1 /* $OpenBSD: monitor.c,v 1.150 2015/06/22 23:42:16 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 #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 SKEY 59 #include <skey.h> 60 #endif 61 62 #ifdef WITH_OPENSSL 63 #include <openssl/dh.h> 64 #endif 65 66 #include "openbsd-compat/sys-queue.h" 67 #include "atomicio.h" 68 #include "xmalloc.h" 69 #include "ssh.h" 70 #include "key.h" 71 #include "buffer.h" 72 #include "hostfile.h" 73 #include "auth.h" 74 #include "cipher.h" 75 #include "kex.h" 76 #include "dh.h" 77 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 78 #undef TARGET_OS_MAC 79 #include "zlib.h" 80 #define TARGET_OS_MAC 1 81 #else 82 #include "zlib.h" 83 #endif 84 #include "packet.h" 85 #include "auth-options.h" 86 #include "sshpty.h" 87 #include "channels.h" 88 #include "session.h" 89 #include "sshlogin.h" 90 #include "canohost.h" 91 #include "log.h" 92 #include "misc.h" 93 #include "servconf.h" 94 #include "monitor.h" 95 #include "monitor_mm.h" 96 #ifdef GSSAPI 97 #include "ssh-gss.h" 98 #endif 99 #include "monitor_wrap.h" 100 #include "monitor_fdpass.h" 101 #include "compat.h" 102 #include "ssh2.h" 103 #include "roaming.h" 104 #include "authfd.h" 105 #include "match.h" 106 #include "ssherr.h" 107 108 #ifdef GSSAPI 109 static Gssctxt *gsscontext = NULL; 110 #endif 111 112 /* Imports */ 113 extern ServerOptions options; 114 extern u_int utmp_len; 115 extern u_char session_id[]; 116 extern Buffer auth_debug; 117 extern int auth_debug_init; 118 extern Buffer loginmsg; 119 120 /* State exported from the child */ 121 static struct sshbuf *child_state; 122 123 /* Functions on the monitor that answer unprivileged requests */ 124 125 int mm_answer_moduli(int, Buffer *); 126 int mm_answer_sign(int, Buffer *); 127 int mm_answer_pwnamallow(int, Buffer *); 128 int mm_answer_auth2_read_banner(int, Buffer *); 129 int mm_answer_authserv(int, Buffer *); 130 int mm_answer_authpassword(int, Buffer *); 131 int mm_answer_bsdauthquery(int, Buffer *); 132 int mm_answer_bsdauthrespond(int, Buffer *); 133 int mm_answer_skeyquery(int, Buffer *); 134 int mm_answer_skeyrespond(int, Buffer *); 135 int mm_answer_keyallowed(int, Buffer *); 136 int mm_answer_keyverify(int, Buffer *); 137 int mm_answer_pty(int, Buffer *); 138 int mm_answer_pty_cleanup(int, Buffer *); 139 int mm_answer_term(int, Buffer *); 140 int mm_answer_rsa_keyallowed(int, Buffer *); 141 int mm_answer_rsa_challenge(int, Buffer *); 142 int mm_answer_rsa_response(int, Buffer *); 143 int mm_answer_sesskey(int, Buffer *); 144 int mm_answer_sessid(int, Buffer *); 145 146 #ifdef USE_PAM 147 int mm_answer_pam_start(int, Buffer *); 148 int mm_answer_pam_account(int, Buffer *); 149 int mm_answer_pam_init_ctx(int, Buffer *); 150 int mm_answer_pam_query(int, Buffer *); 151 int mm_answer_pam_respond(int, Buffer *); 152 int mm_answer_pam_free_ctx(int, Buffer *); 153 #endif 154 155 #ifdef GSSAPI 156 int mm_answer_gss_setup_ctx(int, Buffer *); 157 int mm_answer_gss_accept_ctx(int, Buffer *); 158 int mm_answer_gss_userok(int, Buffer *); 159 int mm_answer_gss_checkmic(int, Buffer *); 160 #endif 161 162 #ifdef SSH_AUDIT_EVENTS 163 int mm_answer_audit_event(int, Buffer *); 164 int mm_answer_audit_command(int, Buffer *); 165 #endif 166 167 static int monitor_read_log(struct monitor *); 168 169 static Authctxt *authctxt; 170 171 #ifdef WITH_SSH1 172 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 173 #endif 174 175 /* local state for key verify */ 176 static u_char *key_blob = NULL; 177 static u_int key_bloblen = 0; 178 static int key_blobtype = MM_NOKEY; 179 static char *hostbased_cuser = NULL; 180 static char *hostbased_chost = NULL; 181 static char *auth_method = "unknown"; 182 static char *auth_submethod = NULL; 183 static u_int session_id2_len = 0; 184 static u_char *session_id2 = NULL; 185 static pid_t monitor_child_pid; 186 187 struct mon_table { 188 enum monitor_reqtype type; 189 int flags; 190 int (*f)(int, Buffer *); 191 }; 192 193 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 194 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 195 #define MON_ONCE 0x0010 /* Disable after calling */ 196 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 197 198 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 199 200 #define MON_PERMIT 0x1000 /* Request is permitted */ 201 202 struct mon_table mon_dispatch_proto20[] = { 203 #ifdef WITH_OPENSSL 204 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 205 #endif 206 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 207 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 208 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 209 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 210 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 211 #ifdef USE_PAM 212 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 213 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 214 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 215 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 216 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 217 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 218 #endif 219 #ifdef SSH_AUDIT_EVENTS 220 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 221 #endif 222 #ifdef BSD_AUTH 223 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 224 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 225 #endif 226 #ifdef SKEY 227 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 228 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 229 #endif 230 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 231 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 232 #ifdef GSSAPI 233 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 234 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 235 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 236 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 237 #endif 238 {0, 0, NULL} 239 }; 240 241 struct mon_table mon_dispatch_postauth20[] = { 242 #ifdef WITH_OPENSSL 243 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 244 #endif 245 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 246 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 247 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 248 {MONITOR_REQ_TERM, 0, mm_answer_term}, 249 #ifdef SSH_AUDIT_EVENTS 250 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 251 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 252 #endif 253 {0, 0, NULL} 254 }; 255 256 struct mon_table mon_dispatch_proto15[] = { 257 #ifdef WITH_SSH1 258 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 259 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 260 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 261 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 262 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 263 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 264 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 265 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 266 #ifdef BSD_AUTH 267 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 268 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 269 #endif 270 #ifdef SKEY 271 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 272 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 273 #endif 274 #ifdef USE_PAM 275 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 276 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 277 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 278 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 279 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 280 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 281 #endif 282 #ifdef SSH_AUDIT_EVENTS 283 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 284 #endif 285 #endif /* WITH_SSH1 */ 286 {0, 0, NULL} 287 }; 288 289 struct mon_table mon_dispatch_postauth15[] = { 290 #ifdef WITH_SSH1 291 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 292 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 293 {MONITOR_REQ_TERM, 0, mm_answer_term}, 294 #ifdef SSH_AUDIT_EVENTS 295 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 296 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 297 #endif 298 #endif /* WITH_SSH1 */ 299 {0, 0, NULL} 300 }; 301 302 struct mon_table *mon_dispatch; 303 304 /* Specifies if a certain message is allowed at the moment */ 305 306 static void 307 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 308 { 309 while (ent->f != NULL) { 310 if (ent->type == type) { 311 ent->flags &= ~MON_PERMIT; 312 ent->flags |= permit ? MON_PERMIT : 0; 313 return; 314 } 315 ent++; 316 } 317 } 318 319 static void 320 monitor_permit_authentications(int permit) 321 { 322 struct mon_table *ent = mon_dispatch; 323 324 while (ent->f != NULL) { 325 if (ent->flags & MON_AUTH) { 326 ent->flags &= ~MON_PERMIT; 327 ent->flags |= permit ? MON_PERMIT : 0; 328 } 329 ent++; 330 } 331 } 332 333 void 334 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 335 { 336 struct mon_table *ent; 337 int authenticated = 0, partial = 0; 338 339 debug3("preauth child monitor started"); 340 341 close(pmonitor->m_recvfd); 342 close(pmonitor->m_log_sendfd); 343 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 344 345 authctxt = _authctxt; 346 memset(authctxt, 0, sizeof(*authctxt)); 347 348 authctxt->loginmsg = &loginmsg; 349 350 if (compat20) { 351 mon_dispatch = mon_dispatch_proto20; 352 353 /* Permit requests for moduli and signatures */ 354 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 355 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 356 } else { 357 mon_dispatch = mon_dispatch_proto15; 358 359 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 360 } 361 362 /* The first few requests do not require asynchronous access */ 363 while (!authenticated) { 364 partial = 0; 365 auth_method = "unknown"; 366 auth_submethod = NULL; 367 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 368 369 /* Special handling for multiple required authentications */ 370 if (options.num_auth_methods != 0) { 371 if (!compat20) 372 fatal("AuthenticationMethods is not supported" 373 "with SSH protocol 1"); 374 if (authenticated && 375 !auth2_update_methods_lists(authctxt, 376 auth_method, auth_submethod)) { 377 debug3("%s: method %s: partial", __func__, 378 auth_method); 379 authenticated = 0; 380 partial = 1; 381 } 382 } 383 384 if (authenticated) { 385 if (!(ent->flags & MON_AUTHDECIDE)) 386 fatal("%s: unexpected authentication from %d", 387 __func__, ent->type); 388 if (authctxt->pw->pw_uid == 0 && 389 !auth_root_allowed(auth_method)) 390 authenticated = 0; 391 #ifdef USE_PAM 392 /* PAM needs to perform account checks after auth */ 393 if (options.use_pam && authenticated) { 394 Buffer m; 395 396 buffer_init(&m); 397 mm_request_receive_expect(pmonitor->m_sendfd, 398 MONITOR_REQ_PAM_ACCOUNT, &m); 399 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 400 buffer_free(&m); 401 } 402 #endif 403 } 404 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 405 auth_log(authctxt, authenticated, partial, 406 auth_method, auth_submethod); 407 if (!partial && !authenticated) 408 authctxt->failures++; 409 } 410 } 411 412 if (!authctxt->valid) 413 fatal("%s: authenticated invalid user", __func__); 414 if (strcmp(auth_method, "unknown") == 0) 415 fatal("%s: authentication method name unknown", __func__); 416 417 debug("%s: %s has been authenticated by privileged process", 418 __func__, authctxt->user); 419 420 mm_get_keystate(pmonitor); 421 422 /* Drain any buffered messages from the child */ 423 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 424 ; 425 426 close(pmonitor->m_sendfd); 427 close(pmonitor->m_log_recvfd); 428 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 429 } 430 431 static void 432 monitor_set_child_handler(pid_t pid) 433 { 434 monitor_child_pid = pid; 435 } 436 437 static void 438 monitor_child_handler(int sig) 439 { 440 kill(monitor_child_pid, sig); 441 } 442 443 void 444 monitor_child_postauth(struct monitor *pmonitor) 445 { 446 close(pmonitor->m_recvfd); 447 pmonitor->m_recvfd = -1; 448 449 monitor_set_child_handler(pmonitor->m_pid); 450 signal(SIGHUP, &monitor_child_handler); 451 signal(SIGTERM, &monitor_child_handler); 452 signal(SIGINT, &monitor_child_handler); 453 #ifdef SIGXFSZ 454 signal(SIGXFSZ, SIG_IGN); 455 #endif 456 457 if (compat20) { 458 mon_dispatch = mon_dispatch_postauth20; 459 460 /* Permit requests for moduli and signatures */ 461 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 462 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 463 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 464 } else { 465 mon_dispatch = mon_dispatch_postauth15; 466 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 467 } 468 if (!no_pty_flag) { 469 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 470 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 471 } 472 473 for (;;) 474 monitor_read(pmonitor, mon_dispatch, NULL); 475 } 476 477 void 478 monitor_sync(struct monitor *pmonitor) 479 { 480 if (options.compression) { 481 /* The member allocation is not visible, so sync it */ 482 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 483 } 484 } 485 486 /* Allocation functions for zlib */ 487 static void * 488 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 489 { 490 size_t len = (size_t) size * ncount; 491 void *address; 492 493 if (len == 0 || ncount > SIZE_MAX / size) 494 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 495 496 address = mm_malloc(mm, len); 497 498 return (address); 499 } 500 501 static void 502 mm_zfree(struct mm_master *mm, void *address) 503 { 504 mm_free(mm, address); 505 } 506 507 static int 508 monitor_read_log(struct monitor *pmonitor) 509 { 510 Buffer logmsg; 511 u_int len, level; 512 char *msg; 513 514 buffer_init(&logmsg); 515 516 /* Read length */ 517 buffer_append_space(&logmsg, 4); 518 if (atomicio(read, pmonitor->m_log_recvfd, 519 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 520 if (errno == EPIPE) { 521 buffer_free(&logmsg); 522 debug("%s: child log fd closed", __func__); 523 close(pmonitor->m_log_recvfd); 524 pmonitor->m_log_recvfd = -1; 525 return -1; 526 } 527 fatal("%s: log fd read: %s", __func__, strerror(errno)); 528 } 529 len = buffer_get_int(&logmsg); 530 if (len <= 4 || len > 8192) 531 fatal("%s: invalid log message length %u", __func__, len); 532 533 /* Read severity, message */ 534 buffer_clear(&logmsg); 535 buffer_append_space(&logmsg, len); 536 if (atomicio(read, pmonitor->m_log_recvfd, 537 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 538 fatal("%s: log fd read: %s", __func__, strerror(errno)); 539 540 /* Log it */ 541 level = buffer_get_int(&logmsg); 542 msg = buffer_get_string(&logmsg, NULL); 543 if (log_level_name(level) == NULL) 544 fatal("%s: invalid log level %u (corrupted message?)", 545 __func__, level); 546 do_log2(level, "%s [preauth]", msg); 547 548 buffer_free(&logmsg); 549 free(msg); 550 551 return 0; 552 } 553 554 int 555 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 556 struct mon_table **pent) 557 { 558 Buffer m; 559 int ret; 560 u_char type; 561 struct pollfd pfd[2]; 562 563 for (;;) { 564 memset(&pfd, 0, sizeof(pfd)); 565 pfd[0].fd = pmonitor->m_sendfd; 566 pfd[0].events = POLLIN; 567 pfd[1].fd = pmonitor->m_log_recvfd; 568 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 569 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 570 if (errno == EINTR || errno == EAGAIN) 571 continue; 572 fatal("%s: poll: %s", __func__, strerror(errno)); 573 } 574 if (pfd[1].revents) { 575 /* 576 * Drain all log messages before processing next 577 * monitor request. 578 */ 579 monitor_read_log(pmonitor); 580 continue; 581 } 582 if (pfd[0].revents) 583 break; /* Continues below */ 584 } 585 586 buffer_init(&m); 587 588 mm_request_receive(pmonitor->m_sendfd, &m); 589 type = buffer_get_char(&m); 590 591 debug3("%s: checking request %d", __func__, type); 592 593 while (ent->f != NULL) { 594 if (ent->type == type) 595 break; 596 ent++; 597 } 598 599 if (ent->f != NULL) { 600 if (!(ent->flags & MON_PERMIT)) 601 fatal("%s: unpermitted request %d", __func__, 602 type); 603 ret = (*ent->f)(pmonitor->m_sendfd, &m); 604 buffer_free(&m); 605 606 /* The child may use this request only once, disable it */ 607 if (ent->flags & MON_ONCE) { 608 debug2("%s: %d used once, disabling now", __func__, 609 type); 610 ent->flags &= ~MON_PERMIT; 611 } 612 613 if (pent != NULL) 614 *pent = ent; 615 616 return ret; 617 } 618 619 fatal("%s: unsupported request: %d", __func__, type); 620 621 /* NOTREACHED */ 622 return (-1); 623 } 624 625 /* allowed key state */ 626 static int 627 monitor_allowed_key(u_char *blob, u_int bloblen) 628 { 629 /* make sure key is allowed */ 630 if (key_blob == NULL || key_bloblen != bloblen || 631 timingsafe_bcmp(key_blob, blob, key_bloblen)) 632 return (0); 633 return (1); 634 } 635 636 static void 637 monitor_reset_key_state(void) 638 { 639 /* reset state */ 640 free(key_blob); 641 free(hostbased_cuser); 642 free(hostbased_chost); 643 key_blob = NULL; 644 key_bloblen = 0; 645 key_blobtype = MM_NOKEY; 646 hostbased_cuser = NULL; 647 hostbased_chost = NULL; 648 } 649 650 #ifdef WITH_OPENSSL 651 int 652 mm_answer_moduli(int sock, Buffer *m) 653 { 654 DH *dh; 655 int min, want, max; 656 657 min = buffer_get_int(m); 658 want = buffer_get_int(m); 659 max = buffer_get_int(m); 660 661 debug3("%s: got parameters: %d %d %d", 662 __func__, min, want, max); 663 /* We need to check here, too, in case the child got corrupted */ 664 if (max < min || want < min || max < want) 665 fatal("%s: bad parameters: %d %d %d", 666 __func__, min, want, max); 667 668 buffer_clear(m); 669 670 dh = choose_dh(min, want, max); 671 if (dh == NULL) { 672 buffer_put_char(m, 0); 673 return (0); 674 } else { 675 /* Send first bignum */ 676 buffer_put_char(m, 1); 677 buffer_put_bignum2(m, dh->p); 678 buffer_put_bignum2(m, dh->g); 679 680 DH_free(dh); 681 } 682 mm_request_send(sock, MONITOR_ANS_MODULI, m); 683 return (0); 684 } 685 #endif 686 687 int 688 mm_answer_sign(int sock, Buffer *m) 689 { 690 struct ssh *ssh = active_state; /* XXX */ 691 extern int auth_sock; /* XXX move to state struct? */ 692 struct sshkey *key; 693 struct sshbuf *sigbuf; 694 u_char *p; 695 u_char *signature; 696 size_t datlen, siglen; 697 int r, keyid, is_proof = 0; 698 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 699 700 debug3("%s", __func__); 701 702 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 703 (r = sshbuf_get_string(m, &p, &datlen)) != 0) 704 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 705 706 /* 707 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 708 * SHA384 (48 bytes) and SHA512 (64 bytes). 709 * 710 * Otherwise, verify the signature request is for a hostkey 711 * proof. 712 * 713 * XXX perform similar check for KEX signature requests too? 714 * it's not trivial, since what is signed is the hash, rather 715 * than the full kex structure... 716 */ 717 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) { 718 /* 719 * Construct expected hostkey proof and compare it to what 720 * the client sent us. 721 */ 722 if (session_id2_len == 0) /* hostkeys is never first */ 723 fatal("%s: bad data length: %zu", __func__, datlen); 724 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL) 725 fatal("%s: no hostkey for index %d", __func__, keyid); 726 if ((sigbuf = sshbuf_new()) == NULL) 727 fatal("%s: sshbuf_new", __func__); 728 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 729 (r = sshbuf_put_string(sigbuf, session_id2, 730 session_id2_len) != 0) || 731 (r = sshkey_puts(key, sigbuf)) != 0) 732 fatal("%s: couldn't prepare private key " 733 "proof buffer: %s", __func__, ssh_err(r)); 734 if (datlen != sshbuf_len(sigbuf) || 735 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0) 736 fatal("%s: bad data length: %zu, hostkey proof len %zu", 737 __func__, datlen, sshbuf_len(sigbuf)); 738 sshbuf_free(sigbuf); 739 is_proof = 1; 740 } 741 742 /* save session id, it will be passed on the first call */ 743 if (session_id2_len == 0) { 744 session_id2_len = datlen; 745 session_id2 = xmalloc(session_id2_len); 746 memcpy(session_id2, p, session_id2_len); 747 } 748 749 if ((key = get_hostkey_by_index(keyid)) != NULL) { 750 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, 751 datafellows)) != 0) 752 fatal("%s: sshkey_sign failed: %s", 753 __func__, ssh_err(r)); 754 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 755 auth_sock > 0) { 756 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 757 p, datlen, datafellows)) != 0) { 758 fatal("%s: ssh_agent_sign failed: %s", 759 __func__, ssh_err(r)); 760 } 761 } else 762 fatal("%s: no hostkey from index %d", __func__, keyid); 763 764 debug3("%s: %s signature %p(%zu)", __func__, 765 is_proof ? "KEX" : "hostkey proof", signature, siglen); 766 767 sshbuf_reset(m); 768 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 769 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 770 771 free(p); 772 free(signature); 773 774 mm_request_send(sock, MONITOR_ANS_SIGN, m); 775 776 /* Turn on permissions for getpwnam */ 777 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 778 779 return (0); 780 } 781 782 /* Retrieves the password entry and also checks if the user is permitted */ 783 784 int 785 mm_answer_pwnamallow(int sock, Buffer *m) 786 { 787 char *username; 788 struct passwd *pwent; 789 int allowed = 0; 790 u_int i; 791 792 debug3("%s", __func__); 793 794 if (authctxt->attempt++ != 0) 795 fatal("%s: multiple attempts for getpwnam", __func__); 796 797 username = buffer_get_string(m, NULL); 798 799 pwent = getpwnamallow(username); 800 801 authctxt->user = xstrdup(username); 802 setproctitle("%s [priv]", pwent ? username : "unknown"); 803 free(username); 804 805 buffer_clear(m); 806 807 if (pwent == NULL) { 808 buffer_put_char(m, 0); 809 authctxt->pw = fakepw(); 810 goto out; 811 } 812 813 allowed = 1; 814 authctxt->pw = pwent; 815 authctxt->valid = 1; 816 817 buffer_put_char(m, 1); 818 buffer_put_string(m, pwent, sizeof(struct passwd)); 819 buffer_put_cstring(m, pwent->pw_name); 820 buffer_put_cstring(m, "*"); 821 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 822 buffer_put_cstring(m, pwent->pw_gecos); 823 #endif 824 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 825 buffer_put_cstring(m, pwent->pw_class); 826 #endif 827 buffer_put_cstring(m, pwent->pw_dir); 828 buffer_put_cstring(m, pwent->pw_shell); 829 830 out: 831 buffer_put_string(m, &options, sizeof(options)); 832 833 #define M_CP_STROPT(x) do { \ 834 if (options.x != NULL) \ 835 buffer_put_cstring(m, options.x); \ 836 } while (0) 837 #define M_CP_STRARRAYOPT(x, nx) do { \ 838 for (i = 0; i < options.nx; i++) \ 839 buffer_put_cstring(m, options.x[i]); \ 840 } while (0) 841 /* See comment in servconf.h */ 842 COPY_MATCH_STRING_OPTS(); 843 #undef M_CP_STROPT 844 #undef M_CP_STRARRAYOPT 845 846 /* Create valid auth method lists */ 847 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 848 /* 849 * The monitor will continue long enough to let the child 850 * run to it's packet_disconnect(), but it must not allow any 851 * authentication to succeed. 852 */ 853 debug("%s: no valid authentication method lists", __func__); 854 } 855 856 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 857 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 858 859 /* For SSHv1 allow authentication now */ 860 if (!compat20) 861 monitor_permit_authentications(1); 862 else { 863 /* Allow service/style information on the auth context */ 864 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 865 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 866 } 867 #ifdef USE_PAM 868 if (options.use_pam) 869 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 870 #endif 871 872 return (0); 873 } 874 875 int mm_answer_auth2_read_banner(int sock, Buffer *m) 876 { 877 char *banner; 878 879 buffer_clear(m); 880 banner = auth2_read_banner(); 881 buffer_put_cstring(m, banner != NULL ? banner : ""); 882 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 883 free(banner); 884 885 return (0); 886 } 887 888 int 889 mm_answer_authserv(int sock, Buffer *m) 890 { 891 monitor_permit_authentications(1); 892 893 authctxt->service = buffer_get_string(m, NULL); 894 authctxt->style = buffer_get_string(m, NULL); 895 debug3("%s: service=%s, style=%s", 896 __func__, authctxt->service, authctxt->style); 897 898 if (strlen(authctxt->style) == 0) { 899 free(authctxt->style); 900 authctxt->style = NULL; 901 } 902 903 return (0); 904 } 905 906 int 907 mm_answer_authpassword(int sock, Buffer *m) 908 { 909 static int call_count; 910 char *passwd; 911 int authenticated; 912 u_int plen; 913 914 passwd = buffer_get_string(m, &plen); 915 /* Only authenticate if the context is valid */ 916 authenticated = options.password_authentication && 917 auth_password(authctxt, passwd); 918 explicit_bzero(passwd, strlen(passwd)); 919 free(passwd); 920 921 buffer_clear(m); 922 buffer_put_int(m, authenticated); 923 924 debug3("%s: sending result %d", __func__, authenticated); 925 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 926 927 call_count++; 928 if (plen == 0 && call_count == 1) 929 auth_method = "none"; 930 else 931 auth_method = "password"; 932 933 /* Causes monitor loop to terminate if authenticated */ 934 return (authenticated); 935 } 936 937 #ifdef BSD_AUTH 938 int 939 mm_answer_bsdauthquery(int sock, Buffer *m) 940 { 941 char *name, *infotxt; 942 u_int numprompts; 943 u_int *echo_on; 944 char **prompts; 945 u_int success; 946 947 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 948 &prompts, &echo_on) < 0 ? 0 : 1; 949 950 buffer_clear(m); 951 buffer_put_int(m, success); 952 if (success) 953 buffer_put_cstring(m, prompts[0]); 954 955 debug3("%s: sending challenge success: %u", __func__, success); 956 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 957 958 if (success) { 959 free(name); 960 free(infotxt); 961 free(prompts); 962 free(echo_on); 963 } 964 965 return (0); 966 } 967 968 int 969 mm_answer_bsdauthrespond(int sock, Buffer *m) 970 { 971 char *response; 972 int authok; 973 974 if (authctxt->as == 0) 975 fatal("%s: no bsd auth session", __func__); 976 977 response = buffer_get_string(m, NULL); 978 authok = options.challenge_response_authentication && 979 auth_userresponse(authctxt->as, response, 0); 980 authctxt->as = NULL; 981 debug3("%s: <%s> = <%d>", __func__, response, authok); 982 free(response); 983 984 buffer_clear(m); 985 buffer_put_int(m, authok); 986 987 debug3("%s: sending authenticated: %d", __func__, authok); 988 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 989 990 if (compat20) { 991 auth_method = "keyboard-interactive"; 992 auth_submethod = "bsdauth"; 993 } else 994 auth_method = "bsdauth"; 995 996 return (authok != 0); 997 } 998 #endif 999 1000 #ifdef SKEY 1001 int 1002 mm_answer_skeyquery(int sock, Buffer *m) 1003 { 1004 struct skey skey; 1005 char challenge[1024]; 1006 u_int success; 1007 1008 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 1009 sizeof(challenge)) < 0 ? 0 : 1; 1010 1011 buffer_clear(m); 1012 buffer_put_int(m, success); 1013 if (success) 1014 buffer_put_cstring(m, challenge); 1015 1016 debug3("%s: sending challenge success: %u", __func__, success); 1017 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 1018 1019 return (0); 1020 } 1021 1022 int 1023 mm_answer_skeyrespond(int sock, Buffer *m) 1024 { 1025 char *response; 1026 int authok; 1027 1028 response = buffer_get_string(m, NULL); 1029 1030 authok = (options.challenge_response_authentication && 1031 authctxt->valid && 1032 skey_haskey(authctxt->pw->pw_name) == 0 && 1033 skey_passcheck(authctxt->pw->pw_name, response) != -1); 1034 1035 free(response); 1036 1037 buffer_clear(m); 1038 buffer_put_int(m, authok); 1039 1040 debug3("%s: sending authenticated: %d", __func__, authok); 1041 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 1042 1043 auth_method = "skey"; 1044 1045 return (authok != 0); 1046 } 1047 #endif 1048 1049 #ifdef USE_PAM 1050 int 1051 mm_answer_pam_start(int sock, Buffer *m) 1052 { 1053 if (!options.use_pam) 1054 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1055 1056 start_pam(authctxt); 1057 1058 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1059 1060 return (0); 1061 } 1062 1063 int 1064 mm_answer_pam_account(int sock, Buffer *m) 1065 { 1066 u_int ret; 1067 1068 if (!options.use_pam) 1069 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1070 1071 ret = do_pam_account(); 1072 1073 buffer_put_int(m, ret); 1074 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1075 1076 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1077 1078 return (ret); 1079 } 1080 1081 static void *sshpam_ctxt, *sshpam_authok; 1082 extern KbdintDevice sshpam_device; 1083 1084 int 1085 mm_answer_pam_init_ctx(int sock, Buffer *m) 1086 { 1087 debug3("%s", __func__); 1088 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1089 sshpam_authok = NULL; 1090 buffer_clear(m); 1091 if (sshpam_ctxt != NULL) { 1092 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1093 buffer_put_int(m, 1); 1094 } else { 1095 buffer_put_int(m, 0); 1096 } 1097 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1098 return (0); 1099 } 1100 1101 int 1102 mm_answer_pam_query(int sock, Buffer *m) 1103 { 1104 char *name = NULL, *info = NULL, **prompts = NULL; 1105 u_int i, num = 0, *echo_on = 0; 1106 int ret; 1107 1108 debug3("%s", __func__); 1109 sshpam_authok = NULL; 1110 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1111 if (ret == 0 && num == 0) 1112 sshpam_authok = sshpam_ctxt; 1113 if (num > 1 || name == NULL || info == NULL) 1114 ret = -1; 1115 buffer_clear(m); 1116 buffer_put_int(m, ret); 1117 buffer_put_cstring(m, name); 1118 free(name); 1119 buffer_put_cstring(m, info); 1120 free(info); 1121 buffer_put_int(m, num); 1122 for (i = 0; i < num; ++i) { 1123 buffer_put_cstring(m, prompts[i]); 1124 free(prompts[i]); 1125 buffer_put_int(m, echo_on[i]); 1126 } 1127 free(prompts); 1128 free(echo_on); 1129 auth_method = "keyboard-interactive"; 1130 auth_submethod = "pam"; 1131 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1132 return (0); 1133 } 1134 1135 int 1136 mm_answer_pam_respond(int sock, Buffer *m) 1137 { 1138 char **resp; 1139 u_int i, num; 1140 int ret; 1141 1142 debug3("%s", __func__); 1143 sshpam_authok = NULL; 1144 num = buffer_get_int(m); 1145 if (num > 0) { 1146 resp = xcalloc(num, sizeof(char *)); 1147 for (i = 0; i < num; ++i) 1148 resp[i] = buffer_get_string(m, NULL); 1149 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1150 for (i = 0; i < num; ++i) 1151 free(resp[i]); 1152 free(resp); 1153 } else { 1154 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1155 } 1156 buffer_clear(m); 1157 buffer_put_int(m, ret); 1158 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1159 auth_method = "keyboard-interactive"; 1160 auth_submethod = "pam"; 1161 if (ret == 0) 1162 sshpam_authok = sshpam_ctxt; 1163 return (0); 1164 } 1165 1166 int 1167 mm_answer_pam_free_ctx(int sock, Buffer *m) 1168 { 1169 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt; 1170 1171 debug3("%s", __func__); 1172 (sshpam_device.free_ctx)(sshpam_ctxt); 1173 sshpam_ctxt = sshpam_authok = NULL; 1174 buffer_clear(m); 1175 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1176 auth_method = "keyboard-interactive"; 1177 auth_submethod = "pam"; 1178 return r; 1179 } 1180 #endif 1181 1182 int 1183 mm_answer_keyallowed(int sock, Buffer *m) 1184 { 1185 Key *key; 1186 char *cuser, *chost; 1187 u_char *blob; 1188 u_int bloblen, pubkey_auth_attempt; 1189 enum mm_keytype type = 0; 1190 int allowed = 0; 1191 1192 debug3("%s entering", __func__); 1193 1194 type = buffer_get_int(m); 1195 cuser = buffer_get_string(m, NULL); 1196 chost = buffer_get_string(m, NULL); 1197 blob = buffer_get_string(m, &bloblen); 1198 pubkey_auth_attempt = buffer_get_int(m); 1199 1200 key = key_from_blob(blob, bloblen); 1201 1202 if ((compat20 && type == MM_RSAHOSTKEY) || 1203 (!compat20 && type != MM_RSAHOSTKEY)) 1204 fatal("%s: key type and protocol mismatch", __func__); 1205 1206 debug3("%s: key_from_blob: %p", __func__, key); 1207 1208 if (key != NULL && authctxt->valid) { 1209 /* These should not make it past the privsep child */ 1210 if (key_type_plain(key->type) == KEY_RSA && 1211 (datafellows & SSH_BUG_RSASIGMD5) != 0) 1212 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 1213 1214 switch (type) { 1215 case MM_USERKEY: 1216 allowed = options.pubkey_authentication && 1217 !auth2_userkey_already_used(authctxt, key) && 1218 match_pattern_list(sshkey_ssh_name(key), 1219 options.pubkey_key_types, 0) == 1 && 1220 user_key_allowed(authctxt->pw, key, 1221 pubkey_auth_attempt); 1222 pubkey_auth_info(authctxt, key, NULL); 1223 auth_method = "publickey"; 1224 if (options.pubkey_authentication && 1225 (!pubkey_auth_attempt || allowed != 1)) 1226 auth_clear_options(); 1227 break; 1228 case MM_HOSTKEY: 1229 allowed = options.hostbased_authentication && 1230 match_pattern_list(sshkey_ssh_name(key), 1231 options.hostbased_key_types, 0) == 1 && 1232 hostbased_key_allowed(authctxt->pw, 1233 cuser, chost, key); 1234 pubkey_auth_info(authctxt, key, 1235 "client user \"%.100s\", client host \"%.100s\"", 1236 cuser, chost); 1237 auth_method = "hostbased"; 1238 break; 1239 #ifdef WITH_SSH1 1240 case MM_RSAHOSTKEY: 1241 key->type = KEY_RSA1; /* XXX */ 1242 allowed = options.rhosts_rsa_authentication && 1243 auth_rhosts_rsa_key_allowed(authctxt->pw, 1244 cuser, chost, key); 1245 if (options.rhosts_rsa_authentication && allowed != 1) 1246 auth_clear_options(); 1247 auth_method = "rsa"; 1248 break; 1249 #endif 1250 default: 1251 fatal("%s: unknown key type %d", __func__, type); 1252 break; 1253 } 1254 } 1255 if (key != NULL) 1256 key_free(key); 1257 1258 /* clear temporarily storage (used by verify) */ 1259 monitor_reset_key_state(); 1260 1261 if (allowed) { 1262 /* Save temporarily for comparison in verify */ 1263 key_blob = blob; 1264 key_bloblen = bloblen; 1265 key_blobtype = type; 1266 hostbased_cuser = cuser; 1267 hostbased_chost = chost; 1268 } else { 1269 /* Log failed attempt */ 1270 auth_log(authctxt, 0, 0, auth_method, NULL); 1271 free(blob); 1272 free(cuser); 1273 free(chost); 1274 } 1275 1276 debug3("%s: key %p is %s", 1277 __func__, key, allowed ? "allowed" : "not allowed"); 1278 1279 buffer_clear(m); 1280 buffer_put_int(m, allowed); 1281 buffer_put_int(m, forced_command != NULL); 1282 1283 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1284 1285 if (type == MM_RSAHOSTKEY) 1286 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1287 1288 return (0); 1289 } 1290 1291 static int 1292 monitor_valid_userblob(u_char *data, u_int datalen) 1293 { 1294 Buffer b; 1295 char *p, *userstyle; 1296 u_int len; 1297 int fail = 0; 1298 1299 buffer_init(&b); 1300 buffer_append(&b, data, datalen); 1301 1302 if (datafellows & SSH_OLD_SESSIONID) { 1303 p = buffer_ptr(&b); 1304 len = buffer_len(&b); 1305 if ((session_id2 == NULL) || 1306 (len < session_id2_len) || 1307 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1308 fail++; 1309 buffer_consume(&b, session_id2_len); 1310 } else { 1311 p = buffer_get_string(&b, &len); 1312 if ((session_id2 == NULL) || 1313 (len != session_id2_len) || 1314 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1315 fail++; 1316 free(p); 1317 } 1318 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1319 fail++; 1320 p = buffer_get_cstring(&b, NULL); 1321 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1322 authctxt->style ? ":" : "", 1323 authctxt->style ? authctxt->style : ""); 1324 if (strcmp(userstyle, p) != 0) { 1325 logit("wrong user name passed to monitor: expected %s != %.100s", 1326 userstyle, p); 1327 fail++; 1328 } 1329 free(userstyle); 1330 free(p); 1331 buffer_skip_string(&b); 1332 if (datafellows & SSH_BUG_PKAUTH) { 1333 if (!buffer_get_char(&b)) 1334 fail++; 1335 } else { 1336 p = buffer_get_cstring(&b, NULL); 1337 if (strcmp("publickey", p) != 0) 1338 fail++; 1339 free(p); 1340 if (!buffer_get_char(&b)) 1341 fail++; 1342 buffer_skip_string(&b); 1343 } 1344 buffer_skip_string(&b); 1345 if (buffer_len(&b) != 0) 1346 fail++; 1347 buffer_free(&b); 1348 return (fail == 0); 1349 } 1350 1351 static int 1352 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1353 char *chost) 1354 { 1355 Buffer b; 1356 char *p, *userstyle; 1357 u_int len; 1358 int fail = 0; 1359 1360 buffer_init(&b); 1361 buffer_append(&b, data, datalen); 1362 1363 p = buffer_get_string(&b, &len); 1364 if ((session_id2 == NULL) || 1365 (len != session_id2_len) || 1366 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1367 fail++; 1368 free(p); 1369 1370 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1371 fail++; 1372 p = buffer_get_cstring(&b, NULL); 1373 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1374 authctxt->style ? ":" : "", 1375 authctxt->style ? authctxt->style : ""); 1376 if (strcmp(userstyle, p) != 0) { 1377 logit("wrong user name passed to monitor: expected %s != %.100s", 1378 userstyle, p); 1379 fail++; 1380 } 1381 free(userstyle); 1382 free(p); 1383 buffer_skip_string(&b); /* service */ 1384 p = buffer_get_cstring(&b, NULL); 1385 if (strcmp(p, "hostbased") != 0) 1386 fail++; 1387 free(p); 1388 buffer_skip_string(&b); /* pkalg */ 1389 buffer_skip_string(&b); /* pkblob */ 1390 1391 /* verify client host, strip trailing dot if necessary */ 1392 p = buffer_get_string(&b, NULL); 1393 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1394 p[len - 1] = '\0'; 1395 if (strcmp(p, chost) != 0) 1396 fail++; 1397 free(p); 1398 1399 /* verify client user */ 1400 p = buffer_get_string(&b, NULL); 1401 if (strcmp(p, cuser) != 0) 1402 fail++; 1403 free(p); 1404 1405 if (buffer_len(&b) != 0) 1406 fail++; 1407 buffer_free(&b); 1408 return (fail == 0); 1409 } 1410 1411 int 1412 mm_answer_keyverify(int sock, Buffer *m) 1413 { 1414 Key *key; 1415 u_char *signature, *data, *blob; 1416 u_int signaturelen, datalen, bloblen; 1417 int verified = 0; 1418 int valid_data = 0; 1419 1420 blob = buffer_get_string(m, &bloblen); 1421 signature = buffer_get_string(m, &signaturelen); 1422 data = buffer_get_string(m, &datalen); 1423 1424 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1425 !monitor_allowed_key(blob, bloblen)) 1426 fatal("%s: bad key, not previously allowed", __func__); 1427 1428 key = key_from_blob(blob, bloblen); 1429 if (key == NULL) 1430 fatal("%s: bad public key blob", __func__); 1431 1432 switch (key_blobtype) { 1433 case MM_USERKEY: 1434 valid_data = monitor_valid_userblob(data, datalen); 1435 break; 1436 case MM_HOSTKEY: 1437 valid_data = monitor_valid_hostbasedblob(data, datalen, 1438 hostbased_cuser, hostbased_chost); 1439 break; 1440 default: 1441 valid_data = 0; 1442 break; 1443 } 1444 if (!valid_data) 1445 fatal("%s: bad signature data blob", __func__); 1446 1447 verified = key_verify(key, signature, signaturelen, data, datalen); 1448 debug3("%s: key %p signature %s", 1449 __func__, key, (verified == 1) ? "verified" : "unverified"); 1450 1451 /* If auth was successful then record key to ensure it isn't reused */ 1452 if (verified == 1) 1453 auth2_record_userkey(authctxt, key); 1454 else 1455 key_free(key); 1456 1457 free(blob); 1458 free(signature); 1459 free(data); 1460 1461 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1462 1463 monitor_reset_key_state(); 1464 1465 buffer_clear(m); 1466 buffer_put_int(m, verified); 1467 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1468 1469 return (verified == 1); 1470 } 1471 1472 static void 1473 mm_record_login(Session *s, struct passwd *pw) 1474 { 1475 socklen_t fromlen; 1476 struct sockaddr_storage from; 1477 1478 if (options.use_login) 1479 return; 1480 1481 /* 1482 * Get IP address of client. If the connection is not a socket, let 1483 * the address be 0.0.0.0. 1484 */ 1485 memset(&from, 0, sizeof(from)); 1486 fromlen = sizeof(from); 1487 if (packet_connection_is_on_socket()) { 1488 if (getpeername(packet_get_connection_in(), 1489 (struct sockaddr *)&from, &fromlen) < 0) { 1490 debug("getpeername: %.100s", strerror(errno)); 1491 cleanup_exit(255); 1492 } 1493 } 1494 /* Record that there was a login on that tty from the remote host. */ 1495 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1496 get_remote_name_or_ip(utmp_len, options.use_dns), 1497 (struct sockaddr *)&from, fromlen); 1498 } 1499 1500 static void 1501 mm_session_close(Session *s) 1502 { 1503 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1504 if (s->ttyfd != -1) { 1505 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1506 session_pty_cleanup2(s); 1507 } 1508 session_unused(s->self); 1509 } 1510 1511 int 1512 mm_answer_pty(int sock, Buffer *m) 1513 { 1514 extern struct monitor *pmonitor; 1515 Session *s; 1516 int res, fd0; 1517 1518 debug3("%s entering", __func__); 1519 1520 buffer_clear(m); 1521 s = session_new(); 1522 if (s == NULL) 1523 goto error; 1524 s->authctxt = authctxt; 1525 s->pw = authctxt->pw; 1526 s->pid = pmonitor->m_pid; 1527 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1528 if (res == 0) 1529 goto error; 1530 pty_setowner(authctxt->pw, s->tty); 1531 1532 buffer_put_int(m, 1); 1533 buffer_put_cstring(m, s->tty); 1534 1535 /* We need to trick ttyslot */ 1536 if (dup2(s->ttyfd, 0) == -1) 1537 fatal("%s: dup2", __func__); 1538 1539 mm_record_login(s, authctxt->pw); 1540 1541 /* Now we can close the file descriptor again */ 1542 close(0); 1543 1544 /* send messages generated by record_login */ 1545 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1546 buffer_clear(&loginmsg); 1547 1548 mm_request_send(sock, MONITOR_ANS_PTY, m); 1549 1550 if (mm_send_fd(sock, s->ptyfd) == -1 || 1551 mm_send_fd(sock, s->ttyfd) == -1) 1552 fatal("%s: send fds failed", __func__); 1553 1554 /* make sure nothing uses fd 0 */ 1555 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1556 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1557 if (fd0 != 0) 1558 error("%s: fd0 %d != 0", __func__, fd0); 1559 1560 /* slave is not needed */ 1561 close(s->ttyfd); 1562 s->ttyfd = s->ptyfd; 1563 /* no need to dup() because nobody closes ptyfd */ 1564 s->ptymaster = s->ptyfd; 1565 1566 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1567 1568 return (0); 1569 1570 error: 1571 if (s != NULL) 1572 mm_session_close(s); 1573 buffer_put_int(m, 0); 1574 mm_request_send(sock, MONITOR_ANS_PTY, m); 1575 return (0); 1576 } 1577 1578 int 1579 mm_answer_pty_cleanup(int sock, Buffer *m) 1580 { 1581 Session *s; 1582 char *tty; 1583 1584 debug3("%s entering", __func__); 1585 1586 tty = buffer_get_string(m, NULL); 1587 if ((s = session_by_tty(tty)) != NULL) 1588 mm_session_close(s); 1589 buffer_clear(m); 1590 free(tty); 1591 return (0); 1592 } 1593 1594 #ifdef WITH_SSH1 1595 int 1596 mm_answer_sesskey(int sock, Buffer *m) 1597 { 1598 BIGNUM *p; 1599 int rsafail; 1600 1601 /* Turn off permissions */ 1602 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1603 1604 if ((p = BN_new()) == NULL) 1605 fatal("%s: BN_new", __func__); 1606 1607 buffer_get_bignum2(m, p); 1608 1609 rsafail = ssh1_session_key(p); 1610 1611 buffer_clear(m); 1612 buffer_put_int(m, rsafail); 1613 buffer_put_bignum2(m, p); 1614 1615 BN_clear_free(p); 1616 1617 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1618 1619 /* Turn on permissions for sessid passing */ 1620 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1621 1622 return (0); 1623 } 1624 1625 int 1626 mm_answer_sessid(int sock, Buffer *m) 1627 { 1628 int i; 1629 1630 debug3("%s entering", __func__); 1631 1632 if (buffer_len(m) != 16) 1633 fatal("%s: bad ssh1 session id", __func__); 1634 for (i = 0; i < 16; i++) 1635 session_id[i] = buffer_get_char(m); 1636 1637 /* Turn on permissions for getpwnam */ 1638 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1639 1640 return (0); 1641 } 1642 1643 int 1644 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1645 { 1646 BIGNUM *client_n; 1647 Key *key = NULL; 1648 u_char *blob = NULL; 1649 u_int blen = 0; 1650 int allowed = 0; 1651 1652 debug3("%s entering", __func__); 1653 1654 auth_method = "rsa"; 1655 if (options.rsa_authentication && authctxt->valid) { 1656 if ((client_n = BN_new()) == NULL) 1657 fatal("%s: BN_new", __func__); 1658 buffer_get_bignum2(m, client_n); 1659 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1660 BN_clear_free(client_n); 1661 } 1662 buffer_clear(m); 1663 buffer_put_int(m, allowed); 1664 buffer_put_int(m, forced_command != NULL); 1665 1666 /* clear temporarily storage (used by generate challenge) */ 1667 monitor_reset_key_state(); 1668 1669 if (allowed && key != NULL) { 1670 key->type = KEY_RSA; /* cheat for key_to_blob */ 1671 if (key_to_blob(key, &blob, &blen) == 0) 1672 fatal("%s: key_to_blob failed", __func__); 1673 buffer_put_string(m, blob, blen); 1674 1675 /* Save temporarily for comparison in verify */ 1676 key_blob = blob; 1677 key_bloblen = blen; 1678 key_blobtype = MM_RSAUSERKEY; 1679 } 1680 if (key != NULL) 1681 key_free(key); 1682 1683 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1684 1685 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1686 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1687 return (0); 1688 } 1689 1690 int 1691 mm_answer_rsa_challenge(int sock, Buffer *m) 1692 { 1693 Key *key = NULL; 1694 u_char *blob; 1695 u_int blen; 1696 1697 debug3("%s entering", __func__); 1698 1699 if (!authctxt->valid) 1700 fatal("%s: authctxt not valid", __func__); 1701 blob = buffer_get_string(m, &blen); 1702 if (!monitor_allowed_key(blob, blen)) 1703 fatal("%s: bad key, not previously allowed", __func__); 1704 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1705 fatal("%s: key type mismatch", __func__); 1706 if ((key = key_from_blob(blob, blen)) == NULL) 1707 fatal("%s: received bad key", __func__); 1708 if (key->type != KEY_RSA) 1709 fatal("%s: received bad key type %d", __func__, key->type); 1710 key->type = KEY_RSA1; 1711 if (ssh1_challenge) 1712 BN_clear_free(ssh1_challenge); 1713 ssh1_challenge = auth_rsa_generate_challenge(key); 1714 1715 buffer_clear(m); 1716 buffer_put_bignum2(m, ssh1_challenge); 1717 1718 debug3("%s sending reply", __func__); 1719 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1720 1721 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1722 1723 free(blob); 1724 key_free(key); 1725 return (0); 1726 } 1727 1728 int 1729 mm_answer_rsa_response(int sock, Buffer *m) 1730 { 1731 Key *key = NULL; 1732 u_char *blob, *response; 1733 u_int blen, len; 1734 int success; 1735 1736 debug3("%s entering", __func__); 1737 1738 if (!authctxt->valid) 1739 fatal("%s: authctxt not valid", __func__); 1740 if (ssh1_challenge == NULL) 1741 fatal("%s: no ssh1_challenge", __func__); 1742 1743 blob = buffer_get_string(m, &blen); 1744 if (!monitor_allowed_key(blob, blen)) 1745 fatal("%s: bad key, not previously allowed", __func__); 1746 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1747 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1748 if ((key = key_from_blob(blob, blen)) == NULL) 1749 fatal("%s: received bad key", __func__); 1750 response = buffer_get_string(m, &len); 1751 if (len != 16) 1752 fatal("%s: received bad response to challenge", __func__); 1753 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1754 1755 free(blob); 1756 key_free(key); 1757 free(response); 1758 1759 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1760 1761 /* reset state */ 1762 BN_clear_free(ssh1_challenge); 1763 ssh1_challenge = NULL; 1764 monitor_reset_key_state(); 1765 1766 buffer_clear(m); 1767 buffer_put_int(m, success); 1768 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1769 1770 return (success); 1771 } 1772 #endif 1773 1774 int 1775 mm_answer_term(int sock, Buffer *req) 1776 { 1777 extern struct monitor *pmonitor; 1778 int res, status; 1779 1780 debug3("%s: tearing down sessions", __func__); 1781 1782 /* The child is terminating */ 1783 session_destroy_all(&mm_session_close); 1784 1785 #ifdef USE_PAM 1786 if (options.use_pam) 1787 sshpam_cleanup(); 1788 #endif 1789 1790 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1791 if (errno != EINTR) 1792 exit(1); 1793 1794 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1795 1796 /* Terminate process */ 1797 exit(res); 1798 } 1799 1800 #ifdef SSH_AUDIT_EVENTS 1801 /* Report that an audit event occurred */ 1802 int 1803 mm_answer_audit_event(int socket, Buffer *m) 1804 { 1805 ssh_audit_event_t event; 1806 1807 debug3("%s entering", __func__); 1808 1809 event = buffer_get_int(m); 1810 switch(event) { 1811 case SSH_AUTH_FAIL_PUBKEY: 1812 case SSH_AUTH_FAIL_HOSTBASED: 1813 case SSH_AUTH_FAIL_GSSAPI: 1814 case SSH_LOGIN_EXCEED_MAXTRIES: 1815 case SSH_LOGIN_ROOT_DENIED: 1816 case SSH_CONNECTION_CLOSE: 1817 case SSH_INVALID_USER: 1818 audit_event(event); 1819 break; 1820 default: 1821 fatal("Audit event type %d not permitted", event); 1822 } 1823 1824 return (0); 1825 } 1826 1827 int 1828 mm_answer_audit_command(int socket, Buffer *m) 1829 { 1830 u_int len; 1831 char *cmd; 1832 1833 debug3("%s entering", __func__); 1834 cmd = buffer_get_string(m, &len); 1835 /* sanity check command, if so how? */ 1836 audit_run_command(cmd); 1837 free(cmd); 1838 return (0); 1839 } 1840 #endif /* SSH_AUDIT_EVENTS */ 1841 1842 void 1843 monitor_apply_keystate(struct monitor *pmonitor) 1844 { 1845 struct ssh *ssh = active_state; /* XXX */ 1846 struct kex *kex; 1847 int r; 1848 1849 debug3("%s: packet_set_state", __func__); 1850 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1851 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1852 sshbuf_free(child_state); 1853 child_state = NULL; 1854 1855 if ((kex = ssh->kex) != 0) { 1856 /* XXX set callbacks */ 1857 #ifdef WITH_OPENSSL 1858 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1859 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1860 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1861 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1862 # ifdef OPENSSL_HAS_ECC 1863 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1864 # endif 1865 #endif /* WITH_OPENSSL */ 1866 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1867 kex->load_host_public_key=&get_hostkey_public_by_type; 1868 kex->load_host_private_key=&get_hostkey_private_by_type; 1869 kex->host_key_index=&get_hostkey_index; 1870 kex->sign = sshd_hostkey_sign; 1871 } 1872 1873 /* Update with new address */ 1874 if (options.compression) { 1875 ssh_packet_set_compress_hooks(ssh, pmonitor->m_zlib, 1876 (ssh_packet_comp_alloc_func *)mm_zalloc, 1877 (ssh_packet_comp_free_func *)mm_zfree); 1878 } 1879 } 1880 1881 /* This function requries careful sanity checking */ 1882 1883 void 1884 mm_get_keystate(struct monitor *pmonitor) 1885 { 1886 debug3("%s: Waiting for new keys", __func__); 1887 1888 if ((child_state = sshbuf_new()) == NULL) 1889 fatal("%s: sshbuf_new failed", __func__); 1890 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1891 child_state); 1892 debug3("%s: GOT new keys", __func__); 1893 } 1894 1895 1896 /* XXX */ 1897 1898 #define FD_CLOSEONEXEC(x) do { \ 1899 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1900 fatal("fcntl(%d, F_SETFD)", x); \ 1901 } while (0) 1902 1903 static void 1904 monitor_openfds(struct monitor *mon, int do_logfds) 1905 { 1906 int pair[2]; 1907 1908 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1909 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1910 FD_CLOSEONEXEC(pair[0]); 1911 FD_CLOSEONEXEC(pair[1]); 1912 mon->m_recvfd = pair[0]; 1913 mon->m_sendfd = pair[1]; 1914 1915 if (do_logfds) { 1916 if (pipe(pair) == -1) 1917 fatal("%s: pipe: %s", __func__, strerror(errno)); 1918 FD_CLOSEONEXEC(pair[0]); 1919 FD_CLOSEONEXEC(pair[1]); 1920 mon->m_log_recvfd = pair[0]; 1921 mon->m_log_sendfd = pair[1]; 1922 } else 1923 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1924 } 1925 1926 #define MM_MEMSIZE 65536 1927 1928 struct monitor * 1929 monitor_init(void) 1930 { 1931 struct ssh *ssh = active_state; /* XXX */ 1932 struct monitor *mon; 1933 1934 mon = xcalloc(1, sizeof(*mon)); 1935 1936 monitor_openfds(mon, 1); 1937 1938 /* Used to share zlib space across processes */ 1939 if (options.compression) { 1940 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1941 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1942 1943 /* Compression needs to share state across borders */ 1944 ssh_packet_set_compress_hooks(ssh, mon->m_zlib, 1945 (ssh_packet_comp_alloc_func *)mm_zalloc, 1946 (ssh_packet_comp_free_func *)mm_zfree); 1947 } 1948 1949 return mon; 1950 } 1951 1952 void 1953 monitor_reinit(struct monitor *mon) 1954 { 1955 monitor_openfds(mon, 0); 1956 } 1957 1958 #ifdef GSSAPI 1959 int 1960 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1961 { 1962 gss_OID_desc goid; 1963 OM_uint32 major; 1964 u_int len; 1965 1966 goid.elements = buffer_get_string(m, &len); 1967 goid.length = len; 1968 1969 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1970 1971 free(goid.elements); 1972 1973 buffer_clear(m); 1974 buffer_put_int(m, major); 1975 1976 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1977 1978 /* Now we have a context, enable the step */ 1979 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1980 1981 return (0); 1982 } 1983 1984 int 1985 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1986 { 1987 gss_buffer_desc in; 1988 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1989 OM_uint32 major, minor; 1990 OM_uint32 flags = 0; /* GSI needs this */ 1991 u_int len; 1992 1993 in.value = buffer_get_string(m, &len); 1994 in.length = len; 1995 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1996 free(in.value); 1997 1998 buffer_clear(m); 1999 buffer_put_int(m, major); 2000 buffer_put_string(m, out.value, out.length); 2001 buffer_put_int(m, flags); 2002 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2003 2004 gss_release_buffer(&minor, &out); 2005 2006 if (major == GSS_S_COMPLETE) { 2007 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2008 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2009 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2010 } 2011 return (0); 2012 } 2013 2014 int 2015 mm_answer_gss_checkmic(int sock, Buffer *m) 2016 { 2017 gss_buffer_desc gssbuf, mic; 2018 OM_uint32 ret; 2019 u_int len; 2020 2021 gssbuf.value = buffer_get_string(m, &len); 2022 gssbuf.length = len; 2023 mic.value = buffer_get_string(m, &len); 2024 mic.length = len; 2025 2026 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2027 2028 free(gssbuf.value); 2029 free(mic.value); 2030 2031 buffer_clear(m); 2032 buffer_put_int(m, ret); 2033 2034 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2035 2036 if (!GSS_ERROR(ret)) 2037 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2038 2039 return (0); 2040 } 2041 2042 int 2043 mm_answer_gss_userok(int sock, Buffer *m) 2044 { 2045 int authenticated; 2046 2047 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2048 2049 buffer_clear(m); 2050 buffer_put_int(m, authenticated); 2051 2052 debug3("%s: sending result %d", __func__, authenticated); 2053 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2054 2055 auth_method = "gssapi-with-mic"; 2056 2057 /* Monitor loop will terminate if authenticated */ 2058 return (authenticated); 2059 } 2060 #endif /* GSSAPI */ 2061 2062