Title

The SSH daemon must be configured to only use Message Authentication Codes (MACs) employing FIPS 140-2 approved cryptographic hash algorithms. (Cat II impact)

Discussion

DoD information systems are required to use FIPS 140-2 approved cryptographic hash functions.

Check Content

Open a terminal session and enter the following command. grep -i macs /etc/sshd_config | grep -v '^#' If no lines are returned, or the returned MACs list contains any MAC other than "hmac-sha1", this is a finding.

Fix Text

Open a terminal session and edit the SSH daemon configuration file "/etc/sshd_config" and remove any MACs other than "hmac-sha1". If there is no MACs line in "/etc/sshd_config", add "MACs hmac-sha1" to the file. Restart the SSH daemon for the changes to take effect.

Additional Identifiers

Rule ID: SV-39369r2_rule

Vulnerability ID: V-22460

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.