1 /* $OpenBSD: readconf.c,v 1.176 2009/02/12 03:00:56 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Functions for reading the configuration files. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 */ 14 15 #include "includes.h" 16 17 #include <sys/types.h> 18 #include <sys/stat.h> 19 #include <sys/socket.h> 20 21 #include <netinet/in.h> 22 23 #include <ctype.h> 24 #include <errno.h> 25 #include <netdb.h> 26 #include <signal.h> 27 #include <stdarg.h> 28 #include <stdio.h> 29 #include <string.h> 30 #include <unistd.h> 31 32 #include "xmalloc.h" 33 #include "ssh.h" 34 #include "compat.h" 35 #include "cipher.h" 36 #include "pathnames.h" 37 #include "log.h" 38 #include "key.h" 39 #include "readconf.h" 40 #include "match.h" 41 #include "misc.h" 42 #include "buffer.h" 43 #include "kex.h" 44 #include "mac.h" 45 #include "uidswap.h" 46 47 /* Format of the configuration file: 48 49 # Configuration data is parsed as follows: 50 # 1. command line options 51 # 2. user-specific file 52 # 3. system-wide file 53 # Any configuration value is only changed the first time it is set. 54 # Thus, host-specific definitions should be at the beginning of the 55 # configuration file, and defaults at the end. 56 57 # Host-specific declarations. These may override anything above. A single 58 # host may match multiple declarations; these are processed in the order 59 # that they are given in. 60 61 Host *.ngs.fi ngs.fi 62 User foo 63 64 Host fake.com 65 HostName another.host.name.real.org 66 User blaah 67 Port 34289 68 ForwardX11 no 69 ForwardAgent no 70 71 Host books.com 72 RemoteForward 9999 shadows.cs.hut.fi:9999 73 Cipher 3des 74 75 Host fascist.blob.com 76 Port 23123 77 User tylonen 78 PasswordAuthentication no 79 80 Host puukko.hut.fi 81 User t35124p 82 ProxyCommand ssh-proxy %h %p 83 84 Host *.fr 85 PublicKeyAuthentication no 86 87 Host *.su 88 Cipher none 89 PasswordAuthentication no 90 91 Host vpn.fake.com 92 Tunnel yes 93 TunnelDevice 3 94 95 # Defaults for various options 96 Host * 97 ForwardAgent no 98 ForwardX11 no 99 PasswordAuthentication yes 100 RSAAuthentication yes 101 RhostsRSAAuthentication yes 102 StrictHostKeyChecking yes 103 TcpKeepAlive no 104 IdentityFile ~/.ssh/identity 105 Port 22 106 EscapeChar ~ 107 108 */ 109 110 /* Keyword tokens. */ 111 112 typedef enum { 113 oBadOption, 114 oForwardAgent, oForwardX11, oForwardX11Trusted, oGatewayPorts, 115 oExitOnForwardFailure, 116 oPasswordAuthentication, oRSAAuthentication, 117 oChallengeResponseAuthentication, oXAuthLocation, 118 oIdentityFile, oHostName, oPort, oCipher, oRemoteForward, oLocalForward, 119 oUser, oHost, oEscapeChar, oRhostsRSAAuthentication, oProxyCommand, 120 oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts, 121 oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression, 122 oCompressionLevel, oTCPKeepAlive, oNumberOfPasswordPrompts, 123 oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs, 124 oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication, 125 oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias, 126 oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication, 127 oHostKeyAlgorithms, oBindAddress, oSmartcardDevice, 128 oClearAllForwardings, oNoHostAuthenticationForLocalhost, 129 oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, 130 oAddressFamily, oGssAuthentication, oGssDelegateCreds, 131 oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, 132 oVersionAddendum, 133 oSendEnv, oControlPath, oControlMaster, oHashKnownHosts, 134 oTunnel, oTunnelDevice, oLocalCommand, oPermitLocalCommand, 135 oVisualHostKey, oZeroKnowledgePasswordAuthentication, 136 oDeprecated, oUnsupported 137 } OpCodes; 138 139 /* Textual representations of the tokens. */ 140 141 static struct { 142 const char *name; 143 OpCodes opcode; 144 } keywords[] = { 145 { "forwardagent", oForwardAgent }, 146 { "forwardx11", oForwardX11 }, 147 { "forwardx11trusted", oForwardX11Trusted }, 148 { "exitonforwardfailure", oExitOnForwardFailure }, 149 { "xauthlocation", oXAuthLocation }, 150 { "gatewayports", oGatewayPorts }, 151 { "useprivilegedport", oUsePrivilegedPort }, 152 { "rhostsauthentication", oDeprecated }, 153 { "passwordauthentication", oPasswordAuthentication }, 154 { "kbdinteractiveauthentication", oKbdInteractiveAuthentication }, 155 { "kbdinteractivedevices", oKbdInteractiveDevices }, 156 { "rsaauthentication", oRSAAuthentication }, 157 { "pubkeyauthentication", oPubkeyAuthentication }, 158 { "dsaauthentication", oPubkeyAuthentication }, /* alias */ 159 { "rhostsrsaauthentication", oRhostsRSAAuthentication }, 160 { "hostbasedauthentication", oHostbasedAuthentication }, 161 { "challengeresponseauthentication", oChallengeResponseAuthentication }, 162 { "skeyauthentication", oChallengeResponseAuthentication }, /* alias */ 163 { "tisauthentication", oChallengeResponseAuthentication }, /* alias */ 164 { "kerberosauthentication", oUnsupported }, 165 { "kerberostgtpassing", oUnsupported }, 166 { "afstokenpassing", oUnsupported }, 167 #if defined(GSSAPI) 168 { "gssapiauthentication", oGssAuthentication }, 169 { "gssapidelegatecredentials", oGssDelegateCreds }, 170 #else 171 { "gssapiauthentication", oUnsupported }, 172 { "gssapidelegatecredentials", oUnsupported }, 173 #endif 174 { "fallbacktorsh", oDeprecated }, 175 { "usersh", oDeprecated }, 176 { "identityfile", oIdentityFile }, 177 { "identityfile2", oIdentityFile }, /* obsolete */ 178 { "identitiesonly", oIdentitiesOnly }, 179 { "hostname", oHostName }, 180 { "hostkeyalias", oHostKeyAlias }, 181 { "proxycommand", oProxyCommand }, 182 { "port", oPort }, 183 { "cipher", oCipher }, 184 { "ciphers", oCiphers }, 185 { "macs", oMacs }, 186 { "protocol", oProtocol }, 187 { "remoteforward", oRemoteForward }, 188 { "localforward", oLocalForward }, 189 { "user", oUser }, 190 { "host", oHost }, 191 { "escapechar", oEscapeChar }, 192 { "globalknownhostsfile", oGlobalKnownHostsFile }, 193 { "globalknownhostsfile2", oGlobalKnownHostsFile2 }, /* obsolete */ 194 { "userknownhostsfile", oUserKnownHostsFile }, 195 { "userknownhostsfile2", oUserKnownHostsFile2 }, /* obsolete */ 196 { "connectionattempts", oConnectionAttempts }, 197 { "batchmode", oBatchMode }, 198 { "checkhostip", oCheckHostIP }, 199 { "stricthostkeychecking", oStrictHostKeyChecking }, 200 { "compression", oCompression }, 201 { "compressionlevel", oCompressionLevel }, 202 { "tcpkeepalive", oTCPKeepAlive }, 203 { "keepalive", oTCPKeepAlive }, /* obsolete */ 204 { "numberofpasswordprompts", oNumberOfPasswordPrompts }, 205 { "loglevel", oLogLevel }, 206 { "dynamicforward", oDynamicForward }, 207 { "preferredauthentications", oPreferredAuthentications }, 208 { "hostkeyalgorithms", oHostKeyAlgorithms }, 209 { "bindaddress", oBindAddress }, 210 #ifdef SMARTCARD 211 { "smartcarddevice", oSmartcardDevice }, 212 #else 213 { "smartcarddevice", oUnsupported }, 214 #endif 215 { "clearallforwardings", oClearAllForwardings }, 216 { "enablesshkeysign", oEnableSSHKeysign }, 217 { "verifyhostkeydns", oVerifyHostKeyDNS }, 218 { "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost }, 219 { "rekeylimit", oRekeyLimit }, 220 { "connecttimeout", oConnectTimeout }, 221 { "addressfamily", oAddressFamily }, 222 { "serveraliveinterval", oServerAliveInterval }, 223 { "serveralivecountmax", oServerAliveCountMax }, 224 { "versionaddendum", oVersionAddendum }, 225 { "sendenv", oSendEnv }, 226 { "controlpath", oControlPath }, 227 { "controlmaster", oControlMaster }, 228 { "hashknownhosts", oHashKnownHosts }, 229 { "tunnel", oTunnel }, 230 { "tunneldevice", oTunnelDevice }, 231 { "localcommand", oLocalCommand }, 232 { "permitlocalcommand", oPermitLocalCommand }, 233 { "visualhostkey", oVisualHostKey }, 234 #ifdef JPAKE 235 { "zeroknowledgepasswordauthentication", 236 oZeroKnowledgePasswordAuthentication }, 237 #else 238 { "zeroknowledgepasswordauthentication", oUnsupported }, 239 #endif 240 241 { NULL, oBadOption } 242 }; 243 244 /* 245 * Adds a local TCP/IP port forward to options. Never returns if there is an 246 * error. 247 */ 248 249 void 250 add_local_forward(Options *options, const Forward *newfwd) 251 { 252 Forward *fwd; 253 #ifndef NO_IPPORT_RESERVED_CONCEPT 254 extern uid_t original_real_uid; 255 if (newfwd->listen_port < IPPORT_RESERVED && original_real_uid != 0) 256 fatal("Privileged ports can only be forwarded by root."); 257 #endif 258 if (options->num_local_forwards >= SSH_MAX_FORWARDS_PER_DIRECTION) 259 fatal("Too many local forwards (max %d).", SSH_MAX_FORWARDS_PER_DIRECTION); 260 fwd = &options->local_forwards[options->num_local_forwards++]; 261 262 fwd->listen_host = newfwd->listen_host; 263 fwd->listen_port = newfwd->listen_port; 264 fwd->connect_host = newfwd->connect_host; 265 fwd->connect_port = newfwd->connect_port; 266 } 267 268 /* 269 * Adds a remote TCP/IP port forward to options. Never returns if there is 270 * an error. 271 */ 272 273 void 274 add_remote_forward(Options *options, const Forward *newfwd) 275 { 276 Forward *fwd; 277 if (options->num_remote_forwards >= SSH_MAX_FORWARDS_PER_DIRECTION) 278 fatal("Too many remote forwards (max %d).", 279 SSH_MAX_FORWARDS_PER_DIRECTION); 280 fwd = &options->remote_forwards[options->num_remote_forwards++]; 281 282 fwd->listen_host = newfwd->listen_host; 283 fwd->listen_port = newfwd->listen_port; 284 fwd->connect_host = newfwd->connect_host; 285 fwd->connect_port = newfwd->connect_port; 286 } 287 288 static void 289 clear_forwardings(Options *options) 290 { 291 int i; 292 293 for (i = 0; i < options->num_local_forwards; i++) { 294 if (options->local_forwards[i].listen_host != NULL) 295 xfree(options->local_forwards[i].listen_host); 296 xfree(options->local_forwards[i].connect_host); 297 } 298 options->num_local_forwards = 0; 299 for (i = 0; i < options->num_remote_forwards; i++) { 300 if (options->remote_forwards[i].listen_host != NULL) 301 xfree(options->remote_forwards[i].listen_host); 302 xfree(options->remote_forwards[i].connect_host); 303 } 304 options->num_remote_forwards = 0; 305 options->tun_open = SSH_TUNMODE_NO; 306 } 307 308 /* 309 * Returns the number of the token pointed to by cp or oBadOption. 310 */ 311 312 static OpCodes 313 parse_token(const char *cp, const char *filename, int linenum) 314 { 315 u_int i; 316 317 for (i = 0; keywords[i].name; i++) 318 if (strcasecmp(cp, keywords[i].name) == 0) 319 return keywords[i].opcode; 320 321 error("%s: line %d: Bad configuration option: %s", 322 filename, linenum, cp); 323 return oBadOption; 324 } 325 326 /* 327 * Processes a single option line as used in the configuration files. This 328 * only sets those values that have not already been set. 329 */ 330 #define WHITESPACE " \t\r\n" 331 332 int 333 process_config_line(Options *options, const char *host, 334 char *line, const char *filename, int linenum, 335 int *activep) 336 { 337 char *s, **charptr, *endofnumber, *keyword, *arg, *arg2, fwdarg[256]; 338 int opcode, *intptr, value, value2, scale; 339 LogLevel *log_level_ptr; 340 long long orig, val64; 341 size_t len; 342 Forward fwd; 343 344 /* Strip trailing whitespace */ 345 for (len = strlen(line) - 1; len > 0; len--) { 346 if (strchr(WHITESPACE, line[len]) == NULL) 347 break; 348 line[len] = '\0'; 349 } 350 351 s = line; 352 /* Get the keyword. (Each line is supposed to begin with a keyword). */ 353 if ((keyword = strdelim(&s)) == NULL) 354 return 0; 355 /* Ignore leading whitespace. */ 356 if (*keyword == '\0') 357 keyword = strdelim(&s); 358 if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#') 359 return 0; 360 361 opcode = parse_token(keyword, filename, linenum); 362 363 switch (opcode) { 364 case oBadOption: 365 /* don't panic, but count bad options */ 366 return -1; 367 /* NOTREACHED */ 368 case oConnectTimeout: 369 intptr = &options->connection_timeout; 370 parse_time: 371 arg = strdelim(&s); 372 if (!arg || *arg == '\0') 373 fatal("%s line %d: missing time value.", 374 filename, linenum); 375 if ((value = convtime(arg)) == -1) 376 fatal("%s line %d: invalid time value.", 377 filename, linenum); 378 if (*activep && *intptr == -1) 379 *intptr = value; 380 break; 381 382 case oForwardAgent: 383 intptr = &options->forward_agent; 384 parse_flag: 385 arg = strdelim(&s); 386 if (!arg || *arg == '\0') 387 fatal("%.200s line %d: Missing yes/no argument.", filename, linenum); 388 value = 0; /* To avoid compiler warning... */ 389 if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) 390 value = 1; 391 else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) 392 value = 0; 393 else 394 fatal("%.200s line %d: Bad yes/no argument.", filename, linenum); 395 if (*activep && *intptr == -1) 396 *intptr = value; 397 break; 398 399 case oForwardX11: 400 intptr = &options->forward_x11; 401 goto parse_flag; 402 403 case oForwardX11Trusted: 404 intptr = &options->forward_x11_trusted; 405 goto parse_flag; 406 407 case oGatewayPorts: 408 intptr = &options->gateway_ports; 409 goto parse_flag; 410 411 case oExitOnForwardFailure: 412 intptr = &options->exit_on_forward_failure; 413 goto parse_flag; 414 415 case oUsePrivilegedPort: 416 intptr = &options->use_privileged_port; 417 goto parse_flag; 418 419 case oPasswordAuthentication: 420 intptr = &options->password_authentication; 421 goto parse_flag; 422 423 case oZeroKnowledgePasswordAuthentication: 424 intptr = &options->zero_knowledge_password_authentication; 425 goto parse_flag; 426 427 case oKbdInteractiveAuthentication: 428 intptr = &options->kbd_interactive_authentication; 429 goto parse_flag; 430 431 case oKbdInteractiveDevices: 432 charptr = &options->kbd_interactive_devices; 433 goto parse_string; 434 435 case oPubkeyAuthentication: 436 intptr = &options->pubkey_authentication; 437 goto parse_flag; 438 439 case oRSAAuthentication: 440 intptr = &options->rsa_authentication; 441 goto parse_flag; 442 443 case oRhostsRSAAuthentication: 444 intptr = &options->rhosts_rsa_authentication; 445 goto parse_flag; 446 447 case oHostbasedAuthentication: 448 intptr = &options->hostbased_authentication; 449 goto parse_flag; 450 451 case oChallengeResponseAuthentication: 452 intptr = &options->challenge_response_authentication; 453 goto parse_flag; 454 455 case oGssAuthentication: 456 intptr = &options->gss_authentication; 457 goto parse_flag; 458 459 case oGssDelegateCreds: 460 intptr = &options->gss_deleg_creds; 461 goto parse_flag; 462 463 case oBatchMode: 464 intptr = &options->batch_mode; 465 goto parse_flag; 466 467 case oCheckHostIP: 468 intptr = &options->check_host_ip; 469 goto parse_flag; 470 471 case oVerifyHostKeyDNS: 472 intptr = &options->verify_host_key_dns; 473 goto parse_yesnoask; 474 475 case oStrictHostKeyChecking: 476 intptr = &options->strict_host_key_checking; 477 parse_yesnoask: 478 arg = strdelim(&s); 479 if (!arg || *arg == '\0') 480 fatal("%.200s line %d: Missing yes/no/ask argument.", 481 filename, linenum); 482 value = 0; /* To avoid compiler warning... */ 483 if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) 484 value = 1; 485 else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) 486 value = 0; 487 else if (strcmp(arg, "ask") == 0) 488 value = 2; 489 else 490 fatal("%.200s line %d: Bad yes/no/ask argument.", filename, linenum); 491 if (*activep && *intptr == -1) 492 *intptr = value; 493 break; 494 495 case oCompression: 496 intptr = &options->compression; 497 goto parse_flag; 498 499 case oTCPKeepAlive: 500 intptr = &options->tcp_keep_alive; 501 goto parse_flag; 502 503 case oNoHostAuthenticationForLocalhost: 504 intptr = &options->no_host_authentication_for_localhost; 505 goto parse_flag; 506 507 case oNumberOfPasswordPrompts: 508 intptr = &options->number_of_password_prompts; 509 goto parse_int; 510 511 case oCompressionLevel: 512 intptr = &options->compression_level; 513 goto parse_int; 514 515 case oRekeyLimit: 516 arg = strdelim(&s); 517 if (!arg || *arg == '\0') 518 fatal("%.200s line %d: Missing argument.", filename, linenum); 519 if (arg[0] < '0' || arg[0] > '9') 520 fatal("%.200s line %d: Bad number.", filename, linenum); 521 orig = val64 = strtoll(arg, &endofnumber, 10); 522 if (arg == endofnumber) 523 fatal("%.200s line %d: Bad number.", filename, linenum); 524 switch (toupper(*endofnumber)) { 525 case '\0': 526 scale = 1; 527 break; 528 case 'K': 529 scale = 1<<10; 530 break; 531 case 'M': 532 scale = 1<<20; 533 break; 534 case 'G': 535 scale = 1<<30; 536 break; 537 default: 538 fatal("%.200s line %d: Invalid RekeyLimit suffix", 539 filename, linenum); 540 } 541 val64 *= scale; 542 /* detect integer wrap and too-large limits */ 543 if ((val64 / scale) != orig || val64 > UINT_MAX) 544 fatal("%.200s line %d: RekeyLimit too large", 545 filename, linenum); 546 if (val64 < 16) 547 fatal("%.200s line %d: RekeyLimit too small", 548 filename, linenum); 549 if (*activep && options->rekey_limit == -1) 550 options->rekey_limit = (u_int32_t)val64; 551 break; 552 553 case oIdentityFile: 554 arg = strdelim(&s); 555 if (!arg || *arg == '\0') 556 fatal("%.200s line %d: Missing argument.", filename, linenum); 557 if (*activep) { 558 intptr = &options->num_identity_files; 559 if (*intptr >= SSH_MAX_IDENTITY_FILES) 560 fatal("%.200s line %d: Too many identity files specified (max %d).", 561 filename, linenum, SSH_MAX_IDENTITY_FILES); 562 charptr = &options->identity_files[*intptr]; 563 *charptr = xstrdup(arg); 564 *intptr = *intptr + 1; 565 } 566 break; 567 568 case oXAuthLocation: 569 charptr=&options->xauth_location; 570 goto parse_string; 571 572 case oUser: 573 charptr = &options->user; 574 parse_string: 575 arg = strdelim(&s); 576 if (!arg || *arg == '\0') 577 fatal("%.200s line %d: Missing argument.", filename, linenum); 578 if (*activep && *charptr == NULL) 579 *charptr = xstrdup(arg); 580 break; 581 582 case oGlobalKnownHostsFile: 583 charptr = &options->system_hostfile; 584 goto parse_string; 585 586 case oUserKnownHostsFile: 587 charptr = &options->user_hostfile; 588 goto parse_string; 589 590 case oGlobalKnownHostsFile2: 591 charptr = &options->system_hostfile2; 592 goto parse_string; 593 594 case oUserKnownHostsFile2: 595 charptr = &options->user_hostfile2; 596 goto parse_string; 597 598 case oHostName: 599 charptr = &options->hostname; 600 goto parse_string; 601 602 case oHostKeyAlias: 603 charptr = &options->host_key_alias; 604 goto parse_string; 605 606 case oPreferredAuthentications: 607 charptr = &options->preferred_authentications; 608 goto parse_string; 609 610 case oBindAddress: 611 charptr = &options->bind_address; 612 goto parse_string; 613 614 case oSmartcardDevice: 615 charptr = &options->smartcard_device; 616 goto parse_string; 617 618 case oProxyCommand: 619 charptr = &options->proxy_command; 620 parse_command: 621 if (s == NULL) 622 fatal("%.200s line %d: Missing argument.", filename, linenum); 623 len = strspn(s, WHITESPACE "="); 624 if (*activep && *charptr == NULL) 625 *charptr = xstrdup(s + len); 626 return 0; 627 628 case oPort: 629 intptr = &options->port; 630 parse_int: 631 arg = strdelim(&s); 632 if (!arg || *arg == '\0') 633 fatal("%.200s line %d: Missing argument.", filename, linenum); 634 if (arg[0] < '0' || arg[0] > '9') 635 fatal("%.200s line %d: Bad number.", filename, linenum); 636 637 /* Octal, decimal, or hex format? */ 638 value = strtol(arg, &endofnumber, 0); 639 if (arg == endofnumber) 640 fatal("%.200s line %d: Bad number.", filename, linenum); 641 if (*activep && *intptr == -1) 642 *intptr = value; 643 break; 644 645 case oConnectionAttempts: 646 intptr = &options->connection_attempts; 647 goto parse_int; 648 649 case oCipher: 650 intptr = &options->cipher; 651 arg = strdelim(&s); 652 if (!arg || *arg == '\0') 653 fatal("%.200s line %d: Missing argument.", filename, linenum); 654 value = cipher_number(arg); 655 if (value == -1) 656 fatal("%.200s line %d: Bad cipher '%s'.", 657 filename, linenum, arg ? arg : "<NONE>"); 658 if (*activep && *intptr == -1) 659 *intptr = value; 660 break; 661 662 case oCiphers: 663 arg = strdelim(&s); 664 if (!arg || *arg == '\0') 665 fatal("%.200s line %d: Missing argument.", filename, linenum); 666 if (!ciphers_valid(arg)) 667 fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.", 668 filename, linenum, arg ? arg : "<NONE>"); 669 if (*activep && options->ciphers == NULL) 670 options->ciphers = xstrdup(arg); 671 break; 672 673 case oMacs: 674 arg = strdelim(&s); 675 if (!arg || *arg == '\0') 676 fatal("%.200s line %d: Missing argument.", filename, linenum); 677 if (!mac_valid(arg)) 678 fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.", 679 filename, linenum, arg ? arg : "<NONE>"); 680 if (*activep && options->macs == NULL) 681 options->macs = xstrdup(arg); 682 break; 683 684 case oHostKeyAlgorithms: 685 arg = strdelim(&s); 686 if (!arg || *arg == '\0') 687 fatal("%.200s line %d: Missing argument.", filename, linenum); 688 if (!key_names_valid2(arg)) 689 fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.", 690 filename, linenum, arg ? arg : "<NONE>"); 691 if (*activep && options->hostkeyalgorithms == NULL) 692 options->hostkeyalgorithms = xstrdup(arg); 693 break; 694 695 case oProtocol: 696 intptr = &options->protocol; 697 arg = strdelim(&s); 698 if (!arg || *arg == '\0') 699 fatal("%.200s line %d: Missing argument.", filename, linenum); 700 value = proto_spec(arg); 701 if (value == SSH_PROTO_UNKNOWN) 702 fatal("%.200s line %d: Bad protocol spec '%s'.", 703 filename, linenum, arg ? arg : "<NONE>"); 704 if (*activep && *intptr == SSH_PROTO_UNKNOWN) 705 *intptr = value; 706 break; 707 708 case oLogLevel: 709 log_level_ptr = &options->log_level; 710 arg = strdelim(&s); 711 value = log_level_number(arg); 712 if (value == SYSLOG_LEVEL_NOT_SET) 713 fatal("%.200s line %d: unsupported log level '%s'", 714 filename, linenum, arg ? arg : "<NONE>"); 715 if (*activep && *log_level_ptr == SYSLOG_LEVEL_NOT_SET) 716 *log_level_ptr = (LogLevel) value; 717 break; 718 719 case oLocalForward: 720 case oRemoteForward: 721 case oDynamicForward: 722 arg = strdelim(&s); 723 if (arg == NULL || *arg == '\0') 724 fatal("%.200s line %d: Missing port argument.", 725 filename, linenum); 726 727 if (opcode == oLocalForward || 728 opcode == oRemoteForward) { 729 arg2 = strdelim(&s); 730 if (arg2 == NULL || *arg2 == '\0') 731 fatal("%.200s line %d: Missing target argument.", 732 filename, linenum); 733 734 /* construct a string for parse_forward */ 735 snprintf(fwdarg, sizeof(fwdarg), "%s:%s", arg, arg2); 736 } else if (opcode == oDynamicForward) { 737 strlcpy(fwdarg, arg, sizeof(fwdarg)); 738 } 739 740 if (parse_forward(&fwd, fwdarg, 741 opcode == oDynamicForward ? 1 : 0, 742 opcode == oRemoteForward ? 1 : 0) == 0) 743 fatal("%.200s line %d: Bad forwarding specification.", 744 filename, linenum); 745 746 if (*activep) { 747 if (opcode == oLocalForward || 748 opcode == oDynamicForward) 749 add_local_forward(options, &fwd); 750 else if (opcode == oRemoteForward) 751 add_remote_forward(options, &fwd); 752 } 753 break; 754 755 case oClearAllForwardings: 756 intptr = &options->clear_forwardings; 757 goto parse_flag; 758 759 case oHost: 760 *activep = 0; 761 while ((arg = strdelim(&s)) != NULL && *arg != '\0') 762 if (match_pattern(host, arg)) { 763 debug("Applying options for %.100s", arg); 764 *activep = 1; 765 break; 766 } 767 /* Avoid garbage check below, as strdelim is done. */ 768 return 0; 769 770 case oEscapeChar: 771 intptr = &options->escape_char; 772 arg = strdelim(&s); 773 if (!arg || *arg == '\0') 774 fatal("%.200s line %d: Missing argument.", filename, linenum); 775 if (arg[0] == '^' && arg[2] == 0 && 776 (u_char) arg[1] >= 64 && (u_char) arg[1] < 128) 777 value = (u_char) arg[1] & 31; 778 else if (strlen(arg) == 1) 779 value = (u_char) arg[0]; 780 else if (strcmp(arg, "none") == 0) 781 value = SSH_ESCAPECHAR_NONE; 782 else { 783 fatal("%.200s line %d: Bad escape character.", 784 filename, linenum); 785 /* NOTREACHED */ 786 value = 0; /* Avoid compiler warning. */ 787 } 788 if (*activep && *intptr == -1) 789 *intptr = value; 790 break; 791 792 case oAddressFamily: 793 arg = strdelim(&s); 794 if (!arg || *arg == '\0') 795 fatal("%s line %d: missing address family.", 796 filename, linenum); 797 intptr = &options->address_family; 798 if (strcasecmp(arg, "inet") == 0) 799 value = AF_INET; 800 else if (strcasecmp(arg, "inet6") == 0) 801 value = AF_INET6; 802 else if (strcasecmp(arg, "any") == 0) 803 value = AF_UNSPEC; 804 else 805 fatal("Unsupported AddressFamily \"%s\"", arg); 806 if (*activep && *intptr == -1) 807 *intptr = value; 808 break; 809 810 case oEnableSSHKeysign: 811 intptr = &options->enable_ssh_keysign; 812 goto parse_flag; 813 814 case oIdentitiesOnly: 815 intptr = &options->identities_only; 816 goto parse_flag; 817 818 case oServerAliveInterval: 819 intptr = &options->server_alive_interval; 820 goto parse_time; 821 822 case oServerAliveCountMax: 823 intptr = &options->server_alive_count_max; 824 goto parse_int; 825 826 case oVersionAddendum: 827 ssh_version_set_addendum(strtok(s, "\n")); 828 do { 829 arg = strdelim(&s); 830 } while (arg != NULL && *arg != '\0'); 831 break; 832 833 case oSendEnv: 834 while ((arg = strdelim(&s)) != NULL && *arg != '\0') { 835 if (strchr(arg, '=') != NULL) 836 fatal("%s line %d: Invalid environment name.", 837 filename, linenum); 838 if (!*activep) 839 continue; 840 if (options->num_send_env >= MAX_SEND_ENV) 841 fatal("%s line %d: too many send env.", 842 filename, linenum); 843 options->send_env[options->num_send_env++] = 844 xstrdup(arg); 845 } 846 break; 847 848 case oControlPath: 849 charptr = &options->control_path; 850 goto parse_string; 851 852 case oControlMaster: 853 intptr = &options->control_master; 854 arg = strdelim(&s); 855 if (!arg || *arg == '\0') 856 fatal("%.200s line %d: Missing ControlMaster argument.", 857 filename, linenum); 858 value = 0; /* To avoid compiler warning... */ 859 if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) 860 value = SSHCTL_MASTER_YES; 861 else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) 862 value = SSHCTL_MASTER_NO; 863 else if (strcmp(arg, "auto") == 0) 864 value = SSHCTL_MASTER_AUTO; 865 else if (strcmp(arg, "ask") == 0) 866 value = SSHCTL_MASTER_ASK; 867 else if (strcmp(arg, "autoask") == 0) 868 value = SSHCTL_MASTER_AUTO_ASK; 869 else 870 fatal("%.200s line %d: Bad ControlMaster argument.", 871 filename, linenum); 872 if (*activep && *intptr == -1) 873 *intptr = value; 874 break; 875 876 case oHashKnownHosts: 877 intptr = &options->hash_known_hosts; 878 goto parse_flag; 879 880 case oTunnel: 881 intptr = &options->tun_open; 882 arg = strdelim(&s); 883 if (!arg || *arg == '\0') 884 fatal("%s line %d: Missing yes/point-to-point/" 885 "ethernet/no argument.", filename, linenum); 886 value = 0; /* silence compiler */ 887 if (strcasecmp(arg, "ethernet") == 0) 888 value = SSH_TUNMODE_ETHERNET; 889 else if (strcasecmp(arg, "point-to-point") == 0) 890 value = SSH_TUNMODE_POINTOPOINT; 891 else if (strcasecmp(arg, "yes") == 0) 892 value = SSH_TUNMODE_DEFAULT; 893 else if (strcasecmp(arg, "no") == 0) 894 value = SSH_TUNMODE_NO; 895 else 896 fatal("%s line %d: Bad yes/point-to-point/ethernet/" 897 "no argument: %s", filename, linenum, arg); 898 if (*activep) 899 *intptr = value; 900 break; 901 902 case oTunnelDevice: 903 arg = strdelim(&s); 904 if (!arg || *arg == '\0') 905 fatal("%.200s line %d: Missing argument.", filename, linenum); 906 value = a2tun(arg, &value2); 907 if (value == SSH_TUNID_ERR) 908 fatal("%.200s line %d: Bad tun device.", filename, linenum); 909 if (*activep) { 910 options->tun_local = value; 911 options->tun_remote = value2; 912 } 913 break; 914 915 case oLocalCommand: 916 charptr = &options->local_command; 917 goto parse_command; 918 919 case oPermitLocalCommand: 920 intptr = &options->permit_local_command; 921 goto parse_flag; 922 923 case oVisualHostKey: 924 intptr = &options->visual_host_key; 925 goto parse_flag; 926 927 case oDeprecated: 928 debug("%s line %d: Deprecated option \"%s\"", 929 filename, linenum, keyword); 930 return 0; 931 932 case oUnsupported: 933 error("%s line %d: Unsupported option \"%s\"", 934 filename, linenum, keyword); 935 return 0; 936 937 default: 938 fatal("process_config_line: Unimplemented opcode %d", opcode); 939 } 940 941 /* Check that there is no garbage at end of line. */ 942 if ((arg = strdelim(&s)) != NULL && *arg != '\0') { 943 fatal("%.200s line %d: garbage at end of line; \"%.200s\".", 944 filename, linenum, arg); 945 } 946 return 0; 947 } 948 949 950 /* 951 * Reads the config file and modifies the options accordingly. Options 952 * should already be initialized before this call. This never returns if 953 * there is an error. If the file does not exist, this returns 0. 954 */ 955 956 int 957 read_config_file(const char *filename, const char *host, Options *options, 958 int checkperm) 959 { 960 FILE *f; 961 char line[1024]; 962 int active, linenum; 963 int bad_options = 0; 964 965 if ((f = fopen(filename, "r")) == NULL) 966 return 0; 967 968 if (checkperm) { 969 struct stat sb; 970 971 if (fstat(fileno(f), &sb) == -1) 972 fatal("fstat %s: %s", filename, strerror(errno)); 973 if (((sb.st_uid != 0 && sb.st_uid != getuid()) || 974 (sb.st_mode & 022) != 0)) 975 fatal("Bad owner or permissions on %s", filename); 976 } 977 978 debug("Reading configuration data %.200s", filename); 979 980 /* 981 * Mark that we are now processing the options. This flag is turned 982 * on/off by Host specifications. 983 */ 984 active = 1; 985 linenum = 0; 986 while (fgets(line, sizeof(line), f)) { 987 /* Update line number counter. */ 988 linenum++; 989 if (process_config_line(options, host, line, filename, linenum, &active) != 0) 990 bad_options++; 991 } 992 fclose(f); 993 if (bad_options > 0) 994 fatal("%s: terminating, %d bad configuration options", 995 filename, bad_options); 996 return 1; 997 } 998 999 /* 1000 * Initializes options to special values that indicate that they have not yet 1001 * been set. Read_config_file will only set options with this value. Options 1002 * are processed in the following order: command line, user config file, 1003 * system config file. Last, fill_default_options is called. 1004 */ 1005 1006 void 1007 initialize_options(Options * options) 1008 { 1009 memset(options, 'X', sizeof(*options)); 1010 options->forward_agent = -1; 1011 options->forward_x11 = -1; 1012 options->forward_x11_trusted = -1; 1013 options->exit_on_forward_failure = -1; 1014 options->xauth_location = NULL; 1015 options->gateway_ports = -1; 1016 options->use_privileged_port = -1; 1017 options->rsa_authentication = -1; 1018 options->pubkey_authentication = -1; 1019 options->challenge_response_authentication = -1; 1020 options->gss_authentication = -1; 1021 options->gss_deleg_creds = -1; 1022 options->password_authentication = -1; 1023 options->kbd_interactive_authentication = -1; 1024 options->kbd_interactive_devices = NULL; 1025 options->rhosts_rsa_authentication = -1; 1026 options->hostbased_authentication = -1; 1027 options->batch_mode = -1; 1028 options->check_host_ip = -1; 1029 options->strict_host_key_checking = -1; 1030 options->compression = -1; 1031 options->tcp_keep_alive = -1; 1032 options->compression_level = -1; 1033 options->port = -1; 1034 options->address_family = -1; 1035 options->connection_attempts = -1; 1036 options->connection_timeout = -1; 1037 options->number_of_password_prompts = -1; 1038 options->cipher = -1; 1039 options->ciphers = NULL; 1040 options->macs = NULL; 1041 options->hostkeyalgorithms = NULL; 1042 options->protocol = SSH_PROTO_UNKNOWN; 1043 options->num_identity_files = 0; 1044 options->hostname = NULL; 1045 options->host_key_alias = NULL; 1046 options->proxy_command = NULL; 1047 options->user = NULL; 1048 options->escape_char = -1; 1049 options->system_hostfile = NULL; 1050 options->user_hostfile = NULL; 1051 options->system_hostfile2 = NULL; 1052 options->user_hostfile2 = NULL; 1053 options->num_local_forwards = 0; 1054 options->num_remote_forwards = 0; 1055 options->clear_forwardings = -1; 1056 options->log_level = SYSLOG_LEVEL_NOT_SET; 1057 options->preferred_authentications = NULL; 1058 options->bind_address = NULL; 1059 options->smartcard_device = NULL; 1060 options->enable_ssh_keysign = - 1; 1061 options->no_host_authentication_for_localhost = - 1; 1062 options->identities_only = - 1; 1063 options->rekey_limit = - 1; 1064 options->verify_host_key_dns = -1; 1065 options->server_alive_interval = -1; 1066 options->server_alive_count_max = -1; 1067 options->num_send_env = 0; 1068 options->control_path = NULL; 1069 options->control_master = -1; 1070 options->hash_known_hosts = -1; 1071 options->tun_open = -1; 1072 options->tun_local = -1; 1073 options->tun_remote = -1; 1074 options->local_command = NULL; 1075 options->permit_local_command = -1; 1076 options->visual_host_key = -1; 1077 options->zero_knowledge_password_authentication = -1; 1078 } 1079 1080 /* 1081 * Called after processing other sources of option data, this fills those 1082 * options for which no value has been specified with their default values. 1083 */ 1084 1085 void 1086 fill_default_options(Options * options) 1087 { 1088 int len; 1089 1090 if (options->forward_agent == -1) 1091 options->forward_agent = 0; 1092 if (options->forward_x11 == -1) 1093 options->forward_x11 = 0; 1094 if (options->forward_x11_trusted == -1) 1095 options->forward_x11_trusted = 0; 1096 if (options->exit_on_forward_failure == -1) 1097 options->exit_on_forward_failure = 0; 1098 if (options->xauth_location == NULL) 1099 options->xauth_location = _PATH_XAUTH; 1100 if (options->gateway_ports == -1) 1101 options->gateway_ports = 0; 1102 if (options->use_privileged_port == -1) 1103 options->use_privileged_port = 0; 1104 if (options->rsa_authentication == -1) 1105 options->rsa_authentication = 1; 1106 if (options->pubkey_authentication == -1) 1107 options->pubkey_authentication = 1; 1108 if (options->challenge_response_authentication == -1) 1109 options->challenge_response_authentication = 1; 1110 if (options->gss_authentication == -1) 1111 options->gss_authentication = 0; 1112 if (options->gss_deleg_creds == -1) 1113 options->gss_deleg_creds = 0; 1114 if (options->password_authentication == -1) 1115 options->password_authentication = 1; 1116 if (options->kbd_interactive_authentication == -1) 1117 options->kbd_interactive_authentication = 1; 1118 if (options->rhosts_rsa_authentication == -1) 1119 options->rhosts_rsa_authentication = 0; 1120 if (options->hostbased_authentication == -1) 1121 options->hostbased_authentication = 0; 1122 if (options->batch_mode == -1) 1123 options->batch_mode = 0; 1124 if (options->check_host_ip == -1) 1125 options->check_host_ip = 0; 1126 if (options->strict_host_key_checking == -1) 1127 options->strict_host_key_checking = 2; /* 2 is default */ 1128 if (options->compression == -1) 1129 options->compression = 0; 1130 if (options->tcp_keep_alive == -1) 1131 options->tcp_keep_alive = 1; 1132 if (options->compression_level == -1) 1133 options->compression_level = 6; 1134 if (options->port == -1) 1135 options->port = 0; /* Filled in ssh_connect. */ 1136 if (options->address_family == -1) 1137 options->address_family = AF_UNSPEC; 1138 if (options->connection_attempts == -1) 1139 options->connection_attempts = 1; 1140 if (options->number_of_password_prompts == -1) 1141 options->number_of_password_prompts = 3; 1142 /* Selected in ssh_login(). */ 1143 if (options->cipher == -1) 1144 options->cipher = SSH_CIPHER_NOT_SET; 1145 /* options->ciphers, default set in myproposals.h */ 1146 /* options->macs, default set in myproposals.h */ 1147 /* options->hostkeyalgorithms, default set in myproposals.h */ 1148 if (options->protocol == SSH_PROTO_UNKNOWN) 1149 options->protocol = SSH_PROTO_1|SSH_PROTO_2; 1150 if (options->num_identity_files == 0) { 1151 if (options->protocol & SSH_PROTO_1) { 1152 len = 2 + strlen(_PATH_SSH_CLIENT_IDENTITY) + 1; 1153 options->identity_files[options->num_identity_files] = 1154 xmalloc(len); 1155 snprintf(options->identity_files[options->num_identity_files++], 1156 len, "~/%.100s", _PATH_SSH_CLIENT_IDENTITY); 1157 } 1158 if (options->protocol & SSH_PROTO_2) { 1159 len = 2 + strlen(_PATH_SSH_CLIENT_ID_RSA) + 1; 1160 options->identity_files[options->num_identity_files] = 1161 xmalloc(len); 1162 snprintf(options->identity_files[options->num_identity_files++], 1163 len, "~/%.100s", _PATH_SSH_CLIENT_ID_RSA); 1164 1165 len = 2 + strlen(_PATH_SSH_CLIENT_ID_DSA) + 1; 1166 options->identity_files[options->num_identity_files] = 1167 xmalloc(len); 1168 snprintf(options->identity_files[options->num_identity_files++], 1169 len, "~/%.100s", _PATH_SSH_CLIENT_ID_DSA); 1170 } 1171 } 1172 if (options->escape_char == -1) 1173 options->escape_char = '~'; 1174 if (options->system_hostfile == NULL) 1175 options->system_hostfile = _PATH_SSH_SYSTEM_HOSTFILE; 1176 if (options->user_hostfile == NULL) 1177 options->user_hostfile = _PATH_SSH_USER_HOSTFILE; 1178 if (options->system_hostfile2 == NULL) 1179 options->system_hostfile2 = _PATH_SSH_SYSTEM_HOSTFILE2; 1180 if (options->user_hostfile2 == NULL) 1181 options->user_hostfile2 = _PATH_SSH_USER_HOSTFILE2; 1182 if (options->log_level == SYSLOG_LEVEL_NOT_SET) 1183 options->log_level = SYSLOG_LEVEL_INFO; 1184 if (options->clear_forwardings == 1) 1185 clear_forwardings(options); 1186 if (options->no_host_authentication_for_localhost == - 1) 1187 options->no_host_authentication_for_localhost = 0; 1188 if (options->identities_only == -1) 1189 options->identities_only = 0; 1190 if (options->enable_ssh_keysign == -1) 1191 options->enable_ssh_keysign = 0; 1192 if (options->rekey_limit == -1) 1193 options->rekey_limit = 0; 1194 if (options->verify_host_key_dns == -1) 1195 options->verify_host_key_dns = 0; 1196 if (options->server_alive_interval == -1) 1197 options->server_alive_interval = 0; 1198 if (options->server_alive_count_max == -1) 1199 options->server_alive_count_max = 3; 1200 if (options->control_master == -1) 1201 options->control_master = 0; 1202 if (options->hash_known_hosts == -1) 1203 options->hash_known_hosts = 0; 1204 if (options->tun_open == -1) 1205 options->tun_open = SSH_TUNMODE_NO; 1206 if (options->tun_local == -1) 1207 options->tun_local = SSH_TUNID_ANY; 1208 if (options->tun_remote == -1) 1209 options->tun_remote = SSH_TUNID_ANY; 1210 if (options->permit_local_command == -1) 1211 options->permit_local_command = 0; 1212 if (options->visual_host_key == -1) 1213 options->visual_host_key = 0; 1214 if (options->zero_knowledge_password_authentication == -1) 1215 options->zero_knowledge_password_authentication = 0; 1216 /* options->local_command should not be set by default */ 1217 /* options->proxy_command should not be set by default */ 1218 /* options->user will be set in the main program if appropriate */ 1219 /* options->hostname will be set in the main program if appropriate */ 1220 /* options->host_key_alias should not be set by default */ 1221 /* options->preferred_authentications will be set in ssh */ 1222 } 1223 1224 /* 1225 * parse_forward 1226 * parses a string containing a port forwarding specification of the form: 1227 * dynamicfwd == 0 1228 * [listenhost:]listenport:connecthost:connectport 1229 * dynamicfwd == 1 1230 * [listenhost:]listenport 1231 * returns number of arguments parsed or zero on error 1232 */ 1233 int 1234 parse_forward(Forward *fwd, const char *fwdspec, int dynamicfwd, int remotefwd) 1235 { 1236 int i; 1237 char *p, *cp, *fwdarg[4]; 1238 1239 memset(fwd, '\0', sizeof(*fwd)); 1240 1241 cp = p = xstrdup(fwdspec); 1242 1243 /* skip leading spaces */ 1244 while (isspace(*cp)) 1245 cp++; 1246 1247 for (i = 0; i < 4; ++i) 1248 if ((fwdarg[i] = hpdelim(&cp)) == NULL) 1249 break; 1250 1251 /* Check for trailing garbage */ 1252 if (cp != NULL) 1253 i = 0; /* failure */ 1254 1255 switch (i) { 1256 case 1: 1257 fwd->listen_host = NULL; 1258 fwd->listen_port = a2port(fwdarg[0]); 1259 fwd->connect_host = xstrdup("socks"); 1260 break; 1261 1262 case 2: 1263 fwd->listen_host = xstrdup(cleanhostname(fwdarg[0])); 1264 fwd->listen_port = a2port(fwdarg[1]); 1265 fwd->connect_host = xstrdup("socks"); 1266 break; 1267 1268 case 3: 1269 fwd->listen_host = NULL; 1270 fwd->listen_port = a2port(fwdarg[0]); 1271 fwd->connect_host = xstrdup(cleanhostname(fwdarg[1])); 1272 fwd->connect_port = a2port(fwdarg[2]); 1273 break; 1274 1275 case 4: 1276 fwd->listen_host = xstrdup(cleanhostname(fwdarg[0])); 1277 fwd->listen_port = a2port(fwdarg[1]); 1278 fwd->connect_host = xstrdup(cleanhostname(fwdarg[2])); 1279 fwd->connect_port = a2port(fwdarg[3]); 1280 break; 1281 default: 1282 i = 0; /* failure */ 1283 } 1284 1285 xfree(p); 1286 1287 if (dynamicfwd) { 1288 if (!(i == 1 || i == 2)) 1289 goto fail_free; 1290 } else { 1291 if (!(i == 3 || i == 4)) 1292 goto fail_free; 1293 if (fwd->connect_port <= 0) 1294 goto fail_free; 1295 } 1296 1297 if (fwd->listen_port < 0 || (!remotefwd && fwd->listen_port == 0)) 1298 goto fail_free; 1299 1300 if (fwd->connect_host != NULL && 1301 strlen(fwd->connect_host) >= NI_MAXHOST) 1302 goto fail_free; 1303 if (fwd->listen_host != NULL && 1304 strlen(fwd->listen_host) >= NI_MAXHOST) 1305 goto fail_free; 1306 1307 1308 return (i); 1309 1310 fail_free: 1311 if (fwd->connect_host != NULL) { 1312 xfree(fwd->connect_host); 1313 fwd->connect_host = NULL; 1314 } 1315 if (fwd->listen_host != NULL) { 1316 xfree(fwd->listen_host); 1317 fwd->listen_host = NULL; 1318 } 1319 return (0); 1320 } 1321