1.6.3 Ensure 'RSA key pair' is greater than or equal to 2048 bits


Generates an RSA key pair used by SSH protocol of at least 2048 bits


Secure Shell (SSH) is a secure remote-login protocol. The ASA allows SSH connections to the ASA for management purposes and supports the SSH DES and 3DES ciphers. SSH uses a key-exchange method based on Rivest-Shamir-Adleman (RSA) public-key. Since RSA 1024-bit keys are likely to become crackable, it is recommended to have RSA keys of at least 2048 bits.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.


Step 1: Acquire the enterprise standard RSA key size greater or equal than 2048 bits

Step 2: If the audit procedure revealed existing non-compliant key pairs, run the following to remove them:

hostname(config)#crypto key zeroize rsa

Step 3: Run the following to generate compliant RSA key pair:

hostname(config)# crypto key generate rsa modulus <enterprise_RSA_key_size>

Step 4: Run the following to save the RSA keys to persistent Flash memory

hostname(config)#write memory

See Also


Item Details


References: 800-53|CM-2, CSCv7|11.1

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