常见的加密算法

1.Base64加密算法

严格来说Base64并不是一种加密/解密算法，而是一种编码方式。Base64不生成密钥，通过Base64编码后的密文就可以直接“翻译”为明文，但是可以通过向明文中添加混淆字符来达到加密的效果。

主要就是BASE64Encoder加密类、BASE64Decoder解密类两个类，我们只需要知道使用对应的方法即可。

//**************************BASE64加密与解密************************************
/**
 * BASE64加密
 *
 * @param key
 * @return
 * @throws Exception
 */
public static String encryptBASE64(byte[] key) throws Exception {
    return (new BASE64Encoder()).encodeBuffer(key);
}

/**
 * BASE64解密
 *
 * @param key
 * @return
 * @throws Exception
 */
public static byte[] decryptBASE64(String key) throws Exception {
    return (new BASE64Decoder()).decodeBuffer(key);
}

测试

String inputStr = "简单加密";
System.err.println("原文:" + inputStr);

//**************************BASE64加密与解密************************************
byte[] inputData = inputStr.getBytes();
String code = Coder.encryptBASE64(inputData);
System.err.println("BASE64加密后:" + code);
byte[] output = Coder.decryptBASE64(code);
String outputStr = new String(output);
System.err.println("BASE64解密后:" + outputStr);

结果

2.MD5与SHA加密算法

可谓是非可逆加密，就是不可解密的加密方法，我们称之为单向加密算法。

//**************************MD5加密************************************
/**
 * MD5加密
 *
 * @param data
 * @return
 * @throws Exception
 */
public static byte[] encryptMD5(byte[] data) throws Exception {
    MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
    md5.update(data);
    return md5.digest();
}

//**************************SHA加密************************************
/**
 * SHA加密
 *
 * @param data
 * @return
 * @throws Exception
 */
public static byte[] encryptSHA(byte[] data) throws Exception {
    MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
    sha.update(data);
    return sha.digest();

}

测试

//**************************MD5加密************************************
BigInteger md51 = new BigInteger(Coder.encryptMD5(inputData));
BigInteger md52 = new BigInteger(Coder.encryptMD5(inputData));
System.err.println("MD51:" + md51.toString());
System.err.println("MD52:" + md52.toString());
boolean md5equals = md51.equals(md52);
System.out.println("MD51==MD52="+ md5equals);

//**************************SHA加密************************************
BigInteger SHA1 = new BigInteger(Coder.encryptSHA(inputData));
BigInteger SHA2 = new BigInteger(Coder.encryptSHA(inputData));
System.err.println("SHA1:" + SHA1.toString());
System.err.println("SHA2:" + SHA2.toString());
boolean SHAequals = SHA1.equals(SHA2);
System.out.println("SHA1==SHA2="+ SHAequals);

结果

3.HMAC加密算法

初始化一个HMAC密钥，然后在通过密钥进行加密，对比是需要用到密钥对其加密再和一起加密后的结果进行对比。

/**************************初始化HMAC密钥************************************
/**
 * 初始化HMAC密钥
 *
 * @return
 * @throws Exception
 */
public static String initMacKey() throws Exception {
    KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);
    SecretKey secretKey = keyGenerator.generateKey();
    return encryptBASE64(secretKey.getEncoded());
}


//**************************HMAC加密************************************
/**
 * HMAC加密
 *
 * @param data
 * @param key
 * @return
 * @throws Exception
 */
public static byte[] encryptHMAC(byte[] data, String key) throws Exception {

    SecretKey secretKey = new SecretKeySpec(decryptBASE64(key), KEY_MAC);
    Mac mac = Mac.getInstance(secretKey.getAlgorithm());
    mac.init(secretKey);
    return mac.doFinal(data);

}

测试

//**************************HMAC加密************************************
String initMacKey = Coder.initMacKey();
BigInteger HMAC1 = new BigInteger(Coder.encryptHMAC(inputData,initMacKey));
BigInteger HMAC2 = new BigInteger(Coder.encryptHMAC(inputData,initMacKey));
System.err.println("HMAC1:" + HMAC1.toString());
System.err.println("HMAC2:" + HMAC2.toString());
System.out.println("Mac密钥="+initMacKey);
boolean HMACequals = HMAC1.equals(HMAC2);
System.out.println("HMAC1==HMAC2="+ HMACequals);

结果

全部类

public class Coder {

    public static final String KEY_SHA = "SHA";
    public static final String KEY_MD5 = "MD5";

    /**
     * MAC算法可选以下多种算法
     *
     * 
     * HmacMD5
     * HmacSHA1
     * HmacSHA256
     * HmacSHA384
     * HmacSHA512
     * 
     */
    public static final String KEY_MAC = "HmacMD5";

    //**************************BASE64加密与解密************************************
    /**
     * BASE64加密
     *
     * @param key
     * @return
     * @throws Exception
     */
    public static String encryptBASE64(byte[] key) throws Exception {
        return (new BASE64Encoder()).encodeBuffer(key);
    }

    /**
     * BASE64解密
     *
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] decryptBASE64(String key) throws Exception {
        return (new BASE64Decoder()).decodeBuffer(key);
    }


    //**************************MD5加密************************************
    /**
     * MD5加密
     *
     * @param data
     * @return
     * @throws Exception
     */
    public static byte[] encryptMD5(byte[] data) throws Exception {
        MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
        md5.update(data);
        return md5.digest();
    }

    //**************************SHA加密************************************
    /**
     * SHA加密
     *
     * @param data
     * @return
     * @throws Exception
     */
    public static byte[] encryptSHA(byte[] data) throws Exception {
        MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
        sha.update(data);
        return sha.digest();

    }

    //**************************初始化HMAC密钥************************************
    /**
     * 初始化HMAC密钥
     *
     * @return
     * @throws Exception
     */
    public static String initMacKey() throws Exception {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);
        SecretKey secretKey = keyGenerator.generateKey();
        return encryptBASE64(secretKey.getEncoded());
    }


    //**************************HMAC加密************************************
    /**
     * HMAC加密
     *
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] encryptHMAC(byte[] data, String key) throws Exception {

        SecretKey secretKey = new SecretKeySpec(decryptBASE64(key), KEY_MAC);
        Mac mac = Mac.getInstance(secretKey.getAlgorithm());
        mac.init(secretKey);
        return mac.doFinal(data);

    }

    public static void main(String[] args) throws Exception {
        String inputStr = "简单加密";
        System.err.println("原文:" + inputStr);

        //**************************BASE64加密与解密************************************
        byte[] inputData = inputStr.getBytes();
        String code = Coder.encryptBASE64(inputData);
        System.err.println("BASE64加密后:" + code);
        byte[] output = Coder.decryptBASE64(code);
        String outputStr = new String(output);
        System.err.println("BASE64解密后:" + outputStr);


        //**************************MD5加密************************************
        BigInteger md51 = new BigInteger(Coder.encryptMD5(inputData));
        BigInteger md52 = new BigInteger(Coder.encryptMD5(inputData));
        System.err.println("MD51:" + md51.toString());
        System.err.println("MD52:" + md52.toString());
        boolean md5equals = md51.equals(md52);
        System.out.println("MD51==MD52="+ md5equals);

        //**************************SHA加密************************************
        BigInteger SHA1 = new BigInteger(Coder.encryptSHA(inputData));
        BigInteger SHA2 = new BigInteger(Coder.encryptSHA(inputData));
        System.err.println("SHA1:" + SHA1.toString());
        System.err.println("SHA2:" + SHA2.toString());
        boolean SHAequals = SHA1.equals(SHA2);
        System.out.println("SHA1==SHA2="+ SHAequals);

        //**************************HMAC加密************************************
        String initMacKey = Coder.initMacKey();
        BigInteger HMAC1 = new BigInteger(Coder.encryptHMAC(inputData,initMacKey));
        BigInteger HMAC2 = new BigInteger(Coder.encryptHMAC(inputData,initMacKey));
        System.err.println("HMAC1:" + HMAC1.toString());
        System.err.println("HMAC2:" + HMAC2.toString());
        System.out.println("Mac密钥="+initMacKey);
        boolean HMACequals = HMAC1.equals(HMAC2);
        System.out.println("HMAC1==HMAC2="+ HMACequals);

    }


}