/*

* Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

* (c) 1999-2003 Symbian Ltd

*

*/

/**

 @file

 @publishedAll

 @released

*/

#ifndef __RANDOM_H__

#define __RANDOM_H__

#include <e32base.h>

class CRandom : public CBase

/**

 * @publishedAll

 * @released

 */

	{

public:

	/**

	 * Implementations of this method should fill the passed

	 * buffer with securely generated random data up to the 

	 * current length, discarding any current contents.

	 *

	 * @param aDest The buffer in to which to write random data.

	 *

	 */

	virtual void GenerateBytesL(TDes8& aDest) = 0;

protected:

	IMPORT_C CRandom(void);

private:

	CRandom(const CRandom&);

	CRandom& operator=(const CRandom&);

	};

/**

 *

 * Sets a secure random number generator implementation to use

 * for this thread.

 * 

 * @param aRNG The secure random number generator to use.

 *

 */

IMPORT_C void SetThreadRandomL(CRandom* aRNG);

/**

 *

 * Sets a secure random number generator implementation to use

 * for this thread, placing it on the cleanup stack.

 * 

 * @param aRNG The secure random number generator to use.

 *

 */

IMPORT_C void SetThreadRandomLC(CRandom* aRNG);

/** @internalAll */

void DeleteThreadRandom(TAny* aPtr);

/**

 *

 * Destroys the currently installed random number generator

 * that is in use for this thread.

 *

 */

IMPORT_C void DestroyThreadRandom(void);

/**

 *

 * Generates cryptographically secure random data, filling

 * the provided buffer up to its current length, discarding

 * any data that it may currently contain.

 *

 * @param aDest The buffer to fill with random data

 *

 */

IMPORT_C void GenerateRandomBytesL(TDes8& aDest);

class CRandomShim;

class CSystemRandom : public CRandom

/**

 *

 * This default secure random number generator uses

 * system state to generate entropy for the generation

 * of cryptographically secure random numbers.

 *

 * @publishedAll

 * @released

 *

 */

	{

public:

	/**

	 *

	 * Constructs a new system random number generator.

	 *

	 * @return A ready-to-use random number generator.

	 */

	IMPORT_C static CSystemRandom* NewL(void);

	/**

	 *

	 * Constructs a new system random number generator,

	 * and places it on the cleanup stack.

	 *

	 * @return A ready-to-use random number generator.

	 *

	 */

	IMPORT_C static CSystemRandom* NewLC(void);

	/**

	 *

	 * Implements the contract as specified in the base

	 * class, CRandom, filling the buffer supplied with

	 * cryptographically secure random data up to its

	 * current length, discarding its current content.

	 *

	 * @param aDest The buffer to which to write random data

	 *

	 */

	virtual void GenerateBytesL(TDes8& aDest);

	~CSystemRandom();

private:

	CSystemRandom(void);

	CSystemRandom(const CSystemRandom&);

	CSystemRandom& operator=(const CSystemRandom&);

	void ConstructL();

	CRandomShim *iShim;

	};

class TRandom

/**

 *

 * The user interface to the system cryptographically 

 * secure random number generator.

 *

 * @publishedAll

 * @released

 */

	{

public:

	/**

	 * 

	 * Fills the provided buffer with secure random data up to its

	 * current length, discarding any current content.

	 *

	 * @param aDestination The buffer in which to write the random data.

	 * @deprecated Use RandomL() instead

	 * @panic This function can panic under low memory conditions

	 *

	 */

	IMPORT_C static void Random(TDes8& aDestination);

	/**

	 * 

	 * Fills the provided buffer with secure random data up to its

	 * current length, discarding any current content.

	 *

	 * @param aDestination The buffer in which to write the random data.

	 * @leave This function can leave under low memory conditions

	 *

	 */

	IMPORT_C static void RandomL(TDes8& aDestination);

	};

class RRandomSession:public RSessionBase

/**

 *

 * The client interface to the system random number generator. End

 * users should use TRandom instead of this interface.

 *

 * @publishedAll

 * @released

 */

	{

public:

	IMPORT_C RRandomSession(void);

	/**

	 * 

	 * Fills the provided buffer with secure random data up to its

	 * current length, discarding any current content.

	 *

	 * @param aDestination The buffer in to which to write the random data 

	 *

	 */

	IMPORT_C TInt GetRandom(TDes8& aDestination);

	/**

	 *

	 * Opens a new session with the random number server.

	 *

	 */

	IMPORT_C void ConnectL(void);

	};

#endif // __RANDOM_H__