1 /* $OpenBSD: servconf.h,v 1.160 2023/09/06 23:35:35 djm Exp $ */ 2 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * Definitions for server configuration data and for the functions reading it. 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 */ 15 16 #ifndef SERVCONF_H 17 #define SERVCONF_H 18 19 #include <openbsd-compat/sys-queue.h> 20 21 #define MAX_PORTS 256 /* Max # ports. */ 22 23 /* permit_root_login */ 24 #define PERMIT_NOT_SET -1 25 #define PERMIT_NO 0 26 #define PERMIT_FORCED_ONLY 1 27 #define PERMIT_NO_PASSWD 2 28 #define PERMIT_YES 3 29 30 /* use_privsep */ 31 #define PRIVSEP_OFF 0 32 #define PRIVSEP_ON 1 33 #define PRIVSEP_NOSANDBOX 2 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 struct fwd_perm_list; 56 57 /* 58 * Used to store addresses from ListenAddr directives. These may be 59 * incomplete, as they may specify addresses that need to be merged 60 * with any ports requested by ListenPort. 61 */ 62 struct queued_listenaddr { 63 char *addr; 64 int port; /* <=0 if unspecified */ 65 char *rdomain; 66 }; 67 68 /* Resolved listen addresses, grouped by optional routing domain */ 69 struct listenaddr { 70 char *rdomain; 71 struct addrinfo *addrs; 72 }; 73 74 typedef struct { 75 u_int num_ports; 76 u_int ports_from_cmdline; 77 int ports[MAX_PORTS]; /* Port number to listen on. */ 78 struct queued_listenaddr *queued_listen_addrs; 79 u_int num_queued_listens; 80 struct listenaddr *listen_addrs; 81 u_int num_listen_addrs; 82 int address_family; /* Address family used by the server. */ 83 84 char *routing_domain; /* Bind session to routing domain */ 85 86 char **host_key_files; /* Files containing host keys. */ 87 int *host_key_file_userprovided; /* Key was specified by user. */ 88 u_int num_host_key_files; /* Number of files for host keys. */ 89 char **host_cert_files; /* Files containing host certs. */ 90 u_int num_host_cert_files; /* Number of files for host certs. */ 91 92 char *host_key_agent; /* ssh-agent socket for host keys. */ 93 char *pid_file; /* Where to put our pid */ 94 char *moduli_file; /* moduli file for DH-GEX */ 95 int login_grace_time; /* Disconnect if no auth in this time 96 * (sec). */ 97 int permit_root_login; /* PERMIT_*, see above */ 98 int ignore_rhosts; /* Ignore .rhosts and .shosts. */ 99 int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts 100 * for RhostsRsaAuth */ 101 int print_motd; /* If true, print /etc/motd. */ 102 int print_lastlog; /* If true, print lastlog */ 103 int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */ 104 int x11_display_offset; /* What DISPLAY number to start 105 * searching at */ 106 int x11_use_localhost; /* If true, use localhost for fake X11 server. */ 107 char *xauth_location; /* Location of xauth program */ 108 int permit_tty; /* If false, deny pty allocation */ 109 int permit_user_rc; /* If false, deny ~/.ssh/rc execution */ 110 int strict_modes; /* If true, require string home dir modes. */ 111 int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */ 112 int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */ 113 int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */ 114 char *ciphers; /* Supported SSH2 ciphers. */ 115 char *macs; /* Supported SSH2 macs. */ 116 char *kex_algorithms; /* SSH2 kex methods in order of preference. */ 117 struct ForwardOptions fwd_opts; /* forwarding options */ 118 SyslogFacility log_facility; /* Facility for system logging. */ 119 LogLevel log_level; /* Level for system logging. */ 120 u_int num_log_verbose; /* Verbose log overrides */ 121 char **log_verbose; 122 int hostbased_authentication; /* If true, permit ssh2 hostbased auth */ 123 int hostbased_uses_name_from_packet_only; /* experimental */ 124 char *hostbased_accepted_algos; /* Algos allowed for hostbased */ 125 char *hostkeyalgorithms; /* SSH2 server key types */ 126 char *ca_sign_algorithms; /* Allowed CA signature algorithms */ 127 int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */ 128 char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */ 129 int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */ 130 int kerberos_authentication; /* If true, permit Kerberos 131 * authentication. */ 132 int kerberos_or_local_passwd; /* If true, permit kerberos 133 * and any other password 134 * authentication mechanism, 135 * such as SecurID or 136 * /etc/passwd */ 137 int kerberos_ticket_cleanup; /* If true, destroy ticket 138 * file on logout. */ 139 int kerberos_get_afs_token; /* If true, try to get AFS token if 140 * authenticated with Kerberos. */ 141 int gss_authentication; /* If true, permit GSSAPI authentication */ 142 int gss_cleanup_creds; /* If true, destroy cred cache on logout */ 143 int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ 144 int password_authentication; /* If true, permit password 145 * authentication. */ 146 int kbd_interactive_authentication; /* If true, permit */ 147 int permit_empty_passwd; /* If false, do not permit empty 148 * passwords. */ 149 int permit_user_env; /* If true, read ~/.ssh/environment */ 150 char *permit_user_env_allowlist; /* pattern-list of allowed env names */ 151 int compression; /* If true, compression is allowed */ 152 int allow_tcp_forwarding; /* One of FORWARD_* */ 153 int allow_streamlocal_forwarding; /* One of FORWARD_* */ 154 int allow_agent_forwarding; 155 int disable_forwarding; 156 u_int num_allow_users; 157 char **allow_users; 158 u_int num_deny_users; 159 char **deny_users; 160 u_int num_allow_groups; 161 char **allow_groups; 162 u_int num_deny_groups; 163 char **deny_groups; 164 165 u_int num_subsystems; 166 char **subsystem_name; 167 char **subsystem_command; 168 char **subsystem_args; 169 170 u_int num_accept_env; 171 char **accept_env; 172 u_int num_setenv; 173 char **setenv; 174 175 int max_startups_begin; 176 int max_startups_rate; 177 int max_startups; 178 int per_source_max_startups; 179 int per_source_masklen_ipv4; 180 int per_source_masklen_ipv6; 181 int max_authtries; 182 int max_sessions; 183 char *banner; /* SSH-2 banner message */ 184 int use_dns; 185 int client_alive_interval; /* 186 * poke the client this often to 187 * see if it's still there 188 */ 189 int client_alive_count_max; /* 190 * If the client is unresponsive 191 * for this many intervals above, 192 * disconnect the session 193 */ 194 195 u_int num_authkeys_files; /* Files containing public keys */ 196 char **authorized_keys_files; 197 198 char *adm_forced_command; 199 200 int use_pam; /* Enable auth via PAM */ 201 202 int permit_tun; 203 204 char **permitted_opens; /* May also be one of PERMITOPEN_* */ 205 u_int num_permitted_opens; 206 char **permitted_listens; /* May also be one of PERMITOPEN_* */ 207 u_int num_permitted_listens; 208 209 char *chroot_directory; 210 char *revoked_keys_file; 211 char *trusted_user_ca_keys; 212 char *authorized_keys_command; 213 char *authorized_keys_command_user; 214 char *authorized_principals_file; 215 char *authorized_principals_command; 216 char *authorized_principals_command_user; 217 218 int64_t rekey_limit; 219 int rekey_interval; 220 221 char *version_addendum; /* Appended to SSH banner */ 222 223 u_int num_auth_methods; 224 char **auth_methods; 225 226 int fingerprint_hash; 227 int expose_userauth_info; 228 u_int64_t timing_secret; 229 char *sk_provider; 230 int required_rsa_size; /* minimum size of RSA keys */ 231 232 char **channel_timeouts; /* inactivity timeout by channel type */ 233 u_int num_channel_timeouts; 234 235 int unused_connection_timeout; 236 237 int use_blacklist; 238 } ServerOptions; 239 240 /* Information about the incoming connection as used by Match */ 241 struct connection_info { 242 const char *user; 243 const char *host; /* possibly resolved hostname */ 244 const char *address; /* remote address */ 245 const char *laddress; /* local address */ 246 int lport; /* local port */ 247 const char *rdomain; /* routing domain if available */ 248 int test; /* test mode, allow some attributes to be 249 * unspecified */ 250 }; 251 252 /* List of included files for re-exec from the parsed configuration */ 253 struct include_item { 254 char *selector; 255 char *filename; 256 struct sshbuf *contents; 257 TAILQ_ENTRY(include_item) entry; 258 }; 259 TAILQ_HEAD(include_list, include_item); 260 261 262 /* 263 * These are string config options that must be copied between the 264 * Match sub-config and the main config, and must be sent from the 265 * privsep child to the privsep master. We use a macro to ensure all 266 * the options are copied and the copies are done in the correct order. 267 * 268 * NB. an option must appear in servconf.c:copy_set_server_options() or 269 * COPY_MATCH_STRING_OPTS here but never both. 270 */ 271 #define COPY_MATCH_STRING_OPTS() do { \ 272 M_CP_STROPT(banner); \ 273 M_CP_STROPT(trusted_user_ca_keys); \ 274 M_CP_STROPT(revoked_keys_file); \ 275 M_CP_STROPT(authorized_keys_command); \ 276 M_CP_STROPT(authorized_keys_command_user); \ 277 M_CP_STROPT(authorized_principals_file); \ 278 M_CP_STROPT(authorized_principals_command); \ 279 M_CP_STROPT(authorized_principals_command_user); \ 280 M_CP_STROPT(hostbased_accepted_algos); \ 281 M_CP_STROPT(pubkey_accepted_algos); \ 282 M_CP_STROPT(ca_sign_algorithms); \ 283 M_CP_STROPT(routing_domain); \ 284 M_CP_STROPT(permit_user_env_allowlist); \ 285 M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \ 286 M_CP_STRARRAYOPT(allow_users, num_allow_users); \ 287 M_CP_STRARRAYOPT(deny_users, num_deny_users); \ 288 M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \ 289 M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \ 290 M_CP_STRARRAYOPT(accept_env, num_accept_env); \ 291 M_CP_STRARRAYOPT(setenv, num_setenv); \ 292 M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ 293 M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \ 294 M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \ 295 M_CP_STRARRAYOPT(channel_timeouts, num_channel_timeouts); \ 296 M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \ 297 M_CP_STRARRAYOPT(subsystem_name, num_subsystems); \ 298 M_CP_STRARRAYOPT(subsystem_command, num_subsystems); \ 299 M_CP_STRARRAYOPT(subsystem_args, num_subsystems); \ 300 } while (0) 301 302 struct connection_info *get_connection_info(struct ssh *, int, int); 303 void initialize_server_options(ServerOptions *); 304 void fill_default_server_options(ServerOptions *); 305 int process_server_config_line(ServerOptions *, char *, const char *, int, 306 int *, struct connection_info *, struct include_list *includes); 307 void process_permitopen(struct ssh *ssh, ServerOptions *options); 308 void process_channel_timeouts(struct ssh *ssh, ServerOptions *); 309 void load_server_config(const char *, struct sshbuf *); 310 void parse_server_config(ServerOptions *, const char *, struct sshbuf *, 311 struct include_list *includes, struct connection_info *, int); 312 void parse_server_match_config(ServerOptions *, 313 struct include_list *includes, struct connection_info *); 314 int parse_server_match_testspec(struct connection_info *, char *); 315 int server_match_spec_complete(struct connection_info *); 316 void servconf_merge_subsystems(ServerOptions *, ServerOptions *); 317 void copy_set_server_options(ServerOptions *, ServerOptions *, int); 318 void dump_config(ServerOptions *); 319 char *derelativise_path(const char *); 320 void servconf_add_hostkey(const char *, const int, 321 ServerOptions *, const char *path, int); 322 void servconf_add_hostcert(const char *, const int, 323 ServerOptions *, const char *path); 324 325 #endif /* SERVCONF_H */ 326