os_sshd_client_alive_interval_configure Configure SSHD ClientAliveInterval to $ODV
All changes in this version
Title
Configure SSHD ClientAliveInterval to $ODV
Control
/usr/sbin/sshd -G | /usr/bin/awk '/clientaliveinterval/{print $2}'
Discussion
If SSHD is enabled then it _MUST_ be configured with the Client Alive Interval set to $ODV.
Sets a timeout interval in seconds after which if no data has been received from the client, sshd(8) will send a message through the encrypted channel to request a response from the client.
This setting works in conjunction with ClientAliveCountMax to determine the termination of the connection after the threshold has been reached.
NOTE: This setting is not intended to manage idle user sessions where there is no input from the client. Its purpose is to monitor for interruptions in network connectivity and force the session to terminate after the connection appears to be broken.
NOTE: On macOS 15.2 and higher the SSH configuration can be reset to the macOS default by running /usr/libexec/reset-ssh-configuration.
Related controls
ac-12, sc-10
Fix
[source,bash]
----
include_dir=$(/usr/bin/awk '/^Include/ {print $2}' /etc/ssh/sshd_config | /usr/bin/tr -d '*')
if [[ -z $include_dir ]]; then
/usr/bin/sed -i.bk "1s/.*/Include \/etc\/ssh\/sshd_config.d\/\*/" /etc/ssh/sshd_config
fi
/usr/bin/grep -qxF 'clientaliveinterval $ODV' "${include_dir}01-mscp-sshd.conf" 2>/dev/null || echo "clientaliveinterval $ODV" >> "${include_dir}01-mscp-sshd.conf"
for file in $(ls ${include_dir}); do
if [[ "$file" == "100-macos.conf" ]]; then
continue
fi
if [[ "$file" == "01-mscp-sshd.conf" ]]; then
break
fi
/bin/mv ${include_dir}${file} ${include_dir}20-${file}
done
----