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-rw-r--r--crypto/secp256k1/curve.go46
-rw-r--r--crypto/secp256k1/ext.h63
-rw-r--r--crypto/secp256k1/secp256.go51
3 files changed, 128 insertions, 32 deletions
diff --git a/crypto/secp256k1/curve.go b/crypto/secp256k1/curve.go
index ec6d266ce..df8048185 100644
--- a/crypto/secp256k1/curve.go
+++ b/crypto/secp256k1/curve.go
@@ -34,7 +34,6 @@ package secp256k1
import (
"crypto/elliptic"
"math/big"
- "sync"
"unsafe"
"github.com/ethereum/go-ethereum/common/math"
@@ -42,7 +41,7 @@ import (
/*
#include "libsecp256k1/include/secp256k1.h"
-extern int secp256k1_pubkey_scalar_mul(const secp256k1_context* ctx, const unsigned char *point, const unsigned char *scalar);
+extern int secp256k1_ext_scalar_mul(const secp256k1_context* ctx, const unsigned char *point, const unsigned char *scalar);
*/
import "C"
@@ -236,7 +235,7 @@ func (BitCurve *BitCurve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int,
math.ReadBits(By, point[32:])
pointPtr := (*C.uchar)(unsafe.Pointer(&point[0]))
scalarPtr := (*C.uchar)(unsafe.Pointer(&scalar[0]))
- res := C.secp256k1_pubkey_scalar_mul(context, pointPtr, scalarPtr)
+ res := C.secp256k1_ext_scalar_mul(context, pointPtr, scalarPtr)
// Unpack the result and clear temporaries.
x := new(big.Int).SetBytes(point[:32])
@@ -263,14 +262,10 @@ func (BitCurve *BitCurve) ScalarBaseMult(k []byte) (*big.Int, *big.Int) {
// X9.62.
func (BitCurve *BitCurve) Marshal(x, y *big.Int) []byte {
byteLen := (BitCurve.BitSize + 7) >> 3
-
ret := make([]byte, 1+2*byteLen)
- ret[0] = 4 // uncompressed point
-
- xBytes := x.Bytes()
- copy(ret[1+byteLen-len(xBytes):], xBytes)
- yBytes := y.Bytes()
- copy(ret[1+2*byteLen-len(yBytes):], yBytes)
+ ret[0] = 4 // uncompressed point flag
+ math.ReadBits(x, ret[1:1+byteLen])
+ math.ReadBits(y, ret[1+byteLen:])
return ret
}
@@ -289,24 +284,21 @@ func (BitCurve *BitCurve) Unmarshal(data []byte) (x, y *big.Int) {
return
}
-var (
- initonce sync.Once
- theCurve *BitCurve
-)
+var theCurve = new(BitCurve)
+
+func init() {
+ // See SEC 2 section 2.7.1
+ // curve parameters taken from:
+ // http://www.secg.org/collateral/sec2_final.pdf
+ theCurve.P, _ = new(big.Int).SetString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F", 16)
+ theCurve.N, _ = new(big.Int).SetString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", 16)
+ theCurve.B, _ = new(big.Int).SetString("0000000000000000000000000000000000000000000000000000000000000007", 16)
+ theCurve.Gx, _ = new(big.Int).SetString("79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798", 16)
+ theCurve.Gy, _ = new(big.Int).SetString("483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8", 16)
+ theCurve.BitSize = 256
+}
-// S256 returns a BitCurve which implements secp256k1 (see SEC 2 section 2.7.1)
+// S256 returns a BitCurve which implements secp256k1.
func S256() *BitCurve {
- initonce.Do(func() {
- // See SEC 2 section 2.7.1
- // curve parameters taken from:
- // http://www.secg.org/collateral/sec2_final.pdf
- theCurve = new(BitCurve)
- theCurve.P, _ = new(big.Int).SetString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F", 16)
- theCurve.N, _ = new(big.Int).SetString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", 16)
- theCurve.B, _ = new(big.Int).SetString("0000000000000000000000000000000000000000000000000000000000000007", 16)
- theCurve.Gx, _ = new(big.Int).SetString("79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798", 16)
- theCurve.Gy, _ = new(big.Int).SetString("483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8", 16)
- theCurve.BitSize = 256
- })
return theCurve
}
diff --git a/crypto/secp256k1/ext.h b/crypto/secp256k1/ext.h
index ee759fde6..9b043c724 100644
--- a/crypto/secp256k1/ext.h
+++ b/crypto/secp256k1/ext.h
@@ -19,7 +19,7 @@ static secp256k1_context* secp256k1_context_create_sign_verify() {
return secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
}
-// secp256k1_ecdsa_recover_pubkey recovers the public key of an encoded compact signature.
+// secp256k1_ext_ecdsa_recover recovers the public key of an encoded compact signature.
//
// Returns: 1: recovery was successful
// 0: recovery was not successful
@@ -27,7 +27,7 @@ static secp256k1_context* secp256k1_context_create_sign_verify() {
// Out: pubkey_out: the serialized 65-byte public key of the signer (cannot be NULL)
// In: sigdata: pointer to a 65-byte signature with the recovery id at the end (cannot be NULL)
// msgdata: pointer to a 32-byte message (cannot be NULL)
-static int secp256k1_ecdsa_recover_pubkey(
+static int secp256k1_ext_ecdsa_recover(
const secp256k1_context* ctx,
unsigned char *pubkey_out,
const unsigned char *sigdata,
@@ -46,7 +46,62 @@ static int secp256k1_ecdsa_recover_pubkey(
return secp256k1_ec_pubkey_serialize(ctx, pubkey_out, &outputlen, &pubkey, SECP256K1_EC_UNCOMPRESSED);
}
-// secp256k1_pubkey_scalar_mul multiplies a point by a scalar in constant time.
+// secp256k1_ext_ecdsa_verify verifies an encoded compact signature.
+//
+// Returns: 1: signature is valid
+// 0: signature is invalid
+// Args: ctx: pointer to a context object (cannot be NULL)
+// In: sigdata: pointer to a 64-byte signature (cannot be NULL)
+// msgdata: pointer to a 32-byte message (cannot be NULL)
+// pubkeydata: pointer to public key data (cannot be NULL)
+// pubkeylen: length of pubkeydata
+static int secp256k1_ext_ecdsa_verify(
+ const secp256k1_context* ctx,
+ const unsigned char *sigdata,
+ const unsigned char *msgdata,
+ const unsigned char *pubkeydata,
+ size_t pubkeylen
+) {
+ secp256k1_ecdsa_signature sig;
+ secp256k1_pubkey pubkey;
+
+ if (!secp256k1_ecdsa_signature_parse_compact(ctx, &sig, sigdata)) {
+ return 0;
+ }
+ if (!secp256k1_ec_pubkey_parse(ctx, &pubkey, pubkeydata, pubkeylen)) {
+ return 0;
+ }
+ return secp256k1_ecdsa_verify(ctx, &sig, msgdata, &pubkey);
+}
+
+// secp256k1_ext_reencode_pubkey decodes then encodes a public key. It can be used to
+// convert between public key formats. The input/output formats are chosen depending on the
+// length of the input/output buffers.
+//
+// Returns: 1: conversion successful
+// 0: conversion unsuccessful
+// Args: ctx: pointer to a context object (cannot be NULL)
+// Out: out: output buffer that will contain the reencoded key (cannot be NULL)
+// In: outlen: length of out (33 for compressed keys, 65 for uncompressed keys)
+// pubkeydata: the input public key (cannot be NULL)
+// pubkeylen: length of pubkeydata
+static int secp256k1_ext_reencode_pubkey(
+ const secp256k1_context* ctx,
+ unsigned char *out,
+ size_t outlen,
+ const unsigned char *pubkeydata,
+ size_t pubkeylen
+) {
+ secp256k1_pubkey pubkey;
+
+ if (!secp256k1_ec_pubkey_parse(ctx, &pubkey, pubkeydata, pubkeylen)) {
+ return 0;
+ }
+ unsigned int flag = (outlen == 33) ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED;
+ return secp256k1_ec_pubkey_serialize(ctx, out, &outlen, &pubkey, flag);
+}
+
+// secp256k1_ext_scalar_mul multiplies a point by a scalar in constant time.
//
// Returns: 1: multiplication was successful
// 0: scalar was invalid (zero or overflow)
@@ -55,7 +110,7 @@ static int secp256k1_ecdsa_recover_pubkey(
// In: point: pointer to a 64-byte public point,
// encoded as two 256bit big-endian numbers.
// scalar: a 32-byte scalar with which to multiply the point
-int secp256k1_pubkey_scalar_mul(const secp256k1_context* ctx, unsigned char *point, const unsigned char *scalar) {
+int secp256k1_ext_scalar_mul(const secp256k1_context* ctx, unsigned char *point, const unsigned char *scalar) {
int ret = 0;
int overflow = 0;
secp256k1_fe feX, feY;
diff --git a/crypto/secp256k1/secp256.go b/crypto/secp256k1/secp256.go
index 0ffa04fe0..eefbb99ee 100644
--- a/crypto/secp256k1/secp256.go
+++ b/crypto/secp256k1/secp256.go
@@ -38,6 +38,7 @@ import "C"
import (
"errors"
+ "math/big"
"unsafe"
)
@@ -55,6 +56,7 @@ var (
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")
)
@@ -113,12 +115,59 @@ func RecoverPubkey(msg []byte, sig []byte) ([]byte, error) {
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 {
+ 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
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-12 14:17:41 +0800