java加密码算法实现

   import java.math.BigInteger;
   import java.security.InvalidKeyException;
   import java.security.MessageDigest;
   import java.security.NoSuchAlgorithmException;
   import javax.crypto.KeyGenerator;
   import javax.crypto.Mac;
   import javax.crypto.SecretKey;
   import javax.crypto.spec.SecretKeySpec;
   import org.apache.commons.codec.binary.Base64;
  
  public class MyEncrypt {
  public static final String KEY_SHA = "SHA";
  public static final String KEY_MD5 = "MD5";
  public static final String KEY_MAC = "HmacMD5";
  
  
  // sun不推荐使用它们自己的base64,用apache的挺好
  /**
  * BASE64解密
  */
  public static byte[] decryptBASE64(byte[] dest) {
  if (dest == null) {
  return null;
  }
  return Base64.decodeBase64(dest);
  }
  
  /**
  * BASE64加密
  */
  public static byte[] encryptBASE64(byte[] origin) {
  if (origin == null) {
  return null;
  }
  return Base64.encodeBase64(origin);
  }
  
  /**
  * MD5加密
  * 
  * @throws NoSuchAlgorithmException
  */
  public static byte[] encryptMD5(byte[] data)
  throws NoSuchAlgorithmException {
  if (data == null) {
  return null;
  }
  MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
  md5.update(data);
  return md5.digest();
  }
  
  /**
  * SHA加密
  * 
  * @throws NoSuchAlgorithmException
  */
  public static byte[] encryptSHA(byte[] data)
  throws NoSuchAlgorithmException {
  if (data == null) {
  return null;
  }
  MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
  sha.update(data);
  return sha.digest();
  }
  
  /**
  * 初始化HMAC密钥
  * 
  * @throws NoSuchAlgorithmException
  */
  public static String initMacKey() throws NoSuchAlgorithmException {
  KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);
  SecretKey secretKey = keyGenerator.generateKey();
  return new String(encryptBASE64(secretKey.getEncoded()));
  }
  
  /**
  * HMAC加密
  * 
  * @throws NoSuchAlgorithmException
  * @throws InvalidKeyException
  */
  public static byte[] encryptHMAC(byte[] data, String key)
  throws NoSuchAlgorithmException, InvalidKeyException {
  SecretKey secretKey = new SecretKeySpec(decryptBASE64(key.getBytes()),
  KEY_MAC);
  Mac mac = Mac.getInstance(secretKey.getAlgorithm());
  mac.init(secretKey);
  return mac.doFinal(data);
  
  }
  
  public static void main(String[] args) throws Exception {
  // TODO Auto-generated method stub
  String data = "简单加密";
  System.out.println(new BigInteger(encryptBASE64(data.getBytes())).toString(16));
  System.out.println(new BigInteger(encryptBASE64(data.getBytes())).toString(32));
 System.out.println(new String(decryptBASE64(encryptBASE64(data.getBytes()))));
 
 System.out.println(new BigInteger(encryptMD5(data.getBytes())).toString());
 System.out.println(new BigInteger(encryptSHA(data.getBytes())).toString());
 
 System.out.println(new BigInteger(encryptHMAC(data.getBytes(), initMacKey())).toString());
 }
 
 }