1 /* 2 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 3 * Copyright 2002 Markus Friedl <markus@openbsd.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "includes.h" 28 RCSID("$OpenBSD: monitor.c,v 1.55 2004/02/05 05:37:17 dtucker Exp $"); 29 30 #include <openssl/dh.h> 31 32 #ifdef SKEY 33 #include <skey.h> 34 #endif 35 36 #include "ssh.h" 37 #include "auth.h" 38 #include "kex.h" 39 #include "dh.h" 40 #include "zlib.h" 41 #include "packet.h" 42 #include "auth-options.h" 43 #include "sshpty.h" 44 #include "channels.h" 45 #include "session.h" 46 #include "sshlogin.h" 47 #include "canohost.h" 48 #include "log.h" 49 #include "servconf.h" 50 #include "monitor.h" 51 #include "monitor_mm.h" 52 #include "monitor_wrap.h" 53 #include "monitor_fdpass.h" 54 #include "xmalloc.h" 55 #include "misc.h" 56 #include "buffer.h" 57 #include "bufaux.h" 58 #include "compat.h" 59 #include "ssh2.h" 60 #include "mpaux.h" 61 62 #ifdef GSSAPI 63 #include "ssh-gss.h" 64 static Gssctxt *gsscontext = NULL; 65 #endif 66 67 /* Imports */ 68 extern ServerOptions options; 69 extern u_int utmp_len; 70 extern Newkeys *current_keys[]; 71 extern z_stream incoming_stream; 72 extern z_stream outgoing_stream; 73 extern u_char session_id[]; 74 extern Buffer input, output; 75 extern Buffer auth_debug; 76 extern int auth_debug_init; 77 78 /* State exported from the child */ 79 80 struct { 81 z_stream incoming; 82 z_stream outgoing; 83 u_char *keyin; 84 u_int keyinlen; 85 u_char *keyout; 86 u_int keyoutlen; 87 u_char *ivin; 88 u_int ivinlen; 89 u_char *ivout; 90 u_int ivoutlen; 91 u_char *ssh1key; 92 u_int ssh1keylen; 93 int ssh1cipher; 94 int ssh1protoflags; 95 u_char *input; 96 u_int ilen; 97 u_char *output; 98 u_int olen; 99 } child_state; 100 101 /* Functions on the monitor that answer unprivileged requests */ 102 103 int mm_answer_moduli(int, Buffer *); 104 int mm_answer_sign(int, Buffer *); 105 int mm_answer_pwnamallow(int, Buffer *); 106 int mm_answer_auth2_read_banner(int, Buffer *); 107 int mm_answer_authserv(int, Buffer *); 108 int mm_answer_authpassword(int, Buffer *); 109 int mm_answer_bsdauthquery(int, Buffer *); 110 int mm_answer_bsdauthrespond(int, Buffer *); 111 int mm_answer_skeyquery(int, Buffer *); 112 int mm_answer_skeyrespond(int, Buffer *); 113 int mm_answer_keyallowed(int, Buffer *); 114 int mm_answer_keyverify(int, Buffer *); 115 int mm_answer_pty(int, Buffer *); 116 int mm_answer_pty_cleanup(int, Buffer *); 117 int mm_answer_term(int, Buffer *); 118 int mm_answer_rsa_keyallowed(int, Buffer *); 119 int mm_answer_rsa_challenge(int, Buffer *); 120 int mm_answer_rsa_response(int, Buffer *); 121 int mm_answer_sesskey(int, Buffer *); 122 int mm_answer_sessid(int, Buffer *); 123 124 #ifdef GSSAPI 125 int mm_answer_gss_setup_ctx(int, Buffer *); 126 int mm_answer_gss_accept_ctx(int, Buffer *); 127 int mm_answer_gss_userok(int, Buffer *); 128 int mm_answer_gss_checkmic(int, Buffer *); 129 #endif 130 131 static Authctxt *authctxt; 132 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 133 134 /* local state for key verify */ 135 static u_char *key_blob = NULL; 136 static u_int key_bloblen = 0; 137 static int key_blobtype = MM_NOKEY; 138 static char *hostbased_cuser = NULL; 139 static char *hostbased_chost = NULL; 140 static char *auth_method = "unknown"; 141 static u_int session_id2_len = 0; 142 static u_char *session_id2 = NULL; 143 static pid_t monitor_child_pid; 144 145 struct mon_table { 146 enum monitor_reqtype type; 147 int flags; 148 int (*f)(int, Buffer *); 149 }; 150 151 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 152 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 153 #define MON_ONCE 0x0010 /* Disable after calling */ 154 155 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 156 157 #define MON_PERMIT 0x1000 /* Request is permitted */ 158 159 struct mon_table mon_dispatch_proto20[] = { 160 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 161 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 162 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 163 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 164 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 165 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 166 #ifdef BSD_AUTH 167 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 168 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 169 #endif 170 #ifdef SKEY 171 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 172 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 173 #endif 174 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 175 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 176 #ifdef GSSAPI 177 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 178 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 179 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 180 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 181 #endif 182 {0, 0, NULL} 183 }; 184 185 struct mon_table mon_dispatch_postauth20[] = { 186 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 187 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 188 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 189 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 190 {MONITOR_REQ_TERM, 0, mm_answer_term}, 191 {0, 0, NULL} 192 }; 193 194 struct mon_table mon_dispatch_proto15[] = { 195 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 196 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 197 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 198 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 199 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed}, 200 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 201 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 202 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 203 #ifdef BSD_AUTH 204 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 205 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 206 #endif 207 #ifdef SKEY 208 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 209 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 210 #endif 211 {0, 0, NULL} 212 }; 213 214 struct mon_table mon_dispatch_postauth15[] = { 215 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 216 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 217 {MONITOR_REQ_TERM, 0, mm_answer_term}, 218 {0, 0, NULL} 219 }; 220 221 struct mon_table *mon_dispatch; 222 223 /* Specifies if a certain message is allowed at the moment */ 224 225 static void 226 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 227 { 228 while (ent->f != NULL) { 229 if (ent->type == type) { 230 ent->flags &= ~MON_PERMIT; 231 ent->flags |= permit ? MON_PERMIT : 0; 232 return; 233 } 234 ent++; 235 } 236 } 237 238 static void 239 monitor_permit_authentications(int permit) 240 { 241 struct mon_table *ent = mon_dispatch; 242 243 while (ent->f != NULL) { 244 if (ent->flags & MON_AUTH) { 245 ent->flags &= ~MON_PERMIT; 246 ent->flags |= permit ? MON_PERMIT : 0; 247 } 248 ent++; 249 } 250 } 251 252 void 253 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 254 { 255 struct mon_table *ent; 256 int authenticated = 0; 257 258 debug3("preauth child monitor started"); 259 260 authctxt = _authctxt; 261 memset(authctxt, 0, sizeof(*authctxt)); 262 263 if (compat20) { 264 mon_dispatch = mon_dispatch_proto20; 265 266 /* Permit requests for moduli and signatures */ 267 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 268 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 269 } else { 270 mon_dispatch = mon_dispatch_proto15; 271 272 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 273 } 274 275 /* The first few requests do not require asynchronous access */ 276 while (!authenticated) { 277 authenticated = monitor_read(pmonitor, mon_dispatch, &ent); 278 if (authenticated) { 279 if (!(ent->flags & MON_AUTHDECIDE)) 280 fatal("%s: unexpected authentication from %d", 281 __func__, ent->type); 282 if (authctxt->pw->pw_uid == 0 && 283 !auth_root_allowed(auth_method)) 284 authenticated = 0; 285 } 286 287 if (ent->flags & MON_AUTHDECIDE) { 288 auth_log(authctxt, authenticated, auth_method, 289 compat20 ? " ssh2" : ""); 290 if (!authenticated) 291 authctxt->failures++; 292 } 293 } 294 295 if (!authctxt->valid) 296 fatal("%s: authenticated invalid user", __func__); 297 298 debug("%s: %s has been authenticated by privileged process", 299 __func__, authctxt->user); 300 301 mm_get_keystate(pmonitor); 302 } 303 304 static void 305 monitor_set_child_handler(pid_t pid) 306 { 307 monitor_child_pid = pid; 308 } 309 310 static void 311 monitor_child_handler(int signal) 312 { 313 kill(monitor_child_pid, signal); 314 } 315 316 void 317 monitor_child_postauth(struct monitor *pmonitor) 318 { 319 monitor_set_child_handler(pmonitor->m_pid); 320 signal(SIGHUP, &monitor_child_handler); 321 signal(SIGTERM, &monitor_child_handler); 322 323 if (compat20) { 324 mon_dispatch = mon_dispatch_postauth20; 325 326 /* Permit requests for moduli and signatures */ 327 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 328 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 329 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 330 } else { 331 mon_dispatch = mon_dispatch_postauth15; 332 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 333 } 334 if (!no_pty_flag) { 335 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 336 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 337 } 338 339 for (;;) 340 monitor_read(pmonitor, mon_dispatch, NULL); 341 } 342 343 void 344 monitor_sync(struct monitor *pmonitor) 345 { 346 if (options.compression) { 347 /* The member allocation is not visible, so sync it */ 348 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 349 } 350 } 351 352 int 353 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 354 struct mon_table **pent) 355 { 356 Buffer m; 357 int ret; 358 u_char type; 359 360 buffer_init(&m); 361 362 mm_request_receive(pmonitor->m_sendfd, &m); 363 type = buffer_get_char(&m); 364 365 debug3("%s: checking request %d", __func__, type); 366 367 while (ent->f != NULL) { 368 if (ent->type == type) 369 break; 370 ent++; 371 } 372 373 if (ent->f != NULL) { 374 if (!(ent->flags & MON_PERMIT)) 375 fatal("%s: unpermitted request %d", __func__, 376 type); 377 ret = (*ent->f)(pmonitor->m_sendfd, &m); 378 buffer_free(&m); 379 380 /* The child may use this request only once, disable it */ 381 if (ent->flags & MON_ONCE) { 382 debug2("%s: %d used once, disabling now", __func__, 383 type); 384 ent->flags &= ~MON_PERMIT; 385 } 386 387 if (pent != NULL) 388 *pent = ent; 389 390 return ret; 391 } 392 393 fatal("%s: unsupported request: %d", __func__, type); 394 395 /* NOTREACHED */ 396 return (-1); 397 } 398 399 /* allowed key state */ 400 static int 401 monitor_allowed_key(u_char *blob, u_int bloblen) 402 { 403 /* make sure key is allowed */ 404 if (key_blob == NULL || key_bloblen != bloblen || 405 memcmp(key_blob, blob, key_bloblen)) 406 return (0); 407 return (1); 408 } 409 410 static void 411 monitor_reset_key_state(void) 412 { 413 /* reset state */ 414 if (key_blob != NULL) 415 xfree(key_blob); 416 if (hostbased_cuser != NULL) 417 xfree(hostbased_cuser); 418 if (hostbased_chost != NULL) 419 xfree(hostbased_chost); 420 key_blob = NULL; 421 key_bloblen = 0; 422 key_blobtype = MM_NOKEY; 423 hostbased_cuser = NULL; 424 hostbased_chost = NULL; 425 } 426 427 int 428 mm_answer_moduli(int socket, Buffer *m) 429 { 430 DH *dh; 431 int min, want, max; 432 433 min = buffer_get_int(m); 434 want = buffer_get_int(m); 435 max = buffer_get_int(m); 436 437 debug3("%s: got parameters: %d %d %d", 438 __func__, min, want, max); 439 /* We need to check here, too, in case the child got corrupted */ 440 if (max < min || want < min || max < want) 441 fatal("%s: bad parameters: %d %d %d", 442 __func__, min, want, max); 443 444 buffer_clear(m); 445 446 dh = choose_dh(min, want, max); 447 if (dh == NULL) { 448 buffer_put_char(m, 0); 449 return (0); 450 } else { 451 /* Send first bignum */ 452 buffer_put_char(m, 1); 453 buffer_put_bignum2(m, dh->p); 454 buffer_put_bignum2(m, dh->g); 455 456 DH_free(dh); 457 } 458 mm_request_send(socket, MONITOR_ANS_MODULI, m); 459 return (0); 460 } 461 462 int 463 mm_answer_sign(int socket, Buffer *m) 464 { 465 Key *key; 466 u_char *p; 467 u_char *signature; 468 u_int siglen, datlen; 469 int keyid; 470 471 debug3("%s", __func__); 472 473 keyid = buffer_get_int(m); 474 p = buffer_get_string(m, &datlen); 475 476 if (datlen != 20) 477 fatal("%s: data length incorrect: %u", __func__, datlen); 478 479 /* save session id, it will be passed on the first call */ 480 if (session_id2_len == 0) { 481 session_id2_len = datlen; 482 session_id2 = xmalloc(session_id2_len); 483 memcpy(session_id2, p, session_id2_len); 484 } 485 486 if ((key = get_hostkey_by_index(keyid)) == NULL) 487 fatal("%s: no hostkey from index %d", __func__, keyid); 488 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 489 fatal("%s: key_sign failed", __func__); 490 491 debug3("%s: signature %p(%u)", __func__, signature, siglen); 492 493 buffer_clear(m); 494 buffer_put_string(m, signature, siglen); 495 496 xfree(p); 497 xfree(signature); 498 499 mm_request_send(socket, MONITOR_ANS_SIGN, m); 500 501 /* Turn on permissions for getpwnam */ 502 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 503 504 return (0); 505 } 506 507 /* Retrieves the password entry and also checks if the user is permitted */ 508 509 int 510 mm_answer_pwnamallow(int socket, Buffer *m) 511 { 512 char *login; 513 struct passwd *pwent; 514 int allowed = 0; 515 516 debug3("%s", __func__); 517 518 if (authctxt->attempt++ != 0) 519 fatal("%s: multiple attempts for getpwnam", __func__); 520 521 login = buffer_get_string(m, NULL); 522 523 pwent = getpwnamallow(login); 524 525 authctxt->user = xstrdup(login); 526 setproctitle("%s [priv]", pwent ? login : "unknown"); 527 xfree(login); 528 529 buffer_clear(m); 530 531 if (pwent == NULL) { 532 buffer_put_char(m, 0); 533 authctxt->pw = fakepw(); 534 goto out; 535 } 536 537 allowed = 1; 538 authctxt->pw = pwent; 539 authctxt->valid = 1; 540 541 buffer_put_char(m, 1); 542 buffer_put_string(m, pwent, sizeof(struct passwd)); 543 buffer_put_cstring(m, pwent->pw_name); 544 buffer_put_cstring(m, "*"); 545 buffer_put_cstring(m, pwent->pw_gecos); 546 buffer_put_cstring(m, pwent->pw_class); 547 buffer_put_cstring(m, pwent->pw_dir); 548 buffer_put_cstring(m, pwent->pw_shell); 549 550 out: 551 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 552 mm_request_send(socket, MONITOR_ANS_PWNAM, m); 553 554 /* For SSHv1 allow authentication now */ 555 if (!compat20) 556 monitor_permit_authentications(1); 557 else { 558 /* Allow service/style information on the auth context */ 559 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 560 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 561 } 562 563 564 return (0); 565 } 566 567 int mm_answer_auth2_read_banner(int socket, Buffer *m) 568 { 569 char *banner; 570 571 buffer_clear(m); 572 banner = auth2_read_banner(); 573 buffer_put_cstring(m, banner != NULL ? banner : ""); 574 mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m); 575 576 if (banner != NULL) 577 xfree(banner); 578 579 return (0); 580 } 581 582 int 583 mm_answer_authserv(int socket, Buffer *m) 584 { 585 monitor_permit_authentications(1); 586 587 authctxt->service = buffer_get_string(m, NULL); 588 authctxt->style = buffer_get_string(m, NULL); 589 debug3("%s: service=%s, style=%s", 590 __func__, authctxt->service, authctxt->style); 591 592 if (strlen(authctxt->style) == 0) { 593 xfree(authctxt->style); 594 authctxt->style = NULL; 595 } 596 597 return (0); 598 } 599 600 int 601 mm_answer_authpassword(int socket, Buffer *m) 602 { 603 static int call_count; 604 char *passwd; 605 int authenticated; 606 u_int plen; 607 608 passwd = buffer_get_string(m, &plen); 609 /* Only authenticate if the context is valid */ 610 authenticated = options.password_authentication && 611 auth_password(authctxt, passwd); 612 memset(passwd, 0, strlen(passwd)); 613 xfree(passwd); 614 615 buffer_clear(m); 616 buffer_put_int(m, authenticated); 617 618 debug3("%s: sending result %d", __func__, authenticated); 619 mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m); 620 621 call_count++; 622 if (plen == 0 && call_count == 1) 623 auth_method = "none"; 624 else 625 auth_method = "password"; 626 627 /* Causes monitor loop to terminate if authenticated */ 628 return (authenticated); 629 } 630 631 #ifdef BSD_AUTH 632 int 633 mm_answer_bsdauthquery(int socket, Buffer *m) 634 { 635 char *name, *infotxt; 636 u_int numprompts; 637 u_int *echo_on; 638 char **prompts; 639 u_int success; 640 641 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 642 &prompts, &echo_on) < 0 ? 0 : 1; 643 644 buffer_clear(m); 645 buffer_put_int(m, success); 646 if (success) 647 buffer_put_cstring(m, prompts[0]); 648 649 debug3("%s: sending challenge success: %u", __func__, success); 650 mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m); 651 652 if (success) { 653 xfree(name); 654 xfree(infotxt); 655 xfree(prompts); 656 xfree(echo_on); 657 } 658 659 return (0); 660 } 661 662 int 663 mm_answer_bsdauthrespond(int socket, Buffer *m) 664 { 665 char *response; 666 int authok; 667 668 if (authctxt->as == 0) 669 fatal("%s: no bsd auth session", __func__); 670 671 response = buffer_get_string(m, NULL); 672 authok = options.challenge_response_authentication && 673 auth_userresponse(authctxt->as, response, 0); 674 authctxt->as = NULL; 675 debug3("%s: <%s> = <%d>", __func__, response, authok); 676 xfree(response); 677 678 buffer_clear(m); 679 buffer_put_int(m, authok); 680 681 debug3("%s: sending authenticated: %d", __func__, authok); 682 mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m); 683 684 auth_method = "bsdauth"; 685 686 return (authok != 0); 687 } 688 #endif 689 690 #ifdef SKEY 691 int 692 mm_answer_skeyquery(int socket, Buffer *m) 693 { 694 struct skey skey; 695 char challenge[1024]; 696 u_int success; 697 698 success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1; 699 700 buffer_clear(m); 701 buffer_put_int(m, success); 702 if (success) 703 buffer_put_cstring(m, challenge); 704 705 debug3("%s: sending challenge success: %u", __func__, success); 706 mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m); 707 708 return (0); 709 } 710 711 int 712 mm_answer_skeyrespond(int socket, Buffer *m) 713 { 714 char *response; 715 int authok; 716 717 response = buffer_get_string(m, NULL); 718 719 authok = (options.challenge_response_authentication && 720 authctxt->valid && 721 skey_haskey(authctxt->pw->pw_name) == 0 && 722 skey_passcheck(authctxt->pw->pw_name, response) != -1); 723 724 xfree(response); 725 726 buffer_clear(m); 727 buffer_put_int(m, authok); 728 729 debug3("%s: sending authenticated: %d", __func__, authok); 730 mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m); 731 732 auth_method = "skey"; 733 734 return (authok != 0); 735 } 736 #endif 737 738 static void 739 mm_append_debug(Buffer *m) 740 { 741 if (auth_debug_init && buffer_len(&auth_debug)) { 742 debug3("%s: Appending debug messages for child", __func__); 743 buffer_append(m, buffer_ptr(&auth_debug), 744 buffer_len(&auth_debug)); 745 buffer_clear(&auth_debug); 746 } 747 } 748 749 int 750 mm_answer_keyallowed(int socket, Buffer *m) 751 { 752 Key *key; 753 char *cuser, *chost; 754 u_char *blob; 755 u_int bloblen; 756 enum mm_keytype type = 0; 757 int allowed = 0; 758 759 debug3("%s entering", __func__); 760 761 type = buffer_get_int(m); 762 cuser = buffer_get_string(m, NULL); 763 chost = buffer_get_string(m, NULL); 764 blob = buffer_get_string(m, &bloblen); 765 766 key = key_from_blob(blob, bloblen); 767 768 if ((compat20 && type == MM_RSAHOSTKEY) || 769 (!compat20 && type != MM_RSAHOSTKEY)) 770 fatal("%s: key type and protocol mismatch", __func__); 771 772 debug3("%s: key_from_blob: %p", __func__, key); 773 774 if (key != NULL && authctxt->valid) { 775 switch(type) { 776 case MM_USERKEY: 777 allowed = options.pubkey_authentication && 778 user_key_allowed(authctxt->pw, key); 779 break; 780 case MM_HOSTKEY: 781 allowed = options.hostbased_authentication && 782 hostbased_key_allowed(authctxt->pw, 783 cuser, chost, key); 784 break; 785 case MM_RSAHOSTKEY: 786 key->type = KEY_RSA1; /* XXX */ 787 allowed = options.rhosts_rsa_authentication && 788 auth_rhosts_rsa_key_allowed(authctxt->pw, 789 cuser, chost, key); 790 break; 791 default: 792 fatal("%s: unknown key type %d", __func__, type); 793 break; 794 } 795 } 796 if (key != NULL) 797 key_free(key); 798 799 /* clear temporarily storage (used by verify) */ 800 monitor_reset_key_state(); 801 802 if (allowed) { 803 /* Save temporarily for comparison in verify */ 804 key_blob = blob; 805 key_bloblen = bloblen; 806 key_blobtype = type; 807 hostbased_cuser = cuser; 808 hostbased_chost = chost; 809 } 810 811 debug3("%s: key %p is %s", 812 __func__, key, allowed ? "allowed" : "disallowed"); 813 814 buffer_clear(m); 815 buffer_put_int(m, allowed); 816 buffer_put_int(m, forced_command != NULL); 817 818 mm_append_debug(m); 819 820 mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m); 821 822 if (type == MM_RSAHOSTKEY) 823 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 824 825 return (0); 826 } 827 828 static int 829 monitor_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 (memcmp(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 (memcmp(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 } 883 884 static int 885 monitor_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 (memcmp(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 } 939 940 int 941 mm_answer_keyverify(int socket, 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 ? "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(socket, MONITOR_ANS_KEYVERIFY, m); 992 993 return (verified); 994 } 995 996 static void 997 mm_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 1021 static void 1022 mm_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 s->used = 0; 1030 } 1031 1032 int 1033 mm_answer_pty(int socket, 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 mm_request_send(socket, MONITOR_ANS_PTY, m); 1056 1057 mm_send_fd(socket, s->ptyfd); 1058 mm_send_fd(socket, s->ttyfd); 1059 1060 /* We need to trick ttyslot */ 1061 if (dup2(s->ttyfd, 0) == -1) 1062 fatal("%s: dup2", __func__); 1063 1064 mm_record_login(s, authctxt->pw); 1065 1066 /* Now we can close the file descriptor again */ 1067 close(0); 1068 1069 /* make sure nothing uses fd 0 */ 1070 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1071 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1072 if (fd0 != 0) 1073 error("%s: fd0 %d != 0", __func__, fd0); 1074 1075 /* slave is not needed */ 1076 close(s->ttyfd); 1077 s->ttyfd = s->ptyfd; 1078 /* no need to dup() because nobody closes ptyfd */ 1079 s->ptymaster = s->ptyfd; 1080 1081 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1082 1083 return (0); 1084 1085 error: 1086 if (s != NULL) 1087 mm_session_close(s); 1088 buffer_put_int(m, 0); 1089 mm_request_send(socket, MONITOR_ANS_PTY, m); 1090 return (0); 1091 } 1092 1093 int 1094 mm_answer_pty_cleanup(int socket, Buffer *m) 1095 { 1096 Session *s; 1097 char *tty; 1098 1099 debug3("%s entering", __func__); 1100 1101 tty = buffer_get_string(m, NULL); 1102 if ((s = session_by_tty(tty)) != NULL) 1103 mm_session_close(s); 1104 buffer_clear(m); 1105 xfree(tty); 1106 return (0); 1107 } 1108 1109 int 1110 mm_answer_sesskey(int socket, Buffer *m) 1111 { 1112 BIGNUM *p; 1113 int rsafail; 1114 1115 /* Turn off permissions */ 1116 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 1117 1118 if ((p = BN_new()) == NULL) 1119 fatal("%s: BN_new", __func__); 1120 1121 buffer_get_bignum2(m, p); 1122 1123 rsafail = ssh1_session_key(p); 1124 1125 buffer_clear(m); 1126 buffer_put_int(m, rsafail); 1127 buffer_put_bignum2(m, p); 1128 1129 BN_clear_free(p); 1130 1131 mm_request_send(socket, MONITOR_ANS_SESSKEY, m); 1132 1133 /* Turn on permissions for sessid passing */ 1134 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1135 1136 return (0); 1137 } 1138 1139 int 1140 mm_answer_sessid(int socket, Buffer *m) 1141 { 1142 int i; 1143 1144 debug3("%s entering", __func__); 1145 1146 if (buffer_len(m) != 16) 1147 fatal("%s: bad ssh1 session id", __func__); 1148 for (i = 0; i < 16; i++) 1149 session_id[i] = buffer_get_char(m); 1150 1151 /* Turn on permissions for getpwnam */ 1152 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1153 1154 return (0); 1155 } 1156 1157 int 1158 mm_answer_rsa_keyallowed(int socket, Buffer *m) 1159 { 1160 BIGNUM *client_n; 1161 Key *key = NULL; 1162 u_char *blob = NULL; 1163 u_int blen = 0; 1164 int allowed = 0; 1165 1166 debug3("%s entering", __func__); 1167 1168 if (options.rsa_authentication && authctxt->valid) { 1169 if ((client_n = BN_new()) == NULL) 1170 fatal("%s: BN_new", __func__); 1171 buffer_get_bignum2(m, client_n); 1172 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1173 BN_clear_free(client_n); 1174 } 1175 buffer_clear(m); 1176 buffer_put_int(m, allowed); 1177 buffer_put_int(m, forced_command != NULL); 1178 1179 /* clear temporarily storage (used by generate challenge) */ 1180 monitor_reset_key_state(); 1181 1182 if (allowed && key != NULL) { 1183 key->type = KEY_RSA; /* cheat for key_to_blob */ 1184 if (key_to_blob(key, &blob, &blen) == 0) 1185 fatal("%s: key_to_blob failed", __func__); 1186 buffer_put_string(m, blob, blen); 1187 1188 /* Save temporarily for comparison in verify */ 1189 key_blob = blob; 1190 key_bloblen = blen; 1191 key_blobtype = MM_RSAUSERKEY; 1192 } 1193 if (key != NULL) 1194 key_free(key); 1195 1196 mm_append_debug(m); 1197 1198 mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m); 1199 1200 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1201 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1202 return (0); 1203 } 1204 1205 int 1206 mm_answer_rsa_challenge(int socket, Buffer *m) 1207 { 1208 Key *key = NULL; 1209 u_char *blob; 1210 u_int blen; 1211 1212 debug3("%s entering", __func__); 1213 1214 if (!authctxt->valid) 1215 fatal("%s: authctxt not valid", __func__); 1216 blob = buffer_get_string(m, &blen); 1217 if (!monitor_allowed_key(blob, blen)) 1218 fatal("%s: bad key, not previously allowed", __func__); 1219 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1220 fatal("%s: key type mismatch", __func__); 1221 if ((key = key_from_blob(blob, blen)) == NULL) 1222 fatal("%s: received bad key", __func__); 1223 1224 if (ssh1_challenge) 1225 BN_clear_free(ssh1_challenge); 1226 ssh1_challenge = auth_rsa_generate_challenge(key); 1227 1228 buffer_clear(m); 1229 buffer_put_bignum2(m, ssh1_challenge); 1230 1231 debug3("%s sending reply", __func__); 1232 mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m); 1233 1234 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1235 1236 xfree(blob); 1237 key_free(key); 1238 return (0); 1239 } 1240 1241 int 1242 mm_answer_rsa_response(int socket, Buffer *m) 1243 { 1244 Key *key = NULL; 1245 u_char *blob, *response; 1246 u_int blen, len; 1247 int success; 1248 1249 debug3("%s entering", __func__); 1250 1251 if (!authctxt->valid) 1252 fatal("%s: authctxt not valid", __func__); 1253 if (ssh1_challenge == NULL) 1254 fatal("%s: no ssh1_challenge", __func__); 1255 1256 blob = buffer_get_string(m, &blen); 1257 if (!monitor_allowed_key(blob, blen)) 1258 fatal("%s: bad key, not previously allowed", __func__); 1259 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1260 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1261 if ((key = key_from_blob(blob, blen)) == NULL) 1262 fatal("%s: received bad key", __func__); 1263 response = buffer_get_string(m, &len); 1264 if (len != 16) 1265 fatal("%s: received bad response to challenge", __func__); 1266 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1267 1268 xfree(blob); 1269 key_free(key); 1270 xfree(response); 1271 1272 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1273 1274 /* reset state */ 1275 BN_clear_free(ssh1_challenge); 1276 ssh1_challenge = NULL; 1277 monitor_reset_key_state(); 1278 1279 buffer_clear(m); 1280 buffer_put_int(m, success); 1281 mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m); 1282 1283 return (success); 1284 } 1285 1286 int 1287 mm_answer_term(int socket, Buffer *req) 1288 { 1289 extern struct monitor *pmonitor; 1290 int res, status; 1291 1292 debug3("%s: tearing down sessions", __func__); 1293 1294 /* The child is terminating */ 1295 session_destroy_all(&mm_session_close); 1296 1297 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1298 if (errno != EINTR) 1299 exit(1); 1300 1301 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1302 1303 /* Terminate process */ 1304 exit (res); 1305 } 1306 1307 void 1308 monitor_apply_keystate(struct monitor *pmonitor) 1309 { 1310 if (compat20) { 1311 set_newkeys(MODE_IN); 1312 set_newkeys(MODE_OUT); 1313 } else { 1314 packet_set_protocol_flags(child_state.ssh1protoflags); 1315 packet_set_encryption_key(child_state.ssh1key, 1316 child_state.ssh1keylen, child_state.ssh1cipher); 1317 xfree(child_state.ssh1key); 1318 } 1319 1320 /* for rc4 and other stateful ciphers */ 1321 packet_set_keycontext(MODE_OUT, child_state.keyout); 1322 xfree(child_state.keyout); 1323 packet_set_keycontext(MODE_IN, child_state.keyin); 1324 xfree(child_state.keyin); 1325 1326 if (!compat20) { 1327 packet_set_iv(MODE_OUT, child_state.ivout); 1328 xfree(child_state.ivout); 1329 packet_set_iv(MODE_IN, child_state.ivin); 1330 xfree(child_state.ivin); 1331 } 1332 1333 memcpy(&incoming_stream, &child_state.incoming, 1334 sizeof(incoming_stream)); 1335 memcpy(&outgoing_stream, &child_state.outgoing, 1336 sizeof(outgoing_stream)); 1337 1338 /* Update with new address */ 1339 if (options.compression) 1340 mm_init_compression(pmonitor->m_zlib); 1341 1342 /* Network I/O buffers */ 1343 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1344 buffer_clear(&input); 1345 buffer_append(&input, child_state.input, child_state.ilen); 1346 memset(child_state.input, 0, child_state.ilen); 1347 xfree(child_state.input); 1348 1349 buffer_clear(&output); 1350 buffer_append(&output, child_state.output, child_state.olen); 1351 memset(child_state.output, 0, child_state.olen); 1352 xfree(child_state.output); 1353 } 1354 1355 static Kex * 1356 mm_get_kex(Buffer *m) 1357 { 1358 Kex *kex; 1359 void *blob; 1360 u_int bloblen; 1361 1362 kex = xmalloc(sizeof(*kex)); 1363 memset(kex, 0, sizeof(*kex)); 1364 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1365 if ((session_id2 == NULL) || 1366 (kex->session_id_len != session_id2_len) || 1367 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1368 fatal("mm_get_get: internal error: bad session id"); 1369 kex->we_need = buffer_get_int(m); 1370 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1371 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1372 kex->server = 1; 1373 kex->hostkey_type = buffer_get_int(m); 1374 kex->kex_type = buffer_get_int(m); 1375 blob = buffer_get_string(m, &bloblen); 1376 buffer_init(&kex->my); 1377 buffer_append(&kex->my, blob, bloblen); 1378 xfree(blob); 1379 blob = buffer_get_string(m, &bloblen); 1380 buffer_init(&kex->peer); 1381 buffer_append(&kex->peer, blob, bloblen); 1382 xfree(blob); 1383 kex->done = 1; 1384 kex->flags = buffer_get_int(m); 1385 kex->client_version_string = buffer_get_string(m, NULL); 1386 kex->server_version_string = buffer_get_string(m, NULL); 1387 kex->load_host_key=&get_hostkey_by_type; 1388 kex->host_key_index=&get_hostkey_index; 1389 1390 return (kex); 1391 } 1392 1393 /* This function requries careful sanity checking */ 1394 1395 void 1396 mm_get_keystate(struct monitor *pmonitor) 1397 { 1398 Buffer m; 1399 u_char *blob, *p; 1400 u_int bloblen, plen; 1401 u_int32_t seqnr, packets; 1402 u_int64_t blocks; 1403 1404 debug3("%s: Waiting for new keys", __func__); 1405 1406 buffer_init(&m); 1407 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1408 if (!compat20) { 1409 child_state.ssh1protoflags = buffer_get_int(&m); 1410 child_state.ssh1cipher = buffer_get_int(&m); 1411 child_state.ssh1key = buffer_get_string(&m, 1412 &child_state.ssh1keylen); 1413 child_state.ivout = buffer_get_string(&m, 1414 &child_state.ivoutlen); 1415 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1416 goto skip; 1417 } else { 1418 /* Get the Kex for rekeying */ 1419 *pmonitor->m_pkex = mm_get_kex(&m); 1420 } 1421 1422 blob = buffer_get_string(&m, &bloblen); 1423 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1424 xfree(blob); 1425 1426 debug3("%s: Waiting for second key", __func__); 1427 blob = buffer_get_string(&m, &bloblen); 1428 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1429 xfree(blob); 1430 1431 /* Now get sequence numbers for the packets */ 1432 seqnr = buffer_get_int(&m); 1433 blocks = buffer_get_int64(&m); 1434 packets = buffer_get_int(&m); 1435 packet_set_state(MODE_OUT, seqnr, blocks, packets); 1436 seqnr = buffer_get_int(&m); 1437 blocks = buffer_get_int64(&m); 1438 packets = buffer_get_int(&m); 1439 packet_set_state(MODE_IN, seqnr, blocks, packets); 1440 1441 skip: 1442 /* Get the key context */ 1443 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1444 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1445 1446 debug3("%s: Getting compression state", __func__); 1447 /* Get compression state */ 1448 p = buffer_get_string(&m, &plen); 1449 if (plen != sizeof(child_state.outgoing)) 1450 fatal("%s: bad request size", __func__); 1451 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1452 xfree(p); 1453 1454 p = buffer_get_string(&m, &plen); 1455 if (plen != sizeof(child_state.incoming)) 1456 fatal("%s: bad request size", __func__); 1457 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1458 xfree(p); 1459 1460 /* Network I/O buffers */ 1461 debug3("%s: Getting Network I/O buffers", __func__); 1462 child_state.input = buffer_get_string(&m, &child_state.ilen); 1463 child_state.output = buffer_get_string(&m, &child_state.olen); 1464 1465 buffer_free(&m); 1466 } 1467 1468 1469 /* Allocation functions for zlib */ 1470 void * 1471 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1472 { 1473 size_t len = (size_t) size * ncount; 1474 void *address; 1475 1476 if (len == 0 || ncount > SIZE_T_MAX / size) 1477 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1478 1479 address = mm_malloc(mm, len); 1480 1481 return (address); 1482 } 1483 1484 void 1485 mm_zfree(struct mm_master *mm, void *address) 1486 { 1487 mm_free(mm, address); 1488 } 1489 1490 void 1491 mm_init_compression(struct mm_master *mm) 1492 { 1493 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1494 outgoing_stream.zfree = (free_func)mm_zfree; 1495 outgoing_stream.opaque = mm; 1496 1497 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1498 incoming_stream.zfree = (free_func)mm_zfree; 1499 incoming_stream.opaque = mm; 1500 } 1501 1502 /* XXX */ 1503 1504 #define FD_CLOSEONEXEC(x) do { \ 1505 if (fcntl(x, F_SETFD, 1) == -1) \ 1506 fatal("fcntl(%d, F_SETFD)", x); \ 1507 } while (0) 1508 1509 static void 1510 monitor_socketpair(int *pair) 1511 { 1512 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1513 fatal("%s: socketpair", __func__); 1514 FD_CLOSEONEXEC(pair[0]); 1515 FD_CLOSEONEXEC(pair[1]); 1516 } 1517 1518 #define MM_MEMSIZE 65536 1519 1520 struct monitor * 1521 monitor_init(void) 1522 { 1523 struct monitor *mon; 1524 int pair[2]; 1525 1526 mon = xmalloc(sizeof(*mon)); 1527 1528 mon->m_pid = 0; 1529 monitor_socketpair(pair); 1530 1531 mon->m_recvfd = pair[0]; 1532 mon->m_sendfd = pair[1]; 1533 1534 /* Used to share zlib space across processes */ 1535 if (options.compression) { 1536 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1537 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1538 1539 /* Compression needs to share state across borders */ 1540 mm_init_compression(mon->m_zlib); 1541 } 1542 1543 return mon; 1544 } 1545 1546 void 1547 monitor_reinit(struct monitor *mon) 1548 { 1549 int pair[2]; 1550 1551 monitor_socketpair(pair); 1552 1553 mon->m_recvfd = pair[0]; 1554 mon->m_sendfd = pair[1]; 1555 } 1556 1557 #ifdef GSSAPI 1558 int 1559 mm_answer_gss_setup_ctx(int socket, Buffer *m) 1560 { 1561 gss_OID_desc oid; 1562 OM_uint32 major; 1563 u_int len; 1564 1565 oid.elements = buffer_get_string(m, &len); 1566 oid.length = len; 1567 1568 major = ssh_gssapi_server_ctx(&gsscontext, &oid); 1569 1570 xfree(oid.elements); 1571 1572 buffer_clear(m); 1573 buffer_put_int(m, major); 1574 1575 mm_request_send(socket,MONITOR_ANS_GSSSETUP, m); 1576 1577 /* Now we have a context, enable the step */ 1578 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1579 1580 return (0); 1581 } 1582 1583 int 1584 mm_answer_gss_accept_ctx(int socket, Buffer *m) 1585 { 1586 gss_buffer_desc in; 1587 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1588 OM_uint32 major,minor; 1589 OM_uint32 flags = 0; /* GSI needs this */ 1590 u_int len; 1591 1592 in.value = buffer_get_string(m, &len); 1593 in.length = len; 1594 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1595 xfree(in.value); 1596 1597 buffer_clear(m); 1598 buffer_put_int(m, major); 1599 buffer_put_string(m, out.value, out.length); 1600 buffer_put_int(m, flags); 1601 mm_request_send(socket, MONITOR_ANS_GSSSTEP, m); 1602 1603 gss_release_buffer(&minor, &out); 1604 1605 if (major==GSS_S_COMPLETE) { 1606 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1607 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1608 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1609 } 1610 return (0); 1611 } 1612 1613 int 1614 mm_answer_gss_checkmic(int socket, Buffer *m) 1615 { 1616 gss_buffer_desc gssbuf, mic; 1617 OM_uint32 ret; 1618 u_int len; 1619 1620 gssbuf.value = buffer_get_string(m, &len); 1621 gssbuf.length = len; 1622 mic.value = buffer_get_string(m, &len); 1623 mic.length = len; 1624 1625 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1626 1627 xfree(gssbuf.value); 1628 xfree(mic.value); 1629 1630 buffer_clear(m); 1631 buffer_put_int(m, ret); 1632 1633 mm_request_send(socket, MONITOR_ANS_GSSCHECKMIC, m); 1634 1635 if (!GSS_ERROR(ret)) 1636 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1637 1638 return (0); 1639 } 1640 1641 int 1642 mm_answer_gss_userok(int socket, Buffer *m) 1643 { 1644 int authenticated; 1645 1646 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1647 1648 buffer_clear(m); 1649 buffer_put_int(m, authenticated); 1650 1651 debug3("%s: sending result %d", __func__, authenticated); 1652 mm_request_send(socket, MONITOR_ANS_GSSUSEROK, m); 1653 1654 auth_method="gssapi-with-mic"; 1655 1656 /* Monitor loop will terminate if authenticated */ 1657 return (authenticated); 1658 } 1659 #endif /* GSSAPI */ 1660