Interface for NIST DRBGs from SP 800-90A. More...

#include <drbg.h>

Inheritance diagram for NIST_DRBG:

Classes
class	Err
	Exception thrown when a NIST DRBG encounters an error. More...

Public Member Functions
virtual bool	CanIncorporateEntropy () const
	Determines if a generator can accept additional entropy.

virtual void	IncorporateEntropy (const byte *input, size_t length)=0
	Update RNG state with additional unpredictable values.

virtual void	IncorporateEntropy (const byte entropy, size_t entropyLength, const byte additional, size_t additionaLength)=0
	Update RNG state with additional unpredictable values.

virtual void	GenerateBlock (byte *output, size_t size)=0
	Generate random array of bytes.

virtual void	GenerateBlock (const byte additional, size_t additionaLength, byte output, size_t size)=0
	Generate random array of bytes.

virtual unsigned int	SecurityStrength () const =0
	Provides the security strength.

virtual unsigned int	SeedLength () const =0
	Provides the seed length.

virtual unsigned int	MinEntropyLength () const =0
	Provides the minimum entropy size.

virtual unsigned int	MaxEntropyLength () const =0
	Provides the maximum entropy size.

virtual unsigned int	MinNonceLength () const =0
	Provides the minimum nonce size.

virtual unsigned int	MaxNonceLength () const =0
	Provides the maximum nonce size.

virtual unsigned int	MaxBytesPerRequest () const =0
	Provides the maximum size of a request to GenerateBlock.

virtual unsigned int	MaxRequestBeforeReseed () const =0
	Provides the maximum number of requests before a reseed.

Public Member Functions inherited from RandomNumberGenerator
virtual byte	GenerateByte ()
	Generate new random byte and return it.

virtual unsigned int	GenerateBit ()
	Generate new random bit and return it.

virtual word32	GenerateWord32 (word32 min=0, word32 max=0xffffffffUL)
	Generate a random 32 bit word in the range min to max, inclusive.

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

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

Interface for NIST DRBGs from SP 800-90A.

NIST_DRBG is the base class interface for NIST DRBGs from SP 800-90A Rev 1 (June 2015)

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

See also: Recommendation for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015)

Since: Crypto++ 6.0

Definition at line 26 of file drbg.h.

Constructor & Destructor Documentation

◆ ~NIST_DRBG()

virtual NIST_DRBG::~NIST_DRBG ( )

inlinevirtual

Definition at line 38 of file drbg.h.

Member Function Documentation

◆ CanIncorporateEntropy()

virtual bool NIST_DRBG::CanIncorporateEntropy ( ) const

inlinevirtual

Determines if a generator can accept additional entropy.

Returns: true

All NIST_DRBG return true

Reimplemented from RandomNumberGenerator.

Definition at line 43 of file drbg.h.

◆ IncorporateEntropy() [1/2]

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

pure 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

NIST_DRBG::Err if the generator is reseeded with insufficient entropy

NIST instantiation and reseed requirements demand the generator is constructed with at least MINIMUM_ENTROPY entropy. The byte array for input must meet NIST SP 800-90B or SP 800-90C requirements.

Reimplemented from RandomNumberGenerator.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ IncorporateEntropy() [2/2]

virtual void NIST_DRBG::IncorporateEntropy	(	const byte *	entropy,
		size_t	entropyLength,
		const byte *	additional,
		size_t	additionaLength
	)

pure virtual

Update RNG state with additional unpredictable values.

Parameters

entropy	the entropy to add to the generator
entropyLength	the size of the input buffer
additional	additional input to add to the generator
additionaLength	the size of the additional input buffer

Exceptions

NIST_DRBG::Err if the generator is reseeded with insufficient entropy

IncorporateEntropy() is an overload provided to match NIST requirements. NIST instantiation and reseed requirements demand the generator is constructed with at least MINIMUM_ENTROPY entropy. The byte array for entropy must meet NIST SP 800-90B or SP 800-90C requirements.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ GenerateBlock() [1/2]

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

pure virtual

Generate random array of bytes.

Parameters

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

Exceptions

NIST_DRBG::Err	if a reseed is required
NIST_DRBG::Err	if the size exceeds `MAXIMUM_BYTES_PER_REQUEST`

Reimplemented from RandomNumberGenerator.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ GenerateBlock() [2/2]

virtual void NIST_DRBG::GenerateBlock	(	const byte *	additional,
		size_t	additionaLength,
		byte *	output,
		size_t	size
	)

pure virtual

Generate random array of bytes.

Parameters

additional	additional input to add to the generator
additionaLength	the size of the additional input buffer
output	the byte buffer
size	the length of the buffer, in bytes

Exceptions

NIST_DRBG::Err	if a reseed is required
NIST_DRBG::Err	if the size exceeds `MAXIMUM_BYTES_PER_REQUEST`

GenerateBlock() is an overload provided to match NIST requirements. The byte array for additional input is optional. If present the additional randomness is mixed before generating the output bytes.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ SecurityStrength()

virtual unsigned int NIST_DRBG::SecurityStrength ( ) const

pure virtual

Provides the security strength.

Returns: The security strength of the generator, in bytes

The equivalent class constant is SECURITY_STRENGTH

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ SeedLength()

virtual unsigned int NIST_DRBG::SeedLength ( ) const

pure virtual

Provides the seed length.

Returns: The seed size of the generator, in bytes

The equivalent class constant is SEED_LENGTH. The size is used to maintain internal state of V and C.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ MinEntropyLength()

virtual unsigned int NIST_DRBG::MinEntropyLength ( ) const

pure virtual

Provides the minimum entropy size.

Returns: The minimum entropy size required by the generator, in bytes

The equivalent class constant is MINIMUM_ENTROPY. All NIST DRBGs must be instaniated with at least MINIMUM_ENTROPY bytes of entropy. The bytes must meet NIST SP 800-90B or SP 800-90C requirements.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ MaxEntropyLength()

virtual unsigned int NIST_DRBG::MaxEntropyLength ( ) const

pure virtual

Provides the maximum entropy size.

Returns: The maximum entropy size that can be consumed by the generator, in bytes

The equivalent class constant is MAXIMUM_ENTROPY. The bytes must meet NIST SP 800-90B or SP 800-90C requirements. MAXIMUM_ENTROPY has been reduced from 2³⁵ to INT_MAX to fit the underlying C++ datatype.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ MinNonceLength()

virtual unsigned int NIST_DRBG::MinNonceLength ( ) const

pure virtual

Provides the minimum nonce size.

Returns: The minimum nonce size recommended for the generator, in bytes

The equivalent class constant is MINIMUM_NONCE. If a nonce is not required then MINIMUM_NONCE is 0. Hash_DRBG does not require a nonce, while HMAC_DRBG and CTR_DRBG require a nonce.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ MaxNonceLength()

virtual unsigned int NIST_DRBG::MaxNonceLength ( ) const

pure virtual

Provides the maximum nonce size.

Returns: The maximum nonce that can be consumed by the generator, in bytes

The equivalent class constant is MAXIMUM_NONCE. MAXIMUM_NONCE has been reduced from 2³⁵ to INT_MAX to fit the underlying C++ datatype. If a nonce is not required then MINIMUM_NONCE is 0. Hash_DRBG does not require a nonce, while HMAC_DRBG and CTR_DRBG require a nonce.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ MaxBytesPerRequest()

virtual unsigned int NIST_DRBG::MaxBytesPerRequest ( ) const

pure virtual

Provides the maximum size of a request to GenerateBlock.

Returns: The maximum size of a request to GenerateBlock(), in bytes

The equivalent class constant is MAXIMUM_BYTES_PER_REQUEST

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

◆ MaxRequestBeforeReseed()

virtual unsigned int NIST_DRBG::MaxRequestBeforeReseed ( ) const

pure virtual

Provides the maximum number of requests before a reseed.

Returns: The maximum number of requests before a reseed, in bytes

The equivalent class constant is MAXIMUM_REQUESTS_BEFORE_RESEED. MAXIMUM_REQUESTS_BEFORE_RESEED has been reduced from 2⁴⁸ to INT_MAX to fit the underlying C++ datatype.

Implemented in Hash_DRBG< HASH, STRENGTH, SEEDLENGTH >, and HMAC_DRBG< HASH, STRENGTH, SEEDLENGTH >.

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

drbg.h

Classes

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ~NIST_DRBG()

Member Function Documentation

◆ CanIncorporateEntropy()

◆ IncorporateEntropy() [1/2]

◆ IncorporateEntropy() [2/2]

◆ GenerateBlock() [1/2]

◆ GenerateBlock() [2/2]

◆ SecurityStrength()

◆ SeedLength()

◆ MinEntropyLength()

◆ MaxEntropyLength()

◆ MinNonceLength()

◆ MaxNonceLength()

◆ MaxBytesPerRequest()

◆ MaxRequestBeforeReseed()