text: /*
   *    Copyright (C) 2014 MongoDB Inc.
   *
   *    This program is free software: you can redistribute it and/or  modify
   *    it under the terms of the GNU Affero General Public License, version 3,
   *    as published by the Free Software Foundation.
   *
   *    This program is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU Affero General Public License for more details.
   *
   *    You should have received a copy of the GNU Affero General Public License
   *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   *    As a special exception, the copyright holders give permission to link the
   *    code of portions of this program with the OpenSSL library under certain
   *    conditions as described in each individual source file and distribute
   *    linked combinations including the program with the OpenSSL library. You
   *    must comply with the GNU Affero General Public License in all respects for
   *    all of the code used other than as permitted herein. If you modify file(s)
   *    with this exception, you may extend this exception to your version of the
   *    file(s), but you are not obligated to do so. If you do not wish to do so,
   *    delete this exception statement from your version. If you delete this
   *    exception statement from all source files in the program, then also delete
   *    it in the license file.
   */
  
  #pragma once
  
  #include <string>
  
  #include "mongo/base/disallow_copying.h"
  #include "mongo/base/string_data.h"
  
  namespace mongo {
      
      class SaslClientSession;
      template <typename T> class StatusWith;
      
      /**
       * Abstract class for implementing the clent-side
       * of a SASL mechanism conversation.
       */
      class SaslClientConversation {
          MONGO_DISALLOW_COPYING(SaslClientConversation);
      public:
          /**
           * Implements the client side of a SASL authentication mechanism.
           *
           * "saslClientSession" is the corresponding SASLClientSession.
           * "saslClientSession" must stay in scope until the SaslClientConversation's 
           *  destructor completes.
           * 
           **/
          explicit SaslClientConversation(SaslClientSession* saslClientSession) :
              _saslClientSession(saslClientSession) {}
  
          virtual ~SaslClientConversation();
  
          /**
           * Performs one step of the client side of the authentication session,
           * consuming "inputData" and producing "*outputData".
           *
           * A return of Status::OK() indicates successful progress towards authentication. 
           * A return of !Status::OK() indicates failed authentication
           *
           * A return of true means that the authentication process has finished.
           * A return of false means that the authentication process has more steps.
           *
           */
          virtual StatusWith<bool> step(const StringData& inputData, std::string* outputData) = 0;
  
      protected:
          SaslClientSession* _saslClientSession;
      };
  
  }  // namespace mongo
  