Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.IdentityModel/System/IdentityModel/CookieTransform.cs

@@ -0,0 +1,31 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace System.IdentityModel
+{
+    /// <summary>
+    /// Applies a reversible data transform to cookie data. 
+    /// </summary>
+    public abstract class CookieTransform
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CookieTransform"/> class.
+        /// </summary>
+        protected CookieTransform() { }
+
+        /// <summary>
+        /// Reverses the transform.
+        /// </summary>
+        /// <param name="encoded">The encoded form of the cookie.</param>
+        /// <returns>The decoded byte array.</returns>
+        public abstract byte[] Decode( byte[] encoded );
+
+        /// <summary>
+        /// Applies the transform.
+        /// </summary>
+        /// <param name="value">The byte array to be encoded.</param>
+        /// <returns>The encoded cookie.</returns>
+        public abstract byte[] Encode( byte[] value );
+    }
+}