1 files changed, 108 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.OpenId/OpenId/XriDiscoveryProxyService.cs b/src/DotNetOpenAuth.OpenId/OpenId/XriDiscoveryProxyService.cs
new file mode 100644
index 0000000..d80c59e
--- /dev/null
+++ b/src/DotNetOpenAuth.OpenId/OpenId/XriDiscoveryProxyService.cs
@@ -0,0 +1,108 @@
+//-----------------------------------------------------------------------
+// <copyright file="XriDiscoveryProxyService.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OpenId {
+	using System;
+	using System.Collections.Generic;
+	using System.Diagnostics.CodeAnalysis;
+	using System.Diagnostics.Contracts;
+	using System.Globalization;
+	using System.Linq;
+	using System.Text;
+	using System.Xml;
+	using DotNetOpenAuth.Configuration;
+	using DotNetOpenAuth.Messaging;
+	using DotNetOpenAuth.OpenId.RelyingParty;
+	using DotNetOpenAuth.Xrds;
+	using DotNetOpenAuth.Yadis;
+
+	/// <summary>
+	/// The discovery service for XRI identifiers that uses an XRI proxy resolver for discovery.
+	/// </summary>
+	[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xri", Justification = "Acronym")]
+	public class XriDiscoveryProxyService : IIdentifierDiscoveryService {
+		/// <summary>
+		/// The magic URL that will provide us an XRDS document for a given XRI identifier.
+		/// </summary>
+		/// <remarks>
+		/// We use application/xrd+xml instead of application/xrds+xml because it gets
+		/// xri.net to automatically give us exactly the right XRD element for community i-names
+		/// automatically, saving us having to choose which one to use out of the result.
+		/// The ssl=true parameter tells the proxy resolver to accept only SSL connections
+		/// when resolving community i-names.
+		/// </remarks>
+		private const string XriResolverProxyTemplate = "https://{1}/{0}?_xrd_r=application/xrd%2Bxml;sep=false";
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="XriDiscoveryProxyService"/> class.
+		/// </summary>
+		public XriDiscoveryProxyService() {
+		}
+
+		#region IDiscoveryService Members
+
+		/// <summary>
+		/// Performs discovery on the specified identifier.
+		/// </summary>
+		/// <param name="identifier">The identifier to perform discovery on.</param>
+		/// <param name="requestHandler">The means to place outgoing HTTP requests.</param>
+		/// <param name="abortDiscoveryChain">if set to <c>true</c>, no further discovery services will be called for this identifier.</param>
+		/// <returns>
+		/// A sequence of service endpoints yielded by discovery.  Must not be null, but may be empty.
+		/// </returns>
+		public IEnumerable<IdentifierDiscoveryResult> Discover(Identifier identifier, IDirectWebRequestHandler requestHandler, out bool abortDiscoveryChain) {
+			abortDiscoveryChain = false;
+			var xriIdentifier = identifier as XriIdentifier;
+			if (xriIdentifier == null) {
+				return Enumerable.Empty<IdentifierDiscoveryResult>();
+			}
+
+			return DownloadXrds(xriIdentifier, requestHandler).XrdElements.CreateServiceEndpoints(xriIdentifier);
+		}
+
+		#endregion
+
+		/// <summary>
+		/// Downloads the XRDS document for this XRI.
+		/// </summary>
+		/// <param name="identifier">The identifier.</param>
+		/// <param name="requestHandler">The request handler.</param>
+		/// <returns>The XRDS document.</returns>
+		private static XrdsDocument DownloadXrds(XriIdentifier identifier, IDirectWebRequestHandler requestHandler) {
+			Contract.Requires<ArgumentNullException>(identifier != null);
+			Contract.Requires<ArgumentNullException>(requestHandler != null);
+			Contract.Ensures(Contract.Result<XrdsDocument>() != null);
+			XrdsDocument doc;
+			using (var xrdsResponse = Yadis.Request(requestHandler, GetXrdsUrl(identifier), identifier.IsDiscoverySecureEndToEnd)) {
+				doc = new XrdsDocument(XmlReader.Create(xrdsResponse.ResponseStream));
+			}
+			ErrorUtilities.VerifyProtocol(doc.IsXrdResolutionSuccessful, OpenIdStrings.XriResolutionFailed);
+			return doc;
+		}
+
+		/// <summary>
+		/// Gets the URL from which this XRI's XRDS document may be downloaded.
+		/// </summary>
+		/// <param name="identifier">The identifier.</param>
+		/// <returns>The URI to HTTP GET from to get the services.</returns>
+		private static Uri GetXrdsUrl(XriIdentifier identifier) {
+			ErrorUtilities.VerifyProtocol(OpenIdElement.Configuration.XriResolver.Enabled, OpenIdStrings.XriResolutionDisabled);
+			string xriResolverProxy = XriResolverProxyTemplate;
+			if (identifier.IsDiscoverySecureEndToEnd) {
+				// Indicate to xri.net that we require SSL to be used for delegated resolution
+				// of community i-names.
+				xriResolverProxy += ";https=true";
+			}
+
+			return new Uri(
+				string.Format(
+					CultureInfo.InvariantCulture,
+					xriResolverProxy,
+					identifier,
+					OpenIdElement.Configuration.XriResolver.Proxy.Name));
+		}
+	}
+}