1 /* $OpenBSD: monitor.c,v 1.166 2016/09/28 16:33:06 djm Exp $ */ 2 /* 3 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus@openbsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/types.h> 29 #include <sys/wait.h> 30 #include <sys/socket.h> 31 #include <sys/tree.h> 32 #include <sys/queue.h> 33 34 #ifdef WITH_OPENSSL 35 #include <openssl/dh.h> 36 #endif 37 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <limits.h> 41 #include <paths.h> 42 #include <poll.h> 43 #include <pwd.h> 44 #include <signal.h> 45 #include <stdarg.h> 46 #include <stdint.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 #include "atomicio.h" 52 #include "xmalloc.h" 53 #include "ssh.h" 54 #include "key.h" 55 #include "buffer.h" 56 #include "hostfile.h" 57 #include "auth.h" 58 #include "cipher.h" 59 #include "kex.h" 60 #include "dh.h" 61 #include <zlib.h> 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" 70 #include "misc.h" 71 #include "servconf.h" 72 #include "monitor.h" 73 #ifdef GSSAPI 74 #include "ssh-gss.h" 75 #endif 76 #include "monitor_wrap.h" 77 #include "monitor_fdpass.h" 78 #include "compat.h" 79 #include "ssh2.h" 80 #include "authfd.h" 81 #include "match.h" 82 #include "ssherr.h" 83 84 #ifdef GSSAPI 85 static Gssctxt *gsscontext = NULL; 86 #endif 87 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; 94 extern Buffer loginmsg; 95 96 /* State exported from the child */ 97 static struct sshbuf *child_state; 98 99 /* Functions on the monitor that answer unprivileged requests */ 100 101 int mm_answer_moduli(int, Buffer *); 102 int mm_answer_sign(int, Buffer *); 103 int mm_answer_pwnamallow(int, Buffer *); 104 int mm_answer_auth2_read_banner(int, Buffer *); 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 *); 121 122 #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 *); 126 int mm_answer_gss_checkmic(int, Buffer *); 127 #endif 128 129 static int monitor_read_log(struct monitor *); 130 131 static Authctxt *authctxt; 132 133 /* 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; 137 static char *hostbased_cuser = NULL; 138 static char *hostbased_chost = NULL; 139 static char *auth_method = "unknown"; 140 static char *auth_submethod = NULL; 141 static u_int session_id2_len = 0; 142 static u_char *session_id2 = NULL; 143 static pid_t monitor_child_pid; 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 */ 154 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 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[] = { 161 #ifdef WITH_OPENSSL 162 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 163 #endif 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}, 167 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 168 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 169 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 170 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 171 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 172 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 173 #ifdef GSSAPI 174 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 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}, 178 #endif 179 {0, 0, NULL} 180 }; 181 182 struct mon_table mon_dispatch_postauth20[] = { 183 #ifdef WITH_OPENSSL 184 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 185 #endif 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 } 223 224 void 225 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 226 { 227 struct mon_table *ent; 228 int authenticated = 0, partial = 0; 229 230 debug3("preauth child monitor started"); 231 232 close(pmonitor->m_recvfd); 233 close(pmonitor->m_log_sendfd); 234 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 235 236 authctxt = _authctxt; 237 memset(authctxt, 0, sizeof(*authctxt)); 238 239 mon_dispatch = mon_dispatch_proto20; 240 /* Permit requests for moduli and signatures */ 241 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 242 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 243 244 /* The first few requests do not require asynchronous access */ 245 while (!authenticated) { 246 partial = 0; 247 auth_method = "unknown"; 248 auth_submethod = NULL; 249 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 250 251 /* Special handling for multiple required authentications */ 252 if (options.num_auth_methods != 0) { 253 if (authenticated && 254 !auth2_update_methods_lists(authctxt, 255 auth_method, auth_submethod)) { 256 debug3("%s: method %s: partial", __func__, 257 auth_method); 258 authenticated = 0; 259 partial = 1; 260 } 261 } 262 263 if (authenticated) { 264 if (!(ent->flags & MON_AUTHDECIDE)) 265 fatal("%s: unexpected authentication from %d", 266 __func__, ent->type); 267 if (authctxt->pw->pw_uid == 0 && 268 !auth_root_allowed(auth_method)) 269 authenticated = 0; 270 } 271 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 272 auth_log(authctxt, authenticated, partial, 273 auth_method, auth_submethod); 274 if (!partial && !authenticated) 275 authctxt->failures++; 276 } 277 } 278 279 if (!authctxt->valid) 280 fatal("%s: authenticated invalid user", __func__); 281 if (strcmp(auth_method, "unknown") == 0) 282 fatal("%s: authentication method name unknown", __func__); 283 284 debug("%s: %s has been authenticated by privileged process", 285 __func__, authctxt->user); 286 287 mm_get_keystate(pmonitor); 288 289 /* Drain any buffered messages from the child */ 290 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 291 ; 292 293 close(pmonitor->m_sendfd); 294 close(pmonitor->m_log_recvfd); 295 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 296 } 297 298 static void 299 monitor_set_child_handler(pid_t pid) 300 { 301 monitor_child_pid = pid; 302 } 303 304 static void 305 monitor_child_handler(int sig) 306 { 307 kill(monitor_child_pid, sig); 308 } 309 310 void 311 monitor_child_postauth(struct monitor *pmonitor) 312 { 313 close(pmonitor->m_recvfd); 314 pmonitor->m_recvfd = -1; 315 316 monitor_set_child_handler(pmonitor->m_pid); 317 signal(SIGHUP, &monitor_child_handler); 318 signal(SIGTERM, &monitor_child_handler); 319 signal(SIGINT, &monitor_child_handler); 320 321 mon_dispatch = mon_dispatch_postauth20; 322 323 /* Permit requests for moduli and signatures */ 324 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 325 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 326 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 327 328 if (!no_pty_flag) { 329 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 330 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 331 } 332 333 for (;;) 334 monitor_read(pmonitor, mon_dispatch, NULL); 335 } 336 337 static int 338 monitor_read_log(struct monitor *pmonitor) 339 { 340 Buffer logmsg; 341 u_int len, level; 342 char *msg; 343 344 buffer_init(&logmsg); 345 346 /* Read length */ 347 buffer_append_space(&logmsg, 4); 348 if (atomicio(read, pmonitor->m_log_recvfd, 349 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 350 if (errno == EPIPE) { 351 buffer_free(&logmsg); 352 debug("%s: child log fd closed", __func__); 353 close(pmonitor->m_log_recvfd); 354 pmonitor->m_log_recvfd = -1; 355 return -1; 356 } 357 fatal("%s: log fd read: %s", __func__, strerror(errno)); 358 } 359 len = buffer_get_int(&logmsg); 360 if (len <= 4 || len > 8192) 361 fatal("%s: invalid log message length %u", __func__, len); 362 363 /* Read severity, message */ 364 buffer_clear(&logmsg); 365 buffer_append_space(&logmsg, len); 366 if (atomicio(read, pmonitor->m_log_recvfd, 367 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 368 fatal("%s: log fd read: %s", __func__, strerror(errno)); 369 370 /* Log it */ 371 level = buffer_get_int(&logmsg); 372 msg = buffer_get_string(&logmsg, NULL); 373 if (log_level_name(level) == NULL) 374 fatal("%s: invalid log level %u (corrupted message?)", 375 __func__, level); 376 do_log2(level, "%s [preauth]", msg); 377 378 buffer_free(&logmsg); 379 free(msg); 380 381 return 0; 382 } 383 384 int 385 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 386 struct mon_table **pent) 387 { 388 Buffer m; 389 int ret; 390 u_char type; 391 struct pollfd pfd[2]; 392 393 for (;;) { 394 memset(&pfd, 0, sizeof(pfd)); 395 pfd[0].fd = pmonitor->m_sendfd; 396 pfd[0].events = POLLIN; 397 pfd[1].fd = pmonitor->m_log_recvfd; 398 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 399 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 400 if (errno == EINTR || errno == EAGAIN) 401 continue; 402 fatal("%s: poll: %s", __func__, strerror(errno)); 403 } 404 if (pfd[1].revents) { 405 /* 406 * Drain all log messages before processing next 407 * monitor request. 408 */ 409 monitor_read_log(pmonitor); 410 continue; 411 } 412 if (pfd[0].revents) 413 break; /* Continues below */ 414 } 415 416 buffer_init(&m); 417 418 mm_request_receive(pmonitor->m_sendfd, &m); 419 type = buffer_get_char(&m); 420 421 debug3("%s: checking request %d", __func__, type); 422 423 while (ent->f != NULL) { 424 if (ent->type == type) 425 break; 426 ent++; 427 } 428 429 if (ent->f != NULL) { 430 if (!(ent->flags & MON_PERMIT)) 431 fatal("%s: unpermitted request %d", __func__, 432 type); 433 ret = (*ent->f)(pmonitor->m_sendfd, &m); 434 buffer_free(&m); 435 436 /* The child may use this request only once, disable it */ 437 if (ent->flags & MON_ONCE) { 438 debug2("%s: %d used once, disabling now", __func__, 439 type); 440 ent->flags &= ~MON_PERMIT; 441 } 442 443 if (pent != NULL) 444 *pent = ent; 445 446 return ret; 447 } 448 449 fatal("%s: unsupported request: %d", __func__, type); 450 451 /* NOTREACHED */ 452 return (-1); 453 } 454 455 /* allowed key state */ 456 static int 457 monitor_allowed_key(u_char *blob, u_int bloblen) 458 { 459 /* make sure key is allowed */ 460 if (key_blob == NULL || key_bloblen != bloblen || 461 timingsafe_bcmp(key_blob, blob, key_bloblen)) 462 return (0); 463 return (1); 464 } 465 466 static void 467 monitor_reset_key_state(void) 468 { 469 /* reset state */ 470 free(key_blob); 471 free(hostbased_cuser); 472 free(hostbased_chost); 473 key_blob = NULL; 474 key_bloblen = 0; 475 key_blobtype = MM_NOKEY; 476 hostbased_cuser = NULL; 477 hostbased_chost = NULL; 478 } 479 480 #ifdef WITH_OPENSSL 481 int 482 mm_answer_moduli(int sock, Buffer *m) 483 { 484 DH *dh; 485 int min, want, max; 486 487 min = buffer_get_int(m); 488 want = buffer_get_int(m); 489 max = buffer_get_int(m); 490 491 debug3("%s: got parameters: %d %d %d", 492 __func__, min, want, max); 493 /* We need to check here, too, in case the child got corrupted */ 494 if (max < min || want < min || max < want) 495 fatal("%s: bad parameters: %d %d %d", 496 __func__, min, want, max); 497 498 buffer_clear(m); 499 500 dh = choose_dh(min, want, max); 501 if (dh == NULL) { 502 buffer_put_char(m, 0); 503 return (0); 504 } else { 505 /* Send first bignum */ 506 buffer_put_char(m, 1); 507 buffer_put_bignum2(m, dh->p); 508 buffer_put_bignum2(m, dh->g); 509 510 DH_free(dh); 511 } 512 mm_request_send(sock, MONITOR_ANS_MODULI, m); 513 return (0); 514 } 515 #endif 516 517 int 518 mm_answer_sign(int sock, Buffer *m) 519 { 520 struct ssh *ssh = active_state; /* XXX */ 521 extern int auth_sock; /* XXX move to state struct? */ 522 struct sshkey *key; 523 struct sshbuf *sigbuf = NULL; 524 u_char *p = NULL, *signature = NULL; 525 char *alg = NULL; 526 size_t datlen, siglen, alglen; 527 int r, is_proof = 0; 528 u_int keyid; 529 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 530 531 debug3("%s", __func__); 532 533 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 534 (r = sshbuf_get_string(m, &p, &datlen)) != 0 || 535 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0) 536 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 537 if (keyid > INT_MAX) 538 fatal("%s: invalid key ID", __func__); 539 540 /* 541 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 542 * SHA384 (48 bytes) and SHA512 (64 bytes). 543 * 544 * Otherwise, verify the signature request is for a hostkey 545 * proof. 546 * 547 * XXX perform similar check for KEX signature requests too? 548 * it's not trivial, since what is signed is the hash, rather 549 * than the full kex structure... 550 */ 551 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) { 552 /* 553 * Construct expected hostkey proof and compare it to what 554 * the client sent us. 555 */ 556 if (session_id2_len == 0) /* hostkeys is never first */ 557 fatal("%s: bad data length: %zu", __func__, datlen); 558 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL) 559 fatal("%s: no hostkey for index %d", __func__, keyid); 560 if ((sigbuf = sshbuf_new()) == NULL) 561 fatal("%s: sshbuf_new", __func__); 562 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 563 (r = sshbuf_put_string(sigbuf, session_id2, 564 session_id2_len)) != 0 || 565 (r = sshkey_puts(key, sigbuf)) != 0) 566 fatal("%s: couldn't prepare private key " 567 "proof buffer: %s", __func__, ssh_err(r)); 568 if (datlen != sshbuf_len(sigbuf) || 569 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0) 570 fatal("%s: bad data length: %zu, hostkey proof len %zu", 571 __func__, datlen, sshbuf_len(sigbuf)); 572 sshbuf_free(sigbuf); 573 is_proof = 1; 574 } 575 576 /* save session id, it will be passed on the first call */ 577 if (session_id2_len == 0) { 578 session_id2_len = datlen; 579 session_id2 = xmalloc(session_id2_len); 580 memcpy(session_id2, p, session_id2_len); 581 } 582 583 if ((key = get_hostkey_by_index(keyid)) != NULL) { 584 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, 585 datafellows)) != 0) 586 fatal("%s: sshkey_sign failed: %s", 587 __func__, ssh_err(r)); 588 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 589 auth_sock > 0) { 590 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 591 p, datlen, alg, datafellows)) != 0) { 592 fatal("%s: ssh_agent_sign failed: %s", 593 __func__, ssh_err(r)); 594 } 595 } else 596 fatal("%s: no hostkey from index %d", __func__, keyid); 597 598 debug3("%s: %s signature %p(%zu)", __func__, 599 is_proof ? "KEX" : "hostkey proof", signature, siglen); 600 601 sshbuf_reset(m); 602 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 603 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 604 605 free(alg); 606 free(p); 607 free(signature); 608 609 mm_request_send(sock, MONITOR_ANS_SIGN, m); 610 611 /* Turn on permissions for getpwnam */ 612 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 613 614 return (0); 615 } 616 617 /* Retrieves the password entry and also checks if the user is permitted */ 618 619 int 620 mm_answer_pwnamallow(int sock, Buffer *m) 621 { 622 char *username; 623 struct passwd *pwent; 624 int allowed = 0; 625 u_int i; 626 627 debug3("%s", __func__); 628 629 if (authctxt->attempt++ != 0) 630 fatal("%s: multiple attempts for getpwnam", __func__); 631 632 username = buffer_get_string(m, NULL); 633 634 pwent = getpwnamallow(username); 635 636 authctxt->user = xstrdup(username); 637 setproctitle("%s [priv]", pwent ? username : "unknown"); 638 free(username); 639 640 buffer_clear(m); 641 642 if (pwent == NULL) { 643 buffer_put_char(m, 0); 644 authctxt->pw = fakepw(); 645 goto out; 646 } 647 648 allowed = 1; 649 authctxt->pw = pwent; 650 authctxt->valid = 1; 651 652 buffer_put_char(m, 1); 653 buffer_put_string(m, pwent, sizeof(struct passwd)); 654 buffer_put_cstring(m, pwent->pw_name); 655 buffer_put_cstring(m, "*"); 656 buffer_put_cstring(m, pwent->pw_gecos); 657 buffer_put_cstring(m, pwent->pw_class); 658 buffer_put_cstring(m, pwent->pw_dir); 659 buffer_put_cstring(m, pwent->pw_shell); 660 661 out: 662 buffer_put_string(m, &options, sizeof(options)); 663 664 #define M_CP_STROPT(x) do { \ 665 if (options.x != NULL) \ 666 buffer_put_cstring(m, options.x); \ 667 } while (0) 668 #define M_CP_STRARRAYOPT(x, nx) do { \ 669 for (i = 0; i < options.nx; i++) \ 670 buffer_put_cstring(m, options.x[i]); \ 671 } while (0) 672 /* See comment in servconf.h */ 673 COPY_MATCH_STRING_OPTS(); 674 #undef M_CP_STROPT 675 #undef M_CP_STRARRAYOPT 676 677 /* Create valid auth method lists */ 678 if (auth2_setup_methods_lists(authctxt) != 0) { 679 /* 680 * The monitor will continue long enough to let the child 681 * run to it's packet_disconnect(), but it must not allow any 682 * authentication to succeed. 683 */ 684 debug("%s: no valid authentication method lists", __func__); 685 } 686 687 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 688 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 689 690 /* Allow service/style information on the auth context */ 691 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 692 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 693 694 return (0); 695 } 696 697 int mm_answer_auth2_read_banner(int sock, Buffer *m) 698 { 699 char *banner; 700 701 buffer_clear(m); 702 banner = auth2_read_banner(); 703 buffer_put_cstring(m, banner != NULL ? banner : ""); 704 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 705 free(banner); 706 707 return (0); 708 } 709 710 int 711 mm_answer_authserv(int sock, Buffer *m) 712 { 713 monitor_permit_authentications(1); 714 715 authctxt->service = buffer_get_string(m, NULL); 716 authctxt->style = buffer_get_string(m, NULL); 717 debug3("%s: service=%s, style=%s", 718 __func__, authctxt->service, authctxt->style); 719 720 if (strlen(authctxt->style) == 0) { 721 free(authctxt->style); 722 authctxt->style = NULL; 723 } 724 725 return (0); 726 } 727 728 int 729 mm_answer_authpassword(int sock, Buffer *m) 730 { 731 static int call_count; 732 char *passwd; 733 int authenticated; 734 u_int plen; 735 736 if (!options.password_authentication) 737 fatal("%s: password authentication not enabled", __func__); 738 passwd = buffer_get_string(m, &plen); 739 /* Only authenticate if the context is valid */ 740 authenticated = options.password_authentication && 741 auth_password(authctxt, passwd); 742 explicit_bzero(passwd, strlen(passwd)); 743 free(passwd); 744 745 buffer_clear(m); 746 buffer_put_int(m, authenticated); 747 748 debug3("%s: sending result %d", __func__, authenticated); 749 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 750 751 call_count++; 752 if (plen == 0 && call_count == 1) 753 auth_method = "none"; 754 else 755 auth_method = "password"; 756 757 /* Causes monitor loop to terminate if authenticated */ 758 return (authenticated); 759 } 760 761 int 762 mm_answer_bsdauthquery(int sock, Buffer *m) 763 { 764 char *name, *infotxt; 765 u_int numprompts; 766 u_int *echo_on; 767 char **prompts; 768 u_int success; 769 770 if (!options.kbd_interactive_authentication) 771 fatal("%s: kbd-int authentication not enabled", __func__); 772 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 773 &prompts, &echo_on) < 0 ? 0 : 1; 774 775 buffer_clear(m); 776 buffer_put_int(m, success); 777 if (success) 778 buffer_put_cstring(m, prompts[0]); 779 780 debug3("%s: sending challenge success: %u", __func__, success); 781 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 782 783 if (success) { 784 free(name); 785 free(infotxt); 786 free(prompts); 787 free(echo_on); 788 } 789 790 return (0); 791 } 792 793 int 794 mm_answer_bsdauthrespond(int sock, Buffer *m) 795 { 796 char *response; 797 int authok; 798 799 if (!options.kbd_interactive_authentication) 800 fatal("%s: kbd-int authentication not enabled", __func__); 801 if (authctxt->as == NULL) 802 fatal("%s: no bsd auth session", __func__); 803 804 response = buffer_get_string(m, NULL); 805 authok = options.challenge_response_authentication && 806 auth_userresponse(authctxt->as, response, 0); 807 authctxt->as = NULL; 808 debug3("%s: <%s> = <%d>", __func__, response, authok); 809 free(response); 810 811 buffer_clear(m); 812 buffer_put_int(m, authok); 813 814 debug3("%s: sending authenticated: %d", __func__, authok); 815 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 816 817 auth_method = "keyboard-interactive"; 818 auth_submethod = "bsdauth"; 819 820 return (authok != 0); 821 } 822 823 int 824 mm_answer_keyallowed(int sock, Buffer *m) 825 { 826 Key *key; 827 char *cuser, *chost; 828 u_char *blob; 829 u_int bloblen, pubkey_auth_attempt; 830 enum mm_keytype type = 0; 831 int allowed = 0; 832 833 debug3("%s entering", __func__); 834 835 type = buffer_get_int(m); 836 cuser = buffer_get_string(m, NULL); 837 chost = buffer_get_string(m, NULL); 838 blob = buffer_get_string(m, &bloblen); 839 pubkey_auth_attempt = buffer_get_int(m); 840 841 key = key_from_blob(blob, bloblen); 842 843 debug3("%s: key_from_blob: %p", __func__, key); 844 845 if (key != NULL && authctxt->valid) { 846 /* These should not make it past the privsep child */ 847 if (key_type_plain(key->type) == KEY_RSA && 848 (datafellows & SSH_BUG_RSASIGMD5) != 0) 849 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 850 851 switch (type) { 852 case MM_USERKEY: 853 allowed = options.pubkey_authentication && 854 !auth2_userkey_already_used(authctxt, key) && 855 match_pattern_list(sshkey_ssh_name(key), 856 options.pubkey_key_types, 0) == 1 && 857 user_key_allowed(authctxt->pw, key, 858 pubkey_auth_attempt); 859 pubkey_auth_info(authctxt, key, NULL); 860 auth_method = "publickey"; 861 if (options.pubkey_authentication && 862 (!pubkey_auth_attempt || allowed != 1)) 863 auth_clear_options(); 864 break; 865 case MM_HOSTKEY: 866 allowed = options.hostbased_authentication && 867 match_pattern_list(sshkey_ssh_name(key), 868 options.hostbased_key_types, 0) == 1 && 869 hostbased_key_allowed(authctxt->pw, 870 cuser, chost, key); 871 pubkey_auth_info(authctxt, key, 872 "client user \"%.100s\", client host \"%.100s\"", 873 cuser, chost); 874 auth_method = "hostbased"; 875 break; 876 default: 877 fatal("%s: unknown key type %d", __func__, type); 878 break; 879 } 880 } 881 882 debug3("%s: key %p is %s", 883 __func__, key, allowed ? "allowed" : "not allowed"); 884 885 if (key != NULL) 886 key_free(key); 887 888 /* clear temporarily storage (used by verify) */ 889 monitor_reset_key_state(); 890 891 if (allowed) { 892 /* Save temporarily for comparison in verify */ 893 key_blob = blob; 894 key_bloblen = bloblen; 895 key_blobtype = type; 896 hostbased_cuser = cuser; 897 hostbased_chost = chost; 898 } else { 899 /* Log failed attempt */ 900 auth_log(authctxt, 0, 0, auth_method, NULL); 901 free(blob); 902 free(cuser); 903 free(chost); 904 } 905 906 buffer_clear(m); 907 buffer_put_int(m, allowed); 908 buffer_put_int(m, forced_command != NULL); 909 910 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 911 912 return (0); 913 } 914 915 static int 916 monitor_valid_userblob(u_char *data, u_int datalen) 917 { 918 Buffer b; 919 u_char *p; 920 char *userstyle, *cp; 921 u_int len; 922 int fail = 0; 923 924 buffer_init(&b); 925 buffer_append(&b, data, datalen); 926 927 if (datafellows & SSH_OLD_SESSIONID) { 928 p = buffer_ptr(&b); 929 len = buffer_len(&b); 930 if ((session_id2 == NULL) || 931 (len < session_id2_len) || 932 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 933 fail++; 934 buffer_consume(&b, session_id2_len); 935 } else { 936 p = buffer_get_string(&b, &len); 937 if ((session_id2 == NULL) || 938 (len != session_id2_len) || 939 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 940 fail++; 941 free(p); 942 } 943 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 944 fail++; 945 cp = buffer_get_cstring(&b, NULL); 946 xasprintf(&userstyle, "%s%s%s", authctxt->user, 947 authctxt->style ? ":" : "", 948 authctxt->style ? authctxt->style : ""); 949 if (strcmp(userstyle, cp) != 0) { 950 logit("wrong user name passed to monitor: " 951 "expected %s != %.100s", userstyle, cp); 952 fail++; 953 } 954 free(userstyle); 955 free(cp); 956 buffer_skip_string(&b); 957 if (datafellows & SSH_BUG_PKAUTH) { 958 if (!buffer_get_char(&b)) 959 fail++; 960 } else { 961 cp = buffer_get_cstring(&b, NULL); 962 if (strcmp("publickey", cp) != 0) 963 fail++; 964 free(cp); 965 if (!buffer_get_char(&b)) 966 fail++; 967 buffer_skip_string(&b); 968 } 969 buffer_skip_string(&b); 970 if (buffer_len(&b) != 0) 971 fail++; 972 buffer_free(&b); 973 return (fail == 0); 974 } 975 976 static int 977 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 978 char *chost) 979 { 980 Buffer b; 981 char *p, *userstyle; 982 u_int len; 983 int fail = 0; 984 985 buffer_init(&b); 986 buffer_append(&b, data, datalen); 987 988 p = buffer_get_string(&b, &len); 989 if ((session_id2 == NULL) || 990 (len != session_id2_len) || 991 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 992 fail++; 993 free(p); 994 995 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 996 fail++; 997 p = buffer_get_cstring(&b, NULL); 998 xasprintf(&userstyle, "%s%s%s", authctxt->user, 999 authctxt->style ? ":" : "", 1000 authctxt->style ? authctxt->style : ""); 1001 if (strcmp(userstyle, p) != 0) { 1002 logit("wrong user name passed to monitor: expected %s != %.100s", 1003 userstyle, p); 1004 fail++; 1005 } 1006 free(userstyle); 1007 free(p); 1008 buffer_skip_string(&b); /* service */ 1009 p = buffer_get_cstring(&b, NULL); 1010 if (strcmp(p, "hostbased") != 0) 1011 fail++; 1012 free(p); 1013 buffer_skip_string(&b); /* pkalg */ 1014 buffer_skip_string(&b); /* pkblob */ 1015 1016 /* verify client host, strip trailing dot if necessary */ 1017 p = buffer_get_string(&b, NULL); 1018 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1019 p[len - 1] = '\0'; 1020 if (strcmp(p, chost) != 0) 1021 fail++; 1022 free(p); 1023 1024 /* verify client user */ 1025 p = buffer_get_string(&b, NULL); 1026 if (strcmp(p, cuser) != 0) 1027 fail++; 1028 free(p); 1029 1030 if (buffer_len(&b) != 0) 1031 fail++; 1032 buffer_free(&b); 1033 return (fail == 0); 1034 } 1035 1036 int 1037 mm_answer_keyverify(int sock, Buffer *m) 1038 { 1039 Key *key; 1040 u_char *signature, *data, *blob; 1041 u_int signaturelen, datalen, bloblen; 1042 int verified = 0; 1043 int valid_data = 0; 1044 1045 blob = buffer_get_string(m, &bloblen); 1046 signature = buffer_get_string(m, &signaturelen); 1047 data = buffer_get_string(m, &datalen); 1048 1049 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1050 !monitor_allowed_key(blob, bloblen)) 1051 fatal("%s: bad key, not previously allowed", __func__); 1052 1053 key = key_from_blob(blob, bloblen); 1054 if (key == NULL) 1055 fatal("%s: bad public key blob", __func__); 1056 1057 switch (key_blobtype) { 1058 case MM_USERKEY: 1059 valid_data = monitor_valid_userblob(data, datalen); 1060 break; 1061 case MM_HOSTKEY: 1062 valid_data = monitor_valid_hostbasedblob(data, datalen, 1063 hostbased_cuser, hostbased_chost); 1064 break; 1065 default: 1066 valid_data = 0; 1067 break; 1068 } 1069 if (!valid_data) 1070 fatal("%s: bad signature data blob", __func__); 1071 1072 verified = key_verify(key, signature, signaturelen, data, datalen); 1073 debug3("%s: key %p signature %s", 1074 __func__, key, (verified == 1) ? "verified" : "unverified"); 1075 1076 /* If auth was successful then record key to ensure it isn't reused */ 1077 if (verified == 1 && key_blobtype == MM_USERKEY) 1078 auth2_record_userkey(authctxt, key); 1079 else 1080 key_free(key); 1081 1082 free(blob); 1083 free(signature); 1084 free(data); 1085 1086 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1087 1088 monitor_reset_key_state(); 1089 1090 buffer_clear(m); 1091 buffer_put_int(m, verified); 1092 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1093 1094 return (verified == 1); 1095 } 1096 1097 static void 1098 mm_record_login(Session *s, struct passwd *pw) 1099 { 1100 struct ssh *ssh = active_state; /* XXX */ 1101 socklen_t fromlen; 1102 struct sockaddr_storage from; 1103 1104 /* 1105 * Get IP address of client. If the connection is not a socket, let 1106 * the address be 0.0.0.0. 1107 */ 1108 memset(&from, 0, sizeof(from)); 1109 fromlen = sizeof(from); 1110 if (packet_connection_is_on_socket()) { 1111 if (getpeername(packet_get_connection_in(), 1112 (struct sockaddr *)&from, &fromlen) < 0) { 1113 debug("getpeername: %.100s", strerror(errno)); 1114 cleanup_exit(255); 1115 } 1116 } 1117 /* Record that there was a login on that tty from the remote host. */ 1118 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1119 session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns), 1120 (struct sockaddr *)&from, fromlen); 1121 } 1122 1123 static void 1124 mm_session_close(Session *s) 1125 { 1126 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1127 if (s->ttyfd != -1) { 1128 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1129 session_pty_cleanup2(s); 1130 } 1131 session_unused(s->self); 1132 } 1133 1134 int 1135 mm_answer_pty(int sock, Buffer *m) 1136 { 1137 extern struct monitor *pmonitor; 1138 Session *s; 1139 int res, fd0; 1140 1141 debug3("%s entering", __func__); 1142 1143 buffer_clear(m); 1144 s = session_new(); 1145 if (s == NULL) 1146 goto error; 1147 s->authctxt = authctxt; 1148 s->pw = authctxt->pw; 1149 s->pid = pmonitor->m_pid; 1150 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1151 if (res == 0) 1152 goto error; 1153 pty_setowner(authctxt->pw, s->tty); 1154 1155 buffer_put_int(m, 1); 1156 buffer_put_cstring(m, s->tty); 1157 1158 /* We need to trick ttyslot */ 1159 if (dup2(s->ttyfd, 0) == -1) 1160 fatal("%s: dup2", __func__); 1161 1162 mm_record_login(s, authctxt->pw); 1163 1164 /* Now we can close the file descriptor again */ 1165 close(0); 1166 1167 /* send messages generated by record_login */ 1168 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1169 buffer_clear(&loginmsg); 1170 1171 mm_request_send(sock, MONITOR_ANS_PTY, m); 1172 1173 if (mm_send_fd(sock, s->ptyfd) == -1 || 1174 mm_send_fd(sock, s->ttyfd) == -1) 1175 fatal("%s: send fds failed", __func__); 1176 1177 /* make sure nothing uses fd 0 */ 1178 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1179 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1180 if (fd0 != 0) 1181 error("%s: fd0 %d != 0", __func__, fd0); 1182 1183 /* slave is not needed */ 1184 close(s->ttyfd); 1185 s->ttyfd = s->ptyfd; 1186 /* no need to dup() because nobody closes ptyfd */ 1187 s->ptymaster = s->ptyfd; 1188 1189 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1190 1191 return (0); 1192 1193 error: 1194 if (s != NULL) 1195 mm_session_close(s); 1196 buffer_put_int(m, 0); 1197 mm_request_send(sock, MONITOR_ANS_PTY, m); 1198 return (0); 1199 } 1200 1201 int 1202 mm_answer_pty_cleanup(int sock, Buffer *m) 1203 { 1204 Session *s; 1205 char *tty; 1206 1207 debug3("%s entering", __func__); 1208 1209 tty = buffer_get_string(m, NULL); 1210 if ((s = session_by_tty(tty)) != NULL) 1211 mm_session_close(s); 1212 buffer_clear(m); 1213 free(tty); 1214 return (0); 1215 } 1216 1217 int 1218 mm_answer_term(int sock, Buffer *req) 1219 { 1220 extern struct monitor *pmonitor; 1221 int res, status; 1222 1223 debug3("%s: tearing down sessions", __func__); 1224 1225 /* The child is terminating */ 1226 session_destroy_all(&mm_session_close); 1227 1228 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1229 if (errno != EINTR) 1230 exit(1); 1231 1232 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1233 1234 /* Terminate process */ 1235 exit(res); 1236 } 1237 1238 void 1239 monitor_apply_keystate(struct monitor *pmonitor) 1240 { 1241 struct ssh *ssh = active_state; /* XXX */ 1242 struct kex *kex; 1243 int r; 1244 1245 debug3("%s: packet_set_state", __func__); 1246 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1247 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1248 sshbuf_free(child_state); 1249 child_state = NULL; 1250 1251 if ((kex = ssh->kex) != NULL) { 1252 /* XXX set callbacks */ 1253 #ifdef WITH_OPENSSL 1254 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1255 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1256 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server; 1257 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server; 1258 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server; 1259 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1260 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1261 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1262 #endif 1263 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1264 kex->load_host_public_key=&get_hostkey_public_by_type; 1265 kex->load_host_private_key=&get_hostkey_private_by_type; 1266 kex->host_key_index=&get_hostkey_index; 1267 kex->sign = sshd_hostkey_sign; 1268 } 1269 } 1270 1271 /* This function requries careful sanity checking */ 1272 1273 void 1274 mm_get_keystate(struct monitor *pmonitor) 1275 { 1276 debug3("%s: Waiting for new keys", __func__); 1277 1278 if ((child_state = sshbuf_new()) == NULL) 1279 fatal("%s: sshbuf_new failed", __func__); 1280 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1281 child_state); 1282 debug3("%s: GOT new keys", __func__); 1283 } 1284 1285 1286 /* XXX */ 1287 1288 #define FD_CLOSEONEXEC(x) do { \ 1289 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1290 fatal("fcntl(%d, F_SETFD)", x); \ 1291 } while (0) 1292 1293 static void 1294 monitor_openfds(struct monitor *mon, int do_logfds) 1295 { 1296 int pair[2]; 1297 1298 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1299 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1300 FD_CLOSEONEXEC(pair[0]); 1301 FD_CLOSEONEXEC(pair[1]); 1302 mon->m_recvfd = pair[0]; 1303 mon->m_sendfd = pair[1]; 1304 1305 if (do_logfds) { 1306 if (pipe(pair) == -1) 1307 fatal("%s: pipe: %s", __func__, strerror(errno)); 1308 FD_CLOSEONEXEC(pair[0]); 1309 FD_CLOSEONEXEC(pair[1]); 1310 mon->m_log_recvfd = pair[0]; 1311 mon->m_log_sendfd = pair[1]; 1312 } else 1313 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1314 } 1315 1316 #define MM_MEMSIZE 65536 1317 1318 struct monitor * 1319 monitor_init(void) 1320 { 1321 struct monitor *mon; 1322 1323 mon = xcalloc(1, sizeof(*mon)); 1324 monitor_openfds(mon, 1); 1325 1326 return mon; 1327 } 1328 1329 void 1330 monitor_reinit(struct monitor *mon) 1331 { 1332 monitor_openfds(mon, 0); 1333 } 1334 1335 #ifdef GSSAPI 1336 int 1337 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1338 { 1339 gss_OID_desc goid; 1340 OM_uint32 major; 1341 u_int len; 1342 1343 if (!options.gss_authentication) 1344 fatal("%s: GSSAPI authentication not enabled", __func__); 1345 1346 goid.elements = buffer_get_string(m, &len); 1347 goid.length = len; 1348 1349 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1350 1351 free(goid.elements); 1352 1353 buffer_clear(m); 1354 buffer_put_int(m, major); 1355 1356 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1357 1358 /* Now we have a context, enable the step */ 1359 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1360 1361 return (0); 1362 } 1363 1364 int 1365 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1366 { 1367 gss_buffer_desc in; 1368 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1369 OM_uint32 major, minor; 1370 OM_uint32 flags = 0; /* GSI needs this */ 1371 u_int len; 1372 1373 if (!options.gss_authentication) 1374 fatal("%s: GSSAPI authentication not enabled", __func__); 1375 1376 in.value = buffer_get_string(m, &len); 1377 in.length = len; 1378 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1379 free(in.value); 1380 1381 buffer_clear(m); 1382 buffer_put_int(m, major); 1383 buffer_put_string(m, out.value, out.length); 1384 buffer_put_int(m, flags); 1385 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1386 1387 gss_release_buffer(&minor, &out); 1388 1389 if (major == GSS_S_COMPLETE) { 1390 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1391 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1392 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1393 } 1394 return (0); 1395 } 1396 1397 int 1398 mm_answer_gss_checkmic(int sock, Buffer *m) 1399 { 1400 gss_buffer_desc gssbuf, mic; 1401 OM_uint32 ret; 1402 u_int len; 1403 1404 if (!options.gss_authentication) 1405 fatal("%s: GSSAPI authentication not enabled", __func__); 1406 1407 gssbuf.value = buffer_get_string(m, &len); 1408 gssbuf.length = len; 1409 mic.value = buffer_get_string(m, &len); 1410 mic.length = len; 1411 1412 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1413 1414 free(gssbuf.value); 1415 free(mic.value); 1416 1417 buffer_clear(m); 1418 buffer_put_int(m, ret); 1419 1420 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1421 1422 if (!GSS_ERROR(ret)) 1423 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1424 1425 return (0); 1426 } 1427 1428 int 1429 mm_answer_gss_userok(int sock, Buffer *m) 1430 { 1431 int authenticated; 1432 1433 if (!options.gss_authentication) 1434 fatal("%s: GSSAPI authentication not enabled", __func__); 1435 1436 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1437 1438 buffer_clear(m); 1439 buffer_put_int(m, authenticated); 1440 1441 debug3("%s: sending result %d", __func__, authenticated); 1442 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1443 1444 auth_method = "gssapi-with-mic"; 1445 1446 /* Monitor loop will terminate if authenticated */ 1447 return (authenticated); 1448 } 1449 #endif /* GSSAPI */ 1450 1451