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