package com.laoer.bbscs.tool;/** * Title:        BBS-CS * Description:  BBS-CS(BBS式虛擬社區系統) * Copyright:    Copyright (c) 2002 * Company:      loveroom.com.cn * @author laoer * @version 3.0 */import java.lang.reflect.*;/*************************************************md5 類實現了RSA Data Security, Inc.在提交給IETF的RFC1321中的MD5 message-digest 算法。*************************************************/public class MD5 {	/* 下面這些S11-S44實際上是一個4*4的矩陣，在原始的C實現中是用#define 實現的，	這里把它們實現成為static final是表示了只讀，切能在同一個進程空間內的多個	Instance間共享*/        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 };        /* 下面的三個成員是MD5計算過程中用到的3個核心數據，在原始的C實現中           被定義到MD5_CTX結構中         */        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的唯一一個公共成員，是最新一次計算結果的	　 16進制ASCII表示.	*/        public String digestHexStr;        /* digest,是最新一次計算結果的2進制內部表示，表示128bit的MD5值.	*/        private byte[] digest = new byte[16];	/*	  getMD5ofStr是類MD5最主要的公共方法，入口參數是你想要進行MD5變換的字符串	  返回的是變換完的結果，這個結果是從公共成員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;        }        // 這是MD5這個類的標準構造函數，JavaBean要求有一個public的并且沒有參數的構造函數        public MD5() {                md5Init();                return;        }        /* md5Init是一個初始化函數，初始化核心變量，裝入標準的幻數 */        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個基本的MD5函數，在原始的MD5的C實現中，由于它們是        簡單的位運算，可能出于效率的考慮把它們實現成了宏，在java中，我們把它們     　　實現成了private方法，名字保持了原來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將調用F,G,H,I進行近一步變換          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的主計算過程，inbuf是要變換的字節串，inputlen是長度，這個         函數由getMD5ofStr調用，調用之前需要調用md5init，因此把它設計成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整理和填寫輸出結果        */        private void md5Final () {