/// <summary>
/// Searches for an XRDS document at the realm URL.
/// </summary>
/// <param name="hostFactories">The host factories.</param>
/// <param name="allowRedirects">Whether redirects may be followed when discovering the Realm.
/// This may be true when creating an unsolicited assertion, but must be
/// false when performing return URL verification per 2.0 spec section 9.2.1.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>
/// The XRDS document if found; or <c>null</c> if no service document was discovered.
/// </returns>
internal virtual async Task <XrdsDocument> DiscoverAsync(IHostFactories hostFactories, bool allowRedirects, CancellationToken cancellationToken)
{
// Attempt YADIS discovery
DiscoveryResult yadisResult = await Yadis.DiscoverAsync(hostFactories, this.UriWithWildcardChangedToWww, false, cancellationToken);
if (yadisResult != null)
{
// Detect disallowed redirects, since realm discovery never allows them for security.
ErrorUtilities.VerifyProtocol(allowRedirects || yadisResult.NormalizedUri == yadisResult.RequestUri, OpenIdStrings.RealmCausedRedirectUponDiscovery, yadisResult.RequestUri);
if (yadisResult.IsXrds)
{
try {
return(new XrdsDocument(yadisResult.ResponseText));
} catch (XmlException ex) {
throw ErrorUtilities.Wrap(ex, XrdsStrings.InvalidXRDSDocument);
}
}
}
return(null);
}
/// <summary>
/// Performs discovery on the specified identifier.
/// </summary>
/// <param name="identifier">The identifier to perform discovery on.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>
/// A sequence of service endpoints yielded by discovery. Must not be null, but may be empty.
/// </returns>
public async Task <IdentifierDiscoveryServiceResult> DiscoverAsync(Identifier identifier, CancellationToken cancellationToken)
{
Requires.NotNull(identifier, "identifier");
Verify.Operation(this.HostFactories != null, Strings.HostFactoriesRequired);
cancellationToken.ThrowIfCancellationRequested();
var uriIdentifier = identifier as UriIdentifier;
if (uriIdentifier == null)
{
return(new IdentifierDiscoveryServiceResult(Enumerable.Empty <IdentifierDiscoveryResult>()));
}
var endpoints = new List <IdentifierDiscoveryResult>();
// Attempt YADIS discovery
DiscoveryResult yadisResult = await Yadis.DiscoverAsync(this.HostFactories, uriIdentifier, identifier.IsDiscoverySecureEndToEnd, cancellationToken);
cancellationToken.ThrowIfCancellationRequested();
if (yadisResult != null)
{
if (yadisResult.IsXrds)
{
try {
XrdsDocument xrds = new XrdsDocument(yadisResult.ResponseText);
var xrdsEndpoints = xrds.XrdElements.CreateServiceEndpoints(yadisResult.NormalizedUri, uriIdentifier);
// Filter out insecure endpoints if high security is required.
if (uriIdentifier.IsDiscoverySecureEndToEnd)
{
xrdsEndpoints = xrdsEndpoints.Where(se => se.ProviderEndpoint.IsTransportSecure());
}
endpoints.AddRange(xrdsEndpoints);
} catch (XmlException ex) {
Logger.Yadis.ErrorException("Error while parsing the XRDS document. Falling back to HTML discovery.", ex);
}
}
// Failing YADIS discovery of an XRDS document, we try HTML discovery.
if (endpoints.Count == 0)
{
await yadisResult.TryRevertToHtmlResponseAsync();
var htmlEndpoints = new List <IdentifierDiscoveryResult>(DiscoverFromHtml(yadisResult.NormalizedUri, uriIdentifier, yadisResult.ResponseText));
if (htmlEndpoints.Any())
{
Logger.Yadis.DebugFormat("Total services discovered in HTML: {0}", htmlEndpoints.Count);
Logger.Yadis.Debug(htmlEndpoints.ToStringDeferred(true).ToString());
endpoints.AddRange(htmlEndpoints.Where(ep => !uriIdentifier.IsDiscoverySecureEndToEnd || ep.ProviderEndpoint.IsTransportSecure()));
if (endpoints.Count == 0)
{
Logger.Yadis.Info("No HTML discovered endpoints met the security requirements.");
}
}
else
{
Logger.Yadis.Debug("HTML discovery failed to find any endpoints.");
}
}
else
{
Logger.Yadis.Debug("Skipping HTML discovery because XRDS contained service endpoints.");
}
}
return(new IdentifierDiscoveryServiceResult(endpoints));
}