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-rw-r--r--sshd_config.554
1 files changed, 51 insertions, 3 deletions
diff --git a/sshd_config.5 b/sshd_config.5
index 6c3ef6947..522ac103f 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):
@@ -177,8 +204,7 @@ This option is only available for protocol version 2.
177By default, no banner is displayed. 204By default, no banner is displayed.
178.It Cm ChallengeResponseAuthentication 205.It Cm ChallengeResponseAuthentication
179Specifies whether challenge-response authentication is allowed (e.g. via 206Specifies whether challenge-response authentication is allowed (e.g. via
180PAM or though authentication styles supported in 207PAM).
181.Xr login.conf 5 )
182The default is 208The default is
183.Dq yes . 209.Dq yes .
184.It Cm ChrootDirectory 210.It Cm ChrootDirectory
@@ -295,6 +321,11 @@ or
295.Dq no . 321.Dq no .
296The default is 322The default is
297.Dq delayed . 323.Dq delayed .
324.It Cm DebianBanner
325Specifies whether the distribution-specified extra version suffix is
326included during initial protocol handshake.
327The default is
328.Dq yes .
298.It Cm DenyGroups 329.It Cm DenyGroups
299This keyword can be followed by a list of group name patterns, separated 330This keyword can be followed by a list of group name patterns, separated
300by spaces. 331by spaces.
@@ -567,7 +598,7 @@ The default is 120 seconds.
567Gives the verbosity level that is used when logging messages from 598Gives the verbosity level that is used when logging messages from
568.Xr sshd 8 . 599.Xr sshd 8 .
569The possible values are: 600The possible values are:
570QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. 601SILENT, QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3.
571The default is INFO. 602The default is INFO.
572DEBUG and DEBUG1 are equivalent. 603DEBUG and DEBUG1 are equivalent.
573DEBUG2 and DEBUG3 each specify higher levels of debugging output. 604DEBUG2 and DEBUG3 each specify higher levels of debugging output.
@@ -685,6 +716,20 @@ are refused if the number of unauthenticated connections reaches
685Specifies whether password authentication is allowed. 716Specifies whether password authentication is allowed.
686The default is 717The default is
687.Dq yes . 718.Dq yes .
719.It Cm PermitBlacklistedKeys
720Specifies whether
721.Xr sshd 8
722should allow keys recorded in its blacklist of known-compromised keys (see
723.Xr ssh-vulnkey 1 ) .
724If
725.Dq yes ,
726then attempts to authenticate with compromised keys will be logged but
727accepted.
728If
729.Dq no ,
730then attempts to authenticate with compromised keys will be rejected.
731The default is
732.Dq no .
688.It Cm PermitEmptyPasswords 733.It Cm PermitEmptyPasswords
689When password authentication is allowed, it specifies whether the 734When password authentication is allowed, it specifies whether the
690server allows login to accounts with empty password strings. 735server allows login to accounts with empty password strings.
@@ -905,6 +950,9 @@ This avoids infinitely hanging sessions.
905.Pp 950.Pp
906To disable TCP keepalive messages, the value should be set to 951To disable TCP keepalive messages, the value should be set to
907.Dq no . 952.Dq no .
953.Pp
954This option was formerly called
955.Cm KeepAlive .
908.It Cm UseDNS 956.It Cm UseDNS
909Specifies whether 957Specifies whether
910.Xr sshd 8 958.Xr sshd 8