1 /* $OpenBSD: monitor.c,v 1.101 2009/02/12 03:26:22 djm Exp $ */ 2 /* 3 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus@openbsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/types.h> 29 #include <sys/wait.h> 30 #include <sys/socket.h> 31 #include <sys/tree.h> 32 #include <sys/param.h> 33 #include <sys/queue.h> 34 35 #include <openssl/dh.h> 36 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <paths.h> 40 #include <pwd.h> 41 #include <signal.h> 42 #include <stdlib.h> 43 #include <string.h> 44 45 46 #include "xmalloc.h" 47 #include "ssh.h" 48 #include "key.h" 49 #include "buffer.h" 50 #include "hostfile.h" 51 #include "auth.h" 52 #include "cipher.h" 53 #include "kex.h" 54 #include "dh.h" 55 #include <zlib.h> 56 #include "packet.h" 57 #include "auth-options.h" 58 #include "sshpty.h" 59 #include "channels.h" 60 #include "session.h" 61 #include "sshlogin.h" 62 #include "canohost.h" 63 #include "log.h" 64 #include "servconf.h" 65 #include "monitor.h" 66 #include "monitor_mm.h" 67 #ifdef GSSAPI 68 #include "ssh-gss.h" 69 #endif 70 #include "monitor_wrap.h" 71 #include "monitor_fdpass.h" 72 #include "misc.h" 73 #include "compat.h" 74 #include "ssh2.h" 75 #include "jpake.h" 76 77 #ifdef GSSAPI 78 static Gssctxt *gsscontext = NULL; 79 #endif 80 81 /* Imports */ 82 extern ServerOptions options; 83 extern u_int utmp_len; 84 extern Newkeys *current_keys[]; 85 extern z_stream incoming_stream; 86 extern z_stream outgoing_stream; 87 extern u_char session_id[]; 88 extern Buffer input, output; 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 } child_state; 115 116 /* Functions on the monitor that answer unprivileged requests */ 117 118 int mm_answer_moduli(int, Buffer *); 119 int mm_answer_sign(int, Buffer *); 120 int mm_answer_pwnamallow(int, Buffer *); 121 int mm_answer_auth2_read_banner(int, Buffer *); 122 int mm_answer_authserv(int, Buffer *); 123 int mm_answer_authpassword(int, Buffer *); 124 int mm_answer_bsdauthquery(int, Buffer *); 125 int mm_answer_bsdauthrespond(int, Buffer *); 126 int mm_answer_skeyquery(int, Buffer *); 127 int mm_answer_skeyrespond(int, Buffer *); 128 int mm_answer_keyallowed(int, Buffer *); 129 int mm_answer_keyverify(int, Buffer *); 130 int mm_answer_pty(int, Buffer *); 131 int mm_answer_pty_cleanup(int, Buffer *); 132 int mm_answer_term(int, Buffer *); 133 int mm_answer_rsa_keyallowed(int, Buffer *); 134 int mm_answer_rsa_challenge(int, Buffer *); 135 int mm_answer_rsa_response(int, Buffer *); 136 int mm_answer_sesskey(int, Buffer *); 137 int mm_answer_sessid(int, Buffer *); 138 int mm_answer_jpake_get_pwdata(int, Buffer *); 139 int mm_answer_jpake_step1(int, Buffer *); 140 int mm_answer_jpake_step2(int, Buffer *); 141 int mm_answer_jpake_key_confirm(int, Buffer *); 142 int mm_answer_jpake_check_confirm(int, Buffer *); 143 144 #ifdef GSSAPI 145 int mm_answer_gss_setup_ctx(int, Buffer *); 146 int mm_answer_gss_accept_ctx(int, Buffer *); 147 int mm_answer_gss_userok(int, Buffer *); 148 int mm_answer_gss_checkmic(int, Buffer *); 149 #endif 150 151 static Authctxt *authctxt; 152 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 153 154 /* local state for key verify */ 155 static u_char *key_blob = NULL; 156 static u_int key_bloblen = 0; 157 static int key_blobtype = MM_NOKEY; 158 static char *hostbased_cuser = NULL; 159 static char *hostbased_chost = NULL; 160 static char *auth_method = "unknown"; 161 static u_int session_id2_len = 0; 162 static u_char *session_id2 = NULL; 163 static pid_t monitor_child_pid; 164 165 struct mon_table { 166 enum monitor_reqtype type; 167 int flags; 168 int (*f)(int, Buffer *); 169 }; 170 171 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 172 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 173 #define MON_ONCE 0x0010 /* Disable after calling */ 174 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 175 176 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 177 178 #define MON_PERMIT 0x1000 /* Request is permitted */ 179 180 struct mon_table mon_dispatch_proto20[] = { 181 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 182 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 183 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 184 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 185 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 186 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 187 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 188 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 189 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 190 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 191 #ifdef GSSAPI 192 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 193 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 194 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 195 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 196 #endif 197 #ifdef JPAKE 198 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 199 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 200 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 201 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 202 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 203 #endif 204 {0, 0, NULL} 205 }; 206 207 struct mon_table mon_dispatch_postauth20[] = { 208 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 209 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 210 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 211 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 212 {MONITOR_REQ_TERM, 0, mm_answer_term}, 213 {0, 0, NULL} 214 }; 215 216 struct mon_table mon_dispatch_proto15[] = { 217 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 218 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 219 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 220 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 221 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 222 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 223 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 224 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 225 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 226 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 227 {0, 0, NULL} 228 }; 229 230 struct mon_table mon_dispatch_postauth15[] = { 231 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 232 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 233 {MONITOR_REQ_TERM, 0, mm_answer_term}, 234 {0, 0, NULL} 235 }; 236 237 struct mon_table *mon_dispatch; 238 239 /* Specifies if a certain message is allowed at the moment */ 240 241 static void 242 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 243 { 244 while (ent->f != NULL) { 245 if (ent->type == type) { 246 ent->flags &= ~MON_PERMIT; 247 ent->flags |= permit ? MON_PERMIT : 0; 248 return; 249 } 250 ent++; 251 } 252 } 253 254 static void 255 monitor_permit_authentications(int permit) 256 { 257 struct mon_table *ent = mon_dispatch; 258 259 while (ent->f != NULL) { 260 if (ent->flags & MON_AUTH) { 261 ent->flags &= ~MON_PERMIT; 262 ent->flags |= permit ? MON_PERMIT : 0; 263 } 264 ent++; 265 } 266 } 267 268 void 269 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 270 { 271 struct mon_table *ent; 272 int authenticated = 0; 273 274 debug3("preauth child monitor started"); 275 276 authctxt = _authctxt; 277 memset(authctxt, 0, sizeof(*authctxt)); 278 279 if (compat20) { 280 mon_dispatch = mon_dispatch_proto20; 281 282 /* Permit requests for moduli and signatures */ 283 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 284 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 285 } else { 286 mon_dispatch = mon_dispatch_proto15; 287 288 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 289 } 290 291 /* The first few requests do not require asynchronous access */ 292 while (!authenticated) { 293 auth_method = "unknown"; 294 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 295 if (authenticated) { 296 if (!(ent->flags & MON_AUTHDECIDE)) 297 fatal("%s: unexpected authentication from %d", 298 __func__, ent->type); 299 if (authctxt->pw->pw_uid == 0 && 300 !auth_root_allowed(auth_method)) 301 authenticated = 0; 302 } 303 304 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 305 auth_log(authctxt, authenticated, auth_method, 306 compat20 ? " ssh2" : ""); 307 if (!authenticated) 308 authctxt->failures++; 309 } 310 #ifdef JPAKE 311 /* Cleanup JPAKE context after authentication */ 312 if (ent->flags & MON_AUTHDECIDE) { 313 if (authctxt->jpake_ctx != NULL) { 314 jpake_free(authctxt->jpake_ctx); 315 authctxt->jpake_ctx = NULL; 316 } 317 } 318 #endif 319 } 320 321 if (!authctxt->valid) 322 fatal("%s: authenticated invalid user", __func__); 323 if (strcmp(auth_method, "unknown") == 0) 324 fatal("%s: authentication method name unknown", __func__); 325 326 debug("%s: %s has been authenticated by privileged process", 327 __func__, authctxt->user); 328 329 mm_get_keystate(pmonitor); 330 } 331 332 static void 333 monitor_set_child_handler(pid_t pid) 334 { 335 monitor_child_pid = pid; 336 } 337 338 static void 339 monitor_child_handler(int sig) 340 { 341 kill(monitor_child_pid, sig); 342 } 343 344 void 345 monitor_child_postauth(struct monitor *pmonitor) 346 { 347 monitor_set_child_handler(pmonitor->m_pid); 348 signal(SIGHUP, &monitor_child_handler); 349 signal(SIGTERM, &monitor_child_handler); 350 signal(SIGINT, &monitor_child_handler); 351 352 if (compat20) { 353 mon_dispatch = mon_dispatch_postauth20; 354 355 /* Permit requests for moduli and signatures */ 356 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 357 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 358 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 359 } else { 360 mon_dispatch = mon_dispatch_postauth15; 361 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 362 } 363 if (!no_pty_flag) { 364 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 365 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 366 } 367 368 for (;;) 369 monitor_read(pmonitor, mon_dispatch, NULL); 370 } 371 372 void 373 monitor_sync(struct monitor *pmonitor) 374 { 375 if (options.compression) { 376 /* The member allocation is not visible, so sync it */ 377 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 378 } 379 } 380 381 int 382 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 383 struct mon_table **pent) 384 { 385 Buffer m; 386 int ret; 387 u_char type; 388 389 buffer_init(&m); 390 391 mm_request_receive(pmonitor->m_sendfd, &m); 392 type = buffer_get_char(&m); 393 394 debug3("%s: checking request %d", __func__, type); 395 396 while (ent->f != NULL) { 397 if (ent->type == type) 398 break; 399 ent++; 400 } 401 402 if (ent->f != NULL) { 403 if (!(ent->flags & MON_PERMIT)) 404 fatal("%s: unpermitted request %d", __func__, 405 type); 406 ret = (*ent->f)(pmonitor->m_sendfd, &m); 407 buffer_free(&m); 408 409 /* The child may use this request only once, disable it */ 410 if (ent->flags & MON_ONCE) { 411 debug2("%s: %d used once, disabling now", __func__, 412 type); 413 ent->flags &= ~MON_PERMIT; 414 } 415 416 if (pent != NULL) 417 *pent = ent; 418 419 return ret; 420 } 421 422 fatal("%s: unsupported request: %d", __func__, type); 423 424 /* NOTREACHED */ 425 return (-1); 426 } 427 428 /* allowed key state */ 429 static int 430 monitor_allowed_key(u_char *blob, u_int bloblen) 431 { 432 /* make sure key is allowed */ 433 if (key_blob == NULL || key_bloblen != bloblen || 434 memcmp(key_blob, blob, key_bloblen)) 435 return (0); 436 return (1); 437 } 438 439 static void 440 monitor_reset_key_state(void) 441 { 442 /* reset state */ 443 if (key_blob != NULL) 444 xfree(key_blob); 445 if (hostbased_cuser != NULL) 446 xfree(hostbased_cuser); 447 if (hostbased_chost != NULL) 448 xfree(hostbased_chost); 449 key_blob = NULL; 450 key_bloblen = 0; 451 key_blobtype = MM_NOKEY; 452 hostbased_cuser = NULL; 453 hostbased_chost = NULL; 454 } 455 456 int 457 mm_answer_moduli(int sock, Buffer *m) 458 { 459 DH *dh; 460 int min, want, max; 461 462 min = buffer_get_int(m); 463 want = buffer_get_int(m); 464 max = buffer_get_int(m); 465 466 debug3("%s: got parameters: %d %d %d", 467 __func__, min, want, max); 468 /* We need to check here, too, in case the child got corrupted */ 469 if (max < min || want < min || max < want) 470 fatal("%s: bad parameters: %d %d %d", 471 __func__, min, want, max); 472 473 buffer_clear(m); 474 475 dh = choose_dh(min, want, max); 476 if (dh == NULL) { 477 buffer_put_char(m, 0); 478 return (0); 479 } else { 480 /* Send first bignum */ 481 buffer_put_char(m, 1); 482 buffer_put_bignum2(m, dh->p); 483 buffer_put_bignum2(m, dh->g); 484 485 DH_free(dh); 486 } 487 mm_request_send(sock, MONITOR_ANS_MODULI, m); 488 return (0); 489 } 490 491 int 492 mm_answer_sign(int sock, Buffer *m) 493 { 494 Key *key; 495 u_char *p; 496 u_char *signature; 497 u_int siglen, datlen; 498 int keyid; 499 500 debug3("%s", __func__); 501 502 keyid = buffer_get_int(m); 503 p = buffer_get_string(m, &datlen); 504 505 /* 506 * Supported KEX types will only return SHA1 (20 byte) or 507 * SHA256 (32 byte) hashes 508 */ 509 if (datlen != 20 && datlen != 32) 510 fatal("%s: data length incorrect: %u", __func__, datlen); 511 512 /* save session id, it will be passed on the first call */ 513 if (session_id2_len == 0) { 514 session_id2_len = datlen; 515 session_id2 = xmalloc(session_id2_len); 516 memcpy(session_id2, p, session_id2_len); 517 } 518 519 if ((key = get_hostkey_by_index(keyid)) == NULL) 520 fatal("%s: no hostkey from index %d", __func__, keyid); 521 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 522 fatal("%s: key_sign failed", __func__); 523 524 debug3("%s: signature %p(%u)", __func__, signature, siglen); 525 526 buffer_clear(m); 527 buffer_put_string(m, signature, siglen); 528 529 xfree(p); 530 xfree(signature); 531 532 mm_request_send(sock, MONITOR_ANS_SIGN, m); 533 534 /* Turn on permissions for getpwnam */ 535 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 536 537 return (0); 538 } 539 540 /* Retrieves the password entry and also checks if the user is permitted */ 541 542 int 543 mm_answer_pwnamallow(int sock, Buffer *m) 544 { 545 char *username; 546 struct passwd *pwent; 547 int allowed = 0; 548 549 debug3("%s", __func__); 550 551 if (authctxt->attempt++ != 0) 552 fatal("%s: multiple attempts for getpwnam", __func__); 553 554 username = buffer_get_string(m, NULL); 555 556 pwent = getpwnamallow(username); 557 558 authctxt->user = xstrdup(username); 559 setproctitle("%s [priv]", pwent ? username : "unknown"); 560 xfree(username); 561 562 buffer_clear(m); 563 564 if (pwent == NULL) { 565 buffer_put_char(m, 0); 566 authctxt->pw = fakepw(); 567 goto out; 568 } 569 570 allowed = 1; 571 authctxt->pw = pwent; 572 authctxt->valid = 1; 573 574 buffer_put_char(m, 1); 575 buffer_put_string(m, pwent, sizeof(struct passwd)); 576 buffer_put_cstring(m, pwent->pw_name); 577 buffer_put_cstring(m, "*"); 578 buffer_put_cstring(m, pwent->pw_gecos); 579 buffer_put_cstring(m, pwent->pw_class); 580 buffer_put_cstring(m, pwent->pw_dir); 581 buffer_put_cstring(m, pwent->pw_shell); 582 583 out: 584 buffer_put_string(m, &options, sizeof(options)); 585 if (options.banner != NULL) 586 buffer_put_cstring(m, options.banner); 587 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 588 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 589 590 /* For SSHv1 allow authentication now */ 591 if (!compat20) 592 monitor_permit_authentications(1); 593 else { 594 /* Allow service/style information on the auth context */ 595 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 596 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 597 } 598 599 600 return (0); 601 } 602 603 int mm_answer_auth2_read_banner(int sock, Buffer *m) 604 { 605 char *banner; 606 607 buffer_clear(m); 608 banner = auth2_read_banner(); 609 buffer_put_cstring(m, banner != NULL ? banner : ""); 610 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 611 612 if (banner != NULL) 613 xfree(banner); 614 615 return (0); 616 } 617 618 int 619 mm_answer_authserv(int sock, Buffer *m) 620 { 621 monitor_permit_authentications(1); 622 623 authctxt->service = buffer_get_string(m, NULL); 624 authctxt->style = buffer_get_string(m, NULL); 625 debug3("%s: service=%s, style=%s", 626 __func__, authctxt->service, authctxt->style); 627 628 if (strlen(authctxt->style) == 0) { 629 xfree(authctxt->style); 630 authctxt->style = NULL; 631 } 632 633 return (0); 634 } 635 636 int 637 mm_answer_authpassword(int sock, Buffer *m) 638 { 639 static int call_count; 640 char *passwd; 641 int authenticated; 642 u_int plen; 643 644 passwd = buffer_get_string(m, &plen); 645 /* Only authenticate if the context is valid */ 646 authenticated = options.password_authentication && 647 auth_password(authctxt, passwd); 648 memset(passwd, 0, strlen(passwd)); 649 xfree(passwd); 650 651 buffer_clear(m); 652 buffer_put_int(m, authenticated); 653 654 debug3("%s: sending result %d", __func__, authenticated); 655 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 656 657 call_count++; 658 if (plen == 0 && call_count == 1) 659 auth_method = "none"; 660 else 661 auth_method = "password"; 662 663 /* Causes monitor loop to terminate if authenticated */ 664 return (authenticated); 665 } 666 667 int 668 mm_answer_bsdauthquery(int sock, Buffer *m) 669 { 670 char *name, *infotxt; 671 u_int numprompts; 672 u_int *echo_on; 673 char **prompts; 674 u_int success; 675 676 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 677 &prompts, &echo_on) < 0 ? 0 : 1; 678 679 buffer_clear(m); 680 buffer_put_int(m, success); 681 if (success) 682 buffer_put_cstring(m, prompts[0]); 683 684 debug3("%s: sending challenge success: %u", __func__, success); 685 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 686 687 if (success) { 688 xfree(name); 689 xfree(infotxt); 690 xfree(prompts); 691 xfree(echo_on); 692 } 693 694 return (0); 695 } 696 697 int 698 mm_answer_bsdauthrespond(int sock, Buffer *m) 699 { 700 char *response; 701 int authok; 702 703 if (authctxt->as == 0) 704 fatal("%s: no bsd auth session", __func__); 705 706 response = buffer_get_string(m, NULL); 707 authok = options.challenge_response_authentication && 708 auth_userresponse(authctxt->as, response, 0); 709 authctxt->as = NULL; 710 debug3("%s: <%s> = <%d>", __func__, response, authok); 711 xfree(response); 712 713 buffer_clear(m); 714 buffer_put_int(m, authok); 715 716 debug3("%s: sending authenticated: %d", __func__, authok); 717 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 718 719 auth_method = "bsdauth"; 720 721 return (authok != 0); 722 } 723 724 725 static void 726 mm_append_debug(Buffer *m) 727 { 728 if (auth_debug_init && buffer_len(&auth_debug)) { 729 debug3("%s: Appending debug messages for child", __func__); 730 buffer_append(m, buffer_ptr(&auth_debug), 731 buffer_len(&auth_debug)); 732 buffer_clear(&auth_debug); 733 } 734 } 735 736 int 737 mm_answer_keyallowed(int sock, Buffer *m) 738 { 739 Key *key; 740 char *cuser, *chost; 741 u_char *blob; 742 u_int bloblen; 743 enum mm_keytype type = 0; 744 int allowed = 0; 745 746 debug3("%s entering", __func__); 747 748 type = buffer_get_int(m); 749 cuser = buffer_get_string(m, NULL); 750 chost = buffer_get_string(m, NULL); 751 blob = buffer_get_string(m, &bloblen); 752 753 key = key_from_blob(blob, bloblen); 754 755 if ((compat20 && type == MM_RSAHOSTKEY) || 756 (!compat20 && type != MM_RSAHOSTKEY)) 757 fatal("%s: key type and protocol mismatch", __func__); 758 759 debug3("%s: key_from_blob: %p", __func__, key); 760 761 if (key != NULL && authctxt->valid) { 762 switch (type) { 763 case MM_USERKEY: 764 allowed = options.pubkey_authentication && 765 user_key_allowed(authctxt->pw, key); 766 auth_method = "publickey"; 767 if (options.pubkey_authentication && allowed != 1) 768 auth_clear_options(); 769 break; 770 case MM_HOSTKEY: 771 allowed = options.hostbased_authentication && 772 hostbased_key_allowed(authctxt->pw, 773 cuser, chost, key); 774 auth_method = "hostbased"; 775 break; 776 case MM_RSAHOSTKEY: 777 key->type = KEY_RSA1; /* XXX */ 778 allowed = options.rhosts_rsa_authentication && 779 auth_rhosts_rsa_key_allowed(authctxt->pw, 780 cuser, chost, key); 781 if (options.rhosts_rsa_authentication && allowed != 1) 782 auth_clear_options(); 783 auth_method = "rsa"; 784 break; 785 default: 786 fatal("%s: unknown key type %d", __func__, type); 787 break; 788 } 789 } 790 if (key != NULL) 791 key_free(key); 792 793 /* clear temporarily storage (used by verify) */ 794 monitor_reset_key_state(); 795 796 if (allowed) { 797 /* Save temporarily for comparison in verify */ 798 key_blob = blob; 799 key_bloblen = bloblen; 800 key_blobtype = type; 801 hostbased_cuser = cuser; 802 hostbased_chost = chost; 803 } else { 804 /* Log failed attempt */ 805 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 806 xfree(blob); 807 xfree(cuser); 808 xfree(chost); 809 } 810 811 debug3("%s: key %p is %s", 812 __func__, key, allowed ? "allowed" : "not allowed"); 813 814 buffer_clear(m); 815 buffer_put_int(m, allowed); 816 buffer_put_int(m, forced_command != NULL); 817 818 mm_append_debug(m); 819 820 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 821 822 if (type == MM_RSAHOSTKEY) 823 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 824 825 return (0); 826 } 827 828 static int 829 monitor_valid_userblob(u_char *data, u_int datalen) 830 { 831 Buffer b; 832 char *p; 833 u_int len; 834 int fail = 0; 835 836 buffer_init(&b); 837 buffer_append(&b, data, datalen); 838 839 if (datafellows & SSH_OLD_SESSIONID) { 840 p = buffer_ptr(&b); 841 len = buffer_len(&b); 842 if ((session_id2 == NULL) || 843 (len < session_id2_len) || 844 (memcmp(p, session_id2, session_id2_len) != 0)) 845 fail++; 846 buffer_consume(&b, session_id2_len); 847 } else { 848 p = buffer_get_string(&b, &len); 849 if ((session_id2 == NULL) || 850 (len != session_id2_len) || 851 (memcmp(p, session_id2, session_id2_len) != 0)) 852 fail++; 853 xfree(p); 854 } 855 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 856 fail++; 857 p = buffer_get_string(&b, NULL); 858 if (strcmp(authctxt->user, p) != 0) { 859 logit("wrong user name passed to monitor: expected %s != %.100s", 860 authctxt->user, p); 861 fail++; 862 } 863 xfree(p); 864 buffer_skip_string(&b); 865 if (datafellows & SSH_BUG_PKAUTH) { 866 if (!buffer_get_char(&b)) 867 fail++; 868 } else { 869 p = buffer_get_string(&b, NULL); 870 if (strcmp("publickey", p) != 0) 871 fail++; 872 xfree(p); 873 if (!buffer_get_char(&b)) 874 fail++; 875 buffer_skip_string(&b); 876 } 877 buffer_skip_string(&b); 878 if (buffer_len(&b) != 0) 879 fail++; 880 buffer_free(&b); 881 return (fail == 0); 882 } 883 884 static int 885 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 886 char *chost) 887 { 888 Buffer b; 889 char *p; 890 u_int len; 891 int fail = 0; 892 893 buffer_init(&b); 894 buffer_append(&b, data, datalen); 895 896 p = buffer_get_string(&b, &len); 897 if ((session_id2 == NULL) || 898 (len != session_id2_len) || 899 (memcmp(p, session_id2, session_id2_len) != 0)) 900 fail++; 901 xfree(p); 902 903 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 904 fail++; 905 p = buffer_get_string(&b, NULL); 906 if (strcmp(authctxt->user, p) != 0) { 907 logit("wrong user name passed to monitor: expected %s != %.100s", 908 authctxt->user, p); 909 fail++; 910 } 911 xfree(p); 912 buffer_skip_string(&b); /* service */ 913 p = buffer_get_string(&b, NULL); 914 if (strcmp(p, "hostbased") != 0) 915 fail++; 916 xfree(p); 917 buffer_skip_string(&b); /* pkalg */ 918 buffer_skip_string(&b); /* pkblob */ 919 920 /* verify client host, strip trailing dot if necessary */ 921 p = buffer_get_string(&b, NULL); 922 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 923 p[len - 1] = '\0'; 924 if (strcmp(p, chost) != 0) 925 fail++; 926 xfree(p); 927 928 /* verify client user */ 929 p = buffer_get_string(&b, NULL); 930 if (strcmp(p, cuser) != 0) 931 fail++; 932 xfree(p); 933 934 if (buffer_len(&b) != 0) 935 fail++; 936 buffer_free(&b); 937 return (fail == 0); 938 } 939 940 int 941 mm_answer_keyverify(int sock, Buffer *m) 942 { 943 Key *key; 944 u_char *signature, *data, *blob; 945 u_int signaturelen, datalen, bloblen; 946 int verified = 0; 947 int valid_data = 0; 948 949 blob = buffer_get_string(m, &bloblen); 950 signature = buffer_get_string(m, &signaturelen); 951 data = buffer_get_string(m, &datalen); 952 953 if (hostbased_cuser == NULL || hostbased_chost == NULL || 954 !monitor_allowed_key(blob, bloblen)) 955 fatal("%s: bad key, not previously allowed", __func__); 956 957 key = key_from_blob(blob, bloblen); 958 if (key == NULL) 959 fatal("%s: bad public key blob", __func__); 960 961 switch (key_blobtype) { 962 case MM_USERKEY: 963 valid_data = monitor_valid_userblob(data, datalen); 964 break; 965 case MM_HOSTKEY: 966 valid_data = monitor_valid_hostbasedblob(data, datalen, 967 hostbased_cuser, hostbased_chost); 968 break; 969 default: 970 valid_data = 0; 971 break; 972 } 973 if (!valid_data) 974 fatal("%s: bad signature data blob", __func__); 975 976 verified = key_verify(key, signature, signaturelen, data, datalen); 977 debug3("%s: key %p signature %s", 978 __func__, key, (verified == 1) ? "verified" : "unverified"); 979 980 key_free(key); 981 xfree(blob); 982 xfree(signature); 983 xfree(data); 984 985 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 986 987 monitor_reset_key_state(); 988 989 buffer_clear(m); 990 buffer_put_int(m, verified); 991 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 992 993 return (verified == 1); 994 } 995 996 static void 997 mm_record_login(Session *s, struct passwd *pw) 998 { 999 socklen_t fromlen; 1000 struct sockaddr_storage from; 1001 1002 /* 1003 * Get IP address of client. If the connection is not a socket, let 1004 * the address be 0.0.0.0. 1005 */ 1006 memset(&from, 0, sizeof(from)); 1007 fromlen = sizeof(from); 1008 if (packet_connection_is_on_socket()) { 1009 if (getpeername(packet_get_connection_in(), 1010 (struct sockaddr *)&from, &fromlen) < 0) { 1011 debug("getpeername: %.100s", strerror(errno)); 1012 cleanup_exit(255); 1013 } 1014 } 1015 /* Record that there was a login on that tty from the remote host. */ 1016 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1017 get_remote_name_or_ip(utmp_len, options.use_dns), 1018 (struct sockaddr *)&from, fromlen); 1019 } 1020 1021 static void 1022 mm_session_close(Session *s) 1023 { 1024 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1025 if (s->ttyfd != -1) { 1026 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1027 session_pty_cleanup2(s); 1028 } 1029 session_unused(s->self); 1030 } 1031 1032 int 1033 mm_answer_pty(int sock, Buffer *m) 1034 { 1035 extern struct monitor *pmonitor; 1036 Session *s; 1037 int res, fd0; 1038 1039 debug3("%s entering", __func__); 1040 1041 buffer_clear(m); 1042 s = session_new(); 1043 if (s == NULL) 1044 goto error; 1045 s->authctxt = authctxt; 1046 s->pw = authctxt->pw; 1047 s->pid = pmonitor->m_pid; 1048 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1049 if (res == 0) 1050 goto error; 1051 pty_setowner(authctxt->pw, s->tty); 1052 1053 buffer_put_int(m, 1); 1054 buffer_put_cstring(m, s->tty); 1055 1056 /* We need to trick ttyslot */ 1057 if (dup2(s->ttyfd, 0) == -1) 1058 fatal("%s: dup2", __func__); 1059 1060 mm_record_login(s, authctxt->pw); 1061 1062 /* Now we can close the file descriptor again */ 1063 close(0); 1064 1065 /* send messages generated by record_login */ 1066 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1067 buffer_clear(&loginmsg); 1068 1069 mm_request_send(sock, MONITOR_ANS_PTY, m); 1070 1071 if (mm_send_fd(sock, s->ptyfd) == -1 || 1072 mm_send_fd(sock, s->ttyfd) == -1) 1073 fatal("%s: send fds failed", __func__); 1074 1075 /* make sure nothing uses fd 0 */ 1076 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1077 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1078 if (fd0 != 0) 1079 error("%s: fd0 %d != 0", __func__, fd0); 1080 1081 /* slave is not needed */ 1082 close(s->ttyfd); 1083 s->ttyfd = s->ptyfd; 1084 /* no need to dup() because nobody closes ptyfd */ 1085 s->ptymaster = s->ptyfd; 1086 1087 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1088 1089 return (0); 1090 1091 error: 1092 if (s != NULL) 1093 mm_session_close(s); 1094 buffer_put_int(m, 0); 1095 mm_request_send(sock, MONITOR_ANS_PTY, m); 1096 return (0); 1097 } 1098 1099 int 1100 mm_answer_pty_cleanup(int sock, Buffer *m) 1101 { 1102 Session *s; 1103 char *tty; 1104 1105 debug3("%s entering", __func__); 1106 1107 tty = buffer_get_string(m, NULL); 1108 if ((s = session_by_tty(tty)) != NULL) 1109 mm_session_close(s); 1110 buffer_clear(m); 1111 xfree(tty); 1112 return (0); 1113 } 1114 1115 int 1116 mm_answer_sesskey(int sock, Buffer *m) 1117 { 1118 BIGNUM *p; 1119 int rsafail; 1120 1121 /* Turn off permissions */ 1122 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1123 1124 if ((p = BN_new()) == NULL) 1125 fatal("%s: BN_new", __func__); 1126 1127 buffer_get_bignum2(m, p); 1128 1129 rsafail = ssh1_session_key(p); 1130 1131 buffer_clear(m); 1132 buffer_put_int(m, rsafail); 1133 buffer_put_bignum2(m, p); 1134 1135 BN_clear_free(p); 1136 1137 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1138 1139 /* Turn on permissions for sessid passing */ 1140 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1141 1142 return (0); 1143 } 1144 1145 int 1146 mm_answer_sessid(int sock, Buffer *m) 1147 { 1148 int i; 1149 1150 debug3("%s entering", __func__); 1151 1152 if (buffer_len(m) != 16) 1153 fatal("%s: bad ssh1 session id", __func__); 1154 for (i = 0; i < 16; i++) 1155 session_id[i] = buffer_get_char(m); 1156 1157 /* Turn on permissions for getpwnam */ 1158 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1159 1160 return (0); 1161 } 1162 1163 int 1164 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1165 { 1166 BIGNUM *client_n; 1167 Key *key = NULL; 1168 u_char *blob = NULL; 1169 u_int blen = 0; 1170 int allowed = 0; 1171 1172 debug3("%s entering", __func__); 1173 1174 auth_method = "rsa"; 1175 if (options.rsa_authentication && authctxt->valid) { 1176 if ((client_n = BN_new()) == NULL) 1177 fatal("%s: BN_new", __func__); 1178 buffer_get_bignum2(m, client_n); 1179 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1180 BN_clear_free(client_n); 1181 } 1182 buffer_clear(m); 1183 buffer_put_int(m, allowed); 1184 buffer_put_int(m, forced_command != NULL); 1185 1186 /* clear temporarily storage (used by generate challenge) */ 1187 monitor_reset_key_state(); 1188 1189 if (allowed && key != NULL) { 1190 key->type = KEY_RSA; /* cheat for key_to_blob */ 1191 if (key_to_blob(key, &blob, &blen) == 0) 1192 fatal("%s: key_to_blob failed", __func__); 1193 buffer_put_string(m, blob, blen); 1194 1195 /* Save temporarily for comparison in verify */ 1196 key_blob = blob; 1197 key_bloblen = blen; 1198 key_blobtype = MM_RSAUSERKEY; 1199 } 1200 if (key != NULL) 1201 key_free(key); 1202 1203 mm_append_debug(m); 1204 1205 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1206 1207 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1208 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1209 return (0); 1210 } 1211 1212 int 1213 mm_answer_rsa_challenge(int sock, Buffer *m) 1214 { 1215 Key *key = NULL; 1216 u_char *blob; 1217 u_int blen; 1218 1219 debug3("%s entering", __func__); 1220 1221 if (!authctxt->valid) 1222 fatal("%s: authctxt not valid", __func__); 1223 blob = buffer_get_string(m, &blen); 1224 if (!monitor_allowed_key(blob, blen)) 1225 fatal("%s: bad key, not previously allowed", __func__); 1226 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1227 fatal("%s: key type mismatch", __func__); 1228 if ((key = key_from_blob(blob, blen)) == NULL) 1229 fatal("%s: received bad key", __func__); 1230 if (key->type != KEY_RSA) 1231 fatal("%s: received bad key type %d", __func__, key->type); 1232 key->type = KEY_RSA1; 1233 if (ssh1_challenge) 1234 BN_clear_free(ssh1_challenge); 1235 ssh1_challenge = auth_rsa_generate_challenge(key); 1236 1237 buffer_clear(m); 1238 buffer_put_bignum2(m, ssh1_challenge); 1239 1240 debug3("%s sending reply", __func__); 1241 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1242 1243 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1244 1245 xfree(blob); 1246 key_free(key); 1247 return (0); 1248 } 1249 1250 int 1251 mm_answer_rsa_response(int sock, Buffer *m) 1252 { 1253 Key *key = NULL; 1254 u_char *blob, *response; 1255 u_int blen, len; 1256 int success; 1257 1258 debug3("%s entering", __func__); 1259 1260 if (!authctxt->valid) 1261 fatal("%s: authctxt not valid", __func__); 1262 if (ssh1_challenge == NULL) 1263 fatal("%s: no ssh1_challenge", __func__); 1264 1265 blob = buffer_get_string(m, &blen); 1266 if (!monitor_allowed_key(blob, blen)) 1267 fatal("%s: bad key, not previously allowed", __func__); 1268 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1269 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1270 if ((key = key_from_blob(blob, blen)) == NULL) 1271 fatal("%s: received bad key", __func__); 1272 response = buffer_get_string(m, &len); 1273 if (len != 16) 1274 fatal("%s: received bad response to challenge", __func__); 1275 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1276 1277 xfree(blob); 1278 key_free(key); 1279 xfree(response); 1280 1281 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1282 1283 /* reset state */ 1284 BN_clear_free(ssh1_challenge); 1285 ssh1_challenge = NULL; 1286 monitor_reset_key_state(); 1287 1288 buffer_clear(m); 1289 buffer_put_int(m, success); 1290 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1291 1292 return (success); 1293 } 1294 1295 int 1296 mm_answer_term(int sock, Buffer *req) 1297 { 1298 extern struct monitor *pmonitor; 1299 int res, status; 1300 1301 debug3("%s: tearing down sessions", __func__); 1302 1303 /* The child is terminating */ 1304 session_destroy_all(&mm_session_close); 1305 1306 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1307 if (errno != EINTR) 1308 exit(1); 1309 1310 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1311 1312 /* Terminate process */ 1313 exit(res); 1314 } 1315 1316 void 1317 monitor_apply_keystate(struct monitor *pmonitor) 1318 { 1319 if (compat20) { 1320 set_newkeys(MODE_IN); 1321 set_newkeys(MODE_OUT); 1322 } else { 1323 packet_set_protocol_flags(child_state.ssh1protoflags); 1324 packet_set_encryption_key(child_state.ssh1key, 1325 child_state.ssh1keylen, child_state.ssh1cipher); 1326 xfree(child_state.ssh1key); 1327 } 1328 1329 /* for rc4 and other stateful ciphers */ 1330 packet_set_keycontext(MODE_OUT, child_state.keyout); 1331 xfree(child_state.keyout); 1332 packet_set_keycontext(MODE_IN, child_state.keyin); 1333 xfree(child_state.keyin); 1334 1335 if (!compat20) { 1336 packet_set_iv(MODE_OUT, child_state.ivout); 1337 xfree(child_state.ivout); 1338 packet_set_iv(MODE_IN, child_state.ivin); 1339 xfree(child_state.ivin); 1340 } 1341 1342 memcpy(&incoming_stream, &child_state.incoming, 1343 sizeof(incoming_stream)); 1344 memcpy(&outgoing_stream, &child_state.outgoing, 1345 sizeof(outgoing_stream)); 1346 1347 /* Update with new address */ 1348 if (options.compression) 1349 mm_init_compression(pmonitor->m_zlib); 1350 1351 /* Network I/O buffers */ 1352 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1353 buffer_clear(&input); 1354 buffer_append(&input, child_state.input, child_state.ilen); 1355 memset(child_state.input, 0, child_state.ilen); 1356 xfree(child_state.input); 1357 1358 buffer_clear(&output); 1359 buffer_append(&output, child_state.output, child_state.olen); 1360 memset(child_state.output, 0, child_state.olen); 1361 xfree(child_state.output); 1362 } 1363 1364 static Kex * 1365 mm_get_kex(Buffer *m) 1366 { 1367 Kex *kex; 1368 void *blob; 1369 u_int bloblen; 1370 1371 kex = xcalloc(1, sizeof(*kex)); 1372 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1373 if ((session_id2 == NULL) || 1374 (kex->session_id_len != session_id2_len) || 1375 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1376 fatal("mm_get_get: internal error: bad session id"); 1377 kex->we_need = buffer_get_int(m); 1378 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1379 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1380 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1381 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1382 kex->server = 1; 1383 kex->hostkey_type = buffer_get_int(m); 1384 kex->kex_type = buffer_get_int(m); 1385 blob = buffer_get_string(m, &bloblen); 1386 buffer_init(&kex->my); 1387 buffer_append(&kex->my, blob, bloblen); 1388 xfree(blob); 1389 blob = buffer_get_string(m, &bloblen); 1390 buffer_init(&kex->peer); 1391 buffer_append(&kex->peer, blob, bloblen); 1392 xfree(blob); 1393 kex->done = 1; 1394 kex->flags = buffer_get_int(m); 1395 kex->client_version_string = buffer_get_string(m, NULL); 1396 kex->server_version_string = buffer_get_string(m, NULL); 1397 kex->load_host_key=&get_hostkey_by_type; 1398 kex->host_key_index=&get_hostkey_index; 1399 1400 return (kex); 1401 } 1402 1403 /* This function requries careful sanity checking */ 1404 1405 void 1406 mm_get_keystate(struct monitor *pmonitor) 1407 { 1408 Buffer m; 1409 u_char *blob, *p; 1410 u_int bloblen, plen; 1411 u_int32_t seqnr, packets; 1412 u_int64_t blocks, bytes; 1413 1414 debug3("%s: Waiting for new keys", __func__); 1415 1416 buffer_init(&m); 1417 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1418 if (!compat20) { 1419 child_state.ssh1protoflags = buffer_get_int(&m); 1420 child_state.ssh1cipher = buffer_get_int(&m); 1421 child_state.ssh1key = buffer_get_string(&m, 1422 &child_state.ssh1keylen); 1423 child_state.ivout = buffer_get_string(&m, 1424 &child_state.ivoutlen); 1425 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1426 goto skip; 1427 } else { 1428 /* Get the Kex for rekeying */ 1429 *pmonitor->m_pkex = mm_get_kex(&m); 1430 } 1431 1432 blob = buffer_get_string(&m, &bloblen); 1433 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1434 xfree(blob); 1435 1436 debug3("%s: Waiting for second key", __func__); 1437 blob = buffer_get_string(&m, &bloblen); 1438 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1439 xfree(blob); 1440 1441 /* Now get sequence numbers for the packets */ 1442 seqnr = buffer_get_int(&m); 1443 blocks = buffer_get_int64(&m); 1444 packets = buffer_get_int(&m); 1445 bytes = buffer_get_int64(&m); 1446 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1447 seqnr = buffer_get_int(&m); 1448 blocks = buffer_get_int64(&m); 1449 packets = buffer_get_int(&m); 1450 bytes = buffer_get_int64(&m); 1451 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1452 1453 skip: 1454 /* Get the key context */ 1455 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1456 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1457 1458 debug3("%s: Getting compression state", __func__); 1459 /* Get compression state */ 1460 p = buffer_get_string(&m, &plen); 1461 if (plen != sizeof(child_state.outgoing)) 1462 fatal("%s: bad request size", __func__); 1463 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1464 xfree(p); 1465 1466 p = buffer_get_string(&m, &plen); 1467 if (plen != sizeof(child_state.incoming)) 1468 fatal("%s: bad request size", __func__); 1469 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1470 xfree(p); 1471 1472 /* Network I/O buffers */ 1473 debug3("%s: Getting Network I/O buffers", __func__); 1474 child_state.input = buffer_get_string(&m, &child_state.ilen); 1475 child_state.output = buffer_get_string(&m, &child_state.olen); 1476 1477 buffer_free(&m); 1478 } 1479 1480 1481 /* Allocation functions for zlib */ 1482 void * 1483 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1484 { 1485 size_t len = (size_t) size * ncount; 1486 void *address; 1487 1488 if (len == 0 || ncount > SIZE_T_MAX / size) 1489 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1490 1491 address = mm_malloc(mm, len); 1492 1493 return (address); 1494 } 1495 1496 void 1497 mm_zfree(struct mm_master *mm, void *address) 1498 { 1499 mm_free(mm, address); 1500 } 1501 1502 void 1503 mm_init_compression(struct mm_master *mm) 1504 { 1505 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1506 outgoing_stream.zfree = (free_func)mm_zfree; 1507 outgoing_stream.opaque = mm; 1508 1509 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1510 incoming_stream.zfree = (free_func)mm_zfree; 1511 incoming_stream.opaque = mm; 1512 } 1513 1514 /* XXX */ 1515 1516 #define FD_CLOSEONEXEC(x) do { \ 1517 if (fcntl(x, F_SETFD, 1) == -1) \ 1518 fatal("fcntl(%d, F_SETFD)", x); \ 1519 } while (0) 1520 1521 static void 1522 monitor_socketpair(int *pair) 1523 { 1524 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1525 fatal("%s: socketpair", __func__); 1526 FD_CLOSEONEXEC(pair[0]); 1527 FD_CLOSEONEXEC(pair[1]); 1528 } 1529 1530 #define MM_MEMSIZE 65536 1531 1532 struct monitor * 1533 monitor_init(void) 1534 { 1535 struct monitor *mon; 1536 int pair[2]; 1537 1538 mon = xcalloc(1, sizeof(*mon)); 1539 1540 monitor_socketpair(pair); 1541 1542 mon->m_recvfd = pair[0]; 1543 mon->m_sendfd = pair[1]; 1544 1545 /* Used to share zlib space across processes */ 1546 if (options.compression) { 1547 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1548 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1549 1550 /* Compression needs to share state across borders */ 1551 mm_init_compression(mon->m_zlib); 1552 } 1553 1554 return mon; 1555 } 1556 1557 void 1558 monitor_reinit(struct monitor *mon) 1559 { 1560 int pair[2]; 1561 1562 monitor_socketpair(pair); 1563 1564 mon->m_recvfd = pair[0]; 1565 mon->m_sendfd = pair[1]; 1566 } 1567 1568 #ifdef GSSAPI 1569 int 1570 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1571 { 1572 gss_OID_desc goid; 1573 OM_uint32 major; 1574 u_int len; 1575 1576 goid.elements = buffer_get_string(m, &len); 1577 goid.length = len; 1578 1579 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1580 1581 xfree(goid.elements); 1582 1583 buffer_clear(m); 1584 buffer_put_int(m, major); 1585 1586 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1587 1588 /* Now we have a context, enable the step */ 1589 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1590 1591 return (0); 1592 } 1593 1594 int 1595 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1596 { 1597 gss_buffer_desc in; 1598 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1599 OM_uint32 major, minor; 1600 OM_uint32 flags = 0; /* GSI needs this */ 1601 u_int len; 1602 1603 in.value = buffer_get_string(m, &len); 1604 in.length = len; 1605 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1606 xfree(in.value); 1607 1608 buffer_clear(m); 1609 buffer_put_int(m, major); 1610 buffer_put_string(m, out.value, out.length); 1611 buffer_put_int(m, flags); 1612 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1613 1614 gss_release_buffer(&minor, &out); 1615 1616 if (major == GSS_S_COMPLETE) { 1617 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1618 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1619 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1620 } 1621 return (0); 1622 } 1623 1624 int 1625 mm_answer_gss_checkmic(int sock, Buffer *m) 1626 { 1627 gss_buffer_desc gssbuf, mic; 1628 OM_uint32 ret; 1629 u_int len; 1630 1631 gssbuf.value = buffer_get_string(m, &len); 1632 gssbuf.length = len; 1633 mic.value = buffer_get_string(m, &len); 1634 mic.length = len; 1635 1636 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1637 1638 xfree(gssbuf.value); 1639 xfree(mic.value); 1640 1641 buffer_clear(m); 1642 buffer_put_int(m, ret); 1643 1644 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1645 1646 if (!GSS_ERROR(ret)) 1647 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1648 1649 return (0); 1650 } 1651 1652 int 1653 mm_answer_gss_userok(int sock, Buffer *m) 1654 { 1655 int authenticated; 1656 1657 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1658 1659 buffer_clear(m); 1660 buffer_put_int(m, authenticated); 1661 1662 debug3("%s: sending result %d", __func__, authenticated); 1663 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1664 1665 auth_method = "gssapi-with-mic"; 1666 1667 /* Monitor loop will terminate if authenticated */ 1668 return (authenticated); 1669 } 1670 #endif /* GSSAPI */ 1671 1672 #ifdef JPAKE 1673 int 1674 mm_answer_jpake_step1(int sock, Buffer *m) 1675 { 1676 struct jpake_ctx *pctx; 1677 u_char *x3_proof, *x4_proof; 1678 u_int x3_proof_len, x4_proof_len; 1679 1680 if (!options.zero_knowledge_password_authentication) 1681 fatal("zero_knowledge_password_authentication disabled"); 1682 1683 if (authctxt->jpake_ctx != NULL) 1684 fatal("%s: authctxt->jpake_ctx already set (%p)", 1685 __func__, authctxt->jpake_ctx); 1686 authctxt->jpake_ctx = pctx = jpake_new(); 1687 1688 jpake_step1(pctx->grp, 1689 &pctx->server_id, &pctx->server_id_len, 1690 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 1691 &x3_proof, &x3_proof_len, 1692 &x4_proof, &x4_proof_len); 1693 1694 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 1695 1696 buffer_clear(m); 1697 1698 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 1699 buffer_put_bignum2(m, pctx->g_x3); 1700 buffer_put_bignum2(m, pctx->g_x4); 1701 buffer_put_string(m, x3_proof, x3_proof_len); 1702 buffer_put_string(m, x4_proof, x4_proof_len); 1703 1704 debug3("%s: sending step1", __func__); 1705 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 1706 1707 bzero(x3_proof, x3_proof_len); 1708 bzero(x4_proof, x4_proof_len); 1709 xfree(x3_proof); 1710 xfree(x4_proof); 1711 1712 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 1713 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 1714 1715 return 0; 1716 } 1717 1718 int 1719 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 1720 { 1721 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1722 char *hash_scheme, *salt; 1723 1724 if (pctx == NULL) 1725 fatal("%s: pctx == NULL", __func__); 1726 1727 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 1728 1729 buffer_clear(m); 1730 /* pctx->s is sensitive, not returned to slave */ 1731 buffer_put_cstring(m, hash_scheme); 1732 buffer_put_cstring(m, salt); 1733 1734 debug3("%s: sending pwdata", __func__); 1735 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 1736 1737 bzero(hash_scheme, strlen(hash_scheme)); 1738 bzero(salt, strlen(salt)); 1739 xfree(hash_scheme); 1740 xfree(salt); 1741 1742 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 1743 1744 return 0; 1745 } 1746 1747 int 1748 mm_answer_jpake_step2(int sock, Buffer *m) 1749 { 1750 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1751 u_char *x1_proof, *x2_proof, *x4_s_proof; 1752 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 1753 1754 if (pctx == NULL) 1755 fatal("%s: pctx == NULL", __func__); 1756 1757 if ((pctx->g_x1 = BN_new()) == NULL || 1758 (pctx->g_x2 = BN_new()) == NULL) 1759 fatal("%s: BN_new", __func__); 1760 buffer_get_bignum2(m, pctx->g_x1); 1761 buffer_get_bignum2(m, pctx->g_x2); 1762 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 1763 x1_proof = buffer_get_string(m, &x1_proof_len); 1764 x2_proof = buffer_get_string(m, &x2_proof_len); 1765 1766 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 1767 pctx->g_x1, pctx->g_x2, pctx->x4, 1768 pctx->client_id, pctx->client_id_len, 1769 pctx->server_id, pctx->server_id_len, 1770 x1_proof, x1_proof_len, 1771 x2_proof, x2_proof_len, 1772 &pctx->b, 1773 &x4_s_proof, &x4_s_proof_len); 1774 1775 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 1776 1777 bzero(x1_proof, x1_proof_len); 1778 bzero(x2_proof, x2_proof_len); 1779 xfree(x1_proof); 1780 xfree(x2_proof); 1781 1782 buffer_clear(m); 1783 1784 buffer_put_bignum2(m, pctx->b); 1785 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 1786 1787 debug3("%s: sending step2", __func__); 1788 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 1789 1790 bzero(x4_s_proof, x4_s_proof_len); 1791 xfree(x4_s_proof); 1792 1793 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 1794 1795 return 0; 1796 } 1797 1798 int 1799 mm_answer_jpake_key_confirm(int sock, Buffer *m) 1800 { 1801 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1802 u_char *x2_s_proof; 1803 u_int x2_s_proof_len; 1804 1805 if (pctx == NULL) 1806 fatal("%s: pctx == NULL", __func__); 1807 1808 if ((pctx->a = BN_new()) == NULL) 1809 fatal("%s: BN_new", __func__); 1810 buffer_get_bignum2(m, pctx->a); 1811 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 1812 1813 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 1814 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 1815 pctx->server_id, pctx->server_id_len, 1816 pctx->client_id, pctx->client_id_len, 1817 session_id2, session_id2_len, 1818 x2_s_proof, x2_s_proof_len, 1819 &pctx->k, 1820 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 1821 1822 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 1823 1824 bzero(x2_s_proof, x2_s_proof_len); 1825 buffer_clear(m); 1826 1827 /* pctx->k is sensitive, not sent */ 1828 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 1829 1830 debug3("%s: sending confirmation hash", __func__); 1831 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 1832 1833 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 1834 1835 return 0; 1836 } 1837 1838 int 1839 mm_answer_jpake_check_confirm(int sock, Buffer *m) 1840 { 1841 int authenticated = 0; 1842 u_char *peer_confirm_hash; 1843 u_int peer_confirm_hash_len; 1844 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1845 1846 if (pctx == NULL) 1847 fatal("%s: pctx == NULL", __func__); 1848 1849 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 1850 1851 authenticated = jpake_check_confirm(pctx->k, 1852 pctx->client_id, pctx->client_id_len, 1853 session_id2, session_id2_len, 1854 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 1855 1856 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 1857 1858 bzero(peer_confirm_hash, peer_confirm_hash_len); 1859 xfree(peer_confirm_hash); 1860 1861 buffer_clear(m); 1862 buffer_put_int(m, authenticated); 1863 1864 debug3("%s: sending result %d", __func__, authenticated); 1865 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 1866 1867 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 1868 1869 auth_method = "jpake-01@openssh.com"; 1870 return authenticated; 1871 } 1872 1873 #endif /* JPAKE */ 1874