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package org.openjdk.bench.javax.crypto.full;

import org.openjdk.jmh.annotations.Benchmark;

import org.openjdk.jmh.annotations.Param;

import org.openjdk.jmh.annotations.Setup;

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import javax.crypto.NoSuchPaddingException;

import javax.crypto.spec.GCMParameterSpec;

import javax.crypto.spec.SecretKeySpec;

import java.security.InvalidAlgorithmParameterException;

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import java.security.spec.InvalidParameterSpecException;

public class AESGCMBench extends CryptoBase {

    private String algorithm;

    @Param({"128"})

    private int keyLength;

    @Param({""+16*1024})

    private int dataSize;

    byte[] data;

    byte[] encryptedData;

    private Cipher encryptCipher;

    private Cipher decryptCipher;

    SecretKeySpec ks;

    GCMParameterSpec gcm_spec;

    byte[] aad;

    byte[] iv;

    public static final int IV_BUFFER_SIZE = 32;

    public static final int IV_MODULO = IV_BUFFER_SIZE - 16;

    int iv_index = 0;

    private int next_iv_index() {

        int r = iv_index;

        iv_index = (iv_index + 1) % IV_MODULO;

        return r;

    }

    @Setup

    public void setup() throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidAlgorithmParameterException, InvalidParameterSpecException {

        setupProvider();

        assert algorithm.split("/")[1].compareToIgnoreCase("GCM") == 0;

        byte[] keystring = fillSecureRandom(new byte[keyLength / 8]);

        ks = new SecretKeySpec(keystring, "AES");

        iv = fillSecureRandom(new byte[IV_BUFFER_SIZE]);

        gcm_spec = new GCMParameterSpec(96, iv, next_iv_index(), 16);

        aad = fillSecureRandom(new byte[5]);

        encryptCipher = makeCipher(prov, algorithm);

        encryptCipher.init(Cipher.ENCRYPT_MODE, ks, gcm_spec);

        encryptCipher.updateAAD(aad);

        decryptCipher = makeCipher(prov, algorithm);

        decryptCipher.init(Cipher.DECRYPT_MODE, ks, encryptCipher.getParameters().getParameterSpec(GCMParameterSpec.class));

        decryptCipher.updateAAD(aad);

        data = fillRandom(new byte[dataSize]);

        encryptedData = encryptCipher.doFinal(data);

    }

    @Benchmark

    public byte[] encrypt() throws BadPaddingException, IllegalBlockSizeException, InvalidAlgorithmParameterException, InvalidKeyException {

        gcm_spec = new GCMParameterSpec(96, iv, next_iv_index(), 16);

        encryptCipher.init(Cipher.ENCRYPT_MODE, ks, gcm_spec);

        encryptCipher.updateAAD(aad);

        return encryptCipher.doFinal(data);

    }

    @Benchmark

    public byte[] decrypt() throws BadPaddingException, IllegalBlockSizeException, InvalidParameterSpecException, InvalidAlgorithmParameterException, InvalidKeyException {

        decryptCipher.init(Cipher.DECRYPT_MODE, ks, encryptCipher.getParameters().getParameterSpec(GCMParameterSpec.class));

        decryptCipher.updateAAD(aad);

        return decryptCipher.doFinal(encryptedData);

    }

}