md5_encoding.java

张新曼 精通JSP Web 开发技术与典型应用 随书光盘源码

package ch22;

import java.lang.reflect.*;

/***
 * 
 * @author Administrator
 *
 * MD5数据加密
 */

public class MD5_Encoding {
	
	 //  一个4*4矩阵,且是只读的
	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 };
	   
	// MD5计算过程中的3个核心数据  
	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
	    
	// 最新一次计算结果的16进制ASCII表示
    public String digestHexStr;
	    
    // 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];
	    
	// MD5最主要的公共方法，进行数据加密变换
	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;
    }
    
	// Bean标准构造函数
	public MD5_Encoding() {
		
	    md5Init();
        return;
    }
	    
	// 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;
	    state[0] = 0x67452301L;
	    state[1] = 0xefcdab89L;
	    state[2] = 0x98badcfeL;
	    state[3] = 0x10325476L;
        return;
	}
	    
	// 4个基本的MD5函数,简单的位运算
	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进行进一步变换
	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;
	}
	    
	// MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度
	private void md5Update(byte[] inbuf, int inputLen) {
	    int i, index, partLen;
	    byte[] block = new byte[64];
	    index = (int)(count[0] >>> 3) & 0x3F;
	    if ((count[0] += (inputLen << 3)) < (inputLen << 3))
	          count[1]++;
	    count[1] += (inputLen >>> 29);
	    partLen = 64 - index;
        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;
	    md5Memcpy(buffer, inbuf, index, i, inputLen - i);
    }
	    
	// 整理和填写输出结果
	private void md5Final () {
		
	    byte[] bits = new byte[8];
	    int index, padLen;
	    Encode (bits, count, 8);
	    index = (int)(count[0] >>> 3) & 0x3f;
	    padLen = (index < 56) ? (56 - index) : (120 - index);
	    md5Update (PADDING, padLen);
	    md5Update(bits, 8);
        Encode (digest, state, 16);
	}
	      
	// byte数组的块拷贝函数
    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];
	}
	    
	//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;
	}
	    
	// 把long数组按顺序拆成byte数组
	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);
	    }
	}

	// 把byte数组按顺序合成成long数组
	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;
	}
	    
	// 把byte转换为不考虑正负号的＂升位＂程序
	public static long b2iu(byte b) {
	    return b < 0 ? b & 0x7F + 128 : b;
	}
	    
	// 把byte类型的数转换成十六进制的ASCII表示
	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;
	}
}