import os import logging from abc import ABCMeta, abstractmethod from six import add_metaclass from urlparse import urljoin import requests from flask import url_for from data.database import CloseForLongOperation from data import model from data.model.storage import get_storage_locations from util import get_app_url, slash_join from util.abchelpers import nooper from util.failover import failover, FailoverException from util.secscan.validator import SecurityConfigValidator from util.security.instancekeys import InstanceKeys from util.security.registry_jwt import generate_bearer_token, build_context_and_subject from _init import CONF_DIR TOKEN_VALIDITY_LIFETIME_S = 60 # Amount of time the security scanner has to call the layer URL UNKNOWN_PARENT_LAYER_ERROR_MSG = 'worker: parent layer is unknown, it must be processed first' MITM_CERT_PATH = os.path.join(CONF_DIR, 'mitm.cert') DEFAULT_HTTP_HEADERS = {'Connection': 'close'} logger = logging.getLogger(__name__) class AnalyzeLayerException(Exception): """ Exception raised when a layer fails to analyze due to a request issue. """ class AnalyzeLayerRetryException(Exception): """ Exception raised when a layer fails to analyze due to a request issue, and the request should be retried. """ class MissingParentLayerException(AnalyzeLayerException): """ Exception raised when the parent of the layer is missing from the security scanner. """ class InvalidLayerException(AnalyzeLayerException): """ Exception raised when the layer itself cannot be handled by the security scanner. """ class APIRequestFailure(Exception): """ Exception raised when there is a failure to conduct an API request. """ class Non200ResponseException(Exception): """ Exception raised when the upstream API returns a non-200 HTTP status code. """ def __init__(self, response): super(Non200ResponseException, self).__init__() self.response = response _API_METHOD_INSERT = 'layers' _API_METHOD_GET_LAYER = 'layers/%s' _API_METHOD_DELETE_LAYER = 'layers/%s' _API_METHOD_MARK_NOTIFICATION_READ = 'notifications/%s' _API_METHOD_GET_NOTIFICATION = 'notifications/%s' _API_METHOD_PING = 'metrics' def compute_layer_id(layer): """ Returns the ID for the layer in the security scanner. """ return '%s.%s' % (layer.docker_image_id, layer.storage.uuid) class SecurityScannerAPI(object): """ Helper class for talking to the Security Scan service (usually Clair). """ def __init__(self, app, config, storage, client=None, skip_validation=False): feature_enabled = config.get('FEATURE_SECURITY_SCANNER', False) has_valid_config = skip_validation if not skip_validation and feature_enabled: config_validator = SecurityConfigValidator(config) has_valid_config = config_validator.valid() if feature_enabled and has_valid_config: self.state = ImplementedSecurityScannerAPI(app, config, storage, client=client) else: self.state = NoopSecurityScannerAPI() def __getattr__(self, name): return getattr(self.state, name, None) @add_metaclass(ABCMeta) class SecurityScannerAPIInterface(object): """ Helper class for talking to the Security Scan service (usually Clair). """ @abstractmethod def cleanup_layers(self, layers): """ Callback invoked by garbage collection to cleanup any layers that no longer need to be stored in the security scanner. """ pass @abstractmethod def ping(self): """ Calls GET on the metrics endpoint of the security scanner to ensure it is running and properly configured. Returns the HTTP response. """ pass @abstractmethod def delete_layer(self, layer): """ Calls DELETE on the given layer in the security scanner, removing it from its database. """ pass @abstractmethod def analyze_layer(self, layer): """ Posts the given layer to the security scanner for analysis, blocking until complete. Returns the analysis version on success or raises an exception deriving from AnalyzeLayerException on failure. Callers should handle all cases of AnalyzeLayerException. """ pass @abstractmethod def check_layer_vulnerable(self, layer_id, cve_name): """ Checks to see if the layer with the given ID is vulnerable to the specified CVE. """ pass @abstractmethod def get_notification(self, notification_name, layer_limit=100, page=None): """ Gets the data for a specific notification, with optional page token. Returns a tuple of the data (None on failure) and whether to retry. """ pass @abstractmethod def mark_notification_read(self, notification_name): """ Marks a security scanner notification as read. """ pass @abstractmethod def get_layer_data(self, layer, include_features=False, include_vulnerabilities=False): """ Returns the layer data for the specified layer. On error, returns None. """ pass @nooper class NoopSecurityScannerAPI(SecurityScannerAPIInterface): """ No-op version of the security scanner API. """ pass class ImplementedSecurityScannerAPI(SecurityScannerAPIInterface): """ Helper class for talking to the Security Scan service (Clair). """ def __init__(self, app, config, storage, client=None): self._app = app self._config = config self._instance_keys = InstanceKeys(app) self._client = client or config['HTTPCLIENT'] self._storage = storage self._default_storage_locations = config['DISTRIBUTED_STORAGE_PREFERENCE'] self._target_version = config.get('SECURITY_SCANNER_ENGINE_VERSION_TARGET', 2) def _get_image_url_and_auth(self, image): """ Returns a tuple of the url and the auth header value that must be used to fetch the layer data itself. If the image can't be addressed, we return None. """ path = model.storage.get_layer_path(image.storage) locations = self._default_storage_locations if not self._storage.exists(locations, path): locations = get_storage_locations(image.storage.uuid) if not locations or not self._storage.exists(locations, path): logger.warning('Could not find a valid location to download layer %s out of %s', compute_layer_id(image), locations) return None, None uri = self._storage.get_direct_download_url(locations, path) auth_header = None if uri is None: # Use the registry API instead, with a signed JWT giving access repo_name = image.repository.name namespace_name = image.repository.namespace_user.username repository_and_namespace = '/'.join([namespace_name, repo_name]) # Generate the JWT which will authorize this audience = self._app.config['SERVER_HOSTNAME'] context, subject = build_context_and_subject() access = [{ 'type': 'repository', 'name': repository_and_namespace, 'actions': ['pull'], }] auth_token = generate_bearer_token(audience, subject, context, access, TOKEN_VALIDITY_LIFETIME_S, self._instance_keys) auth_header = 'Bearer ' + auth_token with self._app.test_request_context('/'): relative_layer_url = url_for('v2.download_blob', repository=repository_and_namespace, digest=image.storage.content_checksum) uri = urljoin(get_app_url(self._config), relative_layer_url) return uri, auth_header def _new_analyze_request(self, layer): """ Create the request body to submit the given layer for analysis. If the layer's URL cannot be found, returns None. """ url, auth_header = self._get_image_url_and_auth(layer) if url is None: return None layer_request = { 'Name': compute_layer_id(layer), 'Path': url, 'Format': 'Docker', } if auth_header is not None: layer_request['Headers'] = { 'Authorization': auth_header, } if layer.parent.docker_image_id and layer.parent.storage.uuid: layer_request['ParentName'] = compute_layer_id(layer.parent) return { 'Layer': layer_request, } def cleanup_layers(self, layers): """ Callback invoked by garbage collection to cleanup any layers that no longer need to be stored in the security scanner. """ for layer in layers: self.delete_layer(layer) def ping(self): """ Calls GET on the metrics endpoint of the security scanner to ensure it is running and properly configured. Returns the HTTP response. """ try: return self._call('GET', _API_METHOD_PING) except requests.exceptions.Timeout as tie: logger.exception('Timeout when trying to connect to security scanner endpoint') msg = 'Timeout when trying to connect to security scanner endpoint: %s' % tie.message raise Exception(msg) except requests.exceptions.ConnectionError as ce: logger.exception('Connection error when trying to connect to security scanner endpoint') msg = 'Connection error when trying to connect to security scanner endpoint: %s' % ce.message raise Exception(msg) except (requests.exceptions.RequestException, ValueError) as ve: logger.exception('Exception when trying to connect to security scanner endpoint') msg = 'Exception when trying to connect to security scanner endpoint: %s' % ve raise Exception(msg) def delete_layer(self, layer): """ Calls DELETE on the given layer in the security scanner, removing it from its database. """ layer_id = compute_layer_id(layer) try: self._call('DELETE', _API_METHOD_DELETE_LAYER % layer_id) return True except Non200ResponseException: return False except requests.exceptions.RequestException: logger.exception('Failed to delete layer: %s', layer_id) return False def analyze_layer(self, layer): """ Posts the given layer to the security scanner for analysis, blocking until complete. Returns the analysis version on success or raises an exception deriving from AnalyzeLayerException on failure. Callers should handle all cases of AnalyzeLayerException. """ def _response_json(request, response): try: return response.json() except ValueError: logger.exception('Failed to decode JSON when analyzing layer %s', request['Layer']['Name']) raise AnalyzeLayerException request = self._new_analyze_request(layer) if not request: logger.error('Could not build analyze request for layer %s', layer.id) raise AnalyzeLayerException logger.info('Analyzing layer %s', request['Layer']['Name']) try: response = self._call('POST', _API_METHOD_INSERT, body=request) except requests.exceptions.Timeout: logger.exception('Timeout when trying to post layer data response for %s', layer.id) raise AnalyzeLayerRetryException except requests.exceptions.ConnectionError: logger.exception('Connection error when trying to post layer data response for %s', layer.id) raise AnalyzeLayerRetryException except (requests.exceptions.RequestException) as re: logger.exception('Failed to post layer data response for %s: %s', layer.id, re) raise AnalyzeLayerException except Non200ResponseException as ex: message = _response_json(request, ex.response).get('Error').get('Message', '') logger.warning('A warning event occurred when analyzing layer %s (status code %s): %s', request['Layer']['Name'], ex.response.status_code, message) # 400 means the layer could not be analyzed due to a bad request. if ex.response.status_code == 400: if message == UNKNOWN_PARENT_LAYER_ERROR_MSG: raise MissingParentLayerException('Bad request to security scanner: %s' % message) else: logger.exception('Got non-200 response for analyze of layer %s', layer.id) raise AnalyzeLayerException('Bad request to security scanner: %s' % message) # 422 means that the layer could not be analyzed: # - the layer could not be extracted (might be a manifest or an invalid .tar.gz) # - the layer operating system / package manager is unsupported elif ex.response.status_code == 422: raise InvalidLayerException # Otherwise, it is some other error and we should retry. raise AnalyzeLayerRetryException # Return the parsed API version. return _response_json(request, response)['Layer']['IndexedByVersion'] def check_layer_vulnerable(self, layer_id, cve_name): """ Checks to see if the layer with the given ID is vulnerable to the specified CVE. """ layer_data = self._get_layer_data(layer_id, include_vulnerabilities=True) if layer_data is None or 'Layer' not in layer_data or 'Features' not in layer_data['Layer']: return False for feature in layer_data['Layer']['Features']: for vuln in feature.get('Vulnerabilities', []): if vuln['Name'] == cve_name: return True return False def get_notification(self, notification_name, layer_limit=100, page=None): """ Gets the data for a specific notification, with optional page token. Returns a tuple of the data (None on failure) and whether to retry. """ try: params = { 'limit': layer_limit } if page is not None: params['page'] = page response = self._call('GET', _API_METHOD_GET_NOTIFICATION % notification_name, params=params) json_response = response.json() except requests.exceptions.Timeout: logger.exception('Timeout when trying to get notification for %s', notification_name) return None, True except requests.exceptions.ConnectionError: logger.exception('Connection error when trying to get notification for %s', notification_name) return None, True except (requests.exceptions.RequestException, ValueError): logger.exception('Failed to get notification for %s', notification_name) return None, False except Non200ResponseException as ex: return None, ex.response.status_code != 404 and ex.response.status_code != 400 return json_response, False def mark_notification_read(self, notification_name): """ Marks a security scanner notification as read. """ try: self._call('DELETE', _API_METHOD_MARK_NOTIFICATION_READ % notification_name) return True except Non200ResponseException: return False except requests.exceptions.RequestException: logger.exception('Failed to mark notification as read: %s', notification_name) return False def get_layer_data(self, layer, include_features=False, include_vulnerabilities=False): """ Returns the layer data for the specified layer. On error, returns None. """ layer_id = compute_layer_id(layer) return self._get_layer_data(layer_id, include_features, include_vulnerabilities) def _get_layer_data(self, layer_id, include_features=False, include_vulnerabilities=False): params = {} if include_features: params = {'features': True} if include_vulnerabilities: params = {'vulnerabilities': True} try: response = self._call('GET', _API_METHOD_GET_LAYER % layer_id, params=params) logger.debug('Got response %s for vulnerabilities for layer %s', response.status_code, layer_id) try: return response.json() except ValueError: logger.exception('Failed to decode response JSON') return None except Non200ResponseException as ex: logger.debug('Got failed response %s for vulnerabilities for layer %s', ex.response.status_code, layer_id) if ex.response.status_code == 404: return None else: logger.error( 'downstream security service failure: status %d, text: %s', ex.response.status_code, ex.response.text, ) if ex.response.status_code // 100 == 5: raise APIRequestFailure('Downstream service returned 5xx') else: raise APIRequestFailure('Downstream service returned non-200') except requests.exceptions.Timeout: raise APIRequestFailure('API call timed out') except requests.exceptions.ConnectionError: raise APIRequestFailure('Could not connect to security service') except requests.exceptions.RequestException: logger.exception('Failed to get layer data response for %s', layer_id) raise APIRequestFailure() def _request(self, method, endpoint, path, body, params, timeout): """ Issues an HTTP request to the security endpoint. """ url = _join_api_url(endpoint, self._config.get('SECURITY_SCANNER_API_VERSION', 'v1'), path) signer_proxy_url = self._config.get('JWTPROXY_SIGNER', 'localhost:8080') logger.debug('%sing security URL %s', method.upper(), url) resp = self._client.request(method, url, json=body, params=params, timeout=timeout, verify=MITM_CERT_PATH, headers=DEFAULT_HTTP_HEADERS, proxies={'https': 'https://' + signer_proxy_url, 'http': 'http://' + signer_proxy_url}) if resp.status_code // 100 != 2: raise Non200ResponseException(resp) return resp def _call(self, method, path, params=None, body=None): """ Issues an HTTP request to the security endpoint handling the logic of using an alternative BATCH endpoint for non-GET requests and failover for GET requests. """ timeout = self._config.get('SECURITY_SCANNER_API_TIMEOUT_SECONDS', 1) endpoint = self._config['SECURITY_SCANNER_ENDPOINT'] with CloseForLongOperation(self._config): # If the request isn't a read, attempt to use a batch stack and do not fail over. if method != 'GET': if self._config.get('SECURITY_SCANNER_ENDPOINT_BATCH') is not None: endpoint = self._config['SECURITY_SCANNER_ENDPOINT_BATCH'] timeout = self._config.get('SECURITY_SCANNER_API_BATCH_TIMEOUT_SECONDS') or timeout return self._request(method, endpoint, path, body, params, timeout) # The request is read-only and can failover. all_endpoints = [endpoint] + self._config.get('SECURITY_SCANNER_READONLY_FAILOVER_ENDPOINTS', []) return _failover_read_request(*[((self._request, endpoint, path, body, params, timeout), {}) for endpoint in all_endpoints]) def _join_api_url(endpoint, api_version, path): pathless_url = urljoin(endpoint, '/' + api_version) + '/' return urljoin(pathless_url, path) @failover def _failover_read_request(request_fn, endpoint, path, body, params, timeout): """ This function auto-retries read-only requests until they return a 2xx status code. """ try: return request_fn('GET', endpoint, path, body, params, timeout) except (requests.exceptions.RequestException, Non200ResponseException) as ex: raise FailoverException(ex)