feat(ttp): E.3.18b worker fans session-ended payloads into per-command events

R0001–R0030 declare `applies_to: [command]` and match per command, not
per session. The worker now translates one `attacker.session.ended`
payload carrying a `commands: list` into:
  - one source_kind="session" event (behavioral / cross-event lifters)
  - one source_kind="command" event per command (RuleEngineTagger)

Both string and dict command shapes are accepted; dicts contribute
their `id` / `uuid` / `command_id` as the per-command source_id so
the deterministic `compute_tag_uuid` keeps replays idempotent. Tags
from session + per-command dispatch are aggregated into a single
`ttp.tagged` envelope per upstream session.
This commit is contained in:
2026-05-02 01:27:37 -04:00
parent 44ade3eb63
commit 65435f1427
2 changed files with 211 additions and 32 deletions

View File

@@ -113,6 +113,76 @@ def _span(name: str, **attrs: Any) -> Iterator[Any]:
yield span
def _build_events(topic: str, payload: dict[str, Any]) -> list[TaggerEvent]:
"""Translate one bus payload into one OR MORE :class:`TaggerEvent`s.
A single ``attacker.session.ended`` event carries a *bag* of commands
issued during that session. The R0001R0030 rule pack matches per
command, not per session, so we fan the session payload out into
one ``source_kind="command"`` event per command (in addition to the
session-level event itself for behavioral / cross-event rules).
The session event still fires; lifters that key on
``source_kind="session"`` (e.g. :class:`BehavioralLifter`) see it.
Lifters keyed on ``source_kind="command"`` (the
:class:`RuleEngineTagger` shell-rule path) see one event per
command. Idempotent inserts keep duplicate emits safe.
Recognized payload shapes for the per-command fan-out:
* ``commands: list[str]`` — bare command strings.
* ``commands: list[{"command_text": str, "id": str?, ...}]`` — dicts
with at least a ``command_text`` field; any ``id`` / ``uuid`` /
``command_id`` becomes the ``source_id`` for idempotency.
"""
base = _build_event(topic, payload)
if base is None:
return []
out = [base]
if base.source_kind != "session":
return out
commands = payload.get("commands")
if not isinstance(commands, list):
return out
for idx, cmd in enumerate(commands):
cmd_event = _build_command_event(base, cmd, idx)
if cmd_event is not None:
out.append(cmd_event)
return out
def _build_command_event(
base: TaggerEvent, cmd: Any, idx: int,
) -> TaggerEvent | None:
if isinstance(cmd, str):
text = cmd
cmd_id = f"{base.source_id}#cmd{idx}"
cmd_payload: dict[str, Any] = {"command_text": text}
elif isinstance(cmd, dict):
text_obj = cmd.get("command_text") or cmd.get("text")
if not isinstance(text_obj, str):
return None
cmd_id_obj = (
cmd.get("id")
or cmd.get("uuid")
or cmd.get("command_id")
or f"{base.source_id}#cmd{idx}"
)
cmd_id = str(cmd_id_obj)
cmd_payload = {**cmd, "command_text": text_obj}
else:
return None
return TaggerEvent(
source_kind="command",
source_id=cmd_id,
attacker_uuid=base.attacker_uuid,
identity_uuid=base.identity_uuid,
session_id=base.session_id,
decky_id=base.decky_id,
payload=cmd_payload,
)
def _build_event(topic: str, payload: dict[str, Any]) -> TaggerEvent | None:
"""Translate one bus payload into a :class:`TaggerEvent`.
@@ -288,39 +358,47 @@ async def _process_event(
replay of the same upstream event hits the idempotent
``INSERT OR IGNORE`` and writes zero rows → publishes zero events.
"""
tagger_event = _build_event(topic, event.payload)
if tagger_event is None:
tagger_events = _build_events(topic, event.payload)
if not tagger_events:
return
with _span(
"ttp.worker.tick",
topic=topic,
source_kind=tagger_event.source_kind,
):
try:
tags = await tagger.tag(tagger_event)
except Exception: # noqa: BLE001
# Composite + TolerantTagger normally swallow per-lifter
# blow-ups already; this is the worst-case backstop so a
# single bad event can't take down the whole loop.
log.exception(
"ttp worker: tagger raised on topic=%r", topic,
)
return
if not tags:
return
try:
inserted = await repo.insert_tags(tags)
except Exception: # noqa: BLE001
log.exception(
"ttp worker: insert_tags failed on topic=%r", topic,
)
return
if inserted <= 0:
# Idempotent re-eval — the loop-prevention invariant
# forbids publishing here.
return
if bus is not None:
await _publish_tagged(bus, tags)
# Aggregate tags across the session-level event AND any per-command
# fan-out so the bus publish sees a single ttp.tagged envelope per
# upstream session. The repository's INSERT OR IGNORE keeps replay
# idempotent across the entire batch.
all_tags: list[TTPTag] = []
for tagger_event in tagger_events:
with _span(
"ttp.worker.tick",
topic=topic,
source_kind=tagger_event.source_kind,
):
try:
tags = await tagger.tag(tagger_event)
except Exception: # noqa: BLE001
# Composite + TolerantTagger normally swallow per-lifter
# blow-ups already; this is the worst-case backstop so a
# single bad event can't take down the whole loop.
log.exception(
"ttp worker: tagger raised on topic=%r source_kind=%r",
topic, tagger_event.source_kind,
)
continue
all_tags.extend(tags)
if not all_tags:
return
try:
inserted = await repo.insert_tags(all_tags)
except Exception: # noqa: BLE001
log.exception(
"ttp worker: insert_tags failed on topic=%r", topic,
)
return
if inserted <= 0:
# Idempotent re-eval — the loop-prevention invariant
# forbids publishing here.
return
if bus is not None:
await _publish_tagged(bus, all_tags)
async def _publish_tagged(bus: BaseBus, tags: list[TTPTag]) -> None:

View File

@@ -0,0 +1,101 @@
"""E.3.18b — Worker fans `attacker.session.ended` into per-command events.
Pins the fan-out from ``development/TTP_TAGGING.md`` §"Worker shape" +
§"One event maps to many techniques": the R0001R0030 shell rules
declare ``applies_to: [command]`` and match per command, not per
session. The worker translates one ``session.ended`` payload carrying a
``commands: list`` into:
[TaggerEvent(source_kind="session", ...),
TaggerEvent(source_kind="command", source_id="<id>", ...) * N]
so behavioral / cross-event lifters still see the session view AND the
:class:`RuleEngineTagger` (commit 3) sees one ``command`` event per
shell command.
"""
from __future__ import annotations
from decnet.bus import topics as _topics
from decnet.ttp.worker import _build_events
_TOPIC = _topics.attacker(_topics.ATTACKER_SESSION_ENDED)
def _payload_with(commands: object) -> dict[str, object]:
return {
"session_id": "sess-42",
"attacker_uuid": "att-1",
"identity_uuid": "id-1",
"decky_id": "decky-7",
"commands": commands,
}
def test_session_without_commands_emits_only_session_event() -> None:
events = _build_events(_TOPIC, {"session_id": "sess-42"})
assert len(events) == 1
assert events[0].source_kind == "session"
def test_session_with_string_commands_fans_out_one_per_command() -> None:
events = _build_events(
_TOPIC, _payload_with(["whoami", "id", "uname -a"]),
)
assert events[0].source_kind == "session"
cmd_events = [e for e in events if e.source_kind == "command"]
assert len(cmd_events) == 3
assert [e.payload["command_text"] for e in cmd_events] == [
"whoami", "id", "uname -a",
]
# Per-command source_id must be unique so INSERT OR IGNORE on
# compute_tag_uuid produces a distinct row per command.
assert len({e.source_id for e in cmd_events}) == 3
def test_session_with_dict_commands_preserves_id_for_idempotency() -> None:
events = _build_events(_TOPIC, _payload_with([
{"id": "cmd-aaa", "command_text": "whoami"},
{"command_id": "cmd-bbb", "command_text": "id"},
{"uuid": "cmd-ccc", "command_text": "uname -a"},
]))
cmd_events = [e for e in events if e.source_kind == "command"]
assert [e.source_id for e in cmd_events] == ["cmd-aaa", "cmd-bbb", "cmd-ccc"]
def test_session_with_dict_commands_falls_back_to_synthetic_id() -> None:
events = _build_events(
_TOPIC, _payload_with([{"command_text": "whoami"}]),
)
cmd_events = [e for e in events if e.source_kind == "command"]
assert len(cmd_events) == 1
assert cmd_events[0].source_id.endswith("#cmd0")
def test_command_event_inherits_session_identifiers() -> None:
events = _build_events(_TOPIC, _payload_with(["whoami"]))
cmd = next(e for e in events if e.source_kind == "command")
assert cmd.attacker_uuid == "att-1"
assert cmd.identity_uuid == "id-1"
assert cmd.session_id == "sess-42"
assert cmd.decky_id == "decky-7"
def test_malformed_command_entries_are_skipped() -> None:
events = _build_events(_TOPIC, _payload_with([
"ok",
42, # not a string/dict
{"no_text_field": True}, # dict without command_text
{"command_text": "good"},
]))
cmd_events = [e for e in events if e.source_kind == "command"]
assert [e.payload["command_text"] for e in cmd_events] == ["ok", "good"]
def test_non_session_topic_is_unchanged_by_fanout() -> None:
events = _build_events(
_topics.attacker(_topics.ATTACKER_INTEL_ENRICHED),
{"attacker_uuid": "att-1", "verdict": "abuser"},
)
assert len(events) == 1
assert events[0].source_kind == "intel"