1 /* $NetBSD: servconf.h,v 1.29 2023/07/26 17:58:15 christos Exp $ */ 2 /* $OpenBSD: servconf.h,v 1.159 2023/01/17 09:44:48 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 #define MAX_SUBSYSTEMS 256 /* Max # subsystems. */ 29 30 /* permit_root_login */ 31 #define PERMIT_NOT_SET -1 32 #define PERMIT_NO 0 33 #define PERMIT_FORCED_ONLY 1 34 #define PERMIT_NO_PASSWD 2 35 #define PERMIT_YES 3 36 37 /* use_privsep */ 38 #define PRIVSEP_OFF 0 39 #define PRIVSEP_ON 1 40 #define PRIVSEP_NOSANDBOX 2 41 42 /* PermitOpen */ 43 #define PERMITOPEN_ANY 0 44 #define PERMITOPEN_NONE -2 45 46 /* IgnoreRhosts */ 47 #define IGNORE_RHOSTS_NO 0 48 #define IGNORE_RHOSTS_YES 1 49 #define IGNORE_RHOSTS_SHOSTS 2 50 51 #define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */ 52 #define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */ 53 54 /* Magic name for internal sftp-server */ 55 #define INTERNAL_SFTP_NAME "internal-sftp" 56 57 /* PubkeyAuthOptions flags */ 58 #define PUBKEYAUTH_TOUCH_REQUIRED (1) 59 #define PUBKEYAUTH_VERIFY_REQUIRED (1<<1) 60 61 struct ssh; 62 struct fwd_perm_list; 63 64 /* 65 * Used to store addresses from ListenAddr directives. These may be 66 * incomplete, as they may specify addresses that need to be merged 67 * with any ports requested by ListenPort. 68 */ 69 struct queued_listenaddr { 70 char *addr; 71 int port; /* <=0 if unspecified */ 72 char *rdomain; 73 }; 74 75 /* Resolved listen addresses, grouped by optional routing domain */ 76 struct listenaddr { 77 char *rdomain; 78 struct addrinfo *addrs; 79 }; 80 81 typedef struct { 82 u_int num_ports; 83 u_int ports_from_cmdline; 84 int ports[MAX_PORTS]; /* Port number to listen on. */ 85 struct queued_listenaddr *queued_listen_addrs; 86 u_int num_queued_listens; 87 struct listenaddr *listen_addrs; 88 u_int num_listen_addrs; 89 int address_family; /* Address family used by the server. */ 90 91 char *routing_domain; /* Bind session to routing domain */ 92 93 char **host_key_files; /* Files containing host keys. */ 94 int *host_key_file_userprovided; /* Key was specified by user. */ 95 u_int num_host_key_files; /* Number of files for host keys. */ 96 char **host_cert_files; /* Files containing host certs. */ 97 u_int num_host_cert_files; /* Number of files for host certs. */ 98 99 char *host_key_agent; /* ssh-agent socket for host keys. */ 100 char *pid_file; /* Where to put our pid */ 101 char *moduli_file; /* moduli file for DH-GEX */ 102 int login_grace_time; /* Disconnect if no auth in this time 103 * (sec). */ 104 int permit_root_login; /* PERMIT_*, see above */ 105 int ignore_rhosts; /* Ignore .rhosts and .shosts. */ 106 int ignore_root_rhosts; /* Ignore .rhosts and .shosts for root; 107 defaults to ignore_rhosts if not 108 given. */ 109 int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts 110 * for RhostsRsaAuth */ 111 int print_motd; /* If true, print /etc/motd. */ 112 int print_lastlog; /* If true, print lastlog */ 113 int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */ 114 int x11_display_offset; /* What DISPLAY number to start 115 * searching at */ 116 int x11_use_localhost; /* If true, use localhost for fake X11 server. */ 117 char *xauth_location; /* Location of xauth program */ 118 int permit_tty; /* If false, deny pty allocation */ 119 int permit_user_rc; /* If false, deny ~/.ssh/rc execution */ 120 int strict_modes; /* If true, require string home dir modes. */ 121 int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */ 122 int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */ 123 int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */ 124 char *ciphers; /* Supported SSH2 ciphers. */ 125 char *macs; /* Supported SSH2 macs. */ 126 char *kex_algorithms; /* SSH2 kex methods in order of preference. */ 127 struct ForwardOptions fwd_opts; /* forwarding options */ 128 SyslogFacility log_facility; /* Facility for system logging. */ 129 LogLevel log_level; /* Level for system logging. */ 130 u_int num_log_verbose; /* Verbose log overrides */ 131 char **log_verbose; 132 int hostbased_authentication; /* If true, permit ssh2 hostbased auth */ 133 int hostbased_uses_name_from_packet_only; /* experimental */ 134 char *hostbased_accepted_algos; /* Algos allowed for hostbased */ 135 char *hostkeyalgorithms; /* SSH2 server key types */ 136 char *ca_sign_algorithms; /* Allowed CA signature algorithms */ 137 int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */ 138 char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */ 139 int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */ 140 int kerberos_authentication; /* If true, permit Kerberos 141 * authentication. */ 142 int kerberos_or_local_passwd; /* If true, permit kerberos 143 * and any other password 144 * authentication mechanism, 145 * such as SecurID or 146 * /etc/passwd */ 147 int kerberos_ticket_cleanup; /* If true, destroy ticket 148 * file on logout. */ 149 int kerberos_tgt_passing; /* If true, permit Kerberos TGT 150 * passing. */ 151 int kerberos_get_afs_token; /* If true, try to get AFS token if 152 * authenticated with Kerberos. */ 153 #ifdef AFS 154 int afs_token_passing; /* If true, permit AFS token passing. */ 155 #endif 156 int gss_authentication; /* If true, permit GSSAPI authentication */ 157 int gss_cleanup_creds; /* If true, destroy cred cache on logout */ 158 int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ 159 int password_authentication; /* If true, permit password 160 * authentication. */ 161 int kbd_interactive_authentication; /* If true, permit */ 162 int permit_empty_passwd; /* If false, do not permit empty 163 * passwords. */ 164 int permit_user_env; /* If true, read ~/.ssh/environment */ 165 char *permit_user_env_allowlist; /* pattern-list of allowed env names */ 166 int compression; /* If true, compression is allowed */ 167 int allow_tcp_forwarding; /* One of FORWARD_* */ 168 int allow_streamlocal_forwarding; /* One of FORWARD_* */ 169 int allow_agent_forwarding; 170 int disable_forwarding; 171 u_int num_allow_users; 172 char **allow_users; 173 u_int num_deny_users; 174 char **deny_users; 175 u_int num_allow_groups; 176 char **allow_groups; 177 u_int num_deny_groups; 178 char **deny_groups; 179 180 u_int num_subsystems; 181 char *subsystem_name[MAX_SUBSYSTEMS]; 182 char *subsystem_command[MAX_SUBSYSTEMS]; 183 char *subsystem_args[MAX_SUBSYSTEMS]; 184 185 u_int num_accept_env; 186 char **accept_env; 187 u_int num_setenv; 188 char **setenv; 189 190 int max_startups_begin; 191 int max_startups_rate; 192 int max_startups; 193 int per_source_max_startups; 194 int per_source_masklen_ipv4; 195 int per_source_masklen_ipv6; 196 int max_authtries; 197 int max_sessions; 198 char *banner; /* SSH-2 banner message */ 199 int use_dns; 200 int client_alive_interval; /* 201 * poke the client this often to 202 * see if it's still there 203 */ 204 int client_alive_count_max; /* 205 * If the client is unresponsive 206 * for this many intervals above, 207 * disconnect the session 208 */ 209 210 u_int num_authkeys_files; /* Files containing public keys */ 211 char **authorized_keys_files; 212 213 int use_pam; /* Enable auth via PAM */ 214 int none_enabled; /* enable NONE cipher switch */ 215 int tcp_rcv_buf_poll; /* poll tcp rcv window in autotuning kernels*/ 216 int hpn_disabled; /* disable hpn functionality. false by default */ 217 int hpn_buffer_size; /* set the hpn buffer size - default 3MB */ 218 219 char *adm_forced_command; 220 221 int permit_tun; 222 #ifdef WITH_LDAP_PUBKEY 223 ldap_opt_t lpk; 224 #endif 225 226 char **permitted_opens; /* May also be one of PERMITOPEN_* */ 227 u_int num_permitted_opens; 228 char **permitted_listens; /* May also be one of PERMITOPEN_* */ 229 u_int num_permitted_listens; 230 231 char *chroot_directory; 232 char *revoked_keys_file; 233 char *trusted_user_ca_keys; 234 char *authorized_keys_command; 235 char *authorized_keys_command_user; 236 char *authorized_principals_file; 237 char *authorized_principals_command; 238 char *authorized_principals_command_user; 239 240 int64_t rekey_limit; 241 int rekey_interval; 242 243 char *version_addendum; /* Appended to SSH banner */ 244 245 u_int num_auth_methods; 246 char **auth_methods; 247 248 int fingerprint_hash; 249 int expose_userauth_info; 250 u_int64_t timing_secret; 251 char *sk_provider; 252 int required_rsa_size; /* minimum size of RSA keys */ 253 254 char **channel_timeouts; /* inactivity timeout by channel type */ 255 u_int num_channel_timeouts; 256 257 int unused_connection_timeout; 258 } ServerOptions; 259 260 /* Information about the incoming connection as used by Match */ 261 struct connection_info { 262 const char *user; 263 const char *host; /* possibly resolved hostname */ 264 const char *address; /* remote address */ 265 const char *laddress; /* local address */ 266 int lport; /* local port */ 267 const char *rdomain; /* routing domain if available */ 268 int test; /* test mode, allow some attributes to be 269 * unspecified */ 270 }; 271 272 /* List of included files for re-exec from the parsed configuration */ 273 struct include_item { 274 char *selector; 275 char *filename; 276 struct sshbuf *contents; 277 TAILQ_ENTRY(include_item) entry; 278 }; 279 TAILQ_HEAD(include_list, include_item); 280 281 282 /* 283 * These are string config options that must be copied between the 284 * Match sub-config and the main config, and must be sent from the 285 * privsep child to the privsep master. We use a macro to ensure all 286 * the options are copied and the copies are done in the correct order. 287 * 288 * NB. an option must appear in servconf.c:copy_set_server_options() or 289 * COPY_MATCH_STRING_OPTS here but never both. 290 */ 291 #define COPY_MATCH_STRING_OPTS() do { \ 292 M_CP_STROPT(banner); \ 293 M_CP_STROPT(trusted_user_ca_keys); \ 294 M_CP_STROPT(revoked_keys_file); \ 295 M_CP_STROPT(authorized_keys_command); \ 296 M_CP_STROPT(authorized_keys_command_user); \ 297 M_CP_STROPT(authorized_principals_file); \ 298 M_CP_STROPT(authorized_principals_command); \ 299 M_CP_STROPT(authorized_principals_command_user); \ 300 M_CP_STROPT(hostbased_accepted_algos); \ 301 M_CP_STROPT(pubkey_accepted_algos); \ 302 M_CP_STROPT(ca_sign_algorithms); \ 303 M_CP_STROPT(routing_domain); \ 304 M_CP_STROPT(permit_user_env_allowlist); \ 305 M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \ 306 M_CP_STRARRAYOPT(allow_users, num_allow_users); \ 307 M_CP_STRARRAYOPT(deny_users, num_deny_users); \ 308 M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \ 309 M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \ 310 M_CP_STRARRAYOPT(accept_env, num_accept_env); \ 311 M_CP_STRARRAYOPT(setenv, num_setenv); \ 312 M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ 313 M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \ 314 M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \ 315 M_CP_STRARRAYOPT(channel_timeouts, num_channel_timeouts); \ 316 M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \ 317 } while (0) 318 319 struct connection_info *get_connection_info(struct ssh *, int, int); 320 void initialize_server_options(ServerOptions *); 321 void fill_default_server_options(ServerOptions *); 322 int process_server_config_line(ServerOptions *, char *, const char *, int, 323 int *, struct connection_info *, struct include_list *includes); 324 void process_permitopen(struct ssh *ssh, ServerOptions *options); 325 void process_channel_timeouts(struct ssh *ssh, ServerOptions *); 326 void load_server_config(const char *, struct sshbuf *); 327 void parse_server_config(ServerOptions *, const char *, struct sshbuf *, 328 struct include_list *includes, struct connection_info *, int); 329 void parse_server_match_config(ServerOptions *, 330 struct include_list *includes, struct connection_info *); 331 int parse_server_match_testspec(struct connection_info *, char *); 332 int server_match_spec_complete(struct connection_info *); 333 void copy_set_server_options(ServerOptions *, ServerOptions *, int); 334 void dump_config(ServerOptions *); 335 char *derelativise_path(const char *); 336 void servconf_add_hostkey(const char *, const int, 337 ServerOptions *, const char *path, int); 338 void servconf_add_hostcert(const char *, const int, 339 ServerOptions *, const char *path); 340 341 #endif /* SERVCONF_H */ 342