Crypto++  5.6.3
Free C++ class library of cryptographic schemes
Public Types | Public Member Functions | Static Public Member Functions | List of all members
CTR_ModePolicy Class Referenceabstract
+ Inheritance diagram for CTR_ModePolicy:

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

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
 
bool IsValidKeyLength (size_t n) const
 Returns whether keylength is a valid key length. More...
 
unsigned int OptimalDataAlignment () const
 Provides input and output data alignment for optimal performance. More...
 
unsigned int IVSize () const
 Returns length of the IV accepted by this object. More...
 
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)
 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...
 
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)
 
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...
 
StreamTransformationRef ()
 Provides a reference to this object. More...
 
virtual unsigned int MandatoryBlockSize () const
 Provides the mandatory block size of the cipher. More...
 
virtual unsigned int OptimalBlockSize () const
 Provides the input block size most efficient for this cipher. More...
 
virtual unsigned int GetOptimalBlockSizeUsed () const
 Provides the number of bytes used in the current block when processing at optimal block size. More...
 
virtual void ProcessData (byte *outString, const byte *inString, size_t length)=0
 Encrypt or decrypt an array of bytes. More...
 
virtual void ProcessLastBlock (byte *outString, const byte *inString, size_t length)
 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)
 Encrypt or decrypt a string of bytes. More...
 
void ProcessString (byte *outString, const byte *inString, size_t length)
 Encrypt or decrypt a string of bytes. More...
 
byte ProcessByte (byte input)
 Encrypt or decrypt a byte. More...
 
virtual bool IsRandomAccess () const =0
 Determines whether the cipher supports random access. More...
 
virtual void Seek (lword pos)
 Seek to an absolute position. More...
 
virtual bool IsSelfInverting () const =0
 Determines whether the cipher is self-inverting. More...
 
virtual bool IsForwardTransformation () const =0
 Determines if the cipher is being operated in its forward direction. More...
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
virtual ClonableClone () const
 Copies this object. More...
 
virtual unsigned int GetOptimalBlockSize () const
 

Static Public Member Functions

static const char * StaticAlgorithmName ()
 

Detailed Description

Definition at line 146 of file modes.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

size_t CipherModeBase::GetValidKeyLength ( size_t  n) const
inlinevirtualinherited
Returns
the smallest valid key length in bytes that is greater than or equal to min(n, GetMaxKeyLength())

Implements SimpleKeyingInterface.

Definition at line 40 of file modes.h.

bool CipherModeBase::IsValidKeyLength ( size_t  keylength) const
inlinevirtualinherited

Returns whether keylength is a valid key length.

Internally the function calls GetValidKeyLength()

Reimplemented from SimpleKeyingInterface.

Definition at line 41 of file modes.h.

unsigned int CipherModeBase::OptimalDataAlignment ( ) const
inlinevirtualinherited

Provides input and output data alignment for optimal performance.

Returns
the input data alignment that provides optimal performance

Reimplemented from StreamTransformation.

Definition at line 43 of file modes.h.

unsigned int CipherModeBase::IVSize ( ) const
inlinevirtualinherited

Returns length of the IV accepted by this object.

The default implementation throws NotImplemented

Reimplemented from SimpleKeyingInterface.

Definition at line 45 of file modes.h.

References Name::BlockSize(), SimpleKeyingInterface::IsResynchronizable(), SimpleKeyingInterface::IVRequirement(), and SimpleKeyingInterface::Resynchronize().

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().

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().

StreamTransformation& StreamTransformation::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 758 of file cryptlib.h.

virtual unsigned int StreamTransformation::MandatoryBlockSize ( ) const
inlinevirtualinherited

Provides the mandatory block size of the cipher.

Returns
The block size of the cipher if input must be processed in blocks, 1 otherwise

Reimplemented in BlockOrientedCipherModeBase.

Definition at line 762 of file cryptlib.h.

Referenced by ArrayXorSink::Put2().

virtual unsigned int StreamTransformation::OptimalBlockSize ( ) const
inlinevirtualinherited

Provides the input block size most efficient for this cipher.

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 ECB_OneWay.

Definition at line 769 of file cryptlib.h.

virtual unsigned int StreamTransformation::GetOptimalBlockSizeUsed ( ) const
inlinevirtualinherited

Provides the number of bytes used in the current block when processing at optimal block size.

Returns
the number of bytes used in the current block when processing at the optimal block size

Definition at line 773 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.

Parameters
outStringthe output byte buffer
inStringthe input byte buffer
lengththe size of the input and output byte buffers, in bytes

Either inString == outString, or they must not overlap.

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

Referenced by AuthenticatedSymmetricCipherBase::ProcessData().

void StreamTransformation::ProcessLastBlock ( byte *  outString,
const byte *  inString,
size_t  length 
)
virtualinherited

Encrypt or decrypt the last block of data.

Parameters
outStringthe output byte buffer
inStringthe input byte buffer
lengththe size of the input and output byte buffers, in bytes ProcessLastBlock is used when the last block of data is special. Currently the only use of this function is CBC-CTS mode.

Reimplemented in CBC_CTS_Decryption, and CBC_CTS_Encryption.

Definition at line 247 of file cryptlib.cpp.

void StreamTransformation::ProcessString ( byte *  inoutString,
size_t  length 
)
inlineinherited

Encrypt or decrypt a string of bytes.

Parameters
inoutStringthe string to process
lengththe size of the inoutString, in bytes

Internally, the base class implementation calls ProcessData().

Definition at line 801 of file cryptlib.h.

Referenced by TestDataNameValuePairs::GetVoidValue().

void StreamTransformation::ProcessString ( byte *  outString,
const byte *  inString,
size_t  length 
)
inlineinherited

Encrypt or decrypt a string of bytes.

Parameters
outStringthe output string to process
inStringthe input string to process
lengththe size of the input and output strings, in bytes

Internally, the base class implementation calls ProcessData().

Definition at line 809 of file cryptlib.h.

byte StreamTransformation::ProcessByte ( byte  input)
inlineinherited

Encrypt or decrypt a byte.

Parameters
inputthe input byte to process

Internally, the base class implementation calls ProcessData() with a size of 1.

Definition at line 815 of file cryptlib.h.

virtual bool StreamTransformation::IsRandomAccess ( ) const
pure virtualinherited

Determines whether the cipher supports random access.

Returns
true if the cipher supports random access, false otherwise

Implemented in BlockOrientedCipherModeBase, BlumBlumShub, Weak::ARC4_Base, and AuthenticatedSymmetricCipherBase.

virtual void StreamTransformation::Seek ( lword  pos)
inlinevirtualinherited

Seek to an absolute position.

Parameters
posposition to seek
Exceptions
NotImplemented

The base class implementation throws NotImplemented. The function asserts IsRandomAccess() in debug builds.

Reimplemented in BlumBlumShub.

Definition at line 827 of file cryptlib.h.

Referenced by TestDataNameValuePairs::GetVoidValue().

virtual bool StreamTransformation::IsSelfInverting ( ) const
pure virtualinherited

Determines whether the cipher is self-inverting.

Returns
true if the cipher is self-inverting, false otherwise

IsSelfInverting determines whether this transformation is self-inverting (e.g. xor with a keystream).

Implemented in BlockOrientedCipherModeBase, Weak::ARC4_Base, PublicBlumBlumShub, and AuthenticatedSymmetricCipherBase.

Referenced by AuthenticatedDecryptionFilter::AuthenticatedDecryptionFilter().

virtual bool StreamTransformation::IsForwardTransformation ( ) const
pure virtualinherited
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.


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