add error codes

mockid/route.go

@@ -153,6 +153,7 @@ func Route(jwksPrefix string, privkey keypairs.PrivateKey) http.Handler {
 			http.Error(w, "Bad Request", http.StatusBadRequest)
 			b, _ := json.Marshal(&HTTPResponse{
 				Error: "missing require query parameter 'contact'",
+				Code:  "E_USER",
 			})
 			w.Write(b)
 			return
@@ -253,6 +254,7 @@ func Route(jwksPrefix string, privkey keypairs.PrivateKey) http.Handler {
 			if errTokenNotVerified == err {
 				b, _ := json.Marshal(&HTTPResponse{
 					Error: err.Error(),
+					Code:  "E_RETRY",
 				})
 				w.Write(b)
 				return