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