private static void AddRequestHeaders(
SafeWinHttpHandle requestHandle,
HttpRequestMessage requestMessage,
CookieContainer cookies)
{
var requestHeadersBuffer = new StringBuilder();
// Manually add cookies.
if (cookies != null)
{
string cookieHeader = WinHttpCookieContainerAdapter.GetCookieHeader(requestMessage.RequestUri, cookies);
if (!string.IsNullOrEmpty(cookieHeader))
{
requestHeadersBuffer.AppendLine(cookieHeader);
}
}
// Serialize general request headers.
requestHeadersBuffer.AppendLine(requestMessage.Headers.ToString());
// Serialize entity-body (content) headers.
if (requestMessage.Content != null)
{
// TODO: Content-Length header isn't getting correctly placed using ToString()
// This is a bug in HttpContentHeaders that needs to be fixed.
if (requestMessage.Content.Headers.ContentLength.HasValue)
{
long contentLength = requestMessage.Content.Headers.ContentLength.Value;
requestMessage.Content.Headers.ContentLength = null;
requestMessage.Content.Headers.ContentLength = contentLength;
}
requestHeadersBuffer.AppendLine(requestMessage.Content.Headers.ToString());
}
// Add request headers to WinHTTP request handle.
if (!Interop.WinHttp.WinHttpAddRequestHeaders(
requestHandle,
requestHeadersBuffer,
(uint)requestHeadersBuffer.Length,
Interop.WinHttp.WINHTTP_ADDREQ_FLAG_ADD))
{
WinHttpException.ThrowExceptionUsingLastError();
}
}
private static void OnRequestRedirect(WinHttpRequestState state, Uri redirectUri)
{
Debug.Assert(state != null, "OnRequestRedirect: state is null");
Debug.Assert(state.Handler != null, "OnRequestRedirect: state.Handler is null");
Debug.Assert(state.RequestMessage != null, "OnRequestRedirect: state.RequestMessage is null");
Debug.Assert(redirectUri != null, "OnRequestRedirect: redirectUri is null");
// If we're manually handling cookies, we need to reset them based on the new URI.
if (state.Handler.CookieUsePolicy == CookieUsePolicy.UseSpecifiedCookieContainer)
{
// Add any cookies that may have arrived with redirect response.
WinHttpCookieContainerAdapter.AddResponseCookiesToContainer(state);
// Reset cookie request headers based on redirectUri.
WinHttpCookieContainerAdapter.ResetCookieRequestHeaders(state, redirectUri);
}
state.RequestMessage.RequestUri = redirectUri;
// Redirection to a new uri may require a new connection through a potentially different proxy.
// If so, we will need to respond to additional 407 proxy auth demands and re-attach any
// proxy credentials. The ProcessResponse() method looks at the state.LastStatusCode
// before attaching proxy credentials and marking the HTTP request to be re-submitted.
// So we need to reset the LastStatusCode remembered. Otherwise, it will see additional 407
// responses as an indication that proxy auth failed and won't retry the HTTP request.
if (state.LastStatusCode == HttpStatusCode.ProxyAuthenticationRequired)
{
state.LastStatusCode = 0;
}
// For security reasons, we drop the server credential if it is a
// NetworkCredential. But we allow credentials in a CredentialCache
// since they are specifically tied to URI's.
if (!(state.ServerCredentials is CredentialCache))
{
state.ServerCredentials = null;
}
// Similarly, we need to clear any Auth headers that were added to the request manually or
// through the default headers.
ResetAuthRequestHeaders(state);
}
private async void StartRequest(object obj)
{
WinHttpRequestState state = (WinHttpRequestState)obj;
bool secureConnection = false;
HttpResponseMessage responseMessage = null;
Exception savedException = null;
SafeWinHttpHandle connectHandle = null;
if (state.CancellationToken.IsCancellationRequested)
{
state.Tcs.TrySetCanceled(state.CancellationToken);
return;
}
try
{
EnsureSessionHandleExists(state);
SetSessionHandleOptions();
// Specify an HTTP server.
connectHandle = Interop.WinHttp.WinHttpConnect(
_sessionHandle,
state.RequestMessage.RequestUri.Host,
(ushort)state.RequestMessage.RequestUri.Port,
0);
ThrowOnInvalidHandle(connectHandle);
connectHandle.SetParentHandle(_sessionHandle);
if (state.RequestMessage.RequestUri.Scheme == UriScheme.Https)
{
secureConnection = true;
}
else
{
secureConnection = false;
}
// Try to use the requested version if a known/supported version was explicitly requested.
// Otherwise, we simply use winhttp's default.
string httpVersion = null;
if (state.RequestMessage.Version == HttpVersion.Version10)
{
httpVersion = "HTTP/1.0";
}
else if (state.RequestMessage.Version == HttpVersion.Version11)
{
httpVersion = "HTTP/1.1";
}
// Create an HTTP request handle.
state.RequestHandle = Interop.WinHttp.WinHttpOpenRequest(
connectHandle,
state.RequestMessage.Method.Method,
state.RequestMessage.RequestUri.PathAndQuery,
httpVersion,
Interop.WinHttp.WINHTTP_NO_REFERER,
Interop.WinHttp.WINHTTP_DEFAULT_ACCEPT_TYPES,
secureConnection ? Interop.WinHttp.WINHTTP_FLAG_SECURE : 0);
ThrowOnInvalidHandle(state.RequestHandle);
state.RequestHandle.SetParentHandle(connectHandle);
// Set callback function.
SetStatusCallback(state.RequestHandle, WinHttpRequestCallback.StaticCallbackDelegate);
// Set needed options on the request handle.
SetRequestHandleOptions(state);
bool chunkedModeForSend = IsChunkedModeForSend(state.RequestMessage);
AddRequestHeaders(
state.RequestHandle,
state.RequestMessage,
_cookieUsePolicy == CookieUsePolicy.UseSpecifiedCookieContainer ? _cookieContainer : null);
uint proxyAuthScheme = 0;
uint serverAuthScheme = 0;
state.RetryRequest = false;
// The only way to abort pending async operations in WinHTTP is to close the WinHTTP handle.
// We will detect a cancellation request on the cancellation token by registering a callback.
// If the callback is invoked, then we begin the abort process by disposing the handle. This
// will have the side-effect of WinHTTP cancelling any pending I/O and accelerating its callbacks
// on the handle and thus releasing the awaiting tasks in the loop below. This helps to provide
// a more timely, cooperative, cancellation pattern.
using (state.CancellationToken.Register(s => ((WinHttpRequestState)s).RequestHandle.Dispose(), state))
{
do
{
_authHelper.PreAuthenticateRequest(state, proxyAuthScheme);
await InternalSendRequestAsync(state).ConfigureAwait(false);
if (state.RequestMessage.Content != null)
{
await InternalSendRequestBodyAsync(state, chunkedModeForSend).ConfigureAwait(false);
}
bool receivedResponse = await InternalReceiveResponseHeadersAsync(state).ConfigureAwait(false);
if (receivedResponse)
{
// If we're manually handling cookies, we need to add them to the container after
// each response has been received.
if (state.Handler.CookieUsePolicy == CookieUsePolicy.UseSpecifiedCookieContainer)
{
WinHttpCookieContainerAdapter.AddResponseCookiesToContainer(state);
}
_authHelper.CheckResponseForAuthentication(
state,
ref proxyAuthScheme,
ref serverAuthScheme);
}
} while (state.RetryRequest);
}
state.CancellationToken.ThrowIfCancellationRequested();
responseMessage = WinHttpResponseParser.CreateResponseMessage(state, _doManualDecompressionCheck);
// Since the headers have been read, set the "receive" timeout to be based on each read
// call of the response body data. WINHTTP_OPTION_RECEIVE_TIMEOUT sets a timeout on each
// lower layer winsock read.
uint optionData = (uint)_receiveDataTimeout.TotalMilliseconds;
SetWinHttpOption(state.RequestHandle, Interop.WinHttp.WINHTTP_OPTION_RECEIVE_TIMEOUT, ref optionData);
}
catch (Exception ex)
{
if (state.SavedException != null)
{
savedException = state.SavedException;
}
else
{
savedException = ex;
}
}
finally
{
SafeWinHttpHandle.DisposeAndClearHandle(ref connectHandle);
}
// Move the main task to a terminal state. This releases any callers of SendAsync() that are awaiting.
if (responseMessage != null)
{
state.Tcs.TrySetResult(responseMessage);
}
else
{
HandleAsyncException(state, savedException);
}
}