1 /* 2 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 3 * Copyright 2002 Markus Friedl <markus@openbsd.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "includes.h" 28 RCSID("$OpenBSD: monitor.c,v 1.29 2002/09/26 11:38:43 markus Exp $"); 29 RCSID("$FreeBSD: src/crypto/openssh/monitor.c,v 1.7.2.3 2003/02/03 17:31:07 des Exp $"); 30 RCSID("$DragonFly: src/crypto/openssh/Attic/monitor.c,v 1.2 2003/06/17 04:24:36 dillon Exp $"); 31 32 #include <openssl/dh.h> 33 34 #ifdef SKEY 35 #ifdef OPIE 36 #include <opie.h> 37 #define skey opie 38 #define skeychallenge(k, u, c) opiechallenge((k), (u), (c)) 39 #define skey_haskey(u) opie_haskey((u)) 40 #define skey_passcheck(u, r) opie_passverify((u), (r)) 41 #else 42 #include <skey.h> 43 #endif 44 #endif 45 46 #include "ssh.h" 47 #include "auth.h" 48 #include "kex.h" 49 #include "dh.h" 50 #include "zlib.h" 51 #include "packet.h" 52 #include "auth-options.h" 53 #include "sshpty.h" 54 #include "channels.h" 55 #include "session.h" 56 #include "sshlogin.h" 57 #include "canohost.h" 58 #include "log.h" 59 #include "servconf.h" 60 #include "monitor.h" 61 #include "monitor_mm.h" 62 #include "monitor_wrap.h" 63 #include "monitor_fdpass.h" 64 #include "xmalloc.h" 65 #include "misc.h" 66 #include "buffer.h" 67 #include "bufaux.h" 68 #include "compat.h" 69 #include "ssh2.h" 70 #include "mpaux.h" 71 72 /* Imports */ 73 extern ServerOptions options; 74 extern u_int utmp_len; 75 extern Newkeys *current_keys[]; 76 extern z_stream incoming_stream; 77 extern z_stream outgoing_stream; 78 extern u_char session_id[]; 79 extern Buffer input, output; 80 extern Buffer auth_debug; 81 extern int auth_debug_init; 82 83 /* State exported from the child */ 84 85 struct { 86 z_stream incoming; 87 z_stream outgoing; 88 u_char *keyin; 89 u_int keyinlen; 90 u_char *keyout; 91 u_int keyoutlen; 92 u_char *ivin; 93 u_int ivinlen; 94 u_char *ivout; 95 u_int ivoutlen; 96 u_char *ssh1key; 97 u_int ssh1keylen; 98 int ssh1cipher; 99 int ssh1protoflags; 100 u_char *input; 101 u_int ilen; 102 u_char *output; 103 u_int olen; 104 } child_state; 105 106 /* Functions on the montior that answer unprivileged requests */ 107 108 int mm_answer_moduli(int, Buffer *); 109 int mm_answer_sign(int, Buffer *); 110 int mm_answer_pwnamallow(int, Buffer *); 111 int mm_answer_auth2_read_banner(int, Buffer *); 112 int mm_answer_authserv(int, Buffer *); 113 int mm_answer_authpassword(int, Buffer *); 114 int mm_answer_bsdauthquery(int, Buffer *); 115 int mm_answer_bsdauthrespond(int, Buffer *); 116 int mm_answer_skeyquery(int, Buffer *); 117 int mm_answer_skeyrespond(int, Buffer *); 118 int mm_answer_keyallowed(int, Buffer *); 119 int mm_answer_keyverify(int, Buffer *); 120 int mm_answer_pty(int, Buffer *); 121 int mm_answer_pty_cleanup(int, Buffer *); 122 int mm_answer_term(int, Buffer *); 123 int mm_answer_rsa_keyallowed(int, Buffer *); 124 int mm_answer_rsa_challenge(int, Buffer *); 125 int mm_answer_rsa_response(int, Buffer *); 126 int mm_answer_sesskey(int, Buffer *); 127 int mm_answer_sessid(int, Buffer *); 128 129 #ifdef USE_PAM 130 int mm_answer_pam_start(int, Buffer *); 131 int mm_answer_pam_init_ctx(int, Buffer *); 132 int mm_answer_pam_query(int, Buffer *); 133 int mm_answer_pam_respond(int, Buffer *); 134 int mm_answer_pam_free_ctx(int, Buffer *); 135 #endif 136 137 #ifdef KRB4 138 int mm_answer_krb4(int, Buffer *); 139 #endif 140 #ifdef KRB5 141 int mm_answer_krb5(int, Buffer *); 142 #endif 143 144 static Authctxt *authctxt; 145 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 146 147 /* local state for key verify */ 148 static u_char *key_blob = NULL; 149 static u_int key_bloblen = 0; 150 static int key_blobtype = MM_NOKEY; 151 static char *hostbased_cuser = NULL; 152 static char *hostbased_chost = NULL; 153 static char *auth_method = "unknown"; 154 static int session_id2_len = 0; 155 static u_char *session_id2 = NULL; 156 157 struct mon_table { 158 enum monitor_reqtype type; 159 int flags; 160 int (*f)(int, Buffer *); 161 }; 162 163 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 164 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 165 #define MON_ONCE 0x0010 /* Disable after calling */ 166 167 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 168 169 #define MON_PERMIT 0x1000 /* Request is permitted */ 170 171 struct mon_table mon_dispatch_proto20[] = { 172 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 173 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 174 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 175 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 176 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 177 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 178 #ifdef USE_PAM 179 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 180 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 181 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 182 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 183 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 184 #endif 185 #ifdef BSD_AUTH 186 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 187 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 188 #endif 189 #ifdef SKEY 190 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 191 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 192 #endif 193 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 194 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 195 {0, 0, NULL} 196 }; 197 198 struct mon_table mon_dispatch_postauth20[] = { 199 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 200 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 201 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 202 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 203 {MONITOR_REQ_TERM, 0, mm_answer_term}, 204 {0, 0, NULL} 205 }; 206 207 struct mon_table mon_dispatch_proto15[] = { 208 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 209 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 210 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 211 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 212 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed}, 213 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 214 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 215 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 216 #ifdef BSD_AUTH 217 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 218 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 219 #endif 220 #ifdef SKEY 221 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 222 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 223 #endif 224 #ifdef USE_PAM 225 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 226 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 227 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 228 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 229 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 230 #endif 231 #ifdef KRB4 232 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4}, 233 #endif 234 #ifdef KRB5 235 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 236 #endif 237 {0, 0, NULL} 238 }; 239 240 struct mon_table mon_dispatch_postauth15[] = { 241 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 242 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 243 {MONITOR_REQ_TERM, 0, mm_answer_term}, 244 {0, 0, NULL} 245 }; 246 247 struct mon_table *mon_dispatch; 248 249 /* Specifies if a certain message is allowed at the moment */ 250 251 static void 252 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 253 { 254 while (ent->f != NULL) { 255 if (ent->type == type) { 256 ent->flags &= ~MON_PERMIT; 257 ent->flags |= permit ? MON_PERMIT : 0; 258 return; 259 } 260 ent++; 261 } 262 } 263 264 static void 265 monitor_permit_authentications(int permit) 266 { 267 struct mon_table *ent = mon_dispatch; 268 269 while (ent->f != NULL) { 270 if (ent->flags & MON_AUTH) { 271 ent->flags &= ~MON_PERMIT; 272 ent->flags |= permit ? MON_PERMIT : 0; 273 } 274 ent++; 275 } 276 } 277 278 Authctxt * 279 monitor_child_preauth(struct monitor *pmonitor) 280 { 281 struct mon_table *ent; 282 int authenticated = 0; 283 284 debug3("preauth child monitor started"); 285 286 if (compat20) { 287 mon_dispatch = mon_dispatch_proto20; 288 289 /* Permit requests for moduli and signatures */ 290 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 291 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 292 } else { 293 mon_dispatch = mon_dispatch_proto15; 294 295 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 296 } 297 298 authctxt = authctxt_new(); 299 300 /* The first few requests do not require asynchronous access */ 301 while (!authenticated) { 302 authenticated = monitor_read(pmonitor, mon_dispatch, &ent); 303 if (authenticated) { 304 if (!(ent->flags & MON_AUTHDECIDE)) 305 fatal("%s: unexpected authentication from %d", 306 __func__, ent->type); 307 if (authctxt->pw->pw_uid == 0 && 308 !auth_root_allowed(auth_method)) 309 authenticated = 0; 310 } 311 312 if (ent->flags & MON_AUTHDECIDE) { 313 auth_log(authctxt, authenticated, auth_method, 314 compat20 ? " ssh2" : ""); 315 if (!authenticated) 316 authctxt->failures++; 317 } 318 } 319 320 if (!authctxt->valid) 321 fatal("%s: authenticated invalid user", __func__); 322 323 debug("%s: %s has been authenticated by privileged process", 324 __func__, authctxt->user); 325 326 mm_get_keystate(pmonitor); 327 328 return (authctxt); 329 } 330 331 void 332 monitor_child_postauth(struct monitor *pmonitor) 333 { 334 if (compat20) { 335 mon_dispatch = mon_dispatch_postauth20; 336 337 /* Permit requests for moduli and signatures */ 338 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 339 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 340 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 341 342 } else { 343 mon_dispatch = mon_dispatch_postauth15; 344 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 345 } 346 if (!no_pty_flag) { 347 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 348 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 349 } 350 351 for (;;) 352 monitor_read(pmonitor, mon_dispatch, NULL); 353 } 354 355 void 356 monitor_sync(struct monitor *pmonitor) 357 { 358 if (options.compression) { 359 /* The member allocation is not visible, so sync it */ 360 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 361 } 362 } 363 364 int 365 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 366 struct mon_table **pent) 367 { 368 Buffer m; 369 int ret; 370 u_char type; 371 372 buffer_init(&m); 373 374 mm_request_receive(pmonitor->m_sendfd, &m); 375 type = buffer_get_char(&m); 376 377 debug3("%s: checking request %d", __func__, type); 378 379 while (ent->f != NULL) { 380 if (ent->type == type) 381 break; 382 ent++; 383 } 384 385 if (ent->f != NULL) { 386 if (!(ent->flags & MON_PERMIT)) 387 fatal("%s: unpermitted request %d", __func__, 388 type); 389 ret = (*ent->f)(pmonitor->m_sendfd, &m); 390 buffer_free(&m); 391 392 /* The child may use this request only once, disable it */ 393 if (ent->flags & MON_ONCE) { 394 debug2("%s: %d used once, disabling now", __func__, 395 type); 396 ent->flags &= ~MON_PERMIT; 397 } 398 399 if (pent != NULL) 400 *pent = ent; 401 402 return ret; 403 } 404 405 fatal("%s: unsupported request: %d", __func__, type); 406 407 /* NOTREACHED */ 408 return (-1); 409 } 410 411 /* allowed key state */ 412 static int 413 monitor_allowed_key(u_char *blob, u_int bloblen) 414 { 415 /* make sure key is allowed */ 416 if (key_blob == NULL || key_bloblen != bloblen || 417 memcmp(key_blob, blob, key_bloblen)) 418 return (0); 419 return (1); 420 } 421 422 static void 423 monitor_reset_key_state(void) 424 { 425 /* reset state */ 426 if (key_blob != NULL) 427 xfree(key_blob); 428 if (hostbased_cuser != NULL) 429 xfree(hostbased_cuser); 430 if (hostbased_chost != NULL) 431 xfree(hostbased_chost); 432 key_blob = NULL; 433 key_bloblen = 0; 434 key_blobtype = MM_NOKEY; 435 hostbased_cuser = NULL; 436 hostbased_chost = NULL; 437 } 438 439 int 440 mm_answer_moduli(int socket, Buffer *m) 441 { 442 DH *dh; 443 int min, want, max; 444 445 min = buffer_get_int(m); 446 want = buffer_get_int(m); 447 max = buffer_get_int(m); 448 449 debug3("%s: got parameters: %d %d %d", 450 __func__, min, want, max); 451 /* We need to check here, too, in case the child got corrupted */ 452 if (max < min || want < min || max < want) 453 fatal("%s: bad parameters: %d %d %d", 454 __func__, min, want, max); 455 456 buffer_clear(m); 457 458 dh = choose_dh(min, want, max); 459 if (dh == NULL) { 460 buffer_put_char(m, 0); 461 return (0); 462 } else { 463 /* Send first bignum */ 464 buffer_put_char(m, 1); 465 buffer_put_bignum2(m, dh->p); 466 buffer_put_bignum2(m, dh->g); 467 468 DH_free(dh); 469 } 470 mm_request_send(socket, MONITOR_ANS_MODULI, m); 471 return (0); 472 } 473 474 int 475 mm_answer_sign(int socket, Buffer *m) 476 { 477 Key *key; 478 u_char *p; 479 u_char *signature; 480 u_int siglen, datlen; 481 int keyid; 482 483 debug3("%s", __func__); 484 485 keyid = buffer_get_int(m); 486 p = buffer_get_string(m, &datlen); 487 488 if (datlen != 20) 489 fatal("%s: data length incorrect: %u", __func__, datlen); 490 491 /* save session id, it will be passed on the first call */ 492 if (session_id2_len == 0) { 493 session_id2_len = datlen; 494 session_id2 = xmalloc(session_id2_len); 495 memcpy(session_id2, p, session_id2_len); 496 } 497 498 if ((key = get_hostkey_by_index(keyid)) == NULL) 499 fatal("%s: no hostkey from index %d", __func__, keyid); 500 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 501 fatal("%s: key_sign failed", __func__); 502 503 debug3("%s: signature %p(%u)", __func__, signature, siglen); 504 505 buffer_clear(m); 506 buffer_put_string(m, signature, siglen); 507 508 xfree(p); 509 xfree(signature); 510 511 mm_request_send(socket, MONITOR_ANS_SIGN, m); 512 513 /* Turn on permissions for getpwnam */ 514 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 515 516 return (0); 517 } 518 519 /* Retrieves the password entry and also checks if the user is permitted */ 520 521 int 522 mm_answer_pwnamallow(int socket, Buffer *m) 523 { 524 char *login; 525 struct passwd *pwent; 526 int allowed = 0; 527 528 debug3("%s", __func__); 529 530 if (authctxt->attempt++ != 0) 531 fatal("%s: multiple attempts for getpwnam", __func__); 532 533 login = buffer_get_string(m, NULL); 534 535 pwent = getpwnamallow(login); 536 537 authctxt->user = xstrdup(login); 538 setproctitle("%s [priv]", pwent ? login : "unknown"); 539 xfree(login); 540 541 buffer_clear(m); 542 543 if (pwent == NULL) { 544 buffer_put_char(m, 0); 545 goto out; 546 } 547 548 allowed = 1; 549 authctxt->pw = pwent; 550 authctxt->valid = 1; 551 552 buffer_put_char(m, 1); 553 buffer_put_string(m, pwent, sizeof(struct passwd)); 554 buffer_put_cstring(m, pwent->pw_name); 555 buffer_put_cstring(m, "*"); 556 buffer_put_cstring(m, pwent->pw_gecos); 557 #ifdef HAVE_PW_CLASS_IN_PASSWD 558 buffer_put_cstring(m, pwent->pw_class); 559 #endif 560 buffer_put_cstring(m, pwent->pw_dir); 561 buffer_put_cstring(m, pwent->pw_shell); 562 563 out: 564 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 565 mm_request_send(socket, MONITOR_ANS_PWNAM, m); 566 567 /* For SSHv1 allow authentication now */ 568 if (!compat20) 569 monitor_permit_authentications(1); 570 else { 571 /* Allow service/style information on the auth context */ 572 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 573 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 574 } 575 576 #ifdef USE_PAM 577 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 578 #endif 579 580 return (0); 581 } 582 583 int mm_answer_auth2_read_banner(int socket, Buffer *m) 584 { 585 char *banner; 586 587 buffer_clear(m); 588 banner = auth2_read_banner(); 589 buffer_put_cstring(m, banner != NULL ? banner : ""); 590 mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m); 591 592 if (banner != NULL) 593 xfree(banner); 594 595 return (0); 596 } 597 598 int 599 mm_answer_authserv(int socket, Buffer *m) 600 { 601 monitor_permit_authentications(1); 602 603 authctxt->service = buffer_get_string(m, NULL); 604 authctxt->style = buffer_get_string(m, NULL); 605 debug3("%s: service=%s, style=%s", 606 __func__, authctxt->service, authctxt->style); 607 608 if (strlen(authctxt->style) == 0) { 609 xfree(authctxt->style); 610 authctxt->style = NULL; 611 } 612 613 return (0); 614 } 615 616 int 617 mm_answer_authpassword(int socket, Buffer *m) 618 { 619 static int call_count; 620 char *passwd; 621 int authenticated; 622 u_int plen; 623 624 passwd = buffer_get_string(m, &plen); 625 /* Only authenticate if the context is valid */ 626 authenticated = options.password_authentication && 627 authctxt->valid && auth_password(authctxt, passwd); 628 memset(passwd, 0, strlen(passwd)); 629 xfree(passwd); 630 631 buffer_clear(m); 632 buffer_put_int(m, authenticated); 633 634 debug3("%s: sending result %d", __func__, authenticated); 635 mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m); 636 637 call_count++; 638 if (plen == 0 && call_count == 1) 639 auth_method = "none"; 640 else 641 auth_method = "password"; 642 643 /* Causes monitor loop to terminate if authenticated */ 644 return (authenticated); 645 } 646 647 #ifdef BSD_AUTH 648 int 649 mm_answer_bsdauthquery(int socket, Buffer *m) 650 { 651 char *name, *infotxt; 652 u_int numprompts; 653 u_int *echo_on; 654 char **prompts; 655 int res; 656 657 res = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 658 &prompts, &echo_on); 659 660 buffer_clear(m); 661 buffer_put_int(m, res); 662 if (res != -1) 663 buffer_put_cstring(m, prompts[0]); 664 665 debug3("%s: sending challenge res: %d", __func__, res); 666 mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m); 667 668 if (res != -1) { 669 xfree(name); 670 xfree(infotxt); 671 xfree(prompts); 672 xfree(echo_on); 673 } 674 675 return (0); 676 } 677 678 int 679 mm_answer_bsdauthrespond(int socket, Buffer *m) 680 { 681 char *response; 682 int authok; 683 684 if (authctxt->as == 0) 685 fatal("%s: no bsd auth session", __func__); 686 687 response = buffer_get_string(m, NULL); 688 authok = options.challenge_response_authentication && 689 auth_userresponse(authctxt->as, response, 0); 690 authctxt->as = NULL; 691 debug3("%s: <%s> = <%d>", __func__, response, authok); 692 xfree(response); 693 694 buffer_clear(m); 695 buffer_put_int(m, authok); 696 697 debug3("%s: sending authenticated: %d", __func__, authok); 698 mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m); 699 700 auth_method = "bsdauth"; 701 702 return (authok != 0); 703 } 704 #endif 705 706 #ifdef SKEY 707 int 708 mm_answer_skeyquery(int socket, Buffer *m) 709 { 710 struct skey skey; 711 char challenge[1024]; 712 int res; 713 714 res = skeychallenge(&skey, authctxt->user, challenge); 715 716 buffer_clear(m); 717 buffer_put_int(m, res); 718 if (res != -1) 719 buffer_put_cstring(m, challenge); 720 721 debug3("%s: sending challenge res: %d", __func__, res); 722 mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m); 723 724 return (0); 725 } 726 727 int 728 mm_answer_skeyrespond(int socket, Buffer *m) 729 { 730 char *response; 731 int authok; 732 733 response = buffer_get_string(m, NULL); 734 735 authok = (options.challenge_response_authentication && 736 authctxt->valid && 737 skey_haskey(authctxt->pw->pw_name) == 0 && 738 skey_passcheck(authctxt->pw->pw_name, response) != -1); 739 740 xfree(response); 741 742 buffer_clear(m); 743 buffer_put_int(m, authok); 744 745 debug3("%s: sending authenticated: %d", __func__, authok); 746 mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m); 747 748 auth_method = "skey"; 749 750 return (authok != 0); 751 } 752 #endif 753 754 #ifdef USE_PAM 755 int 756 mm_answer_pam_start(int socket, Buffer *m) 757 { 758 char *user; 759 760 user = buffer_get_string(m, NULL); 761 762 start_pam(user); 763 764 xfree(user); 765 766 return (0); 767 } 768 769 static void *pam_ctxt, *pam_authok; 770 extern KbdintDevice pam_device; 771 772 int 773 mm_answer_pam_init_ctx(int socket, Buffer *m) 774 { 775 776 debug3("%s", __func__); 777 authctxt->user = buffer_get_string(m, NULL); 778 pam_ctxt = (pam_device.init_ctx)(authctxt); 779 pam_authok = NULL; 780 buffer_clear(m); 781 if (pam_ctxt != NULL) { 782 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 783 buffer_put_int(m, 1); 784 } else { 785 buffer_put_int(m, 0); 786 } 787 mm_request_send(socket, MONITOR_ANS_PAM_INIT_CTX, m); 788 return (0); 789 } 790 791 int 792 mm_answer_pam_query(int socket, Buffer *m) 793 { 794 char *name, *info, **prompts; 795 u_int num, *echo_on; 796 int i, ret; 797 798 debug3("%s", __func__); 799 pam_authok = NULL; 800 ret = (pam_device.query)(pam_ctxt, &name, &info, &num, &prompts, &echo_on); 801 if (ret == 0 && num == 0) 802 pam_authok = pam_ctxt; 803 if (num > 1 || name == NULL || info == NULL) 804 ret = -1; 805 buffer_clear(m); 806 buffer_put_int(m, ret); 807 buffer_put_cstring(m, name); 808 xfree(name); 809 buffer_put_cstring(m, info); 810 xfree(info); 811 buffer_put_int(m, num); 812 for (i = 0; i < num; ++i) { 813 buffer_put_cstring(m, prompts[i]); 814 xfree(prompts[i]); 815 buffer_put_int(m, echo_on[i]); 816 } 817 if (prompts != NULL) 818 xfree(prompts); 819 if (echo_on != NULL) 820 xfree(echo_on); 821 mm_request_send(socket, MONITOR_ANS_PAM_QUERY, m); 822 return (0); 823 } 824 825 int 826 mm_answer_pam_respond(int socket, Buffer *m) 827 { 828 char **resp; 829 u_int num; 830 int i, ret; 831 832 debug3("%s", __func__); 833 pam_authok = NULL; 834 num = buffer_get_int(m); 835 if (num > 0) { 836 resp = xmalloc(num * sizeof(char *)); 837 for (i = 0; i < num; ++i) 838 resp[i] = buffer_get_string(m, NULL); 839 ret = (pam_device.respond)(pam_ctxt, num, resp); 840 for (i = 0; i < num; ++i) 841 xfree(resp[i]); 842 xfree(resp); 843 } else { 844 ret = (pam_device.respond)(pam_ctxt, num, NULL); 845 } 846 buffer_clear(m); 847 buffer_put_int(m, ret); 848 mm_request_send(socket, MONITOR_ANS_PAM_RESPOND, m); 849 auth_method = "keyboard-interactive/pam"; 850 if (ret == 0) 851 pam_authok = pam_ctxt; 852 return (0); 853 } 854 855 int 856 mm_answer_pam_free_ctx(int socket, Buffer *m) 857 { 858 859 debug3("%s", __func__); 860 (pam_device.free_ctx)(pam_ctxt); 861 buffer_clear(m); 862 mm_request_send(socket, MONITOR_ANS_PAM_FREE_CTX, m); 863 return (pam_authok == pam_ctxt); 864 } 865 #endif 866 867 static void 868 mm_append_debug(Buffer *m) 869 { 870 if (auth_debug_init && buffer_len(&auth_debug)) { 871 debug3("%s: Appending debug messages for child", __func__); 872 buffer_append(m, buffer_ptr(&auth_debug), 873 buffer_len(&auth_debug)); 874 buffer_clear(&auth_debug); 875 } 876 } 877 878 int 879 mm_answer_keyallowed(int socket, Buffer *m) 880 { 881 Key *key; 882 char *cuser, *chost; 883 u_char *blob; 884 u_int bloblen; 885 enum mm_keytype type = 0; 886 int allowed = 0; 887 888 debug3("%s entering", __func__); 889 890 type = buffer_get_int(m); 891 cuser = buffer_get_string(m, NULL); 892 chost = buffer_get_string(m, NULL); 893 blob = buffer_get_string(m, &bloblen); 894 895 key = key_from_blob(blob, bloblen); 896 897 if ((compat20 && type == MM_RSAHOSTKEY) || 898 (!compat20 && type != MM_RSAHOSTKEY)) 899 fatal("%s: key type and protocol mismatch", __func__); 900 901 debug3("%s: key_from_blob: %p", __func__, key); 902 903 if (key != NULL && authctxt->pw != NULL) { 904 switch(type) { 905 case MM_USERKEY: 906 allowed = options.pubkey_authentication && 907 user_key_allowed(authctxt->pw, key); 908 break; 909 case MM_HOSTKEY: 910 allowed = options.hostbased_authentication && 911 hostbased_key_allowed(authctxt->pw, 912 cuser, chost, key); 913 break; 914 case MM_RSAHOSTKEY: 915 key->type = KEY_RSA1; /* XXX */ 916 allowed = options.rhosts_rsa_authentication && 917 auth_rhosts_rsa_key_allowed(authctxt->pw, 918 cuser, chost, key); 919 break; 920 default: 921 fatal("%s: unknown key type %d", __func__, type); 922 break; 923 } 924 key_free(key); 925 } 926 927 /* clear temporarily storage (used by verify) */ 928 monitor_reset_key_state(); 929 930 if (allowed) { 931 /* Save temporarily for comparison in verify */ 932 key_blob = blob; 933 key_bloblen = bloblen; 934 key_blobtype = type; 935 hostbased_cuser = cuser; 936 hostbased_chost = chost; 937 } 938 939 debug3("%s: key %p is %s", 940 __func__, key, allowed ? "allowed" : "disallowed"); 941 942 buffer_clear(m); 943 buffer_put_int(m, allowed); 944 945 mm_append_debug(m); 946 947 mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m); 948 949 if (type == MM_RSAHOSTKEY) 950 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 951 952 return (0); 953 } 954 955 static int 956 monitor_valid_userblob(u_char *data, u_int datalen) 957 { 958 Buffer b; 959 char *p; 960 u_int len; 961 int fail = 0; 962 963 buffer_init(&b); 964 buffer_append(&b, data, datalen); 965 966 if (datafellows & SSH_OLD_SESSIONID) { 967 p = buffer_ptr(&b); 968 len = buffer_len(&b); 969 if ((session_id2 == NULL) || 970 (len < session_id2_len) || 971 (memcmp(p, session_id2, session_id2_len) != 0)) 972 fail++; 973 buffer_consume(&b, session_id2_len); 974 } else { 975 p = buffer_get_string(&b, &len); 976 if ((session_id2 == NULL) || 977 (len != session_id2_len) || 978 (memcmp(p, session_id2, session_id2_len) != 0)) 979 fail++; 980 xfree(p); 981 } 982 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 983 fail++; 984 p = buffer_get_string(&b, NULL); 985 if (strcmp(authctxt->user, p) != 0) { 986 log("wrong user name passed to monitor: expected %s != %.100s", 987 authctxt->user, p); 988 fail++; 989 } 990 xfree(p); 991 buffer_skip_string(&b); 992 if (datafellows & SSH_BUG_PKAUTH) { 993 if (!buffer_get_char(&b)) 994 fail++; 995 } else { 996 p = buffer_get_string(&b, NULL); 997 if (strcmp("publickey", p) != 0) 998 fail++; 999 xfree(p); 1000 if (!buffer_get_char(&b)) 1001 fail++; 1002 buffer_skip_string(&b); 1003 } 1004 buffer_skip_string(&b); 1005 if (buffer_len(&b) != 0) 1006 fail++; 1007 buffer_free(&b); 1008 return (fail == 0); 1009 } 1010 1011 static int 1012 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1013 char *chost) 1014 { 1015 Buffer b; 1016 char *p; 1017 u_int len; 1018 int fail = 0; 1019 1020 buffer_init(&b); 1021 buffer_append(&b, data, datalen); 1022 1023 p = buffer_get_string(&b, &len); 1024 if ((session_id2 == NULL) || 1025 (len != session_id2_len) || 1026 (memcmp(p, session_id2, session_id2_len) != 0)) 1027 fail++; 1028 xfree(p); 1029 1030 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1031 fail++; 1032 p = buffer_get_string(&b, NULL); 1033 if (strcmp(authctxt->user, p) != 0) { 1034 log("wrong user name passed to monitor: expected %s != %.100s", 1035 authctxt->user, p); 1036 fail++; 1037 } 1038 xfree(p); 1039 buffer_skip_string(&b); /* service */ 1040 p = buffer_get_string(&b, NULL); 1041 if (strcmp(p, "hostbased") != 0) 1042 fail++; 1043 xfree(p); 1044 buffer_skip_string(&b); /* pkalg */ 1045 buffer_skip_string(&b); /* pkblob */ 1046 1047 /* verify client host, strip trailing dot if necessary */ 1048 p = buffer_get_string(&b, NULL); 1049 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1050 p[len - 1] = '\0'; 1051 if (strcmp(p, chost) != 0) 1052 fail++; 1053 xfree(p); 1054 1055 /* verify client user */ 1056 p = buffer_get_string(&b, NULL); 1057 if (strcmp(p, cuser) != 0) 1058 fail++; 1059 xfree(p); 1060 1061 if (buffer_len(&b) != 0) 1062 fail++; 1063 buffer_free(&b); 1064 return (fail == 0); 1065 } 1066 1067 int 1068 mm_answer_keyverify(int socket, Buffer *m) 1069 { 1070 Key *key; 1071 u_char *signature, *data, *blob; 1072 u_int signaturelen, datalen, bloblen; 1073 int verified = 0; 1074 int valid_data = 0; 1075 1076 blob = buffer_get_string(m, &bloblen); 1077 signature = buffer_get_string(m, &signaturelen); 1078 data = buffer_get_string(m, &datalen); 1079 1080 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1081 !monitor_allowed_key(blob, bloblen)) 1082 fatal("%s: bad key, not previously allowed", __func__); 1083 1084 key = key_from_blob(blob, bloblen); 1085 if (key == NULL) 1086 fatal("%s: bad public key blob", __func__); 1087 1088 switch (key_blobtype) { 1089 case MM_USERKEY: 1090 valid_data = monitor_valid_userblob(data, datalen); 1091 break; 1092 case MM_HOSTKEY: 1093 valid_data = monitor_valid_hostbasedblob(data, datalen, 1094 hostbased_cuser, hostbased_chost); 1095 break; 1096 default: 1097 valid_data = 0; 1098 break; 1099 } 1100 if (!valid_data) 1101 fatal("%s: bad signature data blob", __func__); 1102 1103 verified = key_verify(key, signature, signaturelen, data, datalen); 1104 debug3("%s: key %p signature %s", 1105 __func__, key, verified ? "verified" : "unverified"); 1106 1107 key_free(key); 1108 xfree(blob); 1109 xfree(signature); 1110 xfree(data); 1111 1112 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1113 1114 monitor_reset_key_state(); 1115 1116 buffer_clear(m); 1117 buffer_put_int(m, verified); 1118 mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m); 1119 1120 return (verified); 1121 } 1122 1123 static void 1124 mm_record_login(Session *s, struct passwd *pw) 1125 { 1126 socklen_t fromlen; 1127 struct sockaddr_storage from; 1128 1129 /* 1130 * Get IP address of client. If the connection is not a socket, let 1131 * the address be 0.0.0.0. 1132 */ 1133 memset(&from, 0, sizeof(from)); 1134 fromlen = sizeof(from); 1135 if (packet_connection_is_on_socket()) { 1136 if (getpeername(packet_get_connection_in(), 1137 (struct sockaddr *) & from, &fromlen) < 0) { 1138 debug("getpeername: %.100s", strerror(errno)); 1139 fatal_cleanup(); 1140 } 1141 } 1142 /* Record that there was a login on that tty from the remote host. */ 1143 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1144 get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), 1145 (struct sockaddr *)&from, fromlen); 1146 } 1147 1148 static void 1149 mm_session_close(Session *s) 1150 { 1151 debug3("%s: session %d pid %d", __func__, s->self, s->pid); 1152 if (s->ttyfd != -1) { 1153 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1154 fatal_remove_cleanup(session_pty_cleanup2, (void *)s); 1155 session_pty_cleanup2(s); 1156 } 1157 s->used = 0; 1158 } 1159 1160 int 1161 mm_answer_pty(int socket, Buffer *m) 1162 { 1163 extern struct monitor *pmonitor; 1164 Session *s; 1165 int res, fd0; 1166 1167 debug3("%s entering", __func__); 1168 1169 buffer_clear(m); 1170 s = session_new(); 1171 if (s == NULL) 1172 goto error; 1173 s->authctxt = authctxt; 1174 s->pw = authctxt->pw; 1175 s->pid = pmonitor->m_pid; 1176 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1177 if (res == 0) 1178 goto error; 1179 fatal_add_cleanup(session_pty_cleanup2, (void *)s); 1180 pty_setowner(authctxt->pw, s->tty); 1181 1182 buffer_put_int(m, 1); 1183 buffer_put_cstring(m, s->tty); 1184 mm_request_send(socket, MONITOR_ANS_PTY, m); 1185 1186 mm_send_fd(socket, s->ptyfd); 1187 mm_send_fd(socket, s->ttyfd); 1188 1189 /* We need to trick ttyslot */ 1190 if (dup2(s->ttyfd, 0) == -1) 1191 fatal("%s: dup2", __func__); 1192 1193 mm_record_login(s, authctxt->pw); 1194 1195 /* Now we can close the file descriptor again */ 1196 close(0); 1197 1198 /* make sure nothing uses fd 0 */ 1199 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1200 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1201 if (fd0 != 0) 1202 error("%s: fd0 %d != 0", __func__, fd0); 1203 1204 /* slave is not needed */ 1205 close(s->ttyfd); 1206 s->ttyfd = s->ptyfd; 1207 /* no need to dup() because nobody closes ptyfd */ 1208 s->ptymaster = s->ptyfd; 1209 1210 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1211 1212 return (0); 1213 1214 error: 1215 if (s != NULL) 1216 mm_session_close(s); 1217 buffer_put_int(m, 0); 1218 mm_request_send(socket, MONITOR_ANS_PTY, m); 1219 return (0); 1220 } 1221 1222 int 1223 mm_answer_pty_cleanup(int socket, Buffer *m) 1224 { 1225 Session *s; 1226 char *tty; 1227 1228 debug3("%s entering", __func__); 1229 1230 tty = buffer_get_string(m, NULL); 1231 if ((s = session_by_tty(tty)) != NULL) 1232 mm_session_close(s); 1233 buffer_clear(m); 1234 xfree(tty); 1235 return (0); 1236 } 1237 1238 int 1239 mm_answer_sesskey(int socket, Buffer *m) 1240 { 1241 BIGNUM *p; 1242 int rsafail; 1243 1244 /* Turn off permissions */ 1245 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 1246 1247 if ((p = BN_new()) == NULL) 1248 fatal("%s: BN_new", __func__); 1249 1250 buffer_get_bignum2(m, p); 1251 1252 rsafail = ssh1_session_key(p); 1253 1254 buffer_clear(m); 1255 buffer_put_int(m, rsafail); 1256 buffer_put_bignum2(m, p); 1257 1258 BN_clear_free(p); 1259 1260 mm_request_send(socket, MONITOR_ANS_SESSKEY, m); 1261 1262 /* Turn on permissions for sessid passing */ 1263 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1264 1265 return (0); 1266 } 1267 1268 int 1269 mm_answer_sessid(int socket, Buffer *m) 1270 { 1271 int i; 1272 1273 debug3("%s entering", __func__); 1274 1275 if (buffer_len(m) != 16) 1276 fatal("%s: bad ssh1 session id", __func__); 1277 for (i = 0; i < 16; i++) 1278 session_id[i] = buffer_get_char(m); 1279 1280 /* Turn on permissions for getpwnam */ 1281 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1282 1283 return (0); 1284 } 1285 1286 int 1287 mm_answer_rsa_keyallowed(int socket, Buffer *m) 1288 { 1289 BIGNUM *client_n; 1290 Key *key = NULL; 1291 u_char *blob = NULL; 1292 u_int blen = 0; 1293 int allowed = 0; 1294 1295 debug3("%s entering", __func__); 1296 1297 if (options.rsa_authentication && authctxt->valid) { 1298 if ((client_n = BN_new()) == NULL) 1299 fatal("%s: BN_new", __func__); 1300 buffer_get_bignum2(m, client_n); 1301 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1302 BN_clear_free(client_n); 1303 } 1304 buffer_clear(m); 1305 buffer_put_int(m, allowed); 1306 1307 /* clear temporarily storage (used by generate challenge) */ 1308 monitor_reset_key_state(); 1309 1310 if (allowed && key != NULL) { 1311 key->type = KEY_RSA; /* cheat for key_to_blob */ 1312 if (key_to_blob(key, &blob, &blen) == 0) 1313 fatal("%s: key_to_blob failed", __func__); 1314 buffer_put_string(m, blob, blen); 1315 1316 /* Save temporarily for comparison in verify */ 1317 key_blob = blob; 1318 key_bloblen = blen; 1319 key_blobtype = MM_RSAUSERKEY; 1320 key_free(key); 1321 } 1322 1323 mm_append_debug(m); 1324 1325 mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m); 1326 1327 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1328 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1329 return (0); 1330 } 1331 1332 int 1333 mm_answer_rsa_challenge(int socket, Buffer *m) 1334 { 1335 Key *key = NULL; 1336 u_char *blob; 1337 u_int blen; 1338 1339 debug3("%s entering", __func__); 1340 1341 if (!authctxt->valid) 1342 fatal("%s: authctxt not valid", __func__); 1343 blob = buffer_get_string(m, &blen); 1344 if (!monitor_allowed_key(blob, blen)) 1345 fatal("%s: bad key, not previously allowed", __func__); 1346 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1347 fatal("%s: key type mismatch", __func__); 1348 if ((key = key_from_blob(blob, blen)) == NULL) 1349 fatal("%s: received bad key", __func__); 1350 1351 if (ssh1_challenge) 1352 BN_clear_free(ssh1_challenge); 1353 ssh1_challenge = auth_rsa_generate_challenge(key); 1354 1355 buffer_clear(m); 1356 buffer_put_bignum2(m, ssh1_challenge); 1357 1358 debug3("%s sending reply", __func__); 1359 mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m); 1360 1361 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1362 return (0); 1363 } 1364 1365 int 1366 mm_answer_rsa_response(int socket, Buffer *m) 1367 { 1368 Key *key = NULL; 1369 u_char *blob, *response; 1370 u_int blen, len; 1371 int success; 1372 1373 debug3("%s entering", __func__); 1374 1375 if (!authctxt->valid) 1376 fatal("%s: authctxt not valid", __func__); 1377 if (ssh1_challenge == NULL) 1378 fatal("%s: no ssh1_challenge", __func__); 1379 1380 blob = buffer_get_string(m, &blen); 1381 if (!monitor_allowed_key(blob, blen)) 1382 fatal("%s: bad key, not previously allowed", __func__); 1383 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1384 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1385 if ((key = key_from_blob(blob, blen)) == NULL) 1386 fatal("%s: received bad key", __func__); 1387 response = buffer_get_string(m, &len); 1388 if (len != 16) 1389 fatal("%s: received bad response to challenge", __func__); 1390 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1391 1392 key_free(key); 1393 xfree(response); 1394 1395 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1396 1397 /* reset state */ 1398 BN_clear_free(ssh1_challenge); 1399 ssh1_challenge = NULL; 1400 monitor_reset_key_state(); 1401 1402 buffer_clear(m); 1403 buffer_put_int(m, success); 1404 mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m); 1405 1406 return (success); 1407 } 1408 1409 #ifdef KRB4 1410 int 1411 mm_answer_krb4(int socket, Buffer *m) 1412 { 1413 KTEXT_ST auth, reply; 1414 char *client, *p; 1415 int success; 1416 u_int alen; 1417 1418 reply.length = auth.length = 0; 1419 1420 p = buffer_get_string(m, &alen); 1421 if (alen >= MAX_KTXT_LEN) 1422 fatal("%s: auth too large", __func__); 1423 memcpy(auth.dat, p, alen); 1424 auth.length = alen; 1425 memset(p, 0, alen); 1426 xfree(p); 1427 1428 success = options.kerberos_authentication && 1429 authctxt->valid && 1430 auth_krb4(authctxt, &auth, &client, &reply); 1431 1432 memset(auth.dat, 0, alen); 1433 buffer_clear(m); 1434 buffer_put_int(m, success); 1435 1436 if (success) { 1437 buffer_put_cstring(m, client); 1438 buffer_put_string(m, reply.dat, reply.length); 1439 if (client) 1440 xfree(client); 1441 if (reply.length) 1442 memset(reply.dat, 0, reply.length); 1443 } 1444 1445 debug3("%s: sending result %d", __func__, success); 1446 mm_request_send(socket, MONITOR_ANS_KRB4, m); 1447 1448 auth_method = "kerberos"; 1449 1450 /* Causes monitor loop to terminate if authenticated */ 1451 return (success); 1452 } 1453 #endif 1454 1455 #ifdef KRB5 1456 int 1457 mm_answer_krb5(int socket, Buffer *m) 1458 { 1459 krb5_data tkt, reply; 1460 char *client_user; 1461 u_int len; 1462 int success; 1463 1464 /* use temporary var to avoid size issues on 64bit arch */ 1465 tkt.data = buffer_get_string(m, &len); 1466 tkt.length = len; 1467 1468 success = options.kerberos_authentication && 1469 authctxt->valid && 1470 auth_krb5(authctxt, &tkt, &client_user, &reply); 1471 1472 if (tkt.length) 1473 xfree(tkt.data); 1474 1475 buffer_clear(m); 1476 buffer_put_int(m, success); 1477 1478 if (success) { 1479 buffer_put_cstring(m, client_user); 1480 buffer_put_string(m, reply.data, reply.length); 1481 if (client_user) 1482 xfree(client_user); 1483 if (reply.length) 1484 xfree(reply.data); 1485 } 1486 mm_request_send(socket, MONITOR_ANS_KRB5, m); 1487 1488 return success; 1489 } 1490 #endif 1491 1492 int 1493 mm_answer_term(int socket, Buffer *req) 1494 { 1495 extern struct monitor *pmonitor; 1496 int res, status; 1497 1498 debug3("%s: tearing down sessions", __func__); 1499 1500 /* The child is terminating */ 1501 session_destroy_all(&mm_session_close); 1502 1503 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1504 if (errno != EINTR) 1505 exit(1); 1506 1507 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1508 1509 /* Terminate process */ 1510 exit (res); 1511 } 1512 1513 void 1514 monitor_apply_keystate(struct monitor *pmonitor) 1515 { 1516 if (compat20) { 1517 set_newkeys(MODE_IN); 1518 set_newkeys(MODE_OUT); 1519 } else { 1520 packet_set_protocol_flags(child_state.ssh1protoflags); 1521 packet_set_encryption_key(child_state.ssh1key, 1522 child_state.ssh1keylen, child_state.ssh1cipher); 1523 xfree(child_state.ssh1key); 1524 } 1525 1526 /* for rc4 and other stateful ciphers */ 1527 packet_set_keycontext(MODE_OUT, child_state.keyout); 1528 xfree(child_state.keyout); 1529 packet_set_keycontext(MODE_IN, child_state.keyin); 1530 xfree(child_state.keyin); 1531 1532 if (!compat20) { 1533 packet_set_iv(MODE_OUT, child_state.ivout); 1534 xfree(child_state.ivout); 1535 packet_set_iv(MODE_IN, child_state.ivin); 1536 xfree(child_state.ivin); 1537 } 1538 1539 memcpy(&incoming_stream, &child_state.incoming, 1540 sizeof(incoming_stream)); 1541 memcpy(&outgoing_stream, &child_state.outgoing, 1542 sizeof(outgoing_stream)); 1543 1544 /* Update with new address */ 1545 if (options.compression) 1546 mm_init_compression(pmonitor->m_zlib); 1547 1548 /* Network I/O buffers */ 1549 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1550 buffer_clear(&input); 1551 buffer_append(&input, child_state.input, child_state.ilen); 1552 memset(child_state.input, 0, child_state.ilen); 1553 xfree(child_state.input); 1554 1555 buffer_clear(&output); 1556 buffer_append(&output, child_state.output, child_state.olen); 1557 memset(child_state.output, 0, child_state.olen); 1558 xfree(child_state.output); 1559 } 1560 1561 static Kex * 1562 mm_get_kex(Buffer *m) 1563 { 1564 Kex *kex; 1565 void *blob; 1566 u_int bloblen; 1567 1568 kex = xmalloc(sizeof(*kex)); 1569 memset(kex, 0, sizeof(*kex)); 1570 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1571 if ((session_id2 == NULL) || 1572 (kex->session_id_len != session_id2_len) || 1573 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1574 fatal("mm_get_get: internal error: bad session id"); 1575 kex->we_need = buffer_get_int(m); 1576 kex->server = 1; 1577 kex->hostkey_type = buffer_get_int(m); 1578 kex->kex_type = buffer_get_int(m); 1579 blob = buffer_get_string(m, &bloblen); 1580 buffer_init(&kex->my); 1581 buffer_append(&kex->my, blob, bloblen); 1582 xfree(blob); 1583 blob = buffer_get_string(m, &bloblen); 1584 buffer_init(&kex->peer); 1585 buffer_append(&kex->peer, blob, bloblen); 1586 xfree(blob); 1587 kex->done = 1; 1588 kex->flags = buffer_get_int(m); 1589 kex->client_version_string = buffer_get_string(m, NULL); 1590 kex->server_version_string = buffer_get_string(m, NULL); 1591 kex->load_host_key=&get_hostkey_by_type; 1592 kex->host_key_index=&get_hostkey_index; 1593 1594 return (kex); 1595 } 1596 1597 /* This function requries careful sanity checking */ 1598 1599 void 1600 mm_get_keystate(struct monitor *pmonitor) 1601 { 1602 Buffer m; 1603 u_char *blob, *p; 1604 u_int bloblen, plen; 1605 1606 debug3("%s: Waiting for new keys", __func__); 1607 1608 buffer_init(&m); 1609 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1610 if (!compat20) { 1611 child_state.ssh1protoflags = buffer_get_int(&m); 1612 child_state.ssh1cipher = buffer_get_int(&m); 1613 child_state.ssh1key = buffer_get_string(&m, 1614 &child_state.ssh1keylen); 1615 child_state.ivout = buffer_get_string(&m, 1616 &child_state.ivoutlen); 1617 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1618 goto skip; 1619 } else { 1620 /* Get the Kex for rekeying */ 1621 *pmonitor->m_pkex = mm_get_kex(&m); 1622 } 1623 1624 blob = buffer_get_string(&m, &bloblen); 1625 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1626 xfree(blob); 1627 1628 debug3("%s: Waiting for second key", __func__); 1629 blob = buffer_get_string(&m, &bloblen); 1630 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1631 xfree(blob); 1632 1633 /* Now get sequence numbers for the packets */ 1634 packet_set_seqnr(MODE_OUT, buffer_get_int(&m)); 1635 packet_set_seqnr(MODE_IN, buffer_get_int(&m)); 1636 1637 skip: 1638 /* Get the key context */ 1639 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1640 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1641 1642 debug3("%s: Getting compression state", __func__); 1643 /* Get compression state */ 1644 p = buffer_get_string(&m, &plen); 1645 if (plen != sizeof(child_state.outgoing)) 1646 fatal("%s: bad request size", __func__); 1647 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1648 xfree(p); 1649 1650 p = buffer_get_string(&m, &plen); 1651 if (plen != sizeof(child_state.incoming)) 1652 fatal("%s: bad request size", __func__); 1653 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1654 xfree(p); 1655 1656 /* Network I/O buffers */ 1657 debug3("%s: Getting Network I/O buffers", __func__); 1658 child_state.input = buffer_get_string(&m, &child_state.ilen); 1659 child_state.output = buffer_get_string(&m, &child_state.olen); 1660 1661 buffer_free(&m); 1662 } 1663 1664 1665 /* Allocation functions for zlib */ 1666 void * 1667 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1668 { 1669 size_t len = size * ncount; 1670 void *address; 1671 1672 if (len == 0 || ncount > SIZE_T_MAX / size) 1673 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1674 1675 address = mm_malloc(mm, len); 1676 1677 return (address); 1678 } 1679 1680 void 1681 mm_zfree(struct mm_master *mm, void *address) 1682 { 1683 mm_free(mm, address); 1684 } 1685 1686 void 1687 mm_init_compression(struct mm_master *mm) 1688 { 1689 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1690 outgoing_stream.zfree = (free_func)mm_zfree; 1691 outgoing_stream.opaque = mm; 1692 1693 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1694 incoming_stream.zfree = (free_func)mm_zfree; 1695 incoming_stream.opaque = mm; 1696 } 1697 1698 /* XXX */ 1699 1700 #define FD_CLOSEONEXEC(x) do { \ 1701 if (fcntl(x, F_SETFD, 1) == -1) \ 1702 fatal("fcntl(%d, F_SETFD)", x); \ 1703 } while (0) 1704 1705 static void 1706 monitor_socketpair(int *pair) 1707 { 1708 #ifdef HAVE_SOCKETPAIR 1709 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1710 fatal("%s: socketpair", __func__); 1711 #else 1712 fatal("%s: UsePrivilegeSeparation=yes not supported", 1713 __func__); 1714 #endif 1715 FD_CLOSEONEXEC(pair[0]); 1716 FD_CLOSEONEXEC(pair[1]); 1717 } 1718 1719 #define MM_MEMSIZE 65536 1720 1721 struct monitor * 1722 monitor_init(void) 1723 { 1724 struct monitor *mon; 1725 int pair[2]; 1726 1727 mon = xmalloc(sizeof(*mon)); 1728 1729 monitor_socketpair(pair); 1730 1731 mon->m_recvfd = pair[0]; 1732 mon->m_sendfd = pair[1]; 1733 1734 /* Used to share zlib space across processes */ 1735 if (options.compression) { 1736 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1737 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1738 1739 /* Compression needs to share state across borders */ 1740 mm_init_compression(mon->m_zlib); 1741 } 1742 1743 return mon; 1744 } 1745 1746 void 1747 monitor_reinit(struct monitor *mon) 1748 { 1749 int pair[2]; 1750 1751 monitor_socketpair(pair); 1752 1753 mon->m_recvfd = pair[0]; 1754 mon->m_sendfd = pair[1]; 1755 } 1756