slip10

Documentation

Overview

Package slip10 implements the SLIP-0010 private key derivation. It only supports the private parent key → private child key derivation for the following curves:

secp256k1 curve
NIST P-256 curve
ed25519 curve

The public key of an SLIP-0010 extended private key can be computed using Curve.Public.

SLIP-0010 provides an extension of BIP-0032. As such, when the secp256k1 curve is selected this package is fully compatible to the corresponding derivations described in BIP-0032.

This package is tested against the test vectors provided in the official SLIP-0010 specification.

Index

• Constants
• Variables
• type Curve
• type ExtendedKey
  • func DeriveKeyFromPath(seed []byte, curve Curve, path []uint32) (*ExtendedKey, error)
  • func NewMasterKey(seed []byte, curve Curve) (*ExtendedKey, error)
  • func (e *ExtendedKey) DeriveChild(index uint32) (*ExtendedKey, error)
  • func (e *ExtendedKey) Fingerprint() []byte
  • func (e *ExtendedKey) IsPrivate() bool
  • func (e *ExtendedKey) Public() *ExtendedKey
• type Key

Constants

const (
	// FingerprintSize is the size, in bytes, of the key fingerprint.
	FingerprintSize = 4
	// ChainCodeSize is the size, in bytes, of the chain code.
	ChainCodeSize = 32
	// PrivateKeySize is the size, in bytes, of the normal private key.
	PrivateKeySize = 32
	// PublicKeySize is the size, in bytes, of the normal public key.
	PublicKeySize = 33

	// Hardened returns the first hardened index.
	Hardened uint32 = 1 << 31
)

Variables

var ErrHardenedChildPublicKey = errors.New("cannot create hardened child from public parent key")

ErrHardenedChildPublicKey is returned when ExtendedKey.DeriveChild is called with a hardened index on a public key.

var ErrInvalidKey = errors.New("invalid key")

ErrInvalidKey is returned when the input led to an invalid private or public key.

Types

type Curve

type Curve interface {
	// Name returns the canonical name of the curve.
	Name() string

	// HmacKey returns the HMAC key used for the master key generation.
	HmacKey() []byte

	// NewPrivateKey generates a private key based on buf.
	// If an ErrInvalidKey is returned, generation will be retried with a different buf.
	// Any other errors are considered permanent and returned to the caller.
	NewPrivateKey(buf []byte) (Key, error)
}

A Curve represents a curve type to derive private and public key pairs for.

type ExtendedKey

type ExtendedKey struct {
	ChainCode []byte
	Key       Key
	// contains filtered or unexported fields
}

ExtendedKey represents a SLIP-10 extended private or public key.

func DeriveKeyFromPath

func DeriveKeyFromPath(seed []byte, curve Curve, path []uint32) (*ExtendedKey, error)

DeriveKeyFromPath derives an extended private key for the curve from seed and path as outlined by SLIP-10.

func NewMasterKey

func NewMasterKey(seed []byte, curve Curve) (*ExtendedKey, error)

NewMasterKey creates a new master private extended key for the curve from a seed.

func (*ExtendedKey) DeriveChild

func (e *ExtendedKey) DeriveChild(index uint32) (*ExtendedKey, error)

DeriveChild derives an extended key from a given parent extended key as outlined by SLIP-10. If the parent is an extended public key, the child will also be an extended public key.

func (*ExtendedKey) Fingerprint

func (e *ExtendedKey) Fingerprint() []byte

Fingerprint returns the fingerprint of the parent's key.

func (*ExtendedKey) IsPrivate

func (e *ExtendedKey) IsPrivate() bool

IsPrivate returns whether the key is an extended private key or extended public key.

func (*ExtendedKey) Public

func (e *ExtendedKey) Public() *ExtendedKey

Public returns the public version of key. If key is already an extended public key, a copy is returned.

type Key

type Key interface {
	// Bytes serializes the key as a byte slice.
	// The number of bytes must match PrivateKeySize or PublicKeySize respectively.
	Bytes() []byte

	// IsPrivate returns whether the key corresponds to a private or public key.
	IsPrivate() bool

	// Public returns the corresponding public key.
	Public() Key

	// Shift derives a new key using the provided additive shift.
	// It must not modify the receiver.
	// If an ErrInvalidKey is returned, generation will be retried with a different shift.
	// Any other errors are considered permanent and returned to the caller.
	Shift([]byte) (Key, error)
}

A Key represents a private or public key for a curve.