public Task <MessageProtections?> ProcessOutgoingMessageAsync(IProtocolMessage message, CancellationToken cancellationToken)
{
var extendableMessage = message as IProtocolMessageWithExtensions;
if (extendableMessage != null)
{
Protocol protocol = Protocol.Lookup(message.Version);
MessageDictionary baseMessageDictionary = this.Channel.MessageDescriptions.GetAccessor(message);
// We have a helper class that will do all the heavy-lifting of organizing
// all the extensions, their aliases, and their parameters.
var extensionManager = ExtensionArgumentsManager.CreateOutgoingExtensions(protocol);
foreach (IExtensionMessage protocolExtension in extendableMessage.Extensions)
{
var extension = protocolExtension as IOpenIdMessageExtension;
if (extension != null)
{
Reporting.RecordFeatureUse(protocolExtension);
// Give extensions that require custom serialization a chance to do their work.
var customSerializingExtension = extension as IMessageWithEvents;
if (customSerializingExtension != null)
{
customSerializingExtension.OnSending();
}
// OpenID 2.0 Section 12 forbids two extensions with the same TypeURI in the same message.
ErrorUtilities.VerifyProtocol(!extensionManager.ContainsExtension(extension.TypeUri), OpenIdStrings.ExtensionAlreadyAddedWithSameTypeURI, extension.TypeUri);
// Ensure that we're sending out a valid extension.
var extensionDescription = this.Channel.MessageDescriptions.Get(extension);
var extensionDictionary = extensionDescription.GetDictionary(extension).Serialize();
extensionDescription.EnsureMessagePartsPassBasicValidation(extensionDictionary);
// Add the extension to the outgoing message payload.
extensionManager.AddExtensionArguments(extension.TypeUri, extensionDictionary);
}
else
{
Logger.OpenId.WarnFormat("Unexpected extension type {0} did not implement {1}.", protocolExtension.GetType(), typeof(IOpenIdMessageExtension).Name);
}
}
// We use a cheap trick (for now at least) to determine whether the 'openid.' prefix
// belongs on the parameters by just looking at what other parameters do.
// Technically, direct message responses from Provider to Relying Party are the only
// messages that leave off the 'openid.' prefix.
bool includeOpenIdPrefix = baseMessageDictionary.Keys.Any(key => key.StartsWith(protocol.openid.Prefix, StringComparison.Ordinal));
// Add the extension parameters to the base message for transmission.
baseMessageDictionary.AddExtraParameters(extensionManager.GetArgumentsToSend(includeOpenIdPrefix));
return(NoneTask);
}
return(NullTask);
}