package com.cs.coder.util;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

/**
 * @author Vince
 * @date 2019/12/10 14:24
 */
public class AES {
    private static final String AES_MODE = "AES/ECB/PKCS5Padding";
//    private static final int keySize = 16;

    // test search key gitwanlishi
    // wwww


    public static byte[] decrypt(byte[] key, byte[] data, int keySize) {
        try {
            SecretKeySpec secretKeySpec = new SecretKeySpec(trimKeySize(key, keySize), "AES");
            Cipher instance = Cipher.getInstance(AES_MODE);
            instance.init(2, secretKeySpec);
            return instance.doFinal(data);
        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException e) {
            e.printStackTrace();
            return null;
        }
    }

    @SuppressWarnings("SameParameterValue")
    private static byte[] trimKeySize(byte[] key, int keySize) {
        byte[] bArr2 = new byte[keySize];
        if (key.length <= keySize) {
            keySize = key.length;
        }
        System.arraycopy(key, 0, bArr2, 0, keySize);
        return bArr2;
    }

    public static byte[] encrypt(byte[] key, byte[] data, int keySize) {
        try {
            SecretKeySpec secretKeySpec = new SecretKeySpec(trimKeySize(key, keySize), "AES");
            Cipher instance = Cipher.getInstance(AES_MODE);
            instance.init(1, secretKeySpec);
            return instance.doFinal(data);
        } catch (NoSuchAlgorithmException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException | NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        }
    }
}