1 /* $OpenBSD: monitor.c,v 1.115 2011/06/23 23:35:42 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 #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 buffer_put_cstring(m, pwent->pw_gecos); 765 #ifdef HAVE_PW_CLASS_IN_PASSWD 766 buffer_put_cstring(m, pwent->pw_class); 767 #endif 768 buffer_put_cstring(m, pwent->pw_dir); 769 buffer_put_cstring(m, pwent->pw_shell); 770 771 out: 772 buffer_put_string(m, &options, sizeof(options)); 773 774 #define M_CP_STROPT(x) do { \ 775 if (options.x != NULL) \ 776 buffer_put_cstring(m, options.x); \ 777 } while (0) 778 #define M_CP_STRARRAYOPT(x, nx) do { \ 779 for (i = 0; i < options.nx; i++) \ 780 buffer_put_cstring(m, options.x[i]); \ 781 } while (0) 782 /* See comment in servconf.h */ 783 COPY_MATCH_STRING_OPTS(); 784 #undef M_CP_STROPT 785 #undef M_CP_STRARRAYOPT 786 787 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 788 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 789 790 /* For SSHv1 allow authentication now */ 791 if (!compat20) 792 monitor_permit_authentications(1); 793 else { 794 /* Allow service/style information on the auth context */ 795 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 796 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 797 } 798 #ifdef USE_PAM 799 if (options.use_pam) 800 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 801 #endif 802 803 return (0); 804 } 805 806 int mm_answer_auth2_read_banner(int sock, Buffer *m) 807 { 808 char *banner; 809 810 buffer_clear(m); 811 banner = auth2_read_banner(); 812 buffer_put_cstring(m, banner != NULL ? banner : ""); 813 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 814 815 if (banner != NULL) 816 xfree(banner); 817 818 return (0); 819 } 820 821 int 822 mm_answer_authserv(int sock, Buffer *m) 823 { 824 monitor_permit_authentications(1); 825 826 authctxt->service = buffer_get_string(m, NULL); 827 authctxt->style = buffer_get_string(m, NULL); 828 debug3("%s: service=%s, style=%s", 829 __func__, authctxt->service, authctxt->style); 830 831 if (strlen(authctxt->style) == 0) { 832 xfree(authctxt->style); 833 authctxt->style = NULL; 834 } 835 836 return (0); 837 } 838 839 int 840 mm_answer_authpassword(int sock, Buffer *m) 841 { 842 static int call_count; 843 char *passwd; 844 int authenticated; 845 u_int plen; 846 847 passwd = buffer_get_string(m, &plen); 848 /* Only authenticate if the context is valid */ 849 authenticated = options.password_authentication && 850 auth_password(authctxt, passwd); 851 memset(passwd, 0, strlen(passwd)); 852 xfree(passwd); 853 854 buffer_clear(m); 855 buffer_put_int(m, authenticated); 856 857 debug3("%s: sending result %d", __func__, authenticated); 858 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 859 860 call_count++; 861 if (plen == 0 && call_count == 1) 862 auth_method = "none"; 863 else 864 auth_method = "password"; 865 866 /* Causes monitor loop to terminate if authenticated */ 867 return (authenticated); 868 } 869 870 #ifdef BSD_AUTH 871 int 872 mm_answer_bsdauthquery(int sock, Buffer *m) 873 { 874 char *name, *infotxt; 875 u_int numprompts; 876 u_int *echo_on; 877 char **prompts; 878 u_int success; 879 880 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 881 &prompts, &echo_on) < 0 ? 0 : 1; 882 883 buffer_clear(m); 884 buffer_put_int(m, success); 885 if (success) 886 buffer_put_cstring(m, prompts[0]); 887 888 debug3("%s: sending challenge success: %u", __func__, success); 889 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 890 891 if (success) { 892 xfree(name); 893 xfree(infotxt); 894 xfree(prompts); 895 xfree(echo_on); 896 } 897 898 return (0); 899 } 900 901 int 902 mm_answer_bsdauthrespond(int sock, Buffer *m) 903 { 904 char *response; 905 int authok; 906 907 if (authctxt->as == 0) 908 fatal("%s: no bsd auth session", __func__); 909 910 response = buffer_get_string(m, NULL); 911 authok = options.challenge_response_authentication && 912 auth_userresponse(authctxt->as, response, 0); 913 authctxt->as = NULL; 914 debug3("%s: <%s> = <%d>", __func__, response, authok); 915 xfree(response); 916 917 buffer_clear(m); 918 buffer_put_int(m, authok); 919 920 debug3("%s: sending authenticated: %d", __func__, authok); 921 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 922 923 auth_method = "bsdauth"; 924 925 return (authok != 0); 926 } 927 #endif 928 929 #ifdef SKEY 930 int 931 mm_answer_skeyquery(int sock, Buffer *m) 932 { 933 struct skey skey; 934 char challenge[1024]; 935 u_int success; 936 937 success = _compat_skeychallenge(&skey, authctxt->user, challenge, 938 sizeof(challenge)) < 0 ? 0 : 1; 939 940 buffer_clear(m); 941 buffer_put_int(m, success); 942 if (success) 943 buffer_put_cstring(m, challenge); 944 945 debug3("%s: sending challenge success: %u", __func__, success); 946 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 947 948 return (0); 949 } 950 951 int 952 mm_answer_skeyrespond(int sock, Buffer *m) 953 { 954 char *response; 955 int authok; 956 957 response = buffer_get_string(m, NULL); 958 959 authok = (options.challenge_response_authentication && 960 authctxt->valid && 961 skey_haskey(authctxt->pw->pw_name) == 0 && 962 skey_passcheck(authctxt->pw->pw_name, response) != -1); 963 964 xfree(response); 965 966 buffer_clear(m); 967 buffer_put_int(m, authok); 968 969 debug3("%s: sending authenticated: %d", __func__, authok); 970 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 971 972 auth_method = "skey"; 973 974 return (authok != 0); 975 } 976 #endif 977 978 #ifdef USE_PAM 979 int 980 mm_answer_pam_start(int sock, Buffer *m) 981 { 982 if (!options.use_pam) 983 fatal("UsePAM not set, but ended up in %s anyway", __func__); 984 985 start_pam(authctxt); 986 987 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 988 989 return (0); 990 } 991 992 int 993 mm_answer_pam_account(int sock, Buffer *m) 994 { 995 u_int ret; 996 997 if (!options.use_pam) 998 fatal("UsePAM not set, but ended up in %s anyway", __func__); 999 1000 ret = do_pam_account(); 1001 1002 buffer_put_int(m, ret); 1003 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1004 1005 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1006 1007 return (ret); 1008 } 1009 1010 static void *sshpam_ctxt, *sshpam_authok; 1011 extern KbdintDevice sshpam_device; 1012 1013 int 1014 mm_answer_pam_init_ctx(int sock, Buffer *m) 1015 { 1016 1017 debug3("%s", __func__); 1018 authctxt->user = buffer_get_string(m, NULL); 1019 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1020 sshpam_authok = NULL; 1021 buffer_clear(m); 1022 if (sshpam_ctxt != NULL) { 1023 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1024 buffer_put_int(m, 1); 1025 } else { 1026 buffer_put_int(m, 0); 1027 } 1028 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1029 return (0); 1030 } 1031 1032 int 1033 mm_answer_pam_query(int sock, Buffer *m) 1034 { 1035 char *name = NULL, *info = NULL, **prompts = NULL; 1036 u_int i, num = 0, *echo_on = 0; 1037 int ret; 1038 1039 debug3("%s", __func__); 1040 sshpam_authok = NULL; 1041 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1042 if (ret == 0 && num == 0) 1043 sshpam_authok = sshpam_ctxt; 1044 if (num > 1 || name == NULL || info == NULL) 1045 ret = -1; 1046 buffer_clear(m); 1047 buffer_put_int(m, ret); 1048 buffer_put_cstring(m, name); 1049 xfree(name); 1050 buffer_put_cstring(m, info); 1051 xfree(info); 1052 buffer_put_int(m, num); 1053 for (i = 0; i < num; ++i) { 1054 buffer_put_cstring(m, prompts[i]); 1055 xfree(prompts[i]); 1056 buffer_put_int(m, echo_on[i]); 1057 } 1058 if (prompts != NULL) 1059 xfree(prompts); 1060 if (echo_on != NULL) 1061 xfree(echo_on); 1062 auth_method = "keyboard-interactive/pam"; 1063 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1064 return (0); 1065 } 1066 1067 int 1068 mm_answer_pam_respond(int sock, Buffer *m) 1069 { 1070 char **resp; 1071 u_int i, num; 1072 int ret; 1073 1074 debug3("%s", __func__); 1075 sshpam_authok = NULL; 1076 num = buffer_get_int(m); 1077 if (num > 0) { 1078 resp = xcalloc(num, sizeof(char *)); 1079 for (i = 0; i < num; ++i) 1080 resp[i] = buffer_get_string(m, NULL); 1081 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1082 for (i = 0; i < num; ++i) 1083 xfree(resp[i]); 1084 xfree(resp); 1085 } else { 1086 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1087 } 1088 buffer_clear(m); 1089 buffer_put_int(m, ret); 1090 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1091 auth_method = "keyboard-interactive/pam"; 1092 if (ret == 0) 1093 sshpam_authok = sshpam_ctxt; 1094 return (0); 1095 } 1096 1097 int 1098 mm_answer_pam_free_ctx(int sock, Buffer *m) 1099 { 1100 1101 debug3("%s", __func__); 1102 (sshpam_device.free_ctx)(sshpam_ctxt); 1103 buffer_clear(m); 1104 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1105 auth_method = "keyboard-interactive/pam"; 1106 return (sshpam_authok == sshpam_ctxt); 1107 } 1108 #endif 1109 1110 int 1111 mm_answer_keyallowed(int sock, Buffer *m) 1112 { 1113 Key *key; 1114 char *cuser, *chost; 1115 u_char *blob; 1116 u_int bloblen; 1117 enum mm_keytype type = 0; 1118 int allowed = 0; 1119 1120 debug3("%s entering", __func__); 1121 1122 type = buffer_get_int(m); 1123 cuser = buffer_get_string(m, NULL); 1124 chost = buffer_get_string(m, NULL); 1125 blob = buffer_get_string(m, &bloblen); 1126 1127 key = key_from_blob(blob, bloblen); 1128 1129 if ((compat20 && type == MM_RSAHOSTKEY) || 1130 (!compat20 && type != MM_RSAHOSTKEY)) 1131 fatal("%s: key type and protocol mismatch", __func__); 1132 1133 debug3("%s: key_from_blob: %p", __func__, key); 1134 1135 if (key != NULL && authctxt->valid) { 1136 switch (type) { 1137 case MM_USERKEY: 1138 allowed = options.pubkey_authentication && 1139 user_key_allowed(authctxt->pw, key); 1140 auth_method = "publickey"; 1141 if (options.pubkey_authentication && allowed != 1) 1142 auth_clear_options(); 1143 break; 1144 case MM_HOSTKEY: 1145 allowed = options.hostbased_authentication && 1146 hostbased_key_allowed(authctxt->pw, 1147 cuser, chost, key); 1148 auth_method = "hostbased"; 1149 break; 1150 case MM_RSAHOSTKEY: 1151 key->type = KEY_RSA1; /* XXX */ 1152 allowed = options.rhosts_rsa_authentication && 1153 auth_rhosts_rsa_key_allowed(authctxt->pw, 1154 cuser, chost, key); 1155 if (options.rhosts_rsa_authentication && allowed != 1) 1156 auth_clear_options(); 1157 auth_method = "rsa"; 1158 break; 1159 default: 1160 fatal("%s: unknown key type %d", __func__, type); 1161 break; 1162 } 1163 } 1164 if (key != NULL) 1165 key_free(key); 1166 1167 /* clear temporarily storage (used by verify) */ 1168 monitor_reset_key_state(); 1169 1170 if (allowed) { 1171 /* Save temporarily for comparison in verify */ 1172 key_blob = blob; 1173 key_bloblen = bloblen; 1174 key_blobtype = type; 1175 hostbased_cuser = cuser; 1176 hostbased_chost = chost; 1177 } else { 1178 /* Log failed attempt */ 1179 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); 1180 xfree(blob); 1181 xfree(cuser); 1182 xfree(chost); 1183 } 1184 1185 debug3("%s: key %p is %s", 1186 __func__, key, allowed ? "allowed" : "not allowed"); 1187 1188 buffer_clear(m); 1189 buffer_put_int(m, allowed); 1190 buffer_put_int(m, forced_command != NULL); 1191 1192 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1193 1194 if (type == MM_RSAHOSTKEY) 1195 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1196 1197 return (0); 1198 } 1199 1200 static int 1201 monitor_valid_userblob(u_char *data, u_int datalen) 1202 { 1203 Buffer b; 1204 char *p; 1205 u_int len; 1206 int fail = 0; 1207 1208 buffer_init(&b); 1209 buffer_append(&b, data, datalen); 1210 1211 if (datafellows & SSH_OLD_SESSIONID) { 1212 p = buffer_ptr(&b); 1213 len = buffer_len(&b); 1214 if ((session_id2 == NULL) || 1215 (len < session_id2_len) || 1216 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1217 fail++; 1218 buffer_consume(&b, session_id2_len); 1219 } else { 1220 p = buffer_get_string(&b, &len); 1221 if ((session_id2 == NULL) || 1222 (len != session_id2_len) || 1223 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1224 fail++; 1225 xfree(p); 1226 } 1227 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1228 fail++; 1229 p = buffer_get_string(&b, NULL); 1230 if (strcmp(authctxt->user, p) != 0) { 1231 logit("wrong user name passed to monitor: expected %s != %.100s", 1232 authctxt->user, p); 1233 fail++; 1234 } 1235 xfree(p); 1236 buffer_skip_string(&b); 1237 if (datafellows & SSH_BUG_PKAUTH) { 1238 if (!buffer_get_char(&b)) 1239 fail++; 1240 } else { 1241 p = buffer_get_string(&b, NULL); 1242 if (strcmp("publickey", p) != 0) 1243 fail++; 1244 xfree(p); 1245 if (!buffer_get_char(&b)) 1246 fail++; 1247 buffer_skip_string(&b); 1248 } 1249 buffer_skip_string(&b); 1250 if (buffer_len(&b) != 0) 1251 fail++; 1252 buffer_free(&b); 1253 return (fail == 0); 1254 } 1255 1256 static int 1257 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1258 char *chost) 1259 { 1260 Buffer b; 1261 char *p; 1262 u_int len; 1263 int fail = 0; 1264 1265 buffer_init(&b); 1266 buffer_append(&b, data, datalen); 1267 1268 p = buffer_get_string(&b, &len); 1269 if ((session_id2 == NULL) || 1270 (len != session_id2_len) || 1271 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1272 fail++; 1273 xfree(p); 1274 1275 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1276 fail++; 1277 p = buffer_get_string(&b, NULL); 1278 if (strcmp(authctxt->user, p) != 0) { 1279 logit("wrong user name passed to monitor: expected %s != %.100s", 1280 authctxt->user, p); 1281 fail++; 1282 } 1283 xfree(p); 1284 buffer_skip_string(&b); /* service */ 1285 p = buffer_get_string(&b, NULL); 1286 if (strcmp(p, "hostbased") != 0) 1287 fail++; 1288 xfree(p); 1289 buffer_skip_string(&b); /* pkalg */ 1290 buffer_skip_string(&b); /* pkblob */ 1291 1292 /* verify client host, strip trailing dot if necessary */ 1293 p = buffer_get_string(&b, NULL); 1294 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1295 p[len - 1] = '\0'; 1296 if (strcmp(p, chost) != 0) 1297 fail++; 1298 xfree(p); 1299 1300 /* verify client user */ 1301 p = buffer_get_string(&b, NULL); 1302 if (strcmp(p, cuser) != 0) 1303 fail++; 1304 xfree(p); 1305 1306 if (buffer_len(&b) != 0) 1307 fail++; 1308 buffer_free(&b); 1309 return (fail == 0); 1310 } 1311 1312 int 1313 mm_answer_keyverify(int sock, Buffer *m) 1314 { 1315 Key *key; 1316 u_char *signature, *data, *blob; 1317 u_int signaturelen, datalen, bloblen; 1318 int verified = 0; 1319 int valid_data = 0; 1320 1321 blob = buffer_get_string(m, &bloblen); 1322 signature = buffer_get_string(m, &signaturelen); 1323 data = buffer_get_string(m, &datalen); 1324 1325 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1326 !monitor_allowed_key(blob, bloblen)) 1327 fatal("%s: bad key, not previously allowed", __func__); 1328 1329 key = key_from_blob(blob, bloblen); 1330 if (key == NULL) 1331 fatal("%s: bad public key blob", __func__); 1332 1333 switch (key_blobtype) { 1334 case MM_USERKEY: 1335 valid_data = monitor_valid_userblob(data, datalen); 1336 break; 1337 case MM_HOSTKEY: 1338 valid_data = monitor_valid_hostbasedblob(data, datalen, 1339 hostbased_cuser, hostbased_chost); 1340 break; 1341 default: 1342 valid_data = 0; 1343 break; 1344 } 1345 if (!valid_data) 1346 fatal("%s: bad signature data blob", __func__); 1347 1348 verified = key_verify(key, signature, signaturelen, data, datalen); 1349 debug3("%s: key %p signature %s", 1350 __func__, key, (verified == 1) ? "verified" : "unverified"); 1351 1352 key_free(key); 1353 xfree(blob); 1354 xfree(signature); 1355 xfree(data); 1356 1357 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1358 1359 monitor_reset_key_state(); 1360 1361 buffer_clear(m); 1362 buffer_put_int(m, verified); 1363 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1364 1365 return (verified == 1); 1366 } 1367 1368 static void 1369 mm_record_login(Session *s, struct passwd *pw) 1370 { 1371 socklen_t fromlen; 1372 struct sockaddr_storage from; 1373 1374 /* 1375 * Get IP address of client. If the connection is not a socket, let 1376 * the address be 0.0.0.0. 1377 */ 1378 memset(&from, 0, sizeof(from)); 1379 fromlen = sizeof(from); 1380 if (packet_connection_is_on_socket()) { 1381 if (getpeername(packet_get_connection_in(), 1382 (struct sockaddr *)&from, &fromlen) < 0) { 1383 debug("getpeername: %.100s", strerror(errno)); 1384 cleanup_exit(255); 1385 } 1386 } 1387 /* Record that there was a login on that tty from the remote host. */ 1388 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1389 get_remote_name_or_ip(utmp_len, options.use_dns), 1390 (struct sockaddr *)&from, fromlen); 1391 } 1392 1393 static void 1394 mm_session_close(Session *s) 1395 { 1396 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1397 if (s->ttyfd != -1) { 1398 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1399 session_pty_cleanup2(s); 1400 } 1401 session_unused(s->self); 1402 } 1403 1404 int 1405 mm_answer_pty(int sock, Buffer *m) 1406 { 1407 extern struct monitor *pmonitor; 1408 Session *s; 1409 int res, fd0; 1410 1411 debug3("%s entering", __func__); 1412 1413 buffer_clear(m); 1414 s = session_new(); 1415 if (s == NULL) 1416 goto error; 1417 s->authctxt = authctxt; 1418 s->pw = authctxt->pw; 1419 s->pid = pmonitor->m_pid; 1420 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1421 if (res == 0) 1422 goto error; 1423 pty_setowner(authctxt->pw, s->tty); 1424 1425 buffer_put_int(m, 1); 1426 buffer_put_cstring(m, s->tty); 1427 1428 /* We need to trick ttyslot */ 1429 if (dup2(s->ttyfd, 0) == -1) 1430 fatal("%s: dup2", __func__); 1431 1432 mm_record_login(s, authctxt->pw); 1433 1434 /* Now we can close the file descriptor again */ 1435 close(0); 1436 1437 /* send messages generated by record_login */ 1438 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1439 buffer_clear(&loginmsg); 1440 1441 mm_request_send(sock, MONITOR_ANS_PTY, m); 1442 1443 if (mm_send_fd(sock, s->ptyfd) == -1 || 1444 mm_send_fd(sock, s->ttyfd) == -1) 1445 fatal("%s: send fds failed", __func__); 1446 1447 /* make sure nothing uses fd 0 */ 1448 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1449 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1450 if (fd0 != 0) 1451 error("%s: fd0 %d != 0", __func__, fd0); 1452 1453 /* slave is not needed */ 1454 close(s->ttyfd); 1455 s->ttyfd = s->ptyfd; 1456 /* no need to dup() because nobody closes ptyfd */ 1457 s->ptymaster = s->ptyfd; 1458 1459 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1460 1461 return (0); 1462 1463 error: 1464 if (s != NULL) 1465 mm_session_close(s); 1466 buffer_put_int(m, 0); 1467 mm_request_send(sock, MONITOR_ANS_PTY, m); 1468 return (0); 1469 } 1470 1471 int 1472 mm_answer_pty_cleanup(int sock, Buffer *m) 1473 { 1474 Session *s; 1475 char *tty; 1476 1477 debug3("%s entering", __func__); 1478 1479 tty = buffer_get_string(m, NULL); 1480 if ((s = session_by_tty(tty)) != NULL) 1481 mm_session_close(s); 1482 buffer_clear(m); 1483 xfree(tty); 1484 return (0); 1485 } 1486 1487 int 1488 mm_answer_sesskey(int sock, Buffer *m) 1489 { 1490 BIGNUM *p; 1491 int rsafail; 1492 1493 /* Turn off permissions */ 1494 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1495 1496 if ((p = BN_new()) == NULL) 1497 fatal("%s: BN_new", __func__); 1498 1499 buffer_get_bignum2(m, p); 1500 1501 rsafail = ssh1_session_key(p); 1502 1503 buffer_clear(m); 1504 buffer_put_int(m, rsafail); 1505 buffer_put_bignum2(m, p); 1506 1507 BN_clear_free(p); 1508 1509 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1510 1511 /* Turn on permissions for sessid passing */ 1512 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1513 1514 return (0); 1515 } 1516 1517 int 1518 mm_answer_sessid(int sock, Buffer *m) 1519 { 1520 int i; 1521 1522 debug3("%s entering", __func__); 1523 1524 if (buffer_len(m) != 16) 1525 fatal("%s: bad ssh1 session id", __func__); 1526 for (i = 0; i < 16; i++) 1527 session_id[i] = buffer_get_char(m); 1528 1529 /* Turn on permissions for getpwnam */ 1530 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1531 1532 return (0); 1533 } 1534 1535 int 1536 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1537 { 1538 BIGNUM *client_n; 1539 Key *key = NULL; 1540 u_char *blob = NULL; 1541 u_int blen = 0; 1542 int allowed = 0; 1543 1544 debug3("%s entering", __func__); 1545 1546 auth_method = "rsa"; 1547 if (options.rsa_authentication && authctxt->valid) { 1548 if ((client_n = BN_new()) == NULL) 1549 fatal("%s: BN_new", __func__); 1550 buffer_get_bignum2(m, client_n); 1551 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1552 BN_clear_free(client_n); 1553 } 1554 buffer_clear(m); 1555 buffer_put_int(m, allowed); 1556 buffer_put_int(m, forced_command != NULL); 1557 1558 /* clear temporarily storage (used by generate challenge) */ 1559 monitor_reset_key_state(); 1560 1561 if (allowed && key != NULL) { 1562 key->type = KEY_RSA; /* cheat for key_to_blob */ 1563 if (key_to_blob(key, &blob, &blen) == 0) 1564 fatal("%s: key_to_blob failed", __func__); 1565 buffer_put_string(m, blob, blen); 1566 1567 /* Save temporarily for comparison in verify */ 1568 key_blob = blob; 1569 key_bloblen = blen; 1570 key_blobtype = MM_RSAUSERKEY; 1571 } 1572 if (key != NULL) 1573 key_free(key); 1574 1575 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1576 1577 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1578 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1579 return (0); 1580 } 1581 1582 int 1583 mm_answer_rsa_challenge(int sock, Buffer *m) 1584 { 1585 Key *key = NULL; 1586 u_char *blob; 1587 u_int blen; 1588 1589 debug3("%s entering", __func__); 1590 1591 if (!authctxt->valid) 1592 fatal("%s: authctxt not valid", __func__); 1593 blob = buffer_get_string(m, &blen); 1594 if (!monitor_allowed_key(blob, blen)) 1595 fatal("%s: bad key, not previously allowed", __func__); 1596 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1597 fatal("%s: key type mismatch", __func__); 1598 if ((key = key_from_blob(blob, blen)) == NULL) 1599 fatal("%s: received bad key", __func__); 1600 if (key->type != KEY_RSA) 1601 fatal("%s: received bad key type %d", __func__, key->type); 1602 key->type = KEY_RSA1; 1603 if (ssh1_challenge) 1604 BN_clear_free(ssh1_challenge); 1605 ssh1_challenge = auth_rsa_generate_challenge(key); 1606 1607 buffer_clear(m); 1608 buffer_put_bignum2(m, ssh1_challenge); 1609 1610 debug3("%s sending reply", __func__); 1611 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1612 1613 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1614 1615 xfree(blob); 1616 key_free(key); 1617 return (0); 1618 } 1619 1620 int 1621 mm_answer_rsa_response(int sock, Buffer *m) 1622 { 1623 Key *key = NULL; 1624 u_char *blob, *response; 1625 u_int blen, len; 1626 int success; 1627 1628 debug3("%s entering", __func__); 1629 1630 if (!authctxt->valid) 1631 fatal("%s: authctxt not valid", __func__); 1632 if (ssh1_challenge == NULL) 1633 fatal("%s: no ssh1_challenge", __func__); 1634 1635 blob = buffer_get_string(m, &blen); 1636 if (!monitor_allowed_key(blob, blen)) 1637 fatal("%s: bad key, not previously allowed", __func__); 1638 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1639 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1640 if ((key = key_from_blob(blob, blen)) == NULL) 1641 fatal("%s: received bad key", __func__); 1642 response = buffer_get_string(m, &len); 1643 if (len != 16) 1644 fatal("%s: received bad response to challenge", __func__); 1645 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1646 1647 xfree(blob); 1648 key_free(key); 1649 xfree(response); 1650 1651 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1652 1653 /* reset state */ 1654 BN_clear_free(ssh1_challenge); 1655 ssh1_challenge = NULL; 1656 monitor_reset_key_state(); 1657 1658 buffer_clear(m); 1659 buffer_put_int(m, success); 1660 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1661 1662 return (success); 1663 } 1664 1665 int 1666 mm_answer_term(int sock, Buffer *req) 1667 { 1668 extern struct monitor *pmonitor; 1669 int res, status; 1670 1671 debug3("%s: tearing down sessions", __func__); 1672 1673 /* The child is terminating */ 1674 session_destroy_all(&mm_session_close); 1675 1676 #ifdef USE_PAM 1677 if (options.use_pam) 1678 sshpam_cleanup(); 1679 #endif 1680 1681 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1682 if (errno != EINTR) 1683 exit(1); 1684 1685 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1686 1687 /* Terminate process */ 1688 exit(res); 1689 } 1690 1691 #ifdef SSH_AUDIT_EVENTS 1692 /* Report that an audit event occurred */ 1693 int 1694 mm_answer_audit_event(int socket, Buffer *m) 1695 { 1696 ssh_audit_event_t event; 1697 1698 debug3("%s entering", __func__); 1699 1700 event = buffer_get_int(m); 1701 switch(event) { 1702 case SSH_AUTH_FAIL_PUBKEY: 1703 case SSH_AUTH_FAIL_HOSTBASED: 1704 case SSH_AUTH_FAIL_GSSAPI: 1705 case SSH_LOGIN_EXCEED_MAXTRIES: 1706 case SSH_LOGIN_ROOT_DENIED: 1707 case SSH_CONNECTION_CLOSE: 1708 case SSH_INVALID_USER: 1709 audit_event(event); 1710 break; 1711 default: 1712 fatal("Audit event type %d not permitted", event); 1713 } 1714 1715 return (0); 1716 } 1717 1718 int 1719 mm_answer_audit_command(int socket, Buffer *m) 1720 { 1721 u_int len; 1722 char *cmd; 1723 1724 debug3("%s entering", __func__); 1725 cmd = buffer_get_string(m, &len); 1726 /* sanity check command, if so how? */ 1727 audit_run_command(cmd); 1728 xfree(cmd); 1729 return (0); 1730 } 1731 #endif /* SSH_AUDIT_EVENTS */ 1732 1733 void 1734 monitor_apply_keystate(struct monitor *pmonitor) 1735 { 1736 if (compat20) { 1737 set_newkeys(MODE_IN); 1738 set_newkeys(MODE_OUT); 1739 } else { 1740 packet_set_protocol_flags(child_state.ssh1protoflags); 1741 packet_set_encryption_key(child_state.ssh1key, 1742 child_state.ssh1keylen, child_state.ssh1cipher); 1743 xfree(child_state.ssh1key); 1744 } 1745 1746 /* for rc4 and other stateful ciphers */ 1747 packet_set_keycontext(MODE_OUT, child_state.keyout); 1748 xfree(child_state.keyout); 1749 packet_set_keycontext(MODE_IN, child_state.keyin); 1750 xfree(child_state.keyin); 1751 1752 if (!compat20) { 1753 packet_set_iv(MODE_OUT, child_state.ivout); 1754 xfree(child_state.ivout); 1755 packet_set_iv(MODE_IN, child_state.ivin); 1756 xfree(child_state.ivin); 1757 } 1758 1759 memcpy(&incoming_stream, &child_state.incoming, 1760 sizeof(incoming_stream)); 1761 memcpy(&outgoing_stream, &child_state.outgoing, 1762 sizeof(outgoing_stream)); 1763 1764 /* Update with new address */ 1765 if (options.compression) 1766 mm_init_compression(pmonitor->m_zlib); 1767 1768 /* Network I/O buffers */ 1769 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1770 buffer_clear(packet_get_input()); 1771 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1772 memset(child_state.input, 0, child_state.ilen); 1773 xfree(child_state.input); 1774 1775 buffer_clear(packet_get_output()); 1776 buffer_append(packet_get_output(), child_state.output, 1777 child_state.olen); 1778 memset(child_state.output, 0, child_state.olen); 1779 xfree(child_state.output); 1780 1781 /* Roaming */ 1782 if (compat20) 1783 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1784 } 1785 1786 static Kex * 1787 mm_get_kex(Buffer *m) 1788 { 1789 Kex *kex; 1790 void *blob; 1791 u_int bloblen; 1792 1793 kex = xcalloc(1, sizeof(*kex)); 1794 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1795 if (session_id2 == NULL || 1796 kex->session_id_len != session_id2_len || 1797 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1798 fatal("mm_get_get: internal error: bad session id"); 1799 kex->we_need = buffer_get_int(m); 1800 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1801 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1802 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1803 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1804 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1805 kex->server = 1; 1806 kex->hostkey_type = buffer_get_int(m); 1807 kex->kex_type = buffer_get_int(m); 1808 blob = buffer_get_string(m, &bloblen); 1809 buffer_init(&kex->my); 1810 buffer_append(&kex->my, blob, bloblen); 1811 xfree(blob); 1812 blob = buffer_get_string(m, &bloblen); 1813 buffer_init(&kex->peer); 1814 buffer_append(&kex->peer, blob, bloblen); 1815 xfree(blob); 1816 kex->done = 1; 1817 kex->flags = buffer_get_int(m); 1818 kex->client_version_string = buffer_get_string(m, NULL); 1819 kex->server_version_string = buffer_get_string(m, NULL); 1820 kex->load_host_public_key=&get_hostkey_public_by_type; 1821 kex->load_host_private_key=&get_hostkey_private_by_type; 1822 kex->host_key_index=&get_hostkey_index; 1823 1824 return (kex); 1825 } 1826 1827 /* This function requries careful sanity checking */ 1828 1829 void 1830 mm_get_keystate(struct monitor *pmonitor) 1831 { 1832 Buffer m; 1833 u_char *blob, *p; 1834 u_int bloblen, plen; 1835 u_int32_t seqnr, packets; 1836 u_int64_t blocks, bytes; 1837 1838 debug3("%s: Waiting for new keys", __func__); 1839 1840 buffer_init(&m); 1841 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1842 if (!compat20) { 1843 child_state.ssh1protoflags = buffer_get_int(&m); 1844 child_state.ssh1cipher = buffer_get_int(&m); 1845 child_state.ssh1key = buffer_get_string(&m, 1846 &child_state.ssh1keylen); 1847 child_state.ivout = buffer_get_string(&m, 1848 &child_state.ivoutlen); 1849 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1850 goto skip; 1851 } else { 1852 /* Get the Kex for rekeying */ 1853 *pmonitor->m_pkex = mm_get_kex(&m); 1854 } 1855 1856 blob = buffer_get_string(&m, &bloblen); 1857 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1858 xfree(blob); 1859 1860 debug3("%s: Waiting for second key", __func__); 1861 blob = buffer_get_string(&m, &bloblen); 1862 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1863 xfree(blob); 1864 1865 /* Now get sequence numbers for the packets */ 1866 seqnr = buffer_get_int(&m); 1867 blocks = buffer_get_int64(&m); 1868 packets = buffer_get_int(&m); 1869 bytes = buffer_get_int64(&m); 1870 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1871 seqnr = buffer_get_int(&m); 1872 blocks = buffer_get_int64(&m); 1873 packets = buffer_get_int(&m); 1874 bytes = buffer_get_int64(&m); 1875 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1876 1877 skip: 1878 /* Get the key context */ 1879 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1880 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1881 1882 debug3("%s: Getting compression state", __func__); 1883 /* Get compression state */ 1884 p = buffer_get_string(&m, &plen); 1885 if (plen != sizeof(child_state.outgoing)) 1886 fatal("%s: bad request size", __func__); 1887 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1888 xfree(p); 1889 1890 p = buffer_get_string(&m, &plen); 1891 if (plen != sizeof(child_state.incoming)) 1892 fatal("%s: bad request size", __func__); 1893 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1894 xfree(p); 1895 1896 /* Network I/O buffers */ 1897 debug3("%s: Getting Network I/O buffers", __func__); 1898 child_state.input = buffer_get_string(&m, &child_state.ilen); 1899 child_state.output = buffer_get_string(&m, &child_state.olen); 1900 1901 /* Roaming */ 1902 if (compat20) { 1903 child_state.sent_bytes = buffer_get_int64(&m); 1904 child_state.recv_bytes = buffer_get_int64(&m); 1905 } 1906 1907 buffer_free(&m); 1908 } 1909 1910 1911 /* Allocation functions for zlib */ 1912 void * 1913 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1914 { 1915 size_t len = (size_t) size * ncount; 1916 void *address; 1917 1918 if (len == 0 || ncount > SIZE_T_MAX / size) 1919 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1920 1921 address = mm_malloc(mm, len); 1922 1923 return (address); 1924 } 1925 1926 void 1927 mm_zfree(struct mm_master *mm, void *address) 1928 { 1929 mm_free(mm, address); 1930 } 1931 1932 void 1933 mm_init_compression(struct mm_master *mm) 1934 { 1935 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 1936 outgoing_stream.zfree = (free_func)mm_zfree; 1937 outgoing_stream.opaque = mm; 1938 1939 incoming_stream.zalloc = (alloc_func)mm_zalloc; 1940 incoming_stream.zfree = (free_func)mm_zfree; 1941 incoming_stream.opaque = mm; 1942 } 1943 1944 /* XXX */ 1945 1946 #define FD_CLOSEONEXEC(x) do { \ 1947 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 1948 fatal("fcntl(%d, F_SETFD)", x); \ 1949 } while (0) 1950 1951 static void 1952 monitor_openfds(struct monitor *mon, int do_logfds) 1953 { 1954 int pair[2]; 1955 1956 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 1957 fatal("%s: socketpair: %s", __func__, strerror(errno)); 1958 FD_CLOSEONEXEC(pair[0]); 1959 FD_CLOSEONEXEC(pair[1]); 1960 mon->m_recvfd = pair[0]; 1961 mon->m_sendfd = pair[1]; 1962 1963 if (do_logfds) { 1964 if (pipe(pair) == -1) 1965 fatal("%s: pipe: %s", __func__, strerror(errno)); 1966 FD_CLOSEONEXEC(pair[0]); 1967 FD_CLOSEONEXEC(pair[1]); 1968 mon->m_log_recvfd = pair[0]; 1969 mon->m_log_sendfd = pair[1]; 1970 } else 1971 mon->m_log_recvfd = mon->m_log_sendfd = -1; 1972 } 1973 1974 #define MM_MEMSIZE 65536 1975 1976 struct monitor * 1977 monitor_init(void) 1978 { 1979 struct monitor *mon; 1980 1981 mon = xcalloc(1, sizeof(*mon)); 1982 1983 monitor_openfds(mon, 1); 1984 1985 /* Used to share zlib space across processes */ 1986 if (options.compression) { 1987 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 1988 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 1989 1990 /* Compression needs to share state across borders */ 1991 mm_init_compression(mon->m_zlib); 1992 } 1993 1994 return mon; 1995 } 1996 1997 void 1998 monitor_reinit(struct monitor *mon) 1999 { 2000 monitor_openfds(mon, 0); 2001 } 2002 2003 #ifdef GSSAPI 2004 int 2005 mm_answer_gss_setup_ctx(int sock, Buffer *m) 2006 { 2007 gss_OID_desc goid; 2008 OM_uint32 major; 2009 u_int len; 2010 2011 goid.elements = buffer_get_string(m, &len); 2012 goid.length = len; 2013 2014 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 2015 2016 xfree(goid.elements); 2017 2018 buffer_clear(m); 2019 buffer_put_int(m, major); 2020 2021 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 2022 2023 /* Now we have a context, enable the step */ 2024 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 2025 2026 return (0); 2027 } 2028 2029 int 2030 mm_answer_gss_accept_ctx(int sock, Buffer *m) 2031 { 2032 gss_buffer_desc in; 2033 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2034 OM_uint32 major, minor; 2035 OM_uint32 flags = 0; /* GSI needs this */ 2036 u_int len; 2037 2038 in.value = buffer_get_string(m, &len); 2039 in.length = len; 2040 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2041 xfree(in.value); 2042 2043 buffer_clear(m); 2044 buffer_put_int(m, major); 2045 buffer_put_string(m, out.value, out.length); 2046 buffer_put_int(m, flags); 2047 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2048 2049 gss_release_buffer(&minor, &out); 2050 2051 if (major == GSS_S_COMPLETE) { 2052 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2053 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2054 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2055 } 2056 return (0); 2057 } 2058 2059 int 2060 mm_answer_gss_checkmic(int sock, Buffer *m) 2061 { 2062 gss_buffer_desc gssbuf, mic; 2063 OM_uint32 ret; 2064 u_int len; 2065 2066 gssbuf.value = buffer_get_string(m, &len); 2067 gssbuf.length = len; 2068 mic.value = buffer_get_string(m, &len); 2069 mic.length = len; 2070 2071 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2072 2073 xfree(gssbuf.value); 2074 xfree(mic.value); 2075 2076 buffer_clear(m); 2077 buffer_put_int(m, ret); 2078 2079 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2080 2081 if (!GSS_ERROR(ret)) 2082 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2083 2084 return (0); 2085 } 2086 2087 int 2088 mm_answer_gss_userok(int sock, Buffer *m) 2089 { 2090 int authenticated; 2091 2092 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2093 2094 buffer_clear(m); 2095 buffer_put_int(m, authenticated); 2096 2097 debug3("%s: sending result %d", __func__, authenticated); 2098 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2099 2100 auth_method = "gssapi-with-mic"; 2101 2102 /* Monitor loop will terminate if authenticated */ 2103 return (authenticated); 2104 } 2105 #endif /* GSSAPI */ 2106 2107 #ifdef JPAKE 2108 int 2109 mm_answer_jpake_step1(int sock, Buffer *m) 2110 { 2111 struct jpake_ctx *pctx; 2112 u_char *x3_proof, *x4_proof; 2113 u_int x3_proof_len, x4_proof_len; 2114 2115 if (!options.zero_knowledge_password_authentication) 2116 fatal("zero_knowledge_password_authentication disabled"); 2117 2118 if (authctxt->jpake_ctx != NULL) 2119 fatal("%s: authctxt->jpake_ctx already set (%p)", 2120 __func__, authctxt->jpake_ctx); 2121 authctxt->jpake_ctx = pctx = jpake_new(); 2122 2123 jpake_step1(pctx->grp, 2124 &pctx->server_id, &pctx->server_id_len, 2125 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 2126 &x3_proof, &x3_proof_len, 2127 &x4_proof, &x4_proof_len); 2128 2129 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 2130 2131 buffer_clear(m); 2132 2133 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 2134 buffer_put_bignum2(m, pctx->g_x3); 2135 buffer_put_bignum2(m, pctx->g_x4); 2136 buffer_put_string(m, x3_proof, x3_proof_len); 2137 buffer_put_string(m, x4_proof, x4_proof_len); 2138 2139 debug3("%s: sending step1", __func__); 2140 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 2141 2142 bzero(x3_proof, x3_proof_len); 2143 bzero(x4_proof, x4_proof_len); 2144 xfree(x3_proof); 2145 xfree(x4_proof); 2146 2147 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 2148 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 2149 2150 return 0; 2151 } 2152 2153 int 2154 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 2155 { 2156 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2157 char *hash_scheme, *salt; 2158 2159 if (pctx == NULL) 2160 fatal("%s: pctx == NULL", __func__); 2161 2162 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 2163 2164 buffer_clear(m); 2165 /* pctx->s is sensitive, not returned to slave */ 2166 buffer_put_cstring(m, hash_scheme); 2167 buffer_put_cstring(m, salt); 2168 2169 debug3("%s: sending pwdata", __func__); 2170 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 2171 2172 bzero(hash_scheme, strlen(hash_scheme)); 2173 bzero(salt, strlen(salt)); 2174 xfree(hash_scheme); 2175 xfree(salt); 2176 2177 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 2178 2179 return 0; 2180 } 2181 2182 int 2183 mm_answer_jpake_step2(int sock, Buffer *m) 2184 { 2185 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2186 u_char *x1_proof, *x2_proof, *x4_s_proof; 2187 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 2188 2189 if (pctx == NULL) 2190 fatal("%s: pctx == NULL", __func__); 2191 2192 if ((pctx->g_x1 = BN_new()) == NULL || 2193 (pctx->g_x2 = BN_new()) == NULL) 2194 fatal("%s: BN_new", __func__); 2195 buffer_get_bignum2(m, pctx->g_x1); 2196 buffer_get_bignum2(m, pctx->g_x2); 2197 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 2198 x1_proof = buffer_get_string(m, &x1_proof_len); 2199 x2_proof = buffer_get_string(m, &x2_proof_len); 2200 2201 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 2202 pctx->g_x1, pctx->g_x2, pctx->x4, 2203 pctx->client_id, pctx->client_id_len, 2204 pctx->server_id, pctx->server_id_len, 2205 x1_proof, x1_proof_len, 2206 x2_proof, x2_proof_len, 2207 &pctx->b, 2208 &x4_s_proof, &x4_s_proof_len); 2209 2210 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 2211 2212 bzero(x1_proof, x1_proof_len); 2213 bzero(x2_proof, x2_proof_len); 2214 xfree(x1_proof); 2215 xfree(x2_proof); 2216 2217 buffer_clear(m); 2218 2219 buffer_put_bignum2(m, pctx->b); 2220 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 2221 2222 debug3("%s: sending step2", __func__); 2223 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 2224 2225 bzero(x4_s_proof, x4_s_proof_len); 2226 xfree(x4_s_proof); 2227 2228 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 2229 2230 return 0; 2231 } 2232 2233 int 2234 mm_answer_jpake_key_confirm(int sock, Buffer *m) 2235 { 2236 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2237 u_char *x2_s_proof; 2238 u_int x2_s_proof_len; 2239 2240 if (pctx == NULL) 2241 fatal("%s: pctx == NULL", __func__); 2242 2243 if ((pctx->a = BN_new()) == NULL) 2244 fatal("%s: BN_new", __func__); 2245 buffer_get_bignum2(m, pctx->a); 2246 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 2247 2248 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 2249 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 2250 pctx->server_id, pctx->server_id_len, 2251 pctx->client_id, pctx->client_id_len, 2252 session_id2, session_id2_len, 2253 x2_s_proof, x2_s_proof_len, 2254 &pctx->k, 2255 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 2256 2257 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 2258 2259 bzero(x2_s_proof, x2_s_proof_len); 2260 buffer_clear(m); 2261 2262 /* pctx->k is sensitive, not sent */ 2263 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 2264 2265 debug3("%s: sending confirmation hash", __func__); 2266 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 2267 2268 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 2269 2270 return 0; 2271 } 2272 2273 int 2274 mm_answer_jpake_check_confirm(int sock, Buffer *m) 2275 { 2276 int authenticated = 0; 2277 u_char *peer_confirm_hash; 2278 u_int peer_confirm_hash_len; 2279 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2280 2281 if (pctx == NULL) 2282 fatal("%s: pctx == NULL", __func__); 2283 2284 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 2285 2286 authenticated = jpake_check_confirm(pctx->k, 2287 pctx->client_id, pctx->client_id_len, 2288 session_id2, session_id2_len, 2289 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 2290 2291 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 2292 2293 bzero(peer_confirm_hash, peer_confirm_hash_len); 2294 xfree(peer_confirm_hash); 2295 2296 buffer_clear(m); 2297 buffer_put_int(m, authenticated); 2298 2299 debug3("%s: sending result %d", __func__, authenticated); 2300 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 2301 2302 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 2303 2304 auth_method = "jpake-01@openssh.com"; 2305 return authenticated; 2306 } 2307 2308 #endif /* JPAKE */ 2309