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-rw-r--r--sshd_config.569
1 files changed, 68 insertions, 1 deletions
diff --git a/sshd_config.5 b/sshd_config.5
index 7255b1c22..d5f19ea3d 100644
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -58,6 +58,33 @@ Arguments may optionally be enclosed in double quotes
58.Pq \&" 58.Pq \&"
59in order to represent arguments containing spaces. 59in order to represent arguments containing spaces.
60.Pp 60.Pp
61Note that the Debian
62.Ic openssh-server
63package sets several options as standard in
64.Pa /etc/ssh/sshd_config
65which are not the default in
66.Xr sshd 8 .
67The exact list depends on whether the package was installed fresh or
68upgraded from various possible previous versions, but includes at least the
69following:
70.Pp
71.Bl -bullet -offset indent -compact
72.It
73.Cm Protocol No 2
74.It
75.Cm ChallengeResponseAuthentication No no
76.It
77.Cm X11Forwarding No yes
78.It
79.Cm PrintMotd No no
80.It
81.Cm AcceptEnv No LANG LC_*
82.It
83.Cm Subsystem No sftp /usr/lib/openssh/sftp-server
84.It
85.Cm UsePAM No yes
86.El
87.Pp
61The possible 88The possible
62keywords and their meanings are as follows (note that 89keywords and their meanings are as follows (note that
63keywords are case-insensitive and arguments are case-sensitive): 90keywords are case-insensitive and arguments are case-sensitive):
@@ -374,12 +401,35 @@ Specifies whether user authentication based on GSSAPI is allowed.
374The default is 401The default is
375.Dq no . 402.Dq no .
376Note that this option applies to protocol version 2 only. 403Note that this option applies to protocol version 2 only.
404.It Cm GSSAPIKeyExchange
405Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange
406doesn't rely on ssh keys to verify host identity.
407The default is
408.Dq no .
409Note that this option applies to protocol version 2 only.
377.It Cm GSSAPICleanupCredentials 410.It Cm GSSAPICleanupCredentials
378Specifies whether to automatically destroy the user's credentials cache 411Specifies whether to automatically destroy the user's credentials cache
379on logout. 412on logout.
380The default is 413The default is
381.Dq yes . 414.Dq yes .
382Note that this option applies to protocol version 2 only. 415Note that this option applies to protocol version 2 only.
416.It Cm GSSAPIStrictAcceptorCheck
417Determines whether to be strict about the identity of the GSSAPI acceptor
418a client authenticates against. If
419.Dq yes
420then the client must authenticate against the
421.Pa host
422service on the current hostname. If
423.Dq no
424then the client may authenticate against any service key stored in the
425machine's default store. This facility is provided to assist with operation
426on multi homed machines.
427The default is
428.Dq yes .
429Note that this option applies only to protocol version 2 GSSAPI connections,
430and setting it to
431.Dq no
432may only work with recent Kerberos GSSAPI libraries.
383.It Cm HostbasedAuthentication 433.It Cm HostbasedAuthentication
384Specifies whether rhosts or /etc/hosts.equiv authentication together 434Specifies whether rhosts or /etc/hosts.equiv authentication together
385with successful public key client host authentication is allowed 435with successful public key client host authentication is allowed
@@ -534,7 +584,7 @@ The default is 120 seconds.
534Gives the verbosity level that is used when logging messages from 584Gives the verbosity level that is used when logging messages from
535.Xr sshd 8 . 585.Xr sshd 8 .
536The possible values are: 586The possible values are:
537QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. 587SILENT, QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3.
538The default is INFO. 588The default is INFO.
539DEBUG and DEBUG1 are equivalent. 589DEBUG and DEBUG1 are equivalent.
540DEBUG2 and DEBUG3 each specify higher levels of debugging output. 590DEBUG2 and DEBUG3 each specify higher levels of debugging output.
@@ -650,6 +700,20 @@ are refused if the number of unauthenticated connections reaches
650Specifies whether password authentication is allowed. 700Specifies whether password authentication is allowed.
651The default is 701The default is
652.Dq yes . 702.Dq yes .
703.It Cm PermitBlacklistedKeys
704Specifies whether
705.Xr sshd 8
706should allow keys recorded in its blacklist of known-compromised keys (see
707.Xr ssh-vulnkey 1 ) .
708If
709.Dq yes ,
710then attempts to authenticate with compromised keys will be logged but
711accepted.
712If
713.Dq no ,
714then attempts to authenticate with compromised keys will be rejected.
715The default is
716.Dq no .
653.It Cm PermitEmptyPasswords 717.It Cm PermitEmptyPasswords
654When password authentication is allowed, it specifies whether the 718When password authentication is allowed, it specifies whether the
655server allows login to accounts with empty password strings. 719server allows login to accounts with empty password strings.
@@ -870,6 +934,9 @@ This avoids infinitely hanging sessions.
870.Pp 934.Pp
871To disable TCP keepalive messages, the value should be set to 935To disable TCP keepalive messages, the value should be set to
872.Dq no . 936.Dq no .
937.Pp
938This option was formerly called
939.Cm KeepAlive .
873.It Cm UseDNS 940.It Cm UseDNS
874Specifies whether 941Specifies whether
875.Xr sshd 8 942.Xr sshd 8