Mirrors the IP-ID classifier for TCP ISN values: per-source-IP rolling
deque (maxlen=8) populated from each inbound SYN's tcp.seq, classified
on every emission. A 'random' verdict is the modern norm; 'incremental',
'zero', or 'constant' indicates legacy stacks or hand-rolled raw-socket
tooling — a strong fingerprint signal.
Active prober now also captures server_isn (single sample, not classified
in-flight; downstream consumers correlating multi-probe results can apply
seq_class.classify_sequence themselves).
Profiler rollup carries the latest non-'unknown' label into
attacker.tcp_fingerprint. Dedup key already covers isn_class from
the previous commit, so transitions emit cleanly.
UI surfaces ISN class as a colour-coded tag with a ⚠ glyph for
non-random verdicts, since they're the genuinely interesting case.
Adds a per-source-IP rolling sample buffer (deque, maxlen=8) for IP-ID
values seen on attacker SYNs and a stdlib-only classifier in
decnet/sniffer/seq_class.py. Each new SYN appends ip.id and re-classifies
the buffer; the result is logged on tcp_syn_fingerprint events alongside
sample count.
The dedup key now folds in ipid_class so a transition from 'unknown' to
a definitive verdict emits exactly one fresh event instead of being
suppressed by the old (os|options) key. Profiler rollup carries the
latest non-'unknown' label into attacker.tcp_fingerprint.
UI surfaces it as a colour-coded tag in the TCP STACK panel: random
neutral, incremental amber, zero/constant green (the strong signal).
Active prober now reads ip.tos from the SYN-ACK and emits tos/dscp/ecn
alongside the existing TTL/window/options fields. dscp is folded into the
fingerprint hash so different DSCP markings produce distinct signatures.
Passive sniffer logs the same three fields on tcp_syn_fingerprint events;
profiler rollup carries them into the attacker tcp_fingerprint snapshot;
AttackerDetail's TCP STACK panel now surfaces DSCP and ECN cells.
The ~30-signature hand-rolled p0f-lite table in decnet/sniffer/p0f.py
misses most real-world attackers (yesterday's SLOW SCAN being a
textbook case — 9 hours of events, 19 hits, os_guess = NULL). The
375-sig vendored p0f v2 DB was already there; this commit actually
calls it.
New resolution chain in sniffer_rollup:
1. Enabled OS-fingerprint providers (p0f-v2 default, via
DECNET_OSFP_PROVIDERS) tried in declared order. Provider with
highest-confidence match across all enabled sources wins.
2. Modal os_guess label from the sniffer's hand-rolled p0f.py.
Kept as fallback because v2's DB predates post-2006 kernels.
3. TTL bucket (linux / windows / embedded). Coarse but never wrong.
Wiring details:
- _match_via_osfp_providers: never raises — factory / provider
failures collapse to None and the chain falls through to the
old modal-label / TTL path. A corrupt .fp file or misconfigured
DECNET_OSFP_PROVIDERS must never wedge a profile rebuild.
- tcp_fp_context tracks whether the LATEST tcp_fp snapshot came
from a passive SYN ('syn' → p0f.fp) or an active prober probe
('synack' → p0fa.fp). Routes to the right sig list.
- initial-TTL normalisation via decnet.sniffer.p0f.initial_ttl.
Observation's TTL may be N hops below the OS's initial; v2
signatures match on the canonical bucket.
Soft-field semantics on Signature.score(): df and total_len are now
skip-checked when the observation is missing them. Sniffer doesn't
currently emit either SD field; a literal-constraint sig
shouldn't hard-reject a match solely because of upstream
incompleteness. Hard fields (window, ttl, options_sig, quirks)
still hard-reject on absent/mismatched input — those are the real
discriminators. Promote df / total_len back to hard the moment the
sniffer starts emitting them.
+2 integration tests on TestSnifferRollup, +2 soft-field tests on
test_signature. Full regression: 166 tests across tests/prober/osfp
+ tests/profiler all green.
Parse RFC 4253 §4.2 identification strings from the first attacker→decky
data segment on TCP/22; emit ssh_client_banner syslog events and bus
fan-out. Profiler's sniffer_rollup dedupes observed banners into a new
AttackerBehavior.ssh_client_banners JSON column.
Closes gap #3 from SIGNAL_CAPTURE_AUDIT.md.
Prober already emits kex_algorithms in hassh_fingerprint syslog events, but
the raw ordered list was only queryable via the generic bounty store. Add a
dedicated AttackerBehavior.kex_order_raw column (TEXT, JSON list) so
post-v1 KEX-order fingerprinting has a typed, indexable home.
Pipeline:
- sniffer_rollup() now consumes hassh_fingerprint events and collects
distinct kex_algorithms strings across ports.
- build_behavior_record() JSON-encodes the list (NULL when empty).
- sqlmodel_repo._deserialize_behavior() parses it back into a list.
Closes pre-v1 gap #1 from SIGNAL_CAPTURE_AUDIT.md.
Break the 603-line behavioral.py into timing/classify/tools/phases/fingerprint
sibling modules plus a slim orchestrator. Public API unchanged: behavioral.py
re-exports every previously-exposed symbol, so worker.py and existing tests
keep working with zero import changes.
No behavior change; all 64 profiler tests pass.
