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/**
*********************************************** MD5 算法的Java Bean
*@author:Topcat Tuppin Last Modified:10,Mar,2001
*/
/** md5 类实现了RSA Data Security, Inc.在提交给IETF 的RFC1321中的MD5 message-digest 算法。 */
public class MD5Bean implements PassWord {
/* 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 S12 = 12;
static final int S11 = 7;
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 MD5Bean() {
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 = 0, j = 0;
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;
}
public String encode(String s) {
return s;
}
public String decode(String s) {
return getMD5ofStr(s);
}
public static void main(String args[]) {
CMd5Bean m = new CMd5Bean();
if (Array.getLength(args) == 0) { //如果没有参数，执行标准的Test Suite
m.getMD5ofStr("abcdefghijklmnopqrstuvwxyz");
m.getMD5ofStr("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
}
else
System.out.println("MD5(" + args[0] + ")=" + m.getMD5ofStr(args[0]));
}
*/
}
