1 /* $OpenBSD: monitor.c,v 1.115 2011/06/23 23:35:42 djm Exp $ */ 2 /* 3 * Copyright 2002 Niels Provos <provos (at) citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus (at) 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 #ifdef HAVE_POLL_H 48 #include <poll.h> 49 #else 50 # ifdef HAVE_SYS_POLL_H 51 # include <sys/poll.h> 52 # endif 53 #endif 54 55 #ifdef SKEY 56 #include <skey.h> 57 #endif 58 59 #include <openssl/dh.h> 60 61 #include "openbsd-compat/sys-queue.h" 62 #include "atomicio.h" 63 #include "xmalloc.h" 64 #include "ssh.h" 65 #include "key.h" 66 #include "buffer.h" 67 #include "hostfile.h" 68 #include "auth.h" 69 #include "cipher.h" 70 #include "kex.h" 71 #include "dh.h" 72 #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ 73 #undef TARGET_OS_MAC 74 #include "zlib.h" 75 #define TARGET_OS_MAC 1 76 #else 77 #include "zlib.h" 78 #endif 79 #include "packet.h" 80 #include "auth-options.h" 81 #include "sshpty.h" 82 #include "channels.h" 83 #include "session.h" 84 #include "sshlogin.h" 85 #include "canohost.h" 86 #include "log.h" 87 #include "servconf.h" 88 #include "monitor.h" 89 #include "monitor_mm.h" 90 #ifdef GSSAPI 91 #include "ssh-gss.h" 92 #endif 93 #include "monitor_wrap.h" 94 #include "monitor_fdpass.h" 95 #include "misc.h" 96 #include "compat.h" 97 #include "ssh2.h" 98 #include "jpake.h" 99 #include "roaming.h" 100 101 #ifdef GSSAPI 102 static Gssctxt *gsscontext = NULL; 103 #endif 104 105 /* Imports */ 106 extern ServerOptions options; 107 extern u_int utmp_len; 108 extern Newkeys *current_keys[]; 109 extern z_stream incoming_stream; 110 extern z_stream outgoing_stream; 111 extern u_char session_id[]; 112 extern Buffer auth_debug; 113 extern int auth_debug_init; 114 extern Buffer loginmsg; 115 116 /* State exported from the child */ 117 118 struct { 119 z_stream incoming; 120 z_stream outgoing; 121 u_char *keyin; 122 u_int keyinlen; 123 u_char *keyout; 124 u_int keyoutlen; 125 u_char *ivin; 126 u_int ivinlen; 127 u_char *ivout; 128 u_int ivoutlen; 129 u_char *ssh1key; 130 u_int ssh1keylen; 131 int ssh1cipher; 132 int ssh1protoflags; 133 u_char *input; 134 u_int ilen; 135 u_char *output; 136 u_int olen; 137 u_int64_t sent_bytes; 138 u_int64_t recv_bytes; 139 } child_state; 140 141 /* Functions on the monitor that answer unprivileged requests */ 142 143 int mm_answer_moduli(int, Buffer *); 144 int mm_answer_sign(int, Buffer *); 145 int mm_answer_pwnamallow(int, Buffer *); 146 int mm_answer_auth2_read_banner(int, Buffer *); 147 int mm_answer_authserv(int, Buffer *); 148 int mm_answer_authpassword(int, Buffer *); 149 int mm_answer_bsdauthquery(int, Buffer *); 150 int mm_answer_bsdauthrespond(int, Buffer *); 151 int mm_answer_skeyquery(int, Buffer *); 152 int mm_answer_skeyrespond(int, Buffer *); 153 int mm_answer_keyallowed(int, Buffer *); 154 int mm_answer_keyverify(int, Buffer *); 155 int mm_answer_pty(int, Buffer *); 156 int mm_answer_pty_cleanup(int, Buffer *); 157 int mm_answer_term(int, Buffer *); 158 int mm_answer_rsa_keyallowed(int, Buffer *); 159 int mm_answer_rsa_challenge(int, Buffer *); 160 int mm_answer_rsa_response(int, Buffer *); 161 int mm_answer_sesskey(int, Buffer *); 162 int mm_answer_sessid(int, Buffer *); 163 int mm_answer_jpake_get_pwdata(int, Buffer *); 164 int mm_answer_jpake_step1(int, Buffer *); 165 int mm_answer_jpake_step2(int, Buffer *); 166 int mm_answer_jpake_key_confirm(int, Buffer *); 167 int mm_answer_jpake_check_confirm(int, Buffer *); 168 169 #ifdef USE_PAM 170 int mm_answer_pam_start(int, Buffer *); 171 int mm_answer_pam_account(int, Buffer *); 172 int mm_answer_pam_init_ctx(int, Buffer *); 173 int mm_answer_pam_query(int, Buffer *); 174 int mm_answer_pam_respond(int, Buffer *); 175 int mm_answer_pam_free_ctx(int, Buffer *); 176 #endif 177 178 #ifdef GSSAPI 179 int mm_answer_gss_setup_ctx(int, Buffer *); 180 int mm_answer_gss_accept_ctx(int, Buffer *); 181 int mm_answer_gss_userok(int, Buffer *); 182 int mm_answer_gss_checkmic(int, Buffer *); 183 #endif 184 185 #ifdef SSH_AUDIT_EVENTS 186 int mm_answer_audit_event(int, Buffer *); 187 int mm_answer_audit_command(int, Buffer *); 188 #endif 189 190 static int monitor_read_log(struct monitor *); 191 192 static Authctxt *authctxt; 193 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 194 195 /* local state for key verify */ 196 static u_char *key_blob = NULL; 197 static u_int key_bloblen = 0; 198 static int key_blobtype = MM_NOKEY; 199 static char *hostbased_cuser = NULL; 200 static char *hostbased_chost = NULL; 201 static char *auth_method = "unknown"; 202 static u_int session_id2_len = 0; 203 static u_char *session_id2 = NULL; 204 static pid_t monitor_child_pid; 205 206 struct mon_table { 207 enum monitor_reqtype type; 208 int flags; 209 int (*f)(int, Buffer *); 210 }; 211 212 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 213 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 214 #define MON_ONCE 0x0010 /* Disable after calling */ 215 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 216 217 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 218 219 #define MON_PERMIT 0x1000 /* Request is permitted */ 220 221 struct mon_table mon_dispatch_proto20[] = { 222 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 223 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 224 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 225 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 226 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 227 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 228 #ifdef USE_PAM 229 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 230 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 231 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 232 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 233 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 234 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 235 #endif 236 #ifdef SSH_AUDIT_EVENTS 237 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 238 #endif 239 #ifdef BSD_AUTH 240 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 241 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 242 #endif 243 #ifdef SKEY 244 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 245 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 246 #endif 247 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 248 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 249 #ifdef GSSAPI 250 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 251 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 252 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 253 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 254 #endif 255 #ifdef JPAKE 256 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 257 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 258 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 259 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 260 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 261 #endif 262 {0, 0, NULL} 263 }; 264 265 struct mon_table mon_dispatch_postauth20[] = { 266 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 267 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 268 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 269 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 270 {MONITOR_REQ_TERM, 0, mm_answer_term}, 271 #ifdef SSH_AUDIT_EVENTS 272 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 273 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, 274 #endif 275 {0, 0, NULL} 276 }; 277 278 struct mon_table mon_dispatch_proto15[] = { 279 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 280 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 281 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 282 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 283 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 284 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 285 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 286 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 287 #ifdef BSD_AUTH 288 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 289 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 290 #endif 291 #ifdef SKEY 292 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 293 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 294 #endif 295 #ifdef USE_PAM 296 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 297 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 298 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 299 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 300 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 301 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 302 #endif 303 #ifdef SSH_AUDIT_EVENTS 304 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 305 #endif 306 {0, 0, NULL} 307 }; 308 309 struct mon_table mon_dispatch_postauth15[] = { 310 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 311 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 312 {MONITOR_REQ_TERM, 0, mm_answer_term}, 313 #ifdef SSH_AUDIT_EVENTS 314 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, 315 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, 316 #endif 317 {0, 0, NULL} 318 }; 319 320 struct mon_table *mon_dispatch; 321 322 /* Specifies if a certain message is allowed at the moment */ 323 324 static void 325 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 326 { 327 while (ent->f != NULL) { 328 if (ent->type == type) { 329 ent->flags &= ~MON_PERMIT; 330 ent->flags |= permit ? MON_PERMIT : 0; 331 return; 332 } 333 ent++; 334 } 335 } 336 337 static void 338 monitor_permit_authentications(int permit) 339 { 340 struct mon_table *ent = mon_dispatch; 341 342 while (ent->f != NULL) { 343 if (ent->flags & MON_AUTH) { 344 ent->flags &= ~MON_PERMIT; 345 ent->flags |= permit ? MON_PERMIT : 0; 346 } 347 ent++; 348 } 349 } 350 351 void 352 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 353 { 354 struct mon_table *ent; 355 int authenticated = 0; 356 357 debug3("preauth child monitor started"); 358 359 close(pmonitor->m_recvfd); 360 close(pmonitor->m_log_sendfd); 361 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 362 363 authctxt = _authctxt; 364 memset(authctxt, 0, sizeof(*authctxt)); 365 366 authctxt->loginmsg = &loginmsg; 367 368 if (compat20) { 369 mon_dispatch = mon_dispatch_proto20; 370 371 /* Permit requests for moduli and signatures */ 372 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 373 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 374 } else { 375 mon_dispatch = mon_dispatch_proto15; 376 377 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 378 } 379 380 /* The first few requests do not require asynchronous access */ 381 while (!authenticated) { 382 auth_method = "unknown"; 383 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 384 if (authenticated) { 385 if (!(ent->flags & MON_AUTHDECIDE)) 386 fatal("%s: unexpected authentication from %d", 387 __func__, ent->type); 388 if (authctxt->pw->pw_uid == 0 && 389 !auth_root_allowed(auth_method)) 390 authenticated = 0; 391 #ifdef USE_PAM 392 /* PAM needs to perform account checks after auth */ 393 if (options.use_pam && authenticated) { 394 Buffer m; 395 396 buffer_init(&m); 397 mm_request_receive_expect(pmonitor->m_sendfd, 398 MONITOR_REQ_PAM_ACCOUNT, &m); 399 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 400 buffer_free(&m); 401 } 402 #endif 403 } 404 405 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 406 auth_log(authctxt, authenticated, auth_method, 407 compat20 ? " ssh2" : ""); 408 if (!authenticated) 409 authctxt->failures++; 410 } 411 #ifdef JPAKE 412 /* Cleanup JPAKE context after authentication */ 413 if (ent->flags & MON_AUTHDECIDE) { 414 if (authctxt->jpake_ctx != NULL) { 415 jpake_free(authctxt->jpake_ctx); 416 authctxt->jpake_ctx = NULL; 417 } 418 } 419 #endif 420 } 421 422 /* Drain any buffered messages from the child */ 423 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 424 ; 425 426 if (!authctxt->valid) 427 fatal("%s: authenticated invalid user", __func__); 428 if (strcmp(auth_method, "unknown") == 0) 429 fatal("%s: authentication method name unknown", __func__); 430 431 debug("%s: %s has been authenticated by privileged process", 432 __func__, authctxt->user); 433 434 mm_get_keystate(pmonitor); 435 436 close(pmonitor->m_sendfd); 437 close(pmonitor->m_log_recvfd); 438 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 439 } 440 441 static void 442 monitor_set_child_handler(pid_t pid) 443 { 444 monitor_child_pid = pid; 445 } 446 447 static void 448 monitor_child_handler(int sig) 449 { 450 kill(monitor_child_pid, sig); 451 } 452 453 void 454 monitor_child_postauth(struct monitor *pmonitor) 455 { 456 close(pmonitor->m_recvfd); 457 pmonitor->m_recvfd = -1; 458 459 monitor_set_child_handler(pmonitor->m_pid); 460 signal(SIGHUP, &monitor_child_handler); 461 signal(SIGTERM, &monitor_child_handler); 462 signal(SIGINT, &monitor_child_handler); 463 464 if (compat20) { 465 mon_dispatch = mon_dispatch_postauth20; 466 467 /* Permit requests for moduli and signatures */ 468 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 469 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 470 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 471 } else { 472 mon_dispatch = mon_dispatch_postauth15; 473 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 474 } 475 if (!no_pty_flag) { 476 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 477 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 478 } 479 480 for (;;) 481 monitor_read(pmonitor, mon_dispatch, NULL); 482 483 close(pmonitor->m_sendfd); 484 pmonitor->m_sendfd = -1; 485 } 486 487 void 488 monitor_sync(struct monitor *pmonitor) 489 { 490 if (options.compression) { 491 /* The member allocation is not visible, so sync it */ 492 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 493 } 494 } 495 496 static int 497 monitor_read_log(struct monitor *pmonitor) 498 { 499 Buffer logmsg; 500 u_int len, level; 501 char *msg; 502 503 buffer_init(&logmsg); 504 505 /* Read length */ 506 buffer_append_space(&logmsg, 4); 507 if (atomicio(read, pmonitor->m_log_recvfd, 508 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 509 if (errno == EPIPE) { 510 debug("%s: child log fd closed", __func__); 511 close(pmonitor->m_log_recvfd); 512 pmonitor->m_log_recvfd = -1; 513 return -1; 514 } 515 fatal("%s: log fd read: %s", __func__, strerror(errno)); 516 } 517 len = buffer_get_int(&logmsg); 518 if (len <= 4 || len > 8192) 519 fatal("%s: invalid log message length %u", __func__, len); 520 521 /* Read severity, message */ 522 buffer_clear(&logmsg); 523 buffer_append_space(&logmsg, len); 524 if (atomicio(read, pmonitor->m_log_recvfd, 525 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) 526 fatal("%s: log fd read: %s", __func__, strerror(errno)); 527 528 /* Log it */ 529 level = buffer_get_int(&logmsg); 530 msg = buffer_get_string(&logmsg, NULL); 531 if (log_level_name(level) == NULL) 532 fatal("%s: invalid log level %u (corrupted message?)", 533 __func__, level); 534 do_log2(level, "%s [preauth]", msg); 535 536 buffer_free(&logmsg); 537 xfree(msg); 538 539 return 0; 540 } 541 542 int 543 monitor_read(struct monitor *pmonitor, struct mon_table *ent, 544 struct mon_table **pent) 545 { 546 Buffer m; 547 int ret; 548 u_char type; 549 struct pollfd pfd[2]; 550 551 for (;;) { 552 bzero(&pfd, sizeof(pfd)); 553 pfd[0].fd = pmonitor->m_sendfd; 554 pfd[0].events = POLLIN; 555 pfd[1].fd = pmonitor->m_log_recvfd; 556 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; 557 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { 558 if (errno == EINTR || errno == EAGAIN) 559 continue; 560 fatal("%s: poll: %s", __func__, strerror(errno)); 561 } 562 if (pfd[1].revents) { 563 /* 564 * Drain all log messages before processing next 565 * monitor request. 566 */ 567 monitor_read_log(pmonitor); 568 continue; 569 } 570 if (pfd[0].revents) 571 break; /* Continues below */ 572 } 573 574 buffer_init(&m); 575 576 mm_request_receive(pmonitor->m_sendfd, &m); 577 type = buffer_get_char(&m); 578 579 debug3("%s: checking request %d", __func__, type); 580 581 while (ent->f != NULL) { 582 if (ent->type == type) 583 break; 584 ent++; 585 } 586 587 if (ent->f != NULL) { 588 if (!(ent->flags & MON_PERMIT)) 589 fatal("%s: unpermitted request %d", __func__, 590 type); 591 ret = (*ent->f)(pmonitor->m_sendfd, &m); 592 buffer_free(&m); 593 594 /* The child may use this request only once, disable it */ 595 if (ent->flags & MON_ONCE) { 596 debug2("%s: %d used once, disabling now", __func__, 597 type); 598 ent->flags &= ~MON_PERMIT; 599 } 600 601 if (pent != NULL) 602 *pent = ent; 603 604 return ret; 605 } 606 607 fatal("%s: unsupported request: %d", __func__, type); 608 609 /* NOTREACHED */ 610 return (-1); 611 } 612 613 /* allowed key state */ 614 static int 615 monitor_allowed_key(u_char *blob, u_int bloblen) 616 { 617 /* make sure key is allowed */ 618 if (key_blob == NULL || key_bloblen != bloblen || 619 timingsafe_bcmp(key_blob, blob, key_bloblen)) 620 return (0); 621 return (1); 622 } 623 624 static void 625 monitor_reset_key_state(void) 626 { 627 /* reset state */ 628 if (key_blob != NULL) 629 xfree(key_blob); 630 if (hostbased_cuser != NULL) 631 xfree(hostbased_cuser); 632 if (hostbased_chost != NULL) 633 xfree(hostbased_chost); 634 key_blob = NULL; 635 key_bloblen = 0; 636 key_blobtype = MM_NOKEY; 637 hostbased_cuser = NULL; 638 hostbased_chost = NULL; 639 } 640 641 int 642 mm_answer_moduli(int sock, Buffer *m) 643 { 644 DH *dh; 645 int min, want, max; 646 647 min = buffer_get_int(m); 648 want = buffer_get_int(m); 649 max = buffer_get_int(m); 650 651 debug3("%s: got parameters: %d %d %d", 652 __func__, min, want, max); 653 /* We need to check here, too, in case the child got corrupted */ 654 if (max < min || want < min || max < want) 655 fatal("%s: bad parameters: %d %d %d", 656 __func__, min, want, max); 657 658 buffer_clear(m); 659 660 dh = choose_dh(min, want, max); 661 if (dh == NULL) { 662 buffer_put_char(m, 0); 663 return (0); 664 } else { 665 /* Send first bignum */ 666 buffer_put_char(m, 1); 667 buffer_put_bignum2(m, dh->p); 668 buffer_put_bignum2(m, dh->g); 669 670 DH_free(dh); 671 } 672 mm_request_send(sock, MONITOR_ANS_MODULI, m); 673 return (0); 674 } 675 676 int 677 mm_answer_sign(int sock, Buffer *m) 678 { 679 Key *key; 680 u_char *p; 681 u_char *signature; 682 u_int siglen, datlen; 683 int keyid; 684 685 debug3("%s", __func__); 686 687 keyid = buffer_get_int(m); 688 p = buffer_get_string(m, &datlen); 689 690 /* 691 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 692 * SHA384 (48 bytes) and SHA512 (64 bytes). 693 */ 694 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) 695 fatal("%s: data length incorrect: %u", __func__, datlen); 696 697 /* save session id, it will be passed on the first call */ 698 if (session_id2_len == 0) { 699 session_id2_len = datlen; 700 session_id2 = xmalloc(session_id2_len); 701 memcpy(session_id2, p, session_id2_len); 702 } 703 704 if ((key = get_hostkey_by_index(keyid)) == NULL) 705 fatal("%s: no hostkey from index %d", __func__, keyid); 706 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 707 fatal("%s: key_sign failed", __func__); 708 709 debug3("%s: signature %p(%u)", __func__, signature, siglen); 710 711 buffer_clear(m); 712 buffer_put_string(m, signature, siglen); 713 714 xfree(p); 715 xfree(signature); 716 717 mm_request_send(sock, MONITOR_ANS_SIGN, m); 718 719 /* Turn on permissions for getpwnam */ 720 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 721 722 return (0); 723 } 724 725 /* Retrieves the password entry and also checks if the user is permitted */ 726 727 int 728 mm_answer_pwnamallow(int sock, Buffer *m) 729 { 730 char *username; 731 struct passwd *pwent; 732 int allowed = 0; 733 u_int i; 734 735 debug3("%s", __func__); 736 737 if (authctxt->attempt++ != 0) 738 fatal("%s: multiple attempts for getpwnam", __func__); 739 740 username = buffer_get_string(m, NULL); 741 742 pwent = getpwnamallow(username); 743 744 authctxt->user = xstrdup(username); 745 setproctitle("%s [priv]", pwent ? username : "unknown"); 746 xfree(username); 747 748 buffer_clear(m); 749 750 if (pwent == NULL) { 751 buffer_put_char(m, 0); 752 authctxt->pw = fakepw(); 753 goto out; 754 } 755 756 allowed = 1; 757 authctxt->pw = pwent; 758 authctxt->valid = 1; 759 760 buffer_put_char(m, 1); 761 buffer_put_string(m, pwent, sizeof(struct passwd)); 762 buffer_put_cstring(m, pwent->pw_name); 763 buffer_put_cstring(m, "*"); 764 #ifdef HAVE_PW_GECOS_IN_PASSWD 765 buffer_put_cstring(m, pwent->pw_gecos); 766 #endif 767 #ifdef HAVE_PW_CLASS_IN_PASSWD 768 buffer_put_cstring(m, pwent->pw_class); 769 #endif 770 buffer_put_cstring(m, pwent->pw_dir); 771 buffer_put_cstring(m, pwent->pw_shell); 772 773 out: 774 buffer_put_string(m, &options, sizeof(options)); 775 776 #define M_CP_STROPT(x) do { \ 777 if (options.x != NULL) \ 778 buffer_put_cstring(m, options.x); \ 779 } while (0) 780 #define M_CP_STRARRAYOPT(x, nx) do { \ 781 for (i = 0; i < options.nx; i++) \ 782 buffer_put_cstring(m, options.x[i]); \ 783 } while (0) 784 /* See comment in servconf.h */ 785 COPY_MATCH_STRING_OPTS(); 786 #undef M_CP_STROPT 787 #undef M_CP_STRARRAYOPT 788 789 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 790 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 791 792 /* For SSHv1 allow authentication now */ 793 if (!compat20) 794 monitor_permit_authentications(1); 795 else { 796 /* Allow service/style information on the auth context */ 797 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 798 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 799 } 800 #ifdef USE_PAM 801 if (options.use_pam) 802 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 803 #endif 804 805 return (0); 806 } 807 808 int mm_answer_auth2_read_banner(int sock, Buffer *m) 809 { 810 char *banner; 811 812 buffer_clear(m); 813 banner = auth2_read_banner(); 814 buffer_put_cstring(m, banner != NULL ? banner : ""); 815 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 816 817 if (banner != NULL) 818 xfree(banner); 819 820 return (0); 821 } 822 823 int 824 mm_answer_authserv(int sock, Buffer *m) 825 { 826 monitor_permit_authentications(1); 827 828 authctxt->service = buffer_get_string(m, NULL); 829 authctxt->style = buffer_get_string(m, NULL); 830 debug3("%s: service=%s, style=%s", 831 __func__, authctxt->service, authctxt->style); 832 833 if (strlen(authctxt->style) == 0) { 834 xfree(authctxt->style); 835 authctxt->style = NULL; 836 } 837 838 return (0); 839 } 840 841 int 842 mm_answer_authpassword(int sock, Buffer *m) 843 { 844 static int call_count; 845 char *passwd; 846 int authenticated; 847 u_int plen; 848 849 passwd = buffer_get_string(m, &plen); 850 /* Only authenticate if the context is valid */ 851 #ifndef ANDROID 852 /* no password authentication in android */ 853 authenticated = options.password_authentication && 854 auth_password(authctxt, passwd); 855 #else 856 authenticated = 0; 857 #endif 858 memset(passwd, 0, strlen(passwd)); 859 xfree(passwd); 860 861 buffer_clear(m); 862 buffer_put_int(m, authenticated); 863 864 debug3("%s: sending result %d", __func__, authenticated); 865 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 866 867 call_count++; 868 if (plen == 0 && call_count == 1) 869 auth_method = "none"; 870 else 871 auth_method = "password"; 872 873 /* Causes monitor loop to terminate if authenticated */ 874 return (authenticated); 875 } 876 877 #ifdef BSD_AUTH 878 int 879 mm_answer_bsdauthquery(int sock, Buffer *m) 880 { 881 char *name, *infotxt; 882 u_int numprompts; 883 u_int *echo_on; 884 char **prompts; 885 u_int success; 886 887 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 888 &prompts, &echo_on) < 0 ? 0 : 1; 889 890 buffer_clear(m); 891 buffer_put_int(m, success); 892 if (success) 893 buffer_put_cstring(m, prompts[0]); 894 895 debug3("%s: sending challenge success: %u", __func__, success); 896 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 897 898 if (success) { 899 xfree(name); 900 xfree(infotxt); 901 xfree(prompts); 902 xfree(echo_on); 903 } 904 905 return (0); 906 } 907 908 int 909 mm_answer_bsdauthrespond(int sock, Buffer *m) 910 { 911 char *response; 912 int authok; 913 914 if (authctxt->as == 0) 915 fatal("%s: no bsd auth session", __func__); 916 917 response = buffer_get_string(m, NULL); 918 authok = options.challenge_response_authentication && 919 auth_userresponse(authctxt->as, response, 0); 920 authctxt->as = NULL; 921 debug3("%s: <%s> = <%d>", __func__, response, authok); 922 xfree(response); 923 924 buffer_clear(m); 925 buffer_put_int(m, authok); 926 927 debug3("%s: sending authenticated: %d", __func__, authok); 928 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 929 930 auth_method = "bsdauth"; 931 932 return (authok != 0); 933 } 934 #endif 935 936 #ifdef SKEY 937 int 938 mm_answer_skeyquery(int sock, Buffer *m) 939 { 940 struct skey skey; 941 char challenge[1024]; 942 u_int success; 943 944 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 945 sizeof(challenge)) < 0 ? 0 : 1; 946 947 buffer_clear(m); 948 buffer_put_int(m, success); 949 if (success) 950 buffer_put_cstring(m, challenge); 951 952 debug3("%s: sending challenge success: %u", __func__, success); 953 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 954 955 return (0); 956 } 957 958 int 959 mm_answer_skeyrespond(int sock, Buffer *m) 960 { 961 char *response; 962 int authok; 963 964 response = buffer_get_string(m, NULL); 965 966 authok = (options.challenge_response_authentication && 967 authctxt->valid && 968 skey_haskey(authctxt->pw->pw_name) == 0 && 969 skey_passcheck(authctxt->pw->pw_name, response) != -1); 970 971 xfree(response); 972 973 buffer_clear(m); 974 buffer_put_int(m, authok); 975 976 debug3("%s: sending authenticated: %d", __func__, authok); 977 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 978 979 auth_method = "skey"; 980 981 return (authok != 0); 982 } 983 #endif 984 985 #ifdef USE_PAM 986 int 987 mm_answer_pam_start(int sock, Buffer *m) 988 { 989 if (!options.use_pam) 990 fatal("UsePAM not set, but ended up in %s anyway", __func__); 991 992 start_pam(authctxt); 993 994 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 995 996 return (0); 997 } 998 999 int 1000 mm_answer_pam_account(int sock, Buffer *m) 1001 { 1002 u_int ret; 1003 1004 if (!options.use_pam) 1005 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1006 1007 ret = do_pam_account(); 1008 1009 buffer_put_int(m, ret); 1010 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1011 1012 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1013 1014 return (ret); 1015 } 1016 1017 static void *sshpam_ctxt, *sshpam_authok; 1018 extern KbdintDevice sshpam_device; 1019 1020 int 1021 mm_answer_pam_init_ctx(int sock, Buffer *m) 1022 { 1023 1024 debug3("%s", __func__); 1025 authctxt->user = buffer_get_string(m, NULL); 1026 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1027 sshpam_authok = NULL; 1028 buffer_clear(m); 1029 if (sshpam_ctxt != NULL) { 1030 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1031 buffer_put_int(m, 1); 1032 } else { 1033 buffer_put_int(m, 0); 1034 } 1035 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1036 return (0); 1037 } 1038 1039 int 1040 mm_answer_pam_query(int sock, Buffer *m) 1041 { 1042 char *name = NULL, *info = NULL, **prompts = NULL; 1043 u_int i, num = 0, *echo_on = 0; 1044 int ret; 1045 1046 debug3("%s", __func__); 1047 sshpam_authok = NULL; 1048 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1049 if (ret == 0 && num == 0) 1050 sshpam_authok = sshpam_ctxt; 1051 if (num > 1 || name == NULL || info == NULL) 1052 ret = -1; 1053 buffer_clear(m); 1054 buffer_put_int(m, ret); 1055 buffer_put_cstring(m, name); 1056 xfree(name); 1057 buffer_put_cstring(m, info); 1058 xfree(info); 1059 buffer_put_int(m, num); 1060 for (i = 0; i < num; ++i) { 1061 buffer_put_cstring(m, prompts[i]); 1062 xfree(prompts[i]); 1063 buffer_put_int(m, echo_on[i]); 1064 } 1065 if (prompts != NULL) 1066 xfree(prompts); 1067 if (echo_on != NULL) 1068 xfree(echo_on); 1069 auth_method = "keyboard-interactive/pam"; 1070 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1071 return (0); 1072 } 1073 1074 int 1075 mm_answer_pam_respond(int sock, Buffer *m) 1076 { 1077 char **resp; 1078 u_int i, num; 1079 int ret; 1080 1081 debug3("%s", __func__); 1082 sshpam_authok = NULL; 1083 num = buffer_get_int(m); 1084 if (num > 0) { 1085 resp = xcalloc(num, sizeof(char *)); 1086 for (i = 0; i < num; ++i) 1087 resp[i] = buffer_get_string(m, NULL); 1088 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1089 for (i = 0; i < num; ++i) 1090 xfree(resp[i]); 1091 xfree(resp); 1092 } else { 1093 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1094 } 1095 buffer_clear(m); 1096 buffer_put_int(m, ret); 1097 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1098 auth_method = "keyboard-interactive/pam"; 1099 if (ret == 0) 1100 sshpam_authok = sshpam_ctxt; 1101 return (0); 1102 } 1103 1104 int 1105 mm_answer_pam_free_ctx(int sock, Buffer *m) 1106 { 1107 1108 debug3("%s", __func__); 1109 (sshpam_device.free_ctx)(sshpam_ctxt); 1110 buffer_clear(m); 1111 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1112 auth_method = "keyboard-interactive/pam"; 1113 return (sshpam_authok == sshpam_ctxt); 1114 } 1115 #endif 1116 1117 int 1118 mm_answer_keyallowed(int sock, Buffer *m) 1119 { 1120 Key *key; 1121 char *cuser, *chost; 1122 u_char *blob; 1123 u_int bloblen; 1124 enum mm_keytype type = 0; 1125 int allowed = 0; 1126 1127 debug3("%s entering", __func__); 1128 1129 type = buffer_get_int(m); 1130 cuser = buffer_get_string(m, NULL); 1131 chost = buffer_get_string(m, NULL); 1132 blob = buffer_get_string(m, &bloblen); 1133 1134 key = key_from_blob(blob, bloblen); 1135 1136 if ((compat20 && type == MM_RSAHOSTKEY) || 1137 (!compat20 && type != MM_RSAHOSTKEY)) 1138 fatal("%s: key type and protocol mismatch", __func__); 1139 1140 debug3("%s: key_from_blob: %p", __func__, key); 1141 1142 if (key != NULL && authctxt->valid) { 1143 switch (type) { 1144 case MM_USERKEY: 1145 allowed = options.pubkey_authentication && 1146 user_key_allowed(authctxt->pw, key); 1147 auth_method = "publickey"; 1148 if (options.pubkey_authentication && allowed != 1) 1149 auth_clear_options(); 1150 break; 1151 case MM_HOSTKEY: 1152 allowed = options.hostbased_authentication && 1153 hostbased_key_allowed(authctxt->pw, 1154 cuser, chost, key); 1155 auth_method = "hostbased"; 1156 break; 1157 case MM_RSAHOSTKEY: 1158 key->type = KEY_RSA1; /* XXX */ 1159 allowed = options.rhosts_rsa_authentication && 1160 auth_rhosts_rsa_key_allowed(authctxt->pw, 1161 cuser, chost, key); 1162 if (options.rhosts_rsa_authentication && allowed != 1) 1163 auth_clear_options(); 1164 auth_method = "rsa"; 1165 break; 1166 default: 1167 fatal("%s: unknown key type %d", __func__, type); 1168 break; 1169 } 1170 } 1171 if (key != NULL) 1172 key_free(key); 1173 1174 /* clear temporarily storage (used by verify) */ 1175 monitor_reset_key_state(); 1176 1177 if (allowed) { 1178 /* Save temporarily for comparison in verify */ 1179 key_blob = blob; 1180 key_bloblen = bloblen; 1181 key_blobtype = type; 1182 hostbased_cuser = cuser; 1183 hostbased_chost = chost; 1184 } else { 1185 /* Log failed attempt */ 1186 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 1187 xfree(blob); 1188 xfree(cuser); 1189 xfree(chost); 1190 } 1191 1192 debug3("%s: key %p is %s", 1193 __func__, key, allowed ? "allowed" : "not allowed"); 1194 1195 buffer_clear(m); 1196 buffer_put_int(m, allowed); 1197 buffer_put_int(m, forced_command != NULL); 1198 1199 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1200 1201 if (type == MM_RSAHOSTKEY) 1202 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1203 1204 return (0); 1205 } 1206 1207 static int 1208 monitor_valid_userblob(u_char *data, u_int datalen) 1209 { 1210 Buffer b; 1211 char *p; 1212 u_int len; 1213 int fail = 0; 1214 1215 buffer_init(&b); 1216 buffer_append(&b, data, datalen); 1217 1218 if (datafellows & SSH_OLD_SESSIONID) { 1219 p = buffer_ptr(&b); 1220 len = buffer_len(&b); 1221 if ((session_id2 == NULL) || 1222 (len < session_id2_len) || 1223 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1224 fail++; 1225 buffer_consume(&b, session_id2_len); 1226 } else { 1227 p = buffer_get_string(&b, &len); 1228 if ((session_id2 == NULL) || 1229 (len != session_id2_len) || 1230 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1231 fail++; 1232 xfree(p); 1233 } 1234 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1235 fail++; 1236 p = buffer_get_string(&b, NULL); 1237 if (strcmp(authctxt->user, p) != 0) { 1238 logit("wrong user name passed to monitor: expected %s != %.100s", 1239 authctxt->user, p); 1240 fail++; 1241 } 1242 xfree(p); 1243 buffer_skip_string(&b); 1244 if (datafellows & SSH_BUG_PKAUTH) { 1245 if (!buffer_get_char(&b)) 1246 fail++; 1247 } else { 1248 p = buffer_get_string(&b, NULL); 1249 if (strcmp("publickey", p) != 0) 1250 fail++; 1251 xfree(p); 1252 if (!buffer_get_char(&b)) 1253 fail++; 1254 buffer_skip_string(&b); 1255 } 1256 buffer_skip_string(&b); 1257 if (buffer_len(&b) != 0) 1258 fail++; 1259 buffer_free(&b); 1260 return (fail == 0); 1261 } 1262 1263 static int 1264 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1265 char *chost) 1266 { 1267 Buffer b; 1268 char *p; 1269 u_int len; 1270 int fail = 0; 1271 1272 buffer_init(&b); 1273 buffer_append(&b, data, datalen); 1274 1275 p = buffer_get_string(&b, &len); 1276 if ((session_id2 == NULL) || 1277 (len != session_id2_len) || 1278 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1279 fail++; 1280 xfree(p); 1281 1282 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1283 fail++; 1284 p = buffer_get_string(&b, NULL); 1285 if (strcmp(authctxt->user, p) != 0) { 1286 logit("wrong user name passed to monitor: expected %s != %.100s", 1287 authctxt->user, p); 1288 fail++; 1289 } 1290 xfree(p); 1291 buffer_skip_string(&b); /* service */ 1292 p = buffer_get_string(&b, NULL); 1293 if (strcmp(p, "hostbased") != 0) 1294 fail++; 1295 xfree(p); 1296 buffer_skip_string(&b); /* pkalg */ 1297 buffer_skip_string(&b); /* pkblob */ 1298 1299 /* verify client host, strip trailing dot if necessary */ 1300 p = buffer_get_string(&b, NULL); 1301 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1302 p[len - 1] = '\0'; 1303 if (strcmp(p, chost) != 0) 1304 fail++; 1305 xfree(p); 1306 1307 /* verify client user */ 1308 p = buffer_get_string(&b, NULL); 1309 if (strcmp(p, cuser) != 0) 1310 fail++; 1311 xfree(p); 1312 1313 if (buffer_len(&b) != 0) 1314 fail++; 1315 buffer_free(&b); 1316 return (fail == 0); 1317 } 1318 1319 int 1320 mm_answer_keyverify(int sock, Buffer *m) 1321 { 1322 Key *key; 1323 u_char *signature, *data, *blob; 1324 u_int signaturelen, datalen, bloblen; 1325 int verified = 0; 1326 int valid_data = 0; 1327 1328 blob = buffer_get_string(m, &bloblen); 1329 signature = buffer_get_string(m, &signaturelen); 1330 data = buffer_get_string(m, &datalen); 1331 1332 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1333 !monitor_allowed_key(blob, bloblen)) 1334 fatal("%s: bad key, not previously allowed", __func__); 1335 1336 key = key_from_blob(blob, bloblen); 1337 if (key == NULL) 1338 fatal("%s: bad public key blob", __func__); 1339 1340 switch (key_blobtype) { 1341 case MM_USERKEY: 1342 valid_data = monitor_valid_userblob(data, datalen); 1343 break; 1344 case MM_HOSTKEY: 1345 valid_data = monitor_valid_hostbasedblob(data, datalen, 1346 hostbased_cuser, hostbased_chost); 1347 break; 1348 default: 1349 valid_data = 0; 1350 break; 1351 } 1352 if (!valid_data) 1353 fatal("%s: bad signature data blob", __func__); 1354 1355 verified = key_verify(key, signature, signaturelen, data, datalen); 1356 debug3("%s: key %p signature %s", 1357 __func__, key, (verified == 1) ? "verified" : "unverified"); 1358 1359 key_free(key); 1360 xfree(blob); 1361 xfree(signature); 1362 xfree(data); 1363 1364 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1365 1366 monitor_reset_key_state(); 1367 1368 buffer_clear(m); 1369 buffer_put_int(m, verified); 1370 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1371 1372 return (verified == 1); 1373 } 1374 1375 static void 1376 mm_record_login(Session *s, struct passwd *pw) 1377 { 1378 socklen_t fromlen; 1379 struct sockaddr_storage from; 1380 1381 /* 1382 * Get IP address of client. If the connection is not a socket, let 1383 * the address be 0.0.0.0. 1384 */ 1385 memset(&from, 0, sizeof(from)); 1386 fromlen = sizeof(from); 1387 if (packet_connection_is_on_socket()) { 1388 if (getpeername(packet_get_connection_in(), 1389 (struct sockaddr *)&from, &fromlen) < 0) { 1390 debug("getpeername: %.100s", strerror(errno)); 1391 cleanup_exit(255); 1392 } 1393 } 1394 /* Record that there was a login on that tty from the remote host. */ 1395 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1396 get_remote_name_or_ip(utmp_len, options.use_dns), 1397 (struct sockaddr *)&from, fromlen); 1398 } 1399 1400 static void 1401 mm_session_close(Session *s) 1402 { 1403 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1404 if (s->ttyfd != -1) { 1405 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1406 session_pty_cleanup2(s); 1407 } 1408 session_unused(s->self); 1409 } 1410 1411 int 1412 mm_answer_pty(int sock, Buffer *m) 1413 { 1414 extern struct monitor *pmonitor; 1415 Session *s; 1416 int res, fd0; 1417 1418 debug3("%s entering", __func__); 1419 1420 buffer_clear(m); 1421 s = session_new(); 1422 if (s == NULL) 1423 goto error; 1424 s->authctxt = authctxt; 1425 s->pw = authctxt->pw; 1426 s->pid = pmonitor->m_pid; 1427 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1428 if (res == 0) 1429 goto error; 1430 pty_setowner(authctxt->pw, s->tty); 1431 1432 buffer_put_int(m, 1); 1433 buffer_put_cstring(m, s->tty); 1434 1435 /* We need to trick ttyslot */ 1436 if (dup2(s->ttyfd, 0) == -1) 1437 fatal("%s: dup2", __func__); 1438 1439 mm_record_login(s, authctxt->pw); 1440 1441 /* Now we can close the file descriptor again */ 1442 close(0); 1443 1444 /* send messages generated by record_login */ 1445 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1446 buffer_clear(&loginmsg); 1447 1448 mm_request_send(sock, MONITOR_ANS_PTY, m); 1449 1450 if (mm_send_fd(sock, s->ptyfd) == -1 || 1451 mm_send_fd(sock, s->ttyfd) == -1) 1452 fatal("%s: send fds failed", __func__); 1453 1454 /* make sure nothing uses fd 0 */ 1455 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1456 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1457 if (fd0 != 0) 1458 error("%s: fd0 %d != 0", __func__, fd0); 1459 1460 /* slave is not needed */ 1461 close(s->ttyfd); 1462 s->ttyfd = s->ptyfd; 1463 /* no need to dup() because nobody closes ptyfd */ 1464 s->ptymaster = s->ptyfd; 1465 1466 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1467 1468 return (0); 1469 1470 error: 1471 if (s != NULL) 1472 mm_session_close(s); 1473 buffer_put_int(m, 0); 1474 mm_request_send(sock, MONITOR_ANS_PTY, m); 1475 return (0); 1476 } 1477 1478 int 1479 mm_answer_pty_cleanup(int sock, Buffer *m) 1480 { 1481 Session *s; 1482 char *tty; 1483 1484 debug3("%s entering", __func__); 1485 1486 tty = buffer_get_string(m, NULL); 1487 if ((s = session_by_tty(tty)) != NULL) 1488 mm_session_close(s); 1489 buffer_clear(m); 1490 xfree(tty); 1491 return (0); 1492 } 1493 1494 int 1495 mm_answer_sesskey(int sock, Buffer *m) 1496 { 1497 BIGNUM *p; 1498 int rsafail; 1499 1500 /* Turn off permissions */ 1501 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1502 1503 if ((p = BN_new()) == NULL) 1504 fatal("%s: BN_new", __func__); 1505 1506 buffer_get_bignum2(m, p); 1507 1508 rsafail = ssh1_session_key(p); 1509 1510 buffer_clear(m); 1511 buffer_put_int(m, rsafail); 1512 buffer_put_bignum2(m, p); 1513 1514 BN_clear_free(p); 1515 1516 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1517 1518 /* Turn on permissions for sessid passing */ 1519 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1520 1521 return (0); 1522 } 1523 1524 int 1525 mm_answer_sessid(int sock, Buffer *m) 1526 { 1527 int i; 1528 1529 debug3("%s entering", __func__); 1530 1531 if (buffer_len(m) != 16) 1532 fatal("%s: bad ssh1 session id", __func__); 1533 for (i = 0; i < 16; i++) 1534 session_id[i] = buffer_get_char(m); 1535 1536 /* Turn on permissions for getpwnam */ 1537 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1538 1539 return (0); 1540 } 1541 1542 int 1543 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1544 { 1545 BIGNUM *client_n; 1546 Key *key = NULL; 1547 u_char *blob = NULL; 1548 u_int blen = 0; 1549 int allowed = 0; 1550 1551 debug3("%s entering", __func__); 1552 1553 auth_method = "rsa"; 1554 if (options.rsa_authentication && authctxt->valid) { 1555 if ((client_n = BN_new()) == NULL) 1556 fatal("%s: BN_new", __func__); 1557 buffer_get_bignum2(m, client_n); 1558 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1559 BN_clear_free(client_n); 1560 } 1561 buffer_clear(m); 1562 buffer_put_int(m, allowed); 1563 buffer_put_int(m, forced_command != NULL); 1564 1565 /* clear temporarily storage (used by generate challenge) */ 1566 monitor_reset_key_state(); 1567 1568 if (allowed && key != NULL) { 1569 key->type = KEY_RSA; /* cheat for key_to_blob */ 1570 if (key_to_blob(key, &blob, &blen) == 0) 1571 fatal("%s: key_to_blob failed", __func__); 1572 buffer_put_string(m, blob, blen); 1573 1574 /* Save temporarily for comparison in verify */ 1575 key_blob = blob; 1576 key_bloblen = blen; 1577 key_blobtype = MM_RSAUSERKEY; 1578 } 1579 if (key != NULL) 1580 key_free(key); 1581 1582 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1583 1584 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1585 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1586 return (0); 1587 } 1588 1589 int 1590 mm_answer_rsa_challenge(int sock, Buffer *m) 1591 { 1592 Key *key = NULL; 1593 u_char *blob; 1594 u_int blen; 1595 1596 debug3("%s entering", __func__); 1597 1598 if (!authctxt->valid) 1599 fatal("%s: authctxt not valid", __func__); 1600 blob = buffer_get_string(m, &blen); 1601 if (!monitor_allowed_key(blob, blen)) 1602 fatal("%s: bad key, not previously allowed", __func__); 1603 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1604 fatal("%s: key type mismatch", __func__); 1605 if ((key = key_from_blob(blob, blen)) == NULL) 1606 fatal("%s: received bad key", __func__); 1607 if (key->type != KEY_RSA) 1608 fatal("%s: received bad key type %d", __func__, key->type); 1609 key->type = KEY_RSA1; 1610 if (ssh1_challenge) 1611 BN_clear_free(ssh1_challenge); 1612 ssh1_challenge = auth_rsa_generate_challenge(key); 1613 1614 buffer_clear(m); 1615 buffer_put_bignum2(m, ssh1_challenge); 1616 1617 debug3("%s sending reply", __func__); 1618 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1619 1620 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1621 1622 xfree(blob); 1623 key_free(key); 1624 return (0); 1625 } 1626 1627 int 1628 mm_answer_rsa_response(int sock, Buffer *m) 1629 { 1630 Key *key = NULL; 1631 u_char *blob, *response; 1632 u_int blen, len; 1633 int success; 1634 1635 debug3("%s entering", __func__); 1636 1637 if (!authctxt->valid) 1638 fatal("%s: authctxt not valid", __func__); 1639 if (ssh1_challenge == NULL) 1640 fatal("%s: no ssh1_challenge", __func__); 1641 1642 blob = buffer_get_string(m, &blen); 1643 if (!monitor_allowed_key(blob, blen)) 1644 fatal("%s: bad key, not previously allowed", __func__); 1645 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1646 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1647 if ((key = key_from_blob(blob, blen)) == NULL) 1648 fatal("%s: received bad key", __func__); 1649 response = buffer_get_string(m, &len); 1650 if (len != 16) 1651 fatal("%s: received bad response to challenge", __func__); 1652 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1653 1654 xfree(blob); 1655 key_free(key); 1656 xfree(response); 1657 1658 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1659 1660 /* reset state */ 1661 BN_clear_free(ssh1_challenge); 1662 ssh1_challenge = NULL; 1663 monitor_reset_key_state(); 1664 1665 buffer_clear(m); 1666 buffer_put_int(m, success); 1667 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1668 1669 return (success); 1670 } 1671 1672 int 1673 mm_answer_term(int sock, Buffer *req) 1674 { 1675 extern struct monitor *pmonitor; 1676 int res, status; 1677 1678 debug3("%s: tearing down sessions", __func__); 1679 1680 /* The child is terminating */ 1681 session_destroy_all(&mm_session_close); 1682 1683 #ifdef USE_PAM 1684 if (options.use_pam) 1685 sshpam_cleanup(); 1686 #endif 1687 1688 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1689 if (errno != EINTR) 1690 exit(1); 1691 1692 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1693 1694 /* Terminate process */ 1695 exit(res); 1696 } 1697 1698 #ifdef SSH_AUDIT_EVENTS 1699 /* Report that an audit event occurred */ 1700 int 1701 mm_answer_audit_event(int socket, Buffer *m) 1702 { 1703 ssh_audit_event_t event; 1704 1705 debug3("%s entering", __func__); 1706 1707 event = buffer_get_int(m); 1708 switch(event) { 1709 case SSH_AUTH_FAIL_PUBKEY: 1710 case SSH_AUTH_FAIL_HOSTBASED: 1711 case SSH_AUTH_FAIL_GSSAPI: 1712 case SSH_LOGIN_EXCEED_MAXTRIES: 1713 case SSH_LOGIN_ROOT_DENIED: 1714 case SSH_CONNECTION_CLOSE: 1715 case SSH_INVALID_USER: 1716 audit_event(event); 1717 break; 1718 default: 1719 fatal("Audit event type %d not permitted", event); 1720 } 1721 1722 return (0); 1723 } 1724 1725 int 1726 mm_answer_audit_command(int socket, Buffer *m) 1727 { 1728 u_int len; 1729 char *cmd; 1730 1731 debug3("%s entering", __func__); 1732 cmd = buffer_get_string(m, &len); 1733 /* sanity check command, if so how? */ 1734 audit_run_command(cmd); 1735 xfree(cmd); 1736 return (0); 1737 } 1738 #endif /* SSH_AUDIT_EVENTS */ 1739 1740 void 1741 monitor_apply_keystate(struct monitor *pmonitor) 1742 { 1743 if (compat20) { 1744 set_newkeys(MODE_IN); 1745 set_newkeys(MODE_OUT); 1746 } else { 1747 packet_set_protocol_flags(child_state.ssh1protoflags); 1748 packet_set_encryption_key(child_state.ssh1key, 1749 child_state.ssh1keylen, child_state.ssh1cipher); 1750 xfree(child_state.ssh1key); 1751 } 1752 1753 /* for rc4 and other stateful ciphers */ 1754 packet_set_keycontext(MODE_OUT, child_state.keyout); 1755 xfree(child_state.keyout); 1756 packet_set_keycontext(MODE_IN, child_state.keyin); 1757 xfree(child_state.keyin); 1758 1759 if (!compat20) { 1760 packet_set_iv(MODE_OUT, child_state.ivout); 1761 xfree(child_state.ivout); 1762 packet_set_iv(MODE_IN, child_state.ivin); 1763 xfree(child_state.ivin); 1764 } 1765 1766 memcpy(&incoming_stream, &child_state.incoming, 1767 sizeof(incoming_stream)); 1768 memcpy(&outgoing_stream, &child_state.outgoing, 1769 sizeof(outgoing_stream)); 1770 1771 /* Update with new address */ 1772 if (options.compression) 1773 mm_init_compression(pmonitor->m_zlib); 1774 1775 /* Network I/O buffers */ 1776 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1777 buffer_clear(packet_get_input()); 1778 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1779 memset(child_state.input, 0, child_state.ilen); 1780 xfree(child_state.input); 1781 1782 buffer_clear(packet_get_output()); 1783 buffer_append(packet_get_output(), child_state.output, 1784 child_state.olen); 1785 memset(child_state.output, 0, child_state.olen); 1786 xfree(child_state.output); 1787 1788 /* Roaming */ 1789 if (compat20) 1790 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1791 } 1792 1793 static Kex * 1794 mm_get_kex(Buffer *m) 1795 { 1796 Kex *kex; 1797 void *blob; 1798 u_int bloblen; 1799 1800 kex = xcalloc(1, sizeof(*kex)); 1801 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1802 if (session_id2 == NULL || 1803 kex->session_id_len != session_id2_len || 1804 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1805 fatal("mm_get_get: internal error: bad session id"); 1806 kex->we_need = buffer_get_int(m); 1807 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1808 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1809 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1810 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1811 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1812 kex->server = 1; 1813 kex->hostkey_type = buffer_get_int(m); 1814 kex->kex_type = buffer_get_int(m); 1815 blob = buffer_get_string(m, &bloblen); 1816 buffer_init(&kex->my); 1817 buffer_append(&kex->my, blob, bloblen); 1818 xfree(blob); 1819 blob = buffer_get_string(m, &bloblen); 1820 buffer_init(&kex->peer); 1821 buffer_append(&kex->peer, blob, bloblen); 1822 xfree(blob); 1823 kex->done = 1; 1824 kex->flags = buffer_get_int(m); 1825 kex->client_version_string = buffer_get_string(m, NULL); 1826 kex->server_version_string = buffer_get_string(m, NULL); 1827 kex->load_host_public_key=&get_hostkey_public_by_type; 1828 kex->load_host_private_key=&get_hostkey_private_by_type; 1829 kex->host_key_index=&get_hostkey_index; 1830 1831 return (kex); 1832 } 1833 1834 /* This function requries careful sanity checking */ 1835 1836 void 1837 mm_get_keystate(struct monitor *pmonitor) 1838 { 1839 Buffer m; 1840 u_char *blob, *p; 1841 u_int bloblen, plen; 1842 u_int32_t seqnr, packets; 1843 u_int64_t blocks, bytes; 1844 1845 debug3("%s: Waiting for new keys", __func__); 1846 1847 buffer_init(&m); 1848 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1849 if (!compat20) { 1850 child_state.ssh1protoflags = buffer_get_int(&m); 1851 child_state.ssh1cipher = buffer_get_int(&m); 1852 child_state.ssh1key = buffer_get_string(&m, 1853 &child_state.ssh1keylen); 1854 child_state.ivout = buffer_get_string(&m, 1855 &child_state.ivoutlen); 1856 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1857 goto skip; 1858 } else { 1859 /* Get the Kex for rekeying */ 1860 *pmonitor->m_pkex = mm_get_kex(&m); 1861 } 1862 1863 blob = buffer_get_string(&m, &bloblen); 1864 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1865 xfree(blob); 1866 1867 debug3("%s: Waiting for second key", __func__); 1868 blob = buffer_get_string(&m, &bloblen); 1869 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1870 xfree(blob); 1871 1872 /* Now get sequence numbers for the packets */ 1873 seqnr = buffer_get_int(&m); 1874 blocks = buffer_get_int64(&m); 1875 packets = buffer_get_int(&m); 1876 bytes = buffer_get_int64(&m); 1877 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1878 seqnr = buffer_get_int(&m); 1879 blocks = buffer_get_int64(&m); 1880 packets = buffer_get_int(&m); 1881 bytes = buffer_get_int64(&m); 1882 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1883 1884 skip: 1885 /* Get the key context */ 1886 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1887 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1888 1889 debug3("%s: Getting compression state", __func__); 1890 /* Get compression state */ 1891 p = buffer_get_string(&m, &plen); 1892 if (plen != sizeof(child_state.outgoing)) 1893 fatal("%s: bad request size", __func__); 1894 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1895 xfree(p); 1896 1897 p = buffer_get_string(&m, &plen); 1898 if (plen != sizeof(child_state.incoming)) 1899 fatal("%s: bad request size", __func__); 1900 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1901 xfree(p); 1902 1903 /* Network I/O buffers */ 1904 debug3("%s: Getting Network I/O buffers", __func__); 1905 child_state.input = buffer_get_string(&m, &child_state.ilen); 1906 child_state.output = buffer_get_string(&m, &child_state.olen); 1907 1908 /* Roaming */ 1909 if (compat20) { 1910 child_state.sent_bytes = buffer_get_int64(&m); 1911 child_state.recv_bytes = buffer_get_int64(&m); 1912 } 1913 1914 buffer_free(&m); 1915 } 1916 1917 1918 /* Allocation functions for zlib */ 1919 void * 1920 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1921 { 1922 size_t len = (size_t) size * ncount; 1923 void *address; 1924 1925 if (len == 0 || ncount > SIZE_T_MAX / size) 1926 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1927 1928 address = mm_malloc(mm, len); 1929 1930 return (address); 1931 } 1932 1933 void 1934 mm_zfree(struct mm_master *mm, void *address) 1935 { 1936 mm_free(mm, address); 1937 } 1938 1939 void 1940 mm_init_compression(struct mm_master *mm) 1941 { 1942 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1943 outgoing_stream.zfree = (free_func)mm_zfree; 1944 outgoing_stream.opaque = mm; 1945 1946 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1947 incoming_stream.zfree = (free_func)mm_zfree; 1948 incoming_stream.opaque = mm; 1949 } 1950 1951 /* XXX */ 1952 1953 #define FD_CLOSEONEXEC(x) do { \ 1954 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1955 fatal("fcntl(%d, F_SETFD)", x); \ 1956 } while (0) 1957 1958 static void 1959 monitor_openfds(struct monitor *mon, int do_logfds) 1960 { 1961 int pair[2]; 1962 1963 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1964 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1965 FD_CLOSEONEXEC(pair[0]); 1966 FD_CLOSEONEXEC(pair[1]); 1967 mon->m_recvfd = pair[0]; 1968 mon->m_sendfd = pair[1]; 1969 1970 if (do_logfds) { 1971 if (pipe(pair) == -1) 1972 fatal("%s: pipe: %s", __func__, strerror(errno)); 1973 FD_CLOSEONEXEC(pair[0]); 1974 FD_CLOSEONEXEC(pair[1]); 1975 mon->m_log_recvfd = pair[0]; 1976 mon->m_log_sendfd = pair[1]; 1977 } else 1978 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1979 } 1980 1981 #define MM_MEMSIZE 65536 1982 1983 struct monitor * 1984 monitor_init(void) 1985 { 1986 struct monitor *mon; 1987 1988 mon = xcalloc(1, sizeof(*mon)); 1989 1990 monitor_openfds(mon, 1); 1991 1992 /* Used to share zlib space across processes */ 1993 if (options.compression) { 1994 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1995 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1996 1997 /* Compression needs to share state across borders */ 1998 mm_init_compression(mon->m_zlib); 1999 } 2000 2001 return mon; 2002 } 2003 2004 void 2005 monitor_reinit(struct monitor *mon) 2006 { 2007 monitor_openfds(mon, 0); 2008 } 2009 2010 #ifdef GSSAPI 2011 int 2012 mm_answer_gss_setup_ctx(int sock, Buffer *m) 2013 { 2014 gss_OID_desc goid; 2015 OM_uint32 major; 2016 u_int len; 2017 2018 goid.elements = buffer_get_string(m, &len); 2019 goid.length = len; 2020 2021 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 2022 2023 xfree(goid.elements); 2024 2025 buffer_clear(m); 2026 buffer_put_int(m, major); 2027 2028 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 2029 2030 /* Now we have a context, enable the step */ 2031 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 2032 2033 return (0); 2034 } 2035 2036 int 2037 mm_answer_gss_accept_ctx(int sock, Buffer *m) 2038 { 2039 gss_buffer_desc in; 2040 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2041 OM_uint32 major, minor; 2042 OM_uint32 flags = 0; /* GSI needs this */ 2043 u_int len; 2044 2045 in.value = buffer_get_string(m, &len); 2046 in.length = len; 2047 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2048 xfree(in.value); 2049 2050 buffer_clear(m); 2051 buffer_put_int(m, major); 2052 buffer_put_string(m, out.value, out.length); 2053 buffer_put_int(m, flags); 2054 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2055 2056 gss_release_buffer(&minor, &out); 2057 2058 if (major == GSS_S_COMPLETE) { 2059 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2060 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2061 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2062 } 2063 return (0); 2064 } 2065 2066 int 2067 mm_answer_gss_checkmic(int sock, Buffer *m) 2068 { 2069 gss_buffer_desc gssbuf, mic; 2070 OM_uint32 ret; 2071 u_int len; 2072 2073 gssbuf.value = buffer_get_string(m, &len); 2074 gssbuf.length = len; 2075 mic.value = buffer_get_string(m, &len); 2076 mic.length = len; 2077 2078 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2079 2080 xfree(gssbuf.value); 2081 xfree(mic.value); 2082 2083 buffer_clear(m); 2084 buffer_put_int(m, ret); 2085 2086 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2087 2088 if (!GSS_ERROR(ret)) 2089 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2090 2091 return (0); 2092 } 2093 2094 int 2095 mm_answer_gss_userok(int sock, Buffer *m) 2096 { 2097 int authenticated; 2098 2099 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2100 2101 buffer_clear(m); 2102 buffer_put_int(m, authenticated); 2103 2104 debug3("%s: sending result %d", __func__, authenticated); 2105 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2106 2107 auth_method = "gssapi-with-mic"; 2108 2109 /* Monitor loop will terminate if authenticated */ 2110 return (authenticated); 2111 } 2112 #endif /* GSSAPI */ 2113 2114 #ifdef JPAKE 2115 int 2116 mm_answer_jpake_step1(int sock, Buffer *m) 2117 { 2118 struct jpake_ctx *pctx; 2119 u_char *x3_proof, *x4_proof; 2120 u_int x3_proof_len, x4_proof_len; 2121 2122 if (!options.zero_knowledge_password_authentication) 2123 fatal("zero_knowledge_password_authentication disabled"); 2124 2125 if (authctxt->jpake_ctx != NULL) 2126 fatal("%s: authctxt->jpake_ctx already set (%p)", 2127 __func__, authctxt->jpake_ctx); 2128 authctxt->jpake_ctx = pctx = jpake_new(); 2129 2130 jpake_step1(pctx->grp, 2131 &pctx->server_id, &pctx->server_id_len, 2132 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 2133 &x3_proof, &x3_proof_len, 2134 &x4_proof, &x4_proof_len); 2135 2136 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 2137 2138 buffer_clear(m); 2139 2140 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 2141 buffer_put_bignum2(m, pctx->g_x3); 2142 buffer_put_bignum2(m, pctx->g_x4); 2143 buffer_put_string(m, x3_proof, x3_proof_len); 2144 buffer_put_string(m, x4_proof, x4_proof_len); 2145 2146 debug3("%s: sending step1", __func__); 2147 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 2148 2149 bzero(x3_proof, x3_proof_len); 2150 bzero(x4_proof, x4_proof_len); 2151 xfree(x3_proof); 2152 xfree(x4_proof); 2153 2154 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 2155 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 2156 2157 return 0; 2158 } 2159 2160 int 2161 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 2162 { 2163 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2164 char *hash_scheme, *salt; 2165 2166 if (pctx == NULL) 2167 fatal("%s: pctx == NULL", __func__); 2168 2169 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 2170 2171 buffer_clear(m); 2172 /* pctx->s is sensitive, not returned to slave */ 2173 buffer_put_cstring(m, hash_scheme); 2174 buffer_put_cstring(m, salt); 2175 2176 debug3("%s: sending pwdata", __func__); 2177 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 2178 2179 bzero(hash_scheme, strlen(hash_scheme)); 2180 bzero(salt, strlen(salt)); 2181 xfree(hash_scheme); 2182 xfree(salt); 2183 2184 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 2185 2186 return 0; 2187 } 2188 2189 int 2190 mm_answer_jpake_step2(int sock, Buffer *m) 2191 { 2192 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2193 u_char *x1_proof, *x2_proof, *x4_s_proof; 2194 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 2195 2196 if (pctx == NULL) 2197 fatal("%s: pctx == NULL", __func__); 2198 2199 if ((pctx->g_x1 = BN_new()) == NULL || 2200 (pctx->g_x2 = BN_new()) == NULL) 2201 fatal("%s: BN_new", __func__); 2202 buffer_get_bignum2(m, pctx->g_x1); 2203 buffer_get_bignum2(m, pctx->g_x2); 2204 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 2205 x1_proof = buffer_get_string(m, &x1_proof_len); 2206 x2_proof = buffer_get_string(m, &x2_proof_len); 2207 2208 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 2209 pctx->g_x1, pctx->g_x2, pctx->x4, 2210 pctx->client_id, pctx->client_id_len, 2211 pctx->server_id, pctx->server_id_len, 2212 x1_proof, x1_proof_len, 2213 x2_proof, x2_proof_len, 2214 &pctx->b, 2215 &x4_s_proof, &x4_s_proof_len); 2216 2217 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 2218 2219 bzero(x1_proof, x1_proof_len); 2220 bzero(x2_proof, x2_proof_len); 2221 xfree(x1_proof); 2222 xfree(x2_proof); 2223 2224 buffer_clear(m); 2225 2226 buffer_put_bignum2(m, pctx->b); 2227 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 2228 2229 debug3("%s: sending step2", __func__); 2230 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 2231 2232 bzero(x4_s_proof, x4_s_proof_len); 2233 xfree(x4_s_proof); 2234 2235 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 2236 2237 return 0; 2238 } 2239 2240 int 2241 mm_answer_jpake_key_confirm(int sock, Buffer *m) 2242 { 2243 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2244 u_char *x2_s_proof; 2245 u_int x2_s_proof_len; 2246 2247 if (pctx == NULL) 2248 fatal("%s: pctx == NULL", __func__); 2249 2250 if ((pctx->a = BN_new()) == NULL) 2251 fatal("%s: BN_new", __func__); 2252 buffer_get_bignum2(m, pctx->a); 2253 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 2254 2255 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 2256 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 2257 pctx->server_id, pctx->server_id_len, 2258 pctx->client_id, pctx->client_id_len, 2259 session_id2, session_id2_len, 2260 x2_s_proof, x2_s_proof_len, 2261 &pctx->k, 2262 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 2263 2264 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 2265 2266 bzero(x2_s_proof, x2_s_proof_len); 2267 buffer_clear(m); 2268 2269 /* pctx->k is sensitive, not sent */ 2270 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 2271 2272 debug3("%s: sending confirmation hash", __func__); 2273 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 2274 2275 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 2276 2277 return 0; 2278 } 2279 2280 int 2281 mm_answer_jpake_check_confirm(int sock, Buffer *m) 2282 { 2283 int authenticated = 0; 2284 u_char *peer_confirm_hash; 2285 u_int peer_confirm_hash_len; 2286 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2287 2288 if (pctx == NULL) 2289 fatal("%s: pctx == NULL", __func__); 2290 2291 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 2292 2293 authenticated = jpake_check_confirm(pctx->k, 2294 pctx->client_id, pctx->client_id_len, 2295 session_id2, session_id2_len, 2296 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 2297 2298 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 2299 2300 bzero(peer_confirm_hash, peer_confirm_hash_len); 2301 xfree(peer_confirm_hash); 2302 2303 buffer_clear(m); 2304 buffer_put_int(m, authenticated); 2305 2306 debug3("%s: sending result %d", __func__, authenticated); 2307 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 2308 2309 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 2310 2311 auth_method = "jpake-01 (at) openssh.com"; 2312 return authenticated; 2313 } 2314 2315 #endif /* JPAKE */ 2316
