285 lines
8.5 KiB
Go
285 lines
8.5 KiB
Go
// Copyright 2014 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 crypto
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import (
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"bufio"
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"crypto/ecdsa"
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"crypto/elliptic"
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"crypto/rand"
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"encoding/hex"
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"errors"
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"fmt"
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"hash"
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"io"
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"math/big"
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"os"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/common/math"
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"github.com/ethereum/go-ethereum/rlp"
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"golang.org/x/crypto/sha3"
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)
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// SignatureLength indicates the byte length required to carry a signature with recovery id.
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const SignatureLength = 64 + 1 // 64 bytes ECDSA signature + 1 byte recovery id
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// RecoveryIDOffset points to the byte offset within the signature that contains the recovery id.
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const RecoveryIDOffset = 64
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// DigestLength sets the signature digest exact length
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const DigestLength = 32
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var (
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secp256k1N, _ = new(big.Int).SetString("fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141", 16)
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secp256k1halfN = new(big.Int).Div(secp256k1N, big.NewInt(2))
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)
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var errInvalidPubkey = errors.New("invalid secp256k1 public key")
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// KeccakState wraps sha3.state. In addition to the usual hash methods, it also supports
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// Read to get a variable amount of data from the hash state. Read is faster than Sum
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// because it doesn't copy the internal state, but also modifies the internal state.
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type KeccakState interface {
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hash.Hash
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Read([]byte) (int, error)
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}
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// NewKeccakState creates a new KeccakState
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func NewKeccakState() KeccakState {
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return sha3.NewLegacyKeccak256().(KeccakState)
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}
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// HashData hashes the provided data using the KeccakState and returns a 32 byte hash
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func HashData(kh KeccakState, data []byte) (h common.Hash) {
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kh.Reset()
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kh.Write(data)
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kh.Read(h[:])
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return h
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}
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// Keccak256 calculates and returns the Keccak256 hash of the input data.
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func Keccak256(data ...[]byte) []byte {
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b := make([]byte, 32)
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d := NewKeccakState()
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for _, b := range data {
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d.Write(b)
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}
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d.Read(b)
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return b
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}
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// Keccak256Hash calculates and returns the Keccak256 hash of the input data,
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// converting it to an internal Hash data structure.
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func Keccak256Hash(data ...[]byte) (h common.Hash) {
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d := NewKeccakState()
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for _, b := range data {
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d.Write(b)
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}
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d.Read(h[:])
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return h
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}
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// Keccak512 calculates and returns the Keccak512 hash of the input data.
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func Keccak512(data ...[]byte) []byte {
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d := sha3.NewLegacyKeccak512()
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for _, b := range data {
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d.Write(b)
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}
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return d.Sum(nil)
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}
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// CreateAddress creates an ethereum address given the bytes and the nonce
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func CreateAddress(b common.Address, nonce uint64) common.Address {
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data, _ := rlp.EncodeToBytes([]interface{}{b, nonce})
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return common.BytesToAddress(Keccak256(data)[12:])
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}
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// CreateAddress2 creates an ethereum address given the address bytes, initial
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// contract code hash and a salt.
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func CreateAddress2(b common.Address, salt [32]byte, inithash []byte) common.Address {
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return common.BytesToAddress(Keccak256([]byte{0xff}, b.Bytes(), salt[:], inithash)[12:])
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}
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// ToECDSA creates a private key with the given D value.
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func ToECDSA(d []byte) (*ecdsa.PrivateKey, error) {
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return toECDSA(d, true)
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}
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// ToECDSAUnsafe blindly converts a binary blob to a private key. It should almost
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// never be used unless you are sure the input is valid and want to avoid hitting
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// errors due to bad origin encoding (0 prefixes cut off).
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func ToECDSAUnsafe(d []byte) *ecdsa.PrivateKey {
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priv, _ := toECDSA(d, false)
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return priv
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}
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// toECDSA creates a private key with the given D value. The strict parameter
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// controls whether the key's length should be enforced at the curve size or
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// it can also accept legacy encodings (0 prefixes).
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func toECDSA(d []byte, strict bool) (*ecdsa.PrivateKey, error) {
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priv := new(ecdsa.PrivateKey)
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priv.PublicKey.Curve = S256()
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if strict && 8*len(d) != priv.Params().BitSize {
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return nil, fmt.Errorf("invalid length, need %d bits", priv.Params().BitSize)
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}
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priv.D = new(big.Int).SetBytes(d)
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// The priv.D must < N
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if priv.D.Cmp(secp256k1N) >= 0 {
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return nil, errors.New("invalid private key, >=N")
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}
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// The priv.D must not be zero or negative.
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if priv.D.Sign() <= 0 {
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return nil, errors.New("invalid private key, zero or negative")
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}
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priv.PublicKey.X, priv.PublicKey.Y = priv.PublicKey.Curve.ScalarBaseMult(d)
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if priv.PublicKey.X == nil {
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return nil, errors.New("invalid private key")
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}
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return priv, nil
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}
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// FromECDSA exports a private key into a binary dump.
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func FromECDSA(priv *ecdsa.PrivateKey) []byte {
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if priv == nil {
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return nil
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}
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return math.PaddedBigBytes(priv.D, priv.Params().BitSize/8)
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}
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// UnmarshalPubkey converts bytes to a secp256k1 public key.
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func UnmarshalPubkey(pub []byte) (*ecdsa.PublicKey, error) {
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x, y := elliptic.Unmarshal(S256(), pub)
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if x == nil {
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return nil, errInvalidPubkey
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}
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return &ecdsa.PublicKey{Curve: S256(), X: x, Y: y}, nil
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}
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func FromECDSAPub(pub *ecdsa.PublicKey) []byte {
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if pub == nil || pub.X == nil || pub.Y == nil {
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return nil
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}
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return elliptic.Marshal(S256(), pub.X, pub.Y)
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}
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// HexToECDSA parses a secp256k1 private key.
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func HexToECDSA(hexkey string) (*ecdsa.PrivateKey, error) {
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b, err := hex.DecodeString(hexkey)
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if byteErr, ok := err.(hex.InvalidByteError); ok {
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return nil, fmt.Errorf("invalid hex character %q in private key", byte(byteErr))
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} else if err != nil {
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return nil, errors.New("invalid hex data for private key")
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}
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return ToECDSA(b)
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}
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// LoadECDSA loads a secp256k1 private key from the given file.
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func LoadECDSA(file string) (*ecdsa.PrivateKey, error) {
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fd, err := os.Open(file)
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if err != nil {
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return nil, err
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}
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defer fd.Close()
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r := bufio.NewReader(fd)
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buf := make([]byte, 64)
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n, err := readASCII(buf, r)
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if err != nil {
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return nil, err
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} else if n != len(buf) {
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return nil, errors.New("key file too short, want 64 hex characters")
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}
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if err := checkKeyFileEnd(r); err != nil {
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return nil, err
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}
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return HexToECDSA(string(buf))
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}
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// readASCII reads into 'buf', stopping when the buffer is full or
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// when a non-printable control character is encountered.
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func readASCII(buf []byte, r *bufio.Reader) (n int, err error) {
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for ; n < len(buf); n++ {
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buf[n], err = r.ReadByte()
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switch {
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case err == io.EOF || buf[n] < '!':
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return n, nil
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case err != nil:
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return n, err
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}
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}
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return n, nil
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}
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// checkKeyFileEnd skips over additional newlines at the end of a key file.
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func checkKeyFileEnd(r *bufio.Reader) error {
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for i := 0; ; i++ {
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b, err := r.ReadByte()
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switch {
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case err == io.EOF:
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return nil
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case err != nil:
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return err
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case b != '\n' && b != '\r':
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return fmt.Errorf("invalid character %q at end of key file", b)
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case i >= 2:
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return errors.New("key file too long, want 64 hex characters")
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}
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}
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}
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// SaveECDSA saves a secp256k1 private key to the given file with
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// restrictive permissions. The key data is saved hex-encoded.
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func SaveECDSA(file string, key *ecdsa.PrivateKey) error {
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k := hex.EncodeToString(FromECDSA(key))
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return os.WriteFile(file, []byte(k), 0600)
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}
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// GenerateKey generates a new private key.
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func GenerateKey() (*ecdsa.PrivateKey, error) {
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return ecdsa.GenerateKey(S256(), rand.Reader)
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}
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// ValidateSignatureValues verifies whether the signature values are valid with
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// the given chain rules. The v value is assumed to be either 0 or 1.
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func ValidateSignatureValues(v byte, r, s *big.Int, homestead bool) bool {
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if r.Cmp(common.Big1) < 0 || s.Cmp(common.Big1) < 0 {
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return false
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}
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// reject upper range of s values (ECDSA malleability)
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// see discussion in secp256k1/libsecp256k1/include/secp256k1.h
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if homestead && s.Cmp(secp256k1halfN) > 0 {
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return false
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}
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// Frontier: allow s to be in full N range
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return r.Cmp(secp256k1N) < 0 && s.Cmp(secp256k1N) < 0 && (v == 0 || v == 1)
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}
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func PubkeyToAddress(p ecdsa.PublicKey) common.Address {
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pubBytes := FromECDSAPub(&p)
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return common.BytesToAddress(Keccak256(pubBytes[1:])[12:])
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}
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func zeroBytes(bytes []byte) {
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for i := range bytes {
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bytes[i] = 0
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}
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}
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