Method _cryptBytesAES

src/main/java/com/trsst/Crypto.java:121–127

(byte[] input, byte[] key,
            boolean forEncryption)

    // h/t Steve Weis, Michael Rogers, and liberationtech
    private static byte[] _cryptBytesAES(byte[] input, byte[] key,
            boolean forEncryption) throws InvalidCipherTextException {
        assert key.length == 32; // 32 bytes == 256 bits
        return process(input, new PaddedBufferedBlockCipher(new CBCBlockCipher(
                new AESEngine())), new KeyParameter(key), forEncryption);
        // note: using zero IV because we generate a new key for every message
    }

    // h/t Adam Paynter http://stackoverflow.com/users/41619/
    private static byte[] process(byte[] input,