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 1.45 2003/07/22 13:35:22 markus 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 /* Imports */ 63 extern ServerOptions options; 64 extern u_int utmp_len; 65 extern Newkeys *current_keys[]; 66 extern z_stream incoming_stream; 67 extern z_stream outgoing_stream; 68 extern u_char session_id[]; 69 extern Buffer input, output; 70 extern Buffer auth_debug; 71 extern int auth_debug_init; 72 73 /* State exported from the child */ 74 75 struct { 76 z_stream incoming; 77 z_stream outgoing; 78 u_char *keyin; 79 u_int keyinlen; 80 u_char *keyout; 81 u_int keyoutlen; 82 u_char *ivin; 83 u_int ivinlen; 84 u_char *ivout; 85 u_int ivoutlen; 86 u_char *ssh1key; 87 u_int ssh1keylen; 88 int ssh1cipher; 89 int ssh1protoflags; 90 u_char *input; 91 u_int ilen; 92 u_char *output; 93 u_int olen; 94 } child_state; 95 96 /* Functions on the monitor that answer unprivileged requests */ 97 98 int mm_answer_moduli(int, Buffer *); 99 int mm_answer_sign(int, Buffer *); 100 int mm_answer_pwnamallow(int, Buffer *); 101 int mm_answer_auth2_read_banner(int, Buffer *); 102 int mm_answer_authserv(int, Buffer *); 103 int mm_answer_authpassword(int, Buffer *); 104 int mm_answer_bsdauthquery(int, Buffer *); 105 int mm_answer_bsdauthrespond(int, Buffer *); 106 int mm_answer_skeyquery(int, Buffer *); 107 int mm_answer_skeyrespond(int, Buffer *); 108 int mm_answer_keyallowed(int, Buffer *); 109 int mm_answer_keyverify(int, Buffer *); 110 int mm_answer_pty(int, Buffer *); 111 int mm_answer_pty_cleanup(int, Buffer *); 112 int mm_answer_term(int, Buffer *); 113 int mm_answer_rsa_keyallowed(int, Buffer *); 114 int mm_answer_rsa_challenge(int, Buffer *); 115 int mm_answer_rsa_response(int, Buffer *); 116 int mm_answer_sesskey(int, Buffer *); 117 int mm_answer_sessid(int, Buffer *); 118 119 #ifdef KRB5 120 int mm_answer_krb5(int, Buffer *); 121 #endif 122 123 static Authctxt *authctxt; 124 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 125 126 /* local state for key verify */ 127 static u_char *key_blob = NULL; 128 static u_int key_bloblen = 0; 129 static int key_blobtype = MM_NOKEY; 130 static char *hostbased_cuser = NULL; 131 static char *hostbased_chost = NULL; 132 static char *auth_method = "unknown"; 133 static u_int session_id2_len = 0; 134 static u_char *session_id2 = NULL; 135 static pid_t monitor_child_pid; 136 137 struct mon_table { 138 enum monitor_reqtype type; 139 int flags; 140 int (*f)(int, Buffer *); 141 }; 142 143 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 144 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 145 #define MON_ONCE 0x0010 /* Disable after calling */ 146 147 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 148 149 #define MON_PERMIT 0x1000 /* Request is permitted */ 150 151 struct mon_table mon_dispatch_proto20[] = { 152 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 153 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 154 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 155 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 156 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 157 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 158 #ifdef BSD_AUTH 159 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 160 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 161 #endif 162 #ifdef SKEY 163 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 164 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 165 #endif 166 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 167 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 168 #ifdef KRB5 169 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 170 #endif 171 {0, 0, NULL} 172 }; 173 174 struct mon_table mon_dispatch_postauth20[] = { 175 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 176 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 177 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 178 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 179 {MONITOR_REQ_TERM, 0, mm_answer_term}, 180 {0, 0, NULL} 181 }; 182 183 struct mon_table mon_dispatch_proto15[] = { 184 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 185 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 186 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 187 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 188 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed}, 189 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 190 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 191 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 192 #ifdef BSD_AUTH 193 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 194 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 195 #endif 196 #ifdef SKEY 197 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 198 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 199 #endif 200 #ifdef KRB5 201 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 202 #endif 203 {0, 0, NULL} 204 }; 205 206 struct mon_table mon_dispatch_postauth15[] = { 207 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 208 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 209 {MONITOR_REQ_TERM, 0, mm_answer_term}, 210 {0, 0, NULL} 211 }; 212 213 struct mon_table *mon_dispatch; 214 215 /* Specifies if a certain message is allowed at the moment */ 216 217 static void 218 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 219 { 220 while (ent->f != NULL) { 221 if (ent->type == type) { 222 ent->flags &= ~MON_PERMIT; 223 ent->flags |= permit ? MON_PERMIT : 0; 224 return; 225 } 226 ent++; 227 } 228 } 229 230 static void 231 monitor_permit_authentications(int permit) 232 { 233 struct mon_table *ent = mon_dispatch; 234 235 while (ent->f != NULL) { 236 if (ent->flags & MON_AUTH) { 237 ent->flags &= ~MON_PERMIT; 238 ent->flags |= permit ? MON_PERMIT : 0; 239 } 240 ent++; 241 } 242 } 243 244 Authctxt * 245 monitor_child_preauth(struct monitor *pmonitor) 246 { 247 struct mon_table *ent; 248 int authenticated = 0; 249 250 debug3("preauth child monitor started"); 251 252 if (compat20) { 253 mon_dispatch = mon_dispatch_proto20; 254 255 /* Permit requests for moduli and signatures */ 256 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 257 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 258 } else { 259 mon_dispatch = mon_dispatch_proto15; 260 261 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 262 } 263 264 authctxt = authctxt_new(); 265 266 /* The first few requests do not require asynchronous access */ 267 while (!authenticated) { 268 authenticated = monitor_read(pmonitor, mon_dispatch, &ent); 269 if (authenticated) { 270 if (!(ent->flags & MON_AUTHDECIDE)) 271 fatal("%s: unexpected authentication from %d", 272 __func__, ent->type); 273 if (authctxt->pw->pw_uid == 0 && 274 !auth_root_allowed(auth_method)) 275 authenticated = 0; 276 } 277 278 if (ent->flags & MON_AUTHDECIDE) { 279 auth_log(authctxt, authenticated, auth_method, 280 compat20 ? " ssh2" : ""); 281 if (!authenticated) 282 authctxt->failures++; 283 } 284 } 285 286 if (!authctxt->valid) 287 fatal("%s: authenticated invalid user", __func__); 288 289 debug("%s: %s has been authenticated by privileged process", 290 __func__, authctxt->user); 291 292 mm_get_keystate(pmonitor); 293 294 return (authctxt); 295 } 296 297 static void 298 monitor_set_child_handler(pid_t pid) 299 { 300 monitor_child_pid = pid; 301 } 302 303 static void 304 monitor_child_handler(int signal) 305 { 306 kill(monitor_child_pid, signal); 307 } 308 309 void 310 monitor_child_postauth(struct monitor *pmonitor) 311 { 312 monitor_set_child_handler(pmonitor->m_pid); 313 signal(SIGHUP, &monitor_child_handler); 314 signal(SIGTERM, &monitor_child_handler); 315 316 if (compat20) { 317 mon_dispatch = mon_dispatch_postauth20; 318 319 /* Permit requests for moduli and signatures */ 320 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 321 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 322 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 323 324 } else { 325 mon_dispatch = mon_dispatch_postauth15; 326 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 327 } 328 if (!no_pty_flag) { 329 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 330 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 331 } 332 333 for (;;) 334 monitor_read(pmonitor, mon_dispatch, NULL); 335 } 336 337 void 338 monitor_sync(struct monitor *pmonitor) 339 { 340 if (options.compression) { 341 /* The member allocation is not visible, so sync it */ 342 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 343 } 344 } 345 346 int 347 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 348 struct mon_table **pent) 349 { 350 Buffer m; 351 int ret; 352 u_char type; 353 354 buffer_init(&m); 355 356 mm_request_receive(pmonitor->m_sendfd, &m); 357 type = buffer_get_char(&m); 358 359 debug3("%s: checking request %d", __func__, type); 360 361 while (ent->f != NULL) { 362 if (ent->type == type) 363 break; 364 ent++; 365 } 366 367 if (ent->f != NULL) { 368 if (!(ent->flags & MON_PERMIT)) 369 fatal("%s: unpermitted request %d", __func__, 370 type); 371 ret = (*ent->f)(pmonitor->m_sendfd, &m); 372 buffer_free(&m); 373 374 /* The child may use this request only once, disable it */ 375 if (ent->flags & MON_ONCE) { 376 debug2("%s: %d used once, disabling now", __func__, 377 type); 378 ent->flags &= ~MON_PERMIT; 379 } 380 381 if (pent != NULL) 382 *pent = ent; 383 384 return ret; 385 } 386 387 fatal("%s: unsupported request: %d", __func__, type); 388 389 /* NOTREACHED */ 390 return (-1); 391 } 392 393 /* allowed key state */ 394 static int 395 monitor_allowed_key(u_char *blob, u_int bloblen) 396 { 397 /* make sure key is allowed */ 398 if (key_blob == NULL || key_bloblen != bloblen || 399 memcmp(key_blob, blob, key_bloblen)) 400 return (0); 401 return (1); 402 } 403 404 static void 405 monitor_reset_key_state(void) 406 { 407 /* reset state */ 408 if (key_blob != NULL) 409 xfree(key_blob); 410 if (hostbased_cuser != NULL) 411 xfree(hostbased_cuser); 412 if (hostbased_chost != NULL) 413 xfree(hostbased_chost); 414 key_blob = NULL; 415 key_bloblen = 0; 416 key_blobtype = MM_NOKEY; 417 hostbased_cuser = NULL; 418 hostbased_chost = NULL; 419 } 420 421 int 422 mm_answer_moduli(int socket, Buffer *m) 423 { 424 DH *dh; 425 int min, want, max; 426 427 min = buffer_get_int(m); 428 want = buffer_get_int(m); 429 max = buffer_get_int(m); 430 431 debug3("%s: got parameters: %d %d %d", 432 __func__, min, want, max); 433 /* We need to check here, too, in case the child got corrupted */ 434 if (max < min || want < min || max < want) 435 fatal("%s: bad parameters: %d %d %d", 436 __func__, min, want, max); 437 438 buffer_clear(m); 439 440 dh = choose_dh(min, want, max); 441 if (dh == NULL) { 442 buffer_put_char(m, 0); 443 return (0); 444 } else { 445 /* Send first bignum */ 446 buffer_put_char(m, 1); 447 buffer_put_bignum2(m, dh->p); 448 buffer_put_bignum2(m, dh->g); 449 450 DH_free(dh); 451 } 452 mm_request_send(socket, MONITOR_ANS_MODULI, m); 453 return (0); 454 } 455 456 int 457 mm_answer_sign(int socket, Buffer *m) 458 { 459 Key *key; 460 u_char *p; 461 u_char *signature; 462 u_int siglen, datlen; 463 int keyid; 464 465 debug3("%s", __func__); 466 467 keyid = buffer_get_int(m); 468 p = buffer_get_string(m, &datlen); 469 470 if (datlen != 20) 471 fatal("%s: data length incorrect: %u", __func__, datlen); 472 473 /* save session id, it will be passed on the first call */ 474 if (session_id2_len == 0) { 475 session_id2_len = datlen; 476 session_id2 = xmalloc(session_id2_len); 477 memcpy(session_id2, p, session_id2_len); 478 } 479 480 if ((key = get_hostkey_by_index(keyid)) == NULL) 481 fatal("%s: no hostkey from index %d", __func__, keyid); 482 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 483 fatal("%s: key_sign failed", __func__); 484 485 debug3("%s: signature %p(%u)", __func__, signature, siglen); 486 487 buffer_clear(m); 488 buffer_put_string(m, signature, siglen); 489 490 xfree(p); 491 xfree(signature); 492 493 mm_request_send(socket, MONITOR_ANS_SIGN, m); 494 495 /* Turn on permissions for getpwnam */ 496 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 497 498 return (0); 499 } 500 501 /* Retrieves the password entry and also checks if the user is permitted */ 502 503 int 504 mm_answer_pwnamallow(int socket, Buffer *m) 505 { 506 char *login; 507 struct passwd *pwent; 508 int allowed = 0; 509 510 debug3("%s", __func__); 511 512 if (authctxt->attempt++ != 0) 513 fatal("%s: multiple attempts for getpwnam", __func__); 514 515 login = buffer_get_string(m, NULL); 516 517 pwent = getpwnamallow(login); 518 519 authctxt->user = xstrdup(login); 520 setproctitle("%s [priv]", pwent ? login : "unknown"); 521 xfree(login); 522 523 buffer_clear(m); 524 525 if (pwent == NULL) { 526 buffer_put_char(m, 0); 527 goto out; 528 } 529 530 allowed = 1; 531 authctxt->pw = pwent; 532 authctxt->valid = 1; 533 534 buffer_put_char(m, 1); 535 buffer_put_string(m, pwent, sizeof(struct passwd)); 536 buffer_put_cstring(m, pwent->pw_name); 537 buffer_put_cstring(m, "*"); 538 buffer_put_cstring(m, pwent->pw_gecos); 539 buffer_put_cstring(m, pwent->pw_class); 540 buffer_put_cstring(m, pwent->pw_dir); 541 buffer_put_cstring(m, pwent->pw_shell); 542 543 out: 544 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 545 mm_request_send(socket, MONITOR_ANS_PWNAM, m); 546 547 /* For SSHv1 allow authentication now */ 548 if (!compat20) 549 monitor_permit_authentications(1); 550 else { 551 /* Allow service/style information on the auth context */ 552 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 553 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 554 } 555 556 557 return (0); 558 } 559 560 int mm_answer_auth2_read_banner(int socket, Buffer *m) 561 { 562 char *banner; 563 564 buffer_clear(m); 565 banner = auth2_read_banner(); 566 buffer_put_cstring(m, banner != NULL ? banner : ""); 567 mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m); 568 569 if (banner != NULL) 570 xfree(banner); 571 572 return (0); 573 } 574 575 int 576 mm_answer_authserv(int socket, Buffer *m) 577 { 578 monitor_permit_authentications(1); 579 580 authctxt->service = buffer_get_string(m, NULL); 581 authctxt->style = buffer_get_string(m, NULL); 582 debug3("%s: service=%s, style=%s", 583 __func__, authctxt->service, authctxt->style); 584 585 if (strlen(authctxt->style) == 0) { 586 xfree(authctxt->style); 587 authctxt->style = NULL; 588 } 589 590 return (0); 591 } 592 593 int 594 mm_answer_authpassword(int socket, Buffer *m) 595 { 596 static int call_count; 597 char *passwd; 598 int authenticated; 599 u_int plen; 600 601 passwd = buffer_get_string(m, &plen); 602 /* Only authenticate if the context is valid */ 603 authenticated = options.password_authentication && 604 authctxt->valid && auth_password(authctxt, passwd); 605 memset(passwd, 0, strlen(passwd)); 606 xfree(passwd); 607 608 buffer_clear(m); 609 buffer_put_int(m, authenticated); 610 611 debug3("%s: sending result %d", __func__, authenticated); 612 mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m); 613 614 call_count++; 615 if (plen == 0 && call_count == 1) 616 auth_method = "none"; 617 else 618 auth_method = "password"; 619 620 /* Causes monitor loop to terminate if authenticated */ 621 return (authenticated); 622 } 623 624 #ifdef BSD_AUTH 625 int 626 mm_answer_bsdauthquery(int socket, Buffer *m) 627 { 628 char *name, *infotxt; 629 u_int numprompts; 630 u_int *echo_on; 631 char **prompts; 632 u_int success; 633 634 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 635 &prompts, &echo_on) < 0 ? 0 : 1; 636 637 buffer_clear(m); 638 buffer_put_int(m, success); 639 if (success) 640 buffer_put_cstring(m, prompts[0]); 641 642 debug3("%s: sending challenge success: %u", __func__, success); 643 mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m); 644 645 if (success) { 646 xfree(name); 647 xfree(infotxt); 648 xfree(prompts); 649 xfree(echo_on); 650 } 651 652 return (0); 653 } 654 655 int 656 mm_answer_bsdauthrespond(int socket, Buffer *m) 657 { 658 char *response; 659 int authok; 660 661 if (authctxt->as == 0) 662 fatal("%s: no bsd auth session", __func__); 663 664 response = buffer_get_string(m, NULL); 665 authok = options.challenge_response_authentication && 666 auth_userresponse(authctxt->as, response, 0); 667 authctxt->as = NULL; 668 debug3("%s: <%s> = <%d>", __func__, response, authok); 669 xfree(response); 670 671 buffer_clear(m); 672 buffer_put_int(m, authok); 673 674 debug3("%s: sending authenticated: %d", __func__, authok); 675 mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m); 676 677 auth_method = "bsdauth"; 678 679 return (authok != 0); 680 } 681 #endif 682 683 #ifdef SKEY 684 int 685 mm_answer_skeyquery(int socket, Buffer *m) 686 { 687 struct skey skey; 688 char challenge[1024]; 689 u_int success; 690 691 success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1; 692 693 buffer_clear(m); 694 buffer_put_int(m, success); 695 if (success) 696 buffer_put_cstring(m, challenge); 697 698 debug3("%s: sending challenge success: %u", __func__, success); 699 mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m); 700 701 return (0); 702 } 703 704 int 705 mm_answer_skeyrespond(int socket, Buffer *m) 706 { 707 char *response; 708 int authok; 709 710 response = buffer_get_string(m, NULL); 711 712 authok = (options.challenge_response_authentication && 713 authctxt->valid && 714 skey_haskey(authctxt->pw->pw_name) == 0 && 715 skey_passcheck(authctxt->pw->pw_name, response) != -1); 716 717 xfree(response); 718 719 buffer_clear(m); 720 buffer_put_int(m, authok); 721 722 debug3("%s: sending authenticated: %d", __func__, authok); 723 mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m); 724 725 auth_method = "skey"; 726 727 return (authok != 0); 728 } 729 #endif 730 731 static void 732 mm_append_debug(Buffer *m) 733 { 734 if (auth_debug_init && buffer_len(&auth_debug)) { 735 debug3("%s: Appending debug messages for child", __func__); 736 buffer_append(m, buffer_ptr(&auth_debug), 737 buffer_len(&auth_debug)); 738 buffer_clear(&auth_debug); 739 } 740 } 741 742 int 743 mm_answer_keyallowed(int socket, Buffer *m) 744 { 745 Key *key; 746 char *cuser, *chost; 747 u_char *blob; 748 u_int bloblen; 749 enum mm_keytype type = 0; 750 int allowed = 0; 751 752 debug3("%s entering", __func__); 753 754 type = buffer_get_int(m); 755 cuser = buffer_get_string(m, NULL); 756 chost = buffer_get_string(m, NULL); 757 blob = buffer_get_string(m, &bloblen); 758 759 key = key_from_blob(blob, bloblen); 760 761 if ((compat20 && type == MM_RSAHOSTKEY) || 762 (!compat20 && type != MM_RSAHOSTKEY)) 763 fatal("%s: key type and protocol mismatch", __func__); 764 765 debug3("%s: key_from_blob: %p", __func__, key); 766 767 if (key != NULL && authctxt->pw != NULL) { 768 switch(type) { 769 case MM_USERKEY: 770 allowed = options.pubkey_authentication && 771 user_key_allowed(authctxt->pw, key); 772 break; 773 case MM_HOSTKEY: 774 allowed = options.hostbased_authentication && 775 hostbased_key_allowed(authctxt->pw, 776 cuser, chost, key); 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 break; 784 default: 785 fatal("%s: unknown key type %d", __func__, type); 786 break; 787 } 788 } 789 if (key != NULL) 790 key_free(key); 791 792 /* clear temporarily storage (used by verify) */ 793 monitor_reset_key_state(); 794 795 if (allowed) { 796 /* Save temporarily for comparison in verify */ 797 key_blob = blob; 798 key_bloblen = bloblen; 799 key_blobtype = type; 800 hostbased_cuser = cuser; 801 hostbased_chost = chost; 802 } 803 804 debug3("%s: key %p is %s", 805 __func__, key, allowed ? "allowed" : "disallowed"); 806 807 buffer_clear(m); 808 buffer_put_int(m, allowed); 809 buffer_put_int(m, forced_command != NULL); 810 811 mm_append_debug(m); 812 813 mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m); 814 815 if (type == MM_RSAHOSTKEY) 816 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 817 818 return (0); 819 } 820 821 static int 822 monitor_valid_userblob(u_char *data, u_int datalen) 823 { 824 Buffer b; 825 char *p; 826 u_int len; 827 int fail = 0; 828 829 buffer_init(&b); 830 buffer_append(&b, data, datalen); 831 832 if (datafellows & SSH_OLD_SESSIONID) { 833 p = buffer_ptr(&b); 834 len = buffer_len(&b); 835 if ((session_id2 == NULL) || 836 (len < session_id2_len) || 837 (memcmp(p, session_id2, session_id2_len) != 0)) 838 fail++; 839 buffer_consume(&b, session_id2_len); 840 } else { 841 p = buffer_get_string(&b, &len); 842 if ((session_id2 == NULL) || 843 (len != session_id2_len) || 844 (memcmp(p, session_id2, session_id2_len) != 0)) 845 fail++; 846 xfree(p); 847 } 848 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 849 fail++; 850 p = buffer_get_string(&b, NULL); 851 if (strcmp(authctxt->user, p) != 0) { 852 logit("wrong user name passed to monitor: expected %s != %.100s", 853 authctxt->user, p); 854 fail++; 855 } 856 xfree(p); 857 buffer_skip_string(&b); 858 if (datafellows & SSH_BUG_PKAUTH) { 859 if (!buffer_get_char(&b)) 860 fail++; 861 } else { 862 p = buffer_get_string(&b, NULL); 863 if (strcmp("publickey", p) != 0) 864 fail++; 865 xfree(p); 866 if (!buffer_get_char(&b)) 867 fail++; 868 buffer_skip_string(&b); 869 } 870 buffer_skip_string(&b); 871 if (buffer_len(&b) != 0) 872 fail++; 873 buffer_free(&b); 874 return (fail == 0); 875 } 876 877 static int 878 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 879 char *chost) 880 { 881 Buffer b; 882 char *p; 883 u_int len; 884 int fail = 0; 885 886 buffer_init(&b); 887 buffer_append(&b, data, datalen); 888 889 p = buffer_get_string(&b, &len); 890 if ((session_id2 == NULL) || 891 (len != session_id2_len) || 892 (memcmp(p, session_id2, session_id2_len) != 0)) 893 fail++; 894 xfree(p); 895 896 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 897 fail++; 898 p = buffer_get_string(&b, NULL); 899 if (strcmp(authctxt->user, p) != 0) { 900 logit("wrong user name passed to monitor: expected %s != %.100s", 901 authctxt->user, p); 902 fail++; 903 } 904 xfree(p); 905 buffer_skip_string(&b); /* service */ 906 p = buffer_get_string(&b, NULL); 907 if (strcmp(p, "hostbased") != 0) 908 fail++; 909 xfree(p); 910 buffer_skip_string(&b); /* pkalg */ 911 buffer_skip_string(&b); /* pkblob */ 912 913 /* verify client host, strip trailing dot if necessary */ 914 p = buffer_get_string(&b, NULL); 915 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 916 p[len - 1] = '\0'; 917 if (strcmp(p, chost) != 0) 918 fail++; 919 xfree(p); 920 921 /* verify client user */ 922 p = buffer_get_string(&b, NULL); 923 if (strcmp(p, cuser) != 0) 924 fail++; 925 xfree(p); 926 927 if (buffer_len(&b) != 0) 928 fail++; 929 buffer_free(&b); 930 return (fail == 0); 931 } 932 933 int 934 mm_answer_keyverify(int socket, Buffer *m) 935 { 936 Key *key; 937 u_char *signature, *data, *blob; 938 u_int signaturelen, datalen, bloblen; 939 int verified = 0; 940 int valid_data = 0; 941 942 blob = buffer_get_string(m, &bloblen); 943 signature = buffer_get_string(m, &signaturelen); 944 data = buffer_get_string(m, &datalen); 945 946 if (hostbased_cuser == NULL || hostbased_chost == NULL || 947 !monitor_allowed_key(blob, bloblen)) 948 fatal("%s: bad key, not previously allowed", __func__); 949 950 key = key_from_blob(blob, bloblen); 951 if (key == NULL) 952 fatal("%s: bad public key blob", __func__); 953 954 switch (key_blobtype) { 955 case MM_USERKEY: 956 valid_data = monitor_valid_userblob(data, datalen); 957 break; 958 case MM_HOSTKEY: 959 valid_data = monitor_valid_hostbasedblob(data, datalen, 960 hostbased_cuser, hostbased_chost); 961 break; 962 default: 963 valid_data = 0; 964 break; 965 } 966 if (!valid_data) 967 fatal("%s: bad signature data blob", __func__); 968 969 verified = key_verify(key, signature, signaturelen, data, datalen); 970 debug3("%s: key %p signature %s", 971 __func__, key, verified ? "verified" : "unverified"); 972 973 key_free(key); 974 xfree(blob); 975 xfree(signature); 976 xfree(data); 977 978 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 979 980 monitor_reset_key_state(); 981 982 buffer_clear(m); 983 buffer_put_int(m, verified); 984 mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m); 985 986 return (verified); 987 } 988 989 static void 990 mm_record_login(Session *s, struct passwd *pw) 991 { 992 socklen_t fromlen; 993 struct sockaddr_storage from; 994 995 /* 996 * Get IP address of client. If the connection is not a socket, let 997 * the address be 0.0.0.0. 998 */ 999 memset(&from, 0, sizeof(from)); 1000 fromlen = sizeof(from); 1001 if (packet_connection_is_on_socket()) { 1002 if (getpeername(packet_get_connection_in(), 1003 (struct sockaddr *) & from, &fromlen) < 0) { 1004 debug("getpeername: %.100s", strerror(errno)); 1005 fatal_cleanup(); 1006 } 1007 } 1008 /* Record that there was a login on that tty from the remote host. */ 1009 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1010 get_remote_name_or_ip(utmp_len, options.use_dns), 1011 (struct sockaddr *)&from, fromlen); 1012 } 1013 1014 static void 1015 mm_session_close(Session *s) 1016 { 1017 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1018 if (s->ttyfd != -1) { 1019 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1020 fatal_remove_cleanup(session_pty_cleanup2, (void *)s); 1021 session_pty_cleanup2(s); 1022 } 1023 s->used = 0; 1024 } 1025 1026 int 1027 mm_answer_pty(int socket, Buffer *m) 1028 { 1029 extern struct monitor *pmonitor; 1030 Session *s; 1031 int res, fd0; 1032 1033 debug3("%s entering", __func__); 1034 1035 buffer_clear(m); 1036 s = session_new(); 1037 if (s == NULL) 1038 goto error; 1039 s->authctxt = authctxt; 1040 s->pw = authctxt->pw; 1041 s->pid = pmonitor->m_pid; 1042 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1043 if (res == 0) 1044 goto error; 1045 fatal_add_cleanup(session_pty_cleanup2, (void *)s); 1046 pty_setowner(authctxt->pw, s->tty); 1047 1048 buffer_put_int(m, 1); 1049 buffer_put_cstring(m, s->tty); 1050 mm_request_send(socket, MONITOR_ANS_PTY, m); 1051 1052 mm_send_fd(socket, s->ptyfd); 1053 mm_send_fd(socket, s->ttyfd); 1054 1055 /* We need to trick ttyslot */ 1056 if (dup2(s->ttyfd, 0) == -1) 1057 fatal("%s: dup2", __func__); 1058 1059 mm_record_login(s, authctxt->pw); 1060 1061 /* Now we can close the file descriptor again */ 1062 close(0); 1063 1064 /* make sure nothing uses fd 0 */ 1065 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1066 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1067 if (fd0 != 0) 1068 error("%s: fd0 %d != 0", __func__, fd0); 1069 1070 /* slave is not needed */ 1071 close(s->ttyfd); 1072 s->ttyfd = s->ptyfd; 1073 /* no need to dup() because nobody closes ptyfd */ 1074 s->ptymaster = s->ptyfd; 1075 1076 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1077 1078 return (0); 1079 1080 error: 1081 if (s != NULL) 1082 mm_session_close(s); 1083 buffer_put_int(m, 0); 1084 mm_request_send(socket, MONITOR_ANS_PTY, m); 1085 return (0); 1086 } 1087 1088 int 1089 mm_answer_pty_cleanup(int socket, Buffer *m) 1090 { 1091 Session *s; 1092 char *tty; 1093 1094 debug3("%s entering", __func__); 1095 1096 tty = buffer_get_string(m, NULL); 1097 if ((s = session_by_tty(tty)) != NULL) 1098 mm_session_close(s); 1099 buffer_clear(m); 1100 xfree(tty); 1101 return (0); 1102 } 1103 1104 int 1105 mm_answer_sesskey(int socket, Buffer *m) 1106 { 1107 BIGNUM *p; 1108 int rsafail; 1109 1110 /* Turn off permissions */ 1111 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 1112 1113 if ((p = BN_new()) == NULL) 1114 fatal("%s: BN_new", __func__); 1115 1116 buffer_get_bignum2(m, p); 1117 1118 rsafail = ssh1_session_key(p); 1119 1120 buffer_clear(m); 1121 buffer_put_int(m, rsafail); 1122 buffer_put_bignum2(m, p); 1123 1124 BN_clear_free(p); 1125 1126 mm_request_send(socket, MONITOR_ANS_SESSKEY, m); 1127 1128 /* Turn on permissions for sessid passing */ 1129 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1130 1131 return (0); 1132 } 1133 1134 int 1135 mm_answer_sessid(int socket, Buffer *m) 1136 { 1137 int i; 1138 1139 debug3("%s entering", __func__); 1140 1141 if (buffer_len(m) != 16) 1142 fatal("%s: bad ssh1 session id", __func__); 1143 for (i = 0; i < 16; i++) 1144 session_id[i] = buffer_get_char(m); 1145 1146 /* Turn on permissions for getpwnam */ 1147 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1148 1149 return (0); 1150 } 1151 1152 int 1153 mm_answer_rsa_keyallowed(int socket, Buffer *m) 1154 { 1155 BIGNUM *client_n; 1156 Key *key = NULL; 1157 u_char *blob = NULL; 1158 u_int blen = 0; 1159 int allowed = 0; 1160 1161 debug3("%s entering", __func__); 1162 1163 if (options.rsa_authentication && authctxt->valid) { 1164 if ((client_n = BN_new()) == NULL) 1165 fatal("%s: BN_new", __func__); 1166 buffer_get_bignum2(m, client_n); 1167 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1168 BN_clear_free(client_n); 1169 } 1170 buffer_clear(m); 1171 buffer_put_int(m, allowed); 1172 buffer_put_int(m, forced_command != NULL); 1173 1174 /* clear temporarily storage (used by generate challenge) */ 1175 monitor_reset_key_state(); 1176 1177 if (allowed && key != NULL) { 1178 key->type = KEY_RSA; /* cheat for key_to_blob */ 1179 if (key_to_blob(key, &blob, &blen) == 0) 1180 fatal("%s: key_to_blob failed", __func__); 1181 buffer_put_string(m, blob, blen); 1182 1183 /* Save temporarily for comparison in verify */ 1184 key_blob = blob; 1185 key_bloblen = blen; 1186 key_blobtype = MM_RSAUSERKEY; 1187 } 1188 if (key != NULL) 1189 key_free(key); 1190 1191 mm_append_debug(m); 1192 1193 mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m); 1194 1195 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1196 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1197 return (0); 1198 } 1199 1200 int 1201 mm_answer_rsa_challenge(int socket, Buffer *m) 1202 { 1203 Key *key = NULL; 1204 u_char *blob; 1205 u_int blen; 1206 1207 debug3("%s entering", __func__); 1208 1209 if (!authctxt->valid) 1210 fatal("%s: authctxt not valid", __func__); 1211 blob = buffer_get_string(m, &blen); 1212 if (!monitor_allowed_key(blob, blen)) 1213 fatal("%s: bad key, not previously allowed", __func__); 1214 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1215 fatal("%s: key type mismatch", __func__); 1216 if ((key = key_from_blob(blob, blen)) == NULL) 1217 fatal("%s: received bad key", __func__); 1218 1219 if (ssh1_challenge) 1220 BN_clear_free(ssh1_challenge); 1221 ssh1_challenge = auth_rsa_generate_challenge(key); 1222 1223 buffer_clear(m); 1224 buffer_put_bignum2(m, ssh1_challenge); 1225 1226 debug3("%s sending reply", __func__); 1227 mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m); 1228 1229 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1230 1231 xfree(blob); 1232 key_free(key); 1233 return (0); 1234 } 1235 1236 int 1237 mm_answer_rsa_response(int socket, Buffer *m) 1238 { 1239 Key *key = NULL; 1240 u_char *blob, *response; 1241 u_int blen, len; 1242 int success; 1243 1244 debug3("%s entering", __func__); 1245 1246 if (!authctxt->valid) 1247 fatal("%s: authctxt not valid", __func__); 1248 if (ssh1_challenge == NULL) 1249 fatal("%s: no ssh1_challenge", __func__); 1250 1251 blob = buffer_get_string(m, &blen); 1252 if (!monitor_allowed_key(blob, blen)) 1253 fatal("%s: bad key, not previously allowed", __func__); 1254 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1255 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1256 if ((key = key_from_blob(blob, blen)) == NULL) 1257 fatal("%s: received bad key", __func__); 1258 response = buffer_get_string(m, &len); 1259 if (len != 16) 1260 fatal("%s: received bad response to challenge", __func__); 1261 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1262 1263 xfree(blob); 1264 key_free(key); 1265 xfree(response); 1266 1267 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1268 1269 /* reset state */ 1270 BN_clear_free(ssh1_challenge); 1271 ssh1_challenge = NULL; 1272 monitor_reset_key_state(); 1273 1274 buffer_clear(m); 1275 buffer_put_int(m, success); 1276 mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m); 1277 1278 return (success); 1279 } 1280 1281 #ifdef KRB5 1282 int 1283 mm_answer_krb5(int socket, Buffer *m) 1284 { 1285 krb5_data tkt, reply; 1286 char *client_user; 1287 u_int len; 1288 int success; 1289 1290 /* use temporary var to avoid size issues on 64bit arch */ 1291 tkt.data = buffer_get_string(m, &len); 1292 tkt.length = len; 1293 1294 success = options.kerberos_authentication && 1295 authctxt->valid && 1296 auth_krb5(authctxt, &tkt, &client_user, &reply); 1297 1298 if (tkt.length) 1299 xfree(tkt.data); 1300 1301 buffer_clear(m); 1302 buffer_put_int(m, success); 1303 1304 if (success) { 1305 buffer_put_cstring(m, client_user); 1306 buffer_put_string(m, reply.data, reply.length); 1307 if (client_user) 1308 xfree(client_user); 1309 if (reply.length) 1310 xfree(reply.data); 1311 } 1312 mm_request_send(socket, MONITOR_ANS_KRB5, m); 1313 1314 auth_method = "kerberos"; 1315 1316 return success; 1317 } 1318 #endif 1319 1320 int 1321 mm_answer_term(int socket, Buffer *req) 1322 { 1323 extern struct monitor *pmonitor; 1324 int res, status; 1325 1326 debug3("%s: tearing down sessions", __func__); 1327 1328 /* The child is terminating */ 1329 session_destroy_all(&mm_session_close); 1330 1331 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1332 if (errno != EINTR) 1333 exit(1); 1334 1335 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1336 1337 /* Terminate process */ 1338 exit (res); 1339 } 1340 1341 void 1342 monitor_apply_keystate(struct monitor *pmonitor) 1343 { 1344 if (compat20) { 1345 set_newkeys(MODE_IN); 1346 set_newkeys(MODE_OUT); 1347 } else { 1348 packet_set_protocol_flags(child_state.ssh1protoflags); 1349 packet_set_encryption_key(child_state.ssh1key, 1350 child_state.ssh1keylen, child_state.ssh1cipher); 1351 xfree(child_state.ssh1key); 1352 } 1353 1354 /* for rc4 and other stateful ciphers */ 1355 packet_set_keycontext(MODE_OUT, child_state.keyout); 1356 xfree(child_state.keyout); 1357 packet_set_keycontext(MODE_IN, child_state.keyin); 1358 xfree(child_state.keyin); 1359 1360 if (!compat20) { 1361 packet_set_iv(MODE_OUT, child_state.ivout); 1362 xfree(child_state.ivout); 1363 packet_set_iv(MODE_IN, child_state.ivin); 1364 xfree(child_state.ivin); 1365 } 1366 1367 memcpy(&incoming_stream, &child_state.incoming, 1368 sizeof(incoming_stream)); 1369 memcpy(&outgoing_stream, &child_state.outgoing, 1370 sizeof(outgoing_stream)); 1371 1372 /* Update with new address */ 1373 if (options.compression) 1374 mm_init_compression(pmonitor->m_zlib); 1375 1376 /* Network I/O buffers */ 1377 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1378 buffer_clear(&input); 1379 buffer_append(&input, child_state.input, child_state.ilen); 1380 memset(child_state.input, 0, child_state.ilen); 1381 xfree(child_state.input); 1382 1383 buffer_clear(&output); 1384 buffer_append(&output, child_state.output, child_state.olen); 1385 memset(child_state.output, 0, child_state.olen); 1386 xfree(child_state.output); 1387 } 1388 1389 static Kex * 1390 mm_get_kex(Buffer *m) 1391 { 1392 Kex *kex; 1393 void *blob; 1394 u_int bloblen; 1395 1396 kex = xmalloc(sizeof(*kex)); 1397 memset(kex, 0, sizeof(*kex)); 1398 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1399 if ((session_id2 == NULL) || 1400 (kex->session_id_len != session_id2_len) || 1401 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1402 fatal("mm_get_get: internal error: bad session id"); 1403 kex->we_need = buffer_get_int(m); 1404 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1405 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1406 kex->server = 1; 1407 kex->hostkey_type = buffer_get_int(m); 1408 kex->kex_type = buffer_get_int(m); 1409 blob = buffer_get_string(m, &bloblen); 1410 buffer_init(&kex->my); 1411 buffer_append(&kex->my, blob, bloblen); 1412 xfree(blob); 1413 blob = buffer_get_string(m, &bloblen); 1414 buffer_init(&kex->peer); 1415 buffer_append(&kex->peer, blob, bloblen); 1416 xfree(blob); 1417 kex->done = 1; 1418 kex->flags = buffer_get_int(m); 1419 kex->client_version_string = buffer_get_string(m, NULL); 1420 kex->server_version_string = buffer_get_string(m, NULL); 1421 kex->load_host_key=&get_hostkey_by_type; 1422 kex->host_key_index=&get_hostkey_index; 1423 1424 return (kex); 1425 } 1426 1427 /* This function requries careful sanity checking */ 1428 1429 void 1430 mm_get_keystate(struct monitor *pmonitor) 1431 { 1432 Buffer m; 1433 u_char *blob, *p; 1434 u_int bloblen, plen; 1435 u_int32_t seqnr, packets; 1436 u_int64_t blocks; 1437 1438 debug3("%s: Waiting for new keys", __func__); 1439 1440 buffer_init(&m); 1441 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1442 if (!compat20) { 1443 child_state.ssh1protoflags = buffer_get_int(&m); 1444 child_state.ssh1cipher = buffer_get_int(&m); 1445 child_state.ssh1key = buffer_get_string(&m, 1446 &child_state.ssh1keylen); 1447 child_state.ivout = buffer_get_string(&m, 1448 &child_state.ivoutlen); 1449 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1450 goto skip; 1451 } else { 1452 /* Get the Kex for rekeying */ 1453 *pmonitor->m_pkex = mm_get_kex(&m); 1454 } 1455 1456 blob = buffer_get_string(&m, &bloblen); 1457 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1458 xfree(blob); 1459 1460 debug3("%s: Waiting for second key", __func__); 1461 blob = buffer_get_string(&m, &bloblen); 1462 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1463 xfree(blob); 1464 1465 /* Now get sequence numbers for the packets */ 1466 seqnr = buffer_get_int(&m); 1467 blocks = buffer_get_int64(&m); 1468 packets = buffer_get_int(&m); 1469 packet_set_state(MODE_OUT, seqnr, blocks, packets); 1470 seqnr = buffer_get_int(&m); 1471 blocks = buffer_get_int64(&m); 1472 packets = buffer_get_int(&m); 1473 packet_set_state(MODE_IN, seqnr, blocks, packets); 1474 1475 skip: 1476 /* Get the key context */ 1477 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1478 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1479 1480 debug3("%s: Getting compression state", __func__); 1481 /* Get compression state */ 1482 p = buffer_get_string(&m, &plen); 1483 if (plen != sizeof(child_state.outgoing)) 1484 fatal("%s: bad request size", __func__); 1485 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1486 xfree(p); 1487 1488 p = buffer_get_string(&m, &plen); 1489 if (plen != sizeof(child_state.incoming)) 1490 fatal("%s: bad request size", __func__); 1491 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1492 xfree(p); 1493 1494 /* Network I/O buffers */ 1495 debug3("%s: Getting Network I/O buffers", __func__); 1496 child_state.input = buffer_get_string(&m, &child_state.ilen); 1497 child_state.output = buffer_get_string(&m, &child_state.olen); 1498 1499 buffer_free(&m); 1500 } 1501 1502 1503 /* Allocation functions for zlib */ 1504 void * 1505 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1506 { 1507 size_t len = (size_t) size * ncount; 1508 void *address; 1509 1510 if (len == 0 || ncount > SIZE_T_MAX / size) 1511 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1512 1513 address = mm_malloc(mm, len); 1514 1515 return (address); 1516 } 1517 1518 void 1519 mm_zfree(struct mm_master *mm, void *address) 1520 { 1521 mm_free(mm, address); 1522 } 1523 1524 void 1525 mm_init_compression(struct mm_master *mm) 1526 { 1527 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1528 outgoing_stream.zfree = (free_func)mm_zfree; 1529 outgoing_stream.opaque = mm; 1530 1531 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1532 incoming_stream.zfree = (free_func)mm_zfree; 1533 incoming_stream.opaque = mm; 1534 } 1535 1536 /* XXX */ 1537 1538 #define FD_CLOSEONEXEC(x) do { \ 1539 if (fcntl(x, F_SETFD, 1) == -1) \ 1540 fatal("fcntl(%d, F_SETFD)", x); \ 1541 } while (0) 1542 1543 static void 1544 monitor_socketpair(int *pair) 1545 { 1546 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1547 fatal("%s: socketpair", __func__); 1548 FD_CLOSEONEXEC(pair[0]); 1549 FD_CLOSEONEXEC(pair[1]); 1550 } 1551 1552 #define MM_MEMSIZE 65536 1553 1554 struct monitor * 1555 monitor_init(void) 1556 { 1557 struct monitor *mon; 1558 int pair[2]; 1559 1560 mon = xmalloc(sizeof(*mon)); 1561 1562 monitor_socketpair(pair); 1563 1564 mon->m_recvfd = pair[0]; 1565 mon->m_sendfd = pair[1]; 1566 1567 /* Used to share zlib space across processes */ 1568 if (options.compression) { 1569 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1570 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1571 1572 /* Compression needs to share state across borders */ 1573 mm_init_compression(mon->m_zlib); 1574 } 1575 1576 return mon; 1577 } 1578 1579 void 1580 monitor_reinit(struct monitor *mon) 1581 { 1582 int pair[2]; 1583 1584 monitor_socketpair(pair); 1585 1586 mon->m_recvfd = pair[0]; 1587 mon->m_sendfd = pair[1]; 1588 } 1589