To get the SHA256 hash of an existing public key, simply run
ssh-keygen -lvf path/to/key.pub
If you want the MD5 hash (or another supported format), run something like
ssh-keygen -lv -E MD5 -f path/to/key.pub
To get the SHA256 hash of an existing public key, simply run
ssh-keygen -lvf path/to/key.pub
If you want the MD5 hash (or another supported format), run something like
ssh-keygen -lv -E MD5 -f path/to/key.pub