Crypto++
Public Types | Public Member Functions | Static Public Member Functions | Static Public Attributes | Protected Member Functions | Protected Attributes | List of all members
Weak1::ARC4_Base Class Referenceabstract

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#include <arc4.h>

Inheritance diagram for Weak1::ARC4_Base:
VariableKeyLength< 16, 1, 256 > RandomNumberGenerator SymmetricCipher SymmetricCipherDocumentation Algorithm SimpleKeyingInterface StreamTransformation Clonable Algorithm Clonable Weak1::MARC4_Base

Public Types

typedef SymmetricCipherFinal
< ARC4_Base
Encryption
 
typedef SymmetricCipherFinal
< ARC4_Base
Decryption
 
enum  IV_Requirement {
  UNIQUE_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV,
  NOT_RESYNCHRONIZABLE
}
 

Public Member Functions

void GenerateBlock (byte *output, size_t size)
 generate random array of bytes
 
void DiscardBytes (size_t n)
 generate and discard n bytes
 
void ProcessData (byte *outString, const byte *inString, size_t length)
 encrypt or decrypt an array of bytes of specified length More...
 
bool IsRandomAccess () const
 returns whether this cipher supports random access
 
bool IsSelfInverting () const
 returns whether this transformation is self-inverting (e.g. xor with a keystream)
 
bool IsForwardTransformation () const
 returns whether this is an encryption object
 
virtual void IncorporateEntropy (const byte *input, size_t length)
 update RNG state with additional unpredictable values
 
virtual bool CanIncorporateEntropy () const
 returns true if IncorporateEntropy is implemented
 
virtual byte GenerateByte ()
 generate new random byte and return it
 
virtual unsigned int GenerateBit ()
 generate new random bit and return it More...
 
virtual word32 GenerateWord32 (word32 a=0, word32 b=0xffffffffL)
 generate a random 32 bit word in the range min to max, inclusive
 
virtual void GenerateIntoBufferedTransformation (BufferedTransformation &target, const std::string &channel, lword length)
 generate random bytes as input to a BufferedTransformation
 
template<class IT >
void Shuffle (IT begin, IT end)
 randomly shuffle the specified array, resulting permutation is uniformly distributed
 
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 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 More...
 
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) More...
 
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 More...
 
StreamTransformationRef ()
 return a reference to this object, useful for passing a temporary object to a function that takes a non-const reference
 
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 More...
 
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 ProcessLastBlock (byte *outString, const byte *inString, size_t length)
 for ciphers where the last block of data is special, encrypt or decrypt the last block of data More...
 
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, size_t length)
 same as ProcessData(inoutString, inoutString, length)
 
void ProcessString (byte *outString, const byte *inString, size_t length)
 same as ProcessData(outString, inString, length)
 
byte ProcessByte (byte input)
 implemented as {ProcessData(&input, &input, 1); return input;}
 
virtual void Seek (lword n)
 for random access ciphers, seek to an absolute position
 

Static Public Member Functions

static const char * StaticAlgorithmName ()
 
static size_t StaticGetValidKeyLength (size_t n)
 

Static Public Attributes

static const int MIN_KEYLENGTH
 
static const int MAX_KEYLENGTH
 
static const int DEFAULT_KEYLENGTH
 
static const int KEYLENGTH_MULTIPLE
 
static const int IV_REQUIREMENT
 
static const int IV_LENGTH
 

Protected Member Functions

void UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)
 
virtual unsigned int GetDefaultDiscardBytes () const
 
const AlgorithmGetAlgorithm () const
 
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
 

Protected Attributes

FixedSizeSecBlock< byte, 256 > m_state
 
byte m_x
 
byte m_y
 

Detailed Description

_

Definition at line 11 of file arc4.h.

Member Function Documentation

void Weak1::ARC4_Base::ProcessData ( byte *  outString,
const byte *  inString,
size_t  length 
)
virtual

encrypt or decrypt an array of bytes of specified length

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

Implements StreamTransformation.

virtual unsigned int RandomNumberGenerator::GenerateBit ( )
virtualinherited

generate new random bit and return it

Default implementation is to call GenerateByte() and return its lowest bit.

Reimplemented in PublicBlumBlumShub.

virtual void SimpleKeyingInterface::SetKey ( const byte *  key,
size_t  length,
const NameValuePairs params = g_nullNameValuePairs 
)
virtualinherited

set or reset the key of this object

Parameters
paramsis used to specify Rounds, BlockSize, etc.

Reimplemented in ECB_OneWay, and AuthenticatedSymmetricCipherBase.

bool SimpleKeyingInterface::IsResynchronizable ( ) const
inlineinherited

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 385 of file cryptlib.h.

virtual void SimpleKeyingInterface::GetNextIV ( RandomNumberGenerator rng,
byte *  IV 
)
virtualinherited

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.

Reimplemented in VMAC_Base.

virtual unsigned int StreamTransformation::OptimalBlockSize ( ) const
inlinevirtualinherited

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

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

Reimplemented in ECB_OneWay.

Definition at line 480 of file cryptlib.h.

virtual void StreamTransformation::ProcessLastBlock ( byte *  outString,
const byte *  inString,
size_t  length 
)
virtualinherited

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.

Reimplemented in CBC_CTS_Decryption, and CBC_CTS_Encryption.


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