BASE64,MD5,SHA,HMAC加密與解密算法(java)

package com.ice.webos.util.security;



import java.io.UnsupportedEncodingException;

import java.math.BigInteger;

import java.security.Key;

import java.security.MessageDigest;

import java.security.SecureRandom;



import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.Mac;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import javax.crypto.spec.SecretKeySpec;



import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;



/**

* <ul>

* <li>BASE64的加密解密是双向的，可以求反解。</li>

* <li>MD5、SHA以及HMAC是单向加密，任何数据加密后只会产生唯一的一个加密串，通常用来校验数据在传输过程中是否被修改。</li>

* <li>HMAC算法有一个密钥，增强了数据传输过程中的安全性，强化了算法外的不可控因素。</li>

* <li>DES DES-Data Encryption Standard,即数据加密算法。

* DES算法的入口参数有三个:Key、Data、Mode。

* <ul>

* <li>Key:8个字节共64位,是DES算法的工作密钥;</li>

* <li>Data:8个字节64位,是要被加密或被解密的数据;</li>

* <li>Mode:DES的工作方式,有两种:加密或解密。</li>

* </ul>

* </li>

* <ul>

* 

* @author Ice_Liu

* 

*/

public class CryptUtil {

private static final String KEY_MD5 = "MD5";

private static final String KEY_SHA = "SHA";

/**

* MAC算法可选以下多种算法

* 

* <pre>

* 

* HmacMD5 

* HmacSHA1 

* HmacSHA256 

* HmacSHA384 

* HmacSHA512 

* </pre>

*/

public static final String KEY_MAC = "HmacMD5";



/**

* BASE64解密

* 

* @param key

* @return

* @throws Exception

*/

public static byte[] decryptBASE64(String key) throws Exception {

return (new BASE64Decoder()).decodeBuffer(key);

}



/**

* BASE64 加密

* 

* @param key

* @return

* @throws Exception

*/

public static String encryptBASE64(byte[] key) throws Exception {

return (new BASE64Encoder()).encodeBuffer(key);

}



/**

* 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

* 

* @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

* 

* @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

* 

* @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);

}



/**

* DES 算法 <br>

* 可替换为以下任意一种算法，同时key值的size相应改变。

* 

* <pre>

* DES key size must be equal to 56 

* DESede(TripleDES) key size must be equal to 112 or 168 

* AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available 

* Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive) 

* RC2 key size must be between 40 and 1024 bits 

* RC4(ARCFOUR) key size must be between 40 and 1024 bits 

* </pre>

*/

public static final String ALGORITHM = "DES";



/**

* DES 算法转换密钥<br>

* 

* @param key

* @return

* @throws Exception

*/

private static Key toKey(byte[] key) throws Exception {

SecretKey secretKey = null;

if (ALGORITHM.equals("DES") || ALGORITHM.equals("DESede")) {

DESKeySpec dks = new DESKeySpec(key);

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);

secretKey = keyFactory.generateSecret(dks);

} else {

// 当使用其他对称加密算法时，如AES、Blowfish等算法时，用下述代码替换上述三行代码

secretKey = new SecretKeySpec(key, ALGORITHM);

}

return secretKey;

}



/**

* DES 算法解密

* 

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] decrypt(byte[] data, String key) throws Exception {

Key k = toKey(decryptBASE64(key));

Cipher cipher = Cipher.getInstance(ALGORITHM);

cipher.init(Cipher.DECRYPT_MODE, k);

return cipher.doFinal(data);

}



/**

* DES 算法加密

* 

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] encrypt(byte[] data, String key) throws Exception {

Key k = toKey(decryptBASE64(key));

Cipher cipher = Cipher.getInstance(ALGORITHM);

cipher.init(Cipher.ENCRYPT_MODE, k);

return cipher.doFinal(data);

}



/**

* DES 算法生成密钥

* 

* @return

* @throws Exception

*/

public static String initKey() throws Exception {

return initKey(null);

}



/**

* DES 算法生成密钥

* 

* @param seed

* @return

* @throws Exception

*/

public static String initKey(String seed) throws Exception {

SecureRandom secureRandom = null;

if (seed != null) {

secureRandom = new SecureRandom(decryptBASE64(seed));

} else {

secureRandom = new SecureRandom();

}

KeyGenerator kg = KeyGenerator.getInstance(ALGORITHM);

kg.init(secureRandom);

SecretKey secretKey = kg.generateKey();

return encryptBASE64(secretKey.getEncoded());

}



public static void main(String[] args) {

try {

String s = "阿伯才的覆盖";

String b = CryptUtil.encryptBASE64(s.getBytes("UTF-8"));

System.out.println("BASE64加密后:" + b);

byte[] c = CryptUtil.decryptBASE64(b);

System.out.println("BASE64解密后:" + new String(c, "UTF-8"));



c = encryptMD5(s.getBytes());

System.out.println("MD5 加密后:" + new BigInteger(c).toString(16));



c = encryptSHA(s.getBytes());

System.out.println("SHA 加密后:" + new BigInteger(c).toString(16));



String key = initMacKey();

System.out.println("HMAC密匙:" + key);

c = encryptHMAC(s.getBytes(), key);

System.out.println("HMAC 加密后:" + new BigInteger(c).toString(16));



key = initKey();

System.out.println(ALGORITHM + "密钥:\t" + key);

c = encrypt(s.getBytes("UTF-8"), key);

System.out.println(ALGORITHM + " 加密后:" + new BigInteger(c).toString(16));

c = decrypt(c, key);

System.out.println(ALGORITHM + " 解密后:" + new String(c, "UTF-8"));

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

 

转发 http://www.cnblogs.com/liubin0509/archive/2012/01/29/2331066.html