52 lines
1.4 KiB
Go
52 lines
1.4 KiB
Go
// Copyright (c) 2013-2014 Conformal Systems LLC.
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package btcec
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import (
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"crypto/ecdsa"
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"crypto/rand"
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"math/big"
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)
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// PrivateKey is an ecdsa.PrivateKey
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// It provides a method Sign
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type PrivateKey ecdsa.PrivateKey
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// PrivKeyFromBytes returns a private and public key for `curve' based on the
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// private key passed as an argument as a byte slice.
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func PrivKeyFromBytes(curve *KoblitzCurve, pk []byte) (*PrivateKey,
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*PublicKey) {
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x, y := curve.ScalarBaseMult(pk)
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priv := &ecdsa.PrivateKey{
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PublicKey: ecdsa.PublicKey{
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Curve: curve,
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X: x,
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Y: y,
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},
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D: new(big.Int).SetBytes(pk),
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}
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return (*PrivateKey)(priv), (*PublicKey)(&priv.PublicKey)
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}
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// ToECDSA returns the private key as a *ecdsa.PrivateKey.
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func (p *PrivateKey) ToECDSA() *ecdsa.PrivateKey {
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return (*ecdsa.PrivateKey)(p)
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}
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// Sign wraps ecdsa.Sign to sign an arbitrary length hash (which should be the result of hashing a larger message) using the private key.
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// It returns the signature as a *Signature. The security of the private key depends on the entropy of rand (crypto/rand.Reader).
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func (p *PrivateKey) Sign(hash []byte) (*Signature, error) {
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r, s, err := ecdsa.Sign(rand.Reader, p.ToECDSA(), hash)
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if err != nil {
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return nil, err
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}
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sig := &Signature{
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R: r,
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S: s,
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}
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return sig, nil
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}
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