I need to implement functions to test the deletion of a ssh key given a fingerprint, and one scenario is to delete a "non-existing" key by providing it with a fake public key fingerprint.
The public keys are generated randomly, how do I come up with a fake fingerprint which will never collide with any real public key fingerprints?
Checking the Public key fingerprint didn't give me enough information about the valid range of a public key fingerprint, the generation of valid fingerprint from public key is MD5
You could generate a public key, get the public key fingerprint, then throw the public key away. It doesn't guarantee that it will never collide with a "real" public key fingerprint (i.e. one of your randomly generated ones), but it would be quite unlikely.