5f7826270c
* common/math: optimize PaddedBigBytes, use it more
name old time/op new time/op delta
PaddedBigBytes-8 71.1ns ± 5% 46.1ns ± 1% -35.15% (p=0.000 n=20+19)
name old alloc/op new alloc/op delta
PaddedBigBytes-8 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=20+20)
* all: unify big.Int zero checks
Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.
eg templates:
func before(x *big.Int) bool { return x.BitLen() == 0 }
func after(x *big.Int) bool { return x.Sign() == 0 }
func before(x *big.Int) bool { return x.BitLen() > 0 }
func after(x *big.Int) bool { return x.Sign() != 0 }
func before(x *big.Int) int { return x.Cmp(common.Big0) }
func after(x *big.Int) int { return x.Sign() }
* common/math, crypto/secp256k1: make ReadBits public in package math
131 lines
4.2 KiB
Go
131 lines
4.2 KiB
Go
// Copyright 2015 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
// Package secp256k1 wraps the bitcoin secp256k1 C library.
|
|
package secp256k1
|
|
|
|
/*
|
|
#cgo CFLAGS: -I./libsecp256k1
|
|
#cgo CFLAGS: -I./libsecp256k1/src/
|
|
#define USE_NUM_NONE
|
|
#define USE_FIELD_10X26
|
|
#define USE_FIELD_INV_BUILTIN
|
|
#define USE_SCALAR_8X32
|
|
#define USE_SCALAR_INV_BUILTIN
|
|
#define NDEBUG
|
|
#include "./libsecp256k1/src/secp256k1.c"
|
|
#include "./libsecp256k1/src/modules/recovery/main_impl.h"
|
|
#include "ext.h"
|
|
|
|
typedef void (*callbackFunc) (const char* msg, void* data);
|
|
extern void secp256k1GoPanicIllegal(const char* msg, void* data);
|
|
extern void secp256k1GoPanicError(const char* msg, void* data);
|
|
*/
|
|
import "C"
|
|
|
|
import (
|
|
"errors"
|
|
"unsafe"
|
|
)
|
|
|
|
var context *C.secp256k1_context
|
|
|
|
func init() {
|
|
// around 20 ms on a modern CPU.
|
|
context = C.secp256k1_context_create_sign_verify()
|
|
C.secp256k1_context_set_illegal_callback(context, C.callbackFunc(C.secp256k1GoPanicIllegal), nil)
|
|
C.secp256k1_context_set_error_callback(context, C.callbackFunc(C.secp256k1GoPanicError), nil)
|
|
}
|
|
|
|
var (
|
|
ErrInvalidMsgLen = errors.New("invalid message length, need 32 bytes")
|
|
ErrInvalidSignatureLen = errors.New("invalid signature length")
|
|
ErrInvalidRecoveryID = errors.New("invalid signature recovery id")
|
|
ErrInvalidKey = errors.New("invalid private key")
|
|
ErrSignFailed = errors.New("signing failed")
|
|
ErrRecoverFailed = errors.New("recovery failed")
|
|
)
|
|
|
|
// Sign creates a recoverable ECDSA signature.
|
|
// The produced signature is in the 65-byte [R || S || V] format where V is 0 or 1.
|
|
//
|
|
// The caller is responsible for ensuring that msg cannot be chosen
|
|
// directly by an attacker. It is usually preferable to use a cryptographic
|
|
// hash function on any input before handing it to this function.
|
|
func Sign(msg []byte, seckey []byte) ([]byte, error) {
|
|
if len(msg) != 32 {
|
|
return nil, ErrInvalidMsgLen
|
|
}
|
|
if len(seckey) != 32 {
|
|
return nil, ErrInvalidKey
|
|
}
|
|
seckeydata := (*C.uchar)(unsafe.Pointer(&seckey[0]))
|
|
if C.secp256k1_ec_seckey_verify(context, seckeydata) != 1 {
|
|
return nil, ErrInvalidKey
|
|
}
|
|
|
|
var (
|
|
msgdata = (*C.uchar)(unsafe.Pointer(&msg[0]))
|
|
noncefunc = C.secp256k1_nonce_function_rfc6979
|
|
sigstruct C.secp256k1_ecdsa_recoverable_signature
|
|
)
|
|
if C.secp256k1_ecdsa_sign_recoverable(context, &sigstruct, msgdata, seckeydata, noncefunc, nil) == 0 {
|
|
return nil, ErrSignFailed
|
|
}
|
|
|
|
var (
|
|
sig = make([]byte, 65)
|
|
sigdata = (*C.uchar)(unsafe.Pointer(&sig[0]))
|
|
recid C.int
|
|
)
|
|
C.secp256k1_ecdsa_recoverable_signature_serialize_compact(context, sigdata, &recid, &sigstruct)
|
|
sig[64] = byte(recid) // add back recid to get 65 bytes sig
|
|
return sig, nil
|
|
}
|
|
|
|
// RecoverPubkey returns the the public key of the signer.
|
|
// msg must be the 32-byte hash of the message to be signed.
|
|
// sig must be a 65-byte compact ECDSA signature containing the
|
|
// recovery id as the last element.
|
|
func RecoverPubkey(msg []byte, sig []byte) ([]byte, error) {
|
|
if len(msg) != 32 {
|
|
return nil, ErrInvalidMsgLen
|
|
}
|
|
if err := checkSignature(sig); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
var (
|
|
pubkey = make([]byte, 65)
|
|
sigdata = (*C.uchar)(unsafe.Pointer(&sig[0]))
|
|
msgdata = (*C.uchar)(unsafe.Pointer(&msg[0]))
|
|
)
|
|
if C.secp256k1_ecdsa_recover_pubkey(context, (*C.uchar)(unsafe.Pointer(&pubkey[0])), sigdata, msgdata) == 0 {
|
|
return nil, ErrRecoverFailed
|
|
}
|
|
return pubkey, nil
|
|
}
|
|
|
|
func checkSignature(sig []byte) error {
|
|
if len(sig) != 65 {
|
|
return ErrInvalidSignatureLen
|
|
}
|
|
if sig[64] >= 4 {
|
|
return ErrInvalidRecoveryID
|
|
}
|
|
return nil
|
|
}
|