Switch to stdlib

Author: connorwstein

keystore/kms/asn1.go

@@ -240,22 +240,3 @@ func padTo32Bytes(buffer []byte) []byte {
 
 	return buffer
 }
-
-// ASN1ToEd25519PublicKey extracts an Ed25519 public key from AWS KMS ASN.1 DER-encoded SPKI format.
-//
-// AWS KMS returns Ed25519 public keys in ASN.1 DER-encoded SubjectPublicKeyInfo (SPKI) format.
-// The actual Ed25519 public key is 32 bytes and is contained in the SubjectPublicKey BitString.
-func ASN1ToEd25519PublicKey(asn1PublicKey []byte) ([]byte, error) {
-	var spki SPKI
-	if _, err := asn1.Unmarshal(asn1PublicKey, &spki); err != nil {
-		return nil, fmt.Errorf("failed to unmarshal ASN.1 public key: %w", err)
-	}
-
-	// Ed25519 public keys are 32 bytes raw in the BitString
-	pubKeyBytes := spki.SubjectPublicKey.Bytes
-	if len(pubKeyBytes) != 32 {
-		return nil, fmt.Errorf("invalid Ed25519 public key length in BitString: expected 32 bytes, got %d", len(pubKeyBytes))
-	}
-
-	return pubKeyBytes, nil
-}

keystore/kms/keystore.go

@@ -8,6 +8,9 @@ import (
 	"github.com/aws/aws-sdk-go-v2/service/kms"
 	kmstypes "github.com/aws/aws-sdk-go-v2/service/kms/types"
 
+	"crypto/ed25519"
+	"crypto/x509"
+
 	"github.com/smartcontractkit/chainlink-common/keystore"
 )
 
@@ -89,10 +92,16 @@ func (k *keystoreSignerReader) GetKeys(ctx context.Context, req keystore.GetKeys
 				return keystore.GetKeysResponse{}, fmt.Errorf("failed to convert public key for key %s: %w", keyID, err)
 			}
 		case keystore.Ed25519:
-			publicKeyBytes, err = ASN1ToEd25519PublicKey(key.PublicKey)
+			// ed25519 supported by standard libraries unlike secp256k1.
+			pubKey, err := x509.ParsePKIXPublicKey(key.PublicKey)
 			if err != nil {
 				return keystore.GetKeysResponse{}, fmt.Errorf("failed to convert Ed25519 public key for key %s: %w", keyID, err)
 			}
+			ed25519PubKey, ok := pubKey.(ed25519.PublicKey)
+			if !ok {
+				return keystore.GetKeysResponse{}, fmt.Errorf("failed to convert Ed25519 public key for key %s to ed25519.PublicKey: %w", keyID, err)
+			}
+			publicKeyBytes = ed25519PubKey
 		default:
 			return keystore.GetKeysResponse{}, fmt.Errorf("unsupported key type: %s", keyType)
 		}