# 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 ::

# The default requires explicit activation of protocol 1
Protocol 2

# HostKeys for protocol version 2
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 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
#Subsystem   sftp    /usr/lib/ssh/sftp-server
## Debian
#Subsystem sftp /usr/lib/openssh/sftp-server

# Nothing is Accepted for security reasons, e.g. shellshock worked with
# remotely accepted environment variables.
#AcceptEnv LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION

# Logging
LogLevel VERBOSE

# Authentication:
PermitRootLogin No

# 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

# Password based logins are disabled - only public key based logins are
# allowed.
AuthenticationMethods publickey

# Disable tunneled clear text passwords!
PasswordAuthentication no

# Disable s/key passwords
ChallengeResponseAuthentication no

# 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
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes

PrintMotd no # pam does that
UsePrivilegeSeparation sandbox      # Default for new installations.

Banner /etc/issue.net

# If the client doesn't reply in "three" pings, connection is dead.
# Defaults to 3 anyway, but I add it here for clearity and
# in case it decides to change in the future.
ClientAliveCountMax 3

# "ping" the client every minute.
ClientAliveInterval 60