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());
}

}