s3proxy: handle Range header on GetObject

We currently can't support the range header as we
have to parse it ourself, fetch the full file, decrypt it
and serve the requested slice.
For now, fail loudly to make users aware of the limitation.
AB#3466.

s3proxy/internal/router/router.go

@@ -73,6 +73,11 @@ func (r Router) Serve(w http.ResponseWriter, req *http.Request) {
 		parts := strings.Split(req.Host, ".")
 		bucket := parts[0]
 
+		if req.Header.Get("Range") != "" {
+			r.log.Error("GetObject Range header unsupported")
+			http.Error(w, "s3proxy currently does not support Range headers", http.StatusNotImplemented)
+		}
+
 		obj := object{
 			client: client,
 			key:    key,
@@ -82,6 +87,11 @@ func (r Router) Serve(w http.ResponseWriter, req *http.Request) {
 		}
 		h = get(obj.get)
 	case !containsBucket(req.Host) && match(path, "/([^/?]+)/(.+)", &bucket, &key) && req.Method == "GET" && !isGetObjectX(req.URL.Query()):
+		if req.Header.Get("Range") != "" {
+			r.log.Error("GetObject Range header unsupported")
+			http.Error(w, "s3proxy currently does not support Range headers", http.StatusNotImplemented)
+		}
+
 		obj := object{
 			client: client,
 			key:    key,