v0.28.0

src/proxy/websocket/handshake.rs

@@ -283,8 +283,15 @@ pub fn validate_response(
             "invalid upstream upgrade"
         );
         ensure!(
-            !headers.contains_key("transfer-encoding") && !headers.contains_key("content-length"),
-            "101 response must not include body framing"
+            !headers.contains_key("transfer-encoding"),
+            "101 response must not use Transfer-Encoding"
+        );
+        ensure!(
+            headers.get_all("content-length").iter().count() <= 1
+                && headers
+                    .get("content-length")
+                    .is_none_or(|value| value.to_str().is_ok_and(|value| value.trim() == "0")),
+            "101 response Content-Length must be 0 when present"
         );
         for value in headers.get_all("connection").iter() {
             for field in value.to_str()?.split(',') {