Rejected, but with error 0x106 where the specification requires 0x201. The violation was detected; the code reported is wrong.
The client did something the clause forbids, or failed to do what it requires.
What was measured
- Client
- xquic — Alibaba xquic + BoringSSL, 2060a44
- Test
- Encoder stream setting a dynamic table capacity above the client's limit —
h-qpack-encoder-overflow - Clause
- RFC 9204 §4.3.1, §6 (MUST)
- Class
- correctness — Rejected something invalid, with the code the RFC names.
- Required behaviour
- Close the connection with QPACK_ENCODER_STREAM_ERROR (0x201). §4.3.1 says the new capacity "MUST be lower than or equal to the limit" the decoder advertised, and that a decoder "MUST treat a new dynamic table capacity value that exceeds this limit as a connection error of type QPACK_ENCODER_STREAM_ERROR". Unlike the other two dynamic-table tests, this one runs against every client, because the capacity asked for is computed from the one that client advertised: one byte more, whatever it said. It was a fixed 4096 until 2026-09-20, which exceeded the zero every client then advertised and would have exceeded nothing at all for a client that granted a 4096-byte table.
- Measured
- 2026-10-27
Reproduce it
The suite is the judge, so the reproduction is to point the same client at the same test and let the server report what it saw.
SESSION=$(curl -sX POST https://conformance.pqcrypta.com/session | jq -r .id)
# then drive xquic at the test URL and read the verdict:
curl -s https://conformance.pqcrypta.com/report/$SESSION.json | jq '.results["h-qpack-encoder-overflow"]'