[X509] simplify ParsePKIXPublicKey

smx509/x509.go

@@ -52,35 +52,11 @@ func ParsePKIXPublicKey(derBytes []byte) (interface{}, error) {
 	} else if len(rest) != 0 {
 		return nil, errors.New("x509: trailing data after ASN.1 of public-key")
 	}
-
-	if !pki.Algorithm.Algorithm.Equal(oidPublicKeyECDSA) {
-		return x509.ParsePKIXPublicKey(derBytes)
-	}
-	keyData := &pki
-	asn1Data := keyData.PublicKey.RightAlign()
-	paramsData := keyData.Algorithm.Parameters.FullBytes
-	namedCurveOID := new(asn1.ObjectIdentifier)
-	rest, err := asn1.Unmarshal(paramsData, namedCurveOID)
-	if err != nil {
-		return nil, errors.New("x509: failed to parse ECDSA parameters as named curve")
-	}
-	if len(rest) != 0 {
-		return nil, errors.New("x509: trailing data after ECDSA parameters")
-	}
-	if !namedCurveOID.Equal(oidNamedCurveP256SM2) {
-		return x509.ParsePKIXPublicKey(derBytes)
-	}
-	namedCurve := sm2.P256()
-	x, y := elliptic.Unmarshal(namedCurve, asn1Data)
-	if x == nil {
-		return nil, errors.New("x509: failed to unmarshal elliptic curve point")
-	}
-	pub := &ecdsa.PublicKey{
-		Curve: namedCurve,
-		X:     x,
-		Y:     y,
+	algo := getPublicKeyAlgorithmFromOID(pki.Algorithm.Algorithm)
+	if algo == UnknownPublicKeyAlgorithm {
+		return nil, errors.New("x509: unknown public key algorithm")
 	}
-	return pub, nil
+	return parsePublicKey(algo, &pki)
 }
 
 func marshalPublicKey(pub interface{}) (publicKeyBytes []byte, publicKeyAlgorithm pkix.AlgorithmIdentifier, err error) {