SSH – Show Supported (Encryption) Algorithms

If you want to verify what your SSH server is providing to clients as options of supported algorithms you can use the following command:

nmap -Pn -n -p22 -vv --open --script=ssh2-enum-algos.nse sshserver.domain.com

It makes use of an NMAP script “ssh2-enum-algos.nse” to enumerate the list of algorithms that the SSH server supports. Useful if you are having issues with clients connecting using supported methods, or in the case of this verifying which algorithms an SSH server was supporting to ensure that security hardening to turn off certain weak algorithms was indeed working as expected.