parse export key response

command_set.go

@@ -229,7 +229,7 @@ func (cs *CommandSet) DeriveKey(path string) error {
 	return cs.checkOK(resp, err)
 }
 
-func (cs *CommandSet) ExportKey(derive bool, makeCurrent bool, onlyPublic bool, path string) ([]byte, error) {
+func (cs *CommandSet) ExportKey(derive bool, makeCurrent bool, onlyPublic bool, path string) ([]byte, []byte, error) {
 	var p1 uint8
 	if derive == false {
 		p1 = P1ExportKeyCurrent
@@ -244,18 +244,19 @@ func (cs *CommandSet) ExportKey(derive bool, makeCurrent bool, onlyPublic bool,
 	} else {
 		p2 = P2ExportKeyPrivateAndPublic
 	}
+
 	cmd, err := NewCommandExportKey(p1, p2, path)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	resp, err := cs.sc.Send(cmd)
 	err = cs.checkOK(resp, err)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	return resp.Data, nil
 
+	return types.ParseExportKeyResponse(resp.Data)
 }
 
 func (cs *CommandSet) SetPinlessPath(path string) error {

types/exported_key.go

@@ -0,0 +1,32 @@
+package types
+
+import (
+	"fmt"
+
+	ethcrypto "github.com/ethereum/go-ethereum/crypto"
+	"github.com/status-im/keycard-go/apdu"
+)
+
+var (
+	TagExportKeyTemplate = uint8(0xA1)
+	TagExportKeyPublic   = uint8(0x81)
+)
+
+func ParseExportKeyResponse(data []byte) ([]byte, []byte, error) {
+	tpl, err := apdu.FindTag(data, apdu.Tag{0xA1})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	privKey, err := apdu.FindTag(tpl, apdu.Tag{0x81})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	ecdsaKey, err := ethcrypto.HexToECDSA(fmt.Sprintf("%x", privKey))
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return privKey, ethcrypto.FromECDSAPub(&ecdsaKey.PublicKey), nil
+}