
/** *//************************************************
MD5 算法的Java Bean
@author:Topcat Tuppin
Last Modified:10,Mar,2001
*************************************************/
package org.waityou.news.util;

import java.lang.reflect.*;


/** *//*******************************************************************************
* 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 MD5
{

/**//*
* 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 MD5()
{
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;
}


public static void main(String args[])
{

MD5 m = new MD5();

if (Array.getLength(args) == 0)
{ //如果没有参数,执行标准的Test Suite

System.out.println("MD5 Test suite:");
System.out.println("MD5(\"850817\"):" + m.getMD5ofStr("850817"));
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]));

}

}