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  @file 

    23  @publishedPartner

    24  @released 

    25 */

    26  

    27 #ifndef __MODE_H__

    28 #define __MODE_H__

    29 

    30 #include <blocktransformation.h>

    31 

    32 /**

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

    34 * chaining modes.

    35 *

    36 * It is initialised with a subclass of CBlockTransformation,

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

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

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

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

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

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

    43 * Transform().

    44 * 

    45 * @publishedPartner

    46 * @released 

    47 */

    48 class CBlockChainingMode : public CBlockTransformation

    49 {

    50 public:

    51 	virtual void Reset();

    52 	virtual TInt BlockSize() const;

    53 	virtual TInt KeySize() const;

    54 public:

    55 	/**

    56 	* Sets the initialization vector.

    57 	* 

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

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

    60 	*/

    61 	virtual void SetIV(const TDesC8& aIV);

    62 protected:

    63 	/** Default constructor */

    64 	IMPORT_C CBlockChainingMode();

    65 	/** 

    66 	 * Second phase constructor

    67 	 * 

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

    69 	 *

    70 	 * @param aBT	A block transformation object

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

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

    73 	 */

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

    75 	

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

    77 	IMPORT_C virtual ~CBlockChainingMode();

    78 protected:

    79 	/** A block transformation object */

    80 	CBlockTransformation* iBT;

    81 

    82 	/** 

    83 	 * A buffer containing the feedback register

    84 	 *

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

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

    87 	 */

    88 	HBufC8* iRegisterBuf;

    89 

    90 	/** Encapsulates a pointer to iRegisterBuf */

    91 	TPtr8 iRegister;

    92 

    93 	/** 

    94 	 * A buffer containing the Initialisation Vector (IV) 

    95 	 *

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

    97 	 */

    98 	HBufC8* iIVBuf;

    99 

   100 	/** Encapsulates a pointer to iIVBuf */

   101 	TPtr8 iIV;

   102 };

   103 

   104 #endif	//	__MODE_H__