diff options
Diffstat (limited to 'sshd_config.5')
| -rw-r--r-- | sshd_config.5 | 196 |
1 files changed, 160 insertions, 36 deletions
diff --git a/sshd_config.5 b/sshd_config.5 index ce71efe3c100..fd44abe75e4c 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -33,8 +33,8 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: sshd_config.5,v 1.172 2014/02/27 22:47:07 djm Exp $ -.Dd $Mdocdate: February 27 2014 $ +.\" $OpenBSD: sshd_config.5,v 1.176 2014/07/28 15:40:08 schwarze Exp $ +.Dd $Mdocdate: July 28 2014 $ .Dt SSHD_CONFIG 5 .Os .Sh NAME @@ -140,6 +140,26 @@ The default is Note that disabling TCP forwarding does not improve security unless users are also denied shell access, as they can always install their own forwarders. +.It Cm AllowStreamLocalForwarding +Specifies whether StreamLocal (Unix-domain socket) forwarding is permitted. +The available options are +.Dq yes +or +.Dq all +to allow StreamLocal forwarding, +.Dq no +to prevent all StreamLocal forwarding, +.Dq local +to allow local (from the perspective of +.Xr ssh 1 ) +forwarding only or +.Dq remote +to allow remote forwarding only. +The default is +.Dq yes . +Note that disabling StreamLocal forwarding does not improve security unless +users are also denied shell access, as they can always install their +own forwarders. .It Cm AllowUsers This keyword can be followed by a list of user name patterns, separated by spaces. @@ -283,7 +303,7 @@ This option is only available for protocol version 2. By default, no banner is displayed. .It Cm ChallengeResponseAuthentication Specifies whether challenge-response authentication is allowed (e.g. via -PAM or though authentication styles supported in +PAM or through authentication styles supported in .Xr login.conf 5 ) The default is .Dq yes . @@ -324,9 +344,9 @@ For file transfer sessions using .Dq sftp , no additional configuration of the environment is necessary if the in-process sftp server is used, -though sessions which use logging do require +though sessions which use logging may require .Pa /dev/log -inside the chroot directory (see +inside the chroot directory on some operating systems (see .Xr sftp-server 8 for details). .Pp @@ -337,30 +357,44 @@ Specifies the ciphers allowed for protocol version 2. Multiple ciphers must be comma-separated. The supported ciphers are: .Pp -.Dq 3des-cbc , -.Dq aes128-cbc , -.Dq aes192-cbc , -.Dq aes256-cbc , -.Dq aes128-ctr , -.Dq aes192-ctr , -.Dq aes256-ctr , -.Dq aes128-gcm@openssh.com , -.Dq aes256-gcm@openssh.com , -.Dq arcfour128 , -.Dq arcfour256 , -.Dq arcfour , -.Dq blowfish-cbc , -.Dq cast128-cbc , -and -.Dq chacha20-poly1305@openssh.com . +.Bl -item -compact -offset indent +.It +3des-cbc +.It +aes128-cbc +.It +aes192-cbc +.It +aes256-cbc +.It +aes128-ctr +.It +aes192-ctr +.It +aes256-ctr +.It +aes128-gcm@openssh.com +.It +aes256-gcm@openssh.com +.It +arcfour +.It +arcfour128 +.It +arcfour256 +.It +blowfish-cbc +.It +cast128-cbc +.It +chacha20-poly1305@openssh.com +.El .Pp The default is: -.Bd -literal -offset 3n -aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128, +.Bd -literal -offset indent +aes128-ctr,aes192-ctr,aes256-ctr, aes128-gcm@openssh.com,aes256-gcm@openssh.com, -chacha20-poly1305@openssh.com, -aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc, -aes256-cbc,arcfour +chacha20-poly1305@openssh.com .Ed .Pp The list of available ciphers may also be obtained using the @@ -672,14 +706,33 @@ The default is .It Cm KexAlgorithms Specifies the available KEX (Key Exchange) algorithms. Multiple algorithms must be comma-separated. -The default is +The supported algorithms are: +.Pp +.Bl -item -compact -offset indent +.It +curve25519-sha256@libssh.org +.It +diffie-hellman-group1-sha1 +.It +diffie-hellman-group14-sha1 +.It +diffie-hellman-group-exchange-sha1 +.It +diffie-hellman-group-exchange-sha256 +.It +ecdh-sha2-nistp256 +.It +ecdh-sha2-nistp384 +.It +ecdh-sha2-nistp521 +.El +.Pp +The default is: .Bd -literal -offset indent curve25519-sha256@libssh.org, ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521, diffie-hellman-group-exchange-sha256, -diffie-hellman-group-exchange-sha1, -diffie-hellman-group14-sha1, -diffie-hellman-group1-sha1 +diffie-hellman-group14-sha1 .Ed .It Cm KeyRegenerationInterval In protocol version 1, the ephemeral server key is automatically regenerated @@ -751,16 +804,53 @@ The algorithms that contain .Dq -etm calculate the MAC after encryption (encrypt-then-mac). These are considered safer and their use recommended. +The supported MACs are: +.Pp +.Bl -item -compact -offset indent +.It +hmac-md5 +.It +hmac-md5-96 +.It +hmac-ripemd160 +.It +hmac-sha1 +.It +hmac-sha1-96 +.It +hmac-sha2-256 +.It +hmac-sha2-512 +.It +umac-64@openssh.com +.It +umac-128@openssh.com +.It +hmac-md5-etm@openssh.com +.It +hmac-md5-96-etm@openssh.com +.It +hmac-ripemd160-etm@openssh.com +.It +hmac-sha1-etm@openssh.com +.It +hmac-sha1-96-etm@openssh.com +.It +hmac-sha2-256-etm@openssh.com +.It +hmac-sha2-512-etm@openssh.com +.It +umac-64-etm@openssh.com +.It +umac-128-etm@openssh.com +.El +.Pp The default is: .Bd -literal -offset indent -hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com, umac-64-etm@openssh.com,umac-128-etm@openssh.com, hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com, -hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com, -hmac-md5-96-etm@openssh.com, -hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com, -hmac-sha2-256,hmac-sha2-512,hmac-ripemd160, -hmac-sha1-96,hmac-md5-96 +umac-64@openssh.com,umac-128@openssh.com, +hmac-sha2-256,hmac-sha2-512 .Ed .It Cm Match Introduces a conditional block. @@ -842,6 +932,7 @@ Available keywords are .Cm PermitRootLogin , .Cm PermitTTY , .Cm PermitTunnel , +.Cm PermitUserRC , .Cm PubkeyAuthentication , .Cm RekeyLimit , .Cm RhostsRSAAuthentication , @@ -990,6 +1081,12 @@ The default is Enabling environment processing may enable users to bypass access restrictions in some configurations using mechanisms such as .Ev LD_PRELOAD . +.It Cm PermitUserRC +Specifies whether any +.Pa ~/.ssh/rc +file is executed. +The default is +.Dq yes . .It Cm PidFile Specifies the file that contains the process ID of the SSH daemon. @@ -1094,6 +1191,33 @@ This option applies to protocol version 1 only. .It Cm ServerKeyBits Defines the number of bits in the ephemeral protocol version 1 server key. The minimum value is 512, and the default is 1024. +.It Cm StreamLocalBindMask +Sets the octal file creation mode mask +.Pq umask +used when creating a Unix-domain socket file for local or remote +port forwarding. +This option is only used for port forwarding to a Unix-domain socket file. +.Pp +The default value is 0177, which creates a Unix-domain socket file that is +readable and writable only by the owner. +Note that not all operating systems honor the file mode on Unix-domain +socket files. +.It Cm StreamLocalBindUnlink +Specifies whether to remove an existing Unix-domain socket file for local +or remote port forwarding before creating a new one. +If the socket file already exists and +.Cm StreamLocalBindUnlink +is not enabled, +.Nm sshd +will be unable to forward the port to the Unix-domain socket file. +This option is only used for port forwarding to a Unix-domain socket file. +.Pp +The argument must be +.Dq yes +or +.Dq no . +The default is +.Dq no . .It Cm StrictModes Specifies whether .Xr sshd 8 |