/* * 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" RCSID("$OpenBSD: servconf.c,v 1.53 2000/10/14 12:12:09 markus Exp $"); RCSID("$FreeBSD$"); #include "ssh.h" #include "servconf.h" #include "xmalloc.h" #include "compat.h" /* add listen address */ void add_listen_addr(ServerOptions *options, char *addr); /* 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->host_key_file = NULL; options->host_dsa_key_file = NULL; options->pid_file = NULL; options->server_key_bits = -1; options->login_grace_time = -1; options->key_regeneration_time = -1; options->permit_root_login = -1; options->ignore_rhosts = -1; options->ignore_user_known_hosts = -1; options->print_motd = -1; options->check_mail = -1; options->x11_forwarding = -1; options->x11_display_offset = -1; options->xauth_location = NULL; options->strict_modes = -1; options->keepalives = -1; options->log_facility = (SyslogFacility) - 1; options->log_level = (LogLevel) - 1; options->rhosts_authentication = -1; options->rhosts_rsa_authentication = -1; options->rsa_authentication = -1; options->dsa_authentication = -1; #ifdef KRB4 options->krb4_authentication = -1; options->krb4_or_local_passwd = -1; options->krb4_ticket_cleanup = -1; #endif #ifdef KRB5 options->krb5_authentication = -1; options->krb5_tgt_passing = -1; #endif /* KRB5 */ #ifdef AFS options->krb4_tgt_passing = -1; options->afs_token_passing = -1; #endif options->password_authentication = -1; options->kbd_interactive_authentication = -1; #ifdef SKEY options->skey_authentication = -1; #endif options->permit_empty_passwd = -1; options->use_login = -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->protocol = SSH_PROTO_UNKNOWN; options->gateway_ports = -1; options->connections_per_period = 0; options->connections_period = 0; options->num_subsystems = 0; options->max_startups_begin = -1; options->max_startups_rate = -1; options->max_startups = -1; } void fill_default_server_options(ServerOptions *options) { if (options->num_ports == 0) options->ports[options->num_ports++] = SSH_DEFAULT_PORT; if (options->listen_addrs == NULL) add_listen_addr(options, NULL); if (options->host_key_file == NULL) options->host_key_file = HOST_KEY_FILE; if (options->host_dsa_key_file == NULL) options->host_dsa_key_file = HOST_DSA_KEY_FILE; if (options->pid_file == NULL) options->pid_file = 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 == -1) options->permit_root_login = 0; /* no */ if (options->ignore_rhosts == -1) options->ignore_rhosts = 1; if (options->ignore_user_known_hosts == -1) options->ignore_user_known_hosts = 0; if (options->check_mail == -1) options->check_mail = 1; if (options->print_motd == -1) options->print_motd = 1; if (options->x11_forwarding == -1) options->x11_forwarding = 1; if (options->x11_display_offset == -1) options->x11_display_offset = 10; #ifdef XAUTH_PATH if (options->xauth_location == NULL) options->xauth_location = XAUTH_PATH; #endif /* XAUTH_PATH */ if (options->strict_modes == -1) options->strict_modes = 1; if (options->keepalives == -1) options->keepalives = 1; if (options->log_facility == (SyslogFacility) (-1)) options->log_facility = SYSLOG_FACILITY_AUTH; if (options->log_level == (LogLevel) (-1)) options->log_level = SYSLOG_LEVEL_INFO; if (options->rhosts_authentication == -1) options->rhosts_authentication = 0; if (options->rhosts_rsa_authentication == -1) options->rhosts_rsa_authentication = 0; if (options->rsa_authentication == -1) options->rsa_authentication = 1; if (options->dsa_authentication == -1) options->dsa_authentication = 1; #ifdef KRB4 if (options->krb4_authentication == -1) options->krb4_authentication = (access(KEYFILE, R_OK) == 0); if (options->krb4_or_local_passwd == -1) options->krb4_or_local_passwd = 1; if (options->krb4_ticket_cleanup == -1) options->krb4_ticket_cleanup = 1; #endif /* KRB4 */ #ifdef KRB5 if (options->krb5_authentication == -1) options->krb5_authentication = 1; if (options->krb5_tgt_passing == -1) options->krb5_tgt_passing = 1; #endif /* KRB5 */ #ifdef AFS if (options->krb4_tgt_passing == -1) options->krb4_tgt_passing = 0; if (options->afs_token_passing == -1) options->afs_token_passing = k_hasafs(); #endif /* AFS */ if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) options->kbd_interactive_authentication = 0; #ifdef SKEY if (options->skey_authentication == -1) options->skey_authentication = 1; #endif if (options->permit_empty_passwd == -1) options->permit_empty_passwd = 0; if (options->use_login == -1) options->use_login = 0; if (options->allow_tcp_forwarding == -1) options->allow_tcp_forwarding = 1; if (options->protocol == SSH_PROTO_UNKNOWN) options->protocol = SSH_PROTO_1|SSH_PROTO_2; 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; } /* Keyword tokens. */ typedef enum { sBadOption, /* == unknown option */ sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime, sPermitRootLogin, sLogFacility, sLogLevel, sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication, #ifdef KRB4 sKrb4Authentication, sKrb4OrLocalPasswd, sKrb4TicketCleanup, #endif #ifdef KRB5 sKrb5Authentication, sKrb5TgtPassing, #endif /* KRB5 */ #ifdef AFS sKrb4TgtPassing, sAFSTokenPassing, #endif #ifdef SKEY sSkeyAuthentication, #endif sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress, sPrintMotd, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset, sStrictModes, sEmptyPasswd, sRandomSeedFile, sKeepAlives, sCheckMail, sUseLogin, sAllowTcpForwarding, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups, sIgnoreUserKnownHosts, sHostDSAKeyFile, sCiphers, sProtocol, sPidFile, sGatewayPorts, sDSAAuthentication, sConnectionsPerPeriod, sXAuthLocation, sSubsystem, sMaxStartups } ServerOpCodes; /* Textual representation of the tokens. */ static struct { const char *name; ServerOpCodes opcode; } keywords[] = { { "port", sPort }, { "hostkey", sHostKeyFile }, { "hostdsakey", sHostDSAKeyFile }, { "pidfile", sPidFile }, { "serverkeybits", sServerKeyBits }, { "logingracetime", sLoginGraceTime }, { "keyregenerationinterval", sKeyRegenerationTime }, { "permitrootlogin", sPermitRootLogin }, { "syslogfacility", sLogFacility }, { "loglevel", sLogLevel }, { "rhostsauthentication", sRhostsAuthentication }, { "rhostsrsaauthentication", sRhostsRSAAuthentication }, { "rsaauthentication", sRSAAuthentication }, { "dsaauthentication", sDSAAuthentication }, #ifdef KRB4 { "kerberos4authentication", sKrb4Authentication }, { "kerberos4orlocalpasswd", sKrb4OrLocalPasswd }, { "kerberos4ticketcleanup", sKrb4TicketCleanup }, #endif #ifdef KRB5 { "kerberos5authentication", sKrb5Authentication }, { "kerberos5tgtpassing", sKrb5TgtPassing }, #endif /* KRB5 */ #ifdef AFS { "kerberos4tgtpassing", sKrb4TgtPassing }, { "afstokenpassing", sAFSTokenPassing }, #endif { "passwordauthentication", sPasswordAuthentication }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication }, #ifdef SKEY { "skeyauthentication", sSkeyAuthentication }, #endif { "checkmail", sCheckMail }, { "listenaddress", sListenAddress }, { "printmotd", sPrintMotd }, { "ignorerhosts", sIgnoreRhosts }, { "ignoreuserknownhosts", sIgnoreUserKnownHosts }, { "x11forwarding", sX11Forwarding }, { "x11displayoffset", sX11DisplayOffset }, { "xauthlocation", sXAuthLocation }, { "strictmodes", sStrictModes }, { "permitemptypasswords", sEmptyPasswd }, { "uselogin", sUseLogin }, { "randomseed", sRandomSeedFile }, { "keepalive", sKeepAlives }, { "allowtcpforwarding", sAllowTcpForwarding }, { "allowusers", sAllowUsers }, { "denyusers", sDenyUsers }, { "allowgroups", sAllowGroups }, { "denygroups", sDenyGroups }, { "ciphers", sCiphers }, { "protocol", sProtocol }, { "gatewayports", sGatewayPorts }, { "connectionsperperiod", sConnectionsPerPeriod }, { "subsystem", sSubsystem }, { "maxstartups", sMaxStartups }, { NULL, 0 } }; /* * Returns the number of the token pointed to by cp of length len. Never * returns if the token is not known. */ static ServerOpCodes parse_token(const char *cp, const char *filename, int linenum) { unsigned int i; for (i = 0; keywords[i].name; i++) if (strcasecmp(cp, keywords[i].name) == 0) return keywords[i].opcode; fprintf(stderr, "%s: line %d: Bad configuration option: %s\n", filename, linenum, cp); return sBadOption; } /* * add listen address */ void add_listen_addr(ServerOptions *options, char *addr) { extern int IPv4or6; struct addrinfo hints, *ai, *aitop; char strport[NI_MAXSERV]; int gaierr; int i; if (options->num_ports == 0) options->ports[options->num_ports++] = SSH_DEFAULT_PORT; for (i = 0; i < options->num_ports; i++) { memset(&hints, 0, sizeof(hints)); hints.ai_family = IPv4or6; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0; snprintf(strport, sizeof strport, "%d", options->ports[i]); if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0) fatal("bad addr or host: %s (%s)\n", 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; } } /* Reads the server configuration file. */ void read_server_config(ServerOptions *options, const char *filename) { FILE *f; char line[1024]; char *cp, **charptr, *arg; int linenum, *intptr, value; int bad_options = 0; ServerOpCodes opcode; int i; f = fopen(filename, "r"); if (!f) { perror(filename); exit(1); } linenum = 0; while (fgets(line, sizeof(line), f)) { linenum++; cp = line; arg = strdelim(&cp); /* Ignore leading whitespace */ if (*arg == '\0') arg = strdelim(&cp); if (!*arg || *arg == '#') continue; opcode = parse_token(arg, filename, linenum); switch (opcode) { case sBadOption: bad_options++; continue; case sPort: /* ignore ports from configfile if cmdline specifies ports */ if (options->ports_from_cmdline) continue; if (options->listen_addrs != NULL) fatal("%s line %d: ports must be specified before " "ListenAdress.\n", filename, linenum); if (options->num_ports >= MAX_PORTS) fatal("%s line %d: too many ports.\n", filename, linenum); arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing port number.\n", filename, linenum); options->ports[options->num_ports++] = atoi(arg); break; case sServerKeyBits: intptr = &options->server_key_bits; parse_int: arg = strdelim(&cp); if (!arg || *arg == '\0') { fprintf(stderr, "%s line %d: missing integer value.\n", filename, linenum); exit(1); } value = atoi(arg); if (value == 0) { fprintf(stderr, "%s line %d: invalid integer value.\n", filename, linenum); exit(1); } if (*intptr == -1) *intptr = value; break; case sLoginGraceTime: intptr = &options->login_grace_time; goto parse_int; case sKeyRegenerationTime: intptr = &options->key_regeneration_time; goto parse_int; case sListenAddress: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing inet addr.\n", filename, linenum); add_listen_addr(options, arg); break; case sHostKeyFile: case sHostDSAKeyFile: charptr = (opcode == sHostKeyFile ) ? &options->host_key_file : &options->host_dsa_key_file; parse_filename: arg = strdelim(&cp); if (!arg || *arg == '\0') { fprintf(stderr, "%s line %d: missing file name.\n", filename, linenum); exit(1); } if (*charptr == NULL) *charptr = tilde_expand_filename(arg, getuid()); break; case sPidFile: charptr = &options->pid_file; goto parse_filename; case sRandomSeedFile: fprintf(stderr, "%s line %d: \"randomseed\" option is obsolete.\n", filename, linenum); arg = strdelim(&cp); break; case sPermitRootLogin: intptr = &options->permit_root_login; arg = strdelim(&cp); if (!arg || *arg == '\0') { fprintf(stderr, "%s line %d: missing yes/without-password/no argument.\n", filename, linenum); exit(1); } if (strcmp(arg, "without-password") == 0) value = 2; else if (strcmp(arg, "yes") == 0) value = 1; else if (strcmp(arg, "no") == 0) value = 0; else { fprintf(stderr, "%s line %d: Bad yes/without-password/no argument: %s\n", filename, linenum, arg); exit(1); } if (*intptr == -1) *intptr = value; break; case sIgnoreRhosts: intptr = &options->ignore_rhosts; parse_flag: arg = strdelim(&cp); if (!arg || *arg == '\0') { fprintf(stderr, "%s line %d: missing yes/no argument.\n", filename, linenum); exit(1); } if (strcmp(arg, "yes") == 0) value = 1; else if (strcmp(arg, "no") == 0) value = 0; else { fprintf(stderr, "%s line %d: Bad yes/no argument: %s\n", filename, linenum, arg); exit(1); } if (*intptr == -1) *intptr = value; break; case sIgnoreUserKnownHosts: intptr = &options->ignore_user_known_hosts; goto parse_flag; case sRhostsAuthentication: intptr = &options->rhosts_authentication; goto parse_flag; case sRhostsRSAAuthentication: intptr = &options->rhosts_rsa_authentication; goto parse_flag; case sRSAAuthentication: intptr = &options->rsa_authentication; goto parse_flag; case sDSAAuthentication: intptr = &options->dsa_authentication; goto parse_flag; #ifdef KRB4 case sKrb4Authentication: intptr = &options->krb4_authentication; goto parse_flag; case sKrb4OrLocalPasswd: intptr = &options->krb4_or_local_passwd; goto parse_flag; case sKrb4TicketCleanup: intptr = &options->krb4_ticket_cleanup; goto parse_flag; #endif #ifdef KRB5 case sKrb5Authentication: intptr = &options->krb5_authentication; goto parse_flag; case sKrb5TgtPassing: intptr = &options->krb5_tgt_passing; goto parse_flag; #endif /* KRB5 */ #ifdef AFS case sKrb4TgtPassing: intptr = &options->krb4_tgt_passing; goto parse_flag; case sAFSTokenPassing: intptr = &options->afs_token_passing; goto parse_flag; #endif case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; case sKbdInteractiveAuthentication: intptr = &options->kbd_interactive_authentication; goto parse_flag; case sCheckMail: intptr = &options->check_mail; goto parse_flag; #ifdef SKEY case sSkeyAuthentication: intptr = &options->skey_authentication; goto parse_flag; #endif case sPrintMotd: intptr = &options->print_motd; goto parse_flag; case sX11Forwarding: intptr = &options->x11_forwarding; goto parse_flag; case sX11DisplayOffset: intptr = &options->x11_display_offset; goto parse_int; case sXAuthLocation: charptr = &options->xauth_location; goto parse_filename; case sStrictModes: intptr = &options->strict_modes; goto parse_flag; case sKeepAlives: intptr = &options->keepalives; goto parse_flag; case sEmptyPasswd: intptr = &options->permit_empty_passwd; goto parse_flag; case sUseLogin: intptr = &options->use_login; goto parse_flag; case sGatewayPorts: intptr = &options->gateway_ports; goto parse_flag; case sLogFacility: intptr = (int *) &options->log_facility; arg = strdelim(&cp); value = log_facility_number(arg); if (value == (SyslogFacility) - 1) fatal("%.200s line %d: unsupported log facility '%s'\n", 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 == (LogLevel) - 1) fatal("%.200s line %d: unsupported log level '%s'\n", filename, linenum, arg ? arg : ""); if (*intptr == -1) *intptr = (LogLevel) value; break; case sAllowTcpForwarding: intptr = &options->allow_tcp_forwarding; goto parse_flag; case sAllowUsers: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_allow_users >= MAX_ALLOW_USERS) fatal("%.200s line %d: too many allow users.\n", 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("%.200s line %d: too many deny users.\n", 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("%.200s line %d: too many allow groups.\n", 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("%.200s line %d: too many deny groups.\n", 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 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 sConnectionsPerPeriod: error("ConnectionsPerPeriod has been deprecated!"); 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); 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); options->num_subsystems++; break; case sMaxStartups: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing MaxStartups spec.", filename, linenum); if (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); break; } intptr = &options->max_startups; goto parse_int; default: fatal("%.200s line %d: Missing handler for opcode %s (%d)\n", filename, linenum,arg, opcode); } if ((arg = strdelim(&cp)) != NULL && *arg != '\0') { fprintf(stderr, "%s line %d: garbage at end of line; \"%.200s\".\n", filename, linenum, arg); exit(1); } } fclose(f); if (bad_options > 0) { fatal("%.200s: terminating, %d bad configuration options\n", filename, bad_options); } }