1 /* $NetBSD: monitor.c,v 1.12 2013/12/03 17:14:35 spz Exp $ */ 2 /* $OpenBSD: monitor.c,v 1.127 2013/07/19 07:37:48 markus Exp $ */ 3 /* 4 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 5 * Copyright 2002 Markus Friedl <markus@openbsd.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include "includes.h" 30 __RCSID("$NetBSD: monitor.c,v 1.12 2013/12/03 17:14:35 spz Exp $"); 31 #include <sys/types.h> 32 #include <sys/wait.h> 33 #include <sys/socket.h> 34 #include <sys/tree.h> 35 #include <sys/param.h> 36 #include <sys/queue.h> 37 38 #include <openssl/dh.h> 39 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <paths.h> 43 #include <poll.h> 44 #include <pwd.h> 45 #include <signal.h> 46 #include <stdlib.h> 47 #include <string.h> 48 49 #ifdef SKEY 50 #include <skey.h> 51 #endif 52 53 #include "atomicio.h" 54 #include "xmalloc.h" 55 #include "ssh.h" 56 #include "key.h" 57 #include "buffer.h" 58 #include "hostfile.h" 59 #include "auth.h" 60 #include "cipher.h" 61 #include "kex.h" 62 #include "dh.h" 63 #include <zlib.h> 64 #include "packet.h" 65 #include "auth-options.h" 66 #include "sshpty.h" 67 #include "channels.h" 68 #include "session.h" 69 #include "sshlogin.h" 70 #include "canohost.h" 71 #include "log.h" 72 #include "servconf.h" 73 #include "monitor.h" 74 #include "monitor_mm.h" 75 #ifdef GSSAPI 76 #include "ssh-gss.h" 77 #endif 78 #include "monitor_wrap.h" 79 #include "monitor_fdpass.h" 80 #include "misc.h" 81 #include "compat.h" 82 #include "ssh2.h" 83 #include "jpake.h" 84 #include "roaming.h" 85 #include "authfd.h" 86 87 #ifdef GSSAPI 88 static Gssctxt *gsscontext = NULL; 89 #endif 90 91 /* Imports */ 92 extern ServerOptions options; 93 extern u_int utmp_len; 94 extern Newkeys *current_keys[]; 95 extern z_stream incoming_stream; 96 extern z_stream outgoing_stream; 97 extern u_char session_id[]; 98 extern Buffer auth_debug; 99 extern int auth_debug_init; 100 extern Buffer loginmsg; 101 102 /* State exported from the child */ 103 104 struct { 105 z_stream incoming; 106 z_stream outgoing; 107 u_char *keyin; 108 u_int keyinlen; 109 u_char *keyout; 110 u_int keyoutlen; 111 u_char *ivin; 112 u_int ivinlen; 113 u_char *ivout; 114 u_int ivoutlen; 115 u_char *ssh1key; 116 u_int ssh1keylen; 117 int ssh1cipher; 118 int ssh1protoflags; 119 u_char *input; 120 u_int ilen; 121 u_char *output; 122 u_int olen; 123 u_int64_t sent_bytes; 124 u_int64_t recv_bytes; 125 } child_state; 126 127 /* Functions on the monitor that answer unprivileged requests */ 128 129 int mm_answer_moduli(int, Buffer *); 130 int mm_answer_sign(int, Buffer *); 131 int mm_answer_pwnamallow(int, Buffer *); 132 int mm_answer_auth2_read_banner(int, Buffer *); 133 int mm_answer_authserv(int, Buffer *); 134 int mm_answer_authpassword(int, Buffer *); 135 int mm_answer_bsdauthquery(int, Buffer *); 136 int mm_answer_bsdauthrespond(int, Buffer *); 137 int mm_answer_skeyquery(int, Buffer *); 138 int mm_answer_skeyrespond(int, Buffer *); 139 int mm_answer_keyallowed(int, Buffer *); 140 int mm_answer_keyverify(int, Buffer *); 141 int mm_answer_pty(int, Buffer *); 142 int mm_answer_pty_cleanup(int, Buffer *); 143 int mm_answer_term(int, Buffer *); 144 int mm_answer_rsa_keyallowed(int, Buffer *); 145 int mm_answer_rsa_challenge(int, Buffer *); 146 int mm_answer_rsa_response(int, Buffer *); 147 int mm_answer_sesskey(int, Buffer *); 148 int mm_answer_sessid(int, Buffer *); 149 int mm_answer_jpake_get_pwdata(int, Buffer *); 150 int mm_answer_jpake_step1(int, Buffer *); 151 int mm_answer_jpake_step2(int, Buffer *); 152 int mm_answer_jpake_key_confirm(int, Buffer *); 153 int mm_answer_jpake_check_confirm(int, Buffer *); 154 155 #ifdef USE_PAM 156 int mm_answer_pam_start(int, Buffer *); 157 int mm_answer_pam_account(int, Buffer *); 158 int mm_answer_pam_init_ctx(int, Buffer *); 159 int mm_answer_pam_query(int, Buffer *); 160 int mm_answer_pam_respond(int, Buffer *); 161 int mm_answer_pam_free_ctx(int, Buffer *); 162 #endif 163 164 #ifdef KRB4 165 int mm_answer_krb4(int, Buffer *); 166 #endif 167 #ifdef KRB5 168 int mm_answer_krb5(int, Buffer *); 169 #endif 170 171 #ifdef GSSAPI 172 int mm_answer_gss_setup_ctx(int, Buffer *); 173 int mm_answer_gss_accept_ctx(int, Buffer *); 174 int mm_answer_gss_userok(int, Buffer *); 175 int mm_answer_gss_checkmic(int, Buffer *); 176 #endif 177 178 static int monitor_read_log(struct monitor *); 179 180 static Authctxt *authctxt; 181 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ 182 183 /* local state for key verify */ 184 static u_char *key_blob = NULL; 185 static u_int key_bloblen = 0; 186 static int key_blobtype = MM_NOKEY; 187 static char *hostbased_cuser = NULL; 188 static char *hostbased_chost = NULL; 189 static const char *auth_method = "unknown"; 190 static const char *auth_submethod = NULL; 191 static u_int session_id2_len = 0; 192 static u_char *session_id2 = NULL; 193 static pid_t monitor_child_pid; 194 195 struct mon_table { 196 enum monitor_reqtype type; 197 int flags; 198 int (*f)(int, Buffer *); 199 }; 200 201 #define MON_ISAUTH 0x0004 /* Required for Authentication */ 202 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ 203 #define MON_ONCE 0x0010 /* Disable after calling */ 204 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ 205 206 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) 207 208 #define MON_PERMIT 0x1000 /* Request is permitted */ 209 210 struct mon_table mon_dispatch_proto20[] = { 211 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, 212 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, 213 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 214 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, 215 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, 216 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 217 #ifdef USE_PAM 218 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 219 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 220 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 221 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 222 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 223 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 224 #endif 225 #ifdef BSD_AUTH 226 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 227 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 228 #endif 229 #ifdef SKEY 230 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 231 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 232 #endif 233 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, 234 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, 235 #ifdef KRB4 236 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4}, 237 #endif 238 #ifdef KRB5 239 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 240 #endif 241 #ifdef GSSAPI 242 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, 243 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, 244 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, 245 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, 246 #endif 247 #ifdef JPAKE 248 {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata}, 249 {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1}, 250 {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2}, 251 {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm}, 252 {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm}, 253 #endif 254 {0, 0, NULL} 255 }; 256 257 struct mon_table mon_dispatch_postauth20[] = { 258 {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, 259 {MONITOR_REQ_SIGN, 0, mm_answer_sign}, 260 {MONITOR_REQ_PTY, 0, mm_answer_pty}, 261 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, 262 {MONITOR_REQ_TERM, 0, mm_answer_term}, 263 {0, 0, NULL} 264 }; 265 266 struct mon_table mon_dispatch_proto15[] = { 267 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, 268 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, 269 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, 270 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, 271 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, 272 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, 273 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, 274 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, 275 #ifdef BSD_AUTH 276 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, 277 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, 278 #endif 279 #ifdef SKEY 280 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, 281 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, 282 #endif 283 #ifdef USE_PAM 284 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, 285 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, 286 {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, 287 {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, 288 {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, 289 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, 290 #endif 291 #ifdef KRB4 292 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4}, 293 #endif 294 #ifdef KRB5 295 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, 296 #endif 297 {0, 0, NULL} 298 }; 299 300 struct mon_table mon_dispatch_postauth15[] = { 301 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, 302 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, 303 {MONITOR_REQ_TERM, 0, mm_answer_term}, 304 {0, 0, NULL} 305 }; 306 307 struct mon_table *mon_dispatch; 308 309 /* Specifies if a certain message is allowed at the moment */ 310 311 static void 312 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) 313 { 314 while (ent->f != NULL) { 315 if (ent->type == type) { 316 ent->flags &= ~MON_PERMIT; 317 ent->flags |= permit ? MON_PERMIT : 0; 318 return; 319 } 320 ent++; 321 } 322 } 323 324 static void 325 monitor_permit_authentications(int permit) 326 { 327 struct mon_table *ent = mon_dispatch; 328 329 while (ent->f != NULL) { 330 if (ent->flags & MON_AUTH) { 331 ent->flags &= ~MON_PERMIT; 332 ent->flags |= permit ? MON_PERMIT : 0; 333 } 334 ent++; 335 } 336 } 337 338 void 339 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) 340 { 341 struct mon_table *ent; 342 int authenticated = 0, partial = 0; 343 344 debug3("preauth child monitor started"); 345 346 close(pmonitor->m_recvfd); 347 close(pmonitor->m_log_sendfd); 348 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; 349 350 authctxt = _authctxt; 351 memset(authctxt, 0, sizeof(*authctxt)); 352 353 if (compat20) { 354 mon_dispatch = mon_dispatch_proto20; 355 356 /* Permit requests for moduli and signatures */ 357 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 358 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 359 } else { 360 mon_dispatch = mon_dispatch_proto15; 361 362 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); 363 } 364 365 /* The first few requests do not require asynchronous access */ 366 while (!authenticated) { 367 partial = 0; 368 auth_method = "unknown"; 369 auth_submethod = NULL; 370 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); 371 372 /* Special handling for multiple required authentications */ 373 if (options.num_auth_methods != 0) { 374 if (!compat20) 375 fatal("AuthenticationMethods is not supported" 376 "with SSH protocol 1"); 377 if (authenticated && 378 !auth2_update_methods_lists(authctxt, 379 auth_method, auth_submethod)) { 380 debug3("%s: method %s: partial", __func__, 381 auth_method); 382 authenticated = 0; 383 partial = 1; 384 } 385 } 386 387 if (authenticated) { 388 if (!(ent->flags & MON_AUTHDECIDE)) 389 fatal("%s: unexpected authentication from %d", 390 __func__, ent->type); 391 if (authctxt->pw->pw_uid == 0 && 392 !auth_root_allowed(auth_method)) 393 authenticated = 0; 394 #ifdef USE_PAM 395 /* PAM needs to perform account checks after auth */ 396 if (options.use_pam && authenticated) { 397 Buffer m; 398 399 buffer_init(&m); 400 mm_request_receive_expect(pmonitor->m_sendfd, 401 MONITOR_REQ_PAM_ACCOUNT, &m); 402 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); 403 buffer_free(&m); 404 } 405 #endif 406 } 407 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { 408 auth_log(authctxt, authenticated, partial, 409 auth_method, auth_submethod); 410 if (!authenticated) 411 authctxt->failures++; 412 } 413 #ifdef JPAKE 414 /* Cleanup JPAKE context after authentication */ 415 if (ent->flags & MON_AUTHDECIDE) { 416 if (authctxt->jpake_ctx != NULL) { 417 jpake_free(authctxt->jpake_ctx); 418 authctxt->jpake_ctx = NULL; 419 } 420 } 421 #endif 422 } 423 424 if (!authctxt->valid) 425 fatal("%s: authenticated invalid user", __func__); 426 if (strcmp(auth_method, "unknown") == 0) 427 fatal("%s: authentication method name unknown", __func__); 428 429 debug("%s: %s has been authenticated by privileged process", 430 __func__, authctxt->user); 431 432 mm_get_keystate(pmonitor); 433 434 /* Drain any buffered messages from the child */ 435 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) 436 ; 437 438 close(pmonitor->m_sendfd); 439 close(pmonitor->m_log_recvfd); 440 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; 441 } 442 443 static void 444 monitor_set_child_handler(pid_t pid) 445 { 446 monitor_child_pid = pid; 447 } 448 449 static void 450 monitor_child_handler(int sig) 451 { 452 kill(monitor_child_pid, sig); 453 } 454 455 void 456 monitor_child_postauth(struct monitor *pmonitor) 457 { 458 close(pmonitor->m_recvfd); 459 pmonitor->m_recvfd = -1; 460 461 monitor_set_child_handler(pmonitor->m_pid); 462 signal(SIGHUP, &monitor_child_handler); 463 signal(SIGTERM, &monitor_child_handler); 464 signal(SIGINT, &monitor_child_handler); 465 466 if (compat20) { 467 mon_dispatch = mon_dispatch_postauth20; 468 469 /* Permit requests for moduli and signatures */ 470 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); 471 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); 472 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 473 } else { 474 mon_dispatch = mon_dispatch_postauth15; 475 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); 476 } 477 if (!no_pty_flag) { 478 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); 479 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); 480 } 481 482 for (;;) 483 monitor_read(pmonitor, mon_dispatch, NULL); 484 } 485 486 void 487 monitor_sync(struct monitor *pmonitor) 488 { 489 if (options.compression) { 490 /* The member allocation is not visible, so sync it */ 491 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); 492 } 493 } 494 495 static int 496 monitor_read_log(struct monitor *pmonitor) 497 { 498 Buffer logmsg; 499 u_int len, level; 500 char *msg; 501 502 buffer_init(&logmsg); 503 504 /* Read length */ 505 buffer_append_space(&logmsg, 4); 506 if (atomicio(read, pmonitor->m_log_recvfd, 507 buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { 508 if (errno == EPIPE) { 509 buffer_free(&logmsg); 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 free(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 free(key_blob); 629 free(hostbased_cuser); 630 free(hostbased_chost); 631 key_blob = NULL; 632 key_bloblen = 0; 633 key_blobtype = MM_NOKEY; 634 hostbased_cuser = NULL; 635 hostbased_chost = NULL; 636 } 637 638 int 639 mm_answer_moduli(int sock, Buffer *m) 640 { 641 DH *dh; 642 int min, want, max; 643 644 min = buffer_get_int(m); 645 want = buffer_get_int(m); 646 max = buffer_get_int(m); 647 648 debug3("%s: got parameters: %d %d %d", 649 __func__, min, want, max); 650 /* We need to check here, too, in case the child got corrupted */ 651 if (max < min || want < min || max < want) 652 fatal("%s: bad parameters: %d %d %d", 653 __func__, min, want, max); 654 655 buffer_clear(m); 656 657 dh = choose_dh(min, want, max); 658 if (dh == NULL) { 659 buffer_put_char(m, 0); 660 return (0); 661 } else { 662 /* Send first bignum */ 663 buffer_put_char(m, 1); 664 buffer_put_bignum2(m, dh->p); 665 buffer_put_bignum2(m, dh->g); 666 667 DH_free(dh); 668 } 669 mm_request_send(sock, MONITOR_ANS_MODULI, m); 670 return (0); 671 } 672 673 extern AuthenticationConnection *auth_conn; 674 675 int 676 mm_answer_sign(int sock, Buffer *m) 677 { 678 Key *key; 679 u_char *p; 680 u_char *signature; 681 u_int siglen, datlen; 682 int keyid; 683 684 debug3("%s", __func__); 685 686 keyid = buffer_get_int(m); 687 p = buffer_get_string(m, &datlen); 688 689 /* 690 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), 691 * SHA384 (48 bytes) and SHA512 (64 bytes). 692 */ 693 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) 694 fatal("%s: data length incorrect: %u", __func__, datlen); 695 696 /* save session id, it will be passed on the first call */ 697 if (session_id2_len == 0) { 698 session_id2_len = datlen; 699 session_id2 = xmalloc(session_id2_len); 700 memcpy(session_id2, p, session_id2_len); 701 } 702 703 if ((key = get_hostkey_by_index(keyid)) != NULL) { 704 if (key_sign(key, &signature, &siglen, p, datlen) < 0) 705 fatal("%s: key_sign failed", __func__); 706 } else if ((key = get_hostkey_public_by_index(keyid)) != NULL && 707 auth_conn != NULL) { 708 if (ssh_agent_sign(auth_conn, key, &signature, &siglen, p, 709 datlen) < 0) 710 fatal("%s: ssh_agent_sign failed", __func__); 711 } else 712 fatal("%s: no hostkey from index %d", __func__, keyid); 713 714 debug3("%s: signature %p(%u)", __func__, signature, siglen); 715 716 buffer_clear(m); 717 buffer_put_string(m, signature, siglen); 718 719 free(p); 720 free(signature); 721 722 mm_request_send(sock, MONITOR_ANS_SIGN, m); 723 724 /* Turn on permissions for getpwnam */ 725 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 726 727 return (0); 728 } 729 730 /* Retrieves the password entry and also checks if the user is permitted */ 731 732 int 733 mm_answer_pwnamallow(int sock, Buffer *m) 734 { 735 char *username; 736 struct passwd *pwent; 737 int allowed = 0; 738 u_int i; 739 740 debug3("%s", __func__); 741 742 if (authctxt->attempt++ != 0) 743 fatal("%s: multiple attempts for getpwnam", __func__); 744 745 username = buffer_get_string(m, NULL); 746 747 pwent = getpwnamallow(username); 748 749 authctxt->user = xstrdup(username); 750 setproctitle("%s [priv]", pwent ? username : "unknown"); 751 free(username); 752 753 buffer_clear(m); 754 755 if (pwent == NULL) { 756 buffer_put_char(m, 0); 757 authctxt->pw = fakepw(); 758 goto out; 759 } 760 761 allowed = 1; 762 authctxt->pw = pwent; 763 authctxt->valid = 1; 764 765 buffer_put_char(m, 1); 766 buffer_put_string(m, pwent, sizeof(struct passwd)); 767 buffer_put_cstring(m, pwent->pw_name); 768 buffer_put_cstring(m, "*"); 769 buffer_put_cstring(m, pwent->pw_gecos); 770 buffer_put_cstring(m, pwent->pw_class); 771 buffer_put_cstring(m, pwent->pw_dir); 772 buffer_put_cstring(m, pwent->pw_shell); 773 774 out: 775 buffer_put_string(m, &options, sizeof(options)); 776 777 #define M_CP_STROPT(x) do { \ 778 if (options.x != NULL) \ 779 buffer_put_cstring(m, options.x); \ 780 } while (0) 781 #define M_CP_STRARRAYOPT(x, nx) do { \ 782 for (i = 0; i < options.nx; i++) \ 783 buffer_put_cstring(m, options.x[i]); \ 784 } while (0) 785 /* See comment in servconf.h */ 786 COPY_MATCH_STRING_OPTS(); 787 #undef M_CP_STROPT 788 #undef M_CP_STRARRAYOPT 789 790 /* Create valid auth method lists */ 791 if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { 792 /* 793 * The monitor will continue long enough to let the child 794 * run to it's packet_disconnect(), but it must not allow any 795 * authentication to succeed. 796 */ 797 debug("%s: no valid authentication method lists", __func__); 798 } 799 800 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); 801 mm_request_send(sock, MONITOR_ANS_PWNAM, m); 802 803 /* For SSHv1 allow authentication now */ 804 if (!compat20) 805 monitor_permit_authentications(1); 806 else { 807 /* Allow service/style information on the auth context */ 808 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); 809 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); 810 } 811 812 #ifdef USE_PAM 813 if (options.use_pam) 814 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); 815 #endif 816 817 return (0); 818 } 819 820 int mm_answer_auth2_read_banner(int sock, Buffer *m) 821 { 822 char *banner; 823 824 buffer_clear(m); 825 banner = auth2_read_banner(); 826 buffer_put_cstring(m, banner != NULL ? banner : ""); 827 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); 828 free(banner); 829 830 return (0); 831 } 832 833 int 834 mm_answer_authserv(int sock, Buffer *m) 835 { 836 monitor_permit_authentications(1); 837 838 authctxt->service = buffer_get_string(m, NULL); 839 authctxt->style = buffer_get_string(m, NULL); 840 debug3("%s: service=%s, style=%s", 841 __func__, authctxt->service, authctxt->style); 842 843 if (strlen(authctxt->style) == 0) { 844 free(authctxt->style); 845 authctxt->style = NULL; 846 } 847 848 return (0); 849 } 850 851 int 852 mm_answer_authpassword(int sock, Buffer *m) 853 { 854 static int call_count; 855 char *passwd; 856 int authenticated; 857 u_int plen; 858 859 passwd = buffer_get_string(m, &plen); 860 /* Only authenticate if the context is valid */ 861 authenticated = options.password_authentication && 862 auth_password(authctxt, passwd); 863 memset(passwd, 0, strlen(passwd)); 864 free(passwd); 865 866 buffer_clear(m); 867 buffer_put_int(m, authenticated); 868 869 debug3("%s: sending result %d", __func__, authenticated); 870 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); 871 872 call_count++; 873 if (plen == 0 && call_count == 1) 874 auth_method = "none"; 875 else 876 auth_method = "password"; 877 878 /* Causes monitor loop to terminate if authenticated */ 879 return (authenticated); 880 } 881 882 #ifdef BSD_AUTH 883 int 884 mm_answer_bsdauthquery(int sock, Buffer *m) 885 { 886 char *name, *infotxt; 887 u_int numprompts; 888 u_int *echo_on; 889 char **prompts; 890 u_int success; 891 892 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, 893 &prompts, &echo_on) < 0 ? 0 : 1; 894 895 buffer_clear(m); 896 buffer_put_int(m, success); 897 if (success) 898 buffer_put_cstring(m, prompts[0]); 899 900 debug3("%s: sending challenge success: %u", __func__, success); 901 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); 902 903 if (success) { 904 free(name); 905 free(infotxt); 906 free(prompts); 907 free(echo_on); 908 } 909 910 return (0); 911 } 912 913 int 914 mm_answer_bsdauthrespond(int sock, Buffer *m) 915 { 916 char *response; 917 int authok; 918 919 if (authctxt->as == 0) 920 fatal("%s: no bsd auth session", __func__); 921 922 response = buffer_get_string(m, NULL); 923 authok = options.challenge_response_authentication && 924 auth_userresponse(authctxt->as, response, 0); 925 authctxt->as = NULL; 926 debug3("%s: <%s> = <%d>", __func__, response, authok); 927 free(response); 928 929 buffer_clear(m); 930 buffer_put_int(m, authok); 931 932 debug3("%s: sending authenticated: %d", __func__, authok); 933 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); 934 935 if (compat20) { 936 auth_method = "keyboard-interactive"; 937 auth_submethod = "bsdauth"; 938 } else 939 auth_method = "bsdauth"; 940 941 return (authok != 0); 942 } 943 #endif 944 945 #ifdef SKEY 946 int 947 mm_answer_skeyquery(int sock, Buffer *m) 948 { 949 struct skey skey; 950 char challenge[1024]; 951 u_int success; 952 953 success = skeychallenge(&skey, authctxt->user, challenge, 954 sizeof(challenge)) < 0 ? 0 : 1; 955 956 buffer_clear(m); 957 buffer_put_int(m, success); 958 if (success) 959 buffer_put_cstring(m, challenge); 960 961 debug3("%s: sending challenge success: %u", __func__, success); 962 mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); 963 964 return (0); 965 } 966 967 int 968 mm_answer_skeyrespond(int sock, Buffer *m) 969 { 970 char *response; 971 int authok; 972 973 response = buffer_get_string(m, NULL); 974 975 authok = (options.challenge_response_authentication && 976 authctxt->valid && 977 skey_haskey(authctxt->pw->pw_name) == 0 && 978 skey_passcheck(authctxt->pw->pw_name, response) != -1); 979 980 free(response); 981 982 buffer_clear(m); 983 buffer_put_int(m, authok); 984 985 debug3("%s: sending authenticated: %d", __func__, authok); 986 mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); 987 988 auth_method = "skey"; 989 990 return (authok != 0); 991 } 992 #endif 993 994 #ifdef USE_PAM 995 int 996 mm_answer_pam_start(int sock, Buffer *m) 997 { 998 if (!options.use_pam) 999 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1000 1001 start_pam(authctxt); 1002 1003 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); 1004 1005 return (0); 1006 } 1007 1008 int 1009 mm_answer_pam_account(int sock, Buffer *m) 1010 { 1011 u_int ret; 1012 1013 if (!options.use_pam) 1014 fatal("UsePAM not set, but ended up in %s anyway", __func__); 1015 1016 ret = do_pam_account(); 1017 1018 buffer_put_int(m, ret); 1019 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1020 1021 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); 1022 1023 return (ret); 1024 } 1025 1026 static void *sshpam_ctxt, *sshpam_authok; 1027 extern KbdintDevice sshpam_device; 1028 1029 int 1030 mm_answer_pam_init_ctx(int sock, Buffer *m) 1031 { 1032 1033 debug3("%s", __func__); 1034 authctxt->user = buffer_get_string(m, NULL); 1035 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); 1036 sshpam_authok = NULL; 1037 buffer_clear(m); 1038 if (sshpam_ctxt != NULL) { 1039 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); 1040 buffer_put_int(m, 1); 1041 } else { 1042 buffer_put_int(m, 0); 1043 } 1044 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); 1045 return (0); 1046 } 1047 1048 int 1049 mm_answer_pam_query(int sock, Buffer *m) 1050 { 1051 char *name, *info, **prompts; 1052 u_int i, num, *echo_on; 1053 int ret; 1054 1055 debug3("%s", __func__); 1056 sshpam_authok = NULL; 1057 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); 1058 if (ret == 0 && num == 0) 1059 sshpam_authok = sshpam_ctxt; 1060 if (num > 1 || name == NULL || info == NULL) 1061 ret = -1; 1062 buffer_clear(m); 1063 buffer_put_int(m, ret); 1064 buffer_put_cstring(m, name); 1065 free(name); 1066 buffer_put_cstring(m, info); 1067 free(info); 1068 buffer_put_int(m, num); 1069 for (i = 0; i < num; ++i) { 1070 buffer_put_cstring(m, prompts[i]); 1071 free(prompts[i]); 1072 buffer_put_int(m, echo_on[i]); 1073 } 1074 if (prompts != NULL) 1075 free(prompts); 1076 if (echo_on != NULL) 1077 free(echo_on); 1078 auth_method = "keyboard-interactive/pam"; 1079 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); 1080 return (0); 1081 } 1082 1083 int 1084 mm_answer_pam_respond(int sock, Buffer *m) 1085 { 1086 char **resp; 1087 u_int i, num; 1088 int ret; 1089 1090 debug3("%s", __func__); 1091 sshpam_authok = NULL; 1092 num = buffer_get_int(m); 1093 if (num > 0) { 1094 resp = xmalloc(num * sizeof(char *)); 1095 for (i = 0; i < num; ++i) 1096 resp[i] = buffer_get_string(m, NULL); 1097 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); 1098 for (i = 0; i < num; ++i) 1099 free(resp[i]); 1100 free(resp); 1101 } else { 1102 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); 1103 } 1104 buffer_clear(m); 1105 buffer_put_int(m, ret); 1106 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); 1107 auth_method = "keyboard-interactive/pam"; 1108 if (ret == 0) 1109 sshpam_authok = sshpam_ctxt; 1110 return (0); 1111 } 1112 1113 int 1114 mm_answer_pam_free_ctx(int sock, Buffer *m) 1115 { 1116 1117 debug3("%s", __func__); 1118 (sshpam_device.free_ctx)(sshpam_ctxt); 1119 buffer_clear(m); 1120 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); 1121 auth_method = "keyboard-interactive/pam"; 1122 return (sshpam_authok == sshpam_ctxt); 1123 } 1124 #endif 1125 1126 int 1127 mm_answer_keyallowed(int sock, Buffer *m) 1128 { 1129 Key *key; 1130 char *cuser, *chost; 1131 u_char *blob; 1132 u_int bloblen; 1133 enum mm_keytype type = 0; 1134 int allowed = 0; 1135 1136 debug3("%s entering", __func__); 1137 1138 type = buffer_get_int(m); 1139 cuser = buffer_get_string(m, NULL); 1140 chost = buffer_get_string(m, NULL); 1141 blob = buffer_get_string(m, &bloblen); 1142 1143 key = key_from_blob(blob, bloblen); 1144 1145 if ((compat20 && type == MM_RSAHOSTKEY) || 1146 (!compat20 && type != MM_RSAHOSTKEY)) 1147 fatal("%s: key type and protocol mismatch", __func__); 1148 1149 debug3("%s: key_from_blob: %p", __func__, key); 1150 1151 if (key != NULL && authctxt->valid) { 1152 switch (type) { 1153 case MM_USERKEY: 1154 allowed = options.pubkey_authentication && 1155 user_key_allowed(authctxt->pw, key); 1156 pubkey_auth_info(authctxt, key, NULL); 1157 auth_method = "publickey"; 1158 if (options.pubkey_authentication && allowed != 1) 1159 auth_clear_options(); 1160 break; 1161 case MM_HOSTKEY: 1162 allowed = options.hostbased_authentication && 1163 hostbased_key_allowed(authctxt->pw, 1164 cuser, chost, key); 1165 pubkey_auth_info(authctxt, key, 1166 "client user \"%.100s\", client host \"%.100s\"", 1167 cuser, chost); 1168 auth_method = "hostbased"; 1169 break; 1170 case MM_RSAHOSTKEY: 1171 key->type = KEY_RSA1; /* XXX */ 1172 allowed = options.rhosts_rsa_authentication && 1173 auth_rhosts_rsa_key_allowed(authctxt->pw, 1174 cuser, chost, key); 1175 if (options.rhosts_rsa_authentication && allowed != 1) 1176 auth_clear_options(); 1177 auth_method = "rsa"; 1178 break; 1179 default: 1180 fatal("%s: unknown key type %d", __func__, type); 1181 break; 1182 } 1183 } 1184 debug3("%s: key %p is %s", 1185 __func__, key, allowed ? "allowed" : "not allowed"); 1186 1187 if (key != NULL) 1188 key_free(key); 1189 1190 /* clear temporarily storage (used by verify) */ 1191 monitor_reset_key_state(); 1192 1193 if (allowed) { 1194 /* Save temporarily for comparison in verify */ 1195 key_blob = blob; 1196 key_bloblen = bloblen; 1197 key_blobtype = type; 1198 hostbased_cuser = cuser; 1199 hostbased_chost = chost; 1200 } else { 1201 /* Log failed attempt */ 1202 auth_log(authctxt, 0, 0, auth_method, NULL); 1203 free(blob); 1204 free(cuser); 1205 free(chost); 1206 } 1207 1208 buffer_clear(m); 1209 buffer_put_int(m, allowed); 1210 buffer_put_int(m, forced_command != NULL); 1211 1212 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); 1213 1214 if (type == MM_RSAHOSTKEY) 1215 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1216 1217 return (0); 1218 } 1219 1220 static int 1221 monitor_valid_userblob(u_char *data, u_int datalen) 1222 { 1223 Buffer b; 1224 char *p, *userstyle; 1225 u_int len; 1226 int fail = 0; 1227 1228 buffer_init(&b); 1229 buffer_append(&b, data, datalen); 1230 1231 if (datafellows & SSH_OLD_SESSIONID) { 1232 p = buffer_ptr(&b); 1233 len = buffer_len(&b); 1234 if ((session_id2 == NULL) || 1235 (len < session_id2_len) || 1236 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1237 fail++; 1238 buffer_consume(&b, session_id2_len); 1239 } else { 1240 p = buffer_get_string(&b, &len); 1241 if ((session_id2 == NULL) || 1242 (len != session_id2_len) || 1243 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1244 fail++; 1245 free(p); 1246 } 1247 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1248 fail++; 1249 p = buffer_get_cstring(&b, NULL); 1250 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1251 authctxt->style ? ":" : "", 1252 authctxt->style ? authctxt->style : ""); 1253 if (strcmp(userstyle, p) != 0) { 1254 logit("wrong user name passed to monitor: expected %s != %.100s", 1255 userstyle, p); 1256 fail++; 1257 } 1258 free(userstyle); 1259 free(p); 1260 buffer_skip_string(&b); 1261 if (datafellows & SSH_BUG_PKAUTH) { 1262 if (!buffer_get_char(&b)) 1263 fail++; 1264 } else { 1265 p = buffer_get_cstring(&b, NULL); 1266 if (strcmp("publickey", p) != 0) 1267 fail++; 1268 free(p); 1269 if (!buffer_get_char(&b)) 1270 fail++; 1271 buffer_skip_string(&b); 1272 } 1273 buffer_skip_string(&b); 1274 if (buffer_len(&b) != 0) 1275 fail++; 1276 buffer_free(&b); 1277 return (fail == 0); 1278 } 1279 1280 static int 1281 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, 1282 char *chost) 1283 { 1284 Buffer b; 1285 char *p, *userstyle; 1286 u_int len; 1287 int fail = 0; 1288 1289 buffer_init(&b); 1290 buffer_append(&b, data, datalen); 1291 1292 p = buffer_get_string(&b, &len); 1293 if ((session_id2 == NULL) || 1294 (len != session_id2_len) || 1295 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) 1296 fail++; 1297 free(p); 1298 1299 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) 1300 fail++; 1301 p = buffer_get_cstring(&b, NULL); 1302 xasprintf(&userstyle, "%s%s%s", authctxt->user, 1303 authctxt->style ? ":" : "", 1304 authctxt->style ? authctxt->style : ""); 1305 if (strcmp(userstyle, p) != 0) { 1306 logit("wrong user name passed to monitor: expected %s != %.100s", 1307 userstyle, p); 1308 fail++; 1309 } 1310 free(userstyle); 1311 free(p); 1312 buffer_skip_string(&b); /* service */ 1313 p = buffer_get_cstring(&b, NULL); 1314 if (strcmp(p, "hostbased") != 0) 1315 fail++; 1316 free(p); 1317 buffer_skip_string(&b); /* pkalg */ 1318 buffer_skip_string(&b); /* pkblob */ 1319 1320 /* verify client host, strip trailing dot if necessary */ 1321 p = buffer_get_string(&b, NULL); 1322 if (((len = strlen(p)) > 0) && p[len - 1] == '.') 1323 p[len - 1] = '\0'; 1324 if (strcmp(p, chost) != 0) 1325 fail++; 1326 free(p); 1327 1328 /* verify client user */ 1329 p = buffer_get_string(&b, NULL); 1330 if (strcmp(p, cuser) != 0) 1331 fail++; 1332 free(p); 1333 1334 if (buffer_len(&b) != 0) 1335 fail++; 1336 buffer_free(&b); 1337 return (fail == 0); 1338 } 1339 1340 int 1341 mm_answer_keyverify(int sock, Buffer *m) 1342 { 1343 Key *key; 1344 u_char *signature, *data, *blob; 1345 u_int signaturelen, datalen, bloblen; 1346 int verified = 0; 1347 int valid_data = 0; 1348 1349 blob = buffer_get_string(m, &bloblen); 1350 signature = buffer_get_string(m, &signaturelen); 1351 data = buffer_get_string(m, &datalen); 1352 1353 if (hostbased_cuser == NULL || hostbased_chost == NULL || 1354 !monitor_allowed_key(blob, bloblen)) 1355 fatal("%s: bad key, not previously allowed", __func__); 1356 1357 key = key_from_blob(blob, bloblen); 1358 if (key == NULL) 1359 fatal("%s: bad public key blob", __func__); 1360 1361 switch (key_blobtype) { 1362 case MM_USERKEY: 1363 valid_data = monitor_valid_userblob(data, datalen); 1364 break; 1365 case MM_HOSTKEY: 1366 valid_data = monitor_valid_hostbasedblob(data, datalen, 1367 hostbased_cuser, hostbased_chost); 1368 break; 1369 default: 1370 valid_data = 0; 1371 break; 1372 } 1373 if (!valid_data) 1374 fatal("%s: bad signature data blob", __func__); 1375 1376 verified = key_verify(key, signature, signaturelen, data, datalen); 1377 debug3("%s: key %p signature %s", 1378 __func__, key, (verified == 1) ? "verified" : "unverified"); 1379 1380 key_free(key); 1381 free(blob); 1382 free(signature); 1383 free(data); 1384 1385 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; 1386 1387 monitor_reset_key_state(); 1388 1389 buffer_clear(m); 1390 buffer_put_int(m, verified); 1391 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); 1392 1393 return (verified == 1); 1394 } 1395 1396 static void 1397 mm_record_login(Session *s, struct passwd *pw) 1398 { 1399 socklen_t fromlen; 1400 struct sockaddr_storage from; 1401 1402 /* 1403 * Get IP address of client. If the connection is not a socket, let 1404 * the address be 0.0.0.0. 1405 */ 1406 memset(&from, 0, sizeof(from)); 1407 fromlen = sizeof(from); 1408 if (packet_connection_is_on_socket()) { 1409 if (getpeername(packet_get_connection_in(), 1410 (struct sockaddr *)&from, &fromlen) < 0) { 1411 debug("getpeername: %.100s", strerror(errno)); 1412 cleanup_exit(255); 1413 } 1414 } 1415 /* Record that there was a login on that tty from the remote host. */ 1416 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, 1417 get_remote_name_or_ip(utmp_len, options.use_dns), 1418 (struct sockaddr *)&from, fromlen); 1419 } 1420 1421 static void 1422 mm_session_close(Session *s) 1423 { 1424 debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); 1425 if (s->ttyfd != -1) { 1426 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); 1427 session_pty_cleanup2(s); 1428 } 1429 session_unused(s->self); 1430 } 1431 1432 int 1433 mm_answer_pty(int sock, Buffer *m) 1434 { 1435 extern struct monitor *pmonitor; 1436 Session *s; 1437 int res, fd0; 1438 1439 debug3("%s entering", __func__); 1440 1441 buffer_clear(m); 1442 s = session_new(); 1443 if (s == NULL) 1444 goto error; 1445 s->authctxt = authctxt; 1446 s->pw = authctxt->pw; 1447 s->pid = pmonitor->m_pid; 1448 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); 1449 if (res == 0) 1450 goto error; 1451 pty_setowner(authctxt->pw, s->tty); 1452 1453 buffer_put_int(m, 1); 1454 buffer_put_cstring(m, s->tty); 1455 1456 /* We need to trick ttyslot */ 1457 if (dup2(s->ttyfd, 0) == -1) 1458 fatal("%s: dup2", __func__); 1459 1460 mm_record_login(s, authctxt->pw); 1461 1462 /* Now we can close the file descriptor again */ 1463 close(0); 1464 1465 /* send messages generated by record_login */ 1466 buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); 1467 buffer_clear(&loginmsg); 1468 1469 mm_request_send(sock, MONITOR_ANS_PTY, m); 1470 1471 if (mm_send_fd(sock, s->ptyfd) == -1 || 1472 mm_send_fd(sock, s->ttyfd) == -1) 1473 fatal("%s: send fds failed", __func__); 1474 1475 /* make sure nothing uses fd 0 */ 1476 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) 1477 fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); 1478 if (fd0 != 0) 1479 error("%s: fd0 %d != 0", __func__, fd0); 1480 1481 /* slave is not needed */ 1482 close(s->ttyfd); 1483 s->ttyfd = s->ptyfd; 1484 /* no need to dup() because nobody closes ptyfd */ 1485 s->ptymaster = s->ptyfd; 1486 1487 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); 1488 1489 return (0); 1490 1491 error: 1492 if (s != NULL) 1493 mm_session_close(s); 1494 buffer_put_int(m, 0); 1495 mm_request_send(sock, MONITOR_ANS_PTY, m); 1496 return (0); 1497 } 1498 1499 int 1500 mm_answer_pty_cleanup(int sock, Buffer *m) 1501 { 1502 Session *s; 1503 char *tty; 1504 1505 debug3("%s entering", __func__); 1506 1507 tty = buffer_get_string(m, NULL); 1508 if ((s = session_by_tty(tty)) != NULL) 1509 mm_session_close(s); 1510 buffer_clear(m); 1511 free(tty); 1512 return (0); 1513 } 1514 1515 int 1516 mm_answer_sesskey(int sock, Buffer *m) 1517 { 1518 BIGNUM *p; 1519 int rsafail; 1520 1521 /* Turn off permissions */ 1522 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); 1523 1524 if ((p = BN_new()) == NULL) 1525 fatal("%s: BN_new", __func__); 1526 1527 buffer_get_bignum2(m, p); 1528 1529 rsafail = ssh1_session_key(p); 1530 1531 buffer_clear(m); 1532 buffer_put_int(m, rsafail); 1533 buffer_put_bignum2(m, p); 1534 1535 BN_clear_free(p); 1536 1537 mm_request_send(sock, MONITOR_ANS_SESSKEY, m); 1538 1539 /* Turn on permissions for sessid passing */ 1540 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); 1541 1542 return (0); 1543 } 1544 1545 int 1546 mm_answer_sessid(int sock, Buffer *m) 1547 { 1548 int i; 1549 1550 debug3("%s entering", __func__); 1551 1552 if (buffer_len(m) != 16) 1553 fatal("%s: bad ssh1 session id", __func__); 1554 for (i = 0; i < 16; i++) 1555 session_id[i] = buffer_get_char(m); 1556 1557 /* Turn on permissions for getpwnam */ 1558 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); 1559 1560 return (0); 1561 } 1562 1563 int 1564 mm_answer_rsa_keyallowed(int sock, Buffer *m) 1565 { 1566 BIGNUM *client_n; 1567 Key *key = NULL; 1568 u_char *blob = NULL; 1569 u_int blen = 0; 1570 int allowed = 0; 1571 1572 debug3("%s entering", __func__); 1573 1574 auth_method = "rsa"; 1575 if (options.rsa_authentication && authctxt->valid) { 1576 if ((client_n = BN_new()) == NULL) 1577 fatal("%s: BN_new", __func__); 1578 buffer_get_bignum2(m, client_n); 1579 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); 1580 BN_clear_free(client_n); 1581 } 1582 buffer_clear(m); 1583 buffer_put_int(m, allowed); 1584 buffer_put_int(m, forced_command != NULL); 1585 1586 /* clear temporarily storage (used by generate challenge) */ 1587 monitor_reset_key_state(); 1588 1589 if (allowed && key != NULL) { 1590 key->type = KEY_RSA; /* cheat for key_to_blob */ 1591 if (key_to_blob(key, &blob, &blen) == 0) 1592 fatal("%s: key_to_blob failed", __func__); 1593 buffer_put_string(m, blob, blen); 1594 1595 /* Save temporarily for comparison in verify */ 1596 key_blob = blob; 1597 key_bloblen = blen; 1598 key_blobtype = MM_RSAUSERKEY; 1599 } 1600 if (key != NULL) 1601 key_free(key); 1602 1603 mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); 1604 1605 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); 1606 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); 1607 return (0); 1608 } 1609 1610 int 1611 mm_answer_rsa_challenge(int sock, Buffer *m) 1612 { 1613 Key *key = NULL; 1614 u_char *blob; 1615 u_int blen; 1616 1617 debug3("%s entering", __func__); 1618 1619 if (!authctxt->valid) 1620 fatal("%s: authctxt not valid", __func__); 1621 blob = buffer_get_string(m, &blen); 1622 if (!monitor_allowed_key(blob, blen)) 1623 fatal("%s: bad key, not previously allowed", __func__); 1624 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1625 fatal("%s: key type mismatch", __func__); 1626 if ((key = key_from_blob(blob, blen)) == NULL) 1627 fatal("%s: received bad key", __func__); 1628 if (key->type != KEY_RSA) 1629 fatal("%s: received bad key type %d", __func__, key->type); 1630 key->type = KEY_RSA1; 1631 if (ssh1_challenge) 1632 BN_clear_free(ssh1_challenge); 1633 ssh1_challenge = auth_rsa_generate_challenge(key); 1634 1635 buffer_clear(m); 1636 buffer_put_bignum2(m, ssh1_challenge); 1637 1638 debug3("%s sending reply", __func__); 1639 mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); 1640 1641 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); 1642 1643 free(blob); 1644 key_free(key); 1645 return (0); 1646 } 1647 1648 int 1649 mm_answer_rsa_response(int sock, Buffer *m) 1650 { 1651 Key *key = NULL; 1652 u_char *blob, *response; 1653 u_int blen, len; 1654 int success; 1655 1656 debug3("%s entering", __func__); 1657 1658 if (!authctxt->valid) 1659 fatal("%s: authctxt not valid", __func__); 1660 if (ssh1_challenge == NULL) 1661 fatal("%s: no ssh1_challenge", __func__); 1662 1663 blob = buffer_get_string(m, &blen); 1664 if (!monitor_allowed_key(blob, blen)) 1665 fatal("%s: bad key, not previously allowed", __func__); 1666 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) 1667 fatal("%s: key type mismatch: %d", __func__, key_blobtype); 1668 if ((key = key_from_blob(blob, blen)) == NULL) 1669 fatal("%s: received bad key", __func__); 1670 response = buffer_get_string(m, &len); 1671 if (len != 16) 1672 fatal("%s: received bad response to challenge", __func__); 1673 success = auth_rsa_verify_response(key, ssh1_challenge, response); 1674 1675 free(blob); 1676 key_free(key); 1677 free(response); 1678 1679 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; 1680 1681 /* reset state */ 1682 BN_clear_free(ssh1_challenge); 1683 ssh1_challenge = NULL; 1684 monitor_reset_key_state(); 1685 1686 buffer_clear(m); 1687 buffer_put_int(m, success); 1688 mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); 1689 1690 return (success); 1691 } 1692 1693 #ifdef KRB4 1694 int 1695 mm_answer_krb4(int socket, Buffer *m) 1696 { 1697 KTEXT_ST auth, reply; 1698 char *client, *p; 1699 int success; 1700 u_int alen; 1701 1702 reply.length = auth.length = 0; 1703 1704 p = buffer_get_string(m, &alen); 1705 if (alen >= MAX_KTXT_LEN) 1706 fatal("%s: auth too large", __func__); 1707 memcpy(auth.dat, p, alen); 1708 auth.length = alen; 1709 memset(p, 0, alen); 1710 free(p); 1711 1712 success = options.kerberos_authentication && 1713 authctxt->valid && 1714 auth_krb4(authctxt, &auth, &client, &reply); 1715 1716 memset(auth.dat, 0, alen); 1717 buffer_clear(m); 1718 buffer_put_int(m, success); 1719 1720 if (success) { 1721 buffer_put_cstring(m, client); 1722 buffer_put_string(m, reply.dat, reply.length); 1723 if (client) 1724 free(client); 1725 if (reply.length) 1726 memset(reply.dat, 0, reply.length); 1727 } 1728 1729 debug3("%s: sending result %d", __func__, success); 1730 mm_request_send(socket, MONITOR_ANS_KRB4, m); 1731 1732 auth_method = "kerberos"; 1733 1734 /* Causes monitor loop to terminate if authenticated */ 1735 return (success); 1736 } 1737 #endif 1738 1739 #ifdef KRB5 1740 int 1741 mm_answer_krb5(int xsocket, Buffer *m) 1742 { 1743 krb5_data tkt, reply; 1744 char *client_user; 1745 u_int len; 1746 int success; 1747 1748 /* use temporary var to avoid size issues on 64bit arch */ 1749 tkt.data = buffer_get_string(m, &len); 1750 tkt.length = len; 1751 1752 success = options.kerberos_authentication && 1753 authctxt->valid && 1754 auth_krb5(authctxt, &tkt, &client_user, &reply); 1755 1756 if (tkt.length) 1757 free(tkt.data); 1758 1759 buffer_clear(m); 1760 buffer_put_int(m, success); 1761 1762 if (success) { 1763 buffer_put_cstring(m, client_user); 1764 buffer_put_string(m, reply.data, reply.length); 1765 if (client_user) 1766 free(client_user); 1767 if (reply.length) 1768 free(reply.data); 1769 } 1770 mm_request_send(xsocket, MONITOR_ANS_KRB5, m); 1771 1772 auth_method = "kerberos"; 1773 1774 return success; 1775 } 1776 #endif 1777 1778 int 1779 mm_answer_term(int sock, Buffer *req) 1780 { 1781 extern struct monitor *pmonitor; 1782 int res, status; 1783 1784 debug3("%s: tearing down sessions", __func__); 1785 1786 /* The child is terminating */ 1787 session_destroy_all(&mm_session_close); 1788 1789 while (waitpid(pmonitor->m_pid, &status, 0) == -1) 1790 if (errno != EINTR) 1791 exit(1); 1792 1793 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; 1794 1795 /* Terminate process */ 1796 exit(res); 1797 } 1798 1799 void 1800 monitor_apply_keystate(struct monitor *pmonitor) 1801 { 1802 if (compat20) { 1803 set_newkeys(MODE_IN); 1804 set_newkeys(MODE_OUT); 1805 } else { 1806 packet_set_protocol_flags(child_state.ssh1protoflags); 1807 packet_set_encryption_key(child_state.ssh1key, 1808 child_state.ssh1keylen, child_state.ssh1cipher); 1809 free(child_state.ssh1key); 1810 } 1811 1812 /* for rc4 and other stateful ciphers */ 1813 packet_set_keycontext(MODE_OUT, child_state.keyout); 1814 free(child_state.keyout); 1815 packet_set_keycontext(MODE_IN, child_state.keyin); 1816 free(child_state.keyin); 1817 1818 if (!compat20) { 1819 packet_set_iv(MODE_OUT, child_state.ivout); 1820 free(child_state.ivout); 1821 packet_set_iv(MODE_IN, child_state.ivin); 1822 free(child_state.ivin); 1823 } 1824 1825 memcpy(&incoming_stream, &child_state.incoming, 1826 sizeof(incoming_stream)); 1827 memcpy(&outgoing_stream, &child_state.outgoing, 1828 sizeof(outgoing_stream)); 1829 1830 /* Update with new address */ 1831 if (options.compression) 1832 mm_init_compression(pmonitor->m_zlib); 1833 1834 if (options.rekey_limit || options.rekey_interval) 1835 packet_set_rekey_limits((u_int32_t)options.rekey_limit, 1836 (time_t)options.rekey_interval); 1837 1838 /* Network I/O buffers */ 1839 /* XXX inefficient for large buffers, need: buffer_init_from_string */ 1840 buffer_clear(packet_get_input()); 1841 buffer_append(packet_get_input(), child_state.input, child_state.ilen); 1842 memset(child_state.input, 0, child_state.ilen); 1843 free(child_state.input); 1844 1845 buffer_clear(packet_get_output()); 1846 buffer_append(packet_get_output(), child_state.output, 1847 child_state.olen); 1848 memset(child_state.output, 0, child_state.olen); 1849 free(child_state.output); 1850 1851 /* Roaming */ 1852 if (compat20) 1853 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); 1854 } 1855 1856 static Kex * 1857 mm_get_kex(Buffer *m) 1858 { 1859 Kex *kex; 1860 void *blob; 1861 u_int bloblen; 1862 1863 kex = xcalloc(1, sizeof(*kex)); 1864 kex->session_id = buffer_get_string(m, &kex->session_id_len); 1865 if (session_id2 == NULL || 1866 kex->session_id_len != session_id2_len || 1867 timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) 1868 fatal("mm_get_get: internal error: bad session id"); 1869 kex->we_need = buffer_get_int(m); 1870 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; 1871 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; 1872 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; 1873 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; 1874 kex->kex[KEX_ECDH_SHA2] = kexecdh_server; 1875 kex->server = 1; 1876 kex->hostkey_type = buffer_get_int(m); 1877 kex->kex_type = buffer_get_int(m); 1878 blob = buffer_get_string(m, &bloblen); 1879 buffer_init(&kex->my); 1880 buffer_append(&kex->my, blob, bloblen); 1881 free(blob); 1882 blob = buffer_get_string(m, &bloblen); 1883 buffer_init(&kex->peer); 1884 buffer_append(&kex->peer, blob, bloblen); 1885 free(blob); 1886 kex->done = 1; 1887 kex->flags = buffer_get_int(m); 1888 kex->client_version_string = buffer_get_string(m, NULL); 1889 kex->server_version_string = buffer_get_string(m, NULL); 1890 kex->load_host_public_key=&get_hostkey_public_by_type; 1891 kex->load_host_private_key=&get_hostkey_private_by_type; 1892 kex->host_key_index=&get_hostkey_index; 1893 kex->sign = sshd_hostkey_sign; 1894 1895 return (kex); 1896 } 1897 1898 /* This function requries careful sanity checking */ 1899 1900 void 1901 mm_get_keystate(struct monitor *pmonitor) 1902 { 1903 Buffer m; 1904 u_char *blob, *p; 1905 u_int bloblen, plen; 1906 u_int32_t seqnr, packets; 1907 u_int64_t blocks, bytes; 1908 1909 debug3("%s: Waiting for new keys", __func__); 1910 1911 buffer_init(&m); 1912 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); 1913 if (!compat20) { 1914 child_state.ssh1protoflags = buffer_get_int(&m); 1915 child_state.ssh1cipher = buffer_get_int(&m); 1916 child_state.ssh1key = buffer_get_string(&m, 1917 &child_state.ssh1keylen); 1918 child_state.ivout = buffer_get_string(&m, 1919 &child_state.ivoutlen); 1920 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); 1921 goto skip; 1922 } else { 1923 /* Get the Kex for rekeying */ 1924 *pmonitor->m_pkex = mm_get_kex(&m); 1925 } 1926 1927 blob = buffer_get_string(&m, &bloblen); 1928 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); 1929 free(blob); 1930 1931 debug3("%s: Waiting for second key", __func__); 1932 blob = buffer_get_string(&m, &bloblen); 1933 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); 1934 free(blob); 1935 1936 /* Now get sequence numbers for the packets */ 1937 seqnr = buffer_get_int(&m); 1938 blocks = buffer_get_int64(&m); 1939 packets = buffer_get_int(&m); 1940 bytes = buffer_get_int64(&m); 1941 packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); 1942 seqnr = buffer_get_int(&m); 1943 blocks = buffer_get_int64(&m); 1944 packets = buffer_get_int(&m); 1945 bytes = buffer_get_int64(&m); 1946 packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); 1947 1948 skip: 1949 /* Get the key context */ 1950 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); 1951 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); 1952 1953 debug3("%s: Getting compression state", __func__); 1954 /* Get compression state */ 1955 p = buffer_get_string(&m, &plen); 1956 if (plen != sizeof(child_state.outgoing)) 1957 fatal("%s: bad request size", __func__); 1958 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); 1959 free(p); 1960 1961 p = buffer_get_string(&m, &plen); 1962 if (plen != sizeof(child_state.incoming)) 1963 fatal("%s: bad request size", __func__); 1964 memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); 1965 free(p); 1966 1967 /* Network I/O buffers */ 1968 debug3("%s: Getting Network I/O buffers", __func__); 1969 child_state.input = buffer_get_string(&m, &child_state.ilen); 1970 child_state.output = buffer_get_string(&m, &child_state.olen); 1971 1972 /* Roaming */ 1973 if (compat20) { 1974 child_state.sent_bytes = buffer_get_int64(&m); 1975 child_state.recv_bytes = buffer_get_int64(&m); 1976 } 1977 1978 buffer_free(&m); 1979 } 1980 1981 1982 /* Allocation functions for zlib */ 1983 void * 1984 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) 1985 { 1986 size_t len = (size_t) size * ncount; 1987 void *address; 1988 1989 if (len == 0 || ncount > SIZE_T_MAX / size) 1990 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); 1991 1992 address = mm_malloc(mm, len); 1993 1994 return (address); 1995 } 1996 1997 void 1998 mm_zfree(struct mm_master *mm, void *address) 1999 { 2000 mm_free(mm, address); 2001 } 2002 2003 void 2004 mm_init_compression(struct mm_master *mm) 2005 { 2006 outgoing_stream.zalloc = (alloc_func)mm_zalloc; 2007 outgoing_stream.zfree = (free_func)mm_zfree; 2008 outgoing_stream.opaque = mm; 2009 2010 incoming_stream.zalloc = (alloc_func)mm_zalloc; 2011 incoming_stream.zfree = (free_func)mm_zfree; 2012 incoming_stream.opaque = mm; 2013 } 2014 2015 /* XXX */ 2016 2017 #define FD_CLOSEONEXEC(x) do { \ 2018 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ 2019 fatal("fcntl(%d, F_SETFD)", x); \ 2020 } while (0) 2021 2022 static void 2023 monitor_openfds(struct monitor *mon, int do_logfds) 2024 { 2025 int pair[2]; 2026 2027 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) 2028 fatal("%s: socketpair: %s", __func__, strerror(errno)); 2029 FD_CLOSEONEXEC(pair[0]); 2030 FD_CLOSEONEXEC(pair[1]); 2031 mon->m_recvfd = pair[0]; 2032 mon->m_sendfd = pair[1]; 2033 2034 if (do_logfds) { 2035 if (pipe(pair) == -1) 2036 fatal("%s: pipe: %s", __func__, strerror(errno)); 2037 FD_CLOSEONEXEC(pair[0]); 2038 FD_CLOSEONEXEC(pair[1]); 2039 mon->m_log_recvfd = pair[0]; 2040 mon->m_log_sendfd = pair[1]; 2041 } else 2042 mon->m_log_recvfd = mon->m_log_sendfd = -1; 2043 } 2044 2045 #define MM_MEMSIZE 65536 2046 2047 struct monitor * 2048 monitor_init(void) 2049 { 2050 struct monitor *mon; 2051 2052 mon = xcalloc(1, sizeof(*mon)); 2053 2054 monitor_openfds(mon, 1); 2055 2056 /* Used to share zlib space across processes */ 2057 if (options.compression) { 2058 mon->m_zback = mm_create(NULL, MM_MEMSIZE); 2059 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); 2060 2061 /* Compression needs to share state across borders */ 2062 mm_init_compression(mon->m_zlib); 2063 } 2064 2065 return mon; 2066 } 2067 2068 void 2069 monitor_reinit(struct monitor *mon) 2070 { 2071 monitor_openfds(mon, 0); 2072 } 2073 2074 #ifdef GSSAPI 2075 int 2076 mm_answer_gss_setup_ctx(int sock, Buffer *m) 2077 { 2078 gss_OID_desc goid; 2079 OM_uint32 major; 2080 u_int len; 2081 2082 goid.elements = buffer_get_string(m, &len); 2083 goid.length = len; 2084 2085 major = ssh_gssapi_server_ctx(&gsscontext, &goid); 2086 2087 free(goid.elements); 2088 2089 buffer_clear(m); 2090 buffer_put_int(m, major); 2091 2092 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); 2093 2094 /* Now we have a context, enable the step */ 2095 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); 2096 2097 return (0); 2098 } 2099 2100 int 2101 mm_answer_gss_accept_ctx(int sock, Buffer *m) 2102 { 2103 gss_buffer_desc in; 2104 gss_buffer_desc out = GSS_C_EMPTY_BUFFER; 2105 OM_uint32 major, minor; 2106 OM_uint32 flags = 0; /* GSI needs this */ 2107 u_int len; 2108 2109 in.value = buffer_get_string(m, &len); 2110 in.length = len; 2111 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); 2112 free(in.value); 2113 2114 buffer_clear(m); 2115 buffer_put_int(m, major); 2116 buffer_put_string(m, out.value, out.length); 2117 buffer_put_int(m, flags); 2118 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); 2119 2120 gss_release_buffer(&minor, &out); 2121 2122 if (major == GSS_S_COMPLETE) { 2123 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); 2124 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2125 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); 2126 } 2127 return (0); 2128 } 2129 2130 int 2131 mm_answer_gss_checkmic(int sock, Buffer *m) 2132 { 2133 gss_buffer_desc gssbuf, mic; 2134 OM_uint32 ret; 2135 u_int len; 2136 2137 gssbuf.value = buffer_get_string(m, &len); 2138 gssbuf.length = len; 2139 mic.value = buffer_get_string(m, &len); 2140 mic.length = len; 2141 2142 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); 2143 2144 free(gssbuf.value); 2145 free(mic.value); 2146 2147 buffer_clear(m); 2148 buffer_put_int(m, ret); 2149 2150 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); 2151 2152 if (!GSS_ERROR(ret)) 2153 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); 2154 2155 return (0); 2156 } 2157 2158 int 2159 mm_answer_gss_userok(int sock, Buffer *m) 2160 { 2161 int authenticated; 2162 2163 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); 2164 2165 buffer_clear(m); 2166 buffer_put_int(m, authenticated); 2167 2168 debug3("%s: sending result %d", __func__, authenticated); 2169 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); 2170 2171 auth_method = "gssapi-with-mic"; 2172 2173 /* Monitor loop will terminate if authenticated */ 2174 return (authenticated); 2175 } 2176 #endif /* GSSAPI */ 2177 2178 #ifdef JPAKE 2179 int 2180 mm_answer_jpake_step1(int sock, Buffer *m) 2181 { 2182 struct jpake_ctx *pctx; 2183 u_char *x3_proof, *x4_proof; 2184 u_int x3_proof_len, x4_proof_len; 2185 2186 if (!options.zero_knowledge_password_authentication) 2187 fatal("zero_knowledge_password_authentication disabled"); 2188 2189 if (authctxt->jpake_ctx != NULL) 2190 fatal("%s: authctxt->jpake_ctx already set (%p)", 2191 __func__, authctxt->jpake_ctx); 2192 authctxt->jpake_ctx = pctx = jpake_new(); 2193 2194 jpake_step1(pctx->grp, 2195 &pctx->server_id, &pctx->server_id_len, 2196 &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, 2197 &x3_proof, &x3_proof_len, 2198 &x4_proof, &x4_proof_len); 2199 2200 JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__)); 2201 2202 buffer_clear(m); 2203 2204 buffer_put_string(m, pctx->server_id, pctx->server_id_len); 2205 buffer_put_bignum2(m, pctx->g_x3); 2206 buffer_put_bignum2(m, pctx->g_x4); 2207 buffer_put_string(m, x3_proof, x3_proof_len); 2208 buffer_put_string(m, x4_proof, x4_proof_len); 2209 2210 debug3("%s: sending step1", __func__); 2211 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m); 2212 2213 bzero(x3_proof, x3_proof_len); 2214 bzero(x4_proof, x4_proof_len); 2215 free(x3_proof); 2216 free(x4_proof); 2217 2218 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1); 2219 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0); 2220 2221 return 0; 2222 } 2223 2224 int 2225 mm_answer_jpake_get_pwdata(int sock, Buffer *m) 2226 { 2227 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2228 char *hash_scheme, *salt; 2229 2230 if (pctx == NULL) 2231 fatal("%s: pctx == NULL", __func__); 2232 2233 auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt); 2234 2235 buffer_clear(m); 2236 /* pctx->s is sensitive, not returned to slave */ 2237 buffer_put_cstring(m, hash_scheme); 2238 buffer_put_cstring(m, salt); 2239 2240 debug3("%s: sending pwdata", __func__); 2241 mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m); 2242 2243 bzero(hash_scheme, strlen(hash_scheme)); 2244 bzero(salt, strlen(salt)); 2245 free(hash_scheme); 2246 free(salt); 2247 2248 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1); 2249 2250 return 0; 2251 } 2252 2253 int 2254 mm_answer_jpake_step2(int sock, Buffer *m) 2255 { 2256 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2257 u_char *x1_proof, *x2_proof, *x4_s_proof; 2258 u_int x1_proof_len, x2_proof_len, x4_s_proof_len; 2259 2260 if (pctx == NULL) 2261 fatal("%s: pctx == NULL", __func__); 2262 2263 if ((pctx->g_x1 = BN_new()) == NULL || 2264 (pctx->g_x2 = BN_new()) == NULL) 2265 fatal("%s: BN_new", __func__); 2266 buffer_get_bignum2(m, pctx->g_x1); 2267 buffer_get_bignum2(m, pctx->g_x2); 2268 pctx->client_id = buffer_get_string(m, &pctx->client_id_len); 2269 x1_proof = buffer_get_string(m, &x1_proof_len); 2270 x2_proof = buffer_get_string(m, &x2_proof_len); 2271 2272 jpake_step2(pctx->grp, pctx->s, pctx->g_x3, 2273 pctx->g_x1, pctx->g_x2, pctx->x4, 2274 pctx->client_id, pctx->client_id_len, 2275 pctx->server_id, pctx->server_id_len, 2276 x1_proof, x1_proof_len, 2277 x2_proof, x2_proof_len, 2278 &pctx->b, 2279 &x4_s_proof, &x4_s_proof_len); 2280 2281 JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__)); 2282 2283 bzero(x1_proof, x1_proof_len); 2284 bzero(x2_proof, x2_proof_len); 2285 free(x1_proof); 2286 free(x2_proof); 2287 2288 buffer_clear(m); 2289 2290 buffer_put_bignum2(m, pctx->b); 2291 buffer_put_string(m, x4_s_proof, x4_s_proof_len); 2292 2293 debug3("%s: sending step2", __func__); 2294 mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m); 2295 2296 bzero(x4_s_proof, x4_s_proof_len); 2297 free(x4_s_proof); 2298 2299 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1); 2300 2301 return 0; 2302 } 2303 2304 int 2305 mm_answer_jpake_key_confirm(int sock, Buffer *m) 2306 { 2307 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2308 u_char *x2_s_proof; 2309 u_int x2_s_proof_len; 2310 2311 if (pctx == NULL) 2312 fatal("%s: pctx == NULL", __func__); 2313 2314 if ((pctx->a = BN_new()) == NULL) 2315 fatal("%s: BN_new", __func__); 2316 buffer_get_bignum2(m, pctx->a); 2317 x2_s_proof = buffer_get_string(m, &x2_s_proof_len); 2318 2319 jpake_key_confirm(pctx->grp, pctx->s, pctx->a, 2320 pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, 2321 pctx->server_id, pctx->server_id_len, 2322 pctx->client_id, pctx->client_id_len, 2323 session_id2, session_id2_len, 2324 x2_s_proof, x2_s_proof_len, 2325 &pctx->k, 2326 &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len); 2327 2328 JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__)); 2329 2330 bzero(x2_s_proof, x2_s_proof_len); 2331 buffer_clear(m); 2332 2333 /* pctx->k is sensitive, not sent */ 2334 buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); 2335 2336 debug3("%s: sending confirmation hash", __func__); 2337 mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m); 2338 2339 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1); 2340 2341 return 0; 2342 } 2343 2344 int 2345 mm_answer_jpake_check_confirm(int sock, Buffer *m) 2346 { 2347 int authenticated = 0; 2348 u_char *peer_confirm_hash; 2349 u_int peer_confirm_hash_len; 2350 struct jpake_ctx *pctx = authctxt->jpake_ctx; 2351 2352 if (pctx == NULL) 2353 fatal("%s: pctx == NULL", __func__); 2354 2355 peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len); 2356 2357 authenticated = jpake_check_confirm(pctx->k, 2358 pctx->client_id, pctx->client_id_len, 2359 session_id2, session_id2_len, 2360 peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid; 2361 2362 JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__)); 2363 2364 bzero(peer_confirm_hash, peer_confirm_hash_len); 2365 free(peer_confirm_hash); 2366 2367 buffer_clear(m); 2368 buffer_put_int(m, authenticated); 2369 2370 debug3("%s: sending result %d", __func__, authenticated); 2371 mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m); 2372 2373 monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1); 2374 2375 auth_method = "jpake-01@openssh.com"; 2376 return authenticated; 2377 } 2378 2379 #endif /* JPAKE */ 2380