code: private static MessageDigest SHA512_Init() {
  		Log.d("Ed25519", "SHA512_Init");
  		try {
  			return MessageDigest.getInstance("SHA-512");
  		} catch (NoSuchAlgorithmException e) {
  			e.printStackTrace();
  		}
  		return null;
  	}
docs: jni c code calls this for sha512.