Closes the highest-priority Tier 1 gap. Without this, a from-scratch
client can't learn any peers exist; known_destinations stays empty and
every outbound message fails at recall(dest_hash).
SPEC.md §4.5 (new): announce validation rules with full citations to
RNS/Identity.py::validate_announce (line 496) and the dispatch path in
RNS/Transport.py:1623-2024. Covers the body parse with context_flag
branch, signed_data reconstruction (including the empty-bytes-not-absent
ratchet rule), Ed25519 signature verification, dest_hash recomputation,
public-key collision rejection, blackhole list, cache update order
(known_destinations -> known_ratchets -> path_table), PATH_RESPONSE
distinction, and the implementation-private SHOULD rules around
ingress rate limiting, random_blob history caps, and self-announce
filtering.
flows/receive-announce.md: chronological walk through 9 steps from
deframing to handler dispatch, with the cheap-pre-filter design
(signature-checked-then-counted) called out, the burst-active ingress
limiter explained against IC_BURST_FREQ_NEW=6Hz / IC_BURST_FREQ=35Hz,
the path-table decision tree, and the announce_handlers fan-out with
aspect_filter and PATH_RESPONSE filtering. Ends with a wire-byte
diagram and a per-step source map.
Two side fixes found while drafting:
- SPEC.md §4.1 had random_hash described as "10 random bytes". It's
actually random_hash = get_random_hash()[0:5] + int(time.time()).to_bytes(5, "big")
per RNS/Destination.py:282. Transit relays parse the trailing 5
bytes via timebase_from_random_blob (RNS/Transport.py:3100) for
replay-ordering decisions.
- SPEC.md §2.5 contexts table was missing PATH_RESPONSE = 0x0B
(RNS/Packet.py:83).
flows/README.md status table updated; the priority-ordered todo list
also gets a few new entries spun off from the work
(send-announce, forward-announce, send-resource, path-discovery flows).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
