Rejected with the required error code 0x201.
The client did what the clause requires.
What was measured
- Client
- neqo — neqo (Firefox), 0.31.1
- Test
- Encoder instruction naming a static index that does not exist —
h-qpack-encoder-bad-name-index - Clause
- RFC 9204 §3.1, §4.3.2 (MUST)
- Class
- correctness — Rejected something invalid, with the code the RFC names.
- Required behaviour
- Close the connection with QPACK_ENCODER_STREAM_ERROR (0x201). The same bad index means different things depending on where it arrives, and §3.1 says both: on a field line it is QPACK_DECOMPRESSION_FAILED, and "if this index is received on the encoder stream, this MUST be treated as a connection error of type QPACK_ENCODER_STREAM_ERROR". Paired deliberately with the field-line version on the neighbouring port: a client that answers both with the same code has collapsed a distinction the specification draws twice in one paragraph.
- Measured
- 2026-09-18
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=$(curl -sX POST https://conformance.pqcrypta.com/session | jq -r .id)
# then drive neqo at the test URL and read the verdict:
curl -s https://conformance.pqcrypta.com/report/$SESSION.json | jq '.results["h-qpack-encoder-bad-name-index"]'