void checkSupportedTagLength(int tagLenBits)
            throws InvalidAlgorithmParameterException {
        if (tagLenBits % 8 != 0) {
            throw new InvalidAlgorithmParameterException(
                    "Tag length must be a multiple of 8; was " + tagLenBits);
        }
    }
Constant-time array comparison.  Since we are using this to compare keys, we want to
ensure there's no opportunity for a timing attack.
common/src/main/java/org/conscrypt/OpenSSLAeadCipher.java