Hashes com OpenSSL

hashes.cpp

void calc_hash(LPCWSTR lpFileName, const char* algo, char* output)
{
	HANDLE hFile = NULL;
	DWORD cbRead = 0;
	unsigned char *data;
	size_t  data_size;

	hFile = CreateFile(lpFileName,
		GENERIC_READ,
		FILE_SHARE_READ,
		NULL,
		OPEN_EXISTING,
		FILE_FLAG_SEQUENTIAL_SCAN,
		NULL);

	if (hFile != INVALID_HANDLE_VALUE)
	{
		data_size = GetFileSize(hFile, NULL);
		//char *rgbFile  = ( char *) malloc (data_size);
		data = ( unsigned char *) malloc (data_size);

		if(data != NULL)
		{	
			while (ReadFile(hFile, data, data_size, 
				&cbRead, NULL))
			{
				if (0 == cbRead)
				{
					break;
				}	
			}
			//free(data);
		}
		CloseHandle(hFile);
	}

	OpenSSL_add_all_digests();
	char hash_value[EVP_MAX_MD_SIZE * 2 + 1];

	const EVP_MD *md = EVP_get_digestbyname(algo);
	unsigned char md_value[EVP_MAX_MD_SIZE];
	unsigned int md_len;
    EVP_MD_CTX md_ctx;
    // FIXME: Handle errors - Check return values.
    EVP_MD_CTX_init(&md_ctx);
    EVP_DigestInit_ex(&md_ctx, md, NULL);
    EVP_DigestUpdate(&md_ctx, data, data_size);
    EVP_DigestFinal_ex(&md_ctx, md_value, &md_len);
    EVP_MD_CTX_cleanup(&md_ctx);

    for (unsigned int i=0; i < md_len; i++)
            sprintf(&output[i * 2], "%02x", md_value[i]);

	free(data);
	EVP_cleanup(); // Clean OpenSSL_add_all_digests.
}

void CfwVipreDlg::OnBnClickedButton9()
{
	char outMD5[EVP_MAX_MD_SIZE * 2 + 1];
	char outSHA1[EVP_MAX_MD_SIZE * 2 + 1];
	char outSHA256[EVP_MAX_MD_SIZE * 2 + 1];
	char outSHA512[EVP_MAX_MD_SIZE * 2 + 1];

	calc_hash(L"C:\\windows\\notepad.exe", "MD5", outMD5);
	OutputDebugStringA(outMD5);
	OutputDebugStringA("\n");

	calc_hash(L"C:\\windows\\notepad.exe", "SHA1", outSHA1);
	OutputDebugStringA(outSHA1);
	OutputDebugStringA("\n");

	calc_hash(L"C:\\windows\\notepad.exe", "SHA256", outSHA256);
	OutputDebugStringA(outSHA256);
	OutputDebugStringA("\n");

	calc_hash(L"C:\\windows\\notepad.exe", "SHA512", outSHA512);
	OutputDebugStringA(outSHA512);
	OutputDebugStringA("\n");

	SecureZeroMemory(outMD5, MD5_DIGEST_LENGTH);
	SecureZeroMemory(outSHA1, SHA_DIGEST_LENGTH);
	SecureZeroMemory(outSHA256, SHA256_DIGEST_LENGTH);
	SecureZeroMemory(outSHA512, EVP_MAX_MD_SIZE * 2 + 1);
}