diff options
author | Colin Watson <cjwatson@debian.org> | 2003-09-23 18:08:35 +0000 |
---|---|---|
committer | Colin Watson <cjwatson@debian.org> | 2003-09-23 18:08:35 +0000 |
commit | d59fd3e421aa81b8e5e118f3f806081df2aca879 (patch) | |
tree | 356a4e607edc979c625bb33db63c656d771478bd /sshd_config.5 | |
parent | 7505658c58e96b8d270f1928a0e1fa7f3e0c266b (diff) | |
parent | 45431c9b4677608680cd071768cbf156b316a7e8 (diff) |
Merge 3.7.1p2 to the trunk. I have absolutely no idea yet whether this will
work.
Diffstat (limited to 'sshd_config.5')
-rw-r--r-- | sshd_config.5 | 115 |
1 files changed, 58 insertions, 57 deletions
diff --git a/sshd_config.5 b/sshd_config.5 index 6f38a260a..727fdb12a 100644 --- a/sshd_config.5 +++ b/sshd_config.5 | |||
@@ -34,7 +34,7 @@ | |||
34 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 34 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
35 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 35 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
36 | .\" | 36 | .\" |
37 | .\" $OpenBSD: sshd_config.5,v 1.15 2003/03/28 10:11:43 jmc Exp $ | 37 | .\" $OpenBSD: sshd_config.5,v 1.25 2003/09/01 09:50:04 markus Exp $ |
38 | .Dd September 25, 1999 | 38 | .Dd September 25, 1999 |
39 | .Dt SSHD_CONFIG 5 | 39 | .Dt SSHD_CONFIG 5 |
40 | .Os | 40 | .Os |
@@ -61,10 +61,6 @@ The possible | |||
61 | keywords and their meanings are as follows (note that | 61 | keywords and their meanings are as follows (note that |
62 | keywords are case-insensitive and arguments are case-sensitive): | 62 | keywords are case-insensitive and arguments are case-sensitive): |
63 | .Bl -tag -width Ds | 63 | .Bl -tag -width Ds |
64 | .It Cm AFSTokenPassing | ||
65 | Specifies whether an AFS token may be forwarded to the server. | ||
66 | Default is | ||
67 | .Dq no . | ||
68 | .It Cm AllowGroups | 64 | .It Cm AllowGroups |
69 | This keyword can be followed by a list of group name patterns, separated | 65 | This keyword can be followed by a list of group name patterns, separated |
70 | by spaces. | 66 | by spaces. |
@@ -72,7 +68,7 @@ If specified, login is allowed only for users whose primary | |||
72 | group or supplementary group list matches one of the patterns. | 68 | group or supplementary group list matches one of the patterns. |
73 | .Ql \&* | 69 | .Ql \&* |
74 | and | 70 | and |
75 | .Ql ? | 71 | .Ql \&? |
76 | can be used as | 72 | can be used as |
77 | wildcards in the patterns. | 73 | wildcards in the patterns. |
78 | Only group names are valid; a numerical group ID is not recognized. | 74 | Only group names are valid; a numerical group ID is not recognized. |
@@ -93,7 +89,7 @@ If specified, login is allowed only for user names that | |||
93 | match one of the patterns. | 89 | match one of the patterns. |
94 | .Ql \&* | 90 | .Ql \&* |
95 | and | 91 | and |
96 | .Ql ? | 92 | .Ql \&? |
97 | can be used as | 93 | can be used as |
98 | wildcards in the patterns. | 94 | wildcards in the patterns. |
99 | Only user names are valid; a numerical user ID is not recognized. | 95 | Only user names are valid; a numerical user ID is not recognized. |
@@ -107,7 +103,8 @@ Specifies the file that contains the public keys that can be used | |||
107 | for user authentication. | 103 | for user authentication. |
108 | .Cm AuthorizedKeysFile | 104 | .Cm AuthorizedKeysFile |
109 | may contain tokens of the form %T which are substituted during connection | 105 | may contain tokens of the form %T which are substituted during connection |
110 | set-up. The following tokens are defined: %% is replaced by a literal '%', | 106 | set-up. |
107 | The following tokens are defined: %% is replaced by a literal '%', | ||
111 | %h is replaced by the home directory of the user being authenticated and | 108 | %h is replaced by the home directory of the user being authenticated and |
112 | %u is replaced by the username of that user. | 109 | %u is replaced by the username of that user. |
113 | After expansion, | 110 | After expansion, |
@@ -138,7 +135,7 @@ The default is | |||
138 | .Pp | 135 | .Pp |
139 | .Bd -literal | 136 | .Bd -literal |
140 | ``aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour, | 137 | ``aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour, |
141 | aes192-cbc,aes256-cbc'' | 138 | aes192-cbc,aes256-cbc,aes128-ctr,aes192-ctr,aes256-ctr'' |
142 | .Ed | 139 | .Ed |
143 | .It Cm ClientAliveInterval | 140 | .It Cm ClientAliveInterval |
144 | Sets a timeout interval in seconds after which if no data has been received | 141 | Sets a timeout interval in seconds after which if no data has been received |
@@ -153,20 +150,24 @@ This option applies to protocol version 2 only. | |||
153 | Sets the number of client alive messages (see above) which may be | 150 | Sets the number of client alive messages (see above) which may be |
154 | sent without | 151 | sent without |
155 | .Nm sshd | 152 | .Nm sshd |
156 | receiving any messages back from the client. If this threshold is | 153 | receiving any messages back from the client. |
157 | reached while client alive messages are being sent, | 154 | If this threshold is reached while client alive messages are being sent, |
158 | .Nm sshd | 155 | .Nm sshd |
159 | will disconnect the client, terminating the session. It is important | 156 | will disconnect the client, terminating the session. |
160 | to note that the use of client alive messages is very different from | 157 | It is important to note that the use of client alive messages is very |
158 | different from | ||
161 | .Cm KeepAlive | 159 | .Cm KeepAlive |
162 | (below). The client alive messages are sent through the | 160 | (below). |
163 | encrypted channel and therefore will not be spoofable. The TCP keepalive | 161 | The client alive messages are sent through the encrypted channel |
164 | option enabled by | 162 | and therefore will not be spoofable. |
163 | The TCP keepalive option enabled by | ||
165 | .Cm KeepAlive | 164 | .Cm KeepAlive |
166 | is spoofable. The client alive mechanism is valuable when the client or | 165 | is spoofable. |
166 | The client alive mechanism is valuable when the client or | ||
167 | server depend on knowing when a connection has become inactive. | 167 | server depend on knowing when a connection has become inactive. |
168 | .Pp | 168 | .Pp |
169 | The default value is 3. If | 169 | The default value is 3. |
170 | If | ||
170 | .Cm ClientAliveInterval | 171 | .Cm ClientAliveInterval |
171 | (above) is set to 15, and | 172 | (above) is set to 15, and |
172 | .Cm ClientAliveCountMax | 173 | .Cm ClientAliveCountMax |
@@ -187,7 +188,7 @@ Login is disallowed for users whose primary group or supplementary | |||
187 | group list matches one of the patterns. | 188 | group list matches one of the patterns. |
188 | .Ql \&* | 189 | .Ql \&* |
189 | and | 190 | and |
190 | .Ql ? | 191 | .Ql \&? |
191 | can be used as | 192 | can be used as |
192 | wildcards in the patterns. | 193 | wildcards in the patterns. |
193 | Only group names are valid; a numerical group ID is not recognized. | 194 | Only group names are valid; a numerical group ID is not recognized. |
@@ -199,7 +200,7 @@ by spaces. | |||
199 | Login is disallowed for user names that match one of the patterns. | 200 | Login is disallowed for user names that match one of the patterns. |
200 | .Ql \&* | 201 | .Ql \&* |
201 | and | 202 | and |
202 | .Ql ? | 203 | .Ql \&? |
203 | can be used as wildcards in the patterns. | 204 | can be used as wildcards in the patterns. |
204 | Only user names are valid; a numerical user ID is not recognized. | 205 | Only user names are valid; a numerical user ID is not recognized. |
205 | By default, login is allowed for all users. | 206 | By default, login is allowed for all users. |
@@ -224,6 +225,17 @@ or | |||
224 | .Dq no . | 225 | .Dq no . |
225 | The default is | 226 | The default is |
226 | .Dq no . | 227 | .Dq no . |
228 | .It Cm GSSAPIAuthentication | ||
229 | Specifies whether user authentication based on GSSAPI is allowed. | ||
230 | The default is | ||
231 | .Dq no . | ||
232 | Note that this option applies to protocol version 2 only. | ||
233 | .It Cm GSSAPICleanupCredentials | ||
234 | Specifies whether to automatically destroy the user's credentials cache | ||
235 | on logout. | ||
236 | The default is | ||
237 | .Dq yes . | ||
238 | Note that this option applies to protocol version 2 only. | ||
227 | .It Cm HostbasedAuthentication | 239 | .It Cm HostbasedAuthentication |
228 | Specifies whether rhosts or /etc/hosts.equiv authentication together | 240 | Specifies whether rhosts or /etc/hosts.equiv authentication together |
229 | with successful public key client host authentication is allowed | 241 | with successful public key client host authentication is allowed |
@@ -259,7 +271,6 @@ Specifies that | |||
259 | and | 271 | and |
260 | .Pa .shosts | 272 | .Pa .shosts |
261 | files will not be used in | 273 | files will not be used in |
262 | .Cm RhostsAuthentication , | ||
263 | .Cm RhostsRSAAuthentication | 274 | .Cm RhostsRSAAuthentication |
264 | or | 275 | or |
265 | .Cm HostbasedAuthentication . | 276 | .Cm HostbasedAuthentication . |
@@ -303,11 +314,9 @@ This avoids infinitely hanging sessions. | |||
303 | To disable keepalives, the value should be set to | 314 | To disable keepalives, the value should be set to |
304 | .Dq no . | 315 | .Dq no . |
305 | .It Cm KerberosAuthentication | 316 | .It Cm KerberosAuthentication |
306 | Specifies whether Kerberos authentication is allowed. | 317 | Specifies whether the password provided by the user for |
307 | This can be in the form of a Kerberos ticket, or if | ||
308 | .Cm PasswordAuthentication | 318 | .Cm PasswordAuthentication |
309 | is yes, the password provided by the user will be validated through | 319 | will be validated through the Kerberos KDC. |
310 | the Kerberos KDC. | ||
311 | To use this option, the server needs a | 320 | To use this option, the server needs a |
312 | Kerberos servtab which allows the verification of the KDC's identity. | 321 | Kerberos servtab which allows the verification of the KDC's identity. |
313 | Default is | 322 | Default is |
@@ -319,11 +328,6 @@ such as | |||
319 | .Pa /etc/passwd . | 328 | .Pa /etc/passwd . |
320 | Default is | 329 | Default is |
321 | .Dq yes . | 330 | .Dq yes . |
322 | .It Cm KerberosTgtPassing | ||
323 | Specifies whether a Kerberos TGT may be forwarded to the server. | ||
324 | Default is | ||
325 | .Dq no , | ||
326 | as this only works when the Kerberos KDC is actually an AFS kaserver. | ||
327 | .It Cm KerberosTicketCleanup | 331 | .It Cm KerberosTicketCleanup |
328 | Specifies whether to automatically destroy the user's ticket cache | 332 | Specifies whether to automatically destroy the user's ticket cache |
329 | file on logout. | 333 | file on logout. |
@@ -369,11 +373,12 @@ is not specified, | |||
369 | .Nm sshd | 373 | .Nm sshd |
370 | will listen on the address and all prior | 374 | will listen on the address and all prior |
371 | .Cm Port | 375 | .Cm Port |
372 | options specified. The default is to listen on all local | 376 | options specified. |
373 | addresses. | 377 | The default is to listen on all local addresses. |
374 | Multiple | 378 | Multiple |
375 | .Cm ListenAddress | 379 | .Cm ListenAddress |
376 | options are permitted. Additionally, any | 380 | options are permitted. |
381 | Additionally, any | ||
377 | .Cm Port | 382 | .Cm Port |
378 | options must precede this option for non port qualified addresses. | 383 | options must precede this option for non port qualified addresses. |
379 | .It Cm LoginGraceTime | 384 | .It Cm LoginGraceTime |
@@ -422,12 +427,6 @@ The probability increases linearly and all connection attempts | |||
422 | are refused if the number of unauthenticated connections reaches | 427 | are refused if the number of unauthenticated connections reaches |
423 | .Dq full | 428 | .Dq full |
424 | (60). | 429 | (60). |
425 | .It Cm PAMAuthenticationViaKbdInt | ||
426 | Specifies whether PAM challenge response authentication is allowed. This | ||
427 | allows the use of most PAM challenge response authentication modules, but | ||
428 | it will allow password authentication regardless of whether | ||
429 | .Cm PasswordAuthentication | ||
430 | is enabled. | ||
431 | .It Cm PasswordAuthentication | 430 | .It Cm PasswordAuthentication |
432 | Specifies whether password authentication is allowed. | 431 | Specifies whether password authentication is allowed. |
433 | The default is | 432 | The default is |
@@ -460,8 +459,8 @@ but only if the | |||
460 | .Ar command | 459 | .Ar command |
461 | option has been specified | 460 | option has been specified |
462 | (which may be useful for taking remote backups even if root login is | 461 | (which may be useful for taking remote backups even if root login is |
463 | normally not allowed). All other authentication methods are disabled | 462 | normally not allowed). |
464 | for root. | 463 | All other authentication methods are disabled for root. |
465 | .Pp | 464 | .Pp |
466 | If this option is set to | 465 | If this option is set to |
467 | .Dq no | 466 | .Dq no |
@@ -534,10 +533,6 @@ Specifies whether public key authentication is allowed. | |||
534 | The default is | 533 | The default is |
535 | .Dq yes . | 534 | .Dq yes . |
536 | Note that this option applies to protocol version 2 only. | 535 | Note that this option applies to protocol version 2 only. |
537 | .It Cm RhostsAuthentication | ||
538 | Specifies whether authentication using rhosts or /etc/hosts.equiv | ||
539 | files is sufficient. | ||
540 | Normally, this method should not be permitted because it is insecure. | ||
541 | .Cm RhostsRSAAuthentication | 536 | .Cm RhostsRSAAuthentication |
542 | should be used | 537 | should be used |
543 | instead, because it performs RSA-based host authentication in addition | 538 | instead, because it performs RSA-based host authentication in addition |
@@ -585,6 +580,14 @@ Gives the facility code that is used when logging messages from | |||
585 | The possible values are: DAEMON, USER, AUTH, LOCAL0, LOCAL1, LOCAL2, | 580 | The possible values are: DAEMON, USER, AUTH, LOCAL0, LOCAL1, LOCAL2, |
586 | LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7. | 581 | LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7. |
587 | The default is AUTH. | 582 | The default is AUTH. |
583 | .It Cm UseDNS | ||
584 | Specifies whether | ||
585 | .Nm sshd | ||
586 | should lookup the remote host name and check that | ||
587 | the resolved host name for the remote IP address maps back to the | ||
588 | very same IP address. | ||
589 | The default is | ||
590 | .Dq yes . | ||
588 | .It Cm UseLogin | 591 | .It Cm UseLogin |
589 | Specifies whether | 592 | Specifies whether |
590 | .Xr login 1 | 593 | .Xr login 1 |
@@ -604,6 +607,13 @@ cookies. | |||
604 | If | 607 | If |
605 | .Cm UsePrivilegeSeparation | 608 | .Cm UsePrivilegeSeparation |
606 | is specified, it will be disabled after authentication. | 609 | is specified, it will be disabled after authentication. |
610 | .It Cm UsePAM | ||
611 | Enables PAM authentication (via challenge-response) and session set up. | ||
612 | If you enable this, you should probably disable | ||
613 | .Cm PasswordAuthentication . | ||
614 | If you enable | ||
615 | .CM UsePAM | ||
616 | then you will not be able to run sshd as a non-root user. | ||
607 | .It Cm UsePrivilegeSeparation | 617 | .It Cm UsePrivilegeSeparation |
608 | Specifies whether | 618 | Specifies whether |
609 | .Nm sshd | 619 | .Nm sshd |
@@ -615,14 +625,6 @@ The goal of privilege separation is to prevent privilege | |||
615 | escalation by containing any corruption within the unprivileged processes. | 625 | escalation by containing any corruption within the unprivileged processes. |
616 | The default is | 626 | The default is |
617 | .Dq yes . | 627 | .Dq yes . |
618 | .It Cm VerifyReverseMapping | ||
619 | Specifies whether | ||
620 | .Nm sshd | ||
621 | should try to verify the remote host name and check that | ||
622 | the resolved host name for the remote IP address maps back to the | ||
623 | very same IP address. | ||
624 | The default is | ||
625 | .Dq no . | ||
626 | .It Cm X11DisplayOffset | 628 | .It Cm X11DisplayOffset |
627 | Specifies the first display number available for | 629 | Specifies the first display number available for |
628 | .Nm sshd Ns 's | 630 | .Nm sshd Ns 's |
@@ -653,7 +655,7 @@ display server may be exposed to attack when the ssh client requests | |||
653 | forwarding (see the warnings for | 655 | forwarding (see the warnings for |
654 | .Cm ForwardX11 | 656 | .Cm ForwardX11 |
655 | in | 657 | in |
656 | .Xr ssh_config 5 ). | 658 | .Xr ssh_config 5 ) . |
657 | A system administrator may have a stance in which they want to | 659 | A system administrator may have a stance in which they want to |
658 | protect clients that may expose themselves to attack by unwittingly | 660 | protect clients that may expose themselves to attack by unwittingly |
659 | requesting X11 forwarding, which can warrant a | 661 | requesting X11 forwarding, which can warrant a |
@@ -699,7 +701,6 @@ The default is | |||
699 | .Pa /usr/X11R6/bin/xauth . | 701 | .Pa /usr/X11R6/bin/xauth . |
700 | .El | 702 | .El |
701 | .Ss Time Formats | 703 | .Ss Time Formats |
702 | .Pp | ||
703 | .Nm sshd | 704 | .Nm sshd |
704 | command-line arguments and configuration file options that specify time | 705 | command-line arguments and configuration file options that specify time |
705 | may be expressed using a sequence of the form: | 706 | may be expressed using a sequence of the form: |
@@ -748,6 +749,8 @@ Contains configuration data for | |||
748 | This file should be writable by root only, but it is recommended | 749 | This file should be writable by root only, but it is recommended |
749 | (though not necessary) that it be world-readable. | 750 | (though not necessary) that it be world-readable. |
750 | .El | 751 | .El |
752 | .Sh SEE ALSO | ||
753 | .Xr sshd 8 | ||
751 | .Sh AUTHORS | 754 | .Sh AUTHORS |
752 | OpenSSH is a derivative of the original and free | 755 | OpenSSH is a derivative of the original and free |
753 | ssh 1.2.12 release by Tatu Ylonen. | 756 | ssh 1.2.12 release by Tatu Ylonen. |
@@ -759,5 +762,3 @@ Markus Friedl contributed the support for SSH | |||
759 | protocol versions 1.5 and 2.0. | 762 | protocol versions 1.5 and 2.0. |
760 | Niels Provos and Markus Friedl contributed support | 763 | Niels Provos and Markus Friedl contributed support |
761 | for privilege separation. | 764 | for privilege separation. |
762 | .Sh SEE ALSO | ||
763 | .Xr sshd 8 | ||