1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * Functions for reading the configuration files. 6 * 7 * As far as I am concerned, the code I have written for this software 8 * can be used freely for any purpose. Any derived versions of this 9 * software must be clearly marked as such, and if the derived work is 10 * incompatible with the protocol description in the RFC file, it must be 11 * called by a name other than "ssh" or "Secure Shell". 12 */ 13 14 #include "includes.h" 15 RCSID("$FreeBSD$"); 16 RCSID("$OpenBSD: readconf.c,v 1.127 2003/12/16 15:49:51 markus Exp $"); 17 18 #include "ssh.h" 19 #include "xmalloc.h" 20 #include "compat.h" 21 #include "cipher.h" 22 #include "pathnames.h" 23 #include "log.h" 24 #include "readconf.h" 25 #include "match.h" 26 #include "misc.h" 27 #include "kex.h" 28 #include "mac.h" 29 30 /* Format of the configuration file: 31 32 # Configuration data is parsed as follows: 33 # 1. command line options 34 # 2. user-specific file 35 # 3. system-wide file 36 # Any configuration value is only changed the first time it is set. 37 # Thus, host-specific definitions should be at the beginning of the 38 # configuration file, and defaults at the end. 39 40 # Host-specific declarations. These may override anything above. A single 41 # host may match multiple declarations; these are processed in the order 42 # that they are given in. 43 44 Host *.ngs.fi ngs.fi 45 User foo 46 47 Host fake.com 48 HostName another.host.name.real.org 49 User blaah 50 Port 34289 51 ForwardX11 no 52 ForwardAgent no 53 54 Host books.com 55 RemoteForward 9999 shadows.cs.hut.fi:9999 56 Cipher 3des 57 58 Host fascist.blob.com 59 Port 23123 60 User tylonen 61 PasswordAuthentication no 62 63 Host puukko.hut.fi 64 User t35124p 65 ProxyCommand ssh-proxy %h %p 66 67 Host *.fr 68 PublicKeyAuthentication no 69 70 Host *.su 71 Cipher none 72 PasswordAuthentication no 73 74 # Defaults for various options 75 Host * 76 ForwardAgent no 77 ForwardX11 no 78 PasswordAuthentication yes 79 RSAAuthentication yes 80 RhostsRSAAuthentication yes 81 StrictHostKeyChecking yes 82 TcpKeepAlive no 83 IdentityFile ~/.ssh/identity 84 Port 22 85 EscapeChar ~ 86 87 */ 88 89 /* Keyword tokens. */ 90 91 typedef enum { 92 oBadOption, 93 oForwardAgent, oForwardX11, oForwardX11Trusted, oGatewayPorts, 94 oPasswordAuthentication, oRSAAuthentication, 95 oChallengeResponseAuthentication, oXAuthLocation, 96 oIdentityFile, oHostName, oPort, oCipher, oRemoteForward, oLocalForward, 97 oUser, oHost, oEscapeChar, oRhostsRSAAuthentication, oProxyCommand, 98 oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts, 99 oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression, 100 oCompressionLevel, oTCPKeepAlive, oNumberOfPasswordPrompts, 101 oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs, 102 oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication, 103 oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias, 104 oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication, 105 oHostKeyAlgorithms, oBindAddress, oSmartcardDevice, 106 oClearAllForwardings, oNoHostAuthenticationForLocalhost, 107 oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, 108 oAddressFamily, oGssAuthentication, oGssDelegateCreds, 109 oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, 110 oVersionAddendum, 111 oDeprecated, oUnsupported 112 } OpCodes; 113 114 /* Textual representations of the tokens. */ 115 116 static struct { 117 const char *name; 118 OpCodes opcode; 119 } keywords[] = { 120 { "forwardagent", oForwardAgent }, 121 { "forwardx11", oForwardX11 }, 122 { "forwardx11trusted", oForwardX11Trusted }, 123 { "xauthlocation", oXAuthLocation }, 124 { "gatewayports", oGatewayPorts }, 125 { "useprivilegedport", oUsePrivilegedPort }, 126 { "rhostsauthentication", oDeprecated }, 127 { "passwordauthentication", oPasswordAuthentication }, 128 { "kbdinteractiveauthentication", oKbdInteractiveAuthentication }, 129 { "kbdinteractivedevices", oKbdInteractiveDevices }, 130 { "rsaauthentication", oRSAAuthentication }, 131 { "pubkeyauthentication", oPubkeyAuthentication }, 132 { "dsaauthentication", oPubkeyAuthentication }, /* alias */ 133 { "rhostsrsaauthentication", oRhostsRSAAuthentication }, 134 { "hostbasedauthentication", oHostbasedAuthentication }, 135 { "challengeresponseauthentication", oChallengeResponseAuthentication }, 136 { "skeyauthentication", oChallengeResponseAuthentication }, /* alias */ 137 { "tisauthentication", oChallengeResponseAuthentication }, /* alias */ 138 { "kerberosauthentication", oUnsupported }, 139 { "kerberostgtpassing", oUnsupported }, 140 { "afstokenpassing", oUnsupported }, 141 #if defined(GSSAPI) 142 { "gssapiauthentication", oGssAuthentication }, 143 { "gssapidelegatecredentials", oGssDelegateCreds }, 144 #else 145 { "gssapiauthentication", oUnsupported }, 146 { "gssapidelegatecredentials", oUnsupported }, 147 #endif 148 { "fallbacktorsh", oDeprecated }, 149 { "usersh", oDeprecated }, 150 { "identityfile", oIdentityFile }, 151 { "identityfile2", oIdentityFile }, /* alias */ 152 { "identitiesonly", oIdentitiesOnly }, 153 { "hostname", oHostName }, 154 { "hostkeyalias", oHostKeyAlias }, 155 { "proxycommand", oProxyCommand }, 156 { "port", oPort }, 157 { "cipher", oCipher }, 158 { "ciphers", oCiphers }, 159 { "macs", oMacs }, 160 { "protocol", oProtocol }, 161 { "remoteforward", oRemoteForward }, 162 { "localforward", oLocalForward }, 163 { "user", oUser }, 164 { "host", oHost }, 165 { "escapechar", oEscapeChar }, 166 { "globalknownhostsfile", oGlobalKnownHostsFile }, 167 { "userknownhostsfile", oUserKnownHostsFile }, /* obsolete */ 168 { "globalknownhostsfile2", oGlobalKnownHostsFile2 }, 169 { "userknownhostsfile2", oUserKnownHostsFile2 }, /* obsolete */ 170 { "connectionattempts", oConnectionAttempts }, 171 { "batchmode", oBatchMode }, 172 { "checkhostip", oCheckHostIP }, 173 { "stricthostkeychecking", oStrictHostKeyChecking }, 174 { "compression", oCompression }, 175 { "compressionlevel", oCompressionLevel }, 176 { "tcpkeepalive", oTCPKeepAlive }, 177 { "keepalive", oTCPKeepAlive }, /* obsolete */ 178 { "numberofpasswordprompts", oNumberOfPasswordPrompts }, 179 { "loglevel", oLogLevel }, 180 { "dynamicforward", oDynamicForward }, 181 { "preferredauthentications", oPreferredAuthentications }, 182 { "hostkeyalgorithms", oHostKeyAlgorithms }, 183 { "bindaddress", oBindAddress }, 184 #ifdef SMARTCARD 185 { "smartcarddevice", oSmartcardDevice }, 186 #else 187 { "smartcarddevice", oUnsupported }, 188 #endif 189 { "clearallforwardings", oClearAllForwardings }, 190 { "enablesshkeysign", oEnableSSHKeysign }, 191 { "verifyhostkeydns", oVerifyHostKeyDNS }, 192 { "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost }, 193 { "rekeylimit", oRekeyLimit }, 194 { "connecttimeout", oConnectTimeout }, 195 { "addressfamily", oAddressFamily }, 196 { "serveraliveinterval", oServerAliveInterval }, 197 { "serveralivecountmax", oServerAliveCountMax }, 198 { "versionaddendum", oVersionAddendum }, 199 { NULL, oBadOption } 200 }; 201 202 /* 203 * Adds a local TCP/IP port forward to options. Never returns if there is an 204 * error. 205 */ 206 207 void 208 add_local_forward(Options *options, u_short port, const char *host, 209 u_short host_port) 210 { 211 Forward *fwd; 212 #ifndef NO_IPPORT_RESERVED_CONCEPT 213 extern uid_t original_real_uid; 214 if (port < IPPORT_RESERVED && original_real_uid != 0) 215 fatal("Privileged ports can only be forwarded by root."); 216 #endif 217 if (options->num_local_forwards >= SSH_MAX_FORWARDS_PER_DIRECTION) 218 fatal("Too many local forwards (max %d).", SSH_MAX_FORWARDS_PER_DIRECTION); 219 fwd = &options->local_forwards[options->num_local_forwards++]; 220 fwd->port = port; 221 fwd->host = xstrdup(host); 222 fwd->host_port = host_port; 223 } 224 225 /* 226 * Adds a remote TCP/IP port forward to options. Never returns if there is 227 * an error. 228 */ 229 230 void 231 add_remote_forward(Options *options, u_short port, const char *host, 232 u_short host_port) 233 { 234 Forward *fwd; 235 if (options->num_remote_forwards >= SSH_MAX_FORWARDS_PER_DIRECTION) 236 fatal("Too many remote forwards (max %d).", 237 SSH_MAX_FORWARDS_PER_DIRECTION); 238 fwd = &options->remote_forwards[options->num_remote_forwards++]; 239 fwd->port = port; 240 fwd->host = xstrdup(host); 241 fwd->host_port = host_port; 242 } 243 244 static void 245 clear_forwardings(Options *options) 246 { 247 int i; 248 249 for (i = 0; i < options->num_local_forwards; i++) 250 xfree(options->local_forwards[i].host); 251 options->num_local_forwards = 0; 252 for (i = 0; i < options->num_remote_forwards; i++) 253 xfree(options->remote_forwards[i].host); 254 options->num_remote_forwards = 0; 255 } 256 257 /* 258 * Returns the number of the token pointed to by cp or oBadOption. 259 */ 260 261 static OpCodes 262 parse_token(const char *cp, const char *filename, int linenum) 263 { 264 u_int i; 265 266 for (i = 0; keywords[i].name; i++) 267 if (strcasecmp(cp, keywords[i].name) == 0) 268 return keywords[i].opcode; 269 270 error("%s: line %d: Bad configuration option: %s", 271 filename, linenum, cp); 272 return oBadOption; 273 } 274 275 /* 276 * Processes a single option line as used in the configuration files. This 277 * only sets those values that have not already been set. 278 */ 279 #define WHITESPACE " \t\r\n" 280 281 int 282 process_config_line(Options *options, const char *host, 283 char *line, const char *filename, int linenum, 284 int *activep) 285 { 286 char buf[256], *s, **charptr, *endofnumber, *keyword, *arg; 287 int opcode, *intptr, value; 288 size_t len; 289 u_short fwd_port, fwd_host_port; 290 char sfwd_host_port[6]; 291 292 /* Strip trailing whitespace */ 293 for(len = strlen(line) - 1; len > 0; len--) { 294 if (strchr(WHITESPACE, line[len]) == NULL) 295 break; 296 line[len] = '\0'; 297 } 298 299 s = line; 300 /* Get the keyword. (Each line is supposed to begin with a keyword). */ 301 keyword = strdelim(&s); 302 /* Ignore leading whitespace. */ 303 if (*keyword == '\0') 304 keyword = strdelim(&s); 305 if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#') 306 return 0; 307 308 opcode = parse_token(keyword, filename, linenum); 309 310 switch (opcode) { 311 case oBadOption: 312 /* don't panic, but count bad options */ 313 return -1; 314 /* NOTREACHED */ 315 case oConnectTimeout: 316 intptr = &options->connection_timeout; 317 parse_time: 318 arg = strdelim(&s); 319 if (!arg || *arg == '\0') 320 fatal("%s line %d: missing time value.", 321 filename, linenum); 322 if ((value = convtime(arg)) == -1) 323 fatal("%s line %d: invalid time value.", 324 filename, linenum); 325 if (*intptr == -1) 326 *intptr = value; 327 break; 328 329 case oForwardAgent: 330 intptr = &options->forward_agent; 331 parse_flag: 332 arg = strdelim(&s); 333 if (!arg || *arg == '\0') 334 fatal("%.200s line %d: Missing yes/no argument.", filename, linenum); 335 value = 0; /* To avoid compiler warning... */ 336 if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) 337 value = 1; 338 else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) 339 value = 0; 340 else 341 fatal("%.200s line %d: Bad yes/no argument.", filename, linenum); 342 if (*activep && *intptr == -1) 343 *intptr = value; 344 break; 345 346 case oForwardX11: 347 intptr = &options->forward_x11; 348 goto parse_flag; 349 350 case oForwardX11Trusted: 351 intptr = &options->forward_x11_trusted; 352 goto parse_flag; 353 354 case oGatewayPorts: 355 intptr = &options->gateway_ports; 356 goto parse_flag; 357 358 case oUsePrivilegedPort: 359 intptr = &options->use_privileged_port; 360 goto parse_flag; 361 362 case oPasswordAuthentication: 363 intptr = &options->password_authentication; 364 goto parse_flag; 365 366 case oKbdInteractiveAuthentication: 367 intptr = &options->kbd_interactive_authentication; 368 goto parse_flag; 369 370 case oKbdInteractiveDevices: 371 charptr = &options->kbd_interactive_devices; 372 goto parse_string; 373 374 case oPubkeyAuthentication: 375 intptr = &options->pubkey_authentication; 376 goto parse_flag; 377 378 case oRSAAuthentication: 379 intptr = &options->rsa_authentication; 380 goto parse_flag; 381 382 case oRhostsRSAAuthentication: 383 intptr = &options->rhosts_rsa_authentication; 384 goto parse_flag; 385 386 case oHostbasedAuthentication: 387 intptr = &options->hostbased_authentication; 388 goto parse_flag; 389 390 case oChallengeResponseAuthentication: 391 intptr = &options->challenge_response_authentication; 392 goto parse_flag; 393 394 case oGssAuthentication: 395 intptr = &options->gss_authentication; 396 goto parse_flag; 397 398 case oGssDelegateCreds: 399 intptr = &options->gss_deleg_creds; 400 goto parse_flag; 401 402 case oBatchMode: 403 intptr = &options->batch_mode; 404 goto parse_flag; 405 406 case oCheckHostIP: 407 intptr = &options->check_host_ip; 408 goto parse_flag; 409 410 case oVerifyHostKeyDNS: 411 intptr = &options->verify_host_key_dns; 412 goto parse_yesnoask; 413 414 case oStrictHostKeyChecking: 415 intptr = &options->strict_host_key_checking; 416 parse_yesnoask: 417 arg = strdelim(&s); 418 if (!arg || *arg == '\0') 419 fatal("%.200s line %d: Missing yes/no/ask argument.", 420 filename, linenum); 421 value = 0; /* To avoid compiler warning... */ 422 if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) 423 value = 1; 424 else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) 425 value = 0; 426 else if (strcmp(arg, "ask") == 0) 427 value = 2; 428 else 429 fatal("%.200s line %d: Bad yes/no/ask argument.", filename, linenum); 430 if (*activep && *intptr == -1) 431 *intptr = value; 432 break; 433 434 case oCompression: 435 intptr = &options->compression; 436 goto parse_flag; 437 438 case oTCPKeepAlive: 439 intptr = &options->tcp_keep_alive; 440 goto parse_flag; 441 442 case oNoHostAuthenticationForLocalhost: 443 intptr = &options->no_host_authentication_for_localhost; 444 goto parse_flag; 445 446 case oNumberOfPasswordPrompts: 447 intptr = &options->number_of_password_prompts; 448 goto parse_int; 449 450 case oCompressionLevel: 451 intptr = &options->compression_level; 452 goto parse_int; 453 454 case oRekeyLimit: 455 intptr = &options->rekey_limit; 456 arg = strdelim(&s); 457 if (!arg || *arg == '\0') 458 fatal("%.200s line %d: Missing argument.", filename, linenum); 459 if (arg[0] < '0' || arg[0] > '9') 460 fatal("%.200s line %d: Bad number.", filename, linenum); 461 value = strtol(arg, &endofnumber, 10); 462 if (arg == endofnumber) 463 fatal("%.200s line %d: Bad number.", filename, linenum); 464 switch (toupper(*endofnumber)) { 465 case 'K': 466 value *= 1<<10; 467 break; 468 case 'M': 469 value *= 1<<20; 470 break; 471 case 'G': 472 value *= 1<<30; 473 break; 474 } 475 if (*activep && *intptr == -1) 476 *intptr = value; 477 break; 478 479 case oIdentityFile: 480 arg = strdelim(&s); 481 if (!arg || *arg == '\0') 482 fatal("%.200s line %d: Missing argument.", filename, linenum); 483 if (*activep) { 484 intptr = &options->num_identity_files; 485 if (*intptr >= SSH_MAX_IDENTITY_FILES) 486 fatal("%.200s line %d: Too many identity files specified (max %d).", 487 filename, linenum, SSH_MAX_IDENTITY_FILES); 488 charptr = &options->identity_files[*intptr]; 489 *charptr = xstrdup(arg); 490 *intptr = *intptr + 1; 491 } 492 break; 493 494 case oXAuthLocation: 495 charptr=&options->xauth_location; 496 goto parse_string; 497 498 case oUser: 499 charptr = &options->user; 500 parse_string: 501 arg = strdelim(&s); 502 if (!arg || *arg == '\0') 503 fatal("%.200s line %d: Missing argument.", filename, linenum); 504 if (*activep && *charptr == NULL) 505 *charptr = xstrdup(arg); 506 break; 507 508 case oGlobalKnownHostsFile: 509 charptr = &options->system_hostfile; 510 goto parse_string; 511 512 case oUserKnownHostsFile: 513 charptr = &options->user_hostfile; 514 goto parse_string; 515 516 case oGlobalKnownHostsFile2: 517 charptr = &options->system_hostfile2; 518 goto parse_string; 519 520 case oUserKnownHostsFile2: 521 charptr = &options->user_hostfile2; 522 goto parse_string; 523 524 case oHostName: 525 charptr = &options->hostname; 526 goto parse_string; 527 528 case oHostKeyAlias: 529 charptr = &options->host_key_alias; 530 goto parse_string; 531 532 case oPreferredAuthentications: 533 charptr = &options->preferred_authentications; 534 goto parse_string; 535 536 case oBindAddress: 537 charptr = &options->bind_address; 538 goto parse_string; 539 540 case oSmartcardDevice: 541 charptr = &options->smartcard_device; 542 goto parse_string; 543 544 case oProxyCommand: 545 if (s == NULL) 546 fatal("%.200s line %d: Missing argument.", filename, linenum); 547 charptr = &options->proxy_command; 548 len = strspn(s, WHITESPACE "="); 549 if (*activep && *charptr == NULL) 550 *charptr = xstrdup(s + len); 551 return 0; 552 553 case oPort: 554 intptr = &options->port; 555 parse_int: 556 arg = strdelim(&s); 557 if (!arg || *arg == '\0') 558 fatal("%.200s line %d: Missing argument.", filename, linenum); 559 if (arg[0] < '0' || arg[0] > '9') 560 fatal("%.200s line %d: Bad number.", filename, linenum); 561 562 /* Octal, decimal, or hex format? */ 563 value = strtol(arg, &endofnumber, 0); 564 if (arg == endofnumber) 565 fatal("%.200s line %d: Bad number.", filename, linenum); 566 if (*activep && *intptr == -1) 567 *intptr = value; 568 break; 569 570 case oConnectionAttempts: 571 intptr = &options->connection_attempts; 572 goto parse_int; 573 574 case oCipher: 575 intptr = &options->cipher; 576 arg = strdelim(&s); 577 if (!arg || *arg == '\0') 578 fatal("%.200s line %d: Missing argument.", filename, linenum); 579 value = cipher_number(arg); 580 if (value == -1) 581 fatal("%.200s line %d: Bad cipher '%s'.", 582 filename, linenum, arg ? arg : "<NONE>"); 583 if (*activep && *intptr == -1) 584 *intptr = value; 585 break; 586 587 case oCiphers: 588 arg = strdelim(&s); 589 if (!arg || *arg == '\0') 590 fatal("%.200s line %d: Missing argument.", filename, linenum); 591 if (!ciphers_valid(arg)) 592 fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.", 593 filename, linenum, arg ? arg : "<NONE>"); 594 if (*activep && options->ciphers == NULL) 595 options->ciphers = xstrdup(arg); 596 break; 597 598 case oMacs: 599 arg = strdelim(&s); 600 if (!arg || *arg == '\0') 601 fatal("%.200s line %d: Missing argument.", filename, linenum); 602 if (!mac_valid(arg)) 603 fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.", 604 filename, linenum, arg ? arg : "<NONE>"); 605 if (*activep && options->macs == NULL) 606 options->macs = xstrdup(arg); 607 break; 608 609 case oHostKeyAlgorithms: 610 arg = strdelim(&s); 611 if (!arg || *arg == '\0') 612 fatal("%.200s line %d: Missing argument.", filename, linenum); 613 if (!key_names_valid2(arg)) 614 fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.", 615 filename, linenum, arg ? arg : "<NONE>"); 616 if (*activep && options->hostkeyalgorithms == NULL) 617 options->hostkeyalgorithms = xstrdup(arg); 618 break; 619 620 case oProtocol: 621 intptr = &options->protocol; 622 arg = strdelim(&s); 623 if (!arg || *arg == '\0') 624 fatal("%.200s line %d: Missing argument.", filename, linenum); 625 value = proto_spec(arg); 626 if (value == SSH_PROTO_UNKNOWN) 627 fatal("%.200s line %d: Bad protocol spec '%s'.", 628 filename, linenum, arg ? arg : "<NONE>"); 629 if (*activep && *intptr == SSH_PROTO_UNKNOWN) 630 *intptr = value; 631 break; 632 633 case oLogLevel: 634 intptr = (int *) &options->log_level; 635 arg = strdelim(&s); 636 value = log_level_number(arg); 637 if (value == SYSLOG_LEVEL_NOT_SET) 638 fatal("%.200s line %d: unsupported log level '%s'", 639 filename, linenum, arg ? arg : "<NONE>"); 640 if (*activep && (LogLevel) *intptr == SYSLOG_LEVEL_NOT_SET) 641 *intptr = (LogLevel) value; 642 break; 643 644 case oLocalForward: 645 case oRemoteForward: 646 arg = strdelim(&s); 647 if (!arg || *arg == '\0') 648 fatal("%.200s line %d: Missing port argument.", 649 filename, linenum); 650 if ((fwd_port = a2port(arg)) == 0) 651 fatal("%.200s line %d: Bad listen port.", 652 filename, linenum); 653 arg = strdelim(&s); 654 if (!arg || *arg == '\0') 655 fatal("%.200s line %d: Missing second argument.", 656 filename, linenum); 657 if (sscanf(arg, "%255[^:]:%5[0-9]", buf, sfwd_host_port) != 2 && 658 sscanf(arg, "%255[^/]/%5[0-9]", buf, sfwd_host_port) != 2) 659 fatal("%.200s line %d: Bad forwarding specification.", 660 filename, linenum); 661 if ((fwd_host_port = a2port(sfwd_host_port)) == 0) 662 fatal("%.200s line %d: Bad forwarding port.", 663 filename, linenum); 664 if (*activep) { 665 if (opcode == oLocalForward) 666 add_local_forward(options, fwd_port, buf, 667 fwd_host_port); 668 else if (opcode == oRemoteForward) 669 add_remote_forward(options, fwd_port, buf, 670 fwd_host_port); 671 } 672 break; 673 674 case oDynamicForward: 675 arg = strdelim(&s); 676 if (!arg || *arg == '\0') 677 fatal("%.200s line %d: Missing port argument.", 678 filename, linenum); 679 fwd_port = a2port(arg); 680 if (fwd_port == 0) 681 fatal("%.200s line %d: Badly formatted port number.", 682 filename, linenum); 683 if (*activep) 684 add_local_forward(options, fwd_port, "socks", 0); 685 break; 686 687 case oClearAllForwardings: 688 intptr = &options->clear_forwardings; 689 goto parse_flag; 690 691 case oHost: 692 *activep = 0; 693 while ((arg = strdelim(&s)) != NULL && *arg != '\0') 694 if (match_pattern(host, arg)) { 695 debug("Applying options for %.100s", arg); 696 *activep = 1; 697 break; 698 } 699 /* Avoid garbage check below, as strdelim is done. */ 700 return 0; 701 702 case oEscapeChar: 703 intptr = &options->escape_char; 704 arg = strdelim(&s); 705 if (!arg || *arg == '\0') 706 fatal("%.200s line %d: Missing argument.", filename, linenum); 707 if (arg[0] == '^' && arg[2] == 0 && 708 (u_char) arg[1] >= 64 && (u_char) arg[1] < 128) 709 value = (u_char) arg[1] & 31; 710 else if (strlen(arg) == 1) 711 value = (u_char) arg[0]; 712 else if (strcmp(arg, "none") == 0) 713 value = SSH_ESCAPECHAR_NONE; 714 else { 715 fatal("%.200s line %d: Bad escape character.", 716 filename, linenum); 717 /* NOTREACHED */ 718 value = 0; /* Avoid compiler warning. */ 719 } 720 if (*activep && *intptr == -1) 721 *intptr = value; 722 break; 723 724 case oAddressFamily: 725 arg = strdelim(&s); 726 intptr = &options->address_family; 727 if (strcasecmp(arg, "inet") == 0) 728 value = AF_INET; 729 else if (strcasecmp(arg, "inet6") == 0) 730 value = AF_INET6; 731 else if (strcasecmp(arg, "any") == 0) 732 value = AF_UNSPEC; 733 else 734 fatal("Unsupported AddressFamily \"%s\"", arg); 735 if (*activep && *intptr == -1) 736 *intptr = value; 737 break; 738 739 case oEnableSSHKeysign: 740 intptr = &options->enable_ssh_keysign; 741 goto parse_flag; 742 743 case oIdentitiesOnly: 744 intptr = &options->identities_only; 745 goto parse_flag; 746 747 case oServerAliveInterval: 748 intptr = &options->server_alive_interval; 749 goto parse_time; 750 751 case oServerAliveCountMax: 752 intptr = &options->server_alive_count_max; 753 goto parse_int; 754 755 case oVersionAddendum: 756 ssh_version_set_addendum(strtok(s, "\n")); 757 do { 758 arg = strdelim(&s); 759 } while (arg != NULL && *arg != '\0'); 760 break; 761 762 case oDeprecated: 763 debug("%s line %d: Deprecated option \"%s\"", 764 filename, linenum, keyword); 765 return 0; 766 767 case oUnsupported: 768 error("%s line %d: Unsupported option \"%s\"", 769 filename, linenum, keyword); 770 return 0; 771 772 default: 773 fatal("process_config_line: Unimplemented opcode %d", opcode); 774 } 775 776 /* Check that there is no garbage at end of line. */ 777 if ((arg = strdelim(&s)) != NULL && *arg != '\0') { 778 fatal("%.200s line %d: garbage at end of line; \"%.200s\".", 779 filename, linenum, arg); 780 } 781 return 0; 782 } 783 784 785 /* 786 * Reads the config file and modifies the options accordingly. Options 787 * should already be initialized before this call. This never returns if 788 * there is an error. If the file does not exist, this returns 0. 789 */ 790 791 int 792 read_config_file(const char *filename, const char *host, Options *options) 793 { 794 FILE *f; 795 char line[1024]; 796 int active, linenum; 797 int bad_options = 0; 798 799 /* Open the file. */ 800 f = fopen(filename, "r"); 801 if (!f) 802 return 0; 803 804 debug("Reading configuration data %.200s", filename); 805 806 /* 807 * Mark that we are now processing the options. This flag is turned 808 * on/off by Host specifications. 809 */ 810 active = 1; 811 linenum = 0; 812 while (fgets(line, sizeof(line), f)) { 813 /* Update line number counter. */ 814 linenum++; 815 if (process_config_line(options, host, line, filename, linenum, &active) != 0) 816 bad_options++; 817 } 818 fclose(f); 819 if (bad_options > 0) 820 fatal("%s: terminating, %d bad configuration options", 821 filename, bad_options); 822 return 1; 823 } 824 825 /* 826 * Initializes options to special values that indicate that they have not yet 827 * been set. Read_config_file will only set options with this value. Options 828 * are processed in the following order: command line, user config file, 829 * system config file. Last, fill_default_options is called. 830 */ 831 832 void 833 initialize_options(Options * options) 834 { 835 memset(options, 'X', sizeof(*options)); 836 options->forward_agent = -1; 837 options->forward_x11 = -1; 838 options->forward_x11_trusted = -1; 839 options->xauth_location = NULL; 840 options->gateway_ports = -1; 841 options->use_privileged_port = -1; 842 options->rsa_authentication = -1; 843 options->pubkey_authentication = -1; 844 options->challenge_response_authentication = -1; 845 options->gss_authentication = -1; 846 options->gss_deleg_creds = -1; 847 options->password_authentication = -1; 848 options->kbd_interactive_authentication = -1; 849 options->kbd_interactive_devices = NULL; 850 options->rhosts_rsa_authentication = -1; 851 options->hostbased_authentication = -1; 852 options->batch_mode = -1; 853 options->check_host_ip = -1; 854 options->strict_host_key_checking = -1; 855 options->compression = -1; 856 options->tcp_keep_alive = -1; 857 options->compression_level = -1; 858 options->port = -1; 859 options->address_family = -1; 860 options->connection_attempts = -1; 861 options->connection_timeout = -1; 862 options->number_of_password_prompts = -1; 863 options->cipher = -1; 864 options->ciphers = NULL; 865 options->macs = NULL; 866 options->hostkeyalgorithms = NULL; 867 options->protocol = SSH_PROTO_UNKNOWN; 868 options->num_identity_files = 0; 869 options->hostname = NULL; 870 options->host_key_alias = NULL; 871 options->proxy_command = NULL; 872 options->user = NULL; 873 options->escape_char = -1; 874 options->system_hostfile = NULL; 875 options->user_hostfile = NULL; 876 options->system_hostfile2 = NULL; 877 options->user_hostfile2 = NULL; 878 options->num_local_forwards = 0; 879 options->num_remote_forwards = 0; 880 options->clear_forwardings = -1; 881 options->log_level = SYSLOG_LEVEL_NOT_SET; 882 options->preferred_authentications = NULL; 883 options->bind_address = NULL; 884 options->smartcard_device = NULL; 885 options->enable_ssh_keysign = - 1; 886 options->no_host_authentication_for_localhost = - 1; 887 options->identities_only = - 1; 888 options->rekey_limit = - 1; 889 options->verify_host_key_dns = -1; 890 options->server_alive_interval = -1; 891 options->server_alive_count_max = -1; 892 } 893 894 /* 895 * Called after processing other sources of option data, this fills those 896 * options for which no value has been specified with their default values. 897 */ 898 899 void 900 fill_default_options(Options * options) 901 { 902 int len; 903 904 if (options->forward_agent == -1) 905 options->forward_agent = 0; 906 if (options->forward_x11 == -1) 907 options->forward_x11 = 0; 908 if (options->forward_x11_trusted == -1) 909 options->forward_x11_trusted = 0; 910 if (options->xauth_location == NULL) 911 options->xauth_location = _PATH_XAUTH; 912 if (options->gateway_ports == -1) 913 options->gateway_ports = 0; 914 if (options->use_privileged_port == -1) 915 options->use_privileged_port = 0; 916 if (options->rsa_authentication == -1) 917 options->rsa_authentication = 1; 918 if (options->pubkey_authentication == -1) 919 options->pubkey_authentication = 1; 920 if (options->challenge_response_authentication == -1) 921 options->challenge_response_authentication = 1; 922 if (options->gss_authentication == -1) 923 options->gss_authentication = 0; 924 if (options->gss_deleg_creds == -1) 925 options->gss_deleg_creds = 0; 926 if (options->password_authentication == -1) 927 options->password_authentication = 1; 928 if (options->kbd_interactive_authentication == -1) 929 options->kbd_interactive_authentication = 1; 930 if (options->rhosts_rsa_authentication == -1) 931 options->rhosts_rsa_authentication = 0; 932 if (options->hostbased_authentication == -1) 933 options->hostbased_authentication = 0; 934 if (options->batch_mode == -1) 935 options->batch_mode = 0; 936 if (options->check_host_ip == -1) 937 options->check_host_ip = 0; 938 if (options->strict_host_key_checking == -1) 939 options->strict_host_key_checking = 2; /* 2 is default */ 940 if (options->compression == -1) 941 options->compression = 0; 942 if (options->tcp_keep_alive == -1) 943 options->tcp_keep_alive = 1; 944 if (options->compression_level == -1) 945 options->compression_level = 6; 946 if (options->port == -1) 947 options->port = 0; /* Filled in ssh_connect. */ 948 if (options->address_family == -1) 949 options->address_family = AF_UNSPEC; 950 if (options->connection_attempts == -1) 951 options->connection_attempts = 1; 952 if (options->number_of_password_prompts == -1) 953 options->number_of_password_prompts = 3; 954 /* Selected in ssh_login(). */ 955 if (options->cipher == -1) 956 options->cipher = SSH_CIPHER_NOT_SET; 957 /* options->ciphers, default set in myproposals.h */ 958 /* options->macs, default set in myproposals.h */ 959 /* options->hostkeyalgorithms, default set in myproposals.h */ 960 if (options->protocol == SSH_PROTO_UNKNOWN) 961 options->protocol = SSH_PROTO_1|SSH_PROTO_2; 962 if (options->num_identity_files == 0) { 963 if (options->protocol & SSH_PROTO_1) { 964 len = 2 + strlen(_PATH_SSH_CLIENT_IDENTITY) + 1; 965 options->identity_files[options->num_identity_files] = 966 xmalloc(len); 967 snprintf(options->identity_files[options->num_identity_files++], 968 len, "~/%.100s", _PATH_SSH_CLIENT_IDENTITY); 969 } 970 if (options->protocol & SSH_PROTO_2) { 971 len = 2 + strlen(_PATH_SSH_CLIENT_ID_RSA) + 1; 972 options->identity_files[options->num_identity_files] = 973 xmalloc(len); 974 snprintf(options->identity_files[options->num_identity_files++], 975 len, "~/%.100s", _PATH_SSH_CLIENT_ID_RSA); 976 977 len = 2 + strlen(_PATH_SSH_CLIENT_ID_DSA) + 1; 978 options->identity_files[options->num_identity_files] = 979 xmalloc(len); 980 snprintf(options->identity_files[options->num_identity_files++], 981 len, "~/%.100s", _PATH_SSH_CLIENT_ID_DSA); 982 } 983 } 984 if (options->escape_char == -1) 985 options->escape_char = '~'; 986 if (options->system_hostfile == NULL) 987 options->system_hostfile = _PATH_SSH_SYSTEM_HOSTFILE; 988 if (options->user_hostfile == NULL) 989 options->user_hostfile = _PATH_SSH_USER_HOSTFILE; 990 if (options->system_hostfile2 == NULL) 991 options->system_hostfile2 = _PATH_SSH_SYSTEM_HOSTFILE2; 992 if (options->user_hostfile2 == NULL) 993 options->user_hostfile2 = _PATH_SSH_USER_HOSTFILE2; 994 if (options->log_level == SYSLOG_LEVEL_NOT_SET) 995 options->log_level = SYSLOG_LEVEL_INFO; 996 if (options->clear_forwardings == 1) 997 clear_forwardings(options); 998 if (options->no_host_authentication_for_localhost == - 1) 999 options->no_host_authentication_for_localhost = 0; 1000 if (options->identities_only == -1) 1001 options->identities_only = 0; 1002 if (options->enable_ssh_keysign == -1) 1003 options->enable_ssh_keysign = 0; 1004 if (options->rekey_limit == -1) 1005 options->rekey_limit = 0; 1006 if (options->verify_host_key_dns == -1) 1007 options->verify_host_key_dns = 0; 1008 if (options->server_alive_interval == -1) 1009 options->server_alive_interval = 0; 1010 if (options->server_alive_count_max == -1) 1011 options->server_alive_count_max = 3; 1012 /* options->proxy_command should not be set by default */ 1013 /* options->user will be set in the main program if appropriate */ 1014 /* options->hostname will be set in the main program if appropriate */ 1015 /* options->host_key_alias should not be set by default */ 1016 /* options->preferred_authentications will be set in ssh */ 1017 } 1018