/* $OpenBSD: readconf.c,v 1.193 2011/05/24 07:15:47 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland * All rights reserved * Functions for reading the configuration files. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ #include "includes.h" #include <sys/types.h> #include <sys/stat.h> #include <sys/socket.h> #include <netinet/in.h> #include <netinet/in_systm.h> #include <netinet/ip.h> #include <ctype.h> #include <errno.h> #include <netdb.h> #include <signal.h> #include <stdarg.h> #include <stdio.h> #include <string.h> #include <unistd.h> #include "xmalloc.h" #include "ssh.h" #include "compat.h" #include "cipher.h" #include "pathnames.h" #include "log.h" #include "key.h" #include "readconf.h" #include "match.h" #include "misc.h" #include "buffer.h" #include "kex.h" #include "mac.h" /* Format of the configuration file: # Configuration data is parsed as follows: # 1. command line options # 2. user-specific file # 3. system-wide file # Any configuration value is only changed the first time it is set. # Thus, host-specific definitions should be at the beginning of the # configuration file, and defaults at the end. # Host-specific declarations. These may override anything above. A single # host may match multiple declarations; these are processed in the order # that they are given in. Host *.ngs.fi ngs.fi User foo Host fake.com HostName another.host.name.real.org User blaah Port 34289 ForwardX11 no ForwardAgent no Host books.com RemoteForward 9999 shadows.cs.hut.fi:9999 Cipher 3des Host fascist.blob.com Port 23123 User tylonen PasswordAuthentication no Host puukko.hut.fi User t35124p ProxyCommand ssh-proxy %h %p Host *.fr PublicKeyAuthentication no Host *.su Cipher none PasswordAuthentication no Host vpn.fake.com Tunnel yes TunnelDevice 3 # Defaults for various options Host * ForwardAgent no ForwardX11 no PasswordAuthentication yes RSAAuthentication yes RhostsRSAAuthentication yes StrictHostKeyChecking yes TcpKeepAlive no IdentityFile ~/.ssh/identity Port 22 EscapeChar ~ */ /* Keyword tokens. */ typedef enum { oBadOption, oForwardAgent, oForwardX11, oForwardX11Trusted, oForwardX11Timeout, oGatewayPorts, oExitOnForwardFailure, oPasswordAuthentication, oRSAAuthentication, oChallengeResponseAuthentication, oXAuthLocation, oIdentityFile, oHostName, oPort, oCipher, oRemoteForward, oLocalForward, oUser, oHost, oEscapeChar, oRhostsRSAAuthentication, oProxyCommand, oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts, oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression, oCompressionLevel, oTCPKeepAlive, oNumberOfPasswordPrompts, oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs, oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication, oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias, oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication, oHostKeyAlgorithms, oBindAddress, oPKCS11Provider, oClearAllForwardings, oNoHostAuthenticationForLocalhost, oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, oAddressFamily, oGssAuthentication, oGssDelegateCreds, oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, oSendEnv, oControlPath, oControlMaster, oControlPersist, oHashKnownHosts, oTunnel, oTunnelDevice, oLocalCommand, oPermitLocalCommand, oVisualHostKey, oUseRoaming, oZeroKnowledgePasswordAuthentication, oKexAlgorithms, oIPQoS, oRequestTTY, oDeprecated, oUnsupported } OpCodes; /* Textual representations of the tokens. */ static struct { const char *name; OpCodes opcode; } keywords[] = { { "forwardagent", oForwardAgent }, { "forwardx11", oForwardX11 }, { "forwardx11trusted", oForwardX11Trusted }, { "forwardx11timeout", oForwardX11Timeout }, { "exitonforwardfailure", oExitOnForwardFailure }, { "xauthlocation", oXAuthLocation }, { "gatewayports", oGatewayPorts }, { "useprivilegedport", oUsePrivilegedPort }, { "rhostsauthentication", oDeprecated }, { "passwordauthentication", oPasswordAuthentication }, { "kbdinteractiveauthentication", oKbdInteractiveAuthentication }, { "kbdinteractivedevices", oKbdInteractiveDevices }, { "rsaauthentication", oRSAAuthentication }, { "pubkeyauthentication", oPubkeyAuthentication }, { "dsaauthentication", oPubkeyAuthentication }, /* alias */ { "rhostsrsaauthentication", oRhostsRSAAuthentication }, { "hostbasedauthentication", oHostbasedAuthentication }, { "challengeresponseauthentication", oChallengeResponseAuthentication }, { "skeyauthentication", oChallengeResponseAuthentication }, /* alias */ { "tisauthentication", oChallengeResponseAuthentication }, /* alias */ { "kerberosauthentication", oUnsupported }, { "kerberostgtpassing", oUnsupported }, { "afstokenpassing", oUnsupported }, #if defined(GSSAPI) { "gssapiauthentication", oGssAuthentication }, { "gssapidelegatecredentials", oGssDelegateCreds }, #else { "gssapiauthentication", oUnsupported }, { "gssapidelegatecredentials", oUnsupported }, #endif { "fallbacktorsh", oDeprecated }, { "usersh", oDeprecated }, { "identityfile", oIdentityFile }, { "identityfile2", oIdentityFile }, /* obsolete */ { "identitiesonly", oIdentitiesOnly }, { "hostname", oHostName }, { "hostkeyalias", oHostKeyAlias }, { "proxycommand", oProxyCommand }, { "port", oPort }, { "cipher", oCipher }, { "ciphers", oCiphers }, { "macs", oMacs }, { "protocol", oProtocol }, { "remoteforward", oRemoteForward }, { "localforward", oLocalForward }, { "user", oUser }, { "host", oHost }, { "escapechar", oEscapeChar }, { "globalknownhostsfile", oGlobalKnownHostsFile }, { "globalknownhostsfile2", oDeprecated }, { "userknownhostsfile", oUserKnownHostsFile }, { "userknownhostsfile2", oDeprecated }, { "connectionattempts", oConnectionAttempts }, { "batchmode", oBatchMode }, { "checkhostip", oCheckHostIP }, { "stricthostkeychecking", oStrictHostKeyChecking }, { "compression", oCompression }, { "compressionlevel", oCompressionLevel }, { "tcpkeepalive", oTCPKeepAlive }, { "keepalive", oTCPKeepAlive }, /* obsolete */ { "numberofpasswordprompts", oNumberOfPasswordPrompts }, { "loglevel", oLogLevel }, { "dynamicforward", oDynamicForward }, { "preferredauthentications", oPreferredAuthentications }, { "hostkeyalgorithms", oHostKeyAlgorithms }, { "bindaddress", oBindAddress }, #ifdef ENABLE_PKCS11 { "smartcarddevice", oPKCS11Provider }, { "pkcs11provider", oPKCS11Provider }, #else { "smartcarddevice", oUnsupported }, { "pkcs11provider", oUnsupported }, #endif { "clearallforwardings", oClearAllForwardings }, { "enablesshkeysign", oEnableSSHKeysign }, { "verifyhostkeydns", oVerifyHostKeyDNS }, { "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost }, { "rekeylimit", oRekeyLimit }, { "connecttimeout", oConnectTimeout }, { "addressfamily", oAddressFamily }, { "serveraliveinterval", oServerAliveInterval }, { "serveralivecountmax", oServerAliveCountMax }, { "sendenv", oSendEnv }, { "controlpath", oControlPath }, { "controlmaster", oControlMaster }, { "controlpersist", oControlPersist }, { "hashknownhosts", oHashKnownHosts }, { "tunnel", oTunnel }, { "tunneldevice", oTunnelDevice }, { "localcommand", oLocalCommand }, { "permitlocalcommand", oPermitLocalCommand }, { "visualhostkey", oVisualHostKey }, { "useroaming", oUseRoaming }, #ifdef JPAKE { "zeroknowledgepasswordauthentication", oZeroKnowledgePasswordAuthentication }, #else { "zeroknowledgepasswordauthentication", oUnsupported }, #endif { "kexalgorithms", oKexAlgorithms }, { "ipqos", oIPQoS }, { "requesttty", oRequestTTY }, { NULL, oBadOption } }; /* * Adds a local TCP/IP port forward to options. Never returns if there is an * error. */ void add_local_forward(Options *options, const Forward *newfwd) { Forward *fwd; #ifndef NO_IPPORT_RESERVED_CONCEPT extern uid_t original_real_uid; if (newfwd->listen_port < IPPORT_RESERVED && original_real_uid != 0) fatal("Privileged ports can only be forwarded by root."); #endif options->local_forwards = xrealloc(options->local_forwards, options->num_local_forwards + 1, sizeof(*options->local_forwards)); fwd = &options->local_forwards[options->num_local_forwards++]; fwd->listen_host = newfwd->listen_host; fwd->listen_port = newfwd->listen_port; fwd->connect_host = newfwd->connect_host; fwd->connect_port = newfwd->connect_port; } /* * Adds a remote TCP/IP port forward to options. Never returns if there is * an error. */ void add_remote_forward(Options *options, const Forward *newfwd) { Forward *fwd; options->remote_forwards = xrealloc(options->remote_forwards, options->num_remote_forwards + 1, sizeof(*options->remote_forwards)); fwd = &options->remote_forwards[options->num_remote_forwards++]; fwd->listen_host = newfwd->listen_host; fwd->listen_port = newfwd->listen_port; fwd->connect_host = newfwd->connect_host; fwd->connect_port = newfwd->connect_port; fwd->allocated_port = 0; } static void clear_forwardings(Options *options) { int i; for (i = 0; i < options->num_local_forwards; i++) { if (options->local_forwards[i].listen_host != NULL) xfree(options->local_forwards[i].listen_host); xfree(options->local_forwards[i].connect_host); } if (options->num_local_forwards > 0) { xfree(options->local_forwards); options->local_forwards = NULL; } options->num_local_forwards = 0; for (i = 0; i < options->num_remote_forwards; i++) { if (options->remote_forwards[i].listen_host != NULL) xfree(options->remote_forwards[i].listen_host); xfree(options->remote_forwards[i].connect_host); } if (options->num_remote_forwards > 0) { xfree(options->remote_forwards); options->remote_forwards = NULL; } options->num_remote_forwards = 0; options->tun_open = SSH_TUNMODE_NO; } /* * Returns the number of the token pointed to by cp or oBadOption. */ static OpCodes parse_token(const char *cp, const char *filename, int linenum) { u_int i; for (i = 0; keywords[i].name; i++) if (strcasecmp(cp, keywords[i].name) == 0) return keywords[i].opcode; error("%s: line %d: Bad configuration option: %s", filename, linenum, cp); return oBadOption; } /* * Processes a single option line as used in the configuration files. This * only sets those values that have not already been set. */ #define WHITESPACE " \t\r\n" int process_config_line(Options *options, const char *host, char *line, const char *filename, int linenum, int *activep) { char *s, **charptr, *endofnumber, *keyword, *arg, *arg2; char **cpptr, fwdarg[256]; u_int *uintptr, max_entries = 0; int negated, opcode, *intptr, value, value2, scale; LogLevel *log_level_ptr; long long orig, val64; size_t len; Forward fwd; /* Strip trailing whitespace */ for (len = strlen(line) - 1; len > 0; len--) { if (strchr(WHITESPACE, line[len]) == NULL) break; line[len] = '\0'; } s = line; /* Get the keyword. (Each line is supposed to begin with a keyword). */ if ((keyword = strdelim(&s)) == NULL) return 0; /* Ignore leading whitespace. */ if (*keyword == '\0') keyword = strdelim(&s); if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#') return 0; opcode = parse_token(keyword, filename, linenum); switch (opcode) { case oBadOption: /* don't panic, but count bad options */ return -1; /* NOTREACHED */ case oConnectTimeout: intptr = &options->connection_timeout; parse_time: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%s line %d: missing time value.", filename, linenum); if ((value = convtime(arg)) == -1) fatal("%s line %d: invalid time value.", filename, linenum); if (*activep && *intptr == -1) *intptr = value; break; case oForwardAgent: intptr = &options->forward_agent; parse_flag: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing yes/no argument.", filename, linenum); value = 0; /* To avoid compiler warning... */ if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) value = 1; else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) value = 0; else fatal("%.200s line %d: Bad yes/no argument.", filename, linenum); if (*activep && *intptr == -1) *intptr = value; break; case oForwardX11: intptr = &options->forward_x11; goto parse_flag; case oForwardX11Trusted: intptr = &options->forward_x11_trusted; goto parse_flag; case oForwardX11Timeout: intptr = &options->forward_x11_timeout; goto parse_time; case oGatewayPorts: intptr = &options->gateway_ports; goto parse_flag; case oExitOnForwardFailure: intptr = &options->exit_on_forward_failure; goto parse_flag; case oUsePrivilegedPort: intptr = &options->use_privileged_port; goto parse_flag; case oPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; case oZeroKnowledgePasswordAuthentication: intptr = &options->zero_knowledge_password_authentication; goto parse_flag; case oKbdInteractiveAuthentication: intptr = &options->kbd_interactive_authentication; goto parse_flag; case oKbdInteractiveDevices: charptr = &options->kbd_interactive_devices; goto parse_string; case oPubkeyAuthentication: intptr = &options->pubkey_authentication; goto parse_flag; case oRSAAuthentication: intptr = &options->rsa_authentication; goto parse_flag; case oRhostsRSAAuthentication: intptr = &options->rhosts_rsa_authentication; goto parse_flag; case oHostbasedAuthentication: intptr = &options->hostbased_authentication; goto parse_flag; case oChallengeResponseAuthentication: intptr = &options->challenge_response_authentication; goto parse_flag; case oGssAuthentication: intptr = &options->gss_authentication; goto parse_flag; case oGssDelegateCreds: intptr = &options->gss_deleg_creds; goto parse_flag; case oBatchMode: intptr = &options->batch_mode; goto parse_flag; case oCheckHostIP: intptr = &options->check_host_ip; goto parse_flag; case oVerifyHostKeyDNS: intptr = &options->verify_host_key_dns; goto parse_yesnoask; case oStrictHostKeyChecking: intptr = &options->strict_host_key_checking; parse_yesnoask: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing yes/no/ask argument.", filename, linenum); value = 0; /* To avoid compiler warning... */ if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) value = 1; else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) value = 0; else if (strcmp(arg, "ask") == 0) value = 2; else fatal("%.200s line %d: Bad yes/no/ask argument.", filename, linenum); if (*activep && *intptr == -1) *intptr = value; break; case oCompression: intptr = &options->compression; goto parse_flag; case oTCPKeepAlive: intptr = &options->tcp_keep_alive; goto parse_flag; case oNoHostAuthenticationForLocalhost: intptr = &options->no_host_authentication_for_localhost; goto parse_flag; case oNumberOfPasswordPrompts: intptr = &options->number_of_password_prompts; goto parse_int; case oCompressionLevel: intptr = &options->compression_level; goto parse_int; case oRekeyLimit: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (arg[0] < '0' || arg[0] > '9') fatal("%.200s line %d: Bad number.", filename, linenum); orig = val64 = strtoll(arg, &endofnumber, 10); if (arg == endofnumber) fatal("%.200s line %d: Bad number.", filename, linenum); switch (toupper(*endofnumber)) { case '\0': scale = 1; break; case 'K': scale = 1<<10; break; case 'M': scale = 1<<20; break; case 'G': scale = 1<<30; break; default: fatal("%.200s line %d: Invalid RekeyLimit suffix", filename, linenum); } val64 *= scale; /* detect integer wrap and too-large limits */ if ((val64 / scale) != orig || val64 > UINT_MAX) fatal("%.200s line %d: RekeyLimit too large", filename, linenum); if (val64 < 16) fatal("%.200s line %d: RekeyLimit too small", filename, linenum); if (*activep && options->rekey_limit == -1) options->rekey_limit = (u_int32_t)val64; break; case oIdentityFile: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (*activep) { intptr = &options->num_identity_files; if (*intptr >= SSH_MAX_IDENTITY_FILES) fatal("%.200s line %d: Too many identity files specified (max %d).", filename, linenum, SSH_MAX_IDENTITY_FILES); charptr = &options->identity_files[*intptr]; *charptr = xstrdup(arg); *intptr = *intptr + 1; } break; case oXAuthLocation: charptr=&options->xauth_location; goto parse_string; case oUser: charptr = &options->user; parse_string: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case oGlobalKnownHostsFile: cpptr = (char **)&options->system_hostfiles; uintptr = &options->num_system_hostfiles; max_entries = SSH_MAX_HOSTS_FILES; parse_char_array: if (*activep && *uintptr == 0) { while ((arg = strdelim(&s)) != NULL && *arg != '\0') { if ((*uintptr) >= max_entries) fatal("%s line %d: " "too many authorized keys files.", filename, linenum); cpptr[(*uintptr)++] = xstrdup(arg); } } return 0; case oUserKnownHostsFile: cpptr = (char **)&options->user_hostfiles; uintptr = &options->num_user_hostfiles; max_entries = SSH_MAX_HOSTS_FILES; goto parse_char_array; case oHostName: charptr = &options->hostname; goto parse_string; case oHostKeyAlias: charptr = &options->host_key_alias; goto parse_string; case oPreferredAuthentications: charptr = &options->preferred_authentications; goto parse_string; case oBindAddress: charptr = &options->bind_address; goto parse_string; case oPKCS11Provider: charptr = &options->pkcs11_provider; goto parse_string; case oProxyCommand: charptr = &options->proxy_command; parse_command: if (s == NULL) fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(s, WHITESPACE "="); if (*activep && *charptr == NULL) *charptr = xstrdup(s + len); return 0; case oPort: intptr = &options->port; parse_int: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (arg[0] < '0' || arg[0] > '9') fatal("%.200s line %d: Bad number.", filename, linenum); /* Octal, decimal, or hex format? */ value = strtol(arg, &endofnumber, 0); if (arg == endofnumber) fatal("%.200s line %d: Bad number.", filename, linenum); if (*activep && *intptr == -1) *intptr = value; break; case oConnectionAttempts: intptr = &options->connection_attempts; goto parse_int; case oCipher: intptr = &options->cipher; arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); value = cipher_number(arg); if (value == -1) fatal("%.200s line %d: Bad cipher '%s'.", filename, linenum, arg ? arg : "<NONE>"); if (*activep && *intptr == -1) *intptr = value; break; case oCiphers: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (!ciphers_valid(arg)) fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.", filename, linenum, arg ? arg : "<NONE>"); if (*activep && options->ciphers == NULL) options->ciphers = xstrdup(arg); break; case oMacs: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (!mac_valid(arg)) fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.", filename, linenum, arg ? arg : "<NONE>"); if (*activep && options->macs == NULL) options->macs = xstrdup(arg); break; case oKexAlgorithms: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (!kex_names_valid(arg)) fatal("%.200s line %d: Bad SSH2 KexAlgorithms '%s'.", filename, linenum, arg ? arg : "<NONE>"); if (*activep && options->kex_algorithms == NULL) options->kex_algorithms = xstrdup(arg); break; case oHostKeyAlgorithms: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (!key_names_valid2(arg)) fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.", filename, linenum, arg ? arg : "<NONE>"); if (*activep && options->hostkeyalgorithms == NULL) options->hostkeyalgorithms = xstrdup(arg); break; case oProtocol: intptr = &options->protocol; arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); value = proto_spec(arg); if (value == SSH_PROTO_UNKNOWN) fatal("%.200s line %d: Bad protocol spec '%s'.", filename, linenum, arg ? arg : "<NONE>"); if (*activep && *intptr == SSH_PROTO_UNKNOWN) *intptr = value; break; case oLogLevel: log_level_ptr = &options->log_level; arg = strdelim(&s); value = log_level_number(arg); if (value == SYSLOG_LEVEL_NOT_SET) fatal("%.200s line %d: unsupported log level '%s'", filename, linenum, arg ? arg : "<NONE>"); if (*activep && *log_level_ptr == SYSLOG_LEVEL_NOT_SET) *log_level_ptr = (LogLevel) value; break; case oLocalForward: case oRemoteForward: case oDynamicForward: arg = strdelim(&s); if (arg == NULL || *arg == '\0') fatal("%.200s line %d: Missing port argument.", filename, linenum); if (opcode == oLocalForward || opcode == oRemoteForward) { arg2 = strdelim(&s); if (arg2 == NULL || *arg2 == '\0') fatal("%.200s line %d: Missing target argument.", filename, linenum); /* construct a string for parse_forward */ snprintf(fwdarg, sizeof(fwdarg), "%s:%s", arg, arg2); } else if (opcode == oDynamicForward) { strlcpy(fwdarg, arg, sizeof(fwdarg)); } if (parse_forward(&fwd, fwdarg, opcode == oDynamicForward ? 1 : 0, opcode == oRemoteForward ? 1 : 0) == 0) fatal("%.200s line %d: Bad forwarding specification.", filename, linenum); if (*activep) { if (opcode == oLocalForward || opcode == oDynamicForward) add_local_forward(options, &fwd); else if (opcode == oRemoteForward) add_remote_forward(options, &fwd); } break; case oClearAllForwardings: intptr = &options->clear_forwardings; goto parse_flag; case oHost: *activep = 0; arg2 = NULL; while ((arg = strdelim(&s)) != NULL && *arg != '\0') { negated = *arg == '!'; if (negated) arg++; if (match_pattern(host, arg)) { if (negated) { debug("%.200s line %d: Skipping Host " "block because of negated match " "for %.100s", filename, linenum, arg); *activep = 0; break; } if (!*activep) arg2 = arg; /* logged below */ *activep = 1; } } if (*activep) debug("%.200s line %d: Applying options for %.100s", filename, linenum, arg2); /* Avoid garbage check below, as strdelim is done. */ return 0; case oEscapeChar: intptr = &options->escape_char; arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (arg[0] == '^' && arg[2] == 0 && (u_char) arg[1] >= 64 && (u_char) arg[1] < 128) value = (u_char) arg[1] & 31; else if (strlen(arg) == 1) value = (u_char) arg[0]; else if (strcmp(arg, "none") == 0) value = SSH_ESCAPECHAR_NONE; else { fatal("%.200s line %d: Bad escape character.", filename, linenum); /* NOTREACHED */ value = 0; /* Avoid compiler warning. */ } if (*activep && *intptr == -1) *intptr = value; break; case oAddressFamily: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%s line %d: missing address family.", filename, linenum); intptr = &options->address_family; if (strcasecmp(arg, "inet") == 0) value = AF_INET; else if (strcasecmp(arg, "inet6") == 0) value = AF_INET6; else if (strcasecmp(arg, "any") == 0) value = AF_UNSPEC; else fatal("Unsupported AddressFamily \"%s\"", arg); if (*activep && *intptr == -1) *intptr = value; break; case oEnableSSHKeysign: intptr = &options->enable_ssh_keysign; goto parse_flag; case oIdentitiesOnly: intptr = &options->identities_only; goto parse_flag; case oServerAliveInterval: intptr = &options->server_alive_interval; goto parse_time; case oServerAliveCountMax: intptr = &options->server_alive_count_max; goto parse_int; case oSendEnv: while ((arg = strdelim(&s)) != NULL && *arg != '\0') { if (strchr(arg, '=') != NULL) fatal("%s line %d: Invalid environment name.", filename, linenum); if (!*activep) continue; if (options->num_send_env >= MAX_SEND_ENV) fatal("%s line %d: too many send env.", filename, linenum); options->send_env[options->num_send_env++] = xstrdup(arg); } break; case oControlPath: charptr = &options->control_path; goto parse_string; case oControlMaster: intptr = &options->control_master; arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing ControlMaster argument.", filename, linenum); value = 0; /* To avoid compiler warning... */ if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) value = SSHCTL_MASTER_YES; else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) value = SSHCTL_MASTER_NO; else if (strcmp(arg, "auto") == 0) value = SSHCTL_MASTER_AUTO; else if (strcmp(arg, "ask") == 0) value = SSHCTL_MASTER_ASK; else if (strcmp(arg, "autoask") == 0) value = SSHCTL_MASTER_AUTO_ASK; else fatal("%.200s line %d: Bad ControlMaster argument.", filename, linenum); if (*activep && *intptr == -1) *intptr = value; break; case oControlPersist: /* no/false/yes/true, or a time spec */ intptr = &options->control_persist; arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing ControlPersist" " argument.", filename, linenum); value = 0; value2 = 0; /* timeout */ if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0) value = 0; else if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0) value = 1; else if ((value2 = convtime(arg)) >= 0) value = 1; else fatal("%.200s line %d: Bad ControlPersist argument.", filename, linenum); if (*activep && *intptr == -1) { *intptr = value; options->control_persist_timeout = value2; } break; case oHashKnownHosts: intptr = &options->hash_known_hosts; goto parse_flag; case oTunnel: intptr = &options->tun_open; arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%s line %d: Missing yes/point-to-point/" "ethernet/no argument.", filename, linenum); value = 0; /* silence compiler */ if (strcasecmp(arg, "ethernet") == 0) value = SSH_TUNMODE_ETHERNET; else if (strcasecmp(arg, "point-to-point") == 0) value = SSH_TUNMODE_POINTOPOINT; else if (strcasecmp(arg, "yes") == 0) value = SSH_TUNMODE_DEFAULT; else if (strcasecmp(arg, "no") == 0) value = SSH_TUNMODE_NO; else fatal("%s line %d: Bad yes/point-to-point/ethernet/" "no argument: %s", filename, linenum, arg); if (*activep) *intptr = value; break; case oTunnelDevice: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); value = a2tun(arg, &value2); if (value == SSH_TUNID_ERR) fatal("%.200s line %d: Bad tun device.", filename, linenum); if (*activep) { options->tun_local = value; options->tun_remote = value2; } break; case oLocalCommand: charptr = &options->local_command; goto parse_command; case oPermitLocalCommand: intptr = &options->permit_local_command; goto parse_flag; case oVisualHostKey: intptr = &options->visual_host_key; goto parse_flag; case oIPQoS: arg = strdelim(&s); if ((value = parse_ipqos(arg)) == -1) fatal("%s line %d: Bad IPQoS value: %s", filename, linenum, arg); arg = strdelim(&s); if (arg == NULL) value2 = value; else if ((value2 = parse_ipqos(arg)) == -1) fatal("%s line %d: Bad IPQoS value: %s", filename, linenum, arg); if (*activep) { options->ip_qos_interactive = value; options->ip_qos_bulk = value2; } break; case oUseRoaming: intptr = &options->use_roaming; goto parse_flag; case oRequestTTY: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%s line %d: missing argument.", filename, linenum); intptr = &options->request_tty; if (strcasecmp(arg, "yes") == 0) value = REQUEST_TTY_YES; else if (strcasecmp(arg, "no") == 0) value = REQUEST_TTY_NO; else if (strcasecmp(arg, "force") == 0) value = REQUEST_TTY_FORCE; else if (strcasecmp(arg, "auto") == 0) value = REQUEST_TTY_AUTO; else fatal("Unsupported RequestTTY \"%s\"", arg); if (*activep && *intptr == -1) *intptr = value; break; case oDeprecated: debug("%s line %d: Deprecated option \"%s\"", filename, linenum, keyword); return 0; case oUnsupported: error("%s line %d: Unsupported option \"%s\"", filename, linenum, keyword); return 0; default: fatal("process_config_line: Unimplemented opcode %d", opcode); } /* Check that there is no garbage at end of line. */ if ((arg = strdelim(&s)) != NULL && *arg != '\0') { fatal("%.200s line %d: garbage at end of line; \"%.200s\".", filename, linenum, arg); } return 0; } /* * Reads the config file and modifies the options accordingly. Options * should already be initialized before this call. This never returns if * there is an error. If the file does not exist, this returns 0. */ int read_config_file(const char *filename, const char *host, Options *options, int checkperm) { FILE *f; char line[1024]; int active, linenum; int bad_options = 0; if ((f = fopen(filename, "r")) == NULL) return 0; if (checkperm) { struct stat sb; if (fstat(fileno(f), &sb) == -1) fatal("fstat %s: %s", filename, strerror(errno)); if (((sb.st_uid != 0 && sb.st_uid != getuid()) || (sb.st_mode & 022) != 0)) fatal("Bad owner or permissions on %s", filename); } debug("Reading configuration data %.200s", filename); /* * Mark that we are now processing the options. This flag is turned * on/off by Host specifications. */ active = 1; linenum = 0; while (fgets(line, sizeof(line), f)) { /* Update line number counter. */ linenum++; if (process_config_line(options, host, line, filename, linenum, &active) != 0) bad_options++; } fclose(f); if (bad_options > 0) fatal("%s: terminating, %d bad configuration options", filename, bad_options); return 1; } /* * Initializes options to special values that indicate that they have not yet * been set. Read_config_file will only set options with this value. Options * are processed in the following order: command line, user config file, * system config file. Last, fill_default_options is called. */ void initialize_options(Options * options) { memset(options, 'X', sizeof(*options)); options->forward_agent = -1; options->forward_x11 = -1; options->forward_x11_trusted = -1; options->forward_x11_timeout = -1; options->exit_on_forward_failure = -1; options->xauth_location = NULL; options->gateway_ports = -1; options->use_privileged_port = -1; options->rsa_authentication = -1; options->pubkey_authentication = -1; options->challenge_response_authentication = -1; options->gss_authentication = -1; options->gss_deleg_creds = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->kbd_interactive_devices = NULL; options->rhosts_rsa_authentication = -1; options->hostbased_authentication = -1; options->batch_mode = -1; options->check_host_ip = -1; options->strict_host_key_checking = -1; options->compression = -1; options->tcp_keep_alive = -1; options->compression_level = -1; options->port = -1; options->address_family = -1; options->connection_attempts = -1; options->connection_timeout = -1; options->number_of_password_prompts = -1; options->cipher = -1; options->ciphers = NULL; options->macs = NULL; options->kex_algorithms = NULL; options->hostkeyalgorithms = NULL; options->protocol = SSH_PROTO_UNKNOWN; options->num_identity_files = 0; options->hostname = NULL; options->host_key_alias = NULL; options->proxy_command = NULL; options->user = NULL; options->escape_char = -1; options->num_system_hostfiles = 0; options->num_user_hostfiles = 0; options->local_forwards = NULL; options->num_local_forwards = 0; options->remote_forwards = NULL; options->num_remote_forwards = 0; options->clear_forwardings = -1; options->log_level = SYSLOG_LEVEL_NOT_SET; options->preferred_authentications = NULL; options->bind_address = NULL; options->pkcs11_provider = NULL; options->enable_ssh_keysign = - 1; options->no_host_authentication_for_localhost = - 1; options->identities_only = - 1; options->rekey_limit = - 1; options->verify_host_key_dns = -1; options->server_alive_interval = -1; options->server_alive_count_max = -1; options->num_send_env = 0; options->control_path = NULL; options->control_master = -1; options->control_persist = -1; options->control_persist_timeout = 0; options->hash_known_hosts = -1; options->tun_open = -1; options->tun_local = -1; options->tun_remote = -1; options->local_command = NULL; options->permit_local_command = -1; options->use_roaming = -1; options->visual_host_key = -1; options->zero_knowledge_password_authentication = -1; options->ip_qos_interactive = -1; options->ip_qos_bulk = -1; options->request_tty = -1; } /* * Called after processing other sources of option data, this fills those * options for which no value has been specified with their default values. */ void fill_default_options(Options * options) { int len; if (options->forward_agent == -1) options->forward_agent = 0; if (options->forward_x11 == -1) options->forward_x11 = 0; if (options->forward_x11_trusted == -1) options->forward_x11_trusted = 0; if (options->forward_x11_timeout == -1) options->forward_x11_timeout = 1200; if (options->exit_on_forward_failure == -1) options->exit_on_forward_failure = 0; if (options->xauth_location == NULL) options->xauth_location = _PATH_XAUTH; if (options->gateway_ports == -1) options->gateway_ports = 0; if (options->use_privileged_port == -1) options->use_privileged_port = 0; if (options->rsa_authentication == -1) options->rsa_authentication = 1; if (options->pubkey_authentication == -1) options->pubkey_authentication = 1; if (options->challenge_response_authentication == -1) options->challenge_response_authentication = 1; if (options->gss_authentication == -1) options->gss_authentication = 0; if (options->gss_deleg_creds == -1) options->gss_deleg_creds = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) options->kbd_interactive_authentication = 1; if (options->rhosts_rsa_authentication == -1) options->rhosts_rsa_authentication = 0; if (options->hostbased_authentication == -1) options->hostbased_authentication = 0; if (options->batch_mode == -1) options->batch_mode = 0; if (options->check_host_ip == -1) options->check_host_ip = 1; if (options->strict_host_key_checking == -1) options->strict_host_key_checking = 2; /* 2 is default */ if (options->compression == -1) options->compression = 0; if (options->tcp_keep_alive == -1) options->tcp_keep_alive = 1; if (options->compression_level == -1) options->compression_level = 6; if (options->port == -1) options->port = 0; /* Filled in ssh_connect. */ if (options->address_family == -1) options->address_family = AF_UNSPEC; if (options->connection_attempts == -1) options->connection_attempts = 1; if (options->number_of_password_prompts == -1) options->number_of_password_prompts = 3; /* Selected in ssh_login(). */ if (options->cipher == -1) options->cipher = SSH_CIPHER_NOT_SET; /* options->ciphers, default set in myproposals.h */ /* options->macs, default set in myproposals.h */ /* options->kex_algorithms, default set in myproposals.h */ /* options->hostkeyalgorithms, default set in myproposals.h */ if (options->protocol == SSH_PROTO_UNKNOWN) options->protocol = SSH_PROTO_2; if (options->num_identity_files == 0) { if (options->protocol & SSH_PROTO_1) { len = 2 + strlen(_PATH_SSH_CLIENT_IDENTITY) + 1; options->identity_files[options->num_identity_files] = xmalloc(len); snprintf(options->identity_files[options->num_identity_files++], len, "~/%.100s", _PATH_SSH_CLIENT_IDENTITY); } if (options->protocol & SSH_PROTO_2) { len = 2 + strlen(_PATH_SSH_CLIENT_ID_RSA) + 1; options->identity_files[options->num_identity_files] = xmalloc(len); snprintf(options->identity_files[options->num_identity_files++], len, "~/%.100s", _PATH_SSH_CLIENT_ID_RSA); len = 2 + strlen(_PATH_SSH_CLIENT_ID_DSA) + 1; options->identity_files[options->num_identity_files] = xmalloc(len); snprintf(options->identity_files[options->num_identity_files++], len, "~/%.100s", _PATH_SSH_CLIENT_ID_DSA); #ifdef OPENSSL_HAS_ECC len = 2 + strlen(_PATH_SSH_CLIENT_ID_ECDSA) + 1; options->identity_files[options->num_identity_files] = xmalloc(len); snprintf(options->identity_files[options->num_identity_files++], len, "~/%.100s", _PATH_SSH_CLIENT_ID_ECDSA); #endif } } if (options->escape_char == -1) options->escape_char = '~'; if (options->num_system_hostfiles == 0) { options->system_hostfiles[options->num_system_hostfiles++] = xstrdup(_PATH_SSH_SYSTEM_HOSTFILE); options->system_hostfiles[options->num_system_hostfiles++] = xstrdup(_PATH_SSH_SYSTEM_HOSTFILE2); } if (options->num_user_hostfiles == 0) { options->user_hostfiles[options->num_user_hostfiles++] = xstrdup(_PATH_SSH_USER_HOSTFILE); options->user_hostfiles[options->num_user_hostfiles++] = xstrdup(_PATH_SSH_USER_HOSTFILE2); } if (options->log_level == SYSLOG_LEVEL_NOT_SET) options->log_level = SYSLOG_LEVEL_INFO; if (options->clear_forwardings == 1) clear_forwardings(options); if (options->no_host_authentication_for_localhost == - 1) options->no_host_authentication_for_localhost = 0; if (options->identities_only == -1) options->identities_only = 0; if (options->enable_ssh_keysign == -1) options->enable_ssh_keysign = 0; if (options->rekey_limit == -1) options->rekey_limit = 0; if (options->verify_host_key_dns == -1) options->verify_host_key_dns = 0; if (options->server_alive_interval == -1) options->server_alive_interval = 0; if (options->server_alive_count_max == -1) options->server_alive_count_max = 3; if (options->control_master == -1) options->control_master = 0; if (options->control_persist == -1) { options->control_persist = 0; options->control_persist_timeout = 0; } if (options->hash_known_hosts == -1) options->hash_known_hosts = 0; if (options->tun_open == -1) options->tun_open = SSH_TUNMODE_NO; if (options->tun_local == -1) options->tun_local = SSH_TUNID_ANY; if (options->tun_remote == -1) options->tun_remote = SSH_TUNID_ANY; if (options->permit_local_command == -1) options->permit_local_command = 0; if (options->use_roaming == -1) options->use_roaming = 1; if (options->visual_host_key == -1) options->visual_host_key = 0; if (options->zero_knowledge_password_authentication == -1) options->zero_knowledge_password_authentication = 0; if (options->ip_qos_interactive == -1) options->ip_qos_interactive = IPTOS_LOWDELAY; if (options->ip_qos_bulk == -1) options->ip_qos_bulk = IPTOS_THROUGHPUT; if (options->request_tty == -1) options->request_tty = REQUEST_TTY_AUTO; /* options->local_command should not be set by default */ /* options->proxy_command should not be set by default */ /* options->user will be set in the main program if appropriate */ /* options->hostname will be set in the main program if appropriate */ /* options->host_key_alias should not be set by default */ /* options->preferred_authentications will be set in ssh */ } /* * parse_forward * parses a string containing a port forwarding specification of the form: * dynamicfwd == 0 * [listenhost:]listenport:connecthost:connectport * dynamicfwd == 1 * [listenhost:]listenport * returns number of arguments parsed or zero on error */ int parse_forward(Forward *fwd, const char *fwdspec, int dynamicfwd, int remotefwd) { int i; char *p, *cp, *fwdarg[4]; memset(fwd, '\0', sizeof(*fwd)); cp = p = xstrdup(fwdspec); /* skip leading spaces */ while (isspace(*cp)) cp++; for (i = 0; i < 4; ++i) if ((fwdarg[i] = hpdelim(&cp)) == NULL) break; /* Check for trailing garbage */ if (cp != NULL) i = 0; /* failure */ switch (i) { case 1: fwd->listen_host = NULL; fwd->listen_port = a2port(fwdarg[0]); fwd->connect_host = xstrdup("socks"); break; case 2: fwd->listen_host = xstrdup(cleanhostname(fwdarg[0])); fwd->listen_port = a2port(fwdarg[1]); fwd->connect_host = xstrdup("socks"); break; case 3: fwd->listen_host = NULL; fwd->listen_port = a2port(fwdarg[0]); fwd->connect_host = xstrdup(cleanhostname(fwdarg[1])); fwd->connect_port = a2port(fwdarg[2]); break; case 4: fwd->listen_host = xstrdup(cleanhostname(fwdarg[0])); fwd->listen_port = a2port(fwdarg[1]); fwd->connect_host = xstrdup(cleanhostname(fwdarg[2])); fwd->connect_port = a2port(fwdarg[3]); break; default: i = 0; /* failure */ } xfree(p); if (dynamicfwd) { if (!(i == 1 || i == 2)) goto fail_free; } else { if (!(i == 3 || i == 4)) goto fail_free; if (fwd->connect_port <= 0) goto fail_free; } if (fwd->listen_port < 0 || (!remotefwd && fwd->listen_port == 0)) goto fail_free; if (fwd->connect_host != NULL && strlen(fwd->connect_host) >= NI_MAXHOST) goto fail_free; if (fwd->listen_host != NULL && strlen(fwd->listen_host) >= NI_MAXHOST) goto fail_free; return (i); fail_free: if (fwd->connect_host != NULL) { xfree(fwd->connect_host); fwd->connect_host = NULL; } if (fwd->listen_host != NULL) { xfree(fwd->listen_host); fwd->listen_host = NULL; } return (0); }