DMAC< T > Class Template Reference

DMAC. More...

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 SimpleKeyingInterface HashTransformation Algorithm Clonable

List of all members.

Public Types

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

Provides IV requirements as an enumerated value.

More...

Public Member Functions

 DMAC (const byte *key, size_t length=DMAC_Base< T >::DEFAULT_KEYLENGTH)
ClonableClone () const
 Copies this object.
std::string AlgorithmName () const
 Provides the name of this algorithm.
size_t MinKeyLength () const
 The minimum key length used by the cipher.
size_t MaxKeyLength () const
 The maximum key length used by the cipher.
size_t DefaultKeyLength () const
 The default key length used by the cipher.
size_t GetValidKeyLength (size_t keylength) const
 Provides a valid key length for the cipher.
SimpleKeyingInterface::IV_Requirement IVRequirement () const
 The default IV requirements for the cipher.
unsigned int IVSize () const
 The default initialization vector length for the cipher.
void UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)
 Sets the key for this object without performing parameter validation.
void Update (const byte *input, size_t length)
 Updates a hash with additional input.
void TruncatedFinal (byte *mac, size_t size)
 Computes the hash of the current message.
unsigned int DigestSize () const
 Provides the digest size of the hash.
virtual bool IsValidKeyLength (size_t keylength) const
 Returns whether keylength is a valid key length.
virtual void SetKey (const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
 Sets or reset the key of this object.
void SetKeyWithRounds (const byte *key, size_t length, int rounds)
 Sets or reset the key of this object.
void SetKeyWithIV (const byte *key, size_t length, const byte *iv, size_t ivLength)
 Sets or reset the key of this object.
void SetKeyWithIV (const byte *key, size_t length, const byte *iv)
 Sets or reset the key of this object.
bool IsResynchronizable () const
 returns whether the object can be resynchronized (i.e. supports initialization vectors)
bool CanUseRandomIVs () const
 returns whether the object can use random IVs (in addition to ones returned by GetNextIV)
bool CanUsePredictableIVs () const
 returns whether the object can use random but possibly predictable IVs (in addition to ones returned by GetNextIV)
bool CanUseStructuredIVs () const
 returns whether the 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)
 Gets a secure IV for the next message.
HashTransformationRef ()
 Provides a reference to this object.
virtual byte * CreateUpdateSpace (size_t &size)
 Request space which can be written into by the caller.
virtual void Final (byte *digest)
 Computes the hash of the current message.
virtual void Restart ()
 Restart the hash.
unsigned int TagSize () const
 Provides the tag size of the hash.
virtual unsigned int BlockSize () const
 Provides the block size of the compression function.
virtual unsigned int OptimalBlockSize () const
 Provides the input block size most efficient for this hash.
virtual unsigned int OptimalDataAlignment () const
 Provides input and output data alignment for optimal performance.
virtual void CalculateDigest (byte *digest, const byte *input, size_t length)
 Updates the hash with additional input and computes the hash of the current message.
virtual bool Verify (const byte *digest)
 Verifies the hash of the current message.
virtual bool VerifyDigest (const byte *digest, const byte *input, size_t length)
 Updates the hash with additional input and verifies the hash of the current message.
virtual void CalculateTruncatedDigest (byte *digest, size_t digestSize, const byte *input, size_t length)
 Updates the hash with additional input and computes the hash of the current message.
virtual bool TruncatedVerify (const byte *digest, size_t digestLength)
 Verifies the hash of the current message.
virtual bool VerifyTruncatedDigest (const byte *digest, size_t digestLength, const byte *input, size_t length)
 Updates the hash with additional input and verifies the hash of the current message.

Static Public Member Functions

static std::string StaticAlgorithmName ()
static size_t StaticGetValidKeyLength (size_t keylength)
 Provides a valid key length for the cipher provided by a static function.

Static Public Attributes

static const int DIGESTSIZE = T::BLOCKSIZE
static const int MIN_KEYLENGTH
 The minimum key length used by the cipher provided as a constant.
static const int MAX_KEYLENGTH
 The maximum key length used by the cipher provided as a constant.
static const int DEFAULT_KEYLENGTH
 The default key length used by the cipher provided as a constant.
static const int IV_REQUIREMENT
 The default IV requirements for the cipher provided as a constant.
static const int IV_LENGTH
 The default initialization vector length for the cipher provided as a constant.

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 45 of file dmac.h.


Member Enumeration Documentation

Provides IV requirements as an enumerated value.

Enumerator:
UNIQUE_IV 

The IV must be unique.

RANDOM_IV 

The IV must be random.

UNPREDICTABLE_RANDOM_IV 

The IV must be unpredictable.

INTERNALLY_GENERATED_IV 

The IV is set by the object.

NOT_RESYNCHRONIZABLE 

The object does not use an IV.

Definition at line 555 of file cryptlib.h.


Member Function Documentation

Clonable* ClonableImpl< MessageAuthenticationCodeFinal< DMAC_Base< T > > , MessageAuthenticationCodeImpl< DMAC_Base< T > > >::Clone (  )  const [inline, virtual, inherited]

Reimplemented from Clonable.

Definition at line 29 of file simple.h.

std::string AlgorithmImpl< SimpleKeyingInterfaceImpl< DMAC_Base< T >, DMAC_Base< T > > , DMAC_Base< T > >::AlgorithmName (  )  const [inline, virtual, inherited]

Reimplemented from Algorithm.

Definition at line 42 of file simple.h.

size_t SimpleKeyingInterfaceImpl< DMAC_Base< T > , DMAC_Base< T > >::GetValidKeyLength ( size_t  keylength  )  const [inline, virtual, inherited]

Provides a valid key length for the cipher.

Parameters:
keylength the size of the key, in bytes

keylength is provided in bytes, not bits. If keylength is less than MIN_KEYLENGTH, then the function returns MIN_KEYLENGTH. If keylength is greater than MAX_KEYLENGTH, then the function returns MAX_KEYLENGTH. if If keylength is a multiple of KEYLENGTH_MULTIPLE, then keylength is returned. Otherwise, the function returns a lower multiple of KEYLENGTH_MULTIPLE.

Implements SimpleKeyingInterface.

Definition at line 273 of file seckey.h.

SimpleKeyingInterface::IV_Requirement SimpleKeyingInterfaceImpl< DMAC_Base< T > , DMAC_Base< T > >::IVRequirement (  )  const [inline, virtual, inherited]

The default IV requirements for the cipher.

The default value is NOT_RESYNCHRONIZABLE. See IV_Requirement in cryptlib.h for allowed values.

Implements SimpleKeyingInterface.

Definition at line 278 of file seckey.h.

unsigned int SimpleKeyingInterfaceImpl< DMAC_Base< T > , DMAC_Base< T > >::IVSize (  )  const [inline, virtual, inherited]

The default initialization vector length for the cipher.

IVSize is provided in bytes, not bits. The default implementation uses IV_LENGTH, which is 0.

Reimplemented from SimpleKeyingInterface.

Definition at line 283 of file seckey.h.

template<class T >
void DMAC_Base< T >::UncheckedSetKey ( const byte *  key,
unsigned int  length,
const NameValuePairs params 
) [inline, virtual, inherited]

Sets the key for this object without performing parameter validation.

Parameters:
key a byte buffer used to key the cipher
length the length of the byte buffer
params additional parameters passed as NameValuePairs

key must be at least DEFAULT_KEYLENGTH in length.

Implements SimpleKeyingInterface.

Definition at line 54 of file dmac.h.

References SecBlock< T, A >::resize(), SecBlock< T, A >::size(), SameKeyLengthAs< T >::StaticGetValidKeyLength(), and UnsignedMin().

template<class T >
void DMAC_Base< T >::Update ( const byte *  input,
size_t  length 
) [inline, virtual, inherited]

Updates a hash with additional input.

Parameters:
input the additional input as a buffer
length the size of the buffer, in bytes

Implements HashTransformation.

Definition at line 65 of file dmac.h.

template<class T >
void DMAC_Base< T >::TruncatedFinal ( byte *  digest,
size_t  digestSize 
) [inline, virtual, inherited]

Computes the hash of the current message.

Parameters:
digest a pointer to the buffer to receive the hash
digestSize the size of the truncated digest, in bytes

TruncatedFinal() call Final() and then copies digestSize bytes to digest

TruncatedFinal() restarts the hash for the next nmessage.

Implements HashTransformation.

Definition at line 72 of file dmac.h.

template<class T >
unsigned int DMAC_Base< T >::DigestSize (  )  const [inline, virtual, inherited]

Provides the digest size of the hash.

Returns:
the digest size of the hash.

Calls to Final() require a buffer that is equal to (or greater than) DigestSize().

Implements HashTransformation.

Definition at line 28 of file dmac.h.

static size_t SameKeyLengthAs< T , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::StaticGetValidKeyLength ( size_t  keylength  )  [inline, static, inherited]

Provides a valid key length for the cipher provided by a static function.

Parameters:
keylength the size of the key, in bytes

If keylength is less than MIN_KEYLENGTH, then the function returns MIN_KEYLENGTH. If keylength is greater than MAX_KEYLENGTH, then the function returns MAX_KEYLENGTH. If keylength is a multiple of KEYLENGTH_MULTIPLE, then keylength is returned. Otherwise, the function returns keylength rounded down to the next smaller multiple of KEYLENGTH_MULTIPLE.

keylength is provided in bytes, not bits.

Definition at line 240 of file seckey.h.

References SameKeyLengthAs< T, IV_REQ, IV_L >::StaticGetValidKeyLength().

Referenced by DMAC_Base< T >::UncheckedSetKey().

virtual bool SimpleKeyingInterface::IsValidKeyLength ( size_t  keylength  )  const [inline, virtual, inherited]

Returns whether keylength is a valid key length.

Internally the function calls GetValidKeyLength()

Reimplemented in CCM_Base, EAX_Base, GCM_Base, and CipherModeBase.

Definition at line 515 of file cryptlib.h.

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

Sets or reset the key of this object.

Parameters:
key the key to use when keying the object
length the size of the key, in bytes
params additional initialization parameters that cannot be passed directly through the constructor

Reimplemented in AuthenticatedSymmetricCipherBase, and ECB_OneWay.

Definition at line 100 of file cryptlib.cpp.

Referenced by HKDF< T >::DeriveKey(), SimpleKeyingInterface::SetKeyWithIV(), SimpleKeyingInterface::SetKeyWithRounds(), VMAC_Base::UncheckedSetKey(), and CMAC_Base::UncheckedSetKey().

void SimpleKeyingInterface::SetKeyWithRounds ( const byte *  key,
size_t  length,
int  rounds 
) [inherited]

Sets or reset the key of this object.

Parameters:
key the key to use when keying the object
length the size of the key, in bytes
rounds the number of rounds to apply the transformation function, if applicable

SetKeyWithRounds calls SetKey with an NameValuePairs object that just specifies rounds. rounds is an integer parameter, and -1 means use the default number of rounds.

Definition at line 106 of file cryptlib.cpp.

References MakeParameters(), Rounds(), and SimpleKeyingInterface::SetKey().

void SimpleKeyingInterface::SetKeyWithIV ( const byte *  key,
size_t  length,
const byte *  iv,
size_t  ivLength 
) [inherited]

Sets or reset the key of this object.

Parameters:
key the key to use when keying the object
length the size of the key, in bytes
iv the intiialization vector to use when keying the object
ivLength the size of the iv, in bytes

SetKeyWithIV calls SetKey with an NameValuePairs object that just specifies iv. iv is a byte buffer with size ivLength.

Definition at line 111 of file cryptlib.cpp.

References IV(), MakeParameters(), and SimpleKeyingInterface::SetKey().

void SimpleKeyingInterface::SetKeyWithIV ( const byte *  key,
size_t  length,
const byte *  iv 
) [inline, inherited]

Sets or reset the key of this object.

Parameters:
key the key to use when keying the object
length the size of the key, in bytes
iv the intiialization vector to use when keying the object

SetKeyWithIV calls SetKey with an NameValuePairs object that just specifies iv. iv is a byte buffer, and it must have a size IVSize.

Definition at line 551 of file cryptlib.h.

References SimpleKeyingInterface::SetKeyWithIV().

Referenced by SimpleKeyingInterface::SetKeyWithIV().

bool SimpleKeyingInterface::IsResynchronizable (  )  const [inline, inherited]

returns whether the 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 573 of file cryptlib.h.

Referenced by BlockOrientedCipherModeBase::UncheckedSetKey().

void SimpleKeyingInterface::GetNextIV ( RandomNumberGenerator rng,
byte *  iv 
) [virtual, inherited]

Gets a secure IV for the next message.

Parameters:
rng a RandomNumberGenerator to produce keying material
iv a block of bytes to receive the IV

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.

key must be at least IVSize() in length.

Note:
This method is not implemented on decryption objects.

Reimplemented in VMAC_Base.

Definition at line 176 of file cryptlib.cpp.

References RandomNumberGenerator::GenerateBlock(), and SimpleKeyingInterface::IVSize().

HashTransformation& HashTransformation::Ref (  )  [inline, inherited]

Provides a reference to this object.

Returns:
A reference to this object

Useful for passing a temporary object to a function that takes a non-const reference

Definition at line 864 of file cryptlib.h.

virtual byte* HashTransformation::CreateUpdateSpace ( size_t &  size  )  [inline, virtual, inherited]

Request space which can be written into by the caller.

Parameters:
size the requested size of the buffer

The purpose of this method is to help avoid extra memory allocations.

size is an IN and OUT parameter and used as a hint. When the call is made, size is the requested size of the buffer. When the call returns, size is the size of the array returned to the caller.

The base class implementation sets size to 0 and returns NULL.

Note:
Some objects, like ArraySink, cannot create a space because its fixed. In the case of

Definition at line 879 of file cryptlib.h.

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

Computes the hash of the current message.

Parameters:
digest a pointer to the buffer to receive the hash

digest must be equal to (or greater than) DigestSize(). Final() restarts the hash for a new message.

Definition at line 885 of file cryptlib.h.

References DigestSize().

Referenced by PKCS5_PBKDF2_HMAC< T >::DeriveKey(), RandomPool::IncorporateEntropy(), and HMAC_Base::TruncatedFinal().

virtual void HashTransformation::Restart (  )  [inline, virtual, inherited]

Restart the hash.

Discards the current state, and restart for a new message

Reimplemented in AuthenticatedSymmetricCipherBase, HMAC_Base, SHA3, and TruncatedHashTemplate< T >.

Definition at line 890 of file cryptlib.h.

Referenced by HMAC_Base::Restart().

unsigned int HashTransformation::TagSize (  )  const [inline, inherited]

Provides the tag size of the hash.

Returns:
the tag size of the hash.

Same as DigestSize().

Definition at line 901 of file cryptlib.h.

References DigestSize().

virtual unsigned int HashTransformation::BlockSize (  )  const [inline, virtual, inherited]

Provides the block size of the compression function.

Returns:
the block size of the compression function, in bytes

BlockSize() will return 0 if the hash is not block based. For example, SHA3 is a recursive hash (not an iterative hash), and it does not have a block size.

Reimplemented in Weak::MD2, and VMAC_Base.

Definition at line 907 of file cryptlib.h.

Referenced by HMAC_Base::TruncatedFinal(), CBC_MAC_Base::TruncatedFinal(), and HMAC_Base::UncheckedSetKey().

virtual unsigned int HashTransformation::OptimalBlockSize (  )  const [inline, virtual, inherited]

Provides the input block size most efficient for this hash.

Returns:
The input block size that is most efficient for the cipher

The base class implemnetation returns MandatoryBlockSize().

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

Reimplemented in CMAC_Base, and HMAC_Base.

Definition at line 914 of file cryptlib.h.

unsigned int HashTransformation::OptimalDataAlignment (  )  const [virtual, inherited]

Provides input and output data alignment for optimal performance.

Returns:
the input data alignment that provides optimal performance

Reimplemented in CCM_Base, CMAC_Base, EAX_Base, GCM_Base, SHA3, and VMAC_Base.

Definition at line 242 of file cryptlib.cpp.

virtual void HashTransformation::CalculateDigest ( byte *  digest,
const byte *  input,
size_t  length 
) [inline, virtual, inherited]

Updates the hash with additional input and computes the hash of the current message.

Parameters:
digest a pointer to the buffer to receive the hash
input the additional input as a buffer
length the size of the buffer, in bytes

Use this if your input is in one piece and you don't want to call Update() and Final() separately

CalculateDigest() restarts the hash for the next nmessage.

Definition at line 927 of file cryptlib.h.

Referenced by PKCS5_PBKDF2_HMAC< T >::DeriveKey(), and HKDF< T >::DeriveKey().

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

Verifies the hash of the current message.

Parameters:
digest a pointer to the buffer of an existing hash
Returns:
true if the existing hash matches the computed hash, false otherwise
Exceptions:
ThrowIfInvalidTruncatedSize() if the existing hash's size exceeds DigestSize()

Calls to Verify() require a buffer that is equal to (or greater than) DigestSize().

Verify() performs a bitwise compare on the buffers using VerifyBufsEqual(), which is a constant time comparison function. digestLength cannot exceed DigestSize().

Verify() restarts the hash for the next nmessage.

Definition at line 938 of file cryptlib.h.

References DigestSize().

virtual bool HashTransformation::VerifyDigest ( const byte *  digest,
const byte *  input,
size_t  length 
) [inline, virtual, inherited]

Updates the hash with additional input and verifies the hash of the current message.

Parameters:
digest a pointer to the buffer of an existing hash
input the additional input as a buffer
length the size of the buffer, in bytes
Returns:
true if the existing hash matches the computed hash, false otherwise
Exceptions:
ThrowIfInvalidTruncatedSize() if the existing hash's size exceeds DigestSize()

Use this if your input is in one piece and you don't want to call Update() and Verify() separately

VerifyDigest() performs a bitwise compare on the buffers using VerifyBufsEqual(), which is a constant time comparison function. digestLength cannot exceed DigestSize().

VerifyDigest() restarts the hash for the next nmessage.

Definition at line 952 of file cryptlib.h.

virtual void HashTransformation::CalculateTruncatedDigest ( byte *  digest,
size_t  digestSize,
const byte *  input,
size_t  length 
) [inline, virtual, inherited]

Updates the hash with additional input and computes the hash of the current message.

Parameters:
digest a pointer to the buffer to receive the hash
digestSize the length of the truncated hash, in bytes
input the additional input as a buffer
length the size of the buffer, in bytes

Use this if your input is in one piece and you don't want to call Update() and CalculateDigest() separately.

CalculateTruncatedDigest() restarts the hash for the next nmessage.

Definition at line 970 of file cryptlib.h.

bool HashTransformation::TruncatedVerify ( const byte *  digest,
size_t  digestLength 
) [virtual, inherited]

Verifies the hash of the current message.

Parameters:
digest a pointer to the buffer of an existing hash
digestLength the size of the truncated hash, in bytes
Returns:
true if the existing hash matches the computed hash, false otherwise
Exceptions:
ThrowIfInvalidTruncatedSize() if digestLength exceeds DigestSize()

TruncatedVerify() is a truncated version of Verify(). It can operate on a buffer smaller than DigestSize(). However, digestLength cannot exceed DigestSize().

Verify() performs a bitwise compare on the buffers using VerifyBufsEqual(), which is a constant time comparison function. digestLength cannot exceed DigestSize().

TruncatedVerify() restarts the hash for the next nmessage.

Reimplemented in NullHash, and TruncatedHashTemplate< T >.

Definition at line 411 of file cryptlib.cpp.

References HashTransformation::TruncatedFinal().

Referenced by AuthenticatedSymmetricCipher::DecryptAndVerify().

virtual bool HashTransformation::VerifyTruncatedDigest ( const byte *  digest,
size_t  digestLength,
const byte *  input,
size_t  length 
) [inline, virtual, inherited]

Updates the hash with additional input and verifies the hash of the current message.

Parameters:
digest a pointer to the buffer of an existing hash
digestLength the size of the truncated hash, in bytes
input the additional input as a buffer
length the size of the buffer, in bytes
Returns:
true if the existing hash matches the computed hash, false otherwise
Exceptions:
ThrowIfInvalidTruncatedSize() if digestLength exceeds DigestSize()

Use this if your input is in one piece and you don't want to call Update() and TruncatedVerify() separately.

VerifyTruncatedDigest() is a truncated version of VerifyDigest(). It can operate on a buffer smaller than DigestSize(). However, digestLength cannot exceed DigestSize().

VerifyTruncatedDigest() restarts the hash for the next nmessage.

Definition at line 997 of file cryptlib.h.


Member Data Documentation

const int SameKeyLengthAs< T , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::MIN_KEYLENGTH [static, inherited]

The minimum key length used by the cipher provided as a constant.

MIN_KEYLENGTH is provided in bytes, not bits

Definition at line 218 of file seckey.h.

const int SameKeyLengthAs< T , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::MAX_KEYLENGTH [static, inherited]

The maximum key length used by the cipher provided as a constant.

MIN_KEYLENGTH is provided in bytes, not bits

Definition at line 221 of file seckey.h.

const int SameKeyLengthAs< T , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::DEFAULT_KEYLENGTH [static, inherited]

The default key length used by the cipher provided as a constant.

MIN_KEYLENGTH is provided in bytes, not bits

Definition at line 224 of file seckey.h.

const int SameKeyLengthAs< T , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::IV_REQUIREMENT [static, inherited]

The default IV requirements for the cipher provided as a constant.

The default value is NOT_RESYNCHRONIZABLE. See IV_Requirement in cryptlib.h for allowed values.

Definition at line 228 of file seckey.h.

const int SameKeyLengthAs< T , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::IV_LENGTH [static, inherited]

The default initialization vector length for the cipher provided as a constant.

IV_LENGTH is provided in bytes, not bits. The default implementation uses 0.

Definition at line 231 of file seckey.h.


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

Generated on 24 Mar 2016 for Crypto++ by  doxygen 1.6.1