/* $OpenBSD: servconf.c,v 1.172 2007/04/23 10:15:39 dtucker Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * * 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 #include #include #include #include #include #include #include #include #include #include "xmalloc.h" #include "ssh.h" #include "log.h" #include "buffer.h" #include "servconf.h" #include "compat.h" #include "pathnames.h" #include "misc.h" #include "cipher.h" #include "key.h" #include "kex.h" #include "mac.h" #include "match.h" #include "channels.h" #include "groupaccess.h" static void add_listen_addr(ServerOptions *, char *, u_short); static void add_one_listen_addr(ServerOptions *, char *, u_short); /* Use of privilege separation or not */ extern int use_privsep; extern Buffer cfg; /* Initializes the server options to their default values. */ void initialize_server_options(ServerOptions *options) { memset(options, 0, sizeof(*options)); options->num_ports = 0; options->ports_from_cmdline = 0; options->listen_addrs = NULL; options->address_family = -1; options->num_host_key_files = 0; options->pid_file = NULL; options->server_key_bits = -1; options->login_grace_time = -1; options->key_regeneration_time = -1; options->permit_root_login = PERMIT_NOT_SET; options->ignore_rhosts = -1; options->ignore_user_known_hosts = -1; options->print_motd = -1; options->print_lastlog = -1; options->x11_forwarding = -1; options->x11_display_offset = -1; options->x11_use_localhost = -1; options->xauth_location = NULL; options->strict_modes = -1; options->tcp_keep_alive = -1; options->log_facility = SYSLOG_FACILITY_NOT_SET; options->log_level = SYSLOG_LEVEL_NOT_SET; options->rhosts_rsa_authentication = -1; options->hostbased_authentication = -1; options->hostbased_uses_name_from_packet_only = -1; options->rsa_authentication = -1; options->pubkey_authentication = -1; options->kerberos_authentication = -1; options->kerberos_or_local_passwd = -1; options->kerberos_ticket_cleanup = -1; options->kerberos_get_afs_token = -1; options->gss_authentication=-1; options->gss_cleanup_creds = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->challenge_response_authentication = -1; options->permit_empty_passwd = -1; options->permit_user_env = -1; options->use_login = -1; options->compression = -1; options->allow_tcp_forwarding = -1; options->num_allow_users = 0; options->num_deny_users = 0; options->num_allow_groups = 0; options->num_deny_groups = 0; options->ciphers = NULL; options->macs = NULL; options->protocol = SSH_PROTO_UNKNOWN; options->gateway_ports = -1; options->num_subsystems = 0; options->max_startups_begin = -1; options->max_startups_rate = -1; options->max_startups = -1; options->max_authtries = -1; options->banner = NULL; options->use_dns = -1; options->client_alive_interval = -1; options->client_alive_count_max = -1; options->authorized_keys_file = NULL; options->authorized_keys_file2 = NULL; options->num_accept_env = 0; options->permit_tun = -1; options->num_permitted_opens = -1; options->adm_forced_command = NULL; } void fill_default_server_options(ServerOptions *options) { if (options->protocol == SSH_PROTO_UNKNOWN) options->protocol = SSH_PROTO_1|SSH_PROTO_2; if (options->num_host_key_files == 0) { /* fill default hostkeys for protocols */ if (options->protocol & SSH_PROTO_1) options->host_key_files[options->num_host_key_files++] = _PATH_HOST_KEY_FILE; if (options->protocol & SSH_PROTO_2) { options->host_key_files[options->num_host_key_files++] = _PATH_HOST_RSA_KEY_FILE; options->host_key_files[options->num_host_key_files++] = _PATH_HOST_DSA_KEY_FILE; } } if (options->num_ports == 0) options->ports[options->num_ports++] = SSH_DEFAULT_PORT; if (options->listen_addrs == NULL) add_listen_addr(options, NULL, 0); if (options->pid_file == NULL) options->pid_file = _PATH_SSH_DAEMON_PID_FILE; if (options->server_key_bits == -1) options->server_key_bits = 768; if (options->login_grace_time == -1) options->login_grace_time = 120; if (options->key_regeneration_time == -1) options->key_regeneration_time = 3600; if (options->permit_root_login == PERMIT_NOT_SET) options->permit_root_login = PERMIT_YES; if (options->ignore_rhosts == -1) options->ignore_rhosts = 1; if (options->ignore_user_known_hosts == -1) options->ignore_user_known_hosts = 0; if (options->print_motd == -1) options->print_motd = 1; if (options->print_lastlog == -1) options->print_lastlog = 1; if (options->x11_forwarding == -1) options->x11_forwarding = 0; if (options->x11_display_offset == -1) options->x11_display_offset = 10; if (options->x11_use_localhost == -1) options->x11_use_localhost = 1; if (options->xauth_location == NULL) options->xauth_location = _PATH_XAUTH; if (options->strict_modes == -1) options->strict_modes = 1; if (options->tcp_keep_alive == -1) options->tcp_keep_alive = 1; if (options->log_facility == SYSLOG_FACILITY_NOT_SET) options->log_facility = SYSLOG_FACILITY_AUTH; if (options->log_level == SYSLOG_LEVEL_NOT_SET) options->log_level = SYSLOG_LEVEL_INFO; if (options->rhosts_rsa_authentication == -1) options->rhosts_rsa_authentication = 0; if (options->hostbased_authentication == -1) options->hostbased_authentication = 0; if (options->hostbased_uses_name_from_packet_only == -1) options->hostbased_uses_name_from_packet_only = 0; if (options->rsa_authentication == -1) options->rsa_authentication = 1; if (options->pubkey_authentication == -1) options->pubkey_authentication = 1; if (options->kerberos_authentication == -1) options->kerberos_authentication = 0; if (options->kerberos_or_local_passwd == -1) options->kerberos_or_local_passwd = 1; if (options->kerberos_ticket_cleanup == -1) options->kerberos_ticket_cleanup = 1; if (options->kerberos_get_afs_token == -1) options->kerberos_get_afs_token = 0; if (options->gss_authentication == -1) options->gss_authentication = 0; if (options->gss_cleanup_creds == -1) options->gss_cleanup_creds = 1; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) options->kbd_interactive_authentication = 0; if (options->challenge_response_authentication == -1) options->challenge_response_authentication = 1; if (options->permit_empty_passwd == -1) options->permit_empty_passwd = 0; if (options->permit_user_env == -1) options->permit_user_env = 0; if (options->use_login == -1) options->use_login = 0; if (options->compression == -1) options->compression = COMP_DELAYED; if (options->allow_tcp_forwarding == -1) options->allow_tcp_forwarding = 1; if (options->gateway_ports == -1) options->gateway_ports = 0; if (options->max_startups == -1) options->max_startups = 10; if (options->max_startups_rate == -1) options->max_startups_rate = 100; /* 100% */ if (options->max_startups_begin == -1) options->max_startups_begin = options->max_startups; if (options->max_authtries == -1) options->max_authtries = DEFAULT_AUTH_FAIL_MAX; if (options->use_dns == -1) options->use_dns = 1; if (options->client_alive_interval == -1) options->client_alive_interval = 0; if (options->client_alive_count_max == -1) options->client_alive_count_max = 3; if (options->authorized_keys_file2 == NULL) { /* authorized_keys_file2 falls back to authorized_keys_file */ if (options->authorized_keys_file != NULL) options->authorized_keys_file2 = options->authorized_keys_file; else options->authorized_keys_file2 = _PATH_SSH_USER_PERMITTED_KEYS2; } if (options->authorized_keys_file == NULL) options->authorized_keys_file = _PATH_SSH_USER_PERMITTED_KEYS; if (options->permit_tun == -1) options->permit_tun = SSH_TUNMODE_NO; /* Turn privilege separation on by default */ if (use_privsep == -1) use_privsep = 1; } /* Keyword tokens. */ typedef enum { sBadOption, /* == unknown option */ sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime, sPermitRootLogin, sLogFacility, sLogLevel, sRhostsRSAAuthentication, sRSAAuthentication, sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup, sKerberosGetAFSToken, sKerberosTgtPassing, sChallengeResponseAuthentication, sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress, sAddressFamily, sPrintMotd, sPrintLastLog, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset, sX11UseLocalhost, sStrictModes, sEmptyPasswd, sTCPKeepAlive, sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups, sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile, sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem, sMaxStartups, sMaxAuthTries, sBanner, sUseDNS, sHostbasedAuthentication, sHostbasedUsesNameFromPacketOnly, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sAuthorizedKeysFile2, sGssAuthentication, sGssCleanupCreds, sAcceptEnv, sPermitTunnel, sMatch, sPermitOpen, sForceCommand, sUsePrivilegeSeparation, sDeprecated, sUnsupported } ServerOpCodes; #define SSHCFG_GLOBAL 0x01 /* allowed in main section of sshd_config */ #define SSHCFG_MATCH 0x02 /* allowed inside a Match section */ #define SSHCFG_ALL (SSHCFG_GLOBAL|SSHCFG_MATCH) /* Textual representation of the tokens. */ static struct { const char *name; ServerOpCodes opcode; u_int flags; } keywords[] = { { "port", sPort, SSHCFG_GLOBAL }, { "hostkey", sHostKeyFile, SSHCFG_GLOBAL }, { "hostdsakey", sHostKeyFile, SSHCFG_GLOBAL }, /* alias */ { "pidfile", sPidFile, SSHCFG_GLOBAL }, { "serverkeybits", sServerKeyBits, SSHCFG_GLOBAL }, { "logingracetime", sLoginGraceTime, SSHCFG_GLOBAL }, { "keyregenerationinterval", sKeyRegenerationTime, SSHCFG_GLOBAL }, { "permitrootlogin", sPermitRootLogin, SSHCFG_GLOBAL }, { "syslogfacility", sLogFacility, SSHCFG_GLOBAL }, { "loglevel", sLogLevel, SSHCFG_GLOBAL }, { "rhostsauthentication", sDeprecated, SSHCFG_GLOBAL }, { "rhostsrsaauthentication", sRhostsRSAAuthentication, SSHCFG_ALL }, { "hostbasedauthentication", sHostbasedAuthentication, SSHCFG_ALL }, { "hostbasedusesnamefrompacketonly", sHostbasedUsesNameFromPacketOnly, SSHCFG_GLOBAL }, { "rsaauthentication", sRSAAuthentication, SSHCFG_ALL }, { "pubkeyauthentication", sPubkeyAuthentication, SSHCFG_ALL }, { "dsaauthentication", sPubkeyAuthentication, SSHCFG_GLOBAL }, /* alias */ #ifdef KRB5 { "kerberosauthentication", sKerberosAuthentication, SSHCFG_ALL }, { "kerberosorlocalpasswd", sKerberosOrLocalPasswd, SSHCFG_GLOBAL }, { "kerberosticketcleanup", sKerberosTicketCleanup, SSHCFG_GLOBAL }, { "kerberosgetafstoken", sKerberosGetAFSToken, SSHCFG_GLOBAL }, #else { "kerberosauthentication", sUnsupported, SSHCFG_ALL }, { "kerberosorlocalpasswd", sUnsupported, SSHCFG_GLOBAL }, { "kerberosticketcleanup", sUnsupported, SSHCFG_GLOBAL }, { "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL }, #endif { "kerberostgtpassing", sUnsupported, SSHCFG_GLOBAL }, { "afstokenpassing", sUnsupported, SSHCFG_GLOBAL }, #ifdef GSSAPI { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL }, { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL }, #else { "gssapiauthentication", sUnsupported, SSHCFG_ALL }, { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL }, #endif { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL }, { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, { "skeyauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, /* alias */ { "checkmail", sDeprecated, SSHCFG_GLOBAL }, { "listenaddress", sListenAddress, SSHCFG_GLOBAL }, { "addressfamily", sAddressFamily, SSHCFG_GLOBAL }, { "printmotd", sPrintMotd, SSHCFG_GLOBAL }, { "printlastlog", sPrintLastLog, SSHCFG_GLOBAL }, { "ignorerhosts", sIgnoreRhosts, SSHCFG_GLOBAL }, { "ignoreuserknownhosts", sIgnoreUserKnownHosts, SSHCFG_GLOBAL }, { "x11forwarding", sX11Forwarding, SSHCFG_ALL }, { "x11displayoffset", sX11DisplayOffset, SSHCFG_ALL }, { "x11uselocalhost", sX11UseLocalhost, SSHCFG_ALL }, { "xauthlocation", sXAuthLocation, SSHCFG_GLOBAL }, { "strictmodes", sStrictModes, SSHCFG_GLOBAL }, { "permitemptypasswords", sEmptyPasswd, SSHCFG_GLOBAL }, { "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL }, { "uselogin", sUseLogin, SSHCFG_GLOBAL }, { "compression", sCompression, SSHCFG_GLOBAL }, { "tcpkeepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, { "keepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, /* obsolete alias */ { "allowtcpforwarding", sAllowTcpForwarding, SSHCFG_ALL }, { "allowusers", sAllowUsers, SSHCFG_GLOBAL }, { "denyusers", sDenyUsers, SSHCFG_GLOBAL }, { "allowgroups", sAllowGroups, SSHCFG_GLOBAL }, { "denygroups", sDenyGroups, SSHCFG_GLOBAL }, { "ciphers", sCiphers, SSHCFG_GLOBAL }, { "macs", sMacs, SSHCFG_GLOBAL }, { "protocol", sProtocol, SSHCFG_GLOBAL }, { "gatewayports", sGatewayPorts, SSHCFG_ALL }, { "subsystem", sSubsystem, SSHCFG_GLOBAL }, { "maxstartups", sMaxStartups, SSHCFG_GLOBAL }, { "maxauthtries", sMaxAuthTries, SSHCFG_GLOBAL }, { "banner", sBanner, SSHCFG_ALL }, { "usedns", sUseDNS, SSHCFG_GLOBAL }, { "verifyreversemapping", sDeprecated, SSHCFG_GLOBAL }, { "reversemappingcheck", sDeprecated, SSHCFG_GLOBAL }, { "clientaliveinterval", sClientAliveInterval, SSHCFG_GLOBAL }, { "clientalivecountmax", sClientAliveCountMax, SSHCFG_GLOBAL }, { "authorizedkeysfile", sAuthorizedKeysFile, SSHCFG_GLOBAL }, { "authorizedkeysfile2", sAuthorizedKeysFile2, SSHCFG_GLOBAL }, { "useprivilegeseparation", sUsePrivilegeSeparation, SSHCFG_GLOBAL}, { "acceptenv", sAcceptEnv, SSHCFG_GLOBAL }, { "permittunnel", sPermitTunnel, SSHCFG_GLOBAL }, { "match", sMatch, SSHCFG_ALL }, { "permitopen", sPermitOpen, SSHCFG_ALL }, { "forcecommand", sForceCommand, SSHCFG_ALL }, { NULL, sBadOption, 0 } }; /* * Returns the number of the token pointed to by cp or sBadOption. */ static ServerOpCodes parse_token(const char *cp, const char *filename, int linenum, u_int *flags) { u_int i; for (i = 0; keywords[i].name; i++) if (strcasecmp(cp, keywords[i].name) == 0) { *flags = keywords[i].flags; return keywords[i].opcode; } error("%s: line %d: Bad configuration option: %s", filename, linenum, cp); return sBadOption; } static void add_listen_addr(ServerOptions *options, char *addr, u_short port) { u_int i; if (options->num_ports == 0) options->ports[options->num_ports++] = SSH_DEFAULT_PORT; if (options->address_family == -1) options->address_family = AF_UNSPEC; if (port == 0) for (i = 0; i < options->num_ports; i++) add_one_listen_addr(options, addr, options->ports[i]); else add_one_listen_addr(options, addr, port); } static void add_one_listen_addr(ServerOptions *options, char *addr, u_short port) { struct addrinfo hints, *ai, *aitop; char strport[NI_MAXSERV]; int gaierr; memset(&hints, 0, sizeof(hints)); hints.ai_family = options->address_family; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0; snprintf(strport, sizeof strport, "%u", port); if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0) fatal("bad addr or host: %s (%s)", addr ? addr : "", gai_strerror(gaierr)); for (ai = aitop; ai->ai_next; ai = ai->ai_next) ; ai->ai_next = options->listen_addrs; options->listen_addrs = aitop; } /* * The strategy for the Match blocks is that the config file is parsed twice. * * The first time is at startup. activep is initialized to 1 and the * directives in the global context are processed and acted on. Hitting a * Match directive unsets activep and the directives inside the block are * checked for syntax only. * * The second time is after a connection has been established but before * authentication. activep is initialized to 2 and global config directives * are ignored since they have already been processed. If the criteria in a * Match block is met, activep is set and the subsequent directives * processed and actioned until EOF or another Match block unsets it. Any * options set are copied into the main server config. * * Potential additions/improvements: * - Add Match support for pre-kex directives, eg Protocol, Ciphers. * * - Add a Tag directive (idea from David Leonard) ala pf, eg: * Match Address 192.168.0.* * Tag trusted * Match Group wheel * Tag trusted * Match Tag trusted * AllowTcpForwarding yes * GatewayPorts clientspecified * [...] * * - Add a PermittedChannelRequests directive * Match Group shell * PermittedChannelRequests session,forwarded-tcpip */ static int match_cfg_line_group(const char *grps, int line, const char *user) { int result = 0; u_int ngrps = 0; char *arg, *p, *cp, *grplist[MAX_MATCH_GROUPS]; struct passwd *pw; /* * Even if we do not have a user yet, we still need to check for * valid syntax. */ arg = cp = xstrdup(grps); while ((p = strsep(&cp, ",")) != NULL && *p != '\0') { if (ngrps >= MAX_MATCH_GROUPS) { error("line %d: too many groups in Match Group", line); result = -1; goto out; } grplist[ngrps++] = p; } if (user == NULL) goto out; if ((pw = getpwnam(user)) == NULL) { debug("Can't match group at line %d because user %.100s does " "not exist", line, user); } else if (ga_init(pw->pw_name, pw->pw_gid) == 0) { debug("Can't Match group because user %.100s not in any group " "at line %d", user, line); } else if (ga_match(grplist, ngrps) != 1) { debug("user %.100s does not match group %.100s at line %d", user, arg, line); } else { debug("user %.100s matched group %.100s at line %d", user, arg, line); result = 1; } out: ga_free(); xfree(arg); return result; } static int match_cfg_line(char **condition, int line, const char *user, const char *host, const char *address) { int result = 1; char *arg, *attrib, *cp = *condition; size_t len; if (user == NULL) debug3("checking syntax for 'Match %s'", cp); else debug3("checking match for '%s' user %s host %s addr %s", cp, user ? user : "(null)", host ? host : "(null)", address ? address : "(null)"); while ((attrib = strdelim(&cp)) && *attrib != '\0') { if ((arg = strdelim(&cp)) == NULL || *arg == '\0') { error("Missing Match criteria for %s", attrib); return -1; } len = strlen(arg); if (strcasecmp(attrib, "user") == 0) { if (!user) { result = 0; continue; } if (match_pattern_list(user, arg, len, 0) != 1) result = 0; else debug("user %.100s matched 'User %.100s' at " "line %d", user, arg, line); } else if (strcasecmp(attrib, "group") == 0) { switch (match_cfg_line_group(arg, line, user)) { case -1: return -1; case 0: result = 0; } } else if (strcasecmp(attrib, "host") == 0) { if (!host) { result = 0; continue; } if (match_hostname(host, arg, len) != 1) result = 0; else debug("connection from %.100s matched 'Host " "%.100s' at line %d", host, arg, line); } else if (strcasecmp(attrib, "address") == 0) { if (!address) { result = 0; continue; } if (match_hostname(address, arg, len) != 1) result = 0; else debug("connection from %.100s matched 'Address " "%.100s' at line %d", address, arg, line); } else { error("Unsupported Match attribute %s", attrib); return -1; } } if (user != NULL) debug3("match %sfound", result ? "" : "not "); *condition = cp; return result; } #define WHITESPACE " \t\r\n" int process_server_config_line(ServerOptions *options, char *line, const char *filename, int linenum, int *activep, const char *user, const char *host, const char *address) { char *cp, **charptr, *arg, *p; int cmdline = 0, *intptr, value, n; ServerOpCodes opcode; u_short port; u_int i, flags = 0; size_t len; cp = line; if ((arg = strdelim(&cp)) == NULL) return 0; /* Ignore leading whitespace */ if (*arg == '\0') arg = strdelim(&cp); if (!arg || !*arg || *arg == '#') return 0; intptr = NULL; charptr = NULL; opcode = parse_token(arg, filename, linenum, &flags); if (activep == NULL) { /* We are processing a command line directive */ cmdline = 1; activep = &cmdline; } if (*activep && opcode != sMatch) debug3("%s:%d setting %s %s", filename, linenum, arg, cp); if (*activep == 0 && !(flags & SSHCFG_MATCH)) { if (user == NULL) { fatal("%s line %d: Directive '%s' is not allowed " "within a Match block", filename, linenum, arg); } else { /* this is a directive we have already processed */ while (arg) arg = strdelim(&cp); return 0; } } switch (opcode) { case sBadOption: return -1; case sPort: /* ignore ports from configfile if cmdline specifies ports */ if (options->ports_from_cmdline) return 0; if (options->listen_addrs != NULL) fatal("%s line %d: ports must be specified before " "ListenAddress.", filename, linenum); if (options->num_ports >= MAX_PORTS) fatal("%s line %d: too many ports.", filename, linenum); arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing port number.", filename, linenum); options->ports[options->num_ports++] = a2port(arg); if (options->ports[options->num_ports-1] == 0) fatal("%s line %d: Badly formatted port number.", filename, linenum); break; case sServerKeyBits: intptr = &options->server_key_bits; parse_int: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing integer value.", filename, linenum); value = atoi(arg); if (*activep && *intptr == -1) *intptr = value; break; case sLoginGraceTime: intptr = &options->login_grace_time; parse_time: arg = strdelim(&cp); 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 (*intptr == -1) *intptr = value; break; case sKeyRegenerationTime: intptr = &options->key_regeneration_time; goto parse_time; case sListenAddress: arg = strdelim(&cp); if (arg == NULL || *arg == '\0') fatal("%s line %d: missing address", filename, linenum); /* check for bare IPv6 address: no "[]" and 2 or more ":" */ if (strchr(arg, '[') == NULL && (p = strchr(arg, ':')) != NULL && strchr(p+1, ':') != NULL) { add_listen_addr(options, arg, 0); break; } p = hpdelim(&arg); if (p == NULL) fatal("%s line %d: bad address:port usage", filename, linenum); p = cleanhostname(p); if (arg == NULL) port = 0; else if ((port = a2port(arg)) == 0) fatal("%s line %d: bad port number", filename, linenum); add_listen_addr(options, p, port); break; case sAddressFamily: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing address family.", filename, linenum); intptr = &options->address_family; if (options->listen_addrs != NULL) fatal("%s line %d: address family must be specified before " "ListenAddress.", filename, linenum); 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("%s line %d: unsupported address family \"%s\".", filename, linenum, arg); if (*intptr == -1) *intptr = value; break; case sHostKeyFile: intptr = &options->num_host_key_files; if (*intptr >= MAX_HOSTKEYS) fatal("%s line %d: too many host keys specified (max %d).", filename, linenum, MAX_HOSTKEYS); charptr = &options->host_key_files[*intptr]; parse_filename: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing file name.", filename, linenum); if (*activep && *charptr == NULL) { *charptr = tilde_expand_filename(arg, getuid()); /* increase optional counter */ if (intptr != NULL) *intptr = *intptr + 1; } break; case sPidFile: charptr = &options->pid_file; goto parse_filename; case sPermitRootLogin: intptr = &options->permit_root_login; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing yes/" "without-password/forced-commands-only/no " "argument.", filename, linenum); value = 0; /* silence compiler */ if (strcmp(arg, "without-password") == 0) value = PERMIT_NO_PASSWD; else if (strcmp(arg, "forced-commands-only") == 0) value = PERMIT_FORCED_ONLY; else if (strcmp(arg, "yes") == 0) value = PERMIT_YES; else if (strcmp(arg, "no") == 0) value = PERMIT_NO; else fatal("%s line %d: Bad yes/" "without-password/forced-commands-only/no " "argument: %s", filename, linenum, arg); if (*intptr == -1) *intptr = value; break; case sIgnoreRhosts: intptr = &options->ignore_rhosts; parse_flag: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing yes/no argument.", filename, linenum); value = 0; /* silence compiler */ if (strcmp(arg, "yes") == 0) value = 1; else if (strcmp(arg, "no") == 0) value = 0; else fatal("%s line %d: Bad yes/no argument: %s", filename, linenum, arg); if (*activep && *intptr == -1) *intptr = value; break; case sIgnoreUserKnownHosts: intptr = &options->ignore_user_known_hosts; goto parse_flag; case sRhostsRSAAuthentication: intptr = &options->rhosts_rsa_authentication; goto parse_flag; case sHostbasedAuthentication: intptr = &options->hostbased_authentication; goto parse_flag; case sHostbasedUsesNameFromPacketOnly: intptr = &options->hostbased_uses_name_from_packet_only; goto parse_flag; case sRSAAuthentication: intptr = &options->rsa_authentication; goto parse_flag; case sPubkeyAuthentication: intptr = &options->pubkey_authentication; goto parse_flag; case sKerberosAuthentication: intptr = &options->kerberos_authentication; goto parse_flag; case sKerberosOrLocalPasswd: intptr = &options->kerberos_or_local_passwd; goto parse_flag; case sKerberosTicketCleanup: intptr = &options->kerberos_ticket_cleanup; goto parse_flag; case sKerberosGetAFSToken: intptr = &options->kerberos_get_afs_token; goto parse_flag; case sGssAuthentication: intptr = &options->gss_authentication; goto parse_flag; case sGssCleanupCreds: intptr = &options->gss_cleanup_creds; goto parse_flag; case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; case sKbdInteractiveAuthentication: intptr = &options->kbd_interactive_authentication; goto parse_flag; case sChallengeResponseAuthentication: intptr = &options->challenge_response_authentication; goto parse_flag; case sPrintMotd: intptr = &options->print_motd; goto parse_flag; case sPrintLastLog: intptr = &options->print_lastlog; goto parse_flag; case sX11Forwarding: intptr = &options->x11_forwarding; goto parse_flag; case sX11DisplayOffset: intptr = &options->x11_display_offset; goto parse_int; case sX11UseLocalhost: intptr = &options->x11_use_localhost; goto parse_flag; case sXAuthLocation: charptr = &options->xauth_location; goto parse_filename; case sStrictModes: intptr = &options->strict_modes; goto parse_flag; case sTCPKeepAlive: intptr = &options->tcp_keep_alive; goto parse_flag; case sEmptyPasswd: intptr = &options->permit_empty_passwd; goto parse_flag; case sPermitUserEnvironment: intptr = &options->permit_user_env; goto parse_flag; case sUseLogin: intptr = &options->use_login; goto parse_flag; case sCompression: intptr = &options->compression; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing yes/no/delayed " "argument.", filename, linenum); value = 0; /* silence compiler */ if (strcmp(arg, "delayed") == 0) value = COMP_DELAYED; else if (strcmp(arg, "yes") == 0) value = COMP_ZLIB; else if (strcmp(arg, "no") == 0) value = COMP_NONE; else fatal("%s line %d: Bad yes/no/delayed " "argument: %s", filename, linenum, arg); if (*intptr == -1) *intptr = value; break; case sGatewayPorts: intptr = &options->gateway_ports; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing yes/no/clientspecified " "argument.", filename, linenum); value = 0; /* silence compiler */ if (strcmp(arg, "clientspecified") == 0) value = 2; else if (strcmp(arg, "yes") == 0) value = 1; else if (strcmp(arg, "no") == 0) value = 0; else fatal("%s line %d: Bad yes/no/clientspecified " "argument: %s", filename, linenum, arg); if (*activep && *intptr == -1) *intptr = value; break; case sUseDNS: intptr = &options->use_dns; goto parse_flag; case sLogFacility: intptr = (int *) &options->log_facility; arg = strdelim(&cp); value = log_facility_number(arg); if (value == SYSLOG_FACILITY_NOT_SET) fatal("%.200s line %d: unsupported log facility '%s'", filename, linenum, arg ? arg : ""); if (*intptr == -1) *intptr = (SyslogFacility) value; break; case sLogLevel: intptr = (int *) &options->log_level; arg = strdelim(&cp); value = log_level_number(arg); if (value == SYSLOG_LEVEL_NOT_SET) fatal("%.200s line %d: unsupported log level '%s'", filename, linenum, arg ? arg : ""); if (*intptr == -1) *intptr = (LogLevel) value; break; case sAllowTcpForwarding: intptr = &options->allow_tcp_forwarding; goto parse_flag; case sUsePrivilegeSeparation: intptr = &use_privsep; goto parse_flag; case sAllowUsers: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_allow_users >= MAX_ALLOW_USERS) fatal("%s line %d: too many allow users.", filename, linenum); options->allow_users[options->num_allow_users++] = xstrdup(arg); } break; case sDenyUsers: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_deny_users >= MAX_DENY_USERS) fatal("%s line %d: too many deny users.", filename, linenum); options->deny_users[options->num_deny_users++] = xstrdup(arg); } break; case sAllowGroups: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_allow_groups >= MAX_ALLOW_GROUPS) fatal("%s line %d: too many allow groups.", filename, linenum); options->allow_groups[options->num_allow_groups++] = xstrdup(arg); } break; case sDenyGroups: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_deny_groups >= MAX_DENY_GROUPS) fatal("%s line %d: too many deny groups.", filename, linenum); options->deny_groups[options->num_deny_groups++] = xstrdup(arg); } break; case sCiphers: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!ciphers_valid(arg)) fatal("%s line %d: Bad SSH2 cipher spec '%s'.", filename, linenum, arg ? arg : ""); if (options->ciphers == NULL) options->ciphers = xstrdup(arg); break; case sMacs: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!mac_valid(arg)) fatal("%s line %d: Bad SSH2 mac spec '%s'.", filename, linenum, arg ? arg : ""); if (options->macs == NULL) options->macs = xstrdup(arg); break; case sProtocol: intptr = &options->protocol; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); value = proto_spec(arg); if (value == SSH_PROTO_UNKNOWN) fatal("%s line %d: Bad protocol spec '%s'.", filename, linenum, arg ? arg : ""); if (*intptr == SSH_PROTO_UNKNOWN) *intptr = value; break; case sSubsystem: if (options->num_subsystems >= MAX_SUBSYSTEMS) { fatal("%s line %d: too many subsystems defined.", filename, linenum); } arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing subsystem name.", filename, linenum); if (!*activep) { arg = strdelim(&cp); break; } for (i = 0; i < options->num_subsystems; i++) if (strcmp(arg, options->subsystem_name[i]) == 0) fatal("%s line %d: Subsystem '%s' already defined.", filename, linenum, arg); options->subsystem_name[options->num_subsystems] = xstrdup(arg); arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing subsystem command.", filename, linenum); options->subsystem_command[options->num_subsystems] = xstrdup(arg); /* Collect arguments (separate to executable) */ p = xstrdup(arg); len = strlen(p) + 1; while ((arg = strdelim(&cp)) != NULL && *arg != '\0') { len += 1 + strlen(arg); p = xrealloc(p, 1, len); strlcat(p, " ", len); strlcat(p, arg, len); } options->subsystem_args[options->num_subsystems] = p; options->num_subsystems++; break; case sMaxStartups: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing MaxStartups spec.", filename, linenum); if ((n = sscanf(arg, "%d:%d:%d", &options->max_startups_begin, &options->max_startups_rate, &options->max_startups)) == 3) { if (options->max_startups_begin > options->max_startups || options->max_startups_rate > 100 || options->max_startups_rate < 1) fatal("%s line %d: Illegal MaxStartups spec.", filename, linenum); } else if (n != 1) fatal("%s line %d: Illegal MaxStartups spec.", filename, linenum); else options->max_startups = options->max_startups_begin; break; case sMaxAuthTries: intptr = &options->max_authtries; goto parse_int; case sBanner: charptr = &options->banner; goto parse_filename; /* * These options can contain %X options expanded at * connect time, so that you can specify paths like: * * AuthorizedKeysFile /etc/ssh_keys/%u */ case sAuthorizedKeysFile: case sAuthorizedKeysFile2: charptr = (opcode == sAuthorizedKeysFile) ? &options->authorized_keys_file : &options->authorized_keys_file2; goto parse_filename; case sClientAliveInterval: intptr = &options->client_alive_interval; goto parse_time; case sClientAliveCountMax: intptr = &options->client_alive_count_max; goto parse_int; case sAcceptEnv: while ((arg = strdelim(&cp)) && *arg != '\0') { if (strchr(arg, '=') != NULL) fatal("%s line %d: Invalid environment name.", filename, linenum); if (options->num_accept_env >= MAX_ACCEPT_ENV) fatal("%s line %d: too many allow env.", filename, linenum); if (!*activep) break; options->accept_env[options->num_accept_env++] = xstrdup(arg); } break; case sPermitTunnel: intptr = &options->permit_tun; arg = strdelim(&cp); 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_YES; 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 (*intptr == -1) *intptr = value; break; case sMatch: if (cmdline) fatal("Match directive not supported as a command-line " "option"); value = match_cfg_line(&cp, linenum, user, host, address); if (value < 0) fatal("%s line %d: Bad Match condition", filename, linenum); *activep = value; break; case sPermitOpen: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing PermitOpen specification", filename, linenum); n = options->num_permitted_opens; /* modified later */ if (strcmp(arg, "any") == 0) { if (*activep && n == -1) { channel_clear_adm_permitted_opens(); options->num_permitted_opens = 0; } break; } if (*activep && n == -1) channel_clear_adm_permitted_opens(); for (; arg != NULL && *arg != '\0'; arg = strdelim(&cp)) { p = hpdelim(&arg); if (p == NULL) fatal("%s line %d: missing host in PermitOpen", filename, linenum); p = cleanhostname(p); if (arg == NULL || (port = a2port(arg)) == 0) fatal("%s line %d: bad port number in " "PermitOpen", filename, linenum); if (*activep && n == -1) options->num_permitted_opens = channel_add_adm_permitted_opens(p, port); } break; case sForceCommand: if (cp == NULL) fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->adm_forced_command == NULL) options->adm_forced_command = xstrdup(cp + len); return 0; case sDeprecated: logit("%s line %d: Deprecated option %s", filename, linenum, arg); while (arg) arg = strdelim(&cp); break; case sUnsupported: logit("%s line %d: Unsupported option %s", filename, linenum, arg); while (arg) arg = strdelim(&cp); break; default: fatal("%s line %d: Missing handler for opcode %s (%d)", filename, linenum, arg, opcode); } if ((arg = strdelim(&cp)) != NULL && *arg != '\0') fatal("%s line %d: garbage at end of line; \"%.200s\".", filename, linenum, arg); return 0; } /* Reads the server configuration file. */ void load_server_config(const char *filename, Buffer *conf) { char line[1024], *cp; FILE *f; debug2("%s: filename %s", __func__, filename); if ((f = fopen(filename, "r")) == NULL) { perror(filename); exit(1); } buffer_clear(conf); while (fgets(line, sizeof(line), f)) { /* * Trim out comments and strip whitespace * NB - preserve newlines, they are needed to reproduce * line numbers later for error messages */ if ((cp = strchr(line, '#')) != NULL) memcpy(cp, "\n", 2); cp = line + strspn(line, " \t\r"); buffer_append(conf, cp, strlen(cp)); } buffer_append(conf, "\0", 1); fclose(f); debug2("%s: done config len = %d", __func__, buffer_len(conf)); } void parse_server_match_config(ServerOptions *options, const char *user, const char *host, const char *address) { ServerOptions mo; initialize_server_options(&mo); parse_server_config(&mo, "reprocess config", &cfg, user, host, address); copy_set_server_options(options, &mo, 0); } /* Helper macros */ #define M_CP_INTOPT(n) do {\ if (src->n != -1) \ dst->n = src->n; \ } while (0) #define M_CP_STROPT(n) do {\ if (src->n != NULL) { \ if (dst->n != NULL) \ xfree(dst->n); \ dst->n = src->n; \ } \ } while(0) /* * Copy any supported values that are set. * * If the preauth flag is set, we do not bother copying the the string or * array values that are not used pre-authentication, because any that we * do use must be explictly sent in mm_getpwnamallow(). */ void copy_set_server_options(ServerOptions *dst, ServerOptions *src, int preauth) { M_CP_INTOPT(password_authentication); M_CP_INTOPT(gss_authentication); M_CP_INTOPT(rsa_authentication); M_CP_INTOPT(pubkey_authentication); M_CP_INTOPT(kerberos_authentication); M_CP_INTOPT(hostbased_authentication); M_CP_INTOPT(kbd_interactive_authentication); M_CP_INTOPT(allow_tcp_forwarding); M_CP_INTOPT(gateway_ports); M_CP_INTOPT(x11_display_offset); M_CP_INTOPT(x11_forwarding); M_CP_INTOPT(x11_use_localhost); M_CP_STROPT(banner); if (preauth) return; M_CP_STROPT(adm_forced_command); } #undef M_CP_INTOPT #undef M_CP_STROPT void parse_server_config(ServerOptions *options, const char *filename, Buffer *conf, const char *user, const char *host, const char *address) { int active, linenum, bad_options = 0; char *cp, *obuf, *cbuf; debug2("%s: config %s len %d", __func__, filename, buffer_len(conf)); obuf = cbuf = xstrdup(buffer_ptr(conf)); active = user ? 0 : 1; linenum = 1; while ((cp = strsep(&cbuf, "\n")) != NULL) { if (process_server_config_line(options, cp, filename, linenum++, &active, user, host, address) != 0) bad_options++; } xfree(obuf); if (bad_options > 0) fatal("%s: terminating, %d bad configuration options", filename, bad_options); }