bitcoin

Documentation

Index

• Variables
• func Base58Decode(s string) (data []byte, err error)
• func Base58Encode(in []byte) string
• func ConvertHash(hash []byte) *math.Int
• func ExportPrivateKey(k *PrivateKey, testnet bool) string
• func Hash160(data []byte) []byte
• func Hash256(data []byte) []byte
• func RipeMD160(data []byte) []byte
• func Sha1(data []byte) []byte
• func Sha256(data []byte) []byte
• func SignY(p *Point) (int, error)
• func Solve(x *math.Int) (*math.Int, bool)
• func Verify(key *PublicKey, hash []byte, sig *Signature) bool
• type Curve
  • func GetCurve() *Curve
• type Point
  • func GetBasePoint() *Point
  • func MultBase(k *math.Int) *Point
  • func NewPoint(a, b *math.Int) *Point
  • func NewPointFromBytes(b []byte) (p *Point, compr bool, err error)
  • func (p *Point) Add(q *Point) *Point
  • func (p *Point) Bytes(compressed bool) []byte
  • func (p *Point) Double() *Point
  • func (p *Point) Equals(q *Point) bool
  • func (p *Point) IsInf() bool
  • func (p *Point) IsOnCurve() bool
  • func (p *Point) Mult(k *math.Int) *Point
  • func (p *Point) Neg() *Point
  • func (p *Point) String() string
  • func (p *Point) X() *math.Int
  • func (p *Point) Y() *math.Int
• type PrivateKey
  • func GenerateKeys(compr bool) *PrivateKey
  • func ImportPrivateKey(keydata string, testnet bool) (*PrivateKey, error)
  • func PrivateKeyFromBytes(b []byte) (*PrivateKey, error)
  • func (k *PrivateKey) Bytes() []byte
• type PublicKey
  • func PublicKeyFromBytes(b []byte) (*PublicKey, error)
  • func (k *PublicKey) Bytes() []byte
• type Signature
  • func NewSignatureFromASN1(b []byte) (*Signature, error)
  • func NewSignatureFromBytes(b []byte) (sig *Signature, err error)
  • func Sign(key *PrivateKey, hash []byte) *Signature
  • func (s *Signature) Bytes() ([]byte, error)

Variables

var (
	ErrBtcBase58Decoding = errors.New("base58 decoding error -- unknown character")
)

Error codes

var (
	ErrSigInvalid = errors.New("invalid ECDSA signature")
)

var Inf = NewPoint(math.ZERO, math.ZERO)

Inf is the point at "infinity"

Functions

func Base58Decode

func Base58Decode(s string) (data []byte, err error)

Base58Decode converts a base58 representation into byte array

func Base58Encode

func Base58Encode(in []byte) string

Base58Encode converts byte array to base58 string representation

func ConvertHash

func ConvertHash(hash []byte) *math.Int

convert hash value to integer [http://www.secg.org/download/aid-780/sec1-v2.pdf]

func ExportPrivateKey

func ExportPrivateKey(k *PrivateKey, testnet bool) string

ExportPrivateKey returns a private key in SIPA format

func Hash160

func Hash160(data []byte) []byte

Hash160 computes RIPEMD-160(SHA-256(data))

func Hash256

func Hash256(data []byte) []byte

Hash256 computes SHA-256(SHA-256(data))

func RipeMD160

func RipeMD160(data []byte) []byte

RipeMD160 computes RIPEMD160(data)

func Sha1

func Sha1(data []byte) []byte

Sha1 computes SHA1(data)

func Sha256

func Sha256(data []byte) []byte

Sha256 computes SHA-256(data)

func SignY

func SignY(p *Point) (int, error)

SignY of a point (y-coordinate) on the Bitcoin curve: +1 if above x-axis, -1 if below.

func Solve

func Solve(x *math.Int) (*math.Int, bool)

Solve the curve equation for given x-ccordinate (returns positive y)

func Verify

func Verify(key *PublicKey, hash []byte, sig *Signature) bool

Verify a hash value with public key. [http://www.nsa.gov/ia/_files/ecdsa.pdf, page 15f]

Types

type Curve

type Curve struct {
	// P is the generator of the underlying field "F_p"
	// = 2^256 - 2^32 - 2^9 - 2^8 - 2^7 - 2^6 - 2^4 - 1
	P *math.Int
	// Gx is the x-coord of the base point
	Gx *math.Int
	// Gy is the y-coord of the base point
	Gy *math.Int
	// N is the order of G
	N *math.Int
	// curve parameter (=7)
	B *math.Int
}

Curve is the elliptic curve used for Bitcoin (Secp256k1)

func GetCurve

func GetCurve() *Curve

GetCurve returns the singleton curve instance

type Point

type Point struct {
	// contains filtered or unexported fields
}

Point (x,y) on the curve

func GetBasePoint

func GetBasePoint() *Point

GetBasePoint returns the base Point of the curve

func MultBase

func MultBase(k *math.Int) *Point

MultBase multiplies the base Point of the curve with a scalar value k

func NewPoint

func NewPoint(a, b *math.Int) *Point

NewPoint instaniates a new Point

func NewPointFromBytes

func NewPointFromBytes(b []byte) (p *Point, compr bool, err error)

NewPointFromBytes reconstructs a Point from binary representation.

func (*Point) Add

func (p *Point) Add(q *Point) *Point

Add two Points on the curve

func (*Point) Bytes

func (p *Point) Bytes(compressed bool) []byte

Bytes returns a byte representation of Point (compressed or uncompressed).

func (*Point) Double

func (p *Point) Double() *Point

Double a Point on the curve

func (*Point) Equals

func (p *Point) Equals(q *Point) bool

Equals checks if two Points are equal

func (*Point) IsInf

func (p *Point) IsInf() bool

IsInf checks if a Point is at infinity

func (*Point) IsOnCurve

func (p *Point) IsOnCurve() bool

IsOnCurve checks if a Point (x,y) is on the curve

func (*Point) Mult

func (p *Point) Mult(k *math.Int) *Point

Mult multiplies a Point on the curve with a scalar value k using a Montgomery multiplication approach

func (*Point) Neg

func (p *Point) Neg() *Point

Neg returns -P for the point P.

func (*Point) String

func (p *Point) String() string

String returns a human-readable representation of a point.

func (*Point) X

func (p *Point) X() *math.Int

X returns the x-coordinate of a point.

func (*Point) Y

func (p *Point) Y() *math.Int

Y returns the y-coordinate of a point.

type PrivateKey

type PrivateKey struct {
	PublicKey
	D *math.Int
}

PrivateKey is a random factor 'd' for the base Point that yields the associated PublicKey (Point on the curve (x,y) = d*G)

func GenerateKeys

func GenerateKeys(compr bool) *PrivateKey

GenerateKeys creates a new set of keys. [http://www.nsa.gov/ia/_files/ecdsa.pdf] page 19f but with a different range (value 1 and 2 for exponent are not allowed)

func ImportPrivateKey

func ImportPrivateKey(keydata string, testnet bool) (*PrivateKey, error)

ImportPrivateKey imports a private key in SIPA format

func PrivateKeyFromBytes

func PrivateKeyFromBytes(b []byte) (*PrivateKey, error)

PrivateKeyFromBytes returns a private key from a byte representation.

func (*PrivateKey) Bytes

func (k *PrivateKey) Bytes() []byte

Bytes returns a byte representation of private key.

type PublicKey

type PublicKey struct {
	Q            *Point
	IsCompressed bool
}

PublicKey is a Point on the elliptic curve: (x,y) = d*G, where 'G' is the base Point of the curve and 'd' is the secret private factor (private key)

func PublicKeyFromBytes

func PublicKeyFromBytes(b []byte) (*PublicKey, error)

PublicKeyFromBytes returns a public key from a byte representation.

func (*PublicKey) Bytes

func (k *PublicKey) Bytes() []byte

Bytes returns the byte representation of public key.

type Signature

type Signature struct {
	R, S *math.Int
}

Signature is a Bitcoin signature in scripts.

func NewSignatureFromASN1

func NewSignatureFromASN1(b []byte) (*Signature, error)

NewSignatureFromASN1 returns a signature from an ASN.1-encoded sequence.

func NewSignatureFromBytes

func NewSignatureFromBytes(b []byte) (sig *Signature, err error)

func Sign

func Sign(key *PrivateKey, hash []byte) *Signature

Sign a hash value with private key. [http://www.nsa.gov/ia/_files/ecdsa.pdf, page 13f]

func (*Signature) Bytes

func (s *Signature) Bytes() ([]byte, error)

Bytes returns an ASN.1-encoded sequence of the signature.