Crypto++
Public Types | Public Member Functions | Protected Member Functions | List of all members
SimpleKeyingInterface Class Referenceabstract

keying interface for crypto algorithms that take byte strings as keys More...

#include <cryptlib.h>

Inheritance diagram for SimpleKeyingInterface:
BlockCipher MessageAuthenticationCode SymmetricCipher SAFER::Base SimpleKeyingInterfaceImpl< BlockCipher, BTEA_Info > AuthenticatedSymmetricCipher CBC_MAC_Base CMAC_Base DMAC_Base< T > HMAC_Base IteratedHashBase< word32, MessageAuthenticationCode > IteratedHashBase< word64, MessageAuthenticationCode > TwoBases< MessageAuthenticationCode, VariableKeyLength< 32, 0, INT_MAX > > CipherModeBase Weak1::ARC4_Base

Public Types

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

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 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...
 

Protected Member Functions

virtual const AlgorithmGetAlgorithm () 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

keying interface for crypto algorithms that take byte strings as keys

Definition at line 346 of file cryptlib.h.

Member Function Documentation

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

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
inline

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 
)
virtual

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.


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