servconf.h revision 1.22 
1/*	$NetBSD: servconf.h,v 1.22 2020/05/28 17:05:49 christos Exp $	*/
2/* $OpenBSD: servconf.h,v 1.144 2020/04/17 03:30:05 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
60struct ssh;
61struct fwd_perm_list;
62
63/*
64 * Used to store addresses from ListenAddr directives. These may be
65 * incomplete, as they may specify addresses that need to be merged
66 * with any ports requested by ListenPort.
67 */
68struct queued_listenaddr {
69	char *addr;
70	int port; /* <=0 if unspecified */
71	char *rdomain;
72};
73
74/* Resolved listen addresses, grouped by optional routing domain */
75struct listenaddr {
76	char *rdomain;
77	struct addrinfo *addrs;
78};
79
80typedef struct {
81	u_int	num_ports;
82	u_int	ports_from_cmdline;
83	int	ports[MAX_PORTS];	/* Port number to listen on. */
84	struct queued_listenaddr *queued_listen_addrs;
85	u_int	num_queued_listens;
86	struct listenaddr *listen_addrs;
87	u_int	num_listen_addrs;
88	int	address_family;		/* Address family used by the server. */
89
90	char	*routing_domain;	/* Bind session to routing domain */
91
92	char   **host_key_files;	/* Files containing host keys. */
93	int	*host_key_file_userprovided; /* Key was specified by user. */
94	u_int	num_host_key_files;     /* Number of files for host keys. */
95	char   **host_cert_files;	/* Files containing host certs. */
96	u_int	num_host_cert_files;	/* Number of files for host certs. */
97
98	char   *host_key_agent;		/* ssh-agent socket for host keys. */
99	char   *pid_file;		/* Where to put our pid */
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	int     hostbased_authentication;	/* If true, permit ssh2 hostbased auth */
129	int     hostbased_uses_name_from_packet_only; /* experimental */
130	char   *hostbased_key_types;	/* Key types allowed for hostbased */
131	char   *hostkeyalgorithms;	/* SSH2 server key types */
132	char   *ca_sign_algorithms;	/* Allowed CA signature algorithms */
133	int     pubkey_authentication;	/* If true, permit ssh2 pubkey authentication. */
134	char   *pubkey_key_types;	/* Key types allowed for public key */
135	int	pubkey_auth_options;	/* -1 or mask of PUBKEYAUTH_* flags */
136	int     kerberos_authentication;	/* If true, permit Kerberos
137						 * authentication. */
138	int     kerberos_or_local_passwd;	/* If true, permit kerberos
139						 * and any other password
140						 * authentication mechanism,
141						 * such as SecurID or
142						 * /etc/passwd */
143	int     kerberos_ticket_cleanup;	/* If true, destroy ticket
144						 * file on logout. */
145	int	kerberos_tgt_passing;		/* If true, permit Kerberos TGT
146						 * passing. */
147	int     kerberos_get_afs_token;		/* If true, try to get AFS token if
148						 * authenticated with Kerberos. */
149#ifdef AFS
150	int     afs_token_passing;      /* If true, permit AFS token passing. */
151#endif
152	int     gss_authentication;	/* If true, permit GSSAPI authentication */
153	int     gss_cleanup_creds;	/* If true, destroy cred cache on logout */
154	int     gss_strict_acceptor;	/* If true, restrict the GSSAPI acceptor name */
155	int     password_authentication;	/* If true, permit password
156						 * authentication. */
157	int     kbd_interactive_authentication;	/* If true, permit */
158	int     challenge_response_authentication;
159	int     permit_empty_passwd;	/* If false, do not permit empty
160					 * passwords. */
161	int     permit_user_env;	/* If true, read ~/.ssh/environment */
162	char   *permit_user_env_whitelist; /* pattern-list whitelist */
163	int     compression;	/* If true, compression is allowed */
164	int	allow_tcp_forwarding; /* One of FORWARD_* */
165	int	allow_streamlocal_forwarding; /* One of FORWARD_* */
166	int	allow_agent_forwarding;
167	int	disable_forwarding;
168	u_int num_allow_users;
169	char   **allow_users;
170	u_int num_deny_users;
171	char   **deny_users;
172	u_int num_allow_groups;
173	char   **allow_groups;
174	u_int num_deny_groups;
175	char   **deny_groups;
176
177	u_int num_subsystems;
178	char   *subsystem_name[MAX_SUBSYSTEMS];
179	char   *subsystem_command[MAX_SUBSYSTEMS];
180	char   *subsystem_args[MAX_SUBSYSTEMS];
181
182	u_int num_accept_env;
183	char   **accept_env;
184	u_int num_setenv;
185	char   **setenv;
186
187	int	max_startups_begin;
188	int	max_startups_rate;
189	int	max_startups;
190	int	max_authtries;
191	int	max_sessions;
192	char   *banner;			/* SSH-2 banner message */
193	int	use_dns;
194	int	client_alive_interval;	/*
195					 * poke the client this often to
196					 * see if it's still there
197					 */
198	int	client_alive_count_max;	/*
199					 * If the client is unresponsive
200					 * for this many intervals above,
201					 * disconnect the session
202					 */
203
204	u_int	num_authkeys_files;	/* Files containing public keys */
205	char   **authorized_keys_files;
206
207	int	use_pam;		/* Enable auth via PAM */
208	int     none_enabled;           /* enable NONE cipher switch */
209	int     tcp_rcv_buf_poll;       /* poll tcp rcv window in autotuning kernels*/
210	int	hpn_disabled;		/* disable hpn functionality. false by default */
211	int	hpn_buffer_size;	/* set the hpn buffer size - default 3MB */
212
213	char   *adm_forced_command;
214
215	int	permit_tun;
216#ifdef WITH_LDAP_PUBKEY
217        ldap_opt_t lpk;
218#endif
219
220	char   **permitted_opens;	/* May also be one of PERMITOPEN_* */
221	u_int   num_permitted_opens;
222	char   **permitted_listens; /* May also be one of PERMITOPEN_* */
223	u_int   num_permitted_listens;
224
225	char   *chroot_directory;
226	char   *revoked_keys_file;
227	char   *trusted_user_ca_keys;
228	char   *authorized_keys_command;
229	char   *authorized_keys_command_user;
230	char   *authorized_principals_file;
231	char   *authorized_principals_command;
232	char   *authorized_principals_command_user;
233
234	int64_t rekey_limit;
235	int	rekey_interval;
236
237	char   *version_addendum;	/* Appended to SSH banner */
238
239	u_int	num_auth_methods;
240	char   **auth_methods;
241
242	int	fingerprint_hash;
243	int	expose_userauth_info;
244	u_int64_t timing_secret;
245	char   *sk_provider;
246}       ServerOptions;
247
248/* Information about the incoming connection as used by Match */
249struct connection_info {
250	const char *user;
251	const char *host;	/* possibly resolved hostname */
252	const char *address; 	/* remote address */
253	const char *laddress;	/* local address */
254	int lport;		/* local port */
255	const char *rdomain;	/* routing domain if available */
256	int test;		/* test mode, allow some attributes to be
257				 * unspecified */
258};
259
260/* List of included files for re-exec from the parsed configuration */
261struct include_item {
262	char *selector;
263	char *filename;
264	struct sshbuf *contents;
265	TAILQ_ENTRY(include_item) entry;
266};
267TAILQ_HEAD(include_list, include_item);
268
269
270/*
271 * These are string config options that must be copied between the
272 * Match sub-config and the main config, and must be sent from the
273 * privsep slave to the privsep master. We use a macro to ensure all
274 * the options are copied and the copies are done in the correct order.
275 *
276 * NB. an option must appear in servconf.c:copy_set_server_options() or
277 * COPY_MATCH_STRING_OPTS here but never both.
278 */
279#define COPY_MATCH_STRING_OPTS() do { \
280		M_CP_STROPT(banner); \
281		M_CP_STROPT(trusted_user_ca_keys); \
282		M_CP_STROPT(revoked_keys_file); \
283		M_CP_STROPT(authorized_keys_command); \
284		M_CP_STROPT(authorized_keys_command_user); \
285		M_CP_STROPT(authorized_principals_file); \
286		M_CP_STROPT(authorized_principals_command); \
287		M_CP_STROPT(authorized_principals_command_user); \
288		M_CP_STROPT(hostbased_key_types); \
289		M_CP_STROPT(pubkey_key_types); \
290		M_CP_STROPT(ca_sign_algorithms); \
291		M_CP_STROPT(routing_domain); \
292		M_CP_STROPT(permit_user_env_whitelist); \
293		M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \
294		M_CP_STRARRAYOPT(allow_users, num_allow_users); \
295		M_CP_STRARRAYOPT(deny_users, num_deny_users); \
296		M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \
297		M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \
298		M_CP_STRARRAYOPT(accept_env, num_accept_env); \
299		M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \
300		M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \
301		M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \
302	} while (0)
303
304struct connection_info *get_connection_info(struct ssh *, int, int);
305void	 initialize_server_options(ServerOptions *);
306void	 fill_default_server_options(ServerOptions *);
307int	 process_server_config_line(ServerOptions *, char *, const char *, int,
308	     int *, struct connection_info *, struct include_list *includes);
309void	 process_permitopen(struct ssh *ssh, ServerOptions *options);
310void	 load_server_config(const char *, struct sshbuf *);
311void	 parse_server_config(ServerOptions *, const char *, struct sshbuf *,
312	     struct include_list *includes, struct connection_info *);
313void	 parse_server_match_config(ServerOptions *,
314	     struct include_list *includes, struct connection_info *);
315int	 parse_server_match_testspec(struct connection_info *, char *);
316int	 server_match_spec_complete(struct connection_info *);
317void	 copy_set_server_options(ServerOptions *, ServerOptions *, int);
318void	 dump_config(ServerOptions *);
319char	*derelativise_path(const char *);
320void	 servconf_add_hostkey(const char *, const int,
321	    ServerOptions *, const char *path, int);
322void	 servconf_add_hostcert(const char *, const int,
323	    ServerOptions *, const char *path);
324
325#endif				/* SERVCONF_H */
326