monitor.c revision 294666
1/* $OpenBSD: monitor.c,v 1.131 2014/02/02 03:44:31 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__RCSID("$FreeBSD: stable/10/crypto/openssh/monitor.c 294666 2016-01-24 15:44:57Z des $"); 30 31#include <sys/types.h> 32#include <sys/param.h> 33#include <sys/socket.h> 34#include "openbsd-compat/sys-tree.h" 35#include <sys/wait.h> 36 37#include <errno.h> 38#include <fcntl.h> 39#ifdef HAVE_PATHS_H 40#include <paths.h> 41#endif 42#include <pwd.h> 43#include <signal.h> 44#include <stdarg.h> 45#include <stdlib.h> 46#include <string.h> 47#include <unistd.h> 48#ifdef HAVE_POLL_H 49#include <poll.h> 50#else 51# ifdef HAVE_SYS_POLL_H 52# include <sys/poll.h> 53# endif 54#endif 55 56#ifdef SKEY 57#include <skey.h> 58#endif 59 60#include <openssl/dh.h> 61 62#include "openbsd-compat/sys-queue.h" 63#include "atomicio.h" 64#include "xmalloc.h" 65#include "ssh.h" 66#include "key.h" 67#include "buffer.h" 68#include "hostfile.h" 69#include "auth.h" 70#include "cipher.h" 71#include "kex.h" 72#include "dh.h" 73#ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 74#undef TARGET_OS_MAC 75#include "zlib.h" 76#define TARGET_OS_MAC 1 77#else 78#include "zlib.h" 79#endif 80#include "packet.h" 81#include "auth-options.h" 82#include "sshpty.h" 83#include "channels.h" 84#include "session.h" 85#include "sshlogin.h" 86#include "canohost.h" 87#include "log.h" 88#include "servconf.h" 89#include "monitor.h" 90#include "monitor_mm.h" 91#ifdef GSSAPI 92#include "ssh-gss.h" 93#endif 94#include "monitor_wrap.h" 95#include "monitor_fdpass.h" 96#include "misc.h" 97#include "compat.h" 98#include "ssh2.h" 99#include "roaming.h" 100#include "authfd.h" 101 102#ifdef GSSAPI 103static Gssctxt *gsscontext = NULL; 104#endif 105 106/* Imports */ 107extern ServerOptions options; 108extern u_int utmp_len; 109extern Newkeys *current_keys[]; 110extern z_stream incoming_stream; 111extern z_stream outgoing_stream; 112extern u_char session_id[]; 113extern Buffer auth_debug; 114extern int auth_debug_init; 115extern Buffer loginmsg; 116 117/* State exported from the child */ 118 119struct { 120 z_stream incoming; 121 z_stream outgoing; 122 u_char *keyin; 123 u_int keyinlen; 124 u_char *keyout; 125 u_int keyoutlen; 126 u_char *ivin; 127 u_int ivinlen; 128 u_char *ivout; 129 u_int ivoutlen; 130 u_char *ssh1key; 131 u_int ssh1keylen; 132 int ssh1cipher; 133 int ssh1protoflags; 134 u_char *input; 135 u_int ilen; 136 u_char *output; 137 u_int olen; 138 u_int64_t sent_bytes; 139 u_int64_t recv_bytes; 140} child_state; 141 142/* Functions on the monitor that answer unprivileged requests */ 143 144int mm_answer_moduli(int, Buffer *); 145int mm_answer_sign(int, Buffer *); 146int mm_answer_pwnamallow(int, Buffer *); 147int mm_answer_auth2_read_banner(int, Buffer *); 148int mm_answer_authserv(int, Buffer *); 149int mm_answer_authpassword(int, Buffer *); 150int mm_answer_bsdauthquery(int, Buffer *); 151int mm_answer_bsdauthrespond(int, Buffer *); 152int mm_answer_skeyquery(int, Buffer *); 153int mm_answer_skeyrespond(int, Buffer *); 154int mm_answer_keyallowed(int, Buffer *); 155int mm_answer_keyverify(int, Buffer *); 156int mm_answer_pty(int, Buffer *); 157int mm_answer_pty_cleanup(int, Buffer *); 158int mm_answer_term(int, Buffer *); 159int mm_answer_rsa_keyallowed(int, Buffer *); 160int mm_answer_rsa_challenge(int, Buffer *); 161int mm_answer_rsa_response(int, Buffer *); 162int mm_answer_sesskey(int, Buffer *); 163int mm_answer_sessid(int, Buffer *); 164 165#ifdef USE_PAM 166int mm_answer_pam_start(int, Buffer *); 167int mm_answer_pam_account(int, Buffer *); 168int mm_answer_pam_init_ctx(int, Buffer *); 169int mm_answer_pam_query(int, Buffer *); 170int mm_answer_pam_respond(int, Buffer *); 171int mm_answer_pam_free_ctx(int, Buffer *); 172#endif 173 174#ifdef GSSAPI 175int mm_answer_gss_setup_ctx(int, Buffer *); 176int mm_answer_gss_accept_ctx(int, Buffer *); 177int mm_answer_gss_userok(int, Buffer *); 178int mm_answer_gss_checkmic(int, Buffer *); 179#endif 180 181#ifdef SSH_AUDIT_EVENTS 182int mm_answer_audit_event(int, Buffer *); 183int mm_answer_audit_command(int, Buffer *); 184#endif 185 186static int monitor_read_log(struct monitor *); 187 188static Authctxt *authctxt; 189static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 190 191/* local state for key verify */ 192static u_char *key_blob = NULL; 193static u_int key_bloblen = 0; 194static int key_blobtype = MM_NOKEY; 195static char *hostbased_cuser = NULL; 196static char *hostbased_chost = NULL; 197static char *auth_method = "unknown"; 198static char *auth_submethod = NULL; 199static u_int session_id2_len = 0; 200static u_char *session_id2 = NULL; 201static pid_t monitor_child_pid; 202 203struct mon_table { 204 enum monitor_reqtype type; 205 int flags; 206 int (*f)(int, Buffer *); 207}; 208 209#define MON_ISAUTH 0x0004 /* Required for Authentication */ 210#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 211#define MON_ONCE 0x0010 /* Disable after calling */ 212#define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 213 214#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 215 216#define MON_PERMIT 0x1000 /* Request is permitted */ 217 218struct mon_table mon_dispatch_proto20[] = { 219 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 220 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 221 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 222 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 223 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 224 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 225#ifdef USE_PAM 226 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 227 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 228 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 229 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 230 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 231 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 232#endif 233#ifdef SSH_AUDIT_EVENTS 234 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 235#endif 236#ifdef BSD_AUTH 237 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 238 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 239#endif 240#ifdef SKEY 241 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 242 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 243#endif 244 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 245 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 246#ifdef GSSAPI 247 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 248 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 249 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 250 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 251#endif 252 {0, 0, NULL} 253}; 254 255struct mon_table mon_dispatch_postauth20[] = { 256 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 257 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 258 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 259 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 260 {MONITOR_REQ_TERM, 0, mm_answer_term}, 261#ifdef SSH_AUDIT_EVENTS 262 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 263 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 264#endif 265 {0, 0, NULL} 266}; 267 268struct mon_table mon_dispatch_proto15[] = { 269 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 270 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 271 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 272 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 273 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 274 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 275 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 276 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 277#ifdef BSD_AUTH 278 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 279 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 280#endif 281#ifdef SKEY 282 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 283 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 284#endif 285#ifdef USE_PAM 286 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 287 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 288 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 289 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 290 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 291 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 292#endif 293#ifdef SSH_AUDIT_EVENTS 294 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 295#endif 296 {0, 0, NULL} 297}; 298 299struct mon_table mon_dispatch_postauth15[] = { 300 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 301 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 302 {MONITOR_REQ_TERM, 0, mm_answer_term}, 303#ifdef SSH_AUDIT_EVENTS 304 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 305 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 306#endif 307 {0, 0, NULL} 308}; 309 310struct mon_table *mon_dispatch; 311 312/* Specifies if a certain message is allowed at the moment */ 313 314static void 315monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 316{ 317 while (ent->f != NULL) { 318 if (ent->type == type) { 319 ent->flags &= ~MON_PERMIT; 320 ent->flags |= permit ? MON_PERMIT : 0; 321 return; 322 } 323 ent++; 324 } 325} 326 327static void 328monitor_permit_authentications(int permit) 329{ 330 struct mon_table *ent = mon_dispatch; 331 332 while (ent->f != NULL) { 333 if (ent->flags & MON_AUTH) { 334 ent->flags &= ~MON_PERMIT; 335 ent->flags |= permit ? MON_PERMIT : 0; 336 } 337 ent++; 338 } 339} 340 341void 342monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 343{ 344 struct mon_table *ent; 345 int authenticated = 0, partial = 0; 346 347 debug3("preauth child monitor started"); 348 349 close(pmonitor->m_recvfd); 350 close(pmonitor->m_log_sendfd); 351 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 352 353 authctxt = _authctxt; 354 memset(authctxt, 0, sizeof(*authctxt)); 355 356 authctxt->loginmsg = &loginmsg; 357 358 if (compat20) { 359 mon_dispatch = mon_dispatch_proto20; 360 361 /* Permit requests for moduli and signatures */ 362 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 363 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 364 } else { 365 mon_dispatch = mon_dispatch_proto15; 366 367 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 368 } 369 370 /* The first few requests do not require asynchronous access */ 371 while (!authenticated) { 372 partial = 0; 373 auth_method = "unknown"; 374 auth_submethod = NULL; 375 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 376 377 /* Special handling for multiple required authentications */ 378 if (options.num_auth_methods != 0) { 379 if (!compat20) 380 fatal("AuthenticationMethods is not supported" 381 "with SSH protocol 1"); 382 if (authenticated && 383 !auth2_update_methods_lists(authctxt, 384 auth_method, auth_submethod)) { 385 debug3("%s: method %s: partial", __func__, 386 auth_method); 387 authenticated = 0; 388 partial = 1; 389 } 390 } 391 392 if (authenticated) { 393 if (!(ent->flags & MON_AUTHDECIDE)) 394 fatal("%s: unexpected authentication from %d", 395 __func__, ent->type); 396 if (authctxt->pw->pw_uid == 0 && 397 !auth_root_allowed(auth_method)) 398 authenticated = 0; 399#ifdef USE_PAM 400 /* PAM needs to perform account checks after auth */ 401 if (options.use_pam && authenticated) { 402 Buffer m; 403 404 buffer_init(&m); 405 mm_request_receive_expect(pmonitor->m_sendfd, 406 MONITOR_REQ_PAM_ACCOUNT, &m); 407 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 408 buffer_free(&m); 409 } 410#endif 411 } 412 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 413 auth_log(authctxt, authenticated, partial, 414 auth_method, auth_submethod); 415 if (!authenticated) 416 authctxt->failures++; 417 } 418 } 419 420 if (!authctxt->valid) 421 fatal("%s: authenticated invalid user", __func__); 422 if (strcmp(auth_method, "unknown") == 0) 423 fatal("%s: authentication method name unknown", __func__); 424 425 debug("%s: %s has been authenticated by privileged process", 426 __func__, authctxt->user); 427 428 mm_get_keystate(pmonitor); 429 430 /* Drain any buffered messages from the child */ 431 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 432 ; 433 434 close(pmonitor->m_sendfd); 435 close(pmonitor->m_log_recvfd); 436 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 437} 438 439static void 440monitor_set_child_handler(pid_t pid) 441{ 442 monitor_child_pid = pid; 443} 444 445static void 446monitor_child_handler(int sig) 447{ 448 kill(monitor_child_pid, sig); 449} 450 451void 452monitor_child_postauth(struct monitor *pmonitor) 453{ 454 close(pmonitor->m_recvfd); 455 pmonitor->m_recvfd = -1; 456 457 monitor_set_child_handler(pmonitor->m_pid); 458 signal(SIGHUP, &monitor_child_handler); 459 signal(SIGTERM, &monitor_child_handler); 460 signal(SIGINT, &monitor_child_handler); 461 462 if (compat20) { 463 mon_dispatch = mon_dispatch_postauth20; 464 465 /* Permit requests for moduli and signatures */ 466 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 467 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 468 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 469 } else { 470 mon_dispatch = mon_dispatch_postauth15; 471 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 472 } 473 if (!no_pty_flag) { 474 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 475 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 476 } 477 478 for (;;) 479 monitor_read(pmonitor, mon_dispatch, NULL); 480} 481 482void 483monitor_sync(struct monitor *pmonitor) 484{ 485 if (options.compression) { 486 /* The member allocation is not visible, so sync it */ 487 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 488 } 489} 490 491static int 492monitor_read_log(struct monitor *pmonitor) 493{ 494 Buffer logmsg; 495 u_int len, level; 496 char *msg; 497 498 buffer_init(&logmsg); 499 500 /* Read length */ 501 buffer_append_space(&logmsg, 4); 502 if (atomicio(read, pmonitor->m_log_recvfd, 503 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 504 if (errno == EPIPE) { 505 buffer_free(&logmsg); 506 debug("%s: child log fd closed", __func__); 507 close(pmonitor->m_log_recvfd); 508 pmonitor->m_log_recvfd = -1; 509 return -1; 510 } 511 fatal("%s: log fd read: %s", __func__, strerror(errno)); 512 } 513 len = buffer_get_int(&logmsg); 514 if (len <= 4 || len > 8192) 515 fatal("%s: invalid log message length %u", __func__, len); 516 517 /* Read severity, message */ 518 buffer_clear(&logmsg); 519 buffer_append_space(&logmsg, len); 520 if (atomicio(read, pmonitor->m_log_recvfd, 521 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 522 fatal("%s: log fd read: %s", __func__, strerror(errno)); 523 524 /* Log it */ 525 level = buffer_get_int(&logmsg); 526 msg = buffer_get_string(&logmsg, NULL); 527 if (log_level_name(level) == NULL) 528 fatal("%s: invalid log level %u (corrupted message?)", 529 __func__, level); 530 do_log2(level, "%s [preauth]", msg); 531 532 buffer_free(&logmsg); 533 free(msg); 534 535 return 0; 536} 537 538int 539monitor_read(struct monitor *pmonitor, struct mon_table *ent, 540 struct mon_table **pent) 541{ 542 Buffer m; 543 int ret; 544 u_char type; 545 struct pollfd pfd[2]; 546 547 for (;;) { 548 memset(&pfd, 0, sizeof(pfd)); 549 pfd[0].fd = pmonitor->m_sendfd; 550 pfd[0].events = POLLIN; 551 pfd[1].fd = pmonitor->m_log_recvfd; 552 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 553 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 554 if (errno == EINTR || errno == EAGAIN) 555 continue; 556 fatal("%s: poll: %s", __func__, strerror(errno)); 557 } 558 if (pfd[1].revents) { 559 /* 560 * Drain all log messages before processing next 561 * monitor request. 562 */ 563 monitor_read_log(pmonitor); 564 continue; 565 } 566 if (pfd[0].revents) 567 break; /* Continues below */ 568 } 569 570 buffer_init(&m); 571 572 mm_request_receive(pmonitor->m_sendfd, &m); 573 type = buffer_get_char(&m); 574 575 debug3("%s: checking request %d", __func__, type); 576 577 while (ent->f != NULL) { 578 if (ent->type == type) 579 break; 580 ent++; 581 } 582 583 if (ent->f != NULL) { 584 if (!(ent->flags & MON_PERMIT)) 585 fatal("%s: unpermitted request %d", __func__, 586 type); 587 ret = (*ent->f)(pmonitor->m_sendfd, &m); 588 buffer_free(&m); 589 590 /* The child may use this request only once, disable it */ 591 if (ent->flags & MON_ONCE) { 592 debug2("%s: %d used once, disabling now", __func__, 593 type); 594 ent->flags &= ~MON_PERMIT; 595 } 596 597 if (pent != NULL) 598 *pent = ent; 599 600 return ret; 601 } 602 603 fatal("%s: unsupported request: %d", __func__, type); 604 605 /* NOTREACHED */ 606 return (-1); 607} 608 609/* allowed key state */ 610static int 611monitor_allowed_key(u_char *blob, u_int bloblen) 612{ 613 /* make sure key is allowed */ 614 if (key_blob == NULL || key_bloblen != bloblen || 615 timingsafe_bcmp(key_blob, blob, key_bloblen)) 616 return (0); 617 return (1); 618} 619 620static void 621monitor_reset_key_state(void) 622{ 623 /* reset state */ 624 free(key_blob); 625 free(hostbased_cuser); 626 free(hostbased_chost); 627 key_blob = NULL; 628 key_bloblen = 0; 629 key_blobtype = MM_NOKEY; 630 hostbased_cuser = NULL; 631 hostbased_chost = NULL; 632} 633 634int 635mm_answer_moduli(int sock, Buffer *m) 636{ 637 DH *dh; 638 int min, want, max; 639 640 min = buffer_get_int(m); 641 want = buffer_get_int(m); 642 max = buffer_get_int(m); 643 644 debug3("%s: got parameters: %d %d %d", 645 __func__, min, want, max); 646 /* We need to check here, too, in case the child got corrupted */ 647 if (max < min || want < min || max < want) 648 fatal("%s: bad parameters: %d %d %d", 649 __func__, min, want, max); 650 651 buffer_clear(m); 652 653 dh = choose_dh(min, want, max); 654 if (dh == NULL) { 655 buffer_put_char(m, 0); 656 return (0); 657 } else { 658 /* Send first bignum */ 659 buffer_put_char(m, 1); 660 buffer_put_bignum2(m, dh->p); 661 buffer_put_bignum2(m, dh->g); 662 663 DH_free(dh); 664 } 665 mm_request_send(sock, MONITOR_ANS_MODULI, m); 666 return (0); 667} 668 669extern AuthenticationConnection *auth_conn; 670 671int 672mm_answer_sign(int sock, Buffer *m) 673{ 674 Key *key; 675 u_char *p; 676 u_char *signature; 677 u_int siglen, datlen; 678 int keyid; 679 680 debug3("%s", __func__); 681 682 keyid = buffer_get_int(m); 683 p = buffer_get_string(m, &datlen); 684 685 /* 686 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 687 * SHA384 (48 bytes) and SHA512 (64 bytes). 688 */ 689 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) 690 fatal("%s: data length incorrect: %u", __func__, datlen); 691 692 /* save session id, it will be passed on the first call */ 693 if (session_id2_len == 0) { 694 session_id2_len = datlen; 695 session_id2 = xmalloc(session_id2_len); 696 memcpy(session_id2, p, session_id2_len); 697 } 698 699 if ((key = get_hostkey_by_index(keyid)) != NULL) { 700 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 701 fatal("%s: key_sign failed", __func__); 702 } else if ((key = get_hostkey_public_by_index(keyid)) != NULL && 703 auth_conn != NULL) { 704 if (ssh_agent_sign(auth_conn, key, &signature, &siglen, p, 705 datlen) < 0) 706 fatal("%s: ssh_agent_sign failed", __func__); 707 } else 708 fatal("%s: no hostkey from index %d", __func__, keyid); 709 710 debug3("%s: signature %p(%u)", __func__, signature, siglen); 711 712 buffer_clear(m); 713 buffer_put_string(m, signature, siglen); 714 715 free(p); 716 free(signature); 717 718 mm_request_send(sock, MONITOR_ANS_SIGN, m); 719 720 /* Turn on permissions for getpwnam */ 721 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 722 723 return (0); 724} 725 726/* Retrieves the password entry and also checks if the user is permitted */ 727 728int 729mm_answer_pwnamallow(int sock, Buffer *m) 730{ 731 char *username; 732 struct passwd *pwent; 733 int allowed = 0; 734 u_int i; 735 736 debug3("%s", __func__); 737 738 if (authctxt->attempt++ != 0) 739 fatal("%s: multiple attempts for getpwnam", __func__); 740 741 username = buffer_get_string(m, NULL); 742 743 pwent = getpwnamallow(username); 744 745 authctxt->user = xstrdup(username); 746 setproctitle("%s [priv]", pwent ? username : "unknown"); 747 free(username); 748 749 buffer_clear(m); 750 751 if (pwent == NULL) { 752 buffer_put_char(m, 0); 753 authctxt->pw = fakepw(); 754 goto out; 755 } 756 757 allowed = 1; 758 authctxt->pw = pwent; 759 authctxt->valid = 1; 760 761 buffer_put_char(m, 1); 762 buffer_put_string(m, pwent, sizeof(struct passwd)); 763 buffer_put_cstring(m, pwent->pw_name); 764 buffer_put_cstring(m, "*"); 765#ifdef HAVE_STRUCT_PASSWD_PW_GECOS 766 buffer_put_cstring(m, pwent->pw_gecos); 767#endif 768#ifdef HAVE_STRUCT_PASSWD_PW_CLASS 769 buffer_put_cstring(m, pwent->pw_class); 770#endif 771 buffer_put_cstring(m, pwent->pw_dir); 772 buffer_put_cstring(m, pwent->pw_shell); 773 774 out: 775 buffer_put_string(m, &options, sizeof(options)); 776 777#define M_CP_STROPT(x) do { \ 778 if (options.x != NULL) \ 779 buffer_put_cstring(m, options.x); \ 780 } while (0) 781#define M_CP_STRARRAYOPT(x, nx) do { \ 782 for (i = 0; i < options.nx; i++) \ 783 buffer_put_cstring(m, options.x[i]); \ 784 } while (0) 785 /* See comment in servconf.h */ 786 COPY_MATCH_STRING_OPTS(); 787#undef M_CP_STROPT 788#undef M_CP_STRARRAYOPT 789 790 /* Create valid auth method lists */ 791 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 792 /* 793 * The monitor will continue long enough to let the child 794 * run to it's packet_disconnect(), but it must not allow any 795 * authentication to succeed. 796 */ 797 debug("%s: no valid authentication method lists", __func__); 798 } 799 800 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 801 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 802 803 /* For SSHv1 allow authentication now */ 804 if (!compat20) 805 monitor_permit_authentications(1); 806 else { 807 /* Allow service/style information on the auth context */ 808 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 809 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 810 } 811#ifdef USE_PAM 812 if (options.use_pam) 813 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 814#endif 815 816 return (0); 817} 818 819int mm_answer_auth2_read_banner(int sock, Buffer *m) 820{ 821 char *banner; 822 823 buffer_clear(m); 824 banner = auth2_read_banner(); 825 buffer_put_cstring(m, banner != NULL ? banner : ""); 826 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 827 free(banner); 828 829 return (0); 830} 831 832int 833mm_answer_authserv(int sock, Buffer *m) 834{ 835 monitor_permit_authentications(1); 836 837 authctxt->service = buffer_get_string(m, NULL); 838 authctxt->style = buffer_get_string(m, NULL); 839 debug3("%s: service=%s, style=%s", 840 __func__, authctxt->service, authctxt->style); 841 842 if (strlen(authctxt->style) == 0) { 843 free(authctxt->style); 844 authctxt->style = NULL; 845 } 846 847 return (0); 848} 849 850int 851mm_answer_authpassword(int sock, Buffer *m) 852{ 853 static int call_count; 854 char *passwd; 855 int authenticated; 856 u_int plen; 857 858 passwd = buffer_get_string(m, &plen); 859 /* Only authenticate if the context is valid */ 860 authenticated = options.password_authentication && 861 auth_password(authctxt, passwd); 862 explicit_bzero(passwd, strlen(passwd)); 863 free(passwd); 864 865 buffer_clear(m); 866 buffer_put_int(m, authenticated); 867 868 debug3("%s: sending result %d", __func__, authenticated); 869 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 870 871 call_count++; 872 if (plen == 0 && call_count == 1) 873 auth_method = "none"; 874 else 875 auth_method = "password"; 876 877 /* Causes monitor loop to terminate if authenticated */ 878 return (authenticated); 879} 880 881#ifdef BSD_AUTH 882int 883mm_answer_bsdauthquery(int sock, Buffer *m) 884{ 885 char *name, *infotxt; 886 u_int numprompts; 887 u_int *echo_on; 888 char **prompts; 889 u_int success; 890 891 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 892 &prompts, &echo_on) < 0 ? 0 : 1; 893 894 buffer_clear(m); 895 buffer_put_int(m, success); 896 if (success) 897 buffer_put_cstring(m, prompts[0]); 898 899 debug3("%s: sending challenge success: %u", __func__, success); 900 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 901 902 if (success) { 903 free(name); 904 free(infotxt); 905 free(prompts); 906 free(echo_on); 907 } 908 909 return (0); 910} 911 912int 913mm_answer_bsdauthrespond(int sock, Buffer *m) 914{ 915 char *response; 916 int authok; 917 918 if (authctxt->as == 0) 919 fatal("%s: no bsd auth session", __func__); 920 921 response = buffer_get_string(m, NULL); 922 authok = options.challenge_response_authentication && 923 auth_userresponse(authctxt->as, response, 0); 924 authctxt->as = NULL; 925 debug3("%s: <%s> = <%d>", __func__, response, authok); 926 free(response); 927 928 buffer_clear(m); 929 buffer_put_int(m, authok); 930 931 debug3("%s: sending authenticated: %d", __func__, authok); 932 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 933 934 if (compat20) { 935 auth_method = "keyboard-interactive"; 936 auth_submethod = "bsdauth"; 937 } else 938 auth_method = "bsdauth"; 939 940 return (authok != 0); 941} 942#endif 943 944#ifdef SKEY 945int 946mm_answer_skeyquery(int sock, Buffer *m) 947{ 948 struct skey skey; 949 char challenge[1024]; 950 u_int success; 951 952 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 953 sizeof(challenge)) < 0 ? 0 : 1; 954 955 buffer_clear(m); 956 buffer_put_int(m, success); 957 if (success) 958 buffer_put_cstring(m, challenge); 959 960 debug3("%s: sending challenge success: %u", __func__, success); 961 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 962 963 return (0); 964} 965 966int 967mm_answer_skeyrespond(int sock, Buffer *m) 968{ 969 char *response; 970 int authok; 971 972 response = buffer_get_string(m, NULL); 973 974 authok = (options.challenge_response_authentication && 975 authctxt->valid && 976 skey_haskey(authctxt->pw->pw_name) == 0 && 977 skey_passcheck(authctxt->pw->pw_name, response) != -1); 978 979 free(response); 980 981 buffer_clear(m); 982 buffer_put_int(m, authok); 983 984 debug3("%s: sending authenticated: %d", __func__, authok); 985 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 986 987 auth_method = "skey"; 988 989 return (authok != 0); 990} 991#endif 992 993#ifdef USE_PAM 994int 995mm_answer_pam_start(int sock, Buffer *m) 996{ 997 if (!options.use_pam) 998 fatal("UsePAM not set, but ended up in %s anyway", __func__); 999 1000 start_pam(authctxt); 1001 1002 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1003 1004 return (0); 1005} 1006 1007int 1008mm_answer_pam_account(int sock, Buffer *m) 1009{ 1010 u_int ret; 1011 1012 if (!options.use_pam) 1013 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1014 1015 ret = do_pam_account(); 1016 1017 buffer_put_int(m, ret); 1018 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1019 1020 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1021 1022 return (ret); 1023} 1024 1025static void *sshpam_ctxt, *sshpam_authok; 1026extern KbdintDevice sshpam_device; 1027 1028int 1029mm_answer_pam_init_ctx(int sock, Buffer *m) 1030{ 1031 debug3("%s", __func__); 1032 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1033 sshpam_authok = NULL; 1034 buffer_clear(m); 1035 if (sshpam_ctxt != NULL) { 1036 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1037 buffer_put_int(m, 1); 1038 } else { 1039 buffer_put_int(m, 0); 1040 } 1041 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1042 return (0); 1043} 1044 1045int 1046mm_answer_pam_query(int sock, Buffer *m) 1047{ 1048 char *name = NULL, *info = NULL, **prompts = NULL; 1049 u_int i, num = 0, *echo_on = 0; 1050 int ret; 1051 1052 debug3("%s", __func__); 1053 sshpam_authok = NULL; 1054 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1055 if (ret == 0 && num == 0) 1056 sshpam_authok = sshpam_ctxt; 1057 if (num > 1 || name == NULL || info == NULL) 1058 ret = -1; 1059 buffer_clear(m); 1060 buffer_put_int(m, ret); 1061 buffer_put_cstring(m, name); 1062 free(name); 1063 buffer_put_cstring(m, info); 1064 free(info); 1065 buffer_put_int(m, num); 1066 for (i = 0; i < num; ++i) { 1067 buffer_put_cstring(m, prompts[i]); 1068 free(prompts[i]); 1069 buffer_put_int(m, echo_on[i]); 1070 } 1071 free(prompts); 1072 free(echo_on); 1073 auth_method = "keyboard-interactive"; 1074 auth_submethod = "pam"; 1075 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1076 return (0); 1077} 1078 1079int 1080mm_answer_pam_respond(int sock, Buffer *m) 1081{ 1082 char **resp; 1083 u_int i, num; 1084 int ret; 1085 1086 debug3("%s", __func__); 1087 sshpam_authok = NULL; 1088 num = buffer_get_int(m); 1089 if (num > 0) { 1090 resp = xcalloc(num, sizeof(char *)); 1091 for (i = 0; i < num; ++i) 1092 resp[i] = buffer_get_string(m, NULL); 1093 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1094 for (i = 0; i < num; ++i) 1095 free(resp[i]); 1096 free(resp); 1097 } else { 1098 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1099 } 1100 buffer_clear(m); 1101 buffer_put_int(m, ret); 1102 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1103 auth_method = "keyboard-interactive"; 1104 auth_submethod = "pam"; 1105 if (ret == 0) 1106 sshpam_authok = sshpam_ctxt; 1107 return (0); 1108} 1109 1110int 1111mm_answer_pam_free_ctx(int sock, Buffer *m) 1112{ 1113 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt; 1114 1115 debug3("%s", __func__); 1116 (sshpam_device.free_ctx)(sshpam_ctxt); 1117 sshpam_ctxt = sshpam_authok = NULL; 1118 buffer_clear(m); 1119 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1120 auth_method = "keyboard-interactive"; 1121 auth_submethod = "pam"; 1122 return r; 1123} 1124#endif 1125 1126int 1127mm_answer_keyallowed(int sock, Buffer *m) 1128{ 1129 Key *key; 1130 char *cuser, *chost; 1131 u_char *blob; 1132 u_int bloblen; 1133 enum mm_keytype type = 0; 1134 int allowed = 0; 1135 1136 debug3("%s entering", __func__); 1137 1138 type = buffer_get_int(m); 1139 cuser = buffer_get_string(m, NULL); 1140 chost = buffer_get_string(m, NULL); 1141 blob = buffer_get_string(m, &bloblen); 1142 1143 key = key_from_blob(blob, bloblen); 1144 1145 if ((compat20 && type == MM_RSAHOSTKEY) || 1146 (!compat20 && type != MM_RSAHOSTKEY)) 1147 fatal("%s: key type and protocol mismatch", __func__); 1148 1149 debug3("%s: key_from_blob: %p", __func__, key); 1150 1151 if (key != NULL && authctxt->valid) { 1152 switch (type) { 1153 case MM_USERKEY: 1154 allowed = options.pubkey_authentication && 1155 user_key_allowed(authctxt->pw, key); 1156 pubkey_auth_info(authctxt, key, NULL); 1157 auth_method = "publickey"; 1158 if (options.pubkey_authentication && allowed != 1) 1159 auth_clear_options(); 1160 break; 1161 case MM_HOSTKEY: 1162 allowed = options.hostbased_authentication && 1163 hostbased_key_allowed(authctxt->pw, 1164 cuser, chost, key); 1165 pubkey_auth_info(authctxt, key, 1166 "client user \"%.100s\", client host \"%.100s\"", 1167 cuser, chost); 1168 auth_method = "hostbased"; 1169 break; 1170 case MM_RSAHOSTKEY: 1171 key->type = KEY_RSA1; /* XXX */ 1172 allowed = options.rhosts_rsa_authentication && 1173 auth_rhosts_rsa_key_allowed(authctxt->pw, 1174 cuser, chost, key); 1175 if (options.rhosts_rsa_authentication && allowed != 1) 1176 auth_clear_options(); 1177 auth_method = "rsa"; 1178 break; 1179 default: 1180 fatal("%s: unknown key type %d", __func__, type); 1181 break; 1182 } 1183 } 1184 if (key != NULL) 1185 key_free(key); 1186 1187 /* clear temporarily storage (used by verify) */ 1188 monitor_reset_key_state(); 1189 1190 if (allowed) { 1191 /* Save temporarily for comparison in verify */ 1192 key_blob = blob; 1193 key_bloblen = bloblen; 1194 key_blobtype = type; 1195 hostbased_cuser = cuser; 1196 hostbased_chost = chost; 1197 } else { 1198 /* Log failed attempt */ 1199 auth_log(authctxt, 0, 0, auth_method, NULL); 1200 free(blob); 1201 free(cuser); 1202 free(chost); 1203 } 1204 1205 debug3("%s: key %p is %s", 1206 __func__, key, allowed ? "allowed" : "not allowed"); 1207 1208 buffer_clear(m); 1209 buffer_put_int(m, allowed); 1210 buffer_put_int(m, forced_command != NULL); 1211 1212 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1213 1214 if (type == MM_RSAHOSTKEY) 1215 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1216 1217 return (0); 1218} 1219 1220static int 1221monitor_valid_userblob(u_char *data, u_int datalen) 1222{ 1223 Buffer b; 1224 char *p, *userstyle; 1225 u_int len; 1226 int fail = 0; 1227 1228 buffer_init(&b); 1229 buffer_append(&b, data, datalen); 1230 1231 if (datafellows & SSH_OLD_SESSIONID) { 1232 p = buffer_ptr(&b); 1233 len = buffer_len(&b); 1234 if ((session_id2 == NULL) || 1235 (len < session_id2_len) || 1236 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1237 fail++; 1238 buffer_consume(&b, session_id2_len); 1239 } else { 1240 p = buffer_get_string(&b, &len); 1241 if ((session_id2 == NULL) || 1242 (len != session_id2_len) || 1243 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1244 fail++; 1245 free(p); 1246 } 1247 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1248 fail++; 1249 p = buffer_get_cstring(&b, NULL); 1250 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1251 authctxt->style ? ":" : "", 1252 authctxt->style ? authctxt->style : ""); 1253 if (strcmp(userstyle, p) != 0) { 1254 logit("wrong user name passed to monitor: expected %s != %.100s", 1255 userstyle, p); 1256 fail++; 1257 } 1258 free(userstyle); 1259 free(p); 1260 buffer_skip_string(&b); 1261 if (datafellows & SSH_BUG_PKAUTH) { 1262 if (!buffer_get_char(&b)) 1263 fail++; 1264 } else { 1265 p = buffer_get_cstring(&b, NULL); 1266 if (strcmp("publickey", p) != 0) 1267 fail++; 1268 free(p); 1269 if (!buffer_get_char(&b)) 1270 fail++; 1271 buffer_skip_string(&b); 1272 } 1273 buffer_skip_string(&b); 1274 if (buffer_len(&b) != 0) 1275 fail++; 1276 buffer_free(&b); 1277 return (fail == 0); 1278} 1279 1280static int 1281monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1282 char *chost) 1283{ 1284 Buffer b; 1285 char *p, *userstyle; 1286 u_int len; 1287 int fail = 0; 1288 1289 buffer_init(&b); 1290 buffer_append(&b, data, datalen); 1291 1292 p = buffer_get_string(&b, &len); 1293 if ((session_id2 == NULL) || 1294 (len != session_id2_len) || 1295 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1296 fail++; 1297 free(p); 1298 1299 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1300 fail++; 1301 p = buffer_get_cstring(&b, NULL); 1302 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1303 authctxt->style ? ":" : "", 1304 authctxt->style ? authctxt->style : ""); 1305 if (strcmp(userstyle, p) != 0) { 1306 logit("wrong user name passed to monitor: expected %s != %.100s", 1307 userstyle, p); 1308 fail++; 1309 } 1310 free(userstyle); 1311 free(p); 1312 buffer_skip_string(&b); /* service */ 1313 p = buffer_get_cstring(&b, NULL); 1314 if (strcmp(p, "hostbased") != 0) 1315 fail++; 1316 free(p); 1317 buffer_skip_string(&b); /* pkalg */ 1318 buffer_skip_string(&b); /* pkblob */ 1319 1320 /* verify client host, strip trailing dot if necessary */ 1321 p = buffer_get_string(&b, NULL); 1322 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1323 p[len - 1] = '\0'; 1324 if (strcmp(p, chost) != 0) 1325 fail++; 1326 free(p); 1327 1328 /* verify client user */ 1329 p = buffer_get_string(&b, NULL); 1330 if (strcmp(p, cuser) != 0) 1331 fail++; 1332 free(p); 1333 1334 if (buffer_len(&b) != 0) 1335 fail++; 1336 buffer_free(&b); 1337 return (fail == 0); 1338} 1339 1340int 1341mm_answer_keyverify(int sock, Buffer *m) 1342{ 1343 Key *key; 1344 u_char *signature, *data, *blob; 1345 u_int signaturelen, datalen, bloblen; 1346 int verified = 0; 1347 int valid_data = 0; 1348 1349 blob = buffer_get_string(m, &bloblen); 1350 signature = buffer_get_string(m, &signaturelen); 1351 data = buffer_get_string(m, &datalen); 1352 1353 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1354 !monitor_allowed_key(blob, bloblen)) 1355 fatal("%s: bad key, not previously allowed", __func__); 1356 1357 key = key_from_blob(blob, bloblen); 1358 if (key == NULL) 1359 fatal("%s: bad public key blob", __func__); 1360 1361 switch (key_blobtype) { 1362 case MM_USERKEY: 1363 valid_data = monitor_valid_userblob(data, datalen); 1364 break; 1365 case MM_HOSTKEY: 1366 valid_data = monitor_valid_hostbasedblob(data, datalen, 1367 hostbased_cuser, hostbased_chost); 1368 break; 1369 default: 1370 valid_data = 0; 1371 break; 1372 } 1373 if (!valid_data) 1374 fatal("%s: bad signature data blob", __func__); 1375 1376 verified = key_verify(key, signature, signaturelen, data, datalen); 1377 debug3("%s: key %p signature %s", 1378 __func__, key, (verified == 1) ? "verified" : "unverified"); 1379 1380 key_free(key); 1381 free(blob); 1382 free(signature); 1383 free(data); 1384 1385 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1386 1387 monitor_reset_key_state(); 1388 1389 buffer_clear(m); 1390 buffer_put_int(m, verified); 1391 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1392 1393 return (verified == 1); 1394} 1395 1396static void 1397mm_record_login(Session *s, struct passwd *pw) 1398{ 1399 socklen_t fromlen; 1400 struct sockaddr_storage from; 1401 1402 /* 1403 * Get IP address of client. If the connection is not a socket, let 1404 * the address be 0.0.0.0. 1405 */ 1406 memset(&from, 0, sizeof(from)); 1407 fromlen = sizeof(from); 1408 if (packet_connection_is_on_socket()) { 1409 if (getpeername(packet_get_connection_in(), 1410 (struct sockaddr *)&from, &fromlen) < 0) { 1411 debug("getpeername: %.100s", strerror(errno)); 1412 cleanup_exit(255); 1413 } 1414 } 1415 /* Record that there was a login on that tty from the remote host. */ 1416 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1417 get_remote_name_or_ip(utmp_len, options.use_dns), 1418 (struct sockaddr *)&from, fromlen); 1419} 1420 1421static void 1422mm_session_close(Session *s) 1423{ 1424 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1425 if (s->ttyfd != -1) { 1426 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1427 session_pty_cleanup2(s); 1428 } 1429 session_unused(s->self); 1430} 1431 1432int 1433mm_answer_pty(int sock, Buffer *m) 1434{ 1435 extern struct monitor *pmonitor; 1436 Session *s; 1437 int res, fd0; 1438 1439 debug3("%s entering", __func__); 1440 1441 buffer_clear(m); 1442 s = session_new(); 1443 if (s == NULL) 1444 goto error; 1445 s->authctxt = authctxt; 1446 s->pw = authctxt->pw; 1447 s->pid = pmonitor->m_pid; 1448 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1449 if (res == 0) 1450 goto error; 1451 pty_setowner(authctxt->pw, s->tty); 1452 1453 buffer_put_int(m, 1); 1454 buffer_put_cstring(m, s->tty); 1455 1456 /* We need to trick ttyslot */ 1457 if (dup2(s->ttyfd, 0) == -1) 1458 fatal("%s: dup2", __func__); 1459 1460 mm_record_login(s, authctxt->pw); 1461 1462 /* Now we can close the file descriptor again */ 1463 close(0); 1464 1465 /* send messages generated by record_login */ 1466 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1467 buffer_clear(&loginmsg); 1468 1469 mm_request_send(sock, MONITOR_ANS_PTY, m); 1470 1471 if (mm_send_fd(sock, s->ptyfd) == -1 || 1472 mm_send_fd(sock, s->ttyfd) == -1) 1473 fatal("%s: send fds failed", __func__); 1474 1475 /* make sure nothing uses fd 0 */ 1476 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1477 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1478 if (fd0 != 0) 1479 error("%s: fd0 %d != 0", __func__, fd0); 1480 1481 /* slave is not needed */ 1482 close(s->ttyfd); 1483 s->ttyfd = s->ptyfd; 1484 /* no need to dup() because nobody closes ptyfd */ 1485 s->ptymaster = s->ptyfd; 1486 1487 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1488 1489 return (0); 1490 1491 error: 1492 if (s != NULL) 1493 mm_session_close(s); 1494 buffer_put_int(m, 0); 1495 mm_request_send(sock, MONITOR_ANS_PTY, m); 1496 return (0); 1497} 1498 1499int 1500mm_answer_pty_cleanup(int sock, Buffer *m) 1501{ 1502 Session *s; 1503 char *tty; 1504 1505 debug3("%s entering", __func__); 1506 1507 tty = buffer_get_string(m, NULL); 1508 if ((s = session_by_tty(tty)) != NULL) 1509 mm_session_close(s); 1510 buffer_clear(m); 1511 free(tty); 1512 return (0); 1513} 1514 1515int 1516mm_answer_sesskey(int sock, Buffer *m) 1517{ 1518 BIGNUM *p; 1519 int rsafail; 1520 1521 /* Turn off permissions */ 1522 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1523 1524 if ((p = BN_new()) == NULL) 1525 fatal("%s: BN_new", __func__); 1526 1527 buffer_get_bignum2(m, p); 1528 1529 rsafail = ssh1_session_key(p); 1530 1531 buffer_clear(m); 1532 buffer_put_int(m, rsafail); 1533 buffer_put_bignum2(m, p); 1534 1535 BN_clear_free(p); 1536 1537 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1538 1539 /* Turn on permissions for sessid passing */ 1540 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1541 1542 return (0); 1543} 1544 1545int 1546mm_answer_sessid(int sock, Buffer *m) 1547{ 1548 int i; 1549 1550 debug3("%s entering", __func__); 1551 1552 if (buffer_len(m) != 16) 1553 fatal("%s: bad ssh1 session id", __func__); 1554 for (i = 0; i < 16; i++) 1555 session_id[i] = buffer_get_char(m); 1556 1557 /* Turn on permissions for getpwnam */ 1558 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1559 1560 return (0); 1561} 1562 1563int 1564mm_answer_rsa_keyallowed(int sock, Buffer *m) 1565{ 1566 BIGNUM *client_n; 1567 Key *key = NULL; 1568 u_char *blob = NULL; 1569 u_int blen = 0; 1570 int allowed = 0; 1571 1572 debug3("%s entering", __func__); 1573 1574 auth_method = "rsa"; 1575 if (options.rsa_authentication && authctxt->valid) { 1576 if ((client_n = BN_new()) == NULL) 1577 fatal("%s: BN_new", __func__); 1578 buffer_get_bignum2(m, client_n); 1579 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1580 BN_clear_free(client_n); 1581 } 1582 buffer_clear(m); 1583 buffer_put_int(m, allowed); 1584 buffer_put_int(m, forced_command != NULL); 1585 1586 /* clear temporarily storage (used by generate challenge) */ 1587 monitor_reset_key_state(); 1588 1589 if (allowed && key != NULL) { 1590 key->type = KEY_RSA; /* cheat for key_to_blob */ 1591 if (key_to_blob(key, &blob, &blen) == 0) 1592 fatal("%s: key_to_blob failed", __func__); 1593 buffer_put_string(m, blob, blen); 1594 1595 /* Save temporarily for comparison in verify */ 1596 key_blob = blob; 1597 key_bloblen = blen; 1598 key_blobtype = MM_RSAUSERKEY; 1599 } 1600 if (key != NULL) 1601 key_free(key); 1602 1603 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1604 1605 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1606 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1607 return (0); 1608} 1609 1610int 1611mm_answer_rsa_challenge(int sock, Buffer *m) 1612{ 1613 Key *key = NULL; 1614 u_char *blob; 1615 u_int blen; 1616 1617 debug3("%s entering", __func__); 1618 1619 if (!authctxt->valid) 1620 fatal("%s: authctxt not valid", __func__); 1621 blob = buffer_get_string(m, &blen); 1622 if (!monitor_allowed_key(blob, blen)) 1623 fatal("%s: bad key, not previously allowed", __func__); 1624 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1625 fatal("%s: key type mismatch", __func__); 1626 if ((key = key_from_blob(blob, blen)) == NULL) 1627 fatal("%s: received bad key", __func__); 1628 if (key->type != KEY_RSA) 1629 fatal("%s: received bad key type %d", __func__, key->type); 1630 key->type = KEY_RSA1; 1631 if (ssh1_challenge) 1632 BN_clear_free(ssh1_challenge); 1633 ssh1_challenge = auth_rsa_generate_challenge(key); 1634 1635 buffer_clear(m); 1636 buffer_put_bignum2(m, ssh1_challenge); 1637 1638 debug3("%s sending reply", __func__); 1639 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1640 1641 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1642 1643 free(blob); 1644 key_free(key); 1645 return (0); 1646} 1647 1648int 1649mm_answer_rsa_response(int sock, Buffer *m) 1650{ 1651 Key *key = NULL; 1652 u_char *blob, *response; 1653 u_int blen, len; 1654 int success; 1655 1656 debug3("%s entering", __func__); 1657 1658 if (!authctxt->valid) 1659 fatal("%s: authctxt not valid", __func__); 1660 if (ssh1_challenge == NULL) 1661 fatal("%s: no ssh1_challenge", __func__); 1662 1663 blob = buffer_get_string(m, &blen); 1664 if (!monitor_allowed_key(blob, blen)) 1665 fatal("%s: bad key, not previously allowed", __func__); 1666 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1667 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1668 if ((key = key_from_blob(blob, blen)) == NULL) 1669 fatal("%s: received bad key", __func__); 1670 response = buffer_get_string(m, &len); 1671 if (len != 16) 1672 fatal("%s: received bad response to challenge", __func__); 1673 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1674 1675 free(blob); 1676 key_free(key); 1677 free(response); 1678 1679 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1680 1681 /* reset state */ 1682 BN_clear_free(ssh1_challenge); 1683 ssh1_challenge = NULL; 1684 monitor_reset_key_state(); 1685 1686 buffer_clear(m); 1687 buffer_put_int(m, success); 1688 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1689 1690 return (success); 1691} 1692 1693int 1694mm_answer_term(int sock, Buffer *req) 1695{ 1696 extern struct monitor *pmonitor; 1697 int res, status; 1698 1699 debug3("%s: tearing down sessions", __func__); 1700 1701 /* The child is terminating */ 1702 session_destroy_all(&mm_session_close); 1703 1704#ifdef USE_PAM 1705 if (options.use_pam) 1706 sshpam_cleanup(); 1707#endif 1708 1709 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1710 if (errno != EINTR) 1711 exit(1); 1712 1713 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1714 1715 /* Terminate process */ 1716 exit(res); 1717} 1718 1719#ifdef SSH_AUDIT_EVENTS 1720/* Report that an audit event occurred */ 1721int 1722mm_answer_audit_event(int socket, Buffer *m) 1723{ 1724 ssh_audit_event_t event; 1725 1726 debug3("%s entering", __func__); 1727 1728 event = buffer_get_int(m); 1729 switch(event) { 1730 case SSH_AUTH_FAIL_PUBKEY: 1731 case SSH_AUTH_FAIL_HOSTBASED: 1732 case SSH_AUTH_FAIL_GSSAPI: 1733 case SSH_LOGIN_EXCEED_MAXTRIES: 1734 case SSH_LOGIN_ROOT_DENIED: 1735 case SSH_CONNECTION_CLOSE: 1736 case SSH_INVALID_USER: 1737 audit_event(event); 1738 break; 1739 default: 1740 fatal("Audit event type %d not permitted", event); 1741 } 1742 1743 return (0); 1744} 1745 1746int 1747mm_answer_audit_command(int socket, Buffer *m) 1748{ 1749 u_int len; 1750 char *cmd; 1751 1752 debug3("%s entering", __func__); 1753 cmd = buffer_get_string(m, &len); 1754 /* sanity check command, if so how? */ 1755 audit_run_command(cmd); 1756 free(cmd); 1757 return (0); 1758} 1759#endif /* SSH_AUDIT_EVENTS */ 1760 1761void 1762monitor_apply_keystate(struct monitor *pmonitor) 1763{ 1764 if (compat20) { 1765 set_newkeys(MODE_IN); 1766 set_newkeys(MODE_OUT); 1767 } else { 1768 packet_set_protocol_flags(child_state.ssh1protoflags); 1769 packet_set_encryption_key(child_state.ssh1key, 1770 child_state.ssh1keylen, child_state.ssh1cipher); 1771 free(child_state.ssh1key); 1772 } 1773 1774 /* for rc4 and other stateful ciphers */ 1775 packet_set_keycontext(MODE_OUT, child_state.keyout); 1776 free(child_state.keyout); 1777 packet_set_keycontext(MODE_IN, child_state.keyin); 1778 free(child_state.keyin); 1779 1780 if (!compat20) { 1781 packet_set_iv(MODE_OUT, child_state.ivout); 1782 free(child_state.ivout); 1783 packet_set_iv(MODE_IN, child_state.ivin); 1784 free(child_state.ivin); 1785 } 1786 1787 memcpy(&incoming_stream, &child_state.incoming, 1788 sizeof(incoming_stream)); 1789 memcpy(&outgoing_stream, &child_state.outgoing, 1790 sizeof(outgoing_stream)); 1791 1792 /* Update with new address */ 1793 if (options.compression) 1794 mm_init_compression(pmonitor->m_zlib); 1795 1796 if (options.rekey_limit || options.rekey_interval) 1797 packet_set_rekey_limits((u_int32_t)options.rekey_limit, 1798 (time_t)options.rekey_interval); 1799 1800 /* Network I/O buffers */ 1801 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1802 buffer_clear(packet_get_input()); 1803 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1804 explicit_bzero(child_state.input, child_state.ilen); 1805 free(child_state.input); 1806 1807 buffer_clear(packet_get_output()); 1808 buffer_append(packet_get_output(), child_state.output, 1809 child_state.olen); 1810 explicit_bzero(child_state.output, child_state.olen); 1811 free(child_state.output); 1812 1813 /* Roaming */ 1814 if (compat20) 1815 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1816} 1817 1818static Kex * 1819mm_get_kex(Buffer *m) 1820{ 1821 Kex *kex; 1822 void *blob; 1823 u_int bloblen; 1824 1825 kex = xcalloc(1, sizeof(*kex)); 1826 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1827 if (session_id2 == NULL || 1828 kex->session_id_len != session_id2_len || 1829 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1830 fatal("mm_get_get: internal error: bad session id"); 1831 kex->we_need = buffer_get_int(m); 1832 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1833 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1834 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1835 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1836 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1837 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1838 kex->server = 1; 1839 kex->hostkey_type = buffer_get_int(m); 1840 kex->kex_type = buffer_get_int(m); 1841 blob = buffer_get_string(m, &bloblen); 1842 buffer_init(&kex->my); 1843 buffer_append(&kex->my, blob, bloblen); 1844 free(blob); 1845 blob = buffer_get_string(m, &bloblen); 1846 buffer_init(&kex->peer); 1847 buffer_append(&kex->peer, blob, bloblen); 1848 free(blob); 1849 kex->done = 1; 1850 kex->flags = buffer_get_int(m); 1851 kex->client_version_string = buffer_get_string(m, NULL); 1852 kex->server_version_string = buffer_get_string(m, NULL); 1853 kex->load_host_public_key=&get_hostkey_public_by_type; 1854 kex->load_host_private_key=&get_hostkey_private_by_type; 1855 kex->host_key_index=&get_hostkey_index; 1856 kex->sign = sshd_hostkey_sign; 1857 1858 return (kex); 1859} 1860 1861/* This function requries careful sanity checking */ 1862 1863void 1864mm_get_keystate(struct monitor *pmonitor) 1865{ 1866 Buffer m; 1867 u_char *blob, *p; 1868 u_int bloblen, plen; 1869 u_int32_t seqnr, packets; 1870 u_int64_t blocks, bytes; 1871 1872 debug3("%s: Waiting for new keys", __func__); 1873 1874 buffer_init(&m); 1875 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1876 if (!compat20) { 1877 child_state.ssh1protoflags = buffer_get_int(&m); 1878 child_state.ssh1cipher = buffer_get_int(&m); 1879 child_state.ssh1key = buffer_get_string(&m, 1880 &child_state.ssh1keylen); 1881 child_state.ivout = buffer_get_string(&m, 1882 &child_state.ivoutlen); 1883 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1884 goto skip; 1885 } else { 1886 /* Get the Kex for rekeying */ 1887 *pmonitor->m_pkex = mm_get_kex(&m); 1888 } 1889 1890 blob = buffer_get_string(&m, &bloblen); 1891 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1892 free(blob); 1893 1894 debug3("%s: Waiting for second key", __func__); 1895 blob = buffer_get_string(&m, &bloblen); 1896 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1897 free(blob); 1898 1899 /* Now get sequence numbers for the packets */ 1900 seqnr = buffer_get_int(&m); 1901 blocks = buffer_get_int64(&m); 1902 packets = buffer_get_int(&m); 1903 bytes = buffer_get_int64(&m); 1904 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1905 seqnr = buffer_get_int(&m); 1906 blocks = buffer_get_int64(&m); 1907 packets = buffer_get_int(&m); 1908 bytes = buffer_get_int64(&m); 1909 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1910 1911 skip: 1912 /* Get the key context */ 1913 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1914 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1915 1916 debug3("%s: Getting compression state", __func__); 1917 /* Get compression state */ 1918 p = buffer_get_string(&m, &plen); 1919 if (plen != sizeof(child_state.outgoing)) 1920 fatal("%s: bad request size", __func__); 1921 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1922 free(p); 1923 1924 p = buffer_get_string(&m, &plen); 1925 if (plen != sizeof(child_state.incoming)) 1926 fatal("%s: bad request size", __func__); 1927 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1928 free(p); 1929 1930 /* Network I/O buffers */ 1931 debug3("%s: Getting Network I/O buffers", __func__); 1932 child_state.input = buffer_get_string(&m, &child_state.ilen); 1933 child_state.output = buffer_get_string(&m, &child_state.olen); 1934 1935 /* Roaming */ 1936 if (compat20) { 1937 child_state.sent_bytes = buffer_get_int64(&m); 1938 child_state.recv_bytes = buffer_get_int64(&m); 1939 } 1940 1941 buffer_free(&m); 1942} 1943 1944 1945/* Allocation functions for zlib */ 1946void * 1947mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1948{ 1949 size_t len = (size_t) size * ncount; 1950 void *address; 1951 1952 if (len == 0 || ncount > SIZE_T_MAX / size) 1953 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1954 1955 address = mm_malloc(mm, len); 1956 1957 return (address); 1958} 1959 1960void 1961mm_zfree(struct mm_master *mm, void *address) 1962{ 1963 mm_free(mm, address); 1964} 1965 1966void 1967mm_init_compression(struct mm_master *mm) 1968{ 1969 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1970 outgoing_stream.zfree = (free_func)mm_zfree; 1971 outgoing_stream.opaque = mm; 1972 1973 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1974 incoming_stream.zfree = (free_func)mm_zfree; 1975 incoming_stream.opaque = mm; 1976} 1977 1978/* XXX */ 1979 1980#define FD_CLOSEONEXEC(x) do { \ 1981 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1982 fatal("fcntl(%d, F_SETFD)", x); \ 1983} while (0) 1984 1985static void 1986monitor_openfds(struct monitor *mon, int do_logfds) 1987{ 1988 int pair[2]; 1989 1990 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1991 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1992 FD_CLOSEONEXEC(pair[0]); 1993 FD_CLOSEONEXEC(pair[1]); 1994 mon->m_recvfd = pair[0]; 1995 mon->m_sendfd = pair[1]; 1996 1997 if (do_logfds) { 1998 if (pipe(pair) == -1) 1999 fatal("%s: pipe: %s", __func__, strerror(errno)); 2000 FD_CLOSEONEXEC(pair[0]); 2001 FD_CLOSEONEXEC(pair[1]); 2002 mon->m_log_recvfd = pair[0]; 2003 mon->m_log_sendfd = pair[1]; 2004 } else 2005 mon->m_log_recvfd = mon->m_log_sendfd = -1; 2006} 2007 2008#define MM_MEMSIZE 65536 2009 2010struct monitor * 2011monitor_init(void) 2012{ 2013 struct monitor *mon; 2014 2015 mon = xcalloc(1, sizeof(*mon)); 2016 2017 monitor_openfds(mon, 1); 2018 2019 /* Used to share zlib space across processes */ 2020 if (options.compression) { 2021 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 2022 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 2023 2024 /* Compression needs to share state across borders */ 2025 mm_init_compression(mon->m_zlib); 2026 } 2027 2028 return mon; 2029} 2030 2031void 2032monitor_reinit(struct monitor *mon) 2033{ 2034 monitor_openfds(mon, 0); 2035} 2036 2037#ifdef GSSAPI 2038int 2039mm_answer_gss_setup_ctx(int sock, Buffer *m) 2040{ 2041 gss_OID_desc goid; 2042 OM_uint32 major; 2043 u_int len; 2044 2045 goid.elements = buffer_get_string(m, &len); 2046 goid.length = len; 2047 2048 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 2049 2050 free(goid.elements); 2051 2052 buffer_clear(m); 2053 buffer_put_int(m, major); 2054 2055 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 2056 2057 /* Now we have a context, enable the step */ 2058 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 2059 2060 return (0); 2061} 2062 2063int 2064mm_answer_gss_accept_ctx(int sock, Buffer *m) 2065{ 2066 gss_buffer_desc in; 2067 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2068 OM_uint32 major, minor; 2069 OM_uint32 flags = 0; /* GSI needs this */ 2070 u_int len; 2071 2072 in.value = buffer_get_string(m, &len); 2073 in.length = len; 2074 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2075 free(in.value); 2076 2077 buffer_clear(m); 2078 buffer_put_int(m, major); 2079 buffer_put_string(m, out.value, out.length); 2080 buffer_put_int(m, flags); 2081 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2082 2083 gss_release_buffer(&minor, &out); 2084 2085 if (major == GSS_S_COMPLETE) { 2086 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2087 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2088 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2089 } 2090 return (0); 2091} 2092 2093int 2094mm_answer_gss_checkmic(int sock, Buffer *m) 2095{ 2096 gss_buffer_desc gssbuf, mic; 2097 OM_uint32 ret; 2098 u_int len; 2099 2100 gssbuf.value = buffer_get_string(m, &len); 2101 gssbuf.length = len; 2102 mic.value = buffer_get_string(m, &len); 2103 mic.length = len; 2104 2105 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2106 2107 free(gssbuf.value); 2108 free(mic.value); 2109 2110 buffer_clear(m); 2111 buffer_put_int(m, ret); 2112 2113 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2114 2115 if (!GSS_ERROR(ret)) 2116 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2117 2118 return (0); 2119} 2120 2121int 2122mm_answer_gss_userok(int sock, Buffer *m) 2123{ 2124 int authenticated; 2125 2126 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2127 2128 buffer_clear(m); 2129 buffer_put_int(m, authenticated); 2130 2131 debug3("%s: sending result %d", __func__, authenticated); 2132 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2133 2134 auth_method = "gssapi-with-mic"; 2135 2136 /* Monitor loop will terminate if authenticated */ 2137 return (authenticated); 2138} 2139#endif /* GSSAPI */ 2140 2141