1 /* $NetBSD: servconf.h,v 1.33 2025/04/09 15:49:32 christos Exp $ */ 2 /* $OpenBSD: servconf.h,v 1.169 2024/10/14 01:57:50 djm Exp $ */ 3 4 /* 5 * Author: Tatu Ylonen <ylo@cs.hut.fi> 6 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 7 * All rights reserved 8 * Definitions for server configuration data and for the functions reading it. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 */ 16 17 #ifndef SERVCONF_H 18 #define SERVCONF_H 19 20 #ifdef WITH_LDAP_PUBKEY 21 #include "ldapauth.h" 22 #endif 23 24 #include <sys/queue.h> 25 26 #define MAX_PORTS 256 /* Max # ports. */ 27 28 /* permit_root_login */ 29 #define PERMIT_NOT_SET -1 30 #define PERMIT_NO 0 31 #define PERMIT_FORCED_ONLY 1 32 #define PERMIT_NO_PASSWD 2 33 #define PERMIT_YES 3 34 35 /* PermitOpen */ 36 #define PERMITOPEN_ANY 0 37 #define PERMITOPEN_NONE -2 38 39 /* IgnoreRhosts */ 40 #define IGNORE_RHOSTS_NO 0 41 #define IGNORE_RHOSTS_YES 1 42 #define IGNORE_RHOSTS_SHOSTS 2 43 44 #define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */ 45 #define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */ 46 47 /* Magic name for internal sftp-server */ 48 #define INTERNAL_SFTP_NAME "internal-sftp" 49 50 /* PubkeyAuthOptions flags */ 51 #define PUBKEYAUTH_TOUCH_REQUIRED (1) 52 #define PUBKEYAUTH_VERIFY_REQUIRED (1<<1) 53 54 struct ssh; 55 56 /* 57 * Used to store addresses from ListenAddr directives. These may be 58 * incomplete, as they may specify addresses that need to be merged 59 * with any ports requested by ListenPort. 60 */ 61 struct queued_listenaddr { 62 char *addr; 63 int port; /* <=0 if unspecified */ 64 char *rdomain; 65 }; 66 67 /* Resolved listen addresses, grouped by optional routing domain */ 68 struct listenaddr { 69 char *rdomain; 70 struct addrinfo *addrs; 71 }; 72 73 #define PER_SOURCE_PENALTY_OVERFLOW_DENY_ALL 1 74 #define PER_SOURCE_PENALTY_OVERFLOW_PERMISSIVE 2 75 struct per_source_penalty { 76 int enabled; 77 int max_sources4; 78 int max_sources6; 79 int overflow_mode; 80 int overflow_mode6; 81 int penalty_crash; 82 int penalty_grace; 83 int penalty_authfail; 84 int penalty_noauth; 85 int penalty_refuseconnection; 86 int penalty_max; 87 int penalty_min; 88 }; 89 90 typedef struct { 91 u_int num_ports; 92 u_int ports_from_cmdline; 93 int ports[MAX_PORTS]; /* Port number to listen on. */ 94 struct queued_listenaddr *queued_listen_addrs; 95 u_int num_queued_listens; 96 struct listenaddr *listen_addrs; 97 u_int num_listen_addrs; 98 int address_family; /* Address family used by the server. */ 99 100 char *routing_domain; /* Bind session to routing domain */ 101 102 char **host_key_files; /* Files containing host keys. */ 103 int *host_key_file_userprovided; /* Key was specified by user. */ 104 u_int num_host_key_files; /* Number of files for host keys. */ 105 char **host_cert_files; /* Files containing host certs. */ 106 u_int num_host_cert_files; /* Number of files for host certs. */ 107 108 char *host_key_agent; /* ssh-agent socket for host keys. */ 109 char *pid_file; /* Where to put our pid */ 110 char *moduli_file; /* moduli file for DH-GEX */ 111 int login_grace_time; /* Disconnect if no auth in this time 112 * (sec). */ 113 int permit_root_login; /* PERMIT_*, see above */ 114 int ignore_rhosts; /* Ignore .rhosts and .shosts. */ 115 int ignore_root_rhosts; /* Ignore .rhosts and .shosts for root; 116 defaults to ignore_rhosts if not 117 given. */ 118 int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts 119 * for RhostsRsaAuth */ 120 int print_motd; /* If true, print /etc/motd. */ 121 int print_lastlog; /* If true, print lastlog */ 122 int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */ 123 int x11_display_offset; /* What DISPLAY number to start 124 * searching at */ 125 int x11_use_localhost; /* If true, use localhost for fake X11 server. */ 126 char *xauth_location; /* Location of xauth program */ 127 int permit_tty; /* If false, deny pty allocation */ 128 int permit_user_rc; /* If false, deny ~/.ssh/rc execution */ 129 int strict_modes; /* If true, require string home dir modes. */ 130 int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */ 131 int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */ 132 int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */ 133 char *ciphers; /* Supported SSH2 ciphers. */ 134 char *macs; /* Supported SSH2 macs. */ 135 char *kex_algorithms; /* SSH2 kex methods in order of preference. */ 136 struct ForwardOptions fwd_opts; /* forwarding options */ 137 SyslogFacility log_facility; /* Facility for system logging. */ 138 LogLevel log_level; /* Level for system logging. */ 139 u_int num_log_verbose; /* Verbose log overrides */ 140 char **log_verbose; 141 int hostbased_authentication; /* If true, permit ssh2 hostbased auth */ 142 int hostbased_uses_name_from_packet_only; /* experimental */ 143 char *hostbased_accepted_algos; /* Algos allowed for hostbased */ 144 char *hostkeyalgorithms; /* SSH2 server key types */ 145 char *ca_sign_algorithms; /* Allowed CA signature algorithms */ 146 int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */ 147 char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */ 148 int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */ 149 int kerberos_authentication; /* If true, permit Kerberos 150 * authentication. */ 151 int kerberos_or_local_passwd; /* If true, permit kerberos 152 * and any other password 153 * authentication mechanism, 154 * such as SecurID or 155 * /etc/passwd */ 156 int kerberos_ticket_cleanup; /* If true, destroy ticket 157 * file on logout. */ 158 int kerberos_tgt_passing; /* If true, permit Kerberos TGT 159 * passing. */ 160 int kerberos_get_afs_token; /* If true, try to get AFS token if 161 * authenticated with Kerberos. */ 162 #ifdef AFS 163 int afs_token_passing; /* If true, permit AFS token passing. */ 164 #endif 165 int gss_authentication; /* If true, permit GSSAPI authentication */ 166 int gss_cleanup_creds; /* If true, destroy cred cache on logout */ 167 int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ 168 int password_authentication; /* If true, permit password 169 * authentication. */ 170 int kbd_interactive_authentication; /* If true, permit */ 171 int permit_empty_passwd; /* If false, do not permit empty 172 * passwords. */ 173 int permit_user_env; /* If true, read ~/.ssh/environment */ 174 char *permit_user_env_allowlist; /* pattern-list of allowed env names */ 175 int compression; /* If true, compression is allowed */ 176 int allow_tcp_forwarding; /* One of FORWARD_* */ 177 int allow_streamlocal_forwarding; /* One of FORWARD_* */ 178 int allow_agent_forwarding; 179 int disable_forwarding; 180 u_int num_allow_users; 181 char **allow_users; 182 u_int num_deny_users; 183 char **deny_users; 184 u_int num_allow_groups; 185 char **allow_groups; 186 u_int num_deny_groups; 187 char **deny_groups; 188 189 u_int num_subsystems; 190 char **subsystem_name; 191 char **subsystem_command; 192 char **subsystem_args; 193 194 u_int num_accept_env; 195 char **accept_env; 196 u_int num_setenv; 197 char **setenv; 198 199 int max_startups_begin; 200 int max_startups_rate; 201 int max_startups; 202 int per_source_max_startups; 203 int per_source_masklen_ipv4; 204 int per_source_masklen_ipv6; 205 char *per_source_penalty_exempt; 206 struct per_source_penalty per_source_penalty; 207 int max_authtries; 208 int max_sessions; 209 char *banner; /* SSH-2 banner message */ 210 int use_dns; 211 int client_alive_interval; /* 212 * poke the client this often to 213 * see if it's still there 214 */ 215 int client_alive_count_max; /* 216 * If the client is unresponsive 217 * for this many intervals above, 218 * disconnect the session 219 */ 220 221 u_int num_authkeys_files; /* Files containing public keys */ 222 char **authorized_keys_files; 223 224 int use_pam; /* Enable auth via PAM */ 225 char *pam_service_name; 226 int none_enabled; /* enable NONE cipher switch */ 227 int tcp_rcv_buf_poll; /* poll tcp rcv window in autotuning kernels*/ 228 int hpn_disabled; /* disable hpn functionality. false by default */ 229 int hpn_buffer_size; /* set the hpn buffer size - default 3MB */ 230 231 char *adm_forced_command; 232 233 int permit_tun; 234 #ifdef WITH_LDAP_PUBKEY 235 ldap_opt_t lpk; 236 #endif 237 238 char **permitted_opens; /* May also be one of PERMITOPEN_* */ 239 u_int num_permitted_opens; 240 char **permitted_listens; /* May also be one of PERMITOPEN_* */ 241 u_int num_permitted_listens; 242 243 char *chroot_directory; 244 char *revoked_keys_file; 245 char *trusted_user_ca_keys; 246 char *authorized_keys_command; 247 char *authorized_keys_command_user; 248 char *authorized_principals_file; 249 char *authorized_principals_command; 250 char *authorized_principals_command_user; 251 252 int64_t rekey_limit; 253 int rekey_interval; 254 255 char *version_addendum; /* Appended to SSH banner */ 256 257 u_int num_auth_methods; 258 char **auth_methods; 259 260 int fingerprint_hash; 261 int expose_userauth_info; 262 u_int64_t timing_secret; 263 char *sk_provider; 264 int required_rsa_size; /* minimum size of RSA keys */ 265 266 char **channel_timeouts; /* inactivity timeout by channel type */ 267 u_int num_channel_timeouts; 268 269 int unused_connection_timeout; 270 271 char *sshd_session_path; 272 char *sshd_auth_path; 273 274 int refuse_connection; 275 } ServerOptions; 276 277 /* Information about the incoming connection as used by Match */ 278 struct connection_info { 279 const char *user; 280 int user_invalid; 281 const char *host; /* possibly resolved hostname */ 282 const char *address; /* remote address */ 283 const char *laddress; /* local address */ 284 int lport; /* local port */ 285 const char *rdomain; /* routing domain if available */ 286 int test; /* test mode, allow some attributes to be 287 * unspecified */ 288 }; 289 290 /* List of included files for re-exec from the parsed configuration */ 291 struct include_item { 292 char *selector; 293 char *filename; 294 struct sshbuf *contents; 295 TAILQ_ENTRY(include_item) entry; 296 }; 297 TAILQ_HEAD(include_list, include_item); 298 299 300 /* 301 * These are string config options that must be copied between the 302 * Match sub-config and the main config, and must be sent from the 303 * privsep child to the privsep master. We use a macro to ensure all 304 * the options are copied and the copies are done in the correct order. 305 * 306 * NB. an option must appear in servconf.c:copy_set_server_options() or 307 * COPY_MATCH_STRING_OPTS here but never both. 308 */ 309 #define COPY_MATCH_STRING_OPTS() do { \ 310 M_CP_STROPT(banner); \ 311 M_CP_STROPT(trusted_user_ca_keys); \ 312 M_CP_STROPT(revoked_keys_file); \ 313 M_CP_STROPT(authorized_keys_command); \ 314 M_CP_STROPT(authorized_keys_command_user); \ 315 M_CP_STROPT(authorized_principals_file); \ 316 M_CP_STROPT(authorized_principals_command); \ 317 M_CP_STROPT(authorized_principals_command_user); \ 318 M_CP_STROPT(hostbased_accepted_algos); \ 319 M_CP_STROPT(pubkey_accepted_algos); \ 320 M_CP_STROPT(ca_sign_algorithms); \ 321 M_CP_STROPT(routing_domain); \ 322 M_CP_STROPT(permit_user_env_allowlist); \ 323 M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \ 324 M_CP_STRARRAYOPT(allow_users, num_allow_users); \ 325 M_CP_STRARRAYOPT(deny_users, num_deny_users); \ 326 M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \ 327 M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \ 328 M_CP_STRARRAYOPT(accept_env, num_accept_env); \ 329 M_CP_STRARRAYOPT(setenv, num_setenv); \ 330 M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ 331 M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \ 332 M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \ 333 M_CP_STRARRAYOPT(channel_timeouts, num_channel_timeouts); \ 334 M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \ 335 M_CP_STRARRAYOPT(subsystem_name, num_subsystems); \ 336 M_CP_STRARRAYOPT(subsystem_command, num_subsystems); \ 337 M_CP_STRARRAYOPT(subsystem_args, num_subsystems); \ 338 } while (0) 339 340 void initialize_server_options(ServerOptions *); 341 void fill_default_server_options(ServerOptions *); 342 int process_server_config_line(ServerOptions *, char *, const char *, int, 343 int *, struct connection_info *, struct include_list *includes); 344 void load_server_config(const char *, struct sshbuf *); 345 void parse_server_config(ServerOptions *, const char *, struct sshbuf *, 346 struct include_list *includes, struct connection_info *, int); 347 void parse_server_match_config(ServerOptions *, 348 struct include_list *includes, struct connection_info *); 349 int parse_server_match_testspec(struct connection_info *, char *); 350 void servconf_merge_subsystems(ServerOptions *, ServerOptions *); 351 void copy_set_server_options(ServerOptions *, ServerOptions *, int); 352 void dump_config(ServerOptions *); 353 char *derelativise_path(const char *); 354 void servconf_add_hostkey(const char *, const int, 355 ServerOptions *, const char *path, int); 356 void servconf_add_hostcert(const char *, const int, 357 ServerOptions *, const char *path); 358 359 #endif /* SERVCONF_H */ 360