1 /* $OpenBSD: monitor.c,v 1.106 2010/03/07 11:57:13 dtucker 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 79 static Gssctxt *gsscontext = NULL; 80 #endif 81 82 /* Imports */ 83 extern ServerOptions options; 84 extern u_int utmp_len; 85 extern Newkeys *current_keys[]; 86 extern z_stream incoming_stream; 87 extern z_stream outgoing_stream; 88 extern u_char session_id[]; 89 extern Buffer auth_debug; 90 extern int auth_debug_init; 91 extern Buffer loginmsg; 92 93 /* State exported from the child */ 94 95 struct { 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 */ 119 120 int mm_answer_moduli(int, Buffer *); 121 int mm_answer_sign(int, Buffer *); 122 int mm_answer_pwnamallow(int, Buffer *); 123 int mm_answer_auth2_read_banner(int, Buffer *); 124 int mm_answer_authserv(int, Buffer *); 125 int mm_answer_authpassword(int, Buffer *); 126 int mm_answer_bsdauthquery(int, Buffer *); 127 int mm_answer_bsdauthrespond(int, Buffer *); 128 int mm_answer_skeyquery(int, Buffer *); 129 int mm_answer_skeyrespond(int, Buffer *); 130 int mm_answer_keyallowed(int, Buffer *); 131 int mm_answer_keyverify(int, Buffer *); 132 int mm_answer_pty(int, Buffer *); 133 int mm_answer_pty_cleanup(int, Buffer *); 134 int mm_answer_term(int, Buffer *); 135 int mm_answer_rsa_keyallowed(int, Buffer *); 136 int mm_answer_rsa_challenge(int, Buffer *); 137 int mm_answer_rsa_response(int, Buffer *); 138 int mm_answer_sesskey(int, Buffer *); 139 int mm_answer_sessid(int, Buffer *); 140 int mm_answer_jpake_get_pwdata(int, Buffer *); 141 int mm_answer_jpake_step1(int, Buffer *); 142 int mm_answer_jpake_step2(int, Buffer *); 143 int mm_answer_jpake_key_confirm(int, Buffer *); 144 int mm_answer_jpake_check_confirm(int, Buffer *); 145 146 #ifdef GSSAPI 147 int mm_answer_gss_setup_ctx(int, Buffer *); 148 int mm_answer_gss_accept_ctx(int, Buffer *); 149 int mm_answer_gss_userok(int, Buffer *); 150 int mm_answer_gss_checkmic(int, Buffer *); 151 #endif 152 153 static Authctxt *authctxt; 154 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 155 156 /* local state for key verify */ 157 static u_char *key_blob = NULL; 158 static u_int key_bloblen = 0; 159 static int key_blobtype = MM_NOKEY; 160 static char *hostbased_cuser = NULL; 161 static char *hostbased_chost = NULL; 162 static char *auth_method = "unknown"; 163 static u_int session_id2_len = 0; 164 static u_char *session_id2 = NULL; 165 static pid_t monitor_child_pid; 166 167 struct 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 */ 181 182 struct 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 }; 208 209 struct 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 }; 217 218 struct 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 }; 231 232 struct 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 }; 238 239 struct mon_table *mon_dispatch; 240 241 /* Specifies if a certain message is allowed at the moment */ 242 243 static void 244 monitor_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 } 255 256 static void 257 monitor_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 } 269 270 void 271 monitor_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 } 333 334 static void 335 monitor_set_child_handler(pid_t pid) 336 { 337 monitor_child_pid = pid; 338 } 339 340 static void 341 monitor_child_handler(int sig) 342 { 343 kill(monitor_child_pid, sig); 344 } 345 346 void 347 monitor_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 } 373 374 void 375 monitor_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 } 382 383 int 384 monitor_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 */ 431 static int 432 monitor_allowed_key(u_char *blob, u_int bloblen) 433 { 434 /* make sure key is allowed */ 435 if (key_blob == NULL || key_bloblen != bloblen || 436 memcmp(key_blob, blob, key_bloblen)) 437 return (0); 438 return (1); 439 } 440 441 static void 442 monitor_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 } 457 458 int 459 mm_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 } 492 493 int 494 mm_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 will only return SHA1 (20 byte) or 509 * SHA256 (32 byte) hashes 510 */ 511 if (datlen != 20 && datlen != 32) 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 */ 543 544 int 545 mm_answer_pwnamallow(int sock, Buffer *m) 546 { 547 char *username; 548 struct passwd *pwent; 549 int allowed = 0; 550 551 debug3("%s", __func__); 552 553 if (authctxt->attempt++ != 0) 554 fatal("%s: multiple attempts for getpwnam", __func__); 555 556 username = buffer_get_string(m, NULL); 557 558 pwent = getpwnamallow(username); 559 560 authctxt->user = xstrdup(username); 561 setproctitle("%s [priv]", pwent ? username : "unknown"); 562 xfree(username); 563 564 buffer_clear(m); 565 566 if (pwent == NULL) { 567 buffer_put_char(m, 0); 568 authctxt->pw = fakepw(); 569 goto out; 570 } 571 572 allowed = 1; 573 authctxt->pw = pwent; 574 authctxt->valid = 1; 575 576 buffer_put_char(m, 1); 577 buffer_put_string(m, pwent, sizeof(struct passwd)); 578 buffer_put_cstring(m, pwent->pw_name); 579 buffer_put_cstring(m, "*"); 580 buffer_put_cstring(m, pwent->pw_gecos); 581 buffer_put_cstring(m, pwent->pw_class); 582 buffer_put_cstring(m, pwent->pw_dir); 583 buffer_put_cstring(m, pwent->pw_shell); 584 585 out: 586 buffer_put_string(m, &options, sizeof(options)); 587 if (options.banner != NULL) 588 buffer_put_cstring(m, options.banner); 589 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 590 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 591 592 /* For SSHv1 allow authentication now */ 593 if (!compat20) 594 monitor_permit_authentications(1); 595 else { 596 /* Allow service/style information on the auth context */ 597 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 598 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 599 } 600 601 602 return (0); 603 } 604 605 int mm_answer_auth2_read_banner(int sock, Buffer *m) 606 { 607 char *banner; 608 609 buffer_clear(m); 610 banner = auth2_read_banner(); 611 buffer_put_cstring(m, banner != NULL ? banner : ""); 612 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 613 614 if (banner != NULL) 615 xfree(banner); 616 617 return (0); 618 } 619 620 int 621 mm_answer_authserv(int sock, Buffer *m) 622 { 623 monitor_permit_authentications(1); 624 625 authctxt->service = buffer_get_string(m, NULL); 626 authctxt->style = buffer_get_string(m, NULL); 627 debug3("%s: service=%s, style=%s", 628 __func__, authctxt->service, authctxt->style); 629 630 if (strlen(authctxt->style) == 0) { 631 xfree(authctxt->style); 632 authctxt->style = NULL; 633 } 634 635 return (0); 636 } 637 638 int 639 mm_answer_authpassword(int sock, Buffer *m) 640 { 641 static int call_count; 642 char *passwd; 643 int authenticated; 644 u_int plen; 645 646 passwd = buffer_get_string(m, &plen); 647 /* Only authenticate if the context is valid */ 648 authenticated = options.password_authentication && 649 auth_password(authctxt, passwd); 650 memset(passwd, 0, strlen(passwd)); 651 xfree(passwd); 652 653 buffer_clear(m); 654 buffer_put_int(m, authenticated); 655 656 debug3("%s: sending result %d", __func__, authenticated); 657 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 658 659 call_count++; 660 if (plen == 0 && call_count == 1) 661 auth_method = "none"; 662 else 663 auth_method = "password"; 664 665 /* Causes monitor loop to terminate if authenticated */ 666 return (authenticated); 667 } 668 669 int 670 mm_answer_bsdauthquery(int sock, Buffer *m) 671 { 672 char *name, *infotxt; 673 u_int numprompts; 674 u_int *echo_on; 675 char **prompts; 676 u_int success; 677 678 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 679 &prompts, &echo_on) < 0 ? 0 : 1; 680 681 buffer_clear(m); 682 buffer_put_int(m, success); 683 if (success) 684 buffer_put_cstring(m, prompts[0]); 685 686 debug3("%s: sending challenge success: %u", __func__, success); 687 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 688 689 if (success) { 690 xfree(name); 691 xfree(infotxt); 692 xfree(prompts); 693 xfree(echo_on); 694 } 695 696 return (0); 697 } 698 699 int 700 mm_answer_bsdauthrespond(int sock, Buffer *m) 701 { 702 char *response; 703 int authok; 704 705 if (authctxt->as == 0) 706 fatal("%s: no bsd auth session", __func__); 707 708 response = buffer_get_string(m, NULL); 709 authok = options.challenge_response_authentication && 710 auth_userresponse(authctxt->as, response, 0); 711 authctxt->as = NULL; 712 debug3("%s: <%s> = <%d>", __func__, response, authok); 713 xfree(response); 714 715 buffer_clear(m); 716 buffer_put_int(m, authok); 717 718 debug3("%s: sending authenticated: %d", __func__, authok); 719 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 720 721 auth_method = "bsdauth"; 722 723 return (authok != 0); 724 } 725 726 int 727 mm_answer_keyallowed(int sock, Buffer *m) 728 { 729 Key *key; 730 char *cuser, *chost; 731 u_char *blob; 732 u_int bloblen; 733 enum mm_keytype type = 0; 734 int allowed = 0; 735 736 debug3("%s entering", __func__); 737 738 type = buffer_get_int(m); 739 cuser = buffer_get_string(m, NULL); 740 chost = buffer_get_string(m, NULL); 741 blob = buffer_get_string(m, &bloblen); 742 743 key = key_from_blob(blob, bloblen); 744 745 if ((compat20 && type == MM_RSAHOSTKEY) || 746 (!compat20 && type != MM_RSAHOSTKEY)) 747 fatal("%s: key type and protocol mismatch", __func__); 748 749 debug3("%s: key_from_blob: %p", __func__, key); 750 751 if (key != NULL && authctxt->valid) { 752 switch (type) { 753 case MM_USERKEY: 754 allowed = options.pubkey_authentication && 755 user_key_allowed(authctxt->pw, key); 756 auth_method = "publickey"; 757 if (options.pubkey_authentication && allowed != 1) 758 auth_clear_options(); 759 break; 760 case MM_HOSTKEY: 761 allowed = options.hostbased_authentication && 762 hostbased_key_allowed(authctxt->pw, 763 cuser, chost, key); 764 auth_method = "hostbased"; 765 break; 766 case MM_RSAHOSTKEY: 767 key->type = KEY_RSA1; /* XXX */ 768 allowed = options.rhosts_rsa_authentication && 769 auth_rhosts_rsa_key_allowed(authctxt->pw, 770 cuser, chost, key); 771 if (options.rhosts_rsa_authentication && allowed != 1) 772 auth_clear_options(); 773 auth_method = "rsa"; 774 break; 775 default: 776 fatal("%s: unknown key type %d", __func__, type); 777 break; 778 } 779 } 780 if (key != NULL) 781 key_free(key); 782 783 /* clear temporarily storage (used by verify) */ 784 monitor_reset_key_state(); 785 786 if (allowed) { 787 /* Save temporarily for comparison in verify */ 788 key_blob = blob; 789 key_bloblen = bloblen; 790 key_blobtype = type; 791 hostbased_cuser = cuser; 792 hostbased_chost = chost; 793 } else { 794 /* Log failed attempt */ 795 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 796 xfree(blob); 797 xfree(cuser); 798 xfree(chost); 799 } 800 801 debug3("%s: key %p is %s", 802 __func__, key, allowed ? "allowed" : "not allowed"); 803 804 buffer_clear(m); 805 buffer_put_int(m, allowed); 806 buffer_put_int(m, forced_command != NULL); 807 808 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 809 810 if (type == MM_RSAHOSTKEY) 811 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 812 813 return (0); 814 } 815 816 static int 817 monitor_valid_userblob(u_char *data, u_int datalen) 818 { 819 Buffer b; 820 char *p; 821 u_int len; 822 int fail = 0; 823 824 buffer_init(&b); 825 buffer_append(&b, data, datalen); 826 827 if (datafellows & SSH_OLD_SESSIONID) { 828 p = buffer_ptr(&b); 829 len = buffer_len(&b); 830 if ((session_id2 == NULL) || 831 (len < session_id2_len) || 832 (memcmp(p, session_id2, session_id2_len) != 0)) 833 fail++; 834 buffer_consume(&b, session_id2_len); 835 } else { 836 p = buffer_get_string(&b, &len); 837 if ((session_id2 == NULL) || 838 (len != session_id2_len) || 839 (memcmp(p, session_id2, session_id2_len) != 0)) 840 fail++; 841 xfree(p); 842 } 843 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 844 fail++; 845 p = buffer_get_string(&b, NULL); 846 if (strcmp(authctxt->user, p) != 0) { 847 logit("wrong user name passed to monitor: expected %s != %.100s", 848 authctxt->user, p); 849 fail++; 850 } 851 xfree(p); 852 buffer_skip_string(&b); 853 if (datafellows & SSH_BUG_PKAUTH) { 854 if (!buffer_get_char(&b)) 855 fail++; 856 } else { 857 p = buffer_get_string(&b, NULL); 858 if (strcmp("publickey", p) != 0) 859 fail++; 860 xfree(p); 861 if (!buffer_get_char(&b)) 862 fail++; 863 buffer_skip_string(&b); 864 } 865 buffer_skip_string(&b); 866 if (buffer_len(&b) != 0) 867 fail++; 868 buffer_free(&b); 869 return (fail == 0); 870 } 871 872 static int 873 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 874 char *chost) 875 { 876 Buffer b; 877 char *p; 878 u_int len; 879 int fail = 0; 880 881 buffer_init(&b); 882 buffer_append(&b, data, datalen); 883 884 p = buffer_get_string(&b, &len); 885 if ((session_id2 == NULL) || 886 (len != session_id2_len) || 887 (memcmp(p, session_id2, session_id2_len) != 0)) 888 fail++; 889 xfree(p); 890 891 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 892 fail++; 893 p = buffer_get_string(&b, NULL); 894 if (strcmp(authctxt->user, p) != 0) { 895 logit("wrong user name passed to monitor: expected %s != %.100s", 896 authctxt->user, p); 897 fail++; 898 } 899 xfree(p); 900 buffer_skip_string(&b); /* service */ 901 p = buffer_get_string(&b, NULL); 902 if (strcmp(p, "hostbased") != 0) 903 fail++; 904 xfree(p); 905 buffer_skip_string(&b); /* pkalg */ 906 buffer_skip_string(&b); /* pkblob */ 907 908 /* verify client host, strip trailing dot if necessary */ 909 p = buffer_get_string(&b, NULL); 910 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 911 p[len - 1] = '\0'; 912 if (strcmp(p, chost) != 0) 913 fail++; 914 xfree(p); 915 916 /* verify client user */ 917 p = buffer_get_string(&b, NULL); 918 if (strcmp(p, cuser) != 0) 919 fail++; 920 xfree(p); 921 922 if (buffer_len(&b) != 0) 923 fail++; 924 buffer_free(&b); 925 return (fail == 0); 926 } 927 928 int 929 mm_answer_keyverify(int sock, Buffer *m) 930 { 931 Key *key; 932 u_char *signature, *data, *blob; 933 u_int signaturelen, datalen, bloblen; 934 int verified = 0; 935 int valid_data = 0; 936 937 blob = buffer_get_string(m, &bloblen); 938 signature = buffer_get_string(m, &signaturelen); 939 data = buffer_get_string(m, &datalen); 940 941 if (hostbased_cuser == NULL || hostbased_chost == NULL || 942 !monitor_allowed_key(blob, bloblen)) 943 fatal("%s: bad key, not previously allowed", __func__); 944 945 key = key_from_blob(blob, bloblen); 946 if (key == NULL) 947 fatal("%s: bad public key blob", __func__); 948 949 switch (key_blobtype) { 950 case MM_USERKEY: 951 valid_data = monitor_valid_userblob(data, datalen); 952 break; 953 case MM_HOSTKEY: 954 valid_data = monitor_valid_hostbasedblob(data, datalen, 955 hostbased_cuser, hostbased_chost); 956 break; 957 default: 958 valid_data = 0; 959 break; 960 } 961 if (!valid_data) 962 fatal("%s: bad signature data blob", __func__); 963 964 verified = key_verify(key, signature, signaturelen, data, datalen); 965 debug3("%s: key %p signature %s", 966 __func__, key, (verified == 1) ? "verified" : "unverified"); 967 968 key_free(key); 969 xfree(blob); 970 xfree(signature); 971 xfree(data); 972 973 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 974 975 monitor_reset_key_state(); 976 977 buffer_clear(m); 978 buffer_put_int(m, verified); 979 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 980 981 return (verified == 1); 982 } 983 984 static void 985 mm_record_login(Session *s, struct passwd *pw) 986 { 987 socklen_t fromlen; 988 struct sockaddr_storage from; 989 990 /* 991 * Get IP address of client. If the connection is not a socket, let 992 * the address be 0.0.0.0. 993 */ 994 memset(&from, 0, sizeof(from)); 995 fromlen = sizeof(from); 996 if (packet_connection_is_on_socket()) { 997 if (getpeername(packet_get_connection_in(), 998 (struct sockaddr *)&from, &fromlen) < 0) { 999 debug("getpeername: %.100s", strerror(errno)); 1000 cleanup_exit(255); 1001 } 1002 } 1003 /* Record that there was a login on that tty from the remote host. */ 1004 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1005 get_remote_name_or_ip(utmp_len, options.use_dns), 1006 (struct sockaddr *)&from, fromlen); 1007 } 1008 1009 static void 1010 mm_session_close(Session *s) 1011 { 1012 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1013 if (s->ttyfd != -1) { 1014 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1015 session_pty_cleanup2(s); 1016 } 1017 session_unused(s->self); 1018 } 1019 1020 int 1021 mm_answer_pty(int sock, Buffer *m) 1022 { 1023 extern struct monitor *pmonitor; 1024 Session *s; 1025 int res, fd0; 1026 1027 debug3("%s entering", __func__); 1028 1029 buffer_clear(m); 1030 s = session_new(); 1031 if (s == NULL) 1032 goto error; 1033 s->authctxt = authctxt; 1034 s->pw = authctxt->pw; 1035 s->pid = pmonitor->m_pid; 1036 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1037 if (res == 0) 1038 goto error; 1039 pty_setowner(authctxt->pw, s->tty); 1040 1041 buffer_put_int(m, 1); 1042 buffer_put_cstring(m, s->tty); 1043 1044 /* We need to trick ttyslot */ 1045 if (dup2(s->ttyfd, 0) == -1) 1046 fatal("%s: dup2", __func__); 1047 1048 mm_record_login(s, authctxt->pw); 1049 1050 /* Now we can close the file descriptor again */ 1051 close(0); 1052 1053 /* send messages generated by record_login */ 1054 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1055 buffer_clear(&loginmsg); 1056 1057 mm_request_send(sock, MONITOR_ANS_PTY, m); 1058 1059 if (mm_send_fd(sock, s->ptyfd) == -1 || 1060 mm_send_fd(sock, s->ttyfd) == -1) 1061 fatal("%s: send fds failed", __func__); 1062 1063 /* make sure nothing uses fd 0 */ 1064 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1065 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1066 if (fd0 != 0) 1067 error("%s: fd0 %d != 0", __func__, fd0); 1068 1069 /* slave is not needed */ 1070 close(s->ttyfd); 1071 s->ttyfd = s->ptyfd; 1072 /* no need to dup() because nobody closes ptyfd */ 1073 s->ptymaster = s->ptyfd; 1074 1075 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1076 1077 return (0); 1078 1079 error: 1080 if (s != NULL) 1081 mm_session_close(s); 1082 buffer_put_int(m, 0); 1083 mm_request_send(sock, MONITOR_ANS_PTY, m); 1084 return (0); 1085 } 1086 1087 int 1088 mm_answer_pty_cleanup(int sock, Buffer *m) 1089 { 1090 Session *s; 1091 char *tty; 1092 1093 debug3("%s entering", __func__); 1094 1095 tty = buffer_get_string(m, NULL); 1096 if ((s = session_by_tty(tty)) != NULL) 1097 mm_session_close(s); 1098 buffer_clear(m); 1099 xfree(tty); 1100 return (0); 1101 } 1102 1103 int 1104 mm_answer_sesskey(int sock, Buffer *m) 1105 { 1106 BIGNUM *p; 1107 int rsafail; 1108 1109 /* Turn off permissions */ 1110 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1111 1112 if ((p = BN_new()) == NULL) 1113 fatal("%s: BN_new", __func__); 1114 1115 buffer_get_bignum2(m, p); 1116 1117 rsafail = ssh1_session_key(p); 1118 1119 buffer_clear(m); 1120 buffer_put_int(m, rsafail); 1121 buffer_put_bignum2(m, p); 1122 1123 BN_clear_free(p); 1124 1125 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1126 1127 /* Turn on permissions for sessid passing */ 1128 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1129 1130 return (0); 1131 } 1132 1133 int 1134 mm_answer_sessid(int sock, Buffer *m) 1135 { 1136 int i; 1137 1138 debug3("%s entering", __func__); 1139 1140 if (buffer_len(m) != 16) 1141 fatal("%s: bad ssh1 session id", __func__); 1142 for (i = 0; i < 16; i++) 1143 session_id[i] = buffer_get_char(m); 1144 1145 /* Turn on permissions for getpwnam */ 1146 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1147 1148 return (0); 1149 } 1150 1151 int 1152 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1153 { 1154 BIGNUM *client_n; 1155 Key *key = NULL; 1156 u_char *blob = NULL; 1157 u_int blen = 0; 1158 int allowed = 0; 1159 1160 debug3("%s entering", __func__); 1161 1162 auth_method = "rsa"; 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_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1192 1193 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1194 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1195 return (0); 1196 } 1197 1198 int 1199 mm_answer_rsa_challenge(int sock, Buffer *m) 1200 { 1201 Key *key = NULL; 1202 u_char *blob; 1203 u_int blen; 1204 1205 debug3("%s entering", __func__); 1206 1207 if (!authctxt->valid) 1208 fatal("%s: authctxt not valid", __func__); 1209 blob = buffer_get_string(m, &blen); 1210 if (!monitor_allowed_key(blob, blen)) 1211 fatal("%s: bad key, not previously allowed", __func__); 1212 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1213 fatal("%s: key type mismatch", __func__); 1214 if ((key = key_from_blob(blob, blen)) == NULL) 1215 fatal("%s: received bad key", __func__); 1216 if (key->type != KEY_RSA) 1217 fatal("%s: received bad key type %d", __func__, key->type); 1218 key->type = KEY_RSA1; 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(sock, 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 sock, 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(sock, MONITOR_ANS_RSARESPONSE, m); 1277 1278 return (success); 1279 } 1280 1281 int 1282 mm_answer_term(int sock, Buffer *req) 1283 { 1284 extern struct monitor *pmonitor; 1285 int res, status; 1286 1287 debug3("%s: tearing down sessions", __func__); 1288 1289 /* The child is terminating */ 1290 session_destroy_all(&mm_session_close); 1291 1292 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1293 if (errno != EINTR) 1294 exit(1); 1295 1296 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1297 1298 /* Terminate process */ 1299 exit(res); 1300 } 1301 1302 void 1303 monitor_apply_keystate(struct monitor *pmonitor) 1304 { 1305 if (compat20) { 1306 set_newkeys(MODE_IN); 1307 set_newkeys(MODE_OUT); 1308 } else { 1309 packet_set_protocol_flags(child_state.ssh1protoflags); 1310 packet_set_encryption_key(child_state.ssh1key, 1311 child_state.ssh1keylen, child_state.ssh1cipher); 1312 xfree(child_state.ssh1key); 1313 } 1314 1315 /* for rc4 and other stateful ciphers */ 1316 packet_set_keycontext(MODE_OUT, child_state.keyout); 1317 xfree(child_state.keyout); 1318 packet_set_keycontext(MODE_IN, child_state.keyin); 1319 xfree(child_state.keyin); 1320 1321 if (!compat20) { 1322 packet_set_iv(MODE_OUT, child_state.ivout); 1323 xfree(child_state.ivout); 1324 packet_set_iv(MODE_IN, child_state.ivin); 1325 xfree(child_state.ivin); 1326 } 1327 1328 memcpy(&incoming_stream, &child_state.incoming, 1329 sizeof(incoming_stream)); 1330 memcpy(&outgoing_stream, &child_state.outgoing, 1331 sizeof(outgoing_stream)); 1332 1333 /* Update with new address */ 1334 if (options.compression) 1335 mm_init_compression(pmonitor->m_zlib); 1336 1337 /* Network I/O buffers */ 1338 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1339 buffer_clear(packet_get_input()); 1340 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1341 memset(child_state.input, 0, child_state.ilen); 1342 xfree(child_state.input); 1343 1344 buffer_clear(packet_get_output()); 1345 buffer_append(packet_get_output(), child_state.output, 1346 child_state.olen); 1347 memset(child_state.output, 0, child_state.olen); 1348 xfree(child_state.output); 1349 1350 /* Roaming */ 1351 if (compat20) 1352 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 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 = xcalloc(1, sizeof(*kex)); 1363 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1364 if ((session_id2 == NULL) || 1365 (kex->session_id_len != session_id2_len) || 1366 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1367 fatal("mm_get_get: internal error: bad session id"); 1368 kex->we_need = buffer_get_int(m); 1369 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1370 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1371 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1372 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1373 kex->server = 1; 1374 kex->hostkey_type = buffer_get_int(m); 1375 kex->kex_type = buffer_get_int(m); 1376 blob = buffer_get_string(m, &bloblen); 1377 buffer_init(&kex->my); 1378 buffer_append(&kex->my, blob, bloblen); 1379 xfree(blob); 1380 blob = buffer_get_string(m, &bloblen); 1381 buffer_init(&kex->peer); 1382 buffer_append(&kex->peer, blob, bloblen); 1383 xfree(blob); 1384 kex->done = 1; 1385 kex->flags = buffer_get_int(m); 1386 kex->client_version_string = buffer_get_string(m, NULL); 1387 kex->server_version_string = buffer_get_string(m, NULL); 1388 kex->load_host_public_key=&get_hostkey_public_by_type; 1389 kex->load_host_private_key=&get_hostkey_private_by_type; 1390 kex->host_key_index=&get_hostkey_index; 1391 1392 return (kex); 1393 } 1394 1395 /* This function requries careful sanity checking */ 1396 1397 void 1398 mm_get_keystate(struct monitor *pmonitor) 1399 { 1400 Buffer m; 1401 u_char *blob, *p; 1402 u_int bloblen, plen; 1403 u_int32_t seqnr, packets; 1404 u_int64_t blocks, bytes; 1405 1406 debug3("%s: Waiting for new keys", __func__); 1407 1408 buffer_init(&m); 1409 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1410 if (!compat20) { 1411 child_state.ssh1protoflags = buffer_get_int(&m); 1412 child_state.ssh1cipher = buffer_get_int(&m); 1413 child_state.ssh1key = buffer_get_string(&m, 1414 &child_state.ssh1keylen); 1415 child_state.ivout = buffer_get_string(&m, 1416 &child_state.ivoutlen); 1417 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1418 goto skip; 1419 } else { 1420 /* Get the Kex for rekeying */ 1421 *pmonitor->m_pkex = mm_get_kex(&m); 1422 } 1423 1424 blob = buffer_get_string(&m, &bloblen); 1425 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1426 xfree(blob); 1427 1428 debug3("%s: Waiting for second key", __func__); 1429 blob = buffer_get_string(&m, &bloblen); 1430 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1431 xfree(blob); 1432 1433 /* Now get sequence numbers for the packets */ 1434 seqnr = buffer_get_int(&m); 1435 blocks = buffer_get_int64(&m); 1436 packets = buffer_get_int(&m); 1437 bytes = buffer_get_int64(&m); 1438 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1439 seqnr = buffer_get_int(&m); 1440 blocks = buffer_get_int64(&m); 1441 packets = buffer_get_int(&m); 1442 bytes = buffer_get_int64(&m); 1443 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1444 1445 skip: 1446 /* Get the key context */ 1447 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1448 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1449 1450 debug3("%s: Getting compression state", __func__); 1451 /* Get compression state */ 1452 p = buffer_get_string(&m, &plen); 1453 if (plen != sizeof(child_state.outgoing)) 1454 fatal("%s: bad request size", __func__); 1455 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1456 xfree(p); 1457 1458 p = buffer_get_string(&m, &plen); 1459 if (plen != sizeof(child_state.incoming)) 1460 fatal("%s: bad request size", __func__); 1461 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1462 xfree(p); 1463 1464 /* Network I/O buffers */ 1465 debug3("%s: Getting Network I/O buffers", __func__); 1466 child_state.input = buffer_get_string(&m, &child_state.ilen); 1467 child_state.output = buffer_get_string(&m, &child_state.olen); 1468 1469 /* Roaming */ 1470 if (compat20) { 1471 child_state.sent_bytes = buffer_get_int64(&m); 1472 child_state.recv_bytes = buffer_get_int64(&m); 1473 } 1474 1475 buffer_free(&m); 1476 } 1477 1478 1479 /* Allocation functions for zlib */ 1480 void * 1481 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1482 { 1483 size_t len = (size_t) size * ncount; 1484 void *address; 1485 1486 if (len == 0 || ncount > SIZE_T_MAX / size) 1487 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1488 1489 address = mm_malloc(mm, len); 1490 1491 return (address); 1492 } 1493 1494 void 1495 mm_zfree(struct mm_master *mm, void *address) 1496 { 1497 mm_free(mm, address); 1498 } 1499 1500 void 1501 mm_init_compression(struct mm_master *mm) 1502 { 1503 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1504 outgoing_stream.zfree = (free_func)mm_zfree; 1505 outgoing_stream.opaque = mm; 1506 1507 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1508 incoming_stream.zfree = (free_func)mm_zfree; 1509 incoming_stream.opaque = mm; 1510 } 1511 1512 /* XXX */ 1513 1514 #define FD_CLOSEONEXEC(x) do { \ 1515 if (fcntl(x, F_SETFD, 1) == -1) \ 1516 fatal("fcntl(%d, F_SETFD)", x); \ 1517 } while (0) 1518 1519 static void 1520 monitor_socketpair(int *pair) 1521 { 1522 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1523 fatal("%s: socketpair", __func__); 1524 FD_CLOSEONEXEC(pair[0]); 1525 FD_CLOSEONEXEC(pair[1]); 1526 } 1527 1528 #define MM_MEMSIZE 65536 1529 1530 struct monitor * 1531 monitor_init(void) 1532 { 1533 struct monitor *mon; 1534 int pair[2]; 1535 1536 mon = xcalloc(1, sizeof(*mon)); 1537 1538 monitor_socketpair(pair); 1539 1540 mon->m_recvfd = pair[0]; 1541 mon->m_sendfd = pair[1]; 1542 1543 /* Used to share zlib space across processes */ 1544 if (options.compression) { 1545 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1546 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1547 1548 /* Compression needs to share state across borders */ 1549 mm_init_compression(mon->m_zlib); 1550 } 1551 1552 return mon; 1553 } 1554 1555 void 1556 monitor_reinit(struct monitor *mon) 1557 { 1558 int pair[2]; 1559 1560 monitor_socketpair(pair); 1561 1562 mon->m_recvfd = pair[0]; 1563 mon->m_sendfd = pair[1]; 1564 } 1565 1566 #ifdef GSSAPI 1567 int 1568 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1569 { 1570 gss_OID_desc goid; 1571 OM_uint32 major; 1572 u_int len; 1573 1574 goid.elements = buffer_get_string(m, &len); 1575 goid.length = len; 1576 1577 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1578 1579 xfree(goid.elements); 1580 1581 buffer_clear(m); 1582 buffer_put_int(m, major); 1583 1584 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1585 1586 /* Now we have a context, enable the step */ 1587 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1588 1589 return (0); 1590 } 1591 1592 int 1593 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1594 { 1595 gss_buffer_desc in; 1596 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1597 OM_uint32 major, minor; 1598 OM_uint32 flags = 0; /* GSI needs this */ 1599 u_int len; 1600 1601 in.value = buffer_get_string(m, &len); 1602 in.length = len; 1603 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1604 xfree(in.value); 1605 1606 buffer_clear(m); 1607 buffer_put_int(m, major); 1608 buffer_put_string(m, out.value, out.length); 1609 buffer_put_int(m, flags); 1610 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1611 1612 gss_release_buffer(&minor, &out); 1613 1614 if (major == GSS_S_COMPLETE) { 1615 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1616 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1617 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1618 } 1619 return (0); 1620 } 1621 1622 int 1623 mm_answer_gss_checkmic(int sock, Buffer *m) 1624 { 1625 gss_buffer_desc gssbuf, mic; 1626 OM_uint32 ret; 1627 u_int len; 1628 1629 gssbuf.value = buffer_get_string(m, &len); 1630 gssbuf.length = len; 1631 mic.value = buffer_get_string(m, &len); 1632 mic.length = len; 1633 1634 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1635 1636 xfree(gssbuf.value); 1637 xfree(mic.value); 1638 1639 buffer_clear(m); 1640 buffer_put_int(m, ret); 1641 1642 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1643 1644 if (!GSS_ERROR(ret)) 1645 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1646 1647 return (0); 1648 } 1649 1650 int 1651 mm_answer_gss_userok(int sock, Buffer *m) 1652 { 1653 int authenticated; 1654 1655 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1656 1657 buffer_clear(m); 1658 buffer_put_int(m, authenticated); 1659 1660 debug3("%s: sending result %d", __func__, authenticated); 1661 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1662 1663 auth_method = "gssapi-with-mic"; 1664 1665 /* Monitor loop will terminate if authenticated */ 1666 return (authenticated); 1667 } 1668 #endif /* GSSAPI */ 1669 1670 #ifdef JPAKE 1671 int 1672 mm_answer_jpake_step1(int sock, Buffer *m) 1673 { 1674 struct jpake_ctx *pctx; 1675 u_char *x3_proof, *x4_proof; 1676 u_int x3_proof_len, x4_proof_len; 1677 1678 if (!options.zero_knowledge_password_authentication) 1679 fatal("zero_knowledge_password_authentication disabled"); 1680 1681 if (authctxt->jpake_ctx != NULL) 1682 fatal("%s: authctxt->jpake_ctx already set (%p)", 1683 __func__, authctxt->jpake_ctx); 1684 authctxt->jpake_ctx = pctx = jpake_new(); 1685 1686 jpake_step1(pctx->grp, 1687 &pctx->server_id, &pctx->server_id_len, 1688 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 1689 &x3_proof, &x3_proof_len, 1690 &x4_proof, &x4_proof_len); 1691 1692 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 1693 1694 buffer_clear(m); 1695 1696 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 1697 buffer_put_bignum2(m, pctx->g_x3); 1698 buffer_put_bignum2(m, pctx->g_x4); 1699 buffer_put_string(m, x3_proof, x3_proof_len); 1700 buffer_put_string(m, x4_proof, x4_proof_len); 1701 1702 debug3("%s: sending step1", __func__); 1703 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 1704 1705 bzero(x3_proof, x3_proof_len); 1706 bzero(x4_proof, x4_proof_len); 1707 xfree(x3_proof); 1708 xfree(x4_proof); 1709 1710 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 1711 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 1712 1713 return 0; 1714 } 1715 1716 int 1717 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 1718 { 1719 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1720 char *hash_scheme, *salt; 1721 1722 if (pctx == NULL) 1723 fatal("%s: pctx == NULL", __func__); 1724 1725 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 1726 1727 buffer_clear(m); 1728 /* pctx->s is sensitive, not returned to slave */ 1729 buffer_put_cstring(m, hash_scheme); 1730 buffer_put_cstring(m, salt); 1731 1732 debug3("%s: sending pwdata", __func__); 1733 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 1734 1735 bzero(hash_scheme, strlen(hash_scheme)); 1736 bzero(salt, strlen(salt)); 1737 xfree(hash_scheme); 1738 xfree(salt); 1739 1740 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 1741 1742 return 0; 1743 } 1744 1745 int 1746 mm_answer_jpake_step2(int sock, Buffer *m) 1747 { 1748 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1749 u_char *x1_proof, *x2_proof, *x4_s_proof; 1750 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 1751 1752 if (pctx == NULL) 1753 fatal("%s: pctx == NULL", __func__); 1754 1755 if ((pctx->g_x1 = BN_new()) == NULL || 1756 (pctx->g_x2 = BN_new()) == NULL) 1757 fatal("%s: BN_new", __func__); 1758 buffer_get_bignum2(m, pctx->g_x1); 1759 buffer_get_bignum2(m, pctx->g_x2); 1760 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 1761 x1_proof = buffer_get_string(m, &x1_proof_len); 1762 x2_proof = buffer_get_string(m, &x2_proof_len); 1763 1764 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 1765 pctx->g_x1, pctx->g_x2, pctx->x4, 1766 pctx->client_id, pctx->client_id_len, 1767 pctx->server_id, pctx->server_id_len, 1768 x1_proof, x1_proof_len, 1769 x2_proof, x2_proof_len, 1770 &pctx->b, 1771 &x4_s_proof, &x4_s_proof_len); 1772 1773 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 1774 1775 bzero(x1_proof, x1_proof_len); 1776 bzero(x2_proof, x2_proof_len); 1777 xfree(x1_proof); 1778 xfree(x2_proof); 1779 1780 buffer_clear(m); 1781 1782 buffer_put_bignum2(m, pctx->b); 1783 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 1784 1785 debug3("%s: sending step2", __func__); 1786 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 1787 1788 bzero(x4_s_proof, x4_s_proof_len); 1789 xfree(x4_s_proof); 1790 1791 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 1792 1793 return 0; 1794 } 1795 1796 int 1797 mm_answer_jpake_key_confirm(int sock, Buffer *m) 1798 { 1799 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1800 u_char *x2_s_proof; 1801 u_int x2_s_proof_len; 1802 1803 if (pctx == NULL) 1804 fatal("%s: pctx == NULL", __func__); 1805 1806 if ((pctx->a = BN_new()) == NULL) 1807 fatal("%s: BN_new", __func__); 1808 buffer_get_bignum2(m, pctx->a); 1809 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 1810 1811 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 1812 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 1813 pctx->server_id, pctx->server_id_len, 1814 pctx->client_id, pctx->client_id_len, 1815 session_id2, session_id2_len, 1816 x2_s_proof, x2_s_proof_len, 1817 &pctx->k, 1818 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 1819 1820 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 1821 1822 bzero(x2_s_proof, x2_s_proof_len); 1823 buffer_clear(m); 1824 1825 /* pctx->k is sensitive, not sent */ 1826 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 1827 1828 debug3("%s: sending confirmation hash", __func__); 1829 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 1830 1831 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 1832 1833 return 0; 1834 } 1835 1836 int 1837 mm_answer_jpake_check_confirm(int sock, Buffer *m) 1838 { 1839 int authenticated = 0; 1840 u_char *peer_confirm_hash; 1841 u_int peer_confirm_hash_len; 1842 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1843 1844 if (pctx == NULL) 1845 fatal("%s: pctx == NULL", __func__); 1846 1847 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 1848 1849 authenticated = jpake_check_confirm(pctx->k, 1850 pctx->client_id, pctx->client_id_len, 1851 session_id2, session_id2_len, 1852 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 1853 1854 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 1855 1856 bzero(peer_confirm_hash, peer_confirm_hash_len); 1857 xfree(peer_confirm_hash); 1858 1859 buffer_clear(m); 1860 buffer_put_int(m, authenticated); 1861 1862 debug3("%s: sending result %d", __func__, authenticated); 1863 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 1864 1865 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 1866 1867 auth_method = "jpake-01@openssh.com"; 1868 return authenticated; 1869 } 1870 1871 #endif /* JPAKE */ 1872