Hardware generated random numbers using RDRAND instruction. More...

#include <rdrand.h>

Inheritance diagram for RDRAND:

Collaboration diagram for RDRAND:

Public Member Functions
std::string	AlgorithmName () const
	Provides the name of this algorithm. More...

	RDRAND (unsigned int retries=4)
	Construct a RDRAND generator. More...

virtual	~RDRAND ()

unsigned int	GetRetries () const
	Retrieve the number of retries used by the generator. More...

void	SetRetries (unsigned int retries)
	Set the number of retries used by the generator. 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...

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

Public Member Functions inherited from RandomNumberGenerator
virtual	~RandomNumberGenerator ()

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

Public Member Functions inherited from Clonable
virtual	~Clonable ()

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

Private Attributes
unsigned int	m_retries

Detailed Description

Hardware generated random numbers using RDRAND instruction.

See also: MaurerRandomnessTest() for random bit generators

Since: Crypto++ 5.6.3

Definition at line 39 of file rdrand.h.

Constructor & Destructor Documentation

RDRAND::RDRAND ( unsigned int retries = 4 )

inline

Construct a RDRAND generator.

Parameters

retries the number of retries for failed calls to the hardware

RDRAND() constructs a generator with a maximum number of retires for failed generation attempts.

According to DJ of Intel, the Intel RDRAND circuit does not underflow. If it did hypothetically underflow, then it would return 0 for the random value. Its not clear what AMD's behavior will be, and what the returned value will be if underflow occurs. Also see RDRAND not really random with Oracle Studio 12.3 + patches

Definition at line 54 of file rdrand.h.

virtual RDRAND::~RDRAND ( )

inlinevirtual

Definition at line 56 of file rdrand.h.

Member Function Documentation

std::string RDRAND::AlgorithmName ( ) const

inlinevirtual

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 from Algorithm.

Definition at line 42 of file rdrand.h.

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virtual void RDRAND::DiscardBytes ( size_t n )

inlinevirtual

Generate and discard n bytes.

Parameters

n	the number of bytes to generate and discard

the RDSEED generator discards words, not bytes. If n is not a multiple of a machine word, then it is rounded up to that size.

Reimplemented from RandomNumberGenerator.

Definition at line 92 of file rdrand.h.

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virtual void RDRAND::GenerateBlock	(	byte *	output,
		size_t	size
	)

inlinevirtual

Generate random array of bytes.

Parameters

output	the byte buffer
size	the length of the buffer, in bytes

Reimplemented from RandomNumberGenerator.

Definition at line 78 of file rdrand.h.

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unsigned int RDRAND::GetRetries ( ) const

inline

Retrieve the number of retries used by the generator.

Returns: the number of times GenerateBlock() will attempt to recover from a failed generation

Definition at line 60 of file rdrand.h.

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virtual void RDRAND::IncorporateEntropy	(	const byte *	input,
		size_t	length
	)

inlinevirtual

Update RNG state with additional unpredictable values.

Parameters

input	unused
length	unused

The operation is a nop for this generator.

Reimplemented from RandomNumberGenerator.

Definition at line 102 of file rdrand.h.

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void RDRAND::SetRetries ( unsigned int retries )

inline

Set the number of retries used by the generator.

Parameters

retries number of times GenerateBlock() will attempt to recover from a failed generation

Definition at line 67 of file rdrand.h.

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Member Data Documentation

unsigned int RDRAND::m_retries

private

Definition at line 110 of file rdrand.h.

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

src/cryptopp/rdrand.h

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation