xref: /freebsd/crypto/openssh/servconf.h (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /* $OpenBSD: servconf.h,v 1.130 2017/10/25 00:19:47 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 #define MAX_PORTS		256	/* Max # ports. */
20 
21 #define MAX_SUBSYSTEMS		256	/* Max # subsystems. */
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 /* AllowTCPForwarding */
36 #define FORWARD_DENY		0
37 #define FORWARD_REMOTE		(1)
38 #define FORWARD_LOCAL		(1<<1)
39 #define FORWARD_ALLOW		(FORWARD_REMOTE|FORWARD_LOCAL)
40 
41 /* PermitOpen */
42 #define PERMITOPEN_ANY		0
43 #define PERMITOPEN_NONE		-2
44 
45 #define DEFAULT_AUTH_FAIL_MAX	6	/* Default for MaxAuthTries */
46 #define DEFAULT_SESSIONS_MAX	10	/* Default for MaxSessions */
47 
48 /* Magic name for internal sftp-server */
49 #define INTERNAL_SFTP_NAME	"internal-sftp"
50 
51 struct ssh;
52 struct fwd_perm_list;
53 
54 /*
55  * Used to store addresses from ListenAddr directives. These may be
56  * incomplete, as they may specify addresses that need to be merged
57  * with any ports requested by ListenPort.
58  */
59 struct queued_listenaddr {
60 	char *addr;
61 	int port; /* <=0 if unspecified */
62 	char *rdomain;
63 };
64 
65 /* Resolved listen addresses, grouped by optional routing domain */
66 struct listenaddr {
67 	char *rdomain;
68 	struct addrinfo *addrs;
69 };
70 
71 typedef struct {
72 	u_int	num_ports;
73 	u_int	ports_from_cmdline;
74 	int	ports[MAX_PORTS];	/* Port number to listen on. */
75 	struct queued_listenaddr *queued_listen_addrs;
76 	u_int	num_queued_listens;
77 	struct listenaddr *listen_addrs;
78 	u_int	num_listen_addrs;
79 	int	address_family;		/* Address family used by the server. */
80 
81 	char	*routing_domain;	/* Bind session to routing domain */
82 
83 	char   **host_key_files;	/* Files containing host keys. */
84 	u_int	num_host_key_files;     /* Number of files for host keys. */
85 	char   **host_cert_files;	/* Files containing host certs. */
86 	u_int	num_host_cert_files;	/* Number of files for host certs. */
87 
88 	char   *host_key_agent;		/* ssh-agent socket for host keys. */
89 	char   *pid_file;		/* Where to put our pid */
90 	int     login_grace_time;	/* Disconnect if no auth in this time
91 					 * (sec). */
92 	int     permit_root_login;	/* PERMIT_*, see above */
93 	int     ignore_rhosts;	/* Ignore .rhosts and .shosts. */
94 	int     ignore_user_known_hosts;	/* Ignore ~/.ssh/known_hosts
95 						 * for RhostsRsaAuth */
96 	int     print_motd;	/* If true, print /etc/motd. */
97 	int	print_lastlog;	/* If true, print lastlog */
98 	int     x11_forwarding;	/* If true, permit inet (spoofing) X11 fwd. */
99 	int     x11_display_offset;	/* What DISPLAY number to start
100 					 * searching at */
101 	int     x11_use_localhost;	/* If true, use localhost for fake X11 server. */
102 	char   *xauth_location;	/* Location of xauth program */
103 	int	permit_tty;	/* If false, deny pty allocation */
104 	int	permit_user_rc;	/* If false, deny ~/.ssh/rc execution */
105 	int     strict_modes;	/* If true, require string home dir modes. */
106 	int     tcp_keep_alive;	/* If true, set SO_KEEPALIVE. */
107 	int	ip_qos_interactive;	/* IP ToS/DSCP/class for interactive */
108 	int	ip_qos_bulk;		/* IP ToS/DSCP/class for bulk traffic */
109 	char   *ciphers;	/* Supported SSH2 ciphers. */
110 	char   *macs;		/* Supported SSH2 macs. */
111 	char   *kex_algorithms;	/* SSH2 kex methods in order of preference. */
112 	struct ForwardOptions fwd_opts;	/* forwarding options */
113 	SyslogFacility log_facility;	/* Facility for system logging. */
114 	LogLevel log_level;	/* Level for system logging. */
115 	int     hostbased_authentication;	/* If true, permit ssh2 hostbased auth */
116 	int     hostbased_uses_name_from_packet_only; /* experimental */
117 	char   *hostbased_key_types;	/* Key types allowed for hostbased */
118 	char   *hostkeyalgorithms;	/* SSH2 server key types */
119 	int     pubkey_authentication;	/* If true, permit ssh2 pubkey authentication. */
120 	char   *pubkey_key_types;	/* Key types allowed for public key */
121 	int     kerberos_authentication;	/* If true, permit Kerberos
122 						 * authentication. */
123 	int     kerberos_or_local_passwd;	/* If true, permit kerberos
124 						 * and any other password
125 						 * authentication mechanism,
126 						 * such as SecurID or
127 						 * /etc/passwd */
128 	int     kerberos_ticket_cleanup;	/* If true, destroy ticket
129 						 * file on logout. */
130 	int     kerberos_get_afs_token;		/* If true, try to get AFS token if
131 						 * authenticated with Kerberos. */
132 	int     gss_authentication;	/* If true, permit GSSAPI authentication */
133 	int     gss_cleanup_creds;	/* If true, destroy cred cache on logout */
134 	int     gss_strict_acceptor;	/* If true, restrict the GSSAPI acceptor name */
135 	int     password_authentication;	/* If true, permit password
136 						 * authentication. */
137 	int     kbd_interactive_authentication;	/* If true, permit */
138 	int     challenge_response_authentication;
139 	int     permit_empty_passwd;	/* If false, do not permit empty
140 					 * passwords. */
141 	int     permit_user_env;	/* If true, read ~/.ssh/environment */
142 	int     compression;	/* If true, compression is allowed */
143 	int	allow_tcp_forwarding; /* One of FORWARD_* */
144 	int	allow_streamlocal_forwarding; /* One of FORWARD_* */
145 	int	allow_agent_forwarding;
146 	int	disable_forwarding;
147 	u_int num_allow_users;
148 	char   **allow_users;
149 	u_int num_deny_users;
150 	char   **deny_users;
151 	u_int num_allow_groups;
152 	char   **allow_groups;
153 	u_int num_deny_groups;
154 	char   **deny_groups;
155 
156 	u_int num_subsystems;
157 	char   *subsystem_name[MAX_SUBSYSTEMS];
158 	char   *subsystem_command[MAX_SUBSYSTEMS];
159 	char   *subsystem_args[MAX_SUBSYSTEMS];
160 
161 	u_int num_accept_env;
162 	char   **accept_env;
163 
164 	int	max_startups_begin;
165 	int	max_startups_rate;
166 	int	max_startups;
167 	int	max_authtries;
168 	int	max_sessions;
169 	char   *banner;			/* SSH-2 banner message */
170 	int	use_dns;
171 	int	client_alive_interval;	/*
172 					 * poke the client this often to
173 					 * see if it's still there
174 					 */
175 	int	client_alive_count_max;	/*
176 					 * If the client is unresponsive
177 					 * for this many intervals above,
178 					 * disconnect the session
179 					 */
180 
181 	u_int	num_authkeys_files;	/* Files containing public keys */
182 	char   **authorized_keys_files;
183 
184 	char   *adm_forced_command;
185 
186 	int	use_pam;		/* Enable auth via PAM */
187 
188 	int	permit_tun;
189 
190 	char   **permitted_opens;
191 	u_int   num_permitted_opens; /* May also be one of PERMITOPEN_* */
192 
193 	char   *chroot_directory;
194 	char   *revoked_keys_file;
195 	char   *trusted_user_ca_keys;
196 	char   *authorized_keys_command;
197 	char   *authorized_keys_command_user;
198 	char   *authorized_principals_file;
199 	char   *authorized_principals_command;
200 	char   *authorized_principals_command_user;
201 
202 	int64_t rekey_limit;
203 	int	rekey_interval;
204 
205 	char   *version_addendum;	/* Appended to SSH banner */
206 
207 	u_int	num_auth_methods;
208 	char   **auth_methods;
209 
210 	int	fingerprint_hash;
211 	int	expose_userauth_info;
212 	int	use_blacklist;
213 }       ServerOptions;
214 
215 /* Information about the incoming connection as used by Match */
216 struct connection_info {
217 	const char *user;
218 	const char *host;	/* possibly resolved hostname */
219 	const char *address; 	/* remote address */
220 	const char *laddress;	/* local address */
221 	int lport;		/* local port */
222 	const char *rdomain;	/* routing domain if available */
223 };
224 
225 
226 /*
227  * These are string config options that must be copied between the
228  * Match sub-config and the main config, and must be sent from the
229  * privsep slave to the privsep master. We use a macro to ensure all
230  * the options are copied and the copies are done in the correct order.
231  *
232  * NB. an option must appear in servconf.c:copy_set_server_options() or
233  * COPY_MATCH_STRING_OPTS here but never both.
234  */
235 #define COPY_MATCH_STRING_OPTS() do { \
236 		M_CP_STROPT(banner); \
237 		M_CP_STROPT(trusted_user_ca_keys); \
238 		M_CP_STROPT(revoked_keys_file); \
239 		M_CP_STROPT(authorized_keys_command); \
240 		M_CP_STROPT(authorized_keys_command_user); \
241 		M_CP_STROPT(authorized_principals_file); \
242 		M_CP_STROPT(authorized_principals_command); \
243 		M_CP_STROPT(authorized_principals_command_user); \
244 		M_CP_STROPT(hostbased_key_types); \
245 		M_CP_STROPT(pubkey_key_types); \
246 		M_CP_STROPT(routing_domain); \
247 		M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \
248 		M_CP_STRARRAYOPT(allow_users, num_allow_users); \
249 		M_CP_STRARRAYOPT(deny_users, num_deny_users); \
250 		M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \
251 		M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \
252 		M_CP_STRARRAYOPT(accept_env, num_accept_env); \
253 		M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \
254 		M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \
255 	} while (0)
256 
257 struct connection_info *get_connection_info(int, int);
258 void	 initialize_server_options(ServerOptions *);
259 void	 fill_default_server_options(ServerOptions *);
260 int	 process_server_config_line(ServerOptions *, char *, const char *, int,
261 	     int *, struct connection_info *);
262 void	 process_permitopen(struct ssh *ssh, ServerOptions *options);
263 void	 load_server_config(const char *, Buffer *);
264 void	 parse_server_config(ServerOptions *, const char *, Buffer *,
265 	     struct connection_info *);
266 void	 parse_server_match_config(ServerOptions *, struct connection_info *);
267 int	 parse_server_match_testspec(struct connection_info *, char *);
268 int	 server_match_spec_complete(struct connection_info *);
269 void	 copy_set_server_options(ServerOptions *, ServerOptions *, int);
270 void	 dump_config(ServerOptions *);
271 char	*derelativise_path(const char *);
272 void	 servconf_add_hostkey(const char *, const int,
273 	    ServerOptions *, const char *path);
274 void	 servconf_add_hostcert(const char *, const int,
275 	    ServerOptions *, const char *path);
276 
277 #endif				/* SERVCONF_H */
278