monitor.c revision 296853
1/* $OpenBSD: monitor.c,v 1.157 2016/02/15 23:32:37 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 "authfd.h" 104#include "match.h" 105#include "ssherr.h" 106 107#ifdef GSSAPI 108static Gssctxt *gsscontext = NULL; 109#endif 110 111/* Imports */ 112extern ServerOptions options; 113extern u_int utmp_len; 114extern u_char session_id[]; 115extern Buffer auth_debug; 116extern int auth_debug_init; 117extern Buffer loginmsg; 118 119/* State exported from the child */ 120static struct sshbuf *child_state; 121 122/* Functions on the monitor that answer unprivileged requests */ 123 124int mm_answer_moduli(int, Buffer *); 125int mm_answer_sign(int, Buffer *); 126int mm_answer_pwnamallow(int, Buffer *); 127int mm_answer_auth2_read_banner(int, Buffer *); 128int mm_answer_authserv(int, Buffer *); 129int mm_answer_authpassword(int, Buffer *); 130int mm_answer_bsdauthquery(int, Buffer *); 131int mm_answer_bsdauthrespond(int, Buffer *); 132int mm_answer_skeyquery(int, Buffer *); 133int mm_answer_skeyrespond(int, Buffer *); 134int mm_answer_keyallowed(int, Buffer *); 135int mm_answer_keyverify(int, Buffer *); 136int mm_answer_pty(int, Buffer *); 137int mm_answer_pty_cleanup(int, Buffer *); 138int mm_answer_term(int, Buffer *); 139int mm_answer_rsa_keyallowed(int, Buffer *); 140int mm_answer_rsa_challenge(int, Buffer *); 141int mm_answer_rsa_response(int, Buffer *); 142int mm_answer_sesskey(int, Buffer *); 143int mm_answer_sessid(int, Buffer *); 144 145#ifdef USE_PAM 146int mm_answer_pam_start(int, Buffer *); 147int mm_answer_pam_account(int, Buffer *); 148int mm_answer_pam_init_ctx(int, Buffer *); 149int mm_answer_pam_query(int, Buffer *); 150int mm_answer_pam_respond(int, Buffer *); 151int mm_answer_pam_free_ctx(int, Buffer *); 152#endif 153 154#ifdef GSSAPI 155int mm_answer_gss_setup_ctx(int, Buffer *); 156int mm_answer_gss_accept_ctx(int, Buffer *); 157int mm_answer_gss_userok(int, Buffer *); 158int mm_answer_gss_checkmic(int, Buffer *); 159#endif 160 161#ifdef SSH_AUDIT_EVENTS 162int mm_answer_audit_event(int, Buffer *); 163int mm_answer_audit_command(int, Buffer *); 164#endif 165 166static int monitor_read_log(struct monitor *); 167 168static Authctxt *authctxt; 169 170#ifdef WITH_SSH1 171static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 172#endif 173 174/* local state for key verify */ 175static u_char *key_blob = NULL; 176static u_int key_bloblen = 0; 177static int key_blobtype = MM_NOKEY; 178static char *hostbased_cuser = NULL; 179static char *hostbased_chost = NULL; 180static char *auth_method = "unknown"; 181static char *auth_submethod = NULL; 182static u_int session_id2_len = 0; 183static u_char *session_id2 = NULL; 184static pid_t monitor_child_pid; 185 186struct mon_table { 187 enum monitor_reqtype type; 188 int flags; 189 int (*f)(int, Buffer *); 190}; 191 192#define MON_ISAUTH 0x0004 /* Required for Authentication */ 193#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 194#define MON_ONCE 0x0010 /* Disable after calling */ 195#define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 196 197#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 198 199#define MON_PERMIT 0x1000 /* Request is permitted */ 200 201struct mon_table mon_dispatch_proto20[] = { 202#ifdef WITH_OPENSSL 203 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 204#endif 205 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 206 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 207 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 208 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 209 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 210#ifdef USE_PAM 211 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 212 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 213 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 214 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 215 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 216 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 217#endif 218#ifdef SSH_AUDIT_EVENTS 219 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 220#endif 221#ifdef BSD_AUTH 222 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 223 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 224#endif 225#ifdef SKEY 226 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 227 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 228#endif 229 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 230 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 231#ifdef GSSAPI 232 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 233 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 234 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 235 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 236#endif 237 {0, 0, NULL} 238}; 239 240struct mon_table mon_dispatch_postauth20[] = { 241#ifdef WITH_OPENSSL 242 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 243#endif 244 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 245 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 246 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 247 {MONITOR_REQ_TERM, 0, mm_answer_term}, 248#ifdef SSH_AUDIT_EVENTS 249 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 250 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 251#endif 252 {0, 0, NULL} 253}; 254 255struct mon_table mon_dispatch_proto15[] = { 256#ifdef WITH_SSH1 257 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 258 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 259 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 260 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 261 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 262 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 263 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 264 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 265#ifdef BSD_AUTH 266 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 267 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 268#endif 269#ifdef SKEY 270 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 271 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 272#endif 273#ifdef USE_PAM 274 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 275 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 276 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 277 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 278 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 279 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 280#endif 281#ifdef SSH_AUDIT_EVENTS 282 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 283#endif 284#endif /* WITH_SSH1 */ 285 {0, 0, NULL} 286}; 287 288struct mon_table mon_dispatch_postauth15[] = { 289#ifdef WITH_SSH1 290 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 291 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 292 {MONITOR_REQ_TERM, 0, mm_answer_term}, 293#ifdef SSH_AUDIT_EVENTS 294 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 295 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 296#endif 297#endif /* WITH_SSH1 */ 298 {0, 0, NULL} 299}; 300 301struct mon_table *mon_dispatch; 302 303/* Specifies if a certain message is allowed at the moment */ 304 305static void 306monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 307{ 308 while (ent->f != NULL) { 309 if (ent->type == type) { 310 ent->flags &= ~MON_PERMIT; 311 ent->flags |= permit ? MON_PERMIT : 0; 312 return; 313 } 314 ent++; 315 } 316} 317 318static void 319monitor_permit_authentications(int permit) 320{ 321 struct mon_table *ent = mon_dispatch; 322 323 while (ent->f != NULL) { 324 if (ent->flags & MON_AUTH) { 325 ent->flags &= ~MON_PERMIT; 326 ent->flags |= permit ? MON_PERMIT : 0; 327 } 328 ent++; 329 } 330} 331 332void 333monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 334{ 335 struct mon_table *ent; 336 int authenticated = 0, partial = 0; 337 338 debug3("preauth child monitor started"); 339 340 close(pmonitor->m_recvfd); 341 close(pmonitor->m_log_sendfd); 342 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 343 344 authctxt = _authctxt; 345 memset(authctxt, 0, sizeof(*authctxt)); 346 347 authctxt->loginmsg = &loginmsg; 348 349 if (compat20) { 350 mon_dispatch = mon_dispatch_proto20; 351 352 /* Permit requests for moduli and signatures */ 353 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 354 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 355 } else { 356 mon_dispatch = mon_dispatch_proto15; 357 358 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 359 } 360 361 /* The first few requests do not require asynchronous access */ 362 while (!authenticated) { 363 partial = 0; 364 auth_method = "unknown"; 365 auth_submethod = NULL; 366 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 367 368 /* Special handling for multiple required authentications */ 369 if (options.num_auth_methods != 0) { 370 if (!compat20) 371 fatal("AuthenticationMethods is not supported" 372 "with SSH protocol 1"); 373 if (authenticated && 374 !auth2_update_methods_lists(authctxt, 375 auth_method, auth_submethod)) { 376 debug3("%s: method %s: partial", __func__, 377 auth_method); 378 authenticated = 0; 379 partial = 1; 380 } 381 } 382 383 if (authenticated) { 384 if (!(ent->flags & MON_AUTHDECIDE)) 385 fatal("%s: unexpected authentication from %d", 386 __func__, ent->type); 387 if (authctxt->pw->pw_uid == 0 && 388 !auth_root_allowed(auth_method)) 389 authenticated = 0; 390#ifdef USE_PAM 391 /* PAM needs to perform account checks after auth */ 392 if (options.use_pam && authenticated) { 393 Buffer m; 394 395 buffer_init(&m); 396 mm_request_receive_expect(pmonitor->m_sendfd, 397 MONITOR_REQ_PAM_ACCOUNT, &m); 398 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 399 buffer_free(&m); 400 } 401#endif 402 } 403 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 404 auth_log(authctxt, authenticated, partial, 405 auth_method, auth_submethod); 406 if (!partial && !authenticated) 407 authctxt->failures++; 408 } 409 } 410 411 if (!authctxt->valid) 412 fatal("%s: authenticated invalid user", __func__); 413 if (strcmp(auth_method, "unknown") == 0) 414 fatal("%s: authentication method name unknown", __func__); 415 416 debug("%s: %s has been authenticated by privileged process", 417 __func__, authctxt->user); 418 419 mm_get_keystate(pmonitor); 420 421 /* Drain any buffered messages from the child */ 422 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 423 ; 424 425 close(pmonitor->m_sendfd); 426 close(pmonitor->m_log_recvfd); 427 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 428} 429 430static void 431monitor_set_child_handler(pid_t pid) 432{ 433 monitor_child_pid = pid; 434} 435 436static void 437monitor_child_handler(int sig) 438{ 439 kill(monitor_child_pid, sig); 440} 441 442void 443monitor_child_postauth(struct monitor *pmonitor) 444{ 445 close(pmonitor->m_recvfd); 446 pmonitor->m_recvfd = -1; 447 448 monitor_set_child_handler(pmonitor->m_pid); 449 signal(SIGHUP, &monitor_child_handler); 450 signal(SIGTERM, &monitor_child_handler); 451 signal(SIGINT, &monitor_child_handler); 452#ifdef SIGXFSZ 453 signal(SIGXFSZ, SIG_IGN); 454#endif 455 456 if (compat20) { 457 mon_dispatch = mon_dispatch_postauth20; 458 459 /* Permit requests for moduli and signatures */ 460 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 461 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 462 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 463 } else { 464 mon_dispatch = mon_dispatch_postauth15; 465 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 466 } 467 if (!no_pty_flag) { 468 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 469 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 470 } 471 472 for (;;) 473 monitor_read(pmonitor, mon_dispatch, NULL); 474} 475 476void 477monitor_sync(struct monitor *pmonitor) 478{ 479 if (options.compression) { 480 /* The member allocation is not visible, so sync it */ 481 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 482 } 483} 484 485/* Allocation functions for zlib */ 486static void * 487mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 488{ 489 if (size == 0 || ncount == 0 || ncount > SIZE_MAX / size) 490 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 491 492 return mm_malloc(mm, size * ncount); 493} 494 495static void 496mm_zfree(struct mm_master *mm, void *address) 497{ 498 mm_free(mm, address); 499} 500 501static int 502monitor_read_log(struct monitor *pmonitor) 503{ 504 Buffer logmsg; 505 u_int len, level; 506 char *msg; 507 508 buffer_init(&logmsg); 509 510 /* Read length */ 511 buffer_append_space(&logmsg, 4); 512 if (atomicio(read, pmonitor->m_log_recvfd, 513 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 514 if (errno == EPIPE) { 515 buffer_free(&logmsg); 516 debug("%s: child log fd closed", __func__); 517 close(pmonitor->m_log_recvfd); 518 pmonitor->m_log_recvfd = -1; 519 return -1; 520 } 521 fatal("%s: log fd read: %s", __func__, strerror(errno)); 522 } 523 len = buffer_get_int(&logmsg); 524 if (len <= 4 || len > 8192) 525 fatal("%s: invalid log message length %u", __func__, len); 526 527 /* Read severity, message */ 528 buffer_clear(&logmsg); 529 buffer_append_space(&logmsg, len); 530 if (atomicio(read, pmonitor->m_log_recvfd, 531 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 532 fatal("%s: log fd read: %s", __func__, strerror(errno)); 533 534 /* Log it */ 535 level = buffer_get_int(&logmsg); 536 msg = buffer_get_string(&logmsg, NULL); 537 if (log_level_name(level) == NULL) 538 fatal("%s: invalid log level %u (corrupted message?)", 539 __func__, level); 540 do_log2(level, "%s [preauth]", msg); 541 542 buffer_free(&logmsg); 543 free(msg); 544 545 return 0; 546} 547 548int 549monitor_read(struct monitor *pmonitor, struct mon_table *ent, 550 struct mon_table **pent) 551{ 552 Buffer m; 553 int ret; 554 u_char type; 555 struct pollfd pfd[2]; 556 557 for (;;) { 558 memset(&pfd, 0, sizeof(pfd)); 559 pfd[0].fd = pmonitor->m_sendfd; 560 pfd[0].events = POLLIN; 561 pfd[1].fd = pmonitor->m_log_recvfd; 562 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 563 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 564 if (errno == EINTR || errno == EAGAIN) 565 continue; 566 fatal("%s: poll: %s", __func__, strerror(errno)); 567 } 568 if (pfd[1].revents) { 569 /* 570 * Drain all log messages before processing next 571 * monitor request. 572 */ 573 monitor_read_log(pmonitor); 574 continue; 575 } 576 if (pfd[0].revents) 577 break; /* Continues below */ 578 } 579 580 buffer_init(&m); 581 582 mm_request_receive(pmonitor->m_sendfd, &m); 583 type = buffer_get_char(&m); 584 585 debug3("%s: checking request %d", __func__, type); 586 587 while (ent->f != NULL) { 588 if (ent->type == type) 589 break; 590 ent++; 591 } 592 593 if (ent->f != NULL) { 594 if (!(ent->flags & MON_PERMIT)) 595 fatal("%s: unpermitted request %d", __func__, 596 type); 597 ret = (*ent->f)(pmonitor->m_sendfd, &m); 598 buffer_free(&m); 599 600 /* The child may use this request only once, disable it */ 601 if (ent->flags & MON_ONCE) { 602 debug2("%s: %d used once, disabling now", __func__, 603 type); 604 ent->flags &= ~MON_PERMIT; 605 } 606 607 if (pent != NULL) 608 *pent = ent; 609 610 return ret; 611 } 612 613 fatal("%s: unsupported request: %d", __func__, type); 614 615 /* NOTREACHED */ 616 return (-1); 617} 618 619/* allowed key state */ 620static int 621monitor_allowed_key(u_char *blob, u_int bloblen) 622{ 623 /* make sure key is allowed */ 624 if (key_blob == NULL || key_bloblen != bloblen || 625 timingsafe_bcmp(key_blob, blob, key_bloblen)) 626 return (0); 627 return (1); 628} 629 630static void 631monitor_reset_key_state(void) 632{ 633 /* reset state */ 634 free(key_blob); 635 free(hostbased_cuser); 636 free(hostbased_chost); 637 key_blob = NULL; 638 key_bloblen = 0; 639 key_blobtype = MM_NOKEY; 640 hostbased_cuser = NULL; 641 hostbased_chost = NULL; 642} 643 644#ifdef WITH_OPENSSL 645int 646mm_answer_moduli(int sock, Buffer *m) 647{ 648 DH *dh; 649 int min, want, max; 650 651 min = buffer_get_int(m); 652 want = buffer_get_int(m); 653 max = buffer_get_int(m); 654 655 debug3("%s: got parameters: %d %d %d", 656 __func__, min, want, max); 657 /* We need to check here, too, in case the child got corrupted */ 658 if (max < min || want < min || max < want) 659 fatal("%s: bad parameters: %d %d %d", 660 __func__, min, want, max); 661 662 buffer_clear(m); 663 664 dh = choose_dh(min, want, max); 665 if (dh == NULL) { 666 buffer_put_char(m, 0); 667 return (0); 668 } else { 669 /* Send first bignum */ 670 buffer_put_char(m, 1); 671 buffer_put_bignum2(m, dh->p); 672 buffer_put_bignum2(m, dh->g); 673 674 DH_free(dh); 675 } 676 mm_request_send(sock, MONITOR_ANS_MODULI, m); 677 return (0); 678} 679#endif 680 681int 682mm_answer_sign(int sock, Buffer *m) 683{ 684 struct ssh *ssh = active_state; /* XXX */ 685 extern int auth_sock; /* XXX move to state struct? */ 686 struct sshkey *key; 687 struct sshbuf *sigbuf = NULL; 688 u_char *p = NULL, *signature = NULL; 689 char *alg = NULL; 690 size_t datlen, siglen, alglen; 691 int r, keyid, is_proof = 0; 692 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 693 694 debug3("%s", __func__); 695 696 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 697 (r = sshbuf_get_string(m, &p, &datlen)) != 0 || 698 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0) 699 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 700 701 /* 702 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 703 * SHA384 (48 bytes) and SHA512 (64 bytes). 704 * 705 * Otherwise, verify the signature request is for a hostkey 706 * proof. 707 * 708 * XXX perform similar check for KEX signature requests too? 709 * it's not trivial, since what is signed is the hash, rather 710 * than the full kex structure... 711 */ 712 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) { 713 /* 714 * Construct expected hostkey proof and compare it to what 715 * the client sent us. 716 */ 717 if (session_id2_len == 0) /* hostkeys is never first */ 718 fatal("%s: bad data length: %zu", __func__, datlen); 719 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL) 720 fatal("%s: no hostkey for index %d", __func__, keyid); 721 if ((sigbuf = sshbuf_new()) == NULL) 722 fatal("%s: sshbuf_new", __func__); 723 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 724 (r = sshbuf_put_string(sigbuf, session_id2, 725 session_id2_len)) != 0 || 726 (r = sshkey_puts(key, sigbuf)) != 0) 727 fatal("%s: couldn't prepare private key " 728 "proof buffer: %s", __func__, ssh_err(r)); 729 if (datlen != sshbuf_len(sigbuf) || 730 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0) 731 fatal("%s: bad data length: %zu, hostkey proof len %zu", 732 __func__, datlen, sshbuf_len(sigbuf)); 733 sshbuf_free(sigbuf); 734 is_proof = 1; 735 } 736 737 /* save session id, it will be passed on the first call */ 738 if (session_id2_len == 0) { 739 session_id2_len = datlen; 740 session_id2 = xmalloc(session_id2_len); 741 memcpy(session_id2, p, session_id2_len); 742 } 743 744 if ((key = get_hostkey_by_index(keyid)) != NULL) { 745 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, 746 datafellows)) != 0) 747 fatal("%s: sshkey_sign failed: %s", 748 __func__, ssh_err(r)); 749 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 750 auth_sock > 0) { 751 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 752 p, datlen, alg, datafellows)) != 0) { 753 fatal("%s: ssh_agent_sign failed: %s", 754 __func__, ssh_err(r)); 755 } 756 } else 757 fatal("%s: no hostkey from index %d", __func__, keyid); 758 759 debug3("%s: %s signature %p(%zu)", __func__, 760 is_proof ? "KEX" : "hostkey proof", signature, siglen); 761 762 sshbuf_reset(m); 763 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 764 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 765 766 free(alg); 767 free(p); 768 free(signature); 769 770 mm_request_send(sock, MONITOR_ANS_SIGN, m); 771 772 /* Turn on permissions for getpwnam */ 773 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 774 775 return (0); 776} 777 778/* Retrieves the password entry and also checks if the user is permitted */ 779 780int 781mm_answer_pwnamallow(int sock, Buffer *m) 782{ 783 char *username; 784 struct passwd *pwent; 785 int allowed = 0; 786 u_int i; 787 788 debug3("%s", __func__); 789 790 if (authctxt->attempt++ != 0) 791 fatal("%s: multiple attempts for getpwnam", __func__); 792 793 username = buffer_get_string(m, NULL); 794 795 pwent = getpwnamallow(username); 796 797 authctxt->user = xstrdup(username); 798 setproctitle("%s [priv]", pwent ? username : "unknown"); 799 free(username); 800 801 buffer_clear(m); 802 803 if (pwent == NULL) { 804 buffer_put_char(m, 0); 805 authctxt->pw = fakepw(); 806 goto out; 807 } 808 809 allowed = 1; 810 authctxt->pw = pwent; 811 authctxt->valid = 1; 812 813 buffer_put_char(m, 1); 814 buffer_put_string(m, pwent, sizeof(struct passwd)); 815 buffer_put_cstring(m, pwent->pw_name); 816 buffer_put_cstring(m, "*"); 817#ifdef HAVE_STRUCT_PASSWD_PW_GECOS 818 buffer_put_cstring(m, pwent->pw_gecos); 819#endif 820#ifdef HAVE_STRUCT_PASSWD_PW_CLASS 821 buffer_put_cstring(m, pwent->pw_class); 822#endif 823 buffer_put_cstring(m, pwent->pw_dir); 824 buffer_put_cstring(m, pwent->pw_shell); 825 826 out: 827 buffer_put_string(m, &options, sizeof(options)); 828 829#define M_CP_STROPT(x) do { \ 830 if (options.x != NULL) \ 831 buffer_put_cstring(m, options.x); \ 832 } while (0) 833#define M_CP_STRARRAYOPT(x, nx) do { \ 834 for (i = 0; i < options.nx; i++) \ 835 buffer_put_cstring(m, options.x[i]); \ 836 } while (0) 837 /* See comment in servconf.h */ 838 COPY_MATCH_STRING_OPTS(); 839#undef M_CP_STROPT 840#undef M_CP_STRARRAYOPT 841 842 /* Create valid auth method lists */ 843 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 844 /* 845 * The monitor will continue long enough to let the child 846 * run to it's packet_disconnect(), but it must not allow any 847 * authentication to succeed. 848 */ 849 debug("%s: no valid authentication method lists", __func__); 850 } 851 852 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 853 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 854 855 /* For SSHv1 allow authentication now */ 856 if (!compat20) 857 monitor_permit_authentications(1); 858 else { 859 /* Allow service/style information on the auth context */ 860 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 861 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 862 } 863#ifdef USE_PAM 864 if (options.use_pam) 865 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 866#endif 867 868 return (0); 869} 870 871int mm_answer_auth2_read_banner(int sock, Buffer *m) 872{ 873 char *banner; 874 875 buffer_clear(m); 876 banner = auth2_read_banner(); 877 buffer_put_cstring(m, banner != NULL ? banner : ""); 878 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 879 free(banner); 880 881 return (0); 882} 883 884int 885mm_answer_authserv(int sock, Buffer *m) 886{ 887 monitor_permit_authentications(1); 888 889 authctxt->service = buffer_get_string(m, NULL); 890 authctxt->style = buffer_get_string(m, NULL); 891 debug3("%s: service=%s, style=%s", 892 __func__, authctxt->service, authctxt->style); 893 894 if (strlen(authctxt->style) == 0) { 895 free(authctxt->style); 896 authctxt->style = NULL; 897 } 898 899 return (0); 900} 901 902int 903mm_answer_authpassword(int sock, Buffer *m) 904{ 905 static int call_count; 906 char *passwd; 907 int authenticated; 908 u_int plen; 909 910 passwd = buffer_get_string(m, &plen); 911 /* Only authenticate if the context is valid */ 912 authenticated = options.password_authentication && 913 auth_password(authctxt, passwd); 914 explicit_bzero(passwd, strlen(passwd)); 915 free(passwd); 916 917 buffer_clear(m); 918 buffer_put_int(m, authenticated); 919 920 debug3("%s: sending result %d", __func__, authenticated); 921 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 922 923 call_count++; 924 if (plen == 0 && call_count == 1) 925 auth_method = "none"; 926 else 927 auth_method = "password"; 928 929 /* Causes monitor loop to terminate if authenticated */ 930 return (authenticated); 931} 932 933#ifdef BSD_AUTH 934int 935mm_answer_bsdauthquery(int sock, Buffer *m) 936{ 937 char *name, *infotxt; 938 u_int numprompts; 939 u_int *echo_on; 940 char **prompts; 941 u_int success; 942 943 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 944 &prompts, &echo_on) < 0 ? 0 : 1; 945 946 buffer_clear(m); 947 buffer_put_int(m, success); 948 if (success) 949 buffer_put_cstring(m, prompts[0]); 950 951 debug3("%s: sending challenge success: %u", __func__, success); 952 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 953 954 if (success) { 955 free(name); 956 free(infotxt); 957 free(prompts); 958 free(echo_on); 959 } 960 961 return (0); 962} 963 964int 965mm_answer_bsdauthrespond(int sock, Buffer *m) 966{ 967 char *response; 968 int authok; 969 970 if (authctxt->as == NULL) 971 fatal("%s: no bsd auth session", __func__); 972 973 response = buffer_get_string(m, NULL); 974 authok = options.challenge_response_authentication && 975 auth_userresponse(authctxt->as, response, 0); 976 authctxt->as = NULL; 977 debug3("%s: <%s> = <%d>", __func__, response, authok); 978 free(response); 979 980 buffer_clear(m); 981 buffer_put_int(m, authok); 982 983 debug3("%s: sending authenticated: %d", __func__, authok); 984 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 985 986 if (compat20) { 987 auth_method = "keyboard-interactive"; 988 auth_submethod = "bsdauth"; 989 } else 990 auth_method = "bsdauth"; 991 992 return (authok != 0); 993} 994#endif 995 996#ifdef SKEY 997int 998mm_answer_skeyquery(int sock, Buffer *m) 999{ 1000 struct skey skey; 1001 char challenge[1024]; 1002 u_int success; 1003 1004 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 1005 sizeof(challenge)) < 0 ? 0 : 1; 1006 1007 buffer_clear(m); 1008 buffer_put_int(m, success); 1009 if (success) 1010 buffer_put_cstring(m, challenge); 1011 1012 debug3("%s: sending challenge success: %u", __func__, success); 1013 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 1014 1015 return (0); 1016} 1017 1018int 1019mm_answer_skeyrespond(int sock, Buffer *m) 1020{ 1021 char *response; 1022 int authok; 1023 1024 response = buffer_get_string(m, NULL); 1025 1026 authok = (options.challenge_response_authentication && 1027 authctxt->valid && 1028 skey_haskey(authctxt->pw->pw_name) == 0 && 1029 skey_passcheck(authctxt->pw->pw_name, response) != -1); 1030 1031 free(response); 1032 1033 buffer_clear(m); 1034 buffer_put_int(m, authok); 1035 1036 debug3("%s: sending authenticated: %d", __func__, authok); 1037 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 1038 1039 auth_method = "keyboard-interactive"; 1040 auth_submethod = "skey"; 1041 1042 return (authok != 0); 1043} 1044#endif 1045 1046#ifdef USE_PAM 1047int 1048mm_answer_pam_start(int sock, Buffer *m) 1049{ 1050 if (!options.use_pam) 1051 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1052 1053 start_pam(authctxt); 1054 1055 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1056 1057 return (0); 1058} 1059 1060int 1061mm_answer_pam_account(int sock, Buffer *m) 1062{ 1063 u_int ret; 1064 1065 if (!options.use_pam) 1066 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1067 1068 ret = do_pam_account(); 1069 1070 buffer_put_int(m, ret); 1071 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1072 1073 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1074 1075 return (ret); 1076} 1077 1078static void *sshpam_ctxt, *sshpam_authok; 1079extern KbdintDevice sshpam_device; 1080 1081int 1082mm_answer_pam_init_ctx(int sock, Buffer *m) 1083{ 1084 debug3("%s", __func__); 1085 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1086 sshpam_authok = NULL; 1087 buffer_clear(m); 1088 if (sshpam_ctxt != NULL) { 1089 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1090 buffer_put_int(m, 1); 1091 } else { 1092 buffer_put_int(m, 0); 1093 } 1094 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1095 return (0); 1096} 1097 1098int 1099mm_answer_pam_query(int sock, Buffer *m) 1100{ 1101 char *name = NULL, *info = NULL, **prompts = NULL; 1102 u_int i, num = 0, *echo_on = 0; 1103 int ret; 1104 1105 debug3("%s", __func__); 1106 sshpam_authok = NULL; 1107 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1108 if (ret == 0 && num == 0) 1109 sshpam_authok = sshpam_ctxt; 1110 if (num > 1 || name == NULL || info == NULL) 1111 ret = -1; 1112 buffer_clear(m); 1113 buffer_put_int(m, ret); 1114 buffer_put_cstring(m, name); 1115 free(name); 1116 buffer_put_cstring(m, info); 1117 free(info); 1118 buffer_put_int(m, num); 1119 for (i = 0; i < num; ++i) { 1120 buffer_put_cstring(m, prompts[i]); 1121 free(prompts[i]); 1122 buffer_put_int(m, echo_on[i]); 1123 } 1124 free(prompts); 1125 free(echo_on); 1126 auth_method = "keyboard-interactive"; 1127 auth_submethod = "pam"; 1128 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1129 return (0); 1130} 1131 1132int 1133mm_answer_pam_respond(int sock, Buffer *m) 1134{ 1135 char **resp; 1136 u_int i, num; 1137 int ret; 1138 1139 debug3("%s", __func__); 1140 sshpam_authok = NULL; 1141 num = buffer_get_int(m); 1142 if (num > 0) { 1143 resp = xcalloc(num, sizeof(char *)); 1144 for (i = 0; i < num; ++i) 1145 resp[i] = buffer_get_string(m, NULL); 1146 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1147 for (i = 0; i < num; ++i) 1148 free(resp[i]); 1149 free(resp); 1150 } else { 1151 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1152 } 1153 buffer_clear(m); 1154 buffer_put_int(m, ret); 1155 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1156 auth_method = "keyboard-interactive"; 1157 auth_submethod = "pam"; 1158 if (ret == 0) 1159 sshpam_authok = sshpam_ctxt; 1160 return (0); 1161} 1162 1163int 1164mm_answer_pam_free_ctx(int sock, Buffer *m) 1165{ 1166 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt; 1167 1168 debug3("%s", __func__); 1169 (sshpam_device.free_ctx)(sshpam_ctxt); 1170 sshpam_ctxt = sshpam_authok = NULL; 1171 buffer_clear(m); 1172 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1173 auth_method = "keyboard-interactive"; 1174 auth_submethod = "pam"; 1175 return r; 1176} 1177#endif 1178 1179int 1180mm_answer_keyallowed(int sock, Buffer *m) 1181{ 1182 Key *key; 1183 char *cuser, *chost; 1184 u_char *blob; 1185 u_int bloblen, pubkey_auth_attempt; 1186 enum mm_keytype type = 0; 1187 int allowed = 0; 1188 1189 debug3("%s entering", __func__); 1190 1191 type = buffer_get_int(m); 1192 cuser = buffer_get_string(m, NULL); 1193 chost = buffer_get_string(m, NULL); 1194 blob = buffer_get_string(m, &bloblen); 1195 pubkey_auth_attempt = buffer_get_int(m); 1196 1197 key = key_from_blob(blob, bloblen); 1198 1199 if ((compat20 && type == MM_RSAHOSTKEY) || 1200 (!compat20 && type != MM_RSAHOSTKEY)) 1201 fatal("%s: key type and protocol mismatch", __func__); 1202 1203 debug3("%s: key_from_blob: %p", __func__, key); 1204 1205 if (key != NULL && authctxt->valid) { 1206 /* These should not make it past the privsep child */ 1207 if (key_type_plain(key->type) == KEY_RSA && 1208 (datafellows & SSH_BUG_RSASIGMD5) != 0) 1209 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 1210 1211 switch (type) { 1212 case MM_USERKEY: 1213 allowed = options.pubkey_authentication && 1214 !auth2_userkey_already_used(authctxt, key) && 1215 match_pattern_list(sshkey_ssh_name(key), 1216 options.pubkey_key_types, 0) == 1 && 1217 user_key_allowed(authctxt->pw, key, 1218 pubkey_auth_attempt); 1219 pubkey_auth_info(authctxt, key, NULL); 1220 auth_method = "publickey"; 1221 if (options.pubkey_authentication && 1222 (!pubkey_auth_attempt || allowed != 1)) 1223 auth_clear_options(); 1224 break; 1225 case MM_HOSTKEY: 1226 allowed = options.hostbased_authentication && 1227 match_pattern_list(sshkey_ssh_name(key), 1228 options.hostbased_key_types, 0) == 1 && 1229 hostbased_key_allowed(authctxt->pw, 1230 cuser, chost, key); 1231 pubkey_auth_info(authctxt, key, 1232 "client user \"%.100s\", client host \"%.100s\"", 1233 cuser, chost); 1234 auth_method = "hostbased"; 1235 break; 1236#ifdef WITH_SSH1 1237 case MM_RSAHOSTKEY: 1238 key->type = KEY_RSA1; /* XXX */ 1239 allowed = options.rhosts_rsa_authentication && 1240 auth_rhosts_rsa_key_allowed(authctxt->pw, 1241 cuser, chost, key); 1242 if (options.rhosts_rsa_authentication && allowed != 1) 1243 auth_clear_options(); 1244 auth_method = "rsa"; 1245 break; 1246#endif 1247 default: 1248 fatal("%s: unknown key type %d", __func__, type); 1249 break; 1250 } 1251 } 1252 if (key != NULL) 1253 key_free(key); 1254 1255 /* clear temporarily storage (used by verify) */ 1256 monitor_reset_key_state(); 1257 1258 if (allowed) { 1259 /* Save temporarily for comparison in verify */ 1260 key_blob = blob; 1261 key_bloblen = bloblen; 1262 key_blobtype = type; 1263 hostbased_cuser = cuser; 1264 hostbased_chost = chost; 1265 } else { 1266 /* Log failed attempt */ 1267 auth_log(authctxt, 0, 0, auth_method, NULL); 1268 free(blob); 1269 free(cuser); 1270 free(chost); 1271 } 1272 1273 debug3("%s: key %p is %s", 1274 __func__, key, allowed ? "allowed" : "not allowed"); 1275 1276 buffer_clear(m); 1277 buffer_put_int(m, allowed); 1278 buffer_put_int(m, forced_command != NULL); 1279 1280 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1281 1282 if (type == MM_RSAHOSTKEY) 1283 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1284 1285 return (0); 1286} 1287 1288static int 1289monitor_valid_userblob(u_char *data, u_int datalen) 1290{ 1291 Buffer b; 1292 char *p, *userstyle; 1293 u_int len; 1294 int fail = 0; 1295 1296 buffer_init(&b); 1297 buffer_append(&b, data, datalen); 1298 1299 if (datafellows & SSH_OLD_SESSIONID) { 1300 p = buffer_ptr(&b); 1301 len = buffer_len(&b); 1302 if ((session_id2 == NULL) || 1303 (len < session_id2_len) || 1304 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1305 fail++; 1306 buffer_consume(&b, session_id2_len); 1307 } else { 1308 p = buffer_get_string(&b, &len); 1309 if ((session_id2 == NULL) || 1310 (len != session_id2_len) || 1311 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1312 fail++; 1313 free(p); 1314 } 1315 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1316 fail++; 1317 p = buffer_get_cstring(&b, NULL); 1318 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1319 authctxt->style ? ":" : "", 1320 authctxt->style ? authctxt->style : ""); 1321 if (strcmp(userstyle, p) != 0) { 1322 logit("wrong user name passed to monitor: expected %s != %.100s", 1323 userstyle, p); 1324 fail++; 1325 } 1326 free(userstyle); 1327 free(p); 1328 buffer_skip_string(&b); 1329 if (datafellows & SSH_BUG_PKAUTH) { 1330 if (!buffer_get_char(&b)) 1331 fail++; 1332 } else { 1333 p = buffer_get_cstring(&b, NULL); 1334 if (strcmp("publickey", p) != 0) 1335 fail++; 1336 free(p); 1337 if (!buffer_get_char(&b)) 1338 fail++; 1339 buffer_skip_string(&b); 1340 } 1341 buffer_skip_string(&b); 1342 if (buffer_len(&b) != 0) 1343 fail++; 1344 buffer_free(&b); 1345 return (fail == 0); 1346} 1347 1348static int 1349monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1350 char *chost) 1351{ 1352 Buffer b; 1353 char *p, *userstyle; 1354 u_int len; 1355 int fail = 0; 1356 1357 buffer_init(&b); 1358 buffer_append(&b, data, datalen); 1359 1360 p = buffer_get_string(&b, &len); 1361 if ((session_id2 == NULL) || 1362 (len != session_id2_len) || 1363 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1364 fail++; 1365 free(p); 1366 1367 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1368 fail++; 1369 p = buffer_get_cstring(&b, NULL); 1370 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1371 authctxt->style ? ":" : "", 1372 authctxt->style ? authctxt->style : ""); 1373 if (strcmp(userstyle, p) != 0) { 1374 logit("wrong user name passed to monitor: expected %s != %.100s", 1375 userstyle, p); 1376 fail++; 1377 } 1378 free(userstyle); 1379 free(p); 1380 buffer_skip_string(&b); /* service */ 1381 p = buffer_get_cstring(&b, NULL); 1382 if (strcmp(p, "hostbased") != 0) 1383 fail++; 1384 free(p); 1385 buffer_skip_string(&b); /* pkalg */ 1386 buffer_skip_string(&b); /* pkblob */ 1387 1388 /* verify client host, strip trailing dot if necessary */ 1389 p = buffer_get_string(&b, NULL); 1390 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1391 p[len - 1] = '\0'; 1392 if (strcmp(p, chost) != 0) 1393 fail++; 1394 free(p); 1395 1396 /* verify client user */ 1397 p = buffer_get_string(&b, NULL); 1398 if (strcmp(p, cuser) != 0) 1399 fail++; 1400 free(p); 1401 1402 if (buffer_len(&b) != 0) 1403 fail++; 1404 buffer_free(&b); 1405 return (fail == 0); 1406} 1407 1408int 1409mm_answer_keyverify(int sock, Buffer *m) 1410{ 1411 Key *key; 1412 u_char *signature, *data, *blob; 1413 u_int signaturelen, datalen, bloblen; 1414 int verified = 0; 1415 int valid_data = 0; 1416 1417 blob = buffer_get_string(m, &bloblen); 1418 signature = buffer_get_string(m, &signaturelen); 1419 data = buffer_get_string(m, &datalen); 1420 1421 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1422 !monitor_allowed_key(blob, bloblen)) 1423 fatal("%s: bad key, not previously allowed", __func__); 1424 1425 key = key_from_blob(blob, bloblen); 1426 if (key == NULL) 1427 fatal("%s: bad public key blob", __func__); 1428 1429 switch (key_blobtype) { 1430 case MM_USERKEY: 1431 valid_data = monitor_valid_userblob(data, datalen); 1432 break; 1433 case MM_HOSTKEY: 1434 valid_data = monitor_valid_hostbasedblob(data, datalen, 1435 hostbased_cuser, hostbased_chost); 1436 break; 1437 default: 1438 valid_data = 0; 1439 break; 1440 } 1441 if (!valid_data) 1442 fatal("%s: bad signature data blob", __func__); 1443 1444 verified = key_verify(key, signature, signaturelen, data, datalen); 1445 debug3("%s: key %p signature %s", 1446 __func__, key, (verified == 1) ? "verified" : "unverified"); 1447 1448 /* If auth was successful then record key to ensure it isn't reused */ 1449 if (verified == 1 && key_blobtype == MM_USERKEY) 1450 auth2_record_userkey(authctxt, key); 1451 else 1452 key_free(key); 1453 1454 free(blob); 1455 free(signature); 1456 free(data); 1457 1458 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1459 1460 monitor_reset_key_state(); 1461 1462 buffer_clear(m); 1463 buffer_put_int(m, verified); 1464 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1465 1466 return (verified == 1); 1467} 1468 1469static void 1470mm_record_login(Session *s, struct passwd *pw) 1471{ 1472 socklen_t fromlen; 1473 struct sockaddr_storage from; 1474 1475 if (options.use_login) 1476 return; 1477 1478 /* 1479 * Get IP address of client. If the connection is not a socket, let 1480 * the address be 0.0.0.0. 1481 */ 1482 memset(&from, 0, sizeof(from)); 1483 fromlen = sizeof(from); 1484 if (packet_connection_is_on_socket()) { 1485 if (getpeername(packet_get_connection_in(), 1486 (struct sockaddr *)&from, &fromlen) < 0) { 1487 debug("getpeername: %.100s", strerror(errno)); 1488 cleanup_exit(255); 1489 } 1490 } 1491 /* Record that there was a login on that tty from the remote host. */ 1492 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1493 get_remote_name_or_ip(utmp_len, options.use_dns), 1494 (struct sockaddr *)&from, fromlen); 1495} 1496 1497static void 1498mm_session_close(Session *s) 1499{ 1500 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1501 if (s->ttyfd != -1) { 1502 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1503 session_pty_cleanup2(s); 1504 } 1505 session_unused(s->self); 1506} 1507 1508int 1509mm_answer_pty(int sock, Buffer *m) 1510{ 1511 extern struct monitor *pmonitor; 1512 Session *s; 1513 int res, fd0; 1514 1515 debug3("%s entering", __func__); 1516 1517 buffer_clear(m); 1518 s = session_new(); 1519 if (s == NULL) 1520 goto error; 1521 s->authctxt = authctxt; 1522 s->pw = authctxt->pw; 1523 s->pid = pmonitor->m_pid; 1524 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1525 if (res == 0) 1526 goto error; 1527 pty_setowner(authctxt->pw, s->tty); 1528 1529 buffer_put_int(m, 1); 1530 buffer_put_cstring(m, s->tty); 1531 1532 /* We need to trick ttyslot */ 1533 if (dup2(s->ttyfd, 0) == -1) 1534 fatal("%s: dup2", __func__); 1535 1536 mm_record_login(s, authctxt->pw); 1537 1538 /* Now we can close the file descriptor again */ 1539 close(0); 1540 1541 /* send messages generated by record_login */ 1542 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1543 buffer_clear(&loginmsg); 1544 1545 mm_request_send(sock, MONITOR_ANS_PTY, m); 1546 1547 if (mm_send_fd(sock, s->ptyfd) == -1 || 1548 mm_send_fd(sock, s->ttyfd) == -1) 1549 fatal("%s: send fds failed", __func__); 1550 1551 /* make sure nothing uses fd 0 */ 1552 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1553 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1554 if (fd0 != 0) 1555 error("%s: fd0 %d != 0", __func__, fd0); 1556 1557 /* slave is not needed */ 1558 close(s->ttyfd); 1559 s->ttyfd = s->ptyfd; 1560 /* no need to dup() because nobody closes ptyfd */ 1561 s->ptymaster = s->ptyfd; 1562 1563 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1564 1565 return (0); 1566 1567 error: 1568 if (s != NULL) 1569 mm_session_close(s); 1570 buffer_put_int(m, 0); 1571 mm_request_send(sock, MONITOR_ANS_PTY, m); 1572 return (0); 1573} 1574 1575int 1576mm_answer_pty_cleanup(int sock, Buffer *m) 1577{ 1578 Session *s; 1579 char *tty; 1580 1581 debug3("%s entering", __func__); 1582 1583 tty = buffer_get_string(m, NULL); 1584 if ((s = session_by_tty(tty)) != NULL) 1585 mm_session_close(s); 1586 buffer_clear(m); 1587 free(tty); 1588 return (0); 1589} 1590 1591#ifdef WITH_SSH1 1592int 1593mm_answer_sesskey(int sock, Buffer *m) 1594{ 1595 BIGNUM *p; 1596 int rsafail; 1597 1598 /* Turn off permissions */ 1599 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1600 1601 if ((p = BN_new()) == NULL) 1602 fatal("%s: BN_new", __func__); 1603 1604 buffer_get_bignum2(m, p); 1605 1606 rsafail = ssh1_session_key(p); 1607 1608 buffer_clear(m); 1609 buffer_put_int(m, rsafail); 1610 buffer_put_bignum2(m, p); 1611 1612 BN_clear_free(p); 1613 1614 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1615 1616 /* Turn on permissions for sessid passing */ 1617 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1618 1619 return (0); 1620} 1621 1622int 1623mm_answer_sessid(int sock, Buffer *m) 1624{ 1625 int i; 1626 1627 debug3("%s entering", __func__); 1628 1629 if (buffer_len(m) != 16) 1630 fatal("%s: bad ssh1 session id", __func__); 1631 for (i = 0; i < 16; i++) 1632 session_id[i] = buffer_get_char(m); 1633 1634 /* Turn on permissions for getpwnam */ 1635 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1636 1637 return (0); 1638} 1639 1640int 1641mm_answer_rsa_keyallowed(int sock, Buffer *m) 1642{ 1643 BIGNUM *client_n; 1644 Key *key = NULL; 1645 u_char *blob = NULL; 1646 u_int blen = 0; 1647 int allowed = 0; 1648 1649 debug3("%s entering", __func__); 1650 1651 auth_method = "rsa"; 1652 if (options.rsa_authentication && authctxt->valid) { 1653 if ((client_n = BN_new()) == NULL) 1654 fatal("%s: BN_new", __func__); 1655 buffer_get_bignum2(m, client_n); 1656 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1657 BN_clear_free(client_n); 1658 } 1659 buffer_clear(m); 1660 buffer_put_int(m, allowed); 1661 buffer_put_int(m, forced_command != NULL); 1662 1663 /* clear temporarily storage (used by generate challenge) */ 1664 monitor_reset_key_state(); 1665 1666 if (allowed && key != NULL) { 1667 key->type = KEY_RSA; /* cheat for key_to_blob */ 1668 if (key_to_blob(key, &blob, &blen) == 0) 1669 fatal("%s: key_to_blob failed", __func__); 1670 buffer_put_string(m, blob, blen); 1671 1672 /* Save temporarily for comparison in verify */ 1673 key_blob = blob; 1674 key_bloblen = blen; 1675 key_blobtype = MM_RSAUSERKEY; 1676 } 1677 if (key != NULL) 1678 key_free(key); 1679 1680 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1681 1682 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1683 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1684 return (0); 1685} 1686 1687int 1688mm_answer_rsa_challenge(int sock, Buffer *m) 1689{ 1690 Key *key = NULL; 1691 u_char *blob; 1692 u_int blen; 1693 1694 debug3("%s entering", __func__); 1695 1696 if (!authctxt->valid) 1697 fatal("%s: authctxt not valid", __func__); 1698 blob = buffer_get_string(m, &blen); 1699 if (!monitor_allowed_key(blob, blen)) 1700 fatal("%s: bad key, not previously allowed", __func__); 1701 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1702 fatal("%s: key type mismatch", __func__); 1703 if ((key = key_from_blob(blob, blen)) == NULL) 1704 fatal("%s: received bad key", __func__); 1705 if (key->type != KEY_RSA) 1706 fatal("%s: received bad key type %d", __func__, key->type); 1707 key->type = KEY_RSA1; 1708 if (ssh1_challenge) 1709 BN_clear_free(ssh1_challenge); 1710 ssh1_challenge = auth_rsa_generate_challenge(key); 1711 1712 buffer_clear(m); 1713 buffer_put_bignum2(m, ssh1_challenge); 1714 1715 debug3("%s sending reply", __func__); 1716 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1717 1718 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1719 1720 free(blob); 1721 key_free(key); 1722 return (0); 1723} 1724 1725int 1726mm_answer_rsa_response(int sock, Buffer *m) 1727{ 1728 Key *key = NULL; 1729 u_char *blob, *response; 1730 u_int blen, len; 1731 int success; 1732 1733 debug3("%s entering", __func__); 1734 1735 if (!authctxt->valid) 1736 fatal("%s: authctxt not valid", __func__); 1737 if (ssh1_challenge == NULL) 1738 fatal("%s: no ssh1_challenge", __func__); 1739 1740 blob = buffer_get_string(m, &blen); 1741 if (!monitor_allowed_key(blob, blen)) 1742 fatal("%s: bad key, not previously allowed", __func__); 1743 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1744 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1745 if ((key = key_from_blob(blob, blen)) == NULL) 1746 fatal("%s: received bad key", __func__); 1747 response = buffer_get_string(m, &len); 1748 if (len != 16) 1749 fatal("%s: received bad response to challenge", __func__); 1750 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1751 1752 free(blob); 1753 key_free(key); 1754 free(response); 1755 1756 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1757 1758 /* reset state */ 1759 BN_clear_free(ssh1_challenge); 1760 ssh1_challenge = NULL; 1761 monitor_reset_key_state(); 1762 1763 buffer_clear(m); 1764 buffer_put_int(m, success); 1765 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1766 1767 return (success); 1768} 1769#endif 1770 1771int 1772mm_answer_term(int sock, Buffer *req) 1773{ 1774 extern struct monitor *pmonitor; 1775 int res, status; 1776 1777 debug3("%s: tearing down sessions", __func__); 1778 1779 /* The child is terminating */ 1780 session_destroy_all(&mm_session_close); 1781 1782#ifdef USE_PAM 1783 if (options.use_pam) 1784 sshpam_cleanup(); 1785#endif 1786 1787 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1788 if (errno != EINTR) 1789 exit(1); 1790 1791 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1792 1793 /* Terminate process */ 1794 exit(res); 1795} 1796 1797#ifdef SSH_AUDIT_EVENTS 1798/* Report that an audit event occurred */ 1799int 1800mm_answer_audit_event(int socket, Buffer *m) 1801{ 1802 ssh_audit_event_t event; 1803 1804 debug3("%s entering", __func__); 1805 1806 event = buffer_get_int(m); 1807 switch(event) { 1808 case SSH_AUTH_FAIL_PUBKEY: 1809 case SSH_AUTH_FAIL_HOSTBASED: 1810 case SSH_AUTH_FAIL_GSSAPI: 1811 case SSH_LOGIN_EXCEED_MAXTRIES: 1812 case SSH_LOGIN_ROOT_DENIED: 1813 case SSH_CONNECTION_CLOSE: 1814 case SSH_INVALID_USER: 1815 audit_event(event); 1816 break; 1817 default: 1818 fatal("Audit event type %d not permitted", event); 1819 } 1820 1821 return (0); 1822} 1823 1824int 1825mm_answer_audit_command(int socket, Buffer *m) 1826{ 1827 u_int len; 1828 char *cmd; 1829 1830 debug3("%s entering", __func__); 1831 cmd = buffer_get_string(m, &len); 1832 /* sanity check command, if so how? */ 1833 audit_run_command(cmd); 1834 free(cmd); 1835 return (0); 1836} 1837#endif /* SSH_AUDIT_EVENTS */ 1838 1839void 1840monitor_apply_keystate(struct monitor *pmonitor) 1841{ 1842 struct ssh *ssh = active_state; /* XXX */ 1843 struct kex *kex; 1844 int r; 1845 1846 debug3("%s: packet_set_state", __func__); 1847 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1848 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1849 sshbuf_free(child_state); 1850 child_state = NULL; 1851 1852 if ((kex = ssh->kex) != NULL) { 1853 /* XXX set callbacks */ 1854#ifdef WITH_OPENSSL 1855 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1856 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1857 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1858 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1859# ifdef OPENSSL_HAS_ECC 1860 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1861# endif 1862#endif /* WITH_OPENSSL */ 1863 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1864 kex->load_host_public_key=&get_hostkey_public_by_type; 1865 kex->load_host_private_key=&get_hostkey_private_by_type; 1866 kex->host_key_index=&get_hostkey_index; 1867 kex->sign = sshd_hostkey_sign; 1868 } 1869 1870 /* Update with new address */ 1871 if (options.compression) { 1872 ssh_packet_set_compress_hooks(ssh, pmonitor->m_zlib, 1873 (ssh_packet_comp_alloc_func *)mm_zalloc, 1874 (ssh_packet_comp_free_func *)mm_zfree); 1875 } 1876} 1877 1878/* This function requries careful sanity checking */ 1879 1880void 1881mm_get_keystate(struct monitor *pmonitor) 1882{ 1883 debug3("%s: Waiting for new keys", __func__); 1884 1885 if ((child_state = sshbuf_new()) == NULL) 1886 fatal("%s: sshbuf_new failed", __func__); 1887 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1888 child_state); 1889 debug3("%s: GOT new keys", __func__); 1890} 1891 1892 1893/* XXX */ 1894 1895#define FD_CLOSEONEXEC(x) do { \ 1896 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1897 fatal("fcntl(%d, F_SETFD)", x); \ 1898} while (0) 1899 1900static void 1901monitor_openfds(struct monitor *mon, int do_logfds) 1902{ 1903 int pair[2]; 1904 1905 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1906 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1907 FD_CLOSEONEXEC(pair[0]); 1908 FD_CLOSEONEXEC(pair[1]); 1909 mon->m_recvfd = pair[0]; 1910 mon->m_sendfd = pair[1]; 1911 1912 if (do_logfds) { 1913 if (pipe(pair) == -1) 1914 fatal("%s: pipe: %s", __func__, strerror(errno)); 1915 FD_CLOSEONEXEC(pair[0]); 1916 FD_CLOSEONEXEC(pair[1]); 1917 mon->m_log_recvfd = pair[0]; 1918 mon->m_log_sendfd = pair[1]; 1919 } else 1920 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1921} 1922 1923#define MM_MEMSIZE 65536 1924 1925struct monitor * 1926monitor_init(void) 1927{ 1928 struct ssh *ssh = active_state; /* XXX */ 1929 struct monitor *mon; 1930 1931 mon = xcalloc(1, sizeof(*mon)); 1932 1933 monitor_openfds(mon, 1); 1934 1935 /* Used to share zlib space across processes */ 1936 if (options.compression) { 1937 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1938 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1939 1940 /* Compression needs to share state across borders */ 1941 ssh_packet_set_compress_hooks(ssh, mon->m_zlib, 1942 (ssh_packet_comp_alloc_func *)mm_zalloc, 1943 (ssh_packet_comp_free_func *)mm_zfree); 1944 } 1945 1946 return mon; 1947} 1948 1949void 1950monitor_reinit(struct monitor *mon) 1951{ 1952 monitor_openfds(mon, 0); 1953} 1954 1955#ifdef GSSAPI 1956int 1957mm_answer_gss_setup_ctx(int sock, Buffer *m) 1958{ 1959 gss_OID_desc goid; 1960 OM_uint32 major; 1961 u_int len; 1962 1963 goid.elements = buffer_get_string(m, &len); 1964 goid.length = len; 1965 1966 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1967 1968 free(goid.elements); 1969 1970 buffer_clear(m); 1971 buffer_put_int(m, major); 1972 1973 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1974 1975 /* Now we have a context, enable the step */ 1976 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1977 1978 return (0); 1979} 1980 1981int 1982mm_answer_gss_accept_ctx(int sock, Buffer *m) 1983{ 1984 gss_buffer_desc in; 1985 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1986 OM_uint32 major, minor; 1987 OM_uint32 flags = 0; /* GSI needs this */ 1988 u_int len; 1989 1990 in.value = buffer_get_string(m, &len); 1991 in.length = len; 1992 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1993 free(in.value); 1994 1995 buffer_clear(m); 1996 buffer_put_int(m, major); 1997 buffer_put_string(m, out.value, out.length); 1998 buffer_put_int(m, flags); 1999 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2000 2001 gss_release_buffer(&minor, &out); 2002 2003 if (major == GSS_S_COMPLETE) { 2004 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2005 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2006 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2007 } 2008 return (0); 2009} 2010 2011int 2012mm_answer_gss_checkmic(int sock, Buffer *m) 2013{ 2014 gss_buffer_desc gssbuf, mic; 2015 OM_uint32 ret; 2016 u_int len; 2017 2018 gssbuf.value = buffer_get_string(m, &len); 2019 gssbuf.length = len; 2020 mic.value = buffer_get_string(m, &len); 2021 mic.length = len; 2022 2023 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2024 2025 free(gssbuf.value); 2026 free(mic.value); 2027 2028 buffer_clear(m); 2029 buffer_put_int(m, ret); 2030 2031 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2032 2033 if (!GSS_ERROR(ret)) 2034 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2035 2036 return (0); 2037} 2038 2039int 2040mm_answer_gss_userok(int sock, Buffer *m) 2041{ 2042 int authenticated; 2043 2044 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2045 2046 buffer_clear(m); 2047 buffer_put_int(m, authenticated); 2048 2049 debug3("%s: sending result %d", __func__, authenticated); 2050 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2051 2052 auth_method = "gssapi-with-mic"; 2053 2054 /* Monitor loop will terminate if authenticated */ 2055 return (authenticated); 2056} 2057#endif /* GSSAPI */ 2058 2059