/* $OpenBSD: servconf.c,v 1.260 2015/02/02 01:57:44 deraadt 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 "includes.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_UTIL_H #include #endif #include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "ssh.h" #include "log.h" #include "buffer.h" #include "misc.h" #include "servconf.h" #include "compat.h" #include "pathnames.h" #include "cipher.h" #include "key.h" #include "kex.h" #include "mac.h" #include "match.h" #include "channels.h" #include "groupaccess.h" #include "canohost.h" #include "packet.h" #include "hostfile.h" #include "auth.h" #include "myproposal.h" #include "digest.h" #ifdef ANDROID #include #endif static void add_listen_addr(ServerOptions *, char *, int); static void add_one_listen_addr(ServerOptions *, char *, int); /* 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)); /* Portable-specific options */ options->use_pam = -1; /* Standard 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->num_host_cert_files = 0; options->host_key_agent = NULL; 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->permit_tty = -1; options->permit_user_rc = -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->hostbased_key_types = NULL; options->rsa_authentication = -1; options->pubkey_authentication = -1; options->pubkey_key_types = NULL; 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->rekey_limit = -1; options->rekey_interval = -1; options->allow_tcp_forwarding = -1; options->allow_streamlocal_forwarding = -1; options->allow_agent_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->kex_algorithms = NULL; options->protocol = SSH_PROTO_UNKNOWN; options->fwd_opts.gateway_ports = -1; options->fwd_opts.streamlocal_bind_mask = (mode_t)-1; options->fwd_opts.streamlocal_bind_unlink = -1; options->num_subsystems = 0; options->max_startups_begin = -1; options->max_startups_rate = -1; options->max_startups = -1; options->max_authtries = -1; options->max_sessions = -1; options->banner = NULL; options->use_dns = -1; options->client_alive_interval = -1; options->client_alive_count_max = -1; options->num_authkeys_files = 0; options->num_accept_env = 0; options->permit_tun = -1; options->num_permitted_opens = -1; options->adm_forced_command = NULL; options->chroot_directory = NULL; options->authorized_keys_command = NULL; options->authorized_keys_command_user = NULL; options->revoked_keys_file = NULL; options->trusted_user_ca_keys = NULL; options->authorized_principals_file = NULL; options->ip_qos_interactive = -1; options->ip_qos_bulk = -1; options->version_addendum = NULL; options->fingerprint_hash = -1; } /* Returns 1 if a string option is unset or set to "none" or 0 otherwise. */ static int option_clear_or_none(const char *o) { return o == NULL || strcasecmp(o, "none") == 0; } void fill_default_server_options(ServerOptions *options) { int i; /* Portable-specific options */ if (options->use_pam == -1) options->use_pam = 0; /* Standard Options */ if (options->protocol == SSH_PROTO_UNKNOWN) options->protocol = 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; #ifdef OPENSSL_HAS_ECC options->host_key_files[options->num_host_key_files++] = _PATH_HOST_ECDSA_KEY_FILE; #endif options->host_key_files[options->num_host_key_files++] = _PATH_HOST_ED25519_KEY_FILE; } } /* No certificates by default */ 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 = xstrdup(_PATH_SSH_DAEMON_PID_FILE); if (options->server_key_bits == -1) options->server_key_bits = 1024; 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 = xstrdup(_PATH_XAUTH); if (options->permit_tty == -1) options->permit_tty = 1; if (options->permit_user_rc == -1) options->permit_user_rc = 1; 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->hostbased_key_types == NULL) options->hostbased_key_types = xstrdup("*"); if (options->rsa_authentication == -1) options->rsa_authentication = 1; if (options->pubkey_authentication == -1) options->pubkey_authentication = 1; if (options->pubkey_key_types == NULL) options->pubkey_key_types = xstrdup("*"); 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->rekey_limit == -1) options->rekey_limit = 0; if (options->rekey_interval == -1) options->rekey_interval = 0; if (options->allow_tcp_forwarding == -1) options->allow_tcp_forwarding = FORWARD_ALLOW; if (options->allow_streamlocal_forwarding == -1) options->allow_streamlocal_forwarding = FORWARD_ALLOW; if (options->allow_agent_forwarding == -1) options->allow_agent_forwarding = 1; if (options->fwd_opts.gateway_ports == -1) options->fwd_opts.gateway_ports = 0; if (options->max_startups == -1) options->max_startups = 100; if (options->max_startups_rate == -1) options->max_startups_rate = 30; /* 30% */ if (options->max_startups_begin == -1) options->max_startups_begin = 10; if (options->max_authtries == -1) options->max_authtries = DEFAULT_AUTH_FAIL_MAX; if (options->max_sessions == -1) options->max_sessions = DEFAULT_SESSIONS_MAX; if (options->use_dns == -1) options->use_dns = 0; 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->num_authkeys_files == 0) { options->authorized_keys_files[options->num_authkeys_files++] = xstrdup(_PATH_SSH_USER_PERMITTED_KEYS); options->authorized_keys_files[options->num_authkeys_files++] = xstrdup(_PATH_SSH_USER_PERMITTED_KEYS2); } if (options->permit_tun == -1) options->permit_tun = SSH_TUNMODE_NO; 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->version_addendum == NULL) options->version_addendum = xstrdup(""); if (options->fwd_opts.streamlocal_bind_mask == (mode_t)-1) options->fwd_opts.streamlocal_bind_mask = 0177; if (options->fwd_opts.streamlocal_bind_unlink == -1) options->fwd_opts.streamlocal_bind_unlink = 0; if (options->fingerprint_hash == -1) options->fingerprint_hash = SSH_FP_HASH_DEFAULT; /* Turn privilege separation on by default */ if (use_privsep == -1) use_privsep = PRIVSEP_NOSANDBOX; #define CLEAR_ON_NONE(v) \ do { \ if (option_clear_or_none(v)) { \ free(v); \ v = NULL; \ } \ } while(0) CLEAR_ON_NONE(options->pid_file); CLEAR_ON_NONE(options->xauth_location); CLEAR_ON_NONE(options->banner); CLEAR_ON_NONE(options->trusted_user_ca_keys); CLEAR_ON_NONE(options->revoked_keys_file); for (i = 0; i < options->num_host_key_files; i++) CLEAR_ON_NONE(options->host_key_files[i]); for (i = 0; i < options->num_host_cert_files; i++) CLEAR_ON_NONE(options->host_cert_files[i]); #undef CLEAR_ON_NONE #ifndef HAVE_MMAP if (use_privsep && options->compression == 1) { error("This platform does not support both privilege " "separation and compression"); error("Compression disabled"); options->compression = 0; } #endif } /* Keyword tokens. */ typedef enum { sBadOption, /* == unknown option */ /* Portable-specific options */ sUsePAM, /* Standard Options */ 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, sPermitTTY, sStrictModes, sEmptyPasswd, sTCPKeepAlive, sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression, sRekeyLimit, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups, sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile, sGatewayPorts, sPubkeyAuthentication, sPubkeyAcceptedKeyTypes, sXAuthLocation, sSubsystem, sMaxStartups, sMaxAuthTries, sMaxSessions, sBanner, sUseDNS, sHostbasedAuthentication, sHostbasedUsesNameFromPacketOnly, sHostbasedAcceptedKeyTypes, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sGssAuthentication, sGssCleanupCreds, sAcceptEnv, sPermitTunnel, sMatch, sPermitOpen, sForceCommand, sChrootDirectory, sUsePrivilegeSeparation, sAllowAgentForwarding, sHostCertificate, sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile, sKexAlgorithms, sIPQoS, sVersionAddendum, sAuthorizedKeysCommand, sAuthorizedKeysCommandUser, sAuthenticationMethods, sHostKeyAgent, sPermitUserRC, sStreamLocalBindMask, sStreamLocalBindUnlink, sAllowStreamLocalForwarding, sFingerprintHash, 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[] = { /* Portable-specific options */ #ifdef USE_PAM { "usepam", sUsePAM, SSHCFG_GLOBAL }, #else { "usepam", sUnsupported, SSHCFG_GLOBAL }, #endif { "pamauthenticationviakbdint", sDeprecated, SSHCFG_GLOBAL }, /* Standard Options */ { "port", sPort, SSHCFG_GLOBAL }, { "hostkey", sHostKeyFile, SSHCFG_GLOBAL }, { "hostdsakey", sHostKeyFile, SSHCFG_GLOBAL }, /* alias */ { "hostkeyagent", sHostKeyAgent, SSHCFG_GLOBAL }, { "pidfile", sPidFile, SSHCFG_GLOBAL }, { "serverkeybits", sServerKeyBits, SSHCFG_GLOBAL }, { "logingracetime", sLoginGraceTime, SSHCFG_GLOBAL }, { "keyregenerationinterval", sKeyRegenerationTime, SSHCFG_GLOBAL }, { "permitrootlogin", sPermitRootLogin, SSHCFG_ALL }, { "syslogfacility", sLogFacility, SSHCFG_GLOBAL }, { "loglevel", sLogLevel, SSHCFG_GLOBAL }, { "rhostsauthentication", sDeprecated, SSHCFG_GLOBAL }, { "rhostsrsaauthentication", sRhostsRSAAuthentication, SSHCFG_ALL }, { "hostbasedauthentication", sHostbasedAuthentication, SSHCFG_ALL }, { "hostbasedusesnamefrompacketonly", sHostbasedUsesNameFromPacketOnly, SSHCFG_ALL }, { "hostbasedacceptedkeytypes", sHostbasedAcceptedKeyTypes, SSHCFG_ALL }, { "rsaauthentication", sRSAAuthentication, SSHCFG_ALL }, { "pubkeyauthentication", sPubkeyAuthentication, SSHCFG_ALL }, { "pubkeyacceptedkeytypes", sPubkeyAcceptedKeyTypes, SSHCFG_ALL }, { "dsaauthentication", sPubkeyAuthentication, SSHCFG_GLOBAL }, /* alias */ #ifdef KRB5 { "kerberosauthentication", sKerberosAuthentication, SSHCFG_ALL }, { "kerberosorlocalpasswd", sKerberosOrLocalPasswd, SSHCFG_GLOBAL }, { "kerberosticketcleanup", sKerberosTicketCleanup, SSHCFG_GLOBAL }, #ifdef USE_AFS { "kerberosgetafstoken", sKerberosGetAFSToken, SSHCFG_GLOBAL }, #else { "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL }, #endif #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_ALL }, { "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL }, { "uselogin", sUseLogin, SSHCFG_GLOBAL }, { "compression", sCompression, SSHCFG_GLOBAL }, { "rekeylimit", sRekeyLimit, SSHCFG_ALL }, { "tcpkeepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, { "keepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, /* obsolete alias */ { "allowtcpforwarding", sAllowTcpForwarding, SSHCFG_ALL }, { "allowagentforwarding", sAllowAgentForwarding, SSHCFG_ALL }, { "allowusers", sAllowUsers, SSHCFG_ALL }, { "denyusers", sDenyUsers, SSHCFG_ALL }, { "allowgroups", sAllowGroups, SSHCFG_ALL }, { "denygroups", sDenyGroups, SSHCFG_ALL }, { "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_ALL }, { "maxsessions", sMaxSessions, SSHCFG_ALL }, { "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_ALL }, { "authorizedkeysfile2", sDeprecated, SSHCFG_ALL }, { "useprivilegeseparation", sUsePrivilegeSeparation, SSHCFG_GLOBAL}, { "acceptenv", sAcceptEnv, SSHCFG_ALL }, { "permittunnel", sPermitTunnel, SSHCFG_ALL }, { "permittty", sPermitTTY, SSHCFG_ALL }, { "permituserrc", sPermitUserRC, SSHCFG_ALL }, { "match", sMatch, SSHCFG_ALL }, { "permitopen", sPermitOpen, SSHCFG_ALL }, { "forcecommand", sForceCommand, SSHCFG_ALL }, { "chrootdirectory", sChrootDirectory, SSHCFG_ALL }, { "hostcertificate", sHostCertificate, SSHCFG_GLOBAL }, { "revokedkeys", sRevokedKeys, SSHCFG_ALL }, { "trustedusercakeys", sTrustedUserCAKeys, SSHCFG_ALL }, { "authorizedprincipalsfile", sAuthorizedPrincipalsFile, SSHCFG_ALL }, { "kexalgorithms", sKexAlgorithms, SSHCFG_GLOBAL }, { "ipqos", sIPQoS, SSHCFG_ALL }, { "authorizedkeyscommand", sAuthorizedKeysCommand, SSHCFG_ALL }, { "authorizedkeyscommanduser", sAuthorizedKeysCommandUser, SSHCFG_ALL }, { "versionaddendum", sVersionAddendum, SSHCFG_GLOBAL }, { "authenticationmethods", sAuthenticationMethods, SSHCFG_ALL }, { "streamlocalbindmask", sStreamLocalBindMask, SSHCFG_ALL }, { "streamlocalbindunlink", sStreamLocalBindUnlink, SSHCFG_ALL }, { "allowstreamlocalforwarding", sAllowStreamLocalForwarding, SSHCFG_ALL }, { "fingerprinthash", sFingerprintHash, SSHCFG_GLOBAL }, { NULL, sBadOption, 0 } }; static struct { int val; char *text; } tunmode_desc[] = { { SSH_TUNMODE_NO, "no" }, { SSH_TUNMODE_POINTOPOINT, "point-to-point" }, { SSH_TUNMODE_ETHERNET, "ethernet" }, { SSH_TUNMODE_YES, "yes" }, { -1, NULL } }; /* * 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; } char * derelativise_path(const char *path) { char *expanded, *ret, cwd[PATH_MAX]; if (strcasecmp(path, "none") == 0) return xstrdup("none"); expanded = tilde_expand_filename(path, getuid()); if (*expanded == '/') return expanded; if (getcwd(cwd, sizeof(cwd)) == NULL) fatal("%s: getcwd: %s", __func__, strerror(errno)); xasprintf(&ret, "%s/%s", cwd, expanded); free(expanded); return ret; } static void add_listen_addr(ServerOptions *options, char *addr, int 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, int 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, "%d", port); if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0) fatal("bad addr or host: %s (%s)", addr ? addr : "", ssh_gai_strerror(gaierr)); for (ai = aitop; ai->ai_next; ai = ai->ai_next) ; ai->ai_next = options->listen_addrs; options->listen_addrs = aitop; } struct connection_info * get_connection_info(int populate, int use_dns) { static struct connection_info ci; if (!populate) return &ci; ci.host = get_canonical_hostname(use_dns); ci.address = get_remote_ipaddr(); ci.laddress = get_local_ipaddr(packet_get_connection_in()); ci.lport = get_local_port(); return &ci; } /* * 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; struct passwd *pw; 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_pattern_list(grps) != 1) { debug("user %.100s does not match group list %.100s at line %d", user, grps, line); } else { debug("user %.100s matched group list %.100s at line %d", user, grps, line); result = 1; } out: ga_free(); return result; } /* * All of the attributes on a single Match line are ANDed together, so we need * to check every attribute and set the result to zero if any attribute does * not match. */ static int match_cfg_line(char **condition, int line, struct connection_info *ci) { int result = 1, attributes = 0, port; char *arg, *attrib, *cp = *condition; size_t len; if (ci == NULL) debug3("checking syntax for 'Match %s'", cp); else debug3("checking match for '%s' user %s host %s addr %s " "laddr %s lport %d", cp, ci->user ? ci->user : "(null)", ci->host ? ci->host : "(null)", ci->address ? ci->address : "(null)", ci->laddress ? ci->laddress : "(null)", ci->lport); while ((attrib = strdelim(&cp)) && *attrib != '\0') { attributes++; if (strcasecmp(attrib, "all") == 0) { if (attributes != 1 || ((arg = strdelim(&cp)) != NULL && *arg != '\0')) { error("'all' cannot be combined with other " "Match attributes"); return -1; } *condition = cp; return 1; } 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 (ci == NULL || ci->user == NULL) { result = 0; continue; } if (match_pattern_list(ci->user, arg, len, 0) != 1) result = 0; else debug("user %.100s matched 'User %.100s' at " "line %d", ci->user, arg, line); } else if (strcasecmp(attrib, "group") == 0) { if (ci == NULL || ci->user == NULL) { result = 0; continue; } switch (match_cfg_line_group(arg, line, ci->user)) { case -1: return -1; case 0: result = 0; } } else if (strcasecmp(attrib, "host") == 0) { if (ci == NULL || ci->host == NULL) { result = 0; continue; } if (match_hostname(ci->host, arg, len) != 1) result = 0; else debug("connection from %.100s matched 'Host " "%.100s' at line %d", ci->host, arg, line); } else if (strcasecmp(attrib, "address") == 0) { if (ci == NULL || ci->address == NULL) { result = 0; continue; } switch (addr_match_list(ci->address, arg)) { case 1: debug("connection from %.100s matched 'Address " "%.100s' at line %d", ci->address, arg, line); break; case 0: case -1: result = 0; break; case -2: return -1; } } else if (strcasecmp(attrib, "localaddress") == 0){ if (ci == NULL || ci->laddress == NULL) { result = 0; continue; } switch (addr_match_list(ci->laddress, arg)) { case 1: debug("connection from %.100s matched " "'LocalAddress %.100s' at line %d", ci->laddress, arg, line); break; case 0: case -1: result = 0; break; case -2: return -1; } } else if (strcasecmp(attrib, "localport") == 0) { if ((port = a2port(arg)) == -1) { error("Invalid LocalPort '%s' on Match line", arg); return -1; } if (ci == NULL || ci->lport == 0) { result = 0; continue; } /* TODO support port lists */ if (port == ci->lport) debug("connection from %.100s matched " "'LocalPort %d' at line %d", ci->laddress, port, line); else result = 0; } else { error("Unsupported Match attribute %s", attrib); return -1; } } if (attributes == 0) { error("One or more attributes required for Match"); return -1; } if (ci != NULL) debug3("match %sfound", result ? "" : "not "); *condition = cp; return result; } #define WHITESPACE " \t\r\n" /* Multistate option parsing */ struct multistate { char *key; int value; }; static const struct multistate multistate_addressfamily[] = { { "inet", AF_INET }, { "inet6", AF_INET6 }, { "any", AF_UNSPEC }, { NULL, -1 } }; static const struct multistate multistate_permitrootlogin[] = { { "without-password", PERMIT_NO_PASSWD }, { "forced-commands-only", PERMIT_FORCED_ONLY }, { "yes", PERMIT_YES }, { "no", PERMIT_NO }, { NULL, -1 } }; static const struct multistate multistate_compression[] = { { "delayed", COMP_DELAYED }, { "yes", COMP_ZLIB }, { "no", COMP_NONE }, { NULL, -1 } }; static const struct multistate multistate_gatewayports[] = { { "clientspecified", 2 }, { "yes", 1 }, { "no", 0 }, { NULL, -1 } }; static const struct multistate multistate_privsep[] = { { "yes", PRIVSEP_NOSANDBOX }, { "sandbox", PRIVSEP_ON }, { "nosandbox", PRIVSEP_NOSANDBOX }, { "no", PRIVSEP_OFF }, { NULL, -1 } }; static const struct multistate multistate_tcpfwd[] = { { "yes", FORWARD_ALLOW }, { "all", FORWARD_ALLOW }, { "no", FORWARD_DENY }, { "remote", FORWARD_REMOTE }, { "local", FORWARD_LOCAL }, { NULL, -1 } }; int process_server_config_line(ServerOptions *options, char *line, const char *filename, int linenum, int *activep, struct connection_info *connectinfo) { char *cp, **charptr, *arg, *p; int cmdline = 0, *intptr, value, value2, n, port; SyslogFacility *log_facility_ptr; LogLevel *log_level_ptr; ServerOpCodes opcode; u_int i, flags = 0; size_t len; long long val64; const struct multistate *multistate_ptr; 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 (connectinfo == 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) { /* Portable-specific options */ case sUsePAM: intptr = &options->use_pam; goto parse_flag; /* Standard Options */ 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: intptr = &options->address_family; multistate_ptr = multistate_addressfamily; if (options->listen_addrs != NULL) fatal("%s line %d: address family must be specified " "before ListenAddress.", filename, linenum); parse_multistate: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing argument.", filename, linenum); value = -1; for (i = 0; multistate_ptr[i].key != NULL; i++) { if (strcasecmp(arg, multistate_ptr[i].key) == 0) { value = multistate_ptr[i].value; break; } } if (value == -1) fatal("%s line %d: unsupported option \"%s\".", filename, linenum, arg); if (*activep && *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 = derelativise_path(arg); /* increase optional counter */ if (intptr != NULL) *intptr = *intptr + 1; } break; case sHostKeyAgent: charptr = &options->host_key_agent; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing socket name.", filename, linenum); if (*activep && *charptr == NULL) *charptr = !strcmp(arg, SSH_AUTHSOCKET_ENV_NAME) ? xstrdup(arg) : derelativise_path(arg); break; case sHostCertificate: intptr = &options->num_host_cert_files; if (*intptr >= MAX_HOSTKEYS) fatal("%s line %d: too many host certificates " "specified (max %d).", filename, linenum, MAX_HOSTCERTS); charptr = &options->host_cert_files[*intptr]; goto parse_filename; break; case sPidFile: charptr = &options->pid_file; goto parse_filename; case sPermitRootLogin: intptr = &options->permit_root_login; multistate_ptr = multistate_permitrootlogin; goto parse_multistate; 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 sHostbasedAcceptedKeyTypes: charptr = &options->hostbased_key_types; parse_keytypes: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!sshkey_names_valid2(arg, 1)) fatal("%s line %d: Bad key types '%s'.", filename, linenum, arg ? arg : ""); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sRSAAuthentication: intptr = &options->rsa_authentication; goto parse_flag; case sPubkeyAuthentication: intptr = &options->pubkey_authentication; goto parse_flag; case sPubkeyAcceptedKeyTypes: charptr = &options->pubkey_key_types; goto parse_keytypes; 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 sPermitTTY: intptr = &options->permit_tty; goto parse_flag; case sPermitUserRC: intptr = &options->permit_user_rc; goto parse_flag; 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; multistate_ptr = multistate_compression; goto parse_multistate; case sRekeyLimit: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (strcmp(arg, "default") == 0) { val64 = 0; } else { if (scan_scaled(arg, &val64) == -1) fatal("%.200s line %d: Bad number '%s': %s", filename, linenum, arg, strerror(errno)); /* check for too-large or too-small limits */ if (val64 > UINT_MAX) fatal("%.200s line %d: RekeyLimit too large", filename, linenum); if (val64 != 0 && val64 < 16) fatal("%.200s line %d: RekeyLimit too small", filename, linenum); } if (*activep && options->rekey_limit == -1) options->rekey_limit = (u_int32_t)val64; if (cp != NULL) { /* optional rekey interval present */ if (strcmp(cp, "none") == 0) { (void)strdelim(&cp); /* discard */ break; } intptr = &options->rekey_interval; goto parse_time; } break; case sGatewayPorts: intptr = &options->fwd_opts.gateway_ports; multistate_ptr = multistate_gatewayports; goto parse_multistate; case sUseDNS: intptr = &options->use_dns; goto parse_flag; case sLogFacility: log_facility_ptr = &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 (*log_facility_ptr == -1) *log_facility_ptr = (SyslogFacility) value; break; case sLogLevel: log_level_ptr = &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 (*log_level_ptr == -1) *log_level_ptr = (LogLevel) value; break; case sAllowTcpForwarding: intptr = &options->allow_tcp_forwarding; multistate_ptr = multistate_tcpfwd; goto parse_multistate; case sAllowStreamLocalForwarding: intptr = &options->allow_streamlocal_forwarding; multistate_ptr = multistate_tcpfwd; goto parse_multistate; case sAllowAgentForwarding: intptr = &options->allow_agent_forwarding; goto parse_flag; case sUsePrivilegeSeparation: intptr = &use_privsep; multistate_ptr = multistate_privsep; goto parse_multistate; 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); if (!*activep) continue; 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); if (!*activep) continue; 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); if (!*activep) continue; 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); if (!*activep) continue; 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 sKexAlgorithms: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!kex_names_valid(arg)) fatal("%s line %d: Bad SSH2 KexAlgorithms '%s'.", filename, linenum, arg ? arg : ""); if (options->kex_algorithms == NULL) options->kex_algorithms = 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 sMaxSessions: intptr = &options->max_sessions; 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: if (*activep && options->num_authkeys_files == 0) { while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_authkeys_files >= MAX_AUTHKEYS_FILES) fatal("%s line %d: " "too many authorized keys files.", filename, linenum); options->authorized_keys_files[ options->num_authkeys_files++] = tilde_expand_filename(arg, getuid()); } } return 0; case sAuthorizedPrincipalsFile: charptr = &options->authorized_principals_file; 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 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) continue; 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 = -1; for (i = 0; tunmode_desc[i].val != -1; i++) if (strcmp(tunmode_desc[i].text, arg) == 0) { value = tunmode_desc[i].val; break; } if (value == -1) 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, connectinfo); 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 (strcmp(arg, "none") == 0) { if (*activep && n == -1) { options->num_permitted_opens = 1; channel_disable_adm_local_opens(); } 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 = permitopen_port(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 sChrootDirectory: charptr = &options->chroot_directory; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing file name.", filename, linenum); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sTrustedUserCAKeys: charptr = &options->trusted_user_ca_keys; goto parse_filename; case sRevokedKeys: charptr = &options->revoked_keys_file; goto parse_filename; case sIPQoS: arg = strdelim(&cp); if ((value = parse_ipqos(arg)) == -1) fatal("%s line %d: Bad IPQoS value: %s", filename, linenum, arg); arg = strdelim(&cp); 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 sVersionAddendum: if (cp == NULL) fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->version_addendum == NULL) { if (strcasecmp(cp + len, "none") == 0) options->version_addendum = xstrdup(""); else if (strchr(cp + len, '\r') != NULL) fatal("%.200s line %d: Invalid argument", filename, linenum); else options->version_addendum = xstrdup(cp + len); } return 0; case sAuthorizedKeysCommand: if (cp == NULL) fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->authorized_keys_command == NULL) { if (cp[len] != '/' && strcasecmp(cp + len, "none") != 0) fatal("%.200s line %d: AuthorizedKeysCommand " "must be an absolute path", filename, linenum); options->authorized_keys_command = xstrdup(cp + len); } return 0; case sAuthorizedKeysCommandUser: charptr = &options->authorized_keys_command_user; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing AuthorizedKeysCommandUser " "argument.", filename, linenum); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sAuthenticationMethods: if (*activep && options->num_auth_methods == 0) { while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_auth_methods >= MAX_AUTH_METHODS) fatal("%s line %d: " "too many authentication methods.", filename, linenum); if (auth2_methods_valid(arg, 0) != 0) fatal("%s line %d: invalid " "authentication method list.", filename, linenum); options->auth_methods[ options->num_auth_methods++] = xstrdup(arg); } } return 0; case sStreamLocalBindMask: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing StreamLocalBindMask argument.", filename, linenum); /* Parse mode in octal format */ value = strtol(arg, &p, 8); if (arg == p || value < 0 || value > 0777) fatal("%s line %d: Bad mask.", filename, linenum); options->fwd_opts.streamlocal_bind_mask = (mode_t)value; break; case sStreamLocalBindUnlink: intptr = &options->fwd_opts.streamlocal_bind_unlink; goto parse_flag; case sFingerprintHash: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if ((value = ssh_digest_alg_by_name(arg)) == -1) fatal("%.200s line %d: Invalid hash algorithm \"%s\".", filename, linenum, arg); if (*activep) options->fingerprint_hash = value; break; 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[4096], *cp; FILE *f; int lineno = 0; 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)) { lineno++; if (strlen(line) == sizeof(line) - 1) fatal("%s line %d too long", filename, lineno); /* * 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, struct connection_info *connectinfo) { ServerOptions mo; #if defined(ANDROID) char value[PROPERTY_VALUE_MAX]; #endif initialize_server_options(&mo); parse_server_config(&mo, "reprocess config", &cfg, connectinfo); #if defined(ANDROID) /* Allow root login if ro.debuggable is set. */ property_get("ro.debuggable", value, ""); if (strcmp(value, "1") == 0) { mo.permit_root_login = PERMIT_YES; } #endif copy_set_server_options(options, &mo, 0); } int parse_server_match_testspec(struct connection_info *ci, char *spec) { char *p; while ((p = strsep(&spec, ",")) && *p != '\0') { if (strncmp(p, "addr=", 5) == 0) { ci->address = xstrdup(p + 5); } else if (strncmp(p, "host=", 5) == 0) { ci->host = xstrdup(p + 5); } else if (strncmp(p, "user=", 5) == 0) { ci->user = xstrdup(p + 5); } else if (strncmp(p, "laddr=", 6) == 0) { ci->laddress = xstrdup(p + 6); } else if (strncmp(p, "lport=", 6) == 0) { ci->lport = a2port(p + 6); if (ci->lport == -1) { fprintf(stderr, "Invalid port '%s' in test mode" " specification %s\n", p+6, p); return -1; } } else { fprintf(stderr, "Invalid test mode specification %s\n", p); return -1; } } return 0; } /* * returns 1 for a complete spec, 0 for partial spec and -1 for an * empty spec. */ int server_match_spec_complete(struct connection_info *ci) { if (ci->user && ci->host && ci->address) return 1; /* complete */ if (!ci->user && !ci->host && !ci->address) return -1; /* empty */ return 0; /* partial */ } /* * Copy any supported values that are set. * * If the preauth flag is set, we do not bother copying 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) { #define M_CP_INTOPT(n) do {\ if (src->n != -1) \ dst->n = src->n; \ } while (0) 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(hostbased_uses_name_from_packet_only); M_CP_INTOPT(kbd_interactive_authentication); M_CP_INTOPT(permit_root_login); M_CP_INTOPT(permit_empty_passwd); M_CP_INTOPT(allow_tcp_forwarding); M_CP_INTOPT(allow_streamlocal_forwarding); M_CP_INTOPT(allow_agent_forwarding); M_CP_INTOPT(permit_tun); M_CP_INTOPT(fwd_opts.gateway_ports); M_CP_INTOPT(x11_display_offset); M_CP_INTOPT(x11_forwarding); M_CP_INTOPT(x11_use_localhost); M_CP_INTOPT(permit_tty); M_CP_INTOPT(permit_user_rc); M_CP_INTOPT(max_sessions); M_CP_INTOPT(max_authtries); M_CP_INTOPT(ip_qos_interactive); M_CP_INTOPT(ip_qos_bulk); M_CP_INTOPT(rekey_limit); M_CP_INTOPT(rekey_interval); /* M_CP_STROPT and M_CP_STRARRAYOPT should not appear before here */ #define M_CP_STROPT(n) do {\ if (src->n != NULL && dst->n != src->n) { \ free(dst->n); \ dst->n = src->n; \ } \ } while(0) #define M_CP_STRARRAYOPT(n, num_n) do {\ if (src->num_n != 0) { \ for (dst->num_n = 0; dst->num_n < src->num_n; dst->num_n++) \ dst->n[dst->num_n] = xstrdup(src->n[dst->num_n]); \ } \ } while(0) /* See comment in servconf.h */ COPY_MATCH_STRING_OPTS(); /* * The only things that should be below this point are string options * which are only used after authentication. */ if (preauth) return; M_CP_STROPT(adm_forced_command); M_CP_STROPT(chroot_directory); } #undef M_CP_INTOPT #undef M_CP_STROPT #undef M_CP_STRARRAYOPT void parse_server_config(ServerOptions *options, const char *filename, Buffer *conf, struct connection_info *connectinfo) { 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 = connectinfo ? 0 : 1; linenum = 1; while ((cp = strsep(&cbuf, "\n")) != NULL) { if (process_server_config_line(options, cp, filename, linenum++, &active, connectinfo) != 0) bad_options++; } free(obuf); if (bad_options > 0) fatal("%s: terminating, %d bad configuration options", filename, bad_options); } static const char * fmt_multistate_int(int val, const struct multistate *m) { u_int i; for (i = 0; m[i].key != NULL; i++) { if (m[i].value == val) return m[i].key; } return "UNKNOWN"; } static const char * fmt_intarg(ServerOpCodes code, int val) { if (val == -1) return "unset"; switch (code) { case sAddressFamily: return fmt_multistate_int(val, multistate_addressfamily); case sPermitRootLogin: return fmt_multistate_int(val, multistate_permitrootlogin); case sGatewayPorts: return fmt_multistate_int(val, multistate_gatewayports); case sCompression: return fmt_multistate_int(val, multistate_compression); case sUsePrivilegeSeparation: return fmt_multistate_int(val, multistate_privsep); case sAllowTcpForwarding: return fmt_multistate_int(val, multistate_tcpfwd); case sAllowStreamLocalForwarding: return fmt_multistate_int(val, multistate_tcpfwd); case sFingerprintHash: return ssh_digest_alg_name(val); case sProtocol: switch (val) { case SSH_PROTO_1: return "1"; case SSH_PROTO_2: return "2"; case (SSH_PROTO_1|SSH_PROTO_2): return "2,1"; default: return "UNKNOWN"; } default: switch (val) { case 0: return "no"; case 1: return "yes"; default: return "UNKNOWN"; } } } static const char * lookup_opcode_name(ServerOpCodes code) { u_int i; for (i = 0; keywords[i].name != NULL; i++) if (keywords[i].opcode == code) return(keywords[i].name); return "UNKNOWN"; } static void dump_cfg_int(ServerOpCodes code, int val) { printf("%s %d\n", lookup_opcode_name(code), val); } static void dump_cfg_fmtint(ServerOpCodes code, int val) { printf("%s %s\n", lookup_opcode_name(code), fmt_intarg(code, val)); } static void dump_cfg_string(ServerOpCodes code, const char *val) { if (val == NULL) return; printf("%s %s\n", lookup_opcode_name(code), val == NULL ? "none" : val); } static void dump_cfg_strarray(ServerOpCodes code, u_int count, char **vals) { u_int i; for (i = 0; i < count; i++) printf("%s %s\n", lookup_opcode_name(code), vals[i]); } static void dump_cfg_strarray_oneline(ServerOpCodes code, u_int count, char **vals) { u_int i; printf("%s", lookup_opcode_name(code)); for (i = 0; i < count; i++) printf(" %s", vals[i]); printf("\n"); } void dump_config(ServerOptions *o) { u_int i; int ret; struct addrinfo *ai; char addr[NI_MAXHOST], port[NI_MAXSERV], *s = NULL; /* these are usually at the top of the config */ for (i = 0; i < o->num_ports; i++) printf("port %d\n", o->ports[i]); dump_cfg_fmtint(sProtocol, o->protocol); dump_cfg_fmtint(sAddressFamily, o->address_family); /* ListenAddress must be after Port */ for (ai = o->listen_addrs; ai; ai = ai->ai_next) { if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), port, sizeof(port), NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { error("getnameinfo failed: %.100s", (ret != EAI_SYSTEM) ? gai_strerror(ret) : strerror(errno)); } else { if (ai->ai_family == AF_INET6) printf("listenaddress [%s]:%s\n", addr, port); else printf("listenaddress %s:%s\n", addr, port); } } /* integer arguments */ #ifdef USE_PAM dump_cfg_int(sUsePAM, o->use_pam); #endif dump_cfg_int(sServerKeyBits, o->server_key_bits); dump_cfg_int(sLoginGraceTime, o->login_grace_time); dump_cfg_int(sKeyRegenerationTime, o->key_regeneration_time); dump_cfg_int(sX11DisplayOffset, o->x11_display_offset); dump_cfg_int(sMaxAuthTries, o->max_authtries); dump_cfg_int(sMaxSessions, o->max_sessions); dump_cfg_int(sClientAliveInterval, o->client_alive_interval); dump_cfg_int(sClientAliveCountMax, o->client_alive_count_max); /* formatted integer arguments */ dump_cfg_fmtint(sPermitRootLogin, o->permit_root_login); dump_cfg_fmtint(sIgnoreRhosts, o->ignore_rhosts); dump_cfg_fmtint(sIgnoreUserKnownHosts, o->ignore_user_known_hosts); dump_cfg_fmtint(sRhostsRSAAuthentication, o->rhosts_rsa_authentication); dump_cfg_fmtint(sHostbasedAuthentication, o->hostbased_authentication); dump_cfg_fmtint(sHostbasedUsesNameFromPacketOnly, o->hostbased_uses_name_from_packet_only); dump_cfg_fmtint(sRSAAuthentication, o->rsa_authentication); dump_cfg_fmtint(sPubkeyAuthentication, o->pubkey_authentication); #ifdef KRB5 dump_cfg_fmtint(sKerberosAuthentication, o->kerberos_authentication); dump_cfg_fmtint(sKerberosOrLocalPasswd, o->kerberos_or_local_passwd); dump_cfg_fmtint(sKerberosTicketCleanup, o->kerberos_ticket_cleanup); # ifdef USE_AFS dump_cfg_fmtint(sKerberosGetAFSToken, o->kerberos_get_afs_token); # endif #endif #ifdef GSSAPI dump_cfg_fmtint(sGssAuthentication, o->gss_authentication); dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds); #endif dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication); dump_cfg_fmtint(sKbdInteractiveAuthentication, o->kbd_interactive_authentication); dump_cfg_fmtint(sChallengeResponseAuthentication, o->challenge_response_authentication); dump_cfg_fmtint(sPrintMotd, o->print_motd); dump_cfg_fmtint(sPrintLastLog, o->print_lastlog); dump_cfg_fmtint(sX11Forwarding, o->x11_forwarding); dump_cfg_fmtint(sX11UseLocalhost, o->x11_use_localhost); dump_cfg_fmtint(sPermitTTY, o->permit_tty); dump_cfg_fmtint(sPermitUserRC, o->permit_user_rc); dump_cfg_fmtint(sStrictModes, o->strict_modes); dump_cfg_fmtint(sTCPKeepAlive, o->tcp_keep_alive); dump_cfg_fmtint(sEmptyPasswd, o->permit_empty_passwd); dump_cfg_fmtint(sPermitUserEnvironment, o->permit_user_env); dump_cfg_fmtint(sUseLogin, o->use_login); dump_cfg_fmtint(sCompression, o->compression); dump_cfg_fmtint(sGatewayPorts, o->fwd_opts.gateway_ports); dump_cfg_fmtint(sUseDNS, o->use_dns); dump_cfg_fmtint(sAllowTcpForwarding, o->allow_tcp_forwarding); dump_cfg_fmtint(sAllowStreamLocalForwarding, o->allow_streamlocal_forwarding); dump_cfg_fmtint(sUsePrivilegeSeparation, use_privsep); dump_cfg_fmtint(sFingerprintHash, o->fingerprint_hash); /* string arguments */ dump_cfg_string(sPidFile, o->pid_file); dump_cfg_string(sXAuthLocation, o->xauth_location); dump_cfg_string(sCiphers, o->ciphers ? o->ciphers : KEX_SERVER_ENCRYPT); dump_cfg_string(sMacs, o->macs ? o->macs : KEX_SERVER_MAC); dump_cfg_string(sBanner, o->banner); dump_cfg_string(sForceCommand, o->adm_forced_command); dump_cfg_string(sChrootDirectory, o->chroot_directory); dump_cfg_string(sTrustedUserCAKeys, o->trusted_user_ca_keys); dump_cfg_string(sRevokedKeys, o->revoked_keys_file); dump_cfg_string(sAuthorizedPrincipalsFile, o->authorized_principals_file); dump_cfg_string(sVersionAddendum, o->version_addendum); dump_cfg_string(sAuthorizedKeysCommand, o->authorized_keys_command); dump_cfg_string(sAuthorizedKeysCommandUser, o->authorized_keys_command_user); dump_cfg_string(sHostKeyAgent, o->host_key_agent); dump_cfg_string(sKexAlgorithms, o->kex_algorithms ? o->kex_algorithms : KEX_SERVER_KEX); dump_cfg_string(sHostbasedAcceptedKeyTypes, o->hostbased_key_types ? o->hostbased_key_types : KEX_DEFAULT_PK_ALG); dump_cfg_string(sPubkeyAcceptedKeyTypes, o->pubkey_key_types ? o->pubkey_key_types : KEX_DEFAULT_PK_ALG); /* string arguments requiring a lookup */ dump_cfg_string(sLogLevel, log_level_name(o->log_level)); dump_cfg_string(sLogFacility, log_facility_name(o->log_facility)); /* string array arguments */ dump_cfg_strarray_oneline(sAuthorizedKeysFile, o->num_authkeys_files, o->authorized_keys_files); dump_cfg_strarray(sHostKeyFile, o->num_host_key_files, o->host_key_files); dump_cfg_strarray(sHostKeyFile, o->num_host_cert_files, o->host_cert_files); dump_cfg_strarray(sAllowUsers, o->num_allow_users, o->allow_users); dump_cfg_strarray(sDenyUsers, o->num_deny_users, o->deny_users); dump_cfg_strarray(sAllowGroups, o->num_allow_groups, o->allow_groups); dump_cfg_strarray(sDenyGroups, o->num_deny_groups, o->deny_groups); dump_cfg_strarray(sAcceptEnv, o->num_accept_env, o->accept_env); dump_cfg_strarray_oneline(sAuthenticationMethods, o->num_auth_methods, o->auth_methods); /* other arguments */ for (i = 0; i < o->num_subsystems; i++) printf("subsystem %s %s\n", o->subsystem_name[i], o->subsystem_args[i]); printf("maxstartups %d:%d:%d\n", o->max_startups_begin, o->max_startups_rate, o->max_startups); for (i = 0; tunmode_desc[i].val != -1; i++) if (tunmode_desc[i].val == o->permit_tun) { s = tunmode_desc[i].text; break; } dump_cfg_string(sPermitTunnel, s); printf("ipqos %s ", iptos2str(o->ip_qos_interactive)); printf("%s\n", iptos2str(o->ip_qos_bulk)); printf("rekeylimit %lld %d\n", (long long)o->rekey_limit, o->rekey_interval); channel_print_adm_permitted_opens(); }