117 lines
2.5 KiB
Go
Executable file
117 lines
2.5 KiB
Go
Executable file
package privatekey
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import (
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"bytes"
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"crypto/rand"
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"crypto/sha256"
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"encoding/hex"
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"errors"
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"fmt"
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"io"
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"math/big"
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"github.com/CityOfZion/neo-go/pkg/crypto/publickey"
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"github.com/CityOfZion/neo-go/pkg/crypto/base58"
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"github.com/CityOfZion/neo-go/pkg/crypto/elliptic"
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"github.com/CityOfZion/neo-go/pkg/crypto/hash"
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"github.com/CityOfZion/neo-go/pkg/crypto/rfc6979"
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)
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// PrivateKey represents a NEO private key.
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type PrivateKey struct {
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b []byte
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}
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func NewPrivateKey() (*PrivateKey, error) {
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curve := elliptic.NewEllipticCurve(elliptic.Secp256r1)
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b := make([]byte, curve.N.BitLen()/8+8)
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if _, err := io.ReadFull(rand.Reader, b); err != nil {
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return nil, err
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}
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d := new(big.Int).SetBytes(b)
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d.Mod(d, new(big.Int).Sub(curve.N, big.NewInt(1)))
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d.Add(d, big.NewInt(1))
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p := &PrivateKey{b: d.Bytes()}
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return p, nil
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}
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func NewPrivateKeyFromHex(str string) (*PrivateKey, error) {
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b, err := hex.DecodeString(str)
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if err != nil {
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return nil, err
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}
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return NewPrivateKeyFromBytes(b)
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}
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// NewPrivateKeyFromBytes returns a NEO PrivateKey from the given byte slice.
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func NewPrivateKeyFromBytes(b []byte) (*PrivateKey, error) {
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if len(b) != 32 {
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return nil, fmt.Errorf(
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"invalid byte length: expected %d bytes got %d", 32, len(b),
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)
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}
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return &PrivateKey{b}, nil
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}
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func (p *PrivateKey) PublicKey() (*publickey.PublicKey, error) {
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var (
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c = elliptic.NewEllipticCurve(elliptic.Secp256r1)
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q = new(big.Int).SetBytes(p.b)
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)
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p1, p2 := c.ScalarBaseMult(q.Bytes())
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point := elliptic.Point{
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X: p1,
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Y: p2,
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}
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if !c.IsOnCurve(p1, p2) {
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return nil, errors.New("failed to derive public key using elliptic curve")
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}
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return &publickey.PublicKey{
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Curve: c,
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Point: point,
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}, nil
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}
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func WIFEncode(key []byte) (s string) {
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if len(key) != 32 {
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return "invalid private key length"
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}
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buf := new(bytes.Buffer)
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buf.WriteByte(0x80)
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buf.Write(key)
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buf.WriteByte(0x01)
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checksum, _ := hash.Checksum(buf.Bytes())
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buf.Write(checksum)
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WIF := base58.Encode(buf.Bytes())
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return WIF
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}
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func (p *PrivateKey) Sign(data []byte) ([]byte, error) {
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curve := elliptic.NewEllipticCurve(elliptic.Secp256r1)
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key := p.b
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digest, _ := hash.Sha256(data)
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r, s, err := rfc6979.SignECDSA(curve, key, digest[:], sha256.New)
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if err != nil {
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return nil, err
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}
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curveOrderByteSize := curve.P.BitLen() / 8
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rBytes, sBytes := r.Bytes(), s.Bytes()
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signature := make([]byte, curveOrderByteSize*2)
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copy(signature[curveOrderByteSize-len(rBytes):], rBytes)
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copy(signature[curveOrderByteSize*2-len(sBytes):], sBytes)
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return signature, nil
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}
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