/*

 * 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 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);

 private:

 	CSystemRandom(void);

 	CSystemRandom(const CSystemRandom&);

 	CSystemRandom& operator=(const CSystemRandom&);

 	};

 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__