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CDES Class Reference

class CDES : public CBlockTransformation

Abstract base class for DES, implementing features common between DES encryption and decryption. From CBlockTransformation

Inherits from

CDES
- CBlockTransformation
  - CBase

Public Member Functions
	~CDES()
TInt	BlockSize()
IMPORT_C TBool	IsWeakKey(const TDesC8 &)
TInt	KeySize()
void	Reset()
void	Transform(TDes8 &)

Protected Member Functions
	CDES()
void	ConstructL(const TDesC8 &, TBool)
void	DoTransform(TUint32 &, TUint32 &, const TUint32 *)
void	SetKey(const TDesC8 &, TUint32 *)

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()
	CBlockTransformation::GetExtension(TUint,TAny &,TAny )

Protected Attributes
TUint32	iK1
HBufC8 *	iKey

Constructor & Destructor Documentation

CDES()

CDES

(

)

[protected]

~CDES()

~CDES

(

)

[virtual]

Member Functions Documentation

BlockSize()

TInt

BlockSize

(

)

const [virtual]

Gets the block size in bytes.

ConstructL(const TDesC8 &, TBool)

void	ConstructL	(	const TDesC8 &	aKey,
			TBool	aCheckWeakKey
		)	[protected, virtual]

Parameters

const TDesC8 & aKey
TBool aCheckWeakKey

DoTransform(TUint32 &, TUint32 &, const TUint32 *)

void	DoTransform	(	TUint32 &	l,
			TUint32 &	r,
			const TUint32 *	aKey
		)	[protected]

Parameters

TUint32 & l
TUint32 & r
const TUint32 * aKey

IsWeakKey(const TDesC8 &)

IMPORT_C TBool

IsWeakKey

(

const TDesC8 &

aKey

)

[static]

Indicates whether a supplied key is weak. If the key is one of the weak keys defined by the crypto library (e.g. {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01}) ETrue is returned.

Parameters

const TDesC8 & aKey

The Key to be checked. The key length must be KDESKeySize = 8 bytes.

KeySize()

TInt

KeySize

(

)

const [virtual]

Gets the key size in bits.

Reset()

void

Reset

(

)

[virtual]

Resets the transformation back to its original state. Clears all its buffers.

SetKey(const TDesC8 &, TUint32 *)

void	SetKey	(	const TDesC8 &	aKey,
			TUint32 *	aKeyBuffer
		)	[protected, virtual]

Parameters

const TDesC8 & aKey
TUint32 * aKeyBuffer

Transform(TDes8 &)

void

Transform

(

TDes8 &

aBlock

)

[virtual]

Transforms the supplied block, returning the new value using the same parameter. aBlock.Size() must be the same length as BlockSize().

Parameters

TDes8 & aBlock

On input, the data to be transformed; on return, the data after transformation.

Member Data Documentation

TUint32 iK1

TUint32

iK1

[protected]

Key schedule array

Also used as the first key in triple-DES

HBufC8 * iKey

HBufC8 *

iKey

[protected]

The initial key.

The key length must be KDESKeySize = 8 bytes.