Information
This sequence describes configuring SSH server ciphers, MACs, and algorithms
SSH server ciphers, MACs, and algorithms allow the admin to select specific values for SSH encryption, allowing for flexibility and/or greater security in the SSH sessions.
Solution
switch(config)# ssh ciphers aes128-ctr aes256-ctr aes128-cbc aes256-cbc
switch(config)# ssh macs hmac-sha2-256 hmac-sha2-512 hmac-sha1
switch(config)# ssh key-exchange-algorithms ecdh-sha2-nistp256 ecdh-sha2-nistp384 diffie-hellman-group14-sha1
switch(config)# ssh host-key-algorithms ecdsa-sha2-nistp256 ecdsa-sha2-nistp384 ecdsa-sha2-nistp521
switch(config)# ssh public-key-algorithms ecdsa-sha2-nistp256 ecdsa-sha2-nistp384 ecdsa-sha2-nistp521
switch(config)#
Impact:
SSH ciphers, message authentication codes (MACs), and algorithms are based on OpenSSH's default settings and are deemed secure by the community.
For highly secure deployments like Federal Accounts which mandates the compliance of NDcPP (Common Criteria Protection Profile), it is recommended to configure more secure ciphers, MACs, and algorithms as per the NDcPP evaluation criteria.
Item Details
Category: ACCESS CONTROL, IDENTIFICATION AND AUTHENTICATION, SYSTEM AND SERVICES ACQUISITION, SYSTEM AND COMMUNICATIONS PROTECTION
References: 800-53|AC-17(2), 800-53|IA-5, 800-53|IA-5(1), 800-53|SA-15, 800-53|SC-8, 800-53|SC-8(1), 800-53|SC-28, 800-53|SC-28(1), CSCv7|13.6, CSCv7|14.4, CSCv7|14.8, CSCv7|16.4, CSCv7|16.5, CSCv7|18.5
Control ID: 197460a84cba30a59b03646aecd3cc6268532a45106f54d636801c3532eb75dc