1 /* $OpenBSD: servconf.h,v 1.157 2022/09/17 10:34:29 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 #define MAX_SUBSYSTEMS 256 /* Max # subsystems. */ 24 25 /* permit_root_login */ 26 #define PERMIT_NOT_SET -1 27 #define PERMIT_NO 0 28 #define PERMIT_FORCED_ONLY 1 29 #define PERMIT_NO_PASSWD 2 30 #define PERMIT_YES 3 31 32 /* use_privsep */ 33 #define PRIVSEP_OFF 0 34 #define PRIVSEP_ON 1 35 #define PRIVSEP_NOSANDBOX 2 36 37 /* PermitOpen */ 38 #define PERMITOPEN_ANY 0 39 #define PERMITOPEN_NONE -2 40 41 /* IgnoreRhosts */ 42 #define IGNORE_RHOSTS_NO 0 43 #define IGNORE_RHOSTS_YES 1 44 #define IGNORE_RHOSTS_SHOSTS 2 45 46 #define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */ 47 #define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */ 48 49 /* Magic name for internal sftp-server */ 50 #define INTERNAL_SFTP_NAME "internal-sftp" 51 52 /* PubkeyAuthOptions flags */ 53 #define PUBKEYAUTH_TOUCH_REQUIRED (1) 54 #define PUBKEYAUTH_VERIFY_REQUIRED (1<<1) 55 56 struct ssh; 57 struct fwd_perm_list; 58 59 /* 60 * Used to store addresses from ListenAddr directives. These may be 61 * incomplete, as they may specify addresses that need to be merged 62 * with any ports requested by ListenPort. 63 */ 64 struct queued_listenaddr { 65 char *addr; 66 int port; /* <=0 if unspecified */ 67 char *rdomain; 68 }; 69 70 /* Resolved listen addresses, grouped by optional routing domain */ 71 struct listenaddr { 72 char *rdomain; 73 struct addrinfo *addrs; 74 }; 75 76 typedef struct { 77 u_int num_ports; 78 u_int ports_from_cmdline; 79 int ports[MAX_PORTS]; /* Port number to listen on. */ 80 struct queued_listenaddr *queued_listen_addrs; 81 u_int num_queued_listens; 82 struct listenaddr *listen_addrs; 83 u_int num_listen_addrs; 84 int address_family; /* Address family used by the server. */ 85 86 char *routing_domain; /* Bind session to routing domain */ 87 88 char **host_key_files; /* Files containing host keys. */ 89 int *host_key_file_userprovided; /* Key was specified by user. */ 90 u_int num_host_key_files; /* Number of files for host keys. */ 91 char **host_cert_files; /* Files containing host certs. */ 92 u_int num_host_cert_files; /* Number of files for host certs. */ 93 94 char *host_key_agent; /* ssh-agent socket for host keys. */ 95 char *pid_file; /* Where to put our pid */ 96 char *moduli_file; /* moduli file for DH-GEX */ 97 int login_grace_time; /* Disconnect if no auth in this time 98 * (sec). */ 99 int permit_root_login; /* PERMIT_*, see above */ 100 int ignore_rhosts; /* Ignore .rhosts and .shosts. */ 101 int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts 102 * for RhostsRsaAuth */ 103 int print_motd; /* If true, print /etc/motd. */ 104 int print_lastlog; /* If true, print lastlog */ 105 int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */ 106 int x11_display_offset; /* What DISPLAY number to start 107 * searching at */ 108 int x11_use_localhost; /* If true, use localhost for fake X11 server. */ 109 char *xauth_location; /* Location of xauth program */ 110 int permit_tty; /* If false, deny pty allocation */ 111 int permit_user_rc; /* If false, deny ~/.ssh/rc execution */ 112 int strict_modes; /* If true, require string home dir modes. */ 113 int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */ 114 int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */ 115 int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */ 116 char *ciphers; /* Supported SSH2 ciphers. */ 117 char *macs; /* Supported SSH2 macs. */ 118 char *kex_algorithms; /* SSH2 kex methods in order of preference. */ 119 struct ForwardOptions fwd_opts; /* forwarding options */ 120 SyslogFacility log_facility; /* Facility for system logging. */ 121 LogLevel log_level; /* Level for system logging. */ 122 u_int num_log_verbose; /* Verbose log overrides */ 123 char **log_verbose; 124 int hostbased_authentication; /* If true, permit ssh2 hostbased auth */ 125 int hostbased_uses_name_from_packet_only; /* experimental */ 126 char *hostbased_accepted_algos; /* Algos allowed for hostbased */ 127 char *hostkeyalgorithms; /* SSH2 server key types */ 128 char *ca_sign_algorithms; /* Allowed CA signature algorithms */ 129 int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */ 130 char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */ 131 int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */ 132 int kerberos_authentication; /* If true, permit Kerberos 133 * authentication. */ 134 int kerberos_or_local_passwd; /* If true, permit kerberos 135 * and any other password 136 * authentication mechanism, 137 * such as SecurID or 138 * /etc/passwd */ 139 int kerberos_ticket_cleanup; /* If true, destroy ticket 140 * file on logout. */ 141 int kerberos_get_afs_token; /* If true, try to get AFS token if 142 * authenticated with Kerberos. */ 143 int gss_authentication; /* If true, permit GSSAPI authentication */ 144 int gss_cleanup_creds; /* If true, destroy cred cache on logout */ 145 int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ 146 int password_authentication; /* If true, permit password 147 * authentication. */ 148 int kbd_interactive_authentication; /* If true, permit */ 149 int permit_empty_passwd; /* If false, do not permit empty 150 * passwords. */ 151 int permit_user_env; /* If true, read ~/.ssh/environment */ 152 char *permit_user_env_allowlist; /* pattern-list of allowed env names */ 153 int compression; /* If true, compression is allowed */ 154 int allow_tcp_forwarding; /* One of FORWARD_* */ 155 int allow_streamlocal_forwarding; /* One of FORWARD_* */ 156 int allow_agent_forwarding; 157 int disable_forwarding; 158 u_int num_allow_users; 159 char **allow_users; 160 u_int num_deny_users; 161 char **deny_users; 162 u_int num_allow_groups; 163 char **allow_groups; 164 u_int num_deny_groups; 165 char **deny_groups; 166 167 u_int num_subsystems; 168 char *subsystem_name[MAX_SUBSYSTEMS]; 169 char *subsystem_command[MAX_SUBSYSTEMS]; 170 char *subsystem_args[MAX_SUBSYSTEMS]; 171 172 u_int num_accept_env; 173 char **accept_env; 174 u_int num_setenv; 175 char **setenv; 176 177 int max_startups_begin; 178 int max_startups_rate; 179 int max_startups; 180 int per_source_max_startups; 181 int per_source_masklen_ipv4; 182 int per_source_masklen_ipv6; 183 int max_authtries; 184 int max_sessions; 185 char *banner; /* SSH-2 banner message */ 186 int use_dns; 187 int client_alive_interval; /* 188 * poke the client this often to 189 * see if it's still there 190 */ 191 int client_alive_count_max; /* 192 * If the client is unresponsive 193 * for this many intervals above, 194 * disconnect the session 195 */ 196 197 u_int num_authkeys_files; /* Files containing public keys */ 198 char **authorized_keys_files; 199 200 char *adm_forced_command; 201 202 int use_pam; /* Enable auth via PAM */ 203 204 int permit_tun; 205 206 char **permitted_opens; /* May also be one of PERMITOPEN_* */ 207 u_int num_permitted_opens; 208 char **permitted_listens; /* May also be one of PERMITOPEN_* */ 209 u_int num_permitted_listens; 210 211 char *chroot_directory; 212 char *revoked_keys_file; 213 char *trusted_user_ca_keys; 214 char *authorized_keys_command; 215 char *authorized_keys_command_user; 216 char *authorized_principals_file; 217 char *authorized_principals_command; 218 char *authorized_principals_command_user; 219 220 int64_t rekey_limit; 221 int rekey_interval; 222 223 char *version_addendum; /* Appended to SSH banner */ 224 225 u_int num_auth_methods; 226 char **auth_methods; 227 228 int fingerprint_hash; 229 int expose_userauth_info; 230 u_int64_t timing_secret; 231 char *sk_provider; 232 int required_rsa_size; /* minimum size of RSA keys */ 233 } ServerOptions; 234 235 /* Information about the incoming connection as used by Match */ 236 struct connection_info { 237 const char *user; 238 const char *host; /* possibly resolved hostname */ 239 const char *address; /* remote address */ 240 const char *laddress; /* local address */ 241 int lport; /* local port */ 242 const char *rdomain; /* routing domain if available */ 243 int test; /* test mode, allow some attributes to be 244 * unspecified */ 245 }; 246 247 /* List of included files for re-exec from the parsed configuration */ 248 struct include_item { 249 char *selector; 250 char *filename; 251 struct sshbuf *contents; 252 TAILQ_ENTRY(include_item) entry; 253 }; 254 TAILQ_HEAD(include_list, include_item); 255 256 257 /* 258 * These are string config options that must be copied between the 259 * Match sub-config and the main config, and must be sent from the 260 * privsep child to the privsep master. We use a macro to ensure all 261 * the options are copied and the copies are done in the correct order. 262 * 263 * NB. an option must appear in servconf.c:copy_set_server_options() or 264 * COPY_MATCH_STRING_OPTS here but never both. 265 */ 266 #define COPY_MATCH_STRING_OPTS() do { \ 267 M_CP_STROPT(banner); \ 268 M_CP_STROPT(trusted_user_ca_keys); \ 269 M_CP_STROPT(revoked_keys_file); \ 270 M_CP_STROPT(authorized_keys_command); \ 271 M_CP_STROPT(authorized_keys_command_user); \ 272 M_CP_STROPT(authorized_principals_file); \ 273 M_CP_STROPT(authorized_principals_command); \ 274 M_CP_STROPT(authorized_principals_command_user); \ 275 M_CP_STROPT(hostbased_accepted_algos); \ 276 M_CP_STROPT(pubkey_accepted_algos); \ 277 M_CP_STROPT(ca_sign_algorithms); \ 278 M_CP_STROPT(routing_domain); \ 279 M_CP_STROPT(permit_user_env_allowlist); \ 280 M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \ 281 M_CP_STRARRAYOPT(allow_users, num_allow_users); \ 282 M_CP_STRARRAYOPT(deny_users, num_deny_users); \ 283 M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \ 284 M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \ 285 M_CP_STRARRAYOPT(accept_env, num_accept_env); \ 286 M_CP_STRARRAYOPT(setenv, num_setenv); \ 287 M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ 288 M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \ 289 M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \ 290 M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \ 291 } while (0) 292 293 struct connection_info *get_connection_info(struct ssh *, int, int); 294 void initialize_server_options(ServerOptions *); 295 void fill_default_server_options(ServerOptions *); 296 int process_server_config_line(ServerOptions *, char *, const char *, int, 297 int *, struct connection_info *, struct include_list *includes); 298 void process_permitopen(struct ssh *ssh, ServerOptions *options); 299 void load_server_config(const char *, struct sshbuf *); 300 void parse_server_config(ServerOptions *, const char *, struct sshbuf *, 301 struct include_list *includes, struct connection_info *, int); 302 void parse_server_match_config(ServerOptions *, 303 struct include_list *includes, struct connection_info *); 304 int parse_server_match_testspec(struct connection_info *, char *); 305 int server_match_spec_complete(struct connection_info *); 306 void copy_set_server_options(ServerOptions *, ServerOptions *, int); 307 void dump_config(ServerOptions *); 308 char *derelativise_path(const char *); 309 void servconf_add_hostkey(const char *, const int, 310 ServerOptions *, const char *path, int); 311 void servconf_add_hostcert(const char *, const int, 312 ServerOptions *, const char *path); 313 314 #endif /* SERVCONF_H */ 315