Crypto++  5.6.4
Free C++ class library of cryptographic schemes
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AutoSeededX917RNG< BLOCK_CIPHER > Class Template Reference

Automatically Seeded X9.17 RNG. More...

+ Inheritance diagram for AutoSeededX917RNG< BLOCK_CIPHER >:

Public Member Functions

 AutoSeededX917RNG (bool blocking=false, bool autoSeed=true)
 Construct an AutoSeededX917RNG. More...
 
void Reseed (bool blocking=false, const byte *additionalEntropy=NULL, size_t length=0)
 Reseed an AutoSeededX917RNG. More...
 
void Reseed (const byte *key, size_t keylength, const byte *seed, const byte *timeVector)
 Deterministically reseed an AutoSeededX917RNG for testing. More...
 
bool CanIncorporateEntropy () const
 Determines if a generator can accept additional entropy. More...
 
void IncorporateEntropy (const byte *input, size_t length)
 Update RNG state with additional unpredictable values. More...
 
void GenerateIntoBufferedTransformation (BufferedTransformation &target, const std::string &channel, lword length)
 Generate random bytes into a BufferedTransformation. More...
 
- Public Member Functions inherited from RandomNumberGenerator
virtual byte GenerateByte ()
 Generate new random byte and return it. More...
 
virtual unsigned int GenerateBit ()
 Generate new random bit and return it. More...
 
virtual word32 GenerateWord32 (word32 min=0, word32 max=0xffffffffUL)
 Generate a random 32 bit word in the range min to max, inclusive. More...
 
virtual void GenerateBlock (byte *output, size_t size)
 Generate random array of bytes. More...
 
virtual void DiscardBytes (size_t n)
 Generate and discard n bytes. More...
 
template<class IT >
void Shuffle (IT begin, IT end)
 Randomly shuffle the specified array. More...
 
- Public Member Functions inherited from Algorithm
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms. More...
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
- Public Member Functions inherited from Clonable
virtual ClonableClone () const
 Copies this object. More...
 

Detailed Description

template<class BLOCK_CIPHER>
class AutoSeededX917RNG< BLOCK_CIPHER >

Automatically Seeded X9.17 RNG.

Template Parameters
BLOCK_CIPHERa block cipher

AutoSeededX917RNG is from ANSI X9.17 Appendix C, seeded using an OS provided RNG. If 3-key TripleDES (DES_EDE3) is used, then its a X9.17 conforming generator. If AES is used, then its a X9.31 conforming generator.

Though ANSI X9 prescribes 3-key TripleDES, the template parameter BLOCK_CIPHER can be any BlockTransformation derived class.

See also
X917RNG, DefaultAutoSeededRNG

Definition at line 178 of file osrng.h.

Constructor & Destructor Documentation

template<class BLOCK_CIPHER>
AutoSeededX917RNG< BLOCK_CIPHER >::AutoSeededX917RNG ( bool  blocking = false,
bool  autoSeed = true 
)
inlineexplicit

Construct an AutoSeededX917RNG.

Parameters
blockingcontrols seeding with BlockingRng or NonblockingRng
autoSeedcontrols auto seeding of the generator

Use blocking to choose seeding with BlockingRng or NonblockingRng. The parameter is ignored if only one of these is available.

See also
X917RNG

Definition at line 187 of file osrng.h.

Member Function Documentation

template<class BLOCK_CIPHER >
void AutoSeededX917RNG< BLOCK_CIPHER >::Reseed ( bool  blocking = false,
const byte *  additionalEntropy = NULL,
size_t  length = 0 
)

Reseed an AutoSeededX917RNG.

Parameters
blockingcontrols seeding with BlockingRng or NonblockingRng
additionalEntropyadditional entropy to add to the generator
lengththe size of the additional entropy, in bytes

Internally, the generator uses SHA256 to extract the entropy from from the seed and then stretch the material for the block cipher's key and initialization vector.

Definition at line 224 of file osrng.h.

template<class BLOCK_CIPHER >
void AutoSeededX917RNG< BLOCK_CIPHER >::Reseed ( const byte *  key,
size_t  keylength,
const byte *  seed,
const byte *  timeVector 
)

Deterministically reseed an AutoSeededX917RNG for testing.

Parameters
keythe key to use for the deterministic reseeding
keylengththe size of the key, in bytes
seedthe seed to use for the deterministic reseeding
timeVectora time vector to use for deterministic reseeding

This is a testing interface for testing purposes, and should NOT be used in production.

Definition at line 218 of file osrng.h.

template<class BLOCK_CIPHER>
bool AutoSeededX917RNG< BLOCK_CIPHER >::CanIncorporateEntropy ( ) const
inlinevirtual

Determines if a generator can accept additional entropy.

Returns
true if IncorporateEntropy() is implemented

Reimplemented from RandomNumberGenerator.

Definition at line 208 of file osrng.h.

template<class BLOCK_CIPHER>
void AutoSeededX917RNG< BLOCK_CIPHER >::IncorporateEntropy ( const byte *  input,
size_t  length 
)
inlinevirtual

Update RNG state with additional unpredictable values.

Parameters
inputthe entropy to add to the generator
lengththe size of the input buffer
Exceptions
NotImplemented

A generator may or may not accept additional entropy. Call CanIncorporateEntropy() to test for the ability to use additional entropy.

If a derived class does not override IncorporateEntropy(), then the base class throws NotImplemented.

Reimplemented from RandomNumberGenerator.

Definition at line 209 of file osrng.h.

template<class BLOCK_CIPHER>
void AutoSeededX917RNG< BLOCK_CIPHER >::GenerateIntoBufferedTransformation ( BufferedTransformation target,
const std::string &  channel,
lword  length 
)
inlinevirtual

Generate random bytes into a BufferedTransformation.

Parameters
targetthe BufferedTransformation object which receives the bytes
channelthe channel on which the bytes should be pumped
lengththe number of bytes to generate

The default implementation calls GenerateBlock() and pumps the result into the DEFAULT_CHANNEL of the target.

All generated values are uniformly distributed over the range specified within the the contraints of a particular generator.

Note
A derived generator must override either GenerateBlock() or GenerateIntoBufferedTransformation(). They can override both, or have one call the other.

Reimplemented from RandomNumberGenerator.

Definition at line 210 of file osrng.h.


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