1 files changed, 46 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.Core/Messaging/MessageProtections.cs b/src/DotNetOpenAuth.Core/Messaging/MessageProtections.cs
new file mode 100644
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+++ b/src/DotNetOpenAuth.Core/Messaging/MessageProtections.cs
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+//-----------------------------------------------------------------------
+// <copyright file="MessageProtections.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.Messaging {
+	using System;
+
+	/// <summary>
+	/// Categorizes the various types of channel binding elements so they can be properly ordered.
+	/// </summary>
+	/// <remarks>
+	/// The order of these enum values is significant.  
+	/// Each successive value requires the protection offered by all the previous values
+	/// in order to be reliable.  For example, message expiration is meaningless without
+	/// tamper protection to prevent a user from changing the timestamp on a message.
+	/// </remarks>
+	[Flags]
+	public enum MessageProtections {
+		/// <summary>
+		/// No protection.
+		/// </summary>
+		None = 0x0,
+
+		/// <summary>
+		/// A binding element that signs a message before sending and validates its signature upon receiving.
+		/// </summary>
+		TamperProtection = 0x1,
+
+		/// <summary>
+		/// A binding element that enforces a maximum message age between sending and processing on the receiving side.
+		/// </summary>
+		Expiration = 0x2,
+
+		/// <summary>
+		/// A binding element that prepares messages for replay detection and detects replayed messages on the receiving side.
+		/// </summary>
+		ReplayProtection = 0x4,
+
+		/// <summary>
+		/// All forms of protection together.
+		/// </summary>
+		All = TamperProtection | Expiration | ReplayProtection,
+	}
+}
+\ No newline at end of file