4.400 - The SSH daemon must be configured to only use Message Authentication Codes (MACs) employing FIPS 140-2 approved algorithms.

Information

DoD information systems are required to use FIPS 140-2 approved cryptographic hash functions. The only SSHv2 hash algorithm meeting this requirement is SHA.

Solution

Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for the "MACs" keyword and set its value to "hmac-sha2-256" and/or "hmac-sha2-512" (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor):

MACs hmac-sha2-256,hmac-sha2-512

The SSH service must be restarted for changes to take effect.

See Also

https://docs.fedoraproject.org/f28/system-administrators-guide/index.html

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-13

Plugin: Unix

Control ID: a2b0dd79110e70862c15b63680bf20390ce2240aa46ec1e386c69403a52b9f1b