sshd_config: cleaning up

etc/ssh/sshd_config

@@ -1,16 +1,9 @@
-#   $OpenBSD: sshd_config,v 1.97 2015/08/06 14:53:21 deraadt Exp $
-
-# This is the sshd server system-wide configuration file.  See
-# sshd_config(5) for more information.
-
-# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin
-
-# The strategy used for options in the default sshd_config shipped with
-# OpenSSH is to specify options with their default value where
-# possible, but leave them commented.  Uncommented options override the
-# default value.
+# OpenSSH /etc/ssh/sshd_config. I am removing commented lines for this to
+# be more clear and if they are missed some day, just download
+# upstream config file or take it from any distribution.
 
 Port 22
+
 AddressFamily any
 ListenAddress 0.0.0.0
 ListenAddress ::
@@ -19,12 +12,12 @@ ListenAddress ::
 Protocol 2
 
 # HostKeys for protocol version 2
-HostKey /etc/ssh/ssh_host_rsa_key
 HostKey /etc/ssh/ssh_host_ed25519_key
+HostKey /etc/ssh/ssh_host_rsa_key
 
 ## IF THE HOST KEYS ARE MISSING, RUN THE FOLLOWING AS ROOT:
-# ssh-keygen -t rsa -N "" -f /etc/ssh/ssh_host_rsa_key
 # ssh-keygen -t ed25519 -N "" -f /etc/ssh/ssh_host_ed25519_key
+# ssh-keygen -t rsa -N "" -f /etc/ssh/ssh_host_rsa_key
 
 # Uncomment one of the following depending on which OS
 ## Arch
@@ -32,65 +25,27 @@ HostKey /etc/ssh/ssh_host_ed25519_key
 ## Debian
 #Subsystem sftp /usr/lib/openssh/sftp-server
 
-# Lifetime and size of ephemeral version 1 server key
-#KeyRegenerationInterval 1h
-#ServerKeyBits 1024
-
-# Ciphers and keying
-#RekeyLimit default none
-
 # Logging
-# obsoletes QuietMode and FascistLogging
-#SyslogFacility AUTH
 LogLevel VERBOSE
 
 # Authentication:
+PermitRootLogin No
 
-#LoginGraceTime 2m
-PermitRootLogin prohibit-password
-#StrictModes yes
-#MaxAuthTries 6
-#MaxSessions 10
-
-#RSAAuthentication yes
-#PubkeyAuthentication yes
-
-# The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2
-# but this is overridden so installations will only check .ssh/authorized_keys
+# The default is to check both .ssh/authorized_keys and
+# .ssh/authorized_keys2 but this is overridden so installations will only
+# check .ssh/authorized_keys
 AuthorizedKeysFile  .ssh/authorized_keys
 
-#AuthorizedPrincipalsFile none
+# Password based logins are disabled - only public key based logins are
+# allowed.
+AuthenticationMethods publickey
 
-#AuthorizedKeysCommand none
-#AuthorizedKeysCommandUser nobody
-
-# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
-#RhostsRSAAuthentication no
-# similar for protocol version 2
-#HostbasedAuthentication no
-# Change to yes if you don't trust ~/.ssh/known_hosts for
-# RhostsRSAAuthentication and HostbasedAuthentication
-#IgnoreUserKnownHosts no
-# Don't read the user's ~/.rhosts and ~/.shosts files
-#IgnoreRhosts yes
-
-# To disable tunneled clear text passwords, change to no here!
+# Disable tunneled clear text passwords!
 PasswordAuthentication no
-#PermitEmptyPasswords no
 
-# Change to no to disable s/key passwords
+# Disable s/key passwords
 ChallengeResponseAuthentication no
 
-# Kerberos options
-#KerberosAuthentication no
-#KerberosOrLocalPasswd yes
-#KerberosTicketCleanup yes
-#KerberosGetAFSToken no
-
-# GSSAPI options
-#GSSAPIAuthentication no
-#GSSAPICleanupCredentials yes
-
 # Set this to 'yes' to enable PAM authentication, account processing,
 # and session processing. If this is enabled, PAM authentication will
 # be allowed through the ChallengeResponseAuthentication and
@@ -102,34 +57,7 @@ ChallengeResponseAuthentication no
 # and ChallengeResponseAuthentication to 'no'.
 UsePAM yes
 
-#AllowAgentForwarding yes
-#AllowTcpForwarding yes
-#GatewayPorts no
-#X11Forwarding no
-#X11DisplayOffset 10
-#X11UseLocalhost yes
-#PermitTTY yes
 PrintMotd no # pam does that
-#PrintLastLog yes
-#TCPKeepAlive yes
-#UseLogin no
 UsePrivilegeSeparation sandbox      # Default for new installations.
-#PermitUserEnvironment no
-#Compression delayed
-#ClientAliveInterval 0
-#ClientAliveCountMax 3
-#UseDNS no
-#PidFile /run/sshd.pid
-#MaxStartups 10:30:100
-#PermitTunnel no
-#ChrootDirectory none
-#VersionAddendum none
 
 Banner /etc/issue.net
-
-# Example of overriding settings on a per-user basis
-#Match User anoncvs
-#   X11Forwarding no
-#   AllowTcpForwarding no
-#   PermitTTY no
-#   ForceCommand cvs server