VC++对字符串进行加密的MD5String和获取文件MD5值的MD5File函数的封装（附源码）
MD5在软件中使用比较多的一种加密方式，比如我们有时需要对字符串进行加密（获取字符串的MD5值），有时我们需要去获取文件的MD5值。我们需要在公开的MD5类的基础上封装加密字符串的MD5String和获取文件MD5值的MD5File，本文给出相关的代码，可以直接拿去使用。
1、MD5类的实现
网上有完整的处理MD5值的类，在此处给出来，可以直接将头文件和源文件拿到项目中使用。MD5类的头文件如下：
/
// MD5.cpp
// Implementation file for MD5 class
//
// This C++ Class implementation of the original RSA Data Security, Inc.
// MD5 Message-Digest Algorithm is copyright (c) 2002, Gary McNickle.
// All rights reserved. This software is a derivative of the "RSA Data
// Security, Inc. MD5 Message-Digest Algorithm"
//
// You may use this software free of any charge, but without any
// warranty or implied warranty, provided that you follow the terms
// of the original RSA copyright, listed below.
//
// Original RSA Data Security, Inc. Copyright notice
/
//
// Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
// rights reserved.
//
// License to copy and use this software is granted provided that it
// is identified as the "RSA Data Security, Inc. MD5 Message-Digest
// Algorithm" in all material mentioning or referencing this software
// or this function.
// License is also granted to make and use derivative works provided
// that such works are identified as "derived from the RSA Data
// Security, Inc. MD5 Message-Digest Algorithm" in all material
// mentioning or referencing the derived work.
// RSA Data Security, Inc. makes no representations concerning either
// the merchantability of this software or the suitability of this
// software for any particular purpose. It is provided "as is"
// without express or implied warranty of any kind.
// These notices must be retained in any copies of any part of this
// documentation and/or software.
/
#ifndef _MD5_H_
#define _MD5_H_
typedef unsigned int uint4;
typedef unsigned short int uint2;
typedef unsigned char uchar;
CString PrintMD5( uchar md5Digest[16] );
class MD5
{
// Methods
public:
MD5() { Init(); }
void Init();
void Update( uchar* chInput, uint4 nInputLen );
void Finalize();
uchar* Digest() { return m_Digest; }
private:
void Transform( uchar* block );
void Encode( uchar* dest, uint4* src, uint4 nLength );
void Decode( uint4* dest, uchar* src, uint4 nLength );
inline uint4 rotate_left(uint4 x, uint4 n){ return ((x << n) | (x >> (32-n))); }
inline uint4 F1(uint4 x, uint4 y, uint4 z){ return ((x & y) | (~x & z)); }
inline uint4 G1(uint4 x, uint4 y, uint4 z){ return ((x & z) | (y & ~z)); }
inline uint4 H1(uint4 x, uint4 y, uint4 z){ return (x ^ y ^ z); }
inline uint4 I1(uint4 x, uint4 y, uint4 z){ return (y ^ (x | ~z)); }
inline void FFF(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += F1(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }
inline void GGG(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += G1(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }
inline void HHH(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += H1(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }
inline void III(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += I1(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }
// Data
private:
uint4 m_State[4];
uint4 m_Count[2];
uchar m_Buffer[64];
uchar m_Digest[16];
uchar m_Finalized;
};
#endifMD5类的cpp文件如下：
/
// MD5.cpp
// Implementation file for MD5 class
//
// This C++ Class implementation of the original RSA Data Security, Inc.
// MD5 Message-Digest Algorithm is copyright (c) 2002, Gary McNickle.
// All rights reserved. This software is a derivative of the "RSA Data
// Security, Inc. MD5 Message-Digest Algorithm"
//
// You may use this software free of any charge, but without any
// warranty or implied warranty, provided that you follow the terms
// of the original RSA copyright, listed below.
//
// Original RSA Data Security, Inc. Copyright notice
/
//
// Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
// rights reserved.
//
// License to copy and use this software is granted provided that it
// is identified as the "RSA Data Security, Inc. MD5 Message-Digest
// Algorithm" in all material mentioning or referencing this software
// or this function.
// License is also granted to make and use derivative works provided
// that such works are identified as "derived from the RSA Data
// Security, Inc. MD5 Message-Digest Algorithm" in all material
// mentioning or referencing the derived work.
// RSA Data Security, Inc. makes no representations concerning either
// the merchantability of this software or the suitability of this
// software for any particular purpose. It is provided "as is"
// without express or implied warranty of any kind.
// These notices must be retained in any copies of any part of this
// documentation and/or software.
/
#include "stdafx.h"
#include "md5.h"
static unsigned char PAD[64] =
{
0x80, 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
};
#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
CString CopyCharToCStringT( const char* pchSrc )
{
CString strDest = _T("");
if ( pchSrc == NULL )
{
return strDest;
}
#ifdef _UNICODE // 使用宽字节
{
// 考虑到该函数定义在公共模块，可能被多个线程调用，暂不使用缓存内存方式，直接使用new/delete
int nTmpLen = MultiByteToWideChar( CP_ACP, 0, pchSrc, -1, NULL, 0 );
WCHAR* pWTemp = new WCHAR[nTmpLen+1];
memset( pWTemp, 0, (nTmpLen+1)*sizeof(WCHAR) );
MultiByteToWideChar( CP_ACP, 0, pchSrc, -1, pWTemp, nTmpLen+1 );
strDest = pWTemp;
delete []pWTemp;
}
#else // 使用窄字节
{
strDest = pchSrc;
}
#endif
return strDest;
}
// PrintMD5: Converts a completed md5 digest into a char* string.
CString PrintMD5( uchar md5Digest[16] )
{
char chBuffer[256];
char chEach[10];
int nCount;
memset( chBuffer,0, 256 );
memset( chEach, 0, 10 );
for (nCount = 0; nCount < 16; nCount++ )
{
sprintf( chEach, "%02x", md5Digest[nCount] );
strncat( chBuffer, chEach, sizeof( chEach ) );
}
CString strMd5 = CopyCharToCStringT( chBuffer );
return strMd5;
}
// md5::Init
// Initializes a new context.
void MD5::Init()
{
memset( m_Count, 0, 2 * sizeof( uint4 ) );
m_State[0] = 0x67452301;
m_State[1] = 0xefcdab89;
m_State[2] = 0x98badcfe;
m_State[3] = 0x10325476;
}
// md5::Update
// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block, and updating the
// context.
void MD5::Update( uchar* chInput, uint4 nInputLen )
{
uint4 i, index, partLen;
// Compute number of bytes mod 64
index = ( unsigned int )(( m_Count[0] >> 3) & 0x3F );
// Update number of bits
if ((m_Count[0] += ( nInputLen << 3 )) < ( nInputLen << 3 ))
m_Count[1]++;
m_Count[1] += ( nInputLen >> 29 );
partLen = 64 - index;
// Transform as many times as possible.
if ( nInputLen >= partLen )
{
memcpy( &m_Buffer[index], chInput, partLen );
Transform( m_Buffer );
for ( i = partLen; i + 63 < nInputLen; i += 64 )
Transform( &chInput[i] );
index = 0;
}
else
i = 0;
// Buffer remaining input
memcpy( &m_Buffer[index], &chInput[i], nInputLen-i );
}
// md5::Finalize
// MD5 finalization. Ends an MD5 message-digest operation, writing
// the message digest and zeroizing the context.
void MD5::Finalize()
{
uchar bits[8];
uint4 index, padLen;
// Save number of bits
Encode( bits, m_Count, 8 );
// Pad out to 56 mod 64
index = ( unsigned int )(( m_Count[0] >> 3) & 0x3f );
padLen = ( index < 56) ? ( 56 - index ) : ( 120 - index );
Update( PAD, padLen );
// Append length (before padding)
Update (bits, 8);
// Store state in digest
Encode ( m_Digest, m_State, 16 );
memset( m_Count, 0, 2 * sizeof( uint4 ));
memset( m_State, 0, 4 * sizeof( uint4 ));
memset( m_Buffer, 0, 64 * sizeof( uchar ));
}
// md5::Transform
// MD5 basic transformation. Transforms state based on block.
void MD5::Transform ( uchar* block )
{
uint4 a = m_State[0], b = m_State[1], c = m_State[2], d = m_State[3], x[16];
Decode ( x, block, 64 );
// Round 1
FFF ( a, b, c, d, x[ 0], S11, 0xd76aa478 );
FFF ( d, a, b, c, x[ 1], S12, 0xe8c7b756 );
FFF ( c, d, a, b, x[ 2], S13, 0x242070db );
FFF ( b, c, d, a, x[ 3], S14, 0xc1bdceee );
FFF ( a, b, c, d, x[ 4], S11, 0xf57c0faf );
FFF ( d, a, b, c, x[ 5], S12, 0x4787c62a );
FFF ( c, d, a, b, x[ 6], S13, 0xa8304613 );
FFF ( b, c, d, a, x[ 7], S14, 0xfd469501 );
FFF ( a, b, c, d, x[ 8], S11, 0x698098d8 );
FFF ( d, a, b, c, x[ 9], S12, 0x8b44f7af );
FFF ( c, d, a, b, x[10], S13, 0xffff5bb1 );
FFF ( b, c, d, a, x[11], S14, 0x895cd7be );
FFF ( a, b, c, d, x[12], S11, 0x6b901122 );
FFF ( d, a, b, c, x[13], S12, 0xfd987193 );
FFF ( c, d, a, b, x[14], S13, 0xa679438e );
FFF ( b, c, d, a, x[15], S14, 0x49b40821 );
// Round 2
GGG ( a, b, c, d, x[ 1], S21, 0xf61e2562 );
GGG ( d, a, b, c, x[ 6], S22, 0xc040b340 );
GGG ( c, d, a, b, x[11], S23, 0x265e5a51 );
GGG ( b, c, d, a, x[ 0], S24, 0xe9b6c7aa );
GGG ( a, b, c, d, x[ 5], S21, 0xd62f105d );
GGG ( d, a, b, c, x[10], S22, 0x2441453 );
GGG ( c, d, a, b, x[15], S23, 0xd8a1e681 );
GGG ( b, c, d, a, x[ 4], S24, 0xe7d3fbc8 );
GGG ( a, b, c, d, x[ 9], S21, 0x21e1cde6 );
GGG ( d, a, b, c, x[14], S22, 0xc33707d6 );
GGG ( c, d, a, b, x[ 3], S23, 0xf4d50d87 );
GGG ( b, c, d, a, x[ 8], S24, 0x455a14ed );
GGG ( a, b, c, d, x[13], S21, 0xa9e3e905 );
GGG ( d, a, b, c, x[ 2], S22, 0xfcefa3f8 );
GGG ( c, d, a, b, x[ 7], S23, 0x676f02d9 );
GGG ( b, c, d, a, x[12], S24, 0x8d2a4c8a );
// Round 3
HHH ( a, b, c, d, x[ 5], S31, 0xfffa3942);
HHH ( d, a, b, c, x[ 8], S32, 0x8771f681);
HHH ( c, d, a, b, x[11], S33, 0x6d9d6122);
HHH ( b, c, d, a, x[14], S34, 0xfde5380c);
HHH ( a, b, c, d, x[ 1], S31, 0xa4beea44);
HHH ( d, a, b, c, x[ 4], S32, 0x4bdecfa9);
HHH ( c, d, a, b, x[ 7], S33, 0xf6bb4b60);
HHH ( b, c, d, a, x[10], S34, 0xbebfbc70);
HHH ( a, b, c, d, x[13], S31, 0x289b7ec6);
HHH ( d, a, b, c, x[ 0], S32, 0xeaa127fa);
HHH ( c, d, a, b, x[ 3], S33, 0xd4ef3085);
HHH ( b, c, d, a, x[ 6], S34, 0x4881d05);
HHH ( a, b, c, d, x[ 9], S31, 0xd9d4d039);
HHH ( d, a, b, c, x[12], S32, 0xe6db99e5);
HHH ( c, d, a, b, x[15], S33, 0x1fa27cf8);
HHH ( b, c, d, a, x[ 2], S34, 0xc4ac5665);
// Round 4
III ( a, b, c, d, x[ 0], S41, 0xf4292244 );
III ( d, a, b, c, x[ 7], S42, 0x432aff97 );
III ( c, d, a, b, x[14], S43, 0xab9423a7 );
III ( b, c, d, a, x[ 5], S44, 0xfc93a039 );
III ( a, b, c, d, x[12], S41, 0x655b59c3 );
III ( d, a, b, c, x[ 3], S42, 0x8f0ccc92 );
III ( c, d, a, b, x[10], S43, 0xffeff47d );
III ( b, c, d, a, x[ 1], S44, 0x85845dd1 );
III ( a, b, c, d, x[ 8], S41, 0x6fa87e4f );
III ( d, a, b, c, x[15], S42, 0xfe2ce6e0 );
III ( c, d, a, b, x[ 6], S43, 0xa3014314 );
III ( b, c, d, a, x[13], S44, 0x4e0811a1 );
III ( a, b, c, d, x[ 4], S41, 0xf7537e82 );
III ( d, a, b, c, x[11], S42, 0xbd3af235 );
III ( c, d, a, b, x[ 2], S43, 0x2ad7d2bb );
III ( b, c, d, a, x[ 9], S44, 0xeb86d391 );
m_State[0] += a;
m_State[1] += b;
m_State[2] += c;
m_State[3] += d;
memset( x, 0, sizeof( x ));
}
// md5::Encode
// Encodes input (uint4) into output (uchar). Assumes nLength is
// a multiple of 4.
void MD5::Encode( uchar* dest, uint4* src, uint4 nLength )
{
uint4 i, j;
assert( nLength % 4 == 0 );
for ( i = 0, j = 0; j < nLength; i++, j += 4 )
{
dest[j] = (uchar)( src[i] & 0xff );
dest[j+1] = (uchar)(( src[i] >> 8) & 0xff );
dest[j+2] = (uchar)(( src[i] >> 16) & 0xff );
dest[j+3] = (uchar)(( src[i] >> 24) & 0xff );
}
}
// md5::Decode
// Decodes input (uchar) into output (uint4). Assumes nLength is
// a multiple of 4.
void MD5::Decode( uint4* dest, uchar* src, uint4 nLength )
{
uint4 i, j;
assert( nLength % 4 == 0 );
for ( i = 0, j = 0; j < nLength; i++, j += 4 )
{
dest[i] = ((uint4)src[j]) | (((uint4)src[j+1])<<8) |
(((uint4)src[j+2])<<16) | (((uint4)src[j+3])<<24 );
}
}
2、加密字符串的MD5String函数的封装
加密字符串其实就是获取字符串的MD5值，比如我们需要对账号的密码进行加密，就可以使用MD5加密。MD5String函数的实现，就是将字符串数据设置到MD5类对象中，调用相关接口获取字符串的MD5值，MD5String的封装如下：
// MD5String: Performs the MD5 algorithm on a char* string, returning
// the results as a char*.
CString MD5String( char* szString )
{
int nLen = strlen( szString );
MD5 md5;
md5.Update( (unsigned char*)szString, (unsigned int)nLen );
md5.Finalize();
return PrintMD5( md5.Digest() );
}3、获取文件MD5值的MD5File函数的封装
有时我们需要获取文件的MD5值，通过判断文件的MD5值是否有变化，判断文件是否被修改或者文件是否被病毒篡改。获取MD5值的MD5File函数实现，是将文件中的内容读出来，将内容数据设置到MD5类对象中，然后调用相关的接口获取文件的MD5值，MD5File函数实现如下：
// MD5File: Performs the MD5 algorithm on a file (binar or text),
// returning the results as a char*. Returns NULL if it fails.
CUIString MD5File( TCHAR* szFilename )
{
CUIFile file;
MD5 md5;
int nLen;
int nLength;
unsigned char chBuffer[1024];
try
{
memset( chBuffer, 0, 1024 );
file = _tfopen(szFilename, _T("rb"));
if (file != NULL)
{
fseek(file, 0, SEEK_END);
nLength = ftell(file);
fseek(file, 0, SEEK_SET);
if ( nLength >= 1024 )
{
for( ; nLength >= 1024; )
{
nLen = fread(chBuffer, 1, 1024, file);
md5.Update( chBuffer, nLen );
nLength -= nLen;
if ( nLength < 1024 )
{
nLen = fread(chBuffer, 1, nLength, file);
md5.Update( chBuffer, nLen );
}
}
}
else
{
nLen = fread(chBuffer, 1, nLength, file);
md5.Update(chBuffer, nLen);
}
md5.Finalize();
fclose(file);
return PrintMD5( md5.Digest() );
}
}
catch(...)
{
}
return _T(""); // failed
}