diff --git a/crypto/signature_nocgo.go b/crypto/signature_nocgo.go index fd1e66c7e6fa..d76127c25888 100644 --- a/crypto/signature_nocgo.go +++ b/crypto/signature_nocgo.go @@ -14,47 +14,64 @@ // You should have received a copy of the GNU Lesser General Public License // along with the go-ethereum library. If not, see . -//go:build nacl || js || !cgo || gofuzz -// +build nacl js !cgo gofuzz +//go:build nacl || js || wasip1 || !cgo || gofuzz || tinygo +// +build nacl js wasip1 !cgo gofuzz tinygo package crypto import ( "crypto/ecdsa" - "crypto/elliptic" "errors" "fmt" "math/big" - "github.com/btcsuite/btcd/btcec" + "github.com/decred/dcrd/dcrec/secp256k1/v4" + decred_ecdsa "github.com/decred/dcrd/dcrec/secp256k1/v4/ecdsa" ) // Ecrecover returns the uncompressed public key that created the given signature. func Ecrecover(hash, sig []byte) ([]byte, error) { - pub, err := SigToPub(hash, sig) + pub, err := sigToPub(hash, sig) if err != nil { return nil, err } - bytes := (*btcec.PublicKey)(pub).SerializeUncompressed() + bytes := pub.SerializeUncompressed() return bytes, err } -// SigToPub returns the public key that created the given signature. -func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) { - // Convert to btcec input format with 'recovery id' v at the beginning. +func sigToPub(hash, sig []byte) (*secp256k1.PublicKey, error) { + if len(sig) != SignatureLength { + return nil, errors.New("invalid signature") + } + // Convert to secp256k1 input format with 'recovery id' v at the beginning. btcsig := make([]byte, SignatureLength) - btcsig[0] = sig[64] + 27 + btcsig[0] = sig[RecoveryIDOffset] + 27 copy(btcsig[1:], sig) - pub, _, err := btcec.RecoverCompact(btcec.S256(), btcsig, hash) - return (*ecdsa.PublicKey)(pub), err + pub, _, err := decred_ecdsa.RecoverCompact(btcsig, hash) + return pub, err +} + +// SigToPub returns the public key that created the given signature. +func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) { + pub, err := sigToPub(hash, sig) + if err != nil { + return nil, err + } + // We need to explicitly set the curve here, because we're wrapping + // the original curve to add (un-)marshalling + return &ecdsa.PublicKey{ + Curve: S256(), + X: pub.X(), + Y: pub.Y(), + }, nil } // Sign calculates an ECDSA signature. // // This function is susceptible to chosen plaintext attacks that can leak // information about the private key that is used for signing. Callers must -// be aware that the given hash cannot be chosen by an adversery. Common +// be aware that the given hash cannot be chosen by an adversary. Common // solution is to hash any input before calculating the signature. // // The produced signature is in the [R || S || V] format where V is 0 or 1. @@ -62,17 +79,20 @@ func Sign(hash []byte, prv *ecdsa.PrivateKey) ([]byte, error) { if len(hash) != 32 { return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(hash)) } - if prv.Curve != btcec.S256() { - return nil, fmt.Errorf("private key curve is not secp256k1") + if prv.Curve != S256() { + return nil, errors.New("private key curve is not secp256k1") } - sig, err := btcec.SignCompact(btcec.S256(), (*btcec.PrivateKey)(prv), hash, false) - if err != nil { - return nil, err + // ecdsa.PrivateKey -> secp256k1.PrivateKey + var priv secp256k1.PrivateKey + if overflow := priv.Key.SetByteSlice(prv.D.Bytes()); overflow || priv.Key.IsZero() { + return nil, errors.New("invalid private key") } + defer priv.Zero() + sig := decred_ecdsa.SignCompact(&priv, hash, false) // ref uncompressed pubkey // Convert to Ethereum signature format with 'recovery id' v at the end. v := sig[0] - 27 copy(sig, sig[1:]) - sig[64] = v + sig[RecoveryIDOffset] = v return sig, nil } @@ -83,13 +103,20 @@ func VerifySignature(pubkey, hash, signature []byte) bool { if len(signature) != 64 { return false } - sig := &btcec.Signature{R: new(big.Int).SetBytes(signature[:32]), S: new(big.Int).SetBytes(signature[32:])} - key, err := btcec.ParsePubKey(pubkey, btcec.S256()) + var r, s secp256k1.ModNScalar + if r.SetByteSlice(signature[:32]) { + return false // overflow + } + if s.SetByteSlice(signature[32:]) { + return false + } + sig := decred_ecdsa.NewSignature(&r, &s) + key, err := secp256k1.ParsePubKey(pubkey) if err != nil { return false } - // Reject malleable signatures. libsecp256k1 does this check but btcec doesn't. - if sig.S.Cmp(secp256k1halfN) > 0 { + // Reject malleable signatures. libsecp256k1 does this check but decred doesn't. + if s.IsOverHalfOrder() { return false } return sig.Verify(hash, key) @@ -100,19 +127,67 @@ func DecompressPubkey(pubkey []byte) (*ecdsa.PublicKey, error) { if len(pubkey) != 33 { return nil, errors.New("invalid compressed public key length") } - key, err := btcec.ParsePubKey(pubkey, btcec.S256()) + key, err := secp256k1.ParsePubKey(pubkey) if err != nil { return nil, err } - return key.ToECDSA(), nil + // We need to explicitly set the curve here, because we're wrapping + // the original curve to add (un-)marshalling + return &ecdsa.PublicKey{ + Curve: S256(), + X: key.X(), + Y: key.Y(), + }, nil } -// CompressPubkey encodes a public key to the 33-byte compressed format. +// CompressPubkey encodes a public key to the 33-byte compressed format. The +// provided PublicKey must be valid. Namely, the coordinates must not be larger +// than 32 bytes each, they must be less than the field prime, and it must be a +// point on the secp256k1 curve. This is the case for a PublicKey constructed by +// elliptic.Unmarshal (see UnmarshalPubkey), or by ToECDSA and ecdsa.GenerateKey +// when constructing a PrivateKey. func CompressPubkey(pubkey *ecdsa.PublicKey) []byte { - return (*btcec.PublicKey)(pubkey).SerializeCompressed() + // NOTE: the coordinates may be validated with + // secp256k1.ParsePubKey(FromECDSAPub(pubkey)) + var x, y secp256k1.FieldVal + x.SetByteSlice(pubkey.X.Bytes()) + y.SetByteSlice(pubkey.Y.Bytes()) + return secp256k1.NewPublicKey(&x, &y).SerializeCompressed() } // S256 returns an instance of the secp256k1 curve. -func S256() elliptic.Curve { - return btcec.S256() +func S256() EllipticCurve { + return btCurve{secp256k1.S256()} +} + +type btCurve struct { + *secp256k1.KoblitzCurve +} + +// Marshal converts a point given as (x, y) into a byte slice. +func (curve btCurve) Marshal(x, y *big.Int) []byte { + byteLen := (curve.Params().BitSize + 7) / 8 + + ret := make([]byte, 1+2*byteLen) + ret[0] = 4 // uncompressed point + + x.FillBytes(ret[1 : 1+byteLen]) + y.FillBytes(ret[1+byteLen : 1+2*byteLen]) + + return ret +} + +// Unmarshal converts a point, serialised by Marshal, into an x, y pair. On +// error, x = nil. +func (curve btCurve) Unmarshal(data []byte) (x, y *big.Int) { + byteLen := (curve.Params().BitSize + 7) / 8 + if len(data) != 1+2*byteLen { + return nil, nil + } + if data[0] != 4 { // uncompressed form + return nil, nil + } + x = new(big.Int).SetBytes(data[1 : 1+byteLen]) + y = new(big.Int).SetBytes(data[1+byteLen:]) + return } diff --git a/go.mod b/go.mod index 1c3397b960a4..0eb3e5dc9812 100644 --- a/go.mod +++ b/go.mod @@ -17,6 +17,7 @@ require ( github.com/crate-crypto/go-kzg-4844 v1.0.0 github.com/davecgh/go-spew v1.1.1 github.com/deckarep/golang-set v0.0.0-20180603214616-504e848d77ea + github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf github.com/dop251/goja v0.0.0-20211011172007-d99e4b8cbf48 github.com/edsrzf/mmap-go v1.0.0 diff --git a/go.sum b/go.sum index a6c9f2ad2aa8..f626c27c4a59 100644 --- a/go.sum +++ b/go.sum @@ -112,6 +112,10 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= github.com/deckarep/golang-set v0.0.0-20180603214616-504e848d77ea h1:j4317fAZh7X6GqbFowYdYdI0L9bwxL07jyPZIdepyZ0= github.com/deckarep/golang-set v0.0.0-20180603214616-504e848d77ea/go.mod h1:93vsz/8Wt4joVM7c2AVqh+YRMiUSc14yDtF28KmMOgQ= +github.com/decred/dcrd/crypto/blake256 v1.1.0 h1:zPMNGQCm0g4QTY27fOCorQW7EryeQ/U0x++OzVrdms8= +github.com/decred/dcrd/crypto/blake256 v1.1.0/go.mod h1:2OfgNZ5wDpcsFmHmCK5gZTPcCXqlm2ArzUIkw9czNJo= +github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 h1:NMZiJj8QnKe1LgsbDayM4UoHwbvwDRwnI3hwNaAHRnc= +github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0/go.mod h1:ZXNYxsqcloTdSy/rNShjYzMhyjf0LaoftYK0p+A3h40= github.com/deepmap/oapi-codegen v1.6.0/go.mod h1:ryDa9AgbELGeB+YEXE1dR53yAjHwFvE9iAUlWl9Al3M= github.com/deepmap/oapi-codegen v1.8.2 h1:SegyeYGcdi0jLLrpbCMoJxnUUn8GBXHsvr4rbzjuhfU= github.com/deepmap/oapi-codegen v1.8.2/go.mod h1:YLgSKSDv/bZQB7N4ws6luhozi3cEdRktEqrX88CvjIw= diff --git a/tests/fuzzers/secp256k1/secp_test.go b/tests/fuzzers/secp256k1/secp_test.go index 76bae87086f5..737e7c53c908 100644 --- a/tests/fuzzers/secp256k1/secp_test.go +++ b/tests/fuzzers/secp256k1/secp_test.go @@ -1,8 +1,53 @@ +// Copyright 2021 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 . + package secp256k1 -import "testing" +import ( + "fmt" + "testing" + + dcred_secp256k1 "github.com/decred/dcrd/dcrec/secp256k1/v4" + "github.com/scroll-tech/go-ethereum/crypto/secp256k1" +) func TestFuzzer(t *testing.T) { - test := "00000000N0000000/R00000000000000000U0000S0000000mkhP000000000000000U" - Fuzz([]byte(test)) + a, b := "00000000N0000000/R0000000000000000", "0U0000S0000000mkhP000000000000000U" + fuzz([]byte(a), []byte(b)) +} + +func Fuzz(f *testing.F) { + f.Fuzz(func(t *testing.T, a, b []byte) { + fuzz(a, b) + }) +} + +func fuzz(dataP1, dataP2 []byte) { + var ( + curveA = secp256k1.S256() + curveB = dcred_secp256k1.S256() + ) + // first point + x1, y1 := curveB.ScalarBaseMult(dataP1) + // second points + x2, y2 := curveB.ScalarBaseMult(dataP2) + resAX, resAY := curveA.Add(x1, y1, x2, y2) + resBX, resBY := curveB.Add(x1, y1, x2, y2) + if resAX.Cmp(resBX) != 0 || resAY.Cmp(resBY) != 0 { + fmt.Printf("%s %s %s %s\n", x1, y1, x2, y2) + panic(fmt.Sprintf("Addition failed: geth: %s %s btcd: %s %s", resAX, resAY, resBX, resBY)) + } }