Crypto++  5.6.5
Free C++ class library of cryptographic schemes
Public Member Functions | List of all members
RDRAND Class Reference

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

+ Inheritance 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...
 
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 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
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms. More...
 
- Public Member Functions inherited from Clonable
virtual ClonableClone () const
 Copies this object. More...
 

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::RDRAND ( unsigned int  retries = 4)
inline

Construct a RDRAND generator.

Parameters
retriesthe 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.

Member Function Documentation

◆ AlgorithmName()

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.

◆ GetRetries()

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.

◆ SetRetries()

void RDRAND::SetRetries ( unsigned int  retries)
inline

Set the number of retries used by the generator.

Parameters
retriesnumber of times GenerateBlock() will attempt to recover from a failed generation

Definition at line 67 of file rdrand.h.

◆ GenerateBlock()

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

Generate random array of bytes.

Parameters
outputthe byte buffer
sizethe length of the buffer, in bytes

Reimplemented from RandomNumberGenerator.

Definition at line 78 of file rdrand.h.

◆ DiscardBytes()

virtual void RDRAND::DiscardBytes ( size_t  n)
inlinevirtual

Generate and discard n bytes.

Parameters
nthe 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.

◆ IncorporateEntropy()

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

Update RNG state with additional unpredictable values.

Parameters
inputunused
lengthunused

The operation is a nop for this generator.

Reimplemented from RandomNumberGenerator.

Definition at line 102 of file rdrand.h.


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