h.inner.(marshalable) if !innerOK { return } marshalableOuter, outerOK := h.outer.(marshalable) if !outerOK { return } imarshal, err := marshalableInner.MarshalBinary() if err != nil { return } h.outer.Reset() h.outer.Write(h.opad) omarshal, err := marshalableOuter.MarshalBinary() if err != nil { return } // Marshaling succeeded; save the marshaled state for later h.ipad = imarshal h.opad = omarshal h.marshaled = true } type errCloneUnsupported struct{} func (e errCloneUnsupported) Error() string { return "crypto/hmac:...