MD5算法简介及编程实现

本文主要包含如下内容：MD5算法概述、处理步骤、编程实现以及安全性分析。

二．MD5算法的编程实现

HeaderFiles

MD5.H如下：

#pragma once

typedef unsigned long int UINT32;

typedef unsigned short int UINT16;

/* MD5 context. */

typedef struct {

UINT32 state[4]; /* state (ABCD) */ UINT32 count[2]; /* number of bits, modulo 2^64 (lsb first) */ unsigned char buffer[64]; /* input buffer */ } MD5_CTX;

void MD5Init (MD5_CTX *);

void MD5Update (MD5_CTX *, unsigned char *, unsigned int);

void MD5Final (unsigned char [16], MD5_CTX *);

SourceFiles

MD5.CPP如下：

#include "md5.h"

#include "memory.h"

#define S11 7

#define S12 12

#define S13 17

#define S14 22

#define S21 5

#define S22 9

#define S23 14

#define S24 20

#define S31 4

#define S32 11

#define S33 16

#define S34 23

#define S41 6

#define S42 10

#define S43 15

#define S44 21

static void MD5Transform (UINT32 a[4], unsigned char b[64]);

static void Encode (unsigned char *, UINT32 *, unsigned int);

static void Decode (UINT32 *, unsigned char *, unsigned int);