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feat(ttp): E.3.7 RuleEngine — evaluate + atomic-swap watch_store

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Implements the rule engine body left empty at contract phase: evaluate()
dispatches by source_kind through self._by_kind, runs the rule's match
spec against event.payload, and emits one TTPTag per emits entry.
watch_store() loads the initial corpus from RuleStore.load_compiled,
then drains subscribe_changes, applying definition changes via
single-statement dict assignment (atomic swap, GIL-atomic to readers)
and state changes via NamedTuple._replace on the existing CompiledRule.

Why: with the FS + DB stores in place (E.3.5/E.3.6), the engine is the
last piece of the rule plane. Lifters (E.3.9–E.3.13) consume the
engine; the worker bootstrap (E.3.14) wires watch_store into the
asyncio event loop. After this commit a CompositeTagger constructed
with a RuleEngine + a populated rules dir will produce real tags.

Notes:
- CompiledRule.emits extended to 4-tuple
  (technique_id, sub_technique_id, tactic, confidence). Tactic + confidence
  ride per-emit so a single rule can carry multiple precision targets
  (the "one event maps to many techniques" property). Compile helpers in
  both backends extract them from the YAML emits dict; missing tactic
  or confidence is a deploy-time error.
- v0 match operator is "pattern" (regex). The field defaults per
  source_kind (command_text / raw_url / subject / verdict / …) and is
  overridable via match.field. Future ops (contains, equals, in_set)
  extend _match_event without touching the engine surface.
- Confidence model: rules with state="clipped" + confidence_max set
  cap the per-emit confidence downward; clipped is a soft suppress, not
  a hard skip. Disabled rules are skipped wholly; expires_at past is
  re-checked at evaluate as defense-in-depth (the store auto-reverts,
  but a racing read between expiry and revert must not fire the rule).
- _span(name, **attrs) helper in engine + both stores short-circuits on
  decnet.telemetry._ENABLED — matches the project's @traced /
  wrap_repository zero-overhead-when-disabled pattern instead of relying
  solely on the no-op tracer indirection.
- Late-bound tracer (telemetry.get_tracer called per-span, not at
  module load) so test_tracing's monkeypatch reaches the production
  code path.

xfails flipped: tests/ttp/test_rule_engine.py multi-emit fan-out +
rule_version-collision-via-engine; tests/ttp/test_multi_mapping.py
N×M engine fan-out + idempotent replay; tests/ttp/test_tracing.py
ttp.eval span hierarchy + ttp.rule.fire span attributes.

Tests: 214 passed, 19 xfailed (gated on E.3.8 lifters / rule pack /
worker bootstrap).
mypy: clean on prod code; pre-existing test-stub arg-type warnings
unchanged.
This commit is contained in:
anti
2026-05-01 08:49:15 -04:00
parent 8a93ee3129
commit ed3f340ea8
10 changed files with 679 additions and 150 deletions
Download Patch File Download Diff File Expand all files Collapse all files

299
decnet/ttp/impl/rule_engine.py
View File

@@ -27,12 +27,17 @@ file is importable before that step lands.
"""
from __future__ import annotations
import re
from collections.abc import Iterator
from contextlib import contextmanager
from typing import TYPE_CHECKING, Any, NamedTuple
from pydantic import BaseModel, Field
from decnet import telemetry as _telemetry
from decnet.logging import get_logger
from decnet.ttp.base import TaggerEvent
from decnet.web.db.models.ttp import TTPTag
from decnet.web.db.models.ttp import TTPTag, compute_tag_uuid
if TYPE_CHECKING:
# Store contracts ship in E.1.11. Forward-referenced under
@@ -40,7 +45,42 @@ if TYPE_CHECKING:
# without creating a circular shape dependency on a not-yet-shipped
# subpackage. Concrete construction happens at the worker layer
# (E.1.7) where both halves are in scope.
from decnet.ttp.store.base import RuleState, RuleStore
from decnet.ttp.store.base import RuleChange, RuleState, RuleStore
_log = get_logger("ttp.engine")
@contextmanager
def _span(name: str, **attrs: Any) -> Iterator[Any]:
"""Span context manager gated on ``DECNET_DEVELOPER_TRACING``.
Same shape as the helpers in :mod:`decnet.ttp.store.impl.filesystem`
/ :mod:`decnet.ttp.store.impl.database`: zero per-call overhead when
tracing is off (single attribute lookup, then yield ``None``);
late-bound tracer when on so the test_tracing monkeypatch reaches
us. Modeled on the project's ``@traced`` / ``wrap_repository``
no-overhead-when-disabled pattern.
"""
if not _telemetry._ENABLED:
yield None
return
tracer = _telemetry.get_tracer("ttp.engine")
with tracer.start_as_current_span(name) as span:
for key, value in attrs.items():
try:
span.set_attribute(key, value)
except (TypeError, ValueError):
continue
yield span
# ATT&CK release stamped on every emitted tag. Pinned at the engine
# layer rather than per-rule because rule authors don't manage ATT&CK
# matrix drift; the engine owns that. Bumping this value invalidates
# tag UUID continuity across deploys, so the bump must land alongside a
# documented ATT&CK upgrade per TTP_TAGGING.md §"Hard parts §8".
_ATTACK_RELEASE: str = "v15.1"
class CompiledRule(NamedTuple):
@@ -71,9 +111,11 @@ class CompiledRule(NamedTuple):
#: phase (E.3). Kept ``dict[str, Any]`` here rather than typed so
#: rule authors can extend match operators without touching the ABC.
match_spec: dict[str, Any]
#: ``((technique_id, sub_technique_id | None), ...)``. Tuple, not
#: list, so the record stays hashable.
emits: tuple[tuple[str, str | None], ...]
#: ``((technique_id, sub_technique_id | None, tactic, confidence), ...)``
#: per emit. Tuple-of-tuples, not list, so the record stays hashable.
#: One YAML rule may emit N tags from a single match — see
#: TTP_TAGGING.md §"One event maps to many techniques".
emits: tuple[tuple[str, str | None, str, float], ...]
#: Names of evidence keys the rule populates on emitted tags.
evidence_fields: tuple[str, ...]
#: Operational state stamped in by the store at compile time.
@@ -95,7 +137,13 @@ class RuleSchema(BaseModel):
name: str
applies_to: list[str]
match: dict[str, Any]
emits: list[dict[str, str]]
#: ``[{"tactic": "TA0007", "technique_id": "T1083",
#: "sub_technique_id": "T1083.001"?, "confidence": 0.85}, ...]``
#: Per-emit tactic + confidence ride here so a single rule can carry
#: multiple precision targets (the "one event maps to many techniques"
#: case from TTP_TAGGING.md, including different confidences per
#: technique on the same match).
emits: list[dict[str, Any]]
evidence_fields: list[str] = Field(default_factory=list)
@@ -116,30 +164,245 @@ class RuleEngine:
def __init__(self, store: "RuleStore") -> None:
self._store = store
# ``source_kind`` → list of compiled rules that claim it.
# Empty here; populated by :meth:`watch_store` once the store
# contract lands (E.1.11).
# Replaced wholesale on per-rule changes via watch_store(); the
# GIL-atomic dict assignment is the "atomic swap" pin from
# TTP_TAGGING.md §"Atomic swap" / E.2.14b.
self._by_kind: dict[str, list[CompiledRule]] = {}
# Mirror keyed by rule_id for definition+state restamping.
# Same atomicity contract: replacement, never in-place mutation.
self._by_rule: dict[str, CompiledRule] = {}
async def evaluate(self, event: TaggerEvent) -> list[TTPTag]:
"""Return zero or more tags produced by rules matching *event*.
Empty in the contract phase. The impl phase fans the event out
to ``self._by_kind[event.source_kind]`` and merges results.
Dispatches by ``event.source_kind``; for each rule whose
``applies_to`` set covers the kind, runs the match spec against
``event.payload`` and emits one :class:`TTPTag` per ``emits``
entry. Confidence is the per-emit base scaled by the rule's
:class:`RuleState.confidence_max` ceiling (no-op when ``None``).
Disabled rules are skipped; the store auto-reverts expired
states, but the engine double-checks ``expires_at`` as
defense-in-depth.
"""
rules = self._by_kind.get(event.source_kind, [])
if not rules:
return []
with _span(
"ttp.eval",
attacker_uuid=str(event.attacker_uuid or ""),
identity_uuid=str(event.identity_uuid or ""),
source_kind=event.source_kind,
):
return _evaluate_rules(rules, event)
async def watch_store(self) -> None:
"""Subscribe to per-rule changes and atomically swap them in.
Reads from :meth:`RuleStore.subscribe_changes`. Each yielded
change is one rule_id; the engine recompiles that rule alone
and replaces the corresponding entries in the dispatch index
in a single assignment. Never returns under normal operation —
the worker cancels it during shutdown.
Empty in the contract phase.
Loads the initial corpus from :meth:`RuleStore.load_compiled`,
builds the dispatch index, then drains
:meth:`RuleStore.subscribe_changes` forever. Each ``definition``
change replaces the affected rule wholesale; each ``state``
change re-stamps the existing :class:`CompiledRule`'s ``state``
field via NamedTuple ``_replace`` (single dict assignment, no
in-place mutation).
"""
return None
# Forward import — avoids the contract-phase circular shape
# dependency captured by the TYPE_CHECKING block above.
from decnet.ttp.store.base import RuleState # noqa: PLC0415
compiled = await self._store.load_compiled()
for rule in compiled:
self._install(rule)
async for change in self._store.subscribe_changes():
try:
self._apply_change(change, RuleState)
except Exception: # noqa: BLE001
_log.exception(
"ttp.engine: rule change apply failed rule_id=%s",
change.rule_id,
)
# ── Internals ───────────────────────────────────────────────────
def _install(self, rule: CompiledRule) -> None:
"""Atomic-swap install of one compiled rule.
Empty ``applies_to`` + empty ``emits`` is the deletion sentinel
used by both backends — drop the rule from the index instead of
adding a no-op entry.
"""
if not rule.applies_to and not rule.emits:
self._evict(rule.rule_id)
return
self._by_rule[rule.rule_id] = rule
for kind in rule.applies_to:
current = self._by_kind.get(kind, [])
replaced = [r for r in current if r.rule_id != rule.rule_id]
replaced.append(rule)
# Single dict assignment — GIL-atomic to readers.
self._by_kind[kind] = replaced
def _evict(self, rule_id: str) -> None:
existing = self._by_rule.pop(rule_id, None)
if existing is None:
return
for kind in existing.applies_to:
current = self._by_kind.get(kind, [])
replaced = [r for r in current if r.rule_id != rule_id]
self._by_kind[kind] = replaced
def _apply_change(
self, change: "RuleChange", state_cls: type,
) -> None:
if change.change_kind == "definition":
value = change.new_value
if isinstance(value, CompiledRule):
self._install(value)
return
# state change
existing = self._by_rule.get(change.rule_id)
if existing is None or not isinstance(change.new_value, state_cls):
return
new_state = change.new_value # narrowed by isinstance above
# NamedTuple._replace returns a fresh frozen tuple — single
# dict assignment swaps it in atomically.
restamped = existing._replace(state=new_state) # type: ignore[arg-type]
self._by_rule[change.rule_id] = restamped
for kind in restamped.applies_to:
current = self._by_kind.get(kind, [])
replaced = [r for r in current if r.rule_id != change.rule_id]
replaced.append(restamped)
self._by_kind[kind] = replaced
def _state_active(state: "RuleState") -> bool:
"""A rule fires iff its state isn't ``disabled``. ``clipped`` rules
still fire — the clip caps confidence, doesn't suppress.
"""
if state.state == "disabled":
return False
if state.expires_at is not None:
# Defense-in-depth: stores auto-revert expired states, but a
# racing read between expiry and revert must not fire a rule
# the operator told us was off.
from datetime import datetime, timezone # noqa: PLC0415
expires = state.expires_at
if expires.tzinfo is None:
expires = expires.replace(tzinfo=timezone.utc)
if expires < datetime.now(tz=timezone.utc):
return False
return True
def _match_event(rule: CompiledRule, event: TaggerEvent) -> bool:
"""Run the rule's match spec against ``event.payload``.
For v0 the only operator is ``pattern`` — a regex against a
payload field. The field name comes from ``match_spec["field"]``
if present, otherwise the per-source-kind default
(``command_text`` for ``command``, ``raw_url`` for
``http_request``, etc.). A future PR can extend this to
``contains``, ``equals``, ``in_set`` without touching the engine
surface — only this function changes.
"""
spec = rule.match_spec
pattern = spec.get("pattern")
if pattern is None:
return False
field = spec.get("field") or _default_field(event.source_kind)
if field is None:
return False
haystack = event.payload.get(field)
if not isinstance(haystack, str):
return False
try:
return re.search(pattern, haystack) is not None
except re.error:
# Malformed regex made it past schema validation — log and
# don't fire. The deploy-time hook (load_compiled) catches
# most of these; this path is the runtime fallback.
_log.warning(
"ttp.engine: bad regex in rule %s: %r", rule.rule_id, pattern,
)
return False
def _default_field(source_kind: str) -> str | None:
return _DEFAULT_MATCH_FIELD.get(source_kind)
# Per-source_kind default field for the ``pattern`` operator. New
# source_kinds can override via ``match.field`` in the YAML rule.
_DEFAULT_MATCH_FIELD: dict[str, str] = {
"command": "command_text",
"http_request": "raw_url",
"email": "subject",
"intel": "verdict",
"canary_fingerprint": "ua_signature",
"auth_attempt": "username",
"payload": "payload_text",
}
def _evaluate_rules(
rules: list[CompiledRule], event: TaggerEvent,
) -> list[TTPTag]:
out: list[TTPTag] = []
for rule in rules:
if not _state_active(rule.state):
continue
if not _match_event(rule, event):
continue
ceiling = (
rule.state.confidence_max
if rule.state.state == "clipped"
and rule.state.confidence_max is not None
else 1.0
)
with _span(
"ttp.rule.fire",
rule_id=rule.rule_id,
rule_version=rule.rule_version,
) as span:
for technique_id, sub_technique_id, tactic, base_conf in rule.emits:
if span is not None:
try:
span.set_attribute("technique_id", technique_id)
except (TypeError, ValueError):
pass
confidence = min(base_conf, base_conf * ceiling) if ceiling < 1.0 else base_conf
tag_uuid = compute_tag_uuid(
source_kind=event.source_kind,
source_id=event.source_id,
rule_id=rule.rule_id,
rule_version=rule.rule_version,
technique_id=technique_id,
sub_technique_id=sub_technique_id,
)
evidence: dict[str, Any] = {
field: event.payload.get(field)
for field in rule.evidence_fields
if field in event.payload
}
out.append(TTPTag(
uuid=tag_uuid,
source_kind=event.source_kind,
source_id=event.source_id,
attacker_uuid=event.attacker_uuid,
identity_uuid=event.identity_uuid,
session_id=event.session_id,
decky_id=event.decky_id,
tactic=tactic,
technique_id=technique_id,
sub_technique_id=sub_technique_id,
confidence=confidence,
rule_id=rule.rule_id,
rule_version=rule.rule_version,
evidence=evidence,
attack_release=_ATTACK_RELEASE,
))
return out
__all__ = [

82
decnet/ttp/store/impl/database.py
View File

@@ -37,7 +37,8 @@ The master-side filesystem→DB sync helper is
from __future__ import annotations
import asyncio
from collections.abc import AsyncIterator
from collections.abc import AsyncIterator, Iterator
from contextlib import contextmanager
from dataclasses import replace
from datetime import datetime, timezone
from typing import TYPE_CHECKING, Any, Final
@@ -64,8 +65,26 @@ if TYPE_CHECKING:
_log = get_logger("ttp.store.database")
def _tracer() -> Any:
return _telemetry.get_tracer("ttp.store")
@contextmanager
def _span(name: str, **attrs: Any) -> Iterator[Any]:
"""Span context manager gated on ``DECNET_DEVELOPER_TRACING``.
Mirrors the helper in :mod:`decnet.ttp.store.impl.filesystem`: zero
per-call overhead when tracing is off, late-bound tracer when on
(so ``test_tracing.py``'s monkeypatch of
:func:`decnet.telemetry.get_tracer` reaches us).
"""
if not _telemetry._ENABLED:
yield None
return
tracer = _telemetry.get_tracer("ttp.store")
with tracer.start_as_current_span(name) as span:
for key, value in attrs.items():
try:
span.set_attribute(key, value)
except (TypeError, ValueError):
continue
yield span
def _utcnow() -> datetime:
@@ -100,27 +119,35 @@ def _row_to_state(row: TTPRuleState) -> RuleState:
)
def _safe_set_attrs(span: Any, **attrs: Any) -> None:
setter = getattr(span, "set_attribute", None)
if setter is None:
return
for key, value in attrs.items():
try:
setter(key, value)
except (TypeError, ValueError):
continue
def _compile_one(parsed: RuleSchema, state: RuleState) -> CompiledRule:
emits: list[tuple[str, str | None]] = []
"""Mirror of :func:`decnet.ttp.store.impl.filesystem._compile_one`.
Same 4-tuple emits shape so a rule round-trips identically through
either backend. Kept as a sibling rather than imported from the FS
module to avoid dragging the asyncinotify import onto non-Linux
hosts that only use the database backend.
"""
emits: list[tuple[str, str | None, str, float]] = []
for entry in parsed.emits:
tid = entry.get("technique_id")
if not tid:
raise ValueError(
f"rule {parsed.rule_id}: every emits entry needs technique_id",
)
sub = entry.get("sub_technique_id") or None
emits.append((tid, sub))
sub_raw = entry.get("sub_technique_id")
sub = sub_raw if sub_raw else None
tactic = entry.get("tactic")
if not tactic:
raise ValueError(
f"rule {parsed.rule_id}: emit for {tid} needs a tactic",
)
confidence_raw = entry.get("confidence")
if confidence_raw is None:
raise ValueError(
f"rule {parsed.rule_id}: emit for {tid} needs a confidence",
)
confidence = float(confidence_raw)
emits.append((str(tid), sub, str(tactic), confidence))
return CompiledRule(
rule_id=parsed.rule_id,
rule_version=parsed.rule_version,
@@ -146,9 +173,13 @@ def _yaml_to_compiled(yaml_text: str, state: RuleState) -> CompiledRule:
def _compiled_to_yaml(compiled: CompiledRule) -> str:
"""Serialize a :class:`CompiledRule` back to a YAML rule body for
master-side filesystem→DB sync. Mirrors :class:`RuleSchema`."""
emits: list[dict[str, str]] = []
for technique_id, sub in compiled.emits:
entry: dict[str, str] = {"technique_id": technique_id}
emits: list[dict[str, Any]] = []
for technique_id, sub, tactic, confidence in compiled.emits:
entry: dict[str, Any] = {
"technique_id": technique_id,
"tactic": tactic,
"confidence": confidence,
}
if sub:
entry["sub_technique_id"] = sub
emits.append(entry)
@@ -275,17 +306,16 @@ class DatabaseRuleStore(RuleStore):
state: RuleState,
set_by: str,
) -> None:
with _tracer().start_as_current_span("ttp.rule.state.change") as span:
_safe_set_attrs(
span,
with _span(
"ttp.rule.state.change",
rule_id=rule_id,
state=state.state,
set_by=set_by,
)
):
stamped = replace(state, set_by=set_by, set_at=_utcnow())
with _tracer().start_as_current_span("ttp.store.write_state"):
with _span("ttp.store.write_state"):
await self._upsert_state_row(rule_id, stamped)
with _tracer().start_as_current_span("ttp.rule.publish"):
with _span("ttp.rule.publish"):
await self._emit_change(
RuleChange("state", rule_id, stamped),
bus_topic=_topics.ttp_rule_state(rule_id),

86
decnet/ttp/store/impl/filesystem.py
View File

@@ -41,7 +41,8 @@ from __future__ import annotations
import asyncio
import re
import sys
from collections.abc import AsyncIterator
from collections.abc import AsyncIterator, Iterator
from contextlib import contextmanager
from dataclasses import replace
from datetime import datetime, timezone
from pathlib import Path
@@ -64,11 +65,30 @@ if TYPE_CHECKING:
_log = get_logger("ttp.store.filesystem")
def _tracer() -> Any:
@contextmanager
def _span(name: str, **attrs: Any) -> Iterator[Any]:
"""Span context manager gated on ``DECNET_DEVELOPER_TRACING``.
When tracing is off, yields ``None`` after a single attribute
lookup — matches the project's ``@traced`` / ``wrap_repository``
pattern of zero per-call overhead in the disabled case. When on,
opens an OTEL span via the (late-bound) tracer and applies
*attrs* defensively.
"""
if not _telemetry._ENABLED:
yield None
return
# Late binding: tests monkeypatch ``decnet.telemetry.get_tracer``
# at fixture setup; capturing the tracer at import time would freeze
# the no-op tracer into the module forever.
return _telemetry.get_tracer("ttp.store")
# at fixture setup; capturing the tracer at import time would
# freeze the no-op tracer into the module forever.
tracer = _telemetry.get_tracer("ttp.store")
with tracer.start_as_current_span(name) as span:
for key, value in attrs.items():
try:
span.set_attribute(key, value)
except (TypeError, ValueError):
continue
yield span
# ── Filename allowlist ──────────────────────────────────────────────
@@ -110,20 +130,6 @@ def _utcnow() -> datetime:
return datetime.now(tz=timezone.utc)
def _safe_set_attrs(span: Any, **attrs: Any) -> None:
"""Best-effort attribute setter on either real OTEL or no-op span."""
setter = getattr(span, "set_attribute", None)
if setter is None:
return
for key, value in attrs.items():
try:
setter(key, value)
except (TypeError, ValueError):
# OTEL rejects un-serializable types; not load-bearing for
# store correctness. Skip the attribute, keep the span.
continue
def _is_expired(state: RuleState, now: datetime) -> bool:
if state.expires_at is None:
return False
@@ -136,19 +142,36 @@ def _is_expired(state: RuleState, now: datetime) -> bool:
def _compile_one(parsed: RuleSchema, state: RuleState) -> CompiledRule:
"""Translate a validated :class:`RuleSchema` into a :class:`CompiledRule`.
Each ``emits`` entry contributes a 4-tuple
``(technique_id, sub_technique_id, tactic, confidence)`` —
consumed by :class:`RuleEngine` when fanning a single match into
one tag per technique. Missing tactic / confidence in the YAML is
a deploy-time error: a tag without a tactic can't render in the
Navigator export, and a missing confidence has no sane default.
The match spec is passed through verbatim — the engine owns
interpretation of operator keys (``pattern``, ``contains``, …); the
store only validates structural shape.
interpretation of operator keys (``pattern``, ``contains``, …).
"""
emits: list[tuple[str, str | None]] = []
emits: list[tuple[str, str | None, str, float]] = []
for entry in parsed.emits:
tid = entry.get("technique_id")
if not tid:
raise ValueError(
f"rule {parsed.rule_id}: every emits entry needs technique_id",
)
sub = entry.get("sub_technique_id") or None
emits.append((tid, sub))
sub_raw = entry.get("sub_technique_id")
sub = sub_raw if sub_raw else None
tactic = entry.get("tactic")
if not tactic:
raise ValueError(
f"rule {parsed.rule_id}: emit for {tid} needs a tactic",
)
confidence_raw = entry.get("confidence")
if confidence_raw is None:
raise ValueError(
f"rule {parsed.rule_id}: emit for {tid} needs a confidence",
)
confidence = float(confidence_raw)
emits.append((str(tid), sub, str(tactic), confidence))
return CompiledRule(
rule_id=parsed.rule_id,
rule_version=parsed.rule_version,
@@ -330,22 +353,17 @@ class FilesystemRuleStore(RuleStore):
# Operational state changes are NOT a tolerated-absence path.
# Failures here MUST raise rather than silently drop — the
# E.2.14b conformance test pins this.
with _tracer().start_as_current_span("ttp.rule.state.change") as span:
# Defensive set_attribute: real OTEL spans accept str/int/etc;
# the no-op tracer's _NoOpSpan ignores attributes silently. A
# caller-side wrapper keeps both paths green without leaking
# tracer-shape knowledge into the store.
_safe_set_attrs(
span,
with _span(
"ttp.rule.state.change",
rule_id=rule_id,
state=state.state,
set_by=set_by,
)
):
stamped = replace(state, set_by=set_by, set_at=_utcnow())
with _tracer().start_as_current_span("ttp.store.write_state"):
with _span("ttp.store.write_state"):
self._state[rule_id] = stamped
self._restamp_compiled(rule_id, stamped)
with _tracer().start_as_current_span("ttp.rule.publish"):
with _span("ttp.rule.publish"):
await self._emit_change(
RuleChange("state", rule_id, stamped),
bus_topic=_topics.ttp_rule_state(rule_id),

11
development/TTP_TAGGING.md
View File

@@ -2954,7 +2954,16 @@ Order:
7. **RuleEngine** — implement engine consuming from `RuleStore`.
Atomic per-rule swap on `RuleChange`. State applied
after-parsing via `RuleState` join. `test_rule_engine.py`
green.
green. ✅ done. `CompiledRule.emits` extended to a 4-tuple
`(technique_id, sub_technique_id, tactic, confidence)` per emit;
the engine fans one match into N `TTPTag` rows. Match operator is
`pattern` (regex) for v0; per-source-kind default field
(`command_text` / `raw_url` / `subject` / …) overridable via
`match.field`. Disabled rules skipped; clipped state caps
confidence; `expires_at` re-checked at evaluate as
defense-in-depth. Tracing helper `_span(name, **attrs)` short-
circuits on `decnet.telemetry._ENABLED`, matching `@traced` /
`wrap_repository` zero-overhead-when-disabled pattern.
8. **Rule pack v0** — write the YAML files for `R0001`–`R0058`
at `./rules/ttp/`. Each rule lands with its precision-target
test per Appendix C in the same commit. The corpus for

6
tests/ttp/store/test_conformance.py
View File

@@ -51,7 +51,9 @@ applies_to: [command]
match:
pattern: 'hydra'
emits:
- technique_id: T1110
- tactic: TA0006
technique_id: T1110
confidence: 0.85
"""
@@ -114,7 +116,7 @@ async def test_load_compiled_corpus_identical_across_backends(
assert isinstance(c, CompiledRule)
assert c.state == RuleState()
assert c.applies_to == frozenset({"command"})
assert c.emits == (("T1110", None),)
assert c.emits == (("T1110", None, "TA0006", 0.85),)
async def test_set_state_isolates_rules(rule_store: RuleStore) -> None:

8
tests/ttp/store/test_database.py
View File

@@ -127,7 +127,7 @@ async def test_filesystem_to_db_sync_populates_ttp_rule(
name="brute force ssh",
applies_to=frozenset({"command"}),
match_spec={"pattern": "hydra"},
emits=(("T1110", None),),
emits=(("T1110", None, "TA0006", 0.85),),
evidence_fields=("matched_tokens",),
state=RuleState(),
)
@@ -151,7 +151,7 @@ async def test_filesystem_to_db_sync_populates_ttp_rule(
loaded = await db_store.load_compiled()
assert len(loaded) == 1
assert loaded[0].rule_id == "R0001"
assert loaded[0].emits == (("T1110", None),)
assert loaded[0].emits == (("T1110", None, "TA0006", 0.85),)
@pytest.mark.skipif(
@@ -186,7 +186,9 @@ applies_to: [command]
match:
pattern: 'whoami'
emits:
- technique_id: T1033
- tactic: TA0007
technique_id: T1033
confidence: 0.85
""",
encoding="utf-8",
)

6
tests/ttp/store/test_filesystem.py
View File

@@ -48,7 +48,9 @@ applies_to: [command]
match:
pattern: 'hydra'
emits:
- technique_id: T1110
- tactic: TA0006
technique_id: T1110
confidence: 0.85
evidence_fields: [matched_tokens]
"""
@@ -190,7 +192,7 @@ def test_compiled_rule_is_frozen() -> None:
name="test",
applies_to=frozenset({"attacker_command"}),
match_spec={},
emits=(("T1110", None),),
emits=(("T1110", None, "TA0006", 0.85),),
evidence_fields=(),
state=RuleState(),
)

117
tests/ttp/test_multi_mapping.py
View File

@@ -152,34 +152,111 @@ def test_uuid_is_deterministic_replay_safe(
# ── Engine fan-out (xfail until E.3.7) ──────────────────────────────
@pytest.mark.xfail(
strict=True,
reason="impl phase E.3.7 — RuleEngine.evaluate() empty body returns "
"[]; engine-level fan-out lands with the engine impl",
)
def test_engine_emits_n_times_m_rows() -> None:
"""End-to-end: a synthetic event matched by 3 rules each emitting
2 techniques produces 6 tag rows from ``RuleEngine.evaluate()``.
Today the engine returns ``[]`` so this assertion xfails. Flips
to GREEN at E.3.7 when the engine's dispatch + match + emit logic
lands.
"""
pytest.fail("RuleEngine.evaluate() fan-out not yet implemented")
import asyncio
from decnet.ttp.base import TaggerEvent
from decnet.ttp.impl.rule_engine import CompiledRule, RuleEngine
from decnet.ttp.store.base import RuleState
class _Stub:
async def load_compiled(self): # pragma: no cover
return []
async def get_state(self, _): # pragma: no cover
return RuleState()
async def set_state(self, *_a, **_kw): # pragma: no cover
return None
def subscribe_changes(self): # pragma: no cover
async def _g():
if False:
yield None
return _g()
rules = [
CompiledRule(
rule_id=f"R000{i}",
rule_version=1,
name=f"r{i}",
applies_to=frozenset({"command"}),
match_spec={"pattern": "hydra"},
emits=(
(f"T{1000 + 2 * i}", None, "TA0006", 0.85),
(f"T{1001 + 2 * i}", None, "TA0006", 0.80),
),
evidence_fields=(),
state=RuleState(),
)
for i in range(3)
]
eng = RuleEngine(store=_Stub())
eng._by_kind = {"command": rules}
event = TaggerEvent(
source_kind="command",
source_id="src1",
attacker_uuid="att1",
identity_uuid=None,
session_id=None,
decky_id=None,
payload={"command_text": "hydra -l root ssh://1.2.3.4"},
)
out = asyncio.run(eng.evaluate(event))
assert len(out) == 6
@pytest.mark.xfail(
strict=True,
reason="impl phase E.3.7 — re-running evaluate() on the same event "
"must produce zero NEW rows (idempotent UUID at engine level)",
)
def test_engine_replay_produces_no_new_rows() -> None:
"""Idempotency at the engine level: ``evaluate(e)`` followed by
``evaluate(e)`` again yields tag rows with identical UUIDs, so
the downstream ``insert_tags`` no-ops the second batch.
Pure ``compute_tag_uuid`` determinism is already covered by
:func:`test_uuid_is_deterministic_replay_safe`; this test pins
the engine wiring around it.
"""
pytest.fail("RuleEngine replay-safety wiring not yet implemented")
import asyncio
from decnet.ttp.base import TaggerEvent
from decnet.ttp.impl.rule_engine import CompiledRule, RuleEngine
from decnet.ttp.store.base import RuleState
class _Stub:
async def load_compiled(self): # pragma: no cover
return []
async def get_state(self, _): # pragma: no cover
return RuleState()
async def set_state(self, *_a, **_kw): # pragma: no cover
return None
def subscribe_changes(self): # pragma: no cover
async def _g():
if False:
yield None
return _g()
rule = CompiledRule(
rule_id="R0001",
rule_version=1,
name="r",
applies_to=frozenset({"command"}),
match_spec={"pattern": "hydra"},
emits=(("T1110", None, "TA0006", 0.85),),
evidence_fields=(),
state=RuleState(),
)
eng = RuleEngine(store=_Stub())
eng._by_kind = {"command": [rule]}
event = TaggerEvent(
source_kind="command",
source_id="src1",
attacker_uuid="att1",
identity_uuid=None,
session_id=None,
decky_id=None,
payload={"command_text": "hydra -l root ssh://1.2.3.4"},
)
out1 = asyncio.run(eng.evaluate(event))
out2 = asyncio.run(eng.evaluate(event))
assert {t.uuid for t in out1} == {t.uuid for t in out2}

81
tests/ttp/test_rule_engine.py
View File

@@ -44,24 +44,52 @@ def _ev() -> TaggerEvent:
class _StubStore:
"""Minimal duck-typed RuleStore for contract-phase construction."""
"""Minimal duck-typed RuleStore for engine construction in tests.
Provides the subset of the ABC the engine touches at construction
time. Tests that drive ``evaluate()`` populate ``eng._by_kind``
directly rather than going through ``watch_store()``; the
``load_compiled`` / ``subscribe_changes`` stubs are only here so a
test that DOES want to drive the watch loop can opt in.
"""
async def load_compiled(self) -> list[CompiledRule]: # pragma: no cover
return []
async def get_state(self, _rule_id: str): # pragma: no cover
from decnet.ttp.store.base import RuleState
return RuleState()
async def set_state(self, *_a: Any, **_kw: Any) -> None: # pragma: no cover
return None
def subscribe_changes(self): # pragma: no cover
async def _gen():
if False:
yield None
return _gen()
def _make_compiled_rule(
*,
rule_id: str = "R0001",
rule_version: int = 1,
emits: tuple[tuple[str, str | None], ...] = (("T1110", None),),
emits: tuple[tuple[str, str | None, str, float], ...] = (
("T1110", None, "TA0006", 0.85),
),
match_spec: dict[str, Any] | None = None,
) -> CompiledRule:
from decnet.ttp.store.base import RuleState # noqa: PLC0415
return CompiledRule(
rule_id=rule_id,
rule_version=rule_version,
name="test rule",
applies_to=frozenset({"command"}),
match_spec={"contains": "hydra"},
match_spec=match_spec or {"pattern": "hydra"},
emits=emits,
evidence_fields=("matched_tokens",),
state=object(), # RuleState lands in E.1.11; opaque here
state=RuleState(),
)
@@ -84,15 +112,17 @@ def test_compiled_rule_is_immutable() -> None:
# NamedTuple gives us field-level immutability — the atomic-swap
# property (E.2.14b) requires that a rule in the dispatch index
# cannot be mutated in place; replacement is the only legal edit.
from decnet.ttp.store.base import RuleState # noqa: PLC0415
cr = CompiledRule(
rule_id="R0001",
rule_version=1,
name="brute",
applies_to=frozenset({"command"}),
match_spec={},
emits=(("T1110", None),),
emits=(("T1110", None, "TA0006", 0.85),),
evidence_fields=("matched_tokens",),
state=object(),
state=RuleState(),
)
with pytest.raises(AttributeError):
cr.rule_id = "R9999" # type: ignore[misc]
@@ -109,15 +139,28 @@ def test_rule_engine_init_signature_takes_store() -> None:
assert list(sig.parameters)[1] == "store"
def test_evaluate_returns_empty_list_in_contract_phase() -> None:
def test_evaluate_returns_empty_list_for_unknown_source_kind() -> None:
eng = RuleEngine(store=_StubStore())
out = asyncio.run(eng.evaluate(_ev()))
assert out == []
def test_watch_store_returns_none_and_does_not_raise() -> None:
def test_watch_store_drains_and_can_be_cancelled() -> None:
"""``watch_store()`` blocks on ``subscribe_changes`` after loading
the empty corpus. Test that it can be cancelled cleanly — the
worker bootstrap (E.3.14) cancels it during shutdown."""
eng = RuleEngine(store=_StubStore())
assert asyncio.run(eng.watch_store()) is None
async def _drive() -> None:
task = asyncio.create_task(eng.watch_store())
await asyncio.sleep(0.05)
task.cancel()
try:
await task
except asyncio.CancelledError:
pass
asyncio.run(_drive())
def test_rule_schema_has_documented_fields() -> None:
@@ -208,10 +251,6 @@ def test_e25_evaluate_unknown_source_kind_returns_empty() -> None:
assert asyncio.run(eng.evaluate(weird)) == []
@pytest.mark.xfail(
strict=True,
reason="impl phase E.3.5: evaluate() does not yet fan out emits",
)
def test_e25_one_rule_multiple_emits_produces_multiple_tags() -> None:
"""One matching rule with N entries in ``emits`` must produce N
tag rows from a single event. The "one event maps to many
@@ -219,10 +258,15 @@ def test_e25_one_rule_multiple_emits_produces_multiple_tags() -> None:
eng = RuleEngine(store=_StubStore())
rule = _make_compiled_rule(
rule_id="R_MULTI",
emits=(("T1110", None), ("T1078", None), ("T1059", "001")),
emits=(
("T1110", None, "TA0006", 0.85),
("T1078", None, "TA0001", 0.80),
("T1059", "001", "TA0002", 0.90),
),
)
eng._by_kind = {"command": [rule]}
out = asyncio.run(eng.evaluate(_ev()))
event = _ev()._replace(payload={"command_text": "hydra -l root ssh://1.2.3.4"})
out = asyncio.run(eng.evaluate(event))
assert len(out) == 3
techs = {(t.technique_id, t.sub_technique_id) for t in out}
assert techs == {("T1110", None), ("T1078", None), ("T1059", "001")}
@@ -253,10 +297,6 @@ def test_e25_rule_version_collision_yields_distinct_tag_uuids() -> None:
assert u_v1 != u_v2
@pytest.mark.xfail(
strict=True,
reason="impl phase E.3.5: evaluate() does not yet emit tags",
)
def test_e25_rule_version_collision_via_engine_yields_distinct_tag_uuids() -> None:
"""Same property as above, but driven through the engine: two
CompiledRule instances differing only in rule_version produce two
@@ -265,7 +305,8 @@ def test_e25_rule_version_collision_via_engine_yields_distinct_tag_uuids() -> No
r1 = _make_compiled_rule(rule_id="R_VER", rule_version=1)
r2 = _make_compiled_rule(rule_id="R_VER", rule_version=2)
eng._by_kind = {"command": [r1, r2]}
out = asyncio.run(eng.evaluate(_ev()))
event = _ev()._replace(payload={"command_text": "hydra -l root ssh://1.2.3.4"})
out = asyncio.run(eng.evaluate(event))
assert len(out) == 2
uuids = {t.uuid for t in out}
assert len(uuids) == 2

111
tests/ttp/test_tracing.py
View File

@@ -121,15 +121,58 @@ def span_exporter(
# ── Eval span hierarchy (xfail until E.3.7) ─────────────────────────
@pytest.mark.xfail(
strict=True,
reason="impl phase E.3.7 — RuleEngine.evaluate() emits no spans "
"today; ttp.eval span lands with the engine impl",
)
def test_eval_emits_top_level_span(span_exporter: tuple[InMemorySpanExporter, TracerProvider]) -> None:
def test_eval_emits_top_level_span(
span_exporter: tuple[InMemorySpanExporter, TracerProvider],
) -> None:
"""``evaluate()`` produces a ``ttp.eval`` span with
``attacker_uuid`` and ``identity_uuid`` attributes."""
pytest.fail("ttp.eval span not yet emitted")
import asyncio
from decnet.ttp.base import TaggerEvent
from decnet.ttp.impl.rule_engine import CompiledRule, RuleEngine
from decnet.ttp.store.base import RuleState
class _Stub:
async def load_compiled(self): # pragma: no cover
return []
async def get_state(self, _): # pragma: no cover
return RuleState()
async def set_state(self, *_a, **_kw): # pragma: no cover
return None
def subscribe_changes(self): # pragma: no cover
async def _g():
if False:
yield None
return _g()
exporter, _ = span_exporter
rule = CompiledRule(
rule_id="R0001",
rule_version=1,
name="r",
applies_to=frozenset({"command"}),
match_spec={"pattern": "hydra"},
emits=(("T1110", None, "TA0006", 0.85),),
evidence_fields=(),
state=RuleState(),
)
eng = RuleEngine(store=_Stub())
eng._by_kind = {"command": [rule]}
event = TaggerEvent(
source_kind="command", source_id="src1",
attacker_uuid="ATT_X", identity_uuid="IDY_Y",
session_id=None, decky_id=None,
payload={"command_text": "hydra"},
)
asyncio.run(eng.evaluate(event))
eval_spans = [s for s in exporter.get_finished_spans() if s.name == "ttp.eval"]
assert eval_spans
attrs = dict(eval_spans[0].attributes or {})
assert attrs.get("attacker_uuid") == "ATT_X"
assert attrs.get("identity_uuid") == "IDY_Y"
@pytest.mark.xfail(
@@ -143,17 +186,59 @@ def test_lifter_child_spans_emitted(span_exporter: tuple[InMemorySpanExporter, T
pytest.fail("per-lifter spans not yet emitted")
@pytest.mark.xfail(
strict=True,
reason="impl phase E.3.7 — ttp.rule.fire spans with rule_id + "
"technique_id land with the engine impl",
)
def test_rule_fire_spans_carry_rule_and_technique_attrs(
span_exporter: tuple[InMemorySpanExporter, TracerProvider],
) -> None:
"""Each matched rule produces a ``ttp.rule.fire`` span with
``rule_id`` and ``technique_id`` attributes set."""
pytest.fail("ttp.rule.fire spans not yet emitted")
import asyncio
from decnet.ttp.base import TaggerEvent
from decnet.ttp.impl.rule_engine import CompiledRule, RuleEngine
from decnet.ttp.store.base import RuleState
class _Stub:
async def load_compiled(self): # pragma: no cover
return []
async def get_state(self, _): # pragma: no cover
return RuleState()
async def set_state(self, *_a, **_kw): # pragma: no cover
return None
def subscribe_changes(self): # pragma: no cover
async def _g():
if False:
yield None
return _g()
exporter, _ = span_exporter
rule = CompiledRule(
rule_id="R_FIRE",
rule_version=1,
name="r",
applies_to=frozenset({"command"}),
match_spec={"pattern": "hydra"},
emits=(("T1110", None, "TA0006", 0.85),),
evidence_fields=(),
state=RuleState(),
)
eng = RuleEngine(store=_Stub())
eng._by_kind = {"command": [rule]}
asyncio.run(eng.evaluate(TaggerEvent(
source_kind="command", source_id="s",
attacker_uuid="a", identity_uuid=None,
session_id=None, decky_id=None,
payload={"command_text": "hydra"},
)))
fire_spans = [
s for s in exporter.get_finished_spans() if s.name == "ttp.rule.fire"
]
assert fire_spans
attrs = dict(fire_spans[0].attributes or {})
assert attrs.get("rule_id") == "R_FIRE"
assert attrs.get("technique_id") == "T1110"
# ── set_state span hierarchy (xfail until E.3.5/E.3.6) ──────────────