Elliptic Curve Parameters. More...

#include <eccrypto.h>

Inheritance diagram for DL_GroupParameters_EC< EC >:

Collaboration diagram for DL_GroupParameters_EC< EC >:

Public Types
typedef EC	EllipticCurve

typedef EllipticCurve::Point	Point

typedef Point	Element

typedef IncompatibleCofactorMultiplication	DefaultCofactorOption

Public Types inherited from DL_GroupParametersImpl< EcPrecomputation< EC > >
typedef EcPrecomputation< EC >	GroupPrecomputation

typedef EcPrecomputation< EC >::Element	Element

typedef DL_FixedBasePrecomputationImpl< typename EcPrecomputation< EC >::Element >	BasePrecomputation

Public Types inherited from DL_GroupParameters< typename EcPrecomputation< EC >::Element >
typedef typename EcPrecomputation< EC >::Element	Element

Public Member Functions
virtual	~DL_GroupParameters_EC ()

	DL_GroupParameters_EC ()
	Construct an EC GroupParameters. More...

	DL_GroupParameters_EC (const OID &oid)
	Construct an EC GroupParameters. More...

	DL_GroupParameters_EC (const EllipticCurve &ec, const Point &G, const Integer &n, const Integer &k=Integer::Zero())
	Construct an EC GroupParameters. More...

	DL_GroupParameters_EC (BufferedTransformation &bt)
	Construct an EC GroupParameters. More...

void	Initialize (const EllipticCurve &ec, const Point &G, const Integer &n, const Integer &k=Integer::Zero())
	Initialize an EC GroupParameters using {EC,G,n,k}. More...

void	Initialize (const OID &oid)
	Initialize a DL_GroupParameters_EC {EC,G,n,k}. 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)
	this implementation doesn't actually generate a curve, it just initializes the parameters with existing values More...

const DL_FixedBasePrecomputation< Element > &	GetBasePrecomputation () const
	Retrieves the group precomputation. More...

DL_FixedBasePrecomputation< Element > &	AccessBasePrecomputation ()
	Retrieves the group precomputation. More...

const Integer &	GetSubgroupOrder () const
	Retrieves the subgroup order. More...

Integer	GetCofactor () const
	Retrieves the cofactor. More...

bool	ValidateGroup (RandomNumberGenerator &rng, unsigned int level) const
	Check the group for errors. More...

bool	ValidateElement (unsigned int level, const Element &element, const DL_FixedBasePrecomputation< Element > *precomp) const

bool	FastSubgroupCheckAvailable () const

void	EncodeElement (bool reversible, const Element &element, byte *encoded) const

virtual unsigned int	GetEncodedElementSize (bool reversible) const
	Retrieves the encoded element's size. More...

Element	DecodeElement (const byte *encoded, bool checkForGroupMembership) const
	Decodes the element. More...

Integer	ConvertElementToInteger (const Element &element) const

Integer	GetMaxExponent () const
	Retrieves the maximum exponent for the group. More...

bool	IsIdentity (const Element &element) const

void	SimultaneousExponentiate (Element results, const Element &base, const Integer exponents, unsigned int exponentsCount) const

OID	GetAlgorithmID () const

Element	MultiplyElements (const Element &a, const Element &b) const

Element	CascadeExponentiate (const Element &element1, const Integer &exponent1, const Element &element2, const Integer &exponent2) const

void	BERDecode (BufferedTransformation &bt)

void	DEREncode (BufferedTransformation &bt) const

void	SetPointCompression (bool compress)

bool	GetPointCompression () const

void	SetEncodeAsOID (bool encodeAsOID)

bool	GetEncodeAsOID () const

const EllipticCurve &	GetCurve () const

bool	operator== (const ThisClass &rhs) const

Public Member Functions inherited from DL_GroupParametersImpl< EcPrecomputation< EC > >
virtual	~DL_GroupParametersImpl ()

const DL_GroupPrecomputation< Element > &	GetGroupPrecomputation () const
	Retrieves the group precomputation. More...

const DL_FixedBasePrecomputation< Element > &	GetBasePrecomputation () const
	Retrieves the group precomputation. More...

DL_FixedBasePrecomputation< Element > &	AccessBasePrecomputation ()
	Retrieves the group precomputation. More...

Public Member Functions inherited from DL_GroupParameters< typename EcPrecomputation< EC >::Element >
virtual	~DL_GroupParameters ()

	DL_GroupParameters ()

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...

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

void	Precompute (unsigned int precomputationStorage=16)
	Perform precomputation. More...

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

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

virtual const Element &	GetSubgroupGenerator () const
	Retrieves the subgroup generator. More...

virtual void	SetSubgroupGenerator (const Element &base)
	Set the subgroup generator. More...

virtual Element	ExponentiateBase (const Integer &exponent) const
	Retrieves the subgroup generator. More...

virtual Element	ExponentiateElement (const Element &base, const Integer &exponent) const
	Exponentiates an element. More...

virtual Integer	GetGroupOrder () const
	Retrieves the order of the group. More...

virtual void	EncodeElement (bool reversible, const Element &element, byte *encoded) const =0
	Encodes the element. More...

virtual Integer	ConvertElementToInteger (const Element &element) const =0
	Converts an element to an Integer. More...

virtual bool	ValidateElement (unsigned int level, const Element &element, const DL_FixedBasePrecomputation< Element > *precomp) const =0
	Check the element for errors. More...

virtual bool	IsIdentity (const Element &element) const =0
	Determines if an element is an identity. More...

virtual void	SimultaneousExponentiate (Element results, const Element &base, const Integer exponents, unsigned int exponentsCount) const =0
	Exponentiates a base to multiple exponents. More...

Public Member Functions inherited from GeneratableCryptoMaterial
virtual	~GeneratableCryptoMaterial ()

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

Public Member Functions inherited from CryptoMaterial
virtual	~CryptoMaterial ()

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

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

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

Static Public Member Functions
static std::string CRYPTOPP_API	StaticAlgorithmNamePrefix ()

static OID CRYPTOPP_API	GetNextRecommendedParametersOID (const OID &oid)

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...

Protected Member Functions
unsigned int	FieldElementLength () const

unsigned int	ExponentLength () const

Protected Member Functions inherited from DL_GroupParameters< typename EcPrecomputation< EC >::Element >
void	ParametersChanged ()

Protected Attributes
OID	m_oid

Integer	m_n

Integer	m_k

bool	m_compress

bool	m_encodeAsOID

Protected Attributes inherited from DL_GroupParametersImpl< EcPrecomputation< EC > >
EcPrecomputation< EC >	m_groupPrecomputation

DL_FixedBasePrecomputationImpl< typename EcPrecomputation< EC >::Element >	m_gpc

Private Types
typedef DL_GroupParameters_EC< EC >	ThisClass

Detailed Description

template<class EC>
class DL_GroupParameters_EC< EC >

Elliptic Curve Parameters.

Template Parameters

EC	elliptic curve field

This class corresponds to the ASN.1 sequence of the same name in ANSI X9.62 and SEC 1. EC is currently defined for ECP and EC2N.

Definition at line 32 of file eccrypto.h.

Member Typedef Documentation

template<class EC>

typedef IncompatibleCofactorMultiplication DL_GroupParameters_EC< EC >::DefaultCofactorOption

Definition at line 40 of file eccrypto.h.

template<class EC>

typedef Point DL_GroupParameters_EC< EC >::Element

Definition at line 39 of file eccrypto.h.

template<class EC>

typedef EC DL_GroupParameters_EC< EC >::EllipticCurve

Definition at line 37 of file eccrypto.h.

template<class EC>

typedef EllipticCurve::Point DL_GroupParameters_EC< EC >::Point

Definition at line 38 of file eccrypto.h.

template<class EC>

typedef DL_GroupParameters_EC<EC> DL_GroupParameters_EC< EC >::ThisClass

private

Definition at line 34 of file eccrypto.h.

Constructor & Destructor Documentation

template<class EC>

virtual DL_GroupParameters_EC< EC >::~DL_GroupParameters_EC ( )

inlinevirtual

Definition at line 42 of file eccrypto.h.

template<class EC>

DL_GroupParameters_EC< EC >::DL_GroupParameters_EC ( )

inline

Construct an EC GroupParameters.

Definition at line 45 of file eccrypto.h.

template<class EC>

DL_GroupParameters_EC< EC >::DL_GroupParameters_EC ( const OID & oid )

inline

Construct an EC GroupParameters.

Parameters

oid	the OID of a curve

Definition at line 49 of file eccrypto.h.

template<class EC>

DL_GroupParameters_EC< EC >::DL_GroupParameters_EC	(	const EllipticCurve &	ec,
		const Point &	G,
		const Integer &	n,
		const Integer &	k = `Integer::Zero()`
	)

inline

Construct an EC GroupParameters.

Parameters

ec	the elliptic curve
G	the base point
n	the order of the base point
k	the cofactor

Definition at line 57 of file eccrypto.h.

template<class EC>

DL_GroupParameters_EC< EC >::DL_GroupParameters_EC ( BufferedTransformation & bt )

inline

Construct an EC GroupParameters.

Parameters

bt	BufferedTransformation with group parameters

Definition at line 62 of file eccrypto.h.

Member Function Documentation

template<class EC>

DL_FixedBasePrecomputation<Element>& DL_GroupParameters_EC< EC >::AccessBasePrecomputation ( )

inlinevirtual

Retrieves the group precomputation.

Returns: a non-const reference to the group precomputation using a fixed base

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 95 of file eccrypto.h.

template<class EC >

void DL_GroupParameters_EC< EC >::AssignFrom ( const NameValuePairs & source )

virtual

Assign values to this object.

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

Implements CryptoMaterial.

Definition at line 486 of file eccrypto.cpp.

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template<class EC >

void DL_GroupParameters_EC< EC >::BERDecode ( BufferedTransformation & bt )

Definition at line 521 of file eccrypto.cpp.

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template<class EC >

DL_GroupParameters_EC< EC >::Element DL_GroupParameters_EC< EC >::CascadeExponentiate	(	const Element &	element1,
		const Integer &	exponent1,
		const Element &	element2,
		const Integer &	exponent2
	)		const

Definition at line 636 of file eccrypto.cpp.

template<class EC >

Integer DL_GroupParameters_EC< EC >::ConvertElementToInteger ( const Element & element ) const

Definition at line 580 of file eccrypto.cpp.

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template<class EC>

Element DL_GroupParameters_EC< EC >::DecodeElement	(	const byte *	encoded,
		bool	checkForGroupMembership
	)		const

inlinevirtual

Decodes the element.

Parameters

encoded	byte array with the encoded element
checkForGroupMembership	flag indicating if the element should be validated

Returns: Element after decoding

DecodeElement() must be implemented in a derived class.

Precondition: COUNTOF(encoded) == GetEncodedElementSize()

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 115 of file eccrypto.h.

template<class EC >

void DL_GroupParameters_EC< EC >::DEREncode ( BufferedTransformation & bt ) const

Definition at line 549 of file eccrypto.cpp.

template<class EC>

void DL_GroupParameters_EC< EC >::EncodeElement	(	bool	reversible,
		const Element &	element,
		byte *	encoded
	)		const

inline

Definition at line 101 of file eccrypto.h.

template<class EC>

unsigned int DL_GroupParameters_EC< EC >::ExponentLength ( ) const

inlineprotected

Definition at line 164 of file eccrypto.h.

template<class EC>

bool DL_GroupParameters_EC< EC >::FastSubgroupCheckAvailable ( ) const

inlinevirtual

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 100 of file eccrypto.h.

template<class EC>

unsigned int DL_GroupParameters_EC< EC >::FieldElementLength ( ) const

inlineprotected

Definition at line 163 of file eccrypto.h.

template<class EC >

void DL_GroupParameters_EC< EC >::GenerateRandom	(	RandomNumberGenerator &	rng,
		const NameValuePairs &	alg
	)

virtual

this implementation doesn't actually generate a curve, it just initializes the parameters with existing values

parameters: (Curve, SubgroupGenerator, SubgroupOrder, Cofactor (optional)), or (GroupOID)

Reimplemented from GeneratableCryptoMaterial.

Definition at line 507 of file eccrypto.cpp.

template<class EC >

OID DL_GroupParameters_EC< EC >::GetAlgorithmID ( ) const

Definition at line 642 of file eccrypto.cpp.

template<class EC>

const DL_FixedBasePrecomputation<Element>& DL_GroupParameters_EC< EC >::GetBasePrecomputation ( ) const

inlinevirtual

Retrieves the group precomputation.

Returns: a const reference to the group precomputation using a fixed base

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 94 of file eccrypto.h.

template<class EC >

Integer DL_GroupParameters_EC< EC >::GetCofactor ( ) const

virtual

Retrieves the cofactor.

Returns: the cofactor

Either GetGroupOrder() or GetCofactor() must be overridden in a derived class.

Reimplemented from DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 567 of file eccrypto.cpp.

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template<class EC>

const EllipticCurve& DL_GroupParameters_EC< EC >::GetCurve ( ) const

inline

Definition at line 151 of file eccrypto.h.

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template<class EC>

bool DL_GroupParameters_EC< EC >::GetEncodeAsOID ( ) const

inline

Definition at line 149 of file eccrypto.h.

template<class EC>

virtual unsigned int DL_GroupParameters_EC< EC >::GetEncodedElementSize ( bool reversible ) const

inlinevirtual

Retrieves the encoded element's size.

Parameters

reversible flag indicating the encoding format

Returns: encoded element's size, in bytes

The format of the encoded element varies by the underlyinhg type of the element and the reversible flag. GetEncodedElementSize() must be implemented in a derived class.

See also: GetEncodedElementSize(), EncodeElement(), DecodeElement()

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 108 of file eccrypto.h.

template<class EC>

Integer DL_GroupParameters_EC< EC >::GetMaxExponent ( ) const

inlinevirtual

Retrieves the maximum exponent for the group.

Returns: the maximum exponent for the group

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 125 of file eccrypto.h.

template<class EC >

OID DL_GroupParameters_EC< EC >::GetNextRecommendedParametersOID ( const OID & oid )

static

Definition at line 434 of file eccrypto.cpp.

template<class EC>

bool DL_GroupParameters_EC< EC >::GetPointCompression ( ) const

inline

Definition at line 146 of file eccrypto.h.

template<class EC>

const Integer& DL_GroupParameters_EC< EC >::GetSubgroupOrder ( ) const

inlinevirtual

Retrieves the subgroup order.

Returns: the order of subgroup generated by the base element

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 96 of file eccrypto.h.

template<class EC >

bool DL_GroupParameters_EC< EC >::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()

Implements NameValuePairs.

Definition at line 469 of file eccrypto.cpp.

template<class EC>

void DL_GroupParameters_EC< EC >::Initialize	(	const EllipticCurve &	ec,
		const Point &	G,
		const Integer &	n,
		const Integer &	k = `Integer::Zero()`
	)

inline

Initialize an EC GroupParameters using {EC,G,n,k}.

Parameters

ec	the elliptic curve
G	the base point
n	the order of the base point
k	the cofactor

This Initialize() function overload initializes group parameters from existing parameters.

Definition at line 71 of file eccrypto.h.

template<class EC >

void DL_GroupParameters_EC< EC >::Initialize ( const OID & oid )

Initialize a DL_GroupParameters_EC {EC,G,n,k}.

Parameters

oid	the OID of a curve

This Initialize() function overload initializes group parameters from existing parameters.

Definition at line 442 of file eccrypto.cpp.

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template<class EC>

bool DL_GroupParameters_EC< EC >::IsIdentity ( const Element & element ) const

inline

Definition at line 126 of file eccrypto.h.

template<class EC >

DL_GroupParameters_EC< EC >::Element DL_GroupParameters_EC< EC >::MultiplyElements	(	const Element &	a,
		const Element &	b
	)		const

Definition at line 630 of file eccrypto.cpp.

template<class EC>

bool DL_GroupParameters_EC< EC >::operator== ( const ThisClass & rhs ) const

inline

Definition at line 153 of file eccrypto.h.

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template<class EC>

void DL_GroupParameters_EC< EC >::SetEncodeAsOID ( bool encodeAsOID )

inline

Definition at line 148 of file eccrypto.h.

template<class EC>

void DL_GroupParameters_EC< EC >::SetPointCompression ( bool compress )

inline

Definition at line 145 of file eccrypto.h.

template<class EC >

void DL_GroupParameters_EC< EC >::SimultaneousExponentiate	(	Element *	results,
		const Element &	base,
		const Integer *	exponents,
		unsigned int	exponentsCount
	)		const

Definition at line 624 of file eccrypto.cpp.

template<class EC>

static std::string CRYPTOPP_API DL_GroupParameters_EC< EC >::StaticAlgorithmNamePrefix ( )

inlinestatic

Definition at line 128 of file eccrypto.h.

template<class EC >

bool DL_GroupParameters_EC< EC >::ValidateElement	(	unsigned int	level,
		const Element &	element,
		const DL_FixedBasePrecomputation< Element > *	precomp
	)		const

Definition at line 606 of file eccrypto.cpp.

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template<class EC >

bool DL_GroupParameters_EC< EC >::ValidateGroup	(	RandomNumberGenerator &	rng,
		unsigned int	level
	)		const

virtual

Check the group for errors.

Parameters

rng	RandomNumberGenerator for objects which use randomized testing
level	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.

ValidateGroup() must be implemented in a derived class.

Implements DL_GroupParameters< typename EcPrecomputation< EC >::Element >.

Definition at line 586 of file eccrypto.cpp.

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Member Data Documentation

template<class EC>

bool DL_GroupParameters_EC< EC >::m_compress

mutableprotected

Definition at line 169 of file eccrypto.h.

template<class EC>

bool DL_GroupParameters_EC< EC >::m_encodeAsOID

mutableprotected

Definition at line 169 of file eccrypto.h.

template<class EC>

Integer DL_GroupParameters_EC< EC >::m_k

mutableprotected

Definition at line 168 of file eccrypto.h.

template<class EC>

Integer DL_GroupParameters_EC< EC >::m_n

protected

Definition at line 167 of file eccrypto.h.

template<class EC>

OID DL_GroupParameters_EC< EC >::m_oid

protected

Definition at line 166 of file eccrypto.h.

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

src/cryptopp/eccrypto.h
src/cryptopp/eccrypto.cpp

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Private Types

Detailed Description

template<class EC> class DL_GroupParameters_EC< EC >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class EC>
class DL_GroupParameters_EC< EC >