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diff --git a/qpid/dotnet/Qpid.Sasl/Mechanisms/CramMD5SaslClient.cs b/qpid/dotnet/Qpid.Sasl/Mechanisms/CramMD5SaslClient.cs
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+++ b/qpid/dotnet/Qpid.Sasl/Mechanisms/CramMD5SaslClient.cs
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+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+using System;
+using System.Collections;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace Apache.Qpid.Sasl.Mechanisms
+{
+   /// <summary>
+   /// Implements the CRAM-MD5 authentication mechanism as outlined
+   /// in RFC 2195
+   /// </summary>
+   public class CramMD5SaslClient : SaslClient
+   {
+      public const string Mechanism = "CRAM-MD5";
+      private const int MinPwdLen = 16;
+
+      public CramMD5SaslClient(
+         string authorizationId, 
+         IDictionary properties, 
+         ISaslCallbackHandler handler)
+         : base(authorizationId, null, null, properties, handler)
+      {
+      }
+
+      #region ISaslClient Implementation
+      //
+      // ISaslClient Implementation
+      //
+
+      public override string MechanismName
+      {
+         get { return Mechanism; }
+      }
+
+      public override bool HasInitialResponse
+      {
+         get { return false; }
+      }
+
+      public override byte[] EvaluateChallenge(byte[] challenge)
+      {
+         if ( challenge == null || challenge.Length == 0 )
+            throw new ArgumentNullException("challenge");
+
+         NameCallback nameCB = new NameCallback(AuthorizationId);
+         PasswordCallback pwdCB = new PasswordCallback();
+         ISaslCallback[] callbacks = { nameCB, pwdCB };
+         Handler.Handle(callbacks);
+
+         string username = nameCB.Text;
+         string passwd = pwdCB.Text.PadRight(MinPwdLen, '\0');
+
+         byte[] secret = Encoding.UTF8.GetBytes(passwd);
+
+         //using ( HMAC hmac = new HMACMD5(secret) )
+         using ( MD5HMAC hmac = new MD5HMAC(secret) )
+         {
+            byte[] value = hmac.ComputeHash(challenge);
+            string encoded = ToHex(value);
+            SetComplete();
+            return Encoding.UTF8.GetBytes(username + " " + encoded);
+         }
+
+      }
+
+      #endregion // ISaslClient Implementation
+
+   } // class CramMD5SaslClient
+
+} // namespace Apache.Qpid.Sasl.Mechanisms