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BlockCipher Class Reference

#include <cryptlib.h>

Inheritance diagram for BlockCipher:

BlockTransformation SimpleKeyingInterface Algorithm Clonable SimpleKeyingInterfaceImpl< BlockCipher, BTEA_Info > AlgorithmImpl< SimpleKeyingInterfaceImpl< BlockCipher, BTEA_Info >, BTEA_Info > List of all members.

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 596 of file cryptlib.h.

Public Types

enum  IV_Requirement {
  STRUCTURED_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV,
  NOT_RESYNCHRONIZABLE
}

Public Member Functions

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 BlockAlignment () const
 block pointers must be divisible by this
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 void ProcessAndXorMultipleBlocks (const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, unsigned int numberOfBlocks) const
 encrypt or decrypt multiple blocks, for bit-slicing implementations
virtual std::string AlgorithmName () const
 returns name of this algorithm, not universally implemented yet
virtual ClonableClone () const
 this is not implemented by most classes yet
virtual unsigned int MinKeyLength () const =0
 returns smallest valid key length in bytes */
virtual unsigned int MaxKeyLength () const =0
 returns largest valid key length in bytes */
virtual unsigned int DefaultKeyLength () const =0
 returns default (recommended) key length in bytes */
virtual unsigned int GetValidKeyLength (unsigned int n) const =0
 returns the smallest valid key length in bytes that is >= min(n, GetMaxKeyLength())
virtual bool IsValidKeyLength (unsigned int n) const
 returns whether n is a valid key length
virtual void SetKey (const byte *key, unsigned int length, const NameValuePairs &params=g_nullNameValuePairs)=0
 set or reset the key of this object
void SetKeyWithRounds (const byte *key, unsigned int length, int rounds)
 calls SetKey() with an NameValuePairs object that just specifies "Rounds"
void SetKeyWithIV (const byte *key, unsigned int 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
 returns size of IVs used by this object
virtual void Resynchronize (const byte *IV)
 resynchronize with an IV
virtual void GetNextIV (byte *IV)
 get a secure IV for the next message

Protected Member Functions

void ThrowIfInvalidKeyLength (const Algorithm &algorithm, unsigned int length)
void ThrowIfResynchronizable ()
void ThrowIfInvalidIV (const byte *iv)
const byte * GetIVAndThrowIfInvalid (const NameValuePairs &params)
void AssertValidKeyLength (unsigned int length) const


Member Function Documentation

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 430 of file cryptlib.h.

virtual void SimpleKeyingInterface::SetKey const byte *  key,
unsigned int  length,
const NameValuePairs params = g_nullNameValuePairs
[pure virtual, inherited]
 

set or reset the key of this object

Parameters:
params is used to specify Rounds, BlockSize, etc

Implemented in HermeticHashFunctionMAC< T_Hash, T_Info >, and HermeticHashFunctionMAC< PanamaHash< B > >.

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 384 of file cryptlib.h.

virtual void SimpleKeyingInterface::GetNextIV byte *  IV  )  [inline, 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 400 of file cryptlib.h.


The documentation for this class was generated from the following file:
Generated on Wed Jul 21 19:15:41 2004 for Crypto++ by doxygen 1.3.7-20040704