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/* $OpenBSD: servconf.h,v 1.159 2023/01/17 09:44:48 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Definitions for server configuration data and for the functions reading it.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#ifndef SERVCONF_H
#define SERVCONF_H
#include <sys/queue.h>
#define MAX_PORTS 256 /* Max # ports. */
#define MAX_SUBSYSTEMS 256 /* Max # subsystems. */
/* permit_root_login */
#define PERMIT_NOT_SET -1
#define PERMIT_NO 0
#define PERMIT_FORCED_ONLY 1
#define PERMIT_NO_PASSWD 2
#define PERMIT_YES 3
/* use_privsep */
#define PRIVSEP_OFF 0
#define PRIVSEP_ON 1
#define PRIVSEP_NOSANDBOX 2
/* PermitOpen */
#define PERMITOPEN_ANY 0
#define PERMITOPEN_NONE -2
/* IgnoreRhosts */
#define IGNORE_RHOSTS_NO 0
#define IGNORE_RHOSTS_YES 1
#define IGNORE_RHOSTS_SHOSTS 2
#define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */
#define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */
/* Magic name for internal sftp-server */
#define INTERNAL_SFTP_NAME "internal-sftp"
/* PubkeyAuthOptions flags */
#define PUBKEYAUTH_TOUCH_REQUIRED (1)
#define PUBKEYAUTH_VERIFY_REQUIRED (1<<1)
struct ssh;
struct fwd_perm_list;
/*
* Used to store addresses from ListenAddr directives. These may be
* incomplete, as they may specify addresses that need to be merged
* with any ports requested by ListenPort.
*/
struct queued_listenaddr {
char *addr;
int port; /* <=0 if unspecified */
char *rdomain;
};
/* Resolved listen addresses, grouped by optional routing domain */
struct listenaddr {
char *rdomain;
struct addrinfo *addrs;
};
typedef struct {
u_int num_ports;
u_int ports_from_cmdline;
int ports[MAX_PORTS]; /* Port number to listen on. */
struct queued_listenaddr *queued_listen_addrs;
u_int num_queued_listens;
struct listenaddr *listen_addrs;
u_int num_listen_addrs;
int address_family; /* Address family used by the server. */
char *routing_domain; /* Bind session to routing domain */
char **host_key_files; /* Files containing host keys. */
int *host_key_file_userprovided; /* Key was specified by user. */
u_int num_host_key_files; /* Number of files for host keys. */
char **host_cert_files; /* Files containing host certs. */
u_int num_host_cert_files; /* Number of files for host certs. */
char *host_key_agent; /* ssh-agent socket for host keys. */
char *pid_file; /* Where to put our pid */
char *moduli_file; /* moduli file for DH-GEX */
int login_grace_time; /* Disconnect if no auth in this time
* (sec). */
int permit_root_login; /* PERMIT_*, see above */
int ignore_rhosts; /* Ignore .rhosts and .shosts. */
int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts
* for RhostsRsaAuth */
int print_motd; /* If true, print /etc/motd. */
int print_lastlog; /* If true, print lastlog */
int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */
int x11_display_offset; /* What DISPLAY number to start
* searching at */
int x11_use_localhost; /* If true, use localhost for fake X11 server. */
char *xauth_location; /* Location of xauth program */
int permit_tty; /* If false, deny pty allocation */
int permit_user_rc; /* If false, deny ~/.ssh/rc execution */
int strict_modes; /* If true, require string home dir modes. */
int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */
int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */
int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */
char *ciphers; /* Supported SSH2 ciphers. */
char *macs; /* Supported SSH2 macs. */
char *kex_algorithms; /* SSH2 kex methods in order of preference. */
struct ForwardOptions fwd_opts; /* forwarding options */
SyslogFacility log_facility; /* Facility for system logging. */
LogLevel log_level; /* Level for system logging. */
u_int num_log_verbose; /* Verbose log overrides */
char **log_verbose;
int hostbased_authentication; /* If true, permit ssh2 hostbased auth */
int hostbased_uses_name_from_packet_only; /* experimental */
char *hostbased_accepted_algos; /* Algos allowed for hostbased */
char *hostkeyalgorithms; /* SSH2 server key types */
char *ca_sign_algorithms; /* Allowed CA signature algorithms */
int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */
char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */
int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */
int kerberos_authentication; /* If true, permit Kerberos
* authentication. */
int kerberos_or_local_passwd; /* If true, permit kerberos
* and any other password
* authentication mechanism,
* such as SecurID or
* /etc/passwd */
int kerberos_ticket_cleanup; /* If true, destroy ticket
* file on logout. */
int kerberos_get_afs_token; /* If true, try to get AFS token if
* authenticated with Kerberos. */
int gss_authentication; /* If true, permit GSSAPI authentication */
int gss_cleanup_creds; /* If true, destroy cred cache on logout */
int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */
int password_authentication; /* If true, permit password
* authentication. */
int kbd_interactive_authentication; /* If true, permit */
int permit_empty_passwd; /* If false, do not permit empty
* passwords. */
int permit_user_env; /* If true, read ~/.ssh/environment */
char *permit_user_env_allowlist; /* pattern-list of allowed env names */
int compression; /* If true, compression is allowed */
int allow_tcp_forwarding; /* One of FORWARD_* */
int allow_streamlocal_forwarding; /* One of FORWARD_* */
int allow_agent_forwarding;
int disable_forwarding;
u_int num_allow_users;
char **allow_users;
u_int num_deny_users;
char **deny_users;
u_int num_allow_groups;
char **allow_groups;
u_int num_deny_groups;
char **deny_groups;
u_int num_subsystems;
char *subsystem_name[MAX_SUBSYSTEMS];
char *subsystem_command[MAX_SUBSYSTEMS];
char *subsystem_args[MAX_SUBSYSTEMS];
u_int num_accept_env;
char **accept_env;
u_int num_setenv;
char **setenv;
int max_startups_begin;
int max_startups_rate;
int max_startups;
int per_source_max_startups;
int per_source_masklen_ipv4;
int per_source_masklen_ipv6;
int max_authtries;
int max_sessions;
char *banner; /* SSH-2 banner message */
int use_dns;
int client_alive_interval; /*
* poke the client this often to
* see if it's still there
*/
int client_alive_count_max; /*
* If the client is unresponsive
* for this many intervals above,
* disconnect the session
*/
u_int num_authkeys_files; /* Files containing public keys */
char **authorized_keys_files;
char *adm_forced_command;
int permit_tun;
char **permitted_opens; /* May also be one of PERMITOPEN_* */
u_int num_permitted_opens;
char **permitted_listens; /* May also be one of PERMITOPEN_* */
u_int num_permitted_listens;
char *chroot_directory;
char *revoked_keys_file;
char *trusted_user_ca_keys;
char *authorized_keys_command;
char *authorized_keys_command_user;
char *authorized_principals_file;
char *authorized_principals_command;
char *authorized_principals_command_user;
int64_t rekey_limit;
int rekey_interval;
char *version_addendum; /* Appended to SSH banner */
u_int num_auth_methods;
char **auth_methods;
int fingerprint_hash;
int expose_userauth_info;
u_int64_t timing_secret;
char *sk_provider;
int required_rsa_size; /* minimum size of RSA keys */
char **channel_timeouts; /* inactivity timeout by channel type */
u_int num_channel_timeouts;
int unused_connection_timeout;
} ServerOptions;
/* Information about the incoming connection as used by Match */
struct connection_info {
const char *user;
const char *host; /* possibly resolved hostname */
const char *address; /* remote address */
const char *laddress; /* local address */
int lport; /* local port */
const char *rdomain; /* routing domain if available */
int test; /* test mode, allow some attributes to be
* unspecified */
};
/* List of included files for re-exec from the parsed configuration */
struct include_item {
char *selector;
char *filename;
struct sshbuf *contents;
TAILQ_ENTRY(include_item) entry;
};
TAILQ_HEAD(include_list, include_item);
/*
* These are string config options that must be copied between the
* Match sub-config and the main config, and must be sent from the
* privsep child to the privsep master. We use a macro to ensure all
* the options are copied and the copies are done in the correct order.
*
* NB. an option must appear in servconf.c:copy_set_server_options() or
* COPY_MATCH_STRING_OPTS here but never both.
*/
#define COPY_MATCH_STRING_OPTS() do { \
M_CP_STROPT(banner); \
M_CP_STROPT(trusted_user_ca_keys); \
M_CP_STROPT(revoked_keys_file); \
M_CP_STROPT(authorized_keys_command); \
M_CP_STROPT(authorized_keys_command_user); \
M_CP_STROPT(authorized_principals_file); \
M_CP_STROPT(authorized_principals_command); \
M_CP_STROPT(authorized_principals_command_user); \
M_CP_STROPT(hostbased_accepted_algos); \
M_CP_STROPT(pubkey_accepted_algos); \
M_CP_STROPT(ca_sign_algorithms); \
M_CP_STROPT(routing_domain); \
M_CP_STROPT(permit_user_env_allowlist); \
M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \
M_CP_STRARRAYOPT(allow_users, num_allow_users); \
M_CP_STRARRAYOPT(deny_users, num_deny_users); \
M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \
M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \
M_CP_STRARRAYOPT(accept_env, num_accept_env); \
M_CP_STRARRAYOPT(setenv, num_setenv); \
M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \
M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \
M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \
M_CP_STRARRAYOPT(channel_timeouts, num_channel_timeouts); \
M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \
} while (0)
struct connection_info *get_connection_info(struct ssh *, int, int);
void initialize_server_options(ServerOptions *);
void fill_default_server_options(ServerOptions *);
int process_server_config_line(ServerOptions *, char *, const char *, int,
int *, struct connection_info *, struct include_list *includes);
void process_permitopen(struct ssh *ssh, ServerOptions *options);
void process_channel_timeouts(struct ssh *ssh, ServerOptions *);
void load_server_config(const char *, struct sshbuf *);
void parse_server_config(ServerOptions *, const char *, struct sshbuf *,
struct include_list *includes, struct connection_info *, int);
void parse_server_match_config(ServerOptions *,
struct include_list *includes, struct connection_info *);
int parse_server_match_testspec(struct connection_info *, char *);
int server_match_spec_complete(struct connection_info *);
void copy_set_server_options(ServerOptions *, ServerOptions *, int);
void dump_config(ServerOptions *);
char *derelativise_path(const char *);
void servconf_add_hostkey(const char *, const int,
ServerOptions *, const char *path, int);
void servconf_add_hostcert(const char *, const int,
ServerOptions *, const char *path);
#endif /* SERVCONF_H */
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