summaryrefslogtreecommitdiff
path: root/sshd_config.5
diff options
context:
space:
mode:
Diffstat (limited to 'sshd_config.5')
-rw-r--r--sshd_config.552
1 files changed, 50 insertions, 2 deletions
diff --git a/sshd_config.5 b/sshd_config.5
index 525d9c858..faf93fc90 100644
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -57,6 +57,33 @@ Arguments may optionally be enclosed in double quotes
57.Pq \&" 57.Pq \&"
58in order to represent arguments containing spaces. 58in order to represent arguments containing spaces.
59.Pp 59.Pp
60Note that the Debian
61.Ic openssh-server
62package sets several options as standard in
63.Pa /etc/ssh/sshd_config
64which are not the default in
65.Xr sshd 8 .
66The exact list depends on whether the package was installed fresh or
67upgraded from various possible previous versions, but includes at least the
68following:
69.Pp
70.Bl -bullet -offset indent -compact
71.It
72.Cm Protocol No 2
73.It
74.Cm ChallengeResponseAuthentication No no
75.It
76.Cm X11Forwarding No yes
77.It
78.Cm PrintMotd No no
79.It
80.Cm AcceptEnv No LANG LC_*
81.It
82.Cm Subsystem No sftp /usr/lib/openssh/sftp-server
83.It
84.Cm UsePAM No yes
85.El
86.Pp
60The possible 87The possible
61keywords and their meanings are as follows (note that 88keywords and their meanings are as follows (note that
62keywords are case-insensitive and arguments are case-sensitive): 89keywords are case-insensitive and arguments are case-sensitive):
@@ -283,8 +310,7 @@ This option is only available for protocol version 2.
283By default, no banner is displayed. 310By default, no banner is displayed.
284.It Cm ChallengeResponseAuthentication 311.It Cm ChallengeResponseAuthentication
285Specifies whether challenge-response authentication is allowed (e.g. via 312Specifies whether challenge-response authentication is allowed (e.g. via
286PAM or though authentication styles supported in 313PAM).
287.Xr login.conf 5 )
288The default is 314The default is
289.Dq yes . 315.Dq yes .
290.It Cm ChrootDirectory 316.It Cm ChrootDirectory
@@ -404,6 +430,11 @@ or
404.Dq no . 430.Dq no .
405The default is 431The default is
406.Dq delayed . 432.Dq delayed .
433.It Cm DebianBanner
434Specifies whether the distribution-specified extra version suffix is
435included during initial protocol handshake.
436The default is
437.Dq yes .
407.It Cm DenyGroups 438.It Cm DenyGroups
408This keyword can be followed by a list of group name patterns, separated 439This keyword can be followed by a list of group name patterns, separated
409by spaces. 440by spaces.
@@ -885,6 +916,20 @@ are refused if the number of unauthenticated connections reaches
885Specifies whether password authentication is allowed. 916Specifies whether password authentication is allowed.
886The default is 917The default is
887.Dq yes . 918.Dq yes .
919.It Cm PermitBlacklistedKeys
920Specifies whether
921.Xr sshd 8
922should allow keys recorded in its blacklist of known-compromised keys (see
923.Xr ssh-vulnkey 1 ) .
924If
925.Dq yes ,
926then attempts to authenticate with compromised keys will be logged but
927accepted.
928If
929.Dq no ,
930then attempts to authenticate with compromised keys will be rejected.
931The default is
932.Dq no .
888.It Cm PermitEmptyPasswords 933.It Cm PermitEmptyPasswords
889When password authentication is allowed, it specifies whether the 934When password authentication is allowed, it specifies whether the
890server allows login to accounts with empty password strings. 935server allows login to accounts with empty password strings.
@@ -1147,6 +1192,9 @@ This avoids infinitely hanging sessions.
1147.Pp 1192.Pp
1148To disable TCP keepalive messages, the value should be set to 1193To disable TCP keepalive messages, the value should be set to
1149.Dq no . 1194.Dq no .
1195.Pp
1196This option was formerly called
1197.Cm KeepAlive .
1150.It Cm TrustedUserCAKeys 1198.It Cm TrustedUserCAKeys
1151Specifies a file containing public keys of certificate authorities that are 1199Specifies a file containing public keys of certificate authorities that are
1152trusted to sign user certificates for authentication. 1200trusted to sign user certificates for authentication.