Rabin-Williams trapdoor function using the private key. More...

#include <rw.h>

Inheritance diagram for InvertibleRWFunction:

Collaboration diagram for InvertibleRWFunction:

Public Member Functions
	InvertibleRWFunction ()
	Construct an InvertibleRWFunction. More...

void	Initialize (const Integer &n, const Integer &p, const Integer &q, const Integer &u)
	Initialize a Rabin-Williams private key. More...

void	Initialize (RandomNumberGenerator &rng, unsigned int modulusBits)
	Create a Rabin-Williams private key. More...

void	BERDecode (BufferedTransformation &bt)

void	DEREncode (BufferedTransformation &bt) const

void	Save (BufferedTransformation &bt) const
	Saves a key to a BufferedTransformation. More...

void	Load (BufferedTransformation &bt)
	Loads a key from a BufferedTransformation. More...

Integer	CalculateInverse (RandomNumberGenerator &rng, const Integer &x) const
	Calculates the inverse of an element. More...

bool	Validate (RandomNumberGenerator &rng, unsigned int level) const
	Check this object for errors. More...

bool	GetVoidValue (const char name, const std::type_info &valueType, void pValue) const
	Get a named value. More...

void	AssignFrom (const NameValuePairs &source)
	Assign values to this object. More...

void	GenerateRandom (RandomNumberGenerator &rng, const NameValuePairs &alg)

const Integer &	GetPrime1 () const

const Integer &	GetPrime2 () const

const Integer &	GetMultiplicativeInverseOfPrime2ModPrime1 () const

void	SetPrime1 (const Integer &p)

void	SetPrime2 (const Integer &q)

void	SetMultiplicativeInverseOfPrime2ModPrime1 (const Integer &u)

virtual bool	SupportsPrecomputation () const
	Determines whether the object supports precomputation. More...

virtual void	Precompute (unsigned int unused=0)
	Perform precomputation. More...

virtual void	Precompute (unsigned int unused=0) const

virtual void	LoadPrecomputation (BufferedTransformation &storedPrecomputation)
	Retrieve previously saved precomputation. More...

virtual void	SavePrecomputation (BufferedTransformation &storedPrecomputation) const
	Save precomputation for later use. More...

Public Member Functions inherited from RWFunction
void	Initialize (const Integer &n)
	Initialize a Rabin-Williams public key. More...

void	BERDecode (BufferedTransformation &bt)

void	DEREncode (BufferedTransformation &bt) const

Integer	ApplyFunction (const Integer &x) const
	Applies the trapdoor. More...

Integer	PreimageBound () const
	Returns the maximum size of a message before the trapdoor function is applied. More...

Integer	ImageBound () const
	Returns the maximum size of a message after the trapdoor function is applied. More...

const Integer &	GetModulus () const

void	SetModulus (const Integer &n)

Public Member Functions inherited from TrapdoorFunction
virtual	~TrapdoorFunction ()

Integer	ApplyRandomizedFunction (RandomNumberGenerator &rng, const Integer &x) const
	Applies the trapdoor function. More...

bool	IsRandomized () const
	Determines if the encryption algorithm is randomized. More...

Public Member Functions inherited from RandomizedTrapdoorFunction
virtual	~RandomizedTrapdoorFunction ()

Public Member Functions inherited from TrapdoorFunctionBounds
virtual	~TrapdoorFunctionBounds ()

virtual Integer	MaxPreimage () const
	Returns the maximum size of a message before the trapdoor function is applied bound to a public key. More...

virtual Integer	MaxImage () const
	Returns the maximum size of a message after the trapdoor function is applied bound to a public key. More...

Public Member Functions inherited from CryptoMaterial
virtual	~CryptoMaterial ()

virtual void	ThrowIfInvalid (RandomNumberGenerator &rng, unsigned int level) const
	Check this object for errors. More...

void	DoQuickSanityCheck () const
	Perform a quick sanity check. More...

Public Member Functions inherited from NameValuePairs
virtual	~NameValuePairs ()

template<class T >
bool	GetThisObject (T &object) const
	Get a copy of this object or subobject. More...

template<class T >
bool	GetThisPointer (T *&ptr) const
	Get a pointer to this object. More...

template<class T >
bool	GetValue (const char *name, T &value) const
	Get a named value. More...

template<class T >
T	GetValueWithDefault (const char *name, T defaultValue) const
	Get a named value. More...

CRYPTOPP_DLL std::string	GetValueNames () const
	Get a list of value names that can be retrieved. More...

CRYPTOPP_DLL bool	GetIntValue (const char *name, int &value) const
	Get a named value with type int. More...

CRYPTOPP_DLL int	GetIntValueWithDefault (const char *name, int defaultValue) const
	Get a named value with type int, with default. More...

template<class T >
void	GetRequiredParameter (const char className, const char name, T &value) const
	Retrieves a required name/value pair. More...

CRYPTOPP_DLL void	GetRequiredIntParameter (const char className, const char name, int &value) const
	Retrieves a required name/value pair. More...

Public Member Functions inherited from TrapdoorFunctionInverse
virtual	~TrapdoorFunctionInverse ()

Integer	CalculateRandomizedInverse (RandomNumberGenerator &rng, const Integer &x) const
	Applies the inverse of the trapdoor function. More...

bool	IsRandomized () const
	Determines if the decryption algorithm is randomized. More...

Public Member Functions inherited from RandomizedTrapdoorFunctionInverse
virtual	~RandomizedTrapdoorFunctionInverse ()

Public Member Functions inherited from GeneratableCryptoMaterial
virtual	~GeneratableCryptoMaterial ()

void	GenerateRandomWithKeySize (RandomNumberGenerator &rng, unsigned int keySize)
	Generate a random key or crypto parameters. More...

Protected Member Functions
void	PrecomputeTweakedRoots () const

Protected Attributes
Integer	m_p

Integer	m_q

Integer	m_u

Integer	m_pre_2_9p

Integer	m_pre_2_3q

Integer	m_pre_q_p

bool	m_precompute

Protected Attributes inherited from RWFunction
Integer	m_n

Private Types
typedef InvertibleRWFunction	ThisClass

Additional Inherited Members
Static Public Member Functions inherited from NameValuePairs
static CRYPTOPP_DLL void CRYPTOPP_API	ThrowIfTypeMismatch (const char *name, const std::type_info &stored, const std::type_info &retrieving)
	Ensures an expected name and type is present. More...

Detailed Description

Rabin-Williams trapdoor function using the private key.

Since: Crypto++ 2.0, Tweaked roots using e and f since Crypto++ 5.6.4

Definition at line 60 of file rw.h.

Member Typedef Documentation

typedef InvertibleRWFunction InvertibleRWFunction::ThisClass

private

Definition at line 62 of file rw.h.

Constructor & Destructor Documentation

InvertibleRWFunction::InvertibleRWFunction ( )

inline

Construct an InvertibleRWFunction.

Definition at line 66 of file rw.h.

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Member Function Documentation

void InvertibleRWFunction::AssignFrom ( const NameValuePairs & source )

virtual

Assign values to this object.

This function can be used to create a public key from a private key.

Reimplemented from RWFunction.

Definition at line 277 of file rw.cpp.

void InvertibleRWFunction::BERDecode ( BufferedTransformation & bt )

Definition at line 164 of file rw.cpp.

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Integer InvertibleRWFunction::CalculateInverse	(	RandomNumberGenerator &	rng,
		const Integer &	x
	)		const

virtual

Calculates the inverse of an element.

Parameters

rng	a `RandomNumberGenerator` derived class
x	the element

Returns: the inverse of the element in the group

Implements TrapdoorFunctionInverse.

Definition at line 187 of file rw.cpp.

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void InvertibleRWFunction::DEREncode ( BufferedTransformation & bt ) const

Definition at line 176 of file rw.cpp.

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void InvertibleRWFunction::GenerateRandom	(	RandomNumberGenerator &	rng,
		const NameValuePairs &	alg
	)

virtual

parameters: (ModulusSize)

Reimplemented from GeneratableCryptoMaterial.

Definition at line 99 of file rw.cpp.

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const Integer& InvertibleRWFunction::GetMultiplicativeInverseOfPrime2ModPrime1 ( ) const

inline

Definition at line 104 of file rw.h.

const Integer& InvertibleRWFunction::GetPrime1 ( ) const

inline

Definition at line 102 of file rw.h.

const Integer& InvertibleRWFunction::GetPrime2 ( ) const

inline

Definition at line 103 of file rw.h.

bool InvertibleRWFunction::GetVoidValue	(	const char *	name,
		const std::type_info &	valueType,
		void *	pValue
	)		const

virtual

Get a named value.

Parameters

name	the name of the object or value to retrieve
valueType	reference to a variable that receives the value
pValue	void pointer to a variable that receives the value

Returns: true if the value was retrieved, false otherwise

GetVoidValue() retrieves the value of name if it exists.

Note: GetVoidValue() is an internal function and should be implemented by derived classes. Users should use one of the other functions instead.

See also: GetValue(), GetValueWithDefault(), GetIntValue(), GetIntValueWithDefault(), GetRequiredParameter() and GetRequiredIntParameter()

Reimplemented from RWFunction.

Definition at line 268 of file rw.cpp.

void InvertibleRWFunction::Initialize	(	const Integer &	n,
		const Integer &	p,
		const Integer &	q,
		const Integer &	u
	)

Initialize a Rabin-Williams private key.

Parameters

n	modulus
p	first prime factor
q	second prime factor
u	q^-1 mod p

This Initialize() function overload initializes a private key from existing parameters.

Definition at line 117 of file rw.cpp.

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void InvertibleRWFunction::Initialize	(	RandomNumberGenerator &	rng,
		unsigned int	modulusBits
	)

inline

Create a Rabin-Williams private key.

Parameters

rng	a RandomNumberGenerator derived class
modulusBits	the size of the modulus, in bits

This function overload of Initialize() creates a new private key because it takes a RandomNumberGenerator() as a parameter. If you have an existing keypair, then use one of the other Initialize() overloads.

Definition at line 82 of file rw.h.

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void InvertibleRWFunction::Load ( BufferedTransformation & bt )

inlinevirtual

Loads a key from a BufferedTransformation.

Parameters

bt	the source BufferedTransformation

Exceptions

KeyingErr

Load() attempts to read material from a BufferedTransformation. If the material is a key that was generated outside the library, then the following usually applies:

the key should be ASN.1 BER encoded
the key should be a "key info"

"key info" means the key should have an object identifier with an algorthm id, like a subjectPublicKeyInfo.

To read a "raw" key without the "key info", then call the key's BERDecode() method.

Note: Load generally does not check that the key is valid. Call Validate(), if needed.

Reimplemented from RWFunction.

Definition at line 90 of file rw.h.

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void InvertibleRWFunction::LoadPrecomputation ( BufferedTransformation & storedPrecomputation )

virtual

Retrieve previously saved precomputation.

Parameters

storedPrecomputation BufferedTransformation with the saved precomputation

Exceptions

NotImplemented

See also: SupportsPrecomputation(), Precompute()

Reimplemented from CryptoMaterial.

Definition at line 141 of file rw.cpp.

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virtual void InvertibleRWFunction::Precompute ( unsigned int precomputationStorage = 0 )

inlinevirtual

Perform precomputation.

Parameters

precomputationStorage the suggested number of objects for the precompute table

Exceptions

NotImplemented

The exact semantics of Precompute() varies, but it typically means calculate a table of n objects that can be used later to speed up computation.

If a derived class does not override Precompute(), then the base class throws NotImplemented.

See also: SupportsPrecomputation(), LoadPrecomputation(), SavePrecomputation()

Reimplemented from CryptoMaterial.

Definition at line 111 of file rw.h.

virtual void InvertibleRWFunction::Precompute ( unsigned int unused = 0 ) const

inlinevirtual

Definition at line 112 of file rw.h.

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void InvertibleRWFunction::PrecomputeTweakedRoots ( ) const

protected

Definition at line 124 of file rw.cpp.

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void InvertibleRWFunction::Save ( BufferedTransformation & bt ) const

inlinevirtual

Saves a key to a BufferedTransformation.

Parameters

bt	the destination BufferedTransformation

Exceptions

NotImplemented

Save() writes the material to a BufferedTransformation.

If the material is a key, then the key is written with ASN.1 DER encoding. The key includes an object identifier with an algorthm id, like a subjectPublicKeyInfo.

A "raw" key without the "key info" can be saved using a key's DEREncode() method.

If a derived class does not override Save(), then the base class throws NotImplemented().

Reimplemented from RWFunction.

Definition at line 88 of file rw.h.

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void InvertibleRWFunction::SavePrecomputation ( BufferedTransformation & storedPrecomputation ) const

virtual

Save precomputation for later use.

Parameters

storedPrecomputation BufferedTransformation to write the precomputation

Exceptions

NotImplemented

See also: SupportsPrecomputation(), Precompute()

Reimplemented from CryptoMaterial.

Definition at line 152 of file rw.cpp.

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void InvertibleRWFunction::SetMultiplicativeInverseOfPrime2ModPrime1 ( const Integer & u )

inline

Definition at line 108 of file rw.h.

void InvertibleRWFunction::SetPrime1 ( const Integer & p )

inline

Definition at line 106 of file rw.h.

void InvertibleRWFunction::SetPrime2 ( const Integer & q )

inline

Definition at line 107 of file rw.h.

virtual bool InvertibleRWFunction::SupportsPrecomputation ( ) const

inlinevirtual

Determines whether the object supports precomputation.

Returns: true if the object supports precomputation, false otherwise

See also: Precompute()

Reimplemented from CryptoMaterial.

Definition at line 110 of file rw.h.

bool InvertibleRWFunction::Validate	(	RandomNumberGenerator &	rng,
		unsigned int	level
	)		const

virtual

Check this object for errors.

Parameters

rng	a RandomNumberGenerator for objects which use randomized testing
level	the level of thoroughness

Returns: true if the tests succeed, false otherwise

There are four levels of thoroughness:

0 - using this object won't cause a crash or exception
1 - this object will probably function, and encrypt, sign, other operations correctly
2 - ensure this object will function correctly, and perform reasonable security checks
3 - perform reasonable security checks, and do checks that may take a long time

Level 0 does not require a RandomNumberGenerator. A NullRNG() can be used for level 0. Level 1 may not check for weak keys and such. Levels 2 and 3 are recommended.

See also: ThrowIfInvalid()

Reimplemented from RWFunction.

Definition at line 252 of file rw.cpp.

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Member Data Documentation

Integer InvertibleRWFunction::m_p

protected

Definition at line 121 of file rw.h.

Integer InvertibleRWFunction::m_pre_2_3q

mutableprotected

Definition at line 123 of file rw.h.

Integer InvertibleRWFunction::m_pre_2_9p

mutableprotected

Definition at line 123 of file rw.h.

Integer InvertibleRWFunction::m_pre_q_p

mutableprotected

Definition at line 123 of file rw.h.

bool InvertibleRWFunction::m_precompute

mutableprotected

Definition at line 124 of file rw.h.

Integer InvertibleRWFunction::m_q

protected

Definition at line 121 of file rw.h.

Integer InvertibleRWFunction::m_u

protected

Definition at line 121 of file rw.h.

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

src/cryptopp/rw.h
src/cryptopp/rw.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Private Types

Additional Inherited Members

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation