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StreamTransformation Class Reference

#include <cryptlib.h>

Inheritance diagram for StreamTransformation:

Algorithm Clonable PublicBlumBlumShub SapphireDecryption SapphireEncryption SymmetricCipher BlumBlumShub SapphireHash SapphireRNG ARC4_Base MARC4_Base List of all members.

Detailed Description

interface for the data processing part of stream ciphers

Definition at line 435 of file cryptlib.h.

Public Member Functions

StreamTransformationRef ()
 return a reference to this object,

virtual unsigned int MandatoryBlockSize () const
 returns block size, if input must be processed in blocks, otherwise 1

virtual unsigned int OptimalBlockSize () const
 returns the input block size that is most efficient for this cipher

virtual unsigned int GetOptimalBlockSizeUsed () const
 returns how much of the current block is used up

virtual unsigned int OptimalDataAlignment () const
 returns how input should be aligned for optimal performance

virtual void ProcessData (byte *outString, const byte *inString, unsigned int length)=0
 encrypt or decrypt an array of bytes of specified length

virtual void ProcessLastBlock (byte *outString, const byte *inString, unsigned int length)
 for ciphers where the last block of data is special, encrypt or decrypt the last block of data

virtual unsigned int MinLastBlockSize () const
 returns the minimum size of the last block, 0 indicating the last block is not special

void ProcessString (byte *inoutString, unsigned int length)
 same as ProcessData(inoutString, inoutString, length)

void ProcessString (byte *outString, const byte *inString, unsigned int length)
 same as ProcessData(outString, inString, length)

byte ProcessByte (byte input)
 implemented as {ProcessData(&input, &input, 1); return input;}

virtual bool IsRandomAccess () const=0
 returns whether this cipher supports random access

virtual void Seek (dword n)
 for random access ciphers, seek to an absolute position

virtual bool IsSelfInverting () const=0
 returns whether this transformation is self-inverting (e.g. xor with a keystream)

virtual bool IsForwardTransformation () const=0
 returns whether this is an encryption object

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


Member Function Documentation

StreamTransformation& StreamTransformation::Ref  )  [inline]
 

return a reference to this object,

This function is useful for passing a temporary StreamTransformation object to a function that takes a non-const reference.

Definition at line 441 of file cryptlib.h.

virtual unsigned int StreamTransformation::OptimalBlockSize  )  const [inline, virtual]
 

returns the input block size that is most efficient for this cipher

Note:
optimal input length is n * OptimalBlockSize() - GetOptimalBlockSizeUsed() for any n > 0

Definition at line 448 of file cryptlib.h.

References MandatoryBlockSize().

virtual void StreamTransformation::ProcessData byte *  outString,
const byte *  inString,
unsigned int  length
[pure virtual]
 

encrypt or decrypt an array of bytes of specified length

Note:
either inString == outString, or they don't overlap

Implemented in ARC4_Base, and PublicBlumBlumShub.

Referenced by ProcessByte(), ProcessLastBlock(), and ProcessString().

void StreamTransformation::ProcessLastBlock byte *  outString,
const byte *  inString,
unsigned int  length
[virtual]
 

for ciphers where the last block of data is special, encrypt or decrypt the last block of data

For now the only use of this function is for CBC-CTS mode.

Definition at line 73 of file cryptlib.cpp.

References MandatoryBlockSize(), MinLastBlockSize(), and ProcessData().


The documentation for this class was generated from the following files:
Generated on Sun Mar 14 20:44:42 2004 for Crypto++ by doxygen 1.3.6-20040222