Refactor secp256k1 deps and implementations

go.mod

@@ -3,7 +3,7 @@ module github.com/make-software/casper-go-sdk
 go 1.19
 
 require (
-	github.com/btcsuite/btcd v0.22.1
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1
 	github.com/shopspring/decimal v1.3.1
 	github.com/stretchr/testify v1.8.2
 	golang.org/x/crypto v0.9.0

go.sum

@@ -1,9 +1,11 @@
-github.com/btcsuite/btcd v0.22.1 h1:CnwP9LM/M9xuRrGSCGeMVs9iv09uMqwsVX7EeIpgV2c=
-github.com/btcsuite/btcd v0.22.1/go.mod h1:wqgTSL29+50LRkmOVknEdmt8ZojIzhuWvgu/iptuN7Y=
-github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 h1:q0rUy8C/TYNBQS1+CGKw68tLOFYSNEs0TFnxxnS9+4U=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 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/decred/dcrd/crypto/blake256 v1.0.0/go.mod h1:sQl2p6Y26YV+ZOcSTP6thNdn47hh8kt6rqSlvmrXFAc=
+github.com/decred/dcrd/crypto/blake256 v1.0.1 h1:7PltbUIQB7u/FfZ39+DGa/ShuMyJ5ilcvdfma9wOH6Y=
+github.com/decred/dcrd/crypto/blake256 v1.0.1/go.mod h1:2OfgNZ5wDpcsFmHmCK5gZTPcCXqlm2ArzUIkw9czNJo=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 h1:YLtO71vCjJRCBcrPMtQ9nqBsqpA1m5sE92cU+pd5Mcc=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1/go.mod h1:hyedUtir6IdtD/7lIxGeCxkaw7y45JueMRL4DIyJDKs=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=

tests/types/keypair/private_key_test.go

@@ -41,3 +41,23 @@ func Test_SECPKey_CreateAndValidateRawSignature(t *testing.T) {
 	err = privateKeyData.PublicKey().VerifyRawSignature(secretMessage, signature)
 	assert.NoError(t, err)
 }
+
+func Test_ED25PKey_CreateAndValidateSignature(t *testing.T) {
+	secretMessage := []byte("Enigmatic Shadows Concealing Ancient Whispers")
+	privateKeyData, err := keypair.GeneratePrivateKey(keypair.ED25519)
+	require.NoError(t, err)
+	signature, err := privateKeyData.Sign(secretMessage)
+	require.NoError(t, err)
+	err = privateKeyData.PublicKey().VerifySignature(secretMessage, signature)
+	assert.NoError(t, err)
+}
+
+func Test_ED25Key_CreateAndValidateRawSignature(t *testing.T) {
+	secretMessage := []byte("Enigmatic Shadows Concealing Ancient Whispers")
+	privateKeyData, err := keypair.GeneratePrivateKey(keypair.ED25519)
+	require.NoError(t, err)
+	signature, err := privateKeyData.RawSign(secretMessage)
+	require.NoError(t, err)
+	err = privateKeyData.PublicKey().VerifyRawSignature(secretMessage, signature)
+	assert.NoError(t, err)
+}

types/keypair/private_key.go

@@ -23,8 +23,8 @@ func (v PrivateKey) PublicKey() PublicKey {
 }
 
 // Sign creates a Casper compatible cryptographic signature, including the algorithm tag prefix
-func (v PrivateKey) Sign(mes []byte) ([]byte, error) {
-	sign, err := v.priv.Sign(mes)
+func (v PrivateKey) Sign(msg []byte) ([]byte, error) {
+	sign, err := v.priv.Sign(msg)
 	if err != nil {
 		return nil, err
 	}
@@ -83,13 +83,10 @@ func GeneratePrivateKey(algorithm keyAlgorithm) (PrivateKey, error) {
 			return PrivateKey{}, err
 		}
 	case SECP256K1:
-		data, _, err := secp256k1.NewPemPair()
+		priv, err = secp256k1.GeneratePrivateKey()
 		if err != nil {
 			return PrivateKey{}, err
 		}
-		if priv, err = secp256k1.NewPrivateKeyFromPem(data); err != nil {
-			return PrivateKey{}, err
-		}
 	}
 	publicKey, err := NewPublicKeyFromBytes(append([]byte{byte(algorithm)}, priv.PublicKeyBytes()...))
 	if err != nil {

types/keypair/secp256k1/pem_parser.go

@@ -2,13 +2,11 @@ package secp256k1
 
 import (
 	"crypto/elliptic"
-	"crypto/x509/pkix"
 	"encoding/asn1"
 	"encoding/pem"
 	"fmt"
-	"math/big"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
 )
 
 var oid = asn1.ObjectIdentifier{1, 3, 132, 0, 10}
@@ -20,13 +18,8 @@ type ecPrivateKey struct {
 	PublicKey     asn1.BitString        `asn1:"optional,explicit,tag:1"`
 }
 
-type pkixPublicKey struct {
-	Algo      pkix.AlgorithmIdentifier
-	BitString asn1.BitString
-}
-
 func NewPemPair() ([]byte, []byte, error) {
-	priv, err := btcec.NewPrivateKey(btcec.S256())
+	priv, err := secp256k1.GeneratePrivateKey()
 	if err != nil {
 		return nil, nil, fmt.Errorf("creating new S256 private key")
 	}
@@ -44,7 +37,15 @@ func NewPemPair() ([]byte, []byte, error) {
 	return privKeyPem, pubKeyPem, nil
 }
 
-func PrivateKeyToPem(priv *btcec.PrivateKey) ([]byte, error) {
+func GeneratePrivateKey() (PrivateKey, error) {
+	priv, err := secp256k1.GeneratePrivateKey()
+	if err != nil {
+		return PrivateKey{}, fmt.Errorf("creating new S256 private key")
+	}
+	return PrivateKey{key: priv}, nil
+}
+
+func PrivateKeyToPem(priv *secp256k1.PrivateKey) ([]byte, error) {
 	key := priv.ToECDSA()
 
 	privateKey := make([]byte, (key.Curve.Params().N.BitLen()+7)/8)
@@ -66,7 +67,7 @@ func PrivateKeyToPem(priv *btcec.PrivateKey) ([]byte, error) {
 	), nil
 }
 
-func PemToPrivateKey(priv []byte) (*btcec.PrivateKey, error) {
+func PemToPrivateKey(priv []byte) (*secp256k1.PrivateKey, error) {
 	block, _ := pem.Decode(priv)
 	if block == nil {
 		return nil, fmt.Errorf("key not found")
@@ -80,61 +81,14 @@ func PemToPrivateKey(priv []byte) (*btcec.PrivateKey, error) {
 		return nil, fmt.Errorf("x509: unknown EC private key version %d", privKey.Version)
 	}
 
-	curve := btcec.S256()
-
-	k := new(big.Int).SetBytes(privKey.PrivateKey)
-	curveOrder := curve.Params().N
-	if k.Cmp(curveOrder) >= 0 {
-		return nil, fmt.Errorf("x509: invalid elliptic curve private key value")
-	}
-
-	key := new(btcec.PrivateKey)
-	key.Curve = curve
-	key.D = k
-
-	privateKey := make([]byte, (curveOrder.BitLen()+7)/8)
-
-	for len(privKey.PrivateKey) > len(privateKey) {
-		if privKey.PrivateKey[0] != 0 {
-			return nil, fmt.Errorf("x509: invalid private key length")
-		}
-		privKey.PrivateKey = privKey.PrivateKey[1:]
-	}
-
-	copy(privateKey[len(privateKey)-len(privKey.PrivateKey):], privKey.PrivateKey)
-	key.X, key.Y = curve.ScalarBaseMult(privateKey)
-
-	return key, nil
+	return secp256k1.PrivKeyFromBytes(privKey.PrivateKey), nil
 }
 
-func PublicKeyToPem(pub *btcec.PublicKey) ([]byte, error) {
-	pubEDSA := pub.ToECDSA()
-
-	var publicKeyAlgorithm pkix.AlgorithmIdentifier
-
-	publicKeyBytes := elliptic.Marshal(pubEDSA.Curve, pubEDSA.X, pubEDSA.Y)
-
-	publicKeyAlgorithm.Algorithm = oid
-	var paramBytes []byte
-	paramBytes, err := asn1.Marshal(oid)
-	if err != nil {
-		return nil, err
-	}
-
-	publicKeyAlgorithm.Parameters.FullBytes = paramBytes
-
-	pubBytes, _ := asn1.Marshal(pkixPublicKey{
-		Algo: publicKeyAlgorithm,
-		BitString: asn1.BitString{
-			Bytes:     publicKeyBytes,
-			BitLength: 8 * len(publicKeyBytes),
-		},
-	})
-
+func PublicKeyToPem(pub *secp256k1.PublicKey) ([]byte, error) {
 	return pem.EncodeToMemory(
 		&pem.Block{
 			Type:  "EC PUBLIC KEY",
-			Bytes: pubBytes,
+			Bytes: pub.SerializeUncompressed(),
 		},
 	), nil
 }

types/keypair/secp256k1/private_key.go

@@ -5,11 +5,12 @@ import (
 	"errors"
 	"os"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4/ecdsa"
 )
 
 type PrivateKey struct {
-	key *btcec.PrivateKey
+	key *secp256k1.PrivateKey
 }
 
 func (v PrivateKey) PublicKeyBytes() []byte {
@@ -18,12 +19,7 @@ func (v PrivateKey) PublicKeyBytes() []byte {
 
 func (v PrivateKey) Sign(mes []byte) ([]byte, error) {
 	hash := sha256.Sum256(mes)
-	sig, err := v.key.Sign(hash[:])
-	if err != nil {
-		return nil, err
-	}
-
-	return serializeSig(sig), nil
+	return ecdsa.Sign(v.key, hash[:]).Serialize(), nil
 }
 
 func NewPrivateKeyFromPemFile(path string) (PrivateKey, error) {
@@ -44,15 +40,3 @@ func NewPrivateKeyFromPem(content []byte) (PrivateKey, error) {
 		key: private,
 	}, nil
 }
-
-// Serialize signature to R || S.
-// R, S are padded to 32 bytes respectively.
-func serializeSig(sig *btcec.Signature) []byte {
-	rBytes := sig.R.Bytes()
-	sBytes := sig.S.Bytes()
-	sigBytes := make([]byte, 64)
-	// 0 pad the byte arrays from the left if they aren't big enough.
-	copy(sigBytes[32-len(rBytes):32], rBytes)
-	copy(sigBytes[64-len(sBytes):64], sBytes)
-	return sigBytes
-}

types/keypair/secp256k1/public_key.go

@@ -3,66 +3,41 @@ package secp256k1
 import (
 	"crypto/sha256"
 	"fmt"
-	"math/big"
+	"log"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4/ecdsa"
 )
 
 const PublicKeySize = 33
 
-// used to reject malleable signatures
-// see:
-//   - https://github.com/ethereum/go-ethereum/blob/f9401ae011ddf7f8d2d95020b7446c17f8d98dc1/crypto/signature_nocgo.go#L90-L93
-//   - https://github.com/ethereum/go-ethereum/blob/f9401ae011ddf7f8d2d95020b7446c17f8d98dc1/crypto/crypto.go#L39
-var secp256k1halfN = new(big.Int).Rsh(btcec.S256().N, 1)
-
-type PublicKey btcec.PublicKey
+type PublicKey struct {
+	key *secp256k1.PublicKey
+}
 
 func (v PublicKey) Bytes() []byte {
-	key := btcec.PublicKey(v)
-	return key.SerializeCompressed()
+	return v.key.SerializeCompressed()
 }
 
 // VerifySignature verifies a signature of the form R || S.
 // It rejects signatures which are not in lower-S form.
 func (v PublicKey) VerifySignature(msg []byte, sigStr []byte) bool {
-	if len(sigStr) != 64 {
-		return false
-	}
-
-	pub, err := btcec.ParsePubKey(v.Bytes(), btcec.S256())
+	signature, err := ecdsa.ParseDERSignature(sigStr)
 	if err != nil {
+		log.Println(err)
 		return false
 	}
-
-	// parse the signature:
-	signature := signatureFromBytes(sigStr)
-	// Reject malleable signatures. libsecp256k1 does this check but btcec doesn't.
-	// see: https://github.com/ethereum/go-ethereum/blob/f9401ae011ddf7f8d2d95020b7446c17f8d98dc1/crypto/signature_nocgo.go#L90-L93
-	if signature.S.Cmp(secp256k1halfN) > 0 {
-		return false
-	}
-
-	sum256 := sha256.Sum256(msg)
-	return signature.Verify(sum256[:], pub)
-}
-
-// Read Signature struct from R || S. Caller needs to ensure
-// that len(sigStr) == 64.
-func signatureFromBytes(sigStr []byte) *btcec.Signature {
-	return &btcec.Signature{
-		R: new(big.Int).SetBytes(sigStr[:32]),
-		S: new(big.Int).SetBytes(sigStr[32:64]),
-	}
+	hash := sha256.Sum256(msg)
+	return signature.Verify(hash[:], v.key)
 }
 
 func NewPublicKey(data []byte) (PublicKey, error) {
 	if len(data) != PublicKeySize {
 		return PublicKey{}, fmt.Errorf("can't parse wrong size of public key: %d", len(data))
 	}
-	key, err := btcec.ParsePubKey(data, btcec.S256())
+	key, err := secp256k1.ParsePubKey(data)
 	if err != nil {
 		return PublicKey{}, err
 	}
-	return PublicKey(*key), err
+	return PublicKey{key: key}, err
 }