Ed25519 private key. More...

#include <xed25519.h>

Inheritance diagram for ed25519PrivateKey:

Public Member Functions
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.

OID	GetAlgorithmID () const
	Retrieves the OID of the algorithm.

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

void	Save (BufferedTransformation &bt, bool v1) const
	DER encode ASN.1 object.

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

void	MakePublicKey (PublicKey &pub) const
	Initializes a public key from this key.

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

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

void	BERDecodePrivateKey (BufferedTransformation &bt, bool parametersPresent, size_t size)
	Decode privateKey part of privateKeyInfo.

void	DEREncodePrivateKey (BufferedTransformation &bt) const
	Encode privateKey part of privateKeyInfo.

void	DEREncode (BufferedTransformation &bt, int version) const
	DER encode ASN.1 object.

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

void	GenerateRandom (RandomNumberGenerator &rng, const NameValuePairs &params)
	Generate a random key or crypto parameters.

void	SetPrivateExponent (const byte x[SECRET_KEYLENGTH])

void	SetPrivateExponent (const Integer &x)

const Integer &	GetPrivateExponent () const

bool	IsSmallOrder (const byte y[PUBLIC_KEYLENGTH]) const
	Test if a key has small order.

const byte *	GetPrivateKeyBytePtr () const
	Retrieve private key byte array.

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

Public Member Functions inherited from PKCS8PrivateKey
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 optional parameters.

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

virtual void	BERDecodeOptionalAttributes (BufferedTransformation &bt)
	Decode optional attributes.

virtual void	DEREncodeOptionalAttributes (BufferedTransformation &bt) const
	Encode optional attributes.

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

Public Member Functions inherited from GeneratableCryptoMaterial
void	GenerateRandomWithKeySize (RandomNumberGenerator &rng, unsigned int keySize)
	Generate a random key or crypto parameters.

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	SECRET_KEYLENGTH = 32
	Size of the private key.

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

static const int	SIGNATURE_LENGTH = 64
	Size of the signature.

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 private key.

ed25519PrivateKey is somewhat of a hack. It needed to provide DL_PrivateKey interface to fit into the existing framework, but it lacks a lot of the internals of a true DL_PrivateKey. 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.

ed25519PrivateKey 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 GetPrivateExponent() 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 SetPrivateExponent performs a similar internal conversion.

Since: Crypto++ 8.0

Definition at line 355 of file xed25519.h.

Constructor & Destructor Documentation

◆ ~ed25519PrivateKey()

virtual ed25519PrivateKey::~ed25519PrivateKey ( )

inlinevirtual

Definition at line 369 of file xed25519.h.

Member Function Documentation

◆ Validate()

bool ed25519PrivateKey::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 390 of file xed25519.cpp.

◆ GetVoidValue()

bool ed25519PrivateKey::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 410 of file xed25519.cpp.

◆ AssignFrom()

void ed25519PrivateKey::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 439 of file xed25519.cpp.

◆ GetAlgorithmID()

OID ed25519PrivateKey::GetAlgorithmID ( ) const

inlinevirtual

Retrieves the OID of the algorithm.

Returns: OID of the algorithm

Implements PKCS8PrivateKey.

Definition at line 377 of file xed25519.h.

◆ Save() [1/2]

void ed25519PrivateKey::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-Ed25519. 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.

See also: RFC 5958, Asymmetric Key Packages

Reimplemented from ASN1CryptoMaterial< PrivateKey >.

Definition at line 392 of file xed25519.h.

◆ Save() [2/2]

void ed25519PrivateKey::Save	(	BufferedTransformation &	bt,
		bool	v1 ) const

inline

DER encode ASN.1 object.

Parameters

bt	BufferedTransformation object
v1	flag indicating v1

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-Ed25519. The default private key format is RFC 5208.

v1 means INTEGER 0 is written. INTEGER 0 means RFC 5208 format, which is the old format. The old format provides the best interop, and keys will work with OpenSSL. The other option uses INTEGER 1. INTEGER 1 means RFC 5958 format, which is the new format.

See also: RFC 5958, Asymmetric Key Packages

Definition at line 411 of file xed25519.h.

◆ Load()

void ed25519PrivateKey::Load ( BufferedTransformation & bt )

inlinevirtual

BER decode ASN.1 object.

Parameters

bt	BufferedTransformation object

See also: RFC 5958, Asymmetric Key Packages

Reimplemented from ASN1CryptoMaterial< PrivateKey >.

Definition at line 419 of file xed25519.h.

◆ MakePublicKey()

void ed25519PrivateKey::MakePublicKey ( PublicKey & pub ) const

Initializes a public key from this key.

Parameters

pub	reference to a public key

Definition at line 477 of file xed25519.cpp.

◆ BERDecode()

void ed25519PrivateKey::BERDecode ( BufferedTransformation & bt )

virtual

Decode this object from a BufferedTransformation.

Parameters

bt	BufferedTransformation object

Uses Basic Encoding Rules (BER)

Implements ASN1Object.

Definition at line 499 of file xed25519.cpp.

◆ DEREncode() [1/2]

void ed25519PrivateKey::DEREncode ( BufferedTransformation & bt ) const

inlinevirtual

Encode this object into a BufferedTransformation.

Parameters

bt	BufferedTransformation object

Uses Distinguished Encoding Rules (DER)

Implements ASN1Object.

Definition at line 429 of file xed25519.h.

◆ BERDecodePrivateKey()

void ed25519PrivateKey::BERDecodePrivateKey	(	BufferedTransformation &	bt,
		bool	parametersPresent,
		size_t	size )

virtual

Decode privateKey part of privateKeyInfo.

Parameters

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

BERDecodePrivateKey() the decodes privateKey part of privateKeyInfo, without the OCTET STRING header.

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

See also: BERDecodeAlgorithmParameters

Implements PKCS8PrivateKey.

Definition at line 570 of file xed25519.cpp.

◆ DEREncodePrivateKey()

void ed25519PrivateKey::DEREncodePrivateKey ( BufferedTransformation & bt ) const

virtual

Encode privateKey part of privateKeyInfo.

Parameters

bt	BufferedTransformation object

DEREncodePrivateKey() encodes the privateKey part of privateKeyInfo, without the OCTET STRING header.

See also: DEREncodeAlgorithmParameters

Implements PKCS8PrivateKey.

Definition at line 591 of file xed25519.cpp.

◆ DEREncode() [2/2]

void ed25519PrivateKey::DEREncode	(	BufferedTransformation &	bt,
		int	version ) const

DER encode ASN.1 object.

Parameters

bt	BufferedTransformation object
version	indicates version

DEREncode() 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.

The value of version is written as the INTEGER. INTEGER 0 means RFC 5208 format, which is the old format. The old format provides the best interop, and keys will work with OpenSSL. The INTEGER 1 means RFC 5958 format, which is the new format.

Definition at line 543 of file xed25519.cpp.

◆ BERDecodeAndCheckAlgorithmID()

void ed25519PrivateKey::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 484 of file xed25519.cpp.

◆ GenerateRandom()

void ed25519PrivateKey::GenerateRandom	(	RandomNumberGenerator &	rng,
		const NameValuePairs &	params = g_nullNameValuePairs )

virtual

Generate a random key or crypto parameters.

Parameters

rng	a RandomNumberGenerator to produce keying material
params	additional initialization parameters

Exceptions

KeyingErr if a key can't be generated or algorithm parameters are invalid

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

Reimplemented from GeneratableCryptoMaterial.

Definition at line 466 of file xed25519.cpp.

◆ SetPrivateExponent() [1/2]

void ed25519PrivateKey::SetPrivateExponent ( const byte x[SECRET_KEYLENGTH] )

Definition at line 599 of file xed25519.cpp.

◆ SetPrivateExponent() [2/2]

void ed25519PrivateKey::SetPrivateExponent ( const Integer & x )

Definition at line 606 of file xed25519.cpp.

◆ GetPrivateExponent()

const Integer & ed25519PrivateKey::GetPrivateExponent ( ) const

Definition at line 618 of file xed25519.cpp.

◆ IsSmallOrder()

bool ed25519PrivateKey::IsSmallOrder ( const byte y[PUBLIC_KEYLENGTH] ) const

Test if a key has small order.

Parameters

y	public key

Definition at line 385 of file xed25519.cpp.

◆ GetPrivateKeyBytePtr()

const byte * ed25519PrivateKey::GetPrivateKeyBytePtr ( ) const

inline

Retrieve private key byte array.

Returns: the private key byte array

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

Definition at line 474 of file xed25519.h.

◆ GetPublicKeyBytePtr()

const byte * ed25519PrivateKey::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 481 of file xed25519.h.

Member Data Documentation

◆ SECRET_KEYLENGTH

const int ed25519PrivateKey::SECRET_KEYLENGTH = 32

static

Size of the private key.

SECRET_KEYLENGTH is the size of the private key, in bytes.

Definition at line 359 of file xed25519.h.

◆ PUBLIC_KEYLENGTH

const int ed25519PrivateKey::PUBLIC_KEYLENGTH = 32

static

Size of the public key.

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

Definition at line 362 of file xed25519.h.

◆ SIGNATURE_LENGTH

const int ed25519PrivateKey::SIGNATURE_LENGTH = 64

static

Size of the signature.

SIGNATURE_LENGTH is the size of the signature, in bytes. ed25519 is a DL-based signature scheme. The signature is the concatenation of r || s.

Definition at line 367 of file xed25519.h.

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

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ~ed25519PrivateKey()

Member Function Documentation

◆ Validate()

◆ GetVoidValue()

◆ AssignFrom()

◆ GetAlgorithmID()

◆ Save() [1/2]

◆ Save() [2/2]

◆ Load()

◆ MakePublicKey()

◆ BERDecode()

◆ DEREncode() [1/2]

◆ BERDecodePrivateKey()

◆ DEREncodePrivateKey()

◆ DEREncode() [2/2]

◆ BERDecodeAndCheckAlgorithmID()

◆ GenerateRandom()

◆ SetPrivateExponent() [1/2]

◆ SetPrivateExponent() [2/2]

◆ GetPrivateExponent()

◆ IsSmallOrder()

◆ GetPrivateKeyBytePtr()

◆ GetPublicKeyBytePtr()

Member Data Documentation

◆ SECRET_KEYLENGTH

◆ PUBLIC_KEYLENGTH

◆ SIGNATURE_LENGTH