos 1077: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1078: if (res == 0)
1079: goto error;
1080: pty_setowner(authctxt->pw, s->tty);
1081:
1082: buffer_put_int(m, 1);
1083: buffer_put_cstring(m, s->tty);
1084:
1085: /* We need to trick ttyslot */
1086: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1087: fatal("%s: dup2", __func__);
1.1 provos 1088:
1089: mm_record_login(s, authctxt->pw);
1090:
1091: /* Now we can close the file descriptor again */
1092: close(0);
1.61 dtucker 1093:
1094: /* send messages generated by record_login */
1095: buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1096: buffer_clear(&loginmsg);
1097:
1098: mm_request_send(sock, MONITOR_ANS_PTY, m);
1099:
1100: mm_send_fd(sock, s->ptyfd);
1101: mm_send_fd(sock, s->ttyfd);
1.1 provos 1102:
1103: /* make sure nothing uses fd 0 */
1104: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1105: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1106: if (fd0 != 0)
1.14 markus 1107: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1108:
1109: /* slave is not needed */
1110: close(s->ttyfd);
1111: s->ttyfd = s->ptyfd;
1112: /* no need to dup() because nobody closes ptyfd */
1113: s->ptymaster = s->ptyfd;
1114:
1.14 markus 1115: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1116:
1117: return (0);
1118:
1119: error:
1120: if (s != NULL)
1121: mm_session_close(s);
1122: buffer_put_int(m, 0);
1.59 avsm 1123: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1124: return (0);
1125: }
1126:
1127: int
1.59 avsm 1128: mm_answer_pty_cleanup(int sock, Buffer *m)
1.1 provos 1129: {
1130: Session *s;
1131: char *tty;
1132:
1.14 markus 1133: debug3("%s entering", __func__);
1.1 provos 1134:
1135: tty = buffer_get_string(m, NULL);
1136: if ((s = session_by_tty(tty)) != NULL)
1137: mm_session_close(s);
1138: buffer_clear(m);
1139: xfree(tty);
1140: return (0);
1141: }
1142:
1143: int
1.59 avsm 1144: mm_answer_sesskey(int sock, Buffer *m)
1.1 provos 1145: {
1146: BIGNUM *p;
1147: int rsafail;
1148:
1149: /* Turn off permissions */
1.62 dtucker 1150: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1.1 provos 1151:
1152: if ((p = BN_new()) == NULL)
1.14 markus 1153: fatal("%s: BN_new", __func__);
1.1 provos 1154:
1155: buffer_get_bignum2(m, p);
1156:
1157: rsafail = ssh1_session_key(p);
1158:
1159: buffer_clear(m);
1160: buffer_put_int(m, rsafail);
1161: buffer_put_bignum2(m, p);
1162:
1163: BN_clear_free(p);
1164:
1.59 avsm 1165: mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1.1 provos 1166:
1167: /* Turn on permissions for sessid passing */
1168: monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1169:
1170: return (0);
1171: }
1172:
1173: int
1.59 avsm 1174: mm_answer_sessid(int sock, Buffer *m)
1.1 provos 1175: {
1176: int i;
1177:
1.14 markus 1178: debug3("%s entering", __func__);
1.1 provos 1179:
1180: if (buffer_len(m) != 16)
1.14 markus 1181: fatal("%s: bad ssh1 session id", __func__);
1.1 provos 1182: for (i = 0; i < 16; i++)
1183: session_id[i] = buffer_get_char(m);
1184:
1185: /* Turn on permissions for getpwnam */
1186: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1187:
1188: return (0);
1189: }
1190:
1191: int
1.59 avsm 1192: mm_answer_rsa_keyallowed(int sock, Buffer *m)
1.1 provos 1193: {
1194: BIGNUM *client_n;
1195: Key *key = NULL;
1.3 markus 1196: u_char *blob = NULL;
1197: u_int blen = 0;
1.1 provos 1198: int allowed = 0;
1199:
1.14 markus 1200: debug3("%s entering", __func__);
1.1 provos 1201:
1.77 dtucker 1202: auth_method = "rsa";
1.12 markus 1203: if (options.rsa_authentication && authctxt->valid) {
1.1 provos 1204: if ((client_n = BN_new()) == NULL)
1.14 markus 1205: fatal("%s: BN_new", __func__);
1.1 provos 1206: buffer_get_bignum2(m, client_n);
1207: allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1208: BN_clear_free(client_n);
1209: }
1210: buffer_clear(m);
1211: buffer_put_int(m, allowed);
1.32 markus 1212: buffer_put_int(m, forced_command != NULL);
1.1 provos 1213:
1214: /* clear temporarily storage (used by generate challenge) */
1215: monitor_reset_key_state();
1216:
1217: if (allowed && key != NULL) {
1218: key->type = KEY_RSA; /* cheat for key_to_blob */
1219: if (key_to_blob(key, &blob, &blen) == 0)
1.14 markus 1220: fatal("%s: key_to_blob failed", __func__);
1.1 provos 1221: buffer_put_string(m, blob, blen);
1222:
1223: /* Save temporarily for comparison in verify */
1224: key_blob = blob;
1225: key_bloblen = blen;
1226: key_blobtype = MM_RSAUSERKEY;
1.33 markus 1227: }
1228: if (key != NULL)
1.1 provos 1229: key_free(key);
1230:
1231: mm_append_debug(m);
1232:
1.59 avsm 1233: mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1.1 provos 1234:
1235: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1236: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1237: return (0);
1238: }
1239:
1240: int
1.59 avsm 1241: mm_answer_rsa_challenge(int sock, Buffer *m)
1.1 provos 1242: {
1243: Key *key = NULL;
1.3 markus 1244: u_char *blob;
1245: u_int blen;
1.1 provos 1246:
1.14 markus 1247: debug3("%s entering", __func__);
1.1 provos 1248:
1249: if (!authctxt->valid)
1.14 markus 1250: fatal("%s: authctxt not valid", __func__);
1.1 provos 1251: blob = buffer_get_string(m, &blen);
1252: if (!monitor_allowed_key(blob, blen))
1.14 markus 1253: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1254: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1255: fatal("%s: key type mismatch", __func__);
1.1 provos 1256: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1257: fatal("%s: received bad key", __func__);
1.1 provos 1258:
1259: if (ssh1_challenge)
1260: BN_clear_free(ssh1_challenge);
1261: ssh1_challenge = auth_rsa_generate_challenge(key);
1262:
1263: buffer_clear(m);
1264: buffer_put_bignum2(m, ssh1_challenge);
1265:
1.14 markus 1266: debug3("%s sending reply", __func__);
1.59 avsm 1267: mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1.1 provos 1268:
1269: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1.33 markus 1270:
1271: xfree(blob);
1272: key_free(key);
1.1 provos 1273: return (0);
1274: }
1275:
1276: int
1.59 avsm 1277: mm_answer_rsa_response(int sock, Buffer *m)
1.1 provos 1278: {
1279: Key *key = NULL;
1.3 markus 1280: u_char *blob, *response;
1281: u_int blen, len;
1282: int success;
1.1 provos 1283:
1.14 markus 1284: debug3("%s entering", __func__);
1.1 provos 1285:
1286: if (!authctxt->valid)
1.14 markus 1287: fatal("%s: authctxt not valid", __func__);
1.1 provos 1288: if (ssh1_challenge == NULL)
1.14 markus 1289: fatal("%s: no ssh1_challenge", __func__);
1.1 provos 1290:
1291: blob = buffer_get_string(m, &blen);
1292: if (!monitor_allowed_key(blob, blen))
1.14 markus 1293: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1294: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1295: fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1.1 provos 1296: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1297: fatal("%s: received bad key", __func__);
1.1 provos 1298: response = buffer_get_string(m, &len);
1299: if (len != 16)
1.14 markus 1300: fatal("%s: received bad response to challenge", __func__);
1.1 provos 1301: success = auth_rsa_verify_response(key, ssh1_challenge, response);
1302:
1.33 markus 1303: xfree(blob);
1.1 provos 1304: key_free(key);
1305: xfree(response);
1306:
1307: auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1308:
1309: /* reset state */
1310: BN_clear_free(ssh1_challenge);
1311: ssh1_challenge = NULL;
1312: monitor_reset_key_state();
1313:
1314: buffer_clear(m);
1315: buffer_put_int(m, success);
1.59 avsm 1316: mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1.1 provos 1317:
1318: return (success);
1319: }
1320:
1321: int
1.59 avsm 1322: mm_answer_term(int sock, Buffer *req)
1.1 provos 1323: {
1.11 mouring 1324: extern struct monitor *pmonitor;
1.1 provos 1325: int res, status;
1326:
1.14 markus 1327: debug3("%s: tearing down sessions", __func__);
1.1 provos 1328:
1329: /* The child is terminating */
1330: session_destroy_all(&mm_session_close);
1331:
1.11 mouring 1332: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1333: if (errno != EINTR)
1334: exit(1);
1.1 provos 1335:
1336: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1337:
1338: /* Terminate process */
1.57 deraadt 1339: exit(res);
1.1 provos 1340: }
1341:
1342: void
1.11 mouring 1343: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1344: {
1345: if (compat20) {
1346: set_newkeys(MODE_IN);
1347: set_newkeys(MODE_OUT);
1348: } else {
1349: packet_set_protocol_flags(child_state.ssh1protoflags);
1.15 markus 1350: packet_set_encryption_key(child_state.ssh1key,
1351: child_state.ssh1keylen, child_state.ssh1cipher);
1352: xfree(child_state.ssh1key);
1.1 provos 1353: }
1354:
1.15 markus 1355: /* for rc4 and other stateful ciphers */
1.1 provos 1356: packet_set_keycontext(MODE_OUT, child_state.keyout);
1357: xfree(child_state.keyout);
1358: packet_set_keycontext(MODE_IN, child_state.keyin);
1359: xfree(child_state.keyin);
1360:
1361: if (!compat20) {
1362: packet_set_iv(MODE_OUT, child_state.ivout);
1363: xfree(child_state.ivout);
1364: packet_set_iv(MODE_IN, child_state.ivin);
1365: xfree(child_state.ivin);
1366: }
1367:
1368: memcpy(&incoming_stream, &child_state.incoming,
1369: sizeof(incoming_stream));
1370: memcpy(&outgoing_stream, &child_state.outgoing,
1371: sizeof(outgoing_stream));
1.3 markus 1372:
1.1 provos 1373: /* Update with new address */
1.16 djm 1374: if (options.compression)
1375: mm_init_compression(pmonitor->m_zlib);
1.1 provos 1376:
1377: /* Network I/O buffers */
1378: /* XXX inefficient for large buffers, need: buffer_init_from_string */
1379: buffer_clear(&input);
1380: buffer_append(&input, child_state.input, child_state.ilen);
1381: memset(child_state.input, 0, child_state.ilen);
1382: xfree(child_state.input);
1383:
1384: buffer_clear(&output);
1385: buffer_append(&output, child_state.output, child_state.olen);
1386: memset(child_state.output, 0, child_state.olen);
1387: xfree(child_state.output);
1388: }
1389:
1.2 markus 1390: static Kex *
1.1 provos 1391: mm_get_kex(Buffer *m)
1392: {
1393: Kex *kex;
1394: void *blob;
1395: u_int bloblen;
1396:
1.75 djm 1397: kex = xcalloc(1, sizeof(*kex));
1.1 provos 1398: kex->session_id = buffer_get_string(m, &kex->session_id_len);
1.13 markus 1399: if ((session_id2 == NULL) ||
1400: (kex->session_id_len != session_id2_len) ||
1401: (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1402: fatal("mm_get_get: internal error: bad session id");
1.1 provos 1403: kex->we_need = buffer_get_int(m);
1.34 markus 1404: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1.58 djm 1405: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1.34 markus 1406: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.69 djm 1407: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.1 provos 1408: kex->server = 1;
1409: kex->hostkey_type = buffer_get_int(m);
1410: kex->kex_type = buffer_get_int(m);
1411: blob = buffer_get_string(m, &bloblen);
1412: buffer_init(&kex->my);
1413: buffer_append(&kex->my, blob, bloblen);
1414: xfree(blob);
1415: blob = buffer_get_string(m, &bloblen);
1416: buffer_init(&kex->peer);
1417: buffer_append(&kex->peer, blob, bloblen);
1418: xfree(blob);
1419: kex->done = 1;
1420: kex->flags = buffer_get_int(m);
1421: kex->client_version_string = buffer_get_string(m, NULL);
1422: kex->server_version_string = buffer_get_string(m, NULL);
1423: kex->load_host_key=&get_hostkey_by_type;
1424: kex->host_key_index=&get_hostkey_index;
1425:
1426: return (kex);
1427: }
1428:
1429: /* This function requries careful sanity checking */
1430:
1431: void
1.11 mouring 1432: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1433: {
1434: Buffer m;
1435: u_char *blob, *p;
1436: u_int bloblen, plen;
1.37 markus 1437: u_int32_t seqnr, packets;
1438: u_int64_t blocks;
1.1 provos 1439:
1.14 markus 1440: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1441:
1442: buffer_init(&m);
1.11 mouring 1443: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1.1 provos 1444: if (!compat20) {
1445: child_state.ssh1protoflags = buffer_get_int(&m);
1446: child_state.ssh1cipher = buffer_get_int(&m);
1.15 markus 1447: child_state.ssh1key = buffer_get_string(&m,
1448: &child_state.ssh1keylen);
1.1 provos 1449: child_state.ivout = buffer_get_string(&m,
1450: &child_state.ivoutlen);
1451: child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1452: goto skip;
1453: } else {
1454: /* Get the Kex for rekeying */
1.11 mouring 1455: *pmonitor->m_pkex = mm_get_kex(&m);
1.1 provos 1456: }
1457:
1458: blob = buffer_get_string(&m, &bloblen);
1459: current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1460: xfree(blob);
1461:
1.14 markus 1462: debug3("%s: Waiting for second key", __func__);
1.1 provos 1463: blob = buffer_get_string(&m, &bloblen);
1464: current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1465: xfree(blob);
1.3 markus 1466:
1.1 provos 1467: /* Now get sequence numbers for the packets */
1.37 markus 1468: seqnr = buffer_get_int(&m);
1469: blocks = buffer_get_int64(&m);
1470: packets = buffer_get_int(&m);
1471: packet_set_state(MODE_OUT, seqnr, blocks, packets);
1472: seqnr = buffer_get_int(&m);
1473: blocks = buffer_get_int64(&m);
1474: packets = buffer_get_int(&m);
1475: packet_set_state(MODE_IN, seqnr, blocks, packets);
1.1 provos 1476:
1477: skip:
1478: /* Get the key context */
1479: child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1480: child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1481:
1.14 markus 1482: debug3("%s: Getting compression state", __func__);
1.1 provos 1483: /* Get compression state */
1484: p = buffer_get_string(&m, &plen);
1485: if (plen != sizeof(child_state.outgoing))
1.14 markus 1486: fatal("%s: bad request size", __func__);
1.1 provos 1487: memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1488: xfree(p);
1489:
1490: p = buffer_get_string(&m, &plen);
1491: if (plen != sizeof(child_state.incoming))
1.14 markus 1492: fatal("%s: bad request size", __func__);
1.1 provos 1493: memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1494: xfree(p);
1495:
1496: /* Network I/O buffers */
1.14 markus 1497: debug3("%s: Getting Network I/O buffers", __func__);
1.1 provos 1498: child_state.input = buffer_get_string(&m, &child_state.ilen);
1499: child_state.output = buffer_get_string(&m, &child_state.olen);
1500:
1501: buffer_free(&m);
1502: }
1503:
1504:
1505: /* Allocation functions for zlib */
1506: void *
1507: mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1508: {
1.30 markus 1509: size_t len = (size_t) size * ncount;
1.1 provos 1510: void *address;
1511:
1.23 millert 1512: if (len == 0 || ncount > SIZE_T_MAX / size)
1.18 deraadt 1513: fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1514:
1515: address = mm_malloc(mm, len);
1.1 provos 1516:
1517: return (address);
1518: }
1519:
1520: void
1521: mm_zfree(struct mm_master *mm, void *address)
1522: {
1523: mm_free(mm, address);
1524: }
1525:
1526: void
1527: mm_init_compression(struct mm_master *mm)
1528: {
1529: outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1530: outgoing_stream.zfree = (free_func)mm_zfree;
1531: outgoing_stream.opaque = mm;
1532:
1533: incoming_stream.zalloc = (alloc_func)mm_zalloc;
1534: incoming_stream.zfree = (free_func)mm_zfree;
1535: incoming_stream.opaque = mm;
1536: }
1537:
1538: /* XXX */
1539:
1540: #define FD_CLOSEONEXEC(x) do { \
1541: if (fcntl(x, F_SETFD, 1) == -1) \
1542: fatal("fcntl(%d, F_SETFD)", x); \
1543: } while (0)
1544:
1.2 markus 1545: static void
1.1 provos 1546: monitor_socketpair(int *pair)
1.3 markus 1547: {
1.1 provos 1548: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.14 markus 1549: fatal("%s: socketpair", __func__);
1.1 provos 1550: FD_CLOSEONEXEC(pair[0]);
1551: FD_CLOSEONEXEC(pair[1]);
1552: }
1553:
1554: #define MM_MEMSIZE 65536
1555:
1556: struct monitor *
1557: monitor_init(void)
1558: {
1559: struct monitor *mon;
1560: int pair[2];
1561:
1.75 djm 1562: mon = xcalloc(1, sizeof(*mon));
1.1 provos 1563:
1564: monitor_socketpair(pair);
1565:
1566: mon->m_recvfd = pair[0];
1567: mon->m_sendfd = pair[1];
1568:
1569: /* Used to share zlib space across processes */
1.16 djm 1570: if (options.compression) {
1571: mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1572: mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1.1 provos 1573:
1.16 djm 1574: /* Compression needs to share state across borders */
1575: mm_init_compression(mon->m_zlib);
1576: }
1.1 provos 1577:
1578: return mon;
1579: }
1580:
1581: void
1582: monitor_reinit(struct monitor *mon)
1583: {
1584: int pair[2];
1585:
1586: monitor_socketpair(pair);
1587:
1588: mon->m_recvfd = pair[0];
1589: mon->m_sendfd = pair[1];
1590: }
1.46 markus 1591:
1592: #ifdef GSSAPI
1593: int
1.59 avsm 1594: mm_answer_gss_setup_ctx(int sock, Buffer *m)
1.46 markus 1595: {
1.59 avsm 1596: gss_OID_desc goid;
1.46 markus 1597: OM_uint32 major;
1598: u_int len;
1599:
1.59 avsm 1600: goid.elements = buffer_get_string(m, &len);
1601: goid.length = len;
1.46 markus 1602:
1.59 avsm 1603: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1604:
1.59 avsm 1605: xfree(goid.elements);
1.46 markus 1606:
1607: buffer_clear(m);
1608: buffer_put_int(m, major);
1609:
1.64 stevesk 1610: mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1.46 markus 1611:
1612: /* Now we have a context, enable the step */
1613: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1614:
1615: return (0);
1616: }
1617:
1618: int
1.59 avsm 1619: mm_answer_gss_accept_ctx(int sock, Buffer *m)
1.46 markus 1620: {
1621: gss_buffer_desc in;
1622: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1.64 stevesk 1623: OM_uint32 major, minor;
1.46 markus 1624: OM_uint32 flags = 0; /* GSI needs this */
1.47 deraadt 1625: u_int len;
1.46 markus 1626:
1.47 deraadt 1627: in.value = buffer_get_string(m, &len);
1628: in.length = len;
1.46 markus 1629: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1630: xfree(in.value);
1631:
1632: buffer_clear(m);
1633: buffer_put_int(m, major);
1634: buffer_put_string(m, out.value, out.length);
1635: buffer_put_int(m, flags);
1.59 avsm 1636: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1637:
1638: gss_release_buffer(&minor, &out);
1639:
1.64 stevesk 1640: if (major == GSS_S_COMPLETE) {
1.46 markus 1641: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1642: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1643: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1644: }
1645: return (0);
1646: }
1647:
1648: int
1.59 avsm 1649: mm_answer_gss_checkmic(int sock, Buffer *m)
1.52 markus 1650: {
1651: gss_buffer_desc gssbuf, mic;
1652: OM_uint32 ret;
1653: u_int len;
1.54 djm 1654:
1.52 markus 1655: gssbuf.value = buffer_get_string(m, &len);
1656: gssbuf.length = len;
1657: mic.value = buffer_get_string(m, &len);
1658: mic.length = len;
1.54 djm 1659:
1.52 markus 1660: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1661:
1.52 markus 1662: xfree(gssbuf.value);
1663: xfree(mic.value);
1.54 djm 1664:
1.52 markus 1665: buffer_clear(m);
1666: buffer_put_int(m, ret);
1.54 djm 1667:
1.59 avsm 1668: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1669:
1.52 markus 1670: if (!GSS_ERROR(ret))
1671: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1672:
1.52 markus 1673: return (0);
1674: }
1675:
1676: int
1.59 avsm 1677: mm_answer_gss_userok(int sock, Buffer *m)
1.46 markus 1678: {
1679: int authenticated;
1680:
1681: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1682:
1683: buffer_clear(m);
1684: buffer_put_int(m, authenticated);
1685:
1686: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1687: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1688:
1.64 stevesk 1689: auth_method = "gssapi-with-mic";
1.46 markus 1690:
1691: /* Monitor loop will terminate if authenticated */
1692: return (authenticated);
1693: }
1694: #endif /* GSSAPI */
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