Arrrgh….

Im gonna fix this certificate thing once and for all. Porting this crap to Delphi ASAP!

// Sign
void Sign(wchar_t * SignerName, wchar_t * DataFileName, wchar_t * SignatureFileName)
{
	// Variables
	HCERTSTORE hStoreHandle = NULL;
	PCCERT_CONTEXT pSignerCert = NULL;
	HCRYPTPROV hCryptProv = NULL;
	DWORD dwKeySpec = 0;
	HCRYPTHASH hHash = NULL;
	HANDLE hDataFile = NULL; 
	BOOL bResult = FALSE;
	BYTE rgbFile[BUFSIZE];
	DWORD cbRead = 0;
	DWORD dwSigLen = 0;
	BYTE * pbSignature = NULL;
	HANDLE hSignatureFile = NULL;
	DWORD lpNumberOfBytesWritten = 0;

	wprintf(L"SIGNING\n\n");

	// Open the certificate store.
	hStoreHandle = CertOpenStore(
		CERT_STORE_PROV_SYSTEM,
		0,
		NULL,
		CERT_SYSTEM_STORE_CURRENT_USER,
		CERT_PERSONAL_STORE_NAME
	);
	CheckError((BOOL)hStoreHandle, L"CertOpenStore....................... ");

	// Get signer's certificate with access to private key.
	do {
		// Get a certificate that matches the search criteria
		pSignerCert = CertFindCertificateInStore(
			hStoreHandle,
			MY_TYPE,
			0,
			CERT_FIND_SUBJECT_STR,
			SignerName,
			pSignerCert
		);
		CheckError((BOOL)pSignerCert, L"CertFindCertificateInStore.......... ");

		// Get the CSP, and check if we can sign with the private key			
		bResult = CryptAcquireCertificatePrivateKey(
			pSignerCert,
			0,
			NULL,
			&hCryptProv,
			&dwKeySpec,
			NULL
		);
		CheckError(bResult, L"CryptAcquireCertificatePrivateKey... ");

	} while ((dwKeySpec & AT_SIGNATURE) != AT_SIGNATURE);

	// Create the hash object.
	bResult = CryptCreateHash(
		hCryptProv, 
		CALG_MD5, 
		0, 
		0, 
		&hHash
	);
	CheckError(bResult, L"CryptCreateHash..................... ");

	// Open the file with the content to be signed 
	hDataFile = CreateFileW(DataFileName,
		GENERIC_READ,
		FILE_SHARE_READ,
		NULL,
		OPEN_EXISTING,
		FILE_FLAG_SEQUENTIAL_SCAN,
		NULL
	);
	CheckError((hDataFile != INVALID_HANDLE_VALUE), L"CreateFile.......................... ");

	// Compute the cryptographic hash of the data.
	while (bResult = ReadFile(hDataFile, rgbFile, BUFSIZE, &cbRead, NULL))
	{
		if (cbRead == 0)
		{
			break;
		}
		CheckError(bResult, L"ReadFile............................ ");

		bResult = CryptHashData(
			hHash, 
			rgbFile, 
			cbRead, 
			0
		);
		CheckError(bResult, L"CryptHashData....................... ");

	}
	CheckError(bResult, L"ReadFile............................ ");

	// Sign the hash object
	dwSigLen = 0;
	bResult = CryptSignHash(
		hHash, 
		AT_SIGNATURE, 
		NULL, 
		0, 
		NULL, 
		&dwSigLen
	);
	CheckError(bResult, L"CryptSignHash....................... ");

	pbSignature = (BYTE *)malloc(dwSigLen);
	CheckError((BOOL)pbSignature, L"malloc.............................. ");

	bResult = CryptSignHash(
		hHash, 
		AT_SIGNATURE, 
		NULL, 
		0, 
		pbSignature, 
		&dwSigLen
	);
	CheckError(bResult, L"CryptSignHash....................... ");

	// Create a file to save the signature
	hSignatureFile = CreateFileW(
		SignatureFileName,
		GENERIC_WRITE,
		0,
		NULL,
		CREATE_ALWAYS,
		FILE_ATTRIBUTE_NORMAL,
		NULL
	);
	CheckError((hSignatureFile != INVALID_HANDLE_VALUE), L"CreateFile.......................... ");

	// Write the signature to the file
	bResult = WriteFile(
		hSignatureFile, 
		(LPCVOID)pbSignature, 
		dwSigLen, 
		&lpNumberOfBytesWritten, 
		NULL
	);
	CheckError(bResult, L"WriteFile........................... ");

 	// Clean up and free memory.
	free(pbSignature);

	CloseHandle(hDataFile);
	CloseHandle(hSignatureFile);

	bResult = CryptDestroyHash(hHash);
	CheckError(bResult, L"CryptDestroyHash.................... ");

	bResult = CertFreeCertificateContext(pSignerCert);
	CheckError(bResult, L"CertFreeCertificateContext.......... ");

	bResult = CertCloseStore(
		hStoreHandle, 
		CERT_CLOSE_STORE_CHECK_FLAG
	);
	CheckError(bResult, L"CertCloseStore...................... ");

} 
// End of Sign

Advertisements