Hello
Your code has one big problem :
It takes only a string as input.
No more compiler errors !
(And your code is written in MFC and is not usable without modifications in a project (e.g. bad error handling))
But if you need the MD5 of a file and the file is 3 Gigabyte of size you will not be able to load the file into a string !
For that you need an algorithm that is capable to calculate from multiple smaller blocks of the file.
I attach a reusable C++ class (without MFC) which performs this task with highest speed !
After you are ready destroy the MD5 class or call FreeBuffer();
Header :
___________________________________________________________
#if !defined(AFX_CMD5_H__6C2F7C61_93D8_11D8_A8BA_000AE637F271__INCLUDED_)
#define AFX_CMD5_H__6C2F7C61_93D8_11D8_A8BA_000AE637F271__INCLUDED_
#if _MSC_VER > 1000
#pragma once
#endif
#define _ReadBufSize 1000000
class cMD5
{
public:
char* CalcMD5FromString(const char *s8_Input);
char* CalcMD5FromFile (const char *s8_Path);
void FreeBuffer();
cMD5();
virtual ~cMD5();
private:
struct MD5Context
{
unsigned long buf[4];
unsigned long bits[2];
unsigned char in[64];
};
void MD5Init();
void MD5Update(unsigned char *buf, unsigned len);
void MD5Final (unsigned char digest[16]);
void MD5Transform(unsigned long buf[4], unsigned long in[16]);
char* MD5FinalToString();
void byteReverse (unsigned char *buf, unsigned longs);
char *mp_s8ReadBuffer;
MD5Context ctx;
char ms8_MD5[40]; };
#endif
_______________________________________________________
and the cpp file :
________________________________________________________
#include "cMD5.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
cMD5::cMD5()
{
mp_s8ReadBuffer = 0;
}
cMD5::~cMD5()
{
FreeBuffer();
}
void cMD5::FreeBuffer()
{
if (mp_s8ReadBuffer) delete mp_s8ReadBuffer;
}
char* cMD5::CalcMD5FromFile(const char *s8_Path)
{
if (!mp_s8ReadBuffer) mp_s8ReadBuffer = new char[_ReadBufSize];
MD5Init();
HANDLE h_File = CreateFile(s8_Path, GENERIC_READ, FILE_SHARE_READ, 0,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if (h_File == INVALID_HANDLE_VALUE)
return "";
int s32_Size = GetFileSize(h_File, 0);
while (s32_Size > 0)
{
unsigned long u32_Read = 0;
if (!ReadFile(h_File, mp_s8ReadBuffer, _ReadBufSize, &u32_Read, 0))
{
CloseHandle(h_File);
return "";
}
MD5Update((unsigned char*)mp_s8ReadBuffer, u32_Read);
s32_Size = u32_Read;
};
CloseHandle(h_File);
return MD5FinalToString();
}
char* cMD5::CalcMD5FromString(const char *s8_Input)
{
MD5Init();
MD5Update((unsigned char*)s8_Input, strlen(s8_Input));
return MD5FinalToString();
}
void cMD5::MD5Init()
{
ctx.buf[0] = 0x67452301;
ctx.buf[1] = 0xefcdab89;
ctx.buf[2] = 0x98badcfe;
ctx.buf[3] = 0x10325476;
ctx.bits[0] = 0;
ctx.bits[1] = 0;
}
void cMD5::MD5Update(unsigned char *buf, unsigned len)
{
unsigned long t;
t = ctx.bits[0];
if ((ctx.bits[0] = t + ((unsigned long) len << 3)) < t)
ctx.bits[1]++;
ctx.bits[1] += len >> 29;
t = (t >> 3) & 0x3f;
if (t) {
unsigned char *p = (unsigned char *) ctx.in + t;
t = 64  t;
if (len < t) {
memcpy(p, buf, len);
return;
}
memcpy(p, buf, t);
cMD5::byteReverse(ctx.in, 16);
MD5Transform(ctx.buf, (unsigned long *) ctx.in);
buf += t;
len = t;
}
while (len >= 64) {
memcpy(ctx.in, buf, 64);
cMD5::byteReverse(ctx.in, 16);
MD5Transform(ctx.buf, (unsigned long *) ctx.in);
buf += 64;
len = 64;
}
memcpy(ctx.in, buf, len);
}
char* cMD5::MD5FinalToString()
{
unsigned char signature[16];
MD5Final(signature);
ms8_MD5[0] = 0;
char s8_Temp[5];
for (int i=0; i<16; i++)
{
sprintf(s8_Temp, "%02X", signature[i]);
strcat(ms8_MD5, s8_Temp);
}
return ms8_MD5;
}
void cMD5::MD5Final(unsigned char digest[16])
{
unsigned count;
unsigned char *p;
count = (ctx.bits[0] >> 3) & 0x3F;
p = ctx.in + count;
*p++ = 0x80;
count = 64  1  count;
if (count < 8) {
memset(p, 0, count);
cMD5::byteReverse(ctx.in, 16);
MD5Transform(ctx.buf, (unsigned long *) ctx.in);
memset(ctx.in, 0, 56);
} else {
memset(p, 0, count  8);
}
cMD5::byteReverse(ctx.in, 14);
((unsigned long *) ctx.in)[14] = ctx.bits[0];
((unsigned long *) ctx.in)[15] = ctx.bits[1];
MD5Transform(ctx.buf, (unsigned long *) ctx.in);
cMD5::byteReverse((unsigned char *) ctx.buf, 4);
memcpy(digest, ctx.buf, 16);
memset(&ctx, 0, sizeof(MD5Context));
}
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x  ~z))
#define MD5STEP(f, w, x, y, z, data, s) \
( w += f(x, y, z) + data, w = w<<s  w>>(32s), w += x )
void cMD5::MD5Transform(unsigned long buf[4], unsigned long in[16])
{
register unsigned long a, b, c, d;
a = buf[0];
b = buf[1];
c = buf[2];
d = buf[3];
MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
buf[0] += a;
buf[1] += b;
buf[2] += c;
buf[3] += d;
}
#ifdef sgi
#define HIGHFIRST
#endif
#ifdef sun
#define HIGHFIRST
#endif
#ifndef HIGHFIRST
void cMD5::byteReverse(unsigned char *buf, unsigned longs)
{
}
#else
void cMD5::byteReverse(unsigned char *buf, unsigned longs)
{
unsigned long t;
do {
t = (unsigned long) ((unsigned) buf[3] << 8  buf[2]) << 16 
((unsigned) buf[1] << 8  buf[0]);
*(unsigned long *) buf = t;
buf += 4;
} while (longs);
}
#endif
