V-279534

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. Satisfies: SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000125-GPOS-00065

Check Content

Verify Nutanix OS is configured to use approved ciphers. 

1. Configure AOS, Prism Central, and Files OS VMs to use only HMACs employing FIPS 140-3-approved algorithms for remote access using the following command.

$ sudo grep -i macs /etc/crypto-policies/back-ends/opensshserver.config
MACS=hmac-sha2-512,hmac-sha2-256,hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com

2. Verify AHV "Ciphers" configuration using the following command.

$ sudo grep -i ciphers /etc/ssh/sshd_config
Ciphers aes256-ctr

If unapproved ciphers are listed, the "Ciphers" keyword is missing, or the returned line is commented out, this is a finding.