1 /* $NetBSD: monitor.c,v 1.5 2010/11/21 18:59:04 adam Exp $ */ 2 /* $OpenBSD: monitor.c,v 1.108 2010/07/13 23:13:16 djm Exp $ */ 3 /* 4 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 5 * Copyright 2002 Markus Friedl <markus@openbsd.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include "includes.h" 30 __RCSID("$NetBSD: monitor.c,v 1.5 2010/11/21 18:59:04 adam Exp $"); 31 #include <sys/types.h> 32 #include <sys/wait.h> 33 #include <sys/socket.h> 34 #include <sys/tree.h> 35 #include <sys/param.h> 36 #include <sys/queue.h> 37 38 #include <openssl/dh.h> 39 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <paths.h> 43 #include <pwd.h> 44 #include <signal.h> 45 #include <stdlib.h> 46 #include <string.h> 47 48 #ifdef SKEY 49 #include <skey.h> 50 #endif 51 52 #include "xmalloc.h" 53 #include "ssh.h" 54 #include "key.h" 55 #include "buffer.h" 56 #include "hostfile.h" 57 #include "auth.h" 58 #include "cipher.h" 59 #include "kex.h" 60 #include "dh.h" 61 #include <zlib.h> 62 #include "packet.h" 63 #include "auth-options.h" 64 #include "sshpty.h" 65 #include "channels.h" 66 #include "session.h" 67 #include "sshlogin.h" 68 #include "canohost.h" 69 #include "log.h" 70 #include "servconf.h" 71 #include "monitor.h" 72 #include "monitor_mm.h" 73 #ifdef GSSAPI 74 #include "ssh-gss.h" 75 #endif 76 #include "monitor_wrap.h" 77 #include "monitor_fdpass.h" 78 #include "misc.h" 79 #include "compat.h" 80 #include "ssh2.h" 81 #include "jpake.h" 82 #include "roaming.h" 83 84 #ifdef GSSAPI 85 static Gssctxt *gsscontext = NULL; 86 #endif 87 88 /* Imports */ 89 extern ServerOptions options; 90 extern u_int utmp_len; 91 extern Newkeys *current_keys[]; 92 extern z_stream incoming_stream; 93 extern z_stream outgoing_stream; 94 extern u_char session_id[]; 95 extern Buffer auth_debug; 96 extern int auth_debug_init; 97 extern Buffer loginmsg; 98 99 /* State exported from the child */ 100 101 struct { 102 z_stream incoming; 103 z_stream outgoing; 104 u_char *keyin; 105 u_int keyinlen; 106 u_char *keyout; 107 u_int keyoutlen; 108 u_char *ivin; 109 u_int ivinlen; 110 u_char *ivout; 111 u_int ivoutlen; 112 u_char *ssh1key; 113 u_int ssh1keylen; 114 int ssh1cipher; 115 int ssh1protoflags; 116 u_char *input; 117 u_int ilen; 118 u_char *output; 119 u_int olen; 120 u_int64_t sent_bytes; 121 u_int64_t recv_bytes; 122 } child_state; 123 124 /* Functions on the monitor that answer unprivileged requests */ 125 126 int mm_answer_moduli(int, Buffer *); 127 int mm_answer_sign(int, Buffer *); 128 int mm_answer_pwnamallow(int, Buffer *); 129 int mm_answer_auth2_read_banner(int, Buffer *); 130 int mm_answer_authserv(int, Buffer *); 131 int mm_answer_authpassword(int, Buffer *); 132 int mm_answer_bsdauthquery(int, Buffer *); 133 int mm_answer_bsdauthrespond(int, Buffer *); 134 int mm_answer_skeyquery(int, Buffer *); 135 int mm_answer_skeyrespond(int, Buffer *); 136 int mm_answer_keyallowed(int, Buffer *); 137 int mm_answer_keyverify(int, Buffer *); 138 int mm_answer_pty(int, Buffer *); 139 int mm_answer_pty_cleanup(int, Buffer *); 140 int mm_answer_term(int, Buffer *); 141 int mm_answer_rsa_keyallowed(int, Buffer *); 142 int mm_answer_rsa_challenge(int, Buffer *); 143 int mm_answer_rsa_response(int, Buffer *); 144 int mm_answer_sesskey(int, Buffer *); 145 int mm_answer_sessid(int, Buffer *); 146 int mm_answer_jpake_get_pwdata(int, Buffer *); 147 int mm_answer_jpake_step1(int, Buffer *); 148 int mm_answer_jpake_step2(int, Buffer *); 149 int mm_answer_jpake_key_confirm(int, Buffer *); 150 int mm_answer_jpake_check_confirm(int, Buffer *); 151 152 #ifdef USE_PAM 153 int mm_answer_pam_start(int, Buffer *); 154 int mm_answer_pam_account(int, Buffer *); 155 int mm_answer_pam_init_ctx(int, Buffer *); 156 int mm_answer_pam_query(int, Buffer *); 157 int mm_answer_pam_respond(int, Buffer *); 158 int mm_answer_pam_free_ctx(int, Buffer *); 159 #endif 160 161 #ifdef KRB4 162 int mm_answer_krb4(int, Buffer *); 163 #endif 164 #ifdef KRB5 165 int mm_answer_krb5(int, Buffer *); 166 #endif 167 168 #ifdef GSSAPI 169 int mm_answer_gss_setup_ctx(int, Buffer *); 170 int mm_answer_gss_accept_ctx(int, Buffer *); 171 int mm_answer_gss_userok(int, Buffer *); 172 int mm_answer_gss_checkmic(int, Buffer *); 173 #endif 174 175 static Authctxt *authctxt; 176 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 177 178 /* local state for key verify */ 179 static u_char *key_blob = NULL; 180 static u_int key_bloblen = 0; 181 static int key_blobtype = MM_NOKEY; 182 static char *hostbased_cuser = NULL; 183 static char *hostbased_chost = NULL; 184 static char *auth_method = "unknown"; 185 static u_int session_id2_len = 0; 186 static u_char *session_id2 = NULL; 187 static pid_t monitor_child_pid; 188 189 struct mon_table { 190 enum monitor_reqtype type; 191 int flags; 192 int (*f)(int, Buffer *); 193 }; 194 195 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 196 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 197 #define MON_ONCE 0x0010 /* Disable after calling */ 198 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 199 200 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 201 202 #define MON_PERMIT 0x1000 /* Request is permitted */ 203 204 struct mon_table mon_dispatch_proto20[] = { 205 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 206 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 207 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 208 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 209 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 210 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 211 #ifdef USE_PAM 212 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 213 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 214 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 215 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 216 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 217 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 218 #endif 219 #ifdef BSD_AUTH 220 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 221 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 222 #endif 223 #ifdef SKEY 224 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 225 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 226 #endif 227 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 228 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 229 #ifdef KRB4 230 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4}, 231 #endif 232 #ifdef KRB5 233 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 234 #endif 235 #ifdef GSSAPI 236 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 237 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 238 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 239 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 240 #endif 241 #ifdef JPAKE 242 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 243 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 244 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 245 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 246 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 247 #endif 248 {0, 0, NULL} 249 }; 250 251 struct mon_table mon_dispatch_postauth20[] = { 252 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 253 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 254 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 255 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 256 {MONITOR_REQ_TERM, 0, mm_answer_term}, 257 {0, 0, NULL} 258 }; 259 260 struct mon_table mon_dispatch_proto15[] = { 261 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 262 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 263 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 264 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 265 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 266 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 267 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 268 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 269 #ifdef BSD_AUTH 270 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 271 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 272 #endif 273 #ifdef SKEY 274 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 275 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 276 #endif 277 #ifdef USE_PAM 278 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 279 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 280 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 281 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 282 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 283 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 284 #endif 285 #ifdef KRB4 286 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4}, 287 #endif 288 #ifdef KRB5 289 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 290 #endif 291 {0, 0, NULL} 292 }; 293 294 struct mon_table mon_dispatch_postauth15[] = { 295 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 296 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 297 {MONITOR_REQ_TERM, 0, mm_answer_term}, 298 {0, 0, NULL} 299 }; 300 301 struct mon_table *mon_dispatch; 302 303 /* Specifies if a certain message is allowed at the moment */ 304 305 static void 306 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 307 { 308 while (ent->f != NULL) { 309 if (ent->type == type) { 310 ent->flags &= ~MON_PERMIT; 311 ent->flags |= permit ? MON_PERMIT : 0; 312 return; 313 } 314 ent++; 315 } 316 } 317 318 static void 319 monitor_permit_authentications(int permit) 320 { 321 struct mon_table *ent = mon_dispatch; 322 323 while (ent->f != NULL) { 324 if (ent->flags & MON_AUTH) { 325 ent->flags &= ~MON_PERMIT; 326 ent->flags |= permit ? MON_PERMIT : 0; 327 } 328 ent++; 329 } 330 } 331 332 void 333 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 334 { 335 struct mon_table *ent; 336 int authenticated = 0; 337 338 debug3("preauth child monitor started"); 339 340 authctxt = _authctxt; 341 memset(authctxt, 0, sizeof(*authctxt)); 342 343 if (compat20) { 344 mon_dispatch = mon_dispatch_proto20; 345 346 /* Permit requests for moduli and signatures */ 347 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 348 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 349 } else { 350 mon_dispatch = mon_dispatch_proto15; 351 352 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 353 } 354 355 /* The first few requests do not require asynchronous access */ 356 while (!authenticated) { 357 auth_method = "unknown"; 358 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 359 if (authenticated) { 360 if (!(ent->flags & MON_AUTHDECIDE)) 361 fatal("%s: unexpected authentication from %d", 362 __func__, ent->type); 363 if (authctxt->pw->pw_uid == 0 && 364 !auth_root_allowed(auth_method)) 365 authenticated = 0; 366 #ifdef USE_PAM 367 /* PAM needs to perform account checks after auth */ 368 if (options.use_pam && authenticated) { 369 Buffer m; 370 371 buffer_init(&m); 372 mm_request_receive_expect(pmonitor->m_sendfd, 373 MONITOR_REQ_PAM_ACCOUNT, &m); 374 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 375 buffer_free(&m); 376 } 377 #endif 378 } 379 380 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 381 auth_log(authctxt, authenticated, auth_method, 382 compat20 ? " ssh2" : ""); 383 if (!authenticated) 384 authctxt->failures++; 385 } 386 #ifdef JPAKE 387 /* Cleanup JPAKE context after authentication */ 388 if (ent->flags & MON_AUTHDECIDE) { 389 if (authctxt->jpake_ctx != NULL) { 390 jpake_free(authctxt->jpake_ctx); 391 authctxt->jpake_ctx = NULL; 392 } 393 } 394 #endif 395 } 396 397 if (!authctxt->valid) 398 fatal("%s: authenticated invalid user", __func__); 399 if (strcmp(auth_method, "unknown") == 0) 400 fatal("%s: authentication method name unknown", __func__); 401 402 debug("%s: %s has been authenticated by privileged process", 403 __func__, authctxt->user); 404 405 mm_get_keystate(pmonitor); 406 } 407 408 static void 409 monitor_set_child_handler(pid_t pid) 410 { 411 monitor_child_pid = pid; 412 } 413 414 static void 415 monitor_child_handler(int sig) 416 { 417 kill(monitor_child_pid, sig); 418 } 419 420 void 421 monitor_child_postauth(struct monitor *pmonitor) 422 { 423 monitor_set_child_handler(pmonitor->m_pid); 424 signal(SIGHUP, &monitor_child_handler); 425 signal(SIGTERM, &monitor_child_handler); 426 signal(SIGINT, &monitor_child_handler); 427 428 if (compat20) { 429 mon_dispatch = mon_dispatch_postauth20; 430 431 /* Permit requests for moduli and signatures */ 432 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 433 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 434 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 435 } else { 436 mon_dispatch = mon_dispatch_postauth15; 437 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 438 } 439 if (!no_pty_flag) { 440 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 441 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 442 } 443 444 for (;;) 445 monitor_read(pmonitor, mon_dispatch, NULL); 446 } 447 448 void 449 monitor_sync(struct monitor *pmonitor) 450 { 451 if (options.compression) { 452 /* The member allocation is not visible, so sync it */ 453 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 454 } 455 } 456 457 int 458 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 459 struct mon_table **pent) 460 { 461 Buffer m; 462 int ret; 463 u_char type; 464 465 buffer_init(&m); 466 467 mm_request_receive(pmonitor->m_sendfd, &m); 468 type = buffer_get_char(&m); 469 470 debug3("%s: checking request %d", __func__, type); 471 472 while (ent->f != NULL) { 473 if (ent->type == type) 474 break; 475 ent++; 476 } 477 478 if (ent->f != NULL) { 479 if (!(ent->flags & MON_PERMIT)) 480 fatal("%s: unpermitted request %d", __func__, 481 type); 482 ret = (*ent->f)(pmonitor->m_sendfd, &m); 483 buffer_free(&m); 484 485 /* The child may use this request only once, disable it */ 486 if (ent->flags & MON_ONCE) { 487 debug2("%s: %d used once, disabling now", __func__, 488 type); 489 ent->flags &= ~MON_PERMIT; 490 } 491 492 if (pent != NULL) 493 *pent = ent; 494 495 return ret; 496 } 497 498 fatal("%s: unsupported request: %d", __func__, type); 499 500 /* NOTREACHED */ 501 return (-1); 502 } 503 504 /* allowed key state */ 505 static int 506 monitor_allowed_key(u_char *blob, u_int bloblen) 507 { 508 /* make sure key is allowed */ 509 if (key_blob == NULL || key_bloblen != bloblen || 510 timingsafe_bcmp(key_blob, blob, key_bloblen)) 511 return (0); 512 return (1); 513 } 514 515 static void 516 monitor_reset_key_state(void) 517 { 518 /* reset state */ 519 if (key_blob != NULL) 520 xfree(key_blob); 521 if (hostbased_cuser != NULL) 522 xfree(hostbased_cuser); 523 if (hostbased_chost != NULL) 524 xfree(hostbased_chost); 525 key_blob = NULL; 526 key_bloblen = 0; 527 key_blobtype = MM_NOKEY; 528 hostbased_cuser = NULL; 529 hostbased_chost = NULL; 530 } 531 532 int 533 mm_answer_moduli(int sock, Buffer *m) 534 { 535 DH *dh; 536 int min, want, max; 537 538 min = buffer_get_int(m); 539 want = buffer_get_int(m); 540 max = buffer_get_int(m); 541 542 debug3("%s: got parameters: %d %d %d", 543 __func__, min, want, max); 544 /* We need to check here, too, in case the child got corrupted */ 545 if (max < min || want < min || max < want) 546 fatal("%s: bad parameters: %d %d %d", 547 __func__, min, want, max); 548 549 buffer_clear(m); 550 551 dh = choose_dh(min, want, max); 552 if (dh == NULL) { 553 buffer_put_char(m, 0); 554 return (0); 555 } else { 556 /* Send first bignum */ 557 buffer_put_char(m, 1); 558 buffer_put_bignum2(m, dh->p); 559 buffer_put_bignum2(m, dh->g); 560 561 DH_free(dh); 562 } 563 mm_request_send(sock, MONITOR_ANS_MODULI, m); 564 return (0); 565 } 566 567 int 568 mm_answer_sign(int sock, Buffer *m) 569 { 570 Key *key; 571 u_char *p; 572 u_char *signature; 573 u_int siglen, datlen; 574 int keyid; 575 576 debug3("%s", __func__); 577 578 keyid = buffer_get_int(m); 579 p = buffer_get_string(m, &datlen); 580 581 /* 582 * Supported KEX types will only return SHA1 (20 byte) or 583 * SHA256 (32 byte) hashes 584 */ 585 if (datlen != 20 && datlen != 32) 586 fatal("%s: data length incorrect: %u", __func__, datlen); 587 588 /* save session id, it will be passed on the first call */ 589 if (session_id2_len == 0) { 590 session_id2_len = datlen; 591 session_id2 = xmalloc(session_id2_len); 592 memcpy(session_id2, p, session_id2_len); 593 } 594 595 if ((key = get_hostkey_by_index(keyid)) == NULL) 596 fatal("%s: no hostkey from index %d", __func__, keyid); 597 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 598 fatal("%s: key_sign failed", __func__); 599 600 debug3("%s: signature %p(%u)", __func__, signature, siglen); 601 602 buffer_clear(m); 603 buffer_put_string(m, signature, siglen); 604 605 xfree(p); 606 xfree(signature); 607 608 mm_request_send(sock, MONITOR_ANS_SIGN, m); 609 610 /* Turn on permissions for getpwnam */ 611 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 612 613 return (0); 614 } 615 616 /* Retrieves the password entry and also checks if the user is permitted */ 617 618 int 619 mm_answer_pwnamallow(int sock, Buffer *m) 620 { 621 char *username; 622 struct passwd *pwent; 623 int allowed = 0; 624 625 debug3("%s", __func__); 626 627 if (authctxt->attempt++ != 0) 628 fatal("%s: multiple attempts for getpwnam", __func__); 629 630 username = buffer_get_string(m, NULL); 631 632 pwent = getpwnamallow(username); 633 634 authctxt->user = xstrdup(username); 635 setproctitle("%s [priv]", pwent ? username : "unknown"); 636 xfree(username); 637 638 buffer_clear(m); 639 640 if (pwent == NULL) { 641 buffer_put_char(m, 0); 642 authctxt->pw = fakepw(); 643 goto out; 644 } 645 646 allowed = 1; 647 authctxt->pw = pwent; 648 authctxt->valid = 1; 649 650 buffer_put_char(m, 1); 651 buffer_put_string(m, pwent, sizeof(struct passwd)); 652 buffer_put_cstring(m, pwent->pw_name); 653 buffer_put_cstring(m, "*"); 654 buffer_put_cstring(m, pwent->pw_gecos); 655 buffer_put_cstring(m, pwent->pw_class); 656 buffer_put_cstring(m, pwent->pw_dir); 657 buffer_put_cstring(m, pwent->pw_shell); 658 659 out: 660 buffer_put_string(m, &options, sizeof(options)); 661 if (options.banner != NULL) 662 buffer_put_cstring(m, options.banner); 663 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 664 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 665 666 /* For SSHv1 allow authentication now */ 667 if (!compat20) 668 monitor_permit_authentications(1); 669 else { 670 /* Allow service/style information on the auth context */ 671 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 672 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 673 } 674 675 #ifdef USE_PAM 676 if (options.use_pam) 677 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 678 #endif 679 680 return (0); 681 } 682 683 int mm_answer_auth2_read_banner(int sock, Buffer *m) 684 { 685 char *banner; 686 687 buffer_clear(m); 688 banner = auth2_read_banner(); 689 buffer_put_cstring(m, banner != NULL ? banner : ""); 690 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 691 692 if (banner != NULL) 693 xfree(banner); 694 695 return (0); 696 } 697 698 int 699 mm_answer_authserv(int sock, Buffer *m) 700 { 701 monitor_permit_authentications(1); 702 703 authctxt->service = buffer_get_string(m, NULL); 704 authctxt->style = buffer_get_string(m, NULL); 705 debug3("%s: service=%s, style=%s", 706 __func__, authctxt->service, authctxt->style); 707 708 if (strlen(authctxt->style) == 0) { 709 xfree(authctxt->style); 710 authctxt->style = NULL; 711 } 712 713 return (0); 714 } 715 716 int 717 mm_answer_authpassword(int sock, Buffer *m) 718 { 719 static int call_count; 720 char *passwd; 721 int authenticated; 722 u_int plen; 723 724 passwd = buffer_get_string(m, &plen); 725 /* Only authenticate if the context is valid */ 726 authenticated = options.password_authentication && 727 auth_password(authctxt, passwd); 728 memset(passwd, 0, strlen(passwd)); 729 xfree(passwd); 730 731 buffer_clear(m); 732 buffer_put_int(m, authenticated); 733 734 debug3("%s: sending result %d", __func__, authenticated); 735 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 736 737 call_count++; 738 if (plen == 0 && call_count == 1) 739 auth_method = "none"; 740 else 741 auth_method = "password"; 742 743 /* Causes monitor loop to terminate if authenticated */ 744 return (authenticated); 745 } 746 747 #ifdef BSD_AUTH 748 int 749 mm_answer_bsdauthquery(int sock, Buffer *m) 750 { 751 char *name, *infotxt; 752 u_int numprompts; 753 u_int *echo_on; 754 char **prompts; 755 u_int success; 756 757 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 758 &prompts, &echo_on) < 0 ? 0 : 1; 759 760 buffer_clear(m); 761 buffer_put_int(m, success); 762 if (success) 763 buffer_put_cstring(m, prompts[0]); 764 765 debug3("%s: sending challenge success: %u", __func__, success); 766 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 767 768 if (success) { 769 xfree(name); 770 xfree(infotxt); 771 xfree(prompts); 772 xfree(echo_on); 773 } 774 775 return (0); 776 } 777 778 int 779 mm_answer_bsdauthrespond(int sock, Buffer *m) 780 { 781 char *response; 782 int authok; 783 784 if (authctxt->as == 0) 785 fatal("%s: no bsd auth session", __func__); 786 787 response = buffer_get_string(m, NULL); 788 authok = options.challenge_response_authentication && 789 auth_userresponse(authctxt->as, response, 0); 790 authctxt->as = NULL; 791 debug3("%s: <%s> = <%d>", __func__, response, authok); 792 xfree(response); 793 794 buffer_clear(m); 795 buffer_put_int(m, authok); 796 797 debug3("%s: sending authenticated: %d", __func__, authok); 798 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 799 800 auth_method = "bsdauth"; 801 802 return (authok != 0); 803 } 804 #endif 805 806 #ifdef SKEY 807 int 808 mm_answer_skeyquery(int sock, Buffer *m) 809 { 810 struct skey skey; 811 char challenge[1024]; 812 u_int success; 813 814 success = skeychallenge(&skey, authctxt->user, challenge, 815 sizeof(challenge)) < 0 ? 0 : 1; 816 817 buffer_clear(m); 818 buffer_put_int(m, success); 819 if (success) 820 buffer_put_cstring(m, challenge); 821 822 debug3("%s: sending challenge success: %u", __func__, success); 823 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 824 825 return (0); 826 } 827 828 int 829 mm_answer_skeyrespond(int sock, Buffer *m) 830 { 831 char *response; 832 int authok; 833 834 response = buffer_get_string(m, NULL); 835 836 authok = (options.challenge_response_authentication && 837 authctxt->valid && 838 skey_haskey(authctxt->pw->pw_name) == 0 && 839 skey_passcheck(authctxt->pw->pw_name, response) != -1); 840 841 xfree(response); 842 843 buffer_clear(m); 844 buffer_put_int(m, authok); 845 846 debug3("%s: sending authenticated: %d", __func__, authok); 847 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 848 849 auth_method = "skey"; 850 851 return (authok != 0); 852 } 853 #endif 854 855 #ifdef USE_PAM 856 int 857 mm_answer_pam_start(int sock, Buffer *m) 858 { 859 if (!options.use_pam) 860 fatal("UsePAM not set, but ended up in %s anyway", __func__); 861 862 start_pam(authctxt); 863 864 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 865 866 return (0); 867 } 868 869 int 870 mm_answer_pam_account(int sock, Buffer *m) 871 { 872 u_int ret; 873 874 if (!options.use_pam) 875 fatal("UsePAM not set, but ended up in %s anyway", __func__); 876 877 ret = do_pam_account(); 878 879 buffer_put_int(m, ret); 880 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 881 882 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 883 884 return (ret); 885 } 886 887 static void *sshpam_ctxt, *sshpam_authok; 888 extern KbdintDevice sshpam_device; 889 890 int 891 mm_answer_pam_init_ctx(int sock, Buffer *m) 892 { 893 894 debug3("%s", __func__); 895 authctxt->user = buffer_get_string(m, NULL); 896 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 897 sshpam_authok = NULL; 898 buffer_clear(m); 899 if (sshpam_ctxt != NULL) { 900 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 901 buffer_put_int(m, 1); 902 } else { 903 buffer_put_int(m, 0); 904 } 905 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 906 return (0); 907 } 908 909 int 910 mm_answer_pam_query(int sock, Buffer *m) 911 { 912 char *name, *info, **prompts; 913 u_int num, *echo_on; 914 int i, ret; 915 916 debug3("%s", __func__); 917 sshpam_authok = NULL; 918 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 919 if (ret == 0 && num == 0) 920 sshpam_authok = sshpam_ctxt; 921 if (num > 1 || name == NULL || info == NULL) 922 ret = -1; 923 buffer_clear(m); 924 buffer_put_int(m, ret); 925 buffer_put_cstring(m, name); 926 xfree(name); 927 buffer_put_cstring(m, info); 928 xfree(info); 929 buffer_put_int(m, num); 930 for (i = 0; i < num; ++i) { 931 buffer_put_cstring(m, prompts[i]); 932 xfree(prompts[i]); 933 buffer_put_int(m, echo_on[i]); 934 } 935 if (prompts != NULL) 936 xfree(prompts); 937 if (echo_on != NULL) 938 xfree(echo_on); 939 auth_method = "keyboard-interactive/pam"; 940 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 941 return (0); 942 } 943 944 int 945 mm_answer_pam_respond(int sock, Buffer *m) 946 { 947 char **resp; 948 u_int num; 949 int i, ret; 950 951 debug3("%s", __func__); 952 sshpam_authok = NULL; 953 num = buffer_get_int(m); 954 if (num > 0) { 955 resp = xmalloc(num * sizeof(char *)); 956 for (i = 0; i < num; ++i) 957 resp[i] = buffer_get_string(m, NULL); 958 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 959 for (i = 0; i < num; ++i) 960 xfree(resp[i]); 961 xfree(resp); 962 } else { 963 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 964 } 965 buffer_clear(m); 966 buffer_put_int(m, ret); 967 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 968 auth_method = "keyboard-interactive/pam"; 969 if (ret == 0) 970 sshpam_authok = sshpam_ctxt; 971 return (0); 972 } 973 974 int 975 mm_answer_pam_free_ctx(int sock, Buffer *m) 976 { 977 978 debug3("%s", __func__); 979 (sshpam_device.free_ctx)(sshpam_ctxt); 980 buffer_clear(m); 981 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 982 auth_method = "keyboard-interactive/pam"; 983 return (sshpam_authok == sshpam_ctxt); 984 } 985 #endif 986 987 int 988 mm_answer_keyallowed(int sock, Buffer *m) 989 { 990 Key *key; 991 char *cuser, *chost; 992 u_char *blob; 993 u_int bloblen; 994 enum mm_keytype type = 0; 995 int allowed = 0; 996 997 debug3("%s entering", __func__); 998 999 type = buffer_get_int(m); 1000 cuser = buffer_get_string(m, NULL); 1001 chost = buffer_get_string(m, NULL); 1002 blob = buffer_get_string(m, &bloblen); 1003 1004 key = key_from_blob(blob, bloblen); 1005 1006 if ((compat20 && type == MM_RSAHOSTKEY) || 1007 (!compat20 && type != MM_RSAHOSTKEY)) 1008 fatal("%s: key type and protocol mismatch", __func__); 1009 1010 debug3("%s: key_from_blob: %p", __func__, key); 1011 1012 if (key != NULL && authctxt->valid) { 1013 switch (type) { 1014 case MM_USERKEY: 1015 allowed = options.pubkey_authentication && 1016 user_key_allowed(authctxt->pw, key); 1017 auth_method = "publickey"; 1018 if (options.pubkey_authentication && allowed != 1) 1019 auth_clear_options(); 1020 break; 1021 case MM_HOSTKEY: 1022 allowed = options.hostbased_authentication && 1023 hostbased_key_allowed(authctxt->pw, 1024 cuser, chost, key); 1025 auth_method = "hostbased"; 1026 break; 1027 case MM_RSAHOSTKEY: 1028 key->type = KEY_RSA1; /* XXX */ 1029 allowed = options.rhosts_rsa_authentication && 1030 auth_rhosts_rsa_key_allowed(authctxt->pw, 1031 cuser, chost, key); 1032 if (options.rhosts_rsa_authentication && allowed != 1) 1033 auth_clear_options(); 1034 auth_method = "rsa"; 1035 break; 1036 default: 1037 fatal("%s: unknown key type %d", __func__, type); 1038 break; 1039 } 1040 } 1041 if (key != NULL) 1042 key_free(key); 1043 1044 /* clear temporarily storage (used by verify) */ 1045 monitor_reset_key_state(); 1046 1047 if (allowed) { 1048 /* Save temporarily for comparison in verify */ 1049 key_blob = blob; 1050 key_bloblen = bloblen; 1051 key_blobtype = type; 1052 hostbased_cuser = cuser; 1053 hostbased_chost = chost; 1054 } else { 1055 /* Log failed attempt */ 1056 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 1057 xfree(blob); 1058 xfree(cuser); 1059 xfree(chost); 1060 } 1061 1062 debug3("%s: key %p is %s", 1063 __func__, key, allowed ? "allowed" : "not allowed"); 1064 1065 buffer_clear(m); 1066 buffer_put_int(m, allowed); 1067 buffer_put_int(m, forced_command != NULL); 1068 1069 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1070 1071 if (type == MM_RSAHOSTKEY) 1072 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1073 1074 return (0); 1075 } 1076 1077 static int 1078 monitor_valid_userblob(u_char *data, u_int datalen) 1079 { 1080 Buffer b; 1081 char *p; 1082 u_int len; 1083 int fail = 0; 1084 1085 buffer_init(&b); 1086 buffer_append(&b, data, datalen); 1087 1088 if (datafellows & SSH_OLD_SESSIONID) { 1089 p = buffer_ptr(&b); 1090 len = buffer_len(&b); 1091 if ((session_id2 == NULL) || 1092 (len < session_id2_len) || 1093 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1094 fail++; 1095 buffer_consume(&b, session_id2_len); 1096 } else { 1097 p = buffer_get_string(&b, &len); 1098 if ((session_id2 == NULL) || 1099 (len != session_id2_len) || 1100 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1101 fail++; 1102 xfree(p); 1103 } 1104 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1105 fail++; 1106 p = buffer_get_string(&b, NULL); 1107 if (strcmp(authctxt->user, p) != 0) { 1108 logit("wrong user name passed to monitor: expected %s != %.100s", 1109 authctxt->user, p); 1110 fail++; 1111 } 1112 xfree(p); 1113 buffer_skip_string(&b); 1114 if (datafellows & SSH_BUG_PKAUTH) { 1115 if (!buffer_get_char(&b)) 1116 fail++; 1117 } else { 1118 p = buffer_get_string(&b, NULL); 1119 if (strcmp("publickey", p) != 0) 1120 fail++; 1121 xfree(p); 1122 if (!buffer_get_char(&b)) 1123 fail++; 1124 buffer_skip_string(&b); 1125 } 1126 buffer_skip_string(&b); 1127 if (buffer_len(&b) != 0) 1128 fail++; 1129 buffer_free(&b); 1130 return (fail == 0); 1131 } 1132 1133 static int 1134 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1135 char *chost) 1136 { 1137 Buffer b; 1138 char *p; 1139 u_int len; 1140 int fail = 0; 1141 1142 buffer_init(&b); 1143 buffer_append(&b, data, datalen); 1144 1145 p = buffer_get_string(&b, &len); 1146 if ((session_id2 == NULL) || 1147 (len != session_id2_len) || 1148 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1149 fail++; 1150 xfree(p); 1151 1152 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1153 fail++; 1154 p = buffer_get_string(&b, NULL); 1155 if (strcmp(authctxt->user, p) != 0) { 1156 logit("wrong user name passed to monitor: expected %s != %.100s", 1157 authctxt->user, p); 1158 fail++; 1159 } 1160 xfree(p); 1161 buffer_skip_string(&b); /* service */ 1162 p = buffer_get_string(&b, NULL); 1163 if (strcmp(p, "hostbased") != 0) 1164 fail++; 1165 xfree(p); 1166 buffer_skip_string(&b); /* pkalg */ 1167 buffer_skip_string(&b); /* pkblob */ 1168 1169 /* verify client host, strip trailing dot if necessary */ 1170 p = buffer_get_string(&b, NULL); 1171 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1172 p[len - 1] = '\0'; 1173 if (strcmp(p, chost) != 0) 1174 fail++; 1175 xfree(p); 1176 1177 /* verify client user */ 1178 p = buffer_get_string(&b, NULL); 1179 if (strcmp(p, cuser) != 0) 1180 fail++; 1181 xfree(p); 1182 1183 if (buffer_len(&b) != 0) 1184 fail++; 1185 buffer_free(&b); 1186 return (fail == 0); 1187 } 1188 1189 int 1190 mm_answer_keyverify(int sock, Buffer *m) 1191 { 1192 Key *key; 1193 u_char *signature, *data, *blob; 1194 u_int signaturelen, datalen, bloblen; 1195 int verified = 0; 1196 int valid_data = 0; 1197 1198 blob = buffer_get_string(m, &bloblen); 1199 signature = buffer_get_string(m, &signaturelen); 1200 data = buffer_get_string(m, &datalen); 1201 1202 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1203 !monitor_allowed_key(blob, bloblen)) 1204 fatal("%s: bad key, not previously allowed", __func__); 1205 1206 key = key_from_blob(blob, bloblen); 1207 if (key == NULL) 1208 fatal("%s: bad public key blob", __func__); 1209 1210 switch (key_blobtype) { 1211 case MM_USERKEY: 1212 valid_data = monitor_valid_userblob(data, datalen); 1213 break; 1214 case MM_HOSTKEY: 1215 valid_data = monitor_valid_hostbasedblob(data, datalen, 1216 hostbased_cuser, hostbased_chost); 1217 break; 1218 default: 1219 valid_data = 0; 1220 break; 1221 } 1222 if (!valid_data) 1223 fatal("%s: bad signature data blob", __func__); 1224 1225 verified = key_verify(key, signature, signaturelen, data, datalen); 1226 debug3("%s: key %p signature %s", 1227 __func__, key, (verified == 1) ? "verified" : "unverified"); 1228 1229 key_free(key); 1230 xfree(blob); 1231 xfree(signature); 1232 xfree(data); 1233 1234 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1235 1236 monitor_reset_key_state(); 1237 1238 buffer_clear(m); 1239 buffer_put_int(m, verified); 1240 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1241 1242 return (verified == 1); 1243 } 1244 1245 static void 1246 mm_record_login(Session *s, struct passwd *pw) 1247 { 1248 socklen_t fromlen; 1249 struct sockaddr_storage from; 1250 1251 /* 1252 * Get IP address of client. If the connection is not a socket, let 1253 * the address be 0.0.0.0. 1254 */ 1255 memset(&from, 0, sizeof(from)); 1256 fromlen = sizeof(from); 1257 if (packet_connection_is_on_socket()) { 1258 if (getpeername(packet_get_connection_in(), 1259 (struct sockaddr *)&from, &fromlen) < 0) { 1260 debug("getpeername: %.100s", strerror(errno)); 1261 cleanup_exit(255); 1262 } 1263 } 1264 /* Record that there was a login on that tty from the remote host. */ 1265 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1266 get_remote_name_or_ip(utmp_len, options.use_dns), 1267 (struct sockaddr *)&from, fromlen); 1268 } 1269 1270 static void 1271 mm_session_close(Session *s) 1272 { 1273 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1274 if (s->ttyfd != -1) { 1275 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1276 session_pty_cleanup2(s); 1277 } 1278 session_unused(s->self); 1279 } 1280 1281 int 1282 mm_answer_pty(int sock, Buffer *m) 1283 { 1284 extern struct monitor *pmonitor; 1285 Session *s; 1286 int res, fd0; 1287 1288 debug3("%s entering", __func__); 1289 1290 buffer_clear(m); 1291 s = session_new(); 1292 if (s == NULL) 1293 goto error; 1294 s->authctxt = authctxt; 1295 s->pw = authctxt->pw; 1296 s->pid = pmonitor->m_pid; 1297 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1298 if (res == 0) 1299 goto error; 1300 pty_setowner(authctxt->pw, s->tty); 1301 1302 buffer_put_int(m, 1); 1303 buffer_put_cstring(m, s->tty); 1304 1305 /* We need to trick ttyslot */ 1306 if (dup2(s->ttyfd, 0) == -1) 1307 fatal("%s: dup2", __func__); 1308 1309 mm_record_login(s, authctxt->pw); 1310 1311 /* Now we can close the file descriptor again */ 1312 close(0); 1313 1314 /* send messages generated by record_login */ 1315 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1316 buffer_clear(&loginmsg); 1317 1318 mm_request_send(sock, MONITOR_ANS_PTY, m); 1319 1320 if (mm_send_fd(sock, s->ptyfd) == -1 || 1321 mm_send_fd(sock, s->ttyfd) == -1) 1322 fatal("%s: send fds failed", __func__); 1323 1324 /* make sure nothing uses fd 0 */ 1325 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1326 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1327 if (fd0 != 0) 1328 error("%s: fd0 %d != 0", __func__, fd0); 1329 1330 /* slave is not needed */ 1331 close(s->ttyfd); 1332 s->ttyfd = s->ptyfd; 1333 /* no need to dup() because nobody closes ptyfd */ 1334 s->ptymaster = s->ptyfd; 1335 1336 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1337 1338 return (0); 1339 1340 error: 1341 if (s != NULL) 1342 mm_session_close(s); 1343 buffer_put_int(m, 0); 1344 mm_request_send(sock, MONITOR_ANS_PTY, m); 1345 return (0); 1346 } 1347 1348 int 1349 mm_answer_pty_cleanup(int sock, Buffer *m) 1350 { 1351 Session *s; 1352 char *tty; 1353 1354 debug3("%s entering", __func__); 1355 1356 tty = buffer_get_string(m, NULL); 1357 if ((s = session_by_tty(tty)) != NULL) 1358 mm_session_close(s); 1359 buffer_clear(m); 1360 xfree(tty); 1361 return (0); 1362 } 1363 1364 int 1365 mm_answer_sesskey(int sock, Buffer *m) 1366 { 1367 BIGNUM *p; 1368 int rsafail; 1369 1370 /* Turn off permissions */ 1371 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1372 1373 if ((p = BN_new()) == NULL) 1374 fatal("%s: BN_new", __func__); 1375 1376 buffer_get_bignum2(m, p); 1377 1378 rsafail = ssh1_session_key(p); 1379 1380 buffer_clear(m); 1381 buffer_put_int(m, rsafail); 1382 buffer_put_bignum2(m, p); 1383 1384 BN_clear_free(p); 1385 1386 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1387 1388 /* Turn on permissions for sessid passing */ 1389 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1390 1391 return (0); 1392 } 1393 1394 int 1395 mm_answer_sessid(int sock, Buffer *m) 1396 { 1397 int i; 1398 1399 debug3("%s entering", __func__); 1400 1401 if (buffer_len(m) != 16) 1402 fatal("%s: bad ssh1 session id", __func__); 1403 for (i = 0; i < 16; i++) 1404 session_id[i] = buffer_get_char(m); 1405 1406 /* Turn on permissions for getpwnam */ 1407 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1408 1409 return (0); 1410 } 1411 1412 int 1413 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1414 { 1415 BIGNUM *client_n; 1416 Key *key = NULL; 1417 u_char *blob = NULL; 1418 u_int blen = 0; 1419 int allowed = 0; 1420 1421 debug3("%s entering", __func__); 1422 1423 auth_method = "rsa"; 1424 if (options.rsa_authentication && authctxt->valid) { 1425 if ((client_n = BN_new()) == NULL) 1426 fatal("%s: BN_new", __func__); 1427 buffer_get_bignum2(m, client_n); 1428 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1429 BN_clear_free(client_n); 1430 } 1431 buffer_clear(m); 1432 buffer_put_int(m, allowed); 1433 buffer_put_int(m, forced_command != NULL); 1434 1435 /* clear temporarily storage (used by generate challenge) */ 1436 monitor_reset_key_state(); 1437 1438 if (allowed && key != NULL) { 1439 key->type = KEY_RSA; /* cheat for key_to_blob */ 1440 if (key_to_blob(key, &blob, &blen) == 0) 1441 fatal("%s: key_to_blob failed", __func__); 1442 buffer_put_string(m, blob, blen); 1443 1444 /* Save temporarily for comparison in verify */ 1445 key_blob = blob; 1446 key_bloblen = blen; 1447 key_blobtype = MM_RSAUSERKEY; 1448 } 1449 if (key != NULL) 1450 key_free(key); 1451 1452 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1453 1454 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1455 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1456 return (0); 1457 } 1458 1459 int 1460 mm_answer_rsa_challenge(int sock, Buffer *m) 1461 { 1462 Key *key = NULL; 1463 u_char *blob; 1464 u_int blen; 1465 1466 debug3("%s entering", __func__); 1467 1468 if (!authctxt->valid) 1469 fatal("%s: authctxt not valid", __func__); 1470 blob = buffer_get_string(m, &blen); 1471 if (!monitor_allowed_key(blob, blen)) 1472 fatal("%s: bad key, not previously allowed", __func__); 1473 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1474 fatal("%s: key type mismatch", __func__); 1475 if ((key = key_from_blob(blob, blen)) == NULL) 1476 fatal("%s: received bad key", __func__); 1477 if (key->type != KEY_RSA) 1478 fatal("%s: received bad key type %d", __func__, key->type); 1479 key->type = KEY_RSA1; 1480 if (ssh1_challenge) 1481 BN_clear_free(ssh1_challenge); 1482 ssh1_challenge = auth_rsa_generate_challenge(key); 1483 1484 buffer_clear(m); 1485 buffer_put_bignum2(m, ssh1_challenge); 1486 1487 debug3("%s sending reply", __func__); 1488 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1489 1490 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1491 1492 xfree(blob); 1493 key_free(key); 1494 return (0); 1495 } 1496 1497 int 1498 mm_answer_rsa_response(int sock, Buffer *m) 1499 { 1500 Key *key = NULL; 1501 u_char *blob, *response; 1502 u_int blen, len; 1503 int success; 1504 1505 debug3("%s entering", __func__); 1506 1507 if (!authctxt->valid) 1508 fatal("%s: authctxt not valid", __func__); 1509 if (ssh1_challenge == NULL) 1510 fatal("%s: no ssh1_challenge", __func__); 1511 1512 blob = buffer_get_string(m, &blen); 1513 if (!monitor_allowed_key(blob, blen)) 1514 fatal("%s: bad key, not previously allowed", __func__); 1515 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1516 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1517 if ((key = key_from_blob(blob, blen)) == NULL) 1518 fatal("%s: received bad key", __func__); 1519 response = buffer_get_string(m, &len); 1520 if (len != 16) 1521 fatal("%s: received bad response to challenge", __func__); 1522 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1523 1524 xfree(blob); 1525 key_free(key); 1526 xfree(response); 1527 1528 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1529 1530 /* reset state */ 1531 BN_clear_free(ssh1_challenge); 1532 ssh1_challenge = NULL; 1533 monitor_reset_key_state(); 1534 1535 buffer_clear(m); 1536 buffer_put_int(m, success); 1537 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1538 1539 return (success); 1540 } 1541 1542 #ifdef KRB4 1543 int 1544 mm_answer_krb4(int socket, Buffer *m) 1545 { 1546 KTEXT_ST auth, reply; 1547 char *client, *p; 1548 int success; 1549 u_int alen; 1550 1551 reply.length = auth.length = 0; 1552 1553 p = buffer_get_string(m, &alen); 1554 if (alen >= MAX_KTXT_LEN) 1555 fatal("%s: auth too large", __func__); 1556 memcpy(auth.dat, p, alen); 1557 auth.length = alen; 1558 memset(p, 0, alen); 1559 xfree(p); 1560 1561 success = options.kerberos_authentication && 1562 authctxt->valid && 1563 auth_krb4(authctxt, &auth, &client, &reply); 1564 1565 memset(auth.dat, 0, alen); 1566 buffer_clear(m); 1567 buffer_put_int(m, success); 1568 1569 if (success) { 1570 buffer_put_cstring(m, client); 1571 buffer_put_string(m, reply.dat, reply.length); 1572 if (client) 1573 xfree(client); 1574 if (reply.length) 1575 memset(reply.dat, 0, reply.length); 1576 } 1577 1578 debug3("%s: sending result %d", __func__, success); 1579 mm_request_send(socket, MONITOR_ANS_KRB4, m); 1580 1581 auth_method = "kerberos"; 1582 1583 /* Causes monitor loop to terminate if authenticated */ 1584 return (success); 1585 } 1586 #endif 1587 1588 #ifdef KRB5 1589 int 1590 mm_answer_krb5(int socket, Buffer *m) 1591 { 1592 krb5_data tkt, reply; 1593 char *client_user; 1594 u_int len; 1595 int success; 1596 1597 /* use temporary var to avoid size issues on 64bit arch */ 1598 tkt.data = buffer_get_string(m, &len); 1599 tkt.length = len; 1600 1601 success = options.kerberos_authentication && 1602 authctxt->valid && 1603 auth_krb5(authctxt, &tkt, &client_user, &reply); 1604 1605 if (tkt.length) 1606 xfree(tkt.data); 1607 1608 buffer_clear(m); 1609 buffer_put_int(m, success); 1610 1611 if (success) { 1612 buffer_put_cstring(m, client_user); 1613 buffer_put_string(m, reply.data, reply.length); 1614 if (client_user) 1615 xfree(client_user); 1616 if (reply.length) 1617 xfree(reply.data); 1618 } 1619 mm_request_send(socket, MONITOR_ANS_KRB5, m); 1620 1621 auth_method = "kerberos"; 1622 1623 return success; 1624 } 1625 #endif 1626 1627 int 1628 mm_answer_term(int sock, Buffer *req) 1629 { 1630 extern struct monitor *pmonitor; 1631 int res, status; 1632 1633 debug3("%s: tearing down sessions", __func__); 1634 1635 /* The child is terminating */ 1636 session_destroy_all(&mm_session_close); 1637 1638 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1639 if (errno != EINTR) 1640 exit(1); 1641 1642 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1643 1644 /* Terminate process */ 1645 exit(res); 1646 } 1647 1648 void 1649 monitor_apply_keystate(struct monitor *pmonitor) 1650 { 1651 if (compat20) { 1652 set_newkeys(MODE_IN); 1653 set_newkeys(MODE_OUT); 1654 } else { 1655 packet_set_protocol_flags(child_state.ssh1protoflags); 1656 packet_set_encryption_key(child_state.ssh1key, 1657 child_state.ssh1keylen, child_state.ssh1cipher); 1658 xfree(child_state.ssh1key); 1659 } 1660 1661 /* for rc4 and other stateful ciphers */ 1662 packet_set_keycontext(MODE_OUT, child_state.keyout); 1663 xfree(child_state.keyout); 1664 packet_set_keycontext(MODE_IN, child_state.keyin); 1665 xfree(child_state.keyin); 1666 1667 if (!compat20) { 1668 packet_set_iv(MODE_OUT, child_state.ivout); 1669 xfree(child_state.ivout); 1670 packet_set_iv(MODE_IN, child_state.ivin); 1671 xfree(child_state.ivin); 1672 } 1673 1674 memcpy(&incoming_stream, &child_state.incoming, 1675 sizeof(incoming_stream)); 1676 memcpy(&outgoing_stream, &child_state.outgoing, 1677 sizeof(outgoing_stream)); 1678 1679 /* Update with new address */ 1680 if (options.compression) 1681 mm_init_compression(pmonitor->m_zlib); 1682 1683 /* Network I/O buffers */ 1684 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1685 buffer_clear(packet_get_input()); 1686 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1687 memset(child_state.input, 0, child_state.ilen); 1688 xfree(child_state.input); 1689 1690 buffer_clear(packet_get_output()); 1691 buffer_append(packet_get_output(), child_state.output, 1692 child_state.olen); 1693 memset(child_state.output, 0, child_state.olen); 1694 xfree(child_state.output); 1695 1696 /* Roaming */ 1697 if (compat20) 1698 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1699 } 1700 1701 static Kex * 1702 mm_get_kex(Buffer *m) 1703 { 1704 Kex *kex; 1705 void *blob; 1706 u_int bloblen; 1707 1708 kex = xcalloc(1, sizeof(*kex)); 1709 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1710 if (session_id2 == NULL || 1711 kex->session_id_len != session_id2_len || 1712 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1713 fatal("mm_get_get: internal error: bad session id"); 1714 kex->we_need = buffer_get_int(m); 1715 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1716 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1717 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1718 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1719 kex->server = 1; 1720 kex->hostkey_type = buffer_get_int(m); 1721 kex->kex_type = buffer_get_int(m); 1722 blob = buffer_get_string(m, &bloblen); 1723 buffer_init(&kex->my); 1724 buffer_append(&kex->my, blob, bloblen); 1725 xfree(blob); 1726 blob = buffer_get_string(m, &bloblen); 1727 buffer_init(&kex->peer); 1728 buffer_append(&kex->peer, blob, bloblen); 1729 xfree(blob); 1730 kex->done = 1; 1731 kex->flags = buffer_get_int(m); 1732 kex->client_version_string = buffer_get_string(m, NULL); 1733 kex->server_version_string = buffer_get_string(m, NULL); 1734 kex->load_host_public_key=&get_hostkey_public_by_type; 1735 kex->load_host_private_key=&get_hostkey_private_by_type; 1736 kex->host_key_index=&get_hostkey_index; 1737 1738 return (kex); 1739 } 1740 1741 /* This function requries careful sanity checking */ 1742 1743 void 1744 mm_get_keystate(struct monitor *pmonitor) 1745 { 1746 Buffer m; 1747 u_char *blob, *p; 1748 u_int bloblen, plen; 1749 u_int32_t seqnr, packets; 1750 u_int64_t blocks, bytes; 1751 1752 debug3("%s: Waiting for new keys", __func__); 1753 1754 buffer_init(&m); 1755 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1756 if (!compat20) { 1757 child_state.ssh1protoflags = buffer_get_int(&m); 1758 child_state.ssh1cipher = buffer_get_int(&m); 1759 child_state.ssh1key = buffer_get_string(&m, 1760 &child_state.ssh1keylen); 1761 child_state.ivout = buffer_get_string(&m, 1762 &child_state.ivoutlen); 1763 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1764 goto skip; 1765 } else { 1766 /* Get the Kex for rekeying */ 1767 *pmonitor->m_pkex = mm_get_kex(&m); 1768 } 1769 1770 blob = buffer_get_string(&m, &bloblen); 1771 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1772 xfree(blob); 1773 1774 debug3("%s: Waiting for second key", __func__); 1775 blob = buffer_get_string(&m, &bloblen); 1776 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1777 xfree(blob); 1778 1779 /* Now get sequence numbers for the packets */ 1780 seqnr = buffer_get_int(&m); 1781 blocks = buffer_get_int64(&m); 1782 packets = buffer_get_int(&m); 1783 bytes = buffer_get_int64(&m); 1784 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1785 seqnr = buffer_get_int(&m); 1786 blocks = buffer_get_int64(&m); 1787 packets = buffer_get_int(&m); 1788 bytes = buffer_get_int64(&m); 1789 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1790 1791 skip: 1792 /* Get the key context */ 1793 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1794 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1795 1796 debug3("%s: Getting compression state", __func__); 1797 /* Get compression state */ 1798 p = buffer_get_string(&m, &plen); 1799 if (plen != sizeof(child_state.outgoing)) 1800 fatal("%s: bad request size", __func__); 1801 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1802 xfree(p); 1803 1804 p = buffer_get_string(&m, &plen); 1805 if (plen != sizeof(child_state.incoming)) 1806 fatal("%s: bad request size", __func__); 1807 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1808 xfree(p); 1809 1810 /* Network I/O buffers */ 1811 debug3("%s: Getting Network I/O buffers", __func__); 1812 child_state.input = buffer_get_string(&m, &child_state.ilen); 1813 child_state.output = buffer_get_string(&m, &child_state.olen); 1814 1815 /* Roaming */ 1816 if (compat20) { 1817 child_state.sent_bytes = buffer_get_int64(&m); 1818 child_state.recv_bytes = buffer_get_int64(&m); 1819 } 1820 1821 buffer_free(&m); 1822 } 1823 1824 1825 /* Allocation functions for zlib */ 1826 void * 1827 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1828 { 1829 size_t len = (size_t) size * ncount; 1830 void *address; 1831 1832 if (len == 0 || ncount > SIZE_T_MAX / size) 1833 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1834 1835 address = mm_malloc(mm, len); 1836 1837 return (address); 1838 } 1839 1840 void 1841 mm_zfree(struct mm_master *mm, void *address) 1842 { 1843 mm_free(mm, address); 1844 } 1845 1846 void 1847 mm_init_compression(struct mm_master *mm) 1848 { 1849 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1850 outgoing_stream.zfree = (free_func)mm_zfree; 1851 outgoing_stream.opaque = mm; 1852 1853 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1854 incoming_stream.zfree = (free_func)mm_zfree; 1855 incoming_stream.opaque = mm; 1856 } 1857 1858 /* XXX */ 1859 1860 #define FD_CLOSEONEXEC(x) do { \ 1861 if (fcntl(x, F_SETFD, 1) == -1) \ 1862 fatal("fcntl(%d, F_SETFD)", x); \ 1863 } while (0) 1864 1865 static void 1866 monitor_socketpair(int *pair) 1867 { 1868 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1869 fatal("%s: socketpair", __func__); 1870 FD_CLOSEONEXEC(pair[0]); 1871 FD_CLOSEONEXEC(pair[1]); 1872 } 1873 1874 #define MM_MEMSIZE 65536 1875 1876 struct monitor * 1877 monitor_init(void) 1878 { 1879 struct monitor *mon; 1880 int pair[2]; 1881 1882 mon = xcalloc(1, sizeof(*mon)); 1883 1884 monitor_socketpair(pair); 1885 1886 mon->m_recvfd = pair[0]; 1887 mon->m_sendfd = pair[1]; 1888 1889 /* Used to share zlib space across processes */ 1890 if (options.compression) { 1891 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1892 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1893 1894 /* Compression needs to share state across borders */ 1895 mm_init_compression(mon->m_zlib); 1896 } 1897 1898 return mon; 1899 } 1900 1901 void 1902 monitor_reinit(struct monitor *mon) 1903 { 1904 int pair[2]; 1905 1906 monitor_socketpair(pair); 1907 1908 mon->m_recvfd = pair[0]; 1909 mon->m_sendfd = pair[1]; 1910 } 1911 1912 #ifdef GSSAPI 1913 int 1914 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1915 { 1916 gss_OID_desc goid; 1917 OM_uint32 major; 1918 u_int len; 1919 1920 goid.elements = buffer_get_string(m, &len); 1921 goid.length = len; 1922 1923 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1924 1925 xfree(goid.elements); 1926 1927 buffer_clear(m); 1928 buffer_put_int(m, major); 1929 1930 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1931 1932 /* Now we have a context, enable the step */ 1933 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1934 1935 return (0); 1936 } 1937 1938 int 1939 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1940 { 1941 gss_buffer_desc in; 1942 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1943 OM_uint32 major, minor; 1944 OM_uint32 flags = 0; /* GSI needs this */ 1945 u_int len; 1946 1947 in.value = buffer_get_string(m, &len); 1948 in.length = len; 1949 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1950 xfree(in.value); 1951 1952 buffer_clear(m); 1953 buffer_put_int(m, major); 1954 buffer_put_string(m, out.value, out.length); 1955 buffer_put_int(m, flags); 1956 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1957 1958 gss_release_buffer(&minor, &out); 1959 1960 if (major == GSS_S_COMPLETE) { 1961 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1962 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1963 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1964 } 1965 return (0); 1966 } 1967 1968 int 1969 mm_answer_gss_checkmic(int sock, Buffer *m) 1970 { 1971 gss_buffer_desc gssbuf, mic; 1972 OM_uint32 ret; 1973 u_int len; 1974 1975 gssbuf.value = buffer_get_string(m, &len); 1976 gssbuf.length = len; 1977 mic.value = buffer_get_string(m, &len); 1978 mic.length = len; 1979 1980 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1981 1982 xfree(gssbuf.value); 1983 xfree(mic.value); 1984 1985 buffer_clear(m); 1986 buffer_put_int(m, ret); 1987 1988 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1989 1990 if (!GSS_ERROR(ret)) 1991 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1992 1993 return (0); 1994 } 1995 1996 int 1997 mm_answer_gss_userok(int sock, Buffer *m) 1998 { 1999 int authenticated; 2000 2001 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2002 2003 buffer_clear(m); 2004 buffer_put_int(m, authenticated); 2005 2006 debug3("%s: sending result %d", __func__, authenticated); 2007 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2008 2009 auth_method = "gssapi-with-mic"; 2010 2011 /* Monitor loop will terminate if authenticated */ 2012 return (authenticated); 2013 } 2014 #endif /* GSSAPI */ 2015 2016 #ifdef JPAKE 2017 int 2018 mm_answer_jpake_step1(int sock, Buffer *m) 2019 { 2020 struct jpake_ctx *pctx; 2021 u_char *x3_proof, *x4_proof; 2022 u_int x3_proof_len, x4_proof_len; 2023 2024 if (!options.zero_knowledge_password_authentication) 2025 fatal("zero_knowledge_password_authentication disabled"); 2026 2027 if (authctxt->jpake_ctx != NULL) 2028 fatal("%s: authctxt->jpake_ctx already set (%p)", 2029 __func__, authctxt->jpake_ctx); 2030 authctxt->jpake_ctx = pctx = jpake_new(); 2031 2032 jpake_step1(pctx->grp, 2033 &pctx->server_id, &pctx->server_id_len, 2034 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 2035 &x3_proof, &x3_proof_len, 2036 &x4_proof, &x4_proof_len); 2037 2038 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 2039 2040 buffer_clear(m); 2041 2042 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 2043 buffer_put_bignum2(m, pctx->g_x3); 2044 buffer_put_bignum2(m, pctx->g_x4); 2045 buffer_put_string(m, x3_proof, x3_proof_len); 2046 buffer_put_string(m, x4_proof, x4_proof_len); 2047 2048 debug3("%s: sending step1", __func__); 2049 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 2050 2051 bzero(x3_proof, x3_proof_len); 2052 bzero(x4_proof, x4_proof_len); 2053 xfree(x3_proof); 2054 xfree(x4_proof); 2055 2056 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 2057 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 2058 2059 return 0; 2060 } 2061 2062 int 2063 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 2064 { 2065 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2066 char *hash_scheme, *salt; 2067 2068 if (pctx == NULL) 2069 fatal("%s: pctx == NULL", __func__); 2070 2071 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 2072 2073 buffer_clear(m); 2074 /* pctx->s is sensitive, not returned to slave */ 2075 buffer_put_cstring(m, hash_scheme); 2076 buffer_put_cstring(m, salt); 2077 2078 debug3("%s: sending pwdata", __func__); 2079 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 2080 2081 bzero(hash_scheme, strlen(hash_scheme)); 2082 bzero(salt, strlen(salt)); 2083 xfree(hash_scheme); 2084 xfree(salt); 2085 2086 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 2087 2088 return 0; 2089 } 2090 2091 int 2092 mm_answer_jpake_step2(int sock, Buffer *m) 2093 { 2094 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2095 u_char *x1_proof, *x2_proof, *x4_s_proof; 2096 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 2097 2098 if (pctx == NULL) 2099 fatal("%s: pctx == NULL", __func__); 2100 2101 if ((pctx->g_x1 = BN_new()) == NULL || 2102 (pctx->g_x2 = BN_new()) == NULL) 2103 fatal("%s: BN_new", __func__); 2104 buffer_get_bignum2(m, pctx->g_x1); 2105 buffer_get_bignum2(m, pctx->g_x2); 2106 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 2107 x1_proof = buffer_get_string(m, &x1_proof_len); 2108 x2_proof = buffer_get_string(m, &x2_proof_len); 2109 2110 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 2111 pctx->g_x1, pctx->g_x2, pctx->x4, 2112 pctx->client_id, pctx->client_id_len, 2113 pctx->server_id, pctx->server_id_len, 2114 x1_proof, x1_proof_len, 2115 x2_proof, x2_proof_len, 2116 &pctx->b, 2117 &x4_s_proof, &x4_s_proof_len); 2118 2119 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 2120 2121 bzero(x1_proof, x1_proof_len); 2122 bzero(x2_proof, x2_proof_len); 2123 xfree(x1_proof); 2124 xfree(x2_proof); 2125 2126 buffer_clear(m); 2127 2128 buffer_put_bignum2(m, pctx->b); 2129 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 2130 2131 debug3("%s: sending step2", __func__); 2132 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 2133 2134 bzero(x4_s_proof, x4_s_proof_len); 2135 xfree(x4_s_proof); 2136 2137 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 2138 2139 return 0; 2140 } 2141 2142 int 2143 mm_answer_jpake_key_confirm(int sock, Buffer *m) 2144 { 2145 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2146 u_char *x2_s_proof; 2147 u_int x2_s_proof_len; 2148 2149 if (pctx == NULL) 2150 fatal("%s: pctx == NULL", __func__); 2151 2152 if ((pctx->a = BN_new()) == NULL) 2153 fatal("%s: BN_new", __func__); 2154 buffer_get_bignum2(m, pctx->a); 2155 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 2156 2157 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 2158 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 2159 pctx->server_id, pctx->server_id_len, 2160 pctx->client_id, pctx->client_id_len, 2161 session_id2, session_id2_len, 2162 x2_s_proof, x2_s_proof_len, 2163 &pctx->k, 2164 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 2165 2166 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 2167 2168 bzero(x2_s_proof, x2_s_proof_len); 2169 buffer_clear(m); 2170 2171 /* pctx->k is sensitive, not sent */ 2172 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 2173 2174 debug3("%s: sending confirmation hash", __func__); 2175 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 2176 2177 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 2178 2179 return 0; 2180 } 2181 2182 int 2183 mm_answer_jpake_check_confirm(int sock, Buffer *m) 2184 { 2185 int authenticated = 0; 2186 u_char *peer_confirm_hash; 2187 u_int peer_confirm_hash_len; 2188 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2189 2190 if (pctx == NULL) 2191 fatal("%s: pctx == NULL", __func__); 2192 2193 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 2194 2195 authenticated = jpake_check_confirm(pctx->k, 2196 pctx->client_id, pctx->client_id_len, 2197 session_id2, session_id2_len, 2198 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 2199 2200 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 2201 2202 bzero(peer_confirm_hash, peer_confirm_hash_len); 2203 xfree(peer_confirm_hash); 2204 2205 buffer_clear(m); 2206 buffer_put_int(m, authenticated); 2207 2208 debug3("%s: sending result %d", __func__, authenticated); 2209 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 2210 2211 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 2212 2213 auth_method = "jpake-01@openssh.com"; 2214 return authenticated; 2215 } 2216 2217 #endif /* JPAKE */ 2218