Crypto++
Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
CTR_ModePolicy Class Referenceabstract
Inheritance diagram for CTR_ModePolicy:
ModePolicyCommonTemplate< AdditiveCipherAbstractPolicy > CipherModeBase AdditiveCipherAbstractPolicy SymmetricCipher SimpleKeyingInterface StreamTransformation Algorithm Clonable AbstractPolicyHolder< AdditiveCipherAbstractPolicy, CTR_ModePolicy > AdditiveCipherTemplate< AbstractPolicyHolder< AdditiveCipherAbstractPolicy, CTR_ModePolicy > > ConcretePolicyHolder< Empty, AdditiveCipherTemplate< AbstractPolicyHolder< AdditiveCipherAbstractPolicy, CTR_ModePolicy > > > CipherModeFinalTemplate_ExternalCipher< ConcretePolicyHolder< Empty, AdditiveCipherTemplate< AbstractPolicyHolder< AdditiveCipherAbstractPolicy, CTR_ModePolicy > > > > GCM_Base::GCTR

Public Types

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

Public Member Functions

bool CipherIsRandomAccess () const
 
IV_Requirement IVRequirement () const
 returns the minimal requirement for secure IVs
 
size_t MinKeyLength () const
 returns smallest valid key length in bytes */
 
size_t MaxKeyLength () const
 returns largest valid key length in bytes */
 
size_t DefaultKeyLength () const
 returns default (recommended) key length in bytes */
 
size_t GetValidKeyLength (size_t n) const
 returns the smallest valid key length in bytes that is >= min(n, GetMaxKeyLength())
 
bool IsValidKeyLength (size_t n) const
 returns whether n is a valid key length
 
unsigned int OptimalDataAlignment () const
 returns how input should be aligned for optimal performance
 
unsigned int IVSize () const
 
void SetCipher (BlockCipher &cipher)
 
void SetCipherWithIV (BlockCipher &cipher, const byte *iv, int feedbackSize=0)
 
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"
 
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)
 
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 void ProcessData (byte *outString, const byte *inString, size_t length)=0
 encrypt or decrypt an array of bytes of specified length More...
 
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 bool IsRandomAccess () const =0
 returns whether this cipher supports random access
 
virtual void Seek (lword 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
 
virtual unsigned int GetOptimalBlockSize () const
 

Static Public Member Functions

static const char * StaticAlgorithmName ()
 

Protected Member Functions

virtual void IncrementCounterBy256 ()
 
unsigned int GetAlignment () const
 
unsigned int GetBytesPerIteration () const
 
unsigned int GetIterationsToBuffer () const
 
void WriteKeystream (byte *buffer, size_t iterationCount)
 
bool CanOperateKeystream () const
 
void OperateKeystream (KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
 
void CipherResynchronize (byte *keystreamBuffer, const byte *iv, size_t length)
 
void SeekToIteration (lword iterationCount)
 
unsigned int BlockSize () const
 
virtual void SetFeedbackSize (unsigned int feedbackSize)
 
virtual void ResizeBuffers ()
 
const AlgorithmGetAlgorithm () const
 
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
 

Protected Attributes

AlignedSecByteBlock m_counterArray
 
BlockCipherm_cipher
 
AlignedSecByteBlock m_register
 

Detailed Description

Definition at line 137 of file modes.h.

Member Function Documentation

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::ProcessData ( byte *  outString,
const byte *  inString,
size_t  length 
)
pure virtualinherited

encrypt or decrypt an array of bytes of specified length

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

Implemented in CBC_Decryption, CBC_Encryption, ECB_OneWay, AuthenticatedSymmetricCipherBase, Weak1::ARC4_Base, and PublicBlumBlumShub.

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: