帶偏移量的AES加密工具

 自定義的一個對稱加密工具類AESUtil.java

    public static final String ENCRYPTION_ALGORITHM = "AES";
    public static final String CIPHER_PARAM = "AES/CBC/PKCS5Padding";
    private static final String DEFAULT_KEY_AND_IV = "1234567890ABCDEF";//帶偏移量的密鑰和偏移量似乎是固定16位長度的
    private static AESUtil instance = null;

    /** 偏移量 **/
    private static IvParameterSpec iv;
    /** 密鑰 **/
    private static SecretKeySpec key;

    /**
     * @Title: getInstance
     * @Description: 單例AES加密工具，使用默認的密鑰以及偏移量
     * @return AESUtil
     * @author hanzhiyong
     * @date 2019-4-26下午4:51:12
     */
    public static AESUtil getInstance() {
        if (instance == null) {
            instance = new AESUtil(DEFAULT_KEY_AND_IV);
        }
        return instance;
    }
    /**
     * @Title:AESUtil
     * @Description:自定義偏移量構造AES加密工具，使用默認的KEY
     * @param ivParameter 原始偏移量字符串
     */
    public AESUtil(String ivParameter) {
        iv = new IvParameterSpec(ivParameter.getBytes());
        key = new SecretKeySpec(DEFAULT_KEY_AND_IV.getBytes(), ENCRYPTION_ALGORITHM);
    }

    /**
     * @Title:AESUtil
     * @Description:自定義偏移量和密鑰構造AES加密工具
     * @param secretKey 原始密鑰字符串
     * @param ivParameter 原始偏移量字符串
     */
    public AESUtil(String secretKey, String ivParameter) {
        iv = new IvParameterSpec(ivParameter.getBytes());
        key = new SecretKeySpec(secretKey.getBytes(), ENCRYPTION_ALGORITHM);
    }

    /**
     * 取得密鑰
     * 
     * @throws Exception
     */
    public static String getKey() {
        Base64 base64 = new Base64();
        System.out.println("密鑰String:" + new String(key.getEncoded()));
        return base64.encodeToString(key.getEncoded());
    }

    /**
     * 取得偏移量
     */
    public static String getIv() throws Exception {
        Base64 base64 = new Base64();
        System.out.println("偏移量String:" + new String(iv.getIV()));
        return base64.encodeToString(iv.getIV());
    }
    /**
     * @Title: encrypt
     * @Description: AES加密
     * @param enString 用來加密的明文
     * @throws Exception
     * @return String 加密后密文
     * @author hanzhiyong
     * @date 2019-4-26下午3:57:17
     */
    public String encrypt(String enString) throws Exception {
        Base64 base64 = new Base64();
        Cipher cipher = Cipher.getInstance(CIPHER_PARAM);
        cipher.init(Cipher.ENCRYPT_MODE, key, iv);
        byte[] encrypted = cipher.doFinal(enString.getBytes("utf-8"));
        return base64.encodeToString(encrypted);

    }
    /**
     * @Title: decrypt
     * @Description: AES解密
     * @param deString 用來解密的密文
     * @throws Exception
     * @return String 解密后的明文
     * @author hanzhiyong
     * @date 2019-4-26下午3:58:06
     */
    public String decrypt(String deString) throws Exception {
        try {
            Base64 base64 = new Base64();
            Cipher cipher = Cipher.getInstance(CIPHER_PARAM);
            cipher.init(Cipher.DECRYPT_MODE, key, iv);
            byte[] decrypted = base64.decode(deString);
            byte[] original = cipher.doFinal(decrypted);
            return new String(original, "utf-8");
        } catch (Exception ex) {
            return null;
        }
    }

    /**
     * @Title: main
     * @Description: 加密解密測試用例
     * @param args
     * @throws Exception
     * @return void
     * @author hanzhiyong
     * @date 2019-4-23下午6:41:16
     */
    @Deprecated
    public static void main(String args[]) throws Exception {
        String sourceString = "測試用來加密的數據";
        System.out.println("sourceString加密前: " + sourceString);

        System.out.println("=========================單例的加密工具=========================");
        System.out.println("base64加密后密鑰:" + AESUtil.getInstance().getKey());
        System.out.println("base64加密后偏移量:" + AESUtil.getInstance().getIv());        
        System.out.println("加密后sourceString: " + AESUtil.getInstance().encrypt(sourceString));
        System.out.println("解密后sourceString: " + AESUtil.getInstance().decrypt(AESUtil.getInstance().encrypt(sourceString)));

        AESUtil aesUtil = new AESUtil("0123456789111111");
        System.out.println("=========================自定義偏移量的工具=========================");
        System.out.println("base64加密后密鑰：" + aesUtil.getKey());
        System.out.println("base64加密后偏移量：" + aesUtil.getIv());
        System.out.println("加密后sourceString: " + aesUtil.encrypt(sourceString));
        System.out.println("解密后sourceString: " + aesUtil.decrypt(aesUtil.encrypt(sourceString)));

    }