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misc.py
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misc.py
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# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
# or more contributor license agreements. Licensed under the Elastic License
# 2.0; you may not use this file except in compliance with the Elastic License
# 2.0.
"""Misc support."""
import hashlib
import io
import json
import os
import re
import shutil
import time
import uuid
import dataclasses
from dataclasses import dataclass, field
from datetime import datetime
from functools import wraps
from pathlib import Path
from typing import Dict, NoReturn, Tuple
from zipfile import ZipFile
import click
import requests
# this is primarily for type hinting - all use of the github client should come from GithubClient class
try:
from github import Github
from github.Repository import Repository
from github.GitRelease import GitRelease
from github.GitReleaseAsset import GitReleaseAsset
except ImportError:
# for type hinting
Github = None # noqa: N806
Repository = None # noqa: N806
GitRelease = None # noqa: N806
GitReleaseAsset = None # noqa: N806
from .utils import add_params, cached, get_path
_CONFIG = {}
LICENSE_HEADER = """
Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
or more contributor license agreements. Licensed under the Elastic License
2.0; you may not use this file except in compliance with the Elastic License
2.0.
""".strip()
LICENSE_LINES = LICENSE_HEADER.splitlines()
PYTHON_LICENSE = "\n".join("# " + line for line in LICENSE_LINES)
JS_LICENSE = """
/*
{}
*/
""".strip().format("\n".join(' * ' + line for line in LICENSE_LINES))
def get_gh_release(repo: Repository, release_name=None, tag_name=None) -> GitRelease:
"""Get a list of GitHub releases by repo."""
assert release_name or tag_name, 'Must specify a release_name or tag_name'
releases = repo.get_releases()
release = next((r for r in releases
if (release_name and release_name == r.title) or (tag_name and tag_name == r.tag_name)), None)
return release
def upload_gh_release_asset(token, asset: bytes, asset_name, repo=None, content_type='application/zip',
release_name=None, tag_name=None, upload_url=None):
"""Save a Github relase asset."""
if not upload_url:
assert repo, 'You must provide a repo name if not providing an upload_url'
release = get_gh_release(repo, release_name, tag_name)
upload_url = release['upload_url']
suffix = '{?name,label}'
upload_url = upload_url.replace(suffix, f'?name={asset_name}&label={asset_name}')
headers = {'content-type': content_type}
r = requests.post(upload_url, auth=('', token), data=asset, headers=headers)
r.raise_for_status()
click.echo(f'Uploaded {asset_name} to release: {r.json()["url"]}')
def load_zipped_gh_assets_with_metadata(url) -> Tuple[str, dict]:
"""Download and unzip a GitHub assets."""
response = requests.get(url)
zipped_asset = ZipFile(io.BytesIO(response.content))
zipped_sha256 = hashlib.sha256(response.content).hexdigest()
assets = {}
for zipped in zipped_asset.filelist:
if zipped.is_dir():
continue
contents = zipped_asset.read(zipped.filename)
sha256 = hashlib.sha256(contents).hexdigest()
assets[zipped.filename] = {
'contents': contents,
'metadata': {
'compress_size': zipped.compress_size,
# zipfile provides only a 6 tuple datetime; -1 means DST is unknown; 0's set tm_wday and tm_yday
'created_at': time.strftime('%Y-%m-%dT%H:%M:%SZ', zipped.date_time + (0, 0, -1)),
'sha256': sha256,
'size': zipped.file_size,
}
}
return zipped_sha256, assets
def load_json_gh_asset(url) -> dict:
"""Load and return the contents of a json asset file."""
response = requests.get(url)
response.raise_for_status()
return response.json()
def download_gh_asset(url, path, overwrite=False):
"""Download and unzip a GitHub asset."""
zipped = requests.get(url)
z = ZipFile(io.BytesIO(zipped.content))
Path(path).mkdir(exist_ok=True)
if overwrite:
shutil.rmtree(path, ignore_errors=True)
z.extractall(path)
click.echo(f'files saved to {path}')
z.close()
class GithubClient:
"""GitHub client wrapper."""
def __init__(self, token=None):
"""Get an unauthenticated client, verified authenticated client, or a default client."""
if not Github:
raise ModuleNotFoundError('Missing PyGithub - try running `pip install -r requirements-dev.txt`')
self.client: Github = Github(token)
self.unauthenticated_client = Github()
self.__token = token
self.__authenticated_client = None
@property
def authenticated_client(self) -> Github:
if not self.__token:
raise ValueError('Token not defined! Re-instantiate with a token or use add_token method')
if not self.__authenticated_client:
self.__authenticated_client = Github(self.__token)
return self.__authenticated_client
def add_token(self, token):
self.__token = token
@dataclass
class AssetManifestEntry:
compress_size: int
created_at: datetime
name: str
sha256: str
size: int
@dataclass
class AssetManifestMetadata:
relative_url: str
entries: Dict[str, AssetManifestEntry]
zipped_sha256: str
created_at: datetime = field(default_factory=datetime.utcnow)
description: str = None # label
@dataclass
class ReleaseManifest:
assets: Dict[str, AssetManifestMetadata]
assets_url: str
author: str # parsed from GitHub release metadata as: author[login]
created_at: str
html_url: str
id: int
name: str
published_at: str
url: str
zipball_url: str
tag_name: str = None
description: str = None # body
class Manifest:
"""Manifest handler for GitHub releases."""
def __init__(self, repo: str = 'elastic/detection-rules', release_name=None, tag_name=None, token=None):
self.repo_name = repo
self.release_name = release_name
self.tag_name = tag_name
self.gh_client = GithubClient(token)
self.has_token = token is not None
self.repo: Repository = self.gh_client.client.get_repo(repo)
self.release: GitRelease = get_gh_release(self.repo, release_name, tag_name)
if not self.release:
raise ValueError(f'No release found for {tag_name or release_name}')
if not self.release_name:
self.release_name = self.release.title
self.manifest_name = f'manifest-{self.release_name}.json'
self.assets: dict = self._get_enriched_assets_from_release()
self.release_manifest = self._create()
self.__release_manifest_dict = dataclasses.asdict(self.release_manifest)
self.manifest_size = len(json.dumps(self.__release_manifest_dict))
@property
def release_manifest_fl(self):
return io.BytesIO(json.dumps(self.__release_manifest_dict, sort_keys=True).encode('utf-8'))
def _create(self):
"""Create the manifest from GitHub asset metadata and file contents."""
assets = {}
for asset_name, asset_data in self.assets.items():
entries = {}
data = asset_data['data']
metadata = asset_data['metadata']
for file_name, file_data in data.items():
file_metadata = file_data['metadata']
name = Path(file_name).name
file_metadata.update(name=name)
entry = AssetManifestEntry(**file_metadata)
entries[name] = entry
assets[asset_name] = AssetManifestMetadata(metadata['browser_download_url'], entries,
metadata['zipped_sha256'], metadata['created_at'],
metadata['label'])
release_metadata = self._parse_release_metadata()
release_metadata.update(assets=assets)
release_manifest = ReleaseManifest(**release_metadata)
return release_manifest
def _parse_release_metadata(self):
"""Parse relevant info from GitHub metadata for release manifest."""
ignore = ['assets']
manual_set_keys = ['author', 'description']
keys = [f.name for f in dataclasses.fields(ReleaseManifest) if f.name not in ignore + manual_set_keys]
parsed = {k: self.release.raw_data[k] for k in keys}
parsed.update(description=self.release.raw_data['body'], author=self.release.raw_data['author']['login'])
return parsed
def save(self) -> GitReleaseAsset:
"""Save manifest files."""
if not self.has_token:
raise ValueError('You must provide a token to save a manifest to a GitHub release')
asset = self.release.upload_asset_from_memory(self.release_manifest_fl,
self.manifest_size,
self.manifest_name)
click.echo(f'Manifest saved as {self.manifest_name} to {self.release.html_url}')
return asset
@classmethod
def load(cls, name: str, repo: str = 'elastic/detection-rules', token=None) -> dict:
"""Load a manifest."""
gh_client = GithubClient(token)
repo = gh_client.client.get_repo(repo)
release = get_gh_release(repo, tag_name=name)
asset = next((a for a in release.get_assets() if a.name == f'manifest-{name}.json'), None)
if asset is not None:
return load_json_gh_asset(asset.browser_download_url)
@classmethod
def load_all(cls, repo: str = 'elastic/detection-rules', token=None) -> Tuple[Dict[str, dict], list]:
"""Load a consolidated manifest."""
gh_client = GithubClient(token)
repo = gh_client.client.get_repo(repo)
consolidated = {}
missing = set()
for release in repo.get_releases():
name = release.tag_name
asset = next((a for a in release.get_assets() if a.name == f'manifest-{name}.json'), None)
if not asset:
missing.add(name)
else:
consolidated[name] = load_json_gh_asset(asset.browser_download_url)
return consolidated, list(missing)
@classmethod
def get_existing_asset_hashes(cls, repo: str = 'elastic/detection-rules', token=None) -> dict:
"""Load all assets with their hashes, by release."""
flat = {}
consolidated, _ = cls.load_all(repo=repo, token=token)
for release, data in consolidated.items():
for asset in data['assets'].values():
flat_release = flat[release] = {}
for asset_name, asset_data in asset['entries'].items():
flat_release[asset_name] = asset_data['sha256']
return flat
def _get_enriched_assets_from_release(self):
"""Get assets and metadata from a GitHub release."""
assets = {}
for asset in [a.raw_data for a in self.release.get_assets()]:
zipped_sha256, data = load_zipped_gh_assets_with_metadata(asset['browser_download_url'])
asset.update(zipped_sha256=zipped_sha256)
assets[asset['name']] = {
'metadata': asset,
'data': data
}
return assets
def get_ml_model_manifests_by_model_id(repo: str = 'elastic/detection-rules') -> Dict[str, ReleaseManifest]:
"""Load all ML DGA model release manifests by model id."""
manifests, _ = Manifest.load_all(repo=repo)
model_manifests = {}
for manifest_name, manifest in manifests.items():
for asset_name, asset in manifest['assets'].items():
for entry_name, entry_data in asset['entries'].items():
if entry_name.startswith('dga') and entry_name.endswith('model.json'):
model_id, _ = entry_name.rsplit('_', 1)
model_manifests[model_id] = ReleaseManifest(**manifest)
break
return model_manifests
class ClientError(click.ClickException):
"""Custom CLI error to format output or full debug stacktrace."""
def __init__(self, message, original_error=None):
super(ClientError, self).__init__(message)
self.original_error = original_error
self.original_error_type = type(original_error).__name__ if original_error else ''
def show(self, file=None, err=True):
"""Print the error to the console."""
err = f' {self.original_error_type}' if self.original_error else ''
msg = f'{click.style(f"CLI Error{self.original_error_type}", fg="red", bold=True)}: {self.format_message()}'
click.echo(msg, err=err, file=file)
def client_error(message, exc: Exception = None, debug=None, ctx: click.Context = None, file=None,
err=None) -> NoReturn:
config_debug = True if ctx and ctx.ensure_object(dict) and ctx.obj.get('debug') is True else False
debug = debug if debug is not None else config_debug
if debug:
click.echo(click.style('DEBUG: ', fg='yellow') + message, err=err, file=file)
raise
else:
raise ClientError(message, original_error=exc)
def nested_get(_dict, dot_key, default=None):
"""Get a nested field from a nested dict with dot notation."""
if _dict is None or dot_key is None:
return default
elif '.' in dot_key and isinstance(_dict, dict):
dot_key = dot_key.split('.')
this_key = dot_key.pop(0)
return nested_get(_dict.get(this_key, default), '.'.join(dot_key), default)
else:
return _dict.get(dot_key, default)
def nested_set(_dict, dot_key, value):
"""Set a nested field from a a key in dot notation."""
keys = dot_key.split('.')
for key in keys[:-1]:
_dict = _dict.setdefault(key, {})
if isinstance(_dict, dict):
_dict[keys[-1]] = value
else:
raise ValueError('dict cannot set a value to a non-dict for {}'.format(dot_key))
def schema_prompt(name, value=None, required=False, **options):
"""Interactively prompt based on schema requirements."""
name = str(name)
field_type = options.get('type')
pattern = options.get('pattern')
enum = options.get('enum', [])
minimum = options.get('minimum')
maximum = options.get('maximum')
min_item = options.get('min_items', 0)
max_items = options.get('max_items', 9999)
default = options.get('default')
if default is not None and str(default).lower() in ('true', 'false'):
default = str(default).lower()
if 'date' in name:
default = time.strftime('%Y/%m/%d')
if name == 'rule_id':
default = str(uuid.uuid4())
if len(enum) == 1 and required and field_type != "array":
return enum[0]
def _check_type(_val):
if field_type in ('number', 'integer') and not str(_val).isdigit():
print('Number expected but got: {}'.format(_val))
return False
if pattern and (not re.match(pattern, _val) or len(re.match(pattern, _val).group(0)) != len(_val)):
print('{} did not match pattern: {}!'.format(_val, pattern))
return False
if enum and _val not in enum:
print('{} not in valid options: {}'.format(_val, ', '.join(enum)))
return False
if minimum and (type(_val) == int and int(_val) < minimum):
print('{} is less than the minimum: {}'.format(str(_val), str(minimum)))
return False
if maximum and (type(_val) == int and int(_val) > maximum):
print('{} is greater than the maximum: {}'.format(str(_val), str(maximum)))
return False
if field_type == 'boolean' and _val.lower() not in ('true', 'false'):
print('Boolean expected but got: {}'.format(str(_val)))
return False
return True
def _convert_type(_val):
if field_type == 'boolean' and not type(_val) == bool:
_val = True if _val.lower() == 'true' else False
return int(_val) if field_type in ('number', 'integer') else _val
prompt = '{name}{default}{required}{multi}'.format(
name=name,
default=' [{}] ("n/a" to leave blank) '.format(default) if default else '',
required=' (required) ' if required else '',
multi=' (multi, comma separated) ' if field_type == 'array' else '').strip() + ': '
while True:
result = value or input(prompt) or default
if result == 'n/a':
result = None
if not result:
if required:
value = None
continue
else:
return
if field_type == 'array':
result_list = result.split(',')
if not (min_item < len(result_list) < max_items):
if required:
value = None
break
else:
return []
for value in result_list:
if not _check_type(value):
if required:
value = None
break
else:
return []
if required and value is None:
continue
else:
return [_convert_type(r) for r in result_list]
else:
if _check_type(result):
return _convert_type(result)
elif required:
value = None
continue
return
def get_kibana_rules_map(repo='elastic/kibana', branch='master'):
"""Get list of available rules from the Kibana repo and return a list of URLs."""
# ensure branch exists
r = requests.get(f'https://api.github.com/repos/{repo}/branches/{branch}')
r.raise_for_status()
url = ('https://api.github.com/repos/{repo}/contents/x-pack/{legacy}plugins/{app}/server/lib/'
'detection_engine/rules/prepackaged_rules?ref={branch}')
gh_rules = requests.get(url.format(legacy='', app='security_solution', branch=branch, repo=repo)).json()
# pre-7.9 app was siem
if isinstance(gh_rules, dict) and gh_rules.get('message', '') == 'Not Found':
gh_rules = requests.get(url.format(legacy='', app='siem', branch=branch, repo=repo)).json()
# pre-7.8 the siem was under the legacy directory
if isinstance(gh_rules, dict) and gh_rules.get('message', '') == 'Not Found':
gh_rules = requests.get(url.format(legacy='legacy/', app='siem', branch=branch, repo=repo)).json()
if isinstance(gh_rules, dict) and gh_rules.get('message', '') == 'Not Found':
raise ValueError(f'rules directory does not exist for {repo} branch: {branch}')
return {os.path.splitext(r['name'])[0]: r['download_url'] for r in gh_rules if r['name'].endswith('.json')}
def get_kibana_rules(*rule_paths, repo='elastic/kibana', branch='master', verbose=True, threads=50):
"""Retrieve prepackaged rules from kibana repo."""
from multiprocessing.pool import ThreadPool
kibana_rules = {}
if verbose:
thread_use = f' using {threads} threads' if threads > 1 else ''
click.echo(f'Downloading rules from {repo} {branch} branch in kibana repo{thread_use} ...')
rule_paths = [os.path.splitext(os.path.basename(p))[0] for p in rule_paths]
rules_mapping = [(n, u) for n, u in get_kibana_rules_map(repo=repo, branch=branch).items() if n in rule_paths] \
if rule_paths else get_kibana_rules_map(repo=repo, branch=branch).items()
def download_worker(rule_info):
n, u = rule_info
kibana_rules[n] = requests.get(u).json()
pool = ThreadPool(processes=threads)
pool.map(download_worker, rules_mapping)
pool.close()
pool.join()
return kibana_rules
@cached
def parse_config():
"""Parse a default config file."""
config_file = get_path('.detection-rules-cfg.json')
config = {}
if os.path.exists(config_file):
with open(config_file) as f:
config = json.load(f)
click.secho('Loaded config file: {}'.format(config_file), fg='yellow')
return config
def getdefault(name):
"""Callback function for `default` to get an environment variable."""
envvar = f"DR_{name.upper()}"
config = parse_config()
return lambda: os.environ.get(envvar, config.get(name))
client_options = {
'kibana': {
'cloud_id': click.Option(['--cloud-id'], default=getdefault('cloud_id')),
'kibana_cookie': click.Option(['--kibana-cookie', '-kc'], default=getdefault('kibana_cookie'),
help='Cookie from an authed session'),
'kibana_password': click.Option(['--kibana-password', '-kp'], default=getdefault('kibana_password')),
'kibana_url': click.Option(['--kibana-url'], default=getdefault('kibana_url')),
'kibana_user': click.Option(['--kibana-user', '-ku'], default=getdefault('kibana_user')),
'space': click.Option(['--space'], default=None, help='Kibana space')
},
'elasticsearch': {
'cloud_id': click.Option(['--cloud-id'], default=getdefault("cloud_id")),
'elasticsearch_url': click.Option(['--elasticsearch-url'], default=getdefault("elasticsearch_url")),
'es_user': click.Option(['--es-user', '-eu'], default=getdefault("es_user")),
'es_password': click.Option(['--es-password', '-ep'], default=getdefault("es_password")),
'timeout': click.Option(['--timeout', '-et'], default=60, help='Timeout for elasticsearch client')
}
}
kibana_options = list(client_options['kibana'].values())
elasticsearch_options = list(client_options['elasticsearch'].values())
def add_client(*client_type, add_to_ctx=True):
"""Wrapper to add authed client."""
from elasticsearch import Elasticsearch, ElasticsearchException
from kibana import Kibana
from .eswrap import get_elasticsearch_client
from .kbwrap import get_kibana_client
def _wrapper(func):
client_ops_dict = {}
client_ops_keys = {}
for c_type in client_type:
ops = client_options.get(c_type)
client_ops_dict.update(ops)
client_ops_keys[c_type] = list(ops)
if not client_ops_dict:
raise ValueError(f'Unknown client: {client_type} in {func.__name__}')
client_ops = list(client_ops_dict.values())
@wraps(func)
@add_params(*client_ops)
def _wrapped(*args, **kwargs):
ctx: click.Context = next((a for a in args if isinstance(a, click.Context)), None)
es_client_args = {k: kwargs.pop(k, None) for k in client_ops_keys.get('elasticsearch', [])}
# shared args like cloud_id
kibana_client_args = {k: kwargs.pop(k, es_client_args.get(k)) for k in client_ops_keys.get('kibana', [])}
if 'elasticsearch' in client_type:
# for nested ctx invocation, no need to re-auth if an existing client is already passed
elasticsearch_client: Elasticsearch = kwargs.get('elasticsearch_client')
try:
if elasticsearch_client and isinstance(elasticsearch_client, Elasticsearch) and \
elasticsearch_client.info():
pass
else:
elasticsearch_client = get_elasticsearch_client(use_ssl=True, **es_client_args)
except ElasticsearchException:
elasticsearch_client = get_elasticsearch_client(use_ssl=True, **es_client_args)
kwargs['elasticsearch_client'] = elasticsearch_client
if ctx and add_to_ctx:
ctx.obj['es'] = elasticsearch_client
if 'kibana' in client_type:
# for nested ctx invocation, no need to re-auth if an existing client is already passed
kibana_client: Kibana = kwargs.get('kibana_client')
try:
with kibana_client:
if kibana_client and isinstance(kibana_client, Kibana) and kibana_client.version:
pass
else:
kibana_client = get_kibana_client(**kibana_client_args)
except (requests.HTTPError, AttributeError):
kibana_client = get_kibana_client(**kibana_client_args)
kwargs['kibana_client'] = kibana_client
if ctx and add_to_ctx:
ctx.obj['kibana'] = kibana_client
return func(*args, **kwargs)
return _wrapped
return _wrapper