Return error type when parsing keys to differentiate between public/private error

pkg.go

@@ -38,6 +38,15 @@ type Manager struct {
 	Initialized bool
 }
 
+type KeyError struct {
+	Err error
+	KeyType string // PUBLIC or PRIVATE
+}
+
+func (kerr KeyError) Error() string {
+	return fmt.Sprintf("%s [%s]", kerr.Err.Error(), kerr.KeyType)
+}
+
 func NewManager(keyType KeyType, private, public string, expireDays int) (mngr Manager, err error) { // {{{
 	var errPriv, errPub error
 	mngr.KeyType = keyType
@@ -61,12 +70,18 @@ func NewManager(keyType KeyType, private, public string, expireDays int) (mngr M
 	}
 
 	if errPriv != nil {
-		err = errPriv
+		err = KeyError{
+			errPriv,
+			"PRIVATE",
+		}
 		return
 	}
 
 	if errPub != nil {
-		err = errPub
+		err = KeyError {
+			errPub,
+			"PUBLIC",
+		}
 		return
 	}