Annotation of src/usr.bin/ssh/monitor.c, Revision 1.174
1.174 ! djm 1: /* $OpenBSD: monitor.c,v 1.173 2017/09/12 06:32:07 djm Exp $ */
1.1 provos 2: /*
3: * Copyright 2002 Niels Provos <provos@citi.umich.edu>
4: * Copyright 2002 Markus Friedl <markus@openbsd.org>
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26: */
27:
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>
1.159 djm 40: #include <limits.h>
1.65 stevesk 41: #include <paths.h>
1.114 djm 42: #include <poll.h>
1.78 stevesk 43: #include <pwd.h>
1.68 stevesk 44: #include <signal.h>
1.134 djm 45: #include <stdarg.h>
1.142 millert 46: #include <stdint.h>
1.134 djm 47: #include <stdio.h>
1.84 stevesk 48: #include <stdlib.h>
1.82 stevesk 49: #include <string.h>
1.1 provos 50:
1.114 djm 51: #include "atomicio.h"
1.85 deraadt 52: #include "xmalloc.h"
1.1 provos 53: #include "ssh.h"
1.85 deraadt 54: #include "key.h"
55: #include "buffer.h"
56: #include "hostfile.h"
1.1 provos 57: #include "auth.h"
1.85 deraadt 58: #include "cipher.h"
1.1 provos 59: #include "kex.h"
60: #include "dh.h"
1.88 miod 61: #include <zlib.h>
1.1 provos 62: #include "packet.h"
63: #include "auth-options.h"
64: #include "sshpty.h"
65: #include "channels.h"
66: #include "session.h"
67: #include "sshlogin.h"
68: #include "canohost.h"
69: #include "log.h"
1.135 millert 70: #include "misc.h"
1.1 provos 71: #include "servconf.h"
72: #include "monitor.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"
1.127 markus 80: #include "authfd.h"
1.137 djm 81: #include "match.h"
1.138 djm 82: #include "ssherr.h"
1.1 provos 83:
1.46 markus 84: #ifdef GSSAPI
85: static Gssctxt *gsscontext = NULL;
86: #endif
87:
1.1 provos 88: /* Imports */
89: extern ServerOptions options;
90: extern u_int utmp_len;
91: extern u_char session_id[];
92: extern Buffer auth_debug;
93: extern int auth_debug_init;
1.61 dtucker 94: extern Buffer loginmsg;
1.1 provos 95:
96: /* State exported from the child */
1.139 markus 97: static struct sshbuf *child_state;
1.1 provos 98:
1.43 markus 99: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 100:
101: int mm_answer_moduli(int, Buffer *);
102: int mm_answer_sign(int, Buffer *);
103: int mm_answer_pwnamallow(int, Buffer *);
1.10 djm 104: int mm_answer_auth2_read_banner(int, Buffer *);
1.1 provos 105: int mm_answer_authserv(int, Buffer *);
106: int mm_answer_authpassword(int, Buffer *);
107: int mm_answer_bsdauthquery(int, Buffer *);
108: int mm_answer_bsdauthrespond(int, Buffer *);
109: int mm_answer_skeyquery(int, Buffer *);
110: int mm_answer_skeyrespond(int, Buffer *);
111: int mm_answer_keyallowed(int, Buffer *);
112: int mm_answer_keyverify(int, Buffer *);
113: int mm_answer_pty(int, Buffer *);
114: int mm_answer_pty_cleanup(int, Buffer *);
115: int mm_answer_term(int, Buffer *);
116: int mm_answer_rsa_keyallowed(int, Buffer *);
117: int mm_answer_rsa_challenge(int, Buffer *);
118: int mm_answer_rsa_response(int, Buffer *);
119: int mm_answer_sesskey(int, Buffer *);
120: int mm_answer_sessid(int, Buffer *);
121:
1.46 markus 122: #ifdef GSSAPI
123: int mm_answer_gss_setup_ctx(int, Buffer *);
124: int mm_answer_gss_accept_ctx(int, Buffer *);
125: int mm_answer_gss_userok(int, Buffer *);
1.52 markus 126: int mm_answer_gss_checkmic(int, Buffer *);
1.46 markus 127: #endif
1.25 itojun 128:
1.114 djm 129: static int monitor_read_log(struct monitor *);
130:
1.1 provos 131: static Authctxt *authctxt;
1.132 markus 132:
1.1 provos 133: /* local state for key verify */
134: static u_char *key_blob = NULL;
135: static u_int key_bloblen = 0;
136: static int key_blobtype = MM_NOKEY;
1.26 markus 137: static char *hostbased_cuser = NULL;
138: static char *hostbased_chost = NULL;
1.1 provos 139: static char *auth_method = "unknown";
1.119 djm 140: static char *auth_submethod = NULL;
1.44 markus 141: static u_int session_id2_len = 0;
1.13 markus 142: static u_char *session_id2 = NULL;
1.40 markus 143: static pid_t monitor_child_pid;
1.1 provos 144:
145: struct mon_table {
146: enum monitor_reqtype type;
147: int flags;
148: int (*f)(int, Buffer *);
149: };
150:
151: #define MON_ISAUTH 0x0004 /* Required for Authentication */
152: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
153: #define MON_ONCE 0x0010 /* Disable after calling */
1.77 dtucker 154: #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
1.1 provos 155:
156: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
157:
158: #define MON_PERMIT 0x1000 /* Request is permitted */
159:
160: struct mon_table mon_dispatch_proto20[] = {
1.132 markus 161: #ifdef WITH_OPENSSL
1.1 provos 162: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
1.132 markus 163: #endif
1.1 provos 164: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
165: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
166: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 167: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 168: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
169: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 170: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 171: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
172: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 173: #ifdef GSSAPI
174: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
1.165 djm 175: {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
176: {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
177: {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
1.46 markus 178: #endif
1.1 provos 179: {0, 0, NULL}
180: };
181:
182: struct mon_table mon_dispatch_postauth20[] = {
1.132 markus 183: #ifdef WITH_OPENSSL
1.1 provos 184: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
1.132 markus 185: #endif
1.1 provos 186: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
187: {MONITOR_REQ_PTY, 0, mm_answer_pty},
188: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
189: {MONITOR_REQ_TERM, 0, mm_answer_term},
190: {0, 0, NULL}
191: };
192:
193: struct mon_table *mon_dispatch;
194:
195: /* Specifies if a certain message is allowed at the moment */
196:
197: static void
198: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
199: {
200: while (ent->f != NULL) {
201: if (ent->type == type) {
202: ent->flags &= ~MON_PERMIT;
203: ent->flags |= permit ? MON_PERMIT : 0;
204: return;
205: }
206: ent++;
207: }
208: }
209:
210: static void
211: monitor_permit_authentications(int permit)
212: {
213: struct mon_table *ent = mon_dispatch;
214:
215: while (ent->f != NULL) {
216: if (ent->flags & MON_AUTH) {
217: ent->flags &= ~MON_PERMIT;
218: ent->flags |= permit ? MON_PERMIT : 0;
219: }
220: ent++;
221: }
222: }
223:
1.50 markus 224: void
225: monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
1.1 provos 226: {
1.167 djm 227: struct ssh *ssh = active_state; /* XXX */
1.1 provos 228: struct mon_table *ent;
1.119 djm 229: int authenticated = 0, partial = 0;
1.1 provos 230:
231: debug3("preauth child monitor started");
232:
1.114 djm 233: close(pmonitor->m_recvfd);
234: close(pmonitor->m_log_sendfd);
235: pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
236:
1.50 markus 237: authctxt = _authctxt;
238: memset(authctxt, 0, sizeof(*authctxt));
239:
1.162 markus 240: mon_dispatch = mon_dispatch_proto20;
241: /* Permit requests for moduli and signatures */
242: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
243: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
1.1 provos 244:
245: /* The first few requests do not require asynchronous access */
246: while (!authenticated) {
1.119 djm 247: partial = 0;
1.77 dtucker 248: auth_method = "unknown";
1.119 djm 249: auth_submethod = NULL;
1.172 djm 250: auth2_authctxt_reset_info(authctxt);
251:
1.89 markus 252: authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
1.118 djm 253:
254: /* Special handling for multiple required authentications */
255: if (options.num_auth_methods != 0) {
256: if (authenticated &&
257: !auth2_update_methods_lists(authctxt,
1.122 markus 258: auth_method, auth_submethod)) {
1.118 djm 259: debug3("%s: method %s: partial", __func__,
260: auth_method);
261: authenticated = 0;
1.119 djm 262: partial = 1;
1.118 djm 263: }
264: }
265:
1.1 provos 266: if (authenticated) {
267: if (!(ent->flags & MON_AUTHDECIDE))
268: fatal("%s: unexpected authentication from %d",
1.14 markus 269: __func__, ent->type);
1.1 provos 270: if (authctxt->pw->pw_uid == 0 &&
271: !auth_root_allowed(auth_method))
272: authenticated = 0;
273: }
1.77 dtucker 274: if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
1.119 djm 275: auth_log(authctxt, authenticated, partial,
1.125 djm 276: auth_method, auth_submethod);
1.150 djm 277: if (!partial && !authenticated)
1.1 provos 278: authctxt->failures++;
1.172 djm 279: if (authenticated || partial) {
280: auth2_update_session_info(authctxt,
281: auth_method, auth_submethod);
282: }
1.1 provos 283: }
284: }
285:
286: if (!authctxt->valid)
1.14 markus 287: fatal("%s: authenticated invalid user", __func__);
1.77 dtucker 288: if (strcmp(auth_method, "unknown") == 0)
289: fatal("%s: authentication method name unknown", __func__);
1.1 provos 290:
291: debug("%s: %s has been authenticated by privileged process",
1.14 markus 292: __func__, authctxt->user);
1.167 djm 293: ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
1.1 provos 294:
1.11 mouring 295: mm_get_keystate(pmonitor);
1.120 markus 296:
297: /* Drain any buffered messages from the child */
298: while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
299: ;
1.114 djm 300:
301: close(pmonitor->m_sendfd);
302: close(pmonitor->m_log_recvfd);
303: pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
1.1 provos 304: }
305:
1.40 markus 306: static void
307: monitor_set_child_handler(pid_t pid)
308: {
309: monitor_child_pid = pid;
310: }
311:
312: static void
1.59 avsm 313: monitor_child_handler(int sig)
1.40 markus 314: {
1.59 avsm 315: kill(monitor_child_pid, sig);
1.40 markus 316: }
317:
1.1 provos 318: void
1.11 mouring 319: monitor_child_postauth(struct monitor *pmonitor)
1.1 provos 320: {
1.114 djm 321: close(pmonitor->m_recvfd);
322: pmonitor->m_recvfd = -1;
323:
1.40 markus 324: monitor_set_child_handler(pmonitor->m_pid);
325: signal(SIGHUP, &monitor_child_handler);
326: signal(SIGTERM, &monitor_child_handler);
1.91 djm 327: signal(SIGINT, &monitor_child_handler);
1.40 markus 328:
1.162 markus 329: mon_dispatch = mon_dispatch_postauth20;
330:
331: /* Permit requests for moduli and signatures */
332: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
333: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
334: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
1.1 provos 335:
336: if (!no_pty_flag) {
337: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
338: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
339: }
340:
341: for (;;)
1.11 mouring 342: monitor_read(pmonitor, mon_dispatch, NULL);
1.1 provos 343: }
344:
1.114 djm 345: static int
346: monitor_read_log(struct monitor *pmonitor)
347: {
348: Buffer logmsg;
349: u_int len, level;
350: char *msg;
351:
352: buffer_init(&logmsg);
353:
354: /* Read length */
355: buffer_append_space(&logmsg, 4);
356: if (atomicio(read, pmonitor->m_log_recvfd,
357: buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
358: if (errno == EPIPE) {
1.116 djm 359: buffer_free(&logmsg);
1.114 djm 360: debug("%s: child log fd closed", __func__);
361: close(pmonitor->m_log_recvfd);
362: pmonitor->m_log_recvfd = -1;
363: return -1;
364: }
365: fatal("%s: log fd read: %s", __func__, strerror(errno));
366: }
367: len = buffer_get_int(&logmsg);
368: if (len <= 4 || len > 8192)
369: fatal("%s: invalid log message length %u", __func__, len);
370:
371: /* Read severity, message */
372: buffer_clear(&logmsg);
373: buffer_append_space(&logmsg, len);
374: if (atomicio(read, pmonitor->m_log_recvfd,
375: buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
376: fatal("%s: log fd read: %s", __func__, strerror(errno));
377:
378: /* Log it */
379: level = buffer_get_int(&logmsg);
380: msg = buffer_get_string(&logmsg, NULL);
381: if (log_level_name(level) == NULL)
382: fatal("%s: invalid log level %u (corrupted message?)",
383: __func__, level);
384: do_log2(level, "%s [preauth]", msg);
385:
386: buffer_free(&logmsg);
1.124 djm 387: free(msg);
1.114 djm 388:
389: return 0;
390: }
391:
1.1 provos 392: int
1.11 mouring 393: monitor_read(struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 394: struct mon_table **pent)
395: {
396: Buffer m;
397: int ret;
398: u_char type;
1.114 djm 399: struct pollfd pfd[2];
400:
401: for (;;) {
1.130 tedu 402: memset(&pfd, 0, sizeof(pfd));
1.114 djm 403: pfd[0].fd = pmonitor->m_sendfd;
404: pfd[0].events = POLLIN;
405: pfd[1].fd = pmonitor->m_log_recvfd;
406: pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
1.115 djm 407: if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
408: if (errno == EINTR || errno == EAGAIN)
409: continue;
1.114 djm 410: fatal("%s: poll: %s", __func__, strerror(errno));
1.115 djm 411: }
1.114 djm 412: if (pfd[1].revents) {
413: /*
414: * Drain all log messages before processing next
415: * monitor request.
416: */
417: monitor_read_log(pmonitor);
418: continue;
419: }
420: if (pfd[0].revents)
421: break; /* Continues below */
422: }
1.1 provos 423:
424: buffer_init(&m);
425:
1.11 mouring 426: mm_request_receive(pmonitor->m_sendfd, &m);
1.1 provos 427: type = buffer_get_char(&m);
428:
1.14 markus 429: debug3("%s: checking request %d", __func__, type);
1.1 provos 430:
431: while (ent->f != NULL) {
432: if (ent->type == type)
433: break;
434: ent++;
435: }
436:
437: if (ent->f != NULL) {
438: if (!(ent->flags & MON_PERMIT))
1.14 markus 439: fatal("%s: unpermitted request %d", __func__,
1.1 provos 440: type);
1.11 mouring 441: ret = (*ent->f)(pmonitor->m_sendfd, &m);
1.1 provos 442: buffer_free(&m);
443:
444: /* The child may use this request only once, disable it */
445: if (ent->flags & MON_ONCE) {
1.14 markus 446: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 447: type);
448: ent->flags &= ~MON_PERMIT;
449: }
450:
451: if (pent != NULL)
452: *pent = ent;
1.3 markus 453:
1.1 provos 454: return ret;
455: }
456:
1.14 markus 457: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 458:
459: /* NOTREACHED */
460: return (-1);
461: }
462:
463: /* allowed key state */
464: static int
465: monitor_allowed_key(u_char *blob, u_int bloblen)
466: {
467: /* make sure key is allowed */
468: if (key_blob == NULL || key_bloblen != bloblen ||
1.108 djm 469: timingsafe_bcmp(key_blob, blob, key_bloblen))
1.1 provos 470: return (0);
471: return (1);
472: }
473:
474: static void
475: monitor_reset_key_state(void)
476: {
477: /* reset state */
1.124 djm 478: free(key_blob);
479: free(hostbased_cuser);
480: free(hostbased_chost);
1.1 provos 481: key_blob = NULL;
482: key_bloblen = 0;
483: key_blobtype = MM_NOKEY;
484: hostbased_cuser = NULL;
485: hostbased_chost = NULL;
486: }
487:
1.132 markus 488: #ifdef WITH_OPENSSL
1.1 provos 489: int
1.59 avsm 490: mm_answer_moduli(int sock, Buffer *m)
1.1 provos 491: {
492: DH *dh;
493: int min, want, max;
494:
495: min = buffer_get_int(m);
496: want = buffer_get_int(m);
497: max = buffer_get_int(m);
498:
499: debug3("%s: got parameters: %d %d %d",
1.14 markus 500: __func__, min, want, max);
1.1 provos 501: /* We need to check here, too, in case the child got corrupted */
502: if (max < min || want < min || max < want)
503: fatal("%s: bad parameters: %d %d %d",
1.14 markus 504: __func__, min, want, max);
1.1 provos 505:
506: buffer_clear(m);
507:
508: dh = choose_dh(min, want, max);
509: if (dh == NULL) {
510: buffer_put_char(m, 0);
511: return (0);
512: } else {
513: /* Send first bignum */
514: buffer_put_char(m, 1);
515: buffer_put_bignum2(m, dh->p);
516: buffer_put_bignum2(m, dh->g);
1.3 markus 517:
1.1 provos 518: DH_free(dh);
519: }
1.59 avsm 520: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 521: return (0);
522: }
1.132 markus 523: #endif
1.1 provos 524:
525: int
1.59 avsm 526: mm_answer_sign(int sock, Buffer *m)
1.1 provos 527: {
1.144 djm 528: struct ssh *ssh = active_state; /* XXX */
1.138 djm 529: extern int auth_sock; /* XXX move to state struct? */
530: struct sshkey *key;
1.157 djm 531: struct sshbuf *sigbuf = NULL;
532: u_char *p = NULL, *signature = NULL;
533: char *alg = NULL;
1.155 markus 534: size_t datlen, siglen, alglen;
1.159 djm 535: int r, is_proof = 0;
536: u_int keyid;
1.145 djm 537: const char proof_req[] = "hostkeys-prove-00@openssh.com";
1.3 markus 538:
1.14 markus 539: debug3("%s", __func__);
1.1 provos 540:
1.138 djm 541: if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
1.155 markus 542: (r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
543: (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0)
1.138 djm 544: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.159 djm 545: if (keyid > INT_MAX)
546: fatal("%s: invalid key ID", __func__);
1.1 provos 547:
1.69 djm 548: /*
1.110 djm 549: * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
550: * SHA384 (48 bytes) and SHA512 (64 bytes).
1.144 djm 551: *
552: * Otherwise, verify the signature request is for a hostkey
553: * proof.
554: *
555: * XXX perform similar check for KEX signature requests too?
556: * it's not trivial, since what is signed is the hash, rather
557: * than the full kex structure...
1.69 djm 558: */
1.144 djm 559: if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
560: /*
561: * Construct expected hostkey proof and compare it to what
562: * the client sent us.
563: */
564: if (session_id2_len == 0) /* hostkeys is never first */
565: fatal("%s: bad data length: %zu", __func__, datlen);
566: if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
567: fatal("%s: no hostkey for index %d", __func__, keyid);
568: if ((sigbuf = sshbuf_new()) == NULL)
569: fatal("%s: sshbuf_new", __func__);
1.145 djm 570: if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
571: (r = sshbuf_put_string(sigbuf, session_id2,
1.152 jsg 572: session_id2_len)) != 0 ||
1.144 djm 573: (r = sshkey_puts(key, sigbuf)) != 0)
574: fatal("%s: couldn't prepare private key "
575: "proof buffer: %s", __func__, ssh_err(r));
576: if (datlen != sshbuf_len(sigbuf) ||
577: memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
578: fatal("%s: bad data length: %zu, hostkey proof len %zu",
579: __func__, datlen, sshbuf_len(sigbuf));
580: sshbuf_free(sigbuf);
581: is_proof = 1;
582: }
1.1 provos 583:
1.13 markus 584: /* save session id, it will be passed on the first call */
585: if (session_id2_len == 0) {
586: session_id2_len = datlen;
587: session_id2 = xmalloc(session_id2_len);
588: memcpy(session_id2, p, session_id2_len);
589: }
590:
1.127 markus 591: if ((key = get_hostkey_by_index(keyid)) != NULL) {
1.155 markus 592: if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg,
1.138 djm 593: datafellows)) != 0)
594: fatal("%s: sshkey_sign failed: %s",
595: __func__, ssh_err(r));
1.144 djm 596: } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
1.138 djm 597: auth_sock > 0) {
598: if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
1.155 markus 599: p, datlen, alg, datafellows)) != 0) {
1.138 djm 600: fatal("%s: ssh_agent_sign failed: %s",
601: __func__, ssh_err(r));
602: }
1.127 markus 603: } else
1.14 markus 604: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 605:
1.144 djm 606: debug3("%s: %s signature %p(%zu)", __func__,
607: is_proof ? "KEX" : "hostkey proof", signature, siglen);
1.1 provos 608:
1.138 djm 609: sshbuf_reset(m);
610: if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
611: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 612:
1.157 djm 613: free(alg);
1.124 djm 614: free(p);
615: free(signature);
1.1 provos 616:
1.59 avsm 617: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 618:
619: /* Turn on permissions for getpwnam */
620: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
621:
622: return (0);
623: }
624:
625: /* Retrieves the password entry and also checks if the user is permitted */
626:
627: int
1.59 avsm 628: mm_answer_pwnamallow(int sock, Buffer *m)
1.1 provos 629: {
1.167 djm 630: struct ssh *ssh = active_state; /* XXX */
1.60 dtucker 631: char *username;
1.1 provos 632: struct passwd *pwent;
633: int allowed = 0;
1.113 djm 634: u_int i;
1.3 markus 635:
1.14 markus 636: debug3("%s", __func__);
1.1 provos 637:
638: if (authctxt->attempt++ != 0)
1.14 markus 639: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 640:
1.60 dtucker 641: username = buffer_get_string(m, NULL);
1.1 provos 642:
1.60 dtucker 643: pwent = getpwnamallow(username);
1.1 provos 644:
1.60 dtucker 645: authctxt->user = xstrdup(username);
646: setproctitle("%s [priv]", pwent ? username : "unknown");
1.124 djm 647: free(username);
1.1 provos 648:
649: buffer_clear(m);
650:
651: if (pwent == NULL) {
652: buffer_put_char(m, 0);
1.53 djm 653: authctxt->pw = fakepw();
1.1 provos 654: goto out;
655: }
656:
657: allowed = 1;
1.4 markus 658: authctxt->pw = pwent;
1.1 provos 659: authctxt->valid = 1;
660:
661: buffer_put_char(m, 1);
662: buffer_put_string(m, pwent, sizeof(struct passwd));
663: buffer_put_cstring(m, pwent->pw_name);
664: buffer_put_cstring(m, "*");
665: buffer_put_cstring(m, pwent->pw_gecos);
666: buffer_put_cstring(m, pwent->pw_class);
667: buffer_put_cstring(m, pwent->pw_dir);
668: buffer_put_cstring(m, pwent->pw_shell);
1.94 dtucker 669:
670: out:
1.167 djm 671: ssh_packet_set_log_preamble(ssh, "%suser %s",
672: authctxt->valid ? "authenticating" : "invalid ", authctxt->user);
1.90 dtucker 673: buffer_put_string(m, &options, sizeof(options));
1.112 djm 674:
675: #define M_CP_STROPT(x) do { \
676: if (options.x != NULL) \
677: buffer_put_cstring(m, options.x); \
678: } while (0)
1.113 djm 679: #define M_CP_STRARRAYOPT(x, nx) do { \
680: for (i = 0; i < options.nx; i++) \
681: buffer_put_cstring(m, options.x[i]); \
682: } while (0)
1.174 ! djm 683: #define M_CP_STRARRAYOPT_ALLOC(x, nx) M_CP_STRARRAYOPT(x, nx)
1.112 djm 684: /* See comment in servconf.h */
685: COPY_MATCH_STRING_OPTS();
686: #undef M_CP_STROPT
1.113 djm 687: #undef M_CP_STRARRAYOPT
1.174 ! djm 688: #undef M_CP_STRARRAYOPT_ALLOC
1.118 djm 689:
690: /* Create valid auth method lists */
1.162 markus 691: if (auth2_setup_methods_lists(authctxt) != 0) {
1.118 djm 692: /*
693: * The monitor will continue long enough to let the child
694: * run to it's packet_disconnect(), but it must not allow any
695: * authentication to succeed.
696: */
697: debug("%s: no valid authentication method lists", __func__);
698: }
699:
1.14 markus 700: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 701: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 702:
1.162 markus 703: /* Allow service/style information on the auth context */
704: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
705: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
1.10 djm 706:
707: return (0);
708: }
709:
1.59 avsm 710: int mm_answer_auth2_read_banner(int sock, Buffer *m)
1.10 djm 711: {
712: char *banner;
713:
714: buffer_clear(m);
715: banner = auth2_read_banner();
716: buffer_put_cstring(m, banner != NULL ? banner : "");
1.59 avsm 717: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.124 djm 718: free(banner);
1.1 provos 719:
720: return (0);
721: }
722:
723: int
1.59 avsm 724: mm_answer_authserv(int sock, Buffer *m)
1.1 provos 725: {
726: monitor_permit_authentications(1);
727:
728: authctxt->service = buffer_get_string(m, NULL);
729: authctxt->style = buffer_get_string(m, NULL);
1.6 stevesk 730: debug3("%s: service=%s, style=%s",
1.14 markus 731: __func__, authctxt->service, authctxt->style);
1.6 stevesk 732:
1.1 provos 733: if (strlen(authctxt->style) == 0) {
1.124 djm 734: free(authctxt->style);
1.1 provos 735: authctxt->style = NULL;
736: }
737:
738: return (0);
739: }
740:
741: int
1.59 avsm 742: mm_answer_authpassword(int sock, Buffer *m)
1.1 provos 743: {
744: static int call_count;
745: char *passwd;
1.22 stevesk 746: int authenticated;
747: u_int plen;
1.1 provos 748:
1.164 djm 749: if (!options.password_authentication)
750: fatal("%s: password authentication not enabled", __func__);
1.1 provos 751: passwd = buffer_get_string(m, &plen);
752: /* Only authenticate if the context is valid */
1.12 markus 753: authenticated = options.password_authentication &&
1.48 markus 754: auth_password(authctxt, passwd);
1.131 djm 755: explicit_bzero(passwd, strlen(passwd));
1.124 djm 756: free(passwd);
1.1 provos 757:
758: buffer_clear(m);
759: buffer_put_int(m, authenticated);
760:
1.14 markus 761: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 762: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 763:
764: call_count++;
765: if (plen == 0 && call_count == 1)
766: auth_method = "none";
767: else
768: auth_method = "password";
769:
770: /* Causes monitor loop to terminate if authenticated */
771: return (authenticated);
772: }
773:
774: int
1.59 avsm 775: mm_answer_bsdauthquery(int sock, Buffer *m)
1.1 provos 776: {
777: char *name, *infotxt;
778: u_int numprompts;
779: u_int *echo_on;
780: char **prompts;
1.31 markus 781: u_int success;
1.1 provos 782:
1.164 djm 783: if (!options.kbd_interactive_authentication)
784: fatal("%s: kbd-int authentication not enabled", __func__);
1.31 markus 785: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
786: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 787:
788: buffer_clear(m);
1.31 markus 789: buffer_put_int(m, success);
790: if (success)
1.1 provos 791: buffer_put_cstring(m, prompts[0]);
792:
1.31 markus 793: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 794: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 795:
1.31 markus 796: if (success) {
1.124 djm 797: free(name);
798: free(infotxt);
799: free(prompts);
800: free(echo_on);
1.1 provos 801: }
802:
803: return (0);
804: }
805:
806: int
1.59 avsm 807: mm_answer_bsdauthrespond(int sock, Buffer *m)
1.1 provos 808: {
809: char *response;
810: int authok;
811:
1.164 djm 812: if (!options.kbd_interactive_authentication)
813: fatal("%s: kbd-int authentication not enabled", __func__);
1.154 mmcc 814: if (authctxt->as == NULL)
1.14 markus 815: fatal("%s: no bsd auth session", __func__);
1.1 provos 816:
817: response = buffer_get_string(m, NULL);
1.12 markus 818: authok = options.challenge_response_authentication &&
819: auth_userresponse(authctxt->as, response, 0);
1.1 provos 820: authctxt->as = NULL;
1.14 markus 821: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.124 djm 822: free(response);
1.1 provos 823:
824: buffer_clear(m);
825: buffer_put_int(m, authok);
826:
1.14 markus 827: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 828: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 829:
1.162 markus 830: auth_method = "keyboard-interactive";
831: auth_submethod = "bsdauth";
1.1 provos 832:
833: return (authok != 0);
834: }
835:
836: int
1.59 avsm 837: mm_answer_keyallowed(int sock, Buffer *m)
1.1 provos 838: {
1.168 markus 839: struct sshkey *key;
1.26 markus 840: char *cuser, *chost;
841: u_char *blob;
1.148 djm 842: u_int bloblen, pubkey_auth_attempt;
1.1 provos 843: enum mm_keytype type = 0;
844: int allowed = 0;
845:
1.14 markus 846: debug3("%s entering", __func__);
1.3 markus 847:
1.1 provos 848: type = buffer_get_int(m);
849: cuser = buffer_get_string(m, NULL);
850: chost = buffer_get_string(m, NULL);
851: blob = buffer_get_string(m, &bloblen);
1.148 djm 852: pubkey_auth_attempt = buffer_get_int(m);
1.1 provos 853:
854: key = key_from_blob(blob, bloblen);
855:
1.14 markus 856: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 857:
1.51 djm 858: if (key != NULL && authctxt->valid) {
1.137 djm 859: /* These should not make it past the privsep child */
860: if (key_type_plain(key->type) == KEY_RSA &&
861: (datafellows & SSH_BUG_RSASIGMD5) != 0)
862: fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
863:
1.63 deraadt 864: switch (type) {
1.1 provos 865: case MM_USERKEY:
1.12 markus 866: allowed = options.pubkey_authentication &&
1.172 djm 867: !auth2_key_already_used(authctxt, key) &&
1.137 djm 868: match_pattern_list(sshkey_ssh_name(key),
1.149 djm 869: options.pubkey_key_types, 0) == 1 &&
1.148 djm 870: user_key_allowed(authctxt->pw, key,
871: pubkey_auth_attempt);
1.77 dtucker 872: auth_method = "publickey";
1.148 djm 873: if (options.pubkey_authentication &&
874: (!pubkey_auth_attempt || allowed != 1))
1.97 dtucker 875: auth_clear_options();
1.1 provos 876: break;
877: case MM_HOSTKEY:
1.12 markus 878: allowed = options.hostbased_authentication &&
1.172 djm 879: !auth2_key_already_used(authctxt, key) &&
1.137 djm 880: match_pattern_list(sshkey_ssh_name(key),
1.149 djm 881: options.hostbased_key_types, 0) == 1 &&
1.12 markus 882: hostbased_key_allowed(authctxt->pw,
1.1 provos 883: cuser, chost, key);
1.172 djm 884: auth2_record_info(authctxt,
1.126 djm 885: "client user \"%.100s\", client host \"%.100s\"",
886: cuser, chost);
1.77 dtucker 887: auth_method = "hostbased";
1.1 provos 888: break;
889: default:
1.14 markus 890: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 891: break;
892: }
1.33 markus 893: }
1.161 djm 894:
1.172 djm 895: debug3("%s: key is %s", __func__, allowed ? "allowed" : "not allowed");
1.161 djm 896:
1.172 djm 897: auth2_record_key(authctxt, 0, key);
898: sshkey_free(key);
1.1 provos 899:
900: /* clear temporarily storage (used by verify) */
901: monitor_reset_key_state();
902:
903: if (allowed) {
904: /* Save temporarily for comparison in verify */
905: key_blob = blob;
906: key_bloblen = bloblen;
907: key_blobtype = type;
908: hostbased_cuser = cuser;
909: hostbased_chost = chost;
1.72 djm 910: } else {
1.77 dtucker 911: /* Log failed attempt */
1.125 djm 912: auth_log(authctxt, 0, 0, auth_method, NULL);
1.124 djm 913: free(blob);
914: free(cuser);
915: free(chost);
1.1 provos 916: }
917:
918: buffer_clear(m);
919: buffer_put_int(m, allowed);
1.32 markus 920: buffer_put_int(m, forced_command != NULL);
1.1 provos 921:
1.59 avsm 922: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 923:
924: return (0);
925: }
926:
927: static int
928: monitor_valid_userblob(u_char *data, u_int datalen)
929: {
930: Buffer b;
1.159 djm 931: u_char *p;
932: char *userstyle, *cp;
1.1 provos 933: u_int len;
934: int fail = 0;
935:
936: buffer_init(&b);
937: buffer_append(&b, data, datalen);
1.3 markus 938:
1.1 provos 939: if (datafellows & SSH_OLD_SESSIONID) {
1.13 markus 940: p = buffer_ptr(&b);
941: len = buffer_len(&b);
942: if ((session_id2 == NULL) ||
943: (len < session_id2_len) ||
1.108 djm 944: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.13 markus 945: fail++;
1.1 provos 946: buffer_consume(&b, session_id2_len);
947: } else {
1.13 markus 948: p = buffer_get_string(&b, &len);
949: if ((session_id2 == NULL) ||
950: (len != session_id2_len) ||
1.108 djm 951: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 952: fail++;
1.124 djm 953: free(p);
1.1 provos 954: }
955: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
956: fail++;
1.159 djm 957: cp = buffer_get_cstring(&b, NULL);
1.121 djm 958: xasprintf(&userstyle, "%s%s%s", authctxt->user,
959: authctxt->style ? ":" : "",
960: authctxt->style ? authctxt->style : "");
1.159 djm 961: if (strcmp(userstyle, cp) != 0) {
962: logit("wrong user name passed to monitor: "
963: "expected %s != %.100s", userstyle, cp);
1.1 provos 964: fail++;
965: }
1.124 djm 966: free(userstyle);
1.159 djm 967: free(cp);
1.1 provos 968: buffer_skip_string(&b);
969: if (datafellows & SSH_BUG_PKAUTH) {
970: if (!buffer_get_char(&b))
971: fail++;
972: } else {
1.159 djm 973: cp = buffer_get_cstring(&b, NULL);
974: if (strcmp("publickey", cp) != 0)
1.1 provos 975: fail++;
1.159 djm 976: free(cp);
1.1 provos 977: if (!buffer_get_char(&b))
978: fail++;
979: buffer_skip_string(&b);
980: }
981: buffer_skip_string(&b);
982: if (buffer_len(&b) != 0)
983: fail++;
984: buffer_free(&b);
985: return (fail == 0);
986: }
987:
988: static int
1.26 markus 989: monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
990: char *chost)
1.1 provos 991: {
992: Buffer b;
1.121 djm 993: char *p, *userstyle;
1.1 provos 994: u_int len;
995: int fail = 0;
996:
997: buffer_init(&b);
998: buffer_append(&b, data, datalen);
1.3 markus 999:
1.13 markus 1000: p = buffer_get_string(&b, &len);
1001: if ((session_id2 == NULL) ||
1002: (len != session_id2_len) ||
1.108 djm 1003: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 1004: fail++;
1.124 djm 1005: free(p);
1.13 markus 1006:
1.1 provos 1007: if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1008: fail++;
1.121 djm 1009: p = buffer_get_cstring(&b, NULL);
1010: xasprintf(&userstyle, "%s%s%s", authctxt->user,
1011: authctxt->style ? ":" : "",
1012: authctxt->style ? authctxt->style : "");
1013: if (strcmp(userstyle, p) != 0) {
1.38 itojun 1014: logit("wrong user name passed to monitor: expected %s != %.100s",
1.121 djm 1015: userstyle, p);
1.1 provos 1016: fail++;
1017: }
1.121 djm 1018: free(userstyle);
1.124 djm 1019: free(p);
1.1 provos 1020: buffer_skip_string(&b); /* service */
1.121 djm 1021: p = buffer_get_cstring(&b, NULL);
1.1 provos 1022: if (strcmp(p, "hostbased") != 0)
1023: fail++;
1.124 djm 1024: free(p);
1.1 provos 1025: buffer_skip_string(&b); /* pkalg */
1026: buffer_skip_string(&b); /* pkblob */
1027:
1028: /* verify client host, strip trailing dot if necessary */
1029: p = buffer_get_string(&b, NULL);
1030: if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1031: p[len - 1] = '\0';
1032: if (strcmp(p, chost) != 0)
1033: fail++;
1.124 djm 1034: free(p);
1.1 provos 1035:
1036: /* verify client user */
1037: p = buffer_get_string(&b, NULL);
1038: if (strcmp(p, cuser) != 0)
1039: fail++;
1.124 djm 1040: free(p);
1.1 provos 1041:
1042: if (buffer_len(&b) != 0)
1043: fail++;
1044: buffer_free(&b);
1045: return (fail == 0);
1046: }
1047:
1048: int
1.169 markus 1049: mm_answer_keyverify(int sock, struct sshbuf *m)
1.1 provos 1050: {
1.168 markus 1051: struct sshkey *key;
1.1 provos 1052: u_char *signature, *data, *blob;
1.169 markus 1053: size_t signaturelen, datalen, bloblen;
1054: int r, ret, valid_data = 0, encoded_ret;
1.1 provos 1055:
1.169 markus 1056: if ((r = sshbuf_get_string(m, &blob, &bloblen)) != 0 ||
1057: (r = sshbuf_get_string(m, &signature, &signaturelen)) != 0 ||
1058: (r = sshbuf_get_string(m, &data, &datalen)) != 0)
1059: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 1060:
1061: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 1062: !monitor_allowed_key(blob, bloblen))
1.14 markus 1063: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1064:
1.169 markus 1065: /* XXX use sshkey_froms here; need to change key_blob, etc. */
1066: if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
1067: fatal("%s: bad public key blob: %s", __func__, ssh_err(r));
1.1 provos 1068:
1069: switch (key_blobtype) {
1070: case MM_USERKEY:
1071: valid_data = monitor_valid_userblob(data, datalen);
1.172 djm 1072: auth_method = "publickey";
1.1 provos 1073: break;
1074: case MM_HOSTKEY:
1075: valid_data = monitor_valid_hostbasedblob(data, datalen,
1076: hostbased_cuser, hostbased_chost);
1.172 djm 1077: auth_method = "hostbased";
1.1 provos 1078: break;
1079: default:
1080: valid_data = 0;
1081: break;
1082: }
1083: if (!valid_data)
1.14 markus 1084: fatal("%s: bad signature data blob", __func__);
1.1 provos 1085:
1.169 markus 1086: ret = sshkey_verify(key, signature, signaturelen, data, datalen,
1087: active_state->compat);
1.172 djm 1088: debug3("%s: %s %p signature %s", __func__, auth_method, key,
1089: (ret == 0) ? "verified" : "unverified");
1090: auth2_record_key(authctxt, ret == 0, key);
1.136 djm 1091:
1.124 djm 1092: free(blob);
1093: free(signature);
1094: free(data);
1.1 provos 1095:
1096: monitor_reset_key_state();
1.3 markus 1097:
1.172 djm 1098: sshkey_free(key);
1.169 markus 1099: sshbuf_reset(m);
1100:
1101: /* encode ret != 0 as positive integer, since we're sending u32 */
1102: encoded_ret = (ret != 0);
1103: if ((r = sshbuf_put_u32(m, encoded_ret)) != 0)
1104: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.59 avsm 1105: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.1 provos 1106:
1.169 markus 1107: return ret == 0;
1.1 provos 1108: }
1109:
1.2 markus 1110: static void
1.1 provos 1111: mm_record_login(Session *s, struct passwd *pw)
1112: {
1.158 djm 1113: struct ssh *ssh = active_state; /* XXX */
1.1 provos 1114: socklen_t fromlen;
1115: struct sockaddr_storage from;
1116:
1117: /*
1118: * Get IP address of client. If the connection is not a socket, let
1119: * the address be 0.0.0.0.
1120: */
1121: memset(&from, 0, sizeof(from));
1.24 stevesk 1122: fromlen = sizeof(from);
1.1 provos 1123: if (packet_connection_is_on_socket()) {
1124: if (getpeername(packet_get_connection_in(),
1.74 deraadt 1125: (struct sockaddr *)&from, &fromlen) < 0) {
1.1 provos 1126: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1127: cleanup_exit(255);
1.1 provos 1128: }
1129: }
1130: /* Record that there was a login on that tty from the remote host. */
1131: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.158 djm 1132: session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
1.24 stevesk 1133: (struct sockaddr *)&from, fromlen);
1.1 provos 1134: }
1135:
1136: static void
1137: mm_session_close(Session *s)
1138: {
1.41 djm 1139: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1140: if (s->ttyfd != -1) {
1.86 stevesk 1141: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1142: session_pty_cleanup2(s);
1143: }
1.96 djm 1144: session_unused(s->self);
1.1 provos 1145: }
1146:
1147: int
1.59 avsm 1148: mm_answer_pty(int sock, Buffer *m)
1.1 provos 1149: {
1.11 mouring 1150: extern struct monitor *pmonitor;
1.1 provos 1151: Session *s;
1152: int res, fd0;
1153:
1.14 markus 1154: debug3("%s entering", __func__);
1.1 provos 1155:
1156: buffer_clear(m);
1157: s = session_new();
1158: if (s == NULL)
1159: goto error;
1160: s->authctxt = authctxt;
1161: s->pw = authctxt->pw;
1.11 mouring 1162: s->pid = pmonitor->m_pid;
1.1 provos 1163: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1164: if (res == 0)
1165: goto error;
1166: pty_setowner(authctxt->pw, s->tty);
1167:
1168: buffer_put_int(m, 1);
1169: buffer_put_cstring(m, s->tty);
1170:
1171: /* We need to trick ttyslot */
1172: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1173: fatal("%s: dup2", __func__);
1.1 provos 1174:
1175: mm_record_login(s, authctxt->pw);
1176:
1177: /* Now we can close the file descriptor again */
1178: close(0);
1.61 dtucker 1179:
1180: /* send messages generated by record_login */
1181: buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1182: buffer_clear(&loginmsg);
1183:
1184: mm_request_send(sock, MONITOR_ANS_PTY, m);
1185:
1.92 djm 1186: if (mm_send_fd(sock, s->ptyfd) == -1 ||
1187: mm_send_fd(sock, s->ttyfd) == -1)
1188: fatal("%s: send fds failed", __func__);
1.1 provos 1189:
1190: /* make sure nothing uses fd 0 */
1191: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1.14 markus 1192: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1193: if (fd0 != 0)
1.14 markus 1194: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1195:
1196: /* slave is not needed */
1197: close(s->ttyfd);
1198: s->ttyfd = s->ptyfd;
1199: /* no need to dup() because nobody closes ptyfd */
1200: s->ptymaster = s->ptyfd;
1201:
1.86 stevesk 1202: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1203:
1204: return (0);
1205:
1206: error:
1207: if (s != NULL)
1208: mm_session_close(s);
1209: buffer_put_int(m, 0);
1.59 avsm 1210: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1211: return (0);
1212: }
1213:
1214: int
1.59 avsm 1215: mm_answer_pty_cleanup(int sock, Buffer *m)
1.1 provos 1216: {
1217: Session *s;
1218: char *tty;
1219:
1.14 markus 1220: debug3("%s entering", __func__);
1.1 provos 1221:
1222: tty = buffer_get_string(m, NULL);
1223: if ((s = session_by_tty(tty)) != NULL)
1224: mm_session_close(s);
1225: buffer_clear(m);
1.124 djm 1226: free(tty);
1.1 provos 1227: return (0);
1228: }
1229:
1230: int
1.59 avsm 1231: mm_answer_term(int sock, Buffer *req)
1.1 provos 1232: {
1.173 djm 1233: struct ssh *ssh = active_state; /* XXX */
1.11 mouring 1234: extern struct monitor *pmonitor;
1.1 provos 1235: int res, status;
1236:
1.14 markus 1237: debug3("%s: tearing down sessions", __func__);
1.1 provos 1238:
1239: /* The child is terminating */
1.173 djm 1240: session_destroy_all(ssh, &mm_session_close);
1.1 provos 1241:
1.11 mouring 1242: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1243: if (errno != EINTR)
1244: exit(1);
1.1 provos 1245:
1246: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1247:
1248: /* Terminate process */
1.57 deraadt 1249: exit(res);
1.170 markus 1250: }
1251:
1252: void
1253: monitor_clear_keystate(struct monitor *pmonitor)
1254: {
1255: struct ssh *ssh = active_state; /* XXX */
1256:
1257: ssh_clear_newkeys(ssh, MODE_IN);
1258: ssh_clear_newkeys(ssh, MODE_OUT);
1259: sshbuf_free(child_state);
1260: child_state = NULL;
1.1 provos 1261: }
1262:
1263: void
1.11 mouring 1264: monitor_apply_keystate(struct monitor *pmonitor)
1.1 provos 1265: {
1.139 markus 1266: struct ssh *ssh = active_state; /* XXX */
1267: struct kex *kex;
1268: int r;
1269:
1270: debug3("%s: packet_set_state", __func__);
1271: if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
1272: fatal("%s: packet_set_state: %s", __func__, ssh_err(r));
1273: sshbuf_free(child_state);
1274: child_state = NULL;
1275:
1.154 mmcc 1276: if ((kex = ssh->kex) != NULL) {
1.139 markus 1277: /* XXX set callbacks */
1.147 djm 1278: #ifdef WITH_OPENSSL
1.139 markus 1279: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1280: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1.160 djm 1281: kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server;
1282: kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server;
1283: kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server;
1.139 markus 1284: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1285: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1286: kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1.147 djm 1287: #endif
1.139 markus 1288: kex->kex[KEX_C25519_SHA256] = kexc25519_server;
1289: kex->load_host_public_key=&get_hostkey_public_by_type;
1290: kex->load_host_private_key=&get_hostkey_private_by_type;
1291: kex->host_key_index=&get_hostkey_index;
1292: kex->sign = sshd_hostkey_sign;
1293: }
1.1 provos 1294: }
1295:
1296: /* This function requries careful sanity checking */
1297:
1298: void
1.11 mouring 1299: mm_get_keystate(struct monitor *pmonitor)
1.1 provos 1300: {
1.14 markus 1301: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1302:
1.139 markus 1303: if ((child_state = sshbuf_new()) == NULL)
1304: fatal("%s: sshbuf_new failed", __func__);
1305: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
1306: child_state);
1307: debug3("%s: GOT new keys", __func__);
1.1 provos 1308: }
1309:
1310:
1311: /* XXX */
1312:
1313: #define FD_CLOSEONEXEC(x) do { \
1.111 djm 1314: if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1.1 provos 1315: fatal("fcntl(%d, F_SETFD)", x); \
1316: } while (0)
1317:
1.2 markus 1318: static void
1.114 djm 1319: monitor_openfds(struct monitor *mon, int do_logfds)
1.3 markus 1320: {
1.114 djm 1321: int pair[2];
1.171 markus 1322: #ifdef SO_ZEROIZE
1323: int on = 1;
1324: #endif
1.114 djm 1325:
1.1 provos 1326: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.114 djm 1327: fatal("%s: socketpair: %s", __func__, strerror(errno));
1.171 markus 1328: #ifdef SO_ZEROIZE
1329: if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) < 0)
1330: error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno));
1331: if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) < 0)
1332: error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno));
1333: #endif
1.1 provos 1334: FD_CLOSEONEXEC(pair[0]);
1335: FD_CLOSEONEXEC(pair[1]);
1.114 djm 1336: mon->m_recvfd = pair[0];
1337: mon->m_sendfd = pair[1];
1338:
1339: if (do_logfds) {
1340: if (pipe(pair) == -1)
1341: fatal("%s: pipe: %s", __func__, strerror(errno));
1342: FD_CLOSEONEXEC(pair[0]);
1343: FD_CLOSEONEXEC(pair[1]);
1344: mon->m_log_recvfd = pair[0];
1345: mon->m_log_sendfd = pair[1];
1346: } else
1347: mon->m_log_recvfd = mon->m_log_sendfd = -1;
1.1 provos 1348: }
1349:
1350: #define MM_MEMSIZE 65536
1351:
1352: struct monitor *
1353: monitor_init(void)
1354: {
1355: struct monitor *mon;
1356:
1.75 djm 1357: mon = xcalloc(1, sizeof(*mon));
1.114 djm 1358: monitor_openfds(mon, 1);
1.1 provos 1359:
1360: return mon;
1361: }
1362:
1363: void
1364: monitor_reinit(struct monitor *mon)
1365: {
1.114 djm 1366: monitor_openfds(mon, 0);
1.1 provos 1367: }
1.46 markus 1368:
1369: #ifdef GSSAPI
1370: int
1.59 avsm 1371: mm_answer_gss_setup_ctx(int sock, Buffer *m)
1.46 markus 1372: {
1.59 avsm 1373: gss_OID_desc goid;
1.46 markus 1374: OM_uint32 major;
1375: u_int len;
1376:
1.164 djm 1377: if (!options.gss_authentication)
1378: fatal("%s: GSSAPI authentication not enabled", __func__);
1379:
1.59 avsm 1380: goid.elements = buffer_get_string(m, &len);
1381: goid.length = len;
1.46 markus 1382:
1.59 avsm 1383: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1384:
1.124 djm 1385: free(goid.elements);
1.46 markus 1386:
1387: buffer_clear(m);
1388: buffer_put_int(m, major);
1389:
1.64 stevesk 1390: mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1.46 markus 1391:
1392: /* Now we have a context, enable the step */
1393: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1394:
1395: return (0);
1396: }
1397:
1398: int
1.59 avsm 1399: mm_answer_gss_accept_ctx(int sock, Buffer *m)
1.46 markus 1400: {
1401: gss_buffer_desc in;
1402: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1.64 stevesk 1403: OM_uint32 major, minor;
1.46 markus 1404: OM_uint32 flags = 0; /* GSI needs this */
1.47 deraadt 1405: u_int len;
1.46 markus 1406:
1.164 djm 1407: if (!options.gss_authentication)
1408: fatal("%s: GSSAPI authentication not enabled", __func__);
1409:
1.47 deraadt 1410: in.value = buffer_get_string(m, &len);
1411: in.length = len;
1.46 markus 1412: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1.124 djm 1413: free(in.value);
1.46 markus 1414:
1415: buffer_clear(m);
1416: buffer_put_int(m, major);
1417: buffer_put_string(m, out.value, out.length);
1418: buffer_put_int(m, flags);
1.59 avsm 1419: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1420:
1421: gss_release_buffer(&minor, &out);
1422:
1.64 stevesk 1423: if (major == GSS_S_COMPLETE) {
1.46 markus 1424: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1425: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1426: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1427: }
1428: return (0);
1429: }
1430:
1431: int
1.59 avsm 1432: mm_answer_gss_checkmic(int sock, Buffer *m)
1.52 markus 1433: {
1434: gss_buffer_desc gssbuf, mic;
1435: OM_uint32 ret;
1436: u_int len;
1.54 djm 1437:
1.164 djm 1438: if (!options.gss_authentication)
1439: fatal("%s: GSSAPI authentication not enabled", __func__);
1440:
1.52 markus 1441: gssbuf.value = buffer_get_string(m, &len);
1442: gssbuf.length = len;
1443: mic.value = buffer_get_string(m, &len);
1444: mic.length = len;
1.54 djm 1445:
1.52 markus 1446: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1447:
1.124 djm 1448: free(gssbuf.value);
1449: free(mic.value);
1.54 djm 1450:
1.52 markus 1451: buffer_clear(m);
1452: buffer_put_int(m, ret);
1.54 djm 1453:
1.59 avsm 1454: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1455:
1.52 markus 1456: if (!GSS_ERROR(ret))
1457: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1458:
1.52 markus 1459: return (0);
1460: }
1461:
1462: int
1.59 avsm 1463: mm_answer_gss_userok(int sock, Buffer *m)
1.46 markus 1464: {
1465: int authenticated;
1.172 djm 1466: const char *displayname;
1.164 djm 1467:
1468: if (!options.gss_authentication)
1469: fatal("%s: GSSAPI authentication not enabled", __func__);
1.46 markus 1470:
1471: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1472:
1473: buffer_clear(m);
1474: buffer_put_int(m, authenticated);
1475:
1476: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1477: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1478:
1.64 stevesk 1479: auth_method = "gssapi-with-mic";
1.172 djm 1480:
1481: if ((displayname = ssh_gssapi_displayname()) != NULL)
1482: auth2_record_info(authctxt, "%s", displayname);
1.46 markus 1483:
1484: /* Monitor loop will terminate if authenticated */
1485: return (authenticated);
1486: }
1487: #endif /* GSSAPI */
1.100 djm 1488:
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