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DMAC< T > Class Template Reference

#include <dmac.h>

Inheritance diagram for DMAC< T >:

MessageAuthenticationCodeFinal< DMAC_Base< T > > ClonableImpl< MessageAuthenticationCodeFinal< DMAC_Base< T > >, MessageAuthenticationCodeImpl< DMAC_Base< T > > > MessageAuthenticationCodeImpl< DMAC_Base< T > > AlgorithmImpl< SimpleKeyingInterfaceImpl< DMAC_Base< T >, DMAC_Base< T > >, DMAC_Base< T > > SimpleKeyingInterfaceImpl< DMAC_Base< T >, DMAC_Base< T > > DMAC_Base< T > SameKeyLengthAs< T > MessageAuthenticationCode HashTransformation SimpleKeyingInterface Algorithm Clonable List of all members.

Detailed Description

template<class T>
class DMAC< T >

DMAC.

Based on "CBC MAC for Real-Time Data Sources" by Erez Petrank and Charles Rackoff. T should be a class derived from BlockCipherDocumentation.

Definition at line 39 of file dmac.h.

Public Types

enum  { DIGESTSIZE = T::BLOCKSIZE }
enum  { MIN_KEYLENGTH = T::MIN_KEYLENGTH, MAX_KEYLENGTH = T::MAX_KEYLENGTH, DEFAULT_KEYLENGTH = T::DEFAULT_KEYLENGTH }
enum  { IV_REQUIREMENT = T::IV_REQUIREMENT }
enum  IV_Requirement {
  STRUCTURED_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV,
  NOT_RESYNCHRONIZABLE
}

Public Member Functions

 DMAC (const byte *key, unsigned int length=DMAC_Base< T >::DEFAULT_KEYLENGTH)
ClonableClone () const
 this is not implemented by most classes yet
void SetKey (const byte *key, unsigned int length, const NameValuePairs &params=g_nullNameValuePairs)
 set or reset the key of this object
std::string AlgorithmName () const
 returns name of this algorithm, not universally implemented yet
unsigned int MinKeyLength () const
 returns smallest valid key length in bytes */
unsigned int MaxKeyLength () const
 returns largest valid key length in bytes */
unsigned int DefaultKeyLength () const
 returns default (recommended) key length in bytes */
unsigned int GetValidKeyLength (unsigned int n) const
 returns the smallest valid key length in bytes that is >= min(n, GetMaxKeyLength())
DMAC_Base< T >::IV_Requirement IVRequirement () const
 returns the minimal requirement for secure IVs
void CheckedSetKey (void *, Empty empty, const byte *key, unsigned int length, const NameValuePairs &params)
void Update (const byte *input, unsigned int length)
 process more input
void TruncatedFinal (byte *mac, unsigned int size)
 truncated version of Final()
unsigned int DigestSize () const
 size of the hash returned by Final()
virtual byte * CreateUpdateSpace (unsigned int &size)
 request space to write input into
virtual void Final (byte *digest)
 compute hash for current message, then restart for a new message
virtual void Restart ()
 discard the current state, and restart with a new message
virtual unsigned int BlockSize () const
 block size of underlying compression function, or 0 if not block based
virtual unsigned int OptimalBlockSize () const
 input to Update() should have length a multiple of this for optimal speed
virtual unsigned int OptimalDataAlignment () const
 returns how input should be aligned for optimal performance
virtual void CalculateDigest (byte *digest, const byte *input, unsigned int length)
 use this if your input is in one piece and you don't want to call Update() and Final() separately
virtual bool Verify (const byte *digest)
 verify that digest is a valid digest for the current message, then reinitialize the object
virtual bool VerifyDigest (const byte *digest, const byte *input, unsigned int length)
 use this if your input is in one piece and you don't want to call Update() and Verify() separately
virtual void CalculateTruncatedDigest (byte *digest, unsigned int digestSize, const byte *input, unsigned int length)
 truncated version of CalculateDigest()
virtual bool TruncatedVerify (const byte *digest, unsigned int digestLength)
 truncated version of Verify()
virtual bool VerifyTruncatedDigest (const byte *digest, unsigned int digestLength, const byte *input, unsigned int length)
 truncated version of VerifyDigest()
virtual bool IsValidKeyLength (unsigned int n) const
 returns whether n is a valid key length
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"
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

Static Public Member Functions

std::string StaticAlgorithmName ()
unsigned int StaticGetValidKeyLength (unsigned int keylength)

Protected Member Functions

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


Member Function Documentation

void MessageAuthenticationCodeImpl< DMAC_Base< T > , DMAC_Base< T > >::SetKey const byte *  key,
unsigned int  length,
const NameValuePairs params = g_nullNameValuePairs
[inline, virtual, inherited]
 

Implements SimpleKeyingInterface.

Definition at line 188 of file seckey.h.

virtual void HashTransformation::Final byte *  digest  )  [inline, virtual, inherited]
 

compute hash for current message, then restart for a new message

Precondition:
size of digest == DigestSize().
Definition at line 532 of file cryptlib.h.

Referenced by PKCS5_PBKDF2_HMAC< T >::DeriveKey(), HashFilter::Put2(), and HMAC_Base::TruncatedFinal().

virtual bool HashTransformation::Verify const byte *  digest  )  [inline, virtual, inherited]
 

verify that digest is a valid digest for the current message, then reinitialize the object

Default implementation is to call Final() and do a bitwise comparison between its output and digest. Definition at line 558 of file cryptlib.h.

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 19:15:50 2004 for Crypto++ by doxygen 1.3.7-20040704