ANSI X9.17 RNG. More...

#include <rng.h>

Inheritance diagram for X917RNG:

Collaboration diagram for X917RNG:

Public Member Functions
	X917RNG (BlockTransformation cipher, const byte seed, const byte *deterministicTimeVector=0)
	Construct a X917RNG. More...

void	GenerateIntoBufferedTransformation (BufferedTransformation &target, const std::string &channel, lword size)
	Generate random bytes into a BufferedTransformation. More...

Public Member Functions inherited from RandomNumberGenerator
virtual	~RandomNumberGenerator ()

virtual void	IncorporateEntropy (const byte *input, size_t length)
	Update RNG state with additional unpredictable values. More...

virtual bool	CanIncorporateEntropy () const
	Determines if a generator can accept additional entropy. More...

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
virtual	~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	~Clonable ()

virtual Clonable *	Clone () const
	Copies this object. More...

Public Member Functions inherited from NotCopyable
	NotCopyable ()

Private Attributes
member_ptr< BlockTransformation >	m_cipher

const unsigned int	m_size

SecByteBlock	m_datetime

SecByteBlock	m_randseed

SecByteBlock	m_lastBlock

SecByteBlock	m_deterministicTimeVector

Detailed Description

ANSI X9.17 RNG.

X917RNG is from ANSI X9.17 Appendix C, and it uses a 64-bit block cipher, like TripleDES. If you use a 128-bit block cipher, like AES, then you are effectively using an ANSI X9.31 generator.

See also: AutoSeededX917RNG, DefaultAutoSeededRNG

Definition at line 48 of file rng.h.

Constructor & Destructor Documentation

X917RNG::X917RNG	(	BlockTransformation *	cipher,
		const byte *	seed,
		const byte *	deterministicTimeVector = `0`
	)

Construct a X917RNG.

Parameters

cipher	the block cipher to use for the generator
seed	a byte buffer to use as a seed
deterministicTimeVector	additional entropy

cipher will be deleted by the destructor. seed must be at least BlockSize() in length. deterministicTimeVector = 0 means obtain time vector from the system.

When constructing a X917RNG, the generator must be keyed or an access violation will occur because the time vector is encrypted using the block cipher. To key the generator during constructions, perform the following:

  SecByteBlock key(AES::DEFAULT_KEYLENGTH), seed(AES::BLOCKSIZE);
  OS_GenerateRandomBlock(false, key, key.size());
  OS_GenerateRandomBlock(false, seed, seed.size());
  X917RNG prng(new AES::Encryption(key, AES::DEFAULT_KEYLENGTH), seed, NULL);

See also: AutoSeededX917RNG

Definition at line 61 of file rng.cpp.

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Member Function Documentation

void X917RNG::GenerateIntoBufferedTransformation	(	BufferedTransformation &	target,
		const std::string &	channel,
		lword	length
	)

virtual

Generate random bytes into a BufferedTransformation.

Parameters

target	the BufferedTransformation object which receives the bytes
channel	the channel on which the bytes should be pumped
length	the 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 constraints 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 91 of file rng.cpp.

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Member Data Documentation

member_ptr<BlockTransformation> X917RNG::m_cipher

private

Definition at line 72 of file rng.h.

SecByteBlock X917RNG::m_datetime

private

Definition at line 74 of file rng.h.

SecByteBlock X917RNG::m_deterministicTimeVector

private

Definition at line 75 of file rng.h.

SecByteBlock X917RNG::m_lastBlock

private

Definition at line 75 of file rng.h.

SecByteBlock X917RNG::m_randseed

private

Definition at line 75 of file rng.h.

const unsigned int X917RNG::m_size

private

Definition at line 73 of file rng.h.

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

src/cryptopp/rng.h
src/cryptopp/rng.cpp

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation