diff options
Diffstat (limited to 'sshd_config.0')
-rw-r--r-- | sshd_config.0 | 578 |
1 files changed, 267 insertions, 311 deletions
diff --git a/sshd_config.0 b/sshd_config.0 index 85379dca5..022c05226 100644 --- a/sshd_config.0 +++ b/sshd_config.0 | |||
@@ -32,12 +32,12 @@ DESCRIPTION | |||
32 | 32 | ||
33 | AddressFamily | 33 | AddressFamily |
34 | Specifies which address family should be used by sshd(8). Valid | 34 | Specifies which address family should be used by sshd(8). Valid |
35 | arguments are M-bM-^@M-^\anyM-bM-^@M-^], M-bM-^@M-^\inetM-bM-^@M-^] (use IPv4 only), or M-bM-^@M-^\inet6M-bM-^@M-^] (use IPv6 | 35 | arguments are any (the default), inet (use IPv4 only), or inet6 |
36 | only). The default is M-bM-^@M-^\anyM-bM-^@M-^]. | 36 | (use IPv6 only). |
37 | 37 | ||
38 | AllowAgentForwarding | 38 | AllowAgentForwarding |
39 | Specifies whether ssh-agent(1) forwarding is permitted. The | 39 | Specifies whether ssh-agent(1) forwarding is permitted. The |
40 | default is M-bM-^@M-^\yesM-bM-^@M-^]. Note that disabling agent forwarding does not | 40 | default is yes. Note that disabling agent forwarding does not |
41 | improve security unless users are also denied shell access, as | 41 | improve security unless users are also denied shell access, as |
42 | they can always install their own forwarders. | 42 | they can always install their own forwarders. |
43 | 43 | ||
@@ -53,25 +53,24 @@ DESCRIPTION | |||
53 | 53 | ||
54 | See PATTERNS in ssh_config(5) for more information on patterns. | 54 | See PATTERNS in ssh_config(5) for more information on patterns. |
55 | 55 | ||
56 | AllowTcpForwarding | ||
57 | Specifies whether TCP forwarding is permitted. The available | ||
58 | options are M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\allM-bM-^@M-^] to allow TCP forwarding, M-bM-^@M-^\noM-bM-^@M-^] to | ||
59 | prevent all TCP forwarding, M-bM-^@M-^\localM-bM-^@M-^] to allow local (from the | ||
60 | perspective of ssh(1)) forwarding only or M-bM-^@M-^\remoteM-bM-^@M-^] to allow | ||
61 | remote forwarding only. The default is M-bM-^@M-^\yesM-bM-^@M-^]. Note that | ||
62 | disabling TCP forwarding does not improve security unless users | ||
63 | are also denied shell access, as they can always install their | ||
64 | own forwarders. | ||
65 | |||
66 | AllowStreamLocalForwarding | 56 | AllowStreamLocalForwarding |
67 | Specifies whether StreamLocal (Unix-domain socket) forwarding is | 57 | Specifies whether StreamLocal (Unix-domain socket) forwarding is |
68 | permitted. The available options are M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\allM-bM-^@M-^] to allow | 58 | permitted. The available options are yes (the default) or all to |
69 | StreamLocal forwarding, M-bM-^@M-^\noM-bM-^@M-^] to prevent all StreamLocal | 59 | allow StreamLocal forwarding, no to prevent all StreamLocal |
70 | forwarding, M-bM-^@M-^\localM-bM-^@M-^] to allow local (from the perspective of | 60 | forwarding, local to allow local (from the perspective of ssh(1)) |
71 | ssh(1)) forwarding only or M-bM-^@M-^\remoteM-bM-^@M-^] to allow remote forwarding | 61 | forwarding only or remote to allow remote forwarding only. Note |
72 | only. The default is M-bM-^@M-^\yesM-bM-^@M-^]. Note that disabling StreamLocal | 62 | that disabling StreamLocal forwarding does not improve security |
73 | forwarding does not improve security unless users are also denied | 63 | unless users are also denied shell access, as they can always |
74 | shell access, as they can always install their own forwarders. | 64 | install their own forwarders. |
65 | |||
66 | AllowTcpForwarding | ||
67 | Specifies whether TCP forwarding is permitted. The available | ||
68 | options are yes (the default) or all to allow TCP forwarding, no | ||
69 | to prevent all TCP forwarding, local to allow local (from the | ||
70 | perspective of ssh(1)) forwarding only or remote to allow remote | ||
71 | forwarding only. Note that disabling TCP forwarding does not | ||
72 | improve security unless users are also denied shell access, as | ||
73 | they can always install their own forwarders. | ||
75 | 74 | ||
76 | AllowUsers | 75 | AllowUsers |
77 | This keyword can be followed by a list of user name patterns, | 76 | This keyword can be followed by a list of user name patterns, |
@@ -92,53 +91,42 @@ DESCRIPTION | |||
92 | Specifies the authentication methods that must be successfully | 91 | Specifies the authentication methods that must be successfully |
93 | completed for a user to be granted access. This option must be | 92 | completed for a user to be granted access. This option must be |
94 | followed by one or more comma-separated lists of authentication | 93 | followed by one or more comma-separated lists of authentication |
95 | method names, or by the single string M-bM-^@M-^\anyM-bM-^@M-^] to indicate the | 94 | method names, or by the single string any to indicate the default |
96 | default behaviour of accepting any single authentication method. | 95 | behaviour of accepting any single authentication method. If the |
97 | if the default is overridden, then successful authentication | 96 | default is overridden, then successful authentication requires |
98 | requires completion of every method in at least one of these | 97 | completion of every method in at least one of these lists. |
99 | lists. | 98 | |
100 | 99 | For example, "publickey,password publickey,keyboard-interactive" | |
101 | For example, an argument of M-bM-^@M-^\publickey,password | 100 | would require the user to complete public key authentication, |
102 | publickey,keyboard-interactiveM-bM-^@M-^] would require the user to | 101 | followed by either password or keyboard interactive |
103 | complete public key authentication, followed by either password | 102 | authentication. Only methods that are next in one or more lists |
104 | or keyboard interactive authentication. Only methods that are | 103 | are offered at each stage, so for this example it would not be |
105 | next in one or more lists are offered at each stage, so for this | 104 | possible to attempt password or keyboard-interactive |
106 | example, it would not be possible to attempt password or | 105 | authentication before public key. |
107 | keyboard-interactive authentication before public key. | ||
108 | 106 | ||
109 | For keyboard interactive authentication it is also possible to | 107 | For keyboard interactive authentication it is also possible to |
110 | restrict authentication to a specific device by appending a colon | 108 | restrict authentication to a specific device by appending a colon |
111 | followed by the device identifier M-bM-^@M-^\bsdauthM-bM-^@M-^], M-bM-^@M-^\pamM-bM-^@M-^], or M-bM-^@M-^\skeyM-bM-^@M-^], | 109 | followed by the device identifier bsdauth, pam, or skey, |
112 | depending on the server configuration. For example, | 110 | depending on the server configuration. For example, |
113 | M-bM-^@M-^\keyboard-interactive:bsdauthM-bM-^@M-^] would restrict keyboard | 111 | "keyboard-interactive:bsdauth" would restrict keyboard |
114 | interactive authentication to the M-bM-^@M-^\bsdauthM-bM-^@M-^] device. | 112 | interactive authentication to the bsdauth device. |
115 | 113 | ||
116 | If the M-bM-^@M-^\publickeyM-bM-^@M-^] method is listed more than once, sshd(8) | 114 | If the publickey method is listed more than once, sshd(8) |
117 | verifies that keys that have been used successfully are not | 115 | verifies that keys that have been used successfully are not |
118 | reused for subsequent authentications. For example, an | 116 | reused for subsequent authentications. For example, |
119 | AuthenticationMethods of M-bM-^@M-^\publickey,publickeyM-bM-^@M-^] will require | 117 | "publickey,publickey" requires successful authentication using |
120 | successful authentication using two different public keys. | 118 | two different public keys. |
121 | 119 | ||
122 | This option will yield a fatal error if enabled if protocol 1 is | 120 | Note that each authentication method listed should also be |
123 | also enabled. Note that each authentication method listed should | 121 | explicitly enabled in the configuration. |
124 | also be explicitly enabled in the configuration. The default | ||
125 | M-bM-^@M-^\anyM-bM-^@M-^] is not to require multiple authentication; successful | ||
126 | completion of a single authentication method is sufficient. | ||
127 | 122 | ||
128 | AuthorizedKeysCommand | 123 | AuthorizedKeysCommand |
129 | Specifies a program to be used to look up the user's public keys. | 124 | Specifies a program to be used to look up the user's public keys. |
130 | The program must be owned by root, not writable by group or | 125 | The program must be owned by root, not writable by group or |
131 | others and specified by an absolute path. | 126 | others and specified by an absolute path. Arguments to |
132 | 127 | AuthorizedKeysCommand accept the tokens described in the TOKENS | |
133 | Arguments to AuthorizedKeysCommand may be provided using the | 128 | section. If no arguments are specified then the username of the |
134 | following tokens, which will be expanded at runtime: %% is | 129 | target user is used. |
135 | replaced by a literal '%', %u is replaced by the username being | ||
136 | authenticated, %h is replaced by the home directory of the user | ||
137 | being authenticated, %t is replaced with the key type offered for | ||
138 | authentication, %f is replaced with the fingerprint of the key, | ||
139 | and %k is replaced with the key being offered for authentication. | ||
140 | If no arguments are specified then the username of the target | ||
141 | user will be supplied. | ||
142 | 130 | ||
143 | The program should produce on standard output zero or more lines | 131 | The program should produce on standard output zero or more lines |
144 | of authorized_keys output (see AUTHORIZED_KEYS in sshd(8)). If a | 132 | of authorized_keys output (see AUTHORIZED_KEYS in sshd(8)). If a |
@@ -155,31 +143,24 @@ DESCRIPTION | |||
155 | is not, then sshd(8) will refuse to start. | 143 | is not, then sshd(8) will refuse to start. |
156 | 144 | ||
157 | AuthorizedKeysFile | 145 | AuthorizedKeysFile |
158 | Specifies the file that contains the public keys that can be used | 146 | Specifies the file that contains the public keys used for user |
159 | for user authentication. The format is described in the | 147 | authentication. The format is described in the AUTHORIZED_KEYS |
160 | AUTHORIZED_KEYS FILE FORMAT section of sshd(8). | 148 | FILE FORMAT section of sshd(8). Arguments to AuthorizedKeysFile |
161 | AuthorizedKeysFile may contain tokens of the form %T which are | 149 | accept the tokens described in the TOKENS section. After |
162 | substituted during connection setup. The following tokens are | 150 | expansion, AuthorizedKeysFile is taken to be an absolute path or |
163 | defined: %% is replaced by a literal '%', %h is replaced by the | 151 | one relative to the user's home directory. Multiple files may be |
164 | home directory of the user being authenticated, and %u is | ||
165 | replaced by the username of that user. After expansion, | ||
166 | AuthorizedKeysFile is taken to be an absolute path or one | ||
167 | relative to the user's home directory. Multiple files may be | ||
168 | listed, separated by whitespace. Alternately this option may be | 152 | listed, separated by whitespace. Alternately this option may be |
169 | set to M-bM-^@M-^\noneM-bM-^@M-^] to skip checking for user keys in files. The | 153 | set to none to skip checking for user keys in files. The default |
170 | default is M-bM-^@M-^\.ssh/authorized_keys .ssh/authorized_keys2M-bM-^@M-^]. | 154 | is ".ssh/authorized_keys .ssh/authorized_keys2". |
171 | 155 | ||
172 | AuthorizedPrincipalsCommand | 156 | AuthorizedPrincipalsCommand |
173 | Specifies a program to be used to generate the list of allowed | 157 | Specifies a program to be used to generate the list of allowed |
174 | certificate principals as per AuthorizedPrincipalsFile. The | 158 | certificate principals as per AuthorizedPrincipalsFile. The |
175 | program must be owned by root, not writable by group or others | 159 | program must be owned by root, not writable by group or others |
176 | and specified by an absolute path. | 160 | and specified by an absolute path. Arguments to |
177 | 161 | AuthorizedPrincipalsCommand accept the tokens described in the | |
178 | Arguments to AuthorizedPrincipalsCommand may be provided using | 162 | TOKENS section. If no arguments are specified then the username |
179 | the following tokens, which will be expanded at runtime: %% is | 163 | of the target user is used. |
180 | replaced by a literal '%', %u is replaced by the username being | ||
181 | authenticated and %h is replaced by the home directory of the | ||
182 | user being authenticated. | ||
183 | 164 | ||
184 | The program should produce on standard output zero or more lines | 165 | The program should produce on standard output zero or more lines |
185 | of AuthorizedPrincipalsFile output. If either | 166 | of AuthorizedPrincipalsFile output. If either |
@@ -205,31 +186,27 @@ DESCRIPTION | |||
205 | options (as described in AUTHORIZED_KEYS FILE FORMAT in sshd(8)). | 186 | options (as described in AUTHORIZED_KEYS FILE FORMAT in sshd(8)). |
206 | Empty lines and comments starting with M-bM-^@M-^X#M-bM-^@M-^Y are ignored. | 187 | Empty lines and comments starting with M-bM-^@M-^X#M-bM-^@M-^Y are ignored. |
207 | 188 | ||
208 | AuthorizedPrincipalsFile may contain tokens of the form %T which | 189 | Arguments to AuthorizedPrincipalsFile accept the tokens described |
209 | are substituted during connection setup. The following tokens | 190 | in the TOKENS section. After expansion, AuthorizedPrincipalsFile |
210 | are defined: %% is replaced by a literal '%', %h is replaced by | 191 | is taken to be an absolute path or one relative to the user's |
211 | the home directory of the user being authenticated, and %u is | 192 | home directory. The default is none, i.e. not to use a |
212 | replaced by the username of that user. After expansion, | 193 | principals file M-bM-^@M-^S in this case, the username of the user must |
213 | AuthorizedPrincipalsFile is taken to be an absolute path or one | 194 | appear in a certificate's principals list for it to be accepted. |
214 | relative to the user's home directory. | 195 | |
215 | 196 | Note that AuthorizedPrincipalsFile is only used when | |
216 | The default is M-bM-^@M-^\noneM-bM-^@M-^], i.e. not to use a principals file M-bM-^@M-^S in | 197 | authentication proceeds using a CA listed in TrustedUserCAKeys |
217 | this case, the username of the user must appear in a | 198 | and is not consulted for certification authorities trusted via |
218 | certificate's principals list for it to be accepted. Note that | ||
219 | AuthorizedPrincipalsFile is only used when authentication | ||
220 | proceeds using a CA listed in TrustedUserCAKeys and is not | ||
221 | consulted for certification authorities trusted via | ||
222 | ~/.ssh/authorized_keys, though the principals= key option offers | 199 | ~/.ssh/authorized_keys, though the principals= key option offers |
223 | a similar facility (see sshd(8) for details). | 200 | a similar facility (see sshd(8) for details). |
224 | 201 | ||
225 | Banner The contents of the specified file are sent to the remote user | 202 | Banner The contents of the specified file are sent to the remote user |
226 | before authentication is allowed. If the argument is M-bM-^@M-^\noneM-bM-^@M-^] then | 203 | before authentication is allowed. If the argument is none then |
227 | no banner is displayed. By default, no banner is displayed. | 204 | no banner is displayed. By default, no banner is displayed. |
228 | 205 | ||
229 | ChallengeResponseAuthentication | 206 | ChallengeResponseAuthentication |
230 | Specifies whether challenge-response authentication is allowed | 207 | Specifies whether challenge-response authentication is allowed |
231 | (e.g. via PAM or through authentication styles supported in | 208 | (e.g. via PAM or through authentication styles supported in |
232 | login.conf(5)) The default is M-bM-^@M-^\yesM-bM-^@M-^]. | 209 | login.conf(5)) The default is yes. |
233 | 210 | ||
234 | ChrootDirectory | 211 | ChrootDirectory |
235 | Specifies the pathname of a directory to chroot(2) to after | 212 | Specifies the pathname of a directory to chroot(2) to after |
@@ -237,31 +214,25 @@ DESCRIPTION | |||
237 | components of the pathname are root-owned directories which are | 214 | components of the pathname are root-owned directories which are |
238 | not writable by any other user or group. After the chroot, | 215 | not writable by any other user or group. After the chroot, |
239 | sshd(8) changes the working directory to the user's home | 216 | sshd(8) changes the working directory to the user's home |
240 | directory. | 217 | directory. Arguments to ChrootDirectory accept the tokens |
241 | 218 | described in the TOKENS section. | |
242 | The pathname may contain the following tokens that are expanded | ||
243 | at runtime once the connecting user has been authenticated: %% is | ||
244 | replaced by a literal '%', %h is replaced by the home directory | ||
245 | of the user being authenticated, and %u is replaced by the | ||
246 | username of that user. | ||
247 | 219 | ||
248 | The ChrootDirectory must contain the necessary files and | 220 | The ChrootDirectory must contain the necessary files and |
249 | directories to support the user's session. For an interactive | 221 | directories to support the user's session. For an interactive |
250 | session this requires at least a shell, typically sh(1), and | 222 | session this requires at least a shell, typically sh(1), and |
251 | basic /dev nodes such as null(4), zero(4), stdin(4), stdout(4), | 223 | basic /dev nodes such as null(4), zero(4), stdin(4), stdout(4), |
252 | stderr(4), and tty(4) devices. For file transfer sessions using | 224 | stderr(4), and tty(4) devices. For file transfer sessions using |
253 | M-bM-^@M-^\sftpM-bM-^@M-^], no additional configuration of the environment is | 225 | SFTP no additional configuration of the environment is necessary |
254 | necessary if the in-process sftp server is used, though sessions | 226 | if the in-process sftp-server is used, though sessions which use |
255 | which use logging may require /dev/log inside the chroot | 227 | logging may require /dev/log inside the chroot directory on some |
256 | directory on some operating systems (see sftp-server(8) for | 228 | operating systems (see sftp-server(8) for details). |
257 | details). | ||
258 | 229 | ||
259 | For safety, it is very important that the directory hierarchy be | 230 | For safety, it is very important that the directory hierarchy be |
260 | prevented from modification by other processes on the system | 231 | prevented from modification by other processes on the system |
261 | (especially those outside the jail). Misconfiguration can lead | 232 | (especially those outside the jail). Misconfiguration can lead |
262 | to unsafe environments which sshd(8) cannot detect. | 233 | to unsafe environments which sshd(8) cannot detect. |
263 | 234 | ||
264 | The default is M-bM-^@M-^\noneM-bM-^@M-^], indicating not to chroot(2). | 235 | The default is none, indicating not to chroot(2). |
265 | 236 | ||
266 | Ciphers | 237 | Ciphers |
267 | Specifies the ciphers allowed. Multiple ciphers must be comma- | 238 | Specifies the ciphers allowed. Multiple ciphers must be comma- |
@@ -293,26 +264,25 @@ DESCRIPTION | |||
293 | aes128-ctr,aes192-ctr,aes256-ctr, | 264 | aes128-ctr,aes192-ctr,aes256-ctr, |
294 | aes128-gcm@openssh.com,aes256-gcm@openssh.com | 265 | aes128-gcm@openssh.com,aes256-gcm@openssh.com |
295 | 266 | ||
296 | The list of available ciphers may also be obtained using the -Q | 267 | The list of available ciphers may also be obtained using "ssh -Q |
297 | option of ssh(1) with an argument of M-bM-^@M-^\cipherM-bM-^@M-^]. | 268 | cipher". |
298 | 269 | ||
299 | ClientAliveCountMax | 270 | ClientAliveCountMax |
300 | Sets the number of client alive messages (see below) which may be | 271 | Sets the number of client alive messages which may be sent |
301 | sent without sshd(8) receiving any messages back from the client. | 272 | without sshd(8) receiving any messages back from the client. If |
302 | If this threshold is reached while client alive messages are | 273 | this threshold is reached while client alive messages are being |
303 | being sent, sshd will disconnect the client, terminating the | 274 | sent, sshd will disconnect the client, terminating the session. |
304 | session. It is important to note that the use of client alive | 275 | It is important to note that the use of client alive messages is |
305 | messages is very different from TCPKeepAlive (below). The client | 276 | very different from TCPKeepAlive. The client alive messages are |
306 | alive messages are sent through the encrypted channel and | 277 | sent through the encrypted channel and therefore will not be |
307 | therefore will not be spoofable. The TCP keepalive option | 278 | spoofable. The TCP keepalive option enabled by TCPKeepAlive is |
308 | enabled by TCPKeepAlive is spoofable. The client alive mechanism | 279 | spoofable. The client alive mechanism is valuable when the |
309 | is valuable when the client or server depend on knowing when a | 280 | client or server depend on knowing when a connection has become |
310 | connection has become inactive. | 281 | inactive. |
311 | 282 | ||
312 | The default value is 3. If ClientAliveInterval (see below) is | 283 | The default value is 3. If ClientAliveInterval is set to 15, and |
313 | set to 15, and ClientAliveCountMax is left at the default, | 284 | ClientAliveCountMax is left at the default, unresponsive SSH |
314 | unresponsive SSH clients will be disconnected after approximately | 285 | clients will be disconnected after approximately 45 seconds. |
315 | 45 seconds. | ||
316 | 286 | ||
317 | ClientAliveInterval | 287 | ClientAliveInterval |
318 | Sets a timeout interval in seconds after which if no data has | 288 | Sets a timeout interval in seconds after which if no data has |
@@ -322,9 +292,9 @@ DESCRIPTION | |||
322 | not be sent to the client. | 292 | not be sent to the client. |
323 | 293 | ||
324 | Compression | 294 | Compression |
325 | Specifies whether compression is allowed, or delayed until the | 295 | Specifies whether compression is enabled after the user has |
326 | user has authenticated successfully. The argument must be M-bM-^@M-^\yesM-bM-^@M-^], | 296 | authenticated successfully. The argument must be yes, delayed (a |
327 | M-bM-^@M-^\delayedM-bM-^@M-^], or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\delayedM-bM-^@M-^]. | 297 | legacy synonym for yes) or no. The default is yes. |
328 | 298 | ||
329 | DenyGroups | 299 | DenyGroups |
330 | This keyword can be followed by a list of group name patterns, | 300 | This keyword can be followed by a list of group name patterns, |
@@ -352,9 +322,14 @@ DESCRIPTION | |||
352 | 322 | ||
353 | See PATTERNS in ssh_config(5) for more information on patterns. | 323 | See PATTERNS in ssh_config(5) for more information on patterns. |
354 | 324 | ||
325 | DisableForwarding | ||
326 | Disables all forwarding features, including X11, ssh-agent(1), | ||
327 | TCP and StreamLocal. This option overrides all other forwarding- | ||
328 | related options and may simplify restricted configurations. | ||
329 | |||
355 | FingerprintHash | 330 | FingerprintHash |
356 | Specifies the hash algorithm used when logging key fingerprints. | 331 | Specifies the hash algorithm used when logging key fingerprints. |
357 | Valid options are: M-bM-^@M-^\md5M-bM-^@M-^] and M-bM-^@M-^\sha256M-bM-^@M-^]. The default is M-bM-^@M-^\sha256M-bM-^@M-^]. | 332 | Valid options are: md5 and sha256. The default is sha256. |
358 | 333 | ||
359 | ForceCommand | 334 | ForceCommand |
360 | Forces the execution of the command specified by ForceCommand, | 335 | Forces the execution of the command specified by ForceCommand, |
@@ -364,9 +339,9 @@ DESCRIPTION | |||
364 | execution. It is most useful inside a Match block. The command | 339 | execution. It is most useful inside a Match block. The command |
365 | originally supplied by the client is available in the | 340 | originally supplied by the client is available in the |
366 | SSH_ORIGINAL_COMMAND environment variable. Specifying a command | 341 | SSH_ORIGINAL_COMMAND environment variable. Specifying a command |
367 | of M-bM-^@M-^\internal-sftpM-bM-^@M-^] will force the use of an in-process sftp | 342 | of internal-sftp will force the use of an in-process SFTP server |
368 | server that requires no support files when used with | 343 | that requires no support files when used with ChrootDirectory. |
369 | ChrootDirectory. The default is M-bM-^@M-^\noneM-bM-^@M-^]. | 344 | The default is none. |
370 | 345 | ||
371 | GatewayPorts | 346 | GatewayPorts |
372 | Specifies whether remote hosts are allowed to connect to ports | 347 | Specifies whether remote hosts are allowed to connect to ports |
@@ -375,28 +350,28 @@ DESCRIPTION | |||
375 | hosts from connecting to forwarded ports. GatewayPorts can be | 350 | hosts from connecting to forwarded ports. GatewayPorts can be |
376 | used to specify that sshd should allow remote port forwardings to | 351 | used to specify that sshd should allow remote port forwardings to |
377 | bind to non-loopback addresses, thus allowing other hosts to | 352 | bind to non-loopback addresses, thus allowing other hosts to |
378 | connect. The argument may be M-bM-^@M-^\noM-bM-^@M-^] to force remote port | 353 | connect. The argument may be no to force remote port forwardings |
379 | forwardings to be available to the local host only, M-bM-^@M-^\yesM-bM-^@M-^] to | 354 | to be available to the local host only, yes to force remote port |
380 | force remote port forwardings to bind to the wildcard address, or | 355 | forwardings to bind to the wildcard address, or clientspecified |
381 | M-bM-^@M-^\clientspecifiedM-bM-^@M-^] to allow the client to select the address to | 356 | to allow the client to select the address to which the forwarding |
382 | which the forwarding is bound. The default is M-bM-^@M-^\noM-bM-^@M-^]. | 357 | is bound. The default is no. |
383 | 358 | ||
384 | GSSAPIAuthentication | 359 | GSSAPIAuthentication |
385 | Specifies whether user authentication based on GSSAPI is allowed. | 360 | Specifies whether user authentication based on GSSAPI is allowed. |
386 | The default is M-bM-^@M-^\noM-bM-^@M-^]. | 361 | The default is no. |
387 | 362 | ||
388 | GSSAPICleanupCredentials | 363 | GSSAPICleanupCredentials |
389 | Specifies whether to automatically destroy the user's credentials | 364 | Specifies whether to automatically destroy the user's credentials |
390 | cache on logout. The default is M-bM-^@M-^\yesM-bM-^@M-^]. | 365 | cache on logout. The default is yes. |
391 | 366 | ||
392 | GSSAPIStrictAcceptorCheck | 367 | GSSAPIStrictAcceptorCheck |
393 | Determines whether to be strict about the identity of the GSSAPI | 368 | Determines whether to be strict about the identity of the GSSAPI |
394 | acceptor a client authenticates against. If set to M-bM-^@M-^\yesM-bM-^@M-^] then | 369 | acceptor a client authenticates against. If set to yes then the |
395 | the client must authenticate against the host service on the | 370 | client must authenticate against the host service on the current |
396 | current hostname. If set to M-bM-^@M-^\noM-bM-^@M-^] then the client may | 371 | hostname. If set to no then the client may authenticate against |
397 | authenticate against any service key stored in the machine's | 372 | any service key stored in the machine's default store. This |
398 | default store. This facility is provided to assist with | 373 | facility is provided to assist with operation on multi homed |
399 | operation on multi homed machines. The default is M-bM-^@M-^\yesM-bM-^@M-^]. | 374 | machines. The default is yes. |
400 | 375 | ||
401 | HostbasedAcceptedKeyTypes | 376 | HostbasedAcceptedKeyTypes |
402 | Specifies the key types that will be accepted for hostbased | 377 | Specifies the key types that will be accepted for hostbased |
@@ -413,21 +388,22 @@ DESCRIPTION | |||
413 | ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, | 388 | ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, |
414 | ssh-ed25519,ssh-rsa | 389 | ssh-ed25519,ssh-rsa |
415 | 390 | ||
416 | The -Q option of ssh(1) may be used to list supported key types. | 391 | The list of available key types may also be obtained using "ssh |
392 | -Q key". | ||
417 | 393 | ||
418 | HostbasedAuthentication | 394 | HostbasedAuthentication |
419 | Specifies whether rhosts or /etc/hosts.equiv authentication | 395 | Specifies whether rhosts or /etc/hosts.equiv authentication |
420 | together with successful public key client host authentication is | 396 | together with successful public key client host authentication is |
421 | allowed (host-based authentication). The default is M-bM-^@M-^\noM-bM-^@M-^]. | 397 | allowed (host-based authentication). The default is no. |
422 | 398 | ||
423 | HostbasedUsesNameFromPacketOnly | 399 | HostbasedUsesNameFromPacketOnly |
424 | Specifies whether or not the server will attempt to perform a | 400 | Specifies whether or not the server will attempt to perform a |
425 | reverse name lookup when matching the name in the ~/.shosts, | 401 | reverse name lookup when matching the name in the ~/.shosts, |
426 | ~/.rhosts, and /etc/hosts.equiv files during | 402 | ~/.rhosts, and /etc/hosts.equiv files during |
427 | HostbasedAuthentication. A setting of M-bM-^@M-^\yesM-bM-^@M-^] means that sshd(8) | 403 | HostbasedAuthentication. A setting of yes means that sshd(8) |
428 | uses the name supplied by the client rather than attempting to | 404 | uses the name supplied by the client rather than attempting to |
429 | resolve the name from the TCP connection itself. The default is | 405 | resolve the name from the TCP connection itself. The default is |
430 | M-bM-^@M-^\noM-bM-^@M-^]. | 406 | no. |
431 | 407 | ||
432 | HostCertificate | 408 | HostCertificate |
433 | Specifies a file containing a public host certificate. The | 409 | Specifies a file containing a public host certificate. The |
@@ -437,25 +413,23 @@ DESCRIPTION | |||
437 | 413 | ||
438 | HostKey | 414 | HostKey |
439 | Specifies a file containing a private host key used by SSH. The | 415 | Specifies a file containing a private host key used by SSH. The |
440 | default is /etc/ssh/ssh_host_key for protocol version 1, and | 416 | defaults are /etc/ssh/ssh_host_dsa_key, |
441 | /etc/ssh/ssh_host_dsa_key, /etc/ssh/ssh_host_ecdsa_key, | 417 | /etc/ssh/ssh_host_ecdsa_key, /etc/ssh/ssh_host_ed25519_key and |
442 | /etc/ssh/ssh_host_ed25519_key and /etc/ssh/ssh_host_rsa_key for | 418 | /etc/ssh/ssh_host_rsa_key. |
443 | protocol version 2. | ||
444 | 419 | ||
445 | Note that sshd(8) will refuse to use a file if it is group/world- | 420 | Note that sshd(8) will refuse to use a file if it is group/world- |
446 | accessible and that the HostKeyAlgorithms option restricts which | 421 | accessible and that the HostKeyAlgorithms option restricts which |
447 | of the keys are actually used by sshd(8). | 422 | of the keys are actually used by sshd(8). |
448 | 423 | ||
449 | It is possible to have multiple host key files. M-bM-^@M-^\rsa1M-bM-^@M-^] keys are | 424 | It is possible to have multiple host key files. It is also |
450 | used for version 1 and M-bM-^@M-^\dsaM-bM-^@M-^], M-bM-^@M-^\ecdsaM-bM-^@M-^], M-bM-^@M-^\ed25519M-bM-^@M-^] or M-bM-^@M-^\rsaM-bM-^@M-^] are | 425 | possible to specify public host key files instead. In this case |
451 | used for version 2 of the SSH protocol. It is also possible to | 426 | operations on the private key will be delegated to an |
452 | specify public host key files instead. In this case operations | 427 | ssh-agent(1). |
453 | on the private key will be delegated to an ssh-agent(1). | ||
454 | 428 | ||
455 | HostKeyAgent | 429 | HostKeyAgent |
456 | Identifies the UNIX-domain socket used to communicate with an | 430 | Identifies the UNIX-domain socket used to communicate with an |
457 | agent that has access to the private host keys. If the string | 431 | agent that has access to the private host keys. If the string |
458 | M-bM-^@M-^\SSH_AUTH_SOCKM-bM-^@M-^] is specified, the location of the socket will be | 432 | "SSH_AUTH_SOCK" is specified, the location of the socket will be |
459 | read from the SSH_AUTH_SOCK environment variable. | 433 | read from the SSH_AUTH_SOCK environment variable. |
460 | 434 | ||
461 | HostKeyAlgorithms | 435 | HostKeyAlgorithms |
@@ -470,60 +444,59 @@ DESCRIPTION | |||
470 | ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, | 444 | ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, |
471 | ssh-ed25519,ssh-rsa | 445 | ssh-ed25519,ssh-rsa |
472 | 446 | ||
473 | The list of available key types may also be obtained using the -Q | 447 | The list of available key types may also be obtained using "ssh |
474 | option of ssh(1) with an argument of M-bM-^@M-^\keyM-bM-^@M-^]. | 448 | -Q key". |
475 | 449 | ||
476 | IgnoreRhosts | 450 | IgnoreRhosts |
477 | Specifies that .rhosts and .shosts files will not be used in | 451 | Specifies that .rhosts and .shosts files will not be used in |
478 | RhostsRSAAuthentication or HostbasedAuthentication. | 452 | HostbasedAuthentication. |
479 | 453 | ||
480 | /etc/hosts.equiv and /etc/shosts.equiv are still used. The | 454 | /etc/hosts.equiv and /etc/shosts.equiv are still used. The |
481 | default is M-bM-^@M-^\yesM-bM-^@M-^]. | 455 | default is yes. |
482 | 456 | ||
483 | IgnoreUserKnownHosts | 457 | IgnoreUserKnownHosts |
484 | Specifies whether sshd(8) should ignore the user's | 458 | Specifies whether sshd(8) should ignore the user's |
485 | ~/.ssh/known_hosts during RhostsRSAAuthentication or | 459 | ~/.ssh/known_hosts during HostbasedAuthentication. The default |
486 | HostbasedAuthentication. The default is M-bM-^@M-^\noM-bM-^@M-^]. | 460 | is no. |
487 | 461 | ||
488 | IPQoS Specifies the IPv4 type-of-service or DSCP class for the | 462 | IPQoS Specifies the IPv4 type-of-service or DSCP class for the |
489 | connection. Accepted values are M-bM-^@M-^\af11M-bM-^@M-^], M-bM-^@M-^\af12M-bM-^@M-^], M-bM-^@M-^\af13M-bM-^@M-^], M-bM-^@M-^\af21M-bM-^@M-^], | 463 | connection. Accepted values are af11, af12, af13, af21, af22, |
490 | M-bM-^@M-^\af22M-bM-^@M-^], M-bM-^@M-^\af23M-bM-^@M-^], M-bM-^@M-^\af31M-bM-^@M-^], M-bM-^@M-^\af32M-bM-^@M-^], M-bM-^@M-^\af33M-bM-^@M-^], M-bM-^@M-^\af41M-bM-^@M-^], M-bM-^@M-^\af42M-bM-^@M-^], M-bM-^@M-^\af43M-bM-^@M-^], | 464 | af23, af31, af32, af33, af41, af42, af43, cs0, cs1, cs2, cs3, |
491 | M-bM-^@M-^\cs0M-bM-^@M-^], M-bM-^@M-^\cs1M-bM-^@M-^], M-bM-^@M-^\cs2M-bM-^@M-^], M-bM-^@M-^\cs3M-bM-^@M-^], M-bM-^@M-^\cs4M-bM-^@M-^], M-bM-^@M-^\cs5M-bM-^@M-^], M-bM-^@M-^\cs6M-bM-^@M-^], M-bM-^@M-^\cs7M-bM-^@M-^], M-bM-^@M-^\efM-bM-^@M-^], | 465 | cs4, cs5, cs6, cs7, ef, lowdelay, throughput, reliability, or a |
492 | M-bM-^@M-^\lowdelayM-bM-^@M-^], M-bM-^@M-^\throughputM-bM-^@M-^], M-bM-^@M-^\reliabilityM-bM-^@M-^], or a numeric value. | 466 | numeric value. This option may take one or two arguments, |
493 | This option may take one or two arguments, separated by | 467 | separated by whitespace. If one argument is specified, it is |
494 | whitespace. If one argument is specified, it is used as the | 468 | used as the packet class unconditionally. If two values are |
495 | packet class unconditionally. If two values are specified, the | 469 | specified, the first is automatically selected for interactive |
496 | first is automatically selected for interactive sessions and the | 470 | sessions and the second for non-interactive sessions. The |
497 | second for non-interactive sessions. The default is M-bM-^@M-^\lowdelayM-bM-^@M-^] | 471 | default is lowdelay for interactive sessions and throughput for |
498 | for interactive sessions and M-bM-^@M-^\throughputM-bM-^@M-^] for non-interactive | 472 | non-interactive sessions. |
499 | sessions. | ||
500 | 473 | ||
501 | KbdInteractiveAuthentication | 474 | KbdInteractiveAuthentication |
502 | Specifies whether to allow keyboard-interactive authentication. | 475 | Specifies whether to allow keyboard-interactive authentication. |
503 | The argument to this keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default | 476 | The argument to this keyword must be yes or no. The default is |
504 | is to use whatever value ChallengeResponseAuthentication is set | 477 | to use whatever value ChallengeResponseAuthentication is set to |
505 | to (by default M-bM-^@M-^\yesM-bM-^@M-^]). | 478 | (by default yes). |
506 | 479 | ||
507 | KerberosAuthentication | 480 | KerberosAuthentication |
508 | Specifies whether the password provided by the user for | 481 | Specifies whether the password provided by the user for |
509 | PasswordAuthentication will be validated through the Kerberos | 482 | PasswordAuthentication will be validated through the Kerberos |
510 | KDC. To use this option, the server needs a Kerberos servtab | 483 | KDC. To use this option, the server needs a Kerberos servtab |
511 | which allows the verification of the KDC's identity. The default | 484 | which allows the verification of the KDC's identity. The default |
512 | is M-bM-^@M-^\noM-bM-^@M-^]. | 485 | is no. |
513 | 486 | ||
514 | KerberosGetAFSToken | 487 | KerberosGetAFSToken |
515 | If AFS is active and the user has a Kerberos 5 TGT, attempt to | 488 | If AFS is active and the user has a Kerberos 5 TGT, attempt to |
516 | acquire an AFS token before accessing the user's home directory. | 489 | acquire an AFS token before accessing the user's home directory. |
517 | The default is M-bM-^@M-^\noM-bM-^@M-^]. | 490 | The default is no. |
518 | 491 | ||
519 | KerberosOrLocalPasswd | 492 | KerberosOrLocalPasswd |
520 | If password authentication through Kerberos fails then the | 493 | If password authentication through Kerberos fails then the |
521 | password will be validated via any additional local mechanism | 494 | password will be validated via any additional local mechanism |
522 | such as /etc/passwd. The default is M-bM-^@M-^\yesM-bM-^@M-^]. | 495 | such as /etc/passwd. The default is yes. |
523 | 496 | ||
524 | KerberosTicketCleanup | 497 | KerberosTicketCleanup |
525 | Specifies whether to automatically destroy the user's ticket | 498 | Specifies whether to automatically destroy the user's ticket |
526 | cache file on logout. The default is M-bM-^@M-^\yesM-bM-^@M-^]. | 499 | cache file on logout. The default is yes. |
527 | 500 | ||
528 | KexAlgorithms | 501 | KexAlgorithms |
529 | Specifies the available KEX (Key Exchange) algorithms. Multiple | 502 | Specifies the available KEX (Key Exchange) algorithms. Multiple |
@@ -532,6 +505,7 @@ DESCRIPTION | |||
532 | will be appended to the default set instead of replacing them. | 505 | will be appended to the default set instead of replacing them. |
533 | The supported algorithms are: | 506 | The supported algorithms are: |
534 | 507 | ||
508 | curve25519-sha256 | ||
535 | curve25519-sha256@libssh.org | 509 | curve25519-sha256@libssh.org |
536 | diffie-hellman-group1-sha1 | 510 | diffie-hellman-group1-sha1 |
537 | diffie-hellman-group14-sha1 | 511 | diffie-hellman-group14-sha1 |
@@ -543,21 +517,13 @@ DESCRIPTION | |||
543 | 517 | ||
544 | The default is: | 518 | The default is: |
545 | 519 | ||
546 | curve25519-sha256@libssh.org, | 520 | curve25519-sha256,curve25519-sha256@libssh.org, |
547 | ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521, | 521 | ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521, |
548 | diffie-hellman-group-exchange-sha256, | 522 | diffie-hellman-group-exchange-sha256, |
549 | diffie-hellman-group14-sha1 | 523 | diffie-hellman-group14-sha1 |
550 | 524 | ||
551 | The list of available key exchange algorithms may also be | 525 | The list of available key exchange algorithms may also be |
552 | obtained using the -Q option of ssh(1) with an argument of M-bM-^@M-^\kexM-bM-^@M-^]. | 526 | obtained using "ssh -Q kex". |
553 | |||
554 | KeyRegenerationInterval | ||
555 | In protocol version 1, the ephemeral server key is automatically | ||
556 | regenerated after this many seconds (if it has been used). The | ||
557 | purpose of regeneration is to prevent decrypting captured | ||
558 | sessions by later breaking into the machine and stealing the | ||
559 | keys. The key is never stored anywhere. If the value is 0, the | ||
560 | key is never regenerated. The default is 3600 (seconds). | ||
561 | 527 | ||
562 | ListenAddress | 528 | ListenAddress |
563 | Specifies the local addresses sshd(8) should listen on. The | 529 | Specifies the local addresses sshd(8) should listen on. The |
@@ -591,7 +557,7 @@ DESCRIPTION | |||
591 | algorithms will be appended to the default set instead of | 557 | algorithms will be appended to the default set instead of |
592 | replacing them. | 558 | replacing them. |
593 | 559 | ||
594 | The algorithms that contain M-bM-^@M-^\-etmM-bM-^@M-^] calculate the MAC after | 560 | The algorithms that contain "-etm" calculate the MAC after |
595 | encryption (encrypt-then-mac). These are considered safer and | 561 | encryption (encrypt-then-mac). These are considered safer and |
596 | their use recommended. The supported MACs are: | 562 | their use recommended. The supported MACs are: |
597 | 563 | ||
@@ -623,7 +589,7 @@ DESCRIPTION | |||
623 | hmac-sha2-256,hmac-sha2-512,hmac-sha1 | 589 | hmac-sha2-256,hmac-sha2-512,hmac-sha1 |
624 | 590 | ||
625 | The list of available MAC algorithms may also be obtained using | 591 | The list of available MAC algorithms may also be obtained using |
626 | the -Q option of ssh(1) with an argument of M-bM-^@M-^\macM-bM-^@M-^]. | 592 | "ssh -Q mac". |
627 | 593 | ||
628 | Match Introduces a conditional block. If all of the criteria on the | 594 | Match Introduces a conditional block. If all of the criteria on the |
629 | Match line are satisfied, the keywords on the following lines | 595 | Match line are satisfied, the keywords on the following lines |
@@ -640,12 +606,12 @@ DESCRIPTION | |||
640 | operators described in the PATTERNS section of ssh_config(5). | 606 | operators described in the PATTERNS section of ssh_config(5). |
641 | 607 | ||
642 | The patterns in an Address criteria may additionally contain | 608 | The patterns in an Address criteria may additionally contain |
643 | addresses to match in CIDR address/masklen format, e.g. | 609 | addresses to match in CIDR address/masklen format, such as |
644 | M-bM-^@M-^\192.0.2.0/24M-bM-^@M-^] or M-bM-^@M-^\3ffe:ffff::/32M-bM-^@M-^]. Note that the mask length | 610 | 192.0.2.0/24 or 2001:db8::/32. Note that the mask length |
645 | provided must be consistent with the address - it is an error to | 611 | provided must be consistent with the address - it is an error to |
646 | specify a mask length that is too long for the address or one | 612 | specify a mask length that is too long for the address or one |
647 | with bits set in this host portion of the address. For example, | 613 | with bits set in this host portion of the address. For example, |
648 | M-bM-^@M-^\192.0.2.0/33M-bM-^@M-^] and M-bM-^@M-^\192.0.2.0/8M-bM-^@M-^] respectively. | 614 | 192.0.2.0/33 and 192.0.2.0/8, respectively. |
649 | 615 | ||
650 | Only a subset of keywords may be used on the lines following a | 616 | Only a subset of keywords may be used on the lines following a |
651 | Match keyword. Available keywords are AcceptEnv, | 617 | Match keyword. Available keywords are AcceptEnv, |
@@ -654,7 +620,8 @@ DESCRIPTION | |||
654 | AuthorizedKeysCommand, AuthorizedKeysCommandUser, | 620 | AuthorizedKeysCommand, AuthorizedKeysCommandUser, |
655 | AuthorizedKeysFile, AuthorizedPrincipalsCommand, | 621 | AuthorizedKeysFile, AuthorizedPrincipalsCommand, |
656 | AuthorizedPrincipalsCommandUser, AuthorizedPrincipalsFile, | 622 | AuthorizedPrincipalsCommandUser, AuthorizedPrincipalsFile, |
657 | Banner, ChrootDirectory, DenyGroups, DenyUsers, ForceCommand, | 623 | Banner, ChrootDirectory, ClientAliveCountMax, |
624 | ClientAliveInterval, DenyGroups, DenyUsers, ForceCommand, | ||
658 | GatewayPorts, GSSAPIAuthentication, HostbasedAcceptedKeyTypes, | 625 | GatewayPorts, GSSAPIAuthentication, HostbasedAcceptedKeyTypes, |
659 | HostbasedAuthentication, HostbasedUsesNameFromPacketOnly, IPQoS, | 626 | HostbasedAuthentication, HostbasedUsesNameFromPacketOnly, IPQoS, |
660 | KbdInteractiveAuthentication, KerberosAuthentication, | 627 | KbdInteractiveAuthentication, KerberosAuthentication, |
@@ -662,9 +629,8 @@ DESCRIPTION | |||
662 | PermitEmptyPasswords, PermitOpen, PermitRootLogin, PermitTTY, | 629 | PermitEmptyPasswords, PermitOpen, PermitRootLogin, PermitTTY, |
663 | PermitTunnel, PermitUserRC, PubkeyAcceptedKeyTypes, | 630 | PermitTunnel, PermitUserRC, PubkeyAcceptedKeyTypes, |
664 | PubkeyAuthentication, RekeyLimit, RevokedKeys, | 631 | PubkeyAuthentication, RekeyLimit, RevokedKeys, |
665 | RhostsRSAAuthentication, RSAAuthentication, StreamLocalBindMask, | 632 | StreamLocalBindMask, StreamLocalBindUnlink, TrustedUserCAKeys, |
666 | StreamLocalBindUnlink, TrustedUserCAKeys, X11DisplayOffset, | 633 | X11DisplayOffset, X11Forwarding and X11UseLocalHost. |
667 | X11Forwarding and X11UseLocalHost. | ||
668 | 634 | ||
669 | MaxAuthTries | 635 | MaxAuthTries |
670 | Specifies the maximum number of authentication attempts permitted | 636 | Specifies the maximum number of authentication attempts permitted |
@@ -687,21 +653,21 @@ DESCRIPTION | |||
687 | expires for a connection. The default is 10:30:100. | 653 | expires for a connection. The default is 10:30:100. |
688 | 654 | ||
689 | Alternatively, random early drop can be enabled by specifying the | 655 | Alternatively, random early drop can be enabled by specifying the |
690 | three colon separated values M-bM-^@M-^\start:rate:fullM-bM-^@M-^] (e.g. "10:30:60"). | 656 | three colon separated values start:rate:full (e.g. "10:30:60"). |
691 | sshd(8) will refuse connection attempts with a probability of | 657 | sshd(8) will refuse connection attempts with a probability of |
692 | M-bM-^@M-^\rate/100M-bM-^@M-^] (30%) if there are currently M-bM-^@M-^\startM-bM-^@M-^] (10) | 658 | rate/100 (30%) if there are currently start (10) unauthenticated |
693 | unauthenticated connections. The probability increases linearly | 659 | connections. The probability increases linearly and all |
694 | and all connection attempts are refused if the number of | 660 | connection attempts are refused if the number of unauthenticated |
695 | unauthenticated connections reaches M-bM-^@M-^\fullM-bM-^@M-^] (60). | 661 | connections reaches full (60). |
696 | 662 | ||
697 | PasswordAuthentication | 663 | PasswordAuthentication |
698 | Specifies whether password authentication is allowed. The | 664 | Specifies whether password authentication is allowed. The |
699 | default is M-bM-^@M-^\yesM-bM-^@M-^]. | 665 | default is yes. |
700 | 666 | ||
701 | PermitEmptyPasswords | 667 | PermitEmptyPasswords |
702 | When password authentication is allowed, it specifies whether the | 668 | When password authentication is allowed, it specifies whether the |
703 | server allows login to accounts with empty password strings. The | 669 | server allows login to accounts with empty password strings. The |
704 | default is M-bM-^@M-^\noM-bM-^@M-^]. | 670 | default is no. |
705 | 671 | ||
706 | PermitOpen | 672 | PermitOpen |
707 | Specifies the destinations to which TCP port forwarding is | 673 | Specifies the destinations to which TCP port forwarding is |
@@ -713,58 +679,57 @@ DESCRIPTION | |||
713 | PermitOpen [IPv6_addr]:port | 679 | PermitOpen [IPv6_addr]:port |
714 | 680 | ||
715 | Multiple forwards may be specified by separating them with | 681 | Multiple forwards may be specified by separating them with |
716 | whitespace. An argument of M-bM-^@M-^\anyM-bM-^@M-^] can be used to remove all | 682 | whitespace. An argument of any can be used to remove all |
717 | restrictions and permit any forwarding requests. An argument of | 683 | restrictions and permit any forwarding requests. An argument of |
718 | M-bM-^@M-^\noneM-bM-^@M-^] can be used to prohibit all forwarding requests. The | 684 | none can be used to prohibit all forwarding requests. The |
719 | wildcard M-bM-^@M-^\*M-bM-^@M-^] can be used for host or port to allow all hosts or | 685 | wildcard M-bM-^@M-^X*M-bM-^@M-^Y can be used for host or port to allow all hosts or |
720 | ports, respectively. By default all port forwarding requests are | 686 | ports, respectively. By default all port forwarding requests are |
721 | permitted. | 687 | permitted. |
722 | 688 | ||
723 | PermitRootLogin | 689 | PermitRootLogin |
724 | Specifies whether root can log in using ssh(1). The argument | 690 | Specifies whether root can log in using ssh(1). The argument |
725 | must be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\prohibit-passwordM-bM-^@M-^], M-bM-^@M-^\without-passwordM-bM-^@M-^], | 691 | must be yes, prohibit-password, without-password, |
726 | M-bM-^@M-^\forced-commands-onlyM-bM-^@M-^], or M-bM-^@M-^\noM-bM-^@M-^]. The default is | 692 | forced-commands-only, or no. The default is prohibit-password. |
727 | M-bM-^@M-^\prohibit-passwordM-bM-^@M-^]. | ||
728 | 693 | ||
729 | If this option is set to M-bM-^@M-^\prohibit-passwordM-bM-^@M-^] or | 694 | If this option is set to prohibit-password or without-password, |
730 | M-bM-^@M-^\without-passwordM-bM-^@M-^], password and keyboard-interactive | 695 | password and keyboard-interactive authentication are disabled for |
731 | authentication are disabled for root. | 696 | root. |
732 | 697 | ||
733 | If this option is set to M-bM-^@M-^\forced-commands-onlyM-bM-^@M-^], root login with | 698 | If this option is set to forced-commands-only, root login with |
734 | public key authentication will be allowed, but only if the | 699 | public key authentication will be allowed, but only if the |
735 | command option has been specified (which may be useful for taking | 700 | command option has been specified (which may be useful for taking |
736 | remote backups even if root login is normally not allowed). All | 701 | remote backups even if root login is normally not allowed). All |
737 | other authentication methods are disabled for root. | 702 | other authentication methods are disabled for root. |
738 | 703 | ||
739 | If this option is set to M-bM-^@M-^\noM-bM-^@M-^], root is not allowed to log in. | 704 | If this option is set to no, root is not allowed to log in. |
705 | |||
706 | PermitTTY | ||
707 | Specifies whether pty(4) allocation is permitted. The default is | ||
708 | yes. | ||
740 | 709 | ||
741 | PermitTunnel | 710 | PermitTunnel |
742 | Specifies whether tun(4) device forwarding is allowed. The | 711 | Specifies whether tun(4) device forwarding is allowed. The |
743 | argument must be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\point-to-pointM-bM-^@M-^] (layer 3), M-bM-^@M-^\ethernetM-bM-^@M-^] | 712 | argument must be yes, point-to-point (layer 3), ethernet (layer |
744 | (layer 2), or M-bM-^@M-^\noM-bM-^@M-^]. Specifying M-bM-^@M-^\yesM-bM-^@M-^] permits both | 713 | 2), or no. Specifying yes permits both point-to-point and |
745 | M-bM-^@M-^\point-to-pointM-bM-^@M-^] and M-bM-^@M-^\ethernetM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^]. | 714 | ethernet. The default is no. |
746 | 715 | ||
747 | Independent of this setting, the permissions of the selected | 716 | Independent of this setting, the permissions of the selected |
748 | tun(4) device must allow access to the user. | 717 | tun(4) device must allow access to the user. |
749 | 718 | ||
750 | PermitTTY | ||
751 | Specifies whether pty(4) allocation is permitted. The default is | ||
752 | M-bM-^@M-^\yesM-bM-^@M-^]. | ||
753 | |||
754 | PermitUserEnvironment | 719 | PermitUserEnvironment |
755 | Specifies whether ~/.ssh/environment and environment= options in | 720 | Specifies whether ~/.ssh/environment and environment= options in |
756 | ~/.ssh/authorized_keys are processed by sshd(8). The default is | 721 | ~/.ssh/authorized_keys are processed by sshd(8). The default is |
757 | M-bM-^@M-^\noM-bM-^@M-^]. Enabling environment processing may enable users to bypass | 722 | no. Enabling environment processing may enable users to bypass |
758 | access restrictions in some configurations using mechanisms such | 723 | access restrictions in some configurations using mechanisms such |
759 | as LD_PRELOAD. | 724 | as LD_PRELOAD. |
760 | 725 | ||
761 | PermitUserRC | 726 | PermitUserRC |
762 | Specifies whether any ~/.ssh/rc file is executed. The default is | 727 | Specifies whether any ~/.ssh/rc file is executed. The default is |
763 | M-bM-^@M-^\yesM-bM-^@M-^]. | 728 | yes. |
764 | 729 | ||
765 | PidFile | 730 | PidFile |
766 | Specifies the file that contains the process ID of the SSH | 731 | Specifies the file that contains the process ID of the SSH |
767 | daemon, or M-bM-^@M-^\noneM-bM-^@M-^] to not write one. The default is | 732 | daemon, or none to not write one. The default is |
768 | /var/run/sshd.pid. | 733 | /var/run/sshd.pid. |
769 | 734 | ||
770 | Port Specifies the port number that sshd(8) listens on. The default | 735 | Port Specifies the port number that sshd(8) listens on. The default |
@@ -774,24 +739,12 @@ DESCRIPTION | |||
774 | PrintLastLog | 739 | PrintLastLog |
775 | Specifies whether sshd(8) should print the date and time of the | 740 | Specifies whether sshd(8) should print the date and time of the |
776 | last user login when a user logs in interactively. The default | 741 | last user login when a user logs in interactively. The default |
777 | is M-bM-^@M-^\yesM-bM-^@M-^]. | 742 | is yes. |
778 | 743 | ||
779 | PrintMotd | 744 | PrintMotd |
780 | Specifies whether sshd(8) should print /etc/motd when a user logs | 745 | Specifies whether sshd(8) should print /etc/motd when a user logs |
781 | in interactively. (On some systems it is also printed by the | 746 | in interactively. (On some systems it is also printed by the |
782 | shell, /etc/profile, or equivalent.) The default is M-bM-^@M-^\yesM-bM-^@M-^]. | 747 | shell, /etc/profile, or equivalent.) The default is yes. |
783 | |||
784 | Protocol | ||
785 | Specifies the protocol versions sshd(8) supports. The possible | ||
786 | values are M-bM-^@M-^X1M-bM-^@M-^Y and M-bM-^@M-^X2M-bM-^@M-^Y. Multiple versions must be comma- | ||
787 | separated. The default is M-bM-^@M-^X2M-bM-^@M-^Y. Protocol 1 suffers from a number | ||
788 | of cryptographic weaknesses and should not be used. It is only | ||
789 | offered to support legacy devices. | ||
790 | |||
791 | Note that the order of the protocol list does not indicate | ||
792 | preference, because the client selects among multiple protocol | ||
793 | versions offered by the server. Specifying M-bM-^@M-^\2,1M-bM-^@M-^] is identical to | ||
794 | M-bM-^@M-^\1,2M-bM-^@M-^]. | ||
795 | 748 | ||
796 | PubkeyAcceptedKeyTypes | 749 | PubkeyAcceptedKeyTypes |
797 | Specifies the key types that will be accepted for public key | 750 | Specifies the key types that will be accepted for public key |
@@ -808,11 +761,12 @@ DESCRIPTION | |||
808 | ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, | 761 | ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, |
809 | ssh-ed25519,ssh-rsa | 762 | ssh-ed25519,ssh-rsa |
810 | 763 | ||
811 | The -Q option of ssh(1) may be used to list supported key types. | 764 | The list of available key types may also be obtained using "ssh |
765 | -Q key". | ||
812 | 766 | ||
813 | PubkeyAuthentication | 767 | PubkeyAuthentication |
814 | Specifies whether public key authentication is allowed. The | 768 | Specifies whether public key authentication is allowed. The |
815 | default is M-bM-^@M-^\yesM-bM-^@M-^]. | 769 | default is yes. |
816 | 770 | ||
817 | RekeyLimit | 771 | RekeyLimit |
818 | Specifies the maximum amount of data that may be transmitted | 772 | Specifies the maximum amount of data that may be transmitted |
@@ -824,13 +778,13 @@ DESCRIPTION | |||
824 | M-bM-^@M-^X1GM-bM-^@M-^Y and M-bM-^@M-^X4GM-bM-^@M-^Y, depending on the cipher. The optional second | 778 | M-bM-^@M-^X1GM-bM-^@M-^Y and M-bM-^@M-^X4GM-bM-^@M-^Y, depending on the cipher. The optional second |
825 | value is specified in seconds and may use any of the units | 779 | value is specified in seconds and may use any of the units |
826 | documented in the TIME FORMATS section. The default value for | 780 | documented in the TIME FORMATS section. The default value for |
827 | RekeyLimit is M-bM-^@M-^\default noneM-bM-^@M-^], which means that rekeying is | 781 | RekeyLimit is default none, which means that rekeying is |
828 | performed after the cipher's default amount of data has been sent | 782 | performed after the cipher's default amount of data has been sent |
829 | or received and no time based rekeying is done. | 783 | or received and no time based rekeying is done. |
830 | 784 | ||
831 | RevokedKeys | 785 | RevokedKeys |
832 | Specifies revoked public keys file, or M-bM-^@M-^\noneM-bM-^@M-^] to not use one. | 786 | Specifies revoked public keys file, or none to not use one. Keys |
833 | Keys listed in this file will be refused for public key | 787 | listed in this file will be refused for public key |
834 | authentication. Note that if this file is not readable, then | 788 | authentication. Note that if this file is not readable, then |
835 | public key authentication will be refused for all users. Keys | 789 | public key authentication will be refused for all users. Keys |
836 | may be specified as a text file, listing one public key per line, | 790 | may be specified as a text file, listing one public key per line, |
@@ -838,20 +792,6 @@ DESCRIPTION | |||
838 | ssh-keygen(1). For more information on KRLs, see the KEY | 792 | ssh-keygen(1). For more information on KRLs, see the KEY |
839 | REVOCATION LISTS section in ssh-keygen(1). | 793 | REVOCATION LISTS section in ssh-keygen(1). |
840 | 794 | ||
841 | RhostsRSAAuthentication | ||
842 | Specifies whether rhosts or /etc/hosts.equiv authentication | ||
843 | together with successful RSA host authentication is allowed. The | ||
844 | default is M-bM-^@M-^\noM-bM-^@M-^]. This option applies to protocol version 1 only. | ||
845 | |||
846 | RSAAuthentication | ||
847 | Specifies whether pure RSA authentication is allowed. The | ||
848 | default is M-bM-^@M-^\yesM-bM-^@M-^]. This option applies to protocol version 1 | ||
849 | only. | ||
850 | |||
851 | ServerKeyBits | ||
852 | Defines the number of bits in the ephemeral protocol version 1 | ||
853 | server key. The default and minimum value is 1024. | ||
854 | |||
855 | StreamLocalBindMask | 795 | StreamLocalBindMask |
856 | Sets the octal file creation mode mask (umask) used when creating | 796 | Sets the octal file creation mode mask (umask) used when creating |
857 | a Unix-domain socket file for local or remote port forwarding. | 797 | a Unix-domain socket file for local or remote port forwarding. |
@@ -871,14 +811,14 @@ DESCRIPTION | |||
871 | domain socket file. This option is only used for port forwarding | 811 | domain socket file. This option is only used for port forwarding |
872 | to a Unix-domain socket file. | 812 | to a Unix-domain socket file. |
873 | 813 | ||
874 | The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^]. | 814 | The argument must be yes or no. The default is no. |
875 | 815 | ||
876 | StrictModes | 816 | StrictModes |
877 | Specifies whether sshd(8) should check file modes and ownership | 817 | Specifies whether sshd(8) should check file modes and ownership |
878 | of the user's files and home directory before accepting login. | 818 | of the user's files and home directory before accepting login. |
879 | This is normally desirable because novices sometimes accidentally | 819 | This is normally desirable because novices sometimes accidentally |
880 | leave their directory or files world-writable. The default is | 820 | leave their directory or files world-writable. The default is |
881 | M-bM-^@M-^\yesM-bM-^@M-^]. Note that this does not apply to ChrootDirectory, whose | 821 | yes. Note that this does not apply to ChrootDirectory, whose |
882 | permissions and ownership are checked unconditionally. | 822 | permissions and ownership are checked unconditionally. |
883 | 823 | ||
884 | Subsystem | 824 | Subsystem |
@@ -886,12 +826,12 @@ DESCRIPTION | |||
886 | Arguments should be a subsystem name and a command (with optional | 826 | Arguments should be a subsystem name and a command (with optional |
887 | arguments) to execute upon subsystem request. | 827 | arguments) to execute upon subsystem request. |
888 | 828 | ||
889 | The command sftp-server(8) implements the M-bM-^@M-^\sftpM-bM-^@M-^] file transfer | 829 | The command sftp-server implements the SFTP file transfer |
890 | subsystem. | 830 | subsystem. |
891 | 831 | ||
892 | Alternately the name M-bM-^@M-^\internal-sftpM-bM-^@M-^] implements an in-process | 832 | Alternately the name internal-sftp implements an in-process SFTP |
893 | M-bM-^@M-^\sftpM-bM-^@M-^] server. This may simplify configurations using | 833 | server. This may simplify configurations using ChrootDirectory |
894 | ChrootDirectory to force a different filesystem root on clients. | 834 | to force a different filesystem root on clients. |
895 | 835 | ||
896 | By default no subsystems are defined. | 836 | By default no subsystems are defined. |
897 | 837 | ||
@@ -908,23 +848,22 @@ DESCRIPTION | |||
908 | this means that connections will die if the route is down | 848 | this means that connections will die if the route is down |
909 | temporarily, and some people find it annoying. On the other | 849 | temporarily, and some people find it annoying. On the other |
910 | hand, if TCP keepalives are not sent, sessions may hang | 850 | hand, if TCP keepalives are not sent, sessions may hang |
911 | indefinitely on the server, leaving M-bM-^@M-^\ghostM-bM-^@M-^] users and consuming | 851 | indefinitely on the server, leaving "ghost" users and consuming |
912 | server resources. | 852 | server resources. |
913 | 853 | ||
914 | The default is M-bM-^@M-^\yesM-bM-^@M-^] (to send TCP keepalive messages), and the | 854 | The default is yes (to send TCP keepalive messages), and the |
915 | server will notice if the network goes down or the client host | 855 | server will notice if the network goes down or the client host |
916 | crashes. This avoids infinitely hanging sessions. | 856 | crashes. This avoids infinitely hanging sessions. |
917 | 857 | ||
918 | To disable TCP keepalive messages, the value should be set to | 858 | To disable TCP keepalive messages, the value should be set to no. |
919 | M-bM-^@M-^\noM-bM-^@M-^]. | ||
920 | 859 | ||
921 | TrustedUserCAKeys | 860 | TrustedUserCAKeys |
922 | Specifies a file containing public keys of certificate | 861 | Specifies a file containing public keys of certificate |
923 | authorities that are trusted to sign user certificates for | 862 | authorities that are trusted to sign user certificates for |
924 | authentication, or M-bM-^@M-^\noneM-bM-^@M-^] to not use one. Keys are listed one | 863 | authentication, or none to not use one. Keys are listed one per |
925 | per line; empty lines and comments starting with M-bM-^@M-^X#M-bM-^@M-^Y are allowed. | 864 | line; empty lines and comments starting with M-bM-^@M-^X#M-bM-^@M-^Y are allowed. If |
926 | If a certificate is presented for authentication and has its | 865 | a certificate is presented for authentication and has its signing |
927 | signing CA key listed in this file, then it may be used for | 866 | CA key listed in this file, then it may be used for |
928 | authentication for any user listed in the certificate's | 867 | authentication for any user listed in the certificate's |
929 | principals list. Note that certificates that lack a list of | 868 | principals list. Note that certificates that lack a list of |
930 | principals will not be permitted for authentication using | 869 | principals will not be permitted for authentication using |
@@ -935,20 +874,12 @@ DESCRIPTION | |||
935 | and to check that the resolved host name for the remote IP | 874 | and to check that the resolved host name for the remote IP |
936 | address maps back to the very same IP address. | 875 | address maps back to the very same IP address. |
937 | 876 | ||
938 | If this option is set to M-bM-^@M-^\noM-bM-^@M-^] (the default) then only addresses | 877 | If this option is set to no (the default) then only addresses and |
939 | and not host names may be used in ~/.ssh/authorized_keys from and | 878 | not host names may be used in ~/.ssh/authorized_keys from and |
940 | sshd_config Match Host directives. | 879 | sshd_config Match Host directives. |
941 | 880 | ||
942 | UseLogin | ||
943 | Specifies whether login(1) is used for interactive login | ||
944 | sessions. The default is M-bM-^@M-^\noM-bM-^@M-^]. Note that login(1) is never used | ||
945 | for remote command execution. Note also, that if this is | ||
946 | enabled, X11Forwarding will be disabled because login(1) does not | ||
947 | know how to handle xauth(1) cookies. If UsePrivilegeSeparation | ||
948 | is specified, it will be disabled after authentication. | ||
949 | |||
950 | UsePAM Enables the Pluggable Authentication Module interface. If set to | 881 | UsePAM Enables the Pluggable Authentication Module interface. If set to |
951 | M-bM-^@M-^\yesM-bM-^@M-^] this will enable PAM authentication using | 882 | yes this will enable PAM authentication using |
952 | ChallengeResponseAuthentication and PasswordAuthentication in | 883 | ChallengeResponseAuthentication and PasswordAuthentication in |
953 | addition to PAM account and session module processing for all | 884 | addition to PAM account and session module processing for all |
954 | authentication types. | 885 | authentication types. |
@@ -958,7 +889,7 @@ DESCRIPTION | |||
958 | either PasswordAuthentication or ChallengeResponseAuthentication. | 889 | either PasswordAuthentication or ChallengeResponseAuthentication. |
959 | 890 | ||
960 | If UsePAM is enabled, you will not be able to run sshd(8) as a | 891 | If UsePAM is enabled, you will not be able to run sshd(8) as a |
961 | non-root user. The default is M-bM-^@M-^\noM-bM-^@M-^]. | 892 | non-root user. The default is no. |
962 | 893 | ||
963 | UsePrivilegeSeparation | 894 | UsePrivilegeSeparation |
964 | Specifies whether sshd(8) separates privileges by creating an | 895 | Specifies whether sshd(8) separates privileges by creating an |
@@ -967,15 +898,15 @@ DESCRIPTION | |||
967 | that has the privilege of the authenticated user. The goal of | 898 | that has the privilege of the authenticated user. The goal of |
968 | privilege separation is to prevent privilege escalation by | 899 | privilege separation is to prevent privilege escalation by |
969 | containing any corruption within the unprivileged processes. The | 900 | containing any corruption within the unprivileged processes. The |
970 | argument must be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\noM-bM-^@M-^], or M-bM-^@M-^\sandboxM-bM-^@M-^]. If | 901 | argument must be yes, no, or sandbox. If UsePrivilegeSeparation |
971 | UsePrivilegeSeparation is set to M-bM-^@M-^\sandboxM-bM-^@M-^] then the pre- | 902 | is set to sandbox then the pre-authentication unprivileged |
972 | authentication unprivileged process is subject to additional | 903 | process is subject to additional restrictions. The default is |
973 | restrictions. The default is M-bM-^@M-^\sandboxM-bM-^@M-^]. | 904 | sandbox. |
974 | 905 | ||
975 | VersionAddendum | 906 | VersionAddendum |
976 | Optionally specifies additional text to append to the SSH | 907 | Optionally specifies additional text to append to the SSH |
977 | protocol banner sent by the server upon connection. The default | 908 | protocol banner sent by the server upon connection. The default |
978 | is M-bM-^@M-^\noneM-bM-^@M-^]. | 909 | is none. |
979 | 910 | ||
980 | X11DisplayOffset | 911 | X11DisplayOffset |
981 | Specifies the first display number available for sshd(8)'s X11 | 912 | Specifies the first display number available for sshd(8)'s X11 |
@@ -984,41 +915,39 @@ DESCRIPTION | |||
984 | 915 | ||
985 | X11Forwarding | 916 | X11Forwarding |
986 | Specifies whether X11 forwarding is permitted. The argument must | 917 | Specifies whether X11 forwarding is permitted. The argument must |
987 | be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^]. | 918 | be yes or no. The default is no. |
988 | 919 | ||
989 | When X11 forwarding is enabled, there may be additional exposure | 920 | When X11 forwarding is enabled, there may be additional exposure |
990 | to the server and to client displays if the sshd(8) proxy display | 921 | to the server and to client displays if the sshd(8) proxy display |
991 | is configured to listen on the wildcard address (see | 922 | is configured to listen on the wildcard address (see |
992 | X11UseLocalhost below), though this is not the default. | 923 | X11UseLocalhost), though this is not the default. Additionally, |
993 | Additionally, the authentication spoofing and authentication data | 924 | the authentication spoofing and authentication data verification |
994 | verification and substitution occur on the client side. The | 925 | and substitution occur on the client side. The security risk of |
995 | security risk of using X11 forwarding is that the client's X11 | 926 | using X11 forwarding is that the client's X11 display server may |
996 | display server may be exposed to attack when the SSH client | 927 | be exposed to attack when the SSH client requests forwarding (see |
997 | requests forwarding (see the warnings for ForwardX11 in | 928 | the warnings for ForwardX11 in ssh_config(5)). A system |
998 | ssh_config(5)). A system administrator may have a stance in | 929 | administrator may have a stance in which they want to protect |
999 | which they want to protect clients that may expose themselves to | 930 | clients that may expose themselves to attack by unwittingly |
1000 | attack by unwittingly requesting X11 forwarding, which can | 931 | requesting X11 forwarding, which can warrant a no setting. |
1001 | warrant a M-bM-^@M-^\noM-bM-^@M-^] setting. | ||
1002 | 932 | ||
1003 | Note that disabling X11 forwarding does not prevent users from | 933 | Note that disabling X11 forwarding does not prevent users from |
1004 | forwarding X11 traffic, as users can always install their own | 934 | forwarding X11 traffic, as users can always install their own |
1005 | forwarders. X11 forwarding is automatically disabled if UseLogin | 935 | forwarders. |
1006 | is enabled. | ||
1007 | 936 | ||
1008 | X11UseLocalhost | 937 | X11UseLocalhost |
1009 | Specifies whether sshd(8) should bind the X11 forwarding server | 938 | Specifies whether sshd(8) should bind the X11 forwarding server |
1010 | to the loopback address or to the wildcard address. By default, | 939 | to the loopback address or to the wildcard address. By default, |
1011 | sshd binds the forwarding server to the loopback address and sets | 940 | sshd binds the forwarding server to the loopback address and sets |
1012 | the hostname part of the DISPLAY environment variable to | 941 | the hostname part of the DISPLAY environment variable to |
1013 | M-bM-^@M-^\localhostM-bM-^@M-^]. This prevents remote hosts from connecting to the | 942 | localhost. This prevents remote hosts from connecting to the |
1014 | proxy display. However, some older X11 clients may not function | 943 | proxy display. However, some older X11 clients may not function |
1015 | with this configuration. X11UseLocalhost may be set to M-bM-^@M-^\noM-bM-^@M-^] to | 944 | with this configuration. X11UseLocalhost may be set to no to |
1016 | specify that the forwarding server should be bound to the | 945 | specify that the forwarding server should be bound to the |
1017 | wildcard address. The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The | 946 | wildcard address. The argument must be yes or no. The default |
1018 | default is M-bM-^@M-^\yesM-bM-^@M-^]. | 947 | is yes. |
1019 | 948 | ||
1020 | XAuthLocation | 949 | XAuthLocation |
1021 | Specifies the full pathname of the xauth(1) program, or M-bM-^@M-^\noneM-bM-^@M-^] to | 950 | Specifies the full pathname of the xauth(1) program, or none to |
1022 | not use one. The default is /usr/X11R6/bin/xauth. | 951 | not use one. The default is /usr/X11R6/bin/xauth. |
1023 | 952 | ||
1024 | TIME FORMATS | 953 | TIME FORMATS |
@@ -1043,6 +972,33 @@ TIME FORMATS | |||
1043 | 10m 10 minutes | 972 | 10m 10 minutes |
1044 | 1h30m 1 hour 30 minutes (90 minutes) | 973 | 1h30m 1 hour 30 minutes (90 minutes) |
1045 | 974 | ||
975 | TOKENS | ||
976 | Arguments to some keywords can make use of tokens, which are expanded at | ||
977 | runtime: | ||
978 | |||
979 | %% A literal M-bM-^@M-^X%M-bM-^@M-^Y. | ||
980 | %F The fingerprint of the CA key. | ||
981 | %f The fingerprint of the key or certificate. | ||
982 | %h The home directory of the user. | ||
983 | %i The key ID in the certificate. | ||
984 | %K The base64-encoded CA key. | ||
985 | %k The base64-encoded key or certificate for authentication. | ||
986 | %s The serial number of the certificate. | ||
987 | %T The type of the CA key. | ||
988 | %t The key or certificate type. | ||
989 | %u The username. | ||
990 | |||
991 | AuthorizedKeysCommand accepts the tokens %%, %f, %h, %t, and %u. | ||
992 | |||
993 | AuthorizedKeysFile accepts the tokens %%, %h, and %u. | ||
994 | |||
995 | AuthorizedPrincipalsCommand accepts the tokens %%, %F, %f, %K, %k, %h, | ||
996 | %i, %s, %T, %t, and %u. | ||
997 | |||
998 | AuthorizedPrincipalsFile accepts the tokens %%, %h, and %u. | ||
999 | |||
1000 | ChrootDirectory accepts the tokens %%, %h, and %u. | ||
1001 | |||
1046 | FILES | 1002 | FILES |
1047 | /etc/ssh/sshd_config | 1003 | /etc/ssh/sshd_config |
1048 | Contains configuration data for sshd(8). This file should be | 1004 | Contains configuration data for sshd(8). This file should be |
@@ -1050,7 +1006,7 @@ FILES | |||
1050 | necessary) that it be world-readable. | 1006 | necessary) that it be world-readable. |
1051 | 1007 | ||
1052 | SEE ALSO | 1008 | SEE ALSO |
1053 | sshd(8) | 1009 | sftp-server(8), sshd(8) |
1054 | 1010 | ||
1055 | AUTHORS | 1011 | AUTHORS |
1056 | OpenSSH is a derivative of the original and free ssh 1.2.12 release by | 1012 | OpenSSH is a derivative of the original and free ssh 1.2.12 release by |
@@ -1060,4 +1016,4 @@ AUTHORS | |||
1060 | versions 1.5 and 2.0. Niels Provos and Markus Friedl contributed support | 1016 | versions 1.5 and 2.0. Niels Provos and Markus Friedl contributed support |
1061 | for privilege separation. | 1017 | for privilege separation. |
1062 | 1018 | ||
1063 | OpenBSD 6.0 July 19, 2016 OpenBSD 6.0 | 1019 | OpenBSD 6.0 November 30, 2016 OpenBSD 6.0 |