1 /* $OpenBSD: monitor.c,v 1.178 2018/01/23 05:27:21 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 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 auth2_authctxt_reset_info(authctxt); 251 252 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 253 254 /* Special handling for multiple required authentications */ 255 if (options.num_auth_methods != 0) { 256 if (authenticated && 257 !auth2_update_methods_lists(authctxt, 258 auth_method, auth_submethod)) { 259 debug3("%s: method %s: partial", __func__, 260 auth_method); 261 authenticated = 0; 262 partial = 1; 263 } 264 } 265 266 if (authenticated) { 267 if (!(ent->flags & MON_AUTHDECIDE)) 268 fatal("%s: unexpected authentication from %d", 269 __func__, ent->type); 270 if (authctxt->pw->pw_uid == 0 && 271 !auth_root_allowed(auth_method)) 272 authenticated = 0; 273 } 274 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 275 auth_log(authctxt, authenticated, partial, 276 auth_method, auth_submethod); 277 if (!partial && !authenticated) 278 authctxt->failures++; 279 if (authenticated || partial) { 280 auth2_update_session_info(authctxt, 281 auth_method, auth_submethod); 282 } 283 } 284 } 285 286 if (!authctxt->valid) 287 fatal("%s: authenticated invalid user", __func__); 288 if (strcmp(auth_method, "unknown") == 0) 289 fatal("%s: authentication method name unknown", __func__); 290 291 debug("%s: %s has been authenticated by privileged process", 292 __func__, authctxt->user); 293 ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user); 294 295 mm_get_keystate(pmonitor); 296 297 /* Drain any buffered messages from the child */ 298 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 299 ; 300 301 close(pmonitor->m_sendfd); 302 close(pmonitor->m_log_recvfd); 303 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 304 } 305 306 static void 307 monitor_set_child_handler(pid_t pid) 308 { 309 monitor_child_pid = pid; 310 } 311 312 static void 313 monitor_child_handler(int sig) 314 { 315 kill(monitor_child_pid, sig); 316 } 317 318 void 319 monitor_child_postauth(struct monitor *pmonitor) 320 { 321 close(pmonitor->m_recvfd); 322 pmonitor->m_recvfd = -1; 323 324 monitor_set_child_handler(pmonitor->m_pid); 325 signal(SIGHUP, &monitor_child_handler); 326 signal(SIGTERM, &monitor_child_handler); 327 signal(SIGINT, &monitor_child_handler); 328 329 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); 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 (;;) 342 monitor_read(pmonitor, mon_dispatch, NULL); 343 } 344 345 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) { 359 buffer_free(&logmsg); 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); 387 free(msg); 388 389 return 0; 390 } 391 392 int 393 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 394 struct mon_table **pent) 395 { 396 Buffer m; 397 int ret; 398 u_char type; 399 struct pollfd pfd[2]; 400 401 for (;;) { 402 memset(&pfd, 0, sizeof(pfd)); 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; 407 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 408 if (errno == EINTR || errno == EAGAIN) 409 continue; 410 fatal("%s: poll: %s", __func__, strerror(errno)); 411 } 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 } 423 424 buffer_init(&m); 425 426 mm_request_receive(pmonitor->m_sendfd, &m); 427 type = buffer_get_char(&m); 428 429 debug3("%s: checking request %d", __func__, type); 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)) 439 fatal("%s: unpermitted request %d", __func__, 440 type); 441 ret = (*ent->f)(pmonitor->m_sendfd, &m); 442 buffer_free(&m); 443 444 /* The child may use this request only once, disable it */ 445 if (ent->flags & MON_ONCE) { 446 debug2("%s: %d used once, disabling now", __func__, 447 type); 448 ent->flags &= ~MON_PERMIT; 449 } 450 451 if (pent != NULL) 452 *pent = ent; 453 454 return ret; 455 } 456 457 fatal("%s: unsupported request: %d", __func__, type); 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 || 469 timingsafe_bcmp(key_blob, blob, key_bloblen)) 470 return (0); 471 return (1); 472 } 473 474 static void 475 monitor_reset_key_state(void) 476 { 477 /* reset state */ 478 free(key_blob); 479 free(hostbased_cuser); 480 free(hostbased_chost); 481 key_blob = NULL; 482 key_bloblen = 0; 483 key_blobtype = MM_NOKEY; 484 hostbased_cuser = NULL; 485 hostbased_chost = NULL; 486 } 487 488 #ifdef WITH_OPENSSL 489 int 490 mm_answer_moduli(int sock, Buffer *m) 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", 500 __func__, min, want, max); 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", 504 __func__, min, want, max); 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); 517 518 DH_free(dh); 519 } 520 mm_request_send(sock, MONITOR_ANS_MODULI, m); 521 return (0); 522 } 523 #endif 524 525 int 526 mm_answer_sign(int sock, Buffer *m) 527 { 528 struct ssh *ssh = active_state; /* XXX */ 529 extern int auth_sock; /* XXX move to state struct? */ 530 struct sshkey *key; 531 struct sshbuf *sigbuf = NULL; 532 u_char *p = NULL, *signature = NULL; 533 char *alg = NULL; 534 size_t datlen, siglen, alglen; 535 int r, is_proof = 0; 536 u_int keyid; 537 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 538 539 debug3("%s", __func__); 540 541 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 542 (r = sshbuf_get_string(m, &p, &datlen)) != 0 || 543 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0) 544 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 545 if (keyid > INT_MAX) 546 fatal("%s: invalid key ID", __func__); 547 548 /* 549 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 550 * SHA384 (48 bytes) and SHA512 (64 bytes). 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... 558 */ 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__); 570 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 571 (r = sshbuf_put_string(sigbuf, session_id2, 572 session_id2_len)) != 0 || 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 } 583 584 /* 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 } 590 591 if ((key = get_hostkey_by_index(keyid)) != NULL) { 592 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, 593 datafellows)) != 0) 594 fatal("%s: sshkey_sign failed: %s", 595 __func__, ssh_err(r)); 596 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 597 auth_sock > 0) { 598 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 599 p, datlen, alg, datafellows)) != 0) { 600 fatal("%s: ssh_agent_sign failed: %s", 601 __func__, ssh_err(r)); 602 } 603 } else 604 fatal("%s: no hostkey from index %d", __func__, keyid); 605 606 debug3("%s: %s signature %p(%zu)", __func__, 607 is_proof ? "KEX" : "hostkey proof", signature, siglen); 608 609 sshbuf_reset(m); 610 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 611 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 612 613 free(alg); 614 free(p); 615 free(signature); 616 617 mm_request_send(sock, MONITOR_ANS_SIGN, m); 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 628 mm_answer_pwnamallow(int sock, Buffer *m) 629 { 630 struct ssh *ssh = active_state; /* XXX */ 631 char *username; 632 struct passwd *pwent; 633 int allowed = 0; 634 u_int i; 635 636 debug3("%s", __func__); 637 638 if (authctxt->attempt++ != 0) 639 fatal("%s: multiple attempts for getpwnam", __func__); 640 641 username = buffer_get_string(m, NULL); 642 643 pwent = getpwnamallow(username); 644 645 authctxt->user = xstrdup(username); 646 setproctitle("%s [priv]", pwent ? username : "unknown"); 647 free(username); 648 649 buffer_clear(m); 650 651 if (pwent == NULL) { 652 buffer_put_char(m, 0); 653 authctxt->pw = fakepw(); 654 goto out; 655 } 656 657 allowed = 1; 658 authctxt->pw = pwent; 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); 669 670 out: 671 ssh_packet_set_log_preamble(ssh, "%suser %s", 672 authctxt->valid ? "authenticating" : "invalid ", authctxt->user); 673 buffer_put_string(m, &options, sizeof(options)); 674 675 #define M_CP_STROPT(x) do { \ 676 if (options.x != NULL) \ 677 buffer_put_cstring(m, options.x); \ 678 } while (0) 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) 683 /* See comment in servconf.h */ 684 COPY_MATCH_STRING_OPTS(); 685 #undef M_CP_STROPT 686 #undef M_CP_STRARRAYOPT 687 688 /* Create valid auth method lists */ 689 if (auth2_setup_methods_lists(authctxt) != 0) { 690 /* 691 * The monitor will continue long enough to let the child 692 * run to it's packet_disconnect(), but it must not allow any 693 * authentication to succeed. 694 */ 695 debug("%s: no valid authentication method lists", __func__); 696 } 697 698 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 699 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 700 701 /* Allow service/style information on the auth context */ 702 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 703 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 704 705 return (0); 706 } 707 708 int mm_answer_auth2_read_banner(int sock, Buffer *m) 709 { 710 char *banner; 711 712 buffer_clear(m); 713 banner = auth2_read_banner(); 714 buffer_put_cstring(m, banner != NULL ? banner : ""); 715 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 716 free(banner); 717 718 return (0); 719 } 720 721 int 722 mm_answer_authserv(int sock, Buffer *m) 723 { 724 monitor_permit_authentications(1); 725 726 authctxt->service = buffer_get_string(m, NULL); 727 authctxt->style = buffer_get_string(m, NULL); 728 debug3("%s: service=%s, style=%s", 729 __func__, authctxt->service, authctxt->style); 730 731 if (strlen(authctxt->style) == 0) { 732 free(authctxt->style); 733 authctxt->style = NULL; 734 } 735 736 return (0); 737 } 738 739 int 740 mm_answer_authpassword(int sock, Buffer *m) 741 { 742 static int call_count; 743 char *passwd; 744 int authenticated; 745 u_int plen; 746 747 if (!options.password_authentication) 748 fatal("%s: password authentication not enabled", __func__); 749 passwd = buffer_get_string(m, &plen); 750 /* Only authenticate if the context is valid */ 751 authenticated = options.password_authentication && 752 auth_password(authctxt, passwd); 753 explicit_bzero(passwd, strlen(passwd)); 754 free(passwd); 755 756 buffer_clear(m); 757 buffer_put_int(m, authenticated); 758 759 debug3("%s: sending result %d", __func__, authenticated); 760 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 761 762 call_count++; 763 if (plen == 0 && call_count == 1) 764 auth_method = "none"; 765 else 766 auth_method = "password"; 767 768 /* Causes monitor loop to terminate if authenticated */ 769 return (authenticated); 770 } 771 772 int 773 mm_answer_bsdauthquery(int sock, Buffer *m) 774 { 775 char *name, *infotxt; 776 u_int numprompts; 777 u_int *echo_on; 778 char **prompts; 779 u_int success; 780 781 if (!options.kbd_interactive_authentication) 782 fatal("%s: kbd-int authentication not enabled", __func__); 783 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 784 &prompts, &echo_on) < 0 ? 0 : 1; 785 786 buffer_clear(m); 787 buffer_put_int(m, success); 788 if (success) 789 buffer_put_cstring(m, prompts[0]); 790 791 debug3("%s: sending challenge success: %u", __func__, success); 792 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 793 794 if (success) { 795 free(name); 796 free(infotxt); 797 free(prompts); 798 free(echo_on); 799 } 800 801 return (0); 802 } 803 804 int 805 mm_answer_bsdauthrespond(int sock, Buffer *m) 806 { 807 char *response; 808 int authok; 809 810 if (!options.kbd_interactive_authentication) 811 fatal("%s: kbd-int authentication not enabled", __func__); 812 if (authctxt->as == NULL) 813 fatal("%s: no bsd auth session", __func__); 814 815 response = buffer_get_string(m, NULL); 816 authok = options.challenge_response_authentication && 817 auth_userresponse(authctxt->as, response, 0); 818 authctxt->as = NULL; 819 debug3("%s: <%s> = <%d>", __func__, response, authok); 820 free(response); 821 822 buffer_clear(m); 823 buffer_put_int(m, authok); 824 825 debug3("%s: sending authenticated: %d", __func__, authok); 826 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 827 828 auth_method = "keyboard-interactive"; 829 auth_submethod = "bsdauth"; 830 831 return (authok != 0); 832 } 833 834 int 835 mm_answer_keyallowed(int sock, Buffer *m) 836 { 837 struct sshkey *key; 838 char *cuser, *chost; 839 u_char *blob; 840 u_int bloblen, pubkey_auth_attempt; 841 enum mm_keytype type = 0; 842 int allowed = 0; 843 844 debug3("%s entering", __func__); 845 846 type = buffer_get_int(m); 847 cuser = buffer_get_string(m, NULL); 848 chost = buffer_get_string(m, NULL); 849 blob = buffer_get_string(m, &bloblen); 850 pubkey_auth_attempt = buffer_get_int(m); 851 852 key = key_from_blob(blob, bloblen); 853 854 debug3("%s: key_from_blob: %p", __func__, key); 855 856 if (key != NULL && authctxt->valid) { 857 /* These should not make it past the privsep child */ 858 if (key_type_plain(key->type) == KEY_RSA && 859 (datafellows & SSH_BUG_RSASIGMD5) != 0) 860 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 861 862 switch (type) { 863 case MM_USERKEY: 864 allowed = options.pubkey_authentication && 865 !auth2_key_already_used(authctxt, key) && 866 match_pattern_list(sshkey_ssh_name(key), 867 options.pubkey_key_types, 0) == 1 && 868 user_key_allowed(authctxt->pw, key, 869 pubkey_auth_attempt); 870 auth_method = "publickey"; 871 if (options.pubkey_authentication && 872 (!pubkey_auth_attempt || allowed != 1)) 873 auth_clear_options(); 874 break; 875 case MM_HOSTKEY: 876 allowed = options.hostbased_authentication && 877 !auth2_key_already_used(authctxt, key) && 878 match_pattern_list(sshkey_ssh_name(key), 879 options.hostbased_key_types, 0) == 1 && 880 hostbased_key_allowed(authctxt->pw, 881 cuser, chost, key); 882 auth2_record_info(authctxt, 883 "client user \"%.100s\", client host \"%.100s\"", 884 cuser, chost); 885 auth_method = "hostbased"; 886 break; 887 default: 888 fatal("%s: unknown key type %d", __func__, type); 889 break; 890 } 891 } 892 893 debug3("%s: key is %s", __func__, allowed ? "allowed" : "not allowed"); 894 895 auth2_record_key(authctxt, 0, key); 896 sshkey_free(key); 897 898 /* clear temporarily storage (used by verify) */ 899 monitor_reset_key_state(); 900 901 if (allowed) { 902 /* Save temporarily for comparison in verify */ 903 key_blob = blob; 904 key_bloblen = bloblen; 905 key_blobtype = type; 906 hostbased_cuser = cuser; 907 hostbased_chost = chost; 908 } else { 909 /* Log failed attempt */ 910 auth_log(authctxt, 0, 0, auth_method, NULL); 911 free(blob); 912 free(cuser); 913 free(chost); 914 } 915 916 buffer_clear(m); 917 buffer_put_int(m, allowed); 918 buffer_put_int(m, forced_command != NULL); 919 920 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 921 922 return (0); 923 } 924 925 static int 926 monitor_valid_userblob(u_char *data, u_int datalen) 927 { 928 Buffer b; 929 u_char *p; 930 char *userstyle, *cp; 931 u_int len; 932 int fail = 0; 933 934 buffer_init(&b); 935 buffer_append(&b, data, datalen); 936 937 if (datafellows & SSH_OLD_SESSIONID) { 938 p = buffer_ptr(&b); 939 len = buffer_len(&b); 940 if ((session_id2 == NULL) || 941 (len < session_id2_len) || 942 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 943 fail++; 944 buffer_consume(&b, session_id2_len); 945 } else { 946 p = buffer_get_string(&b, &len); 947 if ((session_id2 == NULL) || 948 (len != session_id2_len) || 949 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 950 fail++; 951 free(p); 952 } 953 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 954 fail++; 955 cp = buffer_get_cstring(&b, NULL); 956 xasprintf(&userstyle, "%s%s%s", authctxt->user, 957 authctxt->style ? ":" : "", 958 authctxt->style ? authctxt->style : ""); 959 if (strcmp(userstyle, cp) != 0) { 960 logit("wrong user name passed to monitor: " 961 "expected %s != %.100s", userstyle, cp); 962 fail++; 963 } 964 free(userstyle); 965 free(cp); 966 buffer_skip_string(&b); 967 cp = buffer_get_cstring(&b, NULL); 968 if (strcmp("publickey", cp) != 0) 969 fail++; 970 free(cp); 971 if (!buffer_get_char(&b)) 972 fail++; 973 buffer_skip_string(&b); 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, struct sshbuf *m) 1043 { 1044 struct sshkey *key; 1045 u_char *signature, *data, *blob; 1046 char *sigalg; 1047 size_t signaturelen, datalen, bloblen; 1048 int r, ret, valid_data = 0, encoded_ret; 1049 1050 if ((r = sshbuf_get_string(m, &blob, &bloblen)) != 0 || 1051 (r = sshbuf_get_string(m, &signature, &signaturelen)) != 0 || 1052 (r = sshbuf_get_string(m, &data, &datalen)) != 0 || 1053 (r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0) 1054 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1055 1056 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1057 !monitor_allowed_key(blob, bloblen)) 1058 fatal("%s: bad key, not previously allowed", __func__); 1059 1060 /* Empty signature algorithm means NULL. */ 1061 if (*sigalg == '\0') { 1062 free(sigalg); 1063 sigalg = NULL; 1064 } 1065 1066 /* XXX use sshkey_froms here; need to change key_blob, etc. */ 1067 if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0) 1068 fatal("%s: bad public key blob: %s", __func__, ssh_err(r)); 1069 1070 switch (key_blobtype) { 1071 case MM_USERKEY: 1072 valid_data = monitor_valid_userblob(data, datalen); 1073 auth_method = "publickey"; 1074 break; 1075 case MM_HOSTKEY: 1076 valid_data = monitor_valid_hostbasedblob(data, datalen, 1077 hostbased_cuser, hostbased_chost); 1078 auth_method = "hostbased"; 1079 break; 1080 default: 1081 valid_data = 0; 1082 break; 1083 } 1084 if (!valid_data) 1085 fatal("%s: bad signature data blob", __func__); 1086 1087 ret = sshkey_verify(key, signature, signaturelen, data, datalen, 1088 sigalg, active_state->compat); 1089 debug3("%s: %s %p signature %s", __func__, auth_method, key, 1090 (ret == 0) ? "verified" : "unverified"); 1091 auth2_record_key(authctxt, ret == 0, key); 1092 1093 free(blob); 1094 free(signature); 1095 free(data); 1096 free(sigalg); 1097 1098 monitor_reset_key_state(); 1099 1100 sshkey_free(key); 1101 sshbuf_reset(m); 1102 1103 /* encode ret != 0 as positive integer, since we're sending u32 */ 1104 encoded_ret = (ret != 0); 1105 if ((r = sshbuf_put_u32(m, encoded_ret)) != 0) 1106 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1107 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1108 1109 return ret == 0; 1110 } 1111 1112 static void 1113 mm_record_login(Session *s, struct passwd *pw) 1114 { 1115 struct ssh *ssh = active_state; /* XXX */ 1116 socklen_t fromlen; 1117 struct sockaddr_storage from; 1118 1119 /* 1120 * Get IP address of client. If the connection is not a socket, let 1121 * the address be 0.0.0.0. 1122 */ 1123 memset(&from, 0, sizeof(from)); 1124 fromlen = sizeof(from); 1125 if (packet_connection_is_on_socket()) { 1126 if (getpeername(packet_get_connection_in(), 1127 (struct sockaddr *)&from, &fromlen) < 0) { 1128 debug("getpeername: %.100s", strerror(errno)); 1129 cleanup_exit(255); 1130 } 1131 } 1132 /* Record that there was a login on that tty from the remote host. */ 1133 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1134 session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns), 1135 (struct sockaddr *)&from, fromlen); 1136 } 1137 1138 static void 1139 mm_session_close(Session *s) 1140 { 1141 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1142 if (s->ttyfd != -1) { 1143 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1144 session_pty_cleanup2(s); 1145 } 1146 session_unused(s->self); 1147 } 1148 1149 int 1150 mm_answer_pty(int sock, Buffer *m) 1151 { 1152 extern struct monitor *pmonitor; 1153 Session *s; 1154 int res, fd0; 1155 1156 debug3("%s entering", __func__); 1157 1158 buffer_clear(m); 1159 s = session_new(); 1160 if (s == NULL) 1161 goto error; 1162 s->authctxt = authctxt; 1163 s->pw = authctxt->pw; 1164 s->pid = pmonitor->m_pid; 1165 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1166 if (res == 0) 1167 goto error; 1168 pty_setowner(authctxt->pw, s->tty); 1169 1170 buffer_put_int(m, 1); 1171 buffer_put_cstring(m, s->tty); 1172 1173 /* We need to trick ttyslot */ 1174 if (dup2(s->ttyfd, 0) == -1) 1175 fatal("%s: dup2", __func__); 1176 1177 mm_record_login(s, authctxt->pw); 1178 1179 /* Now we can close the file descriptor again */ 1180 close(0); 1181 1182 /* send messages generated by record_login */ 1183 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1184 buffer_clear(&loginmsg); 1185 1186 mm_request_send(sock, MONITOR_ANS_PTY, m); 1187 1188 if (mm_send_fd(sock, s->ptyfd) == -1 || 1189 mm_send_fd(sock, s->ttyfd) == -1) 1190 fatal("%s: send fds failed", __func__); 1191 1192 /* make sure nothing uses fd 0 */ 1193 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1194 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1195 if (fd0 != 0) 1196 error("%s: fd0 %d != 0", __func__, fd0); 1197 1198 /* slave is not needed */ 1199 close(s->ttyfd); 1200 s->ttyfd = s->ptyfd; 1201 /* no need to dup() because nobody closes ptyfd */ 1202 s->ptymaster = s->ptyfd; 1203 1204 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1205 1206 return (0); 1207 1208 error: 1209 if (s != NULL) 1210 mm_session_close(s); 1211 buffer_put_int(m, 0); 1212 mm_request_send(sock, MONITOR_ANS_PTY, m); 1213 return (0); 1214 } 1215 1216 int 1217 mm_answer_pty_cleanup(int sock, Buffer *m) 1218 { 1219 Session *s; 1220 char *tty; 1221 1222 debug3("%s entering", __func__); 1223 1224 tty = buffer_get_string(m, NULL); 1225 if ((s = session_by_tty(tty)) != NULL) 1226 mm_session_close(s); 1227 buffer_clear(m); 1228 free(tty); 1229 return (0); 1230 } 1231 1232 int 1233 mm_answer_term(int sock, Buffer *req) 1234 { 1235 struct ssh *ssh = active_state; /* XXX */ 1236 extern struct monitor *pmonitor; 1237 int res, status; 1238 1239 debug3("%s: tearing down sessions", __func__); 1240 1241 /* The child is terminating */ 1242 session_destroy_all(ssh, &mm_session_close); 1243 1244 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1245 if (errno != EINTR) 1246 exit(1); 1247 1248 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1249 1250 /* Terminate process */ 1251 exit(res); 1252 } 1253 1254 void 1255 monitor_clear_keystate(struct monitor *pmonitor) 1256 { 1257 struct ssh *ssh = active_state; /* XXX */ 1258 1259 ssh_clear_newkeys(ssh, MODE_IN); 1260 ssh_clear_newkeys(ssh, MODE_OUT); 1261 sshbuf_free(child_state); 1262 child_state = NULL; 1263 } 1264 1265 void 1266 monitor_apply_keystate(struct monitor *pmonitor) 1267 { 1268 struct ssh *ssh = active_state; /* XXX */ 1269 struct kex *kex; 1270 int r; 1271 1272 debug3("%s: packet_set_state", __func__); 1273 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1274 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1275 sshbuf_free(child_state); 1276 child_state = NULL; 1277 1278 if ((kex = ssh->kex) != NULL) { 1279 /* XXX set callbacks */ 1280 #ifdef WITH_OPENSSL 1281 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1282 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1283 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server; 1284 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server; 1285 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server; 1286 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1287 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1288 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1289 #endif 1290 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1291 kex->load_host_public_key=&get_hostkey_public_by_type; 1292 kex->load_host_private_key=&get_hostkey_private_by_type; 1293 kex->host_key_index=&get_hostkey_index; 1294 kex->sign = sshd_hostkey_sign; 1295 } 1296 } 1297 1298 /* This function requries careful sanity checking */ 1299 1300 void 1301 mm_get_keystate(struct monitor *pmonitor) 1302 { 1303 debug3("%s: Waiting for new keys", __func__); 1304 1305 if ((child_state = sshbuf_new()) == NULL) 1306 fatal("%s: sshbuf_new failed", __func__); 1307 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1308 child_state); 1309 debug3("%s: GOT new keys", __func__); 1310 } 1311 1312 1313 /* XXX */ 1314 1315 #define FD_CLOSEONEXEC(x) do { \ 1316 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1317 fatal("fcntl(%d, F_SETFD)", x); \ 1318 } while (0) 1319 1320 static void 1321 monitor_openfds(struct monitor *mon, int do_logfds) 1322 { 1323 int pair[2]; 1324 #ifdef SO_ZEROIZE 1325 int on = 1; 1326 #endif 1327 1328 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1329 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1330 #ifdef SO_ZEROIZE 1331 if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) < 0) 1332 error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno)); 1333 if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) < 0) 1334 error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno)); 1335 #endif 1336 FD_CLOSEONEXEC(pair[0]); 1337 FD_CLOSEONEXEC(pair[1]); 1338 mon->m_recvfd = pair[0]; 1339 mon->m_sendfd = pair[1]; 1340 1341 if (do_logfds) { 1342 if (pipe(pair) == -1) 1343 fatal("%s: pipe: %s", __func__, strerror(errno)); 1344 FD_CLOSEONEXEC(pair[0]); 1345 FD_CLOSEONEXEC(pair[1]); 1346 mon->m_log_recvfd = pair[0]; 1347 mon->m_log_sendfd = pair[1]; 1348 } else 1349 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1350 } 1351 1352 #define MM_MEMSIZE 65536 1353 1354 struct monitor * 1355 monitor_init(void) 1356 { 1357 struct monitor *mon; 1358 1359 mon = xcalloc(1, sizeof(*mon)); 1360 monitor_openfds(mon, 1); 1361 1362 return mon; 1363 } 1364 1365 void 1366 monitor_reinit(struct monitor *mon) 1367 { 1368 monitor_openfds(mon, 0); 1369 } 1370 1371 #ifdef GSSAPI 1372 int 1373 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1374 { 1375 gss_OID_desc goid; 1376 OM_uint32 major; 1377 u_int len; 1378 1379 if (!options.gss_authentication) 1380 fatal("%s: GSSAPI authentication not enabled", __func__); 1381 1382 goid.elements = buffer_get_string(m, &len); 1383 goid.length = len; 1384 1385 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1386 1387 free(goid.elements); 1388 1389 buffer_clear(m); 1390 buffer_put_int(m, major); 1391 1392 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1393 1394 /* Now we have a context, enable the step */ 1395 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1396 1397 return (0); 1398 } 1399 1400 int 1401 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1402 { 1403 gss_buffer_desc in; 1404 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1405 OM_uint32 major, minor; 1406 OM_uint32 flags = 0; /* GSI needs this */ 1407 u_int len; 1408 1409 if (!options.gss_authentication) 1410 fatal("%s: GSSAPI authentication not enabled", __func__); 1411 1412 in.value = buffer_get_string(m, &len); 1413 in.length = len; 1414 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1415 free(in.value); 1416 1417 buffer_clear(m); 1418 buffer_put_int(m, major); 1419 buffer_put_string(m, out.value, out.length); 1420 buffer_put_int(m, flags); 1421 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1422 1423 gss_release_buffer(&minor, &out); 1424 1425 if (major == GSS_S_COMPLETE) { 1426 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1427 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1428 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1429 } 1430 return (0); 1431 } 1432 1433 int 1434 mm_answer_gss_checkmic(int sock, Buffer *m) 1435 { 1436 gss_buffer_desc gssbuf, mic; 1437 OM_uint32 ret; 1438 u_int len; 1439 1440 if (!options.gss_authentication) 1441 fatal("%s: GSSAPI authentication not enabled", __func__); 1442 1443 gssbuf.value = buffer_get_string(m, &len); 1444 gssbuf.length = len; 1445 mic.value = buffer_get_string(m, &len); 1446 mic.length = len; 1447 1448 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1449 1450 free(gssbuf.value); 1451 free(mic.value); 1452 1453 buffer_clear(m); 1454 buffer_put_int(m, ret); 1455 1456 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1457 1458 if (!GSS_ERROR(ret)) 1459 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1460 1461 return (0); 1462 } 1463 1464 int 1465 mm_answer_gss_userok(int sock, Buffer *m) 1466 { 1467 int authenticated; 1468 const char *displayname; 1469 1470 if (!options.gss_authentication) 1471 fatal("%s: GSSAPI authentication not enabled", __func__); 1472 1473 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1474 1475 buffer_clear(m); 1476 buffer_put_int(m, authenticated); 1477 1478 debug3("%s: sending result %d", __func__, authenticated); 1479 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1480 1481 auth_method = "gssapi-with-mic"; 1482 1483 if ((displayname = ssh_gssapi_displayname()) != NULL) 1484 auth2_record_info(authctxt, "%s", displayname); 1485 1486 /* Monitor loop will terminate if authenticated */ 1487 return (authenticated); 1488 } 1489 #endif /* GSSAPI */ 1490 1491