1 files changed, 42 insertions, 0 deletions
diff --git a/src/OpenID/OpenIdProviderMvc/Code/AnonymousIdentifierProvider.cs b/src/OpenID/OpenIdProviderMvc/Code/AnonymousIdentifierProvider.cs
new file mode 100644
index 0000000..6dc210d
--- /dev/null
+++ b/src/OpenID/OpenIdProviderMvc/Code/AnonymousIdentifierProvider.cs
@@ -0,0 +1,42 @@
+namespace OpenIdProviderMvc.Code {
+	using System;
+	using System.Web.Security;
+	using DotNetOpenAuth.OpenId;
+	using DotNetOpenAuth.OpenId.Provider;
+	using OpenIdProviderMvc.Models;
+
+	internal class AnonymousIdentifierProvider : PrivatePersonalIdentifierProviderBase {
+		/// <summary>
+		/// Initializes a new instance of the <see cref="AnonymousIdentifierProvider"/> class.
+		/// </summary>
+		internal AnonymousIdentifierProvider()
+			: base(Util.GetAppPathRootedUri("anon?id=")) {
+		}
+
+		/// <summary>
+		/// Gets the salt to use for generating an anonymous identifier for a given OP local identifier.
+		/// </summary>
+		/// <param name="localIdentifier">The OP local identifier.</param>
+		/// <returns>The salt to use in the hash.</returns>
+		/// <remarks>
+		/// It is important that this method always return the same value for a given
+		/// <paramref name="localIdentifier"/>.
+		/// New salts can be generated for local identifiers without previously assigned salt
+		/// values by calling <see cref="CreateSalt"/> or by a custom method.
+		/// </remarks>
+		protected override byte[] GetHashSaltForLocalIdentifier(Identifier localIdentifier) {
+			// This is just a sample with no database... a real web app MUST return 
+			// a reasonable salt here and have that salt be persistent for each user.
+			var membership = (ReadOnlyXmlMembershipProvider)Membership.Provider;
+			string username = User.GetUserFromClaimedIdentifier(new Uri(localIdentifier));
+			string salt = membership.GetSalt(username);
+			return Convert.FromBase64String(salt);
+
+			// If users were encountered without a salt, one could be generated like this,
+			// and would also need to be saved to the user's account.
+			//// var newSalt = AnonymousIdentifierProviderBase.GetNewSalt(5);
+			//// user.Salt = newSalt;
+			//// return newSalt;
+		}
+	}
+}