1 /*

     2 * Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

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

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 * ** IMPORTANT ** PublishedPartner API's in this file are published to 3rd party developers via the 

    16 * Symbian website. Changes to these API's should be treated as PublishedAll API changes and the Security TA should be consulted.

    17 *

    18 */

    19 

    20 

    21 

    22 

    23 /**

    24  @file 

    25  @publishedPartner

    26  @released 

    27 */

    28  

    29 #ifndef __MODE_H__

    30 #define __MODE_H__

    31 

    32 #include "blocktransformation.h"

    33 

    34 /**

    35 * Abstract class defining the use of block transformation objects as block

    36 * chaining modes.

    37 *

    38 * It is initialised with a subclass of CBlockTransformation,

    39 * which it subsequently owns.  Calls to its Transform() function will call the

    40 * Transform() function in the underlying CBlockTransformation object, and perform

    41 * the additional transformation for block chaining in that mode.  This all means

    42 * that if you want to do, say, AES encryption in CBC mode, you need to construct

    43 * a CAESEncryptor object, then pass it to the CModeCBCEncryptor subclass of

    44 * CBlockChainingMode, and subsequently use the CModeCBCEncryptor object to call

    45 * Transform().

    46 * 

    47 * @publishedPartner

    48 * @released 

    49 */

    50 class CBlockChainingMode : public CBlockTransformation

    51 {

    52 public:

    53 	virtual void Reset();

    54 	virtual TInt BlockSize() const;

    55 	virtual TInt KeySize() const;

    56 public:

    57 	/**

    58 	* Sets the initialization vector.

    59 	* 

    60 	* @param aIV	The initialization vector.  The length of this descriptor must be

    61 	*				the same as the underlying cipher's block size.

    62 	*/

    63 	virtual void SetIV(const TDesC8& aIV);

    64 protected:

    65 	/** Default constructor */

    66 	IMPORT_C CBlockChainingMode();

    67 	/** 

    68 	 * Second phase constructor

    69 	 * 

    70 	 * This should be called last by derived classes' ContructL()s .

    71 	 *

    72 	 * @param aBT	A block transformation object

    73 	 * @param aIV	Initialization vector, the length of this descriptor must be

    74 	 *				the same as the underlying cipher's block size.

    75 	 */

    76 	IMPORT_C void ConstructL(CBlockTransformation* aBT, const TDesC8& aIV);

    77 	

    78 	/** The destructor frees all resources owned by the object, prior to its destruction. */

    79 	IMPORT_C virtual ~CBlockChainingMode();

    80 protected:

    81 	/** A block transformation object */

    82 	CBlockTransformation* iBT;

    83 

    84 	/** 

    85 	 * A buffer containing the feedback register

    86 	 *

    87 	 * This must equal the underlying cipher's block size in length. 

    88 	 * Initially this register is filled with the initialization vector.

    89 	 */

    90 	HBufC8* iRegisterBuf;

    91 

    92 	/** Encapsulates a pointer to iRegisterBuf */

    93 	TPtr8 iRegister;

    94 

    95 	/** 

    96 	 * A buffer containing the Initialisation Vector (IV) 

    97 	 *

    98 	 * This must equal the underlying cipher's block size in length. 

    99 	 */

   100 	HBufC8* iIVBuf;

   101 

   102 	/** Encapsulates a pointer to iIVBuf */

   103 	TPtr8 iIV;

   104 };

   105 

   106 #endif	//	__MODE_H__