import logging from abc import ABCMeta, abstractmethod from six import add_metaclass from urlparse import urljoin from posixpath import join import requests from data.database import CloseForLongOperation from util.abchelpers import nooper from util.failover import failover, FailoverException from util.security.instancekeys import InstanceKeys from util.security.registry_jwt import build_context_and_subject, generate_bearer_token, QUAY_TUF_ROOT DEFAULT_HTTP_HEADERS = {'Connection': 'close'} MITM_CERT_PATH = '/conf/mitm.cert' TOKEN_VALIDITY_LIFETIME_S = 60 * 60 # 1 hour logger = logging.getLogger(__name__) class InvalidMetadataException(Exception): """ Exception raised when the upstream API metadata that doesn't parse correctly. """ pass 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 class TUFMetadataAPI(object): """ Helper class for talking to the Security Scan service (usually Clair). """ def __init__(self, app, config, client=None): feature_enabled = config.get('FEATURE_SIGNING', False) if feature_enabled: self.state = ImplementedTUFMetadataAPI(app, config, client=client) else: self.state = NoopTUFMetadataAPI() def __getattr__(self, name): return getattr(self.state, name, None) @add_metaclass(ABCMeta) class TUFMetadataAPIInterface(object): """ Helper class for talking to the TUF Metadata service (Apostille). """ @abstractmethod def get_default_tags_with_expiration(self, namespace, repository, targets_file=None): """ Gets the tag -> sha mappings for a repo, as well as the expiration of the signatures. Does not verify the metadata, this is purely for display purposes. Args: namespace: namespace containing the repository repository: the repo to get tags for targets_file: the specific delegation to read from. Default: targets/releases.json Returns: targets, expiration or None, None """ pass @abstractmethod def delete_metadata(self, namespace, repository): """ Deletes the TUF metadata for a repo Args: namespace: namespace containing the repository repository: the repo to delete metadata for Returns: True if successful, False otherwise """ pass @nooper class NoopTUFMetadataAPI(TUFMetadataAPIInterface): """ No-op version of the TUF API. """ pass class ImplementedTUFMetadataAPI(TUFMetadataAPIInterface): def __init__(self, app, config, client=None): self._app = app self._instance_keys = InstanceKeys(app) self._config = config self._client = client or config['HTTPCLIENT'] self._gun_prefix = config['TUF_GUN_PREFIX'] or config['SERVER_HOSTNAME'] def get_default_tags_with_expiration(self, namespace, repository, targets_file=None): """ Gets the tag -> sha mappings for a repo, as well as the expiration of the signatures. Does not verify the metadata, this is purely for display purposes. Args: namespace: namespace containing the repository repository: the repo to get tags for targets_file: the specific delegation to read from. Default: targets/releases.json Returns: targets, expiration or None, None """ if not targets_file: targets_file = 'targets/releases.json' gun = self._gun(namespace, repository) try: response = self._get(gun, targets_file) signed = self._parse_signed(response.json()) targets = signed.get('targets') expiration = signed.get('expires') except requests.exceptions.Timeout: logger.exception('Timeout when trying to get metadata for %s', gun) return None, None except requests.exceptions.ConnectionError: logger.exception('Connection error when trying to get metadata for %s', gun) return None, None except (requests.exceptions.RequestException, ValueError): logger.exception('Failed to get metadata for %s', gun) return None, None except Non200ResponseException as ex: logger.exception('Failed request for %s: %s', gun, str(ex)) return None, None except InvalidMetadataException as ex: logger.exception('Failed to parse targets from metadata', str(ex)) return None, None return targets, expiration def delete_metadata(self, namespace, repository): """ Deletes the TUF metadata for a repo Args: namespace: namespace containing the repository repository: the repo to delete metadata for Returns: True if successful, False otherwise """ gun = self._gun(namespace, repository) try: self._delete(gun) except requests.exceptions.Timeout: logger.exception('Timeout when trying to delete metadata for %s', gun) return False except requests.exceptions.ConnectionError: logger.exception('Connection error when trying to delete metadata for %s', gun) return False except (requests.exceptions.RequestException, ValueError): logger.exception('Failed to delete metadata for %s', gun) return False except Non200ResponseException as ex: logger.exception('Failed request for %s: %s', gun, str(ex)) return False return True def _gun(self, namespace, repository): return join(self._gun_prefix, namespace, repository) def _parse_signed(self, json_response): """ Attempts to parse the targets from a metadata response """ signed = json_response.get('signed') if not signed: raise InvalidMetadataException("Could not find `signed` in metadata: %s" % json_response) return signed def _auth_header(self, gun, actions): """ Generate a registry auth token for apostille""" access = [{ 'type': 'repository', 'name': gun, 'actions': actions, }] context, subject = build_context_and_subject(user=None, token=None, oauthtoken=None, tuf_root=QUAY_TUF_ROOT) token = generate_bearer_token(self._config["SERVER_HOSTNAME"], subject, context, access, TOKEN_VALIDITY_LIFETIME_S, self._instance_keys) return {'Authorization': 'Bearer %s' % token} def _get(self, gun, metadata_file): return self._call('GET', '/v2/%s/_trust/tuf/%s' % (gun, metadata_file), headers=self._auth_header(gun, ['pull'])) def _delete(self, gun): return self._call('DELETE', '/v2/%s/_trust/tuf/' % (gun), headers=self._auth_header(gun, ['*'])) def _request(self, method, endpoint, path, body, headers, params, timeout): """ Issues an HTTP request to the signing endpoint. """ url = urljoin(endpoint, path) logger.debug('%sing signing URL %s', method.upper(), url) headers.update(DEFAULT_HTTP_HEADERS) resp = self._client.request(method, url, json=body, params=params, timeout=timeout, verify=MITM_CERT_PATH, headers=headers) if resp.status_code // 100 != 2: raise Non200ResponseException(resp) return resp def _call(self, method, path, params=None, body=None, headers=None): """ Issues an HTTP request to signing service and handles failover for GET requests. """ timeout = self._config.get('TUF_API_TIMEOUT_SECONDS', 1) endpoint = self._config['TUF_SERVER'] with CloseForLongOperation(self._config): # If the request isn't a read do not fail over. if method != 'GET': return self._request(method, endpoint, path, body, headers, params, timeout) # The request is read-only and can failover. all_endpoints = [endpoint] + self._config.get('TUF_READONLY_FAILOVER_ENDPOINTS', []) return _failover_read_request(*[((self._request, endpoint, path, body, headers, params, timeout), {}) for endpoint in all_endpoints]) @failover def _failover_read_request(request_fn, endpoint, path, body, headers, params, timeout): """ This function auto-retries read-only requests until they return a 2xx status code. """ try: return request_fn('GET', endpoint, path, body, headers, params, timeout) except (requests.exceptions.RequestException, Non200ResponseException) as ex: raise FailoverException(ex)