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  • 消息摘要算法-HMAC算法

    一、简述

      mac(Message Authentication Code。消息认证码算法)是含有密钥散列函数算法,兼容了MD和SHA算法的特性,并在此基础上加上了密钥。因此MAC算法也经常被称作HMAC算法。关于hmac算法的详情能够參看RFC 2104(http://www.ietf.org/rfc/rfc2104.txt),这里包括了HmacMD5算法的C语言实现。

      这里须要说明的是经过mac算法得到的摘要值也能够使用十六进制编码表示。其摘要值得长度与实现算法的摘要值长度同样。比如 HmacSHA算法得到的摘要长度就是SHA1算法得到的摘要长度。都是160位二进制数,换算成十六进制的编码为40位。

     

    二、模型分析

    甲乙两方进行数据交换能够採取例如以下流程完毕

    1、甲方向乙方发布摘要算法(就是指定要使用的摘要算法名)

    2、甲乙两方依照约定构造密钥,两方拥有同样的密钥(通常是一方构造密钥后通知另外一方,此过程不须要通过程序实现。就是两方约定个字符串,可是这个字符串可不是随便设定的,也是通过相关算法获取的)

    3、甲方使用密钥对消息做摘要处理。然后将消息和生成的摘要消息一同发送给乙方

    4、乙方收到消息后。使用甲方已经发布的摘要算法+约定好的密钥 对收到的消息进行摘要处理。然后比对自己的摘要消息和甲方发过来的摘要消息。

    甄别消息是否是甲方发送过来的

     

    三、MAC系列算法支持表

     

    算法 摘要长度 备注
    HmacMD5 128 BouncyCastle实现
    HmacSHA1 160 BouncyCastle实现
    HmacSHA256 256 BouncyCastle实现
    HmacSHA384 384 BouncyCastle实现
    HmacSHA512 512 JAVA6实现
    HmacMD2 128 BouncyCastle实现
    HmacMD4 128 BouncyCastle实现
    HmacSHA224 224 BouncyCastle实现

    package com.main;
    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;
    /**
     * MAC消息摘要组件
     * @author kongqz
     * */
    public class HAMC {
    ///////////////////////////HmacMD5///////////////////////////////
    	/**
    	 * 初始化HmacMD5的密钥
    	 * @return byte[] 密钥
    	 * 
    	 * */
    	public static byte[] initHmacMD5Key() throws Exception{
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacMD5");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacMD5消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacMD5(byte[] data,byte[] key) throws Exception{
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//还原密钥。由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacMD5");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	/**
    	 * HmacMD2Hex消息摘要
    	 * @param data 待做消息摘要处理的数据
    	 * @param String 密钥
    	 * @return byte[] 消息摘要
    	 * */
    	public static String encodeHmacMD5Hex(byte[] data,byte[] key) throws Exception{
    		//运行消息摘要处理
    		byte[] b=encodeHmacMD5(data,key);
    		//做十六进制转换
    		return new String(Hex.encode(b));
    	}
    	
    ///////////////////////////////HmacSHA1//////////////////////////////////
    	/**
    	 * 初始化HmacSHA1的密钥
    	 * @return byte[] 密钥
    	 * 
    	 * */
    	public static byte[] initHmacSHAKey() throws Exception{
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacSHA1");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacSHA1消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacSHA(byte[] data,byte[] key) throws Exception{
    		//还原密钥,由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacSHA1");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	
    ///////////////////////////////HmacSHA256//////////////////////////////////
    	/**
    	 * 初始化HmacSHA256的密钥
    	 * @return byte[] 密钥
    	 * 
    	 * */
    	public static byte[] initHmacSHA256Key() throws Exception{
    		Security.addProvider(new BouncyCastleProvider());
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacSHA256");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacSHA256消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacSHA256(byte[] data,byte[] key) throws Exception{
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//还原密钥,由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacSHA256");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	
    ///////////////////////////////HmacSHA384//////////////////////////////////
    	/**
    	 * 初始化HmacSHA384的密钥
    	 * @return byte[] 密钥
    	 * 
    	 * */
    	public static byte[] initHmacSHA384Key() throws Exception{
    		Security.addProvider(new BouncyCastleProvider());
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacSHA384");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacSHA384消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacSHA384(byte[] data,byte[] key) throws Exception{
    		Security.addProvider(new BouncyCastleProvider());
    		//还原密钥,由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacSHA384");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	
    ///////////////////////////////HmacSHA512//////////////////////////////////
    	/**
    	 * 初始化HmacSHA512的密钥
    	 * @return byte[] 密钥
    	 * 
    	 * */
    	public static byte[] initHmacSHA512Key() throws Exception{
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacSHA512");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacSHA512消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacSHA512(byte[] data,byte[] key) throws Exception{
    		//还原密钥,由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacSHA512");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    ///////////////////////////////HmacMD2-BouncyCastle才支持的实现//////////////////////////////////
    	/**
    	 * 初始化HmacMD2的密钥
    	 * @return byte[] 密钥
    	 * */
    	public static byte[] initHmacMD2Key() throws Exception{
    		
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacMD2");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacMD2消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacMD2(byte[] data,byte[] key) throws Exception{
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//还原密钥,由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacMD2");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	/**
    	 * HmacMD2Hex消息摘要
    	 * @param data 待做消息摘要处理的数据
    	 * @param String 密钥
    	 * @return byte[] 消息摘要
    	 * */
    	public static String encodeHmacMD2Hex(byte[] data,byte[] key) throws Exception{
    		//运行消息摘要处理
    		byte[] b=encodeHmacMD2(data,key);
    		//做十六进制转换
    		return new String(Hex.encode(b));
    	}
    	
    ///////////////////////////////HmacMD4-BouncyCastle才支持的实现//////////////////////////////////
    	/**
    	 * 初始化HmacMD2的密钥
    	 * @return byte[] 密钥
    	 * */
    	public static byte[] initHmacMD4Key() throws Exception{
    		
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacMD4");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacMD4消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacMD4(byte[] data,byte[] key) throws Exception{
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//还原密钥,由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacMD4");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	/**
    	 * HmacMD4Hex消息摘要
    	 * @param data 待做消息摘要处理的数据
    	 * @param String 密钥
    	 * @return byte[] 消息摘要
    	 * */
    	public static String encodeHmacMD4Hex(byte[] data,byte[] key) throws Exception{
    		//运行消息摘要处理
    		byte[] b=encodeHmacMD4(data,key);
    		//做十六进制转换
    		return new String(Hex.encode(b));
    	}
    ///////////////////////////////HmacSHA224-BouncyCastle才支持的实现//////////////////////////////////
    	/**
    	 * 初始化HmacSHA224的密钥
    	 * @return byte[] 密钥
    	 * */
    	public static byte[] initHmacSHA224Key() throws Exception{
    		
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//初始化KeyGenerator
    		KeyGenerator keyGenerator=KeyGenerator.getInstance("HmacSHA224");
    		//产生密钥
    		SecretKey secretKey=keyGenerator.generateKey();
    		//获取密钥
    		return secretKey.getEncoded();
    	}
    	/**
    	 * HmacSHA224消息摘要
    	 * @param data 待做摘要处理的数据
    	 * @param key 密钥
    	 * @return  byte[] 消息摘要
    	 * */
    	public static byte[] encodeHmacSHA224(byte[] data,byte[] key) throws Exception{
    		//增加BouncyCastleProvider的支持
    		Security.addProvider(new BouncyCastleProvider());
    		//还原密钥。由于密钥是以byte形式为消息传递算法所拥有
    		SecretKey secretKey=new SecretKeySpec(key,"HmacSHA224");
    		//实例化Mac
    		Mac mac=Mac.getInstance(secretKey.getAlgorithm());
    		//初始化Mac
    		mac.init(secretKey);
    		//运行消息摘要处理
    		return mac.doFinal(data);
    	}
    	/**
    	 * HmacSHA224Hex消息摘要
    	 * @param data 待做消息摘要处理的数据
    	 * @param String 密钥
    	 * @return byte[] 消息摘要
    	 * */
    	public static String encodeHmacSHA224Hex(byte[] data,byte[] key) throws Exception{
    		//运行消息摘要处理
    		byte[] b=encodeHmacSHA224(data,key);
    		//做十六进制转换
    		return new String(Hex.encode(b));
    	}
    	/**
    	 * 进行相关的摘要算法的处理展示
    	 * @throws Exception 
    	 * **/
    	public static void main(String[] args) throws Exception {
    		String str="123000000000090989999999999999999999999999999999999999999999999999999999999999999999111" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"23000000000090989999999999999999999999999999999999999999999999999999999999999999999" +
    				"230000000000909899999999999999999999999999999999999999999999999999999999999999999991";
    		//初始化密钥
    		byte[] key1=HAMC.initHmacMD5Key();
    		//获取摘要信息
    		byte[] data1=HAMC.encodeHmacMD5(str.getBytes(), key1);
    		String datahex1=new String(Hex.encode(data1));
    		
    		System.out.println("原文:"+str);
    		System.out.println();
    		
    		System.out.println("Bouncycastle HmacMD5的密钥内容和长度:"+key1.toString()+"--"+key1.length);
    		System.out.println("Bouncycastle HmacMD5算法摘要:"+data1.toString());
    		System.out.println("Bouncycastle HmacMD5算法摘要HEX:"+datahex1.toString());
    		System.out.println();
    		
    		//初始化密钥
    		byte[] key2=HAMC.initHmacSHA256Key();
    		//获取摘要信息
    		byte[] data2=HAMC.encodeHmacSHA256(str.getBytes(), key2);
    		String datahex2=new String(Hex.encode(data2));
    		System.out.println("Bouncycastle HmacSHA256的密钥:"+key2.toString());
    		System.out.println("Bouncycastle HmacSHA256算法摘要:"+data2.toString());
    		System.out.println("Bouncycastle HmacSHA256算法摘要HEX:"+datahex2);
    		System.out.println();
    		
    		
    		//初始化密钥
    		byte[] key3=HAMC.initHmacSHAKey();
    		//获取摘要信息
    		byte[] data3=HAMC.encodeHmacSHA(str.getBytes(), key3);
    		String datahex3=new String(Hex.encode(data3));
    		System.out.println("Bouncycastle HmacSHA1的密钥:"+key3.toString());
    		System.out.println("Bouncycastle HmacSHA1算法摘要:"+data3.toString());
    		System.out.println("Bouncycastle HmacSHA1算法摘要HEX:"+datahex3);
    		System.out.println();
    		
    		
    		//初始化密钥
    		byte[] key4=HAMC.initHmacSHA384Key();
    		
    		//获取摘要信息
    		byte[] data4=HAMC.encodeHmacSHA384(str.getBytes(), key4);
    		String datahex4=new String(Hex.encode(data4));
    		System.out.println("Bouncycastle HmacSHA384的密钥:"+key4.toString());
    		System.out.println("Bouncycastle HmacSHA384算法摘要:"+data4.toString());
    		System.out.println("Bouncycastle HmacSHA384算法摘要HEX:"+datahex4);
    		System.out.println();
    		
    		
    		//初始化密钥
    		byte[] key5=HAMC.initHmacSHA512Key();
    		//获取摘要信息
    		byte[] data5=HAMC.encodeHmacSHA512(str.getBytes(), key5);
    		System.out.println("HmacSHA512的密钥:"+key5.toString());
    		System.out.println("HmacSHA512算法摘要:"+data5.toString());
    		System.out.println();
    		
    		System.out.println("================下面的算法支持是bouncycastle支持的算法,sun java6不支持=======================");
    		//初始化密钥
    		byte[] key6=HAMC.initHmacMD2Key();
    		//获取摘要信息
    		byte[] data6=HAMC.encodeHmacMD2(str.getBytes(), key6);
    		String datahex6=HAMC.encodeHmacMD2Hex(str.getBytes(), key6);
    		System.out.println("Bouncycastle HmacMD2的密钥:"+key6.toString());
    		System.out.println("Bouncycastle HmacMD2算法摘要:"+data6.toString());
    		System.out.println("Bouncycastle HmacMD2Hex算法摘要:"+datahex6.toString());
    		System.out.println();
    		
    		//初始化密钥
    		byte[] key7=HAMC.initHmacMD4Key();
    		//获取摘要信息
    		byte[] data7=HAMC.encodeHmacMD4(str.getBytes(), key7);
    		String datahex7=HAMC.encodeHmacMD4Hex(str.getBytes(), key7);
    		System.out.println("Bouncycastle HmacMD4的密钥:"+key7.toString());
    		System.out.println("Bouncycastle HmacMD4算法摘要:"+data7.toString());
    		System.out.println("Bouncycastle HmacMD4Hex算法摘要:"+datahex7.toString());
    		System.out.println();
    		
    		//初始化密钥
    		byte[] key8=HAMC.initHmacSHA224Key();
    		//获取摘要信息
    		byte[] data8=HAMC.encodeHmacSHA224(str.getBytes(), key8);
    		String datahex8=HAMC.encodeHmacSHA224Hex(str.getBytes(), key8);
    		System.out.println("Bouncycastle HmacSHA224的密钥:"+key8.toString());
    		System.out.println("Bouncycastle HmacSHA224算法摘要:"+data8.toString());
    		System.out.println("Bouncycastle HmacSHA224算法摘要:"+datahex8.toString());
    		System.out.println();
    	}
    }
    
    运行结果是
    原文:123000000000090989999999999999999999999999999999999999999999999999999999999999999999111230000000000909899999999999999999999999999999999999999999999999999999999999999999992300000000009098999999999999999999999999999999999999999999999999999999999999999999923000000000090989999999999999999999999999999999999999999999999999999999999999999999230000000000909899999999999999999999999999999999999999999999999999999999999999999992300000000009098999999999999999999999999999999999999999999999999999999999999999999923000000000090989999999999999999999999999999999999999999999999999999999999999999999230000000000909899999999999999999999999999999999999999999999999999999999999999999992300000000009098999999999999999999999999999999999999999999999999999999999999999999923000000000090989999999999999999999999999999999999999999999999999999999999999999999230000000000909899999999999999999999999999999999999999999999999999999999999999999992300000000009098999999999999999999999999999999999999999999999999999999999999999999923000000000090989999999999999999999999999999999999999999999999999999999999999999999230000000000909899999999999999999999999999999999999999999999999999999999999999999992300000000009098999999999999999999999999999999999999999999999999999999999999999999923000000000090989999999999999999999999999999999999999999999999999999999999999999999230000000000909899999999999999999999999999999999999999999999999999999999999999999991
    
    Bouncycastle HmacMD5的密钥内容和长度:[B@2fb212f0--64
    Bouncycastle HmacMD5算法摘要:[B@53f96306
    Bouncycastle HmacMD5算法摘要HEX:771093e83aeb659d125100fa465bd34e
    
    Bouncycastle HmacSHA256的密钥:[B@450b9338
    Bouncycastle HmacSHA256算法摘要:[B@7aee64f1
    Bouncycastle HmacSHA256算法摘要HEX:2d211a42cb3fb68cd36255f9af4ef614eea6c8b93634183d333bf3e6e0b79d87
    
    Bouncycastle HmacSHA1的密钥:[B@592bf469
    Bouncycastle HmacSHA1算法摘要:[B@54bb473b
    Bouncycastle HmacSHA1算法摘要HEX:c07963727b485cf6579d103a822382f3159bc6ee
    
    Bouncycastle HmacSHA384的密钥:[B@1527171d
    Bouncycastle HmacSHA384算法摘要:[B@395e7bc4
    Bouncycastle HmacSHA384算法摘要HEX:cae75e5a2ce20d18bf0862215896f8dbe060ac10806925fa5d2bb15cc983543a1d0e53743f1e84ee53ad7db128547cde
    
    HmacSHA512的密钥:[B@5689a400
    HmacSHA512算法摘要:[B@666e2862
    
    ================下面的算法支持是bouncycastle支持的算法,sun java6不支持=======================
    Bouncycastle HmacMD2的密钥:[B@fca1ca
    Bouncycastle HmacMD2算法摘要:[B@49e1d547
    Bouncycastle HmacMD2Hex算法摘要:2fad1ddef0a1d4d9e7bed45c4b714ae5
    
    Bouncycastle HmacMD4的密钥:[B@2ebaa4a4
    Bouncycastle HmacMD4算法摘要:[B@5f8f22f3
    Bouncycastle HmacMD4Hex算法摘要:3f41ccbf594e0170f7073e8c756aa039
    
    Bouncycastle HmacSHA224的密钥:[B@100a384
    Bouncycastle HmacSHA224算法摘要:[B@50ef2f9f
    Bouncycastle HmacSHA224算法摘要:f7d0e74f5c965f7981155206c05deccf0867e9cf348a1e9569b07353
    
     运行结论是

    HMAC的特点,随意的消息大小;固定的输出长度。

    HmacMD5算法摘要HEX:771093e83aeb659d125100fa465bd34e//32*4=128位
    Bouncycastle HmacSHA1算法摘要HEX:c07963727b485cf6579d103a822382f3159bc6ee//40*4=160位
    Bouncycastle HmacSHA256算法摘要HEX:2d211a42cb3fb68cd36255f9af4ef614eea6c8b93634183d333bf3e6e0b79d87//64*4=256


    还有个问题就是,我们在使用HMAC的时候使用了hash函数而且增加了密钥key,那么这个key是怎么增加进去的?

    A=[msg || key]还是B=[key || msg],前缀和后缀的做法,前缀不可缺,有前缀的攻击。參考《深入浅出password学——经常使用加密技术原理与应用》马小婷的,后缀也有一种构建冲突攻击參考《深入浅出password学——经常使用加密技术原理与应用》马小婷

    HMAC方案是由一个内部哈希和一个外部哈希组成,他是Mihir Bellare、Ran Canetti和Hugo Krawczyk于1996年提出的。

    最大的一个有点就是存在安全证明。


    ------------------------------------------结束线----------------------------------------------------------------------------


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  • 原文地址:https://www.cnblogs.com/mqxnongmin/p/10699732.html
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