1 /* $OpenBSD: monitor.c,v 1.104 2009/06/12 20:43:22 andreas 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 } 725 726 727 static void 728 mm_append_debug(Buffer *m) 729 { 730 if (auth_debug_init && buffer_len(&auth_debug)) { 731 debug3("%s: Appending debug messages for child", __func__); 732 buffer_append(m, buffer_ptr(&auth_debug), 733 buffer_len(&auth_debug)); 734 buffer_clear(&auth_debug); 735 } 736 } 737 738 int 739 mm_answer_keyallowed(int sock, Buffer *m) 740 { 741 Key *key; 742 char *cuser, *chost; 743 u_char *blob; 744 u_int bloblen; 745 enum mm_keytype type = 0; 746 int allowed = 0; 747 748 debug3("%s entering", __func__); 749 750 type = buffer_get_int(m); 751 cuser = buffer_get_string(m, NULL); 752 chost = buffer_get_string(m, NULL); 753 blob = buffer_get_string(m, &bloblen); 754 755 key = key_from_blob(blob, bloblen); 756 757 if ((compat20 && type == MM_RSAHOSTKEY) || 758 (!compat20 && type != MM_RSAHOSTKEY)) 759 fatal("%s: key type and protocol mismatch", __func__); 760 761 debug3("%s: key_from_blob: %p", __func__, key); 762 763 if (key != NULL && authctxt->valid) { 764 switch (type) { 765 case MM_USERKEY: 766 allowed = options.pubkey_authentication && 767 user_key_allowed(authctxt->pw, key); 768 auth_method = "publickey"; 769 if (options.pubkey_authentication && allowed != 1) 770 auth_clear_options(); 771 break; 772 case MM_HOSTKEY: 773 allowed = options.hostbased_authentication && 774 hostbased_key_allowed(authctxt->pw, 775 cuser, chost, key); 776 auth_method = "hostbased"; 777 break; 778 case MM_RSAHOSTKEY: 779 key->type = KEY_RSA1; /* XXX */ 780 allowed = options.rhosts_rsa_authentication && 781 auth_rhosts_rsa_key_allowed(authctxt->pw, 782 cuser, chost, key); 783 if (options.rhosts_rsa_authentication && allowed != 1) 784 auth_clear_options(); 785 auth_method = "rsa"; 786 break; 787 default: 788 fatal("%s: unknown key type %d", __func__, type); 789 break; 790 } 791 } 792 if (key != NULL) 793 key_free(key); 794 795 /* clear temporarily storage (used by verify) */ 796 monitor_reset_key_state(); 797 798 if (allowed) { 799 /* Save temporarily for comparison in verify */ 800 key_blob = blob; 801 key_bloblen = bloblen; 802 key_blobtype = type; 803 hostbased_cuser = cuser; 804 hostbased_chost = chost; 805 } else { 806 /* Log failed attempt */ 807 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 808 xfree(blob); 809 xfree(cuser); 810 xfree(chost); 811 } 812 813 debug3("%s: key %p is %s", 814 __func__, key, allowed ? "allowed" : "not allowed"); 815 816 buffer_clear(m); 817 buffer_put_int(m, allowed); 818 buffer_put_int(m, forced_command != NULL); 819 820 mm_append_debug(m); 821 822 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 823 824 if (type == MM_RSAHOSTKEY) 825 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 826 827 return (0); 828 } 829 830 static int 831 monitor_valid_userblob(u_char *data, u_int datalen) 832 { 833 Buffer b; 834 char *p; 835 u_int len; 836 int fail = 0; 837 838 buffer_init(&b); 839 buffer_append(&b, data, datalen); 840 841 if (datafellows & SSH_OLD_SESSIONID) { 842 p = buffer_ptr(&b); 843 len = buffer_len(&b); 844 if ((session_id2 == NULL) || 845 (len < session_id2_len) || 846 (memcmp(p, session_id2, session_id2_len) != 0)) 847 fail++; 848 buffer_consume(&b, session_id2_len); 849 } else { 850 p = buffer_get_string(&b, &len); 851 if ((session_id2 == NULL) || 852 (len != session_id2_len) || 853 (memcmp(p, session_id2, session_id2_len) != 0)) 854 fail++; 855 xfree(p); 856 } 857 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 858 fail++; 859 p = buffer_get_string(&b, NULL); 860 if (strcmp(authctxt->user, p) != 0) { 861 logit("wrong user name passed to monitor: expected %s != %.100s", 862 authctxt->user, p); 863 fail++; 864 } 865 xfree(p); 866 buffer_skip_string(&b); 867 if (datafellows & SSH_BUG_PKAUTH) { 868 if (!buffer_get_char(&b)) 869 fail++; 870 } else { 871 p = buffer_get_string(&b, NULL); 872 if (strcmp("publickey", p) != 0) 873 fail++; 874 xfree(p); 875 if (!buffer_get_char(&b)) 876 fail++; 877 buffer_skip_string(&b); 878 } 879 buffer_skip_string(&b); 880 if (buffer_len(&b) != 0) 881 fail++; 882 buffer_free(&b); 883 return (fail == 0); 884 } 885 886 static int 887 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 888 char *chost) 889 { 890 Buffer b; 891 char *p; 892 u_int len; 893 int fail = 0; 894 895 buffer_init(&b); 896 buffer_append(&b, data, datalen); 897 898 p = buffer_get_string(&b, &len); 899 if ((session_id2 == NULL) || 900 (len != session_id2_len) || 901 (memcmp(p, session_id2, session_id2_len) != 0)) 902 fail++; 903 xfree(p); 904 905 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 906 fail++; 907 p = buffer_get_string(&b, NULL); 908 if (strcmp(authctxt->user, p) != 0) { 909 logit("wrong user name passed to monitor: expected %s != %.100s", 910 authctxt->user, p); 911 fail++; 912 } 913 xfree(p); 914 buffer_skip_string(&b); /* service */ 915 p = buffer_get_string(&b, NULL); 916 if (strcmp(p, "hostbased") != 0) 917 fail++; 918 xfree(p); 919 buffer_skip_string(&b); /* pkalg */ 920 buffer_skip_string(&b); /* pkblob */ 921 922 /* verify client host, strip trailing dot if necessary */ 923 p = buffer_get_string(&b, NULL); 924 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 925 p[len - 1] = '\0'; 926 if (strcmp(p, chost) != 0) 927 fail++; 928 xfree(p); 929 930 /* verify client user */ 931 p = buffer_get_string(&b, NULL); 932 if (strcmp(p, cuser) != 0) 933 fail++; 934 xfree(p); 935 936 if (buffer_len(&b) != 0) 937 fail++; 938 buffer_free(&b); 939 return (fail == 0); 940 } 941 942 int 943 mm_answer_keyverify(int sock, Buffer *m) 944 { 945 Key *key; 946 u_char *signature, *data, *blob; 947 u_int signaturelen, datalen, bloblen; 948 int verified = 0; 949 int valid_data = 0; 950 951 blob = buffer_get_string(m, &bloblen); 952 signature = buffer_get_string(m, &signaturelen); 953 data = buffer_get_string(m, &datalen); 954 955 if (hostbased_cuser == NULL || hostbased_chost == NULL || 956 !monitor_allowed_key(blob, bloblen)) 957 fatal("%s: bad key, not previously allowed", __func__); 958 959 key = key_from_blob(blob, bloblen); 960 if (key == NULL) 961 fatal("%s: bad public key blob", __func__); 962 963 switch (key_blobtype) { 964 case MM_USERKEY: 965 valid_data = monitor_valid_userblob(data, datalen); 966 break; 967 case MM_HOSTKEY: 968 valid_data = monitor_valid_hostbasedblob(data, datalen, 969 hostbased_cuser, hostbased_chost); 970 break; 971 default: 972 valid_data = 0; 973 break; 974 } 975 if (!valid_data) 976 fatal("%s: bad signature data blob", __func__); 977 978 verified = key_verify(key, signature, signaturelen, data, datalen); 979 debug3("%s: key %p signature %s", 980 __func__, key, (verified == 1) ? "verified" : "unverified"); 981 982 key_free(key); 983 xfree(blob); 984 xfree(signature); 985 xfree(data); 986 987 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 988 989 monitor_reset_key_state(); 990 991 buffer_clear(m); 992 buffer_put_int(m, verified); 993 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 994 995 return (verified == 1); 996 } 997 998 static void 999 mm_record_login(Session *s, struct passwd *pw) 1000 { 1001 socklen_t fromlen; 1002 struct sockaddr_storage from; 1003 1004 /* 1005 * Get IP address of client. If the connection is not a socket, let 1006 * the address be 0.0.0.0. 1007 */ 1008 memset(&from, 0, sizeof(from)); 1009 fromlen = sizeof(from); 1010 if (packet_connection_is_on_socket()) { 1011 if (getpeername(packet_get_connection_in(), 1012 (struct sockaddr *)&from, &fromlen) < 0) { 1013 debug("getpeername: %.100s", strerror(errno)); 1014 cleanup_exit(255); 1015 } 1016 } 1017 /* Record that there was a login on that tty from the remote host. */ 1018 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1019 get_remote_name_or_ip(utmp_len, options.use_dns), 1020 (struct sockaddr *)&from, fromlen); 1021 } 1022 1023 static void 1024 mm_session_close(Session *s) 1025 { 1026 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1027 if (s->ttyfd != -1) { 1028 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1029 session_pty_cleanup2(s); 1030 } 1031 session_unused(s->self); 1032 } 1033 1034 int 1035 mm_answer_pty(int sock, Buffer *m) 1036 { 1037 extern struct monitor *pmonitor; 1038 Session *s; 1039 int res, fd0; 1040 1041 debug3("%s entering", __func__); 1042 1043 buffer_clear(m); 1044 s = session_new(); 1045 if (s == NULL) 1046 goto error; 1047 s->authctxt = authctxt; 1048 s->pw = authctxt->pw; 1049 s->pid = pmonitor->m_pid; 1050 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1051 if (res == 0) 1052 goto error; 1053 pty_setowner(authctxt->pw, s->tty); 1054 1055 buffer_put_int(m, 1); 1056 buffer_put_cstring(m, s->tty); 1057 1058 /* We need to trick ttyslot */ 1059 if (dup2(s->ttyfd, 0) == -1) 1060 fatal("%s: dup2", __func__); 1061 1062 mm_record_login(s, authctxt->pw); 1063 1064 /* Now we can close the file descriptor again */ 1065 close(0); 1066 1067 /* send messages generated by record_login */ 1068 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1069 buffer_clear(&loginmsg); 1070 1071 mm_request_send(sock, MONITOR_ANS_PTY, m); 1072 1073 if (mm_send_fd(sock, s->ptyfd) == -1 || 1074 mm_send_fd(sock, s->ttyfd) == -1) 1075 fatal("%s: send fds failed", __func__); 1076 1077 /* make sure nothing uses fd 0 */ 1078 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1079 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1080 if (fd0 != 0) 1081 error("%s: fd0 %d != 0", __func__, fd0); 1082 1083 /* slave is not needed */ 1084 close(s->ttyfd); 1085 s->ttyfd = s->ptyfd; 1086 /* no need to dup() because nobody closes ptyfd */ 1087 s->ptymaster = s->ptyfd; 1088 1089 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1090 1091 return (0); 1092 1093 error: 1094 if (s != NULL) 1095 mm_session_close(s); 1096 buffer_put_int(m, 0); 1097 mm_request_send(sock, MONITOR_ANS_PTY, m); 1098 return (0); 1099 } 1100 1101 int 1102 mm_answer_pty_cleanup(int sock, Buffer *m) 1103 { 1104 Session *s; 1105 char *tty; 1106 1107 debug3("%s entering", __func__); 1108 1109 tty = buffer_get_string(m, NULL); 1110 if ((s = session_by_tty(tty)) != NULL) 1111 mm_session_close(s); 1112 buffer_clear(m); 1113 xfree(tty); 1114 return (0); 1115 } 1116 1117 int 1118 mm_answer_sesskey(int sock, Buffer *m) 1119 { 1120 BIGNUM *p; 1121 int rsafail; 1122 1123 /* Turn off permissions */ 1124 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1125 1126 if ((p = BN_new()) == NULL) 1127 fatal("%s: BN_new", __func__); 1128 1129 buffer_get_bignum2(m, p); 1130 1131 rsafail = ssh1_session_key(p); 1132 1133 buffer_clear(m); 1134 buffer_put_int(m, rsafail); 1135 buffer_put_bignum2(m, p); 1136 1137 BN_clear_free(p); 1138 1139 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1140 1141 /* Turn on permissions for sessid passing */ 1142 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1143 1144 return (0); 1145 } 1146 1147 int 1148 mm_answer_sessid(int sock, Buffer *m) 1149 { 1150 int i; 1151 1152 debug3("%s entering", __func__); 1153 1154 if (buffer_len(m) != 16) 1155 fatal("%s: bad ssh1 session id", __func__); 1156 for (i = 0; i < 16; i++) 1157 session_id[i] = buffer_get_char(m); 1158 1159 /* Turn on permissions for getpwnam */ 1160 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1161 1162 return (0); 1163 } 1164 1165 int 1166 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1167 { 1168 BIGNUM *client_n; 1169 Key *key = NULL; 1170 u_char *blob = NULL; 1171 u_int blen = 0; 1172 int allowed = 0; 1173 1174 debug3("%s entering", __func__); 1175 1176 auth_method = "rsa"; 1177 if (options.rsa_authentication && authctxt->valid) { 1178 if ((client_n = BN_new()) == NULL) 1179 fatal("%s: BN_new", __func__); 1180 buffer_get_bignum2(m, client_n); 1181 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1182 BN_clear_free(client_n); 1183 } 1184 buffer_clear(m); 1185 buffer_put_int(m, allowed); 1186 buffer_put_int(m, forced_command != NULL); 1187 1188 /* clear temporarily storage (used by generate challenge) */ 1189 monitor_reset_key_state(); 1190 1191 if (allowed && key != NULL) { 1192 key->type = KEY_RSA; /* cheat for key_to_blob */ 1193 if (key_to_blob(key, &blob, &blen) == 0) 1194 fatal("%s: key_to_blob failed", __func__); 1195 buffer_put_string(m, blob, blen); 1196 1197 /* Save temporarily for comparison in verify */ 1198 key_blob = blob; 1199 key_bloblen = blen; 1200 key_blobtype = MM_RSAUSERKEY; 1201 } 1202 if (key != NULL) 1203 key_free(key); 1204 1205 mm_append_debug(m); 1206 1207 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1208 1209 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1210 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1211 return (0); 1212 } 1213 1214 int 1215 mm_answer_rsa_challenge(int sock, Buffer *m) 1216 { 1217 Key *key = NULL; 1218 u_char *blob; 1219 u_int blen; 1220 1221 debug3("%s entering", __func__); 1222 1223 if (!authctxt->valid) 1224 fatal("%s: authctxt not valid", __func__); 1225 blob = buffer_get_string(m, &blen); 1226 if (!monitor_allowed_key(blob, blen)) 1227 fatal("%s: bad key, not previously allowed", __func__); 1228 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1229 fatal("%s: key type mismatch", __func__); 1230 if ((key = key_from_blob(blob, blen)) == NULL) 1231 fatal("%s: received bad key", __func__); 1232 if (key->type != KEY_RSA) 1233 fatal("%s: received bad key type %d", __func__, key->type); 1234 key->type = KEY_RSA1; 1235 if (ssh1_challenge) 1236 BN_clear_free(ssh1_challenge); 1237 ssh1_challenge = auth_rsa_generate_challenge(key); 1238 1239 buffer_clear(m); 1240 buffer_put_bignum2(m, ssh1_challenge); 1241 1242 debug3("%s sending reply", __func__); 1243 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1244 1245 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1246 1247 xfree(blob); 1248 key_free(key); 1249 return (0); 1250 } 1251 1252 int 1253 mm_answer_rsa_response(int sock, Buffer *m) 1254 { 1255 Key *key = NULL; 1256 u_char *blob, *response; 1257 u_int blen, len; 1258 int success; 1259 1260 debug3("%s entering", __func__); 1261 1262 if (!authctxt->valid) 1263 fatal("%s: authctxt not valid", __func__); 1264 if (ssh1_challenge == NULL) 1265 fatal("%s: no ssh1_challenge", __func__); 1266 1267 blob = buffer_get_string(m, &blen); 1268 if (!monitor_allowed_key(blob, blen)) 1269 fatal("%s: bad key, not previously allowed", __func__); 1270 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1271 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1272 if ((key = key_from_blob(blob, blen)) == NULL) 1273 fatal("%s: received bad key", __func__); 1274 response = buffer_get_string(m, &len); 1275 if (len != 16) 1276 fatal("%s: received bad response to challenge", __func__); 1277 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1278 1279 xfree(blob); 1280 key_free(key); 1281 xfree(response); 1282 1283 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1284 1285 /* reset state */ 1286 BN_clear_free(ssh1_challenge); 1287 ssh1_challenge = NULL; 1288 monitor_reset_key_state(); 1289 1290 buffer_clear(m); 1291 buffer_put_int(m, success); 1292 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1293 1294 return (success); 1295 } 1296 1297 int 1298 mm_answer_term(int sock, Buffer *req) 1299 { 1300 extern struct monitor *pmonitor; 1301 int res, status; 1302 1303 debug3("%s: tearing down sessions", __func__); 1304 1305 /* The child is terminating */ 1306 session_destroy_all(&mm_session_close); 1307 1308 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1309 if (errno != EINTR) 1310 exit(1); 1311 1312 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1313 1314 /* Terminate process */ 1315 exit(res); 1316 } 1317 1318 void 1319 monitor_apply_keystate(struct monitor *pmonitor) 1320 { 1321 if (compat20) { 1322 set_newkeys(MODE_IN); 1323 set_newkeys(MODE_OUT); 1324 } else { 1325 packet_set_protocol_flags(child_state.ssh1protoflags); 1326 packet_set_encryption_key(child_state.ssh1key, 1327 child_state.ssh1keylen, child_state.ssh1cipher); 1328 xfree(child_state.ssh1key); 1329 } 1330 1331 /* for rc4 and other stateful ciphers */ 1332 packet_set_keycontext(MODE_OUT, child_state.keyout); 1333 xfree(child_state.keyout); 1334 packet_set_keycontext(MODE_IN, child_state.keyin); 1335 xfree(child_state.keyin); 1336 1337 if (!compat20) { 1338 packet_set_iv(MODE_OUT, child_state.ivout); 1339 xfree(child_state.ivout); 1340 packet_set_iv(MODE_IN, child_state.ivin); 1341 xfree(child_state.ivin); 1342 } 1343 1344 memcpy(&incoming_stream, &child_state.incoming, 1345 sizeof(incoming_stream)); 1346 memcpy(&outgoing_stream, &child_state.outgoing, 1347 sizeof(outgoing_stream)); 1348 1349 /* Update with new address */ 1350 if (options.compression) 1351 mm_init_compression(pmonitor->m_zlib); 1352 1353 /* Network I/O buffers */ 1354 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1355 buffer_clear(packet_get_input()); 1356 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1357 memset(child_state.input, 0, child_state.ilen); 1358 xfree(child_state.input); 1359 1360 buffer_clear(packet_get_output()); 1361 buffer_append(packet_get_output(), child_state.output, 1362 child_state.olen); 1363 memset(child_state.output, 0, child_state.olen); 1364 xfree(child_state.output); 1365 1366 /* Roaming */ 1367 if (compat20) 1368 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1369 } 1370 1371 static Kex * 1372 mm_get_kex(Buffer *m) 1373 { 1374 Kex *kex; 1375 void *blob; 1376 u_int bloblen; 1377 1378 kex = xcalloc(1, sizeof(*kex)); 1379 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1380 if ((session_id2 == NULL) || 1381 (kex->session_id_len != session_id2_len) || 1382 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1383 fatal("mm_get_get: internal error: bad session id"); 1384 kex->we_need = buffer_get_int(m); 1385 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1386 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1387 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1388 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1389 kex->server = 1; 1390 kex->hostkey_type = buffer_get_int(m); 1391 kex->kex_type = buffer_get_int(m); 1392 blob = buffer_get_string(m, &bloblen); 1393 buffer_init(&kex->my); 1394 buffer_append(&kex->my, blob, bloblen); 1395 xfree(blob); 1396 blob = buffer_get_string(m, &bloblen); 1397 buffer_init(&kex->peer); 1398 buffer_append(&kex->peer, blob, bloblen); 1399 xfree(blob); 1400 kex->done = 1; 1401 kex->flags = buffer_get_int(m); 1402 kex->client_version_string = buffer_get_string(m, NULL); 1403 kex->server_version_string = buffer_get_string(m, NULL); 1404 kex->load_host_key=&get_hostkey_by_type; 1405 kex->host_key_index=&get_hostkey_index; 1406 1407 return (kex); 1408 } 1409 1410 /* This function requries careful sanity checking */ 1411 1412 void 1413 mm_get_keystate(struct monitor *pmonitor) 1414 { 1415 Buffer m; 1416 u_char *blob, *p; 1417 u_int bloblen, plen; 1418 u_int32_t seqnr, packets; 1419 u_int64_t blocks, bytes; 1420 1421 debug3("%s: Waiting for new keys", __func__); 1422 1423 buffer_init(&m); 1424 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1425 if (!compat20) { 1426 child_state.ssh1protoflags = buffer_get_int(&m); 1427 child_state.ssh1cipher = buffer_get_int(&m); 1428 child_state.ssh1key = buffer_get_string(&m, 1429 &child_state.ssh1keylen); 1430 child_state.ivout = buffer_get_string(&m, 1431 &child_state.ivoutlen); 1432 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1433 goto skip; 1434 } else { 1435 /* Get the Kex for rekeying */ 1436 *pmonitor->m_pkex = mm_get_kex(&m); 1437 } 1438 1439 blob = buffer_get_string(&m, &bloblen); 1440 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1441 xfree(blob); 1442 1443 debug3("%s: Waiting for second key", __func__); 1444 blob = buffer_get_string(&m, &bloblen); 1445 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1446 xfree(blob); 1447 1448 /* Now get sequence numbers for the packets */ 1449 seqnr = buffer_get_int(&m); 1450 blocks = buffer_get_int64(&m); 1451 packets = buffer_get_int(&m); 1452 bytes = buffer_get_int64(&m); 1453 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1454 seqnr = buffer_get_int(&m); 1455 blocks = buffer_get_int64(&m); 1456 packets = buffer_get_int(&m); 1457 bytes = buffer_get_int64(&m); 1458 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1459 1460 skip: 1461 /* Get the key context */ 1462 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1463 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1464 1465 debug3("%s: Getting compression state", __func__); 1466 /* Get compression state */ 1467 p = buffer_get_string(&m, &plen); 1468 if (plen != sizeof(child_state.outgoing)) 1469 fatal("%s: bad request size", __func__); 1470 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1471 xfree(p); 1472 1473 p = buffer_get_string(&m, &plen); 1474 if (plen != sizeof(child_state.incoming)) 1475 fatal("%s: bad request size", __func__); 1476 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1477 xfree(p); 1478 1479 /* Network I/O buffers */ 1480 debug3("%s: Getting Network I/O buffers", __func__); 1481 child_state.input = buffer_get_string(&m, &child_state.ilen); 1482 child_state.output = buffer_get_string(&m, &child_state.olen); 1483 1484 /* Roaming */ 1485 if (compat20) { 1486 child_state.sent_bytes = buffer_get_int64(&m); 1487 child_state.recv_bytes = buffer_get_int64(&m); 1488 } 1489 1490 buffer_free(&m); 1491 } 1492 1493 1494 /* Allocation functions for zlib */ 1495 void * 1496 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1497 { 1498 size_t len = (size_t) size * ncount; 1499 void *address; 1500 1501 if (len == 0 || ncount > SIZE_T_MAX / size) 1502 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1503 1504 address = mm_malloc(mm, len); 1505 1506 return (address); 1507 } 1508 1509 void 1510 mm_zfree(struct mm_master *mm, void *address) 1511 { 1512 mm_free(mm, address); 1513 } 1514 1515 void 1516 mm_init_compression(struct mm_master *mm) 1517 { 1518 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1519 outgoing_stream.zfree = (free_func)mm_zfree; 1520 outgoing_stream.opaque = mm; 1521 1522 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1523 incoming_stream.zfree = (free_func)mm_zfree; 1524 incoming_stream.opaque = mm; 1525 } 1526 1527 /* XXX */ 1528 1529 #define FD_CLOSEONEXEC(x) do { \ 1530 if (fcntl(x, F_SETFD, 1) == -1) \ 1531 fatal("fcntl(%d, F_SETFD)", x); \ 1532 } while (0) 1533 1534 static void 1535 monitor_socketpair(int *pair) 1536 { 1537 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1538 fatal("%s: socketpair", __func__); 1539 FD_CLOSEONEXEC(pair[0]); 1540 FD_CLOSEONEXEC(pair[1]); 1541 } 1542 1543 #define MM_MEMSIZE 65536 1544 1545 struct monitor * 1546 monitor_init(void) 1547 { 1548 struct monitor *mon; 1549 int pair[2]; 1550 1551 mon = xcalloc(1, sizeof(*mon)); 1552 1553 monitor_socketpair(pair); 1554 1555 mon->m_recvfd = pair[0]; 1556 mon->m_sendfd = pair[1]; 1557 1558 /* Used to share zlib space across processes */ 1559 if (options.compression) { 1560 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1561 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1562 1563 /* Compression needs to share state across borders */ 1564 mm_init_compression(mon->m_zlib); 1565 } 1566 1567 return mon; 1568 } 1569 1570 void 1571 monitor_reinit(struct monitor *mon) 1572 { 1573 int pair[2]; 1574 1575 monitor_socketpair(pair); 1576 1577 mon->m_recvfd = pair[0]; 1578 mon->m_sendfd = pair[1]; 1579 } 1580 1581 #ifdef GSSAPI 1582 int 1583 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1584 { 1585 gss_OID_desc goid; 1586 OM_uint32 major; 1587 u_int len; 1588 1589 goid.elements = buffer_get_string(m, &len); 1590 goid.length = len; 1591 1592 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1593 1594 xfree(goid.elements); 1595 1596 buffer_clear(m); 1597 buffer_put_int(m, major); 1598 1599 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1600 1601 /* Now we have a context, enable the step */ 1602 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1603 1604 return (0); 1605 } 1606 1607 int 1608 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1609 { 1610 gss_buffer_desc in; 1611 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1612 OM_uint32 major, minor; 1613 OM_uint32 flags = 0; /* GSI needs this */ 1614 u_int len; 1615 1616 in.value = buffer_get_string(m, &len); 1617 in.length = len; 1618 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1619 xfree(in.value); 1620 1621 buffer_clear(m); 1622 buffer_put_int(m, major); 1623 buffer_put_string(m, out.value, out.length); 1624 buffer_put_int(m, flags); 1625 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1626 1627 gss_release_buffer(&minor, &out); 1628 1629 if (major == GSS_S_COMPLETE) { 1630 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1631 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1632 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1633 } 1634 return (0); 1635 } 1636 1637 int 1638 mm_answer_gss_checkmic(int sock, Buffer *m) 1639 { 1640 gss_buffer_desc gssbuf, mic; 1641 OM_uint32 ret; 1642 u_int len; 1643 1644 gssbuf.value = buffer_get_string(m, &len); 1645 gssbuf.length = len; 1646 mic.value = buffer_get_string(m, &len); 1647 mic.length = len; 1648 1649 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1650 1651 xfree(gssbuf.value); 1652 xfree(mic.value); 1653 1654 buffer_clear(m); 1655 buffer_put_int(m, ret); 1656 1657 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1658 1659 if (!GSS_ERROR(ret)) 1660 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1661 1662 return (0); 1663 } 1664 1665 int 1666 mm_answer_gss_userok(int sock, Buffer *m) 1667 { 1668 int authenticated; 1669 1670 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1671 1672 buffer_clear(m); 1673 buffer_put_int(m, authenticated); 1674 1675 debug3("%s: sending result %d", __func__, authenticated); 1676 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1677 1678 auth_method = "gssapi-with-mic"; 1679 1680 /* Monitor loop will terminate if authenticated */ 1681 return (authenticated); 1682 } 1683 #endif /* GSSAPI */ 1684 1685 #ifdef JPAKE 1686 int 1687 mm_answer_jpake_step1(int sock, Buffer *m) 1688 { 1689 struct jpake_ctx *pctx; 1690 u_char *x3_proof, *x4_proof; 1691 u_int x3_proof_len, x4_proof_len; 1692 1693 if (!options.zero_knowledge_password_authentication) 1694 fatal("zero_knowledge_password_authentication disabled"); 1695 1696 if (authctxt->jpake_ctx != NULL) 1697 fatal("%s: authctxt->jpake_ctx already set (%p)", 1698 __func__, authctxt->jpake_ctx); 1699 authctxt->jpake_ctx = pctx = jpake_new(); 1700 1701 jpake_step1(pctx->grp, 1702 &pctx->server_id, &pctx->server_id_len, 1703 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 1704 &x3_proof, &x3_proof_len, 1705 &x4_proof, &x4_proof_len); 1706 1707 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 1708 1709 buffer_clear(m); 1710 1711 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 1712 buffer_put_bignum2(m, pctx->g_x3); 1713 buffer_put_bignum2(m, pctx->g_x4); 1714 buffer_put_string(m, x3_proof, x3_proof_len); 1715 buffer_put_string(m, x4_proof, x4_proof_len); 1716 1717 debug3("%s: sending step1", __func__); 1718 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 1719 1720 bzero(x3_proof, x3_proof_len); 1721 bzero(x4_proof, x4_proof_len); 1722 xfree(x3_proof); 1723 xfree(x4_proof); 1724 1725 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 1726 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 1727 1728 return 0; 1729 } 1730 1731 int 1732 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 1733 { 1734 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1735 char *hash_scheme, *salt; 1736 1737 if (pctx == NULL) 1738 fatal("%s: pctx == NULL", __func__); 1739 1740 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 1741 1742 buffer_clear(m); 1743 /* pctx->s is sensitive, not returned to slave */ 1744 buffer_put_cstring(m, hash_scheme); 1745 buffer_put_cstring(m, salt); 1746 1747 debug3("%s: sending pwdata", __func__); 1748 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 1749 1750 bzero(hash_scheme, strlen(hash_scheme)); 1751 bzero(salt, strlen(salt)); 1752 xfree(hash_scheme); 1753 xfree(salt); 1754 1755 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 1756 1757 return 0; 1758 } 1759 1760 int 1761 mm_answer_jpake_step2(int sock, Buffer *m) 1762 { 1763 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1764 u_char *x1_proof, *x2_proof, *x4_s_proof; 1765 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 1766 1767 if (pctx == NULL) 1768 fatal("%s: pctx == NULL", __func__); 1769 1770 if ((pctx->g_x1 = BN_new()) == NULL || 1771 (pctx->g_x2 = BN_new()) == NULL) 1772 fatal("%s: BN_new", __func__); 1773 buffer_get_bignum2(m, pctx->g_x1); 1774 buffer_get_bignum2(m, pctx->g_x2); 1775 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 1776 x1_proof = buffer_get_string(m, &x1_proof_len); 1777 x2_proof = buffer_get_string(m, &x2_proof_len); 1778 1779 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 1780 pctx->g_x1, pctx->g_x2, pctx->x4, 1781 pctx->client_id, pctx->client_id_len, 1782 pctx->server_id, pctx->server_id_len, 1783 x1_proof, x1_proof_len, 1784 x2_proof, x2_proof_len, 1785 &pctx->b, 1786 &x4_s_proof, &x4_s_proof_len); 1787 1788 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 1789 1790 bzero(x1_proof, x1_proof_len); 1791 bzero(x2_proof, x2_proof_len); 1792 xfree(x1_proof); 1793 xfree(x2_proof); 1794 1795 buffer_clear(m); 1796 1797 buffer_put_bignum2(m, pctx->b); 1798 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 1799 1800 debug3("%s: sending step2", __func__); 1801 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 1802 1803 bzero(x4_s_proof, x4_s_proof_len); 1804 xfree(x4_s_proof); 1805 1806 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 1807 1808 return 0; 1809 } 1810 1811 int 1812 mm_answer_jpake_key_confirm(int sock, Buffer *m) 1813 { 1814 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1815 u_char *x2_s_proof; 1816 u_int x2_s_proof_len; 1817 1818 if (pctx == NULL) 1819 fatal("%s: pctx == NULL", __func__); 1820 1821 if ((pctx->a = BN_new()) == NULL) 1822 fatal("%s: BN_new", __func__); 1823 buffer_get_bignum2(m, pctx->a); 1824 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 1825 1826 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 1827 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 1828 pctx->server_id, pctx->server_id_len, 1829 pctx->client_id, pctx->client_id_len, 1830 session_id2, session_id2_len, 1831 x2_s_proof, x2_s_proof_len, 1832 &pctx->k, 1833 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 1834 1835 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 1836 1837 bzero(x2_s_proof, x2_s_proof_len); 1838 buffer_clear(m); 1839 1840 /* pctx->k is sensitive, not sent */ 1841 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 1842 1843 debug3("%s: sending confirmation hash", __func__); 1844 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 1845 1846 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 1847 1848 return 0; 1849 } 1850 1851 int 1852 mm_answer_jpake_check_confirm(int sock, Buffer *m) 1853 { 1854 int authenticated = 0; 1855 u_char *peer_confirm_hash; 1856 u_int peer_confirm_hash_len; 1857 struct jpake_ctx *pctx = authctxt->jpake_ctx; 1858 1859 if (pctx == NULL) 1860 fatal("%s: pctx == NULL", __func__); 1861 1862 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 1863 1864 authenticated = jpake_check_confirm(pctx->k, 1865 pctx->client_id, pctx->client_id_len, 1866 session_id2, session_id2_len, 1867 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 1868 1869 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 1870 1871 bzero(peer_confirm_hash, peer_confirm_hash_len); 1872 xfree(peer_confirm_hash); 1873 1874 buffer_clear(m); 1875 buffer_put_int(m, authenticated); 1876 1877 debug3("%s: sending result %d", __func__, authenticated); 1878 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 1879 1880 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 1881 1882 auth_method = "jpake-01@openssh.com"; 1883 return authenticated; 1884 } 1885 1886 #endif /* JPAKE */ 1887