public async Task <Stream> DownloadMetadataFileAsync(CancellationToken cancellationToken)
{
bool authenticateUser;
Stream memoryStream = null;
string errorMsg = null;
HttpWebResponse webResponse = null;
do
{
try
{
authenticateUser = false;
this.GetWebRequest(this.EndpointAddress.Uri, null, null);
IAsyncResult result = _currentRequest.BeginGetResponse(null, null);
while (!result.IsCompleted)
{
if (cancellationToken.IsCancellationRequested)
{
_currentRequest?.Abort();
cancellationToken.ThrowIfCancellationRequested();
}
await Task.Delay(100);
}
webResponse = (HttpWebResponse)_currentRequest.EndGetResponse(result);
memoryStream = HttpWebRequestHelper.ResponseToMemoryStream(webResponse);
_clientAuthenticated = true;
if (webResponse.StatusCode != HttpStatusCode.OK)
{
Encoding encoding = HttpWebRequestHelper.GetEncoding(webResponse.ContentType);
errorMsg = new StreamReader(memoryStream, encoding, true).ReadToEnd();
memoryStream.Dispose();
}
}
catch (Exception ex)
{
if (Utils.IsFatalOrUnexpected(ex))
{
throw;
}
authenticateUser = RequiresAuthentication(ex, this.EndpointAddress.Uri, out bool _);
if (!authenticateUser)
{
// no need to authenticate user then throw.
throw;
}
}
}while (authenticateUser);
if (errorMsg != null)
{
throw new WebException(errorMsg, null, WebExceptionStatus.ProtocolError, webResponse);
}
return(memoryStream);
}