diff options
Diffstat (limited to 'sshd_config.5')
-rw-r--r-- | sshd_config.5 | 97 |
1 files changed, 67 insertions, 30 deletions
diff --git a/sshd_config.5 b/sshd_config.5 index 935bb62fa..525d9c858 100644 --- a/sshd_config.5 +++ b/sshd_config.5 | |||
@@ -33,8 +33,8 @@ | |||
33 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 33 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
34 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 34 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
35 | .\" | 35 | .\" |
36 | .\" $OpenBSD: sshd_config.5,v 1.156 2013/02/06 00:20:42 dtucker Exp $ | 36 | .\" $OpenBSD: sshd_config.5,v 1.162 2013/07/19 07:37:48 markus Exp $ |
37 | .Dd $Mdocdate: February 6 2013 $ | 37 | .Dd $Mdocdate: July 19 2013 $ |
38 | .Dt SSHD_CONFIG 5 | 38 | .Dt SSHD_CONFIG 5 |
39 | .Os | 39 | .Os |
40 | .Sh NAME | 40 | .Sh NAME |
@@ -117,9 +117,7 @@ The allow/deny directives are processed in the following order: | |||
117 | and finally | 117 | and finally |
118 | .Cm AllowGroups . | 118 | .Cm AllowGroups . |
119 | .Pp | 119 | .Pp |
120 | See | 120 | See PATTERNS in |
121 | .Sx PATTERNS | ||
122 | in | ||
123 | .Xr ssh_config 5 | 121 | .Xr ssh_config 5 |
124 | for more information on patterns. | 122 | for more information on patterns. |
125 | .It Cm AllowTcpForwarding | 123 | .It Cm AllowTcpForwarding |
@@ -159,9 +157,7 @@ The allow/deny directives are processed in the following order: | |||
159 | and finally | 157 | and finally |
160 | .Cm AllowGroups . | 158 | .Cm AllowGroups . |
161 | .Pp | 159 | .Pp |
162 | See | 160 | See PATTERNS in |
163 | .Sx PATTERNS | ||
164 | in | ||
165 | .Xr ssh_config 5 | 161 | .Xr ssh_config 5 |
166 | for more information on patterns. | 162 | for more information on patterns. |
167 | .It Cm AuthenticationMethods | 163 | .It Cm AuthenticationMethods |
@@ -180,6 +176,20 @@ Only methods that are next in one or more lists are offered at each stage, | |||
180 | so for this example, it would not be possible to attempt password or | 176 | so for this example, it would not be possible to attempt password or |
181 | keyboard-interactive authentication before public key. | 177 | keyboard-interactive authentication before public key. |
182 | .Pp | 178 | .Pp |
179 | For keyboard interactive authentication it is also possible to | ||
180 | restrict authentication to a specific device by appending a | ||
181 | colon followed by the device identifier | ||
182 | .Dq bsdauth , | ||
183 | .Dq pam , | ||
184 | or | ||
185 | .Dq skey , | ||
186 | depending on the server configuration. | ||
187 | For example, | ||
188 | .Dq keyboard-interactive:bsdauth | ||
189 | would restrict keyboard interactive authentication to the | ||
190 | .Dq bsdauth | ||
191 | device. | ||
192 | .Pp | ||
183 | This option is only available for SSH protocol 2 and will yield a fatal | 193 | This option is only available for SSH protocol 2 and will yield a fatal |
184 | error if enabled if protocol 1 is also enabled. | 194 | error if enabled if protocol 1 is also enabled. |
185 | Note that each authentication method listed should also be explicitly enabled | 195 | Note that each authentication method listed should also be explicitly enabled |
@@ -188,11 +198,10 @@ The default is not to require multiple authentication; successful completion | |||
188 | of a single authentication method is sufficient. | 198 | of a single authentication method is sufficient. |
189 | .It Cm AuthorizedKeysCommand | 199 | .It Cm AuthorizedKeysCommand |
190 | Specifies a program to be used to look up the user's public keys. | 200 | Specifies a program to be used to look up the user's public keys. |
191 | The program will be invoked with a single argument of the username | 201 | The program must be owned by root and not writable by group or others. |
202 | It will be invoked with a single argument of the username | ||
192 | being authenticated, and should produce on standard output zero or | 203 | being authenticated, and should produce on standard output zero or |
193 | more lines of authorized_keys output (see | 204 | more lines of authorized_keys output (see AUTHORIZED_KEYS in |
194 | .Sx AUTHORIZED_KEYS | ||
195 | in | ||
196 | .Xr sshd 8 ) . | 205 | .Xr sshd 8 ) . |
197 | If a key supplied by AuthorizedKeysCommand does not successfully authenticate | 206 | If a key supplied by AuthorizedKeysCommand does not successfully authenticate |
198 | and authorize the user then public key authentication continues using the usual | 207 | and authorize the user then public key authentication continues using the usual |
@@ -207,7 +216,7 @@ than running authorized keys commands. | |||
207 | Specifies the file that contains the public keys that can be used | 216 | Specifies the file that contains the public keys that can be used |
208 | for user authentication. | 217 | for user authentication. |
209 | The format is described in the | 218 | The format is described in the |
210 | .Sx AUTHORIZED_KEYS FILE FORMAT | 219 | AUTHORIZED_KEYS FILE FORMAT |
211 | section of | 220 | section of |
212 | .Xr sshd 8 . | 221 | .Xr sshd 8 . |
213 | .Cm AuthorizedKeysFile | 222 | .Cm AuthorizedKeysFile |
@@ -231,9 +240,7 @@ When using certificates signed by a key listed in | |||
231 | this file lists names, one of which must appear in the certificate for it | 240 | this file lists names, one of which must appear in the certificate for it |
232 | to be accepted for authentication. | 241 | to be accepted for authentication. |
233 | Names are listed one per line preceded by key options (as described | 242 | Names are listed one per line preceded by key options (as described |
234 | in | 243 | in AUTHORIZED_KEYS FILE FORMAT in |
235 | .Sx AUTHORIZED_KEYS FILE FORMAT | ||
236 | in | ||
237 | .Xr sshd 8 ) . | 244 | .Xr sshd 8 ) . |
238 | Empty lines and comments starting with | 245 | Empty lines and comments starting with |
239 | .Ql # | 246 | .Ql # |
@@ -411,9 +418,7 @@ The allow/deny directives are processed in the following order: | |||
411 | and finally | 418 | and finally |
412 | .Cm AllowGroups . | 419 | .Cm AllowGroups . |
413 | .Pp | 420 | .Pp |
414 | See | 421 | See PATTERNS in |
415 | .Sx PATTERNS | ||
416 | in | ||
417 | .Xr ssh_config 5 | 422 | .Xr ssh_config 5 |
418 | for more information on patterns. | 423 | for more information on patterns. |
419 | .It Cm DenyUsers | 424 | .It Cm DenyUsers |
@@ -432,9 +437,7 @@ The allow/deny directives are processed in the following order: | |||
432 | and finally | 437 | and finally |
433 | .Cm AllowGroups . | 438 | .Cm AllowGroups . |
434 | .Pp | 439 | .Pp |
435 | See | 440 | See PATTERNS in |
436 | .Sx PATTERNS | ||
437 | in | ||
438 | .Xr ssh_config 5 | 441 | .Xr ssh_config 5 |
439 | for more information on patterns. | 442 | for more information on patterns. |
440 | .It Cm ForceCommand | 443 | .It Cm ForceCommand |
@@ -571,6 +574,18 @@ keys are used for version 1 and | |||
571 | or | 574 | or |
572 | .Dq rsa | 575 | .Dq rsa |
573 | are used for version 2 of the SSH protocol. | 576 | are used for version 2 of the SSH protocol. |
577 | It is also possible to specify public host key files instead. | ||
578 | In this case operations on the private key will be delegated | ||
579 | to an | ||
580 | .Xr ssh-agent 1 . | ||
581 | .It Cm HostKeyAgent | ||
582 | Identifies the UNIX-domain socket used to communicate | ||
583 | with an agent that has access to the private host keys. | ||
584 | If | ||
585 | .Dq SSH_AUTH_SOCK | ||
586 | is specified, the location of the socket will be read from the | ||
587 | .Ev SSH_AUTH_SOCK | ||
588 | environment variable. | ||
574 | .It Cm IgnoreRhosts | 589 | .It Cm IgnoreRhosts |
575 | Specifies that | 590 | Specifies that |
576 | .Pa .rhosts | 591 | .Pa .rhosts |
@@ -774,8 +789,7 @@ and | |||
774 | .Cm Address . | 789 | .Cm Address . |
775 | The match patterns may consist of single entries or comma-separated | 790 | The match patterns may consist of single entries or comma-separated |
776 | lists and may use the wildcard and negation operators described in the | 791 | lists and may use the wildcard and negation operators described in the |
777 | .Sx PATTERNS | 792 | PATTERNS section of |
778 | section of | ||
779 | .Xr ssh_config 5 . | 793 | .Xr ssh_config 5 . |
780 | .Pp | 794 | .Pp |
781 | The patterns in an | 795 | The patterns in an |
@@ -827,6 +841,7 @@ Available keywords are | |||
827 | .Cm PermitRootLogin , | 841 | .Cm PermitRootLogin , |
828 | .Cm PermitTunnel , | 842 | .Cm PermitTunnel , |
829 | .Cm PubkeyAuthentication , | 843 | .Cm PubkeyAuthentication , |
844 | .Cm RekeyLimit , | ||
830 | .Cm RhostsRSAAuthentication , | 845 | .Cm RhostsRSAAuthentication , |
831 | .Cm RSAAuthentication , | 846 | .Cm RSAAuthentication , |
832 | .Cm X11DisplayOffset , | 847 | .Cm X11DisplayOffset , |
@@ -1021,6 +1036,32 @@ Specifies whether public key authentication is allowed. | |||
1021 | The default is | 1036 | The default is |
1022 | .Dq yes . | 1037 | .Dq yes . |
1023 | Note that this option applies to protocol version 2 only. | 1038 | Note that this option applies to protocol version 2 only. |
1039 | .It Cm RekeyLimit | ||
1040 | Specifies the maximum amount of data that may be transmitted before the | ||
1041 | session key is renegotiated, optionally followed a maximum amount of | ||
1042 | time that may pass before the session key is renegotiated. | ||
1043 | The first argument is specified in bytes and may have a suffix of | ||
1044 | .Sq K , | ||
1045 | .Sq M , | ||
1046 | or | ||
1047 | .Sq G | ||
1048 | to indicate Kilobytes, Megabytes, or Gigabytes, respectively. | ||
1049 | The default is between | ||
1050 | .Sq 1G | ||
1051 | and | ||
1052 | .Sq 4G , | ||
1053 | depending on the cipher. | ||
1054 | The optional second value is specified in seconds and may use any of the | ||
1055 | units documented in the | ||
1056 | .Sx TIME FORMATS | ||
1057 | section. | ||
1058 | The default value for | ||
1059 | .Cm RekeyLimit | ||
1060 | is | ||
1061 | .Dq default none , | ||
1062 | which means that rekeying is performed after the cipher's default amount | ||
1063 | of data has been sent or received and no time based rekeying is done. | ||
1064 | This option applies to protocol version 2 only. | ||
1024 | .It Cm RevokedKeys | 1065 | .It Cm RevokedKeys |
1025 | Specifies revoked public keys. | 1066 | Specifies revoked public keys. |
1026 | Keys listed in this file will be refused for public key authentication. | 1067 | Keys listed in this file will be refused for public key authentication. |
@@ -1029,9 +1070,7 @@ be refused for all users. | |||
1029 | Keys may be specified as a text file, listing one public key per line, or as | 1070 | Keys may be specified as a text file, listing one public key per line, or as |
1030 | an OpenSSH Key Revocation List (KRL) as generated by | 1071 | an OpenSSH Key Revocation List (KRL) as generated by |
1031 | .Xr ssh-keygen 1 . | 1072 | .Xr ssh-keygen 1 . |
1032 | For more information on KRLs, see the | 1073 | For more information on KRLs, see the KEY REVOCATION LISTS section in |
1033 | .Sx KEY REVOCATION LISTS | ||
1034 | section in | ||
1035 | .Xr ssh-keygen 1 . | 1074 | .Xr ssh-keygen 1 . |
1036 | .It Cm RhostsRSAAuthentication | 1075 | .It Cm RhostsRSAAuthentication |
1037 | Specifies whether rhosts or /etc/hosts.equiv authentication together | 1076 | Specifies whether rhosts or /etc/hosts.equiv authentication together |
@@ -1120,9 +1159,7 @@ listed in the certificate's principals list. | |||
1120 | Note that certificates that lack a list of principals will not be permitted | 1159 | Note that certificates that lack a list of principals will not be permitted |
1121 | for authentication using | 1160 | for authentication using |
1122 | .Cm TrustedUserCAKeys . | 1161 | .Cm TrustedUserCAKeys . |
1123 | For more details on certificates, see the | 1162 | For more details on certificates, see the CERTIFICATES section in |
1124 | .Sx CERTIFICATES | ||
1125 | section in | ||
1126 | .Xr ssh-keygen 1 . | 1163 | .Xr ssh-keygen 1 . |
1127 | .It Cm UseDNS | 1164 | .It Cm UseDNS |
1128 | Specifies whether | 1165 | Specifies whether |