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