Crypto++  5.6.3
Free C++ class library of cryptographic schemes
Public Types | Public Member Functions | Static Public Member Functions | Static Public Attributes | List of all members
HMAC_Base Class Referenceabstract

_ More...

+ Inheritance diagram for HMAC_Base:

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

void UncheckedSetKey (const byte *userKey, unsigned int keylength, const NameValuePairs &params)
 Sets the key for this object without performing parameter validation. More...
 
void Restart ()
 Restart the hash. More...
 
void Update (const byte *input, size_t length)
 Updates a hash with additional input. More...
 
void TruncatedFinal (byte *mac, size_t size)
 Computes the hash of the current message. More...
 
unsigned int OptimalBlockSize () const
 Provides the input block size most efficient for this hash. More...
 
unsigned int DigestSize () const
 Provides the digest size of the hash. More...
 
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
 
virtual bool IsValidKeyLength (size_t keylength) const
 Returns whether keylength is a valid key length. More...
 
virtual void SetKey (const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
 Sets or reset the key of this object. More...
 
void SetKeyWithRounds (const byte *key, size_t length, int rounds)
 Sets or reset the key of this object. More...
 
void SetKeyWithIV (const byte *key, size_t length, const byte *iv, size_t ivLength)
 Sets or reset the key of this object. More...
 
void SetKeyWithIV (const byte *key, size_t length, const byte *iv)
 Sets or reset the key of this object. More...
 
virtual IV_Requirement IVRequirement () const =0
 returns the minimal requirement for secure IVs
 
bool IsResynchronizable () const
 returns whether the object can be resynchronized (i.e. supports initialization vectors) More...
 
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)
 
virtual unsigned int IVSize () const
 Returns length of the IV accepted by this object. More...
 
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. More...
 
HashTransformationRef ()
 Provides a reference to this object. More...
 
virtual byte * CreateUpdateSpace (size_t &size)
 Request space which can be written into by the caller. More...
 
virtual void Final (byte *digest)
 Computes the hash of the current message. More...
 
unsigned int TagSize () const
 Provides the tag size of the hash. More...
 
virtual unsigned int BlockSize () const
 Provides the block size of the compression function. More...
 
virtual unsigned int OptimalDataAlignment () const
 Provides input and output data alignment for optimal performance. More...
 
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. More...
 
virtual bool Verify (const byte *digest)
 Verifies the hash of the current message. More...
 
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. More...
 
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. More...
 
virtual bool TruncatedVerify (const byte *digest, size_t digestLength)
 Verifies the hash of the current message. More...
 
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. More...
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
virtual ClonableClone () const
 Copies this object. More...
 

Static Public Member Functions

static size_t StaticGetValidKeyLength (size_t keylength)
 Provides a valid key length for the cipher provided by a static function. More...
 

Static Public Attributes

static const int MIN_KEYLENGTH
 The minimum key length used by the cipher provided as a constant. More...
 
static const int MAX_KEYLENGTH
 The maximum key length used by the cipher provided as a constant. More...
 
static const int DEFAULT_KEYLENGTH
 The default key length used by the cipher provided as a constant. More...
 
static const int KEYLENGTH_MULTIPLE
 The key length multiple used by the cipher provided as a constant. More...
 
static const int IV_REQUIREMENT
 The default IV requirements for the cipher provided as a constant. More...
 
static const int IV_LENGTH
 The default initialization vector length for the cipher provided as a constant. More...
 

Detailed Description

_

Definition at line 15 of file hmac.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

void HMAC_Base::UncheckedSetKey ( const byte *  key,
unsigned int  length,
const NameValuePairs params 
)
virtual

Sets the key for this object without performing parameter validation.

Parameters
keya byte buffer used to key the cipher
lengththe length of the byte buffer
paramsadditional parameters passed as NameValuePairs

key must be at least DEFAULT_KEYLENGTH in length.

Implements SimpleKeyingInterface.

Definition at line 11 of file hmac.cpp.

References Name::BlockSize(), HashTransformation::BlockSize(), Name::DigestSize(), HashTransformation::DigestSize(), and HashTransformation::Update().

void HMAC_Base::Restart ( )
virtual

Restart the hash.

Discards the current state, and restart for a new message

Reimplemented from HashTransformation.

Definition at line 51 of file hmac.cpp.

References HashTransformation::Restart().

void HMAC_Base::Update ( const byte *  input,
size_t  length 
)
virtual

Updates a hash with additional input.

Parameters
inputthe additional input as a buffer
lengththe size of the buffer, in bytes

Implements HashTransformation.

Definition at line 60 of file hmac.cpp.

References HashTransformation::Update().

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

void HMAC_Base::TruncatedFinal ( byte *  digest,
size_t  digestSize 
)
virtual

Computes the hash of the current message.

Parameters
digesta pointer to the buffer to receive the hash
digestSizethe 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 67 of file hmac.cpp.

References HashTransformation::BlockSize(), HashTransformation::DigestSize(), HashTransformation::Final(), HashTransformation::TruncatedFinal(), and HashTransformation::Update().

unsigned int HMAC_Base::OptimalBlockSize ( ) const
inlinevirtual

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 from HashTransformation.

Definition at line 24 of file hmac.h.

References OptimalBlockSize().

Referenced by OptimalBlockSize().

unsigned int HMAC_Base::DigestSize ( ) const
inlinevirtual

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 25 of file hmac.h.

References HashTransformation::BlockSize(), and DigestSize().

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

static size_t VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::StaticGetValidKeyLength ( size_t  keylength)
inlinestaticinherited

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

Parameters
keylengththe 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 190 of file seckey.h.

Referenced by DefaultDecryptor::DefaultDecryptor().

virtual size_t SimpleKeyingInterface::GetValidKeyLength ( size_t  n) const
pure virtualinherited
virtual bool SimpleKeyingInterface::IsValidKeyLength ( size_t  keylength) const
inlinevirtualinherited

Returns whether keylength is a valid key length.

Internally the function calls GetValidKeyLength()

Reimplemented in CipherModeBase, GCM_Base, EAX_Base, and CCM_Base.

Definition at line 515 of file cryptlib.h.

References g_nullNameValuePairs.

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

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
paramsadditional initialization parameters that cannot be passed directly through the constructor

Reimplemented in ECB_OneWay, and AuthenticatedSymmetricCipherBase.

Definition at line 100 of file cryptlib.cpp.

Referenced by HKDF< T >::DeriveKey(), RandomPool::GenerateIntoBufferedTransformation(), TestDataNameValuePairs::GetVoidValue(), CMAC_Base::UncheckedSetKey(), CBC_MAC_Base::UncheckedSetKey(), VMAC_Base::UncheckedSetKey(), and BlockOrientedCipherModeBase::UncheckedSetKey().

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

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
roundsthe 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(), and Name::Rounds().

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
keythe key to use when keying the object
lengththe size of the key, in bytes
ivthe intiialization vector to use when keying the object
ivLengththe 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 NameValuePairs::GetValue(), IntToString(), Name::IV(), and MakeParameters().

void SimpleKeyingInterface::SetKeyWithIV ( const byte *  key,
size_t  length,
const byte *  iv 
)
inlineinherited

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
ivthe 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.

bool SimpleKeyingInterface::IsResynchronizable ( ) const
inlineinherited

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 CipherModeBase::IVSize(), and BlockOrientedCipherModeBase::UncheckedSetKey().

virtual unsigned int SimpleKeyingInterface::IVSize ( ) const
inlinevirtualinherited
void SimpleKeyingInterface::GetNextIV ( RandomNumberGenerator rng,
byte *  iv 
)
virtualinherited

Gets a secure IV for the next message.

Parameters
rnga RandomNumberGenerator to produce keying material
iva 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().

Referenced by VMAC_Base::GetNextIV(), and FilterTester::Put2().

HashTransformation& HashTransformation::Ref ( )
inlineinherited

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)
inlinevirtualinherited

Request space which can be written into by the caller.

Parameters
sizethe 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)
inlinevirtualinherited

Computes the hash of the current message.

Parameters
digesta 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 Name::DigestSize().

Referenced by DefaultDecryptor::DefaultDecryptor(), DefaultEncryptor::DefaultEncryptor(), PKCS5_PBKDF2_HMAC< T >::DeriveKey(), RandomPool::IncorporateEntropy(), PKCS_EncryptionPaddingScheme::MaxUnpaddedLength(), and TruncatedFinal().

unsigned int HashTransformation::TagSize ( ) const
inlineinherited

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 Name::DigestSize().

virtual unsigned int HashTransformation::BlockSize ( ) const
inlinevirtualinherited

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 VMAC_Base, and Weak::MD2.

Definition at line 907 of file cryptlib.h.

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

unsigned int HashTransformation::OptimalDataAlignment ( ) const
virtualinherited

Provides input and output data alignment for optimal performance.

Returns
the input data alignment that provides optimal performance

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

Definition at line 242 of file cryptlib.cpp.

virtual void HashTransformation::CalculateDigest ( byte *  digest,
const byte *  input,
size_t  length 
)
inlinevirtualinherited

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

Parameters
digesta pointer to the buffer to receive the hash
inputthe additional input as a buffer
lengththe 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 HKDF< T >::DeriveKey(), PKCS5_PBKDF2_HMAC< T >::DeriveKey(), and OAEP_Base::MaxUnpaddedLength().

virtual bool HashTransformation::Verify ( const byte *  digest)
inlinevirtualinherited

Verifies the hash of the current message.

Parameters
digesta 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 Name::DigestSize().

Referenced by Gunzip::Gunzip(), and ZlibDecompressor::ZlibDecompressor().

virtual bool HashTransformation::VerifyDigest ( const byte *  digest,
const byte *  input,
size_t  length 
)
inlinevirtualinherited

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

Parameters
digesta pointer to the buffer of an existing hash
inputthe additional input as a buffer
lengththe 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.

Referenced by OAEP_Base::MaxUnpaddedLength().

virtual void HashTransformation::CalculateTruncatedDigest ( byte *  digest,
size_t  digestSize,
const byte *  input,
size_t  length 
)
inlinevirtualinherited

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

Parameters
digesta pointer to the buffer to receive the hash
digestSizethe length of the truncated hash, in bytes
inputthe additional input as a buffer
lengththe 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 
)
virtualinherited

Verifies the hash of the current message.

Parameters
digesta pointer to the buffer of an existing hash
digestLengththe 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 TruncatedHashTemplate< T >, and NullHash.

Definition at line 411 of file cryptlib.cpp.

References Name::DigestSize(), IntToString(), and VerifyBufsEqual().

virtual bool HashTransformation::VerifyTruncatedDigest ( const byte *  digest,
size_t  digestLength,
const byte *  input,
size_t  length 
)
inlinevirtualinherited

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

Parameters
digesta pointer to the buffer of an existing hash
digestLengththe size of the truncated hash, in bytes
inputthe additional input as a buffer
lengththe 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.

virtual std::string Algorithm::AlgorithmName ( ) const
inlinevirtualinherited

Provides the name of this algorithm.

Returns
the standard algorithm name

The standard algorithm name can be a name like AES or AES/GCM. Some algorithms do not have standard names yet. For example, there is no standard algorithm name for Shoup's ECIES.

Note
AlgorithmName is not universally implemented yet

Reimplemented in AuthenticatedSymmetricCipher, SignatureVerificationFilter, SignerFilter, AuthenticatedDecryptionFilter, HashVerificationFilter, HashFilter, StreamTransformationFilter, ClassNullRNG, BitBucket, RDSEED, DH_Domain< GROUP_PARAMETERS, COFACTOR_OPTION >, HMAC< T >, RDRAND, CRC32, GCM_Base, Adler32, EAX_Base, CCM_Base, SHA3, and VMAC_Base.

Definition at line 488 of file cryptlib.h.

Referenced by VariableRounds< 6, 2 >::StaticGetDefaultRounds().

virtual Clonable* Clonable::Clone ( ) const
inlinevirtualinherited

Copies this object.

Returns
a copy of this object
Exceptions
NotImplemented
Note
this is not implemented by most classes
See also
NotCopyable

Definition at line 464 of file cryptlib.h.

Member Data Documentation

const int VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::MIN_KEYLENGTH
staticinherited

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

MIN_KEYLENGTH is provided in bytes, not bits

Definition at line 165 of file seckey.h.

const int VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::MAX_KEYLENGTH
staticinherited

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

MAX_KEYLENGTH is provided in bytes, not bits

Definition at line 168 of file seckey.h.

const int VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::DEFAULT_KEYLENGTH
staticinherited

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

DEFAULT_KEYLENGTH is provided in bytes, not bits

Definition at line 171 of file seckey.h.

const int VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::KEYLENGTH_MULTIPLE
staticinherited

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

MAX_KEYLENGTH is provided in bytes, not bits

Definition at line 174 of file seckey.h.

const int VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::IV_REQUIREMENT
staticinherited

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 178 of file seckey.h.

const int VariableKeyLength< D, N, M, 1 , SimpleKeyingInterface::NOT_RESYNCHRONIZABLE , 0 >::IV_LENGTH
staticinherited

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 181 of file seckey.h.


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