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