MD5 Window

#include <stdio.h>
#include <windows.h>
#include <Wincrypt.h>
#include "mspyLog.h"

#define BUFSIZE 1024
#define MD5LEN  16

DWORD hash(FILE* fp, WCHAR filename[])
{
	DWORD dwStatus = 0;
	BOOL bResult = FALSE;
	HCRYPTPROV hProv = 0;
	HCRYPTHASH hHash = 0;
	HANDLE hFile = NULL;
	BYTE rgbFile[BUFSIZE];
	DWORD cbRead = 0;
	BYTE rgbHash[MD5LEN];
	DWORD cbHash = 0;
	CHAR rgbDigits[] = "0123456789abcdef";
	//LPCWSTR filename = L"filename.txt";
	// Logic to check usage goes here.
	fprintf(fp, "calculate %s\n", filename);
	hFile = CreateFileW(filename,
		GENERIC_READ,
		FILE_SHARE_READ,
		NULL,
		OPEN_EXISTING,
		FILE_FLAG_SEQUENTIAL_SCAN,
		NULL);

	if (INVALID_HANDLE_VALUE == hFile)
	{
		dwStatus = GetLastError();
		fprintf(fp, "Error opening file %s\nError: %d\n", filename,
			dwStatus);
		return dwStatus;
	}
	fwprintf(fp, L"Correct open: %d\n", filename,
		dwStatus);

	// Get handle to the crypto provider
	if (!CryptAcquireContext(&hProv,
		NULL,
		NULL,
		PROV_RSA_FULL,
		CRYPT_VERIFYCONTEXT))
	{
		dwStatus = GetLastError();
		printf("CryptAcquireContext failed: %d\n", dwStatus);
		CloseHandle(hFile);
		return dwStatus;
	}

	if (!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash))
	{
		dwStatus = GetLastError();
		printf("CryptAcquireContext failed: %d\n", dwStatus);
		CloseHandle(hFile);
		CryptReleaseContext(hProv, 0);
		return dwStatus;
	}
	bResult = ReadFile(hFile, rgbFile, BUFSIZE,
		&cbRead, NULL);



	while (bResult)
	{
		if (0 == cbRead)
		{
			break;
		}

		if (!CryptHashData(hHash, rgbFile, cbRead, 0))
		{
			dwStatus = GetLastError();
			printf("CryptHashData failed: %d\n", dwStatus);
			CryptReleaseContext(hProv, 0);
			CryptDestroyHash(hHash);
			CloseHandle(hFile);
			return dwStatus;
		}
	}

	if (!bResult)
	{
		dwStatus = GetLastError();
		printf("ReadFile failed: %d\n", dwStatus);
		CryptReleaseContext(hProv, 0);
		CryptDestroyHash(hHash);
		CloseHandle(hFile);
		return dwStatus;
	}

	cbHash = MD5LEN;
	if (CryptGetHashParam(hHash, HP_HASHVAL, rgbHash, &cbHash, 0))
	{
		fprintf(fp, "MD5 hash of file %s is: ", filename);
		for (DWORD i = 0; i < cbHash; i++)
		{
			fprintf(fp, "%c%c", rgbDigits[rgbHash[i] >> 4],
				rgbDigits[rgbHash[i] & 0xf]);
		}
		fprintf(fp, "\n");
	}
	else
	{
		dwStatus = GetLastError();
		printf("CryptGetHashParam failed: %d\n", dwStatus);
	}

	CryptDestroyHash(hHash);
	CryptReleaseContext(hProv, 0);
	CloseHandle(hFile);

	return dwStatus;
}