/*
 * AuthBackendChallengeResponse.h
 *
 * Copyright (C) 2008 Matthias Schiffer <matthias@gamezock.de>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MAD_MODULES_AUTHBACKENDCHALLENGERESPONSE_AUTHBACKENDCHALLENGERESPONSE_H_
#define MAD_MODULES_AUTHBACKENDCHALLENGERESPONSE_AUTHBACKENDCHALLENGERESPONSE_H_

#include "../export.h"

#include <Common/AuthBackend.h>
#include <Common/AuthContext.h>
#include <Common/AuthProvider.h>
#include <Common/Application.h>

#include <boost/date_time/posix_time/posix_time.hpp>

#include <boost/random/mersenne_twister.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/random/variate_generator.hpp>

namespace Mad {
namespace Modules {
namespace AuthBackendChallengeResponse {

class MAD_MODULE_EXPORT AuthBackendChallengeResponse : public Common::AuthBackend, private boost::noncopyable {
  private:
    class AuthContextChallengeResponse : public Common::AuthContext {
      private:
        friend class AuthBackendChallengeResponse;

        bool authenticated;
        std::vector<boost::uint8_t> challenge;

        AuthContextChallengeResponse(AuthBackendChallengeResponse *backend);

      protected:
        virtual bool isAuthenticated() const {
          return authenticated;
        }
    };

    static const std::string methodName;

    Common::Application *application;

    boost::mt19937 rng;
    boost::uniform_int<boost::uint8_t> byteDistribution;
    boost::variate_generator<boost::mt19937&, boost::uniform_int<boost::uint8_t> > randomGenerator;


  protected:
    virtual const std::string& getMethodName() const {
      return methodName;
    }

    virtual std::vector<std::string> getSubMethods(boost::shared_ptr<Common::AuthProvider> provider) const {
      std::vector<std::string> ret;
      ret.push_back(provider->getHashes().front());

      return ret;
    }

    virtual boost::shared_ptr<Common::AuthContext> authenticate(boost::shared_ptr<Common::AuthProvider> provider, const std::string &subMethod,
        const std::string &user, const std::vector<boost::uint8_t> &data, std::vector<boost::uint8_t> &response,
        boost::shared_ptr<Common::AuthContext> context) throw(Core::Exception);

  public:
    AuthBackendChallengeResponse(Common::Application *application0)
    : application(application0), rng(static_cast<boost::uint32_t>(boost::posix_time::microsec_clock::universal_time().time_of_day().total_milliseconds())),
      byteDistribution(0, 255), randomGenerator(rng, byteDistribution) {}
};

}
}
}

#endif /* MAD_MODULES_AUTHBACKENDCHALLENGERESPONSE_AUTHBACKENDCHALLENGERESPONSE_H_ */