An encapsulated private key. More...

#include <key.h>

Public Member Functions
	CKey () noexcept=default

	CKey (CKey &&) noexcept=default

CKey &	operator= (CKey &&) noexcept=default

CKey &	operator= (const CKey &other)

	CKey (const CKey &other)

template<typename T >
void	Set (const T pbegin, const T pend, bool fCompressedIn)
	Initialize using begin and end iterators to byte data. More...

unsigned int	size () const
	Simple read-only vector-like interface. More...

const std::byte *	data () const

const std::byte *	begin () const

const std::byte *	end () const

bool	IsValid () const
	Check whether this private key is valid. More...

bool	IsCompressed () const
	Check whether the public key corresponding to this private key is (to be) compressed. More...

void	MakeNewKey (bool fCompressed)
	Generate a new private key using a cryptographic PRNG. More...

CPrivKey	GetPrivKey () const
	Convert the private key to a CPrivKey (serialized OpenSSL private key data). More...

CPubKey	GetPubKey () const
	Compute the public key from a private key. More...

bool	Sign (const uint256 &hash, std::vector< unsigned char > &vchSig, bool grind=true, uint32_t test_case=0) const
	Create a DER-serialized signature. More...

bool	SignCompact (const uint256 &hash, std::vector< unsigned char > &vchSig) const
	Create a compact signature (65 bytes), which allows reconstructing the used public key. More...

bool	SignSchnorr (const uint256 &hash, Span< unsigned char > sig, const uint256 *merkle_root, const uint256 &aux) const
	Create a BIP-340 Schnorr signature, for the xonly-pubkey corresponding to this, optionally tweaked by merkle_root. More...

bool	Derive (CKey &keyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode &cc) const
	Derive BIP32 child key. More...

bool	VerifyPubKey (const CPubKey &vchPubKey) const
	Verify thoroughly whether a private key and a public key match. More...

bool	Load (const CPrivKey &privkey, const CPubKey &vchPubKey, bool fSkipCheck)
	Load private key and check that public key matches. More...

EllSwiftPubKey	EllSwiftCreate (Span< const std::byte > entropy) const
	Create an ellswift-encoded public key for this key, with specified entropy. More...

ECDHSecret	ComputeBIP324ECDHSecret (const EllSwiftPubKey &their_ellswift, const EllSwiftPubKey &our_ellswift, bool initiating) const
	Compute a BIP324-style ECDH shared secret. More...

KeyPair	ComputeKeyPair (const uint256 *merkle_root) const
	Compute a KeyPair. More...

Static Public Attributes
static const unsigned int	SIZE = 279
	secp256k1: More...

static const unsigned int	COMPRESSED_SIZE = 214

Private Types
using	KeyType = std::array< unsigned char, 32 >
	see www.keylength.com script supports up to 75 for single byte push More...

Private Member Functions
void	MakeKeyData ()

void	ClearKeyData ()

Static Private Member Functions
static bool	Check (const unsigned char *vch)
	Check whether the 32-byte array pointed to by vch is valid keydata. More...

Private Attributes
bool	fCompressed {false}
	Whether the public key corresponding to this private key is (to be) compressed. More...

secure_unique_ptr< KeyType >	keydata
	The actual byte data. nullptr for invalid keys. More...

Friends
bool	operator== (const CKey &a, const CKey &b)

Detailed Description

An encapsulated private key.

Definition at line 34 of file key.h.

Member Typedef Documentation

◆ KeyType

using CKey::KeyType = std::array<unsigned char, 32>

private

see www.keylength.com script supports up to 75 for single byte push

Internal data container for private key material.

Definition at line 52 of file key.h.

Constructor & Destructor Documentation

◆ CKey() [1/3]

CKey::CKey ( )

defaultnoexcept

◆ CKey() [2/3]

CKey::CKey ( CKey && )

defaultnoexcept

◆ CKey() [3/3]

CKey::CKey ( const CKey & other )

inline

Definition at line 92 of file key.h.

Member Function Documentation

◆ begin()

const std::byte * CKey::begin ( ) const

inline

Definition at line 119 of file key.h.

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◆ Check()

bool CKey::Check ( const unsigned char * vch )

staticprivate

Check whether the 32-byte array pointed to by vch is valid keydata.

Definition at line 157 of file key.cpp.

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◆ ClearKeyData()

void CKey::ClearKeyData ( )

inlineprivate

Definition at line 68 of file key.h.

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◆ ComputeBIP324ECDHSecret()

ECDHSecret CKey::ComputeBIP324ECDHSecret	(	const EllSwiftPubKey &	their_ellswift,
		const EllSwiftPubKey &	our_ellswift,
		bool	initiating
	)		const

Compute a BIP324-style ECDH shared secret.

their_ellswift: EllSwiftPubKey that was received from the other side.
our_ellswift: EllSwiftPubKey that was sent to the other side (must have been generated from *this using EllSwiftCreate()).
initiating: whether we are the initiating party (true) or responding party (false).

Definition at line 327 of file key.cpp.

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◆ ComputeKeyPair()

KeyPair CKey::ComputeKeyPair ( const uint256 * merkle_root ) const

Compute a KeyPair.

Wraps a secp256k1_keypair type.

merkle_root is used to optionally perform tweaking of the internal key, as specified in BIP341:

If merkle_root == nullptr: no tweaking is done, use the internal key directly (this is used for signatures in BIP342 script).
If merkle_root->IsNull(): tweak the internal key with H_TapTweak(pubkey) (this is used for key path spending when no scripts are present).
Otherwise: tweak the internal key with H_TapTweak(pubkey || *merkle_root) (this is used for key path spending with the Merkle root of the script tree).

Definition at line 347 of file key.cpp.

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◆ data()

const std::byte * CKey::data ( ) const

inline

Definition at line 118 of file key.h.

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◆ Derive()

bool CKey::Derive	(	CKey &	keyChild,
		ChainCode &	ccChild,
		unsigned int	nChild,
		const ChainCode &	cc
	)		const

Derive BIP32 child key.

Definition at line 292 of file key.cpp.

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◆ EllSwiftCreate()

EllSwiftPubKey CKey::EllSwiftCreate ( Span< const std::byte > entropy ) const

Create an ellswift-encoded public key for this key, with specified entropy.

entropy must be a 32-byte span with additional entropy to use in the encoding. Every public key has ~2^256 different encodings, and this function will deterministically pick one of them, based on entropy. Note that even without truly random entropy, the resulting encoding will be indistinguishable from uniform to any adversary who does not know the private key (because the private key itself is always used as entropy as well).

Definition at line 311 of file key.cpp.

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◆ end()

const std::byte * CKey::end ( ) const

inline

Definition at line 120 of file key.h.

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◆ GetPrivKey()

CPrivKey CKey::GetPrivKey ( ) const

Convert the private key to a CPrivKey (serialized OpenSSL private key data).

This is expensive.

Definition at line 169 of file key.cpp.

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◆ GetPubKey()

CPubKey CKey::GetPubKey ( ) const

Compute the public key from a private key.

This is expensive.

Definition at line 182 of file key.cpp.

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◆ IsCompressed()

bool CKey::IsCompressed ( ) const

inline

Check whether the public key corresponding to this private key is (to be) compressed.

Definition at line 126 of file key.h.

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◆ IsValid()

bool CKey::IsValid ( ) const

inline

Check whether this private key is valid.

Definition at line 123 of file key.h.

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◆ Load()

bool CKey::Load	(	const CPrivKey &	privkey,
		const CPubKey &	vchPubKey,
		bool	fSkipCheck = `false`
	)

Load private key and check that public key matches.

Definition at line 278 of file key.cpp.

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◆ MakeKeyData()

void CKey::MakeKeyData ( )

inlineprivate

Definition at line 63 of file key.h.

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◆ MakeNewKey()

void CKey::MakeNewKey ( bool fCompressed )

Generate a new private key using a cryptographic PRNG.

Definition at line 161 of file key.cpp.

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◆ operator=() [1/2]

CKey & CKey::operator= ( CKey && )

defaultnoexcept

◆ operator=() [2/2]

CKey & CKey::operator= ( const CKey & other )

inline

Definition at line 78 of file key.h.

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◆ Set()

template<typename T >

void CKey::Set	(	const T	pbegin,
		const T	pend,
		bool	fCompressedIn
	)

inline

Initialize using begin and end iterators to byte data.

Definition at line 103 of file key.h.

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◆ Sign()

bool CKey::Sign	(	const uint256 &	hash,
		std::vector< unsigned char > &	vchSig,
		bool	grind = `true`,
		uint32_t	test_case = `0`
	)		const

Create a DER-serialized signature.

The test_case parameter tweaks the deterministic nonce.

Definition at line 208 of file key.cpp.

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◆ SignCompact()

bool CKey::SignCompact	(	const uint256 &	hash,
		std::vector< unsigned char > &	vchSig
	)		const

Create a compact signature (65 bytes), which allows reconstructing the used public key.

The format is one header byte, followed by two times 32 bytes for the serialized r and s values. The header byte: 0x1B = first key with even y, 0x1C = first key with odd y, 0x1D = second key with even y, 0x1E = second key with odd y, add 0x04 for compressed keys.

Definition at line 249 of file key.cpp.

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◆ SignSchnorr()

bool CKey::SignSchnorr	(	const uint256 &	hash,
		Span< unsigned char >	sig,
		const uint256 *	merkle_root,
		const uint256 &	aux
	)		const

Create a BIP-340 Schnorr signature, for the xonly-pubkey corresponding to *this, optionally tweaked by *merkle_root.

Additional nonce entropy is provided through aux.

merkle_root is used to optionally perform tweaking of the private key, as specified in BIP341:

If merkle_root == nullptr: no tweaking is done, sign with key directly (this is used for signatures in BIP342 script).
If merkle_root->IsNull(): sign with key + H_TapTweak(pubkey) (this is used for key path spending when no scripts are present).
Otherwise: sign with key + H_TapTweak(pubkey || *merkle_root) (this is used for key path spending, with specific Merkle root of the script tree).

Definition at line 272 of file key.cpp.

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◆ size()

unsigned int CKey::size ( ) const

inline

Simple read-only vector-like interface.

Definition at line 117 of file key.h.

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◆ VerifyPubKey()

bool CKey::VerifyPubKey ( const CPubKey & vchPubKey ) const

Verify thoroughly whether a private key and a public key match.

This is done using a different mechanism than just regenerating it.

Definition at line 236 of file key.cpp.

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Friends And Related Function Documentation

◆ operator==

bool operator==	(	const CKey &	a,
		const CKey &	b
	)

friend

Definition at line 94 of file key.h.

Member Data Documentation

◆ COMPRESSED_SIZE

const unsigned int CKey::COMPRESSED_SIZE = 214

static

Definition at line 41 of file key.h.

◆ fCompressed

bool CKey::fCompressed {false}

private

Whether the public key corresponding to this private key is (to be) compressed.

Definition at line 55 of file key.h.

◆ keydata

secure_unique_ptr<KeyType> CKey::keydata

private

The actual byte data. nullptr for invalid keys.

Definition at line 58 of file key.h.

◆ SIZE

const unsigned int CKey::SIZE = 279

static

secp256k1:

Definition at line 40 of file key.h.

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

src/key.h
src/key.cpp

Public Member Functions

Static Public Attributes

Private Types

Private Member Functions

Static Private Member Functions

Private Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ KeyType

Constructor & Destructor Documentation

◆ CKey() [1/3]

◆ CKey() [2/3]

◆ CKey() [3/3]

Member Function Documentation

◆ begin()

◆ Check()

◆ ClearKeyData()

◆ ComputeBIP324ECDHSecret()

◆ ComputeKeyPair()

◆ data()

◆ Derive()

◆ EllSwiftCreate()

◆ end()

◆ GetPrivKey()

◆ GetPubKey()

◆ IsCompressed()

◆ IsValid()

◆ Load()

◆ MakeKeyData()

◆ MakeNewKey()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Set()

◆ Sign()

◆ SignCompact()

◆ SignSchnorr()

◆ size()

◆ VerifyPubKey()

Friends And Related Function Documentation

◆ operator==

Member Data Documentation

◆ COMPRESSED_SIZE

◆ fCompressed

◆ keydata

◆ SIZE