1/* $NetBSD: servconf.h,v 1.30 2023/10/25 20:19:57 christos Exp $ */ 2/* $OpenBSD: servconf.h,v 1.160 2023/09/06 23:35:35 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/* use_privsep */ 36#define PRIVSEP_OFF 0 37#define PRIVSEP_ON 1 38#define PRIVSEP_NOSANDBOX 2 39 40/* PermitOpen */ 41#define PERMITOPEN_ANY 0 42#define PERMITOPEN_NONE -2 43 44/* IgnoreRhosts */ 45#define IGNORE_RHOSTS_NO 0 46#define IGNORE_RHOSTS_YES 1 47#define IGNORE_RHOSTS_SHOSTS 2 48 49#define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */ 50#define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */ 51 52/* Magic name for internal sftp-server */ 53#define INTERNAL_SFTP_NAME "internal-sftp" 54 55/* PubkeyAuthOptions flags */ 56#define PUBKEYAUTH_TOUCH_REQUIRED (1) 57#define PUBKEYAUTH_VERIFY_REQUIRED (1<<1) 58 59struct ssh; 60struct fwd_perm_list; 61 62/* 63 * Used to store addresses from ListenAddr directives. These may be 64 * incomplete, as they may specify addresses that need to be merged 65 * with any ports requested by ListenPort. 66 */ 67struct queued_listenaddr { 68 char *addr; 69 int port; /* <=0 if unspecified */ 70 char *rdomain; 71}; 72 73/* Resolved listen addresses, grouped by optional routing domain */ 74struct listenaddr { 75 char *rdomain; 76 struct addrinfo *addrs; 77}; 78 79typedef struct { 80 u_int num_ports; 81 u_int ports_from_cmdline; 82 int ports[MAX_PORTS]; /* Port number to listen on. */ 83 struct queued_listenaddr *queued_listen_addrs; 84 u_int num_queued_listens; 85 struct listenaddr *listen_addrs; 86 u_int num_listen_addrs; 87 int address_family; /* Address family used by the server. */ 88 89 char *routing_domain; /* Bind session to routing domain */ 90 91 char **host_key_files; /* Files containing host keys. */ 92 int *host_key_file_userprovided; /* Key was specified by user. */ 93 u_int num_host_key_files; /* Number of files for host keys. */ 94 char **host_cert_files; /* Files containing host certs. */ 95 u_int num_host_cert_files; /* Number of files for host certs. */ 96 97 char *host_key_agent; /* ssh-agent socket for host keys. */ 98 char *pid_file; /* Where to put our pid */ 99 char *moduli_file; /* moduli file for DH-GEX */ 100 int login_grace_time; /* Disconnect if no auth in this time 101 * (sec). */ 102 int permit_root_login; /* PERMIT_*, see above */ 103 int ignore_rhosts; /* Ignore .rhosts and .shosts. */ 104 int ignore_root_rhosts; /* Ignore .rhosts and .shosts for root; 105 defaults to ignore_rhosts if not 106 given. */ 107 int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts 108 * for RhostsRsaAuth */ 109 int print_motd; /* If true, print /etc/motd. */ 110 int print_lastlog; /* If true, print lastlog */ 111 int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */ 112 int x11_display_offset; /* What DISPLAY number to start 113 * searching at */ 114 int x11_use_localhost; /* If true, use localhost for fake X11 server. */ 115 char *xauth_location; /* Location of xauth program */ 116 int permit_tty; /* If false, deny pty allocation */ 117 int permit_user_rc; /* If false, deny ~/.ssh/rc execution */ 118 int strict_modes; /* If true, require string home dir modes. */ 119 int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */ 120 int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */ 121 int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */ 122 char *ciphers; /* Supported SSH2 ciphers. */ 123 char *macs; /* Supported SSH2 macs. */ 124 char *kex_algorithms; /* SSH2 kex methods in order of preference. */ 125 struct ForwardOptions fwd_opts; /* forwarding options */ 126 SyslogFacility log_facility; /* Facility for system logging. */ 127 LogLevel log_level; /* Level for system logging. */ 128 u_int num_log_verbose; /* Verbose log overrides */ 129 char **log_verbose; 130 int hostbased_authentication; /* If true, permit ssh2 hostbased auth */ 131 int hostbased_uses_name_from_packet_only; /* experimental */ 132 char *hostbased_accepted_algos; /* Algos allowed for hostbased */ 133 char *hostkeyalgorithms; /* SSH2 server key types */ 134 char *ca_sign_algorithms; /* Allowed CA signature algorithms */ 135 int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */ 136 char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */ 137 int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */ 138 int kerberos_authentication; /* If true, permit Kerberos 139 * authentication. */ 140 int kerberos_or_local_passwd; /* If true, permit kerberos 141 * and any other password 142 * authentication mechanism, 143 * such as SecurID or 144 * /etc/passwd */ 145 int kerberos_ticket_cleanup; /* If true, destroy ticket 146 * file on logout. */ 147 int kerberos_tgt_passing; /* If true, permit Kerberos TGT 148 * passing. */ 149 int kerberos_get_afs_token; /* If true, try to get AFS token if 150 * authenticated with Kerberos. */ 151#ifdef AFS 152 int afs_token_passing; /* If true, permit AFS token passing. */ 153#endif 154 int gss_authentication; /* If true, permit GSSAPI authentication */ 155 int gss_cleanup_creds; /* If true, destroy cred cache on logout */ 156 int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ 157 int password_authentication; /* If true, permit password 158 * authentication. */ 159 int kbd_interactive_authentication; /* If true, permit */ 160 int permit_empty_passwd; /* If false, do not permit empty 161 * passwords. */ 162 int permit_user_env; /* If true, read ~/.ssh/environment */ 163 char *permit_user_env_allowlist; /* pattern-list of allowed env names */ 164 int compression; /* If true, compression is allowed */ 165 int allow_tcp_forwarding; /* One of FORWARD_* */ 166 int allow_streamlocal_forwarding; /* One of FORWARD_* */ 167 int allow_agent_forwarding; 168 int disable_forwarding; 169 u_int num_allow_users; 170 char **allow_users; 171 u_int num_deny_users; 172 char **deny_users; 173 u_int num_allow_groups; 174 char **allow_groups; 175 u_int num_deny_groups; 176 char **deny_groups; 177 178 u_int num_subsystems; 179 char **subsystem_name; 180 char **subsystem_command; 181 char **subsystem_args; 182 183 u_int num_accept_env; 184 char **accept_env; 185 u_int num_setenv; 186 char **setenv; 187 188 int max_startups_begin; 189 int max_startups_rate; 190 int max_startups; 191 int per_source_max_startups; 192 int per_source_masklen_ipv4; 193 int per_source_masklen_ipv6; 194 int max_authtries; 195 int max_sessions; 196 char *banner; /* SSH-2 banner message */ 197 int use_dns; 198 int client_alive_interval; /* 199 * poke the client this often to 200 * see if it's still there 201 */ 202 int client_alive_count_max; /* 203 * If the client is unresponsive 204 * for this many intervals above, 205 * disconnect the session 206 */ 207 208 u_int num_authkeys_files; /* Files containing public keys */ 209 char **authorized_keys_files; 210 211 int use_pam; /* Enable auth via PAM */ 212 int none_enabled; /* enable NONE cipher switch */ 213 int tcp_rcv_buf_poll; /* poll tcp rcv window in autotuning kernels*/ 214 int hpn_disabled; /* disable hpn functionality. false by default */ 215 int hpn_buffer_size; /* set the hpn buffer size - default 3MB */ 216 217 char *adm_forced_command; 218 219 int permit_tun; 220#ifdef WITH_LDAP_PUBKEY 221 ldap_opt_t lpk; 222#endif 223 224 char **permitted_opens; /* May also be one of PERMITOPEN_* */ 225 u_int num_permitted_opens; 226 char **permitted_listens; /* May also be one of PERMITOPEN_* */ 227 u_int num_permitted_listens; 228 229 char *chroot_directory; 230 char *revoked_keys_file; 231 char *trusted_user_ca_keys; 232 char *authorized_keys_command; 233 char *authorized_keys_command_user; 234 char *authorized_principals_file; 235 char *authorized_principals_command; 236 char *authorized_principals_command_user; 237 238 int64_t rekey_limit; 239 int rekey_interval; 240 241 char *version_addendum; /* Appended to SSH banner */ 242 243 u_int num_auth_methods; 244 char **auth_methods; 245 246 int fingerprint_hash; 247 int expose_userauth_info; 248 u_int64_t timing_secret; 249 char *sk_provider; 250 int required_rsa_size; /* minimum size of RSA keys */ 251 252 char **channel_timeouts; /* inactivity timeout by channel type */ 253 u_int num_channel_timeouts; 254 255 int unused_connection_timeout; 256} ServerOptions; 257 258/* Information about the incoming connection as used by Match */ 259struct connection_info { 260 const char *user; 261 const char *host; /* possibly resolved hostname */ 262 const char *address; /* remote address */ 263 const char *laddress; /* local address */ 264 int lport; /* local port */ 265 const char *rdomain; /* routing domain if available */ 266 int test; /* test mode, allow some attributes to be 267 * unspecified */ 268}; 269 270/* List of included files for re-exec from the parsed configuration */ 271struct include_item { 272 char *selector; 273 char *filename; 274 struct sshbuf *contents; 275 TAILQ_ENTRY(include_item) entry; 276}; 277TAILQ_HEAD(include_list, include_item); 278 279 280/* 281 * These are string config options that must be copied between the 282 * Match sub-config and the main config, and must be sent from the 283 * privsep child to the privsep master. We use a macro to ensure all 284 * the options are copied and the copies are done in the correct order. 285 * 286 * NB. an option must appear in servconf.c:copy_set_server_options() or 287 * COPY_MATCH_STRING_OPTS here but never both. 288 */ 289#define COPY_MATCH_STRING_OPTS() do { \ 290 M_CP_STROPT(banner); \ 291 M_CP_STROPT(trusted_user_ca_keys); \ 292 M_CP_STROPT(revoked_keys_file); \ 293 M_CP_STROPT(authorized_keys_command); \ 294 M_CP_STROPT(authorized_keys_command_user); \ 295 M_CP_STROPT(authorized_principals_file); \ 296 M_CP_STROPT(authorized_principals_command); \ 297 M_CP_STROPT(authorized_principals_command_user); \ 298 M_CP_STROPT(hostbased_accepted_algos); \ 299 M_CP_STROPT(pubkey_accepted_algos); \ 300 M_CP_STROPT(ca_sign_algorithms); \ 301 M_CP_STROPT(routing_domain); \ 302 M_CP_STROPT(permit_user_env_allowlist); \ 303 M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \ 304 M_CP_STRARRAYOPT(allow_users, num_allow_users); \ 305 M_CP_STRARRAYOPT(deny_users, num_deny_users); \ 306 M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \ 307 M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \ 308 M_CP_STRARRAYOPT(accept_env, num_accept_env); \ 309 M_CP_STRARRAYOPT(setenv, num_setenv); \ 310 M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ 311 M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \ 312 M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \ 313 M_CP_STRARRAYOPT(channel_timeouts, num_channel_timeouts); \ 314 M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \ 315 M_CP_STRARRAYOPT(subsystem_name, num_subsystems); \ 316 M_CP_STRARRAYOPT(subsystem_command, num_subsystems); \ 317 M_CP_STRARRAYOPT(subsystem_args, num_subsystems); \ 318 } while (0) 319 320struct connection_info *get_connection_info(struct ssh *, int, int); 321void initialize_server_options(ServerOptions *); 322void fill_default_server_options(ServerOptions *); 323int process_server_config_line(ServerOptions *, char *, const char *, int, 324 int *, struct connection_info *, struct include_list *includes); 325void process_permitopen(struct ssh *ssh, ServerOptions *options); 326void process_channel_timeouts(struct ssh *ssh, ServerOptions *); 327void load_server_config(const char *, struct sshbuf *); 328void parse_server_config(ServerOptions *, const char *, struct sshbuf *, 329 struct include_list *includes, struct connection_info *, int); 330void parse_server_match_config(ServerOptions *, 331 struct include_list *includes, struct connection_info *); 332int parse_server_match_testspec(struct connection_info *, char *); 333int server_match_spec_complete(struct connection_info *); 334void servconf_merge_subsystems(ServerOptions *, ServerOptions *); 335void copy_set_server_options(ServerOptions *, ServerOptions *, int); 336void dump_config(ServerOptions *); 337char *derelativise_path(const char *); 338void servconf_add_hostkey(const char *, const int, 339 ServerOptions *, const char *path, int); 340void servconf_add_hostcert(const char *, const int, 341 ServerOptions *, const char *path); 342 343#endif /* SERVCONF_H */ 344