MD5Code密码加密的使用方式

刺骨的言语ヽ痛彻心扉 2022-01-29 15:11 264阅读 0赞

**第一步：准备MD5工具包**

首先要有MD5Code.java的工具类，如果没有的话把代码放在下面，复制过去创建类即可：

复制如下代码直接在工具包下粘贴即可创建 MD5Code.java类

public class MD5Code {
    	/*
    	 * 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的， 这里把它们实现成为static
    	 * final是表示了只读，切能在同一个进程空间内的多个 Instance间共享
    	 */
    static final int S11 = 7;
    
    static final int S12 = 12;
    
    static final int S13 = 17;
    
    static final int S14 = 22;
    
    static final int S21 = 5;
    
    static final int S22 = 9;
    
    static final int S23 = 14;
    
    static final int S24 = 20;
    
    static final int S31 = 4;
    
    static final int S32 = 11;
    
    static final int S33 = 16;
    
    static final int S34 = 23;
    
    static final int S41 = 6;
    
    static final int S42 = 10;
    
    static final int S43 = 15;
    
    static final int S44 = 21;
    
    static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    		0, 0, 0, 0, 0, 0, 0 };
    
    /*
     * 下面的三个成员是MD5计算过程中用到的3个核心数据，在原始的C实现中 被定义到MD5_CTX结构中
     */
    private long[] state = new long[4];// state (ABCD)
    
    private long[] count = new long[2];// number of bits, modulo 2^64 (lsb
    
    // first)
    
    private byte[] buffer = new byte[64]; // input buffer
    
    /*
     * digestHexStr是MD5的唯一一个公共成员，是最新一次计算结果的 16进制ASCII表示.
     */
    
    public String digestHexStr;
    
    /*
     * digest,是最新一次计算结果的2进制内部表示，表示128bit的MD5值.
     */
    private byte[] digest = new byte[16];
    
    /*
     * getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串
     * 返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
     */
    public String getMD5ofStr(String inbuf) {
    	md5Init();
    	md5Update(inbuf.getBytes(), inbuf.length());
    	md5Final();
    	digestHexStr = "";
    	for (int i = 0; i < 16; i++) {
    		digestHexStr += byteHEX(digest[i]);
    	}
    	return digestHexStr;
    }
    
    // 这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数
    public MD5Code() {
    	md5Init();
    	return;
    }
    
    /* md5Init是一个初始化函数，初始化核心变量，装入标准的幻数 */
    private void md5Init() {
    	count[0] = 0L;
    	count[1] = 0L;
    	// /* Load magic initialization constants.
    	state[0] = 0x67452301L;
    	state[1] = 0xefcdab89L;
    	state[2] = 0x98badcfeL;
    	state[3] = 0x10325476L;
    	return;
    }
    
    /*
     * F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是
     * 简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们 实现成了private方法，名字保持了原来C中的。
     */
    private long F(long x, long y, long z) {
    	return (x & y) | ((~x) & z);
    }
    
    private long G(long x, long y, long z) {
    	return (x & z) | (y & (~z));
    }
    
    private long H(long x, long y, long z) {
    	return x ^ y ^ z;
    }
    
    private long I(long x, long y, long z) {
    	return y ^ (x | (~z));
    }
    
    /*
     * FF,GG,HH和II将调用F,G,H,I进行近一步变换 FF, GG, HH, and II transformations for
     * rounds 1, 2, 3, and 4. Rotation is separate from addition to prevent
     * recomputation.
     */
    private long FF(long a, long b, long c, long d, long x, long s, long ac) {
    	a += F(b, c, d) + x + ac;
    	a = ((int) a << s) | ((int) a >>> (32 - s));
    	a += b;
    	return a;
    }
    
    private long GG(long a, long b, long c, long d, long x, long s, long ac) {
    	a += G(b, c, d) + x + ac;
    	a = ((int) a << s) | ((int) a >>> (32 - s));
    	a += b;
    	return a;
    }
    
    private long HH(long a, long b, long c, long d, long x, long s, long ac) {
    	a += H(b, c, d) + x + ac;
    	a = ((int) a << s) | ((int) a >>> (32 - s));
    	a += b;
    	return a;
    }
    
    private long II(long a, long b, long c, long d, long x, long s, long ac) {
    	a += I(b, c, d) + x + ac;
    	a = ((int) a << s) | ((int) a >>> (32 - s));
    	a += b;
    	return a;
    }
    
    /*
     * md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
     * 函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private的
     */
    private void md5Update(byte[] inbuf, int inputLen) {
    	int i, index, partLen;
    	byte[] block = new byte[64];
    	index = (int) (count[0] >>> 3) & 0x3F;
    	// /* Update number of bits */
    	if ((count[0] += (inputLen << 3)) < (inputLen << 3))
    		count[1]++;
    	count[1] += (inputLen >>> 29);
    	partLen = 64 - index;
    	// Transform as many times as possible.
    	if (inputLen >= partLen) {
    		md5Memcpy(buffer, inbuf, index, 0, partLen);
    		md5Transform(buffer);
    		for (i = partLen; i + 63 < inputLen; i += 64) {
    			md5Memcpy(block, inbuf, 0, i, 64);
    			md5Transform(block);
    		}
    		index = 0;
    	} else
    		i = 0;
    	// /* Buffer remaining input */
    	md5Memcpy(buffer, inbuf, index, i, inputLen - i);
    }
    
    /*
     * md5Final整理和填写输出结果
     */
    private void md5Final() {
    	byte[] bits = new byte[8];
    	int index, padLen;
    	// /* Save number of bits */
    	Encode(bits, count, 8);
    	// /* Pad out to 56 mod 64.
    	index = (int) (count[0] >>> 3) & 0x3f;
    	padLen = (index < 56) ? (56 - index) : (120 - index);
    	md5Update(PADDING, padLen);
    	// /* Append length (before padding) */
    	md5Update(bits, 8);
    	// /* Store state in digest */
    	Encode(digest, state, 16);
    }
    
    /*
     * md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
     * 字节拷贝到output的outpos位置开始
     */
    private void md5Memcpy(byte[] output, byte[] input, int outpos, int inpos,
    		int len) {
    	int i;
    	for (i = 0; i < len; i++)
    		output[outpos + i] = input[inpos + i];
    }
    
    /*
     * md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
     */
    private void md5Transform(byte block[]) {
    	long a = state[0], b = state[1], c = state[2], d = state[3];
    	long[] x = new long[16];
    	Decode(x, block, 64);
    	/* Round 1 */
    	a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
    	d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
    	c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
    	b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
    	a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
    	d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
    	c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
    	b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
    	a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
    	d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
    	c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
    	b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
    	a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
    	d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
    	c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
    	b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */
    	/* Round 2 */
    	a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
    	d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
    	c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
    	b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
    	a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
    	d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
    	c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
    	b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
    	a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
    	d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
    	c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
    	b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
    	a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
    	d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
    	c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
    	b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */
    	/* Round 3 */
    	a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
    	d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
    	c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
    	b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
    	a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
    	d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
    	c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
    	b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
    	a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
    	d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
    	c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
    	b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
    	a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
    	d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
    	c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
    	b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */
    	/* Round 4 */
    	a = II(a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
    	d = II(d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
    	c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
    	b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
    	a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
    	d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
    	c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
    	b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
    	a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
    	d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
    	c = II(c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
    	b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
    	a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
    	d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
    	c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
    	b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */
    	state[0] += a;
    	state[1] += b;
    	state[2] += c;
    	state[3] += d;
    }
    
    /*
     * Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的， 只拆低32bit，以适应原始C实现的用途
     */
    private void Encode(byte[] output, long[] input, int len) {
    	int i, j;
    	for (i = 0, j = 0; j < len; i++, j += 4) {
    		output[j] = (byte) (input[i] & 0xffL);
    		output[j + 1] = (byte) ((input[i] >>> 8) & 0xffL);
    		output[j + 2] = (byte) ((input[i] >>> 16) & 0xffL);
    		output[j + 3] = (byte) ((input[i] >>> 24) & 0xffL);
    	}
    }
    
    /*
     * Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
     * 只合成低32bit，高32bit清零，以适应原始C实现的用途
     */
    private void Decode(long[] output, byte[] input, int len) {
    	int i, j;
    	for (i = 0, j = 0; j < len; i++, j += 4)
    		output[i] = b2iu(input[j]) | (b2iu(input[j + 1]) << 8)
    				| (b2iu(input[j + 2]) << 16) | (b2iu(input[j + 3]) << 24);
    	return;
    }
    
    /*
     * b2iu是我写的一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
     */
    public static long b2iu(byte b) {
    	return b < 0 ? b & 0x7F + 128 : b;
    }
    
    /*
     * byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
     * 因为java中的byte的toString无法实现这一点，我们又没有C语言中的 sprintf(outbuf,"%02X",ib)
     */
    public static String byteHEX(byte ib) {
    	char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A',
    			'B', 'C', 'D', 'E', 'F' };
    	char[] ob = new char[2];
    	ob[0] = Digit[(ib >>> 4) & 0X0F];
    	ob[1] = Digit[ib & 0X0F];
    	String s = new String(ob);
    	return s;
    }

**第二步：使用这个工具包**

使用方式：

MD5Code m = new MD5Code();

m.getMD5ofStr(“这里传入要加密的密码”)

这样就可以实现MD5加密了，是不是很简单呢？

如下为示例代码：

public class testMD5 {
    	public static void main(String[] args) {
    		MD5Code m  = new MD5Code();
    		System.out.println(m.getMD5ofStr("xihaibin"));
    	}
    }

执行结果为：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW5nMTUwMTE0_size_16_color_FFFFFF_t_70]

原文：[https://blog.csdn.net/xi\_haibin/article/details/82889005][https_blog.csdn.net_xi_haibin_article_details_82889005]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW5nMTUwMTE0_size_16_color_FFFFFF_t_70]: /images/20220129/3dd4a9d8575941459763738cf604e7a2.png
[https_blog.csdn.net_xi_haibin_article_details_82889005]: https://blog.csdn.net/xi_haibin/article/details/82889005