monitor.c revision 248619
1/* $OpenBSD: monitor.c,v 1.120 2012/12/11 22:16:21 markus 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 "jpake.h" 99#include "roaming.h" 100 101#ifdef GSSAPI 102static Gssctxt *gsscontext = NULL; 103#endif 104 105/* Imports */ 106extern ServerOptions options; 107extern u_int utmp_len; 108extern Newkeys *current_keys[]; 109extern z_stream incoming_stream; 110extern z_stream outgoing_stream; 111extern u_char session_id[]; 112extern Buffer auth_debug; 113extern int auth_debug_init; 114extern Buffer loginmsg; 115 116/* State exported from the child */ 117 118struct { 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 143int mm_answer_moduli(int, Buffer *); 144int mm_answer_sign(int, Buffer *); 145int mm_answer_pwnamallow(int, Buffer *); 146int mm_answer_auth2_read_banner(int, Buffer *); 147int mm_answer_authserv(int, Buffer *); 148int mm_answer_authpassword(int, Buffer *); 149int mm_answer_bsdauthquery(int, Buffer *); 150int mm_answer_bsdauthrespond(int, Buffer *); 151int mm_answer_skeyquery(int, Buffer *); 152int mm_answer_skeyrespond(int, Buffer *); 153int mm_answer_keyallowed(int, Buffer *); 154int mm_answer_keyverify(int, Buffer *); 155int mm_answer_pty(int, Buffer *); 156int mm_answer_pty_cleanup(int, Buffer *); 157int mm_answer_term(int, Buffer *); 158int mm_answer_rsa_keyallowed(int, Buffer *); 159int mm_answer_rsa_challenge(int, Buffer *); 160int mm_answer_rsa_response(int, Buffer *); 161int mm_answer_sesskey(int, Buffer *); 162int mm_answer_sessid(int, Buffer *); 163int mm_answer_jpake_get_pwdata(int, Buffer *); 164int mm_answer_jpake_step1(int, Buffer *); 165int mm_answer_jpake_step2(int, Buffer *); 166int mm_answer_jpake_key_confirm(int, Buffer *); 167int mm_answer_jpake_check_confirm(int, Buffer *); 168 169#ifdef USE_PAM 170int mm_answer_pam_start(int, Buffer *); 171int mm_answer_pam_account(int, Buffer *); 172int mm_answer_pam_init_ctx(int, Buffer *); 173int mm_answer_pam_query(int, Buffer *); 174int mm_answer_pam_respond(int, Buffer *); 175int mm_answer_pam_free_ctx(int, Buffer *); 176#endif 177 178#ifdef GSSAPI 179int mm_answer_gss_setup_ctx(int, Buffer *); 180int mm_answer_gss_accept_ctx(int, Buffer *); 181int mm_answer_gss_userok(int, Buffer *); 182int mm_answer_gss_checkmic(int, Buffer *); 183#endif 184 185#ifdef SSH_AUDIT_EVENTS 186int mm_answer_audit_event(int, Buffer *); 187int mm_answer_audit_command(int, Buffer *); 188#endif 189 190static int monitor_read_log(struct monitor *); 191 192static Authctxt *authctxt; 193static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 194 195/* local state for key verify */ 196static u_char *key_blob = NULL; 197static u_int key_bloblen = 0; 198static int key_blobtype = MM_NOKEY; 199static char *hostbased_cuser = NULL; 200static char *hostbased_chost = NULL; 201static char *auth_method = "unknown"; 202static char *auth_submethod = NULL; 203static u_int session_id2_len = 0; 204static u_char *session_id2 = NULL; 205static pid_t monitor_child_pid; 206 207struct mon_table { 208 enum monitor_reqtype type; 209 int flags; 210 int (*f)(int, Buffer *); 211}; 212 213#define MON_ISAUTH 0x0004 /* Required for Authentication */ 214#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 215#define MON_ONCE 0x0010 /* Disable after calling */ 216#define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 217 218#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 219 220#define MON_PERMIT 0x1000 /* Request is permitted */ 221 222struct mon_table mon_dispatch_proto20[] = { 223 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 224 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 225 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 226 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 227 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 228 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 229#ifdef USE_PAM 230 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 231 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 232 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 233 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 234 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 235 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 236#endif 237#ifdef SSH_AUDIT_EVENTS 238 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 239#endif 240#ifdef BSD_AUTH 241 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 242 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 243#endif 244#ifdef SKEY 245 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 246 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 247#endif 248 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 249 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 250#ifdef GSSAPI 251 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 252 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 253 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 254 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 255#endif 256#ifdef JPAKE 257 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 258 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 259 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 260 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 261 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 262#endif 263 {0, 0, NULL} 264}; 265 266struct mon_table mon_dispatch_postauth20[] = { 267 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 268 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 269 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 270 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 271 {MONITOR_REQ_TERM, 0, mm_answer_term}, 272#ifdef SSH_AUDIT_EVENTS 273 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 274 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 275#endif 276 {0, 0, NULL} 277}; 278 279struct mon_table mon_dispatch_proto15[] = { 280 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 281 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 282 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 283 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 284 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 285 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 286 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 287 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 288#ifdef BSD_AUTH 289 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 290 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 291#endif 292#ifdef SKEY 293 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 294 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 295#endif 296#ifdef USE_PAM 297 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 298 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 299 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 300 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 301 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 302 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 303#endif 304#ifdef SSH_AUDIT_EVENTS 305 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 306#endif 307 {0, 0, NULL} 308}; 309 310struct mon_table mon_dispatch_postauth15[] = { 311 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 312 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 313 {MONITOR_REQ_TERM, 0, mm_answer_term}, 314#ifdef SSH_AUDIT_EVENTS 315 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 316 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 317#endif 318 {0, 0, NULL} 319}; 320 321struct mon_table *mon_dispatch; 322 323/* Specifies if a certain message is allowed at the moment */ 324 325static void 326monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 327{ 328 while (ent->f != NULL) { 329 if (ent->type == type) { 330 ent->flags &= ~MON_PERMIT; 331 ent->flags |= permit ? MON_PERMIT : 0; 332 return; 333 } 334 ent++; 335 } 336} 337 338static void 339monitor_permit_authentications(int permit) 340{ 341 struct mon_table *ent = mon_dispatch; 342 343 while (ent->f != NULL) { 344 if (ent->flags & MON_AUTH) { 345 ent->flags &= ~MON_PERMIT; 346 ent->flags |= permit ? MON_PERMIT : 0; 347 } 348 ent++; 349 } 350} 351 352void 353monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 354{ 355 struct mon_table *ent; 356 int authenticated = 0, partial = 0; 357 358 debug3("preauth child monitor started"); 359 360 close(pmonitor->m_recvfd); 361 close(pmonitor->m_log_sendfd); 362 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 363 364 authctxt = _authctxt; 365 memset(authctxt, 0, sizeof(*authctxt)); 366 367 authctxt->loginmsg = &loginmsg; 368 369 if (compat20) { 370 mon_dispatch = mon_dispatch_proto20; 371 372 /* Permit requests for moduli and signatures */ 373 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 374 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 375 } else { 376 mon_dispatch = mon_dispatch_proto15; 377 378 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 379 } 380 381 /* The first few requests do not require asynchronous access */ 382 while (!authenticated) { 383 partial = 0; 384 auth_method = "unknown"; 385 auth_submethod = NULL; 386 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 387 388 /* Special handling for multiple required authentications */ 389 if (options.num_auth_methods != 0) { 390 if (!compat20) 391 fatal("AuthenticationMethods is not supported" 392 "with SSH protocol 1"); 393 if (authenticated && 394 !auth2_update_methods_lists(authctxt, 395 auth_method)) { 396 debug3("%s: method %s: partial", __func__, 397 auth_method); 398 authenticated = 0; 399 partial = 1; 400 } 401 } 402 403 if (authenticated) { 404 if (!(ent->flags & MON_AUTHDECIDE)) 405 fatal("%s: unexpected authentication from %d", 406 __func__, ent->type); 407 if (authctxt->pw->pw_uid == 0 && 408 !auth_root_allowed(auth_method)) 409 authenticated = 0; 410#ifdef USE_PAM 411 /* PAM needs to perform account checks after auth */ 412 if (options.use_pam && authenticated) { 413 Buffer m; 414 415 buffer_init(&m); 416 mm_request_receive_expect(pmonitor->m_sendfd, 417 MONITOR_REQ_PAM_ACCOUNT, &m); 418 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 419 buffer_free(&m); 420 } 421#endif 422 } 423 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 424 auth_log(authctxt, authenticated, partial, 425 auth_method, auth_submethod, 426 compat20 ? " ssh2" : ""); 427 if (!authenticated) 428 authctxt->failures++; 429 } 430#ifdef JPAKE 431 /* Cleanup JPAKE context after authentication */ 432 if (ent->flags & MON_AUTHDECIDE) { 433 if (authctxt->jpake_ctx != NULL) { 434 jpake_free(authctxt->jpake_ctx); 435 authctxt->jpake_ctx = NULL; 436 } 437 } 438#endif 439 } 440 441 if (!authctxt->valid) 442 fatal("%s: authenticated invalid user", __func__); 443 if (strcmp(auth_method, "unknown") == 0) 444 fatal("%s: authentication method name unknown", __func__); 445 446 debug("%s: %s has been authenticated by privileged process", 447 __func__, authctxt->user); 448 449 mm_get_keystate(pmonitor); 450 451 /* Drain any buffered messages from the child */ 452 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 453 ; 454 455 close(pmonitor->m_sendfd); 456 close(pmonitor->m_log_recvfd); 457 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 458} 459 460static void 461monitor_set_child_handler(pid_t pid) 462{ 463 monitor_child_pid = pid; 464} 465 466static void 467monitor_child_handler(int sig) 468{ 469 kill(monitor_child_pid, sig); 470} 471 472void 473monitor_child_postauth(struct monitor *pmonitor) 474{ 475 close(pmonitor->m_recvfd); 476 pmonitor->m_recvfd = -1; 477 478 monitor_set_child_handler(pmonitor->m_pid); 479 signal(SIGHUP, &monitor_child_handler); 480 signal(SIGTERM, &monitor_child_handler); 481 signal(SIGINT, &monitor_child_handler); 482 483 if (compat20) { 484 mon_dispatch = mon_dispatch_postauth20; 485 486 /* Permit requests for moduli and signatures */ 487 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 488 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 489 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 490 } else { 491 mon_dispatch = mon_dispatch_postauth15; 492 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 493 } 494 if (!no_pty_flag) { 495 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 496 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 497 } 498 499 for (;;) 500 monitor_read(pmonitor, mon_dispatch, NULL); 501} 502 503void 504monitor_sync(struct monitor *pmonitor) 505{ 506 if (options.compression) { 507 /* The member allocation is not visible, so sync it */ 508 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 509 } 510} 511 512static int 513monitor_read_log(struct monitor *pmonitor) 514{ 515 Buffer logmsg; 516 u_int len, level; 517 char *msg; 518 519 buffer_init(&logmsg); 520 521 /* Read length */ 522 buffer_append_space(&logmsg, 4); 523 if (atomicio(read, pmonitor->m_log_recvfd, 524 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 525 if (errno == EPIPE) { 526 buffer_free(&logmsg); 527 debug("%s: child log fd closed", __func__); 528 close(pmonitor->m_log_recvfd); 529 pmonitor->m_log_recvfd = -1; 530 return -1; 531 } 532 fatal("%s: log fd read: %s", __func__, strerror(errno)); 533 } 534 len = buffer_get_int(&logmsg); 535 if (len <= 4 || len > 8192) 536 fatal("%s: invalid log message length %u", __func__, len); 537 538 /* Read severity, message */ 539 buffer_clear(&logmsg); 540 buffer_append_space(&logmsg, len); 541 if (atomicio(read, pmonitor->m_log_recvfd, 542 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 543 fatal("%s: log fd read: %s", __func__, strerror(errno)); 544 545 /* Log it */ 546 level = buffer_get_int(&logmsg); 547 msg = buffer_get_string(&logmsg, NULL); 548 if (log_level_name(level) == NULL) 549 fatal("%s: invalid log level %u (corrupted message?)", 550 __func__, level); 551 do_log2(level, "%s [preauth]", msg); 552 553 buffer_free(&logmsg); 554 xfree(msg); 555 556 return 0; 557} 558 559int 560monitor_read(struct monitor *pmonitor, struct mon_table *ent, 561 struct mon_table **pent) 562{ 563 Buffer m; 564 int ret; 565 u_char type; 566 struct pollfd pfd[2]; 567 568 for (;;) { 569 bzero(&pfd, sizeof(pfd)); 570 pfd[0].fd = pmonitor->m_sendfd; 571 pfd[0].events = POLLIN; 572 pfd[1].fd = pmonitor->m_log_recvfd; 573 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 574 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 575 if (errno == EINTR || errno == EAGAIN) 576 continue; 577 fatal("%s: poll: %s", __func__, strerror(errno)); 578 } 579 if (pfd[1].revents) { 580 /* 581 * Drain all log messages before processing next 582 * monitor request. 583 */ 584 monitor_read_log(pmonitor); 585 continue; 586 } 587 if (pfd[0].revents) 588 break; /* Continues below */ 589 } 590 591 buffer_init(&m); 592 593 mm_request_receive(pmonitor->m_sendfd, &m); 594 type = buffer_get_char(&m); 595 596 debug3("%s: checking request %d", __func__, type); 597 598 while (ent->f != NULL) { 599 if (ent->type == type) 600 break; 601 ent++; 602 } 603 604 if (ent->f != NULL) { 605 if (!(ent->flags & MON_PERMIT)) 606 fatal("%s: unpermitted request %d", __func__, 607 type); 608 ret = (*ent->f)(pmonitor->m_sendfd, &m); 609 buffer_free(&m); 610 611 /* The child may use this request only once, disable it */ 612 if (ent->flags & MON_ONCE) { 613 debug2("%s: %d used once, disabling now", __func__, 614 type); 615 ent->flags &= ~MON_PERMIT; 616 } 617 618 if (pent != NULL) 619 *pent = ent; 620 621 return ret; 622 } 623 624 fatal("%s: unsupported request: %d", __func__, type); 625 626 /* NOTREACHED */ 627 return (-1); 628} 629 630/* allowed key state */ 631static int 632monitor_allowed_key(u_char *blob, u_int bloblen) 633{ 634 /* make sure key is allowed */ 635 if (key_blob == NULL || key_bloblen != bloblen || 636 timingsafe_bcmp(key_blob, blob, key_bloblen)) 637 return (0); 638 return (1); 639} 640 641static void 642monitor_reset_key_state(void) 643{ 644 /* reset state */ 645 if (key_blob != NULL) 646 xfree(key_blob); 647 if (hostbased_cuser != NULL) 648 xfree(hostbased_cuser); 649 if (hostbased_chost != NULL) 650 xfree(hostbased_chost); 651 key_blob = NULL; 652 key_bloblen = 0; 653 key_blobtype = MM_NOKEY; 654 hostbased_cuser = NULL; 655 hostbased_chost = NULL; 656} 657 658int 659mm_answer_moduli(int sock, Buffer *m) 660{ 661 DH *dh; 662 int min, want, max; 663 664 min = buffer_get_int(m); 665 want = buffer_get_int(m); 666 max = buffer_get_int(m); 667 668 debug3("%s: got parameters: %d %d %d", 669 __func__, min, want, max); 670 /* We need to check here, too, in case the child got corrupted */ 671 if (max < min || want < min || max < want) 672 fatal("%s: bad parameters: %d %d %d", 673 __func__, min, want, max); 674 675 buffer_clear(m); 676 677 dh = choose_dh(min, want, max); 678 if (dh == NULL) { 679 buffer_put_char(m, 0); 680 return (0); 681 } else { 682 /* Send first bignum */ 683 buffer_put_char(m, 1); 684 buffer_put_bignum2(m, dh->p); 685 buffer_put_bignum2(m, dh->g); 686 687 DH_free(dh); 688 } 689 mm_request_send(sock, MONITOR_ANS_MODULI, m); 690 return (0); 691} 692 693int 694mm_answer_sign(int sock, Buffer *m) 695{ 696 Key *key; 697 u_char *p; 698 u_char *signature; 699 u_int siglen, datlen; 700 int keyid; 701 702 debug3("%s", __func__); 703 704 keyid = buffer_get_int(m); 705 p = buffer_get_string(m, &datlen); 706 707 /* 708 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 709 * SHA384 (48 bytes) and SHA512 (64 bytes). 710 */ 711 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) 712 fatal("%s: data length incorrect: %u", __func__, datlen); 713 714 /* save session id, it will be passed on the first call */ 715 if (session_id2_len == 0) { 716 session_id2_len = datlen; 717 session_id2 = xmalloc(session_id2_len); 718 memcpy(session_id2, p, session_id2_len); 719 } 720 721 if ((key = get_hostkey_by_index(keyid)) == NULL) 722 fatal("%s: no hostkey from index %d", __func__, keyid); 723 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 724 fatal("%s: key_sign failed", __func__); 725 726 debug3("%s: signature %p(%u)", __func__, signature, siglen); 727 728 buffer_clear(m); 729 buffer_put_string(m, signature, siglen); 730 731 xfree(p); 732 xfree(signature); 733 734 mm_request_send(sock, MONITOR_ANS_SIGN, m); 735 736 /* Turn on permissions for getpwnam */ 737 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 738 739 return (0); 740} 741 742/* Retrieves the password entry and also checks if the user is permitted */ 743 744int 745mm_answer_pwnamallow(int sock, Buffer *m) 746{ 747 char *username; 748 struct passwd *pwent; 749 int allowed = 0; 750 u_int i; 751 752 debug3("%s", __func__); 753 754 if (authctxt->attempt++ != 0) 755 fatal("%s: multiple attempts for getpwnam", __func__); 756 757 username = buffer_get_string(m, NULL); 758 759 pwent = getpwnamallow(username); 760 761 authctxt->user = xstrdup(username); 762 setproctitle("%s [priv]", pwent ? username : "unknown"); 763 xfree(username); 764 765 buffer_clear(m); 766 767 if (pwent == NULL) { 768 buffer_put_char(m, 0); 769 authctxt->pw = fakepw(); 770 goto out; 771 } 772 773 allowed = 1; 774 authctxt->pw = pwent; 775 authctxt->valid = 1; 776 777 buffer_put_char(m, 1); 778 buffer_put_string(m, pwent, sizeof(struct passwd)); 779 buffer_put_cstring(m, pwent->pw_name); 780 buffer_put_cstring(m, "*"); 781 buffer_put_cstring(m, pwent->pw_gecos); 782#ifdef HAVE_PW_CLASS_IN_PASSWD 783 buffer_put_cstring(m, pwent->pw_class); 784#endif 785 buffer_put_cstring(m, pwent->pw_dir); 786 buffer_put_cstring(m, pwent->pw_shell); 787 788 out: 789 buffer_put_string(m, &options, sizeof(options)); 790 791#define M_CP_STROPT(x) do { \ 792 if (options.x != NULL) \ 793 buffer_put_cstring(m, options.x); \ 794 } while (0) 795#define M_CP_STRARRAYOPT(x, nx) do { \ 796 for (i = 0; i < options.nx; i++) \ 797 buffer_put_cstring(m, options.x[i]); \ 798 } while (0) 799 /* See comment in servconf.h */ 800 COPY_MATCH_STRING_OPTS(); 801#undef M_CP_STROPT 802#undef M_CP_STRARRAYOPT 803 804 /* Create valid auth method lists */ 805 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 806 /* 807 * The monitor will continue long enough to let the child 808 * run to it's packet_disconnect(), but it must not allow any 809 * authentication to succeed. 810 */ 811 debug("%s: no valid authentication method lists", __func__); 812 } 813 814 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 815 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 816 817 /* For SSHv1 allow authentication now */ 818 if (!compat20) 819 monitor_permit_authentications(1); 820 else { 821 /* Allow service/style information on the auth context */ 822 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 823 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 824 } 825#ifdef USE_PAM 826 if (options.use_pam) 827 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 828#endif 829 830 return (0); 831} 832 833int mm_answer_auth2_read_banner(int sock, Buffer *m) 834{ 835 char *banner; 836 837 buffer_clear(m); 838 banner = auth2_read_banner(); 839 buffer_put_cstring(m, banner != NULL ? banner : ""); 840 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 841 842 if (banner != NULL) 843 xfree(banner); 844 845 return (0); 846} 847 848int 849mm_answer_authserv(int sock, Buffer *m) 850{ 851 monitor_permit_authentications(1); 852 853 authctxt->service = buffer_get_string(m, NULL); 854 authctxt->style = buffer_get_string(m, NULL); 855 debug3("%s: service=%s, style=%s", 856 __func__, authctxt->service, authctxt->style); 857 858 if (strlen(authctxt->style) == 0) { 859 xfree(authctxt->style); 860 authctxt->style = NULL; 861 } 862 863 return (0); 864} 865 866int 867mm_answer_authpassword(int sock, Buffer *m) 868{ 869 static int call_count; 870 char *passwd; 871 int authenticated; 872 u_int plen; 873 874 passwd = buffer_get_string(m, &plen); 875 /* Only authenticate if the context is valid */ 876 authenticated = options.password_authentication && 877 auth_password(authctxt, passwd); 878 memset(passwd, 0, strlen(passwd)); 879 xfree(passwd); 880 881 buffer_clear(m); 882 buffer_put_int(m, authenticated); 883 884 debug3("%s: sending result %d", __func__, authenticated); 885 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 886 887 call_count++; 888 if (plen == 0 && call_count == 1) 889 auth_method = "none"; 890 else 891 auth_method = "password"; 892 893 /* Causes monitor loop to terminate if authenticated */ 894 return (authenticated); 895} 896 897#ifdef BSD_AUTH 898int 899mm_answer_bsdauthquery(int sock, Buffer *m) 900{ 901 char *name, *infotxt; 902 u_int numprompts; 903 u_int *echo_on; 904 char **prompts; 905 u_int success; 906 907 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 908 &prompts, &echo_on) < 0 ? 0 : 1; 909 910 buffer_clear(m); 911 buffer_put_int(m, success); 912 if (success) 913 buffer_put_cstring(m, prompts[0]); 914 915 debug3("%s: sending challenge success: %u", __func__, success); 916 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 917 918 if (success) { 919 xfree(name); 920 xfree(infotxt); 921 xfree(prompts); 922 xfree(echo_on); 923 } 924 925 return (0); 926} 927 928int 929mm_answer_bsdauthrespond(int sock, Buffer *m) 930{ 931 char *response; 932 int authok; 933 934 if (authctxt->as == 0) 935 fatal("%s: no bsd auth session", __func__); 936 937 response = buffer_get_string(m, NULL); 938 authok = options.challenge_response_authentication && 939 auth_userresponse(authctxt->as, response, 0); 940 authctxt->as = NULL; 941 debug3("%s: <%s> = <%d>", __func__, response, authok); 942 xfree(response); 943 944 buffer_clear(m); 945 buffer_put_int(m, authok); 946 947 debug3("%s: sending authenticated: %d", __func__, authok); 948 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 949 950 if (compat20) 951 auth_method = "keyboard-interactive"; /* XXX auth_submethod */ 952 else 953 auth_method = "bsdauth"; 954 955 return (authok != 0); 956} 957#endif 958 959#ifdef SKEY 960int 961mm_answer_skeyquery(int sock, Buffer *m) 962{ 963 struct skey skey; 964 char challenge[1024]; 965 u_int success; 966 967 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 968 sizeof(challenge)) < 0 ? 0 : 1; 969 970 buffer_clear(m); 971 buffer_put_int(m, success); 972 if (success) 973 buffer_put_cstring(m, challenge); 974 975 debug3("%s: sending challenge success: %u", __func__, success); 976 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 977 978 return (0); 979} 980 981int 982mm_answer_skeyrespond(int sock, Buffer *m) 983{ 984 char *response; 985 int authok; 986 987 response = buffer_get_string(m, NULL); 988 989 authok = (options.challenge_response_authentication && 990 authctxt->valid && 991 skey_haskey(authctxt->pw->pw_name) == 0 && 992 skey_passcheck(authctxt->pw->pw_name, response) != -1); 993 994 xfree(response); 995 996 buffer_clear(m); 997 buffer_put_int(m, authok); 998 999 debug3("%s: sending authenticated: %d", __func__, authok); 1000 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 1001 1002 auth_method = "skey"; 1003 1004 return (authok != 0); 1005} 1006#endif 1007 1008#ifdef USE_PAM 1009int 1010mm_answer_pam_start(int sock, Buffer *m) 1011{ 1012 if (!options.use_pam) 1013 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1014 1015 start_pam(authctxt); 1016 1017 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1018 1019 return (0); 1020} 1021 1022int 1023mm_answer_pam_account(int sock, Buffer *m) 1024{ 1025 u_int ret; 1026 1027 if (!options.use_pam) 1028 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1029 1030 ret = do_pam_account(); 1031 1032 buffer_put_int(m, ret); 1033 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1034 1035 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1036 1037 return (ret); 1038} 1039 1040static void *sshpam_ctxt, *sshpam_authok; 1041extern KbdintDevice sshpam_device; 1042 1043int 1044mm_answer_pam_init_ctx(int sock, Buffer *m) 1045{ 1046 1047 debug3("%s", __func__); 1048 authctxt->user = buffer_get_string(m, NULL); 1049 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1050 sshpam_authok = NULL; 1051 buffer_clear(m); 1052 if (sshpam_ctxt != NULL) { 1053 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1054 buffer_put_int(m, 1); 1055 } else { 1056 buffer_put_int(m, 0); 1057 } 1058 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1059 return (0); 1060} 1061 1062int 1063mm_answer_pam_query(int sock, Buffer *m) 1064{ 1065 char *name = NULL, *info = NULL, **prompts = NULL; 1066 u_int i, num = 0, *echo_on = 0; 1067 int ret; 1068 1069 debug3("%s", __func__); 1070 sshpam_authok = NULL; 1071 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1072 if (ret == 0 && num == 0) 1073 sshpam_authok = sshpam_ctxt; 1074 if (num > 1 || name == NULL || info == NULL) 1075 ret = -1; 1076 buffer_clear(m); 1077 buffer_put_int(m, ret); 1078 buffer_put_cstring(m, name); 1079 xfree(name); 1080 buffer_put_cstring(m, info); 1081 xfree(info); 1082 buffer_put_int(m, num); 1083 for (i = 0; i < num; ++i) { 1084 buffer_put_cstring(m, prompts[i]); 1085 xfree(prompts[i]); 1086 buffer_put_int(m, echo_on[i]); 1087 } 1088 if (prompts != NULL) 1089 xfree(prompts); 1090 if (echo_on != NULL) 1091 xfree(echo_on); 1092 auth_method = "keyboard-interactive"; 1093 auth_submethod = "pam"; 1094 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1095 return (0); 1096} 1097 1098int 1099mm_answer_pam_respond(int sock, Buffer *m) 1100{ 1101 char **resp; 1102 u_int i, num; 1103 int ret; 1104 1105 debug3("%s", __func__); 1106 sshpam_authok = NULL; 1107 num = buffer_get_int(m); 1108 if (num > 0) { 1109 resp = xcalloc(num, sizeof(char *)); 1110 for (i = 0; i < num; ++i) 1111 resp[i] = buffer_get_string(m, NULL); 1112 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1113 for (i = 0; i < num; ++i) 1114 xfree(resp[i]); 1115 xfree(resp); 1116 } else { 1117 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1118 } 1119 buffer_clear(m); 1120 buffer_put_int(m, ret); 1121 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1122 auth_method = "keyboard-interactive"; 1123 auth_submethod = "pam"; 1124 if (ret == 0) 1125 sshpam_authok = sshpam_ctxt; 1126 return (0); 1127} 1128 1129int 1130mm_answer_pam_free_ctx(int sock, Buffer *m) 1131{ 1132 1133 debug3("%s", __func__); 1134 (sshpam_device.free_ctx)(sshpam_ctxt); 1135 buffer_clear(m); 1136 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1137 auth_method = "keyboard-interactive"; 1138 auth_submethod = "pam"; 1139 return (sshpam_authok == sshpam_ctxt); 1140} 1141#endif 1142 1143int 1144mm_answer_keyallowed(int sock, Buffer *m) 1145{ 1146 Key *key; 1147 char *cuser, *chost; 1148 u_char *blob; 1149 u_int bloblen; 1150 enum mm_keytype type = 0; 1151 int allowed = 0; 1152 1153 debug3("%s entering", __func__); 1154 1155 type = buffer_get_int(m); 1156 cuser = buffer_get_string(m, NULL); 1157 chost = buffer_get_string(m, NULL); 1158 blob = buffer_get_string(m, &bloblen); 1159 1160 key = key_from_blob(blob, bloblen); 1161 1162 if ((compat20 && type == MM_RSAHOSTKEY) || 1163 (!compat20 && type != MM_RSAHOSTKEY)) 1164 fatal("%s: key type and protocol mismatch", __func__); 1165 1166 debug3("%s: key_from_blob: %p", __func__, key); 1167 1168 if (key != NULL && authctxt->valid) { 1169 switch (type) { 1170 case MM_USERKEY: 1171 allowed = options.pubkey_authentication && 1172 user_key_allowed(authctxt->pw, key); 1173 auth_method = "publickey"; 1174 if (options.pubkey_authentication && allowed != 1) 1175 auth_clear_options(); 1176 break; 1177 case MM_HOSTKEY: 1178 allowed = options.hostbased_authentication && 1179 hostbased_key_allowed(authctxt->pw, 1180 cuser, chost, key); 1181 auth_method = "hostbased"; 1182 break; 1183 case MM_RSAHOSTKEY: 1184 key->type = KEY_RSA1; /* XXX */ 1185 allowed = options.rhosts_rsa_authentication && 1186 auth_rhosts_rsa_key_allowed(authctxt->pw, 1187 cuser, chost, key); 1188 if (options.rhosts_rsa_authentication && allowed != 1) 1189 auth_clear_options(); 1190 auth_method = "rsa"; 1191 break; 1192 default: 1193 fatal("%s: unknown key type %d", __func__, type); 1194 break; 1195 } 1196 } 1197 if (key != NULL) 1198 key_free(key); 1199 1200 /* clear temporarily storage (used by verify) */ 1201 monitor_reset_key_state(); 1202 1203 if (allowed) { 1204 /* Save temporarily for comparison in verify */ 1205 key_blob = blob; 1206 key_bloblen = bloblen; 1207 key_blobtype = type; 1208 hostbased_cuser = cuser; 1209 hostbased_chost = chost; 1210 } else { 1211 /* Log failed attempt */ 1212 auth_log(authctxt, 0, 0, auth_method, NULL, 1213 compat20 ? " ssh2" : ""); 1214 xfree(blob); 1215 xfree(cuser); 1216 xfree(chost); 1217 } 1218 1219 debug3("%s: key %p is %s", 1220 __func__, key, allowed ? "allowed" : "not allowed"); 1221 1222 buffer_clear(m); 1223 buffer_put_int(m, allowed); 1224 buffer_put_int(m, forced_command != NULL); 1225 1226 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1227 1228 if (type == MM_RSAHOSTKEY) 1229 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1230 1231 return (0); 1232} 1233 1234static int 1235monitor_valid_userblob(u_char *data, u_int datalen) 1236{ 1237 Buffer b; 1238 char *p; 1239 u_int len; 1240 int fail = 0; 1241 1242 buffer_init(&b); 1243 buffer_append(&b, data, datalen); 1244 1245 if (datafellows & SSH_OLD_SESSIONID) { 1246 p = buffer_ptr(&b); 1247 len = buffer_len(&b); 1248 if ((session_id2 == NULL) || 1249 (len < session_id2_len) || 1250 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1251 fail++; 1252 buffer_consume(&b, session_id2_len); 1253 } else { 1254 p = buffer_get_string(&b, &len); 1255 if ((session_id2 == NULL) || 1256 (len != session_id2_len) || 1257 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1258 fail++; 1259 xfree(p); 1260 } 1261 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1262 fail++; 1263 p = buffer_get_string(&b, NULL); 1264 if (strcmp(authctxt->user, p) != 0) { 1265 logit("wrong user name passed to monitor: expected %s != %.100s", 1266 authctxt->user, p); 1267 fail++; 1268 } 1269 xfree(p); 1270 buffer_skip_string(&b); 1271 if (datafellows & SSH_BUG_PKAUTH) { 1272 if (!buffer_get_char(&b)) 1273 fail++; 1274 } else { 1275 p = buffer_get_string(&b, NULL); 1276 if (strcmp("publickey", p) != 0) 1277 fail++; 1278 xfree(p); 1279 if (!buffer_get_char(&b)) 1280 fail++; 1281 buffer_skip_string(&b); 1282 } 1283 buffer_skip_string(&b); 1284 if (buffer_len(&b) != 0) 1285 fail++; 1286 buffer_free(&b); 1287 return (fail == 0); 1288} 1289 1290static int 1291monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1292 char *chost) 1293{ 1294 Buffer b; 1295 char *p; 1296 u_int len; 1297 int fail = 0; 1298 1299 buffer_init(&b); 1300 buffer_append(&b, data, datalen); 1301 1302 p = buffer_get_string(&b, &len); 1303 if ((session_id2 == NULL) || 1304 (len != session_id2_len) || 1305 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1306 fail++; 1307 xfree(p); 1308 1309 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1310 fail++; 1311 p = buffer_get_string(&b, NULL); 1312 if (strcmp(authctxt->user, p) != 0) { 1313 logit("wrong user name passed to monitor: expected %s != %.100s", 1314 authctxt->user, p); 1315 fail++; 1316 } 1317 xfree(p); 1318 buffer_skip_string(&b); /* service */ 1319 p = buffer_get_string(&b, NULL); 1320 if (strcmp(p, "hostbased") != 0) 1321 fail++; 1322 xfree(p); 1323 buffer_skip_string(&b); /* pkalg */ 1324 buffer_skip_string(&b); /* pkblob */ 1325 1326 /* verify client host, strip trailing dot if necessary */ 1327 p = buffer_get_string(&b, NULL); 1328 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1329 p[len - 1] = '\0'; 1330 if (strcmp(p, chost) != 0) 1331 fail++; 1332 xfree(p); 1333 1334 /* verify client user */ 1335 p = buffer_get_string(&b, NULL); 1336 if (strcmp(p, cuser) != 0) 1337 fail++; 1338 xfree(p); 1339 1340 if (buffer_len(&b) != 0) 1341 fail++; 1342 buffer_free(&b); 1343 return (fail == 0); 1344} 1345 1346int 1347mm_answer_keyverify(int sock, Buffer *m) 1348{ 1349 Key *key; 1350 u_char *signature, *data, *blob; 1351 u_int signaturelen, datalen, bloblen; 1352 int verified = 0; 1353 int valid_data = 0; 1354 1355 blob = buffer_get_string(m, &bloblen); 1356 signature = buffer_get_string(m, &signaturelen); 1357 data = buffer_get_string(m, &datalen); 1358 1359 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1360 !monitor_allowed_key(blob, bloblen)) 1361 fatal("%s: bad key, not previously allowed", __func__); 1362 1363 key = key_from_blob(blob, bloblen); 1364 if (key == NULL) 1365 fatal("%s: bad public key blob", __func__); 1366 1367 switch (key_blobtype) { 1368 case MM_USERKEY: 1369 valid_data = monitor_valid_userblob(data, datalen); 1370 break; 1371 case MM_HOSTKEY: 1372 valid_data = monitor_valid_hostbasedblob(data, datalen, 1373 hostbased_cuser, hostbased_chost); 1374 break; 1375 default: 1376 valid_data = 0; 1377 break; 1378 } 1379 if (!valid_data) 1380 fatal("%s: bad signature data blob", __func__); 1381 1382 verified = key_verify(key, signature, signaturelen, data, datalen); 1383 debug3("%s: key %p signature %s", 1384 __func__, key, (verified == 1) ? "verified" : "unverified"); 1385 1386 key_free(key); 1387 xfree(blob); 1388 xfree(signature); 1389 xfree(data); 1390 1391 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1392 1393 monitor_reset_key_state(); 1394 1395 buffer_clear(m); 1396 buffer_put_int(m, verified); 1397 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1398 1399 return (verified == 1); 1400} 1401 1402static void 1403mm_record_login(Session *s, struct passwd *pw) 1404{ 1405 socklen_t fromlen; 1406 struct sockaddr_storage from; 1407 1408 /* 1409 * Get IP address of client. If the connection is not a socket, let 1410 * the address be 0.0.0.0. 1411 */ 1412 memset(&from, 0, sizeof(from)); 1413 fromlen = sizeof(from); 1414 if (packet_connection_is_on_socket()) { 1415 if (getpeername(packet_get_connection_in(), 1416 (struct sockaddr *)&from, &fromlen) < 0) { 1417 debug("getpeername: %.100s", strerror(errno)); 1418 cleanup_exit(255); 1419 } 1420 } 1421 /* Record that there was a login on that tty from the remote host. */ 1422 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1423 get_remote_name_or_ip(utmp_len, options.use_dns), 1424 (struct sockaddr *)&from, fromlen); 1425} 1426 1427static void 1428mm_session_close(Session *s) 1429{ 1430 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1431 if (s->ttyfd != -1) { 1432 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1433 session_pty_cleanup2(s); 1434 } 1435 session_unused(s->self); 1436} 1437 1438int 1439mm_answer_pty(int sock, Buffer *m) 1440{ 1441 extern struct monitor *pmonitor; 1442 Session *s; 1443 int res, fd0; 1444 1445 debug3("%s entering", __func__); 1446 1447 buffer_clear(m); 1448 s = session_new(); 1449 if (s == NULL) 1450 goto error; 1451 s->authctxt = authctxt; 1452 s->pw = authctxt->pw; 1453 s->pid = pmonitor->m_pid; 1454 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1455 if (res == 0) 1456 goto error; 1457 pty_setowner(authctxt->pw, s->tty); 1458 1459 buffer_put_int(m, 1); 1460 buffer_put_cstring(m, s->tty); 1461 1462 /* We need to trick ttyslot */ 1463 if (dup2(s->ttyfd, 0) == -1) 1464 fatal("%s: dup2", __func__); 1465 1466 mm_record_login(s, authctxt->pw); 1467 1468 /* Now we can close the file descriptor again */ 1469 close(0); 1470 1471 /* send messages generated by record_login */ 1472 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1473 buffer_clear(&loginmsg); 1474 1475 mm_request_send(sock, MONITOR_ANS_PTY, m); 1476 1477 if (mm_send_fd(sock, s->ptyfd) == -1 || 1478 mm_send_fd(sock, s->ttyfd) == -1) 1479 fatal("%s: send fds failed", __func__); 1480 1481 /* make sure nothing uses fd 0 */ 1482 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1483 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1484 if (fd0 != 0) 1485 error("%s: fd0 %d != 0", __func__, fd0); 1486 1487 /* slave is not needed */ 1488 close(s->ttyfd); 1489 s->ttyfd = s->ptyfd; 1490 /* no need to dup() because nobody closes ptyfd */ 1491 s->ptymaster = s->ptyfd; 1492 1493 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1494 1495 return (0); 1496 1497 error: 1498 if (s != NULL) 1499 mm_session_close(s); 1500 buffer_put_int(m, 0); 1501 mm_request_send(sock, MONITOR_ANS_PTY, m); 1502 return (0); 1503} 1504 1505int 1506mm_answer_pty_cleanup(int sock, Buffer *m) 1507{ 1508 Session *s; 1509 char *tty; 1510 1511 debug3("%s entering", __func__); 1512 1513 tty = buffer_get_string(m, NULL); 1514 if ((s = session_by_tty(tty)) != NULL) 1515 mm_session_close(s); 1516 buffer_clear(m); 1517 xfree(tty); 1518 return (0); 1519} 1520 1521int 1522mm_answer_sesskey(int sock, Buffer *m) 1523{ 1524 BIGNUM *p; 1525 int rsafail; 1526 1527 /* Turn off permissions */ 1528 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1529 1530 if ((p = BN_new()) == NULL) 1531 fatal("%s: BN_new", __func__); 1532 1533 buffer_get_bignum2(m, p); 1534 1535 rsafail = ssh1_session_key(p); 1536 1537 buffer_clear(m); 1538 buffer_put_int(m, rsafail); 1539 buffer_put_bignum2(m, p); 1540 1541 BN_clear_free(p); 1542 1543 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1544 1545 /* Turn on permissions for sessid passing */ 1546 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1547 1548 return (0); 1549} 1550 1551int 1552mm_answer_sessid(int sock, Buffer *m) 1553{ 1554 int i; 1555 1556 debug3("%s entering", __func__); 1557 1558 if (buffer_len(m) != 16) 1559 fatal("%s: bad ssh1 session id", __func__); 1560 for (i = 0; i < 16; i++) 1561 session_id[i] = buffer_get_char(m); 1562 1563 /* Turn on permissions for getpwnam */ 1564 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1565 1566 return (0); 1567} 1568 1569int 1570mm_answer_rsa_keyallowed(int sock, Buffer *m) 1571{ 1572 BIGNUM *client_n; 1573 Key *key = NULL; 1574 u_char *blob = NULL; 1575 u_int blen = 0; 1576 int allowed = 0; 1577 1578 debug3("%s entering", __func__); 1579 1580 auth_method = "rsa"; 1581 if (options.rsa_authentication && authctxt->valid) { 1582 if ((client_n = BN_new()) == NULL) 1583 fatal("%s: BN_new", __func__); 1584 buffer_get_bignum2(m, client_n); 1585 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1586 BN_clear_free(client_n); 1587 } 1588 buffer_clear(m); 1589 buffer_put_int(m, allowed); 1590 buffer_put_int(m, forced_command != NULL); 1591 1592 /* clear temporarily storage (used by generate challenge) */ 1593 monitor_reset_key_state(); 1594 1595 if (allowed && key != NULL) { 1596 key->type = KEY_RSA; /* cheat for key_to_blob */ 1597 if (key_to_blob(key, &blob, &blen) == 0) 1598 fatal("%s: key_to_blob failed", __func__); 1599 buffer_put_string(m, blob, blen); 1600 1601 /* Save temporarily for comparison in verify */ 1602 key_blob = blob; 1603 key_bloblen = blen; 1604 key_blobtype = MM_RSAUSERKEY; 1605 } 1606 if (key != NULL) 1607 key_free(key); 1608 1609 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1610 1611 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1612 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1613 return (0); 1614} 1615 1616int 1617mm_answer_rsa_challenge(int sock, Buffer *m) 1618{ 1619 Key *key = NULL; 1620 u_char *blob; 1621 u_int blen; 1622 1623 debug3("%s entering", __func__); 1624 1625 if (!authctxt->valid) 1626 fatal("%s: authctxt not valid", __func__); 1627 blob = buffer_get_string(m, &blen); 1628 if (!monitor_allowed_key(blob, blen)) 1629 fatal("%s: bad key, not previously allowed", __func__); 1630 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1631 fatal("%s: key type mismatch", __func__); 1632 if ((key = key_from_blob(blob, blen)) == NULL) 1633 fatal("%s: received bad key", __func__); 1634 if (key->type != KEY_RSA) 1635 fatal("%s: received bad key type %d", __func__, key->type); 1636 key->type = KEY_RSA1; 1637 if (ssh1_challenge) 1638 BN_clear_free(ssh1_challenge); 1639 ssh1_challenge = auth_rsa_generate_challenge(key); 1640 1641 buffer_clear(m); 1642 buffer_put_bignum2(m, ssh1_challenge); 1643 1644 debug3("%s sending reply", __func__); 1645 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1646 1647 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1648 1649 xfree(blob); 1650 key_free(key); 1651 return (0); 1652} 1653 1654int 1655mm_answer_rsa_response(int sock, Buffer *m) 1656{ 1657 Key *key = NULL; 1658 u_char *blob, *response; 1659 u_int blen, len; 1660 int success; 1661 1662 debug3("%s entering", __func__); 1663 1664 if (!authctxt->valid) 1665 fatal("%s: authctxt not valid", __func__); 1666 if (ssh1_challenge == NULL) 1667 fatal("%s: no ssh1_challenge", __func__); 1668 1669 blob = buffer_get_string(m, &blen); 1670 if (!monitor_allowed_key(blob, blen)) 1671 fatal("%s: bad key, not previously allowed", __func__); 1672 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1673 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1674 if ((key = key_from_blob(blob, blen)) == NULL) 1675 fatal("%s: received bad key", __func__); 1676 response = buffer_get_string(m, &len); 1677 if (len != 16) 1678 fatal("%s: received bad response to challenge", __func__); 1679 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1680 1681 xfree(blob); 1682 key_free(key); 1683 xfree(response); 1684 1685 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1686 1687 /* reset state */ 1688 BN_clear_free(ssh1_challenge); 1689 ssh1_challenge = NULL; 1690 monitor_reset_key_state(); 1691 1692 buffer_clear(m); 1693 buffer_put_int(m, success); 1694 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1695 1696 return (success); 1697} 1698 1699int 1700mm_answer_term(int sock, Buffer *req) 1701{ 1702 extern struct monitor *pmonitor; 1703 int res, status; 1704 1705 debug3("%s: tearing down sessions", __func__); 1706 1707 /* The child is terminating */ 1708 session_destroy_all(&mm_session_close); 1709 1710#ifdef USE_PAM 1711 if (options.use_pam) 1712 sshpam_cleanup(); 1713#endif 1714 1715 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1716 if (errno != EINTR) 1717 exit(1); 1718 1719 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1720 1721 /* Terminate process */ 1722 exit(res); 1723} 1724 1725#ifdef SSH_AUDIT_EVENTS 1726/* Report that an audit event occurred */ 1727int 1728mm_answer_audit_event(int socket, Buffer *m) 1729{ 1730 ssh_audit_event_t event; 1731 1732 debug3("%s entering", __func__); 1733 1734 event = buffer_get_int(m); 1735 switch(event) { 1736 case SSH_AUTH_FAIL_PUBKEY: 1737 case SSH_AUTH_FAIL_HOSTBASED: 1738 case SSH_AUTH_FAIL_GSSAPI: 1739 case SSH_LOGIN_EXCEED_MAXTRIES: 1740 case SSH_LOGIN_ROOT_DENIED: 1741 case SSH_CONNECTION_CLOSE: 1742 case SSH_INVALID_USER: 1743 audit_event(event); 1744 break; 1745 default: 1746 fatal("Audit event type %d not permitted", event); 1747 } 1748 1749 return (0); 1750} 1751 1752int 1753mm_answer_audit_command(int socket, Buffer *m) 1754{ 1755 u_int len; 1756 char *cmd; 1757 1758 debug3("%s entering", __func__); 1759 cmd = buffer_get_string(m, &len); 1760 /* sanity check command, if so how? */ 1761 audit_run_command(cmd); 1762 xfree(cmd); 1763 return (0); 1764} 1765#endif /* SSH_AUDIT_EVENTS */ 1766 1767void 1768monitor_apply_keystate(struct monitor *pmonitor) 1769{ 1770 if (compat20) { 1771 set_newkeys(MODE_IN); 1772 set_newkeys(MODE_OUT); 1773 } else { 1774 packet_set_protocol_flags(child_state.ssh1protoflags); 1775 packet_set_encryption_key(child_state.ssh1key, 1776 child_state.ssh1keylen, child_state.ssh1cipher); 1777 xfree(child_state.ssh1key); 1778 } 1779 1780 /* for rc4 and other stateful ciphers */ 1781 packet_set_keycontext(MODE_OUT, child_state.keyout); 1782 xfree(child_state.keyout); 1783 packet_set_keycontext(MODE_IN, child_state.keyin); 1784 xfree(child_state.keyin); 1785 1786 if (!compat20) { 1787 packet_set_iv(MODE_OUT, child_state.ivout); 1788 xfree(child_state.ivout); 1789 packet_set_iv(MODE_IN, child_state.ivin); 1790 xfree(child_state.ivin); 1791 } 1792 1793 memcpy(&incoming_stream, &child_state.incoming, 1794 sizeof(incoming_stream)); 1795 memcpy(&outgoing_stream, &child_state.outgoing, 1796 sizeof(outgoing_stream)); 1797 1798 /* Update with new address */ 1799 if (options.compression) 1800 mm_init_compression(pmonitor->m_zlib); 1801 1802 /* Network I/O buffers */ 1803 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1804 buffer_clear(packet_get_input()); 1805 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1806 memset(child_state.input, 0, child_state.ilen); 1807 xfree(child_state.input); 1808 1809 buffer_clear(packet_get_output()); 1810 buffer_append(packet_get_output(), child_state.output, 1811 child_state.olen); 1812 memset(child_state.output, 0, child_state.olen); 1813 xfree(child_state.output); 1814 1815 /* Roaming */ 1816 if (compat20) 1817 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1818} 1819 1820static Kex * 1821mm_get_kex(Buffer *m) 1822{ 1823 Kex *kex; 1824 void *blob; 1825 u_int bloblen; 1826 1827 kex = xcalloc(1, sizeof(*kex)); 1828 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1829 if (session_id2 == NULL || 1830 kex->session_id_len != session_id2_len || 1831 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1832 fatal("mm_get_get: internal error: bad session id"); 1833 kex->we_need = buffer_get_int(m); 1834 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1835 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1836 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1837 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1838 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1839 kex->server = 1; 1840 kex->hostkey_type = buffer_get_int(m); 1841 kex->kex_type = buffer_get_int(m); 1842 blob = buffer_get_string(m, &bloblen); 1843 buffer_init(&kex->my); 1844 buffer_append(&kex->my, blob, bloblen); 1845 xfree(blob); 1846 blob = buffer_get_string(m, &bloblen); 1847 buffer_init(&kex->peer); 1848 buffer_append(&kex->peer, blob, bloblen); 1849 xfree(blob); 1850 kex->done = 1; 1851 kex->flags = buffer_get_int(m); 1852 kex->client_version_string = buffer_get_string(m, NULL); 1853 kex->server_version_string = buffer_get_string(m, NULL); 1854 kex->load_host_public_key=&get_hostkey_public_by_type; 1855 kex->load_host_private_key=&get_hostkey_private_by_type; 1856 kex->host_key_index=&get_hostkey_index; 1857 1858 return (kex); 1859} 1860 1861/* This function requries careful sanity checking */ 1862 1863void 1864mm_get_keystate(struct monitor *pmonitor) 1865{ 1866 Buffer m; 1867 u_char *blob, *p; 1868 u_int bloblen, plen; 1869 u_int32_t seqnr, packets; 1870 u_int64_t blocks, bytes; 1871 1872 debug3("%s: Waiting for new keys", __func__); 1873 1874 buffer_init(&m); 1875 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1876 if (!compat20) { 1877 child_state.ssh1protoflags = buffer_get_int(&m); 1878 child_state.ssh1cipher = buffer_get_int(&m); 1879 child_state.ssh1key = buffer_get_string(&m, 1880 &child_state.ssh1keylen); 1881 child_state.ivout = buffer_get_string(&m, 1882 &child_state.ivoutlen); 1883 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1884 goto skip; 1885 } else { 1886 /* Get the Kex for rekeying */ 1887 *pmonitor->m_pkex = mm_get_kex(&m); 1888 } 1889 1890 blob = buffer_get_string(&m, &bloblen); 1891 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1892 xfree(blob); 1893 1894 debug3("%s: Waiting for second key", __func__); 1895 blob = buffer_get_string(&m, &bloblen); 1896 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1897 xfree(blob); 1898 1899 /* Now get sequence numbers for the packets */ 1900 seqnr = buffer_get_int(&m); 1901 blocks = buffer_get_int64(&m); 1902 packets = buffer_get_int(&m); 1903 bytes = buffer_get_int64(&m); 1904 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1905 seqnr = buffer_get_int(&m); 1906 blocks = buffer_get_int64(&m); 1907 packets = buffer_get_int(&m); 1908 bytes = buffer_get_int64(&m); 1909 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1910 1911 skip: 1912 /* Get the key context */ 1913 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1914 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1915 1916 debug3("%s: Getting compression state", __func__); 1917 /* Get compression state */ 1918 p = buffer_get_string(&m, &plen); 1919 if (plen != sizeof(child_state.outgoing)) 1920 fatal("%s: bad request size", __func__); 1921 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1922 xfree(p); 1923 1924 p = buffer_get_string(&m, &plen); 1925 if (plen != sizeof(child_state.incoming)) 1926 fatal("%s: bad request size", __func__); 1927 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1928 xfree(p); 1929 1930 /* Network I/O buffers */ 1931 debug3("%s: Getting Network I/O buffers", __func__); 1932 child_state.input = buffer_get_string(&m, &child_state.ilen); 1933 child_state.output = buffer_get_string(&m, &child_state.olen); 1934 1935 /* Roaming */ 1936 if (compat20) { 1937 child_state.sent_bytes = buffer_get_int64(&m); 1938 child_state.recv_bytes = buffer_get_int64(&m); 1939 } 1940 1941 buffer_free(&m); 1942} 1943 1944 1945/* Allocation functions for zlib */ 1946void * 1947mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1948{ 1949 size_t len = (size_t) size * ncount; 1950 void *address; 1951 1952 if (len == 0 || ncount > SIZE_T_MAX / size) 1953 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1954 1955 address = mm_malloc(mm, len); 1956 1957 return (address); 1958} 1959 1960void 1961mm_zfree(struct mm_master *mm, void *address) 1962{ 1963 mm_free(mm, address); 1964} 1965 1966void 1967mm_init_compression(struct mm_master *mm) 1968{ 1969 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1970 outgoing_stream.zfree = (free_func)mm_zfree; 1971 outgoing_stream.opaque = mm; 1972 1973 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1974 incoming_stream.zfree = (free_func)mm_zfree; 1975 incoming_stream.opaque = mm; 1976} 1977 1978/* XXX */ 1979 1980#define FD_CLOSEONEXEC(x) do { \ 1981 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1982 fatal("fcntl(%d, F_SETFD)", x); \ 1983} while (0) 1984 1985static void 1986monitor_openfds(struct monitor *mon, int do_logfds) 1987{ 1988 int pair[2]; 1989 1990 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1991 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1992 FD_CLOSEONEXEC(pair[0]); 1993 FD_CLOSEONEXEC(pair[1]); 1994 mon->m_recvfd = pair[0]; 1995 mon->m_sendfd = pair[1]; 1996 1997 if (do_logfds) { 1998 if (pipe(pair) == -1) 1999 fatal("%s: pipe: %s", __func__, strerror(errno)); 2000 FD_CLOSEONEXEC(pair[0]); 2001 FD_CLOSEONEXEC(pair[1]); 2002 mon->m_log_recvfd = pair[0]; 2003 mon->m_log_sendfd = pair[1]; 2004 } else 2005 mon->m_log_recvfd = mon->m_log_sendfd = -1; 2006} 2007 2008#define MM_MEMSIZE 65536 2009 2010struct monitor * 2011monitor_init(void) 2012{ 2013 struct monitor *mon; 2014 2015 mon = xcalloc(1, sizeof(*mon)); 2016 2017 monitor_openfds(mon, 1); 2018 2019 /* Used to share zlib space across processes */ 2020 if (options.compression) { 2021 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 2022 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 2023 2024 /* Compression needs to share state across borders */ 2025 mm_init_compression(mon->m_zlib); 2026 } 2027 2028 return mon; 2029} 2030 2031void 2032monitor_reinit(struct monitor *mon) 2033{ 2034 monitor_openfds(mon, 0); 2035} 2036 2037#ifdef GSSAPI 2038int 2039mm_answer_gss_setup_ctx(int sock, Buffer *m) 2040{ 2041 gss_OID_desc goid; 2042 OM_uint32 major; 2043 u_int len; 2044 2045 goid.elements = buffer_get_string(m, &len); 2046 goid.length = len; 2047 2048 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 2049 2050 xfree(goid.elements); 2051 2052 buffer_clear(m); 2053 buffer_put_int(m, major); 2054 2055 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 2056 2057 /* Now we have a context, enable the step */ 2058 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 2059 2060 return (0); 2061} 2062 2063int 2064mm_answer_gss_accept_ctx(int sock, Buffer *m) 2065{ 2066 gss_buffer_desc in; 2067 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2068 OM_uint32 major, minor; 2069 OM_uint32 flags = 0; /* GSI needs this */ 2070 u_int len; 2071 2072 in.value = buffer_get_string(m, &len); 2073 in.length = len; 2074 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2075 xfree(in.value); 2076 2077 buffer_clear(m); 2078 buffer_put_int(m, major); 2079 buffer_put_string(m, out.value, out.length); 2080 buffer_put_int(m, flags); 2081 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2082 2083 gss_release_buffer(&minor, &out); 2084 2085 if (major == GSS_S_COMPLETE) { 2086 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2087 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2088 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2089 } 2090 return (0); 2091} 2092 2093int 2094mm_answer_gss_checkmic(int sock, Buffer *m) 2095{ 2096 gss_buffer_desc gssbuf, mic; 2097 OM_uint32 ret; 2098 u_int len; 2099 2100 gssbuf.value = buffer_get_string(m, &len); 2101 gssbuf.length = len; 2102 mic.value = buffer_get_string(m, &len); 2103 mic.length = len; 2104 2105 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2106 2107 xfree(gssbuf.value); 2108 xfree(mic.value); 2109 2110 buffer_clear(m); 2111 buffer_put_int(m, ret); 2112 2113 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2114 2115 if (!GSS_ERROR(ret)) 2116 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2117 2118 return (0); 2119} 2120 2121int 2122mm_answer_gss_userok(int sock, Buffer *m) 2123{ 2124 int authenticated; 2125 2126 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2127 2128 buffer_clear(m); 2129 buffer_put_int(m, authenticated); 2130 2131 debug3("%s: sending result %d", __func__, authenticated); 2132 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2133 2134 auth_method = "gssapi-with-mic"; 2135 2136 /* Monitor loop will terminate if authenticated */ 2137 return (authenticated); 2138} 2139#endif /* GSSAPI */ 2140 2141#ifdef JPAKE 2142int 2143mm_answer_jpake_step1(int sock, Buffer *m) 2144{ 2145 struct jpake_ctx *pctx; 2146 u_char *x3_proof, *x4_proof; 2147 u_int x3_proof_len, x4_proof_len; 2148 2149 if (!options.zero_knowledge_password_authentication) 2150 fatal("zero_knowledge_password_authentication disabled"); 2151 2152 if (authctxt->jpake_ctx != NULL) 2153 fatal("%s: authctxt->jpake_ctx already set (%p)", 2154 __func__, authctxt->jpake_ctx); 2155 authctxt->jpake_ctx = pctx = jpake_new(); 2156 2157 jpake_step1(pctx->grp, 2158 &pctx->server_id, &pctx->server_id_len, 2159 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 2160 &x3_proof, &x3_proof_len, 2161 &x4_proof, &x4_proof_len); 2162 2163 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 2164 2165 buffer_clear(m); 2166 2167 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 2168 buffer_put_bignum2(m, pctx->g_x3); 2169 buffer_put_bignum2(m, pctx->g_x4); 2170 buffer_put_string(m, x3_proof, x3_proof_len); 2171 buffer_put_string(m, x4_proof, x4_proof_len); 2172 2173 debug3("%s: sending step1", __func__); 2174 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 2175 2176 bzero(x3_proof, x3_proof_len); 2177 bzero(x4_proof, x4_proof_len); 2178 xfree(x3_proof); 2179 xfree(x4_proof); 2180 2181 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 2182 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 2183 2184 return 0; 2185} 2186 2187int 2188mm_answer_jpake_get_pwdata(int sock, Buffer *m) 2189{ 2190 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2191 char *hash_scheme, *salt; 2192 2193 if (pctx == NULL) 2194 fatal("%s: pctx == NULL", __func__); 2195 2196 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 2197 2198 buffer_clear(m); 2199 /* pctx->s is sensitive, not returned to slave */ 2200 buffer_put_cstring(m, hash_scheme); 2201 buffer_put_cstring(m, salt); 2202 2203 debug3("%s: sending pwdata", __func__); 2204 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 2205 2206 bzero(hash_scheme, strlen(hash_scheme)); 2207 bzero(salt, strlen(salt)); 2208 xfree(hash_scheme); 2209 xfree(salt); 2210 2211 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 2212 2213 return 0; 2214} 2215 2216int 2217mm_answer_jpake_step2(int sock, Buffer *m) 2218{ 2219 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2220 u_char *x1_proof, *x2_proof, *x4_s_proof; 2221 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 2222 2223 if (pctx == NULL) 2224 fatal("%s: pctx == NULL", __func__); 2225 2226 if ((pctx->g_x1 = BN_new()) == NULL || 2227 (pctx->g_x2 = BN_new()) == NULL) 2228 fatal("%s: BN_new", __func__); 2229 buffer_get_bignum2(m, pctx->g_x1); 2230 buffer_get_bignum2(m, pctx->g_x2); 2231 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 2232 x1_proof = buffer_get_string(m, &x1_proof_len); 2233 x2_proof = buffer_get_string(m, &x2_proof_len); 2234 2235 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 2236 pctx->g_x1, pctx->g_x2, pctx->x4, 2237 pctx->client_id, pctx->client_id_len, 2238 pctx->server_id, pctx->server_id_len, 2239 x1_proof, x1_proof_len, 2240 x2_proof, x2_proof_len, 2241 &pctx->b, 2242 &x4_s_proof, &x4_s_proof_len); 2243 2244 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 2245 2246 bzero(x1_proof, x1_proof_len); 2247 bzero(x2_proof, x2_proof_len); 2248 xfree(x1_proof); 2249 xfree(x2_proof); 2250 2251 buffer_clear(m); 2252 2253 buffer_put_bignum2(m, pctx->b); 2254 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 2255 2256 debug3("%s: sending step2", __func__); 2257 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 2258 2259 bzero(x4_s_proof, x4_s_proof_len); 2260 xfree(x4_s_proof); 2261 2262 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 2263 2264 return 0; 2265} 2266 2267int 2268mm_answer_jpake_key_confirm(int sock, Buffer *m) 2269{ 2270 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2271 u_char *x2_s_proof; 2272 u_int x2_s_proof_len; 2273 2274 if (pctx == NULL) 2275 fatal("%s: pctx == NULL", __func__); 2276 2277 if ((pctx->a = BN_new()) == NULL) 2278 fatal("%s: BN_new", __func__); 2279 buffer_get_bignum2(m, pctx->a); 2280 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 2281 2282 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 2283 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 2284 pctx->server_id, pctx->server_id_len, 2285 pctx->client_id, pctx->client_id_len, 2286 session_id2, session_id2_len, 2287 x2_s_proof, x2_s_proof_len, 2288 &pctx->k, 2289 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 2290 2291 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 2292 2293 bzero(x2_s_proof, x2_s_proof_len); 2294 buffer_clear(m); 2295 2296 /* pctx->k is sensitive, not sent */ 2297 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 2298 2299 debug3("%s: sending confirmation hash", __func__); 2300 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 2301 2302 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 2303 2304 return 0; 2305} 2306 2307int 2308mm_answer_jpake_check_confirm(int sock, Buffer *m) 2309{ 2310 int authenticated = 0; 2311 u_char *peer_confirm_hash; 2312 u_int peer_confirm_hash_len; 2313 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2314 2315 if (pctx == NULL) 2316 fatal("%s: pctx == NULL", __func__); 2317 2318 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 2319 2320 authenticated = jpake_check_confirm(pctx->k, 2321 pctx->client_id, pctx->client_id_len, 2322 session_id2, session_id2_len, 2323 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 2324 2325 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 2326 2327 bzero(peer_confirm_hash, peer_confirm_hash_len); 2328 xfree(peer_confirm_hash); 2329 2330 buffer_clear(m); 2331 buffer_put_int(m, authenticated); 2332 2333 debug3("%s: sending result %d", __func__, authenticated); 2334 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 2335 2336 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 2337 2338 auth_method = "jpake-01@openssh.com"; 2339 return authenticated; 2340} 2341 2342#endif /* JPAKE */ 2343