1 /* $OpenBSD: monitor.c,v 1.101 2009/02/12 03:26:22 djm Exp $ */ 2 /* 3 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus@openbsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 30 #include <sys/types.h> 31 #include <sys/param.h> 32 #include <sys/socket.h> 33 #include "openbsd-compat/sys-tree.h" 34 #include <sys/wait.h> 35 36 #include <errno.h> 37 #include <fcntl.h> 38 #ifdef HAVE_PATHS_H 39 #include <paths.h> 40 #endif 41 #include <pwd.h> 42 #include <signal.h> 43 #include <stdarg.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 48 #ifdef SKEY 49 #include <skey.h> 50 #endif 51 52 #include <openssl/dh.h> 53 54 #include "openbsd-compat/sys-queue.h" 55 #include "xmalloc.h" 56 #include "ssh.h" 57 #include "key.h" 58 #include "buffer.h" 59 #include "hostfile.h" 60 #include "auth.h" 61 #include "cipher.h" 62 #include "kex.h" 63 #include "dh.h" 64 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 65 #undef TARGET_OS_MAC 66 #include "zlib.h" 67 #define TARGET_OS_MAC 1 68 #else 69 #include "zlib.h" 70 #endif 71 #include "packet.h" 72 #include "auth-options.h" 73 #include "sshpty.h" 74 #include "channels.h" 75 #include "session.h" 76 #include "sshlogin.h" 77 #include "canohost.h" 78 #include "log.h" 79 #include "servconf.h" 80 #include "monitor.h" 81 #include "monitor_mm.h" 82 #ifdef GSSAPI 83 #include "ssh-gss.h" 84 #endif 85 #include "monitor_wrap.h" 86 #include "monitor_fdpass.h" 87 #include "misc.h" 88 #include "compat.h" 89 #include "ssh2.h" 90 #include "jpake.h" 91 92 #ifdef GSSAPI 93 static Gssctxt *gsscontext = NULL; 94 #endif 95 96 /* Imports */ 97 extern ServerOptions options; 98 extern u_int utmp_len; 99 extern Newkeys *current_keys[]; 100 extern z_stream incoming_stream; 101 extern z_stream outgoing_stream; 102 extern u_char session_id[]; 103 extern Buffer input, output; 104 extern Buffer auth_debug; 105 extern int auth_debug_init; 106 extern Buffer loginmsg; 107 108 /* State exported from the child */ 109 110 struct { 111 z_stream incoming; 112 z_stream outgoing; 113 u_char *keyin; 114 u_int keyinlen; 115 u_char *keyout; 116 u_int keyoutlen; 117 u_char *ivin; 118 u_int ivinlen; 119 u_char *ivout; 120 u_int ivoutlen; 121 u_char *ssh1key; 122 u_int ssh1keylen; 123 int ssh1cipher; 124 int ssh1protoflags; 125 u_char *input; 126 u_int ilen; 127 u_char *output; 128 u_int olen; 129 } child_state; 130 131 /* Functions on the monitor that answer unprivileged requests */ 132 133 int mm_answer_moduli(int, Buffer *); 134 int mm_answer_sign(int, Buffer *); 135 int mm_answer_pwnamallow(int, Buffer *); 136 int mm_answer_auth2_read_banner(int, Buffer *); 137 int mm_answer_authserv(int, Buffer *); 138 int mm_answer_authpassword(int, Buffer *); 139 int mm_answer_bsdauthquery(int, Buffer *); 140 int mm_answer_bsdauthrespond(int, Buffer *); 141 int mm_answer_skeyquery(int, Buffer *); 142 int mm_answer_skeyrespond(int, Buffer *); 143 int mm_answer_keyallowed(int, Buffer *); 144 int mm_answer_keyverify(int, Buffer *); 145 int mm_answer_pty(int, Buffer *); 146 int mm_answer_pty_cleanup(int, Buffer *); 147 int mm_answer_term(int, Buffer *); 148 int mm_answer_rsa_keyallowed(int, Buffer *); 149 int mm_answer_rsa_challenge(int, Buffer *); 150 int mm_answer_rsa_response(int, Buffer *); 151 int mm_answer_sesskey(int, Buffer *); 152 int mm_answer_sessid(int, Buffer *); 153 int mm_answer_jpake_get_pwdata(int, Buffer *); 154 int mm_answer_jpake_step1(int, Buffer *); 155 int mm_answer_jpake_step2(int, Buffer *); 156 int mm_answer_jpake_key_confirm(int, Buffer *); 157 int mm_answer_jpake_check_confirm(int, Buffer *); 158 159 #ifdef USE_PAM 160 int mm_answer_pam_start(int, Buffer *); 161 int mm_answer_pam_account(int, Buffer *); 162 int mm_answer_pam_init_ctx(int, Buffer *); 163 int mm_answer_pam_query(int, Buffer *); 164 int mm_answer_pam_respond(int, Buffer *); 165 int mm_answer_pam_free_ctx(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 #ifdef SSH_AUDIT_EVENTS 176 int mm_answer_audit_event(int, Buffer *); 177 int mm_answer_audit_command(int, Buffer *); 178 #endif 179 180 static Authctxt *authctxt; 181 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 182 183 /* local state for key verify */ 184 static u_char *key_blob = NULL; 185 static u_int key_bloblen = 0; 186 static int key_blobtype = MM_NOKEY; 187 static char *hostbased_cuser = NULL; 188 static char *hostbased_chost = NULL; 189 static char *auth_method = "unknown"; 190 static u_int session_id2_len = 0; 191 static u_char *session_id2 = NULL; 192 static pid_t monitor_child_pid; 193 194 struct mon_table { 195 enum monitor_reqtype type; 196 int flags; 197 int (*f)(int, Buffer *); 198 }; 199 200 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 201 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 202 #define MON_ONCE 0x0010 /* Disable after calling */ 203 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 204 205 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 206 207 #define MON_PERMIT 0x1000 /* Request is permitted */ 208 209 struct mon_table mon_dispatch_proto20[] = { 210 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 211 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 212 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 213 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 214 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 215 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 216 #ifdef USE_PAM 217 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 218 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 219 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 220 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 221 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 222 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 223 #endif 224 #ifdef SSH_AUDIT_EVENTS 225 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 226 #endif 227 #ifdef BSD_AUTH 228 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 229 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 230 #endif 231 #ifdef SKEY 232 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 233 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 234 #endif 235 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 236 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 237 #ifdef GSSAPI 238 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 239 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 240 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 241 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 242 #endif 243 #ifdef JPAKE 244 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 245 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 246 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 247 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 248 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 249 #endif 250 {0, 0, NULL} 251 }; 252 253 struct mon_table mon_dispatch_postauth20[] = { 254 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 255 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 256 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 257 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 258 {MONITOR_REQ_TERM, 0, mm_answer_term}, 259 #ifdef SSH_AUDIT_EVENTS 260 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 261 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 262 #endif 263 {0, 0, NULL} 264 }; 265 266 struct mon_table mon_dispatch_proto15[] = { 267 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 268 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 269 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 270 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 271 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 272 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 273 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 274 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 275 #ifdef BSD_AUTH 276 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 277 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 278 #endif 279 #ifdef SKEY 280 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 281 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 282 #endif 283 #ifdef USE_PAM 284 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 285 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 286 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 287 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 288 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 289 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 290 #endif 291 #ifdef SSH_AUDIT_EVENTS 292 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 293 #endif 294 {0, 0, NULL} 295 }; 296 297 struct mon_table mon_dispatch_postauth15[] = { 298 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 299 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 300 {MONITOR_REQ_TERM, 0, mm_answer_term}, 301 #ifdef SSH_AUDIT_EVENTS 302 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 303 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 304 #endif 305 {0, 0, NULL} 306 }; 307 308 struct mon_table *mon_dispatch; 309 310 /* Specifies if a certain message is allowed at the moment */ 311 312 static void 313 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 314 { 315 while (ent->f != NULL) { 316 if (ent->type == type) { 317 ent->flags &= ~MON_PERMIT; 318 ent->flags |= permit ? MON_PERMIT : 0; 319 return; 320 } 321 ent++; 322 } 323 } 324 325 static void 326 monitor_permit_authentications(int permit) 327 { 328 struct mon_table *ent = mon_dispatch; 329 330 while (ent->f != NULL) { 331 if (ent->flags & MON_AUTH) { 332 ent->flags &= ~MON_PERMIT; 333 ent->flags |= permit ? MON_PERMIT : 0; 334 } 335 ent++; 336 } 337 } 338 339 void 340 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 341 { 342 struct mon_table *ent; 343 int authenticated = 0; 344 345 debug3("preauth child monitor started"); 346 347 authctxt = _authctxt; 348 memset(authctxt, 0, sizeof(*authctxt)); 349 350 authctxt->loginmsg = &loginmsg; 351 352 if (compat20) { 353 mon_dispatch = mon_dispatch_proto20; 354 355 /* Permit requests for moduli and signatures */ 356 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 357 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 358 } else { 359 mon_dispatch = mon_dispatch_proto15; 360 361 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 362 } 363 364 /* The first few requests do not require asynchronous access */ 365 while (!authenticated) { 366 auth_method = "unknown"; 367 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 368 if (authenticated) { 369 if (!(ent->flags & MON_AUTHDECIDE)) 370 fatal("%s: unexpected authentication from %d", 371 __func__, ent->type); 372 if (authctxt->pw->pw_uid == 0 && 373 !auth_root_allowed(auth_method)) 374 authenticated = 0; 375 #ifdef USE_PAM 376 /* PAM needs to perform account checks after auth */ 377 if (options.use_pam && authenticated) { 378 Buffer m; 379 380 buffer_init(&m); 381 mm_request_receive_expect(pmonitor->m_sendfd, 382 MONITOR_REQ_PAM_ACCOUNT, &m); 383 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 384 buffer_free(&m); 385 } 386 #endif 387 } 388 389 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 390 auth_log(authctxt, authenticated, auth_method, 391 compat20 ? " ssh2" : ""); 392 if (!authenticated) 393 authctxt->failures++; 394 } 395 #ifdef JPAKE 396 /* Cleanup JPAKE context after authentication */ 397 if (ent->flags & MON_AUTHDECIDE) { 398 if (authctxt->jpake_ctx != NULL) { 399 jpake_free(authctxt->jpake_ctx); 400 authctxt->jpake_ctx = NULL; 401 } 402 } 403 #endif 404 } 405 406 if (!authctxt->valid) 407 fatal("%s: authenticated invalid user", __func__); 408 if (strcmp(auth_method, "unknown") == 0) 409 fatal("%s: authentication method name unknown", __func__); 410 411 debug("%s: %s has been authenticated by privileged process", 412 __func__, authctxt->user); 413 414 mm_get_keystate(pmonitor); 415 } 416 417 static void 418 monitor_set_child_handler(pid_t pid) 419 { 420 monitor_child_pid = pid; 421 } 422 423 static void 424 monitor_child_handler(int sig) 425 { 426 kill(monitor_child_pid, sig); 427 } 428 429 void 430 monitor_child_postauth(struct monitor *pmonitor) 431 { 432 monitor_set_child_handler(pmonitor->m_pid); 433 signal(SIGHUP, &monitor_child_handler); 434 signal(SIGTERM, &monitor_child_handler); 435 signal(SIGINT, &monitor_child_handler); 436 437 if (compat20) { 438 mon_dispatch = mon_dispatch_postauth20; 439 440 /* Permit requests for moduli and signatures */ 441 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 442 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 443 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 444 } else { 445 mon_dispatch = mon_dispatch_postauth15; 446 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 447 } 448 if (!no_pty_flag) { 449 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 450 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 451 } 452 453 for (;;) 454 monitor_read(pmonitor, mon_dispatch, NULL); 455 } 456 457 void 458 monitor_sync(struct monitor *pmonitor) 459 { 460 if (options.compression) { 461 /* The member allocation is not visible, so sync it */ 462 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 463 } 464 } 465 466 int 467 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 468 struct mon_table **pent) 469 { 470 Buffer m; 471 int ret; 472 u_char type; 473 474 buffer_init(&m); 475 476 mm_request_receive(pmonitor->m_sendfd, &m); 477 type = buffer_get_char(&m); 478 479 debug3("%s: checking request %d", __func__, type); 480 481 while (ent->f != NULL) { 482 if (ent->type == type) 483 break; 484 ent++; 485 } 486 487 if (ent->f != NULL) { 488 if (!(ent->flags & MON_PERMIT)) 489 fatal("%s: unpermitted request %d", __func__, 490 type); 491 ret = (*ent->f)(pmonitor->m_sendfd, &m); 492 buffer_free(&m); 493 494 /* The child may use this request only once, disable it */ 495 if (ent->flags & MON_ONCE) { 496 debug2("%s: %d used once, disabling now", __func__, 497 type); 498 ent->flags &= ~MON_PERMIT; 499 } 500 501 if (pent != NULL) 502 *pent = ent; 503 504 return ret; 505 } 506 507 fatal("%s: unsupported request: %d", __func__, type); 508 509 /* NOTREACHED */ 510 return (-1); 511 } 512 513 /* allowed key state */ 514 static int 515 monitor_allowed_key(u_char *blob, u_int bloblen) 516 { 517 /* make sure key is allowed */ 518 if (key_blob == NULL || key_bloblen != bloblen || 519 memcmp(key_blob, blob, key_bloblen)) 520 return (0); 521 return (1); 522 } 523 524 static void 525 monitor_reset_key_state(void) 526 { 527 /* reset state */ 528 if (key_blob != NULL) 529 xfree(key_blob); 530 if (hostbased_cuser != NULL) 531 xfree(hostbased_cuser); 532 if (hostbased_chost != NULL) 533 xfree(hostbased_chost); 534 key_blob = NULL; 535 key_bloblen = 0; 536 key_blobtype = MM_NOKEY; 537 hostbased_cuser = NULL; 538 hostbased_chost = NULL; 539 } 540 541 int 542 mm_answer_moduli(int sock, Buffer *m) 543 { 544 DH *dh; 545 int min, want, max; 546 547 min = buffer_get_int(m); 548 want = buffer_get_int(m); 549 max = buffer_get_int(m); 550 551 debug3("%s: got parameters: %d %d %d", 552 __func__, min, want, max); 553 /* We need to check here, too, in case the child got corrupted */ 554 if (max < min || want < min || max < want) 555 fatal("%s: bad parameters: %d %d %d", 556 __func__, min, want, max); 557 558 buffer_clear(m); 559 560 dh = choose_dh(min, want, max); 561 if (dh == NULL) { 562 buffer_put_char(m, 0); 563 return (0); 564 } else { 565 /* Send first bignum */ 566 buffer_put_char(m, 1); 567 buffer_put_bignum2(m, dh->p); 568 buffer_put_bignum2(m, dh->g); 569 570 DH_free(dh); 571 } 572 mm_request_send(sock, MONITOR_ANS_MODULI, m); 573 return (0); 574 } 575 576 int 577 mm_answer_sign(int sock, Buffer *m) 578 { 579 Key *key; 580 u_char *p; 581 u_char *signature; 582 u_int siglen, datlen; 583 int keyid; 584 585 debug3("%s", __func__); 586 587 keyid = buffer_get_int(m); 588 p = buffer_get_string(m, &datlen); 589 590 /* 591 * Supported KEX types will only return SHA1 (20 byte) or 592 * SHA256 (32 byte) hashes 593 */ 594 if (datlen != 20 && datlen != 32) 595 fatal("%s: data length incorrect: %u", __func__, datlen); 596 597 /* save session id, it will be passed on the first call */ 598 if (session_id2_len == 0) { 599 session_id2_len = datlen; 600 session_id2 = xmalloc(session_id2_len); 601 memcpy(session_id2, p, session_id2_len); 602 } 603 604 if ((key = get_hostkey_by_index(keyid)) == NULL) 605 fatal("%s: no hostkey from index %d", __func__, keyid); 606 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 607 fatal("%s: key_sign failed", __func__); 608 609 debug3("%s: signature %p(%u)", __func__, signature, siglen); 610 611 buffer_clear(m); 612 buffer_put_string(m, signature, siglen); 613 614 xfree(p); 615 xfree(signature); 616 617 mm_request_send(sock, MONITOR_ANS_SIGN, m); 618 619 /* Turn on permissions for getpwnam */ 620 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 621 622 return (0); 623 } 624 625 /* Retrieves the password entry and also checks if the user is permitted */ 626 627 int 628 mm_answer_pwnamallow(int sock, Buffer *m) 629 { 630 char *username; 631 struct passwd *pwent; 632 int allowed = 0; 633 634 debug3("%s", __func__); 635 636 if (authctxt->attempt++ != 0) 637 fatal("%s: multiple attempts for getpwnam", __func__); 638 639 username = buffer_get_string(m, NULL); 640 641 pwent = getpwnamallow(username); 642 643 authctxt->user = xstrdup(username); 644 setproctitle("%s [priv]", pwent ? username : "unknown"); 645 xfree(username); 646 647 buffer_clear(m); 648 649 if (pwent == NULL) { 650 buffer_put_char(m, 0); 651 authctxt->pw = fakepw(); 652 goto out; 653 } 654 655 allowed = 1; 656 authctxt->pw = pwent; 657 authctxt->valid = 1; 658 659 buffer_put_char(m, 1); 660 buffer_put_string(m, pwent, sizeof(struct passwd)); 661 buffer_put_cstring(m, pwent->pw_name); 662 buffer_put_cstring(m, "*"); 663 buffer_put_cstring(m, pwent->pw_gecos); 664 #ifdef HAVE_PW_CLASS_IN_PASSWD 665 buffer_put_cstring(m, pwent->pw_class); 666 #endif 667 buffer_put_cstring(m, pwent->pw_dir); 668 buffer_put_cstring(m, pwent->pw_shell); 669 670 out: 671 buffer_put_string(m, &options, sizeof(options)); 672 if (options.banner != NULL) 673 buffer_put_cstring(m, options.banner); 674 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 675 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 676 677 /* For SSHv1 allow authentication now */ 678 if (!compat20) 679 monitor_permit_authentications(1); 680 else { 681 /* Allow service/style information on the auth context */ 682 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 683 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 684 } 685 686 #ifdef USE_PAM 687 if (options.use_pam) 688 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 689 #endif 690 691 return (0); 692 } 693 694 int mm_answer_auth2_read_banner(int sock, Buffer *m) 695 { 696 char *banner; 697 698 buffer_clear(m); 699 banner = auth2_read_banner(); 700 buffer_put_cstring(m, banner != NULL ? banner : ""); 701 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 702 703 if (banner != NULL) 704 xfree(banner); 705 706 return (0); 707 } 708 709 int 710 mm_answer_authserv(int sock, Buffer *m) 711 { 712 monitor_permit_authentications(1); 713 714 authctxt->service = buffer_get_string(m, NULL); 715 authctxt->style = buffer_get_string(m, NULL); 716 debug3("%s: service=%s, style=%s", 717 __func__, authctxt->service, authctxt->style); 718 719 if (strlen(authctxt->style) == 0) { 720 xfree(authctxt->style); 721 authctxt->style = NULL; 722 } 723 724 return (0); 725 } 726 727 int 728 mm_answer_authpassword(int sock, Buffer *m) 729 { 730 static int call_count; 731 char *passwd; 732 int authenticated; 733 u_int plen; 734 735 passwd = buffer_get_string(m, &plen); 736 /* Only authenticate if the context is valid */ 737 authenticated = options.password_authentication && 738 auth_password(authctxt, passwd); 739 memset(passwd, 0, strlen(passwd)); 740 xfree(passwd); 741 742 buffer_clear(m); 743 buffer_put_int(m, authenticated); 744 745 debug3("%s: sending result %d", __func__, authenticated); 746 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 747 748 call_count++; 749 if (plen == 0 && call_count == 1) 750 auth_method = "none"; 751 else 752 auth_method = "password"; 753 754 /* Causes monitor loop to terminate if authenticated */ 755 return (authenticated); 756 } 757 758 #ifdef BSD_AUTH 759 int 760 mm_answer_bsdauthquery(int sock, Buffer *m) 761 { 762 char *name, *infotxt; 763 u_int numprompts; 764 u_int *echo_on; 765 char **prompts; 766 u_int success; 767 768 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 769 &prompts, &echo_on) < 0 ? 0 : 1; 770 771 buffer_clear(m); 772 buffer_put_int(m, success); 773 if (success) 774 buffer_put_cstring(m, prompts[0]); 775 776 debug3("%s: sending challenge success: %u", __func__, success); 777 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 778 779 if (success) { 780 xfree(name); 781 xfree(infotxt); 782 xfree(prompts); 783 xfree(echo_on); 784 } 785 786 return (0); 787 } 788 789 int 790 mm_answer_bsdauthrespond(int sock, Buffer *m) 791 { 792 char *response; 793 int authok; 794 795 if (authctxt->as == 0) 796 fatal("%s: no bsd auth session", __func__); 797 798 response = buffer_get_string(m, NULL); 799 authok = options.challenge_response_authentication && 800 auth_userresponse(authctxt->as, response, 0); 801 authctxt->as = NULL; 802 debug3("%s: <%s> = <%d>", __func__, response, authok); 803 xfree(response); 804 805 buffer_clear(m); 806 buffer_put_int(m, authok); 807 808 debug3("%s: sending authenticated: %d", __func__, authok); 809 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 810 811 auth_method = "bsdauth"; 812 813 return (authok != 0); 814 } 815 #endif 816 817 #ifdef SKEY 818 int 819 mm_answer_skeyquery(int sock, Buffer *m) 820 { 821 struct skey skey; 822 char challenge[1024]; 823 u_int success; 824 825 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 826 sizeof(challenge)) < 0 ? 0 : 1; 827 828 buffer_clear(m); 829 buffer_put_int(m, success); 830 if (success) 831 buffer_put_cstring(m, challenge); 832 833 debug3("%s: sending challenge success: %u", __func__, success); 834 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 835 836 return (0); 837 } 838 839 int 840 mm_answer_skeyrespond(int sock, Buffer *m) 841 { 842 char *response; 843 int authok; 844 845 response = buffer_get_string(m, NULL); 846 847 authok = (options.challenge_response_authentication && 848 authctxt->valid && 849 skey_haskey(authctxt->pw->pw_name) == 0 && 850 skey_passcheck(authctxt->pw->pw_name, response) != -1); 851 852 xfree(response); 853 854 buffer_clear(m); 855 buffer_put_int(m, authok); 856 857 debug3("%s: sending authenticated: %d", __func__, authok); 858 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 859 860 auth_method = "skey"; 861 862 return (authok != 0); 863 } 864 #endif 865 866 #ifdef USE_PAM 867 int 868 mm_answer_pam_start(int sock, Buffer *m) 869 { 870 if (!options.use_pam) 871 fatal("UsePAM not set, but ended up in %s anyway", __func__); 872 873 start_pam(authctxt); 874 875 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 876 877 return (0); 878 } 879 880 int 881 mm_answer_pam_account(int sock, Buffer *m) 882 { 883 u_int ret; 884 885 if (!options.use_pam) 886 fatal("UsePAM not set, but ended up in %s anyway", __func__); 887 888 ret = do_pam_account(); 889 890 buffer_put_int(m, ret); 891 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 892 893 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 894 895 return (ret); 896 } 897 898 static void *sshpam_ctxt, *sshpam_authok; 899 extern KbdintDevice sshpam_device; 900 901 int 902 mm_answer_pam_init_ctx(int sock, Buffer *m) 903 { 904 905 debug3("%s", __func__); 906 authctxt->user = buffer_get_string(m, NULL); 907 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 908 sshpam_authok = NULL; 909 buffer_clear(m); 910 if (sshpam_ctxt != NULL) { 911 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 912 buffer_put_int(m, 1); 913 } else { 914 buffer_put_int(m, 0); 915 } 916 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 917 return (0); 918 } 919 920 int 921 mm_answer_pam_query(int sock, Buffer *m) 922 { 923 char *name, *info, **prompts; 924 u_int i, num, *echo_on; 925 int ret; 926 927 debug3("%s", __func__); 928 sshpam_authok = NULL; 929 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 930 if (ret == 0 && num == 0) 931 sshpam_authok = sshpam_ctxt; 932 if (num > 1 || name == NULL || info == NULL) 933 ret = -1; 934 buffer_clear(m); 935 buffer_put_int(m, ret); 936 buffer_put_cstring(m, name); 937 xfree(name); 938 buffer_put_cstring(m, info); 939 xfree(info); 940 buffer_put_int(m, num); 941 for (i = 0; i < num; ++i) { 942 buffer_put_cstring(m, prompts[i]); 943 xfree(prompts[i]); 944 buffer_put_int(m, echo_on[i]); 945 } 946 if (prompts != NULL) 947 xfree(prompts); 948 if (echo_on != NULL) 949 xfree(echo_on); 950 auth_method = "keyboard-interactive/pam"; 951 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 952 return (0); 953 } 954 955 int 956 mm_answer_pam_respond(int sock, Buffer *m) 957 { 958 char **resp; 959 u_int i, num; 960 int ret; 961 962 debug3("%s", __func__); 963 sshpam_authok = NULL; 964 num = buffer_get_int(m); 965 if (num > 0) { 966 resp = xcalloc(num, sizeof(char *)); 967 for (i = 0; i < num; ++i) 968 resp[i] = buffer_get_string(m, NULL); 969 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 970 for (i = 0; i < num; ++i) 971 xfree(resp[i]); 972 xfree(resp); 973 } else { 974 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 975 } 976 buffer_clear(m); 977 buffer_put_int(m, ret); 978 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 979 auth_method = "keyboard-interactive/pam"; 980 if (ret == 0) 981 sshpam_authok = sshpam_ctxt; 982 return (0); 983 } 984 985 int 986 mm_answer_pam_free_ctx(int sock, Buffer *m) 987 { 988 989 debug3("%s", __func__); 990 (sshpam_device.free_ctx)(sshpam_ctxt); 991 buffer_clear(m); 992 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 993 auth_method = "keyboard-interactive/pam"; 994 return (sshpam_authok == sshpam_ctxt); 995 } 996 #endif 997 998 static void 999 mm_append_debug(Buffer *m) 1000 { 1001 if (auth_debug_init && buffer_len(&auth_debug)) { 1002 debug3("%s: Appending debug messages for child", __func__); 1003 buffer_append(m, buffer_ptr(&auth_debug), 1004 buffer_len(&auth_debug)); 1005 buffer_clear(&auth_debug); 1006 } 1007 } 1008 1009 int 1010 mm_answer_keyallowed(int sock, Buffer *m) 1011 { 1012 Key *key; 1013 char *cuser, *chost; 1014 u_char *blob; 1015 u_int bloblen; 1016 enum mm_keytype type = 0; 1017 int allowed = 0; 1018 1019 debug3("%s entering", __func__); 1020 1021 type = buffer_get_int(m); 1022 cuser = buffer_get_string(m, NULL); 1023 chost = buffer_get_string(m, NULL); 1024 blob = buffer_get_string(m, &bloblen); 1025 1026 key = key_from_blob(blob, bloblen); 1027 1028 if ((compat20 && type == MM_RSAHOSTKEY) || 1029 (!compat20 && type != MM_RSAHOSTKEY)) 1030 fatal("%s: key type and protocol mismatch", __func__); 1031 1032 debug3("%s: key_from_blob: %p", __func__, key); 1033 1034 if (key != NULL && authctxt->valid) { 1035 switch (type) { 1036 case MM_USERKEY: 1037 allowed = options.pubkey_authentication && 1038 user_key_allowed(authctxt->pw, key); 1039 auth_method = "publickey"; 1040 if (options.pubkey_authentication && allowed != 1) 1041 auth_clear_options(); 1042 break; 1043 case MM_HOSTKEY: 1044 allowed = options.hostbased_authentication && 1045 hostbased_key_allowed(authctxt->pw, 1046 cuser, chost, key); 1047 auth_method = "hostbased"; 1048 break; 1049 case MM_RSAHOSTKEY: 1050 key->type = KEY_RSA1; /* XXX */ 1051 allowed = options.rhosts_rsa_authentication && 1052 auth_rhosts_rsa_key_allowed(authctxt->pw, 1053 cuser, chost, key); 1054 if (options.rhosts_rsa_authentication && allowed != 1) 1055 auth_clear_options(); 1056 auth_method = "rsa"; 1057 break; 1058 default: 1059 fatal("%s: unknown key type %d", __func__, type); 1060 break; 1061 } 1062 } 1063 if (key != NULL) 1064 key_free(key); 1065 1066 /* clear temporarily storage (used by verify) */ 1067 monitor_reset_key_state(); 1068 1069 if (allowed) { 1070 /* Save temporarily for comparison in verify */ 1071 key_blob = blob; 1072 key_bloblen = bloblen; 1073 key_blobtype = type; 1074 hostbased_cuser = cuser; 1075 hostbased_chost = chost; 1076 } else { 1077 /* Log failed attempt */ 1078 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 1079 xfree(blob); 1080 xfree(cuser); 1081 xfree(chost); 1082 } 1083 1084 debug3("%s: key %p is %s", 1085 __func__, key, allowed ? "allowed" : "not allowed"); 1086 1087 buffer_clear(m); 1088 buffer_put_int(m, allowed); 1089 buffer_put_int(m, forced_command != NULL); 1090 1091 mm_append_debug(m); 1092 1093 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1094 1095 if (type == MM_RSAHOSTKEY) 1096 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1097 1098 return (0); 1099 } 1100 1101 static int 1102 monitor_valid_userblob(u_char *data, u_int datalen) 1103 { 1104 Buffer b; 1105 char *p; 1106 u_int len; 1107 int fail = 0; 1108 1109 buffer_init(&b); 1110 buffer_append(&b, data, datalen); 1111 1112 if (datafellows & SSH_OLD_SESSIONID) { 1113 p = buffer_ptr(&b); 1114 len = buffer_len(&b); 1115 if ((session_id2 == NULL) || 1116 (len < session_id2_len) || 1117 (memcmp(p, session_id2, session_id2_len) != 0)) 1118 fail++; 1119 buffer_consume(&b, session_id2_len); 1120 } else { 1121 p = buffer_get_string(&b, &len); 1122 if ((session_id2 == NULL) || 1123 (len != session_id2_len) || 1124 (memcmp(p, session_id2, session_id2_len) != 0)) 1125 fail++; 1126 xfree(p); 1127 } 1128 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1129 fail++; 1130 p = buffer_get_string(&b, NULL); 1131 if (strcmp(authctxt->user, p) != 0) { 1132 logit("wrong user name passed to monitor: expected %s != %.100s", 1133 authctxt->user, p); 1134 fail++; 1135 } 1136 xfree(p); 1137 buffer_skip_string(&b); 1138 if (datafellows & SSH_BUG_PKAUTH) { 1139 if (!buffer_get_char(&b)) 1140 fail++; 1141 } else { 1142 p = buffer_get_string(&b, NULL); 1143 if (strcmp("publickey", p) != 0) 1144 fail++; 1145 xfree(p); 1146 if (!buffer_get_char(&b)) 1147 fail++; 1148 buffer_skip_string(&b); 1149 } 1150 buffer_skip_string(&b); 1151 if (buffer_len(&b) != 0) 1152 fail++; 1153 buffer_free(&b); 1154 return (fail == 0); 1155 } 1156 1157 static int 1158 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1159 char *chost) 1160 { 1161 Buffer b; 1162 char *p; 1163 u_int len; 1164 int fail = 0; 1165 1166 buffer_init(&b); 1167 buffer_append(&b, data, datalen); 1168 1169 p = buffer_get_string(&b, &len); 1170 if ((session_id2 == NULL) || 1171 (len != session_id2_len) || 1172 (memcmp(p, session_id2, session_id2_len) != 0)) 1173 fail++; 1174 xfree(p); 1175 1176 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1177 fail++; 1178 p = buffer_get_string(&b, NULL); 1179 if (strcmp(authctxt->user, p) != 0) { 1180 logit("wrong user name passed to monitor: expected %s != %.100s", 1181 authctxt->user, p); 1182 fail++; 1183 } 1184 xfree(p); 1185 buffer_skip_string(&b); /* service */ 1186 p = buffer_get_string(&b, NULL); 1187 if (strcmp(p, "hostbased") != 0) 1188 fail++; 1189 xfree(p); 1190 buffer_skip_string(&b); /* pkalg */ 1191 buffer_skip_string(&b); /* pkblob */ 1192 1193 /* verify client host, strip trailing dot if necessary */ 1194 p = buffer_get_string(&b, NULL); 1195 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1196 p[len - 1] = '\0'; 1197 if (strcmp(p, chost) != 0) 1198 fail++; 1199 xfree(p); 1200 1201 /* verify client user */ 1202 p = buffer_get_string(&b, NULL); 1203 if (strcmp(p, cuser) != 0) 1204 fail++; 1205 xfree(p); 1206 1207 if (buffer_len(&b) != 0) 1208 fail++; 1209 buffer_free(&b); 1210 return (fail == 0); 1211 } 1212 1213 int 1214 mm_answer_keyverify(int sock, Buffer *m) 1215 { 1216 Key *key; 1217 u_char *signature, *data, *blob; 1218 u_int signaturelen, datalen, bloblen; 1219 int verified = 0; 1220 int valid_data = 0; 1221 1222 blob = buffer_get_string(m, &bloblen); 1223 signature = buffer_get_string(m, &signaturelen); 1224 data = buffer_get_string(m, &datalen); 1225 1226 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1227 !monitor_allowed_key(blob, bloblen)) 1228 fatal("%s: bad key, not previously allowed", __func__); 1229 1230 key = key_from_blob(blob, bloblen); 1231 if (key == NULL) 1232 fatal("%s: bad public key blob", __func__); 1233 1234 switch (key_blobtype) { 1235 case MM_USERKEY: 1236 valid_data = monitor_valid_userblob(data, datalen); 1237 break; 1238 case MM_HOSTKEY: 1239 valid_data = monitor_valid_hostbasedblob(data, datalen, 1240 hostbased_cuser, hostbased_chost); 1241 break; 1242 default: 1243 valid_data = 0; 1244 break; 1245 } 1246 if (!valid_data) 1247 fatal("%s: bad signature data blob", __func__); 1248 1249 verified = key_verify(key, signature, signaturelen, data, datalen); 1250 debug3("%s: key %p signature %s", 1251 __func__, key, (verified == 1) ? "verified" : "unverified"); 1252 1253 key_free(key); 1254 xfree(blob); 1255 xfree(signature); 1256 xfree(data); 1257 1258 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1259 1260 monitor_reset_key_state(); 1261 1262 buffer_clear(m); 1263 buffer_put_int(m, verified); 1264 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1265 1266 return (verified == 1); 1267 } 1268 1269 static void 1270 mm_record_login(Session *s, struct passwd *pw) 1271 { 1272 socklen_t fromlen; 1273 struct sockaddr_storage from; 1274 1275 /* 1276 * Get IP address of client. If the connection is not a socket, let 1277 * the address be 0.0.0.0. 1278 */ 1279 memset(&from, 0, sizeof(from)); 1280 fromlen = sizeof(from); 1281 if (packet_connection_is_on_socket()) { 1282 if (getpeername(packet_get_connection_in(), 1283 (struct sockaddr *)&from, &fromlen) < 0) { 1284 debug("getpeername: %.100s", strerror(errno)); 1285 cleanup_exit(255); 1286 } 1287 } 1288 /* Record that there was a login on that tty from the remote host. */ 1289 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1290 get_remote_name_or_ip(utmp_len, options.use_dns), 1291 (struct sockaddr *)&from, fromlen); 1292 } 1293 1294 static void 1295 mm_session_close(Session *s) 1296 { 1297 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1298 if (s->ttyfd != -1) { 1299 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1300 session_pty_cleanup2(s); 1301 } 1302 session_unused(s->self); 1303 } 1304 1305 int 1306 mm_answer_pty(int sock, Buffer *m) 1307 { 1308 extern struct monitor *pmonitor; 1309 Session *s; 1310 int res, fd0; 1311 1312 debug3("%s entering", __func__); 1313 1314 buffer_clear(m); 1315 s = session_new(); 1316 if (s == NULL) 1317 goto error; 1318 s->authctxt = authctxt; 1319 s->pw = authctxt->pw; 1320 s->pid = pmonitor->m_pid; 1321 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1322 if (res == 0) 1323 goto error; 1324 pty_setowner(authctxt->pw, s->tty); 1325 1326 buffer_put_int(m, 1); 1327 buffer_put_cstring(m, s->tty); 1328 1329 /* We need to trick ttyslot */ 1330 if (dup2(s->ttyfd, 0) == -1) 1331 fatal("%s: dup2", __func__); 1332 1333 mm_record_login(s, authctxt->pw); 1334 1335 /* Now we can close the file descriptor again */ 1336 close(0); 1337 1338 /* send messages generated by record_login */ 1339 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1340 buffer_clear(&loginmsg); 1341 1342 mm_request_send(sock, MONITOR_ANS_PTY, m); 1343 1344 if (mm_send_fd(sock, s->ptyfd) == -1 || 1345 mm_send_fd(sock, s->ttyfd) == -1) 1346 fatal("%s: send fds failed", __func__); 1347 1348 /* make sure nothing uses fd 0 */ 1349 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1350 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1351 if (fd0 != 0) 1352 error("%s: fd0 %d != 0", __func__, fd0); 1353 1354 /* slave is not needed */ 1355 close(s->ttyfd); 1356 s->ttyfd = s->ptyfd; 1357 /* no need to dup() because nobody closes ptyfd */ 1358 s->ptymaster = s->ptyfd; 1359 1360 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1361 1362 return (0); 1363 1364 error: 1365 if (s != NULL) 1366 mm_session_close(s); 1367 buffer_put_int(m, 0); 1368 mm_request_send(sock, MONITOR_ANS_PTY, m); 1369 return (0); 1370 } 1371 1372 int 1373 mm_answer_pty_cleanup(int sock, Buffer *m) 1374 { 1375 Session *s; 1376 char *tty; 1377 1378 debug3("%s entering", __func__); 1379 1380 tty = buffer_get_string(m, NULL); 1381 if ((s = session_by_tty(tty)) != NULL) 1382 mm_session_close(s); 1383 buffer_clear(m); 1384 xfree(tty); 1385 return (0); 1386 } 1387 1388 int 1389 mm_answer_sesskey(int sock, Buffer *m) 1390 { 1391 BIGNUM *p; 1392 int rsafail; 1393 1394 /* Turn off permissions */ 1395 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1396 1397 if ((p = BN_new()) == NULL) 1398 fatal("%s: BN_new", __func__); 1399 1400 buffer_get_bignum2(m, p); 1401 1402 rsafail = ssh1_session_key(p); 1403 1404 buffer_clear(m); 1405 buffer_put_int(m, rsafail); 1406 buffer_put_bignum2(m, p); 1407 1408 BN_clear_free(p); 1409 1410 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1411 1412 /* Turn on permissions for sessid passing */ 1413 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1414 1415 return (0); 1416 } 1417 1418 int 1419 mm_answer_sessid(int sock, Buffer *m) 1420 { 1421 int i; 1422 1423 debug3("%s entering", __func__); 1424 1425 if (buffer_len(m) != 16) 1426 fatal("%s: bad ssh1 session id", __func__); 1427 for (i = 0; i < 16; i++) 1428 session_id[i] = buffer_get_char(m); 1429 1430 /* Turn on permissions for getpwnam */ 1431 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1432 1433 return (0); 1434 } 1435 1436 int 1437 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1438 { 1439 BIGNUM *client_n; 1440 Key *key = NULL; 1441 u_char *blob = NULL; 1442 u_int blen = 0; 1443 int allowed = 0; 1444 1445 debug3("%s entering", __func__); 1446 1447 auth_method = "rsa"; 1448 if (options.rsa_authentication && authctxt->valid) { 1449 if ((client_n = BN_new()) == NULL) 1450 fatal("%s: BN_new", __func__); 1451 buffer_get_bignum2(m, client_n); 1452 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1453 BN_clear_free(client_n); 1454 } 1455 buffer_clear(m); 1456 buffer_put_int(m, allowed); 1457 buffer_put_int(m, forced_command != NULL); 1458 1459 /* clear temporarily storage (used by generate challenge) */ 1460 monitor_reset_key_state(); 1461 1462 if (allowed && key != NULL) { 1463 key->type = KEY_RSA; /* cheat for key_to_blob */ 1464 if (key_to_blob(key, &blob, &blen) == 0) 1465 fatal("%s: key_to_blob failed", __func__); 1466 buffer_put_string(m, blob, blen); 1467 1468 /* Save temporarily for comparison in verify */ 1469 key_blob = blob; 1470 key_bloblen = blen; 1471 key_blobtype = MM_RSAUSERKEY; 1472 } 1473 if (key != NULL) 1474 key_free(key); 1475 1476 mm_append_debug(m); 1477 1478 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1479 1480 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1481 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1482 return (0); 1483 } 1484 1485 int 1486 mm_answer_rsa_challenge(int sock, Buffer *m) 1487 { 1488 Key *key = NULL; 1489 u_char *blob; 1490 u_int blen; 1491 1492 debug3("%s entering", __func__); 1493 1494 if (!authctxt->valid) 1495 fatal("%s: authctxt not valid", __func__); 1496 blob = buffer_get_string(m, &blen); 1497 if (!monitor_allowed_key(blob, blen)) 1498 fatal("%s: bad key, not previously allowed", __func__); 1499 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1500 fatal("%s: key type mismatch", __func__); 1501 if ((key = key_from_blob(blob, blen)) == NULL) 1502 fatal("%s: received bad key", __func__); 1503 if (key->type != KEY_RSA) 1504 fatal("%s: received bad key type %d", __func__, key->type); 1505 key->type = KEY_RSA1; 1506 if (ssh1_challenge) 1507 BN_clear_free(ssh1_challenge); 1508 ssh1_challenge = auth_rsa_generate_challenge(key); 1509 1510 buffer_clear(m); 1511 buffer_put_bignum2(m, ssh1_challenge); 1512 1513 debug3("%s sending reply", __func__); 1514 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1515 1516 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1517 1518 xfree(blob); 1519 key_free(key); 1520 return (0); 1521 } 1522 1523 int 1524 mm_answer_rsa_response(int sock, Buffer *m) 1525 { 1526 Key *key = NULL; 1527 u_char *blob, *response; 1528 u_int blen, len; 1529 int success; 1530 1531 debug3("%s entering", __func__); 1532 1533 if (!authctxt->valid) 1534 fatal("%s: authctxt not valid", __func__); 1535 if (ssh1_challenge == NULL) 1536 fatal("%s: no ssh1_challenge", __func__); 1537 1538 blob = buffer_get_string(m, &blen); 1539 if (!monitor_allowed_key(blob, blen)) 1540 fatal("%s: bad key, not previously allowed", __func__); 1541 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1542 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1543 if ((key = key_from_blob(blob, blen)) == NULL) 1544 fatal("%s: received bad key", __func__); 1545 response = buffer_get_string(m, &len); 1546 if (len != 16) 1547 fatal("%s: received bad response to challenge", __func__); 1548 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1549 1550 xfree(blob); 1551 key_free(key); 1552 xfree(response); 1553 1554 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1555 1556 /* reset state */ 1557 BN_clear_free(ssh1_challenge); 1558 ssh1_challenge = NULL; 1559 monitor_reset_key_state(); 1560 1561 buffer_clear(m); 1562 buffer_put_int(m, success); 1563 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1564 1565 return (success); 1566 } 1567 1568 int 1569 mm_answer_term(int sock, Buffer *req) 1570 { 1571 extern struct monitor *pmonitor; 1572 int res, status; 1573 1574 debug3("%s: tearing down sessions", __func__); 1575 1576 /* The child is terminating */ 1577 session_destroy_all(&mm_session_close); 1578 1579 #ifdef USE_PAM 1580 if (options.use_pam) 1581 sshpam_cleanup(); 1582 #endif 1583 1584 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1585 if (errno != EINTR) 1586 exit(1); 1587 1588 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1589 1590 /* Terminate process */ 1591 exit(res); 1592 } 1593 1594 #ifdef SSH_AUDIT_EVENTS 1595 /* Report that an audit event occurred */ 1596 int 1597 mm_answer_audit_event(int socket, Buffer *m) 1598 { 1599 ssh_audit_event_t event; 1600 1601 debug3("%s entering", __func__); 1602 1603 event = buffer_get_int(m); 1604 switch(event) { 1605 case SSH_AUTH_FAIL_PUBKEY: 1606 case SSH_AUTH_FAIL_HOSTBASED: 1607 case SSH_AUTH_FAIL_GSSAPI: 1608 case SSH_LOGIN_EXCEED_MAXTRIES: 1609 case SSH_LOGIN_ROOT_DENIED: 1610 case SSH_CONNECTION_CLOSE: 1611 case SSH_INVALID_USER: 1612 audit_event(event); 1613 break; 1614 default: 1615 fatal("Audit event type %d not permitted", event); 1616 } 1617 1618 return (0); 1619 } 1620 1621 int 1622 mm_answer_audit_command(int socket, Buffer *m) 1623 { 1624 u_int len; 1625 char *cmd; 1626 1627 debug3("%s entering", __func__); 1628 cmd = buffer_get_string(m, &len); 1629 /* sanity check command, if so how? */ 1630 audit_run_command(cmd); 1631 xfree(cmd); 1632 return (0); 1633 } 1634 #endif /* SSH_AUDIT_EVENTS */ 1635 1636 void 1637 monitor_apply_keystate(struct monitor *pmonitor) 1638 { 1639 if (compat20) { 1640 set_newkeys(MODE_IN); 1641 set_newkeys(MODE_OUT); 1642 } else { 1643 packet_set_protocol_flags(child_state.ssh1protoflags); 1644 packet_set_encryption_key(child_state.ssh1key, 1645 child_state.ssh1keylen, child_state.ssh1cipher); 1646 xfree(child_state.ssh1key); 1647 } 1648 1649 /* for rc4 and other stateful ciphers */ 1650 packet_set_keycontext(MODE_OUT, child_state.keyout); 1651 xfree(child_state.keyout); 1652 packet_set_keycontext(MODE_IN, child_state.keyin); 1653 xfree(child_state.keyin); 1654 1655 if (!compat20) { 1656 packet_set_iv(MODE_OUT, child_state.ivout); 1657 xfree(child_state.ivout); 1658 packet_set_iv(MODE_IN, child_state.ivin); 1659 xfree(child_state.ivin); 1660 } 1661 1662 memcpy(&incoming_stream, &child_state.incoming, 1663 sizeof(incoming_stream)); 1664 memcpy(&outgoing_stream, &child_state.outgoing, 1665 sizeof(outgoing_stream)); 1666 1667 /* Update with new address */ 1668 if (options.compression) 1669 mm_init_compression(pmonitor->m_zlib); 1670 1671 /* Network I/O buffers */ 1672 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1673 buffer_clear(&input); 1674 buffer_append(&input, child_state.input, child_state.ilen); 1675 memset(child_state.input, 0, child_state.ilen); 1676 xfree(child_state.input); 1677 1678 buffer_clear(&output); 1679 buffer_append(&output, child_state.output, child_state.olen); 1680 memset(child_state.output, 0, child_state.olen); 1681 xfree(child_state.output); 1682 } 1683 1684 static Kex * 1685 mm_get_kex(Buffer *m) 1686 { 1687 Kex *kex; 1688 void *blob; 1689 u_int bloblen; 1690 1691 kex = xcalloc(1, sizeof(*kex)); 1692 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1693 if ((session_id2 == NULL) || 1694 (kex->session_id_len != session_id2_len) || 1695 (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) 1696 fatal("mm_get_get: internal error: bad session id"); 1697 kex->we_need = buffer_get_int(m); 1698 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1699 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1700 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1701 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1702 kex->server = 1; 1703 kex->hostkey_type = buffer_get_int(m); 1704 kex->kex_type = buffer_get_int(m); 1705 blob = buffer_get_string(m, &bloblen); 1706 buffer_init(&kex->my); 1707 buffer_append(&kex->my, blob, bloblen); 1708 xfree(blob); 1709 blob = buffer_get_string(m, &bloblen); 1710 buffer_init(&kex->peer); 1711 buffer_append(&kex->peer, blob, bloblen); 1712 xfree(blob); 1713 kex->done = 1; 1714 kex->flags = buffer_get_int(m); 1715 kex->client_version_string = buffer_get_string(m, NULL); 1716 kex->server_version_string = buffer_get_string(m, NULL); 1717 kex->load_host_key=&get_hostkey_by_type; 1718 kex->host_key_index=&get_hostkey_index; 1719 1720 return (kex); 1721 } 1722 1723 /* This function requries careful sanity checking */ 1724 1725 void 1726 mm_get_keystate(struct monitor *pmonitor) 1727 { 1728 Buffer m; 1729 u_char *blob, *p; 1730 u_int bloblen, plen; 1731 u_int32_t seqnr, packets; 1732 u_int64_t blocks, bytes; 1733 1734 debug3("%s: Waiting for new keys", __func__); 1735 1736 buffer_init(&m); 1737 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1738 if (!compat20) { 1739 child_state.ssh1protoflags = buffer_get_int(&m); 1740 child_state.ssh1cipher = buffer_get_int(&m); 1741 child_state.ssh1key = buffer_get_string(&m, 1742 &child_state.ssh1keylen); 1743 child_state.ivout = buffer_get_string(&m, 1744 &child_state.ivoutlen); 1745 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1746 goto skip; 1747 } else { 1748 /* Get the Kex for rekeying */ 1749 *pmonitor->m_pkex = mm_get_kex(&m); 1750 } 1751 1752 blob = buffer_get_string(&m, &bloblen); 1753 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1754 xfree(blob); 1755 1756 debug3("%s: Waiting for second key", __func__); 1757 blob = buffer_get_string(&m, &bloblen); 1758 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1759 xfree(blob); 1760 1761 /* Now get sequence numbers for the packets */ 1762 seqnr = buffer_get_int(&m); 1763 blocks = buffer_get_int64(&m); 1764 packets = buffer_get_int(&m); 1765 bytes = buffer_get_int64(&m); 1766 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1767 seqnr = buffer_get_int(&m); 1768 blocks = buffer_get_int64(&m); 1769 packets = buffer_get_int(&m); 1770 bytes = buffer_get_int64(&m); 1771 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1772 1773 skip: 1774 /* Get the key context */ 1775 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1776 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1777 1778 debug3("%s: Getting compression state", __func__); 1779 /* Get compression state */ 1780 p = buffer_get_string(&m, &plen); 1781 if (plen != sizeof(child_state.outgoing)) 1782 fatal("%s: bad request size", __func__); 1783 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1784 xfree(p); 1785 1786 p = buffer_get_string(&m, &plen); 1787 if (plen != sizeof(child_state.incoming)) 1788 fatal("%s: bad request size", __func__); 1789 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1790 xfree(p); 1791 1792 /* Network I/O buffers */ 1793 debug3("%s: Getting Network I/O buffers", __func__); 1794 child_state.input = buffer_get_string(&m, &child_state.ilen); 1795 child_state.output = buffer_get_string(&m, &child_state.olen); 1796 1797 buffer_free(&m); 1798 } 1799 1800 1801 /* Allocation functions for zlib */ 1802 void * 1803 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1804 { 1805 size_t len = (size_t) size * ncount; 1806 void *address; 1807 1808 if (len == 0 || ncount > SIZE_T_MAX / size) 1809 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1810 1811 address = mm_malloc(mm, len); 1812 1813 return (address); 1814 } 1815 1816 void 1817 mm_zfree(struct mm_master *mm, void *address) 1818 { 1819 mm_free(mm, address); 1820 } 1821 1822 void 1823 mm_init_compression(struct mm_master *mm) 1824 { 1825 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1826 outgoing_stream.zfree = (free_func)mm_zfree; 1827 outgoing_stream.opaque = mm; 1828 1829 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1830 incoming_stream.zfree = (free_func)mm_zfree; 1831 incoming_stream.opaque = mm; 1832 } 1833 1834 /* XXX */ 1835 1836 #define FD_CLOSEONEXEC(x) do { \ 1837 if (fcntl(x, F_SETFD, 1) == -1) \ 1838 fatal("fcntl(%d, F_SETFD)", x); \ 1839 } while (0) 1840 1841 static void 1842 monitor_socketpair(int *pair) 1843 { 1844 #ifdef HAVE_SOCKETPAIR 1845 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1846 fatal("%s: socketpair", __func__); 1847 #else 1848 fatal("%s: UsePrivilegeSeparation=yes not supported", 1849 __func__); 1850 #endif 1851 FD_CLOSEONEXEC(pair[0]); 1852 FD_CLOSEONEXEC(pair[1]); 1853 } 1854 1855 #define MM_MEMSIZE 65536 1856 1857 struct monitor * 1858 monitor_init(void) 1859 { 1860 struct monitor *mon; 1861 int pair[2]; 1862 1863 mon = xcalloc(1, sizeof(*mon)); 1864 1865 monitor_socketpair(pair); 1866 1867 mon->m_recvfd = pair[0]; 1868 mon->m_sendfd = pair[1]; 1869 1870 /* Used to share zlib space across processes */ 1871 if (options.compression) { 1872 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1873 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1874 1875 /* Compression needs to share state across borders */ 1876 mm_init_compression(mon->m_zlib); 1877 } 1878 1879 return mon; 1880 } 1881 1882 void 1883 monitor_reinit(struct monitor *mon) 1884 { 1885 int pair[2]; 1886 1887 monitor_socketpair(pair); 1888 1889 mon->m_recvfd = pair[0]; 1890 mon->m_sendfd = pair[1]; 1891 } 1892 1893 #ifdef GSSAPI 1894 int 1895 mm_answer_gss_setup_ctx(int sock, Buffer *m) 1896 { 1897 gss_OID_desc goid; 1898 OM_uint32 major; 1899 u_int len; 1900 1901 goid.elements = buffer_get_string(m, &len); 1902 goid.length = len; 1903 1904 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 1905 1906 xfree(goid.elements); 1907 1908 buffer_clear(m); 1909 buffer_put_int(m, major); 1910 1911 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 1912 1913 /* Now we have a context, enable the step */ 1914 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 1915 1916 return (0); 1917 } 1918 1919 int 1920 mm_answer_gss_accept_ctx(int sock, Buffer *m) 1921 { 1922 gss_buffer_desc in; 1923 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 1924 OM_uint32 major, minor; 1925 OM_uint32 flags = 0; /* GSI needs this */ 1926 u_int len; 1927 1928 in.value = buffer_get_string(m, &len); 1929 in.length = len; 1930 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 1931 xfree(in.value); 1932 1933 buffer_clear(m); 1934 buffer_put_int(m, major); 1935 buffer_put_string(m, out.value, out.length); 1936 buffer_put_int(m, flags); 1937 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 1938 1939 gss_release_buffer(&minor, &out); 1940 1941 if (major == GSS_S_COMPLETE) { 1942 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 1943 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1944 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 1945 } 1946 return (0); 1947 } 1948 1949 int 1950 mm_answer_gss_checkmic(int sock, Buffer *m) 1951 { 1952 gss_buffer_desc gssbuf, mic; 1953 OM_uint32 ret; 1954 u_int len; 1955 1956 gssbuf.value = buffer_get_string(m, &len); 1957 gssbuf.length = len; 1958 mic.value = buffer_get_string(m, &len); 1959 mic.length = len; 1960 1961 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 1962 1963 xfree(gssbuf.value); 1964 xfree(mic.value); 1965 1966 buffer_clear(m); 1967 buffer_put_int(m, ret); 1968 1969 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 1970 1971 if (!GSS_ERROR(ret)) 1972 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 1973 1974 return (0); 1975 } 1976 1977 int 1978 mm_answer_gss_userok(int sock, Buffer *m) 1979 { 1980 int authenticated; 1981 1982 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 1983 1984 buffer_clear(m); 1985 buffer_put_int(m, authenticated); 1986 1987 debug3("%s: sending result %d", __func__, authenticated); 1988 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 1989 1990 auth_method = "gssapi-with-mic"; 1991 1992 /* Monitor loop will terminate if authenticated */ 1993 return (authenticated); 1994 } 1995 #endif /* GSSAPI */ 1996 1997 #ifdef JPAKE 1998 int 1999 mm_answer_jpake_step1(int sock, Buffer *m) 2000 { 2001 struct jpake_ctx *pctx; 2002 u_char *x3_proof, *x4_proof; 2003 u_int x3_proof_len, x4_proof_len; 2004 2005 if (!options.zero_knowledge_password_authentication) 2006 fatal("zero_knowledge_password_authentication disabled"); 2007 2008 if (authctxt->jpake_ctx != NULL) 2009 fatal("%s: authctxt->jpake_ctx already set (%p)", 2010 __func__, authctxt->jpake_ctx); 2011 authctxt->jpake_ctx = pctx = jpake_new(); 2012 2013 jpake_step1(pctx->grp, 2014 &pctx->server_id, &pctx->server_id_len, 2015 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 2016 &x3_proof, &x3_proof_len, 2017 &x4_proof, &x4_proof_len); 2018 2019 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 2020 2021 buffer_clear(m); 2022 2023 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 2024 buffer_put_bignum2(m, pctx->g_x3); 2025 buffer_put_bignum2(m, pctx->g_x4); 2026 buffer_put_string(m, x3_proof, x3_proof_len); 2027 buffer_put_string(m, x4_proof, x4_proof_len); 2028 2029 debug3("%s: sending step1", __func__); 2030 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 2031 2032 bzero(x3_proof, x3_proof_len); 2033 bzero(x4_proof, x4_proof_len); 2034 xfree(x3_proof); 2035 xfree(x4_proof); 2036 2037 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 2038 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 2039 2040 return 0; 2041 } 2042 2043 int 2044 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 2045 { 2046 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2047 char *hash_scheme, *salt; 2048 2049 if (pctx == NULL) 2050 fatal("%s: pctx == NULL", __func__); 2051 2052 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 2053 2054 buffer_clear(m); 2055 /* pctx->s is sensitive, not returned to slave */ 2056 buffer_put_cstring(m, hash_scheme); 2057 buffer_put_cstring(m, salt); 2058 2059 debug3("%s: sending pwdata", __func__); 2060 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 2061 2062 bzero(hash_scheme, strlen(hash_scheme)); 2063 bzero(salt, strlen(salt)); 2064 xfree(hash_scheme); 2065 xfree(salt); 2066 2067 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 2068 2069 return 0; 2070 } 2071 2072 int 2073 mm_answer_jpake_step2(int sock, Buffer *m) 2074 { 2075 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2076 u_char *x1_proof, *x2_proof, *x4_s_proof; 2077 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 2078 2079 if (pctx == NULL) 2080 fatal("%s: pctx == NULL", __func__); 2081 2082 if ((pctx->g_x1 = BN_new()) == NULL || 2083 (pctx->g_x2 = BN_new()) == NULL) 2084 fatal("%s: BN_new", __func__); 2085 buffer_get_bignum2(m, pctx->g_x1); 2086 buffer_get_bignum2(m, pctx->g_x2); 2087 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 2088 x1_proof = buffer_get_string(m, &x1_proof_len); 2089 x2_proof = buffer_get_string(m, &x2_proof_len); 2090 2091 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 2092 pctx->g_x1, pctx->g_x2, pctx->x4, 2093 pctx->client_id, pctx->client_id_len, 2094 pctx->server_id, pctx->server_id_len, 2095 x1_proof, x1_proof_len, 2096 x2_proof, x2_proof_len, 2097 &pctx->b, 2098 &x4_s_proof, &x4_s_proof_len); 2099 2100 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 2101 2102 bzero(x1_proof, x1_proof_len); 2103 bzero(x2_proof, x2_proof_len); 2104 xfree(x1_proof); 2105 xfree(x2_proof); 2106 2107 buffer_clear(m); 2108 2109 buffer_put_bignum2(m, pctx->b); 2110 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 2111 2112 debug3("%s: sending step2", __func__); 2113 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 2114 2115 bzero(x4_s_proof, x4_s_proof_len); 2116 xfree(x4_s_proof); 2117 2118 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 2119 2120 return 0; 2121 } 2122 2123 int 2124 mm_answer_jpake_key_confirm(int sock, Buffer *m) 2125 { 2126 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2127 u_char *x2_s_proof; 2128 u_int x2_s_proof_len; 2129 2130 if (pctx == NULL) 2131 fatal("%s: pctx == NULL", __func__); 2132 2133 if ((pctx->a = BN_new()) == NULL) 2134 fatal("%s: BN_new", __func__); 2135 buffer_get_bignum2(m, pctx->a); 2136 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 2137 2138 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 2139 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 2140 pctx->server_id, pctx->server_id_len, 2141 pctx->client_id, pctx->client_id_len, 2142 session_id2, session_id2_len, 2143 x2_s_proof, x2_s_proof_len, 2144 &pctx->k, 2145 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 2146 2147 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 2148 2149 bzero(x2_s_proof, x2_s_proof_len); 2150 buffer_clear(m); 2151 2152 /* pctx->k is sensitive, not sent */ 2153 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 2154 2155 debug3("%s: sending confirmation hash", __func__); 2156 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 2157 2158 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 2159 2160 return 0; 2161 } 2162 2163 int 2164 mm_answer_jpake_check_confirm(int sock, Buffer *m) 2165 { 2166 int authenticated = 0; 2167 u_char *peer_confirm_hash; 2168 u_int peer_confirm_hash_len; 2169 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2170 2171 if (pctx == NULL) 2172 fatal("%s: pctx == NULL", __func__); 2173 2174 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 2175 2176 authenticated = jpake_check_confirm(pctx->k, 2177 pctx->client_id, pctx->client_id_len, 2178 session_id2, session_id2_len, 2179 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 2180 2181 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 2182 2183 bzero(peer_confirm_hash, peer_confirm_hash_len); 2184 xfree(peer_confirm_hash); 2185 2186 buffer_clear(m); 2187 buffer_put_int(m, authenticated); 2188 2189 debug3("%s: sending result %d", __func__, authenticated); 2190 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 2191 2192 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 2193 2194 auth_method = "jpake-01@openssh.com"; 2195 return authenticated; 2196 } 2197 2198 #endif /* JPAKE */ 2199