1、訊息驗證碼演算法實現支援

2、使用HmacSHA256演算法實現訊息驗證碼

import java.security.Security;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Hex;


/**
 * 訊息驗證碼
 * @author luke
 */
public class HAMC {

	public static byte[] initHmacSHA256Key() throws Exception{
		Security.addProvider(new BouncyCastleProvider());
		KeyGenerator keyGenerator = KeyGenerator.getInstance("HmacSHA256");
		SecretKey secretKey = keyGenerator.generateKey();
		return secretKey.getEncoded();
	}
	
	public static byte[] encodeHmacSHA256(byte[] data,byte[] key) throws Exception{
		Security.addProvider(new BouncyCastleProvider());
		SecretKey secretKey = new SecretKeySpec(key, "HmacSHA256");
		Mac mac = Mac.getInstance(secretKey.getAlgorithm());
		mac.init(secretKey);
		return mac.doFinal(data);
	}
	
	public static void main(String[] args) {
		try {
			//初始化金鑰
			byte[] key=HAMC.initHmacSHA256Key();
			//通過金鑰和訊息獲取訊息驗證碼
			String str="999999999999999999999999999999999999999";//模擬傳送的訊息
			byte[] data=HAMC.encodeHmacSHA256(str.getBytes(), key);
			//訊息驗證碼轉16進位制字串
			String dataHex=new String(Hex.encode(data));
			System.out.println("傳送的訊息："+str);//將訊息和訊息驗證碼傳送出去
			System.out.println("傳送驗證碼HEX："+dataHex);		
			System.out.println("---------------------------------");
			String str2="999999999999999999999999999999999999999";//模擬接收到的訊息
			byte[] data2=HAMC.encodeHmacSHA256(str2.getBytes(), key);
			String data2Hex=new String(Hex.encode(data2));
			System.out.println("接收到的訊息："+str2);//當訊息被篡改，計算出的訊息驗證碼將不一致
			System.out.println("計算出驗證碼HEX："+data2Hex);		
			System.out.println("---------------------------------");
			System.out.println(dataHex.equals(data2Hex));//對比計算出的和接收到的是否一致，驗證訊息的完整性和認證性
		} catch (Exception e) {
			e.printStackTrace();
		}
		
	}
	
}
 

3、測試結果

        傳送的訊息：999999999999999999999999999999999999999
        傳送驗證碼HEX：f6628635b8fe53277ff5b9f003b88bbe35af38f5ee91d34440e9b655efa14f59
        ---------------------------------
       接收到的訊息：999999999999999999999999999999999999999
       計算出驗證碼HEX：f6628635b8fe53277ff5b9f003b88bbe35af38f5ee91d34440e9b655efa14f59
       ---------------------------------
      true