1 /* $OpenBSD: monitor.c,v 1.168 2017/05/30 08:52:19 markus 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 ssh *ssh = active_state; /* XXX */ 228 struct mon_table *ent; 229 int authenticated = 0, partial = 0; 230 231 debug3("preauth child monitor started"); 232 233 close(pmonitor->m_recvfd); 234 close(pmonitor->m_log_sendfd); 235 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 236 237 authctxt = _authctxt; 238 memset(authctxt, 0, sizeof(*authctxt)); 239 240 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); 244 245 /* The first few requests do not require asynchronous access */ 246 while (!authenticated) { 247 partial = 0; 248 auth_method = "unknown"; 249 auth_submethod = NULL; 250 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 251 252 /* Special handling for multiple required authentications */ 253 if (options.num_auth_methods != 0) { 254 if (authenticated && 255 !auth2_update_methods_lists(authctxt, 256 auth_method, auth_submethod)) { 257 debug3("%s: method %s: partial", __func__, 258 auth_method); 259 authenticated = 0; 260 partial = 1; 261 } 262 } 263 264 if (authenticated) { 265 if (!(ent->flags & MON_AUTHDECIDE)) 266 fatal("%s: unexpected authentication from %d", 267 __func__, ent->type); 268 if (authctxt->pw->pw_uid == 0 && 269 !auth_root_allowed(auth_method)) 270 authenticated = 0; 271 } 272 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 273 auth_log(authctxt, authenticated, partial, 274 auth_method, auth_submethod); 275 if (!partial && !authenticated) 276 authctxt->failures++; 277 } 278 } 279 280 if (!authctxt->valid) 281 fatal("%s: authenticated invalid user", __func__); 282 if (strcmp(auth_method, "unknown") == 0) 283 fatal("%s: authentication method name unknown", __func__); 284 285 debug("%s: %s has been authenticated by privileged process", 286 __func__, authctxt->user); 287 ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user); 288 289 mm_get_keystate(pmonitor); 290 291 /* Drain any buffered messages from the child */ 292 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 293 ; 294 295 close(pmonitor->m_sendfd); 296 close(pmonitor->m_log_recvfd); 297 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 298 } 299 300 static void 301 monitor_set_child_handler(pid_t pid) 302 { 303 monitor_child_pid = pid; 304 } 305 306 static void 307 monitor_child_handler(int sig) 308 { 309 kill(monitor_child_pid, sig); 310 } 311 312 void 313 monitor_child_postauth(struct monitor *pmonitor) 314 { 315 close(pmonitor->m_recvfd); 316 pmonitor->m_recvfd = -1; 317 318 monitor_set_child_handler(pmonitor->m_pid); 319 signal(SIGHUP, &monitor_child_handler); 320 signal(SIGTERM, &monitor_child_handler); 321 signal(SIGINT, &monitor_child_handler); 322 323 mon_dispatch = mon_dispatch_postauth20; 324 325 /* Permit requests for moduli and signatures */ 326 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 327 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 328 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 329 330 if (!no_pty_flag) { 331 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 332 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 333 } 334 335 for (;;) 336 monitor_read(pmonitor, mon_dispatch, NULL); 337 } 338 339 static int 340 monitor_read_log(struct monitor *pmonitor) 341 { 342 Buffer logmsg; 343 u_int len, level; 344 char *msg; 345 346 buffer_init(&logmsg); 347 348 /* Read length */ 349 buffer_append_space(&logmsg, 4); 350 if (atomicio(read, pmonitor->m_log_recvfd, 351 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 352 if (errno == EPIPE) { 353 buffer_free(&logmsg); 354 debug("%s: child log fd closed", __func__); 355 close(pmonitor->m_log_recvfd); 356 pmonitor->m_log_recvfd = -1; 357 return -1; 358 } 359 fatal("%s: log fd read: %s", __func__, strerror(errno)); 360 } 361 len = buffer_get_int(&logmsg); 362 if (len <= 4 || len > 8192) 363 fatal("%s: invalid log message length %u", __func__, len); 364 365 /* Read severity, message */ 366 buffer_clear(&logmsg); 367 buffer_append_space(&logmsg, len); 368 if (atomicio(read, pmonitor->m_log_recvfd, 369 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 370 fatal("%s: log fd read: %s", __func__, strerror(errno)); 371 372 /* Log it */ 373 level = buffer_get_int(&logmsg); 374 msg = buffer_get_string(&logmsg, NULL); 375 if (log_level_name(level) == NULL) 376 fatal("%s: invalid log level %u (corrupted message?)", 377 __func__, level); 378 do_log2(level, "%s [preauth]", msg); 379 380 buffer_free(&logmsg); 381 free(msg); 382 383 return 0; 384 } 385 386 int 387 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 388 struct mon_table **pent) 389 { 390 Buffer m; 391 int ret; 392 u_char type; 393 struct pollfd pfd[2]; 394 395 for (;;) { 396 memset(&pfd, 0, sizeof(pfd)); 397 pfd[0].fd = pmonitor->m_sendfd; 398 pfd[0].events = POLLIN; 399 pfd[1].fd = pmonitor->m_log_recvfd; 400 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 401 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 402 if (errno == EINTR || errno == EAGAIN) 403 continue; 404 fatal("%s: poll: %s", __func__, strerror(errno)); 405 } 406 if (pfd[1].revents) { 407 /* 408 * Drain all log messages before processing next 409 * monitor request. 410 */ 411 monitor_read_log(pmonitor); 412 continue; 413 } 414 if (pfd[0].revents) 415 break; /* Continues below */ 416 } 417 418 buffer_init(&m); 419 420 mm_request_receive(pmonitor->m_sendfd, &m); 421 type = buffer_get_char(&m); 422 423 debug3("%s: checking request %d", __func__, type); 424 425 while (ent->f != NULL) { 426 if (ent->type == type) 427 break; 428 ent++; 429 } 430 431 if (ent->f != NULL) { 432 if (!(ent->flags & MON_PERMIT)) 433 fatal("%s: unpermitted request %d", __func__, 434 type); 435 ret = (*ent->f)(pmonitor->m_sendfd, &m); 436 buffer_free(&m); 437 438 /* The child may use this request only once, disable it */ 439 if (ent->flags & MON_ONCE) { 440 debug2("%s: %d used once, disabling now", __func__, 441 type); 442 ent->flags &= ~MON_PERMIT; 443 } 444 445 if (pent != NULL) 446 *pent = ent; 447 448 return ret; 449 } 450 451 fatal("%s: unsupported request: %d", __func__, type); 452 453 /* NOTREACHED */ 454 return (-1); 455 } 456 457 /* allowed key state */ 458 static int 459 monitor_allowed_key(u_char *blob, u_int bloblen) 460 { 461 /* make sure key is allowed */ 462 if (key_blob == NULL || key_bloblen != bloblen || 463 timingsafe_bcmp(key_blob, blob, key_bloblen)) 464 return (0); 465 return (1); 466 } 467 468 static void 469 monitor_reset_key_state(void) 470 { 471 /* reset state */ 472 free(key_blob); 473 free(hostbased_cuser); 474 free(hostbased_chost); 475 key_blob = NULL; 476 key_bloblen = 0; 477 key_blobtype = MM_NOKEY; 478 hostbased_cuser = NULL; 479 hostbased_chost = NULL; 480 } 481 482 #ifdef WITH_OPENSSL 483 int 484 mm_answer_moduli(int sock, Buffer *m) 485 { 486 DH *dh; 487 int min, want, max; 488 489 min = buffer_get_int(m); 490 want = buffer_get_int(m); 491 max = buffer_get_int(m); 492 493 debug3("%s: got parameters: %d %d %d", 494 __func__, min, want, max); 495 /* We need to check here, too, in case the child got corrupted */ 496 if (max < min || want < min || max < want) 497 fatal("%s: bad parameters: %d %d %d", 498 __func__, min, want, max); 499 500 buffer_clear(m); 501 502 dh = choose_dh(min, want, max); 503 if (dh == NULL) { 504 buffer_put_char(m, 0); 505 return (0); 506 } else { 507 /* Send first bignum */ 508 buffer_put_char(m, 1); 509 buffer_put_bignum2(m, dh->p); 510 buffer_put_bignum2(m, dh->g); 511 512 DH_free(dh); 513 } 514 mm_request_send(sock, MONITOR_ANS_MODULI, m); 515 return (0); 516 } 517 #endif 518 519 int 520 mm_answer_sign(int sock, Buffer *m) 521 { 522 struct ssh *ssh = active_state; /* XXX */ 523 extern int auth_sock; /* XXX move to state struct? */ 524 struct sshkey *key; 525 struct sshbuf *sigbuf = NULL; 526 u_char *p = NULL, *signature = NULL; 527 char *alg = NULL; 528 size_t datlen, siglen, alglen; 529 int r, is_proof = 0; 530 u_int keyid; 531 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 532 533 debug3("%s", __func__); 534 535 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 536 (r = sshbuf_get_string(m, &p, &datlen)) != 0 || 537 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0) 538 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 539 if (keyid > INT_MAX) 540 fatal("%s: invalid key ID", __func__); 541 542 /* 543 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 544 * SHA384 (48 bytes) and SHA512 (64 bytes). 545 * 546 * Otherwise, verify the signature request is for a hostkey 547 * proof. 548 * 549 * XXX perform similar check for KEX signature requests too? 550 * it's not trivial, since what is signed is the hash, rather 551 * than the full kex structure... 552 */ 553 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) { 554 /* 555 * Construct expected hostkey proof and compare it to what 556 * the client sent us. 557 */ 558 if (session_id2_len == 0) /* hostkeys is never first */ 559 fatal("%s: bad data length: %zu", __func__, datlen); 560 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL) 561 fatal("%s: no hostkey for index %d", __func__, keyid); 562 if ((sigbuf = sshbuf_new()) == NULL) 563 fatal("%s: sshbuf_new", __func__); 564 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 565 (r = sshbuf_put_string(sigbuf, session_id2, 566 session_id2_len)) != 0 || 567 (r = sshkey_puts(key, sigbuf)) != 0) 568 fatal("%s: couldn't prepare private key " 569 "proof buffer: %s", __func__, ssh_err(r)); 570 if (datlen != sshbuf_len(sigbuf) || 571 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0) 572 fatal("%s: bad data length: %zu, hostkey proof len %zu", 573 __func__, datlen, sshbuf_len(sigbuf)); 574 sshbuf_free(sigbuf); 575 is_proof = 1; 576 } 577 578 /* save session id, it will be passed on the first call */ 579 if (session_id2_len == 0) { 580 session_id2_len = datlen; 581 session_id2 = xmalloc(session_id2_len); 582 memcpy(session_id2, p, session_id2_len); 583 } 584 585 if ((key = get_hostkey_by_index(keyid)) != NULL) { 586 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, 587 datafellows)) != 0) 588 fatal("%s: sshkey_sign failed: %s", 589 __func__, ssh_err(r)); 590 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 591 auth_sock > 0) { 592 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 593 p, datlen, alg, datafellows)) != 0) { 594 fatal("%s: ssh_agent_sign failed: %s", 595 __func__, ssh_err(r)); 596 } 597 } else 598 fatal("%s: no hostkey from index %d", __func__, keyid); 599 600 debug3("%s: %s signature %p(%zu)", __func__, 601 is_proof ? "KEX" : "hostkey proof", signature, siglen); 602 603 sshbuf_reset(m); 604 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 605 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 606 607 free(alg); 608 free(p); 609 free(signature); 610 611 mm_request_send(sock, MONITOR_ANS_SIGN, m); 612 613 /* Turn on permissions for getpwnam */ 614 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 615 616 return (0); 617 } 618 619 /* Retrieves the password entry and also checks if the user is permitted */ 620 621 int 622 mm_answer_pwnamallow(int sock, Buffer *m) 623 { 624 struct ssh *ssh = active_state; /* XXX */ 625 char *username; 626 struct passwd *pwent; 627 int allowed = 0; 628 u_int i; 629 630 debug3("%s", __func__); 631 632 if (authctxt->attempt++ != 0) 633 fatal("%s: multiple attempts for getpwnam", __func__); 634 635 username = buffer_get_string(m, NULL); 636 637 pwent = getpwnamallow(username); 638 639 authctxt->user = xstrdup(username); 640 setproctitle("%s [priv]", pwent ? username : "unknown"); 641 free(username); 642 643 buffer_clear(m); 644 645 if (pwent == NULL) { 646 buffer_put_char(m, 0); 647 authctxt->pw = fakepw(); 648 goto out; 649 } 650 651 allowed = 1; 652 authctxt->pw = pwent; 653 authctxt->valid = 1; 654 655 buffer_put_char(m, 1); 656 buffer_put_string(m, pwent, sizeof(struct passwd)); 657 buffer_put_cstring(m, pwent->pw_name); 658 buffer_put_cstring(m, "*"); 659 buffer_put_cstring(m, pwent->pw_gecos); 660 buffer_put_cstring(m, pwent->pw_class); 661 buffer_put_cstring(m, pwent->pw_dir); 662 buffer_put_cstring(m, pwent->pw_shell); 663 664 out: 665 ssh_packet_set_log_preamble(ssh, "%suser %s", 666 authctxt->valid ? "authenticating" : "invalid ", authctxt->user); 667 buffer_put_string(m, &options, sizeof(options)); 668 669 #define M_CP_STROPT(x) do { \ 670 if (options.x != NULL) \ 671 buffer_put_cstring(m, options.x); \ 672 } while (0) 673 #define M_CP_STRARRAYOPT(x, nx) do { \ 674 for (i = 0; i < options.nx; i++) \ 675 buffer_put_cstring(m, options.x[i]); \ 676 } while (0) 677 /* See comment in servconf.h */ 678 COPY_MATCH_STRING_OPTS(); 679 #undef M_CP_STROPT 680 #undef M_CP_STRARRAYOPT 681 682 /* Create valid auth method lists */ 683 if (auth2_setup_methods_lists(authctxt) != 0) { 684 /* 685 * The monitor will continue long enough to let the child 686 * run to it's packet_disconnect(), but it must not allow any 687 * authentication to succeed. 688 */ 689 debug("%s: no valid authentication method lists", __func__); 690 } 691 692 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 693 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 694 695 /* Allow service/style information on the auth context */ 696 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 697 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 698 699 return (0); 700 } 701 702 int mm_answer_auth2_read_banner(int sock, Buffer *m) 703 { 704 char *banner; 705 706 buffer_clear(m); 707 banner = auth2_read_banner(); 708 buffer_put_cstring(m, banner != NULL ? banner : ""); 709 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 710 free(banner); 711 712 return (0); 713 } 714 715 int 716 mm_answer_authserv(int sock, Buffer *m) 717 { 718 monitor_permit_authentications(1); 719 720 authctxt->service = buffer_get_string(m, NULL); 721 authctxt->style = buffer_get_string(m, NULL); 722 debug3("%s: service=%s, style=%s", 723 __func__, authctxt->service, authctxt->style); 724 725 if (strlen(authctxt->style) == 0) { 726 free(authctxt->style); 727 authctxt->style = NULL; 728 } 729 730 return (0); 731 } 732 733 int 734 mm_answer_authpassword(int sock, Buffer *m) 735 { 736 static int call_count; 737 char *passwd; 738 int authenticated; 739 u_int plen; 740 741 if (!options.password_authentication) 742 fatal("%s: password authentication not enabled", __func__); 743 passwd = buffer_get_string(m, &plen); 744 /* Only authenticate if the context is valid */ 745 authenticated = options.password_authentication && 746 auth_password(authctxt, passwd); 747 explicit_bzero(passwd, strlen(passwd)); 748 free(passwd); 749 750 buffer_clear(m); 751 buffer_put_int(m, authenticated); 752 753 debug3("%s: sending result %d", __func__, authenticated); 754 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 755 756 call_count++; 757 if (plen == 0 && call_count == 1) 758 auth_method = "none"; 759 else 760 auth_method = "password"; 761 762 /* Causes monitor loop to terminate if authenticated */ 763 return (authenticated); 764 } 765 766 int 767 mm_answer_bsdauthquery(int sock, Buffer *m) 768 { 769 char *name, *infotxt; 770 u_int numprompts; 771 u_int *echo_on; 772 char **prompts; 773 u_int success; 774 775 if (!options.kbd_interactive_authentication) 776 fatal("%s: kbd-int authentication not enabled", __func__); 777 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 778 &prompts, &echo_on) < 0 ? 0 : 1; 779 780 buffer_clear(m); 781 buffer_put_int(m, success); 782 if (success) 783 buffer_put_cstring(m, prompts[0]); 784 785 debug3("%s: sending challenge success: %u", __func__, success); 786 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 787 788 if (success) { 789 free(name); 790 free(infotxt); 791 free(prompts); 792 free(echo_on); 793 } 794 795 return (0); 796 } 797 798 int 799 mm_answer_bsdauthrespond(int sock, Buffer *m) 800 { 801 char *response; 802 int authok; 803 804 if (!options.kbd_interactive_authentication) 805 fatal("%s: kbd-int authentication not enabled", __func__); 806 if (authctxt->as == NULL) 807 fatal("%s: no bsd auth session", __func__); 808 809 response = buffer_get_string(m, NULL); 810 authok = options.challenge_response_authentication && 811 auth_userresponse(authctxt->as, response, 0); 812 authctxt->as = NULL; 813 debug3("%s: <%s> = <%d>", __func__, response, authok); 814 free(response); 815 816 buffer_clear(m); 817 buffer_put_int(m, authok); 818 819 debug3("%s: sending authenticated: %d", __func__, authok); 820 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 821 822 auth_method = "keyboard-interactive"; 823 auth_submethod = "bsdauth"; 824 825 return (authok != 0); 826 } 827 828 int 829 mm_answer_keyallowed(int sock, Buffer *m) 830 { 831 struct sshkey *key; 832 char *cuser, *chost; 833 u_char *blob; 834 u_int bloblen, pubkey_auth_attempt; 835 enum mm_keytype type = 0; 836 int allowed = 0; 837 838 debug3("%s entering", __func__); 839 840 type = buffer_get_int(m); 841 cuser = buffer_get_string(m, NULL); 842 chost = buffer_get_string(m, NULL); 843 blob = buffer_get_string(m, &bloblen); 844 pubkey_auth_attempt = buffer_get_int(m); 845 846 key = key_from_blob(blob, bloblen); 847 848 debug3("%s: key_from_blob: %p", __func__, key); 849 850 if (key != NULL && authctxt->valid) { 851 /* These should not make it past the privsep child */ 852 if (key_type_plain(key->type) == KEY_RSA && 853 (datafellows & SSH_BUG_RSASIGMD5) != 0) 854 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 855 856 switch (type) { 857 case MM_USERKEY: 858 allowed = options.pubkey_authentication && 859 !auth2_userkey_already_used(authctxt, key) && 860 match_pattern_list(sshkey_ssh_name(key), 861 options.pubkey_key_types, 0) == 1 && 862 user_key_allowed(authctxt->pw, key, 863 pubkey_auth_attempt); 864 pubkey_auth_info(authctxt, key, NULL); 865 auth_method = "publickey"; 866 if (options.pubkey_authentication && 867 (!pubkey_auth_attempt || allowed != 1)) 868 auth_clear_options(); 869 break; 870 case MM_HOSTKEY: 871 allowed = options.hostbased_authentication && 872 match_pattern_list(sshkey_ssh_name(key), 873 options.hostbased_key_types, 0) == 1 && 874 hostbased_key_allowed(authctxt->pw, 875 cuser, chost, key); 876 pubkey_auth_info(authctxt, key, 877 "client user \"%.100s\", client host \"%.100s\"", 878 cuser, chost); 879 auth_method = "hostbased"; 880 break; 881 default: 882 fatal("%s: unknown key type %d", __func__, type); 883 break; 884 } 885 } 886 887 debug3("%s: key %p is %s", 888 __func__, key, allowed ? "allowed" : "not allowed"); 889 890 if (key != NULL) 891 key_free(key); 892 893 /* clear temporarily storage (used by verify) */ 894 monitor_reset_key_state(); 895 896 if (allowed) { 897 /* Save temporarily for comparison in verify */ 898 key_blob = blob; 899 key_bloblen = bloblen; 900 key_blobtype = type; 901 hostbased_cuser = cuser; 902 hostbased_chost = chost; 903 } else { 904 /* Log failed attempt */ 905 auth_log(authctxt, 0, 0, auth_method, NULL); 906 free(blob); 907 free(cuser); 908 free(chost); 909 } 910 911 buffer_clear(m); 912 buffer_put_int(m, allowed); 913 buffer_put_int(m, forced_command != NULL); 914 915 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 916 917 return (0); 918 } 919 920 static int 921 monitor_valid_userblob(u_char *data, u_int datalen) 922 { 923 Buffer b; 924 u_char *p; 925 char *userstyle, *cp; 926 u_int len; 927 int fail = 0; 928 929 buffer_init(&b); 930 buffer_append(&b, data, datalen); 931 932 if (datafellows & SSH_OLD_SESSIONID) { 933 p = buffer_ptr(&b); 934 len = buffer_len(&b); 935 if ((session_id2 == NULL) || 936 (len < session_id2_len) || 937 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 938 fail++; 939 buffer_consume(&b, session_id2_len); 940 } else { 941 p = buffer_get_string(&b, &len); 942 if ((session_id2 == NULL) || 943 (len != session_id2_len) || 944 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 945 fail++; 946 free(p); 947 } 948 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 949 fail++; 950 cp = buffer_get_cstring(&b, NULL); 951 xasprintf(&userstyle, "%s%s%s", authctxt->user, 952 authctxt->style ? ":" : "", 953 authctxt->style ? authctxt->style : ""); 954 if (strcmp(userstyle, cp) != 0) { 955 logit("wrong user name passed to monitor: " 956 "expected %s != %.100s", userstyle, cp); 957 fail++; 958 } 959 free(userstyle); 960 free(cp); 961 buffer_skip_string(&b); 962 if (datafellows & SSH_BUG_PKAUTH) { 963 if (!buffer_get_char(&b)) 964 fail++; 965 } else { 966 cp = buffer_get_cstring(&b, NULL); 967 if (strcmp("publickey", cp) != 0) 968 fail++; 969 free(cp); 970 if (!buffer_get_char(&b)) 971 fail++; 972 buffer_skip_string(&b); 973 } 974 buffer_skip_string(&b); 975 if (buffer_len(&b) != 0) 976 fail++; 977 buffer_free(&b); 978 return (fail == 0); 979 } 980 981 static int 982 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 983 char *chost) 984 { 985 Buffer b; 986 char *p, *userstyle; 987 u_int len; 988 int fail = 0; 989 990 buffer_init(&b); 991 buffer_append(&b, data, datalen); 992 993 p = buffer_get_string(&b, &len); 994 if ((session_id2 == NULL) || 995 (len != session_id2_len) || 996 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 997 fail++; 998 free(p); 999 1000 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1001 fail++; 1002 p = buffer_get_cstring(&b, NULL); 1003 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1004 authctxt->style ? ":" : "", 1005 authctxt->style ? authctxt->style : ""); 1006 if (strcmp(userstyle, p) != 0) { 1007 logit("wrong user name passed to monitor: expected %s != %.100s", 1008 userstyle, p); 1009 fail++; 1010 } 1011 free(userstyle); 1012 free(p); 1013 buffer_skip_string(&b); /* service */ 1014 p = buffer_get_cstring(&b, NULL); 1015 if (strcmp(p, "hostbased") != 0) 1016 fail++; 1017 free(p); 1018 buffer_skip_string(&b); /* pkalg */ 1019 buffer_skip_string(&b); /* pkblob */ 1020 1021 /* verify client host, strip trailing dot if necessary */ 1022 p = buffer_get_string(&b, NULL); 1023 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1024 p[len - 1] = '\0'; 1025 if (strcmp(p, chost) != 0) 1026 fail++; 1027 free(p); 1028 1029 /* verify client user */ 1030 p = buffer_get_string(&b, NULL); 1031 if (strcmp(p, cuser) != 0) 1032 fail++; 1033 free(p); 1034 1035 if (buffer_len(&b) != 0) 1036 fail++; 1037 buffer_free(&b); 1038 return (fail == 0); 1039 } 1040 1041 int 1042 mm_answer_keyverify(int sock, Buffer *m) 1043 { 1044 struct sshkey *key; 1045 u_char *signature, *data, *blob; 1046 u_int signaturelen, datalen, bloblen; 1047 int verified = 0; 1048 int valid_data = 0; 1049 1050 blob = buffer_get_string(m, &bloblen); 1051 signature = buffer_get_string(m, &signaturelen); 1052 data = buffer_get_string(m, &datalen); 1053 1054 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1055 !monitor_allowed_key(blob, bloblen)) 1056 fatal("%s: bad key, not previously allowed", __func__); 1057 1058 key = key_from_blob(blob, bloblen); 1059 if (key == NULL) 1060 fatal("%s: bad public key blob", __func__); 1061 1062 switch (key_blobtype) { 1063 case MM_USERKEY: 1064 valid_data = monitor_valid_userblob(data, datalen); 1065 break; 1066 case MM_HOSTKEY: 1067 valid_data = monitor_valid_hostbasedblob(data, datalen, 1068 hostbased_cuser, hostbased_chost); 1069 break; 1070 default: 1071 valid_data = 0; 1072 break; 1073 } 1074 if (!valid_data) 1075 fatal("%s: bad signature data blob", __func__); 1076 1077 verified = key_verify(key, signature, signaturelen, data, datalen); 1078 debug3("%s: key %p signature %s", 1079 __func__, key, (verified == 1) ? "verified" : "unverified"); 1080 1081 /* If auth was successful then record key to ensure it isn't reused */ 1082 if (verified == 1 && key_blobtype == MM_USERKEY) 1083 auth2_record_userkey(authctxt, key); 1084 else 1085 key_free(key); 1086 1087 free(blob); 1088 free(signature); 1089 free(data); 1090 1091 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1092 1093 monitor_reset_key_state(); 1094 1095 buffer_clear(m); 1096 buffer_put_int(m, verified); 1097 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1098 1099 return (verified == 1); 1100 } 1101 1102 static void 1103 mm_record_login(Session *s, struct passwd *pw) 1104 { 1105 struct ssh *ssh = active_state; /* XXX */ 1106 socklen_t fromlen; 1107 struct sockaddr_storage from; 1108 1109 /* 1110 * Get IP address of client. If the connection is not a socket, let 1111 * the address be 0.0.0.0. 1112 */ 1113 memset(&from, 0, sizeof(from)); 1114 fromlen = sizeof(from); 1115 if (packet_connection_is_on_socket()) { 1116 if (getpeername(packet_get_connection_in(), 1117 (struct sockaddr *)&from, &fromlen) < 0) { 1118 debug("getpeername: %.100s", strerror(errno)); 1119 cleanup_exit(255); 1120 } 1121 } 1122 /* Record that there was a login on that tty from the remote host. */ 1123 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1124 session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns), 1125 (struct sockaddr *)&from, fromlen); 1126 } 1127 1128 static void 1129 mm_session_close(Session *s) 1130 { 1131 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1132 if (s->ttyfd != -1) { 1133 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1134 session_pty_cleanup2(s); 1135 } 1136 session_unused(s->self); 1137 } 1138 1139 int 1140 mm_answer_pty(int sock, Buffer *m) 1141 { 1142 extern struct monitor *pmonitor; 1143 Session *s; 1144 int res, fd0; 1145 1146 debug3("%s entering", __func__); 1147 1148 buffer_clear(m); 1149 s = session_new(); 1150 if (s == NULL) 1151 goto error; 1152 s->authctxt = authctxt; 1153 s->pw = authctxt->pw; 1154 s->pid = pmonitor->m_pid; 1155 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1156 if (res == 0) 1157 goto error; 1158 pty_setowner(authctxt->pw, s->tty); 1159 1160 buffer_put_int(m, 1); 1161 buffer_put_cstring(m, s->tty); 1162 1163 /* We need to trick ttyslot */ 1164 if (dup2(s->ttyfd, 0) == -1) 1165 fatal("%s: dup2", __func__); 1166 1167 mm_record_login(s, authctxt->pw); 1168 1169 /* Now we can close the file descriptor again */ 1170 close(0); 1171 1172 /* send messages generated by record_login */ 1173 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1174 buffer_clear(&loginmsg); 1175 1176 mm_request_send(sock, MONITOR_ANS_PTY, m); 1177 1178 if (mm_send_fd(sock, s->ptyfd) == -1 || 1179 mm_send_fd(sock, s->ttyfd) == -1) 1180 fatal("%s: send fds failed", __func__); 1181 1182 /* make sure nothing uses fd 0 */ 1183 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1184 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1185 if (fd0 != 0) 1186 error("%s: fd0 %d != 0", __func__, fd0); 1187 1188 /* slave is not needed */ 1189 close(s->ttyfd); 1190 s->ttyfd = s->ptyfd; 1191 /* no need to dup() because nobody closes ptyfd */ 1192 s->ptymaster = s->ptyfd; 1193 1194 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1195 1196 return (0); 1197 1198 error: 1199 if (s != NULL) 1200 mm_session_close(s); 1201 buffer_put_int(m, 0); 1202 mm_request_send(sock, MONITOR_ANS_PTY, m); 1203 return (0); 1204 } 1205 1206 int 1207 mm_answer_pty_cleanup(int sock, Buffer *m) 1208 { 1209 Session *s; 1210 char *tty; 1211 1212 debug3("%s entering", __func__); 1213 1214 tty = buffer_get_string(m, NULL); 1215 if ((s = session_by_tty(tty)) != NULL) 1216 mm_session_close(s); 1217 buffer_clear(m); 1218 free(tty); 1219 return (0); 1220 } 1221 1222 int 1223 mm_answer_term(int sock, Buffer *req) 1224 { 1225 extern struct monitor *pmonitor; 1226 int res, status; 1227 1228 debug3("%s: tearing down sessions", __func__); 1229 1230 /* The child is terminating */ 1231 session_destroy_all(&mm_session_close); 1232 1233 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1234 if (errno != EINTR) 1235 exit(1); 1236 1237 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1238 1239 /* Terminate process */ 1240 exit(res); 1241 } 1242 1243 void 1244 monitor_apply_keystate(struct monitor *pmonitor) 1245 { 1246 struct ssh *ssh = active_state; /* XXX */ 1247 struct kex *kex; 1248 int r; 1249 1250 debug3("%s: packet_set_state", __func__); 1251 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1252 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1253 sshbuf_free(child_state); 1254 child_state = NULL; 1255 1256 if ((kex = ssh->kex) != NULL) { 1257 /* XXX set callbacks */ 1258 #ifdef WITH_OPENSSL 1259 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1260 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1261 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server; 1262 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server; 1263 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server; 1264 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1265 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1266 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1267 #endif 1268 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1269 kex->load_host_public_key=&get_hostkey_public_by_type; 1270 kex->load_host_private_key=&get_hostkey_private_by_type; 1271 kex->host_key_index=&get_hostkey_index; 1272 kex->sign = sshd_hostkey_sign; 1273 } 1274 } 1275 1276 /* This function requries careful sanity checking */ 1277 1278 void 1279 mm_get_keystate(struct monitor *pmonitor) 1280 { 1281 debug3("%s: Waiting for new keys", __func__); 1282 1283 if ((child_state = sshbuf_new()) == NULL) 1284 fatal("%s: sshbuf_new failed", __func__); 1285 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1286 child_state); 1287 debug3("%s: GOT new keys", __func__); 1288 } 1289 1290 1291 /* XXX */ 1292 1293 #define FD_CLOSEONEXEC(x) do { \ 1294 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1295 fatal("fcntl(%d, F_SETFD)", x); \ 1296 } while (0) 1297 1298 static void 1299 monitor_openfds(struct monitor *mon, int do_logfds) 1300 { 1301 int pair[2]; 1302 1303 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1304 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1305 FD_CLOSEONEXEC(pair[0]); 1306 FD_CLOSEONEXEC(pair[1]); 1307 mon->m_recvfd = pair[0]; 1308 mon->m_sendfd = pair[1]; 1309 1310 if (do_logfds) { 1311 if (pipe(pair) == -1) 1312 fatal("%s: pipe: %s", __func__, strerror(errno)); 1313 FD_CLOSEONEXEC(pair[0]); 1314 FD_CLOSEONEXEC(pair[1]); 1315 mon->m_log_recvfd = pair[0]; 1316 mon->m_log_sendfd = pair[1]; 1317 } else 1318 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1319 } 1320 1321 #define MM_MEMSIZE 65536 1322 1323 struct monitor * 1324 monitor_init(void) 1325 { 1326 struct monitor *mon; 1327 1328 mon = xcalloc(1, sizeof(*mon)); 1329 monitor_openfds(mon, 1); 1330 1331 return mon; 1332 } 1333 1334 void 1335 monitor_reinit(struct monitor *mon) 1336 { 1337 monitor_openfds(mon, 0); 1338 } 1339 1340 #ifdef GSSAPI 1341 int 1342 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1343 { 1344 gss_OID_desc goid; 1345 OM_uint32 major; 1346 u_int len; 1347 1348 if (!options.gss_authentication) 1349 fatal("%s: GSSAPI authentication not enabled", __func__); 1350 1351 goid.elements = buffer_get_string(m, &len); 1352 goid.length = len; 1353 1354 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1355 1356 free(goid.elements); 1357 1358 buffer_clear(m); 1359 buffer_put_int(m, major); 1360 1361 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1362 1363 /* Now we have a context, enable the step */ 1364 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1365 1366 return (0); 1367 } 1368 1369 int 1370 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1371 { 1372 gss_buffer_desc in; 1373 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1374 OM_uint32 major, minor; 1375 OM_uint32 flags = 0; /* GSI needs this */ 1376 u_int len; 1377 1378 if (!options.gss_authentication) 1379 fatal("%s: GSSAPI authentication not enabled", __func__); 1380 1381 in.value = buffer_get_string(m, &len); 1382 in.length = len; 1383 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1384 free(in.value); 1385 1386 buffer_clear(m); 1387 buffer_put_int(m, major); 1388 buffer_put_string(m, out.value, out.length); 1389 buffer_put_int(m, flags); 1390 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1391 1392 gss_release_buffer(&minor, &out); 1393 1394 if (major == GSS_S_COMPLETE) { 1395 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1396 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1397 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1398 } 1399 return (0); 1400 } 1401 1402 int 1403 mm_answer_gss_checkmic(int sock, Buffer *m) 1404 { 1405 gss_buffer_desc gssbuf, mic; 1406 OM_uint32 ret; 1407 u_int len; 1408 1409 if (!options.gss_authentication) 1410 fatal("%s: GSSAPI authentication not enabled", __func__); 1411 1412 gssbuf.value = buffer_get_string(m, &len); 1413 gssbuf.length = len; 1414 mic.value = buffer_get_string(m, &len); 1415 mic.length = len; 1416 1417 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1418 1419 free(gssbuf.value); 1420 free(mic.value); 1421 1422 buffer_clear(m); 1423 buffer_put_int(m, ret); 1424 1425 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1426 1427 if (!GSS_ERROR(ret)) 1428 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1429 1430 return (0); 1431 } 1432 1433 int 1434 mm_answer_gss_userok(int sock, Buffer *m) 1435 { 1436 int authenticated; 1437 1438 if (!options.gss_authentication) 1439 fatal("%s: GSSAPI authentication not enabled", __func__); 1440 1441 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1442 1443 buffer_clear(m); 1444 buffer_put_int(m, authenticated); 1445 1446 debug3("%s: sending result %d", __func__, authenticated); 1447 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1448 1449 auth_method = "gssapi-with-mic"; 1450 1451 /* Monitor loop will terminate if authenticated */ 1452 return (authenticated); 1453 } 1454 #endif /* GSSAPI */ 1455 1456