1 files changed, 29 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.Core/Messaging/Bindings/IExpiringProtocolMessage.cs b/src/DotNetOpenAuth.Core/Messaging/Bindings/IExpiringProtocolMessage.cs
new file mode 100644
index 0000000..fc43ae6
--- /dev/null
+++ b/src/DotNetOpenAuth.Core/Messaging/Bindings/IExpiringProtocolMessage.cs
@@ -0,0 +1,29 @@
+//-----------------------------------------------------------------------
+// <copyright file="IExpiringProtocolMessage.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.Messaging.Bindings {
+	using System;
+
+	/// <summary>
+	/// The contract a message that has an allowable time window for processing must implement.
+	/// </summary>
+	/// <remarks>
+	/// All expiring messages must also be signed to prevent tampering with the creation date.
+	/// </remarks>
+	internal interface IExpiringProtocolMessage : IProtocolMessage {
+		/// <summary>
+		/// Gets or sets the UTC date/time the message was originally sent onto the network.
+		/// </summary>
+		/// <remarks>
+		/// The property setter should ensure a UTC date/time,
+		/// and throw an exception if this is not possible.
+		/// </remarks>
+		/// <exception cref="ArgumentException">
+		/// Thrown when a DateTime that cannot be converted to UTC is set.
+		/// </exception>
+		DateTime UtcCreationDate { get; set; }
+	}
+}