MD5算法的java实现类

作者：hxq 2012-3-31

开始吧！！！！！！！！！！！！！！！！！！！！！！

package cn.jbit.security;

public class MD5

{

public MD5(Object ob)

{

this();

Update(ob.toString());

}

public MD5()

{

Init();

}

private int[] Decode(byte buffer[], int len, int shift)

{

int out[] = new int[16];

int j;

int i = j = 0;

for(; j < len; j += 4)

{

out[i] = buffer[j + shift] & 0xff | (buffer[j + 1 + shift] & 0xff) << 8 | (buffer[j + 2 + shift] & 0xff) << 16 | (buffer[j + 3 + shift] & 0xff) << 24;

i++;

}

return out;

}

private byte[] Encode(int input[], int len)

{

byte out[] = new byte[len];

int j;

int i = j = 0;

for(; j < len; j += 4)

{

out[j] = (byte)(input[i] & 0xff);

out[j + 1] = (byte)(input[i] >>> 8 & 0xff);

out[j + 2] = (byte)(input[i] >>> 16 & 0xff);

out[j + 3] = (byte)(input[i] >>> 24 & 0xff);

i++;

}

return out;

}

private int FF(int a, int b, int c, int d, int x, int s, int ac)

{

a = uadd(a, b & c | ~b & d, x, ac);

return uadd(rotate_left(a, s), b);

}

public synchronized byte[] Final()

{

if(finals == null)

{

MD5State fin = new MD5State(state);

byte bits[] = Encode(fin.count, 8);

int index = fin.count[0] >>> 3 & 0x3f;

int padlen = index >= 56 ? 120 - index : 56 - index; Update(fin, padding, 0, padlen);

Update(fin, bits, 0, 8);

finals = fin;

}

return Encode(finals.state, 16);

}

private int GG(int a, int b, int c, int d, int x, int s, int ac)

{

a = uadd(a, b & d | c & ~d, x, ac);

return uadd(rotate_left(a, s), b);

}

private int HH(int a, int b, int c, int d, int x, int s, int ac)

{

a = uadd(a, b ^ c ^ d, x, ac);

return uadd(rotate_left(a, s), b);

}

private int II(int a, int b, int c, int d, int x, int s, int ac)

{

a = uadd(a, c ^ (b | ~d), x, ac);

return uadd(rotate_left(a, s), b);

}

public synchronized void Init()

{

state = new MD5State();

finals = null;

}

private void Transform(MD5State state, byte buffer[], int shift) {

int a = state.state[0];

int b = state.state[1];

int c = state.state[2];

int d = state.state[3];

int x[] = Decode(buffer, 64, shift);

a = FF(a, b, c, d, x[0], 7, 0xd76aa478);

d = FF(d, a, b, c, x[1], 12, 0xe8c7b756);

c = FF(c, d, a, b, x[2], 17, 0x242070db);

b = FF(b, c, d, a, x[3], 22, 0xc1bdceee);

a = FF(a, b, c, d, x[4], 7, 0xf57c0faf);

d = FF(d, a, b, c, x[5], 12, 0x4787c62a);

c = FF(c, d, a, b, x[6], 17, 0xa8304613);

b = FF(b, c, d, a, x[7], 22, 0xfd469501);

a = FF(a, b, c, d, x[8], 7, 0x698098d8);

d = FF(d, a, b, c, x[9], 12, 0x8b44f7af);

c = FF(c, d, a, b, x[10], 17, -42063);

b = FF(b, c, d, a, x[11], 22, 0x895cd7be);

a = FF(a, b, c, d, x[12], 7, 0x6b901122);

d = FF(d, a, b, c, x[13], 12, 0xfd987193);

c = FF(c, d, a, b, x[14], 17, 0xa679438e);

b = FF(b, c, d, a, x[15], 22, 0x49b40821);

a = GG(a, b, c, d, x[1], 5, 0xf61e2562);

d = GG(d, a, b, c, x[6], 9, 0xc040b340);

c = GG(c, d, a, b, x[11], 14, 0x265e5a51);

b = GG(b, c, d, a, x[0], 20, 0xe9b6c7aa);

a = GG(a, b, c, d, x[5], 5, 0xd62f105d);

d = GG(d, a, b, c, x[10], 9, 0x2441453);

c = GG(c, d, a, b, x[15], 14, 0xd8a1e681);

b = GG(b, c, d, a, x[4], 20, 0xe7d3fbc8);

a = GG(a, b, c, d, x[9], 5, 0x21e1cde6);

d = GG(d, a, b, c, x[14], 9, 0xc33707d6);

c = GG(c, d, a, b, x[3], 14, 0xf4d50d87);

b = GG(b, c, d, a, x[8], 20, 0x455a14ed);

a = GG(a, b, c, d, x[13], 5, 0xa9e3e905);

d = GG(d, a, b, c, x[2], 9, 0xfcefa3f8);

c = GG(c, d, a, b, x[7], 14, 0x676f02d9);

b = GG(b, c, d, a, x[12], 20, 0x8d2a4c8a);

a = HH(a, b, c, d, x[5], 4, 0xfffa3942);

d = HH(d, a, b, c, x[8], 11, 0x8771f681);

c = HH(c, d, a, b, x[11], 16, 0x6d9d6122);

b = HH(b, c, d, a, x[14], 23, 0xfde5380c);

a = HH(a, b, c, d, x[1], 4, 0xa4beea44);

d = HH(d, a, b, c, x[4], 11, 0x4bdecfa9);

c = HH(c, d, a, b, x[7], 16, 0xf6bb4b60);

b = HH(b, c, d, a, x[10], 23, 0xbebfbc70);

a = HH(a, b, c, d, x[13], 4, 0x289b7ec6);

d = HH(d, a, b, c, x[0], 11, 0xeaa127fa);

c = HH(c, d, a, b, x[3], 16, 0xd4ef3085);

b = HH(b, c, d, a, x[6], 23, 0x4881d05);

a = HH(a, b, c, d, x[9], 4, 0xd9d4d039);

d = HH(d, a, b, c, x[12], 11, 0xe6db99e5);

c = HH(c, d, a, b, x[15], 16, 0x1fa27cf8);

b = HH(b, c, d, a, x[2], 23, 0xc4ac5665);

a = II(a, b, c, d, x[0], 6, 0xf4292244);

d = II(d, a, b, c, x[7], 10, 0x432aff97);

c = II(c, d, a, b, x[14], 15, 0xab9423a7);

b = II(b, c, d, a, x[5], 21, 0xfc93a039);

a = II(a, b, c, d, x[12], 6, 0x655b59c3);

d = II(d, a, b, c, x[3], 10, 0x8f0ccc92);

c = II(c, d, a, b, x[10], 15, 0xffeff47d);

b = II(b, c, d, a, x[1], 21, 0x85845dd1);

a = II(a, b, c, d, x[8], 6, 0x6fa87e4f);

d = II(d, a, b, c, x[15], 10, 0xfe2ce6e0);

c = II(c, d, a, b, x[6], 15, 0xa3014314);

b = II(b, c, d, a, x[13], 21, 0x4e0811a1);

a = II(a, b, c, d, x[4], 6, 0xf7537e82);

d = II(d, a, b, c, x[11], 10, 0xbd3af235);

c = II(c, d, a, b, x[2], 15, 0x2ad7d2bb);

b = II(b, c, d, a, x[9], 21, 0xeb86d391);

state.state[0] += a;

state.state[1] += b;

state.state[2] += c;

state.state[3] += d;

}

public void Update(String s)

{

byte ch …… 此处隐藏：5334字，全部文档内容请下载后查看。喜欢就下载吧 ……