Currently the hashing system in the new BinaryFileResponse has known limitations. It will be greatly beneficial if these are addressed by offering means to overcome these.

7322696#commitcomment-2193066

An option is to simplify the logic for hashing, by separating the hashing from the setting of the entity tag and from the file-input. This can be done simply by putting sha1_file() in a different method, that can be easily overridden, or by allowing a more OO approach by injecting the hashing strategy. The latter might be a bit more bulky but allows the most flexibility while maintaining clean separation of concerns.