Ed25519 public key. More...

#include <xed25519.h>

Inheritance diagram for ed25519PublicKey:

Public Types
typedef Integer	Element

Public Member Functions
OID	GetAlgorithmID () const
	Retrieves the OID of the algorithm.

void	Save (BufferedTransformation &bt) const
	DER encode ASN.1 object.

void	Load (BufferedTransformation &bt)
	BER decode ASN.1 object.

void	BERDecode (BufferedTransformation &bt)
	Decode this object from a BufferedTransformation.

void	DEREncode (BufferedTransformation &bt) const
	Encode this object into a BufferedTransformation.

void	BERDecodePublicKey (BufferedTransformation &bt, bool parametersPresent, size_t size)
	Decode subjectPublicKey part of subjectPublicKeyInfo.

void	DEREncodePublicKey (BufferedTransformation &bt) const
	Encode subjectPublicKey part of subjectPublicKeyInfo.

void	BERDecodeAndCheckAlgorithmID (BufferedTransformation &bt)
	Determine if OID is valid for this object.

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

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

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

void	SetPublicElement (const byte y[PUBLIC_KEYLENGTH])

void	SetPublicElement (const Element &y)

const Element &	GetPublicElement () const

const byte *	GetPublicKeyBytePtr () const
	Retrieve public key byte array.

Public Member Functions inherited from X509PublicKey
void	BERDecode (BufferedTransformation &bt)
	Decode this object from a BufferedTransformation.

void	DEREncode (BufferedTransformation &bt) const
	Encode this object into a BufferedTransformation.

virtual bool	BERDecodeAlgorithmParameters (BufferedTransformation &bt)
	Decode algorithm parameters.

virtual bool	DEREncodeAlgorithmParameters (BufferedTransformation &bt) const
	Encode algorithm parameters.

Public Member Functions inherited from ASN1Object
virtual void	BEREncode (BufferedTransformation &bt) const
	Encode this object into a BufferedTransformation.

Public Member Functions inherited from CryptoMaterial
virtual void	ThrowIfInvalid (RandomNumberGenerator &rng, unsigned int level) const
	Check this object for errors.

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

virtual void	Precompute (unsigned int precomputationStorage)
	Perform precomputation.

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

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

void	DoQuickSanityCheck () const
	Perform a quick sanity check.

Public Member Functions inherited from NameValuePairs
template<class T >
bool	GetThisObject (T &object) const
	Get a copy of this object or subobject.

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

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

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

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

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

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

CRYPTOPP_DLL bool	GetWord64Value (const char *name, word64 &value) const
	Get a named value with type word64.

CRYPTOPP_DLL word64	GetWord64ValueWithDefault (const char *name, word64 defaultValue) const
	Get a named value with type word64, with default.

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

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

Static Public Attributes
static const int	PUBLIC_KEYLENGTH = 32
	Size of the public key.

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

Detailed Description

Ed25519 public key.

ed25519PublicKey is somewhat of a hack. It needed to provide DL_PublicKey interface to fit into the existing framework, but it lacks a lot of the internals of a true DL_PublicKey. The missing pieces include GroupParameters and Point, which provide the low level field operations found in traditional implementations like NIST curves over prime and binary fields.

ed25519PublicKey is also unusual because the class members of interest are byte arrays and not Integers. In addition, the byte arrays are little-endian meaning LSB is at element 0 and the MSB is at element 31. If you call GetPublicElement() then the little-endian byte array is converted to a big-endian Integer() so it can be returned the way a caller expects. And calling SetPublicElement() performs a similar internal conversion.

Since: Crypto++ 8.0

Definition at line 634 of file xed25519.h.

Member Typedef Documentation

◆ Element

typedef Integer ed25519PublicKey::Element

Definition at line 639 of file xed25519.h.

Constructor & Destructor Documentation

◆ ~ed25519PublicKey()

virtual ed25519PublicKey::~ed25519PublicKey ( )

inlinevirtual

Definition at line 641 of file xed25519.h.

Member Function Documentation

◆ GetAlgorithmID()

OID ed25519PublicKey::GetAlgorithmID ( ) const

inlinevirtual

Retrieves the OID of the algorithm.

Returns: OID of the algorithm

Implements X509PublicKey.

Definition at line 643 of file xed25519.h.

◆ Save()

void ed25519PublicKey::Save ( BufferedTransformation & bt ) const

inlinevirtual

DER encode ASN.1 object.

Parameters

bt	BufferedTransformation object

Save() will write the OID associated with algorithm or scheme. In the case of public and private keys, this function writes the subjectPublicKeyInfo parts.

The default OID is from RFC 8410 using id-X25519. The default private key format is RFC 5208, which is the old format. The old format provides the best interop, and keys will work with OpenSSL.

Reimplemented from ASN1CryptoMaterial< PublicKey >.

Definition at line 656 of file xed25519.h.

◆ Load()

void ed25519PublicKey::Load ( BufferedTransformation & bt )

inlinevirtual

BER decode ASN.1 object.

Parameters

bt	BufferedTransformation object

See also: RFC 5958, Asymmetric Key Packages

Reimplemented from ASN1CryptoMaterial< PublicKey >.

Definition at line 664 of file xed25519.h.

◆ BERDecode()

void ed25519PublicKey::BERDecode ( BufferedTransformation & bt )

virtual

Decode this object from a BufferedTransformation.

Parameters

bt	BufferedTransformation object

Uses Basic Encoding Rules (BER)

Implements ASN1Object.

Definition at line 764 of file xed25519.cpp.

◆ DEREncode()

void ed25519PublicKey::DEREncode ( BufferedTransformation & bt ) const

virtual

Encode this object into a BufferedTransformation.

Parameters

bt	BufferedTransformation object

Uses Distinguished Encoding Rules (DER)

Implements ASN1Object.

Definition at line 778 of file xed25519.cpp.

◆ BERDecodePublicKey()

void ed25519PublicKey::BERDecodePublicKey	(	BufferedTransformation &	bt,
		bool	parametersPresent,
		size_t	size )

virtual

Decode subjectPublicKey part of subjectPublicKeyInfo.

Parameters

bt	BufferedTransformation object
parametersPresent	flag indicating if algorithm parameters are present
size	number of octets to read for the parameters, in bytes

BERDecodePublicKey() the decodes subjectPublicKey part of subjectPublicKeyInfo, without the BIT STRING header.

When parametersPresent = true then BERDecodePublicKey() calls BERDecodeAlgorithmParameters() to parse algorithm parameters.

See also: BERDecodeAlgorithmParameters

Implements X509PublicKey.

Definition at line 791 of file xed25519.cpp.

◆ DEREncodePublicKey()

void ed25519PublicKey::DEREncodePublicKey ( BufferedTransformation & bt ) const

virtual

Encode subjectPublicKey part of subjectPublicKeyInfo.

Parameters

bt	BufferedTransformation object

DEREncodePublicKey() encodes the subjectPublicKey part of subjectPublicKeyInfo, without the BIT STRING header.

See also: DEREncodeAlgorithmParameters

Implements X509PublicKey.

Definition at line 809 of file xed25519.cpp.

◆ BERDecodeAndCheckAlgorithmID()

void ed25519PublicKey::BERDecodeAndCheckAlgorithmID ( BufferedTransformation & bt )

Determine if OID is valid for this object.

BERDecodeAndCheckAlgorithmID() parses the OID from bt and determines if it valid for this object. The problem in practice is there are multiple OIDs available to denote curve25519 operations. The OIDs include an old GNU OID used by SSH, OIDs specified in draft-josefsson-pkix-newcurves, and OIDs specified in draft-ietf-curdle-pkix.

By default BERDecodeAndCheckAlgorithmID() accepts an OID set by the user, ASN1::curve25519() and ASN1::Ed25519(). ASN1::curve25519() is generic and says "this key is valid for curve25519 operations". ASN1::Ed25519() is specific and says "this key is valid for ed25519 signing."

Definition at line 749 of file xed25519.cpp.

◆ Validate()

bool ed25519PublicKey::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()

Implements CryptoMaterial.

Definition at line 835 of file xed25519.cpp.

◆ GetVoidValue()

bool ed25519PublicKey::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 712 of file xed25519.cpp.

◆ AssignFrom()

void ed25519PublicKey::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 734 of file xed25519.cpp.

◆ SetPublicElement() [1/2]

void ed25519PublicKey::SetPublicElement ( const byte y[PUBLIC_KEYLENGTH] )

Definition at line 814 of file xed25519.cpp.

◆ SetPublicElement() [2/2]

void ed25519PublicKey::SetPublicElement ( const Element & y )

Definition at line 819 of file xed25519.cpp.

◆ GetPublicElement()

const Integer & ed25519PublicKey::GetPublicElement ( ) const

Definition at line 829 of file xed25519.cpp.

◆ GetPublicKeyBytePtr()

const byte * ed25519PublicKey::GetPublicKeyBytePtr ( ) const

inline

Retrieve public key byte array.

Returns: the public key byte array

GetPublicKeyBytePtr() is used by signing code to call ed25519_sign.

Definition at line 700 of file xed25519.h.

Member Data Documentation

◆ PUBLIC_KEYLENGTH

const int ed25519PublicKey::PUBLIC_KEYLENGTH = 32

static

Size of the public key.

PUBLIC_KEYLENGTH is the size of the public key, in bytes.

Definition at line 638 of file xed25519.h.

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

Public Types

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Element

Constructor & Destructor Documentation

◆ ~ed25519PublicKey()

Member Function Documentation

◆ GetAlgorithmID()

◆ Save()

◆ Load()

◆ BERDecode()

◆ DEREncode()

◆ BERDecodePublicKey()

◆ DEREncodePublicKey()

◆ BERDecodeAndCheckAlgorithmID()

◆ Validate()

◆ GetVoidValue()

◆ AssignFrom()

◆ SetPublicElement() [1/2]

◆ SetPublicElement() [2/2]

◆ GetPublicElement()

◆ GetPublicKeyBytePtr()

Member Data Documentation

◆ PUBLIC_KEYLENGTH