xquic — Field line indexing a static table entry that does not exist

Inconclusive

The run did not exercise this test: the connection failed during the handshake (detected an error with protocol compliance that was not covered by more specific error codes in STREAMS_BLOCKED_BIDI: illegal frame type in handshake), so the client never reached the anomaly.

The run did not establish what this client does here — either it was never put in the situation, or its answer admits more than one reading. Not a failure, and never counted as one.

What was measured

Client

xquic — Alibaba xquic + BoringSSL, 2060a44

Test

Field line indexing a static table entry that does not exist — h-qpack-static-index-invalid

Clause

RFC 9204 §3.1, §4.5.2 (MUST)

Class

correctness — Rejected something invalid, with the code the RFC names.

Required behaviour

Close the connection with QPACK_DECOMPRESSION_FAILED (0x200). The static table has 99 entries, so index 200 refers to nothing, and §3.1 is explicit: "When the decoder encounters an invalid static table index in a field line representation, it MUST treat this as a connection error of type QPACK_DECOMPRESSION_FAILED." The static table needs no permission and never changes size, so unlike the dynamic-table tests this one applies to every client.

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=$(curl -sX POST https://conformance.pqcrypta.com/session | jq -r .id)
# then drive xquic at the test URL and read the verdict:
curl -s https://conformance.pqcrypta.com/report/$SESSION.json | jq '.results["h-qpack-static-index-invalid"]'