Function GetRegistryString

shared/Registry.c:9–59

LPVOID DELETE_VALUE = (LPVOID)(INT_MIN + 1);

HRESULT GetRegistryString(HKEY key, LPCWSTR subkeyPath, LPCWSTR valueName, REGSAM options, LPWSTR *data, LPDWORD size) {
	if (data == NULL) {
		return E_POINTER;
	}

	HKEY subkey = NULL;
	HRESULT hr = HRESULT_FROM_WIN32(RegOpenKeyEx(key, subkeyPath, 0, GetRegistryWow64Flag(KEY_READ | options), &subkey));
	if (!SUCCEEDED(hr)) {
		goto end;
	}

	if (data) {
		DWORD length = 0;
		hr = HRESULT_FROM_WIN32(RegQueryValueEx(subkey, valueName, NULL, NULL, NULL, &length));
		if (!SUCCEEDED(hr)) {
			goto end;
		}

		LPWSTR buffer = (LPWSTR)LocalAlloc(LPTR, length + sizeof(WCHAR));
		if (!buffer) {
			hr = E_OUTOFMEMORY;
			goto end;
		}

		hr = HRESULT_FROM_WIN32(RegQueryValueEx(subkey, valueName, NULL, NULL, (BYTE *)buffer, &length));
		if (!SUCCEEDED(hr)) {
			LocalFree(buffer);
			goto end;
		}

		DWORD ourSize = length / sizeof(WCHAR);
		buffer[ourSize] = L'\0';
		*data = buffer;

		if (size) {
			*size = ourSize;
		}
	}

end:
	if (subkey) {
		RegCloseKey(subkey);
	}
	if (!SUCCEEDED(hr)) {
		*data = NULL;
		if (size) {
			*size = 0;
		}
	}
	return hr;
}

HRESULT GetRegistryDword(HKEY key, LPCWSTR subkeyPath, LPCWSTR valueName, REGSAM options, LPDWORD data) {
	HKEY subkey = NULL;