monitor.c revision 1.113
1/* $OpenBSD: monitor.c,v 1.113 2011/05/23 03:30:07 djm Exp $ */ 2/* 3 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus@openbsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#include <sys/types.h> 29#include <sys/wait.h> 30#include <sys/socket.h> 31#include <sys/tree.h> 32#include <sys/param.h> 33#include <sys/queue.h> 34 35#include <openssl/dh.h> 36 37#include <errno.h> 38#include <fcntl.h> 39#include <paths.h> 40#include <pwd.h> 41#include <signal.h> 42#include <stdlib.h> 43#include <string.h> 44 45 46#include "xmalloc.h" 47#include "ssh.h" 48#include "key.h" 49#include "buffer.h" 50#include "hostfile.h" 51#include "auth.h" 52#include "cipher.h" 53#include "kex.h" 54#include "dh.h" 55#include <zlib.h> 56#include "packet.h" 57#include "auth-options.h" 58#include "sshpty.h" 59#include "channels.h" 60#include "session.h" 61#include "sshlogin.h" 62#include "canohost.h" 63#include "log.h" 64#include "servconf.h" 65#include "monitor.h" 66#include "monitor_mm.h" 67#ifdef GSSAPI 68#include "ssh-gss.h" 69#endif 70#include "monitor_wrap.h" 71#include "monitor_fdpass.h" 72#include "misc.h" 73#include "compat.h" 74#include "ssh2.h" 75#include "jpake.h" 76#include "roaming.h" 77 78#ifdef GSSAPI 79static Gssctxt *gsscontext = NULL; 80#endif 81 82/* Imports */ 83extern ServerOptions options; 84extern u_int utmp_len; 85extern Newkeys *current_keys[]; 86extern z_stream incoming_stream; 87extern z_stream outgoing_stream; 88extern u_char session_id[]; 89extern Buffer auth_debug; 90extern int auth_debug_init; 91extern Buffer loginmsg; 92 93/* State exported from the child */ 94 95struct { 96 z_stream incoming; 97 z_stream outgoing; 98 u_char *keyin; 99 u_int keyinlen; 100 u_char *keyout; 101 u_int keyoutlen; 102 u_char *ivin; 103 u_int ivinlen; 104 u_char *ivout; 105 u_int ivoutlen; 106 u_char *ssh1key; 107 u_int ssh1keylen; 108 int ssh1cipher; 109 int ssh1protoflags; 110 u_char *input; 111 u_int ilen; 112 u_char *output; 113 u_int olen; 114 u_int64_t sent_bytes; 115 u_int64_t recv_bytes; 116} child_state; 117 118/* Functions on the monitor that answer unprivileged requests */ 119 120int mm_answer_moduli(int, Buffer *); 121int mm_answer_sign(int, Buffer *); 122int mm_answer_pwnamallow(int, Buffer *); 123int mm_answer_auth2_read_banner(int, Buffer *); 124int mm_answer_authserv(int, Buffer *); 125int mm_answer_authpassword(int, Buffer *); 126int mm_answer_bsdauthquery(int, Buffer *); 127int mm_answer_bsdauthrespond(int, Buffer *); 128int mm_answer_skeyquery(int, Buffer *); 129int mm_answer_skeyrespond(int, Buffer *); 130int mm_answer_keyallowed(int, Buffer *); 131int mm_answer_keyverify(int, Buffer *); 132int mm_answer_pty(int, Buffer *); 133int mm_answer_pty_cleanup(int, Buffer *); 134int mm_answer_term(int, Buffer *); 135int mm_answer_rsa_keyallowed(int, Buffer *); 136int mm_answer_rsa_challenge(int, Buffer *); 137int mm_answer_rsa_response(int, Buffer *); 138int mm_answer_sesskey(int, Buffer *); 139int mm_answer_sessid(int, Buffer *); 140int mm_answer_jpake_get_pwdata(int, Buffer *); 141int mm_answer_jpake_step1(int, Buffer *); 142int mm_answer_jpake_step2(int, Buffer *); 143int mm_answer_jpake_key_confirm(int, Buffer *); 144int mm_answer_jpake_check_confirm(int, Buffer *); 145 146#ifdef GSSAPI 147int mm_answer_gss_setup_ctx(int, Buffer *); 148int mm_answer_gss_accept_ctx(int, Buffer *); 149int mm_answer_gss_userok(int, Buffer *); 150int mm_answer_gss_checkmic(int, Buffer *); 151#endif 152 153static Authctxt *authctxt; 154static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 155 156/* local state for key verify */ 157static u_char *key_blob = NULL; 158static u_int key_bloblen = 0; 159static int key_blobtype = MM_NOKEY; 160static char *hostbased_cuser = NULL; 161static char *hostbased_chost = NULL; 162static char *auth_method = "unknown"; 163static u_int session_id2_len = 0; 164static u_char *session_id2 = NULL; 165static pid_t monitor_child_pid; 166 167struct mon_table { 168 enum monitor_reqtype type; 169 int flags; 170 int (*f)(int, Buffer *); 171}; 172 173#define MON_ISAUTH 0x0004 /* Required for Authentication */ 174#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 175#define MON_ONCE 0x0010 /* Disable after calling */ 176#define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 177 178#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 179 180#define MON_PERMIT 0x1000 /* Request is permitted */ 181 182struct mon_table mon_dispatch_proto20[] = { 183 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 184 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 185 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 186 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 187 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 188 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 189 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 190 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 191 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 192 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 193#ifdef GSSAPI 194 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 195 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 196 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 197 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 198#endif 199#ifdef JPAKE 200 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 201 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 202 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 203 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 204 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 205#endif 206 {0, 0, NULL} 207}; 208 209struct mon_table mon_dispatch_postauth20[] = { 210 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 211 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 212 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 213 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 214 {MONITOR_REQ_TERM, 0, mm_answer_term}, 215 {0, 0, NULL} 216}; 217 218struct mon_table mon_dispatch_proto15[] = { 219 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 220 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 221 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 222 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 223 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 224 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 225 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 226 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 227 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 228 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 229 {0, 0, NULL} 230}; 231 232struct mon_table mon_dispatch_postauth15[] = { 233 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 234 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 235 {MONITOR_REQ_TERM, 0, mm_answer_term}, 236 {0, 0, NULL} 237}; 238 239struct mon_table *mon_dispatch; 240 241/* Specifies if a certain message is allowed at the moment */ 242 243static void 244monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 245{ 246 while (ent->f != NULL) { 247 if (ent->type == type) { 248 ent->flags &= ~MON_PERMIT; 249 ent->flags |= permit ? MON_PERMIT : 0; 250 return; 251 } 252 ent++; 253 } 254} 255 256static void 257monitor_permit_authentications(int permit) 258{ 259 struct mon_table *ent = mon_dispatch; 260 261 while (ent->f != NULL) { 262 if (ent->flags & MON_AUTH) { 263 ent->flags &= ~MON_PERMIT; 264 ent->flags |= permit ? MON_PERMIT : 0; 265 } 266 ent++; 267 } 268} 269 270void 271monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 272{ 273 struct mon_table *ent; 274 int authenticated = 0; 275 276 debug3("preauth child monitor started"); 277 278 authctxt = _authctxt; 279 memset(authctxt, 0, sizeof(*authctxt)); 280 281 if (compat20) { 282 mon_dispatch = mon_dispatch_proto20; 283 284 /* Permit requests for moduli and signatures */ 285 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 286 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 287 } else { 288 mon_dispatch = mon_dispatch_proto15; 289 290 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 291 } 292 293 /* The first few requests do not require asynchronous access */ 294 while (!authenticated) { 295 auth_method = "unknown"; 296 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 297 if (authenticated) { 298 if (!(ent->flags & MON_AUTHDECIDE)) 299 fatal("%s: unexpected authentication from %d", 300 __func__, ent->type); 301 if (authctxt->pw->pw_uid == 0 && 302 !auth_root_allowed(auth_method)) 303 authenticated = 0; 304 } 305 306 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 307 auth_log(authctxt, authenticated, auth_method, 308 compat20 ? " ssh2" : ""); 309 if (!authenticated) 310 authctxt->failures++; 311 } 312#ifdef JPAKE 313 /* Cleanup JPAKE context after authentication */ 314 if (ent->flags & MON_AUTHDECIDE) { 315 if (authctxt->jpake_ctx != NULL) { 316 jpake_free(authctxt->jpake_ctx); 317 authctxt->jpake_ctx = NULL; 318 } 319 } 320#endif 321 } 322 323 if (!authctxt->valid) 324 fatal("%s: authenticated invalid user", __func__); 325 if (strcmp(auth_method, "unknown") == 0) 326 fatal("%s: authentication method name unknown", __func__); 327 328 debug("%s: %s has been authenticated by privileged process", 329 __func__, authctxt->user); 330 331 mm_get_keystate(pmonitor); 332} 333 334static void 335monitor_set_child_handler(pid_t pid) 336{ 337 monitor_child_pid = pid; 338} 339 340static void 341monitor_child_handler(int sig) 342{ 343 kill(monitor_child_pid, sig); 344} 345 346void 347monitor_child_postauth(struct monitor *pmonitor) 348{ 349 monitor_set_child_handler(pmonitor->m_pid); 350 signal(SIGHUP, &monitor_child_handler); 351 signal(SIGTERM, &monitor_child_handler); 352 signal(SIGINT, &monitor_child_handler); 353 354 if (compat20) { 355 mon_dispatch = mon_dispatch_postauth20; 356 357 /* Permit requests for moduli and signatures */ 358 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 359 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 360 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 361 } else { 362 mon_dispatch = mon_dispatch_postauth15; 363 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 364 } 365 if (!no_pty_flag) { 366 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 367 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 368 } 369 370 for (;;) 371 monitor_read(pmonitor, mon_dispatch, NULL); 372} 373 374void 375monitor_sync(struct monitor *pmonitor) 376{ 377 if (options.compression) { 378 /* The member allocation is not visible, so sync it */ 379 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 380 } 381} 382 383int 384monitor_read(struct monitor *pmonitor, struct mon_table *ent, 385 struct mon_table **pent) 386{ 387 Buffer m; 388 int ret; 389 u_char type; 390 391 buffer_init(&m); 392 393 mm_request_receive(pmonitor->m_sendfd, &m); 394 type = buffer_get_char(&m); 395 396 debug3("%s: checking request %d", __func__, type); 397 398 while (ent->f != NULL) { 399 if (ent->type == type) 400 break; 401 ent++; 402 } 403 404 if (ent->f != NULL) { 405 if (!(ent->flags & MON_PERMIT)) 406 fatal("%s: unpermitted request %d", __func__, 407 type); 408 ret = (*ent->f)(pmonitor->m_sendfd, &m); 409 buffer_free(&m); 410 411 /* The child may use this request only once, disable it */ 412 if (ent->flags & MON_ONCE) { 413 debug2("%s: %d used once, disabling now", __func__, 414 type); 415 ent->flags &= ~MON_PERMIT; 416 } 417 418 if (pent != NULL) 419 *pent = ent; 420 421 return ret; 422 } 423 424 fatal("%s: unsupported request: %d", __func__, type); 425 426 /* NOTREACHED */ 427 return (-1); 428} 429 430/* allowed key state */ 431static int 432monitor_allowed_key(u_char *blob, u_int bloblen) 433{ 434 /* make sure key is allowed */ 435 if (key_blob == NULL || key_bloblen != bloblen || 436 timingsafe_bcmp(key_blob, blob, key_bloblen)) 437 return (0); 438 return (1); 439} 440 441static void 442monitor_reset_key_state(void) 443{ 444 /* reset state */ 445 if (key_blob != NULL) 446 xfree(key_blob); 447 if (hostbased_cuser != NULL) 448 xfree(hostbased_cuser); 449 if (hostbased_chost != NULL) 450 xfree(hostbased_chost); 451 key_blob = NULL; 452 key_bloblen = 0; 453 key_blobtype = MM_NOKEY; 454 hostbased_cuser = NULL; 455 hostbased_chost = NULL; 456} 457 458int 459mm_answer_moduli(int sock, Buffer *m) 460{ 461 DH *dh; 462 int min, want, max; 463 464 min = buffer_get_int(m); 465 want = buffer_get_int(m); 466 max = buffer_get_int(m); 467 468 debug3("%s: got parameters: %d %d %d", 469 __func__, min, want, max); 470 /* We need to check here, too, in case the child got corrupted */ 471 if (max < min || want < min || max < want) 472 fatal("%s: bad parameters: %d %d %d", 473 __func__, min, want, max); 474 475 buffer_clear(m); 476 477 dh = choose_dh(min, want, max); 478 if (dh == NULL) { 479 buffer_put_char(m, 0); 480 return (0); 481 } else { 482 /* Send first bignum */ 483 buffer_put_char(m, 1); 484 buffer_put_bignum2(m, dh->p); 485 buffer_put_bignum2(m, dh->g); 486 487 DH_free(dh); 488 } 489 mm_request_send(sock, MONITOR_ANS_MODULI, m); 490 return (0); 491} 492 493int 494mm_answer_sign(int sock, Buffer *m) 495{ 496 Key *key; 497 u_char *p; 498 u_char *signature; 499 u_int siglen, datlen; 500 int keyid; 501 502 debug3("%s", __func__); 503 504 keyid = buffer_get_int(m); 505 p = buffer_get_string(m, &datlen); 506 507 /* 508 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 509 * SHA384 (48 bytes) and SHA512 (64 bytes). 510 */ 511 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) 512 fatal("%s: data length incorrect: %u", __func__, datlen); 513 514 /* save session id, it will be passed on the first call */ 515 if (session_id2_len == 0) { 516 session_id2_len = datlen; 517 session_id2 = xmalloc(session_id2_len); 518 memcpy(session_id2, p, session_id2_len); 519 } 520 521 if ((key = get_hostkey_by_index(keyid)) == NULL) 522 fatal("%s: no hostkey from index %d", __func__, keyid); 523 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 524 fatal("%s: key_sign failed", __func__); 525 526 debug3("%s: signature %p(%u)", __func__, signature, siglen); 527 528 buffer_clear(m); 529 buffer_put_string(m, signature, siglen); 530 531 xfree(p); 532 xfree(signature); 533 534 mm_request_send(sock, MONITOR_ANS_SIGN, m); 535 536 /* Turn on permissions for getpwnam */ 537 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 538 539 return (0); 540} 541 542/* Retrieves the password entry and also checks if the user is permitted */ 543 544int 545mm_answer_pwnamallow(int sock, Buffer *m) 546{ 547 char *username; 548 struct passwd *pwent; 549 int allowed = 0; 550 u_int i; 551 552 debug3("%s", __func__); 553 554 if (authctxt->attempt++ != 0) 555 fatal("%s: multiple attempts for getpwnam", __func__); 556 557 username = buffer_get_string(m, NULL); 558 559 pwent = getpwnamallow(username); 560 561 authctxt->user = xstrdup(username); 562 setproctitle("%s [priv]", pwent ? username : "unknown"); 563 xfree(username); 564 565 buffer_clear(m); 566 567 if (pwent == NULL) { 568 buffer_put_char(m, 0); 569 authctxt->pw = fakepw(); 570 goto out; 571 } 572 573 allowed = 1; 574 authctxt->pw = pwent; 575 authctxt->valid = 1; 576 577 buffer_put_char(m, 1); 578 buffer_put_string(m, pwent, sizeof(struct passwd)); 579 buffer_put_cstring(m, pwent->pw_name); 580 buffer_put_cstring(m, "*"); 581 buffer_put_cstring(m, pwent->pw_gecos); 582 buffer_put_cstring(m, pwent->pw_class); 583 buffer_put_cstring(m, pwent->pw_dir); 584 buffer_put_cstring(m, pwent->pw_shell); 585 586 out: 587 buffer_put_string(m, &options, sizeof(options)); 588 589#define M_CP_STROPT(x) do { \ 590 if (options.x != NULL) \ 591 buffer_put_cstring(m, options.x); \ 592 } while (0) 593#define M_CP_STRARRAYOPT(x, nx) do { \ 594 for (i = 0; i < options.nx; i++) \ 595 buffer_put_cstring(m, options.x[i]); \ 596 } while (0) 597 /* See comment in servconf.h */ 598 COPY_MATCH_STRING_OPTS(); 599#undef M_CP_STROPT 600#undef M_CP_STRARRAYOPT 601 602 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 603 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 604 605 /* For SSHv1 allow authentication now */ 606 if (!compat20) 607 monitor_permit_authentications(1); 608 else { 609 /* Allow service/style information on the auth context */ 610 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 611 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 612 } 613 614 return (0); 615} 616 617int mm_answer_auth2_read_banner(int sock, Buffer *m) 618{ 619 char *banner; 620 621 buffer_clear(m); 622 banner = auth2_read_banner(); 623 buffer_put_cstring(m, banner != NULL ? banner : ""); 624 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 625 626 if (banner != NULL) 627 xfree(banner); 628 629 return (0); 630} 631 632int 633mm_answer_authserv(int sock, Buffer *m) 634{ 635 monitor_permit_authentications(1); 636 637 authctxt->service = buffer_get_string(m, NULL); 638 authctxt->style = buffer_get_string(m, NULL); 639 debug3("%s: service=%s, style=%s", 640 __func__, authctxt->service, authctxt->style); 641 642 if (strlen(authctxt->style) == 0) { 643 xfree(authctxt->style); 644 authctxt->style = NULL; 645 } 646 647 return (0); 648} 649 650int 651mm_answer_authpassword(int sock, Buffer *m) 652{ 653 static int call_count; 654 char *passwd; 655 int authenticated; 656 u_int plen; 657 658 passwd = buffer_get_string(m, &plen); 659 /* Only authenticate if the context is valid */ 660 authenticated = options.password_authentication && 661 auth_password(authctxt, passwd); 662 memset(passwd, 0, strlen(passwd)); 663 xfree(passwd); 664 665 buffer_clear(m); 666 buffer_put_int(m, authenticated); 667 668 debug3("%s: sending result %d", __func__, authenticated); 669 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 670 671 call_count++; 672 if (plen == 0 && call_count == 1) 673 auth_method = "none"; 674 else 675 auth_method = "password"; 676 677 /* Causes monitor loop to terminate if authenticated */ 678 return (authenticated); 679} 680 681int 682mm_answer_bsdauthquery(int sock, Buffer *m) 683{ 684 char *name, *infotxt; 685 u_int numprompts; 686 u_int *echo_on; 687 char **prompts; 688 u_int success; 689 690 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 691 &prompts, &echo_on) < 0 ? 0 : 1; 692 693 buffer_clear(m); 694 buffer_put_int(m, success); 695 if (success) 696 buffer_put_cstring(m, prompts[0]); 697 698 debug3("%s: sending challenge success: %u", __func__, success); 699 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 700 701 if (success) { 702 xfree(name); 703 xfree(infotxt); 704 xfree(prompts); 705 xfree(echo_on); 706 } 707 708 return (0); 709} 710 711int 712mm_answer_bsdauthrespond(int sock, Buffer *m) 713{ 714 char *response; 715 int authok; 716 717 if (authctxt->as == 0) 718 fatal("%s: no bsd auth session", __func__); 719 720 response = buffer_get_string(m, NULL); 721 authok = options.challenge_response_authentication && 722 auth_userresponse(authctxt->as, response, 0); 723 authctxt->as = NULL; 724 debug3("%s: <%s> = <%d>", __func__, response, authok); 725 xfree(response); 726 727 buffer_clear(m); 728 buffer_put_int(m, authok); 729 730 debug3("%s: sending authenticated: %d", __func__, authok); 731 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 732 733 auth_method = "bsdauth"; 734 735 return (authok != 0); 736} 737 738int 739mm_answer_keyallowed(int sock, Buffer *m) 740{ 741 Key *key; 742 char *cuser, *chost; 743 u_char *blob; 744 u_int bloblen; 745 enum mm_keytype type = 0; 746 int allowed = 0; 747 748 debug3("%s entering", __func__); 749 750 type = buffer_get_int(m); 751 cuser = buffer_get_string(m, NULL); 752 chost = buffer_get_string(m, NULL); 753 blob = buffer_get_string(m, &bloblen); 754 755 key = key_from_blob(blob, bloblen); 756 757 if ((compat20 && type == MM_RSAHOSTKEY) || 758 (!compat20 && type != MM_RSAHOSTKEY)) 759 fatal("%s: key type and protocol mismatch", __func__); 760 761 debug3("%s: key_from_blob: %p", __func__, key); 762 763 if (key != NULL && authctxt->valid) { 764 switch (type) { 765 case MM_USERKEY: 766 allowed = options.pubkey_authentication && 767 user_key_allowed(authctxt->pw, key); 768 auth_method = "publickey"; 769 if (options.pubkey_authentication && allowed != 1) 770 auth_clear_options(); 771 break; 772 case MM_HOSTKEY: 773 allowed = options.hostbased_authentication && 774 hostbased_key_allowed(authctxt->pw, 775 cuser, chost, key); 776 auth_method = "hostbased"; 777 break; 778 case MM_RSAHOSTKEY: 779 key->type = KEY_RSA1; /* XXX */ 780 allowed = options.rhosts_rsa_authentication && 781 auth_rhosts_rsa_key_allowed(authctxt->pw, 782 cuser, chost, key); 783 if (options.rhosts_rsa_authentication && allowed != 1) 784 auth_clear_options(); 785 auth_method = "rsa"; 786 break; 787 default: 788 fatal("%s: unknown key type %d", __func__, type); 789 break; 790 } 791 } 792 if (key != NULL) 793 key_free(key); 794 795 /* clear temporarily storage (used by verify) */ 796 monitor_reset_key_state(); 797 798 if (allowed) { 799 /* Save temporarily for comparison in verify */ 800 key_blob = blob; 801 key_bloblen = bloblen; 802 key_blobtype = type; 803 hostbased_cuser = cuser; 804 hostbased_chost = chost; 805 } else { 806 /* Log failed attempt */ 807 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 808 xfree(blob); 809 xfree(cuser); 810 xfree(chost); 811 } 812 813 debug3("%s: key %p is %s", 814 __func__, key, allowed ? "allowed" : "not allowed"); 815 816 buffer_clear(m); 817 buffer_put_int(m, allowed); 818 buffer_put_int(m, forced_command != NULL); 819 820 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 821 822 if (type == MM_RSAHOSTKEY) 823 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 824 825 return (0); 826} 827 828static int 829monitor_valid_userblob(u_char *data, u_int datalen) 830{ 831 Buffer b; 832 char *p; 833 u_int len; 834 int fail = 0; 835 836 buffer_init(&b); 837 buffer_append(&b, data, datalen); 838 839 if (datafellows & SSH_OLD_SESSIONID) { 840 p = buffer_ptr(&b); 841 len = buffer_len(&b); 842 if ((session_id2 == NULL) || 843 (len < session_id2_len) || 844 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 845 fail++; 846 buffer_consume(&b, session_id2_len); 847 } else { 848 p = buffer_get_string(&b, &len); 849 if ((session_id2 == NULL) || 850 (len != session_id2_len) || 851 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 852 fail++; 853 xfree(p); 854 } 855 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 856 fail++; 857 p = buffer_get_string(&b, NULL); 858 if (strcmp(authctxt->user, p) != 0) { 859 logit("wrong user name passed to monitor: expected %s != %.100s", 860 authctxt->user, p); 861 fail++; 862 } 863 xfree(p); 864 buffer_skip_string(&b); 865 if (datafellows & SSH_BUG_PKAUTH) { 866 if (!buffer_get_char(&b)) 867 fail++; 868 } else { 869 p = buffer_get_string(&b, NULL); 870 if (strcmp("publickey", p) != 0) 871 fail++; 872 xfree(p); 873 if (!buffer_get_char(&b)) 874 fail++; 875 buffer_skip_string(&b); 876 } 877 buffer_skip_string(&b); 878 if (buffer_len(&b) != 0) 879 fail++; 880 buffer_free(&b); 881 return (fail == 0); 882} 883 884static int 885monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 886 char *chost) 887{ 888 Buffer b; 889 char *p; 890 u_int len; 891 int fail = 0; 892 893 buffer_init(&b); 894 buffer_append(&b, data, datalen); 895 896 p = buffer_get_string(&b, &len); 897 if ((session_id2 == NULL) || 898 (len != session_id2_len) || 899 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 900 fail++; 901 xfree(p); 902 903 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 904 fail++; 905 p = buffer_get_string(&b, NULL); 906 if (strcmp(authctxt->user, p) != 0) { 907 logit("wrong user name passed to monitor: expected %s != %.100s", 908 authctxt->user, p); 909 fail++; 910 } 911 xfree(p); 912 buffer_skip_string(&b); /* service */ 913 p = buffer_get_string(&b, NULL); 914 if (strcmp(p, "hostbased") != 0) 915 fail++; 916 xfree(p); 917 buffer_skip_string(&b); /* pkalg */ 918 buffer_skip_string(&b); /* pkblob */ 919 920 /* verify client host, strip trailing dot if necessary */ 921 p = buffer_get_string(&b, NULL); 922 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 923 p[len - 1] = '\0'; 924 if (strcmp(p, chost) != 0) 925 fail++; 926 xfree(p); 927 928 /* verify client user */ 929 p = buffer_get_string(&b, NULL); 930 if (strcmp(p, cuser) != 0) 931 fail++; 932 xfree(p); 933 934 if (buffer_len(&b) != 0) 935 fail++; 936 buffer_free(&b); 937 return (fail == 0); 938} 939 940int 941mm_answer_keyverify(int sock, Buffer *m) 942{ 943 Key *key; 944 u_char *signature, *data, *blob; 945 u_int signaturelen, datalen, bloblen; 946 int verified = 0; 947 int valid_data = 0; 948 949 blob = buffer_get_string(m, &bloblen); 950 signature = buffer_get_string(m, &signaturelen); 951 data = buffer_get_string(m, &datalen); 952 953 if (hostbased_cuser == NULL || hostbased_chost == NULL || 954 !monitor_allowed_key(blob, bloblen)) 955 fatal("%s: bad key, not previously allowed", __func__); 956 957 key = key_from_blob(blob, bloblen); 958 if (key == NULL) 959 fatal("%s: bad public key blob", __func__); 960 961 switch (key_blobtype) { 962 case MM_USERKEY: 963 valid_data = monitor_valid_userblob(data, datalen); 964 break; 965 case MM_HOSTKEY: 966 valid_data = monitor_valid_hostbasedblob(data, datalen, 967 hostbased_cuser, hostbased_chost); 968 break; 969 default: 970 valid_data = 0; 971 break; 972 } 973 if (!valid_data) 974 fatal("%s: bad signature data blob", __func__); 975 976 verified = key_verify(key, signature, signaturelen, data, datalen); 977 debug3("%s: key %p signature %s", 978 __func__, key, (verified == 1) ? "verified" : "unverified"); 979 980 key_free(key); 981 xfree(blob); 982 xfree(signature); 983 xfree(data); 984 985 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 986 987 monitor_reset_key_state(); 988 989 buffer_clear(m); 990 buffer_put_int(m, verified); 991 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 992 993 return (verified == 1); 994} 995 996static void 997mm_record_login(Session *s, struct passwd *pw) 998{ 999 socklen_t fromlen; 1000 struct sockaddr_storage from; 1001 1002 /* 1003 * Get IP address of client. If the connection is not a socket, let 1004 * the address be 0.0.0.0. 1005 */ 1006 memset(&from, 0, sizeof(from)); 1007 fromlen = sizeof(from); 1008 if (packet_connection_is_on_socket()) { 1009 if (getpeername(packet_get_connection_in(), 1010 (struct sockaddr *)&from, &fromlen) < 0) { 1011 debug("getpeername: %.100s", strerror(errno)); 1012 cleanup_exit(255); 1013 } 1014 } 1015 /* Record that there was a login on that tty from the remote host. */ 1016 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1017 get_remote_name_or_ip(utmp_len, options.use_dns), 1018 (struct sockaddr *)&from, fromlen); 1019} 1020 1021static void 1022mm_session_close(Session *s) 1023{ 1024 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1025 if (s->ttyfd != -1) { 1026 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1027 session_pty_cleanup2(s); 1028 } 1029 session_unused(s->self); 1030} 1031 1032int 1033mm_answer_pty(int sock, Buffer *m) 1034{ 1035 extern struct monitor *pmonitor; 1036 Session *s; 1037 int res, fd0; 1038 1039 debug3("%s entering", __func__); 1040 1041 buffer_clear(m); 1042 s = session_new(); 1043 if (s == NULL) 1044 goto error; 1045 s->authctxt = authctxt; 1046 s->pw = authctxt->pw; 1047 s->pid = pmonitor->m_pid; 1048 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1049 if (res == 0) 1050 goto error; 1051 pty_setowner(authctxt->pw, s->tty); 1052 1053 buffer_put_int(m, 1); 1054 buffer_put_cstring(m, s->tty); 1055 1056 /* We need to trick ttyslot */ 1057 if (dup2(s->ttyfd, 0) == -1) 1058 fatal("%s: dup2", __func__); 1059 1060 mm_record_login(s, authctxt->pw); 1061 1062 /* Now we can close the file descriptor again */ 1063 close(0); 1064 1065 /* send messages generated by record_login */ 1066 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1067 buffer_clear(&loginmsg); 1068 1069 mm_request_send(sock, MONITOR_ANS_PTY, m); 1070 1071 if (mm_send_fd(sock, s->ptyfd) == -1 || 1072 mm_send_fd(sock, s->ttyfd) == -1) 1073 fatal("%s: send fds failed", __func__); 1074 1075 /* make sure nothing uses fd 0 */ 1076 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1077 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1078 if (fd0 != 0) 1079 error("%s: fd0 %d != 0", __func__, fd0); 1080 1081 /* slave is not needed */ 1082 close(s->ttyfd); 1083 s->ttyfd = s->ptyfd; 1084 /* no need to dup() because nobody closes ptyfd */ 1085 s->ptymaster = s->ptyfd; 1086 1087 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1088 1089 return (0); 1090 1091 error: 1092 if (s != NULL) 1093 mm_session_close(s); 1094 buffer_put_int(m, 0); 1095 mm_request_send(sock, MONITOR_ANS_PTY, m); 1096 return (0); 1097} 1098 1099int 1100mm_answer_pty_cleanup(int sock, Buffer *m) 1101{ 1102 Session *s; 1103 char *tty; 1104 1105 debug3("%s entering", __func__); 1106 1107 tty = buffer_get_string(m, NULL); 1108 if ((s = session_by_tty(tty)) != NULL) 1109 mm_session_close(s); 1110 buffer_clear(m); 1111 xfree(tty); 1112 return (0); 1113} 1114 1115int 1116mm_answer_sesskey(int sock, Buffer *m) 1117{ 1118 BIGNUM *p; 1119 int rsafail; 1120 1121 /* Turn off permissions */ 1122 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1123 1124 if ((p = BN_new()) == NULL) 1125 fatal("%s: BN_new", __func__); 1126 1127 buffer_get_bignum2(m, p); 1128 1129 rsafail = ssh1_session_key(p); 1130 1131 buffer_clear(m); 1132 buffer_put_int(m, rsafail); 1133 buffer_put_bignum2(m, p); 1134 1135 BN_clear_free(p); 1136 1137 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1138 1139 /* Turn on permissions for sessid passing */ 1140 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1141 1142 return (0); 1143} 1144 1145int 1146mm_answer_sessid(int sock, Buffer *m) 1147{ 1148 int i; 1149 1150 debug3("%s entering", __func__); 1151 1152 if (buffer_len(m) != 16) 1153 fatal("%s: bad ssh1 session id", __func__); 1154 for (i = 0; i < 16; i++) 1155 session_id[i] = buffer_get_char(m); 1156 1157 /* Turn on permissions for getpwnam */ 1158 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1159 1160 return (0); 1161} 1162 1163int 1164mm_answer_rsa_keyallowed(int sock, Buffer *m) 1165{ 1166 BIGNUM *client_n; 1167 Key *key = NULL; 1168 u_char *blob = NULL; 1169 u_int blen = 0; 1170 int allowed = 0; 1171 1172 debug3("%s entering", __func__); 1173 1174 auth_method = "rsa"; 1175 if (options.rsa_authentication && authctxt->valid) { 1176 if ((client_n = BN_new()) == NULL) 1177 fatal("%s: BN_new", __func__); 1178 buffer_get_bignum2(m, client_n); 1179 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1180 BN_clear_free(client_n); 1181 } 1182 buffer_clear(m); 1183 buffer_put_int(m, allowed); 1184 buffer_put_int(m, forced_command != NULL); 1185 1186 /* clear temporarily storage (used by generate challenge) */ 1187 monitor_reset_key_state(); 1188 1189 if (allowed && key != NULL) { 1190 key->type = KEY_RSA; /* cheat for key_to_blob */ 1191 if (key_to_blob(key, &blob, &blen) == 0) 1192 fatal("%s: key_to_blob failed", __func__); 1193 buffer_put_string(m, blob, blen); 1194 1195 /* Save temporarily for comparison in verify */ 1196 key_blob = blob; 1197 key_bloblen = blen; 1198 key_blobtype = MM_RSAUSERKEY; 1199 } 1200 if (key != NULL) 1201 key_free(key); 1202 1203 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1204 1205 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1206 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1207 return (0); 1208} 1209 1210int 1211mm_answer_rsa_challenge(int sock, Buffer *m) 1212{ 1213 Key *key = NULL; 1214 u_char *blob; 1215 u_int blen; 1216 1217 debug3("%s entering", __func__); 1218 1219 if (!authctxt->valid) 1220 fatal("%s: authctxt not valid", __func__); 1221 blob = buffer_get_string(m, &blen); 1222 if (!monitor_allowed_key(blob, blen)) 1223 fatal("%s: bad key, not previously allowed", __func__); 1224 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1225 fatal("%s: key type mismatch", __func__); 1226 if ((key = key_from_blob(blob, blen)) == NULL) 1227 fatal("%s: received bad key", __func__); 1228 if (key->type != KEY_RSA) 1229 fatal("%s: received bad key type %d", __func__, key->type); 1230 key->type = KEY_RSA1; 1231 if (ssh1_challenge) 1232 BN_clear_free(ssh1_challenge); 1233 ssh1_challenge = auth_rsa_generate_challenge(key); 1234 1235 buffer_clear(m); 1236 buffer_put_bignum2(m, ssh1_challenge); 1237 1238 debug3("%s sending reply", __func__); 1239 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1240 1241 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1242 1243 xfree(blob); 1244 key_free(key); 1245 return (0); 1246} 1247 1248int 1249mm_answer_rsa_response(int sock, Buffer *m) 1250{ 1251 Key *key = NULL; 1252 u_char *blob, *response; 1253 u_int blen, len; 1254 int success; 1255 1256 debug3("%s entering", __func__); 1257 1258 if (!authctxt->valid) 1259 fatal("%s: authctxt not valid", __func__); 1260 if (ssh1_challenge == NULL) 1261 fatal("%s: no ssh1_challenge", __func__); 1262 1263 blob = buffer_get_string(m, &blen); 1264 if (!monitor_allowed_key(blob, blen)) 1265 fatal("%s: bad key, not previously allowed", __func__); 1266 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1267 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1268 if ((key = key_from_blob(blob, blen)) == NULL) 1269 fatal("%s: received bad key", __func__); 1270 response = buffer_get_string(m, &len); 1271 if (len != 16) 1272 fatal("%s: received bad response to challenge", __func__); 1273 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1274 1275 xfree(blob); 1276 key_free(key); 1277 xfree(response); 1278 1279 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1280 1281 /* reset state */ 1282 BN_clear_free(ssh1_challenge); 1283 ssh1_challenge = NULL; 1284 monitor_reset_key_state(); 1285 1286 buffer_clear(m); 1287 buffer_put_int(m, success); 1288 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1289 1290 return (success); 1291} 1292 1293int 1294mm_answer_term(int sock, Buffer *req) 1295{ 1296 extern struct monitor *pmonitor; 1297 int res, status; 1298 1299 debug3("%s: tearing down sessions", __func__); 1300 1301 /* The child is terminating */ 1302 session_destroy_all(&mm_session_close); 1303 1304 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1305 if (errno != EINTR) 1306 exit(1); 1307 1308 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1309 1310 /* Terminate process */ 1311 exit(res); 1312} 1313 1314void 1315monitor_apply_keystate(struct monitor *pmonitor) 1316{ 1317 if (compat20) { 1318 set_newkeys(MODE_IN); 1319 set_newkeys(MODE_OUT); 1320 } else { 1321 packet_set_protocol_flags(child_state.ssh1protoflags); 1322 packet_set_encryption_key(child_state.ssh1key, 1323 child_state.ssh1keylen, child_state.ssh1cipher); 1324 xfree(child_state.ssh1key); 1325 } 1326 1327 /* for rc4 and other stateful ciphers */ 1328 packet_set_keycontext(MODE_OUT, child_state.keyout); 1329 xfree(child_state.keyout); 1330 packet_set_keycontext(MODE_IN, child_state.keyin); 1331 xfree(child_state.keyin); 1332 1333 if (!compat20) { 1334 packet_set_iv(MODE_OUT, child_state.ivout); 1335 xfree(child_state.ivout); 1336 packet_set_iv(MODE_IN, child_state.ivin); 1337 xfree(child_state.ivin); 1338 } 1339 1340 memcpy(&incoming_stream, &child_state.incoming, 1341 sizeof(incoming_stream)); 1342 memcpy(&outgoing_stream, &child_state.outgoing, 1343 sizeof(outgoing_stream)); 1344 1345 /* Update with new address */ 1346 if (options.compression) 1347 mm_init_compression(pmonitor->m_zlib); 1348 1349 /* Network I/O buffers */ 1350 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1351 buffer_clear(packet_get_input()); 1352 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1353 memset(child_state.input, 0, child_state.ilen); 1354 xfree(child_state.input); 1355 1356 buffer_clear(packet_get_output()); 1357 buffer_append(packet_get_output(), child_state.output, 1358 child_state.olen); 1359 memset(child_state.output, 0, child_state.olen); 1360 xfree(child_state.output); 1361 1362 /* Roaming */ 1363 if (compat20) 1364 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1365} 1366 1367static Kex * 1368mm_get_kex(Buffer *m) 1369{ 1370 Kex *kex; 1371 void *blob; 1372 u_int bloblen; 1373 1374 kex = xcalloc(1, sizeof(*kex)); 1375 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1376 if (session_id2 == NULL || 1377 kex->session_id_len != session_id2_len || 1378 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1379 fatal("mm_get_get: internal error: bad session id"); 1380 kex->we_need = buffer_get_int(m); 1381 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1382 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1383 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1384 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1385 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1386 kex->server = 1; 1387 kex->hostkey_type = buffer_get_int(m); 1388 kex->kex_type = buffer_get_int(m); 1389 blob = buffer_get_string(m, &bloblen); 1390 buffer_init(&kex->my); 1391 buffer_append(&kex->my, blob, bloblen); 1392 xfree(blob); 1393 blob = buffer_get_string(m, &bloblen); 1394 buffer_init(&kex->peer); 1395 buffer_append(&kex->peer, blob, bloblen); 1396 xfree(blob); 1397 kex->done = 1; 1398 kex->flags = buffer_get_int(m); 1399 kex->client_version_string = buffer_get_string(m, NULL); 1400 kex->server_version_string = buffer_get_string(m, NULL); 1401 kex->load_host_public_key=&get_hostkey_public_by_type; 1402 kex->load_host_private_key=&get_hostkey_private_by_type; 1403 kex->host_key_index=&get_hostkey_index; 1404 1405 return (kex); 1406} 1407 1408/* This function requries careful sanity checking */ 1409 1410void 1411mm_get_keystate(struct monitor *pmonitor) 1412{ 1413 Buffer m; 1414 u_char *blob, *p; 1415 u_int bloblen, plen; 1416 u_int32_t seqnr, packets; 1417 u_int64_t blocks, bytes; 1418 1419 debug3("%s: Waiting for new keys", __func__); 1420 1421 buffer_init(&m); 1422 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1423 if (!compat20) { 1424 child_state.ssh1protoflags = buffer_get_int(&m); 1425 child_state.ssh1cipher = buffer_get_int(&m); 1426 child_state.ssh1key = buffer_get_string(&m, 1427 &child_state.ssh1keylen); 1428 child_state.ivout = buffer_get_string(&m, 1429 &child_state.ivoutlen); 1430 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1431 goto skip; 1432 } else { 1433 /* Get the Kex for rekeying */ 1434 *pmonitor->m_pkex = mm_get_kex(&m); 1435 } 1436 1437 blob = buffer_get_string(&m, &bloblen); 1438 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1439 xfree(blob); 1440 1441 debug3("%s: Waiting for second key", __func__); 1442 blob = buffer_get_string(&m, &bloblen); 1443 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1444 xfree(blob); 1445 1446 /* Now get sequence numbers for the packets */ 1447 seqnr = buffer_get_int(&m); 1448 blocks = buffer_get_int64(&m); 1449 packets = buffer_get_int(&m); 1450 bytes = buffer_get_int64(&m); 1451 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1452 seqnr = buffer_get_int(&m); 1453 blocks = buffer_get_int64(&m); 1454 packets = buffer_get_int(&m); 1455 bytes = buffer_get_int64(&m); 1456 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1457 1458 skip: 1459 /* Get the key context */ 1460 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1461 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1462 1463 debug3("%s: Getting compression state", __func__); 1464 /* Get compression state */ 1465 p = buffer_get_string(&m, &plen); 1466 if (plen != sizeof(child_state.outgoing)) 1467 fatal("%s: bad request size", __func__); 1468 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1469 xfree(p); 1470 1471 p = buffer_get_string(&m, &plen); 1472 if (plen != sizeof(child_state.incoming)) 1473 fatal("%s: bad request size", __func__); 1474 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1475 xfree(p); 1476 1477 /* Network I/O buffers */ 1478 debug3("%s: Getting Network I/O buffers", __func__); 1479 child_state.input = buffer_get_string(&m, &child_state.ilen); 1480 child_state.output = buffer_get_string(&m, &child_state.olen); 1481 1482 /* Roaming */ 1483 if (compat20) { 1484 child_state.sent_bytes = buffer_get_int64(&m); 1485 child_state.recv_bytes = buffer_get_int64(&m); 1486 } 1487 1488 buffer_free(&m); 1489} 1490 1491 1492/* Allocation functions for zlib */ 1493void * 1494mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1495{ 1496 size_t len = (size_t) size * ncount; 1497 void *address; 1498 1499 if (len == 0 || ncount > SIZE_T_MAX / size) 1500 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1501 1502 address = mm_malloc(mm, len); 1503 1504 return (address); 1505} 1506 1507void 1508mm_zfree(struct mm_master *mm, void *address) 1509{ 1510 mm_free(mm, address); 1511} 1512 1513void 1514mm_init_compression(struct mm_master *mm) 1515{ 1516 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1517 outgoing_stream.zfree = (free_func)mm_zfree; 1518 outgoing_stream.opaque = mm; 1519 1520 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1521 incoming_stream.zfree = (free_func)mm_zfree; 1522 incoming_stream.opaque = mm; 1523} 1524 1525/* XXX */ 1526 1527#define FD_CLOSEONEXEC(x) do { \ 1528 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1529 fatal("fcntl(%d, F_SETFD)", x); \ 1530} while (0) 1531 1532static void 1533monitor_socketpair(int *pair) 1534{ 1535 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1536 fatal("%s: socketpair", __func__); 1537 FD_CLOSEONEXEC(pair[0]); 1538 FD_CLOSEONEXEC(pair[1]); 1539} 1540 1541#define MM_MEMSIZE 65536 1542 1543struct monitor * 1544monitor_init(void) 1545{ 1546 struct monitor *mon; 1547 int pair[2]; 1548 1549 mon = xcalloc(1, sizeof(*mon)); 1550 1551 monitor_socketpair(pair); 1552 1553 mon->m_recvfd = pair[0]; 1554 mon->m_sendfd = pair[1]; 1555 1556 /* Used to share zlib space across processes */ 1557 if (options.compression) { 1558 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1559 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1560 1561 /* Compression needs to share state across borders */ 1562 mm_init_compression(mon->m_zlib); 1563 } 1564 1565 return mon; 1566} 1567 1568void 1569monitor_reinit(struct monitor *mon) 1570{ 1571 int pair[2]; 1572 1573 monitor_socketpair(pair); 1574 1575 mon->m_recvfd = pair[0]; 1576 mon->m_sendfd = pair[1]; 1577} 1578 1579#ifdef GSSAPI 1580int 1581mm_answer_gss_setup_ctx(int sock, Buffer *m) 1582{ 1583 gss_OID_desc goid; 1584 OM_uint32 major; 1585 u_int len; 1586 1587 goid.elements = buffer_get_string(m, &len); 1588 goid.length = len; 1589 1590 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1591 1592 xfree(goid.elements); 1593 1594 buffer_clear(m); 1595 buffer_put_int(m, major); 1596 1597 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1598 1599 /* Now we have a context, enable the step */ 1600 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1601 1602 return (0); 1603} 1604 1605int 1606mm_answer_gss_accept_ctx(int sock, Buffer *m) 1607{ 1608 gss_buffer_desc in; 1609 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1610 OM_uint32 major, minor; 1611 OM_uint32 flags = 0; /* GSI needs this */ 1612 u_int len; 1613 1614 in.value = buffer_get_string(m, &len); 1615 in.length = len; 1616 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1617 xfree(in.value); 1618 1619 buffer_clear(m); 1620 buffer_put_int(m, major); 1621 buffer_put_string(m, out.value, out.length); 1622 buffer_put_int(m, flags); 1623 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1624 1625 gss_release_buffer(&minor, &out); 1626 1627 if (major == GSS_S_COMPLETE) { 1628 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1629 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1630 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1631 } 1632 return (0); 1633} 1634 1635int 1636mm_answer_gss_checkmic(int sock, Buffer *m) 1637{ 1638 gss_buffer_desc gssbuf, mic; 1639 OM_uint32 ret; 1640 u_int len; 1641 1642 gssbuf.value = buffer_get_string(m, &len); 1643 gssbuf.length = len; 1644 mic.value = buffer_get_string(m, &len); 1645 mic.length = len; 1646 1647 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1648 1649 xfree(gssbuf.value); 1650 xfree(mic.value); 1651 1652 buffer_clear(m); 1653 buffer_put_int(m, ret); 1654 1655 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1656 1657 if (!GSS_ERROR(ret)) 1658 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1659 1660 return (0); 1661} 1662 1663int 1664mm_answer_gss_userok(int sock, Buffer *m) 1665{ 1666 int authenticated; 1667 1668 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1669 1670 buffer_clear(m); 1671 buffer_put_int(m, authenticated); 1672 1673 debug3("%s: sending result %d", __func__, authenticated); 1674 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1675 1676 auth_method = "gssapi-with-mic"; 1677 1678 /* Monitor loop will terminate if authenticated */ 1679 return (authenticated); 1680} 1681#endif /* GSSAPI */ 1682 1683#ifdef JPAKE 1684int 1685mm_answer_jpake_step1(int sock, Buffer *m) 1686{ 1687 struct jpake_ctx *pctx; 1688 u_char *x3_proof, *x4_proof; 1689 u_int x3_proof_len, x4_proof_len; 1690 1691 if (!options.zero_knowledge_password_authentication) 1692 fatal("zero_knowledge_password_authentication disabled"); 1693 1694 if (authctxt->jpake_ctx != NULL) 1695 fatal("%s: authctxt->jpake_ctx already set (%p)", 1696 __func__, authctxt->jpake_ctx); 1697 authctxt->jpake_ctx = pctx = jpake_new(); 1698 1699 jpake_step1(pctx->grp, 1700 &pctx->server_id, &pctx->server_id_len, 1701 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 1702 &x3_proof, &x3_proof_len, 1703 &x4_proof, &x4_proof_len); 1704 1705 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 1706 1707 buffer_clear(m); 1708 1709 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 1710 buffer_put_bignum2(m, pctx->g_x3); 1711 buffer_put_bignum2(m, pctx->g_x4); 1712 buffer_put_string(m, x3_proof, x3_proof_len); 1713 buffer_put_string(m, x4_proof, x4_proof_len); 1714 1715 debug3("%s: sending step1", __func__); 1716 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 1717 1718 bzero(x3_proof, x3_proof_len); 1719 bzero(x4_proof, x4_proof_len); 1720 xfree(x3_proof); 1721 xfree(x4_proof); 1722 1723 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 1724 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 1725 1726 return 0; 1727} 1728 1729int 1730mm_answer_jpake_get_pwdata(int sock, Buffer *m) 1731{ 1732 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1733 char *hash_scheme, *salt; 1734 1735 if (pctx == NULL) 1736 fatal("%s: pctx == NULL", __func__); 1737 1738 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 1739 1740 buffer_clear(m); 1741 /* pctx->s is sensitive, not returned to slave */ 1742 buffer_put_cstring(m, hash_scheme); 1743 buffer_put_cstring(m, salt); 1744 1745 debug3("%s: sending pwdata", __func__); 1746 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 1747 1748 bzero(hash_scheme, strlen(hash_scheme)); 1749 bzero(salt, strlen(salt)); 1750 xfree(hash_scheme); 1751 xfree(salt); 1752 1753 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 1754 1755 return 0; 1756} 1757 1758int 1759mm_answer_jpake_step2(int sock, Buffer *m) 1760{ 1761 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1762 u_char *x1_proof, *x2_proof, *x4_s_proof; 1763 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 1764 1765 if (pctx == NULL) 1766 fatal("%s: pctx == NULL", __func__); 1767 1768 if ((pctx->g_x1 = BN_new()) == NULL || 1769 (pctx->g_x2 = BN_new()) == NULL) 1770 fatal("%s: BN_new", __func__); 1771 buffer_get_bignum2(m, pctx->g_x1); 1772 buffer_get_bignum2(m, pctx->g_x2); 1773 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 1774 x1_proof = buffer_get_string(m, &x1_proof_len); 1775 x2_proof = buffer_get_string(m, &x2_proof_len); 1776 1777 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 1778 pctx->g_x1, pctx->g_x2, pctx->x4, 1779 pctx->client_id, pctx->client_id_len, 1780 pctx->server_id, pctx->server_id_len, 1781 x1_proof, x1_proof_len, 1782 x2_proof, x2_proof_len, 1783 &pctx->b, 1784 &x4_s_proof, &x4_s_proof_len); 1785 1786 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 1787 1788 bzero(x1_proof, x1_proof_len); 1789 bzero(x2_proof, x2_proof_len); 1790 xfree(x1_proof); 1791 xfree(x2_proof); 1792 1793 buffer_clear(m); 1794 1795 buffer_put_bignum2(m, pctx->b); 1796 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 1797 1798 debug3("%s: sending step2", __func__); 1799 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 1800 1801 bzero(x4_s_proof, x4_s_proof_len); 1802 xfree(x4_s_proof); 1803 1804 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 1805 1806 return 0; 1807} 1808 1809int 1810mm_answer_jpake_key_confirm(int sock, Buffer *m) 1811{ 1812 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1813 u_char *x2_s_proof; 1814 u_int x2_s_proof_len; 1815 1816 if (pctx == NULL) 1817 fatal("%s: pctx == NULL", __func__); 1818 1819 if ((pctx->a = BN_new()) == NULL) 1820 fatal("%s: BN_new", __func__); 1821 buffer_get_bignum2(m, pctx->a); 1822 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 1823 1824 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 1825 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 1826 pctx->server_id, pctx->server_id_len, 1827 pctx->client_id, pctx->client_id_len, 1828 session_id2, session_id2_len, 1829 x2_s_proof, x2_s_proof_len, 1830 &pctx->k, 1831 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 1832 1833 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 1834 1835 bzero(x2_s_proof, x2_s_proof_len); 1836 buffer_clear(m); 1837 1838 /* pctx->k is sensitive, not sent */ 1839 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 1840 1841 debug3("%s: sending confirmation hash", __func__); 1842 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 1843 1844 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 1845 1846 return 0; 1847} 1848 1849int 1850mm_answer_jpake_check_confirm(int sock, Buffer *m) 1851{ 1852 int authenticated = 0; 1853 u_char *peer_confirm_hash; 1854 u_int peer_confirm_hash_len; 1855 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1856 1857 if (pctx == NULL) 1858 fatal("%s: pctx == NULL", __func__); 1859 1860 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 1861 1862 authenticated = jpake_check_confirm(pctx->k, 1863 pctx->client_id, pctx->client_id_len, 1864 session_id2, session_id2_len, 1865 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 1866 1867 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 1868 1869 bzero(peer_confirm_hash, peer_confirm_hash_len); 1870 xfree(peer_confirm_hash); 1871 1872 buffer_clear(m); 1873 buffer_put_int(m, authenticated); 1874 1875 debug3("%s: sending result %d", __func__, authenticated); 1876 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 1877 1878 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 1879 1880 auth_method = "jpake-01@openssh.com"; 1881 return authenticated; 1882} 1883 1884#endif /* JPAKE */ 1885