/** *//************************************************
MD5 算法的Java Bean@author:Topcat TuppinLast Modified:10,Mar,2001
*************************************************/
package com.shop.bean;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， 這裏把它們實現成爲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的並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，由於它們是 簡單的位運算，可能出於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 () ...{ 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是一個內部使用的byte數組的塊拷貝函數，從input的inpos開始把len長度的 字節拷貝到output的outpos位置開始 */ 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核心變換程序，有md5Update調用，block是分塊的原始字節 */ 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數組按順序拆成byte數組，因爲java的long類型是64bit的， 只拆低32bit，以適應原始C實現的用途 */ 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數組按順序合成成long數組，因爲java的long類型是64bit的， 只合成低32bit，高32bit清零，以適應原始C實現的用途 */ 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是我寫的一個把byte按照不考慮正負號的原則的＂升位＂程序，因爲java沒有unsigned運算 */ public static long b2iu(byte b) ...{ return b < 0 ? b & 0x7F + 128 : b; } /**//*byteHEX()，用來把一個byte類型的數轉換成十六進制的ASCII表示， 因爲java中的byte的toString無法實現這一點，我們又沒有C語言中的 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; } public static void main(String args[]) ...{ MD5 m = new MD5(); if (Array.getLength(args) == 0) ...{ //如果沒有參數，執行標準的Test Suite System.out.println("MD5 Test suite:"); System.out.println("MD5(""):"+m.getMD5ofStr("")); System.out.println("MD5("a"):"+m.getMD5ofStr("a")); System.out.println("MD5("abc"):"+m.getMD5ofStr("abc")); System.out.println("MD5("message digest"):"+m.getMD5ofStr("message digest")); System.out.println("MD5("abcdefghijklmnopqrstuvwxyz"):"+ m.getMD5ofStr("abcdefghijklmnopqrstuvwxyz")); System.out.println("MD5("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"):"+ m.getMD5ofStr("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")); } else System.out.println("MD5(" + args[0] + ")=" + m.getMD5ofStr(args[0])); }}下面還有第二種方法，可以調用JDK，比較簡單：
代碼如下 ：
package md5;import java.security.MessageDigest; public class Md5 ...{ private final static String[] hexDigits = ...{"0","1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"}; /** *//** * 轉換字節數組爲16進制字串 * @param b 字節數組 * @return 16進制字串 */ public String byteArrayToHexString(byte[] b) ...{ StringBuffer resultSb = new StringBuffer(); for (int i = 0; i < b.length; i++) ...{ resultSb.append(byteToHexString(b[i])); } return resultSb.toString(); } private String byteToHexString(byte b) ...{ int n = b; if (n < 0) n = 256 + n; int d1 = n / 16; int d2 = n % 16; return hexDigits[d1] + hexDigits[d2]; } public String MD5Encode(String origin) ...{ String resultString = null; try ...{ resultString=new String(origin); MessageDigest md = MessageDigest.getInstance("MD5"); resultString=byteArrayToHexString(md.digest(resultString.getBytes())); } catch (Exception ex) ...{ } return resultString; } public static void main(String[] args)...{ System.err.println(new Md5().MD5Encode("abc")); } /**//* * 在RFC 1321中，給出了Test suite用來檢驗你的實現是否正確：MD5 ('') = d41d8cd98f00b204e9800998ecf8427eMD5 ('a') = 0cc175b9c0f1b6a831c399e269772661MD5 ('abc') = 900150983cd24fb0d6963f7d28e17f72MD5 ('message digest') = f96b697d7cb7938d525a2f31aaf161d0MD5 ('abcdefghijklmnopqrstuvwxyz') = c3fcd3d76192e4007dfb496cca67e13b * */}