mirror of
https://gitlab.com/pulsechaincom/go-pulse.git
synced 2024-12-25 12:57:17 +00:00
c6069a627c
This adds the inverse to DecompressPubkey and improves a few minor details in crypto/secp256k1.
180 lines
5.9 KiB
Go
180 lines
5.9 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"
|
|
"math/big"
|
|
"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")
|
|
ErrInvalidPubkey = errors.New("invalid public 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_ext_ecdsa_recover(context, (*C.uchar)(unsafe.Pointer(&pubkey[0])), sigdata, msgdata) == 0 {
|
|
return nil, ErrRecoverFailed
|
|
}
|
|
return pubkey, nil
|
|
}
|
|
|
|
// VerifySignature checks that the given pubkey created signature over message.
|
|
// The signature should be in [R || S] format.
|
|
func VerifySignature(pubkey, msg, signature []byte) bool {
|
|
if len(msg) != 32 || len(signature) != 64 || len(pubkey) == 0 {
|
|
return false
|
|
}
|
|
sigdata := (*C.uchar)(unsafe.Pointer(&signature[0]))
|
|
msgdata := (*C.uchar)(unsafe.Pointer(&msg[0]))
|
|
keydata := (*C.uchar)(unsafe.Pointer(&pubkey[0]))
|
|
return C.secp256k1_ext_ecdsa_verify(context, sigdata, msgdata, keydata, C.size_t(len(pubkey))) != 0
|
|
}
|
|
|
|
// DecompressPubkey parses a public key in the 33-byte compressed format.
|
|
// It returns non-nil coordinates if the public key is valid.
|
|
func DecompressPubkey(pubkey []byte) (x, y *big.Int) {
|
|
if len(pubkey) != 33 {
|
|
return nil, nil
|
|
}
|
|
var (
|
|
pubkeydata = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
|
|
pubkeylen = C.size_t(len(pubkey))
|
|
out = make([]byte, 65)
|
|
outdata = (*C.uchar)(unsafe.Pointer(&out[0]))
|
|
outlen = C.size_t(len(out))
|
|
)
|
|
if C.secp256k1_ext_reencode_pubkey(context, outdata, outlen, pubkeydata, pubkeylen) == 0 {
|
|
return nil, nil
|
|
}
|
|
return new(big.Int).SetBytes(out[1:33]), new(big.Int).SetBytes(out[33:])
|
|
}
|
|
|
|
// CompressPubkey encodes a public key to 33-byte compressed format.
|
|
func CompressPubkey(x, y *big.Int) []byte {
|
|
var (
|
|
pubkey = S256().Marshal(x, y)
|
|
pubkeydata = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
|
|
pubkeylen = C.size_t(len(pubkey))
|
|
out = make([]byte, 33)
|
|
outdata = (*C.uchar)(unsafe.Pointer(&out[0]))
|
|
outlen = C.size_t(len(out))
|
|
)
|
|
if C.secp256k1_ext_reencode_pubkey(context, outdata, outlen, pubkeydata, pubkeylen) == 0 {
|
|
panic("libsecp256k1 error")
|
|
}
|
|
return out
|
|
}
|
|
|
|
func checkSignature(sig []byte) error {
|
|
if len(sig) != 65 {
|
|
return ErrInvalidSignatureLen
|
|
}
|
|
if sig[64] >= 4 {
|
|
return ErrInvalidRecoveryID
|
|
}
|
|
return nil
|
|
}
|