1 /* $OpenBSD: monitor.c,v 1.186 2018/07/20 03:46:34 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 "includes.h" 29 30 #include <sys/types.h> 31 #include <sys/socket.h> 32 #include <sys/wait.h> 33 34 #include <errno.h> 35 #include <fcntl.h> 36 #include <limits.h> 37 #ifdef HAVE_PATHS_H 38 #include <paths.h> 39 #endif 40 #include <pwd.h> 41 #include <signal.h> 42 #ifdef HAVE_STDINT_H 43 #include <stdint.h> 44 #endif 45 #include <stdlib.h> 46 #include <string.h> 47 #include <stdarg.h> 48 #include <stdio.h> 49 #include <unistd.h> 50 #ifdef HAVE_POLL_H 51 #include <poll.h> 52 #else 53 # ifdef HAVE_SYS_POLL_H 54 # include <sys/poll.h> 55 # endif 56 #endif 57 58 #ifdef WITH_OPENSSL 59 #include <openssl/dh.h> 60 #endif 61 62 #include "openbsd-compat/sys-tree.h" 63 #include "openbsd-compat/sys-queue.h" 64 #include "openbsd-compat/openssl-compat.h" 65 66 #include "atomicio.h" 67 #include "xmalloc.h" 68 #include "ssh.h" 69 #include "sshkey.h" 70 #include "sshbuf.h" 71 #include "hostfile.h" 72 #include "auth.h" 73 #include "cipher.h" 74 #include "kex.h" 75 #include "dh.h" 76 #include "auth-pam.h" 77 #include "packet.h" 78 #include "auth-options.h" 79 #include "sshpty.h" 80 #include "channels.h" 81 #include "session.h" 82 #include "sshlogin.h" 83 #include "canohost.h" 84 #include "log.h" 85 #include "misc.h" 86 #include "servconf.h" 87 #include "monitor.h" 88 #ifdef GSSAPI 89 #include "ssh-gss.h" 90 #endif 91 #include "monitor_wrap.h" 92 #include "monitor_fdpass.h" 93 #include "compat.h" 94 #include "ssh2.h" 95 #include "authfd.h" 96 #include "match.h" 97 #include "ssherr.h" 98 99 #ifdef GSSAPI 100 static Gssctxt *gsscontext = NULL; 101 #endif 102 103 /* Imports */ 104 extern ServerOptions options; 105 extern u_int utmp_len; 106 extern u_char session_id[]; 107 extern struct sshbuf *loginmsg; 108 extern struct sshauthopt *auth_opts; /* XXX move to permanent ssh->authctxt? */ 109 110 /* State exported from the child */ 111 static struct sshbuf *child_state; 112 113 /* Functions on the monitor that answer unprivileged requests */ 114 115 int mm_answer_moduli(int, struct sshbuf *); 116 int mm_answer_sign(int, struct sshbuf *); 117 int mm_answer_login_getpwclass(int, struct sshbuf *); 118 int mm_answer_pwnamallow(int, struct sshbuf *); 119 int mm_answer_auth2_read_banner(int, struct sshbuf *); 120 int mm_answer_authserv(int, struct sshbuf *); 121 int mm_answer_authpassword(int, struct sshbuf *); 122 int mm_answer_bsdauthquery(int, struct sshbuf *); 123 int mm_answer_bsdauthrespond(int, struct sshbuf *); 124 int mm_answer_keyallowed(int, struct sshbuf *); 125 int mm_answer_keyverify(int, struct sshbuf *); 126 int mm_answer_pty(int, struct sshbuf *); 127 int mm_answer_pty_cleanup(int, struct sshbuf *); 128 int mm_answer_term(int, struct sshbuf *); 129 int mm_answer_rsa_keyallowed(int, struct sshbuf *); 130 int mm_answer_rsa_challenge(int, struct sshbuf *); 131 int mm_answer_rsa_response(int, struct sshbuf *); 132 int mm_answer_sesskey(int, struct sshbuf *); 133 int mm_answer_sessid(int, struct sshbuf *); 134 135 #ifdef USE_PAM 136 int mm_answer_pam_start(int, struct sshbuf *); 137 int mm_answer_pam_account(int, struct sshbuf *); 138 int mm_answer_pam_init_ctx(int, struct sshbuf *); 139 int mm_answer_pam_query(int, struct sshbuf *); 140 int mm_answer_pam_respond(int, struct sshbuf *); 141 int mm_answer_pam_free_ctx(int, struct sshbuf *); 142 #endif 143 144 #ifdef GSSAPI 145 int mm_answer_gss_setup_ctx(int, struct sshbuf *); 146 int mm_answer_gss_accept_ctx(int, struct sshbuf *); 147 int mm_answer_gss_userok(int, struct sshbuf *); 148 int mm_answer_gss_checkmic(int, struct sshbuf *); 149 #endif 150 151 #ifdef SSH_AUDIT_EVENTS 152 int mm_answer_audit_event(int, struct sshbuf *); 153 int mm_answer_audit_command(int, struct sshbuf *); 154 #endif 155 156 static int monitor_read_log(struct monitor *); 157 158 static Authctxt *authctxt; 159 160 /* local state for key verify */ 161 static u_char *key_blob = NULL; 162 static size_t key_bloblen = 0; 163 static int key_blobtype = MM_NOKEY; 164 static struct sshauthopt *key_opts = NULL; 165 static char *hostbased_cuser = NULL; 166 static char *hostbased_chost = NULL; 167 static char *auth_method = "unknown"; 168 static char *auth_submethod = NULL; 169 static u_int session_id2_len = 0; 170 static u_char *session_id2 = NULL; 171 static pid_t monitor_child_pid; 172 173 struct mon_table { 174 enum monitor_reqtype type; 175 int flags; 176 int (*f)(int, struct sshbuf *); 177 }; 178 179 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 180 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 181 #define MON_ONCE 0x0010 /* Disable after calling */ 182 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 183 184 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 185 186 #define MON_PERMIT 0x1000 /* Request is permitted */ 187 188 struct mon_table mon_dispatch_proto20[] = { 189 #ifdef WITH_OPENSSL 190 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 191 #endif 192 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 193 {MONITOR_REQ_GETPWCLASS, MON_AUTH, mm_answer_login_getpwclass}, 194 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 195 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 196 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 197 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 198 #ifdef USE_PAM 199 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 200 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 201 {MONITOR_REQ_PAM_INIT_CTX, MON_ONCE, mm_answer_pam_init_ctx}, 202 {MONITOR_REQ_PAM_QUERY, 0, mm_answer_pam_query}, 203 {MONITOR_REQ_PAM_RESPOND, MON_ONCE, mm_answer_pam_respond}, 204 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 205 #endif 206 #ifdef SSH_AUDIT_EVENTS 207 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 208 #endif 209 #ifdef BSD_AUTH 210 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 211 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 212 #endif 213 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 214 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 215 #ifdef GSSAPI 216 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 217 {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx}, 218 {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok}, 219 {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic}, 220 #endif 221 {0, 0, NULL} 222 }; 223 224 struct mon_table mon_dispatch_postauth20[] = { 225 #ifdef WITH_OPENSSL 226 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 227 #endif 228 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 229 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 230 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 231 {MONITOR_REQ_TERM, 0, mm_answer_term}, 232 #ifdef SSH_AUDIT_EVENTS 233 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 234 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 235 #endif 236 {0, 0, NULL} 237 }; 238 239 struct mon_table *mon_dispatch; 240 241 /* Specifies if a certain message is allowed at the moment */ 242 static void 243 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 244 { 245 while (ent->f != NULL) { 246 if (ent->type == type) { 247 ent->flags &= ~MON_PERMIT; 248 ent->flags |= permit ? MON_PERMIT : 0; 249 return; 250 } 251 ent++; 252 } 253 } 254 255 static void 256 monitor_permit_authentications(int permit) 257 { 258 struct mon_table *ent = mon_dispatch; 259 260 while (ent->f != NULL) { 261 if (ent->flags & MON_AUTH) { 262 ent->flags &= ~MON_PERMIT; 263 ent->flags |= permit ? MON_PERMIT : 0; 264 } 265 ent++; 266 } 267 } 268 269 void 270 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 271 { 272 struct ssh *ssh = active_state; /* XXX */ 273 struct mon_table *ent; 274 int authenticated = 0, partial = 0; 275 276 debug3("preauth child monitor started"); 277 278 if (pmonitor->m_recvfd >= 0) 279 close(pmonitor->m_recvfd); 280 if (pmonitor->m_log_sendfd >= 0) 281 close(pmonitor->m_log_sendfd); 282 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 283 284 authctxt = _authctxt; 285 memset(authctxt, 0, sizeof(*authctxt)); 286 ssh->authctxt = authctxt; 287 288 authctxt->loginmsg = loginmsg; 289 290 mon_dispatch = mon_dispatch_proto20; 291 /* Permit requests for moduli and signatures */ 292 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 293 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 294 295 /* The first few requests do not require asynchronous access */ 296 while (!authenticated) { 297 partial = 0; 298 auth_method = "unknown"; 299 auth_submethod = NULL; 300 auth2_authctxt_reset_info(authctxt); 301 302 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 303 304 /* Special handling for multiple required authentications */ 305 if (options.num_auth_methods != 0) { 306 if (authenticated && 307 !auth2_update_methods_lists(authctxt, 308 auth_method, auth_submethod)) { 309 debug3("%s: method %s: partial", __func__, 310 auth_method); 311 authenticated = 0; 312 partial = 1; 313 } 314 } 315 316 if (authenticated) { 317 if (!(ent->flags & MON_AUTHDECIDE)) 318 fatal("%s: unexpected authentication from %d", 319 __func__, ent->type); 320 if (authctxt->pw->pw_uid == 0 && 321 !auth_root_allowed(ssh, auth_method)) 322 authenticated = 0; 323 #ifdef USE_PAM 324 /* PAM needs to perform account checks after auth */ 325 if (options.use_pam && authenticated) { 326 struct sshbuf *m; 327 328 if ((m = sshbuf_new()) == NULL) 329 fatal("%s: sshbuf_new failed", 330 __func__); 331 mm_request_receive_expect(pmonitor->m_sendfd, 332 MONITOR_REQ_PAM_ACCOUNT, m); 333 authenticated = mm_answer_pam_account( 334 pmonitor->m_sendfd, m); 335 sshbuf_free(m); 336 } 337 #endif 338 } 339 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 340 auth_log(authctxt, authenticated, partial, 341 auth_method, auth_submethod); 342 if (!partial && !authenticated) 343 authctxt->failures++; 344 if (authenticated || partial) { 345 auth2_update_session_info(authctxt, 346 auth_method, auth_submethod); 347 } 348 } 349 } 350 351 if (!authctxt->valid) 352 fatal("%s: authenticated invalid user", __func__); 353 if (strcmp(auth_method, "unknown") == 0) 354 fatal("%s: authentication method name unknown", __func__); 355 356 debug("%s: %s has been authenticated by privileged process", 357 __func__, authctxt->user); 358 ssh->authctxt = NULL; 359 ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user); 360 361 mm_get_keystate(pmonitor); 362 363 /* Drain any buffered messages from the child */ 364 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 365 ; 366 367 if (pmonitor->m_recvfd >= 0) 368 close(pmonitor->m_recvfd); 369 if (pmonitor->m_log_sendfd >= 0) 370 close(pmonitor->m_log_sendfd); 371 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 372 } 373 374 static void 375 monitor_set_child_handler(pid_t pid) 376 { 377 monitor_child_pid = pid; 378 } 379 380 static void 381 monitor_child_handler(int sig) 382 { 383 kill(monitor_child_pid, sig); 384 } 385 386 void 387 monitor_child_postauth(struct monitor *pmonitor) 388 { 389 close(pmonitor->m_recvfd); 390 pmonitor->m_recvfd = -1; 391 392 monitor_set_child_handler(pmonitor->m_pid); 393 signal(SIGHUP, &monitor_child_handler); 394 signal(SIGTERM, &monitor_child_handler); 395 signal(SIGINT, &monitor_child_handler); 396 #ifdef SIGXFSZ 397 signal(SIGXFSZ, SIG_IGN); 398 #endif 399 400 mon_dispatch = mon_dispatch_postauth20; 401 402 /* Permit requests for moduli and signatures */ 403 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 404 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 405 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 406 407 if (auth_opts->permit_pty_flag) { 408 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 409 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 410 } 411 412 for (;;) 413 monitor_read(pmonitor, mon_dispatch, NULL); 414 } 415 416 static int 417 monitor_read_log(struct monitor *pmonitor) 418 { 419 struct sshbuf *logmsg; 420 u_int len, level; 421 char *msg; 422 u_char *p; 423 int r; 424 425 if ((logmsg = sshbuf_new()) == NULL) 426 fatal("%s: sshbuf_new", __func__); 427 428 /* Read length */ 429 if ((r = sshbuf_reserve(logmsg, 4, &p)) != 0) 430 fatal("%s: reserve: %s", __func__, ssh_err(r)); 431 if (atomicio(read, pmonitor->m_log_recvfd, p, 4) != 4) { 432 if (errno == EPIPE) { 433 sshbuf_free(logmsg); 434 debug("%s: child log fd closed", __func__); 435 close(pmonitor->m_log_recvfd); 436 pmonitor->m_log_recvfd = -1; 437 return -1; 438 } 439 fatal("%s: log fd read: %s", __func__, strerror(errno)); 440 } 441 if ((r = sshbuf_get_u32(logmsg, &len)) != 0) 442 fatal("%s: get len: %s", __func__, ssh_err(r)); 443 if (len <= 4 || len > 8192) 444 fatal("%s: invalid log message length %u", __func__, len); 445 446 /* Read severity, message */ 447 sshbuf_reset(logmsg); 448 if ((r = sshbuf_reserve(logmsg, len, &p)) != 0) 449 fatal("%s: reserve: %s", __func__, ssh_err(r)); 450 if (atomicio(read, pmonitor->m_log_recvfd, p, len) != len) 451 fatal("%s: log fd read: %s", __func__, strerror(errno)); 452 if ((r = sshbuf_get_u32(logmsg, &level)) != 0 || 453 (r = sshbuf_get_cstring(logmsg, &msg, NULL)) != 0) 454 fatal("%s: decode: %s", __func__, ssh_err(r)); 455 456 /* Log it */ 457 if (log_level_name(level) == NULL) 458 fatal("%s: invalid log level %u (corrupted message?)", 459 __func__, level); 460 do_log2(level, "%s [preauth]", msg); 461 462 sshbuf_free(logmsg); 463 free(msg); 464 465 return 0; 466 } 467 468 int 469 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 470 struct mon_table **pent) 471 { 472 struct sshbuf *m; 473 int r, ret; 474 u_char type; 475 struct pollfd pfd[2]; 476 477 for (;;) { 478 memset(&pfd, 0, sizeof(pfd)); 479 pfd[0].fd = pmonitor->m_sendfd; 480 pfd[0].events = POLLIN; 481 pfd[1].fd = pmonitor->m_log_recvfd; 482 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 483 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 484 if (errno == EINTR || errno == EAGAIN) 485 continue; 486 fatal("%s: poll: %s", __func__, strerror(errno)); 487 } 488 if (pfd[1].revents) { 489 /* 490 * Drain all log messages before processing next 491 * monitor request. 492 */ 493 monitor_read_log(pmonitor); 494 continue; 495 } 496 if (pfd[0].revents) 497 break; /* Continues below */ 498 } 499 500 if ((m = sshbuf_new()) == NULL) 501 fatal("%s: sshbuf_new", __func__); 502 503 mm_request_receive(pmonitor->m_sendfd, m); 504 if ((r = sshbuf_get_u8(m, &type)) != 0) 505 fatal("%s: decode: %s", __func__, ssh_err(r)); 506 507 debug3("%s: checking request %d", __func__, type); 508 509 while (ent->f != NULL) { 510 if (ent->type == type) 511 break; 512 ent++; 513 } 514 515 if (ent->f != NULL) { 516 if (!(ent->flags & MON_PERMIT)) 517 fatal("%s: unpermitted request %d", __func__, 518 type); 519 ret = (*ent->f)(pmonitor->m_sendfd, m); 520 sshbuf_free(m); 521 522 /* The child may use this request only once, disable it */ 523 if (ent->flags & MON_ONCE) { 524 debug2("%s: %d used once, disabling now", __func__, 525 type); 526 ent->flags &= ~MON_PERMIT; 527 } 528 529 if (pent != NULL) 530 *pent = ent; 531 532 return ret; 533 } 534 535 fatal("%s: unsupported request: %d", __func__, type); 536 537 /* NOTREACHED */ 538 return (-1); 539 } 540 541 /* allowed key state */ 542 static int 543 monitor_allowed_key(u_char *blob, u_int bloblen) 544 { 545 /* make sure key is allowed */ 546 if (key_blob == NULL || key_bloblen != bloblen || 547 timingsafe_bcmp(key_blob, blob, key_bloblen)) 548 return (0); 549 return (1); 550 } 551 552 static void 553 monitor_reset_key_state(void) 554 { 555 /* reset state */ 556 free(key_blob); 557 free(hostbased_cuser); 558 free(hostbased_chost); 559 sshauthopt_free(key_opts); 560 key_blob = NULL; 561 key_bloblen = 0; 562 key_blobtype = MM_NOKEY; 563 key_opts = NULL; 564 hostbased_cuser = NULL; 565 hostbased_chost = NULL; 566 } 567 568 #ifdef WITH_OPENSSL 569 int 570 mm_answer_moduli(int sock, struct sshbuf *m) 571 { 572 DH *dh; 573 const BIGNUM *dh_p, *dh_g; 574 int r; 575 u_int min, want, max; 576 577 if ((r = sshbuf_get_u32(m, &min)) != 0 || 578 (r = sshbuf_get_u32(m, &want)) != 0 || 579 (r = sshbuf_get_u32(m, &max)) != 0) 580 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 581 582 debug3("%s: got parameters: %d %d %d", 583 __func__, min, want, max); 584 /* We need to check here, too, in case the child got corrupted */ 585 if (max < min || want < min || max < want) 586 fatal("%s: bad parameters: %d %d %d", 587 __func__, min, want, max); 588 589 sshbuf_reset(m); 590 591 dh = choose_dh(min, want, max); 592 if (dh == NULL) { 593 if ((r = sshbuf_put_u8(m, 0)) != 0) 594 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 595 return (0); 596 } else { 597 /* Send first bignum */ 598 DH_get0_pqg(dh, &dh_p, NULL, &dh_g); 599 if ((r = sshbuf_put_u8(m, 1)) != 0 || 600 (r = sshbuf_put_bignum2(m, dh_p)) != 0 || 601 (r = sshbuf_put_bignum2(m, dh_g)) != 0) 602 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 603 604 DH_free(dh); 605 } 606 mm_request_send(sock, MONITOR_ANS_MODULI, m); 607 return (0); 608 } 609 #endif 610 611 int 612 mm_answer_sign(int sock, struct sshbuf *m) 613 { 614 struct ssh *ssh = active_state; /* XXX */ 615 extern int auth_sock; /* XXX move to state struct? */ 616 struct sshkey *key; 617 struct sshbuf *sigbuf = NULL; 618 u_char *p = NULL, *signature = NULL; 619 char *alg = NULL; 620 size_t datlen, siglen, alglen; 621 int r, is_proof = 0; 622 u_int keyid, compat; 623 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 624 625 debug3("%s", __func__); 626 627 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 628 (r = sshbuf_get_string(m, &p, &datlen)) != 0 || 629 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0 || 630 (r = sshbuf_get_u32(m, &compat)) != 0) 631 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 632 if (keyid > INT_MAX) 633 fatal("%s: invalid key ID", __func__); 634 635 /* 636 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 637 * SHA384 (48 bytes) and SHA512 (64 bytes). 638 * 639 * Otherwise, verify the signature request is for a hostkey 640 * proof. 641 * 642 * XXX perform similar check for KEX signature requests too? 643 * it's not trivial, since what is signed is the hash, rather 644 * than the full kex structure... 645 */ 646 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) { 647 /* 648 * Construct expected hostkey proof and compare it to what 649 * the client sent us. 650 */ 651 if (session_id2_len == 0) /* hostkeys is never first */ 652 fatal("%s: bad data length: %zu", __func__, datlen); 653 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL) 654 fatal("%s: no hostkey for index %d", __func__, keyid); 655 if ((sigbuf = sshbuf_new()) == NULL) 656 fatal("%s: sshbuf_new", __func__); 657 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 658 (r = sshbuf_put_string(sigbuf, session_id2, 659 session_id2_len)) != 0 || 660 (r = sshkey_puts(key, sigbuf)) != 0) 661 fatal("%s: couldn't prepare private key " 662 "proof buffer: %s", __func__, ssh_err(r)); 663 if (datlen != sshbuf_len(sigbuf) || 664 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0) 665 fatal("%s: bad data length: %zu, hostkey proof len %zu", 666 __func__, datlen, sshbuf_len(sigbuf)); 667 sshbuf_free(sigbuf); 668 is_proof = 1; 669 } 670 671 /* save session id, it will be passed on the first call */ 672 if (session_id2_len == 0) { 673 session_id2_len = datlen; 674 session_id2 = xmalloc(session_id2_len); 675 memcpy(session_id2, p, session_id2_len); 676 } 677 678 if ((key = get_hostkey_by_index(keyid)) != NULL) { 679 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, 680 compat)) != 0) 681 fatal("%s: sshkey_sign failed: %s", 682 __func__, ssh_err(r)); 683 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 684 auth_sock > 0) { 685 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 686 p, datlen, alg, compat)) != 0) { 687 fatal("%s: ssh_agent_sign failed: %s", 688 __func__, ssh_err(r)); 689 } 690 } else 691 fatal("%s: no hostkey from index %d", __func__, keyid); 692 693 debug3("%s: %s signature %p(%zu)", __func__, 694 is_proof ? "KEX" : "hostkey proof", signature, siglen); 695 696 sshbuf_reset(m); 697 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 698 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 699 700 free(alg); 701 free(p); 702 free(signature); 703 704 mm_request_send(sock, MONITOR_ANS_SIGN, m); 705 706 /* Turn on permissions for getpwnam */ 707 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 708 709 return (0); 710 } 711 712 int 713 mm_answer_login_getpwclass(int sock, struct sshbuf *m) 714 { 715 login_cap_t *lc; 716 struct passwd *pw; 717 int r; 718 u_int len; 719 720 debug3("%s", __func__); 721 722 pw = sshbuf_get_passwd(m); 723 if (pw == NULL) 724 fatal("%s: receive get struct passwd failed", __func__); 725 726 lc = login_getpwclass(pw); 727 728 sshbuf_reset(m); 729 730 if (lc == NULL) { 731 if (r = sshbuf_put_u8(m, 0) != 0) 732 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 733 goto out; 734 } 735 736 if ((r = sshbuf_put_u8(m, 1)) != 0 || 737 (r = sshbuf_put_cstring(m, lc->lc_class)) != 0 || 738 (r = sshbuf_put_cstring(m, lc->lc_cap)) != 0 || 739 (r = sshbuf_put_cstring(m, lc->lc_style)) != 0) 740 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 741 742 login_close(lc); 743 out: 744 debug3("%s: sending MONITOR_ANS_GETPWCLASS", __func__); 745 mm_request_send(sock, MONITOR_ANS_GETPWCLASS, m); 746 747 sshbuf_free_passwd(pw); 748 749 return (0); 750 } 751 752 /* Retrieves the password entry and also checks if the user is permitted */ 753 754 int 755 mm_answer_pwnamallow(int sock, struct sshbuf *m) 756 { 757 struct ssh *ssh = active_state; /* XXX */ 758 char *username; 759 struct passwd *pwent; 760 int r, allowed = 0; 761 u_int i; 762 763 debug3("%s", __func__); 764 765 if (authctxt->attempt++ != 0) 766 fatal("%s: multiple attempts for getpwnam", __func__); 767 768 if ((r = sshbuf_get_cstring(m, &username, NULL)) != 0) 769 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 770 771 pwent = getpwnamallow(username); 772 773 authctxt->user = xstrdup(username); 774 setproctitle("%s [priv]", pwent ? username : "unknown"); 775 free(username); 776 777 sshbuf_reset(m); 778 779 if (pwent == NULL) { 780 if ((r = sshbuf_put_u8(m, 0)) != 0) 781 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 782 authctxt->pw = fakepw(); 783 goto out; 784 } 785 786 allowed = 1; 787 authctxt->pw = pwent; 788 authctxt->valid = 1; 789 790 if ((r = sshbuf_put_u8(m, 1)) != 0 || 791 (r = sshbuf_put_passwd(m, pwent)) != 0) 792 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 793 794 out: 795 ssh_packet_set_log_preamble(ssh, "%suser %s", 796 authctxt->valid ? "authenticating" : "invalid ", authctxt->user); 797 if ((r = sshbuf_put_string(m, &options, sizeof(options))) != 0) 798 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 799 800 #define M_CP_STROPT(x) do { \ 801 if (options.x != NULL) { \ 802 if ((r = sshbuf_put_cstring(m, options.x)) != 0) \ 803 fatal("%s: buffer error: %s", \ 804 __func__, ssh_err(r)); \ 805 } \ 806 } while (0) 807 #define M_CP_STRARRAYOPT(x, nx) do { \ 808 for (i = 0; i < options.nx; i++) { \ 809 if ((r = sshbuf_put_cstring(m, options.x[i])) != 0) \ 810 fatal("%s: buffer error: %s", \ 811 __func__, ssh_err(r)); \ 812 } \ 813 } while (0) 814 /* See comment in servconf.h */ 815 COPY_MATCH_STRING_OPTS(); 816 #undef M_CP_STROPT 817 #undef M_CP_STRARRAYOPT 818 819 /* Create valid auth method lists */ 820 if (auth2_setup_methods_lists(authctxt) != 0) { 821 /* 822 * The monitor will continue long enough to let the child 823 * run to it's packet_disconnect(), but it must not allow any 824 * authentication to succeed. 825 */ 826 debug("%s: no valid authentication method lists", __func__); 827 } 828 829 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 830 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 831 832 /* Allow service/style information on the auth context */ 833 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 834 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 835 836 #ifdef USE_PAM 837 if (options.use_pam) 838 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 839 #endif 840 841 return (0); 842 } 843 844 int mm_answer_auth2_read_banner(int sock, struct sshbuf *m) 845 { 846 char *banner; 847 int r; 848 849 sshbuf_reset(m); 850 banner = auth2_read_banner(); 851 if ((r = sshbuf_put_cstring(m, banner != NULL ? banner : "")) != 0) 852 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 853 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 854 free(banner); 855 856 return (0); 857 } 858 859 int 860 mm_answer_authserv(int sock, struct sshbuf *m) 861 { 862 int r; 863 864 monitor_permit_authentications(1); 865 866 if ((r = sshbuf_get_cstring(m, &authctxt->service, NULL)) != 0 || 867 (r = sshbuf_get_cstring(m, &authctxt->style, NULL)) != 0) 868 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 869 debug3("%s: service=%s, style=%s", 870 __func__, authctxt->service, authctxt->style); 871 872 if (strlen(authctxt->style) == 0) { 873 free(authctxt->style); 874 authctxt->style = NULL; 875 } 876 877 return (0); 878 } 879 880 int 881 mm_answer_authpassword(int sock, struct sshbuf *m) 882 { 883 struct ssh *ssh = active_state; /* XXX */ 884 static int call_count; 885 char *passwd; 886 int r, authenticated; 887 size_t plen; 888 889 if (!options.password_authentication) 890 fatal("%s: password authentication not enabled", __func__); 891 if ((r = sshbuf_get_cstring(m, &passwd, &plen)) != 0) 892 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 893 /* Only authenticate if the context is valid */ 894 authenticated = options.password_authentication && 895 auth_password(ssh, passwd); 896 explicit_bzero(passwd, plen); 897 free(passwd); 898 899 sshbuf_reset(m); 900 if ((r = sshbuf_put_u32(m, authenticated)) != 0) 901 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 902 #ifdef USE_PAM 903 if ((r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0) 904 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 905 #endif 906 907 debug3("%s: sending result %d", __func__, authenticated); 908 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 909 910 call_count++; 911 if (plen == 0 && call_count == 1) 912 auth_method = "none"; 913 else 914 auth_method = "password"; 915 916 /* Causes monitor loop to terminate if authenticated */ 917 return (authenticated); 918 } 919 920 #ifdef BSD_AUTH 921 int 922 mm_answer_bsdauthquery(int sock, struct sshbuf *m) 923 { 924 char *name, *infotxt; 925 u_int numprompts, *echo_on, success; 926 char **prompts; 927 int r; 928 929 if (!options.kbd_interactive_authentication) 930 fatal("%s: kbd-int authentication not enabled", __func__); 931 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 932 &prompts, &echo_on) < 0 ? 0 : 1; 933 934 sshbuf_reset(m); 935 if ((r = sshbuf_put_u32(m, success)) != 0) 936 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 937 if (success) { 938 if ((r = sshbuf_put_cstring(m, prompts[0])) != 0) 939 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 940 } 941 942 debug3("%s: sending challenge success: %u", __func__, success); 943 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 944 945 if (success) { 946 free(name); 947 free(infotxt); 948 free(prompts); 949 free(echo_on); 950 } 951 952 return (0); 953 } 954 955 int 956 mm_answer_bsdauthrespond(int sock, struct sshbuf *m) 957 { 958 char *response; 959 int r, authok; 960 961 if (!options.kbd_interactive_authentication) 962 fatal("%s: kbd-int authentication not enabled", __func__); 963 if (authctxt->as == NULL) 964 fatal("%s: no bsd auth session", __func__); 965 966 if ((r = sshbuf_get_cstring(m, &response, NULL)) != 0) 967 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 968 authok = options.challenge_response_authentication && 969 auth_userresponse(authctxt->as, response, 0); 970 authctxt->as = NULL; 971 debug3("%s: <%s> = <%d>", __func__, response, authok); 972 free(response); 973 974 sshbuf_reset(m); 975 if ((r = sshbuf_put_u32(m, authok)) != 0) 976 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 977 978 debug3("%s: sending authenticated: %d", __func__, authok); 979 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 980 981 auth_method = "keyboard-interactive"; 982 auth_submethod = "bsdauth"; 983 984 return (authok != 0); 985 } 986 #endif 987 988 #ifdef USE_PAM 989 int 990 mm_answer_pam_start(int sock, struct sshbuf *m) 991 { 992 if (!options.use_pam) 993 fatal("UsePAM not set, but ended up in %s anyway", __func__); 994 995 start_pam(authctxt); 996 997 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 998 if (options.kbd_interactive_authentication) 999 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1); 1000 1001 return (0); 1002 } 1003 1004 int 1005 mm_answer_pam_account(int sock, struct sshbuf *m) 1006 { 1007 u_int ret; 1008 int r; 1009 1010 if (!options.use_pam) 1011 fatal("%s: PAM not enabled", __func__); 1012 1013 ret = do_pam_account(); 1014 1015 if ((r = sshbuf_put_u32(m, ret)) != 0 || 1016 (r = sshbuf_put_stringb(m, loginmsg)) != 0) 1017 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1018 1019 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1020 1021 return (ret); 1022 } 1023 1024 static void *sshpam_ctxt, *sshpam_authok; 1025 extern KbdintDevice sshpam_device; 1026 1027 int 1028 mm_answer_pam_init_ctx(int sock, struct sshbuf *m) 1029 { 1030 u_int ok = 0; 1031 int r; 1032 1033 debug3("%s", __func__); 1034 if (!options.kbd_interactive_authentication) 1035 fatal("%s: kbd-int authentication not enabled", __func__); 1036 if (sshpam_ctxt != NULL) 1037 fatal("%s: already called", __func__); 1038 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1039 sshpam_authok = NULL; 1040 sshbuf_reset(m); 1041 if (sshpam_ctxt != NULL) { 1042 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1043 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_QUERY, 1); 1044 ok = 1; 1045 } 1046 if ((r = sshbuf_put_u32(m, ok)) != 0) 1047 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1048 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1049 return (0); 1050 } 1051 1052 int 1053 mm_answer_pam_query(int sock, struct sshbuf *m) 1054 { 1055 char *name = NULL, *info = NULL, **prompts = NULL; 1056 u_int i, num = 0, *echo_on = 0; 1057 int r, ret; 1058 1059 debug3("%s", __func__); 1060 sshpam_authok = NULL; 1061 if (sshpam_ctxt == NULL) 1062 fatal("%s: no context", __func__); 1063 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, 1064 &num, &prompts, &echo_on); 1065 if (ret == 0 && num == 0) 1066 sshpam_authok = sshpam_ctxt; 1067 if (num > 1 || name == NULL || info == NULL) 1068 fatal("sshpam_device.query failed"); 1069 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_RESPOND, 1); 1070 sshbuf_reset(m); 1071 if ((r = sshbuf_put_u32(m, ret)) != 0 || 1072 (r = sshbuf_put_cstring(m, name)) != 0 || 1073 (r = sshbuf_put_cstring(m, info)) != 0 || 1074 (r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0 || 1075 (r = sshbuf_put_u32(m, num)) != 0) 1076 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1077 free(name); 1078 free(info); 1079 for (i = 0; i < num; ++i) { 1080 if ((r = sshbuf_put_cstring(m, prompts[i])) != 0 || 1081 (r = sshbuf_put_u32(m, echo_on[i])) != 0) 1082 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1083 free(prompts[i]); 1084 } 1085 free(prompts); 1086 free(echo_on); 1087 auth_method = "keyboard-interactive"; 1088 auth_submethod = "pam"; 1089 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1090 return (0); 1091 } 1092 1093 int 1094 mm_answer_pam_respond(int sock, struct sshbuf *m) 1095 { 1096 char **resp; 1097 u_int i, num; 1098 int r, ret; 1099 1100 debug3("%s", __func__); 1101 if (sshpam_ctxt == NULL) 1102 fatal("%s: no context", __func__); 1103 sshpam_authok = NULL; 1104 if ((r = sshbuf_get_u32(m, &num)) != 0) 1105 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1106 if (num > 0) { 1107 resp = xcalloc(num, sizeof(char *)); 1108 for (i = 0; i < num; ++i) { 1109 if ((r = sshbuf_get_cstring(m, &(resp[i]), NULL)) != 0) 1110 fatal("%s: buffer error: %s", 1111 __func__, ssh_err(r)); 1112 } 1113 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1114 for (i = 0; i < num; ++i) 1115 free(resp[i]); 1116 free(resp); 1117 } else { 1118 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1119 } 1120 sshbuf_reset(m); 1121 if ((r = sshbuf_put_u32(m, ret)) != 0) 1122 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1123 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1124 auth_method = "keyboard-interactive"; 1125 auth_submethod = "pam"; 1126 if (ret == 0) 1127 sshpam_authok = sshpam_ctxt; 1128 return (0); 1129 } 1130 1131 int 1132 mm_answer_pam_free_ctx(int sock, struct sshbuf *m) 1133 { 1134 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt; 1135 1136 debug3("%s", __func__); 1137 if (sshpam_ctxt == NULL) 1138 fatal("%s: no context", __func__); 1139 (sshpam_device.free_ctx)(sshpam_ctxt); 1140 sshpam_ctxt = sshpam_authok = NULL; 1141 sshbuf_reset(m); 1142 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1143 /* Allow another attempt */ 1144 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1); 1145 auth_method = "keyboard-interactive"; 1146 auth_submethod = "pam"; 1147 return r; 1148 } 1149 #endif 1150 1151 int 1152 mm_answer_keyallowed(int sock, struct sshbuf *m) 1153 { 1154 struct ssh *ssh = active_state; /* XXX */ 1155 struct sshkey *key = NULL; 1156 char *cuser, *chost; 1157 u_int pubkey_auth_attempt; 1158 enum mm_keytype type = 0; 1159 int r, allowed = 0; 1160 struct sshauthopt *opts = NULL; 1161 1162 debug3("%s entering", __func__); 1163 if ((r = sshbuf_get_u32(m, &type)) != 0 || 1164 (r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 || 1165 (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 || 1166 (r = sshkey_froms(m, &key)) != 0 || 1167 (r = sshbuf_get_u32(m, &pubkey_auth_attempt)) != 0) 1168 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1169 1170 debug3("%s: key_from_blob: %p", __func__, key); 1171 1172 if (key != NULL && authctxt->valid) { 1173 /* These should not make it past the privsep child */ 1174 if (sshkey_type_plain(key->type) == KEY_RSA && 1175 (datafellows & SSH_BUG_RSASIGMD5) != 0) 1176 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 1177 1178 switch (type) { 1179 case MM_USERKEY: 1180 auth_method = "publickey"; 1181 if (!options.pubkey_authentication) 1182 break; 1183 if (auth2_key_already_used(authctxt, key)) 1184 break; 1185 if (match_pattern_list(sshkey_ssh_name(key), 1186 options.pubkey_key_types, 0) != 1) 1187 break; 1188 allowed = user_key_allowed(ssh, authctxt->pw, key, 1189 pubkey_auth_attempt, &opts); 1190 break; 1191 case MM_HOSTKEY: 1192 auth_method = "hostbased"; 1193 if (!options.hostbased_authentication) 1194 break; 1195 if (auth2_key_already_used(authctxt, key)) 1196 break; 1197 if (match_pattern_list(sshkey_ssh_name(key), 1198 options.hostbased_key_types, 0) != 1) 1199 break; 1200 allowed = hostbased_key_allowed(authctxt->pw, 1201 cuser, chost, key); 1202 auth2_record_info(authctxt, 1203 "client user \"%.100s\", client host \"%.100s\"", 1204 cuser, chost); 1205 break; 1206 default: 1207 fatal("%s: unknown key type %d", __func__, type); 1208 break; 1209 } 1210 } 1211 1212 debug3("%s: %s authentication%s: %s key is %s", __func__, 1213 auth_method, pubkey_auth_attempt ? "" : " test", 1214 (key == NULL || !authctxt->valid) ? "invalid" : sshkey_type(key), 1215 allowed ? "allowed" : "not allowed"); 1216 1217 auth2_record_key(authctxt, 0, key); 1218 1219 /* clear temporarily storage (used by verify) */ 1220 monitor_reset_key_state(); 1221 1222 if (allowed) { 1223 /* Save temporarily for comparison in verify */ 1224 if ((r = sshkey_to_blob(key, &key_blob, &key_bloblen)) != 0) 1225 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1226 key_blobtype = type; 1227 key_opts = opts; 1228 hostbased_cuser = cuser; 1229 hostbased_chost = chost; 1230 } else { 1231 /* Log failed attempt */ 1232 auth_log(authctxt, 0, 0, auth_method, NULL); 1233 free(cuser); 1234 free(chost); 1235 } 1236 sshkey_free(key); 1237 1238 sshbuf_reset(m); 1239 if ((r = sshbuf_put_u32(m, allowed)) != 0) 1240 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1241 if (opts != NULL && (r = sshauthopt_serialise(opts, m, 1)) != 0) 1242 fatal("%s: sshauthopt_serialise: %s", __func__, ssh_err(r)); 1243 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1244 1245 if (!allowed) 1246 sshauthopt_free(opts); 1247 1248 return (0); 1249 } 1250 1251 static int 1252 monitor_valid_userblob(u_char *data, u_int datalen) 1253 { 1254 struct sshbuf *b; 1255 const u_char *p; 1256 char *userstyle, *cp; 1257 size_t len; 1258 u_char type; 1259 int r, fail = 0; 1260 1261 if ((b = sshbuf_new()) == NULL) 1262 fatal("%s: sshbuf_new", __func__); 1263 if ((r = sshbuf_put(b, data, datalen)) != 0) 1264 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1265 1266 if (datafellows & SSH_OLD_SESSIONID) { 1267 p = sshbuf_ptr(b); 1268 len = sshbuf_len(b); 1269 if ((session_id2 == NULL) || 1270 (len < session_id2_len) || 1271 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1272 fail++; 1273 if ((r = sshbuf_consume(b, session_id2_len)) != 0) 1274 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1275 } else { 1276 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) 1277 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1278 if ((session_id2 == NULL) || 1279 (len != session_id2_len) || 1280 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1281 fail++; 1282 } 1283 if ((r = sshbuf_get_u8(b, &type)) != 0) 1284 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1285 if (type != SSH2_MSG_USERAUTH_REQUEST) 1286 fail++; 1287 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0) 1288 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1289 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1290 authctxt->style ? ":" : "", 1291 authctxt->style ? authctxt->style : ""); 1292 if (strcmp(userstyle, cp) != 0) { 1293 logit("wrong user name passed to monitor: " 1294 "expected %s != %.100s", userstyle, cp); 1295 fail++; 1296 } 1297 free(userstyle); 1298 free(cp); 1299 if ((r = sshbuf_skip_string(b)) != 0 || /* service */ 1300 (r = sshbuf_get_cstring(b, &cp, NULL)) != 0) 1301 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1302 if (strcmp("publickey", cp) != 0) 1303 fail++; 1304 free(cp); 1305 if ((r = sshbuf_get_u8(b, &type)) != 0) 1306 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1307 if (type == 0) 1308 fail++; 1309 if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */ 1310 (r = sshbuf_skip_string(b)) != 0) /* pkblob */ 1311 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1312 if (sshbuf_len(b) != 0) 1313 fail++; 1314 sshbuf_free(b); 1315 return (fail == 0); 1316 } 1317 1318 static int 1319 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1320 char *chost) 1321 { 1322 struct sshbuf *b; 1323 const u_char *p; 1324 char *cp, *userstyle; 1325 size_t len; 1326 int r, fail = 0; 1327 u_char type; 1328 1329 if ((b = sshbuf_new()) == NULL) 1330 fatal("%s: sshbuf_new", __func__); 1331 if ((r = sshbuf_put(b, data, datalen)) != 0 || 1332 (r = sshbuf_get_string_direct(b, &p, &len)) != 0) 1333 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1334 1335 if ((session_id2 == NULL) || 1336 (len != session_id2_len) || 1337 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1338 fail++; 1339 1340 if ((r = sshbuf_get_u8(b, &type)) != 0) 1341 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1342 if (type != SSH2_MSG_USERAUTH_REQUEST) 1343 fail++; 1344 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0) 1345 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1346 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1347 authctxt->style ? ":" : "", 1348 authctxt->style ? authctxt->style : ""); 1349 if (strcmp(userstyle, cp) != 0) { 1350 logit("wrong user name passed to monitor: " 1351 "expected %s != %.100s", userstyle, cp); 1352 fail++; 1353 } 1354 free(userstyle); 1355 free(cp); 1356 if ((r = sshbuf_skip_string(b)) != 0 || /* service */ 1357 (r = sshbuf_get_cstring(b, &cp, NULL)) != 0) 1358 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1359 if (strcmp(cp, "hostbased") != 0) 1360 fail++; 1361 free(cp); 1362 if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */ 1363 (r = sshbuf_skip_string(b)) != 0) /* pkblob */ 1364 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1365 1366 /* verify client host, strip trailing dot if necessary */ 1367 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0) 1368 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1369 if (((len = strlen(cp)) > 0) && cp[len - 1] == '.') 1370 cp[len - 1] = '\0'; 1371 if (strcmp(cp, chost) != 0) 1372 fail++; 1373 free(cp); 1374 1375 /* verify client user */ 1376 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0) 1377 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1378 if (strcmp(cp, cuser) != 0) 1379 fail++; 1380 free(cp); 1381 1382 if (sshbuf_len(b) != 0) 1383 fail++; 1384 sshbuf_free(b); 1385 return (fail == 0); 1386 } 1387 1388 int 1389 mm_answer_keyverify(int sock, struct sshbuf *m) 1390 { 1391 struct ssh *ssh = active_state; /* XXX */ 1392 struct sshkey *key; 1393 u_char *signature, *data, *blob; 1394 char *sigalg; 1395 size_t signaturelen, datalen, bloblen; 1396 int r, ret, valid_data = 0, encoded_ret; 1397 1398 if ((r = sshbuf_get_string(m, &blob, &bloblen)) != 0 || 1399 (r = sshbuf_get_string(m, &signature, &signaturelen)) != 0 || 1400 (r = sshbuf_get_string(m, &data, &datalen)) != 0 || 1401 (r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0) 1402 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1403 1404 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1405 !monitor_allowed_key(blob, bloblen)) 1406 fatal("%s: bad key, not previously allowed", __func__); 1407 1408 /* Empty signature algorithm means NULL. */ 1409 if (*sigalg == '\0') { 1410 free(sigalg); 1411 sigalg = NULL; 1412 } 1413 1414 /* XXX use sshkey_froms here; need to change key_blob, etc. */ 1415 if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0) 1416 fatal("%s: bad public key blob: %s", __func__, ssh_err(r)); 1417 1418 switch (key_blobtype) { 1419 case MM_USERKEY: 1420 valid_data = monitor_valid_userblob(data, datalen); 1421 auth_method = "publickey"; 1422 break; 1423 case MM_HOSTKEY: 1424 valid_data = monitor_valid_hostbasedblob(data, datalen, 1425 hostbased_cuser, hostbased_chost); 1426 auth_method = "hostbased"; 1427 break; 1428 default: 1429 valid_data = 0; 1430 break; 1431 } 1432 if (!valid_data) 1433 fatal("%s: bad signature data blob", __func__); 1434 1435 ret = sshkey_verify(key, signature, signaturelen, data, datalen, 1436 sigalg, active_state->compat); 1437 debug3("%s: %s %p signature %s", __func__, auth_method, key, 1438 (ret == 0) ? "verified" : "unverified"); 1439 auth2_record_key(authctxt, ret == 0, key); 1440 1441 free(blob); 1442 free(signature); 1443 free(data); 1444 free(sigalg); 1445 1446 if (key_blobtype == MM_USERKEY) 1447 auth_activate_options(ssh, key_opts); 1448 monitor_reset_key_state(); 1449 1450 sshkey_free(key); 1451 sshbuf_reset(m); 1452 1453 /* encode ret != 0 as positive integer, since we're sending u32 */ 1454 encoded_ret = (ret != 0); 1455 if ((r = sshbuf_put_u32(m, encoded_ret)) != 0) 1456 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1457 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1458 1459 return ret == 0; 1460 } 1461 1462 static void 1463 mm_record_login(Session *s, struct passwd *pw) 1464 { 1465 struct ssh *ssh = active_state; /* XXX */ 1466 socklen_t fromlen; 1467 struct sockaddr_storage from; 1468 1469 /* 1470 * Get IP address of client. If the connection is not a socket, let 1471 * the address be 0.0.0.0. 1472 */ 1473 memset(&from, 0, sizeof(from)); 1474 fromlen = sizeof(from); 1475 if (packet_connection_is_on_socket()) { 1476 if (getpeername(packet_get_connection_in(), 1477 (struct sockaddr *)&from, &fromlen) < 0) { 1478 debug("getpeername: %.100s", strerror(errno)); 1479 cleanup_exit(255); 1480 } 1481 } 1482 /* Record that there was a login on that tty from the remote host. */ 1483 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1484 session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns), 1485 (struct sockaddr *)&from, fromlen); 1486 } 1487 1488 static void 1489 mm_session_close(Session *s) 1490 { 1491 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1492 if (s->ttyfd != -1) { 1493 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1494 session_pty_cleanup2(s); 1495 } 1496 session_unused(s->self); 1497 } 1498 1499 int 1500 mm_answer_pty(int sock, struct sshbuf *m) 1501 { 1502 extern struct monitor *pmonitor; 1503 Session *s; 1504 int r, res, fd0; 1505 1506 debug3("%s entering", __func__); 1507 1508 sshbuf_reset(m); 1509 s = session_new(); 1510 if (s == NULL) 1511 goto error; 1512 s->authctxt = authctxt; 1513 s->pw = authctxt->pw; 1514 s->pid = pmonitor->m_pid; 1515 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1516 if (res == 0) 1517 goto error; 1518 pty_setowner(authctxt->pw, s->tty); 1519 1520 if ((r = sshbuf_put_u32(m, 1)) != 0 || 1521 (r = sshbuf_put_cstring(m, s->tty)) != 0) 1522 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1523 1524 /* We need to trick ttyslot */ 1525 if (dup2(s->ttyfd, 0) == -1) 1526 fatal("%s: dup2", __func__); 1527 1528 mm_record_login(s, authctxt->pw); 1529 1530 /* Now we can close the file descriptor again */ 1531 close(0); 1532 1533 /* send messages generated by record_login */ 1534 if ((r = sshbuf_put_stringb(m, loginmsg)) != 0) 1535 fatal("%s: put login message: %s", __func__, ssh_err(r)); 1536 sshbuf_reset(loginmsg); 1537 1538 mm_request_send(sock, MONITOR_ANS_PTY, m); 1539 1540 if (mm_send_fd(sock, s->ptyfd) == -1 || 1541 mm_send_fd(sock, s->ttyfd) == -1) 1542 fatal("%s: send fds failed", __func__); 1543 1544 /* make sure nothing uses fd 0 */ 1545 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1546 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1547 if (fd0 != 0) 1548 error("%s: fd0 %d != 0", __func__, fd0); 1549 1550 /* slave is not needed */ 1551 close(s->ttyfd); 1552 s->ttyfd = s->ptyfd; 1553 /* no need to dup() because nobody closes ptyfd */ 1554 s->ptymaster = s->ptyfd; 1555 1556 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1557 1558 return (0); 1559 1560 error: 1561 if (s != NULL) 1562 mm_session_close(s); 1563 if ((r = sshbuf_put_u32(m, 0)) != 0) 1564 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1565 mm_request_send(sock, MONITOR_ANS_PTY, m); 1566 return (0); 1567 } 1568 1569 int 1570 mm_answer_pty_cleanup(int sock, struct sshbuf *m) 1571 { 1572 Session *s; 1573 char *tty; 1574 int r; 1575 1576 debug3("%s entering", __func__); 1577 1578 if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0) 1579 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1580 if ((s = session_by_tty(tty)) != NULL) 1581 mm_session_close(s); 1582 sshbuf_reset(m); 1583 free(tty); 1584 return (0); 1585 } 1586 1587 int 1588 mm_answer_term(int sock, struct sshbuf *req) 1589 { 1590 struct ssh *ssh = active_state; /* XXX */ 1591 extern struct monitor *pmonitor; 1592 int res, status; 1593 1594 debug3("%s: tearing down sessions", __func__); 1595 1596 /* The child is terminating */ 1597 session_destroy_all(ssh, &mm_session_close); 1598 1599 #ifdef USE_PAM 1600 if (options.use_pam) 1601 sshpam_cleanup(); 1602 #endif 1603 1604 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1605 if (errno != EINTR) 1606 exit(1); 1607 1608 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1609 1610 /* Terminate process */ 1611 exit(res); 1612 } 1613 1614 #ifdef SSH_AUDIT_EVENTS 1615 /* Report that an audit event occurred */ 1616 int 1617 mm_answer_audit_event(int socket, struct sshbuf *m) 1618 { 1619 u_int n; 1620 ssh_audit_event_t event; 1621 int r; 1622 1623 debug3("%s entering", __func__); 1624 1625 if ((r = sshbuf_get_u32(m, &n)) != 0) 1626 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1627 event = (ssh_audit_event_t)n; 1628 switch (event) { 1629 case SSH_AUTH_FAIL_PUBKEY: 1630 case SSH_AUTH_FAIL_HOSTBASED: 1631 case SSH_AUTH_FAIL_GSSAPI: 1632 case SSH_LOGIN_EXCEED_MAXTRIES: 1633 case SSH_LOGIN_ROOT_DENIED: 1634 case SSH_CONNECTION_CLOSE: 1635 case SSH_INVALID_USER: 1636 audit_event(event); 1637 break; 1638 default: 1639 fatal("Audit event type %d not permitted", event); 1640 } 1641 1642 return (0); 1643 } 1644 1645 int 1646 mm_answer_audit_command(int socket, struct sshbuf *m) 1647 { 1648 char *cmd; 1649 int r; 1650 1651 debug3("%s entering", __func__); 1652 if ((r = sshbuf_get_cstring(m, &cmd, NULL)) != 0) 1653 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1654 /* sanity check command, if so how? */ 1655 audit_run_command(cmd); 1656 free(cmd); 1657 return (0); 1658 } 1659 #endif /* SSH_AUDIT_EVENTS */ 1660 1661 void 1662 monitor_clear_keystate(struct monitor *pmonitor) 1663 { 1664 struct ssh *ssh = active_state; /* XXX */ 1665 1666 ssh_clear_newkeys(ssh, MODE_IN); 1667 ssh_clear_newkeys(ssh, MODE_OUT); 1668 sshbuf_free(child_state); 1669 child_state = NULL; 1670 } 1671 1672 void 1673 monitor_apply_keystate(struct monitor *pmonitor) 1674 { 1675 struct ssh *ssh = active_state; /* XXX */ 1676 struct kex *kex; 1677 int r; 1678 1679 debug3("%s: packet_set_state", __func__); 1680 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1681 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1682 sshbuf_free(child_state); 1683 child_state = NULL; 1684 1685 if ((kex = ssh->kex) != NULL) { 1686 /* XXX set callbacks */ 1687 #ifdef WITH_OPENSSL 1688 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1689 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1690 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server; 1691 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server; 1692 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server; 1693 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1694 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1695 # ifdef OPENSSL_HAS_ECC 1696 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1697 # endif 1698 #endif /* WITH_OPENSSL */ 1699 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1700 kex->load_host_public_key=&get_hostkey_public_by_type; 1701 kex->load_host_private_key=&get_hostkey_private_by_type; 1702 kex->host_key_index=&get_hostkey_index; 1703 kex->sign = sshd_hostkey_sign; 1704 } 1705 } 1706 1707 /* This function requries careful sanity checking */ 1708 1709 void 1710 mm_get_keystate(struct monitor *pmonitor) 1711 { 1712 debug3("%s: Waiting for new keys", __func__); 1713 1714 if ((child_state = sshbuf_new()) == NULL) 1715 fatal("%s: sshbuf_new failed", __func__); 1716 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1717 child_state); 1718 debug3("%s: GOT new keys", __func__); 1719 } 1720 1721 1722 /* XXX */ 1723 1724 #define FD_CLOSEONEXEC(x) do { \ 1725 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1726 fatal("fcntl(%d, F_SETFD)", x); \ 1727 } while (0) 1728 1729 static void 1730 monitor_openfds(struct monitor *mon, int do_logfds) 1731 { 1732 int pair[2]; 1733 #ifdef SO_ZEROIZE 1734 int on = 1; 1735 #endif 1736 1737 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1738 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1739 #ifdef SO_ZEROIZE 1740 if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) < 0) 1741 error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno)); 1742 if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) < 0) 1743 error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno)); 1744 #endif 1745 FD_CLOSEONEXEC(pair[0]); 1746 FD_CLOSEONEXEC(pair[1]); 1747 mon->m_recvfd = pair[0]; 1748 mon->m_sendfd = pair[1]; 1749 1750 if (do_logfds) { 1751 if (pipe(pair) == -1) 1752 fatal("%s: pipe: %s", __func__, strerror(errno)); 1753 FD_CLOSEONEXEC(pair[0]); 1754 FD_CLOSEONEXEC(pair[1]); 1755 mon->m_log_recvfd = pair[0]; 1756 mon->m_log_sendfd = pair[1]; 1757 } else 1758 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1759 } 1760 1761 #define MM_MEMSIZE 65536 1762 1763 struct monitor * 1764 monitor_init(void) 1765 { 1766 struct monitor *mon; 1767 1768 mon = xcalloc(1, sizeof(*mon)); 1769 monitor_openfds(mon, 1); 1770 1771 return mon; 1772 } 1773 1774 void 1775 monitor_reinit(struct monitor *mon) 1776 { 1777 monitor_openfds(mon, 0); 1778 } 1779 1780 #ifdef GSSAPI 1781 int 1782 mm_answer_gss_setup_ctx(int sock, struct sshbuf *m) 1783 { 1784 gss_OID_desc goid; 1785 OM_uint32 major; 1786 size_t len; 1787 u_char *p; 1788 int r; 1789 1790 if (!options.gss_authentication) 1791 fatal("%s: GSSAPI authentication not enabled", __func__); 1792 1793 if ((r = sshbuf_get_string(m, &p, &len)) != 0) 1794 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1795 goid.elements = p; 1796 goid.length = len; 1797 1798 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1799 1800 free(goid.elements); 1801 1802 sshbuf_reset(m); 1803 if ((r = sshbuf_put_u32(m, major)) != 0) 1804 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1805 1806 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1807 1808 /* Now we have a context, enable the step */ 1809 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1810 1811 return (0); 1812 } 1813 1814 int 1815 mm_answer_gss_accept_ctx(int sock, struct sshbuf *m) 1816 { 1817 gss_buffer_desc in; 1818 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1819 OM_uint32 major, minor; 1820 OM_uint32 flags = 0; /* GSI needs this */ 1821 int r; 1822 1823 if (!options.gss_authentication) 1824 fatal("%s: GSSAPI authentication not enabled", __func__); 1825 1826 if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0) 1827 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1828 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1829 free(in.value); 1830 1831 sshbuf_reset(m); 1832 if ((r = sshbuf_put_u32(m, major)) != 0 || 1833 (r = sshbuf_put_string(m, out.value, out.length)) != 0 || 1834 (r = sshbuf_put_u32(m, flags)) != 0) 1835 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1836 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1837 1838 gss_release_buffer(&minor, &out); 1839 1840 if (major == GSS_S_COMPLETE) { 1841 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1842 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1843 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1844 } 1845 return (0); 1846 } 1847 1848 int 1849 mm_answer_gss_checkmic(int sock, struct sshbuf *m) 1850 { 1851 gss_buffer_desc gssbuf, mic; 1852 OM_uint32 ret; 1853 int r; 1854 1855 if (!options.gss_authentication) 1856 fatal("%s: GSSAPI authentication not enabled", __func__); 1857 1858 if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 || 1859 (r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0) 1860 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1861 1862 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1863 1864 free(gssbuf.value); 1865 free(mic.value); 1866 1867 sshbuf_reset(m); 1868 if ((r = sshbuf_put_u32(m, ret)) != 0) 1869 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1870 1871 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1872 1873 if (!GSS_ERROR(ret)) 1874 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1875 1876 return (0); 1877 } 1878 1879 int 1880 mm_answer_gss_userok(int sock, struct sshbuf *m) 1881 { 1882 int r, authenticated; 1883 const char *displayname; 1884 1885 if (!options.gss_authentication) 1886 fatal("%s: GSSAPI authentication not enabled", __func__); 1887 1888 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1889 1890 sshbuf_reset(m); 1891 if ((r = sshbuf_put_u32(m, authenticated)) != 0) 1892 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1893 1894 debug3("%s: sending result %d", __func__, authenticated); 1895 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1896 1897 auth_method = "gssapi-with-mic"; 1898 1899 if ((displayname = ssh_gssapi_displayname()) != NULL) 1900 auth2_record_info(authctxt, "%s", displayname); 1901 1902 /* Monitor loop will terminate if authenticated */ 1903 return (authenticated); 1904 } 1905 #endif /* GSSAPI */ 1906 1907