AES加解密

package cn.anzhongwei.lean.demo.encryption;

import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;


/**
 * AES加密类
 *
 */
public class AESUtils {
    /**
     * 密钥算法
     */
    private static final String KEY_ALGORITHM = "AES";

    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";

    /**
     * 初始化密钥
     *
     * @return byte[] 密钥
     * @throws Exception
     */
    public static byte[] initSecretKey() {
        // 返回生成指定算法的秘密密钥的 KeyGenerator 对象
        KeyGenerator kg = null;
        try {
            kg = KeyGenerator.getInstance(KEY_ALGORITHM);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return new byte[0];
        }
        // 初始化此密钥生成器，使其具有确定的密钥大小
        // AES 要求密钥长度为 128
        kg.init(128);
        // 生成一个密钥
        SecretKey secretKey = kg.generateKey();
        return secretKey.getEncoded();
    }

    /**
     * 转换密钥
     *
     * @param key
     *            二进制密钥
     * @return 密钥
     */
    public static Key toKey(byte[] key) {
        // 生成密钥
        return new SecretKeySpec(key, KEY_ALGORITHM);
    }

    /**
     * 加密
     *
     * @param data
     *            待加密数据
     * @param key
     *            密钥
     * @return byte[] 加密数据
     * @throws Exception
     */
    public static byte[] encrypt(byte[] data, Key key) throws Exception {
        return encrypt(data, key, DEFAULT_CIPHER_ALGORITHM);
    }

    /**
     * 加密
     *
     * @param data
     *            待加密数据
     * @param key
     *            二进制密钥
     * @return byte[] 加密数据
     * @throws Exception
     */
    public static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        return encrypt(data, key, DEFAULT_CIPHER_ALGORITHM);
    }

    /**
     * 加密
     *
     * @param data
     *            待加密数据
     * @param key
     *            二进制密钥
     * @param cipherAlgorithm
     *            加密算法/工作模式/填充方式
     * @return byte[] 加密数据
     * @throws Exception
     */
    public static byte[] encrypt(byte[] data, byte[] key, String cipherAlgorithm) throws Exception {
        // 还原密钥
        Key k = toKey(key);
        return encrypt(data, k, cipherAlgorithm);
    }

    /**
     * 加密
     *
     * @param data
     *            待加密数据
     * @param key
     *            密钥
     * @param cipherAlgorithm
     *            加密算法/工作模式/填充方式
     * @return byte[] 加密数据
     * @throws Exception
     */
    public static byte[] encrypt(byte[] data, Key key, String cipherAlgorithm) throws Exception {
        // 实例化
        Cipher cipher = Cipher.getInstance(cipherAlgorithm);
        // 使用密钥初始化，设置为加密模式
        cipher.init(Cipher.ENCRYPT_MODE, key);
        // 执行操作
        return cipher.doFinal(data);
    }

    /**
     * 解密
     *
     * @param data
     *            待解密数据
     * @param key
     *            二进制密钥
     * @return byte[] 解密数据
     * @throws Exception
     */
    public static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        return decrypt(data, key, DEFAULT_CIPHER_ALGORITHM);
    }

    /**
     * 解密
     *
     * @param data
     *            待解密数据
     * @param key
     *            密钥
     * @return byte[] 解密数据
     * @throws Exception
     */
    public static byte[] decrypt(byte[] data, Key key) throws Exception {
        return decrypt(data, key, DEFAULT_CIPHER_ALGORITHM);
    }

    /**
     * 解密
     *
     * @param data
     *            待解密数据
     * @param key
     *            二进制密钥
     * @param cipherAlgorithm
     *            加密算法/工作模式/填充方式
     * @return byte[] 解密数据
     * @throws Exception
     */
    public static byte[] decrypt(byte[] data, byte[] key, String cipherAlgorithm) throws Exception {
        // 还原密钥
        Key k = toKey(key);
        return decrypt(data, k, cipherAlgorithm);
    }

    /**
     * 解密
     *
     * @param data
     *            待解密数据
     * @param key
     *            密钥
     * @param cipherAlgorithm
     *            加密算法/工作模式/填充方式
     * @return byte[] 解密数据
     * @throws Exception
     */
    public static byte[] decrypt(byte[] data, Key key, String cipherAlgorithm) throws Exception {
        // 实例化
        Cipher cipher = Cipher.getInstance(cipherAlgorithm);
        // 使用密钥初始化，设置为解密模式
        cipher.init(Cipher.DECRYPT_MODE, key);
        // 执行操作
        return cipher.doFinal(data);
    }

    public static String showByteArray(byte[] data) {
        if (null == data) {
            return null;
        }
        StringBuilder sb = new StringBuilder("{");
        for (byte b : data) {
            sb.append(b).append(",");
        }
        sb.deleteCharAt(sb.length() - 1);
        sb.append("}");
        return sb.toString();
    }

    /**
     * 将16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public static byte[] parseHexStr2Byte(String hexStr) {

        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

    /**
     * 将二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * @param str
     * @param key
     * @return
     * @throws Exception
     */
    public static String aesEncrypt(String str, String key) throws Exception {
        if (str == null || key == null)
            return null;
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key.getBytes("utf-8"), "AES"));
        byte[] bytes = cipher.doFinal(str.getBytes("utf-8"));
        return Base64.getEncoder().encodeToString(bytes);
    }

    public static String aesDecrypt(String str, String key) throws Exception {
        if (str == null || key == null)
            return null;
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key.getBytes("utf-8"), "AES"));
        byte[] bytes = Base64.getDecoder().decode(str);
        bytes = cipher.doFinal(bytes);
        return new String(bytes, "utf-8");
    }

    public static void main(String[] args) throws Exception {



        // 指定key
        String base64Str1 = "cmVmb3JtZXJyZWZvcm1lcg==";
        byte[] bs = Base64.getDecoder().decode(base64Str1);
        System.out.println("base64Str1解密："+ Arrays.toString(bs));
        System.out.println("base64Str1解密：" + showByteArray(Base64.getDecoder().decode(base64Str1)));
        Key key1 = toKey(Base64.getDecoder().decode(base64Str1));

        String data1 = "{\"aaa\":\"bbb\"}";
        System.out.println("明文：" + data1);

        byte[] encryptData1 = encrypt(data1.getBytes(), key1);
        String encryptStr1=parseByte2HexStr(encryptData1);
        System.out.println("加密后数据1: byte[]:" + showByteArray(encryptData1));
        System.out.println("加密后数据1: Byte2HexStr:" + encryptStr1);
        System.out.println();

        byte[] encryptStrByte1 = parseHexStr2Byte(encryptStr1);
        byte[] decryptData1 = decrypt(encryptStrByte1, key1);
        System.out.println("解密后数据: byte[]:" + showByteArray(decryptData1));
        System.out.println("解密后数据: string:" + new String(decryptData1));


        System.out.println("--------------------------------------------------------");


        byte[] initKey = initSecretKey();
        System.out.println("key：" + Arrays.toString(Base64.getEncoder().encode(initKey)));
        System.out.println("key：" + showByteArray(initKey));
        Key key2 = toKey(initKey);

        String data2 = "{\"ccc\":\"ddd\"}";
        System.out.println("明文：" + data2);

        byte[] encryptData2 = encrypt(data2.getBytes(), key2);
        String encryptStr2=parseByte2HexStr(encryptData2);
        System.out.println("加密后数据1: byte[]:" + showByteArray(encryptData2));
        System.out.println("加密后数据1: Byte2HexStr:" + encryptStr2);
        System.out.println();

        byte[] encryptStrByte2 = parseHexStr2Byte(encryptStr2);
        byte[] decryptData2 = decrypt(encryptStrByte2, key2);
        System.out.println("解密后数据: byte[]:" + showByteArray(decryptData2));
        System.out.println("解密后数据: string:" + new String(decryptData2));

    }
}