OldRandomPool Class Reference

Randomness Pool based on PGP 2.6.x with MDC. More...

#include <randpool.h>

Inheritance diagram for OldRandomPool:

Public Member Functions
	OldRandomPool (unsigned int poolSize=384)
	Construct an OldRandomPool.
bool	CanIncorporateEntropy () const
	Determines if a generator can accept additional entropy.
void	IncorporateEntropy (const byte *input, size_t length)
	Update RNG state with additional unpredictable values.
void	GenerateIntoBufferedTransformation (BufferedTransformation &target, const std::string &channel, lword size)
	Generate random bytes into a BufferedTransformation.
byte	GenerateByte ()
	Generate new random byte and return it.
void	GenerateBlock (byte *output, size_t size)
	Generate random array of bytes.
word32	GenerateWord32 (word32 min=0, word32 max=0xffffffffUL)
	Generate a random 32 bit word in the range min to max, inclusive.
Public Member Functions inherited from RandomNumberGenerator
virtual unsigned int	GenerateBit ()
	Generate new random bit and return it.
virtual void	DiscardBytes (size_t n)
	Generate and discard n bytes.
template<class IT >
void	Shuffle (IT begin, IT end)
	Randomly shuffle the specified array.
Public Member Functions inherited from Algorithm
	Algorithm (bool checkSelfTestStatus=true)
	Interface for all crypto algorithms.
virtual std::string	AlgorithmName () const
	Provides the name of this algorithm.
virtual std::string	AlgorithmProvider () const
	Retrieve the provider of this algorithm.
Public Member Functions inherited from Clonable
virtual Clonable *	Clone () const
	Copies this object.

Detailed Description

Randomness Pool based on PGP 2.6.x with MDC.

If you need the pre-Crypto++ 5.5 generator then use OldRandomPool class. The OldRandomPool also provides the modern interface, including CanIncorporateEntropy, IncorporateEntropy and GenerateIntoBufferedTransformation.

You should reseed the generator after a fork() to avoid multiple generators with the same internal state.

You should migrate away from OldRandomPool at the earliest opportunity. Use a modern random number generator or key derivation function, like AutoSeededRandomPool or HKDF.

Warning

This class uses an old style PGP 2.6.x with MDC. The generator risks reusing random numbers after state rollback. You should migrate away from OldRandomPool at the earliest opportunity.

See also

RandomPool, AutoSeededRandomPool, HKDF, P1363_KDF2, PKCS12_PBKDF, PKCS5_PBKDF2_HMAC

Since

Crypto++ 6.0

Definition at line 74 of file randpool.h.

Constructor & Destructor Documentation

OldRandomPool()

OldRandomPool::OldRandomPool

(

unsigned int

poolSize = 384

)

Construct an OldRandomPool.

Parameters

poolSize

internal pool size of the generator

poolSize must be greater than 16

Member Function Documentation

CanIncorporateEntropy()

bool OldRandomPool::CanIncorporateEntropy ( ) const

inlinevirtual

Determines if a generator can accept additional entropy.

Returns

true if IncorporateEntropy() is implemented

Reimplemented from RandomNumberGenerator.

Definition at line 83 of file randpool.h.

IncorporateEntropy()

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

virtual

Update RNG state with additional unpredictable values.

Parameters

input	the entropy to add to the generator
length	the 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.

GenerateIntoBufferedTransformation()

void OldRandomPool::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.

GenerateByte()

byte OldRandomPool::GenerateByte ( )

virtual

Generate new random byte and return it.

Returns

a random 8-bit byte

Default implementation calls GenerateBlock() with one byte.

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

Reimplemented from RandomNumberGenerator.

GenerateBlock()

void OldRandomPool::GenerateBlock ( byte * output, size_t size )

virtual

Generate random array of bytes.

Parameters

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

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.

GenerateWord32()

word32 OldRandomPool::GenerateWord32 ( word32 min = 0, word32 max = 0xffffffffUL )

virtual

Generate a random 32 bit word in the range min to max, inclusive.

Parameters

min	the lower bound of the range
max	the upper bound of the range

Returns

a random 32-bit word

The default implementation calls Crop() on the difference between max and min, and then returns the result added to min.

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

Reimplemented from RandomNumberGenerator.

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

• randpool.h