github.com/codingfuture/orig-energi3@v0.8.4/accounts/abi/bind/auth.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package bind
    18  
    19  import (
    20  	"crypto/ecdsa"
    21  	"errors"
    22  	"io"
    23  	"io/ioutil"
    24  
    25  	"github.com/ethereum/go-ethereum/accounts/keystore"
    26  	"github.com/ethereum/go-ethereum/common"
    27  	"github.com/ethereum/go-ethereum/core/types"
    28  	"github.com/ethereum/go-ethereum/crypto"
    29  )
    30  
    31  // NewTransactor is a utility method to easily create a transaction signer from
    32  // an encrypted json key stream and the associated passphrase.
    33  func NewTransactor(keyin io.Reader, passphrase string) (*TransactOpts, error) {
    34  	json, err := ioutil.ReadAll(keyin)
    35  	if err != nil {
    36  		return nil, err
    37  	}
    38  	key, err := keystore.DecryptKey(json, passphrase)
    39  	if err != nil {
    40  		return nil, err
    41  	}
    42  	return NewKeyedTransactor(key.PrivateKey), nil
    43  }
    44  
    45  // NewKeyedTransactor is a utility method to easily create a transaction signer
    46  // from a single private key.
    47  func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts {
    48  	keyAddr := crypto.PubkeyToAddress(key.PublicKey)
    49  	return &TransactOpts{
    50  		From: keyAddr,
    51  		Signer: func(signer types.Signer, address common.Address, tx *types.Transaction) (*types.Transaction, error) {
    52  			if address != keyAddr {
    53  				return nil, errors.New("not authorized to sign this account")
    54  			}
    55  			signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
    56  			if err != nil {
    57  				return nil, err
    58  			}
    59  			return tx.WithSignature(signer, signature)
    60  		},
    61  	}
    62  }