third_party/libjingle/source/talk/xmpp/saslmechanism.h

/*
 * libjingle
 * Copyright 2004--2005, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
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 *  2. Redistributions in binary form must reproduce the above copyright notice,
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 *     derived from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
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 */

#ifndef _SASLMECHANISM_H_
#define _SASLMECHANISM_H_

#include <string>

namespace buzz {

class XmlElement;


// Defines a mechnanism to do SASL authentication.
// Subclass instances should have a self-contained way to present
// credentials.
class SaslMechanism {

public:
  
  // Intended to be subclassed
  virtual ~SaslMechanism() {}

  // Should return the name of the SASL mechanism, e.g., "PLAIN"
  virtual std::string GetMechanismName() = 0;

  // Should generate the initial "auth" request.  Default is just <auth/>.
  virtual XmlElement * StartSaslAuth();

  // Should respond to a SASL "<challenge>" request.  Default is
  // to abort (for mechanisms that do not do challenge-response)
  virtual XmlElement * HandleSaslChallenge(const XmlElement * challenge);

  // Notification of a SASL "<success>".  Sometimes information
  // is passed on success.
  virtual void HandleSaslSuccess(const XmlElement * success);

  // Notification of a SASL "<failure>".  Sometimes information
  // for the user is passed on failure.
  virtual void HandleSaslFailure(const XmlElement * failure);

protected:
  static std::string Base64Encode(const std::string & plain);
  static std::string Base64Decode(const std::string & encoded);
  static std::string Base64EncodeFromArray(const char * plain, size_t length);
};

}

#endif