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 */
/*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;
import java.lang.reflect.*;
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;
/* 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;
}