monitor.c revision 149753
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" 28RCSID("$OpenBSD: monitor.c,v 1.63 2005/03/10 22:01:05 deraadt Exp $"); 29RCSID("$FreeBSD: head/crypto/openssh/monitor.c 149753 2005-09-03 07:04:25Z des $"); 30 31#include <openssl/dh.h> 32 33#ifdef SKEY 34#ifdef OPIE 35#include <opie.h> 36#define skey opie 37#define skeychallenge(k, u, c) opiechallenge((k), (u), (c)) 38#define skey_haskey(u) opie_haskey((u)) 39#define skey_passcheck(u, r) opie_passverify((u), (r)) 40#else 41#include <skey.h> 42#endif 43#endif 44 45#include "ssh.h" 46#include "auth.h" 47#include "kex.h" 48#include "dh.h" 49#ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 50#undef TARGET_OS_MAC 51#include "zlib.h" 52#define TARGET_OS_MAC 1 53#else 54#include "zlib.h" 55#endif 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#include "monitor_wrap.h" 68#include "monitor_fdpass.h" 69#include "xmalloc.h" 70#include "misc.h" 71#include "buffer.h" 72#include "bufaux.h" 73#include "compat.h" 74#include "ssh2.h" 75 76#ifdef GSSAPI 77#include "ssh-gss.h" 78static Gssctxt *gsscontext = NULL; 79#endif 80 81/* Imports */ 82extern ServerOptions options; 83extern u_int utmp_len; 84extern Newkeys *current_keys[]; 85extern z_stream incoming_stream; 86extern z_stream outgoing_stream; 87extern u_char session_id[]; 88extern Buffer input, output; 89extern Buffer auth_debug; 90extern int auth_debug_init; 91extern Buffer loginmsg; 92 93/* State exported from the child */ 94 95struct { 96 z_stream incoming; 97 z_stream outgoing; 98 u_char *keyin; 99 u_int keyinlen; 100 u_char *keyout; 101 u_int keyoutlen; 102 u_char *ivin; 103 u_int ivinlen; 104 u_char *ivout; 105 u_int ivoutlen; 106 u_char *ssh1key; 107 u_int ssh1keylen; 108 int ssh1cipher; 109 int ssh1protoflags; 110 u_char *input; 111 u_int ilen; 112 u_char *output; 113 u_int olen; 114} child_state; 115 116/* Functions on the monitor that answer unprivileged requests */ 117 118int mm_answer_moduli(int, Buffer *); 119int mm_answer_sign(int, Buffer *); 120int mm_answer_pwnamallow(int, Buffer *); 121int mm_answer_auth2_read_banner(int, Buffer *); 122int mm_answer_authserv(int, Buffer *); 123int mm_answer_authpassword(int, Buffer *); 124int mm_answer_bsdauthquery(int, Buffer *); 125int mm_answer_bsdauthrespond(int, Buffer *); 126int mm_answer_skeyquery(int, Buffer *); 127int mm_answer_skeyrespond(int, Buffer *); 128int mm_answer_keyallowed(int, Buffer *); 129int mm_answer_keyverify(int, Buffer *); 130int mm_answer_pty(int, Buffer *); 131int mm_answer_pty_cleanup(int, Buffer *); 132int mm_answer_term(int, Buffer *); 133int mm_answer_rsa_keyallowed(int, Buffer *); 134int mm_answer_rsa_challenge(int, Buffer *); 135int mm_answer_rsa_response(int, Buffer *); 136int mm_answer_sesskey(int, Buffer *); 137int mm_answer_sessid(int, Buffer *); 138 139#ifdef USE_PAM 140int mm_answer_pam_start(int, Buffer *); 141int mm_answer_pam_account(int, Buffer *); 142int mm_answer_pam_init_ctx(int, Buffer *); 143int mm_answer_pam_query(int, Buffer *); 144int mm_answer_pam_respond(int, Buffer *); 145int mm_answer_pam_free_ctx(int, Buffer *); 146#endif 147 148#ifdef GSSAPI 149int mm_answer_gss_setup_ctx(int, Buffer *); 150int mm_answer_gss_accept_ctx(int, Buffer *); 151int mm_answer_gss_userok(int, Buffer *); 152int mm_answer_gss_checkmic(int, Buffer *); 153#endif 154 155#ifdef SSH_AUDIT_EVENTS 156int mm_answer_audit_event(int, Buffer *); 157int mm_answer_audit_command(int, Buffer *); 158#endif 159 160static Authctxt *authctxt; 161static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 162 163/* local state for key verify */ 164static u_char *key_blob = NULL; 165static u_int key_bloblen = 0; 166static int key_blobtype = MM_NOKEY; 167static char *hostbased_cuser = NULL; 168static char *hostbased_chost = NULL; 169static char *auth_method = "unknown"; 170static u_int session_id2_len = 0; 171static u_char *session_id2 = NULL; 172static pid_t monitor_child_pid; 173 174struct mon_table { 175 enum monitor_reqtype type; 176 int flags; 177 int (*f)(int, Buffer *); 178}; 179 180#define MON_ISAUTH 0x0004 /* Required for Authentication */ 181#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 182#define MON_ONCE 0x0010 /* Disable after calling */ 183 184#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 185 186#define MON_PERMIT 0x1000 /* Request is permitted */ 187 188struct mon_table mon_dispatch_proto20[] = { 189 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 190 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 191 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 192 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 193 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 194 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 195#ifdef USE_PAM 196 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 197 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 198 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 199 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 200 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 201 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 202#endif 203#ifdef SSH_AUDIT_EVENTS 204 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 205#endif 206#ifdef BSD_AUTH 207 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 208 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 209#endif 210#ifdef SKEY 211 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 212 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 213#endif 214 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 215 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 216#ifdef GSSAPI 217 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 218 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 219 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 220 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 221#endif 222 {0, 0, NULL} 223}; 224 225struct mon_table mon_dispatch_postauth20[] = { 226 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 227 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 228 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 229 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 230 {MONITOR_REQ_TERM, 0, mm_answer_term}, 231#ifdef SSH_AUDIT_EVENTS 232 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 233 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 234#endif 235 {0, 0, NULL} 236}; 237 238struct mon_table mon_dispatch_proto15[] = { 239 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 240 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 241 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 242 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 243 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed}, 244 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 245 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 246 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 247#ifdef BSD_AUTH 248 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 249 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, 250#endif 251#ifdef SKEY 252 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 253 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 254#endif 255#ifdef USE_PAM 256 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 257 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 258 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 259 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 260 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 261 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 262#endif 263#ifdef SSH_AUDIT_EVENTS 264 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 265#endif 266 {0, 0, NULL} 267}; 268 269struct mon_table mon_dispatch_postauth15[] = { 270 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 271 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 272 {MONITOR_REQ_TERM, 0, mm_answer_term}, 273#ifdef SSH_AUDIT_EVENTS 274 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 275 {MONITOR_REQ_AUDIT_COMMAND, MON_ONCE, mm_answer_audit_command}, 276#endif 277 {0, 0, NULL} 278}; 279 280struct mon_table *mon_dispatch; 281 282/* Specifies if a certain message is allowed at the moment */ 283 284static void 285monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 286{ 287 while (ent->f != NULL) { 288 if (ent->type == type) { 289 ent->flags &= ~MON_PERMIT; 290 ent->flags |= permit ? MON_PERMIT : 0; 291 return; 292 } 293 ent++; 294 } 295} 296 297static void 298monitor_permit_authentications(int permit) 299{ 300 struct mon_table *ent = mon_dispatch; 301 302 while (ent->f != NULL) { 303 if (ent->flags & MON_AUTH) { 304 ent->flags &= ~MON_PERMIT; 305 ent->flags |= permit ? MON_PERMIT : 0; 306 } 307 ent++; 308 } 309} 310 311void 312monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 313{ 314 struct mon_table *ent; 315 int authenticated = 0; 316 317 debug3("preauth child monitor started"); 318 319 authctxt = _authctxt; 320 memset(authctxt, 0, sizeof(*authctxt)); 321 322 authctxt->loginmsg = &loginmsg; 323 324 if (compat20) { 325 mon_dispatch = mon_dispatch_proto20; 326 327 /* Permit requests for moduli and signatures */ 328 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 329 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 330 } else { 331 mon_dispatch = mon_dispatch_proto15; 332 333 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 334 } 335 336 /* The first few requests do not require asynchronous access */ 337 while (!authenticated) { 338 authenticated = monitor_read(pmonitor, mon_dispatch, &ent); 339 if (authenticated) { 340 if (!(ent->flags & MON_AUTHDECIDE)) 341 fatal("%s: unexpected authentication from %d", 342 __func__, ent->type); 343 if (authctxt->pw->pw_uid == 0 && 344 !auth_root_allowed(auth_method)) 345 authenticated = 0; 346#ifdef USE_PAM 347 /* PAM needs to perform account checks after auth */ 348 if (options.use_pam && authenticated) { 349 Buffer m; 350 351 buffer_init(&m); 352 mm_request_receive_expect(pmonitor->m_sendfd, 353 MONITOR_REQ_PAM_ACCOUNT, &m); 354 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 355 buffer_free(&m); 356 } 357#endif 358 } 359 360 if (ent->flags & MON_AUTHDECIDE) { 361 auth_log(authctxt, authenticated, auth_method, 362 compat20 ? " ssh2" : ""); 363 if (!authenticated) 364 authctxt->failures++; 365 } 366 } 367 368 if (!authctxt->valid) 369 fatal("%s: authenticated invalid user", __func__); 370 371 debug("%s: %s has been authenticated by privileged process", 372 __func__, authctxt->user); 373 374 mm_get_keystate(pmonitor); 375} 376 377static void 378monitor_set_child_handler(pid_t pid) 379{ 380 monitor_child_pid = pid; 381} 382 383static void 384monitor_child_handler(int sig) 385{ 386 kill(monitor_child_pid, sig); 387} 388 389void 390monitor_child_postauth(struct monitor *pmonitor) 391{ 392 monitor_set_child_handler(pmonitor->m_pid); 393 signal(SIGHUP, &monitor_child_handler); 394 signal(SIGTERM, &monitor_child_handler); 395 396 if (compat20) { 397 mon_dispatch = mon_dispatch_postauth20; 398 399 /* Permit requests for moduli and signatures */ 400 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 401 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 402 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 403 } else { 404 mon_dispatch = mon_dispatch_postauth15; 405 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 406 } 407 if (!no_pty_flag) { 408 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 409 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 410 } 411 412 for (;;) 413 monitor_read(pmonitor, mon_dispatch, NULL); 414} 415 416void 417monitor_sync(struct monitor *pmonitor) 418{ 419 if (options.compression) { 420 /* The member allocation is not visible, so sync it */ 421 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 422 } 423} 424 425int 426monitor_read(struct monitor *pmonitor, struct mon_table *ent, 427 struct mon_table **pent) 428{ 429 Buffer m; 430 int ret; 431 u_char type; 432 433 buffer_init(&m); 434 435 mm_request_receive(pmonitor->m_sendfd, &m); 436 type = buffer_get_char(&m); 437 438 debug3("%s: checking request %d", __func__, type); 439 440 while (ent->f != NULL) { 441 if (ent->type == type) 442 break; 443 ent++; 444 } 445 446 if (ent->f != NULL) { 447 if (!(ent->flags & MON_PERMIT)) 448 fatal("%s: unpermitted request %d", __func__, 449 type); 450 ret = (*ent->f)(pmonitor->m_sendfd, &m); 451 buffer_free(&m); 452 453 /* The child may use this request only once, disable it */ 454 if (ent->flags & MON_ONCE) { 455 debug2("%s: %d used once, disabling now", __func__, 456 type); 457 ent->flags &= ~MON_PERMIT; 458 } 459 460 if (pent != NULL) 461 *pent = ent; 462 463 return ret; 464 } 465 466 fatal("%s: unsupported request: %d", __func__, type); 467 468 /* NOTREACHED */ 469 return (-1); 470} 471 472/* allowed key state */ 473static int 474monitor_allowed_key(u_char *blob, u_int bloblen) 475{ 476 /* make sure key is allowed */ 477 if (key_blob == NULL || key_bloblen != bloblen || 478 memcmp(key_blob, blob, key_bloblen)) 479 return (0); 480 return (1); 481} 482 483static void 484monitor_reset_key_state(void) 485{ 486 /* reset state */ 487 if (key_blob != NULL) 488 xfree(key_blob); 489 if (hostbased_cuser != NULL) 490 xfree(hostbased_cuser); 491 if (hostbased_chost != NULL) 492 xfree(hostbased_chost); 493 key_blob = NULL; 494 key_bloblen = 0; 495 key_blobtype = MM_NOKEY; 496 hostbased_cuser = NULL; 497 hostbased_chost = NULL; 498} 499 500int 501mm_answer_moduli(int sock, Buffer *m) 502{ 503 DH *dh; 504 int min, want, max; 505 506 min = buffer_get_int(m); 507 want = buffer_get_int(m); 508 max = buffer_get_int(m); 509 510 debug3("%s: got parameters: %d %d %d", 511 __func__, min, want, max); 512 /* We need to check here, too, in case the child got corrupted */ 513 if (max < min || want < min || max < want) 514 fatal("%s: bad parameters: %d %d %d", 515 __func__, min, want, max); 516 517 buffer_clear(m); 518 519 dh = choose_dh(min, want, max); 520 if (dh == NULL) { 521 buffer_put_char(m, 0); 522 return (0); 523 } else { 524 /* Send first bignum */ 525 buffer_put_char(m, 1); 526 buffer_put_bignum2(m, dh->p); 527 buffer_put_bignum2(m, dh->g); 528 529 DH_free(dh); 530 } 531 mm_request_send(sock, MONITOR_ANS_MODULI, m); 532 return (0); 533} 534 535int 536mm_answer_sign(int sock, Buffer *m) 537{ 538 Key *key; 539 u_char *p; 540 u_char *signature; 541 u_int siglen, datlen; 542 int keyid; 543 544 debug3("%s", __func__); 545 546 keyid = buffer_get_int(m); 547 p = buffer_get_string(m, &datlen); 548 549 if (datlen != 20) 550 fatal("%s: data length incorrect: %u", __func__, datlen); 551 552 /* save session id, it will be passed on the first call */ 553 if (session_id2_len == 0) { 554 session_id2_len = datlen; 555 session_id2 = xmalloc(session_id2_len); 556 memcpy(session_id2, p, session_id2_len); 557 } 558 559 if ((key = get_hostkey_by_index(keyid)) == NULL) 560 fatal("%s: no hostkey from index %d", __func__, keyid); 561 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 562 fatal("%s: key_sign failed", __func__); 563 564 debug3("%s: signature %p(%u)", __func__, signature, siglen); 565 566 buffer_clear(m); 567 buffer_put_string(m, signature, siglen); 568 569 xfree(p); 570 xfree(signature); 571 572 mm_request_send(sock, MONITOR_ANS_SIGN, m); 573 574 /* Turn on permissions for getpwnam */ 575 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 576 577 return (0); 578} 579 580/* Retrieves the password entry and also checks if the user is permitted */ 581 582int 583mm_answer_pwnamallow(int sock, Buffer *m) 584{ 585 char *username; 586 struct passwd *pwent; 587 int allowed = 0; 588 589 debug3("%s", __func__); 590 591 if (authctxt->attempt++ != 0) 592 fatal("%s: multiple attempts for getpwnam", __func__); 593 594 username = buffer_get_string(m, NULL); 595 596 pwent = getpwnamallow(username); 597 598 authctxt->user = xstrdup(username); 599 setproctitle("%s [priv]", pwent ? username : "unknown"); 600 xfree(username); 601 602 buffer_clear(m); 603 604 if (pwent == NULL) { 605 buffer_put_char(m, 0); 606 authctxt->pw = fakepw(); 607 goto out; 608 } 609 610 allowed = 1; 611 authctxt->pw = pwent; 612 authctxt->valid = 1; 613 614 buffer_put_char(m, 1); 615 buffer_put_string(m, pwent, sizeof(struct passwd)); 616 buffer_put_cstring(m, pwent->pw_name); 617 buffer_put_cstring(m, "*"); 618 buffer_put_cstring(m, pwent->pw_gecos); 619#ifdef HAVE_PW_CLASS_IN_PASSWD 620 buffer_put_cstring(m, pwent->pw_class); 621#endif 622 buffer_put_cstring(m, pwent->pw_dir); 623 buffer_put_cstring(m, pwent->pw_shell); 624 625 out: 626 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 627 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 628 629 /* For SSHv1 allow authentication now */ 630 if (!compat20) 631 monitor_permit_authentications(1); 632 else { 633 /* Allow service/style information on the auth context */ 634 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 635 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 636 } 637 638#ifdef USE_PAM 639 if (options.use_pam) 640 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 641#endif 642#ifdef SSH_AUDIT_EVENTS 643 monitor_permit(mon_dispatch, MONITOR_REQ_AUDIT_COMMAND, 1); 644#endif 645 646 return (0); 647} 648 649int mm_answer_auth2_read_banner(int sock, Buffer *m) 650{ 651 char *banner; 652 653 buffer_clear(m); 654 banner = auth2_read_banner(); 655 buffer_put_cstring(m, banner != NULL ? banner : ""); 656 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 657 658 if (banner != NULL) 659 xfree(banner); 660 661 return (0); 662} 663 664int 665mm_answer_authserv(int sock, Buffer *m) 666{ 667 monitor_permit_authentications(1); 668 669 authctxt->service = buffer_get_string(m, NULL); 670 authctxt->style = buffer_get_string(m, NULL); 671 debug3("%s: service=%s, style=%s", 672 __func__, authctxt->service, authctxt->style); 673 674 if (strlen(authctxt->style) == 0) { 675 xfree(authctxt->style); 676 authctxt->style = NULL; 677 } 678 679 return (0); 680} 681 682int 683mm_answer_authpassword(int sock, Buffer *m) 684{ 685 static int call_count; 686 char *passwd; 687 int authenticated; 688 u_int plen; 689 690 passwd = buffer_get_string(m, &plen); 691 /* Only authenticate if the context is valid */ 692 authenticated = options.password_authentication && 693 auth_password(authctxt, passwd); 694 memset(passwd, 0, strlen(passwd)); 695 xfree(passwd); 696 697 buffer_clear(m); 698 buffer_put_int(m, authenticated); 699 700 debug3("%s: sending result %d", __func__, authenticated); 701 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 702 703 call_count++; 704 if (plen == 0 && call_count == 1) 705 auth_method = "none"; 706 else 707 auth_method = "password"; 708 709 /* Causes monitor loop to terminate if authenticated */ 710 return (authenticated); 711} 712 713#ifdef BSD_AUTH 714int 715mm_answer_bsdauthquery(int sock, Buffer *m) 716{ 717 char *name, *infotxt; 718 u_int numprompts; 719 u_int *echo_on; 720 char **prompts; 721 u_int success; 722 723 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 724 &prompts, &echo_on) < 0 ? 0 : 1; 725 726 buffer_clear(m); 727 buffer_put_int(m, success); 728 if (success) 729 buffer_put_cstring(m, prompts[0]); 730 731 debug3("%s: sending challenge success: %u", __func__, success); 732 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 733 734 if (success) { 735 xfree(name); 736 xfree(infotxt); 737 xfree(prompts); 738 xfree(echo_on); 739 } 740 741 return (0); 742} 743 744int 745mm_answer_bsdauthrespond(int sock, Buffer *m) 746{ 747 char *response; 748 int authok; 749 750 if (authctxt->as == 0) 751 fatal("%s: no bsd auth session", __func__); 752 753 response = buffer_get_string(m, NULL); 754 authok = options.challenge_response_authentication && 755 auth_userresponse(authctxt->as, response, 0); 756 authctxt->as = NULL; 757 debug3("%s: <%s> = <%d>", __func__, response, authok); 758 xfree(response); 759 760 buffer_clear(m); 761 buffer_put_int(m, authok); 762 763 debug3("%s: sending authenticated: %d", __func__, authok); 764 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 765 766 auth_method = "bsdauth"; 767 768 return (authok != 0); 769} 770#endif 771 772#ifdef SKEY 773int 774mm_answer_skeyquery(int sock, Buffer *m) 775{ 776 struct skey skey; 777 char challenge[1024]; 778 u_int success; 779 780 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 781 sizeof(challenge)) < 0 ? 0 : 1; 782 783 buffer_clear(m); 784 buffer_put_int(m, success); 785 if (success) 786 buffer_put_cstring(m, challenge); 787 788 debug3("%s: sending challenge success: %u", __func__, success); 789 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 790 791 return (0); 792} 793 794int 795mm_answer_skeyrespond(int sock, Buffer *m) 796{ 797 char *response; 798 int authok; 799 800 response = buffer_get_string(m, NULL); 801 802 authok = (options.challenge_response_authentication && 803 authctxt->valid && 804 skey_haskey(authctxt->pw->pw_name) == 0 && 805 skey_passcheck(authctxt->pw->pw_name, response) != -1); 806 807 xfree(response); 808 809 buffer_clear(m); 810 buffer_put_int(m, authok); 811 812 debug3("%s: sending authenticated: %d", __func__, authok); 813 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 814 815 auth_method = "skey"; 816 817 return (authok != 0); 818} 819#endif 820 821#ifdef USE_PAM 822int 823mm_answer_pam_start(int sock, Buffer *m) 824{ 825 if (!options.use_pam) 826 fatal("UsePAM not set, but ended up in %s anyway", __func__); 827 828 start_pam(authctxt); 829 830 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 831 832 return (0); 833} 834 835int 836mm_answer_pam_account(int sock, Buffer *m) 837{ 838 u_int ret; 839 840 if (!options.use_pam) 841 fatal("UsePAM not set, but ended up in %s anyway", __func__); 842 843 ret = do_pam_account(); 844 845 buffer_put_int(m, ret); 846 buffer_append(&loginmsg, "\0", 1); 847 buffer_put_cstring(m, buffer_ptr(&loginmsg)); 848 buffer_clear(&loginmsg); 849 850 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 851 852 return (ret); 853} 854 855static void *sshpam_ctxt, *sshpam_authok; 856extern KbdintDevice sshpam_device; 857 858int 859mm_answer_pam_init_ctx(int sock, Buffer *m) 860{ 861 862 debug3("%s", __func__); 863 authctxt->user = buffer_get_string(m, NULL); 864 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 865 sshpam_authok = NULL; 866 buffer_clear(m); 867 if (sshpam_ctxt != NULL) { 868 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 869 buffer_put_int(m, 1); 870 } else { 871 buffer_put_int(m, 0); 872 } 873 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 874 return (0); 875} 876 877int 878mm_answer_pam_query(int sock, Buffer *m) 879{ 880 char *name, *info, **prompts; 881 u_int i, num, *echo_on; 882 int ret; 883 884 debug3("%s", __func__); 885 sshpam_authok = NULL; 886 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 887 if (ret == 0 && num == 0) 888 sshpam_authok = sshpam_ctxt; 889 if (num > 1 || name == NULL || info == NULL) 890 ret = -1; 891 buffer_clear(m); 892 buffer_put_int(m, ret); 893 buffer_put_cstring(m, name); 894 xfree(name); 895 buffer_put_cstring(m, info); 896 xfree(info); 897 buffer_put_int(m, num); 898 for (i = 0; i < num; ++i) { 899 buffer_put_cstring(m, prompts[i]); 900 xfree(prompts[i]); 901 buffer_put_int(m, echo_on[i]); 902 } 903 if (prompts != NULL) 904 xfree(prompts); 905 if (echo_on != NULL) 906 xfree(echo_on); 907 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 908 return (0); 909} 910 911int 912mm_answer_pam_respond(int sock, Buffer *m) 913{ 914 char **resp; 915 u_int i, num; 916 int ret; 917 918 debug3("%s", __func__); 919 sshpam_authok = NULL; 920 num = buffer_get_int(m); 921 if (num > 0) { 922 resp = xmalloc(num * sizeof(char *)); 923 for (i = 0; i < num; ++i) 924 resp[i] = buffer_get_string(m, NULL); 925 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 926 for (i = 0; i < num; ++i) 927 xfree(resp[i]); 928 xfree(resp); 929 } else { 930 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 931 } 932 buffer_clear(m); 933 buffer_put_int(m, ret); 934 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 935 auth_method = "keyboard-interactive/pam"; 936 if (ret == 0) 937 sshpam_authok = sshpam_ctxt; 938 return (0); 939} 940 941int 942mm_answer_pam_free_ctx(int sock, Buffer *m) 943{ 944 945 debug3("%s", __func__); 946 (sshpam_device.free_ctx)(sshpam_ctxt); 947 buffer_clear(m); 948 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 949 return (sshpam_authok == sshpam_ctxt); 950} 951#endif 952 953static void 954mm_append_debug(Buffer *m) 955{ 956 if (auth_debug_init && buffer_len(&auth_debug)) { 957 debug3("%s: Appending debug messages for child", __func__); 958 buffer_append(m, buffer_ptr(&auth_debug), 959 buffer_len(&auth_debug)); 960 buffer_clear(&auth_debug); 961 } 962} 963 964int 965mm_answer_keyallowed(int sock, Buffer *m) 966{ 967 Key *key; 968 char *cuser, *chost; 969 u_char *blob; 970 u_int bloblen; 971 enum mm_keytype type = 0; 972 int allowed = 0; 973 974 debug3("%s entering", __func__); 975 976 type = buffer_get_int(m); 977 cuser = buffer_get_string(m, NULL); 978 chost = buffer_get_string(m, NULL); 979 blob = buffer_get_string(m, &bloblen); 980 981 key = key_from_blob(blob, bloblen); 982 983 if ((compat20 && type == MM_RSAHOSTKEY) || 984 (!compat20 && type != MM_RSAHOSTKEY)) 985 fatal("%s: key type and protocol mismatch", __func__); 986 987 debug3("%s: key_from_blob: %p", __func__, key); 988 989 if (key != NULL && authctxt->valid) { 990 switch (type) { 991 case MM_USERKEY: 992 allowed = options.pubkey_authentication && 993 user_key_allowed(authctxt->pw, key); 994 break; 995 case MM_HOSTKEY: 996 allowed = options.hostbased_authentication && 997 hostbased_key_allowed(authctxt->pw, 998 cuser, chost, key); 999 break; 1000 case MM_RSAHOSTKEY: 1001 key->type = KEY_RSA1; /* XXX */ 1002 allowed = options.rhosts_rsa_authentication && 1003 auth_rhosts_rsa_key_allowed(authctxt->pw, 1004 cuser, chost, key); 1005 break; 1006 default: 1007 fatal("%s: unknown key type %d", __func__, type); 1008 break; 1009 } 1010 } 1011 if (key != NULL) 1012 key_free(key); 1013 1014 /* clear temporarily storage (used by verify) */ 1015 monitor_reset_key_state(); 1016 1017 if (allowed) { 1018 /* Save temporarily for comparison in verify */ 1019 key_blob = blob; 1020 key_bloblen = bloblen; 1021 key_blobtype = type; 1022 hostbased_cuser = cuser; 1023 hostbased_chost = chost; 1024 } 1025 1026 debug3("%s: key %p is %s", 1027 __func__, key, allowed ? "allowed" : "disallowed"); 1028 1029 buffer_clear(m); 1030 buffer_put_int(m, allowed); 1031 buffer_put_int(m, forced_command != NULL); 1032 1033 mm_append_debug(m); 1034 1035 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1036 1037 if (type == MM_RSAHOSTKEY) 1038 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1039 1040 return (0); 1041} 1042 1043static int 1044monitor_valid_userblob(u_char *data, u_int datalen) 1045{ 1046 Buffer b; 1047 char *p; 1048 u_int len; 1049 int fail = 0; 1050 1051 buffer_init(&b); 1052 buffer_append(&b, data, datalen); 1053 1054 if (datafellows & SSH_OLD_SESSIONID) { 1055 p = buffer_ptr(&b); 1056 len = buffer_len(&b); 1057 if ((session_id2 == NULL) || 1058 (len < session_id2_len) || 1059 (memcmp(p, session_id2, session_id2_len) != 0)) 1060 fail++; 1061 buffer_consume(&b, session_id2_len); 1062 } else { 1063 p = buffer_get_string(&b, &len); 1064 if ((session_id2 == NULL) || 1065 (len != session_id2_len) || 1066 (memcmp(p, session_id2, session_id2_len) != 0)) 1067 fail++; 1068 xfree(p); 1069 } 1070 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1071 fail++; 1072 p = buffer_get_string(&b, NULL); 1073 if (strcmp(authctxt->user, p) != 0) { 1074 logit("wrong user name passed to monitor: expected %s != %.100s", 1075 authctxt->user, p); 1076 fail++; 1077 } 1078 xfree(p); 1079 buffer_skip_string(&b); 1080 if (datafellows & SSH_BUG_PKAUTH) { 1081 if (!buffer_get_char(&b)) 1082 fail++; 1083 } else { 1084 p = buffer_get_string(&b, NULL); 1085 if (strcmp("publickey", p) != 0) 1086 fail++; 1087 xfree(p); 1088 if (!buffer_get_char(&b)) 1089 fail++; 1090 buffer_skip_string(&b); 1091 } 1092 buffer_skip_string(&b); 1093 if (buffer_len(&b) != 0) 1094 fail++; 1095 buffer_free(&b); 1096 return (fail == 0); 1097} 1098 1099static int 1100monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1101 char *chost) 1102{ 1103 Buffer b; 1104 char *p; 1105 u_int len; 1106 int fail = 0; 1107 1108 buffer_init(&b); 1109 buffer_append(&b, data, datalen); 1110 1111 p = buffer_get_string(&b, &len); 1112 if ((session_id2 == NULL) || 1113 (len != session_id2_len) || 1114 (memcmp(p, session_id2, session_id2_len) != 0)) 1115 fail++; 1116 xfree(p); 1117 1118 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1119 fail++; 1120 p = buffer_get_string(&b, NULL); 1121 if (strcmp(authctxt->user, p) != 0) { 1122 logit("wrong user name passed to monitor: expected %s != %.100s", 1123 authctxt->user, p); 1124 fail++; 1125 } 1126 xfree(p); 1127 buffer_skip_string(&b); /* service */ 1128 p = buffer_get_string(&b, NULL); 1129 if (strcmp(p, "hostbased") != 0) 1130 fail++; 1131 xfree(p); 1132 buffer_skip_string(&b); /* pkalg */ 1133 buffer_skip_string(&b); /* pkblob */ 1134 1135 /* verify client host, strip trailing dot if necessary */ 1136 p = buffer_get_string(&b, NULL); 1137 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1138 p[len - 1] = '\0'; 1139 if (strcmp(p, chost) != 0) 1140 fail++; 1141 xfree(p); 1142 1143 /* verify client user */ 1144 p = buffer_get_string(&b, NULL); 1145 if (strcmp(p, cuser) != 0) 1146 fail++; 1147 xfree(p); 1148 1149 if (buffer_len(&b) != 0) 1150 fail++; 1151 buffer_free(&b); 1152 return (fail == 0); 1153} 1154 1155int 1156mm_answer_keyverify(int sock, Buffer *m) 1157{ 1158 Key *key; 1159 u_char *signature, *data, *blob; 1160 u_int signaturelen, datalen, bloblen; 1161 int verified = 0; 1162 int valid_data = 0; 1163 1164 blob = buffer_get_string(m, &bloblen); 1165 signature = buffer_get_string(m, &signaturelen); 1166 data = buffer_get_string(m, &datalen); 1167 1168 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1169 !monitor_allowed_key(blob, bloblen)) 1170 fatal("%s: bad key, not previously allowed", __func__); 1171 1172 key = key_from_blob(blob, bloblen); 1173 if (key == NULL) 1174 fatal("%s: bad public key blob", __func__); 1175 1176 switch (key_blobtype) { 1177 case MM_USERKEY: 1178 valid_data = monitor_valid_userblob(data, datalen); 1179 break; 1180 case MM_HOSTKEY: 1181 valid_data = monitor_valid_hostbasedblob(data, datalen, 1182 hostbased_cuser, hostbased_chost); 1183 break; 1184 default: 1185 valid_data = 0; 1186 break; 1187 } 1188 if (!valid_data) 1189 fatal("%s: bad signature data blob", __func__); 1190 1191 verified = key_verify(key, signature, signaturelen, data, datalen); 1192 debug3("%s: key %p signature %s", 1193 __func__, key, verified ? "verified" : "unverified"); 1194 1195 key_free(key); 1196 xfree(blob); 1197 xfree(signature); 1198 xfree(data); 1199 1200 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1201 1202 monitor_reset_key_state(); 1203 1204 buffer_clear(m); 1205 buffer_put_int(m, verified); 1206 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1207 1208 return (verified); 1209} 1210 1211static void 1212mm_record_login(Session *s, struct passwd *pw) 1213{ 1214 socklen_t fromlen; 1215 struct sockaddr_storage from; 1216 1217 /* 1218 * Get IP address of client. If the connection is not a socket, let 1219 * the address be 0.0.0.0. 1220 */ 1221 memset(&from, 0, sizeof(from)); 1222 fromlen = sizeof(from); 1223 if (packet_connection_is_on_socket()) { 1224 if (getpeername(packet_get_connection_in(), 1225 (struct sockaddr *) & from, &fromlen) < 0) { 1226 debug("getpeername: %.100s", strerror(errno)); 1227 cleanup_exit(255); 1228 } 1229 } 1230 /* Record that there was a login on that tty from the remote host. */ 1231 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1232 get_remote_name_or_ip(utmp_len, options.use_dns), 1233 (struct sockaddr *)&from, fromlen); 1234} 1235 1236static void 1237mm_session_close(Session *s) 1238{ 1239 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1240 if (s->ttyfd != -1) { 1241 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1242 session_pty_cleanup2(s); 1243 } 1244 s->used = 0; 1245} 1246 1247int 1248mm_answer_pty(int sock, Buffer *m) 1249{ 1250 extern struct monitor *pmonitor; 1251 Session *s; 1252 int res, fd0; 1253 1254 debug3("%s entering", __func__); 1255 1256 buffer_clear(m); 1257 s = session_new(); 1258 if (s == NULL) 1259 goto error; 1260 s->authctxt = authctxt; 1261 s->pw = authctxt->pw; 1262 s->pid = pmonitor->m_pid; 1263 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1264 if (res == 0) 1265 goto error; 1266 pty_setowner(authctxt->pw, s->tty); 1267 1268 buffer_put_int(m, 1); 1269 buffer_put_cstring(m, s->tty); 1270 1271 /* We need to trick ttyslot */ 1272 if (dup2(s->ttyfd, 0) == -1) 1273 fatal("%s: dup2", __func__); 1274 1275 mm_record_login(s, authctxt->pw); 1276 1277 /* Now we can close the file descriptor again */ 1278 close(0); 1279 1280 /* send messages generated by record_login */ 1281 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1282 buffer_clear(&loginmsg); 1283 1284 mm_request_send(sock, MONITOR_ANS_PTY, m); 1285 1286 mm_send_fd(sock, s->ptyfd); 1287 mm_send_fd(sock, s->ttyfd); 1288 1289 /* make sure nothing uses fd 0 */ 1290 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1291 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1292 if (fd0 != 0) 1293 error("%s: fd0 %d != 0", __func__, fd0); 1294 1295 /* slave is not needed */ 1296 close(s->ttyfd); 1297 s->ttyfd = s->ptyfd; 1298 /* no need to dup() because nobody closes ptyfd */ 1299 s->ptymaster = s->ptyfd; 1300 1301 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1302 1303 return (0); 1304 1305 error: 1306 if (s != NULL) 1307 mm_session_close(s); 1308 buffer_put_int(m, 0); 1309 mm_request_send(sock, MONITOR_ANS_PTY, m); 1310 return (0); 1311} 1312 1313int 1314mm_answer_pty_cleanup(int sock, Buffer *m) 1315{ 1316 Session *s; 1317 char *tty; 1318 1319 debug3("%s entering", __func__); 1320 1321 tty = buffer_get_string(m, NULL); 1322 if ((s = session_by_tty(tty)) != NULL) 1323 mm_session_close(s); 1324 buffer_clear(m); 1325 xfree(tty); 1326 return (0); 1327} 1328 1329int 1330mm_answer_sesskey(int sock, Buffer *m) 1331{ 1332 BIGNUM *p; 1333 int rsafail; 1334 1335 /* Turn off permissions */ 1336 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1337 1338 if ((p = BN_new()) == NULL) 1339 fatal("%s: BN_new", __func__); 1340 1341 buffer_get_bignum2(m, p); 1342 1343 rsafail = ssh1_session_key(p); 1344 1345 buffer_clear(m); 1346 buffer_put_int(m, rsafail); 1347 buffer_put_bignum2(m, p); 1348 1349 BN_clear_free(p); 1350 1351 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1352 1353 /* Turn on permissions for sessid passing */ 1354 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1355 1356 return (0); 1357} 1358 1359int 1360mm_answer_sessid(int sock, Buffer *m) 1361{ 1362 int i; 1363 1364 debug3("%s entering", __func__); 1365 1366 if (buffer_len(m) != 16) 1367 fatal("%s: bad ssh1 session id", __func__); 1368 for (i = 0; i < 16; i++) 1369 session_id[i] = buffer_get_char(m); 1370 1371 /* Turn on permissions for getpwnam */ 1372 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1373 1374 return (0); 1375} 1376 1377int 1378mm_answer_rsa_keyallowed(int sock, Buffer *m) 1379{ 1380 BIGNUM *client_n; 1381 Key *key = NULL; 1382 u_char *blob = NULL; 1383 u_int blen = 0; 1384 int allowed = 0; 1385 1386 debug3("%s entering", __func__); 1387 1388 if (options.rsa_authentication && authctxt->valid) { 1389 if ((client_n = BN_new()) == NULL) 1390 fatal("%s: BN_new", __func__); 1391 buffer_get_bignum2(m, client_n); 1392 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1393 BN_clear_free(client_n); 1394 } 1395 buffer_clear(m); 1396 buffer_put_int(m, allowed); 1397 buffer_put_int(m, forced_command != NULL); 1398 1399 /* clear temporarily storage (used by generate challenge) */ 1400 monitor_reset_key_state(); 1401 1402 if (allowed && key != NULL) { 1403 key->type = KEY_RSA; /* cheat for key_to_blob */ 1404 if (key_to_blob(key, &blob, &blen) == 0) 1405 fatal("%s: key_to_blob failed", __func__); 1406 buffer_put_string(m, blob, blen); 1407 1408 /* Save temporarily for comparison in verify */ 1409 key_blob = blob; 1410 key_bloblen = blen; 1411 key_blobtype = MM_RSAUSERKEY; 1412 } 1413 if (key != NULL) 1414 key_free(key); 1415 1416 mm_append_debug(m); 1417 1418 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1419 1420 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1421 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1422 return (0); 1423} 1424 1425int 1426mm_answer_rsa_challenge(int sock, Buffer *m) 1427{ 1428 Key *key = NULL; 1429 u_char *blob; 1430 u_int blen; 1431 1432 debug3("%s entering", __func__); 1433 1434 if (!authctxt->valid) 1435 fatal("%s: authctxt not valid", __func__); 1436 blob = buffer_get_string(m, &blen); 1437 if (!monitor_allowed_key(blob, blen)) 1438 fatal("%s: bad key, not previously allowed", __func__); 1439 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1440 fatal("%s: key type mismatch", __func__); 1441 if ((key = key_from_blob(blob, blen)) == NULL) 1442 fatal("%s: received bad key", __func__); 1443 1444 if (ssh1_challenge) 1445 BN_clear_free(ssh1_challenge); 1446 ssh1_challenge = auth_rsa_generate_challenge(key); 1447 1448 buffer_clear(m); 1449 buffer_put_bignum2(m, ssh1_challenge); 1450 1451 debug3("%s sending reply", __func__); 1452 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1453 1454 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1455 1456 xfree(blob); 1457 key_free(key); 1458 return (0); 1459} 1460 1461int 1462mm_answer_rsa_response(int sock, Buffer *m) 1463{ 1464 Key *key = NULL; 1465 u_char *blob, *response; 1466 u_int blen, len; 1467 int success; 1468 1469 debug3("%s entering", __func__); 1470 1471 if (!authctxt->valid) 1472 fatal("%s: authctxt not valid", __func__); 1473 if (ssh1_challenge == NULL) 1474 fatal("%s: no ssh1_challenge", __func__); 1475 1476 blob = buffer_get_string(m, &blen); 1477 if (!monitor_allowed_key(blob, blen)) 1478 fatal("%s: bad key, not previously allowed", __func__); 1479 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1480 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1481 if ((key = key_from_blob(blob, blen)) == NULL) 1482 fatal("%s: received bad key", __func__); 1483 response = buffer_get_string(m, &len); 1484 if (len != 16) 1485 fatal("%s: received bad response to challenge", __func__); 1486 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1487 1488 xfree(blob); 1489 key_free(key); 1490 xfree(response); 1491 1492 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1493 1494 /* reset state */ 1495 BN_clear_free(ssh1_challenge); 1496 ssh1_challenge = NULL; 1497 monitor_reset_key_state(); 1498 1499 buffer_clear(m); 1500 buffer_put_int(m, success); 1501 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1502 1503 return (success); 1504} 1505 1506int 1507mm_answer_term(int sock, Buffer *req) 1508{ 1509 extern struct monitor *pmonitor; 1510 int res, status; 1511 1512 debug3("%s: tearing down sessions", __func__); 1513 1514 /* The child is terminating */ 1515 session_destroy_all(&mm_session_close); 1516 1517 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1518 if (errno != EINTR) 1519 exit(1); 1520 1521 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1522 1523 /* Terminate process */ 1524 exit(res); 1525} 1526 1527#ifdef SSH_AUDIT_EVENTS 1528/* Report that an audit event occurred */ 1529int 1530mm_answer_audit_event(int socket, Buffer *m) 1531{ 1532 ssh_audit_event_t event; 1533 1534 debug3("%s entering", __func__); 1535 1536 event = buffer_get_int(m); 1537 switch(event) { 1538 case SSH_AUTH_FAIL_PUBKEY: 1539 case SSH_AUTH_FAIL_HOSTBASED: 1540 case SSH_AUTH_FAIL_GSSAPI: 1541 case SSH_LOGIN_EXCEED_MAXTRIES: 1542 case SSH_LOGIN_ROOT_DENIED: 1543 case SSH_CONNECTION_CLOSE: 1544 case SSH_INVALID_USER: 1545 audit_event(event); 1546 break; 1547 default: 1548 fatal("Audit event type %d not permitted", event); 1549 } 1550 1551 return (0); 1552} 1553 1554int 1555mm_answer_audit_command(int socket, Buffer *m) 1556{ 1557 u_int len; 1558 char *cmd; 1559 1560 debug3("%s entering", __func__); 1561 cmd = buffer_get_string(m, &len); 1562 /* sanity check command, if so how? */ 1563 audit_run_command(cmd); 1564 xfree(cmd); 1565 return (0); 1566} 1567#endif /* SSH_AUDIT_EVENTS */ 1568 1569void 1570monitor_apply_keystate(struct monitor *pmonitor) 1571{ 1572 if (compat20) { 1573 set_newkeys(MODE_IN); 1574 set_newkeys(MODE_OUT); 1575 } else { 1576 packet_set_protocol_flags(child_state.ssh1protoflags); 1577 packet_set_encryption_key(child_state.ssh1key, 1578 child_state.ssh1keylen, child_state.ssh1cipher); 1579 xfree(child_state.ssh1key); 1580 } 1581 1582 /* for rc4 and other stateful ciphers */ 1583 packet_set_keycontext(MODE_OUT, child_state.keyout); 1584 xfree(child_state.keyout); 1585 packet_set_keycontext(MODE_IN, child_state.keyin); 1586 xfree(child_state.keyin); 1587 1588 if (!compat20) { 1589 packet_set_iv(MODE_OUT, child_state.ivout); 1590 xfree(child_state.ivout); 1591 packet_set_iv(MODE_IN, child_state.ivin); 1592 xfree(child_state.ivin); 1593 } 1594 1595 memcpy(&incoming_stream, &child_state.incoming, 1596 sizeof(incoming_stream)); 1597 memcpy(&outgoing_stream, &child_state.outgoing, 1598 sizeof(outgoing_stream)); 1599 1600 /* Update with new address */ 1601 if (options.compression) 1602 mm_init_compression(pmonitor->m_zlib); 1603 1604 /* Network I/O buffers */ 1605 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1606 buffer_clear(&input); 1607 buffer_append(&input, child_state.input, child_state.ilen); 1608 memset(child_state.input, 0, child_state.ilen); 1609 xfree(child_state.input); 1610 1611 buffer_clear(&output); 1612 buffer_append(&output, child_state.output, child_state.olen); 1613 memset(child_state.output, 0, child_state.olen); 1614 xfree(child_state.output); 1615} 1616 1617static Kex * 1618mm_get_kex(Buffer *m) 1619{ 1620 Kex *kex; 1621 void *blob; 1622 u_int bloblen; 1623 1624 kex = xmalloc(sizeof(*kex)); 1625 memset(kex, 0, sizeof(*kex)); 1626 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1627 if ((session_id2 == NULL) || 1628 (kex->session_id_len != session_id2_len) || 1629 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1630 fatal("mm_get_get: internal error: bad session id"); 1631 kex->we_need = buffer_get_int(m); 1632 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1633 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1634 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1635 kex->server = 1; 1636 kex->hostkey_type = buffer_get_int(m); 1637 kex->kex_type = buffer_get_int(m); 1638 blob = buffer_get_string(m, &bloblen); 1639 buffer_init(&kex->my); 1640 buffer_append(&kex->my, blob, bloblen); 1641 xfree(blob); 1642 blob = buffer_get_string(m, &bloblen); 1643 buffer_init(&kex->peer); 1644 buffer_append(&kex->peer, blob, bloblen); 1645 xfree(blob); 1646 kex->done = 1; 1647 kex->flags = buffer_get_int(m); 1648 kex->client_version_string = buffer_get_string(m, NULL); 1649 kex->server_version_string = buffer_get_string(m, NULL); 1650 kex->load_host_key=&get_hostkey_by_type; 1651 kex->host_key_index=&get_hostkey_index; 1652 1653 return (kex); 1654} 1655 1656/* This function requries careful sanity checking */ 1657 1658void 1659mm_get_keystate(struct monitor *pmonitor) 1660{ 1661 Buffer m; 1662 u_char *blob, *p; 1663 u_int bloblen, plen; 1664 u_int32_t seqnr, packets; 1665 u_int64_t blocks; 1666 1667 debug3("%s: Waiting for new keys", __func__); 1668 1669 buffer_init(&m); 1670 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1671 if (!compat20) { 1672 child_state.ssh1protoflags = buffer_get_int(&m); 1673 child_state.ssh1cipher = buffer_get_int(&m); 1674 child_state.ssh1key = buffer_get_string(&m, 1675 &child_state.ssh1keylen); 1676 child_state.ivout = buffer_get_string(&m, 1677 &child_state.ivoutlen); 1678 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1679 goto skip; 1680 } else { 1681 /* Get the Kex for rekeying */ 1682 *pmonitor->m_pkex = mm_get_kex(&m); 1683 } 1684 1685 blob = buffer_get_string(&m, &bloblen); 1686 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1687 xfree(blob); 1688 1689 debug3("%s: Waiting for second key", __func__); 1690 blob = buffer_get_string(&m, &bloblen); 1691 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1692 xfree(blob); 1693 1694 /* Now get sequence numbers for the packets */ 1695 seqnr = buffer_get_int(&m); 1696 blocks = buffer_get_int64(&m); 1697 packets = buffer_get_int(&m); 1698 packet_set_state(MODE_OUT, seqnr, blocks, packets); 1699 seqnr = buffer_get_int(&m); 1700 blocks = buffer_get_int64(&m); 1701 packets = buffer_get_int(&m); 1702 packet_set_state(MODE_IN, seqnr, blocks, packets); 1703 1704 skip: 1705 /* Get the key context */ 1706 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1707 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1708 1709 debug3("%s: Getting compression state", __func__); 1710 /* Get compression state */ 1711 p = buffer_get_string(&m, &plen); 1712 if (plen != sizeof(child_state.outgoing)) 1713 fatal("%s: bad request size", __func__); 1714 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1715 xfree(p); 1716 1717 p = buffer_get_string(&m, &plen); 1718 if (plen != sizeof(child_state.incoming)) 1719 fatal("%s: bad request size", __func__); 1720 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1721 xfree(p); 1722 1723 /* Network I/O buffers */ 1724 debug3("%s: Getting Network I/O buffers", __func__); 1725 child_state.input = buffer_get_string(&m, &child_state.ilen); 1726 child_state.output = buffer_get_string(&m, &child_state.olen); 1727 1728 buffer_free(&m); 1729} 1730 1731 1732/* Allocation functions for zlib */ 1733void * 1734mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1735{ 1736 size_t len = (size_t) size * ncount; 1737 void *address; 1738 1739 if (len == 0 || ncount > SIZE_T_MAX / size) 1740 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1741 1742 address = mm_malloc(mm, len); 1743 1744 return (address); 1745} 1746 1747void 1748mm_zfree(struct mm_master *mm, void *address) 1749{ 1750 mm_free(mm, address); 1751} 1752 1753void 1754mm_init_compression(struct mm_master *mm) 1755{ 1756 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1757 outgoing_stream.zfree = (free_func)mm_zfree; 1758 outgoing_stream.opaque = mm; 1759 1760 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1761 incoming_stream.zfree = (free_func)mm_zfree; 1762 incoming_stream.opaque = mm; 1763} 1764 1765/* XXX */ 1766 1767#define FD_CLOSEONEXEC(x) do { \ 1768 if (fcntl(x, F_SETFD, 1) == -1) \ 1769 fatal("fcntl(%d, F_SETFD)", x); \ 1770} while (0) 1771 1772static void 1773monitor_socketpair(int *pair) 1774{ 1775#ifdef HAVE_SOCKETPAIR 1776 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1777 fatal("%s: socketpair", __func__); 1778#else 1779 fatal("%s: UsePrivilegeSeparation=yes not supported", 1780 __func__); 1781#endif 1782 FD_CLOSEONEXEC(pair[0]); 1783 FD_CLOSEONEXEC(pair[1]); 1784} 1785 1786#define MM_MEMSIZE 65536 1787 1788struct monitor * 1789monitor_init(void) 1790{ 1791 struct monitor *mon; 1792 int pair[2]; 1793 1794 mon = xmalloc(sizeof(*mon)); 1795 1796 mon->m_pid = 0; 1797 monitor_socketpair(pair); 1798 1799 mon->m_recvfd = pair[0]; 1800 mon->m_sendfd = pair[1]; 1801 1802 /* Used to share zlib space across processes */ 1803 if (options.compression) { 1804 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1805 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1806 1807 /* Compression needs to share state across borders */ 1808 mm_init_compression(mon->m_zlib); 1809 } 1810 1811 return mon; 1812} 1813 1814void 1815monitor_reinit(struct monitor *mon) 1816{ 1817 int pair[2]; 1818 1819 monitor_socketpair(pair); 1820 1821 mon->m_recvfd = pair[0]; 1822 mon->m_sendfd = pair[1]; 1823} 1824 1825#ifdef GSSAPI 1826int 1827mm_answer_gss_setup_ctx(int sock, Buffer *m) 1828{ 1829 gss_OID_desc goid; 1830 OM_uint32 major; 1831 u_int len; 1832 1833 goid.elements = buffer_get_string(m, &len); 1834 goid.length = len; 1835 1836 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1837 1838 xfree(goid.elements); 1839 1840 buffer_clear(m); 1841 buffer_put_int(m, major); 1842 1843 mm_request_send(sock,MONITOR_ANS_GSSSETUP, m); 1844 1845 /* Now we have a context, enable the step */ 1846 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1847 1848 return (0); 1849} 1850 1851int 1852mm_answer_gss_accept_ctx(int sock, Buffer *m) 1853{ 1854 gss_buffer_desc in; 1855 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1856 OM_uint32 major,minor; 1857 OM_uint32 flags = 0; /* GSI needs this */ 1858 u_int len; 1859 1860 in.value = buffer_get_string(m, &len); 1861 in.length = len; 1862 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1863 xfree(in.value); 1864 1865 buffer_clear(m); 1866 buffer_put_int(m, major); 1867 buffer_put_string(m, out.value, out.length); 1868 buffer_put_int(m, flags); 1869 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1870 1871 gss_release_buffer(&minor, &out); 1872 1873 if (major==GSS_S_COMPLETE) { 1874 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1875 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1876 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1877 } 1878 return (0); 1879} 1880 1881int 1882mm_answer_gss_checkmic(int sock, Buffer *m) 1883{ 1884 gss_buffer_desc gssbuf, mic; 1885 OM_uint32 ret; 1886 u_int len; 1887 1888 gssbuf.value = buffer_get_string(m, &len); 1889 gssbuf.length = len; 1890 mic.value = buffer_get_string(m, &len); 1891 mic.length = len; 1892 1893 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1894 1895 xfree(gssbuf.value); 1896 xfree(mic.value); 1897 1898 buffer_clear(m); 1899 buffer_put_int(m, ret); 1900 1901 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1902 1903 if (!GSS_ERROR(ret)) 1904 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1905 1906 return (0); 1907} 1908 1909int 1910mm_answer_gss_userok(int sock, Buffer *m) 1911{ 1912 int authenticated; 1913 1914 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1915 1916 buffer_clear(m); 1917 buffer_put_int(m, authenticated); 1918 1919 debug3("%s: sending result %d", __func__, authenticated); 1920 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1921 1922 auth_method="gssapi-with-mic"; 1923 1924 /* Monitor loop will terminate if authenticated */ 1925 return (authenticated); 1926} 1927#endif /* GSSAPI */ 1928