xref: /freebsd/crypto/openssh/readconf.h (revision a91a246563dffa876a52f53a98de4af9fa364c52)
1 /* $OpenBSD: readconf.h,v 1.156 2024/03/04 02:16:11 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  * Functions for reading the configuration file.
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 READCONF_H
17 #define READCONF_H
18 
19 /* Data structure for representing option data. */
20 
21 #define SSH_MAX_HOSTS_FILES	32
22 #define MAX_CANON_DOMAINS	32
23 #define PATH_MAX_SUN		(sizeof((struct sockaddr_un *)0)->sun_path)
24 
25 struct allowed_cname {
26 	char *source_list;
27 	char *target_list;
28 };
29 
30 typedef struct {
31 	char   *host_arg;	/* Host arg as specified on command line. */
32 	int     forward_agent;	/* Forward authentication agent. */
33 	char   *forward_agent_sock_path; /* Optional path of the agent. */
34 	int     forward_x11;	/* Forward X11 display. */
35 	int     forward_x11_timeout;	/* Expiration for Cookies */
36 	int     forward_x11_trusted;	/* Trust Forward X11 display. */
37 	int     exit_on_forward_failure;	/* Exit if bind(2) fails for -L/-R */
38 	char   *xauth_location;	/* Location for xauth program */
39 	struct ForwardOptions fwd_opts;	/* forwarding options */
40 	int     pubkey_authentication;	/* Try ssh2 pubkey authentication. */
41 	int     hostbased_authentication;	/* ssh2's rhosts_rsa */
42 	int     gss_authentication;	/* Try GSS authentication */
43 	int     gss_deleg_creds;	/* Delegate GSS credentials */
44 	int     password_authentication;	/* Try password
45 						 * authentication. */
46 	int     kbd_interactive_authentication; /* Try keyboard-interactive auth. */
47 	char	*kbd_interactive_devices; /* Keyboard-interactive auth devices. */
48 	int     batch_mode;	/* Batch mode: do not ask for passwords. */
49 	int     check_host_ip;	/* Also keep track of keys for IP address */
50 	int     strict_host_key_checking;	/* Strict host key checking. */
51 	int     compression;	/* Compress packets in both directions. */
52 	int     tcp_keep_alive;	/* Set SO_KEEPALIVE. */
53 	int	ip_qos_interactive;	/* IP ToS/DSCP/class for interactive */
54 	int	ip_qos_bulk;		/* IP ToS/DSCP/class for bulk traffic */
55 	SyslogFacility log_facility;	/* Facility for system logging. */
56 	LogLevel log_level;	/* Level for logging. */
57 	u_int	num_log_verbose;	/* Verbose log overrides */
58 	char   **log_verbose;
59 	int     port;		/* Port to connect. */
60 	int     address_family;
61 	int     connection_attempts;	/* Max attempts (seconds) before
62 					 * giving up */
63 	int     connection_timeout;	/* Max time (seconds) before
64 					 * aborting connection attempt */
65 	int     number_of_password_prompts;	/* Max number of password
66 						 * prompts. */
67 	char   *ciphers;	/* SSH2 ciphers in order of preference. */
68 	char   *macs;		/* SSH2 macs in order of preference. */
69 	char   *hostkeyalgorithms;	/* SSH2 server key types in order of preference. */
70 	char   *kex_algorithms;	/* SSH2 kex methods in order of preference. */
71 	char   *ca_sign_algorithms;	/* Allowed CA signature algorithms */
72 	char   *hostname;	/* Real host to connect. */
73 	char   *tag;		/* Configuration tag name. */
74 	char   *host_key_alias;	/* hostname alias for .ssh/known_hosts */
75 	char   *proxy_command;	/* Proxy command for connecting the host. */
76 	char   *user;		/* User to log in as. */
77 	int     escape_char;	/* Escape character; -2 = none */
78 
79 	u_int	num_system_hostfiles;	/* Paths for /etc/ssh/ssh_known_hosts */
80 	char   *system_hostfiles[SSH_MAX_HOSTS_FILES];
81 	u_int	num_user_hostfiles;	/* Path for $HOME/.ssh/known_hosts */
82 	char   *user_hostfiles[SSH_MAX_HOSTS_FILES];
83 	char   *preferred_authentications;
84 	char   *bind_address;	/* local socket address for connection to sshd */
85 	char   *bind_interface;	/* local interface for bind address */
86 	char   *pkcs11_provider; /* PKCS#11 provider */
87 	char   *sk_provider; /* Security key provider */
88 	int	verify_host_key_dns;	/* Verify host key using DNS */
89 
90 	int     num_identity_files;	/* Number of files for identities. */
91 	char   *identity_files[SSH_MAX_IDENTITY_FILES];
92 	int    identity_file_userprovided[SSH_MAX_IDENTITY_FILES];
93 	struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES];
94 
95 	int	num_certificate_files; /* Number of extra certificates for ssh. */
96 	char	*certificate_files[SSH_MAX_CERTIFICATE_FILES];
97 	int	certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES];
98 	struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
99 
100 	int	add_keys_to_agent;
101 	int	add_keys_to_agent_lifespan;
102 	char   *identity_agent;		/* Optional path to ssh-agent socket */
103 
104 	/* Local TCP/IP forward requests. */
105 	int     num_local_forwards;
106 	struct Forward *local_forwards;
107 
108 	/* Remote TCP/IP forward requests. */
109 	int     num_remote_forwards;
110 	struct Forward *remote_forwards;
111 	int	clear_forwardings;
112 
113 	/* Restrict remote dynamic forwarding */
114 	char  **permitted_remote_opens;
115 	u_int	num_permitted_remote_opens;
116 
117 	/* stdio forwarding (-W) host and port */
118 	char   *stdio_forward_host;
119 	int	stdio_forward_port;
120 
121 	int	enable_ssh_keysign;
122 	int64_t rekey_limit;
123 	int	rekey_interval;
124 	int	no_host_authentication_for_localhost;
125 	int	identities_only;
126 	int	server_alive_interval;
127 	int	server_alive_count_max;
128 
129 	u_int	num_send_env;
130 	char	**send_env;
131 	u_int	num_setenv;
132 	char	**setenv;
133 
134 	char	*control_path;
135 	int	control_master;
136 	int     control_persist; /* ControlPersist flag */
137 	int     control_persist_timeout; /* ControlPersist timeout (seconds) */
138 
139 	int	hash_known_hosts;
140 
141 	int	tun_open;	/* tun(4) */
142 	int     tun_local;	/* force tun device (optional) */
143 	int     tun_remote;	/* force tun device (optional) */
144 
145 	char	*local_command;
146 	int	permit_local_command;
147 	char	*remote_command;
148 	int	visual_host_key;
149 
150 	int	request_tty;
151 	int	session_type;
152 	int	stdin_null;
153 	int	fork_after_authentication;
154 
155 	int	proxy_use_fdpass;
156 
157 	int	num_canonical_domains;
158 	char	**canonical_domains;
159 	int	canonicalize_hostname;
160 	int	canonicalize_max_dots;
161 	int	canonicalize_fallback_local;
162 	int	num_permitted_cnames;
163 	struct allowed_cname *permitted_cnames;
164 
165 	char	*revoked_host_keys;
166 
167 	int	 fingerprint_hash;
168 
169 	int	 update_hostkeys; /* one of SSH_UPDATE_HOSTKEYS_* */
170 
171 	char   *hostbased_accepted_algos;
172 	char   *pubkey_accepted_algos;
173 
174 	char   *jump_user;
175 	char   *jump_host;
176 	int	jump_port;
177 	char   *jump_extra;
178 
179 	char   *known_hosts_command;
180 
181 	int	required_rsa_size;	/* minimum size of RSA keys */
182 	int	enable_escape_commandline;	/* ~C commandline */
183 	int	obscure_keystroke_timing_interval;
184 
185 	char	**channel_timeouts;	/* inactivity timeout by channel type */
186 	u_int	num_channel_timeouts;
187 
188 	char	*ignored_unknown; /* Pattern list of unknown tokens to ignore */
189 }       Options;
190 
191 #define SSH_PUBKEY_AUTH_NO	0x00
192 #define SSH_PUBKEY_AUTH_UNBOUND	0x01
193 #define SSH_PUBKEY_AUTH_HBOUND	0x02
194 #define SSH_PUBKEY_AUTH_ALL	0x03
195 
196 #define SSH_CANONICALISE_NO	0
197 #define SSH_CANONICALISE_YES	1
198 #define SSH_CANONICALISE_ALWAYS	2
199 
200 #define SSHCTL_MASTER_NO	0
201 #define SSHCTL_MASTER_YES	1
202 #define SSHCTL_MASTER_AUTO	2
203 #define SSHCTL_MASTER_ASK	3
204 #define SSHCTL_MASTER_AUTO_ASK	4
205 
206 #define REQUEST_TTY_AUTO	0
207 #define REQUEST_TTY_NO		1
208 #define REQUEST_TTY_YES		2
209 #define REQUEST_TTY_FORCE	3
210 
211 #define SESSION_TYPE_NONE	0
212 #define SESSION_TYPE_SUBSYSTEM	1
213 #define SESSION_TYPE_DEFAULT	2
214 
215 #define SSHCONF_CHECKPERM	1  /* check permissions on config file */
216 #define SSHCONF_USERCONF	2  /* user provided config file not system */
217 #define SSHCONF_FINAL		4  /* Final pass over config, after canon. */
218 #define SSHCONF_NEVERMATCH	8  /* Match/Host never matches; internal only */
219 
220 #define SSH_UPDATE_HOSTKEYS_NO	0
221 #define SSH_UPDATE_HOSTKEYS_YES	1
222 #define SSH_UPDATE_HOSTKEYS_ASK	2
223 
224 #define SSH_STRICT_HOSTKEY_OFF	0
225 #define SSH_STRICT_HOSTKEY_NEW	1
226 #define SSH_STRICT_HOSTKEY_YES	2
227 #define SSH_STRICT_HOSTKEY_ASK	3
228 
229 /* ObscureKeystrokes parameters */
230 #define SSH_KEYSTROKE_DEFAULT_INTERVAL_MS	20
231 #define SSH_KEYSTROKE_CHAFF_MIN_MS		1024
232 #define SSH_KEYSTROKE_CHAFF_RNG_MS		2048
233 
234 const char *kex_default_pk_alg(void);
235 char	*ssh_connection_hash(const char *thishost, const char *host,
236     const char *portstr, const char *user, const char *jump_host);
237 void     initialize_options(Options *);
238 int      fill_default_options(Options *);
239 void	 fill_default_options_for_canonicalization(Options *);
240 void	 free_options(Options *o);
241 int	 process_config_line(Options *, struct passwd *, const char *,
242     const char *, char *, const char *, int, int *, int);
243 int	 read_config_file(const char *, struct passwd *, const char *,
244     const char *, Options *, int, int *);
245 int	 parse_forward(struct Forward *, const char *, int, int);
246 int	 parse_jump(const char *, Options *, int);
247 int	 parse_ssh_uri(const char *, char **, char **, int *);
248 int	 default_ssh_port(void);
249 int	 option_clear_or_none(const char *);
250 int	 config_has_permitted_cnames(Options *);
251 void	 dump_client_config(Options *o, const char *host);
252 
253 void	 add_local_forward(Options *, const struct Forward *);
254 void	 add_remote_forward(Options *, const struct Forward *);
255 void	 add_identity_file(Options *, const char *, const char *, int);
256 void	 add_certificate_file(Options *, const char *, int);
257 
258 #endif				/* READCONF_H */
259