feat(refactor): PEP8, type annotations, docstrings and PyJWT security fix

This commit is contained in:
kitos
2026-06-11 11:09:41 +02:00
161 changed files with 15318 additions and 811 deletions
+190 -6
View File
@@ -21,22 +21,39 @@ rules are identified by ``source = "elastic"`` + ``source_id`` (the
TOML filename).
"""
# Import io
import io
# Import logging
import logging
# Import shutil
import shutil
# Import tempfile
import tempfile
# Import zipfile
import zipfile
# Import datetime from datetime
from datetime import datetime
# Import Path from pathlib
from pathlib import Path
# Import requests
import requests as _requests
# Import Session from sqlalchemy.orm
from sqlalchemy.orm import Session
from app.models.detection_rule import DetectionRule
# Import DataSource from app.models.data_source
from app.models.data_source import DataSource
from app.models.technique import Technique
from app.services.audit_service import log_action
# Assign logger = logging.getLogger(__name__)
logger = logging.getLogger(__name__)
# ---------------------------------------------------------------------------
@@ -44,19 +61,33 @@ logger = logging.getLogger(__name__)
# ---------------------------------------------------------------------------
ELASTIC_ZIP_URL = (
# Literal argument value
"https://github.com/elastic/detection-rules"
# Literal argument value
"/archive/refs/heads/main.zip"
)
# Assign _DOWNLOAD_TIMEOUT = 300
_DOWNLOAD_TIMEOUT = 300
# Assign _ZIP_ROOT_PREFIX = "detection-rules-main"
_ZIP_ROOT_PREFIX = "detection-rules-main"
# Safety limits for ZIP extraction — prevent zip-bomb DoS
_MAX_UNCOMPRESSED_SIZE = 500 * 1024 * 1024 # 500 MB
# Assign _MAX_ENTRIES = 50_000
_MAX_ENTRIES = 50_000
# Severity normalisation
_SEVERITY_MAP = {
# Literal argument value
"informational": "informational",
# Literal argument value
"low": "low",
# Literal argument value
"medium": "medium",
# Literal argument value
"high": "high",
# Literal argument value
"critical": "critical",
}
@@ -68,14 +99,21 @@ _SEVERITY_MAP = {
def _download_zip(url: str = ELASTIC_ZIP_URL) -> bytes:
"""Download the Elastic Detection Rules ZIP and return raw bytes."""
# Log info: "Downloading Elastic Detection Rules ZIP from %s …
logger.info("Downloading Elastic Detection Rules ZIP from %s", url)
# Assign resp = _requests.get(url, timeout=_DOWNLOAD_TIMEOUT, stream=True)
resp = _requests.get(url, timeout=_DOWNLOAD_TIMEOUT, stream=True)
# Call resp.raise_for_status()
resp.raise_for_status()
# Assign content = resp.content
content = resp.content
# Log info: "Downloaded %.1f MB", len(content) / (1024 * 1024
logger.info("Downloaded %.1f MB", len(content) / (1024 * 1024))
# Return content
return content
# Define function _safe_extract_zip
def _safe_extract_zip(zip_bytes: bytes, dest: str) -> None:
"""Extract *zip_bytes* into *dest* with Zip Slip and Zip Bomb protection.
@@ -83,62 +121,85 @@ def _safe_extract_zip(zip_bytes: bytes, dest: str) -> None:
directory (path traversal / Zip Slip) or if the archive exceeds the
safety limits.
"""
# Maximum uncompressed size: 500 MB — prevents zip-bomb DoS
_MAX_UNCOMPRESSED_SIZE = 500 * 1024 * 1024
# Maximum number of entries
_MAX_ENTRIES = 50_000
# Assign dest_path = Path(dest).resolve()
dest_path = Path(dest).resolve()
# Open context manager
with zipfile.ZipFile(io.BytesIO(zip_bytes)) as zf:
# Assign entries = zf.infolist()
entries = zf.infolist()
# Check: len(entries) > _MAX_ENTRIES
if len(entries) > _MAX_ENTRIES:
# Raise ValueError
raise ValueError(
f"ZIP archive contains {len(entries)} entries "
f"(limit: {_MAX_ENTRIES}) — possible zip bomb"
)
# Assign total_size = sum(info.file_size for info in entries)
total_size = sum(info.file_size for info in entries)
# Check: total_size > _MAX_UNCOMPRESSED_SIZE
if total_size > _MAX_UNCOMPRESSED_SIZE:
# Raise ValueError
raise ValueError(
f"ZIP uncompressed size {total_size / (1024 * 1024):.0f} MB "
f"exceeds limit of {_MAX_UNCOMPRESSED_SIZE / (1024 * 1024):.0f} MB"
)
# Iterate over entries
for member in entries:
# Assign target = (dest_path / member.filename).resolve()
target = (dest_path / member.filename).resolve()
# Check: not target.is_relative_to(dest_path)
if not target.is_relative_to(dest_path):
# Raise ValueError
raise ValueError(
f"Zip Slip detected — member '{member.filename}' "
f"resolves outside target directory"
)
# Call zf.extractall()
zf.extractall(dest)
# Define function _extract_zip
def _extract_zip(zip_bytes: bytes, dest: str) -> Path:
"""Extract *zip_bytes* into *dest* and return rules/ dir."""
# Call _safe_extract_zip()
_safe_extract_zip(zip_bytes, dest)
# Assign rules_dir = Path(dest) / _ZIP_ROOT_PREFIX / "rules"
rules_dir = Path(dest) / _ZIP_ROOT_PREFIX / "rules"
# Check: not rules_dir.is_dir()
if not rules_dir.is_dir():
# Raise FileNotFoundError
raise FileNotFoundError(
f"Expected rules directory not found at {rules_dir}"
)
# Return rules_dir
return rules_dir
# Define function _parse_toml_safe
def _parse_toml_safe(path: Path) -> dict | None:
"""Parse a TOML file. Uses the ``toml`` library."""
# Attempt the following; catch errors below
try:
# Import toml
import toml
# Open context manager
with open(path, "r", encoding="utf-8") as fh:
# Return toml.load(fh)
return toml.load(fh)
# Handle Exception
except Exception as exc:
# Log debug: "Failed to parse %s: %s", path, exc
logger.debug("Failed to parse %s: %s", path, exc)
# Return None
return None
# Define function _extract_mitre_techniques
def _extract_mitre_techniques(threat_list: list) -> list[str]:
"""Extract MITRE technique IDs from Elastic's ``rule.threat`` array.
@@ -156,82 +217,132 @@ def _extract_mitre_techniques(threat_list: list) -> list[str]:
name = "LSASS Memory"
id = "T1003.001"
"""
# Assign technique_ids = []
technique_ids = []
# Check: not isinstance(threat_list, list)
if not isinstance(threat_list, list):
# Return technique_ids
return technique_ids
# Iterate over threat_list
for threat_entry in threat_list:
# Check: not isinstance(threat_entry, dict)
if not isinstance(threat_entry, dict):
# Skip to the next loop iteration
continue
# Skip non-MITRE frameworks
framework = threat_entry.get("framework", "")
# Check: "MITRE" not in str(framework).upper()
if "MITRE" not in str(framework).upper():
# Skip to the next loop iteration
continue
# Assign techniques = threat_entry.get("technique", [])
techniques = threat_entry.get("technique", [])
# Check: not isinstance(techniques, list)
if not isinstance(techniques, list):
# Skip to the next loop iteration
continue
# Iterate over techniques
for tech in techniques:
# Check: not isinstance(tech, dict)
if not isinstance(tech, dict):
# Skip to the next loop iteration
continue
# Assign tech_id = tech.get("id", "")
tech_id = tech.get("id", "")
# Check: tech_id and str(tech_id).upper().startswith("T")
if tech_id and str(tech_id).upper().startswith("T"):
# Call technique_ids.append()
technique_ids.append(str(tech_id).upper())
# Check subtechniques
subtechniques = tech.get("subtechnique", [])
# Check: isinstance(subtechniques, list)
if isinstance(subtechniques, list):
# Iterate over subtechniques
for subtech in subtechniques:
# Check: isinstance(subtech, dict)
if isinstance(subtech, dict):
# Assign sub_id = subtech.get("id", "")
sub_id = subtech.get("id", "")
# Check: sub_id and str(sub_id).upper().startswith("T")
if sub_id and str(sub_id).upper().startswith("T"):
# Call technique_ids.append()
technique_ids.append(str(sub_id).upper())
# Return list(set(technique_ids))
return list(set(technique_ids))
# Define function _parse_elastic_rules
def _parse_elastic_rules(rules_dir: Path) -> list[dict]:
"""Walk the rules directory and parse all TOML files.
Returns a flat list of dicts, one per (rule, technique) combination.
"""
# Assign results = []
results: list[dict] = []
# Assign toml_files = sorted(rules_dir.rglob("*.toml"))
toml_files = sorted(rules_dir.rglob("*.toml"))
# Log info: "Found %d TOML files to parse", len(toml_files
logger.info("Found %d TOML files to parse", len(toml_files))
# Iterate over toml_files
for toml_path in toml_files:
# Assign data = _parse_toml_safe(toml_path)
data = _parse_toml_safe(toml_path)
# Check: not data
if not data:
# Skip to the next loop iteration
continue
# Assign rule = data.get("rule", {})
rule = data.get("rule", {})
# Check: not isinstance(rule, dict)
if not isinstance(rule, dict):
# Skip to the next loop iteration
continue
# Assign name = rule.get("name", "").strip()
name = rule.get("name", "").strip()
# Check: not name
if not name:
# Skip to the next loop iteration
continue
# Extract MITRE technique IDs
threat_list = rule.get("threat", [])
# Assign technique_ids = _extract_mitre_techniques(threat_list)
technique_ids = _extract_mitre_techniques(threat_list)
# Check: not technique_ids
if not technique_ids:
# Skip to the next loop iteration
continue
# Assign description = rule.get("description", "")
description = rule.get("description", "")
# Assign query = rule.get("query", "")
query = rule.get("query", "")
# Assign severity = _SEVERITY_MAP.get(str(rule.get("severity", "")).lower())
severity = _SEVERITY_MAP.get(str(rule.get("severity", "")).lower())
# Assign rule_type = rule.get("type", "query") # query, eql, threshold, etc.
rule_type = rule.get("type", "query") # query, eql, threshold, etc.
# Determine rule format based on type
if rule_type == "eql":
# Assign rule_format = "eql"
rule_format = "eql"
# Alternative: rule_type == "esql"
elif rule_type == "esql":
# Assign rule_format = "esql"
rule_format = "esql"
# Fallback: handle remaining cases
else:
# Assign rule_format = "kql"
rule_format = "kql"
# Use filename as source_id
@@ -239,51 +350,79 @@ def _parse_elastic_rules(rules_dir: Path) -> list[dict]:
# Read raw content
try:
# Open context manager
with open(toml_path, "r", encoding="utf-8") as fh:
# Assign raw_content = fh.read()
raw_content = fh.read()
# Handle Exception
except Exception:
# Assign raw_content = query or str(data)
raw_content = query or str(data)
# Build source URL
relative = str(toml_path.relative_to(rules_dir.parent)).replace("\\", "/")
# Assign source_url = (
source_url = (
f"https://github.com/elastic/detection-rules/blob/main/{relative}"
)
# One entry per technique
for tech_id in technique_ids:
# Call results.append()
results.append({
# Literal argument value
"mitre_technique_id": tech_id,
# Literal argument value
"title": name[:500],
# Literal argument value
"description": str(description)[:2000] if description else None,
# Literal argument value
"source_id": source_id,
# Literal argument value
"source_url": source_url,
# Literal argument value
"rule_content": query[:50000] if query else raw_content[:50000],
# Literal argument value
"rule_format": rule_format,
# Literal argument value
"severity": severity,
# Literal argument value
"platforms": _infer_platforms(rules_dir, toml_path),
})
# Log info: "Parsed %d (rule, technique) pairs total", len(res
logger.info("Parsed %d (rule, technique) pairs total", len(results))
# Return results
return results
# Define function _infer_platforms
def _infer_platforms(rules_dir: Path, toml_path: Path) -> list[str] | None:
"""Infer platforms from the rule's directory structure.
Elastic organizes rules by OS: rules/windows/, rules/linux/, etc.
"""
# Assign relative = toml_path.relative_to(rules_dir)
relative = toml_path.relative_to(rules_dir)
# Assign parts = [p.lower() for p in relative.parts]
parts = [p.lower() for p in relative.parts]
# Assign platforms = []
platforms = []
# Check: "windows" in parts
if "windows" in parts:
# Call platforms.append()
platforms.append("windows")
# Check: "linux" in parts
if "linux" in parts:
# Call platforms.append()
platforms.append("linux")
# Check: "macos" in parts
if "macos" in parts:
# Call platforms.append()
platforms.append("macos")
# Return platforms if platforms else None
return platforms if platforms else None
@@ -297,47 +436,78 @@ def sync(db: Session) -> dict:
Returns a summary dict with ``created``, ``skipped_existing``, ``total_parsed``.
"""
# Assign tmp_dir = tempfile.mkdtemp(prefix="aegis_elastic_")
tmp_dir = tempfile.mkdtemp(prefix="aegis_elastic_")
# Attempt the following; catch errors below
try:
# Assign zip_bytes = _download_zip()
zip_bytes = _download_zip()
# Assign rules_dir = _extract_zip(zip_bytes, tmp_dir)
rules_dir = _extract_zip(zip_bytes, tmp_dir)
# Assign parsed_rules = _parse_elastic_rules(rules_dir)
parsed_rules = _parse_elastic_rules(rules_dir)
# Always execute this cleanup block
finally:
# Call shutil.rmtree()
shutil.rmtree(tmp_dir, ignore_errors=True)
# Log info: "Cleaned up temp directory %s", tmp_dir
logger.info("Cleaned up temp directory %s", tmp_dir)
# Pre-load existing source_ids for dedup
existing_ids: set[str] = {
row[0]
for row in db.query(DetectionRule.source_id)
# Chain .filter() call
.filter(DetectionRule.source == "elastic")
# Chain .filter() call
.filter(DetectionRule.source_id.isnot(None))
# Chain .all() call
.all()
}
# Assign created = 0
created = 0
# Assign skipped = 0
skipped = 0
new_technique_ids: set[str] = set()
# Iterate over parsed_rules
for item in parsed_rules:
# Check: item["source_id"] in existing_ids
if item["source_id"] in existing_ids:
# Assign skipped = 1
skipped += 1
# Skip to the next loop iteration
continue
# Assign rule = DetectionRule(
rule = DetectionRule(
# Keyword argument: mitre_technique_id
mitre_technique_id=item["mitre_technique_id"],
# Keyword argument: title
title=item["title"],
# Keyword argument: description
description=item["description"],
# Keyword argument: source
source="elastic",
# Keyword argument: source_id
source_id=item["source_id"],
# Keyword argument: source_url
source_url=item["source_url"],
# Keyword argument: rule_content
rule_content=item["rule_content"],
# Keyword argument: rule_format
rule_format=item["rule_format"],
# Keyword argument: severity
severity=item["severity"],
# Keyword argument: platforms
platforms=item["platforms"],
# Keyword argument: is_active
is_active=True,
)
# Stage new record(s) for database insertion
db.add(rule)
# Call existing_ids.add()
existing_ids.add(item["source_id"])
new_technique_ids.add(item["mitre_technique_id"])
created += 1
@@ -350,22 +520,36 @@ def sync(db: Session) -> dict:
db.commit()
# Assign summary = {
summary = {
# Literal argument value
"created": created,
# Literal argument value
"skipped_existing": skipped,
# Literal argument value
"total_parsed": len(parsed_rules),
}
# Update DataSource record
ds = db.query(DataSource).filter(DataSource.name == "elastic_rules").first()
# Check: ds
if ds:
# Assign ds.last_sync_at = datetime.utcnow()
ds.last_sync_at = datetime.utcnow()
# Assign ds.last_sync_status = "success"
ds.last_sync_status = "success"
# Assign ds.last_sync_stats = summary
ds.last_sync_stats = summary
# Commit all pending changes to the database
db.commit()
# Log info: "Elastic import complete — %s", summary
logger.info("Elastic import complete — %s", summary)
# Call log_action()
log_action(db, user_id=None, action="import_elastic_rules",
# Keyword argument: entity_type
entity_type="detection_rule", entity_id=None, details=summary)
# Commit all pending changes to the database
db.commit()
# Return summary
return summary