APIAuthenticator: Add interface definition for the auth mechanisms

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

server/src/com/cloud/api/auth/APIAuthenticator.java

@@ -0,0 +1,40 @@
+// 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.
+package com.cloud.api.auth;
+
+import org.apache.cloudstack.api.ServerApiException;
+
+import javax.servlet.http.HttpSession;
+import java.util.Map;
+
+/*
+* APIAuthenticator is an interface that defines method that
+* a class should implement that help with Authentication and accepts
+* a command string and an array of parameters. This should be used only
+* in the Servlet that is doing authentication.
+*
+* @param command The API command name such as login, logout etc
+* @param params An array of HTTP parameters
+* @param session HttpSession object
+* */
+public interface APIAuthenticator {
+    public String authenticate(String command, Map<String, Object[]> params,
+                               HttpSession session, String remoteAddress, String responseType,
+                               StringBuilder auditTrailSb) throws ServerApiException;
+    public APIAuthenticationType getAPIType();
+
+}