1 /* $OpenBSD: monitor.c,v 1.161 2016/07/22 03:39:13 djm Exp $ */ 2 /* 3 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus@openbsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 30 #include <sys/types.h> 31 #include <sys/socket.h> 32 #include "openbsd-compat/sys-tree.h" 33 #include <sys/wait.h> 34 35 #include <errno.h> 36 #include <fcntl.h> 37 #include <limits.h> 38 #ifdef HAVE_PATHS_H 39 #include <paths.h> 40 #endif 41 #include <pwd.h> 42 #include <signal.h> 43 #ifdef HAVE_STDINT_H 44 #include <stdint.h> 45 #endif 46 #include <stdlib.h> 47 #include <string.h> 48 #include <stdarg.h> 49 #include <stdio.h> 50 #include <unistd.h> 51 #ifdef HAVE_POLL_H 52 #include <poll.h> 53 #else 54 # ifdef HAVE_SYS_POLL_H 55 # include <sys/poll.h> 56 # endif 57 #endif 58 59 #ifdef SKEY 60 #include <skey.h> 61 #endif 62 63 #ifdef WITH_OPENSSL 64 #include <openssl/dh.h> 65 #endif 66 67 #include "openbsd-compat/sys-queue.h" 68 #include "atomicio.h" 69 #include "xmalloc.h" 70 #include "ssh.h" 71 #include "key.h" 72 #include "buffer.h" 73 #include "hostfile.h" 74 #include "auth.h" 75 #include "cipher.h" 76 #include "kex.h" 77 #include "dh.h" 78 #include "auth-pam.h" 79 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 80 #undef TARGET_OS_MAC 81 #include "zlib.h" 82 #define TARGET_OS_MAC 1 83 #else 84 #include "zlib.h" 85 #endif 86 #include "packet.h" 87 #include "auth-options.h" 88 #include "sshpty.h" 89 #include "channels.h" 90 #include "session.h" 91 #include "sshlogin.h" 92 #include "canohost.h" 93 #include "log.h" 94 #include "misc.h" 95 #include "servconf.h" 96 #include "monitor.h" 97 #include "monitor_mm.h" 98 #ifdef GSSAPI 99 #include "ssh-gss.h" 100 #endif 101 #include "monitor_wrap.h" 102 #include "monitor_fdpass.h" 103 #include "compat.h" 104 #include "ssh2.h" 105 #include "authfd.h" 106 #include "match.h" 107 #include "ssherr.h" 108 109 #ifdef GSSAPI 110 static Gssctxt *gsscontext = NULL; 111 #endif 112 113 /* Imports */ 114 extern ServerOptions options; 115 extern u_int utmp_len; 116 extern u_char session_id[]; 117 extern Buffer auth_debug; 118 extern int auth_debug_init; 119 extern Buffer loginmsg; 120 121 /* State exported from the child */ 122 static struct sshbuf *child_state; 123 124 /* Functions on the monitor that answer unprivileged requests */ 125 126 int mm_answer_moduli(int, Buffer *); 127 int mm_answer_sign(int, Buffer *); 128 int mm_answer_pwnamallow(int, Buffer *); 129 int mm_answer_auth2_read_banner(int, Buffer *); 130 int mm_answer_authserv(int, Buffer *); 131 int mm_answer_authpassword(int, Buffer *); 132 int mm_answer_bsdauthquery(int, Buffer *); 133 int mm_answer_bsdauthrespond(int, Buffer *); 134 int mm_answer_skeyquery(int, Buffer *); 135 int mm_answer_skeyrespond(int, Buffer *); 136 int mm_answer_keyallowed(int, Buffer *); 137 int mm_answer_keyverify(int, Buffer *); 138 int mm_answer_pty(int, Buffer *); 139 int mm_answer_pty_cleanup(int, Buffer *); 140 int mm_answer_term(int, Buffer *); 141 int mm_answer_rsa_keyallowed(int, Buffer *); 142 int mm_answer_rsa_challenge(int, Buffer *); 143 int mm_answer_rsa_response(int, Buffer *); 144 int mm_answer_sesskey(int, Buffer *); 145 int mm_answer_sessid(int, Buffer *); 146 147 #ifdef USE_PAM 148 int mm_answer_pam_start(int, Buffer *); 149 int mm_answer_pam_account(int, Buffer *); 150 int mm_answer_pam_init_ctx(int, Buffer *); 151 int mm_answer_pam_query(int, Buffer *); 152 int mm_answer_pam_respond(int, Buffer *); 153 int mm_answer_pam_free_ctx(int, Buffer *); 154 #endif 155 156 #ifdef GSSAPI 157 int mm_answer_gss_setup_ctx(int, Buffer *); 158 int mm_answer_gss_accept_ctx(int, Buffer *); 159 int mm_answer_gss_userok(int, Buffer *); 160 int mm_answer_gss_checkmic(int, Buffer *); 161 #endif 162 163 #ifdef SSH_AUDIT_EVENTS 164 int mm_answer_audit_event(int, Buffer *); 165 int mm_answer_audit_command(int, Buffer *); 166 #endif 167 168 static int monitor_read_log(struct monitor *); 169 170 static Authctxt *authctxt; 171 172 #ifdef WITH_SSH1 173 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 174 #endif 175 176 /* local state for key verify */ 177 static u_char *key_blob = NULL; 178 static u_int key_bloblen = 0; 179 static int key_blobtype = MM_NOKEY; 180 static char *hostbased_cuser = NULL; 181 static char *hostbased_chost = NULL; 182 static char *auth_method = "unknown"; 183 static char *auth_submethod = NULL; 184 static u_int session_id2_len = 0; 185 static u_char *session_id2 = NULL; 186 static pid_t monitor_child_pid; 187 188 struct mon_table { 189 enum monitor_reqtype type; 190 int flags; 191 int (*f)(int, Buffer *); 192 }; 193 194 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 195 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 196 #define MON_ONCE 0x0010 /* Disable after calling */ 197 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 198 199 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 200 201 #define MON_PERMIT 0x1000 /* Request is permitted */ 202 203 struct mon_table mon_dispatch_proto20[] = { 204 #ifdef WITH_OPENSSL 205 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 206 #endif 207 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 208 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 209 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 210 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 211 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 212 #ifdef USE_PAM 213 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 214 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 215 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 216 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 217 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 218 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 219 #endif 220 #ifdef SSH_AUDIT_EVENTS 221 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 222 #endif 223 #ifdef BSD_AUTH 224 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 225 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 226 #endif 227 #ifdef SKEY 228 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 229 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 230 #endif 231 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 232 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 233 #ifdef GSSAPI 234 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 235 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 236 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 237 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 238 #endif 239 {0, 0, NULL} 240 }; 241 242 struct mon_table mon_dispatch_postauth20[] = { 243 #ifdef WITH_OPENSSL 244 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 245 #endif 246 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 247 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 248 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 249 {MONITOR_REQ_TERM, 0, mm_answer_term}, 250 #ifdef SSH_AUDIT_EVENTS 251 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 252 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 253 #endif 254 {0, 0, NULL} 255 }; 256 257 struct mon_table mon_dispatch_proto15[] = { 258 #ifdef WITH_SSH1 259 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 260 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 261 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 262 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 263 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 264 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 265 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 266 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 267 #ifdef BSD_AUTH 268 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 269 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 270 #endif 271 #ifdef SKEY 272 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 273 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 274 #endif 275 #ifdef USE_PAM 276 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 277 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 278 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 279 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 280 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 281 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 282 #endif 283 #ifdef SSH_AUDIT_EVENTS 284 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 285 #endif 286 #endif /* WITH_SSH1 */ 287 {0, 0, NULL} 288 }; 289 290 struct mon_table mon_dispatch_postauth15[] = { 291 #ifdef WITH_SSH1 292 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 293 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 294 {MONITOR_REQ_TERM, 0, mm_answer_term}, 295 #ifdef SSH_AUDIT_EVENTS 296 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 297 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 298 #endif 299 #endif /* WITH_SSH1 */ 300 {0, 0, NULL} 301 }; 302 303 struct mon_table *mon_dispatch; 304 305 /* Specifies if a certain message is allowed at the moment */ 306 307 static void 308 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 309 { 310 while (ent->f != NULL) { 311 if (ent->type == type) { 312 ent->flags &= ~MON_PERMIT; 313 ent->flags |= permit ? MON_PERMIT : 0; 314 return; 315 } 316 ent++; 317 } 318 } 319 320 static void 321 monitor_permit_authentications(int permit) 322 { 323 struct mon_table *ent = mon_dispatch; 324 325 while (ent->f != NULL) { 326 if (ent->flags & MON_AUTH) { 327 ent->flags &= ~MON_PERMIT; 328 ent->flags |= permit ? MON_PERMIT : 0; 329 } 330 ent++; 331 } 332 } 333 334 void 335 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 336 { 337 struct mon_table *ent; 338 int authenticated = 0, partial = 0; 339 340 debug3("preauth child monitor started"); 341 342 close(pmonitor->m_recvfd); 343 close(pmonitor->m_log_sendfd); 344 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 345 346 authctxt = _authctxt; 347 memset(authctxt, 0, sizeof(*authctxt)); 348 349 authctxt->loginmsg = &loginmsg; 350 351 if (compat20) { 352 mon_dispatch = mon_dispatch_proto20; 353 354 /* Permit requests for moduli and signatures */ 355 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 356 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 357 } else { 358 mon_dispatch = mon_dispatch_proto15; 359 360 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 361 } 362 363 /* The first few requests do not require asynchronous access */ 364 while (!authenticated) { 365 partial = 0; 366 auth_method = "unknown"; 367 auth_submethod = NULL; 368 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 369 370 /* Special handling for multiple required authentications */ 371 if (options.num_auth_methods != 0) { 372 if (!compat20) 373 fatal("AuthenticationMethods is not supported" 374 "with SSH protocol 1"); 375 if (authenticated && 376 !auth2_update_methods_lists(authctxt, 377 auth_method, auth_submethod)) { 378 debug3("%s: method %s: partial", __func__, 379 auth_method); 380 authenticated = 0; 381 partial = 1; 382 } 383 } 384 385 if (authenticated) { 386 if (!(ent->flags & MON_AUTHDECIDE)) 387 fatal("%s: unexpected authentication from %d", 388 __func__, ent->type); 389 if (authctxt->pw->pw_uid == 0 && 390 !auth_root_allowed(auth_method)) 391 authenticated = 0; 392 #ifdef USE_PAM 393 /* PAM needs to perform account checks after auth */ 394 if (options.use_pam && authenticated) { 395 Buffer m; 396 397 buffer_init(&m); 398 mm_request_receive_expect(pmonitor->m_sendfd, 399 MONITOR_REQ_PAM_ACCOUNT, &m); 400 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 401 buffer_free(&m); 402 } 403 #endif 404 } 405 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 406 auth_log(authctxt, authenticated, partial, 407 auth_method, auth_submethod); 408 if (!partial && !authenticated) 409 authctxt->failures++; 410 } 411 } 412 413 if (!authctxt->valid) 414 fatal("%s: authenticated invalid user", __func__); 415 if (strcmp(auth_method, "unknown") == 0) 416 fatal("%s: authentication method name unknown", __func__); 417 418 debug("%s: %s has been authenticated by privileged process", 419 __func__, authctxt->user); 420 421 mm_get_keystate(pmonitor); 422 423 /* Drain any buffered messages from the child */ 424 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 425 ; 426 427 close(pmonitor->m_sendfd); 428 close(pmonitor->m_log_recvfd); 429 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 430 } 431 432 static void 433 monitor_set_child_handler(pid_t pid) 434 { 435 monitor_child_pid = pid; 436 } 437 438 static void 439 monitor_child_handler(int sig) 440 { 441 kill(monitor_child_pid, sig); 442 } 443 444 void 445 monitor_child_postauth(struct monitor *pmonitor) 446 { 447 close(pmonitor->m_recvfd); 448 pmonitor->m_recvfd = -1; 449 450 monitor_set_child_handler(pmonitor->m_pid); 451 signal(SIGHUP, &monitor_child_handler); 452 signal(SIGTERM, &monitor_child_handler); 453 signal(SIGINT, &monitor_child_handler); 454 #ifdef SIGXFSZ 455 signal(SIGXFSZ, SIG_IGN); 456 #endif 457 458 if (compat20) { 459 mon_dispatch = mon_dispatch_postauth20; 460 461 /* Permit requests for moduli and signatures */ 462 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 463 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 464 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 465 } else { 466 mon_dispatch = mon_dispatch_postauth15; 467 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 468 } 469 if (!no_pty_flag) { 470 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 471 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 472 } 473 474 for (;;) 475 monitor_read(pmonitor, mon_dispatch, NULL); 476 } 477 478 void 479 monitor_sync(struct monitor *pmonitor) 480 { 481 if (options.compression) { 482 /* The member allocation is not visible, so sync it */ 483 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 484 } 485 } 486 487 /* Allocation functions for zlib */ 488 static void * 489 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 490 { 491 if (size == 0 || ncount == 0 || ncount > SIZE_MAX / size) 492 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 493 494 return mm_malloc(mm, size * ncount); 495 } 496 497 static void 498 mm_zfree(struct mm_master *mm, void *address) 499 { 500 mm_free(mm, address); 501 } 502 503 static int 504 monitor_read_log(struct monitor *pmonitor) 505 { 506 Buffer logmsg; 507 u_int len, level; 508 char *msg; 509 510 buffer_init(&logmsg); 511 512 /* Read length */ 513 buffer_append_space(&logmsg, 4); 514 if (atomicio(read, pmonitor->m_log_recvfd, 515 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 516 if (errno == EPIPE) { 517 buffer_free(&logmsg); 518 debug("%s: child log fd closed", __func__); 519 close(pmonitor->m_log_recvfd); 520 pmonitor->m_log_recvfd = -1; 521 return -1; 522 } 523 fatal("%s: log fd read: %s", __func__, strerror(errno)); 524 } 525 len = buffer_get_int(&logmsg); 526 if (len <= 4 || len > 8192) 527 fatal("%s: invalid log message length %u", __func__, len); 528 529 /* Read severity, message */ 530 buffer_clear(&logmsg); 531 buffer_append_space(&logmsg, len); 532 if (atomicio(read, pmonitor->m_log_recvfd, 533 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 534 fatal("%s: log fd read: %s", __func__, strerror(errno)); 535 536 /* Log it */ 537 level = buffer_get_int(&logmsg); 538 msg = buffer_get_string(&logmsg, NULL); 539 if (log_level_name(level) == NULL) 540 fatal("%s: invalid log level %u (corrupted message?)", 541 __func__, level); 542 do_log2(level, "%s [preauth]", msg); 543 544 buffer_free(&logmsg); 545 free(msg); 546 547 return 0; 548 } 549 550 int 551 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 552 struct mon_table **pent) 553 { 554 Buffer m; 555 int ret; 556 u_char type; 557 struct pollfd pfd[2]; 558 559 for (;;) { 560 memset(&pfd, 0, sizeof(pfd)); 561 pfd[0].fd = pmonitor->m_sendfd; 562 pfd[0].events = POLLIN; 563 pfd[1].fd = pmonitor->m_log_recvfd; 564 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 565 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 566 if (errno == EINTR || errno == EAGAIN) 567 continue; 568 fatal("%s: poll: %s", __func__, strerror(errno)); 569 } 570 if (pfd[1].revents) { 571 /* 572 * Drain all log messages before processing next 573 * monitor request. 574 */ 575 monitor_read_log(pmonitor); 576 continue; 577 } 578 if (pfd[0].revents) 579 break; /* Continues below */ 580 } 581 582 buffer_init(&m); 583 584 mm_request_receive(pmonitor->m_sendfd, &m); 585 type = buffer_get_char(&m); 586 587 debug3("%s: checking request %d", __func__, type); 588 589 while (ent->f != NULL) { 590 if (ent->type == type) 591 break; 592 ent++; 593 } 594 595 if (ent->f != NULL) { 596 if (!(ent->flags & MON_PERMIT)) 597 fatal("%s: unpermitted request %d", __func__, 598 type); 599 ret = (*ent->f)(pmonitor->m_sendfd, &m); 600 buffer_free(&m); 601 602 /* The child may use this request only once, disable it */ 603 if (ent->flags & MON_ONCE) { 604 debug2("%s: %d used once, disabling now", __func__, 605 type); 606 ent->flags &= ~MON_PERMIT; 607 } 608 609 if (pent != NULL) 610 *pent = ent; 611 612 return ret; 613 } 614 615 fatal("%s: unsupported request: %d", __func__, type); 616 617 /* NOTREACHED */ 618 return (-1); 619 } 620 621 /* allowed key state */ 622 static int 623 monitor_allowed_key(u_char *blob, u_int bloblen) 624 { 625 /* make sure key is allowed */ 626 if (key_blob == NULL || key_bloblen != bloblen || 627 timingsafe_bcmp(key_blob, blob, key_bloblen)) 628 return (0); 629 return (1); 630 } 631 632 static void 633 monitor_reset_key_state(void) 634 { 635 /* reset state */ 636 free(key_blob); 637 free(hostbased_cuser); 638 free(hostbased_chost); 639 key_blob = NULL; 640 key_bloblen = 0; 641 key_blobtype = MM_NOKEY; 642 hostbased_cuser = NULL; 643 hostbased_chost = NULL; 644 } 645 646 #ifdef WITH_OPENSSL 647 int 648 mm_answer_moduli(int sock, Buffer *m) 649 { 650 DH *dh; 651 int min, want, max; 652 653 min = buffer_get_int(m); 654 want = buffer_get_int(m); 655 max = buffer_get_int(m); 656 657 debug3("%s: got parameters: %d %d %d", 658 __func__, min, want, max); 659 /* We need to check here, too, in case the child got corrupted */ 660 if (max < min || want < min || max < want) 661 fatal("%s: bad parameters: %d %d %d", 662 __func__, min, want, max); 663 664 buffer_clear(m); 665 666 dh = choose_dh(min, want, max); 667 if (dh == NULL) { 668 buffer_put_char(m, 0); 669 return (0); 670 } else { 671 /* Send first bignum */ 672 buffer_put_char(m, 1); 673 buffer_put_bignum2(m, dh->p); 674 buffer_put_bignum2(m, dh->g); 675 676 DH_free(dh); 677 } 678 mm_request_send(sock, MONITOR_ANS_MODULI, m); 679 return (0); 680 } 681 #endif 682 683 int 684 mm_answer_sign(int sock, Buffer *m) 685 { 686 struct ssh *ssh = active_state; /* XXX */ 687 extern int auth_sock; /* XXX move to state struct? */ 688 struct sshkey *key; 689 struct sshbuf *sigbuf = NULL; 690 u_char *p = NULL, *signature = NULL; 691 char *alg = NULL; 692 size_t datlen, siglen, alglen; 693 int r, is_proof = 0; 694 u_int keyid; 695 const char proof_req[] = "hostkeys-prove-00@openssh.com"; 696 697 debug3("%s", __func__); 698 699 if ((r = sshbuf_get_u32(m, &keyid)) != 0 || 700 (r = sshbuf_get_string(m, &p, &datlen)) != 0 || 701 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0) 702 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 703 if (keyid > INT_MAX) 704 fatal("%s: invalid key ID", __func__); 705 706 /* 707 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 708 * SHA384 (48 bytes) and SHA512 (64 bytes). 709 * 710 * Otherwise, verify the signature request is for a hostkey 711 * proof. 712 * 713 * XXX perform similar check for KEX signature requests too? 714 * it's not trivial, since what is signed is the hash, rather 715 * than the full kex structure... 716 */ 717 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) { 718 /* 719 * Construct expected hostkey proof and compare it to what 720 * the client sent us. 721 */ 722 if (session_id2_len == 0) /* hostkeys is never first */ 723 fatal("%s: bad data length: %zu", __func__, datlen); 724 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL) 725 fatal("%s: no hostkey for index %d", __func__, keyid); 726 if ((sigbuf = sshbuf_new()) == NULL) 727 fatal("%s: sshbuf_new", __func__); 728 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 || 729 (r = sshbuf_put_string(sigbuf, session_id2, 730 session_id2_len)) != 0 || 731 (r = sshkey_puts(key, sigbuf)) != 0) 732 fatal("%s: couldn't prepare private key " 733 "proof buffer: %s", __func__, ssh_err(r)); 734 if (datlen != sshbuf_len(sigbuf) || 735 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0) 736 fatal("%s: bad data length: %zu, hostkey proof len %zu", 737 __func__, datlen, sshbuf_len(sigbuf)); 738 sshbuf_free(sigbuf); 739 is_proof = 1; 740 } 741 742 /* save session id, it will be passed on the first call */ 743 if (session_id2_len == 0) { 744 session_id2_len = datlen; 745 session_id2 = xmalloc(session_id2_len); 746 memcpy(session_id2, p, session_id2_len); 747 } 748 749 if ((key = get_hostkey_by_index(keyid)) != NULL) { 750 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, 751 datafellows)) != 0) 752 fatal("%s: sshkey_sign failed: %s", 753 __func__, ssh_err(r)); 754 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && 755 auth_sock > 0) { 756 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, 757 p, datlen, alg, datafellows)) != 0) { 758 fatal("%s: ssh_agent_sign failed: %s", 759 __func__, ssh_err(r)); 760 } 761 } else 762 fatal("%s: no hostkey from index %d", __func__, keyid); 763 764 debug3("%s: %s signature %p(%zu)", __func__, 765 is_proof ? "KEX" : "hostkey proof", signature, siglen); 766 767 sshbuf_reset(m); 768 if ((r = sshbuf_put_string(m, signature, siglen)) != 0) 769 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 770 771 free(alg); 772 free(p); 773 free(signature); 774 775 mm_request_send(sock, MONITOR_ANS_SIGN, m); 776 777 /* Turn on permissions for getpwnam */ 778 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 779 780 return (0); 781 } 782 783 /* Retrieves the password entry and also checks if the user is permitted */ 784 785 int 786 mm_answer_pwnamallow(int sock, Buffer *m) 787 { 788 char *username; 789 struct passwd *pwent; 790 int allowed = 0; 791 u_int i; 792 793 debug3("%s", __func__); 794 795 if (authctxt->attempt++ != 0) 796 fatal("%s: multiple attempts for getpwnam", __func__); 797 798 username = buffer_get_string(m, NULL); 799 800 pwent = getpwnamallow(username); 801 802 authctxt->user = xstrdup(username); 803 setproctitle("%s [priv]", pwent ? username : "unknown"); 804 free(username); 805 806 buffer_clear(m); 807 808 if (pwent == NULL) { 809 buffer_put_char(m, 0); 810 authctxt->pw = fakepw(); 811 goto out; 812 } 813 814 allowed = 1; 815 authctxt->pw = pwent; 816 authctxt->valid = 1; 817 818 buffer_put_char(m, 1); 819 buffer_put_string(m, pwent, sizeof(struct passwd)); 820 buffer_put_cstring(m, pwent->pw_name); 821 buffer_put_cstring(m, "*"); 822 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 823 buffer_put_cstring(m, pwent->pw_gecos); 824 #endif 825 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 826 buffer_put_cstring(m, pwent->pw_class); 827 #endif 828 buffer_put_cstring(m, pwent->pw_dir); 829 buffer_put_cstring(m, pwent->pw_shell); 830 831 out: 832 buffer_put_string(m, &options, sizeof(options)); 833 834 #define M_CP_STROPT(x) do { \ 835 if (options.x != NULL) \ 836 buffer_put_cstring(m, options.x); \ 837 } while (0) 838 #define M_CP_STRARRAYOPT(x, nx) do { \ 839 for (i = 0; i < options.nx; i++) \ 840 buffer_put_cstring(m, options.x[i]); \ 841 } while (0) 842 /* See comment in servconf.h */ 843 COPY_MATCH_STRING_OPTS(); 844 #undef M_CP_STROPT 845 #undef M_CP_STRARRAYOPT 846 847 /* Create valid auth method lists */ 848 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 849 /* 850 * The monitor will continue long enough to let the child 851 * run to it's packet_disconnect(), but it must not allow any 852 * authentication to succeed. 853 */ 854 debug("%s: no valid authentication method lists", __func__); 855 } 856 857 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 858 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 859 860 /* For SSHv1 allow authentication now */ 861 if (!compat20) 862 monitor_permit_authentications(1); 863 else { 864 /* Allow service/style information on the auth context */ 865 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 866 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 867 } 868 #ifdef USE_PAM 869 if (options.use_pam) 870 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 871 #endif 872 873 return (0); 874 } 875 876 int mm_answer_auth2_read_banner(int sock, Buffer *m) 877 { 878 char *banner; 879 880 buffer_clear(m); 881 banner = auth2_read_banner(); 882 buffer_put_cstring(m, banner != NULL ? banner : ""); 883 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 884 free(banner); 885 886 return (0); 887 } 888 889 int 890 mm_answer_authserv(int sock, Buffer *m) 891 { 892 monitor_permit_authentications(1); 893 894 authctxt->service = buffer_get_string(m, NULL); 895 authctxt->style = buffer_get_string(m, NULL); 896 debug3("%s: service=%s, style=%s", 897 __func__, authctxt->service, authctxt->style); 898 899 if (strlen(authctxt->style) == 0) { 900 free(authctxt->style); 901 authctxt->style = NULL; 902 } 903 904 return (0); 905 } 906 907 int 908 mm_answer_authpassword(int sock, Buffer *m) 909 { 910 static int call_count; 911 char *passwd; 912 int authenticated; 913 u_int plen; 914 915 passwd = buffer_get_string(m, &plen); 916 /* Only authenticate if the context is valid */ 917 authenticated = options.password_authentication && 918 auth_password(authctxt, passwd); 919 explicit_bzero(passwd, strlen(passwd)); 920 free(passwd); 921 922 buffer_clear(m); 923 buffer_put_int(m, authenticated); 924 #ifdef USE_PAM 925 buffer_put_int(m, sshpam_get_maxtries_reached()); 926 #endif 927 928 debug3("%s: sending result %d", __func__, authenticated); 929 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 930 931 call_count++; 932 if (plen == 0 && call_count == 1) 933 auth_method = "none"; 934 else 935 auth_method = "password"; 936 937 /* Causes monitor loop to terminate if authenticated */ 938 return (authenticated); 939 } 940 941 #ifdef BSD_AUTH 942 int 943 mm_answer_bsdauthquery(int sock, Buffer *m) 944 { 945 char *name, *infotxt; 946 u_int numprompts; 947 u_int *echo_on; 948 char **prompts; 949 u_int success; 950 951 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 952 &prompts, &echo_on) < 0 ? 0 : 1; 953 954 buffer_clear(m); 955 buffer_put_int(m, success); 956 if (success) 957 buffer_put_cstring(m, prompts[0]); 958 959 debug3("%s: sending challenge success: %u", __func__, success); 960 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 961 962 if (success) { 963 free(name); 964 free(infotxt); 965 free(prompts); 966 free(echo_on); 967 } 968 969 return (0); 970 } 971 972 int 973 mm_answer_bsdauthrespond(int sock, Buffer *m) 974 { 975 char *response; 976 int authok; 977 978 if (authctxt->as == NULL) 979 fatal("%s: no bsd auth session", __func__); 980 981 response = buffer_get_string(m, NULL); 982 authok = options.challenge_response_authentication && 983 auth_userresponse(authctxt->as, response, 0); 984 authctxt->as = NULL; 985 debug3("%s: <%s> = <%d>", __func__, response, authok); 986 free(response); 987 988 buffer_clear(m); 989 buffer_put_int(m, authok); 990 991 debug3("%s: sending authenticated: %d", __func__, authok); 992 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 993 994 if (compat20) { 995 auth_method = "keyboard-interactive"; 996 auth_submethod = "bsdauth"; 997 } else 998 auth_method = "bsdauth"; 999 1000 return (authok != 0); 1001 } 1002 #endif 1003 1004 #ifdef SKEY 1005 int 1006 mm_answer_skeyquery(int sock, Buffer *m) 1007 { 1008 struct skey skey; 1009 char challenge[1024]; 1010 u_int success; 1011 1012 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 1013 sizeof(challenge)) < 0 ? 0 : 1; 1014 1015 buffer_clear(m); 1016 buffer_put_int(m, success); 1017 if (success) 1018 buffer_put_cstring(m, challenge); 1019 1020 debug3("%s: sending challenge success: %u", __func__, success); 1021 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 1022 1023 return (0); 1024 } 1025 1026 int 1027 mm_answer_skeyrespond(int sock, Buffer *m) 1028 { 1029 char *response; 1030 int authok; 1031 1032 response = buffer_get_string(m, NULL); 1033 1034 authok = (options.challenge_response_authentication && 1035 authctxt->valid && 1036 skey_haskey(authctxt->pw->pw_name) == 0 && 1037 skey_passcheck(authctxt->pw->pw_name, response) != -1); 1038 1039 free(response); 1040 1041 buffer_clear(m); 1042 buffer_put_int(m, authok); 1043 1044 debug3("%s: sending authenticated: %d", __func__, authok); 1045 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 1046 1047 auth_method = "keyboard-interactive"; 1048 auth_submethod = "skey"; 1049 1050 return (authok != 0); 1051 } 1052 #endif 1053 1054 #ifdef USE_PAM 1055 int 1056 mm_answer_pam_start(int sock, Buffer *m) 1057 { 1058 if (!options.use_pam) 1059 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1060 1061 start_pam(authctxt); 1062 1063 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1064 1065 return (0); 1066 } 1067 1068 int 1069 mm_answer_pam_account(int sock, Buffer *m) 1070 { 1071 u_int ret; 1072 1073 if (!options.use_pam) 1074 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1075 1076 ret = do_pam_account(); 1077 1078 buffer_put_int(m, ret); 1079 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1080 1081 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1082 1083 return (ret); 1084 } 1085 1086 static void *sshpam_ctxt, *sshpam_authok; 1087 extern KbdintDevice sshpam_device; 1088 1089 int 1090 mm_answer_pam_init_ctx(int sock, Buffer *m) 1091 { 1092 debug3("%s", __func__); 1093 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1094 sshpam_authok = NULL; 1095 buffer_clear(m); 1096 if (sshpam_ctxt != NULL) { 1097 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1098 buffer_put_int(m, 1); 1099 } else { 1100 buffer_put_int(m, 0); 1101 } 1102 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1103 return (0); 1104 } 1105 1106 int 1107 mm_answer_pam_query(int sock, Buffer *m) 1108 { 1109 char *name = NULL, *info = NULL, **prompts = NULL; 1110 u_int i, num = 0, *echo_on = 0; 1111 int ret; 1112 1113 debug3("%s", __func__); 1114 sshpam_authok = NULL; 1115 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1116 if (ret == 0 && num == 0) 1117 sshpam_authok = sshpam_ctxt; 1118 if (num > 1 || name == NULL || info == NULL) 1119 ret = -1; 1120 buffer_clear(m); 1121 buffer_put_int(m, ret); 1122 buffer_put_cstring(m, name); 1123 free(name); 1124 buffer_put_cstring(m, info); 1125 free(info); 1126 buffer_put_int(m, sshpam_get_maxtries_reached()); 1127 buffer_put_int(m, num); 1128 for (i = 0; i < num; ++i) { 1129 buffer_put_cstring(m, prompts[i]); 1130 free(prompts[i]); 1131 buffer_put_int(m, echo_on[i]); 1132 } 1133 free(prompts); 1134 free(echo_on); 1135 auth_method = "keyboard-interactive"; 1136 auth_submethod = "pam"; 1137 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1138 return (0); 1139 } 1140 1141 int 1142 mm_answer_pam_respond(int sock, Buffer *m) 1143 { 1144 char **resp; 1145 u_int i, num; 1146 int ret; 1147 1148 debug3("%s", __func__); 1149 sshpam_authok = NULL; 1150 num = buffer_get_int(m); 1151 if (num > 0) { 1152 resp = xcalloc(num, sizeof(char *)); 1153 for (i = 0; i < num; ++i) 1154 resp[i] = buffer_get_string(m, NULL); 1155 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1156 for (i = 0; i < num; ++i) 1157 free(resp[i]); 1158 free(resp); 1159 } else { 1160 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1161 } 1162 buffer_clear(m); 1163 buffer_put_int(m, ret); 1164 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1165 auth_method = "keyboard-interactive"; 1166 auth_submethod = "pam"; 1167 if (ret == 0) 1168 sshpam_authok = sshpam_ctxt; 1169 return (0); 1170 } 1171 1172 int 1173 mm_answer_pam_free_ctx(int sock, Buffer *m) 1174 { 1175 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt; 1176 1177 debug3("%s", __func__); 1178 (sshpam_device.free_ctx)(sshpam_ctxt); 1179 sshpam_ctxt = sshpam_authok = NULL; 1180 buffer_clear(m); 1181 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1182 auth_method = "keyboard-interactive"; 1183 auth_submethod = "pam"; 1184 return r; 1185 } 1186 #endif 1187 1188 int 1189 mm_answer_keyallowed(int sock, Buffer *m) 1190 { 1191 Key *key; 1192 char *cuser, *chost; 1193 u_char *blob; 1194 u_int bloblen, pubkey_auth_attempt; 1195 enum mm_keytype type = 0; 1196 int allowed = 0; 1197 1198 debug3("%s entering", __func__); 1199 1200 type = buffer_get_int(m); 1201 cuser = buffer_get_string(m, NULL); 1202 chost = buffer_get_string(m, NULL); 1203 blob = buffer_get_string(m, &bloblen); 1204 pubkey_auth_attempt = buffer_get_int(m); 1205 1206 key = key_from_blob(blob, bloblen); 1207 1208 if ((compat20 && type == MM_RSAHOSTKEY) || 1209 (!compat20 && type != MM_RSAHOSTKEY)) 1210 fatal("%s: key type and protocol mismatch", __func__); 1211 1212 debug3("%s: key_from_blob: %p", __func__, key); 1213 1214 if (key != NULL && authctxt->valid) { 1215 /* These should not make it past the privsep child */ 1216 if (key_type_plain(key->type) == KEY_RSA && 1217 (datafellows & SSH_BUG_RSASIGMD5) != 0) 1218 fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); 1219 1220 switch (type) { 1221 case MM_USERKEY: 1222 allowed = options.pubkey_authentication && 1223 !auth2_userkey_already_used(authctxt, key) && 1224 match_pattern_list(sshkey_ssh_name(key), 1225 options.pubkey_key_types, 0) == 1 && 1226 user_key_allowed(authctxt->pw, key, 1227 pubkey_auth_attempt); 1228 pubkey_auth_info(authctxt, key, NULL); 1229 auth_method = "publickey"; 1230 if (options.pubkey_authentication && 1231 (!pubkey_auth_attempt || allowed != 1)) 1232 auth_clear_options(); 1233 break; 1234 case MM_HOSTKEY: 1235 allowed = options.hostbased_authentication && 1236 match_pattern_list(sshkey_ssh_name(key), 1237 options.hostbased_key_types, 0) == 1 && 1238 hostbased_key_allowed(authctxt->pw, 1239 cuser, chost, key); 1240 pubkey_auth_info(authctxt, key, 1241 "client user \"%.100s\", client host \"%.100s\"", 1242 cuser, chost); 1243 auth_method = "hostbased"; 1244 break; 1245 #ifdef WITH_SSH1 1246 case MM_RSAHOSTKEY: 1247 key->type = KEY_RSA1; /* XXX */ 1248 allowed = options.rhosts_rsa_authentication && 1249 auth_rhosts_rsa_key_allowed(authctxt->pw, 1250 cuser, chost, key); 1251 if (options.rhosts_rsa_authentication && allowed != 1) 1252 auth_clear_options(); 1253 auth_method = "rsa"; 1254 break; 1255 #endif 1256 default: 1257 fatal("%s: unknown key type %d", __func__, type); 1258 break; 1259 } 1260 } 1261 1262 debug3("%s: key %p is %s", 1263 __func__, key, allowed ? "allowed" : "not allowed"); 1264 1265 if (key != NULL) 1266 key_free(key); 1267 1268 /* clear temporarily storage (used by verify) */ 1269 monitor_reset_key_state(); 1270 1271 if (allowed) { 1272 /* Save temporarily for comparison in verify */ 1273 key_blob = blob; 1274 key_bloblen = bloblen; 1275 key_blobtype = type; 1276 hostbased_cuser = cuser; 1277 hostbased_chost = chost; 1278 } else { 1279 /* Log failed attempt */ 1280 auth_log(authctxt, 0, 0, auth_method, NULL); 1281 free(blob); 1282 free(cuser); 1283 free(chost); 1284 } 1285 1286 buffer_clear(m); 1287 buffer_put_int(m, allowed); 1288 buffer_put_int(m, forced_command != NULL); 1289 1290 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1291 1292 if (type == MM_RSAHOSTKEY) 1293 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1294 1295 return (0); 1296 } 1297 1298 static int 1299 monitor_valid_userblob(u_char *data, u_int datalen) 1300 { 1301 Buffer b; 1302 u_char *p; 1303 char *userstyle, *cp; 1304 u_int len; 1305 int fail = 0; 1306 1307 buffer_init(&b); 1308 buffer_append(&b, data, datalen); 1309 1310 if (datafellows & SSH_OLD_SESSIONID) { 1311 p = buffer_ptr(&b); 1312 len = buffer_len(&b); 1313 if ((session_id2 == NULL) || 1314 (len < session_id2_len) || 1315 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1316 fail++; 1317 buffer_consume(&b, session_id2_len); 1318 } else { 1319 p = buffer_get_string(&b, &len); 1320 if ((session_id2 == NULL) || 1321 (len != session_id2_len) || 1322 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1323 fail++; 1324 free(p); 1325 } 1326 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1327 fail++; 1328 cp = buffer_get_cstring(&b, NULL); 1329 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1330 authctxt->style ? ":" : "", 1331 authctxt->style ? authctxt->style : ""); 1332 if (strcmp(userstyle, cp) != 0) { 1333 logit("wrong user name passed to monitor: " 1334 "expected %s != %.100s", userstyle, cp); 1335 fail++; 1336 } 1337 free(userstyle); 1338 free(cp); 1339 buffer_skip_string(&b); 1340 if (datafellows & SSH_BUG_PKAUTH) { 1341 if (!buffer_get_char(&b)) 1342 fail++; 1343 } else { 1344 cp = buffer_get_cstring(&b, NULL); 1345 if (strcmp("publickey", cp) != 0) 1346 fail++; 1347 free(cp); 1348 if (!buffer_get_char(&b)) 1349 fail++; 1350 buffer_skip_string(&b); 1351 } 1352 buffer_skip_string(&b); 1353 if (buffer_len(&b) != 0) 1354 fail++; 1355 buffer_free(&b); 1356 return (fail == 0); 1357 } 1358 1359 static int 1360 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1361 char *chost) 1362 { 1363 Buffer b; 1364 char *p, *userstyle; 1365 u_int len; 1366 int fail = 0; 1367 1368 buffer_init(&b); 1369 buffer_append(&b, data, datalen); 1370 1371 p = buffer_get_string(&b, &len); 1372 if ((session_id2 == NULL) || 1373 (len != session_id2_len) || 1374 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1375 fail++; 1376 free(p); 1377 1378 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1379 fail++; 1380 p = buffer_get_cstring(&b, NULL); 1381 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1382 authctxt->style ? ":" : "", 1383 authctxt->style ? authctxt->style : ""); 1384 if (strcmp(userstyle, p) != 0) { 1385 logit("wrong user name passed to monitor: expected %s != %.100s", 1386 userstyle, p); 1387 fail++; 1388 } 1389 free(userstyle); 1390 free(p); 1391 buffer_skip_string(&b); /* service */ 1392 p = buffer_get_cstring(&b, NULL); 1393 if (strcmp(p, "hostbased") != 0) 1394 fail++; 1395 free(p); 1396 buffer_skip_string(&b); /* pkalg */ 1397 buffer_skip_string(&b); /* pkblob */ 1398 1399 /* verify client host, strip trailing dot if necessary */ 1400 p = buffer_get_string(&b, NULL); 1401 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1402 p[len - 1] = '\0'; 1403 if (strcmp(p, chost) != 0) 1404 fail++; 1405 free(p); 1406 1407 /* verify client user */ 1408 p = buffer_get_string(&b, NULL); 1409 if (strcmp(p, cuser) != 0) 1410 fail++; 1411 free(p); 1412 1413 if (buffer_len(&b) != 0) 1414 fail++; 1415 buffer_free(&b); 1416 return (fail == 0); 1417 } 1418 1419 int 1420 mm_answer_keyverify(int sock, Buffer *m) 1421 { 1422 Key *key; 1423 u_char *signature, *data, *blob; 1424 u_int signaturelen, datalen, bloblen; 1425 int verified = 0; 1426 int valid_data = 0; 1427 1428 blob = buffer_get_string(m, &bloblen); 1429 signature = buffer_get_string(m, &signaturelen); 1430 data = buffer_get_string(m, &datalen); 1431 1432 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1433 !monitor_allowed_key(blob, bloblen)) 1434 fatal("%s: bad key, not previously allowed", __func__); 1435 1436 key = key_from_blob(blob, bloblen); 1437 if (key == NULL) 1438 fatal("%s: bad public key blob", __func__); 1439 1440 switch (key_blobtype) { 1441 case MM_USERKEY: 1442 valid_data = monitor_valid_userblob(data, datalen); 1443 break; 1444 case MM_HOSTKEY: 1445 valid_data = monitor_valid_hostbasedblob(data, datalen, 1446 hostbased_cuser, hostbased_chost); 1447 break; 1448 default: 1449 valid_data = 0; 1450 break; 1451 } 1452 if (!valid_data) 1453 fatal("%s: bad signature data blob", __func__); 1454 1455 verified = key_verify(key, signature, signaturelen, data, datalen); 1456 debug3("%s: key %p signature %s", 1457 __func__, key, (verified == 1) ? "verified" : "unverified"); 1458 1459 /* If auth was successful then record key to ensure it isn't reused */ 1460 if (verified == 1 && key_blobtype == MM_USERKEY) 1461 auth2_record_userkey(authctxt, key); 1462 else 1463 key_free(key); 1464 1465 free(blob); 1466 free(signature); 1467 free(data); 1468 1469 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1470 1471 monitor_reset_key_state(); 1472 1473 buffer_clear(m); 1474 buffer_put_int(m, verified); 1475 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1476 1477 return (verified == 1); 1478 } 1479 1480 static void 1481 mm_record_login(Session *s, struct passwd *pw) 1482 { 1483 struct ssh *ssh = active_state; /* XXX */ 1484 socklen_t fromlen; 1485 struct sockaddr_storage from; 1486 1487 if (options.use_login) 1488 return; 1489 1490 /* 1491 * Get IP address of client. If the connection is not a socket, let 1492 * the address be 0.0.0.0. 1493 */ 1494 memset(&from, 0, sizeof(from)); 1495 fromlen = sizeof(from); 1496 if (packet_connection_is_on_socket()) { 1497 if (getpeername(packet_get_connection_in(), 1498 (struct sockaddr *)&from, &fromlen) < 0) { 1499 debug("getpeername: %.100s", strerror(errno)); 1500 cleanup_exit(255); 1501 } 1502 } 1503 /* Record that there was a login on that tty from the remote host. */ 1504 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1505 session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns), 1506 (struct sockaddr *)&from, fromlen); 1507 } 1508 1509 static void 1510 mm_session_close(Session *s) 1511 { 1512 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1513 if (s->ttyfd != -1) { 1514 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1515 session_pty_cleanup2(s); 1516 } 1517 session_unused(s->self); 1518 } 1519 1520 int 1521 mm_answer_pty(int sock, Buffer *m) 1522 { 1523 extern struct monitor *pmonitor; 1524 Session *s; 1525 int res, fd0; 1526 1527 debug3("%s entering", __func__); 1528 1529 buffer_clear(m); 1530 s = session_new(); 1531 if (s == NULL) 1532 goto error; 1533 s->authctxt = authctxt; 1534 s->pw = authctxt->pw; 1535 s->pid = pmonitor->m_pid; 1536 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1537 if (res == 0) 1538 goto error; 1539 pty_setowner(authctxt->pw, s->tty); 1540 1541 buffer_put_int(m, 1); 1542 buffer_put_cstring(m, s->tty); 1543 1544 /* We need to trick ttyslot */ 1545 if (dup2(s->ttyfd, 0) == -1) 1546 fatal("%s: dup2", __func__); 1547 1548 mm_record_login(s, authctxt->pw); 1549 1550 /* Now we can close the file descriptor again */ 1551 close(0); 1552 1553 /* send messages generated by record_login */ 1554 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1555 buffer_clear(&loginmsg); 1556 1557 mm_request_send(sock, MONITOR_ANS_PTY, m); 1558 1559 if (mm_send_fd(sock, s->ptyfd) == -1 || 1560 mm_send_fd(sock, s->ttyfd) == -1) 1561 fatal("%s: send fds failed", __func__); 1562 1563 /* make sure nothing uses fd 0 */ 1564 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1565 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1566 if (fd0 != 0) 1567 error("%s: fd0 %d != 0", __func__, fd0); 1568 1569 /* slave is not needed */ 1570 close(s->ttyfd); 1571 s->ttyfd = s->ptyfd; 1572 /* no need to dup() because nobody closes ptyfd */ 1573 s->ptymaster = s->ptyfd; 1574 1575 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1576 1577 return (0); 1578 1579 error: 1580 if (s != NULL) 1581 mm_session_close(s); 1582 buffer_put_int(m, 0); 1583 mm_request_send(sock, MONITOR_ANS_PTY, m); 1584 return (0); 1585 } 1586 1587 int 1588 mm_answer_pty_cleanup(int sock, Buffer *m) 1589 { 1590 Session *s; 1591 char *tty; 1592 1593 debug3("%s entering", __func__); 1594 1595 tty = buffer_get_string(m, NULL); 1596 if ((s = session_by_tty(tty)) != NULL) 1597 mm_session_close(s); 1598 buffer_clear(m); 1599 free(tty); 1600 return (0); 1601 } 1602 1603 #ifdef WITH_SSH1 1604 int 1605 mm_answer_sesskey(int sock, Buffer *m) 1606 { 1607 BIGNUM *p; 1608 int rsafail; 1609 1610 /* Turn off permissions */ 1611 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1612 1613 if ((p = BN_new()) == NULL) 1614 fatal("%s: BN_new", __func__); 1615 1616 buffer_get_bignum2(m, p); 1617 1618 rsafail = ssh1_session_key(p); 1619 1620 buffer_clear(m); 1621 buffer_put_int(m, rsafail); 1622 buffer_put_bignum2(m, p); 1623 1624 BN_clear_free(p); 1625 1626 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1627 1628 /* Turn on permissions for sessid passing */ 1629 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1630 1631 return (0); 1632 } 1633 1634 int 1635 mm_answer_sessid(int sock, Buffer *m) 1636 { 1637 int i; 1638 1639 debug3("%s entering", __func__); 1640 1641 if (buffer_len(m) != 16) 1642 fatal("%s: bad ssh1 session id", __func__); 1643 for (i = 0; i < 16; i++) 1644 session_id[i] = buffer_get_char(m); 1645 1646 /* Turn on permissions for getpwnam */ 1647 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1648 1649 return (0); 1650 } 1651 1652 int 1653 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1654 { 1655 BIGNUM *client_n; 1656 Key *key = NULL; 1657 u_char *blob = NULL; 1658 u_int blen = 0; 1659 int allowed = 0; 1660 1661 debug3("%s entering", __func__); 1662 1663 auth_method = "rsa"; 1664 if (options.rsa_authentication && authctxt->valid) { 1665 if ((client_n = BN_new()) == NULL) 1666 fatal("%s: BN_new", __func__); 1667 buffer_get_bignum2(m, client_n); 1668 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1669 BN_clear_free(client_n); 1670 } 1671 buffer_clear(m); 1672 buffer_put_int(m, allowed); 1673 buffer_put_int(m, forced_command != NULL); 1674 1675 /* clear temporarily storage (used by generate challenge) */ 1676 monitor_reset_key_state(); 1677 1678 if (allowed && key != NULL) { 1679 key->type = KEY_RSA; /* cheat for key_to_blob */ 1680 if (key_to_blob(key, &blob, &blen) == 0) 1681 fatal("%s: key_to_blob failed", __func__); 1682 buffer_put_string(m, blob, blen); 1683 1684 /* Save temporarily for comparison in verify */ 1685 key_blob = blob; 1686 key_bloblen = blen; 1687 key_blobtype = MM_RSAUSERKEY; 1688 } 1689 if (key != NULL) 1690 key_free(key); 1691 1692 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1693 1694 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1695 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1696 return (0); 1697 } 1698 1699 int 1700 mm_answer_rsa_challenge(int sock, Buffer *m) 1701 { 1702 Key *key = NULL; 1703 u_char *blob; 1704 u_int blen; 1705 1706 debug3("%s entering", __func__); 1707 1708 if (!authctxt->valid) 1709 fatal("%s: authctxt not valid", __func__); 1710 blob = buffer_get_string(m, &blen); 1711 if (!monitor_allowed_key(blob, blen)) 1712 fatal("%s: bad key, not previously allowed", __func__); 1713 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1714 fatal("%s: key type mismatch", __func__); 1715 if ((key = key_from_blob(blob, blen)) == NULL) 1716 fatal("%s: received bad key", __func__); 1717 if (key->type != KEY_RSA) 1718 fatal("%s: received bad key type %d", __func__, key->type); 1719 key->type = KEY_RSA1; 1720 if (ssh1_challenge) 1721 BN_clear_free(ssh1_challenge); 1722 ssh1_challenge = auth_rsa_generate_challenge(key); 1723 1724 buffer_clear(m); 1725 buffer_put_bignum2(m, ssh1_challenge); 1726 1727 debug3("%s sending reply", __func__); 1728 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1729 1730 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1731 1732 free(blob); 1733 key_free(key); 1734 return (0); 1735 } 1736 1737 int 1738 mm_answer_rsa_response(int sock, Buffer *m) 1739 { 1740 Key *key = NULL; 1741 u_char *blob, *response; 1742 u_int blen, len; 1743 int success; 1744 1745 debug3("%s entering", __func__); 1746 1747 if (!authctxt->valid) 1748 fatal("%s: authctxt not valid", __func__); 1749 if (ssh1_challenge == NULL) 1750 fatal("%s: no ssh1_challenge", __func__); 1751 1752 blob = buffer_get_string(m, &blen); 1753 if (!monitor_allowed_key(blob, blen)) 1754 fatal("%s: bad key, not previously allowed", __func__); 1755 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1756 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1757 if ((key = key_from_blob(blob, blen)) == NULL) 1758 fatal("%s: received bad key", __func__); 1759 response = buffer_get_string(m, &len); 1760 if (len != 16) 1761 fatal("%s: received bad response to challenge", __func__); 1762 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1763 1764 free(blob); 1765 key_free(key); 1766 free(response); 1767 1768 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1769 1770 /* reset state */ 1771 BN_clear_free(ssh1_challenge); 1772 ssh1_challenge = NULL; 1773 monitor_reset_key_state(); 1774 1775 buffer_clear(m); 1776 buffer_put_int(m, success); 1777 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1778 1779 return (success); 1780 } 1781 #endif 1782 1783 int 1784 mm_answer_term(int sock, Buffer *req) 1785 { 1786 extern struct monitor *pmonitor; 1787 int res, status; 1788 1789 debug3("%s: tearing down sessions", __func__); 1790 1791 /* The child is terminating */ 1792 session_destroy_all(&mm_session_close); 1793 1794 #ifdef USE_PAM 1795 if (options.use_pam) 1796 sshpam_cleanup(); 1797 #endif 1798 1799 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1800 if (errno != EINTR) 1801 exit(1); 1802 1803 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1804 1805 /* Terminate process */ 1806 exit(res); 1807 } 1808 1809 #ifdef SSH_AUDIT_EVENTS 1810 /* Report that an audit event occurred */ 1811 int 1812 mm_answer_audit_event(int socket, Buffer *m) 1813 { 1814 ssh_audit_event_t event; 1815 1816 debug3("%s entering", __func__); 1817 1818 event = buffer_get_int(m); 1819 switch(event) { 1820 case SSH_AUTH_FAIL_PUBKEY: 1821 case SSH_AUTH_FAIL_HOSTBASED: 1822 case SSH_AUTH_FAIL_GSSAPI: 1823 case SSH_LOGIN_EXCEED_MAXTRIES: 1824 case SSH_LOGIN_ROOT_DENIED: 1825 case SSH_CONNECTION_CLOSE: 1826 case SSH_INVALID_USER: 1827 audit_event(event); 1828 break; 1829 default: 1830 fatal("Audit event type %d not permitted", event); 1831 } 1832 1833 return (0); 1834 } 1835 1836 int 1837 mm_answer_audit_command(int socket, Buffer *m) 1838 { 1839 u_int len; 1840 char *cmd; 1841 1842 debug3("%s entering", __func__); 1843 cmd = buffer_get_string(m, &len); 1844 /* sanity check command, if so how? */ 1845 audit_run_command(cmd); 1846 free(cmd); 1847 return (0); 1848 } 1849 #endif /* SSH_AUDIT_EVENTS */ 1850 1851 void 1852 monitor_apply_keystate(struct monitor *pmonitor) 1853 { 1854 struct ssh *ssh = active_state; /* XXX */ 1855 struct kex *kex; 1856 int r; 1857 1858 debug3("%s: packet_set_state", __func__); 1859 if ((r = ssh_packet_set_state(ssh, child_state)) != 0) 1860 fatal("%s: packet_set_state: %s", __func__, ssh_err(r)); 1861 sshbuf_free(child_state); 1862 child_state = NULL; 1863 1864 if ((kex = ssh->kex) != NULL) { 1865 /* XXX set callbacks */ 1866 #ifdef WITH_OPENSSL 1867 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1868 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1869 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server; 1870 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server; 1871 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server; 1872 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1873 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1874 # ifdef OPENSSL_HAS_ECC 1875 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1876 # endif 1877 #endif /* WITH_OPENSSL */ 1878 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1879 kex->load_host_public_key=&get_hostkey_public_by_type; 1880 kex->load_host_private_key=&get_hostkey_private_by_type; 1881 kex->host_key_index=&get_hostkey_index; 1882 kex->sign = sshd_hostkey_sign; 1883 } 1884 1885 /* Update with new address */ 1886 if (options.compression) { 1887 ssh_packet_set_compress_hooks(ssh, pmonitor->m_zlib, 1888 (ssh_packet_comp_alloc_func *)mm_zalloc, 1889 (ssh_packet_comp_free_func *)mm_zfree); 1890 } 1891 } 1892 1893 /* This function requries careful sanity checking */ 1894 1895 void 1896 mm_get_keystate(struct monitor *pmonitor) 1897 { 1898 debug3("%s: Waiting for new keys", __func__); 1899 1900 if ((child_state = sshbuf_new()) == NULL) 1901 fatal("%s: sshbuf_new failed", __func__); 1902 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, 1903 child_state); 1904 debug3("%s: GOT new keys", __func__); 1905 } 1906 1907 1908 /* XXX */ 1909 1910 #define FD_CLOSEONEXEC(x) do { \ 1911 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1912 fatal("fcntl(%d, F_SETFD)", x); \ 1913 } while (0) 1914 1915 static void 1916 monitor_openfds(struct monitor *mon, int do_logfds) 1917 { 1918 int pair[2]; 1919 1920 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1921 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1922 FD_CLOSEONEXEC(pair[0]); 1923 FD_CLOSEONEXEC(pair[1]); 1924 mon->m_recvfd = pair[0]; 1925 mon->m_sendfd = pair[1]; 1926 1927 if (do_logfds) { 1928 if (pipe(pair) == -1) 1929 fatal("%s: pipe: %s", __func__, strerror(errno)); 1930 FD_CLOSEONEXEC(pair[0]); 1931 FD_CLOSEONEXEC(pair[1]); 1932 mon->m_log_recvfd = pair[0]; 1933 mon->m_log_sendfd = pair[1]; 1934 } else 1935 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1936 } 1937 1938 #define MM_MEMSIZE 65536 1939 1940 struct monitor * 1941 monitor_init(void) 1942 { 1943 struct ssh *ssh = active_state; /* XXX */ 1944 struct monitor *mon; 1945 1946 mon = xcalloc(1, sizeof(*mon)); 1947 1948 monitor_openfds(mon, 1); 1949 1950 /* Used to share zlib space across processes */ 1951 if (options.compression) { 1952 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1953 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1954 1955 /* Compression needs to share state across borders */ 1956 ssh_packet_set_compress_hooks(ssh, mon->m_zlib, 1957 (ssh_packet_comp_alloc_func *)mm_zalloc, 1958 (ssh_packet_comp_free_func *)mm_zfree); 1959 } 1960 1961 return mon; 1962 } 1963 1964 void 1965 monitor_reinit(struct monitor *mon) 1966 { 1967 monitor_openfds(mon, 0); 1968 } 1969 1970 #ifdef GSSAPI 1971 int 1972 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1973 { 1974 gss_OID_desc goid; 1975 OM_uint32 major; 1976 u_int len; 1977 1978 goid.elements = buffer_get_string(m, &len); 1979 goid.length = len; 1980 1981 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1982 1983 free(goid.elements); 1984 1985 buffer_clear(m); 1986 buffer_put_int(m, major); 1987 1988 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1989 1990 /* Now we have a context, enable the step */ 1991 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1992 1993 return (0); 1994 } 1995 1996 int 1997 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1998 { 1999 gss_buffer_desc in; 2000 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2001 OM_uint32 major, minor; 2002 OM_uint32 flags = 0; /* GSI needs this */ 2003 u_int len; 2004 2005 in.value = buffer_get_string(m, &len); 2006 in.length = len; 2007 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2008 free(in.value); 2009 2010 buffer_clear(m); 2011 buffer_put_int(m, major); 2012 buffer_put_string(m, out.value, out.length); 2013 buffer_put_int(m, flags); 2014 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2015 2016 gss_release_buffer(&minor, &out); 2017 2018 if (major == GSS_S_COMPLETE) { 2019 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2020 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2021 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2022 } 2023 return (0); 2024 } 2025 2026 int 2027 mm_answer_gss_checkmic(int sock, Buffer *m) 2028 { 2029 gss_buffer_desc gssbuf, mic; 2030 OM_uint32 ret; 2031 u_int len; 2032 2033 gssbuf.value = buffer_get_string(m, &len); 2034 gssbuf.length = len; 2035 mic.value = buffer_get_string(m, &len); 2036 mic.length = len; 2037 2038 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2039 2040 free(gssbuf.value); 2041 free(mic.value); 2042 2043 buffer_clear(m); 2044 buffer_put_int(m, ret); 2045 2046 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2047 2048 if (!GSS_ERROR(ret)) 2049 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2050 2051 return (0); 2052 } 2053 2054 int 2055 mm_answer_gss_userok(int sock, Buffer *m) 2056 { 2057 int authenticated; 2058 2059 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2060 2061 buffer_clear(m); 2062 buffer_put_int(m, authenticated); 2063 2064 debug3("%s: sending result %d", __func__, authenticated); 2065 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2066 2067 auth_method = "gssapi-with-mic"; 2068 2069 /* Monitor loop will terminate if authenticated */ 2070 return (authenticated); 2071 } 2072 #endif /* GSSAPI */ 2073 2074