1 /* $OpenBSD: monitor.c,v 1.135 2014/07/15 15:54:14 millert 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 <stdlib.h> 44 #include <string.h> 45 #include <stdarg.h> 46 #include <stdio.h> 47 #include <unistd.h> 48 #ifdef HAVE_POLL_H 49 #include <poll.h> 50 #else 51 # ifdef HAVE_SYS_POLL_H 52 # include <sys/poll.h> 53 # endif 54 #endif 55 56 #ifdef SKEY 57 #include <skey.h> 58 #endif 59 60 #ifdef WITH_OPENSSL 61 #include <openssl/dh.h> 62 #endif 63 64 #include "openbsd-compat/sys-queue.h" 65 #include "atomicio.h" 66 #include "xmalloc.h" 67 #include "ssh.h" 68 #include "key.h" 69 #include "buffer.h" 70 #include "hostfile.h" 71 #include "auth.h" 72 #include "cipher.h" 73 #include "kex.h" 74 #include "dh.h" 75 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 76 #undef TARGET_OS_MAC 77 #include "zlib.h" 78 #define TARGET_OS_MAC 1 79 #else 80 #include "zlib.h" 81 #endif 82 #include "packet.h" 83 #include "auth-options.h" 84 #include "sshpty.h" 85 #include "channels.h" 86 #include "session.h" 87 #include "sshlogin.h" 88 #include "canohost.h" 89 #include "log.h" 90 #include "misc.h" 91 #include "servconf.h" 92 #include "monitor.h" 93 #include "monitor_mm.h" 94 #ifdef GSSAPI 95 #include "ssh-gss.h" 96 #endif 97 #include "monitor_wrap.h" 98 #include "monitor_fdpass.h" 99 #include "compat.h" 100 #include "ssh2.h" 101 #include "roaming.h" 102 #include "authfd.h" 103 104 #ifdef GSSAPI 105 static Gssctxt *gsscontext = NULL; 106 #endif 107 108 /* Imports */ 109 extern ServerOptions options; 110 extern u_int utmp_len; 111 extern Newkeys *current_keys[]; 112 extern z_stream incoming_stream; 113 extern z_stream outgoing_stream; 114 extern u_char session_id[]; 115 extern Buffer auth_debug; 116 extern int auth_debug_init; 117 extern Buffer loginmsg; 118 119 /* State exported from the child */ 120 121 struct { 122 z_stream incoming; 123 z_stream outgoing; 124 u_char *keyin; 125 u_int keyinlen; 126 u_char *keyout; 127 u_int keyoutlen; 128 u_char *ivin; 129 u_int ivinlen; 130 u_char *ivout; 131 u_int ivoutlen; 132 u_char *ssh1key; 133 u_int ssh1keylen; 134 int ssh1cipher; 135 int ssh1protoflags; 136 u_char *input; 137 u_int ilen; 138 u_char *output; 139 u_int olen; 140 u_int64_t sent_bytes; 141 u_int64_t recv_bytes; 142 } child_state; 143 144 /* Functions on the monitor that answer unprivileged requests */ 145 146 int mm_answer_moduli(int, Buffer *); 147 int mm_answer_sign(int, Buffer *); 148 int mm_answer_pwnamallow(int, Buffer *); 149 int mm_answer_auth2_read_banner(int, Buffer *); 150 int mm_answer_authserv(int, Buffer *); 151 int mm_answer_authpassword(int, Buffer *); 152 int mm_answer_bsdauthquery(int, Buffer *); 153 int mm_answer_bsdauthrespond(int, Buffer *); 154 int mm_answer_skeyquery(int, Buffer *); 155 int mm_answer_skeyrespond(int, Buffer *); 156 int mm_answer_keyallowed(int, Buffer *); 157 int mm_answer_keyverify(int, Buffer *); 158 int mm_answer_pty(int, Buffer *); 159 int mm_answer_pty_cleanup(int, Buffer *); 160 int mm_answer_term(int, Buffer *); 161 int mm_answer_rsa_keyallowed(int, Buffer *); 162 int mm_answer_rsa_challenge(int, Buffer *); 163 int mm_answer_rsa_response(int, Buffer *); 164 int mm_answer_sesskey(int, Buffer *); 165 int mm_answer_sessid(int, Buffer *); 166 167 #ifdef USE_PAM 168 int mm_answer_pam_start(int, Buffer *); 169 int mm_answer_pam_account(int, Buffer *); 170 int mm_answer_pam_init_ctx(int, Buffer *); 171 int mm_answer_pam_query(int, Buffer *); 172 int mm_answer_pam_respond(int, Buffer *); 173 int mm_answer_pam_free_ctx(int, Buffer *); 174 #endif 175 176 #ifdef GSSAPI 177 int mm_answer_gss_setup_ctx(int, Buffer *); 178 int mm_answer_gss_accept_ctx(int, Buffer *); 179 int mm_answer_gss_userok(int, Buffer *); 180 int mm_answer_gss_checkmic(int, Buffer *); 181 #endif 182 183 #ifdef SSH_AUDIT_EVENTS 184 int mm_answer_audit_event(int, Buffer *); 185 int mm_answer_audit_command(int, Buffer *); 186 #endif 187 188 static int monitor_read_log(struct monitor *); 189 190 static Authctxt *authctxt; 191 192 #ifdef WITH_SSH1 193 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 194 #endif 195 196 /* local state for key verify */ 197 static u_char *key_blob = NULL; 198 static u_int key_bloblen = 0; 199 static int key_blobtype = MM_NOKEY; 200 static char *hostbased_cuser = NULL; 201 static char *hostbased_chost = NULL; 202 static char *auth_method = "unknown"; 203 static char *auth_submethod = NULL; 204 static u_int session_id2_len = 0; 205 static u_char *session_id2 = NULL; 206 static pid_t monitor_child_pid; 207 208 struct mon_table { 209 enum monitor_reqtype type; 210 int flags; 211 int (*f)(int, Buffer *); 212 }; 213 214 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 215 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 216 #define MON_ONCE 0x0010 /* Disable after calling */ 217 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 218 219 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 220 221 #define MON_PERMIT 0x1000 /* Request is permitted */ 222 223 struct mon_table mon_dispatch_proto20[] = { 224 #ifdef WITH_OPENSSL 225 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 226 #endif 227 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 228 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 229 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 230 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 231 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 232 #ifdef USE_PAM 233 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 234 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 235 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 236 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 237 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 238 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 239 #endif 240 #ifdef SSH_AUDIT_EVENTS 241 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 242 #endif 243 #ifdef BSD_AUTH 244 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 245 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 246 #endif 247 #ifdef SKEY 248 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 249 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 250 #endif 251 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 252 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 253 #ifdef GSSAPI 254 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 255 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 256 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 257 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 258 #endif 259 {0, 0, NULL} 260 }; 261 262 struct mon_table mon_dispatch_postauth20[] = { 263 #ifdef WITH_OPENSSL 264 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 265 #endif 266 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 267 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 268 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 269 {MONITOR_REQ_TERM, 0, mm_answer_term}, 270 #ifdef SSH_AUDIT_EVENTS 271 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 272 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 273 #endif 274 {0, 0, NULL} 275 }; 276 277 struct mon_table mon_dispatch_proto15[] = { 278 #ifdef WITH_SSH1 279 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 280 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 281 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 282 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 283 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 284 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 285 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 286 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 287 #ifdef BSD_AUTH 288 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 289 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 290 #endif 291 #ifdef SKEY 292 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 293 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 294 #endif 295 #ifdef USE_PAM 296 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 297 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 298 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 299 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 300 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 301 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 302 #endif 303 #ifdef SSH_AUDIT_EVENTS 304 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 305 #endif 306 #endif /* WITH_SSH1 */ 307 {0, 0, NULL} 308 }; 309 310 struct mon_table mon_dispatch_postauth15[] = { 311 #ifdef WITH_SSH1 312 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 313 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 314 {MONITOR_REQ_TERM, 0, mm_answer_term}, 315 #ifdef SSH_AUDIT_EVENTS 316 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 317 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 318 #endif 319 #endif /* WITH_SSH1 */ 320 {0, 0, NULL} 321 }; 322 323 struct mon_table *mon_dispatch; 324 325 /* Specifies if a certain message is allowed at the moment */ 326 327 static void 328 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 329 { 330 while (ent->f != NULL) { 331 if (ent->type == type) { 332 ent->flags &= ~MON_PERMIT; 333 ent->flags |= permit ? MON_PERMIT : 0; 334 return; 335 } 336 ent++; 337 } 338 } 339 340 static void 341 monitor_permit_authentications(int permit) 342 { 343 struct mon_table *ent = mon_dispatch; 344 345 while (ent->f != NULL) { 346 if (ent->flags & MON_AUTH) { 347 ent->flags &= ~MON_PERMIT; 348 ent->flags |= permit ? MON_PERMIT : 0; 349 } 350 ent++; 351 } 352 } 353 354 void 355 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 356 { 357 struct mon_table *ent; 358 int authenticated = 0, partial = 0; 359 360 debug3("preauth child monitor started"); 361 362 close(pmonitor->m_recvfd); 363 close(pmonitor->m_log_sendfd); 364 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 365 366 authctxt = _authctxt; 367 memset(authctxt, 0, sizeof(*authctxt)); 368 369 authctxt->loginmsg = &loginmsg; 370 371 if (compat20) { 372 mon_dispatch = mon_dispatch_proto20; 373 374 /* Permit requests for moduli and signatures */ 375 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 376 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 377 } else { 378 mon_dispatch = mon_dispatch_proto15; 379 380 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 381 } 382 383 /* The first few requests do not require asynchronous access */ 384 while (!authenticated) { 385 partial = 0; 386 auth_method = "unknown"; 387 auth_submethod = NULL; 388 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 389 390 /* Special handling for multiple required authentications */ 391 if (options.num_auth_methods != 0) { 392 if (!compat20) 393 fatal("AuthenticationMethods is not supported" 394 "with SSH protocol 1"); 395 if (authenticated && 396 !auth2_update_methods_lists(authctxt, 397 auth_method, auth_submethod)) { 398 debug3("%s: method %s: partial", __func__, 399 auth_method); 400 authenticated = 0; 401 partial = 1; 402 } 403 } 404 405 if (authenticated) { 406 if (!(ent->flags & MON_AUTHDECIDE)) 407 fatal("%s: unexpected authentication from %d", 408 __func__, ent->type); 409 if (authctxt->pw->pw_uid == 0 && 410 !auth_root_allowed(auth_method)) 411 authenticated = 0; 412 #ifdef USE_PAM 413 /* PAM needs to perform account checks after auth */ 414 if (options.use_pam && authenticated) { 415 Buffer m; 416 417 buffer_init(&m); 418 mm_request_receive_expect(pmonitor->m_sendfd, 419 MONITOR_REQ_PAM_ACCOUNT, &m); 420 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 421 buffer_free(&m); 422 } 423 #endif 424 } 425 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 426 auth_log(authctxt, authenticated, partial, 427 auth_method, auth_submethod); 428 if (!authenticated) 429 authctxt->failures++; 430 } 431 } 432 433 if (!authctxt->valid) 434 fatal("%s: authenticated invalid user", __func__); 435 if (strcmp(auth_method, "unknown") == 0) 436 fatal("%s: authentication method name unknown", __func__); 437 438 debug("%s: %s has been authenticated by privileged process", 439 __func__, authctxt->user); 440 441 mm_get_keystate(pmonitor); 442 443 /* Drain any buffered messages from the child */ 444 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 445 ; 446 447 close(pmonitor->m_sendfd); 448 close(pmonitor->m_log_recvfd); 449 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 450 } 451 452 static void 453 monitor_set_child_handler(pid_t pid) 454 { 455 monitor_child_pid = pid; 456 } 457 458 static void 459 monitor_child_handler(int sig) 460 { 461 kill(monitor_child_pid, sig); 462 } 463 464 void 465 monitor_child_postauth(struct monitor *pmonitor) 466 { 467 close(pmonitor->m_recvfd); 468 pmonitor->m_recvfd = -1; 469 470 monitor_set_child_handler(pmonitor->m_pid); 471 signal(SIGHUP, &monitor_child_handler); 472 signal(SIGTERM, &monitor_child_handler); 473 signal(SIGINT, &monitor_child_handler); 474 #ifdef SIGXFSZ 475 signal(SIGXFSZ, SIG_IGN); 476 #endif 477 478 if (compat20) { 479 mon_dispatch = mon_dispatch_postauth20; 480 481 /* Permit requests for moduli and signatures */ 482 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 483 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 484 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 485 } else { 486 mon_dispatch = mon_dispatch_postauth15; 487 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 488 } 489 if (!no_pty_flag) { 490 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 491 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 492 } 493 494 for (;;) 495 monitor_read(pmonitor, mon_dispatch, NULL); 496 } 497 498 void 499 monitor_sync(struct monitor *pmonitor) 500 { 501 if (options.compression) { 502 /* The member allocation is not visible, so sync it */ 503 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 504 } 505 } 506 507 static int 508 monitor_read_log(struct monitor *pmonitor) 509 { 510 Buffer logmsg; 511 u_int len, level; 512 char *msg; 513 514 buffer_init(&logmsg); 515 516 /* Read length */ 517 buffer_append_space(&logmsg, 4); 518 if (atomicio(read, pmonitor->m_log_recvfd, 519 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 520 if (errno == EPIPE) { 521 buffer_free(&logmsg); 522 debug("%s: child log fd closed", __func__); 523 close(pmonitor->m_log_recvfd); 524 pmonitor->m_log_recvfd = -1; 525 return -1; 526 } 527 fatal("%s: log fd read: %s", __func__, strerror(errno)); 528 } 529 len = buffer_get_int(&logmsg); 530 if (len <= 4 || len > 8192) 531 fatal("%s: invalid log message length %u", __func__, len); 532 533 /* Read severity, message */ 534 buffer_clear(&logmsg); 535 buffer_append_space(&logmsg, len); 536 if (atomicio(read, pmonitor->m_log_recvfd, 537 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 538 fatal("%s: log fd read: %s", __func__, strerror(errno)); 539 540 /* Log it */ 541 level = buffer_get_int(&logmsg); 542 msg = buffer_get_string(&logmsg, NULL); 543 if (log_level_name(level) == NULL) 544 fatal("%s: invalid log level %u (corrupted message?)", 545 __func__, level); 546 do_log2(level, "%s [preauth]", msg); 547 548 buffer_free(&logmsg); 549 free(msg); 550 551 return 0; 552 } 553 554 int 555 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 556 struct mon_table **pent) 557 { 558 Buffer m; 559 int ret; 560 u_char type; 561 struct pollfd pfd[2]; 562 563 for (;;) { 564 memset(&pfd, 0, sizeof(pfd)); 565 pfd[0].fd = pmonitor->m_sendfd; 566 pfd[0].events = POLLIN; 567 pfd[1].fd = pmonitor->m_log_recvfd; 568 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 569 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 570 if (errno == EINTR || errno == EAGAIN) 571 continue; 572 fatal("%s: poll: %s", __func__, strerror(errno)); 573 } 574 if (pfd[1].revents) { 575 /* 576 * Drain all log messages before processing next 577 * monitor request. 578 */ 579 monitor_read_log(pmonitor); 580 continue; 581 } 582 if (pfd[0].revents) 583 break; /* Continues below */ 584 } 585 586 buffer_init(&m); 587 588 mm_request_receive(pmonitor->m_sendfd, &m); 589 type = buffer_get_char(&m); 590 591 debug3("%s: checking request %d", __func__, type); 592 593 while (ent->f != NULL) { 594 if (ent->type == type) 595 break; 596 ent++; 597 } 598 599 if (ent->f != NULL) { 600 if (!(ent->flags & MON_PERMIT)) 601 fatal("%s: unpermitted request %d", __func__, 602 type); 603 ret = (*ent->f)(pmonitor->m_sendfd, &m); 604 buffer_free(&m); 605 606 /* The child may use this request only once, disable it */ 607 if (ent->flags & MON_ONCE) { 608 debug2("%s: %d used once, disabling now", __func__, 609 type); 610 ent->flags &= ~MON_PERMIT; 611 } 612 613 if (pent != NULL) 614 *pent = ent; 615 616 return ret; 617 } 618 619 fatal("%s: unsupported request: %d", __func__, type); 620 621 /* NOTREACHED */ 622 return (-1); 623 } 624 625 /* allowed key state */ 626 static int 627 monitor_allowed_key(u_char *blob, u_int bloblen) 628 { 629 /* make sure key is allowed */ 630 if (key_blob == NULL || key_bloblen != bloblen || 631 timingsafe_bcmp(key_blob, blob, key_bloblen)) 632 return (0); 633 return (1); 634 } 635 636 static void 637 monitor_reset_key_state(void) 638 { 639 /* reset state */ 640 free(key_blob); 641 free(hostbased_cuser); 642 free(hostbased_chost); 643 key_blob = NULL; 644 key_bloblen = 0; 645 key_blobtype = MM_NOKEY; 646 hostbased_cuser = NULL; 647 hostbased_chost = NULL; 648 } 649 650 #ifdef WITH_OPENSSL 651 int 652 mm_answer_moduli(int sock, Buffer *m) 653 { 654 DH *dh; 655 int min, want, max; 656 657 min = buffer_get_int(m); 658 want = buffer_get_int(m); 659 max = buffer_get_int(m); 660 661 debug3("%s: got parameters: %d %d %d", 662 __func__, min, want, max); 663 /* We need to check here, too, in case the child got corrupted */ 664 if (max < min || want < min || max < want) 665 fatal("%s: bad parameters: %d %d %d", 666 __func__, min, want, max); 667 668 buffer_clear(m); 669 670 dh = choose_dh(min, want, max); 671 if (dh == NULL) { 672 buffer_put_char(m, 0); 673 return (0); 674 } else { 675 /* Send first bignum */ 676 buffer_put_char(m, 1); 677 buffer_put_bignum2(m, dh->p); 678 buffer_put_bignum2(m, dh->g); 679 680 DH_free(dh); 681 } 682 mm_request_send(sock, MONITOR_ANS_MODULI, m); 683 return (0); 684 } 685 #endif 686 687 extern AuthenticationConnection *auth_conn; 688 689 int 690 mm_answer_sign(int sock, Buffer *m) 691 { 692 Key *key; 693 u_char *p; 694 u_char *signature; 695 u_int siglen, datlen; 696 int keyid; 697 698 debug3("%s", __func__); 699 700 keyid = buffer_get_int(m); 701 p = buffer_get_string(m, &datlen); 702 703 /* 704 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 705 * SHA384 (48 bytes) and SHA512 (64 bytes). 706 */ 707 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) 708 fatal("%s: data length incorrect: %u", __func__, datlen); 709 710 /* save session id, it will be passed on the first call */ 711 if (session_id2_len == 0) { 712 session_id2_len = datlen; 713 session_id2 = xmalloc(session_id2_len); 714 memcpy(session_id2, p, session_id2_len); 715 } 716 717 if ((key = get_hostkey_by_index(keyid)) != NULL) { 718 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 719 fatal("%s: key_sign failed", __func__); 720 } else if ((key = get_hostkey_public_by_index(keyid)) != NULL && 721 auth_conn != NULL) { 722 if (ssh_agent_sign(auth_conn, key, &signature, &siglen, p, 723 datlen) < 0) 724 fatal("%s: ssh_agent_sign failed", __func__); 725 } else 726 fatal("%s: no hostkey from index %d", __func__, keyid); 727 728 debug3("%s: signature %p(%u)", __func__, signature, siglen); 729 730 buffer_clear(m); 731 buffer_put_string(m, signature, siglen); 732 733 free(p); 734 free(signature); 735 736 mm_request_send(sock, MONITOR_ANS_SIGN, m); 737 738 /* Turn on permissions for getpwnam */ 739 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 740 741 return (0); 742 } 743 744 /* Retrieves the password entry and also checks if the user is permitted */ 745 746 int 747 mm_answer_pwnamallow(int sock, Buffer *m) 748 { 749 char *username; 750 struct passwd *pwent; 751 int allowed = 0; 752 u_int i; 753 754 debug3("%s", __func__); 755 756 if (authctxt->attempt++ != 0) 757 fatal("%s: multiple attempts for getpwnam", __func__); 758 759 username = buffer_get_string(m, NULL); 760 761 pwent = getpwnamallow(username); 762 763 authctxt->user = xstrdup(username); 764 setproctitle("%s [priv]", pwent ? username : "unknown"); 765 free(username); 766 767 buffer_clear(m); 768 769 if (pwent == NULL) { 770 buffer_put_char(m, 0); 771 authctxt->pw = fakepw(); 772 goto out; 773 } 774 775 allowed = 1; 776 authctxt->pw = pwent; 777 authctxt->valid = 1; 778 779 buffer_put_char(m, 1); 780 buffer_put_string(m, pwent, sizeof(struct passwd)); 781 buffer_put_cstring(m, pwent->pw_name); 782 buffer_put_cstring(m, "*"); 783 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 784 buffer_put_cstring(m, pwent->pw_gecos); 785 #endif 786 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 787 buffer_put_cstring(m, pwent->pw_class); 788 #endif 789 buffer_put_cstring(m, pwent->pw_dir); 790 buffer_put_cstring(m, pwent->pw_shell); 791 792 out: 793 buffer_put_string(m, &options, sizeof(options)); 794 795 #define M_CP_STROPT(x) do { \ 796 if (options.x != NULL) \ 797 buffer_put_cstring(m, options.x); \ 798 } while (0) 799 #define M_CP_STRARRAYOPT(x, nx) do { \ 800 for (i = 0; i < options.nx; i++) \ 801 buffer_put_cstring(m, options.x[i]); \ 802 } while (0) 803 /* See comment in servconf.h */ 804 COPY_MATCH_STRING_OPTS(); 805 #undef M_CP_STROPT 806 #undef M_CP_STRARRAYOPT 807 808 /* Create valid auth method lists */ 809 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 810 /* 811 * The monitor will continue long enough to let the child 812 * run to it's packet_disconnect(), but it must not allow any 813 * authentication to succeed. 814 */ 815 debug("%s: no valid authentication method lists", __func__); 816 } 817 818 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 819 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 820 821 /* For SSHv1 allow authentication now */ 822 if (!compat20) 823 monitor_permit_authentications(1); 824 else { 825 /* Allow service/style information on the auth context */ 826 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 827 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 828 } 829 #ifdef USE_PAM 830 if (options.use_pam) 831 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 832 #endif 833 834 return (0); 835 } 836 837 int mm_answer_auth2_read_banner(int sock, Buffer *m) 838 { 839 char *banner; 840 841 buffer_clear(m); 842 banner = auth2_read_banner(); 843 buffer_put_cstring(m, banner != NULL ? banner : ""); 844 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 845 free(banner); 846 847 return (0); 848 } 849 850 int 851 mm_answer_authserv(int sock, Buffer *m) 852 { 853 monitor_permit_authentications(1); 854 855 authctxt->service = buffer_get_string(m, NULL); 856 authctxt->style = buffer_get_string(m, NULL); 857 debug3("%s: service=%s, style=%s", 858 __func__, authctxt->service, authctxt->style); 859 860 if (strlen(authctxt->style) == 0) { 861 free(authctxt->style); 862 authctxt->style = NULL; 863 } 864 865 return (0); 866 } 867 868 int 869 mm_answer_authpassword(int sock, Buffer *m) 870 { 871 static int call_count; 872 char *passwd; 873 int authenticated; 874 u_int plen; 875 876 passwd = buffer_get_string(m, &plen); 877 /* Only authenticate if the context is valid */ 878 authenticated = options.password_authentication && 879 auth_password(authctxt, passwd); 880 explicit_bzero(passwd, strlen(passwd)); 881 free(passwd); 882 883 buffer_clear(m); 884 buffer_put_int(m, authenticated); 885 886 debug3("%s: sending result %d", __func__, authenticated); 887 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 888 889 call_count++; 890 if (plen == 0 && call_count == 1) 891 auth_method = "none"; 892 else 893 auth_method = "password"; 894 895 /* Causes monitor loop to terminate if authenticated */ 896 return (authenticated); 897 } 898 899 #ifdef BSD_AUTH 900 int 901 mm_answer_bsdauthquery(int sock, Buffer *m) 902 { 903 char *name, *infotxt; 904 u_int numprompts; 905 u_int *echo_on; 906 char **prompts; 907 u_int success; 908 909 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 910 &prompts, &echo_on) < 0 ? 0 : 1; 911 912 buffer_clear(m); 913 buffer_put_int(m, success); 914 if (success) 915 buffer_put_cstring(m, prompts[0]); 916 917 debug3("%s: sending challenge success: %u", __func__, success); 918 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 919 920 if (success) { 921 free(name); 922 free(infotxt); 923 free(prompts); 924 free(echo_on); 925 } 926 927 return (0); 928 } 929 930 int 931 mm_answer_bsdauthrespond(int sock, Buffer *m) 932 { 933 char *response; 934 int authok; 935 936 if (authctxt->as == 0) 937 fatal("%s: no bsd auth session", __func__); 938 939 response = buffer_get_string(m, NULL); 940 authok = options.challenge_response_authentication && 941 auth_userresponse(authctxt->as, response, 0); 942 authctxt->as = NULL; 943 debug3("%s: <%s> = <%d>", __func__, response, authok); 944 free(response); 945 946 buffer_clear(m); 947 buffer_put_int(m, authok); 948 949 debug3("%s: sending authenticated: %d", __func__, authok); 950 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 951 952 if (compat20) { 953 auth_method = "keyboard-interactive"; 954 auth_submethod = "bsdauth"; 955 } else 956 auth_method = "bsdauth"; 957 958 return (authok != 0); 959 } 960 #endif 961 962 #ifdef SKEY 963 int 964 mm_answer_skeyquery(int sock, Buffer *m) 965 { 966 struct skey skey; 967 char challenge[1024]; 968 u_int success; 969 970 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 971 sizeof(challenge)) < 0 ? 0 : 1; 972 973 buffer_clear(m); 974 buffer_put_int(m, success); 975 if (success) 976 buffer_put_cstring(m, challenge); 977 978 debug3("%s: sending challenge success: %u", __func__, success); 979 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 980 981 return (0); 982 } 983 984 int 985 mm_answer_skeyrespond(int sock, Buffer *m) 986 { 987 char *response; 988 int authok; 989 990 response = buffer_get_string(m, NULL); 991 992 authok = (options.challenge_response_authentication && 993 authctxt->valid && 994 skey_haskey(authctxt->pw->pw_name) == 0 && 995 skey_passcheck(authctxt->pw->pw_name, response) != -1); 996 997 free(response); 998 999 buffer_clear(m); 1000 buffer_put_int(m, authok); 1001 1002 debug3("%s: sending authenticated: %d", __func__, authok); 1003 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 1004 1005 auth_method = "skey"; 1006 1007 return (authok != 0); 1008 } 1009 #endif 1010 1011 #ifdef USE_PAM 1012 int 1013 mm_answer_pam_start(int sock, Buffer *m) 1014 { 1015 if (!options.use_pam) 1016 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1017 1018 start_pam(authctxt); 1019 1020 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1021 1022 return (0); 1023 } 1024 1025 int 1026 mm_answer_pam_account(int sock, Buffer *m) 1027 { 1028 u_int ret; 1029 1030 if (!options.use_pam) 1031 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1032 1033 ret = do_pam_account(); 1034 1035 buffer_put_int(m, ret); 1036 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1037 1038 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1039 1040 return (ret); 1041 } 1042 1043 static void *sshpam_ctxt, *sshpam_authok; 1044 extern KbdintDevice sshpam_device; 1045 1046 int 1047 mm_answer_pam_init_ctx(int sock, Buffer *m) 1048 { 1049 1050 debug3("%s", __func__); 1051 authctxt->user = buffer_get_string(m, NULL); 1052 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1053 sshpam_authok = NULL; 1054 buffer_clear(m); 1055 if (sshpam_ctxt != NULL) { 1056 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1057 buffer_put_int(m, 1); 1058 } else { 1059 buffer_put_int(m, 0); 1060 } 1061 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1062 return (0); 1063 } 1064 1065 int 1066 mm_answer_pam_query(int sock, Buffer *m) 1067 { 1068 char *name = NULL, *info = NULL, **prompts = NULL; 1069 u_int i, num = 0, *echo_on = 0; 1070 int ret; 1071 1072 debug3("%s", __func__); 1073 sshpam_authok = NULL; 1074 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1075 if (ret == 0 && num == 0) 1076 sshpam_authok = sshpam_ctxt; 1077 if (num > 1 || name == NULL || info == NULL) 1078 ret = -1; 1079 buffer_clear(m); 1080 buffer_put_int(m, ret); 1081 buffer_put_cstring(m, name); 1082 free(name); 1083 buffer_put_cstring(m, info); 1084 free(info); 1085 buffer_put_int(m, num); 1086 for (i = 0; i < num; ++i) { 1087 buffer_put_cstring(m, prompts[i]); 1088 free(prompts[i]); 1089 buffer_put_int(m, echo_on[i]); 1090 } 1091 free(prompts); 1092 free(echo_on); 1093 auth_method = "keyboard-interactive"; 1094 auth_submethod = "pam"; 1095 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1096 return (0); 1097 } 1098 1099 int 1100 mm_answer_pam_respond(int sock, Buffer *m) 1101 { 1102 char **resp; 1103 u_int i, num; 1104 int ret; 1105 1106 debug3("%s", __func__); 1107 sshpam_authok = NULL; 1108 num = buffer_get_int(m); 1109 if (num > 0) { 1110 resp = xcalloc(num, sizeof(char *)); 1111 for (i = 0; i < num; ++i) 1112 resp[i] = buffer_get_string(m, NULL); 1113 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1114 for (i = 0; i < num; ++i) 1115 free(resp[i]); 1116 free(resp); 1117 } else { 1118 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1119 } 1120 buffer_clear(m); 1121 buffer_put_int(m, ret); 1122 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1123 auth_method = "keyboard-interactive"; 1124 auth_submethod = "pam"; 1125 if (ret == 0) 1126 sshpam_authok = sshpam_ctxt; 1127 return (0); 1128 } 1129 1130 int 1131 mm_answer_pam_free_ctx(int sock, Buffer *m) 1132 { 1133 1134 debug3("%s", __func__); 1135 (sshpam_device.free_ctx)(sshpam_ctxt); 1136 buffer_clear(m); 1137 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1138 auth_method = "keyboard-interactive"; 1139 auth_submethod = "pam"; 1140 return (sshpam_authok == sshpam_ctxt); 1141 } 1142 #endif 1143 1144 int 1145 mm_answer_keyallowed(int sock, Buffer *m) 1146 { 1147 Key *key; 1148 char *cuser, *chost; 1149 u_char *blob; 1150 u_int bloblen; 1151 enum mm_keytype type = 0; 1152 int allowed = 0; 1153 1154 debug3("%s entering", __func__); 1155 1156 type = buffer_get_int(m); 1157 cuser = buffer_get_string(m, NULL); 1158 chost = buffer_get_string(m, NULL); 1159 blob = buffer_get_string(m, &bloblen); 1160 1161 key = key_from_blob(blob, bloblen); 1162 1163 if ((compat20 && type == MM_RSAHOSTKEY) || 1164 (!compat20 && type != MM_RSAHOSTKEY)) 1165 fatal("%s: key type and protocol mismatch", __func__); 1166 1167 debug3("%s: key_from_blob: %p", __func__, key); 1168 1169 if (key != NULL && authctxt->valid) { 1170 switch (type) { 1171 case MM_USERKEY: 1172 allowed = options.pubkey_authentication && 1173 user_key_allowed(authctxt->pw, key); 1174 pubkey_auth_info(authctxt, key, NULL); 1175 auth_method = "publickey"; 1176 if (options.pubkey_authentication && allowed != 1) 1177 auth_clear_options(); 1178 break; 1179 case MM_HOSTKEY: 1180 allowed = options.hostbased_authentication && 1181 hostbased_key_allowed(authctxt->pw, 1182 cuser, chost, key); 1183 pubkey_auth_info(authctxt, key, 1184 "client user \"%.100s\", client host \"%.100s\"", 1185 cuser, chost); 1186 auth_method = "hostbased"; 1187 break; 1188 #ifdef WITH_SSH1 1189 case MM_RSAHOSTKEY: 1190 key->type = KEY_RSA1; /* XXX */ 1191 allowed = options.rhosts_rsa_authentication && 1192 auth_rhosts_rsa_key_allowed(authctxt->pw, 1193 cuser, chost, key); 1194 if (options.rhosts_rsa_authentication && allowed != 1) 1195 auth_clear_options(); 1196 auth_method = "rsa"; 1197 break; 1198 #endif 1199 default: 1200 fatal("%s: unknown key type %d", __func__, type); 1201 break; 1202 } 1203 } 1204 if (key != NULL) 1205 key_free(key); 1206 1207 /* clear temporarily storage (used by verify) */ 1208 monitor_reset_key_state(); 1209 1210 if (allowed) { 1211 /* Save temporarily for comparison in verify */ 1212 key_blob = blob; 1213 key_bloblen = bloblen; 1214 key_blobtype = type; 1215 hostbased_cuser = cuser; 1216 hostbased_chost = chost; 1217 } else { 1218 /* Log failed attempt */ 1219 auth_log(authctxt, 0, 0, auth_method, NULL); 1220 free(blob); 1221 free(cuser); 1222 free(chost); 1223 } 1224 1225 debug3("%s: key %p is %s", 1226 __func__, key, allowed ? "allowed" : "not allowed"); 1227 1228 buffer_clear(m); 1229 buffer_put_int(m, allowed); 1230 buffer_put_int(m, forced_command != NULL); 1231 1232 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1233 1234 if (type == MM_RSAHOSTKEY) 1235 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1236 1237 return (0); 1238 } 1239 1240 static int 1241 monitor_valid_userblob(u_char *data, u_int datalen) 1242 { 1243 Buffer b; 1244 char *p, *userstyle; 1245 u_int len; 1246 int fail = 0; 1247 1248 buffer_init(&b); 1249 buffer_append(&b, data, datalen); 1250 1251 if (datafellows & SSH_OLD_SESSIONID) { 1252 p = buffer_ptr(&b); 1253 len = buffer_len(&b); 1254 if ((session_id2 == NULL) || 1255 (len < session_id2_len) || 1256 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1257 fail++; 1258 buffer_consume(&b, session_id2_len); 1259 } else { 1260 p = buffer_get_string(&b, &len); 1261 if ((session_id2 == NULL) || 1262 (len != session_id2_len) || 1263 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1264 fail++; 1265 free(p); 1266 } 1267 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1268 fail++; 1269 p = buffer_get_cstring(&b, NULL); 1270 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1271 authctxt->style ? ":" : "", 1272 authctxt->style ? authctxt->style : ""); 1273 if (strcmp(userstyle, p) != 0) { 1274 logit("wrong user name passed to monitor: expected %s != %.100s", 1275 userstyle, p); 1276 fail++; 1277 } 1278 free(userstyle); 1279 free(p); 1280 buffer_skip_string(&b); 1281 if (datafellows & SSH_BUG_PKAUTH) { 1282 if (!buffer_get_char(&b)) 1283 fail++; 1284 } else { 1285 p = buffer_get_cstring(&b, NULL); 1286 if (strcmp("publickey", p) != 0) 1287 fail++; 1288 free(p); 1289 if (!buffer_get_char(&b)) 1290 fail++; 1291 buffer_skip_string(&b); 1292 } 1293 buffer_skip_string(&b); 1294 if (buffer_len(&b) != 0) 1295 fail++; 1296 buffer_free(&b); 1297 return (fail == 0); 1298 } 1299 1300 static int 1301 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1302 char *chost) 1303 { 1304 Buffer b; 1305 char *p, *userstyle; 1306 u_int len; 1307 int fail = 0; 1308 1309 buffer_init(&b); 1310 buffer_append(&b, data, datalen); 1311 1312 p = buffer_get_string(&b, &len); 1313 if ((session_id2 == NULL) || 1314 (len != session_id2_len) || 1315 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1316 fail++; 1317 free(p); 1318 1319 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1320 fail++; 1321 p = buffer_get_cstring(&b, NULL); 1322 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1323 authctxt->style ? ":" : "", 1324 authctxt->style ? authctxt->style : ""); 1325 if (strcmp(userstyle, p) != 0) { 1326 logit("wrong user name passed to monitor: expected %s != %.100s", 1327 userstyle, p); 1328 fail++; 1329 } 1330 free(userstyle); 1331 free(p); 1332 buffer_skip_string(&b); /* service */ 1333 p = buffer_get_cstring(&b, NULL); 1334 if (strcmp(p, "hostbased") != 0) 1335 fail++; 1336 free(p); 1337 buffer_skip_string(&b); /* pkalg */ 1338 buffer_skip_string(&b); /* pkblob */ 1339 1340 /* verify client host, strip trailing dot if necessary */ 1341 p = buffer_get_string(&b, NULL); 1342 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1343 p[len - 1] = '\0'; 1344 if (strcmp(p, chost) != 0) 1345 fail++; 1346 free(p); 1347 1348 /* verify client user */ 1349 p = buffer_get_string(&b, NULL); 1350 if (strcmp(p, cuser) != 0) 1351 fail++; 1352 free(p); 1353 1354 if (buffer_len(&b) != 0) 1355 fail++; 1356 buffer_free(&b); 1357 return (fail == 0); 1358 } 1359 1360 int 1361 mm_answer_keyverify(int sock, Buffer *m) 1362 { 1363 Key *key; 1364 u_char *signature, *data, *blob; 1365 u_int signaturelen, datalen, bloblen; 1366 int verified = 0; 1367 int valid_data = 0; 1368 1369 blob = buffer_get_string(m, &bloblen); 1370 signature = buffer_get_string(m, &signaturelen); 1371 data = buffer_get_string(m, &datalen); 1372 1373 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1374 !monitor_allowed_key(blob, bloblen)) 1375 fatal("%s: bad key, not previously allowed", __func__); 1376 1377 key = key_from_blob(blob, bloblen); 1378 if (key == NULL) 1379 fatal("%s: bad public key blob", __func__); 1380 1381 switch (key_blobtype) { 1382 case MM_USERKEY: 1383 valid_data = monitor_valid_userblob(data, datalen); 1384 break; 1385 case MM_HOSTKEY: 1386 valid_data = monitor_valid_hostbasedblob(data, datalen, 1387 hostbased_cuser, hostbased_chost); 1388 break; 1389 default: 1390 valid_data = 0; 1391 break; 1392 } 1393 if (!valid_data) 1394 fatal("%s: bad signature data blob", __func__); 1395 1396 verified = key_verify(key, signature, signaturelen, data, datalen); 1397 debug3("%s: key %p signature %s", 1398 __func__, key, (verified == 1) ? "verified" : "unverified"); 1399 1400 key_free(key); 1401 free(blob); 1402 free(signature); 1403 free(data); 1404 1405 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1406 1407 monitor_reset_key_state(); 1408 1409 buffer_clear(m); 1410 buffer_put_int(m, verified); 1411 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1412 1413 return (verified == 1); 1414 } 1415 1416 static void 1417 mm_record_login(Session *s, struct passwd *pw) 1418 { 1419 socklen_t fromlen; 1420 struct sockaddr_storage from; 1421 1422 /* 1423 * Get IP address of client. If the connection is not a socket, let 1424 * the address be 0.0.0.0. 1425 */ 1426 memset(&from, 0, sizeof(from)); 1427 fromlen = sizeof(from); 1428 if (packet_connection_is_on_socket()) { 1429 if (getpeername(packet_get_connection_in(), 1430 (struct sockaddr *)&from, &fromlen) < 0) { 1431 debug("getpeername: %.100s", strerror(errno)); 1432 cleanup_exit(255); 1433 } 1434 } 1435 /* Record that there was a login on that tty from the remote host. */ 1436 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1437 get_remote_name_or_ip(utmp_len, options.use_dns), 1438 (struct sockaddr *)&from, fromlen); 1439 } 1440 1441 static void 1442 mm_session_close(Session *s) 1443 { 1444 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1445 if (s->ttyfd != -1) { 1446 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1447 session_pty_cleanup2(s); 1448 } 1449 session_unused(s->self); 1450 } 1451 1452 int 1453 mm_answer_pty(int sock, Buffer *m) 1454 { 1455 extern struct monitor *pmonitor; 1456 Session *s; 1457 int res, fd0; 1458 1459 debug3("%s entering", __func__); 1460 1461 buffer_clear(m); 1462 s = session_new(); 1463 if (s == NULL) 1464 goto error; 1465 s->authctxt = authctxt; 1466 s->pw = authctxt->pw; 1467 s->pid = pmonitor->m_pid; 1468 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1469 if (res == 0) 1470 goto error; 1471 pty_setowner(authctxt->pw, s->tty); 1472 1473 buffer_put_int(m, 1); 1474 buffer_put_cstring(m, s->tty); 1475 1476 /* We need to trick ttyslot */ 1477 if (dup2(s->ttyfd, 0) == -1) 1478 fatal("%s: dup2", __func__); 1479 1480 mm_record_login(s, authctxt->pw); 1481 1482 /* Now we can close the file descriptor again */ 1483 close(0); 1484 1485 /* send messages generated by record_login */ 1486 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1487 buffer_clear(&loginmsg); 1488 1489 mm_request_send(sock, MONITOR_ANS_PTY, m); 1490 1491 if (mm_send_fd(sock, s->ptyfd) == -1 || 1492 mm_send_fd(sock, s->ttyfd) == -1) 1493 fatal("%s: send fds failed", __func__); 1494 1495 /* make sure nothing uses fd 0 */ 1496 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1497 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1498 if (fd0 != 0) 1499 error("%s: fd0 %d != 0", __func__, fd0); 1500 1501 /* slave is not needed */ 1502 close(s->ttyfd); 1503 s->ttyfd = s->ptyfd; 1504 /* no need to dup() because nobody closes ptyfd */ 1505 s->ptymaster = s->ptyfd; 1506 1507 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1508 1509 return (0); 1510 1511 error: 1512 if (s != NULL) 1513 mm_session_close(s); 1514 buffer_put_int(m, 0); 1515 mm_request_send(sock, MONITOR_ANS_PTY, m); 1516 return (0); 1517 } 1518 1519 int 1520 mm_answer_pty_cleanup(int sock, Buffer *m) 1521 { 1522 Session *s; 1523 char *tty; 1524 1525 debug3("%s entering", __func__); 1526 1527 tty = buffer_get_string(m, NULL); 1528 if ((s = session_by_tty(tty)) != NULL) 1529 mm_session_close(s); 1530 buffer_clear(m); 1531 free(tty); 1532 return (0); 1533 } 1534 1535 #ifdef WITH_SSH1 1536 int 1537 mm_answer_sesskey(int sock, Buffer *m) 1538 { 1539 BIGNUM *p; 1540 int rsafail; 1541 1542 /* Turn off permissions */ 1543 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1544 1545 if ((p = BN_new()) == NULL) 1546 fatal("%s: BN_new", __func__); 1547 1548 buffer_get_bignum2(m, p); 1549 1550 rsafail = ssh1_session_key(p); 1551 1552 buffer_clear(m); 1553 buffer_put_int(m, rsafail); 1554 buffer_put_bignum2(m, p); 1555 1556 BN_clear_free(p); 1557 1558 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1559 1560 /* Turn on permissions for sessid passing */ 1561 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1562 1563 return (0); 1564 } 1565 1566 int 1567 mm_answer_sessid(int sock, Buffer *m) 1568 { 1569 int i; 1570 1571 debug3("%s entering", __func__); 1572 1573 if (buffer_len(m) != 16) 1574 fatal("%s: bad ssh1 session id", __func__); 1575 for (i = 0; i < 16; i++) 1576 session_id[i] = buffer_get_char(m); 1577 1578 /* Turn on permissions for getpwnam */ 1579 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1580 1581 return (0); 1582 } 1583 1584 int 1585 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1586 { 1587 BIGNUM *client_n; 1588 Key *key = NULL; 1589 u_char *blob = NULL; 1590 u_int blen = 0; 1591 int allowed = 0; 1592 1593 debug3("%s entering", __func__); 1594 1595 auth_method = "rsa"; 1596 if (options.rsa_authentication && authctxt->valid) { 1597 if ((client_n = BN_new()) == NULL) 1598 fatal("%s: BN_new", __func__); 1599 buffer_get_bignum2(m, client_n); 1600 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1601 BN_clear_free(client_n); 1602 } 1603 buffer_clear(m); 1604 buffer_put_int(m, allowed); 1605 buffer_put_int(m, forced_command != NULL); 1606 1607 /* clear temporarily storage (used by generate challenge) */ 1608 monitor_reset_key_state(); 1609 1610 if (allowed && key != NULL) { 1611 key->type = KEY_RSA; /* cheat for key_to_blob */ 1612 if (key_to_blob(key, &blob, &blen) == 0) 1613 fatal("%s: key_to_blob failed", __func__); 1614 buffer_put_string(m, blob, blen); 1615 1616 /* Save temporarily for comparison in verify */ 1617 key_blob = blob; 1618 key_bloblen = blen; 1619 key_blobtype = MM_RSAUSERKEY; 1620 } 1621 if (key != NULL) 1622 key_free(key); 1623 1624 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1625 1626 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1627 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1628 return (0); 1629 } 1630 1631 int 1632 mm_answer_rsa_challenge(int sock, Buffer *m) 1633 { 1634 Key *key = NULL; 1635 u_char *blob; 1636 u_int blen; 1637 1638 debug3("%s entering", __func__); 1639 1640 if (!authctxt->valid) 1641 fatal("%s: authctxt not valid", __func__); 1642 blob = buffer_get_string(m, &blen); 1643 if (!monitor_allowed_key(blob, blen)) 1644 fatal("%s: bad key, not previously allowed", __func__); 1645 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1646 fatal("%s: key type mismatch", __func__); 1647 if ((key = key_from_blob(blob, blen)) == NULL) 1648 fatal("%s: received bad key", __func__); 1649 if (key->type != KEY_RSA) 1650 fatal("%s: received bad key type %d", __func__, key->type); 1651 key->type = KEY_RSA1; 1652 if (ssh1_challenge) 1653 BN_clear_free(ssh1_challenge); 1654 ssh1_challenge = auth_rsa_generate_challenge(key); 1655 1656 buffer_clear(m); 1657 buffer_put_bignum2(m, ssh1_challenge); 1658 1659 debug3("%s sending reply", __func__); 1660 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1661 1662 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1663 1664 free(blob); 1665 key_free(key); 1666 return (0); 1667 } 1668 1669 int 1670 mm_answer_rsa_response(int sock, Buffer *m) 1671 { 1672 Key *key = NULL; 1673 u_char *blob, *response; 1674 u_int blen, len; 1675 int success; 1676 1677 debug3("%s entering", __func__); 1678 1679 if (!authctxt->valid) 1680 fatal("%s: authctxt not valid", __func__); 1681 if (ssh1_challenge == NULL) 1682 fatal("%s: no ssh1_challenge", __func__); 1683 1684 blob = buffer_get_string(m, &blen); 1685 if (!monitor_allowed_key(blob, blen)) 1686 fatal("%s: bad key, not previously allowed", __func__); 1687 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1688 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1689 if ((key = key_from_blob(blob, blen)) == NULL) 1690 fatal("%s: received bad key", __func__); 1691 response = buffer_get_string(m, &len); 1692 if (len != 16) 1693 fatal("%s: received bad response to challenge", __func__); 1694 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1695 1696 free(blob); 1697 key_free(key); 1698 free(response); 1699 1700 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1701 1702 /* reset state */ 1703 BN_clear_free(ssh1_challenge); 1704 ssh1_challenge = NULL; 1705 monitor_reset_key_state(); 1706 1707 buffer_clear(m); 1708 buffer_put_int(m, success); 1709 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1710 1711 return (success); 1712 } 1713 #endif 1714 1715 int 1716 mm_answer_term(int sock, Buffer *req) 1717 { 1718 extern struct monitor *pmonitor; 1719 int res, status; 1720 1721 debug3("%s: tearing down sessions", __func__); 1722 1723 /* The child is terminating */ 1724 session_destroy_all(&mm_session_close); 1725 1726 #ifdef USE_PAM 1727 if (options.use_pam) 1728 sshpam_cleanup(); 1729 #endif 1730 1731 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1732 if (errno != EINTR) 1733 exit(1); 1734 1735 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1736 1737 /* Terminate process */ 1738 exit(res); 1739 } 1740 1741 #ifdef SSH_AUDIT_EVENTS 1742 /* Report that an audit event occurred */ 1743 int 1744 mm_answer_audit_event(int socket, Buffer *m) 1745 { 1746 ssh_audit_event_t event; 1747 1748 debug3("%s entering", __func__); 1749 1750 event = buffer_get_int(m); 1751 switch(event) { 1752 case SSH_AUTH_FAIL_PUBKEY: 1753 case SSH_AUTH_FAIL_HOSTBASED: 1754 case SSH_AUTH_FAIL_GSSAPI: 1755 case SSH_LOGIN_EXCEED_MAXTRIES: 1756 case SSH_LOGIN_ROOT_DENIED: 1757 case SSH_CONNECTION_CLOSE: 1758 case SSH_INVALID_USER: 1759 audit_event(event); 1760 break; 1761 default: 1762 fatal("Audit event type %d not permitted", event); 1763 } 1764 1765 return (0); 1766 } 1767 1768 int 1769 mm_answer_audit_command(int socket, Buffer *m) 1770 { 1771 u_int len; 1772 char *cmd; 1773 1774 debug3("%s entering", __func__); 1775 cmd = buffer_get_string(m, &len); 1776 /* sanity check command, if so how? */ 1777 audit_run_command(cmd); 1778 free(cmd); 1779 return (0); 1780 } 1781 #endif /* SSH_AUDIT_EVENTS */ 1782 1783 void 1784 monitor_apply_keystate(struct monitor *pmonitor) 1785 { 1786 if (compat20) { 1787 set_newkeys(MODE_IN); 1788 set_newkeys(MODE_OUT); 1789 } else { 1790 packet_set_protocol_flags(child_state.ssh1protoflags); 1791 packet_set_encryption_key(child_state.ssh1key, 1792 child_state.ssh1keylen, child_state.ssh1cipher); 1793 free(child_state.ssh1key); 1794 } 1795 1796 /* for rc4 and other stateful ciphers */ 1797 packet_set_keycontext(MODE_OUT, child_state.keyout); 1798 free(child_state.keyout); 1799 packet_set_keycontext(MODE_IN, child_state.keyin); 1800 free(child_state.keyin); 1801 1802 if (!compat20) { 1803 packet_set_iv(MODE_OUT, child_state.ivout); 1804 free(child_state.ivout); 1805 packet_set_iv(MODE_IN, child_state.ivin); 1806 free(child_state.ivin); 1807 } 1808 1809 memcpy(&incoming_stream, &child_state.incoming, 1810 sizeof(incoming_stream)); 1811 memcpy(&outgoing_stream, &child_state.outgoing, 1812 sizeof(outgoing_stream)); 1813 1814 /* Update with new address */ 1815 if (options.compression) 1816 mm_init_compression(pmonitor->m_zlib); 1817 1818 packet_set_postauth(); 1819 1820 if (options.rekey_limit || options.rekey_interval) 1821 packet_set_rekey_limits((u_int32_t)options.rekey_limit, 1822 (time_t)options.rekey_interval); 1823 1824 /* Network I/O buffers */ 1825 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1826 buffer_clear(packet_get_input()); 1827 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1828 explicit_bzero(child_state.input, child_state.ilen); 1829 free(child_state.input); 1830 1831 buffer_clear(packet_get_output()); 1832 buffer_append(packet_get_output(), child_state.output, 1833 child_state.olen); 1834 explicit_bzero(child_state.output, child_state.olen); 1835 free(child_state.output); 1836 1837 /* Roaming */ 1838 if (compat20) 1839 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1840 } 1841 1842 static Kex * 1843 mm_get_kex(Buffer *m) 1844 { 1845 Kex *kex; 1846 void *blob; 1847 u_int bloblen; 1848 1849 kex = xcalloc(1, sizeof(*kex)); 1850 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1851 if (session_id2 == NULL || 1852 kex->session_id_len != session_id2_len || 1853 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1854 fatal("mm_get_get: internal error: bad session id"); 1855 kex->we_need = buffer_get_int(m); 1856 #ifdef WITH_OPENSSL 1857 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1858 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1859 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1860 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1861 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1862 #endif 1863 kex->kex[KEX_C25519_SHA256] = kexc25519_server; 1864 kex->server = 1; 1865 kex->hostkey_type = buffer_get_int(m); 1866 kex->kex_type = buffer_get_int(m); 1867 blob = buffer_get_string(m, &bloblen); 1868 buffer_init(&kex->my); 1869 buffer_append(&kex->my, blob, bloblen); 1870 free(blob); 1871 blob = buffer_get_string(m, &bloblen); 1872 buffer_init(&kex->peer); 1873 buffer_append(&kex->peer, blob, bloblen); 1874 free(blob); 1875 kex->done = 1; 1876 kex->flags = buffer_get_int(m); 1877 kex->client_version_string = buffer_get_string(m, NULL); 1878 kex->server_version_string = buffer_get_string(m, NULL); 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 return (kex); 1885 } 1886 1887 /* This function requries careful sanity checking */ 1888 1889 void 1890 mm_get_keystate(struct monitor *pmonitor) 1891 { 1892 Buffer m; 1893 u_char *blob, *p; 1894 u_int bloblen, plen; 1895 u_int32_t seqnr, packets; 1896 u_int64_t blocks, bytes; 1897 1898 debug3("%s: Waiting for new keys", __func__); 1899 1900 buffer_init(&m); 1901 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1902 if (!compat20) { 1903 child_state.ssh1protoflags = buffer_get_int(&m); 1904 child_state.ssh1cipher = buffer_get_int(&m); 1905 child_state.ssh1key = buffer_get_string(&m, 1906 &child_state.ssh1keylen); 1907 child_state.ivout = buffer_get_string(&m, 1908 &child_state.ivoutlen); 1909 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1910 goto skip; 1911 } else { 1912 /* Get the Kex for rekeying */ 1913 *pmonitor->m_pkex = mm_get_kex(&m); 1914 } 1915 1916 blob = buffer_get_string(&m, &bloblen); 1917 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1918 free(blob); 1919 1920 debug3("%s: Waiting for second key", __func__); 1921 blob = buffer_get_string(&m, &bloblen); 1922 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1923 free(blob); 1924 1925 /* Now get sequence numbers for the packets */ 1926 seqnr = buffer_get_int(&m); 1927 blocks = buffer_get_int64(&m); 1928 packets = buffer_get_int(&m); 1929 bytes = buffer_get_int64(&m); 1930 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1931 seqnr = buffer_get_int(&m); 1932 blocks = buffer_get_int64(&m); 1933 packets = buffer_get_int(&m); 1934 bytes = buffer_get_int64(&m); 1935 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1936 1937 skip: 1938 /* Get the key context */ 1939 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1940 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1941 1942 debug3("%s: Getting compression state", __func__); 1943 /* Get compression state */ 1944 p = buffer_get_string(&m, &plen); 1945 if (plen != sizeof(child_state.outgoing)) 1946 fatal("%s: bad request size", __func__); 1947 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1948 free(p); 1949 1950 p = buffer_get_string(&m, &plen); 1951 if (plen != sizeof(child_state.incoming)) 1952 fatal("%s: bad request size", __func__); 1953 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1954 free(p); 1955 1956 /* Network I/O buffers */ 1957 debug3("%s: Getting Network I/O buffers", __func__); 1958 child_state.input = buffer_get_string(&m, &child_state.ilen); 1959 child_state.output = buffer_get_string(&m, &child_state.olen); 1960 1961 /* Roaming */ 1962 if (compat20) { 1963 child_state.sent_bytes = buffer_get_int64(&m); 1964 child_state.recv_bytes = buffer_get_int64(&m); 1965 } 1966 1967 buffer_free(&m); 1968 } 1969 1970 1971 /* Allocation functions for zlib */ 1972 void * 1973 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1974 { 1975 size_t len = (size_t) size * ncount; 1976 void *address; 1977 1978 if (len == 0 || ncount > SIZE_T_MAX / size) 1979 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1980 1981 address = mm_malloc(mm, len); 1982 1983 return (address); 1984 } 1985 1986 void 1987 mm_zfree(struct mm_master *mm, void *address) 1988 { 1989 mm_free(mm, address); 1990 } 1991 1992 void 1993 mm_init_compression(struct mm_master *mm) 1994 { 1995 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1996 outgoing_stream.zfree = (free_func)mm_zfree; 1997 outgoing_stream.opaque = mm; 1998 1999 incoming_stream.zalloc = (alloc_func)mm_zalloc; 2000 incoming_stream.zfree = (free_func)mm_zfree; 2001 incoming_stream.opaque = mm; 2002 } 2003 2004 /* XXX */ 2005 2006 #define FD_CLOSEONEXEC(x) do { \ 2007 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 2008 fatal("fcntl(%d, F_SETFD)", x); \ 2009 } while (0) 2010 2011 static void 2012 monitor_openfds(struct monitor *mon, int do_logfds) 2013 { 2014 int pair[2]; 2015 2016 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 2017 fatal("%s: socketpair: %s", __func__, strerror(errno)); 2018 FD_CLOSEONEXEC(pair[0]); 2019 FD_CLOSEONEXEC(pair[1]); 2020 mon->m_recvfd = pair[0]; 2021 mon->m_sendfd = pair[1]; 2022 2023 if (do_logfds) { 2024 if (pipe(pair) == -1) 2025 fatal("%s: pipe: %s", __func__, strerror(errno)); 2026 FD_CLOSEONEXEC(pair[0]); 2027 FD_CLOSEONEXEC(pair[1]); 2028 mon->m_log_recvfd = pair[0]; 2029 mon->m_log_sendfd = pair[1]; 2030 } else 2031 mon->m_log_recvfd = mon->m_log_sendfd = -1; 2032 } 2033 2034 #define MM_MEMSIZE 65536 2035 2036 struct monitor * 2037 monitor_init(void) 2038 { 2039 struct monitor *mon; 2040 2041 mon = xcalloc(1, sizeof(*mon)); 2042 2043 monitor_openfds(mon, 1); 2044 2045 /* Used to share zlib space across processes */ 2046 if (options.compression) { 2047 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 2048 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 2049 2050 /* Compression needs to share state across borders */ 2051 mm_init_compression(mon->m_zlib); 2052 } 2053 2054 return mon; 2055 } 2056 2057 void 2058 monitor_reinit(struct monitor *mon) 2059 { 2060 monitor_openfds(mon, 0); 2061 } 2062 2063 #ifdef GSSAPI 2064 int 2065 mm_answer_gss_setup_ctx(int sock, Buffer *m) 2066 { 2067 gss_OID_desc goid; 2068 OM_uint32 major; 2069 u_int len; 2070 2071 goid.elements = buffer_get_string(m, &len); 2072 goid.length = len; 2073 2074 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 2075 2076 free(goid.elements); 2077 2078 buffer_clear(m); 2079 buffer_put_int(m, major); 2080 2081 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 2082 2083 /* Now we have a context, enable the step */ 2084 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 2085 2086 return (0); 2087 } 2088 2089 int 2090 mm_answer_gss_accept_ctx(int sock, Buffer *m) 2091 { 2092 gss_buffer_desc in; 2093 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2094 OM_uint32 major, minor; 2095 OM_uint32 flags = 0; /* GSI needs this */ 2096 u_int len; 2097 2098 in.value = buffer_get_string(m, &len); 2099 in.length = len; 2100 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2101 free(in.value); 2102 2103 buffer_clear(m); 2104 buffer_put_int(m, major); 2105 buffer_put_string(m, out.value, out.length); 2106 buffer_put_int(m, flags); 2107 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2108 2109 gss_release_buffer(&minor, &out); 2110 2111 if (major == GSS_S_COMPLETE) { 2112 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2113 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2114 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2115 } 2116 return (0); 2117 } 2118 2119 int 2120 mm_answer_gss_checkmic(int sock, Buffer *m) 2121 { 2122 gss_buffer_desc gssbuf, mic; 2123 OM_uint32 ret; 2124 u_int len; 2125 2126 gssbuf.value = buffer_get_string(m, &len); 2127 gssbuf.length = len; 2128 mic.value = buffer_get_string(m, &len); 2129 mic.length = len; 2130 2131 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2132 2133 free(gssbuf.value); 2134 free(mic.value); 2135 2136 buffer_clear(m); 2137 buffer_put_int(m, ret); 2138 2139 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2140 2141 if (!GSS_ERROR(ret)) 2142 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2143 2144 return (0); 2145 } 2146 2147 int 2148 mm_answer_gss_userok(int sock, Buffer *m) 2149 { 2150 int authenticated; 2151 2152 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2153 2154 buffer_clear(m); 2155 buffer_put_int(m, authenticated); 2156 2157 debug3("%s: sending result %d", __func__, authenticated); 2158 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2159 2160 auth_method = "gssapi-with-mic"; 2161 2162 /* Monitor loop will terminate if authenticated */ 2163 return (authenticated); 2164 } 2165 #endif /* GSSAPI */ 2166 2167