Merge pull request #50 from onflow/tarak/minor-update

Minor ECDSA public key decoding update

Author: turbolent

ecdsa_secp256k1.go

@@ -152,17 +152,6 @@ func publicKeyECDSASecp256k1(a *ecdsaContext, XYBytes []byte) (*pubKeyECDSASecp2
 	}
 
 	x, y := readTwoBigInts(XYBytes, pLen)
-
-	// check the coordinates are valid field elements.
-	// This check is unconditional and must not be removed when go-ethereum is upgraded:
-	// it keeps the set of accepted key encodings independent of the go-ethereum version
-	// that Go module resolution selects, which this package does not control.
-	// Without it, a non-canonical encoding such as `x+p` is accepted whenever
-	// the resolved go-ethereum is v1.16.8 or earlier.
-	if x.Cmp(a.curveP) >= 0 || y.Cmp(a.curveP) >= 0 {
-		return nil, invalidInputsErrorf("at least one coordinate is larger than the field prime for %s", a.algo)
-	}
-
 	// `IsOnCurve` includes checks for x<p and y<p (in go-ethereum versions from v1.16.9 onwards)
 	if !secp256k1.S256().IsOnCurve(x, y) {
 		return nil, invalidInputsErrorf("input point has invalid coordinates or is not on curve")

ecdsa_test.go

@@ -203,7 +203,7 @@ func TestECDSAEncodeDecode(t *testing.T) {
 	//  - public key decoding handles input x-coordinates with x and y larger than p (doesn't result in an exception)
 	//  - public key decoding only accepts reduced x and y
 	t.Run("public key with non-reduced coordinates", func(t *testing.T) {
-		onflowCryptoErr := "at least one coordinate is larger than the field prime"
+		onflowCryptoErr := "input point has invalid coordinates or is not on curve"
 		goCryptoErr := "invalid P256 element encoding"
 
 		invalidPKs := []struct {

go.mod

@@ -6,7 +6,7 @@ require (
 	// Minimum version, not a pin: Go builds with the highest version required across the build.
 	// Keeping this floor low lets consumers choose their own go-ethereum version;
 	// raising it forces the new version on all of them.
-	// Only raise it if this module needs something v1.16.8 lacks,
+	// Only raise it if this module needs something the current version lacks,
 	// and audit the changes under go-ethereum/crypto/secp256k1 when doing so.
 	github.com/ethereum/go-ethereum v1.17.0
 	github.com/sirupsen/logrus v1.9.3