SecurityHeadersMiddleware was the last middleware in the stack still
subclassing BaseHTTPMiddleware, after CommitSession, AuthToken,
WebsocketUpgradeGuard and Redirect were all moved to pure ASGI in
utils/asgi_middleware.py. BaseHTTPMiddleware re-buffers the response
body through an anyio task group, which has known issues with
streaming and Content-Length-bearing responses (e.g. the FileResponse
returned by /api/v1/audio/speech).
Reimplement it as a pure-ASGI middleware that stamps the configured
security headers onto the http.response.start message via
MutableHeaders and forwards all body chunks untouched, matching the
pattern already used by its four siblings. set_security_headers() and
all its helpers are unchanged.
Co-authored-by: classic298 <classic298@users.noreply.github.com>
Introduce CONTENT_SECURITY_POLICY environment variable to set HTTP header "Content-Security-Policy".
Content Security Policy (CSP) is a feature that helps to prevent or minimize the risk of certain types of security threats. It consists of a series of instructions from a website to a browser, which instruct the browser to place restrictions on the things that the code comprising the site is allowed to do.
https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP
