Get public key fingerprint
1ssh-keygen -l [-E "$hash"] -f "$public_key"$hash— fingerprint hash algorithm:sha256(default) ormd5.
Get public key from private key
1ssh-keygen -y -f "$private_key"Change passphrase
1ssh-keygen -p -P "$old_passphrase" -N "$new_passphrase" -f "$private_key"Change comment
1ssh-keygen -c -C "$new_comment" -f "$private_key"