76 lines
2.3 KiB
Go
76 lines
2.3 KiB
Go
// Copyright 2018 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package feed
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import (
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"crypto/ecdsa"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/crypto"
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)
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const signatureLength = 65
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// Signature is an alias for a static byte array with the size of a signature
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type Signature [signatureLength]byte
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// Signer signs feed update payloads
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type Signer interface {
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Sign(common.Hash) (Signature, error)
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Address() common.Address
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}
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// GenericSigner implements the Signer interface
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// It is the vanilla signer that probably should be used in most cases
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type GenericSigner struct {
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PrivKey *ecdsa.PrivateKey
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address common.Address
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}
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// NewGenericSigner builds a signer that will sign everything with the provided private key
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func NewGenericSigner(privKey *ecdsa.PrivateKey) *GenericSigner {
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return &GenericSigner{
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PrivKey: privKey,
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address: crypto.PubkeyToAddress(privKey.PublicKey),
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}
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}
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// Sign signs the supplied data
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// It wraps the ethereum crypto.Sign() method
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func (s *GenericSigner) Sign(data common.Hash) (signature Signature, err error) {
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signaturebytes, err := crypto.Sign(data.Bytes(), s.PrivKey)
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if err != nil {
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return
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}
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copy(signature[:], signaturebytes)
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return
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}
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// Address returns the public key of the signer's private key
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func (s *GenericSigner) Address() common.Address {
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return s.address
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}
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// getUserAddr extracts the address of the feed update signer
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func getUserAddr(digest common.Hash, signature Signature) (common.Address, error) {
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pub, err := crypto.SigToPub(digest.Bytes(), signature[:])
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if err != nil {
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return common.Address{}, err
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}
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return crypto.PubkeyToAddress(*pub), nil
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}
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