MFC decode

MFC_Decode.cpp

http://study.marearts.com/2017/01/mfc-encode-decode-example-souce-code.html
bool Decode()
{

	BYTE    *bBuff;
	DWORD    dwFileLen;
	CString    csFile;
	FILE    *pFile;

	// 암호화된 파일 저장하기
	fopen_s(&pFile, "AutoLogIn.CPR", "rb");
	//pFile = fopen(csFile, "rb");
	if (!pFile)
	{
		::AfxMessageBox(_T("error"));
		return false;
	}

	dwFileLen = _filelength(_fileno(pFile));
	bBuff = new BYTE[dwFileLen];

	// 파일 읽어서 버퍼에 저장
	fread(bBuff, 1, dwFileLen, pFile);
	fclose(pFile);

	HCRYPTPROV    hProv;
	HCRYPTHASH    hHash;
	HCRYPTKEY    hKey;
	//CString        csPass=_T("rlawjdgus");
	char csPass[100] = "rlawjdgus"; //encription key

	//m_Pass.GetWindowText(csPass);

	// CSP(Crystographic Service Provider) 핸들 얻기
	if (!CryptAcquireContext(&hProv, NULL, MS_ENHANCED_PROV, PROV_RSA_FULL, 0))
	{
		if (!CryptAcquireContext(&hProv, NULL, MS_ENHANCED_PROV, PROV_RSA_FULL, CRYPT_NEWKEYSET))
		{
			::AfxMessageBox(_T("ecode fail"));
			return false;
		}
	}

	// 해쉬 만들기
	CryptCreateHash(hProv, CALG_SHA, 0, 0, &hHash);
	// 해쉬 값 계산
	CryptHashData(hHash, (BYTE*)csPass, sizeof(csPass), 0);
	// 키 만들기\tab
	CryptDeriveKey(hProv, CALG_RC4, hHash, 0x0080 * 0x10000, &hKey);
	// 복호화
	CryptDecrypt(hKey, 0, TRUE, 0, bBuff, &dwFileLen);
	// 해쉬 없애기
	CryptDestroyHash(hHash);
	// CSP 핸들 풀어주기
	CryptReleaseContext(hProv, 0);

	CString str;
	str.Format(_T("%s"), CString(bBuff));
	::AfxMessageBox(str);

	return true;
}

http://study.marearts.com/2017/01/mfc-encode-decode-example-souce-code.html