Update Bytes method to use Compress

Update Bytes method to use .Compress() internally. For Point, PublicKey, Signature. Keep old uncompressed .Bytes() methods for backwards compatibility.
2026-02-06 19:16:40 +01:00 · 2021-11-18 16:40:39 +01:00
parent 0e9f71e07e
commit 04b9532b53
3 changed files with 149 additions and 28 deletions
--- a/blindsecp256k1.go
+++ b/blindsecp256k1.go
@@ -77,7 +77,8 @@ func (p *Point) isValid() error {
 	return nil
 }

-// Compress packs a Point to a byte array of 33 bytes, encoded in little-endian.
+// Compress packs a Point to a byte array of 33 bytes, encoded in
+// little-endian.
 func (p *Point) Compress() [33]byte {
 	xBytes := p.X.Bytes()
 	odd := byte(0)
@@ -134,7 +135,7 @@ func DecompressPoint(b [33]byte) (*Point, error) {
 	}

 	p := &Point{X: x, Y: y}
-	return p, nil
+	return p, p.isValid()
 }

 // WIP
--- a/parsers.go
+++ b/parsers.go
@@ -51,12 +51,9 @@ func (p *Point) UnmarshalJSON(b []byte) error {
 	return nil
 }

-// Bytes returns a byte array of length 64, with the X & Y coordinates of the
-// Point encoded in little-endian.  [ X (32 bytes) | Y (32 bytes)]
+// Bytes returns the compressed Point in a little-endian byte array
 func (p *Point) Bytes() []byte {
-	var b [64]byte
-	copy(b[:32], swapEndianness(p.X.Bytes()))
-	copy(b[32:], swapEndianness(p.Y.Bytes()))
+	b := p.Compress()
 	return b[:]
 }

@@ -64,6 +61,31 @@ func (p *Point) Bytes() []byte {
 // 64 which has encoded the point coordinates each one as 32 bytes in
 // little-endian.
 func NewPointFromBytes(b []byte) (*Point, error) {
+	if len(b) != 33 { //nolint:gomnd
+		return nil, fmt.Errorf("Can not parse bytes to Point,"+
+			" expected byte array of length %d, current %d",
+			33, len(b))
+	}
+
+	var pBytes [33]byte
+	copy(pBytes[:], b[:])
+	return DecompressPoint(pBytes)
+}
+
+// BytesUncompressed returns a byte array of length 64, with the X & Y
+// coordinates of the Point encoded in little-endian.  [ X (32 bytes) | Y (32
+// bytes)]
+func (p *Point) BytesUncompressed() []byte {
+	var b [64]byte
+	copy(b[:32], swapEndianness(p.X.Bytes()))
+	copy(b[32:], swapEndianness(p.Y.Bytes()))
+	return b[:]
+}
+
+// NewPointFromBytesUncompressed returns a new *Point from a given byte array
+// with length 64 which has encoded the point coordinates each one as 32 bytes
+// in little-endian.
+func NewPointFromBytesUncompressed(b []byte) (*Point, error) {
 	if len(b) != 64 { //nolint:gomnd
 		return nil, fmt.Errorf("Can not parse bytes to Point,"+
 			" expected byte array of length %d, current %d",
@@ -92,8 +114,7 @@ func (pk *PublicKey) UnmarshalJSON(b []byte) error {
 	return nil
 }

-// Bytes returns a byte array of length 64, with the X & Y coordinates of the
-// PublicKey encoded in little-endian.  [ X (32 bytes) | Y (32 bytes)]
+// Bytes returns the compressed PublicKey in a little-endian byte array
 func (pk *PublicKey) Bytes() []byte {
 	return pk.Point().Bytes()
 }
@@ -110,6 +131,25 @@ func NewPublicKeyFromBytes(b []byte) (*PublicKey, error) {
 	return &pk, nil
 }

+// BytesUncompressed returns a byte array of length 64, with the X & Y
+// coordinates of the PublicKey encoded in little-endian.
+// [ X (32 bytes) | Y (32 bytes)]
+func (pk *PublicKey) BytesUncompressed() []byte {
+	return pk.Point().BytesUncompressed()
+}
+
+// NewPublicKeyFromBytesUncompressed returns a new *PublicKey from a given byte array with
+// length 64 which has encoded the public key coordinates each one as 32 bytes
+// in little-endian.
+func NewPublicKeyFromBytesUncompressed(b []byte) (*PublicKey, error) {
+	p, err := NewPointFromBytesUncompressed(b)
+	if err != nil {
+		return nil, err
+	}
+	pk := PublicKey(*p)
+	return &pk, nil
+}
+
 // NewPublicKeyFromECDSA returns a *PublicKey from a serialized/marshaled array
 // of bytes generated by the ethereum/standard ECDSA PubKey implementation.
 func NewPublicKeyFromECDSA(b []byte) (*PublicKey, error) {
@@ -177,28 +217,55 @@ func (sig *Signature) UnmarshalJSON(b []byte) error {
 	return nil
 }

-// Bytes returns a byte array of length 96, with the S, F.X and F.Y coordinates
-// of the Signature encoded in little-endian.
-// [ S (32 bytes | F.X (32 bytes) | F.Y (32 bytes)]
+// Bytes returns the compressed Signature in a little-endian byte array
 func (sig *Signature) Bytes() []byte {
-	var b [96]byte
-	copy(b[:32], swapEndianness(sig.S.Bytes()))
-	copy(b[32:96], sig.F.Bytes())
-	return b[:]
+	s := sig.Compress()
+	return s[:]
 }

 // NewSignatureFromBytes returns a new *Signature from a given byte array with
 // length 96 which has encoded S and the F point coordinates each one as 32
 // bytes in little-endian.
 func NewSignatureFromBytes(b []byte) (*Signature, error) {
-	if len(b) != 96 { //nolint:gomnd
+	if len(b) != 65 { //nolint:gomnd
 		return nil,
 			fmt.Errorf("Can not parse bytes to Signature,"+
 				" expected byte array of length %d, current %d",
-				96, len(b))
+				65, len(b))
 	}
 	s := new(big.Int).SetBytes(swapEndianness(b[:32]))
-	f, err := NewPointFromBytes(b[32:96])
+	f, err := NewPointFromBytes(b[32:65])
+	if err != nil {
+		return nil, err
+	}
+	return &Signature{
+		S: s,
+		F: f,
+	}, nil
+}
+
+// BytesUncompressed returns a byte array of length 96, with the S, F.X and F.Y
+// coordinates of the Signature encoded in little-endian.
+// [ S (32 bytes | F.X (32 bytes) | F.Y (32 bytes)]
+func (sig *Signature) BytesUncompressed() []byte {
+	var b [96]byte
+	copy(b[:32], swapEndianness(sig.S.Bytes()))
+	copy(b[32:96], sig.F.BytesUncompressed())
+	return b[:]
+}
+
+// NewSignatureFromBytesUncompressed returns a new *Signature from a given byte array with
+// length 96 which has encoded S and the F point coordinates each one as 32
+// bytes in little-endian.
+func NewSignatureFromBytesUncompressed(b []byte) (*Signature, error) {
+	if len(b) != 96 { //nolint:gomnd
+		return nil,
+			fmt.Errorf("Can not parse bytes to Signature,"+
+				" expected byte array of length %d, current %d",
+				96, len(b))
+	}
+	s := new(big.Int).SetBytes(swapEndianness(b[:32]))
+	f, err := NewPointFromBytesUncompressed(b[32:96])
 	if err != nil {
 		return nil, err
 	}
--- a/parsers_test.go
+++ b/parsers_test.go
@@ -57,19 +57,16 @@ func TestMarshalers(t *testing.T) {

 func TestBytes(t *testing.T) {
 	// Point
-	p := &Point{
-		X: big.NewInt(3),
-		Y: big.NewInt(3),
-	}
+	p := G.Mul(big.NewInt(3))
 	b := p.Bytes()
-	assert.Equal(t, "03000000000000000000000000000000000000000000000000000000000000000300000000000000000000000000000000000000000000000000000000000000", hex.EncodeToString(b)) //nolint:lll
+	assert.Equal(t, "f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f900", hex.EncodeToString(b)) //nolint:lll
 	p2, err := NewPointFromBytes(b)
 	assert.Nil(t, err)
 	assert.Equal(t, p, p2)

 	p = G.Mul(big.NewInt(1234))
 	b = p.Bytes()
-	assert.Equal(t, "f258163f65f65865a79a4279e2ebabb5a57b85501dd4b381d1dc605c434876e34c308bd3f18f062d5cc07f34948ced82f9a76f9c3e65ae64f158412da8e92e6d", hex.EncodeToString(b)) //nolint:lll
+	assert.Equal(t, "e37648435c60dcd181b3d41d50857ba5b5abebe279429aa76558f6653f1658f200", hex.EncodeToString(b)) //nolint:lll
 	p2, err = NewPointFromBytes(b)
 	assert.Nil(t, err)
 	assert.Equal(t, p, p2)
@@ -77,7 +74,7 @@ func TestBytes(t *testing.T) {
 	// PublicKey
 	pk := PublicKey(*p)
 	b = pk.Bytes()
-	assert.Equal(t, "f258163f65f65865a79a4279e2ebabb5a57b85501dd4b381d1dc605c434876e34c308bd3f18f062d5cc07f34948ced82f9a76f9c3e65ae64f158412da8e92e6d", hex.EncodeToString(b)) //nolint:lll
+	assert.Equal(t, "e37648435c60dcd181b3d41d50857ba5b5abebe279429aa76558f6653f1658f200", hex.EncodeToString(b)) //nolint:lll
 	pk2, err := NewPublicKeyFromBytes(b)
 	assert.Nil(t, err)
 	assert.Equal(t, &pk, pk2)
@@ -88,7 +85,7 @@ func TestBytes(t *testing.T) {
 		F: p,
 	}
 	b = sig.Bytes()
-	assert.Equal(t, "9426000000000000000000000000000000000000000000000000000000000000f258163f65f65865a79a4279e2ebabb5a57b85501dd4b381d1dc605c434876e34c308bd3f18f062d5cc07f34948ced82f9a76f9c3e65ae64f158412da8e92e6d", hex.EncodeToString(b)) //nolint:lll
+	assert.Equal(t, "9426000000000000000000000000000000000000000000000000000000000000e37648435c60dcd181b3d41d50857ba5b5abebe279429aa76558f6653f1658f200", hex.EncodeToString(b)) //nolint:lll
 	sig2, err := NewSignatureFromBytes(b)
 	assert.Nil(t, err)
 	assert.Equal(t, &sig, sig2)
@@ -105,12 +102,68 @@ func TestBytes(t *testing.T) {
 		F: &Point{X: x, Y: y},
 	}
 	b = sig.Bytes()
-	assert.Equal(t, "d7a75050259cc06415f19bde5460a58325e3050806ba949d9ac9728b71b9b6600457ba001981781ed31acafed3d1e82c2ad53d08e3f293eab2f199ed0193367c98311f1894598c91f10fe415ba4a6d04e1351d07430631c7decdbbdb2615e68a", hex.EncodeToString(b)) //nolint:lll
+	assert.Equal(t, "d7a75050259cc06415f19bde5460a58325e3050806ba949d9ac9728b71b9b6607c369301ed99f1b2ea93f2e3083dd52a2ce8d1d3feca1ad31e78811900ba570400", hex.EncodeToString(b)) //nolint:lll
 	sig2, err = NewSignatureFromBytes(b)
 	assert.Nil(t, err)
 	assert.Equal(t, &sig, sig2)
 }

+func TestBytesUncompressed(t *testing.T) {
+	// Point
+	p := &Point{
+		X: big.NewInt(3),
+		Y: big.NewInt(3),
+	}
+	b := p.BytesUncompressed()
+	assert.Equal(t, "03000000000000000000000000000000000000000000000000000000000000000300000000000000000000000000000000000000000000000000000000000000", hex.EncodeToString(b)) //nolint:lll
+	p2, err := NewPointFromBytesUncompressed(b)
+	assert.Nil(t, err)
+	assert.Equal(t, p, p2)
+
+	p = G.Mul(big.NewInt(1234))
+	b = p.BytesUncompressed()
+	assert.Equal(t, "f258163f65f65865a79a4279e2ebabb5a57b85501dd4b381d1dc605c434876e34c308bd3f18f062d5cc07f34948ced82f9a76f9c3e65ae64f158412da8e92e6d", hex.EncodeToString(b)) //nolint:lll
+	p2, err = NewPointFromBytesUncompressed(b)
+	assert.Nil(t, err)
+	assert.Equal(t, p, p2)
+
+	// PublicKey
+	pk := PublicKey(*p)
+	b = pk.BytesUncompressed()
+	assert.Equal(t, "f258163f65f65865a79a4279e2ebabb5a57b85501dd4b381d1dc605c434876e34c308bd3f18f062d5cc07f34948ced82f9a76f9c3e65ae64f158412da8e92e6d", hex.EncodeToString(b)) //nolint:lll
+	pk2, err := NewPublicKeyFromBytesUncompressed(b)
+	assert.Nil(t, err)
+	assert.Equal(t, &pk, pk2)
+
+	// Signature
+	sig := Signature{
+		S: big.NewInt(9876),
+		F: p,
+	}
+	b = sig.BytesUncompressed()
+	assert.Equal(t, "9426000000000000000000000000000000000000000000000000000000000000f258163f65f65865a79a4279e2ebabb5a57b85501dd4b381d1dc605c434876e34c308bd3f18f062d5cc07f34948ced82f9a76f9c3e65ae64f158412da8e92e6d", hex.EncodeToString(b)) //nolint:lll
+	sig2, err := NewSignatureFromBytesUncompressed(b)
+	assert.Nil(t, err)
+	assert.Equal(t, &sig, sig2)
+
+	// Signature with bigger values
+	s, ok := new(big.Int).SetString("43744879514016998261043792362491545206150700367692876136431010903034023684055", 10) //nolint:lll
+	require.True(t, ok)
+	x, ok := new(big.Int).SetString("56183217574518331862027285308947626162625485037257226169003339923450551228164", 10) //nolint:lll
+	require.True(t, ok)
+	y, ok := new(big.Int).SetString("62825693913681695979055350889339417157462875026935818721506450621762231021976", 10) //nolint:lll
+	require.True(t, ok)
+	sig = Signature{
+		S: s,
+		F: &Point{X: x, Y: y},
+	}
+	b = sig.BytesUncompressed()
+	assert.Equal(t, "d7a75050259cc06415f19bde5460a58325e3050806ba949d9ac9728b71b9b6600457ba001981781ed31acafed3d1e82c2ad53d08e3f293eab2f199ed0193367c98311f1894598c91f10fe415ba4a6d04e1351d07430631c7decdbbdb2615e68a", hex.EncodeToString(b)) //nolint:lll
+	sig2, err = NewSignatureFromBytesUncompressed(b)
+	assert.Nil(t, err)
+	assert.Equal(t, &sig, sig2)
+}
+
 func TestImportECDSApubKey(t *testing.T) {
 	// Generate an ECDSA key
 	k, err := crypto.GenerateKey()