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Issues connecting via Cronet -> demo:app

See original GitHub issue

Hi!

Thanks again for your work on this project. I’ve been setting up a test environment here, to experiment with Android + Cronet HTTP/3 libs for a mobile app.

I am simply using http3_server.py with the demo:app ASGI module, but cannot get Cronet to even negotiate a connection. Here is the error:

Exception in CronetUrlRequest: net::ERR_QUIC_PROTOCOL_ERROR, ErrorCode=10, InternalErrorCode=-356, Retryable=false, QuicDetailedErrorCode=25

Here’s the relevant Cronet code:

private void callCronet() {
        CronetEngine.Builder myBuilder = new CronetEngine.Builder(this);
        cronetEngine = myBuilder
                .addQuicHint("quic.example.com", 8443, 8443)
                .enableHttpCache(CronetEngine.Builder.HTTP_CACHE_IN_MEMORY, 100 * 1024)
                .enableHttp2(true)
                .enableQuic(true)
                .build();

        Executor executor = Executors.newSingleThreadExecutor();
        UrlRequest.Callback callback = new MyUrlRequestCallback();
        UrlRequest.Builder builder = cronetEngine.newUrlRequestBuilder("https://quic.example.com:8443", callback, executor);
        UrlRequest urlRequest = builder.build();
        urlRequest.getStatus(new UrlRequest.StatusListener() {
            @Override
            public void onStatus(int status) {
                Log.e(TAG, status + " ");
            }
        });
        urlRequest.start();
    }

    private void callQuicCronet() {
        CronetEngine.Builder myBuilder = new CronetEngine.Builder(this);
        cronetEngine = myBuilder
                .enableHttpCache(CronetEngine.Builder.HTTP_CACHE_IN_MEMORY, 100 * 1024)
                .enableHttp2(true)
                .enableQuic(true)
                .addQuicHint("quic.tech", 8443, 8443)
                .build();

        Executor executor = Executors.newSingleThreadExecutor();
        UrlRequest.Callback callback = new MyUrlRequestCallback();
        UrlRequest.Builder builder = cronetEngine.newUrlRequestBuilder("https://quic.tech:8443", callback, executor);
        UrlRequest urlRequest = builder.build();
        urlRequest.getStatus(new UrlRequest.StatusListener() {
            @Override
            public void onStatus(int status) {
                Log.e(TAG, status + " ");
            }
        });
        urlRequest.start();
    }

We are able to connect without issue to the public QUIC endpoints above; for this local setup we have signed Let’s Encrypt certs and are using the following command line to serve a one line index.html from examples/htdocs:

python3 examples/http3_server.py --certificate certs/fullchain1.pem --private-key certs/privkey1.pem --host quic.example.com --port 8443 -v -q quiclog "demo:app"

Any ideas?

Thanks in advance!