Big change for authentication, which now supports more SASL mechanisms and

callbacks.  This should address issues SMACK-210 and SMACK-142, as well as 
set the stage for SMACK-234. 



git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/trunk@9498 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smack/sasl/SASLExternalMechanism.java

@@ -0,0 +1,59 @@
+/**
+ * $RCSfile$
+ * $Revision: $
+ * $Date: $
+ *
+ *
+ * All rights reserved. Licensed 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.
+ */
+
+package org.jivesoftware.smack.sasl;
+
+import org.jivesoftware.smack.SASLAuthentication;
+
+/**
+ * Implementation of the SASL EXTERNAL mechanism.
+ *
+ * To effectively use this mechanism, Java must be configured to properly 
+ * supply a client SSL certificate (of some sort) to the server. It is up
+ * to the implementer to determine how to do this.  Here is one method:
+ *
+ * Create a java keystore with your SSL certificate in it:
+ * keytool -genkey -alias username -dname "cn=username,ou=organizationalUnit,o=organizationaName,l=locality,s=state,c=country"
+ *
+ * Next, set the System Properties:
+ *  <ul>
+ *  <li>javax.net.ssl.keyStore to the location of the keyStore
+ *  <li>javax.net.ssl.keyStorePassword to the password of the keyStore
+ *  <li>javax.net.ssl.trustStore to the location of the trustStore
+ *  <li>javax.net.ssl.trustStorePassword to the the password of the trustStore
+ *  </ul>
+ *
+ * Then, when the server requests or requires the client certificate, java will
+ * simply provide the one in the keyStore.
+ *
+ * Also worth noting is the EXTERNAL mechanism in Smack is not enabled by default.
+ * To enable it, the implementer will need to call SASLAuthentication.supportSASLMechamism("EXTERNAL");
+ *
+ * @author Jay Kline
+ */
+public class SASLExternalMechanism extends SASLMechanism  {
+
+    public SASLExternalMechanism(SASLAuthentication saslAuthentication) {
+        super(saslAuthentication);
+    }
+
+    protected String getName() {
+        return "EXTERNAL";
+    }
+}