interface for one direction (encryption or decryption) of a block cipher More...

#include <cryptlib.h>

Inheritance diagram for BlockCipher:

Public Types
enum	IV_Requirement { UNIQUE_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV, NOT_RESYNCHRONIZABLE }
enum	{ BT_InBlockIsCounter = 1, BT_DontIncrementInOutPointers = 2, BT_XorInput = 4, BT_ReverseDirection = 8, BT_AllowParallel = 16 }
Public Member Functions
virtual size_t	MinKeyLength () const =0
	returns smallest valid key length in bytes */
virtual size_t	MaxKeyLength () const =0
	returns largest valid key length in bytes */
virtual size_t	DefaultKeyLength () const =0
	returns default (recommended) key length in bytes */
virtual size_t	GetValidKeyLength (size_t n) const =0
	returns the smallest valid key length in bytes that is >= min(n, GetMaxKeyLength())
virtual bool	IsValidKeyLength (size_t n) const
	returns whether n is a valid key length
virtual void	SetKey (const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
	set or reset the key of this object
void	SetKeyWithRounds (const byte *key, size_t length, int rounds)
	calls SetKey() with an NameValuePairs object that just specifies "Rounds"
void	SetKeyWithIV (const byte key, size_t length, const byte iv, size_t ivLength)
	calls SetKey() with an NameValuePairs object that just specifies "IV"
void	SetKeyWithIV (const byte key, size_t length, const byte iv)
	calls SetKey() with an NameValuePairs object that just specifies "IV"
virtual IV_Requirement	IVRequirement () const =0
	returns the minimal requirement for secure IVs
bool	IsResynchronizable () const
	returns whether this object can be resynchronized (i.e. supports initialization vectors)
bool	CanUseRandomIVs () const
	returns whether this object can use random IVs (in addition to ones returned by GetNextIV)
bool	CanUsePredictableIVs () const
	returns whether this object can use random but possibly predictable IVs (in addition to ones returned by GetNextIV)
bool	CanUseStructuredIVs () const
	returns whether this object can use structured IVs, for example a counter (in addition to ones returned by GetNextIV)
virtual unsigned int	IVSize () const
unsigned int	DefaultIVLength () const
	returns default length of IVs accepted by this object
virtual unsigned int	MinIVLength () const
	returns minimal length of IVs accepted by this object
virtual unsigned int	MaxIVLength () const
	returns maximal length of IVs accepted by this object
virtual void	Resynchronize (const byte *iv, int ivLength=-1)
	resynchronize with an IV. ivLength=-1 means use IVSize()
virtual void	GetNextIV (RandomNumberGenerator &rng, byte *IV)
	get a secure IV for the next message
virtual void	ProcessAndXorBlock (const byte inBlock, const byte xorBlock, byte *outBlock) const =0
	encrypt or decrypt inBlock, xor with xorBlock, and write to outBlock
void	ProcessBlock (const byte inBlock, byte outBlock) const
	encrypt or decrypt one block
void	ProcessBlock (byte *inoutBlock) const
	encrypt or decrypt one block in place
virtual unsigned int	BlockSize () const =0
	block size of the cipher in bytes
virtual unsigned int	OptimalDataAlignment () const
	returns how inputs and outputs should be aligned for optimal performance
virtual bool	IsPermutation () const
	returns true if this is a permutation (i.e. there is an inverse transformation)
virtual bool	IsForwardTransformation () const =0
	returns true if this is an encryption object
virtual unsigned int	OptimalNumberOfParallelBlocks () const
	return number of blocks that can be processed in parallel, for bit-slicing implementations
virtual size_t	AdvancedProcessBlocks (const byte inBlocks, const byte xorBlocks, byte *outBlocks, size_t length, word32 flags) const
	encrypt and xor blocks according to flags (see FlagsForAdvancedProcessBlocks)
CipherDir	GetCipherDirection () const
virtual std::string	AlgorithmName () const
	returns name of this algorithm, not universally implemented yet
virtual Clonable *	Clone () const
	this is not implemented by most classes yet
Public Attributes
enum BlockTransformation:: { ... }	FlagsForAdvancedProcessBlocks
Protected Member Functions
const Algorithm &	GetAlgorithm () const
virtual const Algorithm &	GetAlgorithm () const =0
virtual void	UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)=0
void	ThrowIfInvalidKeyLength (size_t length)
void	ThrowIfResynchronizable ()
void	ThrowIfInvalidIV (const byte *iv)
size_t	ThrowIfInvalidIVLength (int size)
const byte *	GetIVAndThrowIfInvalid (const NameValuePairs &params, size_t &size)
void	AssertValidKeyLength (size_t length) const

Detailed Description

interface for one direction (encryption or decryption) of a block cipher

Note:: These objects usually should not be used directly. See BlockTransformation for more details.

Definition at line 604 of file cryptlib.h.

Member Function Documentation

void SimpleKeyingInterface::SetKey	(	const byte *	key,
		size_t	length,
		const NameValuePairs &	params = `g_nullNameValuePairs`
	)			`[virtual, inherited]`

set or reset the key of this object

Parameters:

params

is used to specify Rounds, BlockSize, etc.

Definition at line 60 of file cryptlib.cpp.

Referenced by SimpleKeyingInterface::SetKeyWithIV(), and SimpleKeyingInterface::SetKeyWithRounds().

bool SimpleKeyingInterface::IsResynchronizable ( ) const [inline, inherited]

returns whether this object can be resynchronized (i.e. supports initialization vectors)

If this function returns true, and no IV is passed to SetKey() and CanUseStructuredIVs()==true, an IV of all 0's will be assumed.

Definition at line 386 of file cryptlib.h.

void SimpleKeyingInterface::GetNextIV	(	RandomNumberGenerator &	rng,
		byte *	IV
	)			`[virtual, inherited]`

get a secure IV for the next message

This method should be called after you finish encrypting one message and are ready to start the next one. After calling it, you must call SetKey() or Resynchronize() before using this object again. This method is not implemented on decryption objects.

Definition at line 136 of file cryptlib.cpp.

References RandomNumberGenerator::GenerateBlock().

void BlockTransformation::ProcessBlock	(	const byte *	inBlock,
		byte *	outBlock
	)			const `[inline, inherited]`

encrypt or decrypt one block

Precondition:: size of inBlock and outBlock == BlockSize()

Definition at line 437 of file cryptlib.h.

Referenced by BlockTransformation::AdvancedProcessBlocks(), CBC_CTS_Decryption::ProcessLastBlock(), CBC_CTS_Encryption::ProcessLastBlock(), and CMAC_Base::Update().

size_t BlockTransformation::AdvancedProcessBlocks	(	const byte *	inBlocks,
		const byte *	xorBlocks,
		byte *	outBlocks,
		size_t	length,
		word32	flags
	)			const `[virtual, inherited]`

encrypt and xor blocks according to flags (see FlagsForAdvancedProcessBlocks)

/note If BT_InBlockIsCounter is set, last byte of inBlocks may be modified.

Definition at line 141 of file cryptlib.cpp.

References BlockTransformation::BlockSize(), BlockTransformation::ProcessAndXorBlock(), and BlockTransformation::ProcessBlock().

Referenced by CBC_Decryption::ProcessData(), CBC_Encryption::ProcessData(), ECB_OneWay::ProcessData(), CMAC_Base::TruncatedFinal(), CMAC_Base::Update(), and CBC_MAC_Base::Update().

The documentation for this class was generated from the following file:

cryptlib.h

BlockCipher Class Reference

Public Types

Public Member Functions

Public Attributes

Protected Member Functions

Detailed Description

Member Function Documentation