code: private static int calcAESKeyLength() {
  		int maxKeyLen;
  
  		try {
  			maxKeyLen = Cipher.getMaxAllowedKeyLength("AES");
  		} catch (NoSuchAlgorithmException e) {
  			throw U.rte(e);
  		}
  
  		return maxKeyLen > 256 ? 256 : 128;
  	}
docs: bits