fix(middleware): early exit if next handler returned error

src/middleware.rs

@@ -57,6 +57,11 @@ pub async fn middleware(
     let req = Request::from_parts(parts, axum::body::Body::from(processed_req.encrypted));
     let res = next.run(req).await;
 
+    // Early exit if next handler returned error
+    if !res.status().is_success() {
+        return res;
+    }
+
     // Process response: decrypt, deserialize, modify, re-encrypt
     let (resp_parts, body) = res.into_parts();
     let body_bytes;