先介绍一款小巧的hash工具，就是下图这个，可以计算文件的md5值，SHA1值和CRC32值。不到100kb，功能也很简单，就是对文件进行校验，检查是否被篡改过。
对于网上下载linux操作系统和windows操作系统，进行安装的人会很方便，校验后对比官方提供的校验值。可知道文件是否被篡改了，是否被添加了不明来源程序。
下面我们通过编程实现它，这个是界面。
这里只实现了md5校验。
关键函数如下，线程中计算md5值。
UINT ThreadProc(LPVOID pParam)
{
b_IsRunning = 1;
g_csThreadRunning.Lock();
CHashDlg *myHashDlg = (CHashDlg*)pParam;
int m_TotalFiles = myHashDlg->m_FileArray.GetCount();
myHashDlg->m_ProgressTotal.SetRange(0, m_TotalFiles);
for (int i = 0; i < m_TotalFiles; i++)
{
MD5_CTX md5_ctx;
unsigned char decrypt[16];
char* m_binbuf;
ULONGLONG m_binlen;
CFile BinFile;
if (!BinFile.Open((LPCTSTR)(myHashDlg->m_FileArray.GetAt(i)), CFile::modeRead | CFile::typeBinary)) {
continue;
}
m_binlen = BinFile.GetLength();
int totalBlock = m_binlen / 102400 + 1;
myHashDlg->m_ProgressFile.SetRange(0, totalBlock);
m_binbuf = new char[1024000];
int totalread = 0;
MD5Init(&md5_ctx);
for (;;) {
int readlen = BinFile.Read(m_binbuf, 1024000);
if (readlen <= 0) {
break;
}
totalread += readlen;
myHashDlg->m_ProgressFile.SetPos(totalread / 102400);
MD5Update(&md5_ctx, (PUCHAR)m_binbuf, readlen);
if (b_IsRunning != 1) {
break;
}
}
myHashDlg->m_ProgressFile.SetPos(totalBlock);
delete[] m_binbuf;
MD5Final(&md5_ctx, decrypt);
BinFile.Close();
myHashDlg->m_ProgressTotal.SetPos(i);
if (b_IsRunning != 1) {
break;
}
CString md5String;
for (int i = 0; i < 16; i++)
{
//printf("%02x", decrypt[i]);
TCHAR szW[20];
_stprintf_s(szW, 20, _T("%02X"), decrypt[i]);
md5String.Append(szW);
}
CString strFileLen;
strFileLen.Format(_T("%lld bytes"), m_binlen);
myHashDlg->m_MD5Result += _T("File: ");
myHashDlg->m_MD5Result += myHashDlg->m_FileArray.GetAt(i);
myHashDlg->m_MD5Result += _T("rn");
myHashDlg->m_MD5Result += _T("Size: ");
myHashDlg->m_MD5Result += strFileLen;
myHashDlg->m_MD5Result += _T("rn");
myHashDlg->m_MD5Result += md5String;
myHashDlg->m_MD5Result += _T("rn");
myHashDlg->m_MD5Result += _T("rn");
myHashDlg->SendMessage(WM_UPDATEMYDATA, FALSE);
}
myHashDlg->m_ProgressTotal.SetPos(m_TotalFiles);
g_csThreadRunning.Unlock();
return 0;
}
选择文件函数，选择后开始计算。
void CHashDlg::OnBnClickedButtonSelectFiles()
{
CFileDialog Dlg(TRUE, NULL, NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_ALLOWMULTISELECT);
if (Dlg.DoModal() == IDOK)
{
b_IsRunning = 0;
g_csThreadRunning.Lock();
m_FileArray.RemoveAll();
POSITION pos = Dlg.GetStartPosition();
while (pos)
{
m_FileArray.Add(Dlg.GetNextPathName(pos));
}
g_csThreadRunning.Unlock();
if (m_FileArray.GetCount() > 0) {
b_IsRunning = 1;
CWinThread* pThread = AfxBeginThread(ThreadProc, this);
}
}
}
下面是md5算法实现文件
#pragma once
#include <string>
#include <fstream>
typedef unsigned char* PUCHAR;
typedef unsigned short int UINT2;
typedef unsigned int UINT4;
typedef unsigned char UCHAR;
typedef struct
{
UINT4 state[4];
UINT4 count[2];
UCHAR buffer[64];
} MD5_CTX;
void MD5Init(MD5_CTX* context);
void MD5Update(MD5_CTX* context, PUCHAR input, UINT4 inputLen);
void MD5Final(MD5_CTX* context, UCHAR digest[16]);
#include "pch.h"
#include "MD5.h"
/* Constants for MD5Transform routine. */
#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(UINT4[4], UCHAR[64]);
static void MD5Encode(PUCHAR, UINT4*, UINT4);
static void MD5Decode(UINT4*, PUCHAR, UINT4);
static void MD5_memcpy(PUCHAR, PUCHAR, UINT4);
static void MD5_memset(PUCHAR, int, UINT4);
static UCHAR PADDING[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
};
/* F, G, H and I are basic MD5 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))
/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
/*
FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation.
*/
#define FF(a, b, c, d, x, s, ac) { (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
#define GG(a, b, c, d, x, s, ac) { (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
#define HH(a, b, c, d, x, s, ac) { (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
#define II(a, b, c, d, x, s, ac) { (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
/* MD5 initialization. Begins an MD5 operation, writing a new context. */
void MD5Init(MD5_CTX* context)
{
context->count[0] = context->count[1] = 0;
/* Load magic initialization constants.*/
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}
/* MD5 block update operation. Continues an MD5 message-digest
operation, processing another message block, and updating the
context.*/
void MD5Update(MD5_CTX* context, PUCHAR input, UINT4 inputLen)
{
UINT4 i, index, partLen;
/* Compute number of bytes mod 64 */
index = (UINT4)((context->count[0] >> 3) & 0x3F);
/* Update number of bits */
if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index;
/* Transform as many times as possible.*/
if (inputLen >= partLen)
{
MD5_memcpy((PUCHAR)&context->buffer[index], (PUCHAR)input, partLen);
MD5Transform(context->state, context->buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
MD5Transform(context->state, &input[i]);
index = 0;
}
else
i = 0;
/* Buffer remAIning input */
MD5_memcpy((PUCHAR)&context->buffer[index], (PUCHAR)&input[i], inputLen - i);
}
/* MD5 finalization. Ends an MD5 message-digest operation, writing the the message digest and zeroizing the context.*/
void MD5Final(MD5_CTX* context, UCHAR digest[16])
{
UCHAR bits[8];
UINT4 index, padLen;
/* Save number of bits */
MD5Encode(bits, context->count, 8);
/* Pad out to 56 mod 64.*/
index = (UINT4)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update(context, PADDING, padLen);
/* Append length (before padding) */
MD5Update(context, bits, 8);
/* Store state in digest */
MD5Encode(digest, context->state, 16);
/* Zeroize sensitive information.*/
MD5_memset((PUCHAR)context, 0, sizeof(*context));
}
/* MD5 basic transformation. Transforms state based on block. */
static void MD5Transform(UINT4 state[], UCHAR block[])
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3];
UINT4 x[16];
MD5Decode(x, block, 64);
/* Round 1 */
FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
/* Round 2 */
GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
/* Round 3 */
HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
/* Round 4 */
II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
/* Zeroize sensitive information.*/
MD5_memset((PUCHAR)x, (int)0, (UINT4)(sizeof(x)));
}
/*Encodes input (UINT4) into output (unsigned char). Assumes len is a multiple of 4.*/
static void MD5Encode(PUCHAR output, UINT4* input, UINT4 len)
{
UINT4 i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
{
output[j] = (UCHAR)(input[i] & 0xff);
output[j + 1] = (UCHAR)((input[i] >> 8) & 0xff);
output[j + 2] = (UCHAR)((input[i] >> 16) & 0xff);
output[j + 3] = (UCHAR)((input[i] >> 24) & 0xff);
}
}
/* Decodes input (unsigned char) into output (UINT4). Assumes len is a multiple of 4.*/
static void MD5Decode(UINT4* output, PUCHAR input, UINT4 len)
{
UINT4 i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j + 1]) << 8) | (((UINT4)input[j + 2]) << 16) | (((UINT4)input[j + 3]) << 24);
}
/* Note: Replace "for loop" with standard memcpy if possible. */
static void MD5_memcpy(PUCHAR output, PUCHAR input, UINT4 len)
{
UINT4 i;
for (i = 0; i < len; i++)
output[i] = input[i];
}
/* Note: Replace "for loop" with standard memset if possible. */
static void MD5_memset(PUCHAR output, int value, UINT4 len)
{
UINT4 i;
for (i = 0; i < len; i++)
((char*)output)[i] = (char)value;
}
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