Annotation of src/usr.bin/ssh/monitor.c, Revision 1.143
1.143 ! markus 1: /* $OpenBSD: monitor.c,v 1.142 2015/02/06 23:21:59 millert 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:
1.67 stevesk 28: #include <sys/types.h>
29: #include <sys/wait.h>
1.79 stevesk 30: #include <sys/socket.h>
1.85 deraadt 31: #include <sys/tree.h>
1.95 djm 32: #include <sys/queue.h>
1.1 provos 33:
1.132 markus 34: #ifdef WITH_OPENSSL
1.78 stevesk 35: #include <openssl/dh.h>
1.132 markus 36: #endif
1.78 stevesk 37:
1.81 stevesk 38: #include <errno.h>
1.80 stevesk 39: #include <fcntl.h>
1.65 stevesk 40: #include <paths.h>
1.114 djm 41: #include <poll.h>
1.78 stevesk 42: #include <pwd.h>
1.68 stevesk 43: #include <signal.h>
1.134 djm 44: #include <stdarg.h>
1.142 millert 45: #include <stdint.h>
1.134 djm 46: #include <stdio.h>
1.84 stevesk 47: #include <stdlib.h>
1.82 stevesk 48: #include <string.h>
1.1 provos 49:
1.114 djm 50: #include "atomicio.h"
1.85 deraadt 51: #include "xmalloc.h"
1.1 provos 52: #include "ssh.h"
1.85 deraadt 53: #include "key.h"
54: #include "buffer.h"
55: #include "hostfile.h"
1.1 provos 56: #include "auth.h"
1.85 deraadt 57: #include "cipher.h"
1.1 provos 58: #include "kex.h"
59: #include "dh.h"
1.88 miod 60: #include <zlib.h>
1.1 provos 61: #include "packet.h"
62: #include "auth-options.h"
63: #include "sshpty.h"
64: #include "channels.h"
65: #include "session.h"
66: #include "sshlogin.h"
67: #include "canohost.h"
68: #include "log.h"
1.135 millert 69: #include "misc.h"
1.1 provos 70: #include "servconf.h"
71: #include "monitor.h"
72: #include "monitor_mm.h"
1.85 deraadt 73: #ifdef GSSAPI
74: #include "ssh-gss.h"
75: #endif
1.1 provos 76: #include "monitor_wrap.h"
77: #include "monitor_fdpass.h"
78: #include "compat.h"
79: #include "ssh2.h"
1.104 andreas 80: #include "roaming.h"
1.127 markus 81: #include "authfd.h"
1.137 djm 82: #include "match.h"
1.138 djm 83: #include "ssherr.h"
1.1 provos 84:
1.46 markus 85: #ifdef GSSAPI
86: static Gssctxt *gsscontext = NULL;
87: #endif
88:
1.1 provos 89: /* Imports */
90: extern ServerOptions options;
91: extern u_int utmp_len;
92: extern u_char session_id[];
93: extern Buffer auth_debug;
94: extern int auth_debug_init;
1.61 dtucker 95: extern Buffer loginmsg;
1.1 provos 96:
97: /* State exported from the child */
1.139 markus 98: static struct sshbuf *child_state;
1.1 provos 99:
1.43 markus 100: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 101:
102: int mm_answer_moduli(int, Buffer *);
103: int mm_answer_sign(int, Buffer *);
104: int mm_answer_pwnamallow(int, Buffer *);
1.10 djm 105: int mm_answer_auth2_read_banner(int, Buffer *);
1.1 provos 106: int mm_answer_authserv(int, Buffer *);
107: int mm_answer_authpassword(int, Buffer *);
108: int mm_answer_bsdauthquery(int, Buffer *);
109: int mm_answer_bsdauthrespond(int, Buffer *);
110: int mm_answer_skeyquery(int, Buffer *);
111: int mm_answer_skeyrespond(int, Buffer *);
112: int mm_answer_keyallowed(int, Buffer *);
113: int mm_answer_keyverify(int, Buffer *);
114: int mm_answer_pty(int, Buffer *);
115: int mm_answer_pty_cleanup(int, Buffer *);
116: int mm_answer_term(int, Buffer *);
117: int mm_answer_rsa_keyallowed(int, Buffer *);
118: int mm_answer_rsa_challenge(int, Buffer *);
119: int mm_answer_rsa_response(int, Buffer *);
120: int mm_answer_sesskey(int, Buffer *);
121: int mm_answer_sessid(int, Buffer *);
122:
1.46 markus 123: #ifdef GSSAPI
124: int mm_answer_gss_setup_ctx(int, Buffer *);
125: int mm_answer_gss_accept_ctx(int, Buffer *);
126: int mm_answer_gss_userok(int, Buffer *);
1.52 markus 127: int mm_answer_gss_checkmic(int, Buffer *);
1.46 markus 128: #endif
1.25 itojun 129:
1.114 djm 130: static int monitor_read_log(struct monitor *);
131:
1.1 provos 132: static Authctxt *authctxt;
1.132 markus 133:
134: #ifdef WITH_SSH1
1.1 provos 135: static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
1.132 markus 136: #endif
1.1 provos 137:
138: /* local state for key verify */
139: static u_char *key_blob = NULL;
140: static u_int key_bloblen = 0;
141: static int key_blobtype = MM_NOKEY;
1.26 markus 142: static char *hostbased_cuser = NULL;
143: static char *hostbased_chost = NULL;
1.1 provos 144: static char *auth_method = "unknown";
1.119 djm 145: static char *auth_submethod = NULL;
1.44 markus 146: static u_int session_id2_len = 0;
1.13 markus 147: static u_char *session_id2 = NULL;
1.40 markus 148: static pid_t monitor_child_pid;
1.1 provos 149:
150: struct mon_table {
151: enum monitor_reqtype type;
152: int flags;
153: int (*f)(int, Buffer *);
154: };
155:
156: #define MON_ISAUTH 0x0004 /* Required for Authentication */
157: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
158: #define MON_ONCE 0x0010 /* Disable after calling */
1.77 dtucker 159: #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
1.1 provos 160:
161: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
162:
163: #define MON_PERMIT 0x1000 /* Request is permitted */
164:
165: struct mon_table mon_dispatch_proto20[] = {
1.132 markus 166: #ifdef WITH_OPENSSL
1.1 provos 167: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
1.132 markus 168: #endif
1.1 provos 169: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
170: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
171: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 172: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 173: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
174: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 175: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 176: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
177: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 178: #ifdef GSSAPI
179: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
180: {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
181: {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
1.52 markus 182: {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
1.46 markus 183: #endif
1.1 provos 184: {0, 0, NULL}
185: };
186:
187: struct mon_table mon_dispatch_postauth20[] = {
1.132 markus 188: #ifdef WITH_OPENSSL
1.1 provos 189: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
1.132 markus 190: #endif
1.1 provos 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[] = {
1.132 markus 199: #ifdef WITH_SSH1
1.1 provos 200: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
201: {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
202: {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
203: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
1.77 dtucker 204: {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
205: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
1.1 provos 206: {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
207: {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
208: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 209: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.132 markus 210: #endif
1.1 provos 211: {0, 0, NULL}
212: };
213:
214: struct mon_table mon_dispatch_postauth15[] = {
1.132 markus 215: #ifdef WITH_SSH1
1.1 provos 216: {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
217: {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
218: {MONITOR_REQ_TERM, 0, mm_answer_term},
1.132 markus 219: #endif
1.1 provos 220: {0, 0, NULL}
221: };
222:
223: struct mon_table *mon_dispatch;
224:
225: /* Specifies if a certain message is allowed at the moment */
226:
227: static void
228: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
229: {
230: while (ent->f != NULL) {
231: if (ent->type == type) {
232: ent->flags &= ~MON_PERMIT;
233: ent->flags |= permit ? MON_PERMIT : 0;
234: return;
235: }
236: ent++;
237: }
238: }
239:
240: static void
241: monitor_permit_authentications(int permit)
242: {
243: struct mon_table *ent = mon_dispatch;
244:
245: while (ent->f != NULL) {
246: if (ent->flags & MON_AUTH) {
247: ent->flags &= ~MON_PERMIT;
248: ent->flags |= permit ? MON_PERMIT : 0;
249: }
250: ent++;
251: }
252: }
253:
1.50 markus 254: void
255: monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
1.1 provos 256: {
257: struct mon_table *ent;
1.119 djm 258: int authenticated = 0, partial = 0;
1.1 provos 259:
260: debug3("preauth child monitor started");
261:
1.114 djm 262: close(pmonitor->m_recvfd);
263: close(pmonitor->m_log_sendfd);
264: pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
265:
1.50 markus 266: authctxt = _authctxt;
267: memset(authctxt, 0, sizeof(*authctxt));
268:
1.1 provos 269: if (compat20) {
270: mon_dispatch = mon_dispatch_proto20;
271:
272: /* Permit requests for moduli and signatures */
273: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
274: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
275: } else {
276: mon_dispatch = mon_dispatch_proto15;
277:
278: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
279: }
280:
281: /* The first few requests do not require asynchronous access */
282: while (!authenticated) {
1.119 djm 283: partial = 0;
1.77 dtucker 284: auth_method = "unknown";
1.119 djm 285: auth_submethod = NULL;
1.89 markus 286: authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
1.118 djm 287:
288: /* Special handling for multiple required authentications */
289: if (options.num_auth_methods != 0) {
290: if (!compat20)
291: fatal("AuthenticationMethods is not supported"
292: "with SSH protocol 1");
293: if (authenticated &&
294: !auth2_update_methods_lists(authctxt,
1.122 markus 295: auth_method, auth_submethod)) {
1.118 djm 296: debug3("%s: method %s: partial", __func__,
297: auth_method);
298: authenticated = 0;
1.119 djm 299: partial = 1;
1.118 djm 300: }
301: }
302:
1.1 provos 303: if (authenticated) {
304: if (!(ent->flags & MON_AUTHDECIDE))
305: fatal("%s: unexpected authentication from %d",
1.14 markus 306: __func__, ent->type);
1.1 provos 307: if (authctxt->pw->pw_uid == 0 &&
308: !auth_root_allowed(auth_method))
309: authenticated = 0;
310: }
1.77 dtucker 311: if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
1.119 djm 312: auth_log(authctxt, authenticated, partial,
1.125 djm 313: auth_method, auth_submethod);
1.1 provos 314: if (!authenticated)
315: authctxt->failures++;
316: }
317: }
318:
319: if (!authctxt->valid)
1.14 markus 320: fatal("%s: authenticated invalid user", __func__);
1.77 dtucker 321: if (strcmp(auth_method, "unknown") == 0)
322: fatal("%s: authentication method name unknown", __func__);
1.1 provos 323:
324: debug("%s: %s has been authenticated by privileged process",
1.14 markus 325: __func__, authctxt->user);
1.1 provos 326:
1.11 mouring 327: mm_get_keystate(pmonitor);
1.120 markus 328:
329: /* Drain any buffered messages from the child */
330: while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
331: ;
1.114 djm 332:
333: close(pmonitor->m_sendfd);
334: close(pmonitor->m_log_recvfd);
335: pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
1.1 provos 336: }
337:
1.40 markus 338: static void
339: monitor_set_child_handler(pid_t pid)
340: {
341: monitor_child_pid = pid;
342: }
343:
344: static void
1.59 avsm 345: monitor_child_handler(int sig)
1.40 markus 346: {
1.59 avsm 347: kill(monitor_child_pid, sig);
1.40 markus 348: }
349:
1.1 provos 350: void
1.11 mouring 351: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 352: {
1.114 djm 353: close(pmonitor->m_recvfd);
354: pmonitor->m_recvfd = -1;
355:
1.40 markus 356: monitor_set_child_handler(pmonitor->m_pid);
357: signal(SIGHUP, &monitor_child_handler);
358: signal(SIGTERM, &monitor_child_handler);
1.91 djm 359: signal(SIGINT, &monitor_child_handler);
1.40 markus 360:
1.1 provos 361: if (compat20) {
362: mon_dispatch = mon_dispatch_postauth20;
363:
364: /* Permit requests for moduli and signatures */
365: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
366: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
367: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
368: } else {
369: mon_dispatch = mon_dispatch_postauth15;
370: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
371: }
372: if (!no_pty_flag) {
373: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
374: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
375: }
376:
377: for (;;)
1.11 mouring 378: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 379: }
380:
381: void
1.11 mouring 382: monitor_sync(struct monitor *pmonitor)
1.1 provos 383: {
1.16 djm 384: if (options.compression) {
385: /* The member allocation is not visible, so sync it */
386: mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
387: }
1.1 provos 388: }
389:
1.139 markus 390: /* Allocation functions for zlib */
391: static void *
392: mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
393: {
394: size_t len = (size_t) size * ncount;
395: void *address;
396:
1.142 millert 397: if (len == 0 || ncount > SIZE_MAX / size)
1.139 markus 398: fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
399:
400: address = mm_malloc(mm, len);
401:
402: return (address);
403: }
404:
405: static void
406: mm_zfree(struct mm_master *mm, void *address)
407: {
408: mm_free(mm, address);
409: }
410:
1.114 djm 411: static int
412: monitor_read_log(struct monitor *pmonitor)
413: {
414: Buffer logmsg;
415: u_int len, level;
416: char *msg;
417:
418: buffer_init(&logmsg);
419:
420: /* Read length */
421: buffer_append_space(&logmsg, 4);
422: if (atomicio(read, pmonitor->m_log_recvfd,
423: buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
424: if (errno == EPIPE) {
1.116 djm 425: buffer_free(&logmsg);
1.114 djm 426: debug("%s: child log fd closed", __func__);
427: close(pmonitor->m_log_recvfd);
428: pmonitor->m_log_recvfd = -1;
429: return -1;
430: }
431: fatal("%s: log fd read: %s", __func__, strerror(errno));
432: }
433: len = buffer_get_int(&logmsg);
434: if (len <= 4 || len > 8192)
435: fatal("%s: invalid log message length %u", __func__, len);
436:
437: /* Read severity, message */
438: buffer_clear(&logmsg);
439: buffer_append_space(&logmsg, len);
440: if (atomicio(read, pmonitor->m_log_recvfd,
441: buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
442: fatal("%s: log fd read: %s", __func__, strerror(errno));
443:
444: /* Log it */
445: level = buffer_get_int(&logmsg);
446: msg = buffer_get_string(&logmsg, NULL);
447: if (log_level_name(level) == NULL)
448: fatal("%s: invalid log level %u (corrupted message?)",
449: __func__, level);
450: do_log2(level, "%s [preauth]", msg);
451:
452: buffer_free(&logmsg);
1.124 djm 453: free(msg);
1.114 djm 454:
455: return 0;
456: }
457:
1.1 provos 458: int
1.11 mouring 459: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 460: struct mon_table **pent)
461: {
462: Buffer m;
463: int ret;
464: u_char type;
1.114 djm 465: struct pollfd pfd[2];
466:
467: for (;;) {
1.130 tedu 468: memset(&pfd, 0, sizeof(pfd));
1.114 djm 469: pfd[0].fd = pmonitor->m_sendfd;
470: pfd[0].events = POLLIN;
471: pfd[1].fd = pmonitor->m_log_recvfd;
472: pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
1.115 djm 473: if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
474: if (errno == EINTR || errno == EAGAIN)
475: continue;
1.114 djm 476: fatal("%s: poll: %s", __func__, strerror(errno));
1.115 djm 477: }
1.114 djm 478: if (pfd[1].revents) {
479: /*
480: * Drain all log messages before processing next
481: * monitor request.
482: */
483: monitor_read_log(pmonitor);
484: continue;
485: }
486: if (pfd[0].revents)
487: break; /* Continues below */
488: }
1.1 provos 489:
490: buffer_init(&m);
491:
1.11 mouring 492: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 493: type = buffer_get_char(&m);
494:
1.14 markus 495: debug3("%s: checking request %d", __func__, type);
1.1 provos 496:
497: while (ent->f != NULL) {
498: if (ent->type == type)
499: break;
500: ent++;
501: }
502:
503: if (ent->f != NULL) {
504: if (!(ent->flags & MON_PERMIT))
1.14 markus 505: fatal("%s: unpermitted request %d", __func__,
1.1 provos 506: type);
1.11 mouring 507: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 508: buffer_free(&m);
509:
510: /* The child may use this request only once, disable it */
511: if (ent->flags & MON_ONCE) {
1.14 markus 512: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 513: type);
514: ent->flags &= ~MON_PERMIT;
515: }
516:
517: if (pent != NULL)
518: *pent = ent;
1.3 markus 519:
1.1 provos 520: return ret;
521: }
522:
1.14 markus 523: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 524:
525: /* NOTREACHED */
526: return (-1);
527: }
528:
529: /* allowed key state */
530: static int
531: monitor_allowed_key(u_char *blob, u_int bloblen)
532: {
533: /* make sure key is allowed */
534: if (key_blob == NULL || key_bloblen != bloblen ||
1.108 djm 535: timingsafe_bcmp(key_blob, blob, key_bloblen))
1.1 provos 536: return (0);
537: return (1);
538: }
539:
540: static void
541: monitor_reset_key_state(void)
542: {
543: /* reset state */
1.124 djm 544: free(key_blob);
545: free(hostbased_cuser);
546: free(hostbased_chost);
1.1 provos 547: key_blob = NULL;
548: key_bloblen = 0;
549: key_blobtype = MM_NOKEY;
550: hostbased_cuser = NULL;
551: hostbased_chost = NULL;
552: }
553:
1.132 markus 554: #ifdef WITH_OPENSSL
1.1 provos 555: int
1.59 avsm 556: mm_answer_moduli(int sock, Buffer *m)
1.1 provos 557: {
558: DH *dh;
559: int min, want, max;
560:
561: min = buffer_get_int(m);
562: want = buffer_get_int(m);
563: max = buffer_get_int(m);
564:
565: debug3("%s: got parameters: %d %d %d",
1.14 markus 566: __func__, min, want, max);
1.1 provos 567: /* We need to check here, too, in case the child got corrupted */
568: if (max < min || want < min || max < want)
569: fatal("%s: bad parameters: %d %d %d",
1.14 markus 570: __func__, min, want, max);
1.1 provos 571:
572: buffer_clear(m);
573:
574: dh = choose_dh(min, want, max);
575: if (dh == NULL) {
576: buffer_put_char(m, 0);
577: return (0);
578: } else {
579: /* Send first bignum */
580: buffer_put_char(m, 1);
581: buffer_put_bignum2(m, dh->p);
582: buffer_put_bignum2(m, dh->g);
1.3 markus 583:
1.1 provos 584: DH_free(dh);
585: }
1.59 avsm 586: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 587: return (0);
588: }
1.132 markus 589: #endif
1.1 provos 590:
591: int
1.59 avsm 592: mm_answer_sign(int sock, Buffer *m)
1.1 provos 593: {
1.138 djm 594: extern int auth_sock; /* XXX move to state struct? */
595: struct sshkey *key;
1.1 provos 596: u_char *p;
597: u_char *signature;
1.138 djm 598: size_t datlen, siglen;
599: int r, keyid;
1.3 markus 600:
1.14 markus 601: debug3("%s", __func__);
1.1 provos 602:
1.138 djm 603: if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
604: (r = sshbuf_get_string(m, &p, &datlen)) != 0)
605: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 606:
1.69 djm 607: /*
1.110 djm 608: * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
609: * SHA384 (48 bytes) and SHA512 (64 bytes).
1.69 djm 610: */
1.110 djm 611: if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64)
1.138 djm 612: fatal("%s: data length incorrect: %zu", __func__, datlen);
1.1 provos 613:
1.13 markus 614: /* save session id, it will be passed on the first call */
615: if (session_id2_len == 0) {
616: session_id2_len = datlen;
617: session_id2 = xmalloc(session_id2_len);
618: memcpy(session_id2, p, session_id2_len);
619: }
620:
1.127 markus 621: if ((key = get_hostkey_by_index(keyid)) != NULL) {
1.138 djm 622: if ((r = sshkey_sign(key, &signature, &siglen, p, datlen,
623: datafellows)) != 0)
624: fatal("%s: sshkey_sign failed: %s",
625: __func__, ssh_err(r));
1.140 markus 626: } else if ((key = get_hostkey_public_by_index(keyid, active_state)) != NULL &&
1.138 djm 627: auth_sock > 0) {
628: if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
629: p, datlen, datafellows)) != 0) {
630: fatal("%s: ssh_agent_sign failed: %s",
631: __func__, ssh_err(r));
632: }
1.127 markus 633: } else
1.14 markus 634: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 635:
1.138 djm 636: debug3("%s: signature %p(%zu)", __func__, signature, siglen);
1.1 provos 637:
1.138 djm 638: sshbuf_reset(m);
639: if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
640: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 641:
1.124 djm 642: free(p);
643: free(signature);
1.1 provos 644:
1.59 avsm 645: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 646:
647: /* Turn on permissions for getpwnam */
648: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
649:
650: return (0);
651: }
652:
653: /* Retrieves the password entry and also checks if the user is permitted */
654:
655: int
1.59 avsm 656: mm_answer_pwnamallow(int sock, Buffer *m)
1.1 provos 657: {
1.60 dtucker 658: char *username;
1.1 provos 659: struct passwd *pwent;
660: int allowed = 0;
1.113 djm 661: u_int i;
1.3 markus 662:
1.14 markus 663: debug3("%s", __func__);
1.1 provos 664:
665: if (authctxt->attempt++ != 0)
1.14 markus 666: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 667:
1.60 dtucker 668: username = buffer_get_string(m, NULL);
1.1 provos 669:
1.60 dtucker 670: pwent = getpwnamallow(username);
1.1 provos 671:
1.60 dtucker 672: authctxt->user = xstrdup(username);
673: setproctitle("%s [priv]", pwent ? username : "unknown");
1.124 djm 674: free(username);
1.1 provos 675:
676: buffer_clear(m);
677:
678: if (pwent == NULL) {
679: buffer_put_char(m, 0);
1.53 djm 680: authctxt->pw = fakepw();
1.1 provos 681: goto out;
682: }
683:
684: allowed = 1;
1.4 markus 685: authctxt->pw = pwent;
1.1 provos 686: authctxt->valid = 1;
687:
688: buffer_put_char(m, 1);
689: buffer_put_string(m, pwent, sizeof(struct passwd));
690: buffer_put_cstring(m, pwent->pw_name);
691: buffer_put_cstring(m, "*");
692: buffer_put_cstring(m, pwent->pw_gecos);
693: buffer_put_cstring(m, pwent->pw_class);
694: buffer_put_cstring(m, pwent->pw_dir);
695: buffer_put_cstring(m, pwent->pw_shell);
1.94 dtucker 696:
697: out:
1.90 dtucker 698: buffer_put_string(m, &options, sizeof(options));
1.112 djm 699:
700: #define M_CP_STROPT(x) do { \
701: if (options.x != NULL) \
702: buffer_put_cstring(m, options.x); \
703: } while (0)
1.113 djm 704: #define M_CP_STRARRAYOPT(x, nx) do { \
705: for (i = 0; i < options.nx; i++) \
706: buffer_put_cstring(m, options.x[i]); \
707: } while (0)
1.112 djm 708: /* See comment in servconf.h */
709: COPY_MATCH_STRING_OPTS();
710: #undef M_CP_STROPT
1.113 djm 711: #undef M_CP_STRARRAYOPT
1.118 djm 712:
713: /* Create valid auth method lists */
714: if (compat20 && auth2_setup_methods_lists(authctxt) != 0) {
715: /*
716: * The monitor will continue long enough to let the child
717: * run to it's packet_disconnect(), but it must not allow any
718: * authentication to succeed.
719: */
720: debug("%s: no valid authentication method lists", __func__);
721: }
722:
1.14 markus 723: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 724: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 725:
726: /* For SSHv1 allow authentication now */
727: if (!compat20)
728: monitor_permit_authentications(1);
1.10 djm 729: else {
1.1 provos 730: /* Allow service/style information on the auth context */
731: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
1.10 djm 732: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
733: }
734:
735: return (0);
736: }
737:
1.59 avsm 738: int mm_answer_auth2_read_banner(int sock, Buffer *m)
1.10 djm 739: {
740: char *banner;
741:
742: buffer_clear(m);
743: banner = auth2_read_banner();
744: buffer_put_cstring(m, banner != NULL ? banner : "");
1.59 avsm 745: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.124 djm 746: free(banner);
1.1 provos 747:
748: return (0);
749: }
750:
751: int
1.59 avsm 752: mm_answer_authserv(int sock, Buffer *m)
1.1 provos 753: {
754: monitor_permit_authentications(1);
755:
756: authctxt->service = buffer_get_string(m, NULL);
757: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 758: debug3("%s: service=%s, style=%s",
1.14 markus 759: __func__, authctxt->service, authctxt->style);
1.6 stevesk 760:
1.1 provos 761: if (strlen(authctxt->style) == 0) {
1.124 djm 762: free(authctxt->style);
1.1 provos 763: authctxt->style = NULL;
764: }
765:
766: return (0);
767: }
768:
769: int
1.59 avsm 770: mm_answer_authpassword(int sock, Buffer *m)
1.1 provos 771: {
772: static int call_count;
773: char *passwd;
1.22 stevesk 774: int authenticated;
775: u_int plen;
1.1 provos 776:
777: passwd = buffer_get_string(m, &plen);
778: /* Only authenticate if the context is valid */
1.12 markus 779: authenticated = options.password_authentication &&
1.48 markus 780: auth_password(authctxt, passwd);
1.131 djm 781: explicit_bzero(passwd, strlen(passwd));
1.124 djm 782: free(passwd);
1.1 provos 783:
784: buffer_clear(m);
785: buffer_put_int(m, authenticated);
786:
1.14 markus 787: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 788: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 789:
790: call_count++;
791: if (plen == 0 && call_count == 1)
792: auth_method = "none";
793: else
794: auth_method = "password";
795:
796: /* Causes monitor loop to terminate if authenticated */
797: return (authenticated);
798: }
799:
800: int
1.59 avsm 801: mm_answer_bsdauthquery(int sock, Buffer *m)
1.1 provos 802: {
803: char *name, *infotxt;
804: u_int numprompts;
805: u_int *echo_on;
806: char **prompts;
1.31 markus 807: u_int success;
1.1 provos 808:
1.31 markus 809: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
810: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 811:
812: buffer_clear(m);
1.31 markus 813: buffer_put_int(m, success);
814: if (success)
1.1 provos 815: buffer_put_cstring(m, prompts[0]);
816:
1.31 markus 817: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 818: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 819:
1.31 markus 820: if (success) {
1.124 djm 821: free(name);
822: free(infotxt);
823: free(prompts);
824: free(echo_on);
1.1 provos 825: }
826:
827: return (0);
828: }
829:
830: int
1.59 avsm 831: mm_answer_bsdauthrespond(int sock, Buffer *m)
1.1 provos 832: {
833: char *response;
834: int authok;
835:
836: if (authctxt->as == 0)
1.14 markus 837: fatal("%s: no bsd auth session", __func__);
1.1 provos 838:
839: response = buffer_get_string(m, NULL);
1.12 markus 840: authok = options.challenge_response_authentication &&
841: auth_userresponse(authctxt->as, response, 0);
1.1 provos 842: authctxt->as = NULL;
1.14 markus 843: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.124 djm 844: free(response);
1.1 provos 845:
846: buffer_clear(m);
847: buffer_put_int(m, authok);
848:
1.14 markus 849: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 850: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 851:
1.122 markus 852: if (compat20) {
853: auth_method = "keyboard-interactive";
854: auth_submethod = "bsdauth";
855: } else
1.118 djm 856: auth_method = "bsdauth";
1.1 provos 857:
858: return (authok != 0);
859: }
860:
861: int
1.59 avsm 862: mm_answer_keyallowed(int sock, Buffer *m)
1.1 provos 863: {
864: Key *key;
1.26 markus 865: char *cuser, *chost;
866: u_char *blob;
1.1 provos 867: u_int bloblen;
868: enum mm_keytype type = 0;
869: int allowed = 0;
870:
1.14 markus 871: debug3("%s entering", __func__);
1.3 markus 872:
1.1 provos 873: type = buffer_get_int(m);
874: cuser = buffer_get_string(m, NULL);
875: chost = buffer_get_string(m, NULL);
876: blob = buffer_get_string(m, &bloblen);
877:
878: key = key_from_blob(blob, bloblen);
879:
880: if ((compat20 && type == MM_RSAHOSTKEY) ||
881: (!compat20 && type != MM_RSAHOSTKEY))
1.14 markus 882: fatal("%s: key type and protocol mismatch", __func__);
1.1 provos 883:
1.14 markus 884: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 885:
1.51 djm 886: if (key != NULL && authctxt->valid) {
1.137 djm 887: /* These should not make it past the privsep child */
888: if (key_type_plain(key->type) == KEY_RSA &&
889: (datafellows & SSH_BUG_RSASIGMD5) != 0)
890: fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
891:
1.63 deraadt 892: switch (type) {
1.1 provos 893: case MM_USERKEY:
1.12 markus 894: allowed = options.pubkey_authentication &&
1.136 djm 895: !auth2_userkey_already_used(authctxt, key) &&
1.137 djm 896: match_pattern_list(sshkey_ssh_name(key),
897: options.pubkey_key_types,
898: strlen(options.pubkey_key_types), 0) == 1 &&
1.12 markus 899: user_key_allowed(authctxt->pw, key);
1.126 djm 900: pubkey_auth_info(authctxt, key, NULL);
1.77 dtucker 901: auth_method = "publickey";
1.97 dtucker 902: if (options.pubkey_authentication && allowed != 1)
903: auth_clear_options();
1.1 provos 904: break;
905: case MM_HOSTKEY:
1.12 markus 906: allowed = options.hostbased_authentication &&
1.137 djm 907: match_pattern_list(sshkey_ssh_name(key),
908: options.hostbased_key_types,
909: strlen(options.hostbased_key_types), 0) == 1 &&
1.12 markus 910: hostbased_key_allowed(authctxt->pw,
1.1 provos 911: cuser, chost, key);
1.126 djm 912: pubkey_auth_info(authctxt, key,
913: "client user \"%.100s\", client host \"%.100s\"",
914: cuser, chost);
1.77 dtucker 915: auth_method = "hostbased";
1.1 provos 916: break;
1.132 markus 917: #ifdef WITH_SSH1
1.1 provos 918: case MM_RSAHOSTKEY:
919: key->type = KEY_RSA1; /* XXX */
1.12 markus 920: allowed = options.rhosts_rsa_authentication &&
921: auth_rhosts_rsa_key_allowed(authctxt->pw,
1.1 provos 922: cuser, chost, key);
1.97 dtucker 923: if (options.rhosts_rsa_authentication && allowed != 1)
924: auth_clear_options();
1.77 dtucker 925: auth_method = "rsa";
1.1 provos 926: break;
1.132 markus 927: #endif
1.1 provos 928: default:
1.14 markus 929: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 930: break;
931: }
1.33 markus 932: }
933: if (key != NULL)
1.1 provos 934: key_free(key);
935:
936: /* clear temporarily storage (used by verify) */
937: monitor_reset_key_state();
938:
939: if (allowed) {
940: /* Save temporarily for comparison in verify */
941: key_blob = blob;
942: key_bloblen = bloblen;
943: key_blobtype = type;
944: hostbased_cuser = cuser;
945: hostbased_chost = chost;
1.72 djm 946: } else {
1.77 dtucker 947: /* Log failed attempt */
1.125 djm 948: auth_log(authctxt, 0, 0, auth_method, NULL);
1.124 djm 949: free(blob);
950: free(cuser);
951: free(chost);
1.1 provos 952: }
953:
954: debug3("%s: key %p is %s",
1.98 dtucker 955: __func__, key, allowed ? "allowed" : "not allowed");
1.1 provos 956:
957: buffer_clear(m);
958: buffer_put_int(m, allowed);
1.32 markus 959: buffer_put_int(m, forced_command != NULL);
1.1 provos 960:
1.59 avsm 961: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 962:
963: if (type == MM_RSAHOSTKEY)
964: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
965:
966: return (0);
967: }
968:
969: static int
970: monitor_valid_userblob(u_char *data, u_int datalen)
971: {
972: Buffer b;
1.121 djm 973: char *p, *userstyle;
1.1 provos 974: u_int len;
975: int fail = 0;
976:
977: buffer_init(&b);
978: buffer_append(&b, data, datalen);
1.3 markus 979:
1.1 provos 980: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 981: p = buffer_ptr(&b);
982: len = buffer_len(&b);
983: if ((session_id2 == NULL) ||
984: (len < session_id2_len) ||
1.108 djm 985: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.13 markus 986: fail++;
1.1 provos 987: buffer_consume(&b, session_id2_len);
988: } else {
1.13 markus 989: p = buffer_get_string(&b, &len);
990: if ((session_id2 == NULL) ||
991: (len != session_id2_len) ||
1.108 djm 992: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 993: fail++;
1.124 djm 994: free(p);
1.1 provos 995: }
996: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
997: fail++;
1.121 djm 998: p = buffer_get_cstring(&b, NULL);
999: xasprintf(&userstyle, "%s%s%s", authctxt->user,
1000: authctxt->style ? ":" : "",
1001: authctxt->style ? authctxt->style : "");
1002: if (strcmp(userstyle, p) != 0) {
1.38 itojun 1003: logit("wrong user name passed to monitor: expected %s != %.100s",
1.121 djm 1004: userstyle, p);
1.1 provos 1005: fail++;
1006: }
1.124 djm 1007: free(userstyle);
1008: free(p);
1.1 provos 1009: buffer_skip_string(&b);
1010: if (datafellows & SSH_BUG_PKAUTH) {
1011: if (!buffer_get_char(&b))
1012: fail++;
1013: } else {
1.121 djm 1014: p = buffer_get_cstring(&b, NULL);
1.1 provos 1015: if (strcmp("publickey", p) != 0)
1016: fail++;
1.124 djm 1017: free(p);
1.1 provos 1018: if (!buffer_get_char(&b))
1019: fail++;
1020: buffer_skip_string(&b);
1021: }
1022: buffer_skip_string(&b);
1023: if (buffer_len(&b) != 0)
1024: fail++;
1025: buffer_free(&b);
1026: return (fail == 0);
1027: }
1028:
1029: static int
1.26 markus 1030: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1031: char *chost)
1.1 provos 1032: {
1033: Buffer b;
1.121 djm 1034: char *p, *userstyle;
1.1 provos 1035: u_int len;
1036: int fail = 0;
1037:
1038: buffer_init(&b);
1039: buffer_append(&b, data, datalen);
1.3 markus 1040:
1.13 markus 1041: p = buffer_get_string(&b, &len);
1042: if ((session_id2 == NULL) ||
1043: (len != session_id2_len) ||
1.108 djm 1044: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 1045: fail++;
1.124 djm 1046: free(p);
1.13 markus 1047:
1.1 provos 1048: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1049: fail++;
1.121 djm 1050: p = buffer_get_cstring(&b, NULL);
1051: xasprintf(&userstyle, "%s%s%s", authctxt->user,
1052: authctxt->style ? ":" : "",
1053: authctxt->style ? authctxt->style : "");
1054: if (strcmp(userstyle, p) != 0) {
1.38 itojun 1055: logit("wrong user name passed to monitor: expected %s != %.100s",
1.121 djm 1056: userstyle, p);
1.1 provos 1057: fail++;
1058: }
1.121 djm 1059: free(userstyle);
1.124 djm 1060: free(p);
1.1 provos 1061: buffer_skip_string(&b); /* service */
1.121 djm 1062: p = buffer_get_cstring(&b, NULL);
1.1 provos 1063: if (strcmp(p, "hostbased") != 0)
1064: fail++;
1.124 djm 1065: free(p);
1.1 provos 1066: buffer_skip_string(&b); /* pkalg */
1067: buffer_skip_string(&b); /* pkblob */
1068:
1069: /* verify client host, strip trailing dot if necessary */
1070: p = buffer_get_string(&b, NULL);
1071: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1072: p[len - 1] = '\0';
1073: if (strcmp(p, chost) != 0)
1074: fail++;
1.124 djm 1075: free(p);
1.1 provos 1076:
1077: /* verify client user */
1078: p = buffer_get_string(&b, NULL);
1079: if (strcmp(p, cuser) != 0)
1080: fail++;
1.124 djm 1081: free(p);
1.1 provos 1082:
1083: if (buffer_len(&b) != 0)
1084: fail++;
1085: buffer_free(&b);
1086: return (fail == 0);
1087: }
1088:
1089: int
1.59 avsm 1090: mm_answer_keyverify(int sock, Buffer *m)
1.1 provos 1091: {
1092: Key *key;
1093: u_char *signature, *data, *blob;
1094: u_int signaturelen, datalen, bloblen;
1095: int verified = 0;
1096: int valid_data = 0;
1097:
1098: blob = buffer_get_string(m, &bloblen);
1099: signature = buffer_get_string(m, &signaturelen);
1100: data = buffer_get_string(m, &datalen);
1101:
1102: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 1103: !monitor_allowed_key(blob, bloblen))
1.14 markus 1104: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1105:
1106: key = key_from_blob(blob, bloblen);
1107: if (key == NULL)
1.14 markus 1108: fatal("%s: bad public key blob", __func__);
1.1 provos 1109:
1110: switch (key_blobtype) {
1111: case MM_USERKEY:
1112: valid_data = monitor_valid_userblob(data, datalen);
1113: break;
1114: case MM_HOSTKEY:
1115: valid_data = monitor_valid_hostbasedblob(data, datalen,
1116: hostbased_cuser, hostbased_chost);
1117: break;
1118: default:
1119: valid_data = 0;
1120: break;
1121: }
1122: if (!valid_data)
1.14 markus 1123: fatal("%s: bad signature data blob", __func__);
1.1 provos 1124:
1125: verified = key_verify(key, signature, signaturelen, data, datalen);
1126: debug3("%s: key %p signature %s",
1.89 markus 1127: __func__, key, (verified == 1) ? "verified" : "unverified");
1.1 provos 1128:
1.136 djm 1129: /* If auth was successful then record key to ensure it isn't reused */
1130: if (verified == 1)
1131: auth2_record_userkey(authctxt, key);
1132: else
1133: key_free(key);
1134:
1.124 djm 1135: free(blob);
1136: free(signature);
1137: free(data);
1.1 provos 1138:
1.17 stevesk 1139: auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1140:
1.1 provos 1141: monitor_reset_key_state();
1.3 markus 1142:
1.1 provos 1143: buffer_clear(m);
1144: buffer_put_int(m, verified);
1.59 avsm 1145: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.1 provos 1146:
1.89 markus 1147: return (verified == 1);
1.1 provos 1148: }
1149:
1.2 markus 1150: static void
1.1 provos 1151: mm_record_login(Session *s, struct passwd *pw)
1152: {
1153: socklen_t fromlen;
1154: struct sockaddr_storage from;
1155:
1156: /*
1157: * Get IP address of client. If the connection is not a socket, let
1158: * the address be 0.0.0.0.
1159: */
1160: memset(&from, 0, sizeof(from));
1.24 stevesk 1161: fromlen = sizeof(from);
1.1 provos 1162: if (packet_connection_is_on_socket()) {
1163: if (getpeername(packet_get_connection_in(),
1.74 deraadt 1164: (struct sockaddr *)&from, &fromlen) < 0) {
1.1 provos 1165: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1166: cleanup_exit(255);
1.1 provos 1167: }
1168: }
1169: /* Record that there was a login on that tty from the remote host. */
1170: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.42 markus 1171: get_remote_name_or_ip(utmp_len, options.use_dns),
1.24 stevesk 1172: (struct sockaddr *)&from, fromlen);
1.1 provos 1173: }
1174:
1175: static void
1176: mm_session_close(Session *s)
1177: {
1.41 djm 1178: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1179: if (s->ttyfd != -1) {
1.86 stevesk 1180: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1181: session_pty_cleanup2(s);
1182: }
1.96 djm 1183: session_unused(s->self);
1.1 provos 1184: }
1185:
1186: int
1.59 avsm 1187: mm_answer_pty(int sock, Buffer *m)
1.1 provos 1188: {
1.11 mouring 1189: extern struct monitor *pmonitor;
1.1 provos 1190: Session *s;
1191: int res, fd0;
1192:
1.14 markus 1193: debug3("%s entering", __func__);
1.1 provos 1194:
1195: buffer_clear(m);
1196: s = session_new();
1197: if (s == NULL)
1198: goto error;
1199: s->authctxt = authctxt;
1200: s->pw = authctxt->pw;
1.11 mouring 1201: s->pid = pmonitor->m_pid;
1.1 provos 1202: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1203: if (res == 0)
1204: goto error;
1205: pty_setowner(authctxt->pw, s->tty);
1206:
1207: buffer_put_int(m, 1);
1208: buffer_put_cstring(m, s->tty);
1209:
1210: /* We need to trick ttyslot */
1211: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1212: fatal("%s: dup2", __func__);
1.1 provos 1213:
1214: mm_record_login(s, authctxt->pw);
1215:
1216: /* Now we can close the file descriptor again */
1217: close(0);
1.61 dtucker 1218:
1219: /* send messages generated by record_login */
1220: buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1221: buffer_clear(&loginmsg);
1222:
1223: mm_request_send(sock, MONITOR_ANS_PTY, m);
1224:
1.92 djm 1225: if (mm_send_fd(sock, s->ptyfd) == -1 ||
1226: mm_send_fd(sock, s->ttyfd) == -1)
1227: fatal("%s: send fds failed", __func__);
1.1 provos 1228:
1229: /* make sure nothing uses fd 0 */
1230: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1231: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1232: if (fd0 != 0)
1.14 markus 1233: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1234:
1235: /* slave is not needed */
1236: close(s->ttyfd);
1237: s->ttyfd = s->ptyfd;
1238: /* no need to dup() because nobody closes ptyfd */
1239: s->ptymaster = s->ptyfd;
1240:
1.86 stevesk 1241: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1242:
1243: return (0);
1244:
1245: error:
1246: if (s != NULL)
1247: mm_session_close(s);
1248: buffer_put_int(m, 0);
1.59 avsm 1249: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1250: return (0);
1251: }
1252:
1253: int
1.59 avsm 1254: mm_answer_pty_cleanup(int sock, Buffer *m)
1.1 provos 1255: {
1256: Session *s;
1257: char *tty;
1258:
1.14 markus 1259: debug3("%s entering", __func__);
1.1 provos 1260:
1261: tty = buffer_get_string(m, NULL);
1262: if ((s = session_by_tty(tty)) != NULL)
1263: mm_session_close(s);
1264: buffer_clear(m);
1.124 djm 1265: free(tty);
1.1 provos 1266: return (0);
1267: }
1268:
1.132 markus 1269: #ifdef WITH_SSH1
1.1 provos 1270: int
1.59 avsm 1271: mm_answer_sesskey(int sock, Buffer *m)
1.1 provos 1272: {
1273: BIGNUM *p;
1274: int rsafail;
1275:
1276: /* Turn off permissions */
1.62 dtucker 1277: monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1.1 provos 1278:
1279: if ((p = BN_new()) == NULL)
1.14 markus 1280: fatal("%s: BN_new", __func__);
1.1 provos 1281:
1282: buffer_get_bignum2(m, p);
1283:
1284: rsafail = ssh1_session_key(p);
1285:
1286: buffer_clear(m);
1287: buffer_put_int(m, rsafail);
1288: buffer_put_bignum2(m, p);
1289:
1290: BN_clear_free(p);
1291:
1.59 avsm 1292: mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1.1 provos 1293:
1294: /* Turn on permissions for sessid passing */
1295: monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1296:
1297: return (0);
1298: }
1299:
1300: int
1.59 avsm 1301: mm_answer_sessid(int sock, Buffer *m)
1.1 provos 1302: {
1303: int i;
1304:
1.14 markus 1305: debug3("%s entering", __func__);
1.1 provos 1306:
1307: if (buffer_len(m) != 16)
1.14 markus 1308: fatal("%s: bad ssh1 session id", __func__);
1.1 provos 1309: for (i = 0; i < 16; i++)
1310: session_id[i] = buffer_get_char(m);
1311:
1312: /* Turn on permissions for getpwnam */
1313: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1314:
1315: return (0);
1316: }
1317:
1318: int
1.59 avsm 1319: mm_answer_rsa_keyallowed(int sock, Buffer *m)
1.1 provos 1320: {
1321: BIGNUM *client_n;
1322: Key *key = NULL;
1.3 markus 1323: u_char *blob = NULL;
1324: u_int blen = 0;
1.1 provos 1325: int allowed = 0;
1326:
1.14 markus 1327: debug3("%s entering", __func__);
1.1 provos 1328:
1.77 dtucker 1329: auth_method = "rsa";
1.12 markus 1330: if (options.rsa_authentication && authctxt->valid) {
1.1 provos 1331: if ((client_n = BN_new()) == NULL)
1.14 markus 1332: fatal("%s: BN_new", __func__);
1.1 provos 1333: buffer_get_bignum2(m, client_n);
1334: allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1335: BN_clear_free(client_n);
1336: }
1337: buffer_clear(m);
1338: buffer_put_int(m, allowed);
1.32 markus 1339: buffer_put_int(m, forced_command != NULL);
1.1 provos 1340:
1341: /* clear temporarily storage (used by generate challenge) */
1342: monitor_reset_key_state();
1343:
1344: if (allowed && key != NULL) {
1345: key->type = KEY_RSA; /* cheat for key_to_blob */
1346: if (key_to_blob(key, &blob, &blen) == 0)
1.14 markus 1347: fatal("%s: key_to_blob failed", __func__);
1.1 provos 1348: buffer_put_string(m, blob, blen);
1349:
1350: /* Save temporarily for comparison in verify */
1351: key_blob = blob;
1352: key_bloblen = blen;
1353: key_blobtype = MM_RSAUSERKEY;
1.33 markus 1354: }
1355: if (key != NULL)
1.1 provos 1356: key_free(key);
1357:
1.59 avsm 1358: mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1.1 provos 1359:
1360: monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1361: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1362: return (0);
1363: }
1364:
1365: int
1.59 avsm 1366: mm_answer_rsa_challenge(int sock, Buffer *m)
1.1 provos 1367: {
1368: Key *key = NULL;
1.3 markus 1369: u_char *blob;
1370: u_int blen;
1.1 provos 1371:
1.14 markus 1372: debug3("%s entering", __func__);
1.1 provos 1373:
1374: if (!authctxt->valid)
1.14 markus 1375: fatal("%s: authctxt not valid", __func__);
1.1 provos 1376: blob = buffer_get_string(m, &blen);
1377: if (!monitor_allowed_key(blob, blen))
1.14 markus 1378: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1379: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1380: fatal("%s: key type mismatch", __func__);
1.1 provos 1381: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1382: fatal("%s: received bad key", __func__);
1.101 djm 1383: if (key->type != KEY_RSA)
1384: fatal("%s: received bad key type %d", __func__, key->type);
1385: key->type = KEY_RSA1;
1.1 provos 1386: if (ssh1_challenge)
1387: BN_clear_free(ssh1_challenge);
1388: ssh1_challenge = auth_rsa_generate_challenge(key);
1389:
1390: buffer_clear(m);
1391: buffer_put_bignum2(m, ssh1_challenge);
1392:
1.14 markus 1393: debug3("%s sending reply", __func__);
1.59 avsm 1394: mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1.1 provos 1395:
1396: monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1.33 markus 1397:
1.124 djm 1398: free(blob);
1.33 markus 1399: key_free(key);
1.1 provos 1400: return (0);
1401: }
1402:
1403: int
1.59 avsm 1404: mm_answer_rsa_response(int sock, Buffer *m)
1.1 provos 1405: {
1406: Key *key = NULL;
1.3 markus 1407: u_char *blob, *response;
1408: u_int blen, len;
1409: int success;
1.1 provos 1410:
1.14 markus 1411: debug3("%s entering", __func__);
1.1 provos 1412:
1413: if (!authctxt->valid)
1.14 markus 1414: fatal("%s: authctxt not valid", __func__);
1.1 provos 1415: if (ssh1_challenge == NULL)
1.14 markus 1416: fatal("%s: no ssh1_challenge", __func__);
1.1 provos 1417:
1418: blob = buffer_get_string(m, &blen);
1419: if (!monitor_allowed_key(blob, blen))
1.14 markus 1420: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1421: if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1.14 markus 1422: fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1.1 provos 1423: if ((key = key_from_blob(blob, blen)) == NULL)
1.14 markus 1424: fatal("%s: received bad key", __func__);
1.1 provos 1425: response = buffer_get_string(m, &len);
1426: if (len != 16)
1.14 markus 1427: fatal("%s: received bad response to challenge", __func__);
1.1 provos 1428: success = auth_rsa_verify_response(key, ssh1_challenge, response);
1429:
1.124 djm 1430: free(blob);
1.1 provos 1431: key_free(key);
1.124 djm 1432: free(response);
1.1 provos 1433:
1434: auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1435:
1436: /* reset state */
1437: BN_clear_free(ssh1_challenge);
1438: ssh1_challenge = NULL;
1439: monitor_reset_key_state();
1440:
1441: buffer_clear(m);
1442: buffer_put_int(m, success);
1.59 avsm 1443: mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1.1 provos 1444:
1445: return (success);
1446: }
1.132 markus 1447: #endif
1.1 provos 1448:
1449: int
1.59 avsm 1450: mm_answer_term(int sock, Buffer *req)
1.1 provos 1451: {
1.11 mouring 1452: extern struct monitor *pmonitor;
1.1 provos 1453: int res, status;
1454:
1.14 markus 1455: debug3("%s: tearing down sessions", __func__);
1.1 provos 1456:
1457: /* The child is terminating */
1458: session_destroy_all(&mm_session_close);
1459:
1.11 mouring 1460: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1461: if (errno != EINTR)
1462: exit(1);
1.1 provos 1463:
1464: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1465:
1466: /* Terminate process */
1.57 deraadt 1467: exit(res);
1.1 provos 1468: }
1469:
1470: void
1.11 mouring 1471: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1472: {
1.139 markus 1473: struct ssh *ssh = active_state; /* XXX */
1474: struct kex *kex;
1475: int r;
1476:
1477: debug3("%s: packet_set_state", __func__);
1478: if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
1479: fatal("%s: packet_set_state: %s", __func__, ssh_err(r));
1480: sshbuf_free(child_state);
1481: child_state = NULL;
1482:
1483: if ((kex = ssh->kex) != 0) {
1484: /* XXX set callbacks */
1485: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1486: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1487: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1488: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1489: kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1490: kex->kex[KEX_C25519_SHA256] = kexc25519_server;
1491: kex->load_host_public_key=&get_hostkey_public_by_type;
1492: kex->load_host_private_key=&get_hostkey_private_by_type;
1493: kex->host_key_index=&get_hostkey_index;
1494: kex->sign = sshd_hostkey_sign;
1495: }
1.3 markus 1496:
1.1 provos 1497: /* Update with new address */
1.139 markus 1498: if (options.compression) {
1499: ssh_packet_set_compress_hooks(ssh, pmonitor->m_zlib,
1500: (ssh_packet_comp_alloc_func *)mm_zalloc,
1501: (ssh_packet_comp_free_func *)mm_zfree);
1502: }
1.1 provos 1503: }
1504:
1505: /* This function requries careful sanity checking */
1506:
1507: void
1.11 mouring 1508: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1509: {
1.14 markus 1510: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1511:
1.139 markus 1512: if ((child_state = sshbuf_new()) == NULL)
1513: fatal("%s: sshbuf_new failed", __func__);
1514: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
1515: child_state);
1516: debug3("%s: GOT new keys", __func__);
1.1 provos 1517: }
1518:
1519:
1520: /* XXX */
1521:
1522: #define FD_CLOSEONEXEC(x) do { \
1.111 djm 1523: if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1.1 provos 1524: fatal("fcntl(%d, F_SETFD)", x); \
1525: } while (0)
1526:
1.2 markus 1527: static void
1.114 djm 1528: monitor_openfds(struct monitor *mon, int do_logfds)
1.3 markus 1529: {
1.114 djm 1530: int pair[2];
1531:
1.1 provos 1532: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.114 djm 1533: fatal("%s: socketpair: %s", __func__, strerror(errno));
1.1 provos 1534: FD_CLOSEONEXEC(pair[0]);
1535: FD_CLOSEONEXEC(pair[1]);
1.114 djm 1536: mon->m_recvfd = pair[0];
1537: mon->m_sendfd = pair[1];
1538:
1539: if (do_logfds) {
1540: if (pipe(pair) == -1)
1541: fatal("%s: pipe: %s", __func__, strerror(errno));
1542: FD_CLOSEONEXEC(pair[0]);
1543: FD_CLOSEONEXEC(pair[1]);
1544: mon->m_log_recvfd = pair[0];
1545: mon->m_log_sendfd = pair[1];
1546: } else
1547: mon->m_log_recvfd = mon->m_log_sendfd = -1;
1.1 provos 1548: }
1549:
1550: #define MM_MEMSIZE 65536
1551:
1552: struct monitor *
1553: monitor_init(void)
1554: {
1.139 markus 1555: struct ssh *ssh = active_state; /* XXX */
1.1 provos 1556: struct monitor *mon;
1557:
1.75 djm 1558: mon = xcalloc(1, sizeof(*mon));
1.1 provos 1559:
1.114 djm 1560: monitor_openfds(mon, 1);
1.1 provos 1561:
1562: /* Used to share zlib space across processes */
1.16 djm 1563: if (options.compression) {
1564: mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1565: mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1.1 provos 1566:
1.16 djm 1567: /* Compression needs to share state across borders */
1.139 markus 1568: ssh_packet_set_compress_hooks(ssh, mon->m_zlib,
1569: (ssh_packet_comp_alloc_func *)mm_zalloc,
1570: (ssh_packet_comp_free_func *)mm_zfree);
1.16 djm 1571: }
1.1 provos 1572:
1573: return mon;
1574: }
1575:
1576: void
1577: monitor_reinit(struct monitor *mon)
1578: {
1.114 djm 1579: monitor_openfds(mon, 0);
1.1 provos 1580: }
1.46 markus 1581:
1582: #ifdef GSSAPI
1583: int
1.59 avsm 1584: mm_answer_gss_setup_ctx(int sock, Buffer *m)
1.46 markus 1585: {
1.59 avsm 1586: gss_OID_desc goid;
1.46 markus 1587: OM_uint32 major;
1588: u_int len;
1589:
1.59 avsm 1590: goid.elements = buffer_get_string(m, &len);
1591: goid.length = len;
1.46 markus 1592:
1.59 avsm 1593: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1594:
1.124 djm 1595: free(goid.elements);
1.46 markus 1596:
1597: buffer_clear(m);
1598: buffer_put_int(m, major);
1599:
1.64 stevesk 1600: mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1.46 markus 1601:
1602: /* Now we have a context, enable the step */
1603: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1604:
1605: return (0);
1606: }
1607:
1608: int
1.59 avsm 1609: mm_answer_gss_accept_ctx(int sock, Buffer *m)
1.46 markus 1610: {
1611: gss_buffer_desc in;
1612: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1.64 stevesk 1613: OM_uint32 major, minor;
1.46 markus 1614: OM_uint32 flags = 0; /* GSI needs this */
1.47 deraadt 1615: u_int len;
1.46 markus 1616:
1.47 deraadt 1617: in.value = buffer_get_string(m, &len);
1618: in.length = len;
1.46 markus 1619: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1.124 djm 1620: free(in.value);
1.46 markus 1621:
1622: buffer_clear(m);
1623: buffer_put_int(m, major);
1624: buffer_put_string(m, out.value, out.length);
1625: buffer_put_int(m, flags);
1.59 avsm 1626: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1627:
1628: gss_release_buffer(&minor, &out);
1629:
1.64 stevesk 1630: if (major == GSS_S_COMPLETE) {
1.46 markus 1631: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1632: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1633: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1634: }
1635: return (0);
1636: }
1637:
1638: int
1.59 avsm 1639: mm_answer_gss_checkmic(int sock, Buffer *m)
1.52 markus 1640: {
1641: gss_buffer_desc gssbuf, mic;
1642: OM_uint32 ret;
1643: u_int len;
1.54 djm 1644:
1.52 markus 1645: gssbuf.value = buffer_get_string(m, &len);
1646: gssbuf.length = len;
1647: mic.value = buffer_get_string(m, &len);
1648: mic.length = len;
1.54 djm 1649:
1.52 markus 1650: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1651:
1.124 djm 1652: free(gssbuf.value);
1653: free(mic.value);
1.54 djm 1654:
1.52 markus 1655: buffer_clear(m);
1656: buffer_put_int(m, ret);
1.54 djm 1657:
1.59 avsm 1658: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1659:
1.52 markus 1660: if (!GSS_ERROR(ret))
1661: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1662:
1.52 markus 1663: return (0);
1664: }
1665:
1666: int
1.59 avsm 1667: mm_answer_gss_userok(int sock, Buffer *m)
1.46 markus 1668: {
1669: int authenticated;
1670:
1671: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1672:
1673: buffer_clear(m);
1674: buffer_put_int(m, authenticated);
1675:
1676: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1677: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1678:
1.64 stevesk 1679: auth_method = "gssapi-with-mic";
1.46 markus 1680:
1681: /* Monitor loop will terminate if authenticated */
1682: return (authenticated);
1683: }
1684: #endif /* GSSAPI */
1.100 djm 1685:
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