osm_nbi/auth.py

   1 # -*- coding: utf-8 -*-
   2
   3 # Copyright 2018 Whitestack, LLC
   4 # Copyright 2018 Telefonica S.A.
   5 #
   6 # Licensed under the Apache License, Version 2.0 (the "License"); you may
   7 # not use this file except in compliance with the License. You may obtain
   8 # a copy of the License at
   9 #
  10 #         http://www.apache.org/licenses/LICENSE-2.0
  11 #
  12 # Unless required by applicable law or agreed to in writing, software
  13 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  14 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  15 # License for the specific language governing permissions and limitations
  16 # under the License.
  17 #
  18 # For those usages not covered by the Apache License, Version 2.0 please
  19 # contact: esousa@whitestack.com or alfonso.tiernosepulveda@telefonica.com
  20 ##
  21
  22
  23 """
  24 Authenticator is responsible for authenticating the users,
  25 create the tokens unscoped and scoped, retrieve the role
  26 list inside the projects that they are inserted
  27 """
  28
  29 __author__ = "Eduardo Sousa <esousa@whitestack.com>; Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
  30 __date__ = "$27-jul-2018 23:59:59$"
  31
  32 import cherrypy
  33 import logging
  34 import yaml
  35 from base64 import standard_b64decode
  36 from copy import deepcopy
  37 # from functools import reduce
  38 from http import HTTPStatus
  39 from time import time
  40 from os import path
  41
  42 from osm_nbi.authconn import AuthException, AuthExceptionUnauthorized
  43 from osm_nbi.authconn_keystone import AuthconnKeystone
  44 from osm_nbi.authconn_internal import AuthconnInternal
  45 from osm_common import dbmemory, dbmongo, msglocal, msgkafka
  46 from osm_common.dbbase import DbException
  47 from osm_nbi.validation import is_valid_uuid
  48 from itertools import chain
  49 from uuid import uuid4
  50
  51
  52 class Authenticator:
  53     """
  54     This class should hold all the mechanisms for User Authentication and
  55     Authorization. Initially it should support Openstack Keystone as a
  56     backend through a plugin model where more backends can be added and a
  57     RBAC model to manage permissions on operations.
  58     This class must be threading safe
  59     """
  60
  61     periodin_db_pruning = 60 * 30  # for the internal backend only. every 30 minutes expired tokens will be pruned
  62     token_limit = 500   # when reached, the token cache will be cleared
  63
  64     def __init__(self, valid_methods, valid_query_string):
  65         """
  66         Authenticator initializer. Setup the initial state of the object,
  67         while it waits for the config dictionary and database initialization.
  68         """
  69         self.backend = None
  70         self.config = None
  71         self.db = None
  72         self.msg = None
  73         self.tokens_cache = dict()
  74         self.next_db_prune_time = 0  # time when next cleaning of expired tokens must be done
  75         self.roles_to_operations_file = None
  76         # self.roles_to_operations_table = None
  77         self.resources_to_operations_mapping = {}
  78         self.operation_to_allowed_roles = {}
  79         self.logger = logging.getLogger("nbi.authenticator")
  80         self.role_permissions = []
  81         self.valid_methods = valid_methods
  82         self.valid_query_string = valid_query_string
  83         self.system_admin_role_id = None   # system_role id
  84         self.test_project_id = None  # test_project_id
  85
  86     def start(self, config):
  87         """
  88         Method to configure the Authenticator object. This method should be called
  89         after object creation. It is responsible by initializing the selected backend,
  90         as well as the initialization of the database connection.
  91
  92         :param config: dictionary containing the relevant parameters for this object.
  93         """
  94         self.config = config
  95
  96         try:
  97             if not self.db:
  98                 if config["database"]["driver"] == "mongo":
  99                     self.db = dbmongo.DbMongo()
 100                     self.db.db_connect(config["database"])
 101                 elif config["database"]["driver"] == "memory":
 102                     self.db = dbmemory.DbMemory()
 103                     self.db.db_connect(config["database"])
 104                 else:
 105                     raise AuthException("Invalid configuration param '{}' at '[database]':'driver'"
 106                                         .format(config["database"]["driver"]))
 107             if not self.msg:
 108                 if config["message"]["driver"] == "local":
 109                     self.msg = msglocal.MsgLocal()
 110                     self.msg.connect(config["message"])
 111                 elif config["message"]["driver"] == "kafka":
 112                     self.msg = msgkafka.MsgKafka()
 113                     self.msg.connect(config["message"])
 114                 else:
 115                     raise AuthException("Invalid configuration param '{}' at '[message]':'driver'"
 116                                         .format(config["message"]["driver"]))
 117             if not self.backend:
 118                 if config["authentication"]["backend"] == "keystone":
 119                     self.backend = AuthconnKeystone(self.config["authentication"], self.db, self.role_permissions)
 120                 elif config["authentication"]["backend"] == "internal":
 121                     self.backend = AuthconnInternal(self.config["authentication"], self.db, self.role_permissions)
 122                     self._internal_tokens_prune()
 123                 else:
 124                     raise AuthException("Unknown authentication backend: {}"
 125                                         .format(config["authentication"]["backend"]))
 126
 127             if not self.roles_to_operations_file:
 128                 if "roles_to_operations" in config["rbac"]:
 129                     self.roles_to_operations_file = config["rbac"]["roles_to_operations"]
 130                 else:
 131                     possible_paths = (
 132                         __file__[:__file__.rfind("auth.py")] + "roles_to_operations.yml",
 133                         "./roles_to_operations.yml"
 134                     )
 135                     for config_file in possible_paths:
 136                         if path.isfile(config_file):
 137                             self.roles_to_operations_file = config_file
 138                             break
 139                 if not self.roles_to_operations_file:
 140                     raise AuthException("Invalid permission configuration: roles_to_operations file missing")
 141
 142             # load role_permissions
 143             def load_role_permissions(method_dict):
 144                 for k in method_dict:
 145                     if k == "ROLE_PERMISSION":
 146                         for method in chain(method_dict.get("METHODS", ()), method_dict.get("TODO", ())):
 147                             permission = method_dict["ROLE_PERMISSION"] + method.lower()
 148                             if permission not in self.role_permissions:
 149                                 self.role_permissions.append(permission)
 150                     elif k in ("TODO", "METHODS"):
 151                         continue
 152                     elif method_dict[k]:
 153                         load_role_permissions(method_dict[k])
 154
 155             load_role_permissions(self.valid_methods)
 156             for query_string in self.valid_query_string:
 157                 for method in ("get", "put", "patch", "post", "delete"):
 158                     permission = query_string.lower() + ":" + method
 159                     if permission not in self.role_permissions:
 160                         self.role_permissions.append(permission)
 161
 162             # get ids of role system_admin and test project
 163             role_system_admin = self.db.get_one("roles", {"name": "system_admin"}, fail_on_empty=False)
 164             if role_system_admin:
 165                 self.system_admin_role_id = role_system_admin["_id"]
 166             test_project_name = self.config["authentication"].get("project_not_authorized", "admin")
 167             test_project = self.db.get_one("projects", {"name": test_project_name}, fail_on_empty=False)
 168             if test_project:
 169                 self.test_project_id = test_project["_id"]
 170
 171         except Exception as e:
 172             raise AuthException(str(e))
 173
 174     def stop(self):
 175         try:
 176             if self.db:
 177                 self.db.db_disconnect()
 178         except DbException as e:
 179             raise AuthException(str(e), http_code=e.http_code)
 180
 181     def create_admin_project(self):
 182         """
 183         Creates a new project 'admin' into database if it doesn't exist. Useful for initialization.
 184         :return: _id identity of the 'admin' project
 185         """
 186
 187         # projects = self.db.get_one("projects", fail_on_empty=False, fail_on_more=False)
 188         project_desc = {"name": "admin"}
 189         projects = self.backend.get_project_list(project_desc)
 190         if projects:
 191             return projects[0]["_id"]
 192         now = time()
 193         project_desc["_id"] = str(uuid4())
 194         project_desc["_admin"] = {"created": now, "modified": now}
 195         pid = self.backend.create_project(project_desc)
 196         self.logger.info("Project '{}' created at database".format(project_desc["name"]))
 197         return pid
 198
 199     def create_admin_user(self, project_id):
 200         """
 201         Creates a new user admin/admin into database if database is empty. Useful for initialization
 202         :return: _id identity of the inserted data, or None
 203         """
 204         # users = self.db.get_one("users", fail_on_empty=False, fail_on_more=False)
 205         users = self.backend.get_user_list()
 206         if users:
 207             return None
 208         # user_desc = {"username": "admin", "password": "admin", "projects": [project_id]}
 209         now = time()
 210         user_desc = {"username": "admin", "password": "admin", "_admin": {"created": now, "modified": now}}
 211         if project_id:
 212             pid = project_id
 213         else:
 214             # proj = self.db.get_one("projects", {"name": "admin"}, fail_on_empty=False, fail_on_more=False)
 215             proj = self.backend.get_project_list({"name": "admin"})
 216             pid = proj[0]["_id"] if proj else None
 217         # role = self.db.get_one("roles", {"name": "system_admin"}, fail_on_empty=False, fail_on_more=False)
 218         roles = self.backend.get_role_list({"name": "system_admin"})
 219         if pid and roles:
 220             user_desc["project_role_mappings"] = [{"project": pid, "role": roles[0]["_id"]}]
 221         uid = self.backend.create_user(user_desc)
 222         self.logger.info("User '{}' created at database".format(user_desc["username"]))
 223         return uid
 224
 225     def init_db(self, target_version='1.0'):
 226         """
 227         Check if the database has been initialized, with at least one user. If not, create the required tables
 228         and insert the predefined mappings between roles and permissions.
 229
 230         :param target_version: schema version that should be present in the database.
 231         :return: None if OK, exception if error or version is different.
 232         """
 233
 234         records = self.backend.get_role_list()
 235
 236         # Loading permissions to MongoDB if there is not any permission.
 237         if not records or (len(records) == 1 and records[0]["name"] == "admin"):
 238             with open(self.roles_to_operations_file, "r") as stream:
 239                 roles_to_operations_yaml = yaml.load(stream, Loader=yaml.Loader)
 240
 241             role_names = []
 242             for role_with_operations in roles_to_operations_yaml["roles"]:
 243                 # Verifying if role already exists. If it does, raise exception
 244                 if role_with_operations["name"] not in role_names:
 245                     role_names.append(role_with_operations["name"])
 246                 else:
 247                     raise AuthException("Duplicated role name '{}' at file '{}''"
 248                                         .format(role_with_operations["name"], self.roles_to_operations_file))
 249
 250                 if not role_with_operations["permissions"]:
 251                     continue
 252
 253                 for permission, is_allowed in role_with_operations["permissions"].items():
 254                     if not isinstance(is_allowed, bool):
 255                         raise AuthException("Invalid value for permission '{}' at role '{}'; at file '{}'"
 256                                             .format(permission, role_with_operations["name"],
 257                                                     self.roles_to_operations_file))
 258
 259                     # TODO chek permission is ok
 260                     if permission[-1] == ":":
 261                         raise AuthException("Invalid permission '{}' terminated in ':' for role '{}'; at file {}"
 262                                             .format(permission, role_with_operations["name"],
 263                                                     self.roles_to_operations_file))
 264
 265                 if "default" not in role_with_operations["permissions"]:
 266                     role_with_operations["permissions"]["default"] = False
 267                 if "admin" not in role_with_operations["permissions"]:
 268                     role_with_operations["permissions"]["admin"] = False
 269
 270                 now = time()
 271                 role_with_operations["_admin"] = {
 272                     "created": now,
 273                     "modified": now,
 274                 }
 275
 276                 # self.db.create(self.roles_to_operations_table, role_with_operations)
 277                 self.backend.create_role(role_with_operations)
 278                 self.logger.info("Role '{}' created at database".format(role_with_operations["name"]))
 279
 280         # Create admin project&user if required
 281         pid = self.create_admin_project()
 282         user_id = self.create_admin_user(pid)
 283
 284         # try to assign system_admin role to user admin if not any user has this role
 285         if not user_id:
 286             try:
 287                 users = self.backend.get_user_list()
 288                 roles = self.backend.get_role_list({"name": "system_admin"})
 289                 role_id = roles[0]["_id"]
 290                 user_with_system_admin = False
 291                 user_admin_id = None
 292                 for user in users:
 293                     if not user_admin_id:
 294                         user_admin_id = user["_id"]
 295                     if user["username"] == "admin":
 296                         user_admin_id = user["_id"]
 297                     for prm in user.get("project_role_mappings", ()):
 298                         if prm["role"] == role_id:
 299                             user_with_system_admin = True
 300                             break
 301                     if user_with_system_admin:
 302                         break
 303                 if not user_with_system_admin:
 304                     self.backend.update_user({"_id": user_admin_id,
 305                                               "add_project_role_mappings": [{"project": pid, "role": role_id}]})
 306                     self.logger.info("Added role system admin to user='{}' project=admin".format(user_admin_id))
 307             except Exception as e:
 308                 self.logger.error("Error in Authorization DataBase initialization: {}: {}".format(type(e).__name__, e))
 309
 310         self.load_operation_to_allowed_roles()
 311
 312     def load_operation_to_allowed_roles(self):
 313         """
 314         Fills the internal self.operation_to_allowed_roles based on database role content and self.role_permissions
 315         It works in a shadow copy and replace at the end to allow other threads working with the old copy
 316         :return: None
 317         """
 318
 319         permissions = {oper: [] for oper in self.role_permissions}
 320         # records = self.db.get_list(self.roles_to_operations_table)
 321         records = self.backend.get_role_list()
 322
 323         ignore_fields = ["_id", "_admin", "name", "default"]
 324         for record in records:
 325             if not record.get("permissions"):
 326                 continue
 327             record_permissions = {oper: record["permissions"].get("default", False) for oper in self.role_permissions}
 328             operations_joined = [(oper, value) for oper, value in record["permissions"].items()
 329                                  if oper not in ignore_fields]
 330             operations_joined.sort(key=lambda x: x[0].count(":"))
 331
 332             for oper in operations_joined:
 333                 match = list(filter(lambda x: x.find(oper[0]) == 0, record_permissions.keys()))
 334
 335                 for m in match:
 336                     record_permissions[m] = oper[1]
 337
 338             allowed_operations = [k for k, v in record_permissions.items() if v is True]
 339
 340             for allowed_op in allowed_operations:
 341                 permissions[allowed_op].append(record["name"])
 342
 343         self.operation_to_allowed_roles = permissions
 344
 345     def authorize(self, role_permission=None, query_string_operations=None, item_id=None):
 346         token = None
 347         user_passwd64 = None
 348         try:
 349             # 1. Get token Authorization bearer
 350             auth = cherrypy.request.headers.get("Authorization")
 351             if auth:
 352                 auth_list = auth.split(" ")
 353                 if auth_list[0].lower() == "bearer":
 354                     token = auth_list[-1]
 355                 elif auth_list[0].lower() == "basic":
 356                     user_passwd64 = auth_list[-1]
 357             if not token:
 358                 if cherrypy.session.get("Authorization"):
 359                     # 2. Try using session before request a new token. If not, basic authentication will generate
 360                     token = cherrypy.session.get("Authorization")
 361                     if token == "logout":
 362                         token = None  # force Unauthorized response to insert user password again
 363                 elif user_passwd64 and cherrypy.request.config.get("auth.allow_basic_authentication"):
 364                     # 3. Get new token from user password
 365                     user = None
 366                     passwd = None
 367                     try:
 368                         user_passwd = standard_b64decode(user_passwd64).decode()
 369                         user, _, passwd = user_passwd.partition(":")
 370                     except Exception:
 371                         pass
 372                     outdata = self.new_token(None, {"username": user, "password": passwd})
 373                     token = outdata["_id"]
 374                     cherrypy.session['Authorization'] = token
 375
 376             if not token:
 377                 raise AuthException("Needed a token or Authorization http header",
 378                                     http_code=HTTPStatus.UNAUTHORIZED)
 379
 380             # try to get from cache first
 381             now = time()
 382             token_info = self.tokens_cache.get(token)
 383             if token_info and token_info["expires"] < now:
 384                 # delete token. MUST be done with care, as another thread maybe already delete it. Do not use del
 385                 self.tokens_cache.pop(token, None)
 386                 token_info = None
 387
 388             # get from database if not in cache
 389             if not token_info:
 390                 token_info = self.backend.validate_token(token)
 391                 # Clear cache if token limit reached
 392                 if len(self.tokens_cache) > self.token_limit:
 393                     self.tokens_cache.clear()
 394                 self.tokens_cache[token] = token_info
 395             # TODO add to token info remote host, port
 396
 397             if role_permission:
 398                 RBAC_auth = self.check_permissions(token_info, cherrypy.request.method, role_permission,
 399                                                    query_string_operations, item_id)
 400                 token_info["allow_show_user_project_role"] = RBAC_auth
 401
 402             return token_info
 403         except AuthException as e:
 404             if not isinstance(e, AuthExceptionUnauthorized):
 405                 if cherrypy.session.get('Authorization'):
 406                     del cherrypy.session['Authorization']
 407                 cherrypy.response.headers["WWW-Authenticate"] = 'Bearer realm="{}"'.format(e)
 408             if self.config["authentication"].get("user_not_authorized"):
 409                 return {"id": "testing-token", "_id": "testing-token",
 410                         "project_id": self.test_project_id,
 411                         "username": self.config["authentication"]["user_not_authorized"],
 412                         "roles": [self.system_admin_role_id],
 413                         "admin": True, "allow_show_user_project_role": True}
 414             raise
 415
 416     def new_token(self, token_info, indata, remote):
 417         new_token_info = self.backend.authenticate(
 418             credentials=indata,
 419             token_info=token_info,
 420         )
 421
 422         new_token_info["remote_port"] = remote.port
 423         if not new_token_info.get("expires"):
 424             new_token_info["expires"] = time() + 3600
 425         if not new_token_info.get("admin"):
 426             new_token_info["admin"] = True if new_token_info.get("project_name") == "admin" else False
 427             # TODO put admin in RBAC
 428
 429         if remote.name:
 430             new_token_info["remote_host"] = remote.name
 431         elif remote.ip:
 432             new_token_info["remote_host"] = remote.ip
 433
 434         # TODO call self._internal_tokens_prune(now) ?
 435         return deepcopy(new_token_info)
 436
 437     def get_token_list(self, token_info):
 438         if self.config["authentication"]["backend"] == "internal":
 439             return self._internal_get_token_list(token_info)
 440         else:
 441             # TODO: check if this can be avoided. Backend may provide enough information
 442             return [deepcopy(token) for token in self.tokens_cache.values()
 443                     if token["username"] == token_info["username"]]
 444
 445     def get_token(self, token_info, token):
 446         if self.config["authentication"]["backend"] == "internal":
 447             return self._internal_get_token(token_info, token)
 448         else:
 449             # TODO: check if this can be avoided. Backend may provide enough information
 450             token_value = self.tokens_cache.get(token)
 451             if not token_value:
 452                 raise AuthException("token not found", http_code=HTTPStatus.NOT_FOUND)
 453             if token_value["username"] != token_info["username"] and not token_info["admin"]:
 454                 raise AuthException("needed admin privileges", http_code=HTTPStatus.UNAUTHORIZED)
 455             return token_value
 456
 457     def del_token(self, token):
 458         try:
 459             self.backend.revoke_token(token)
 460             # self.tokens_cache.pop(token, None)
 461             self.remove_token_from_cache(token)
 462             return "token '{}' deleted".format(token)
 463         except KeyError:
 464             raise AuthException("Token '{}' not found".format(token), http_code=HTTPStatus.NOT_FOUND)
 465
 466     def check_permissions(self, token_info, method, role_permission=None, query_string_operations=None, item_id=None):
 467         """
 468         Checks that operation has permissions to be done, base on the assigned roles to this user project
 469         :param token_info: Dictionary that contains "roles" with a list of assigned roles.
 470             This method fills the token_info["admin"] with True or False based on assigned tokens, if any allows admin
 471             This will be used among others to hide or not the _admin content of topics
 472         :param method: GET,PUT, POST, ...
 473         :param role_permission: role permission name of the operation required
 474         :param query_string_operations: list of possible admin query strings provided by user. It is checked that the
 475             assigned role allows this query string for this method
 476         :param item_id: item identifier if included in the URL, None otherwise
 477         :return: True if access granted by permission rules, False if access granted by default rules (Bug 853)
 478         :raises: AuthExceptionUnauthorized if access denied
 479         """
 480
 481         roles_required = self.operation_to_allowed_roles[role_permission]
 482         roles_allowed = [role["name"] for role in token_info["roles"]]
 483
 484         # fills token_info["admin"] if some roles allows it
 485         token_info["admin"] = False
 486         for role in roles_allowed:
 487             if role in self.operation_to_allowed_roles["admin:" + method.lower()]:
 488                 token_info["admin"] = True
 489                 break
 490
 491         if "anonymous" in roles_required:
 492             return True
 493         operation_allowed = False
 494         for role in roles_allowed:
 495             if role in roles_required:
 496                 operation_allowed = True
 497                 # if query_string operations, check if this role allows it
 498                 if not query_string_operations:
 499                     return True
 500                 for query_string_operation in query_string_operations:
 501                     if role not in self.operation_to_allowed_roles[query_string_operation]:
 502                         break
 503                 else:
 504                     return True
 505
 506         # Bug 853 - Final Solution
 507         # User/Project/Role whole listings are filtered elsewhere
 508         # uid, pid, rid = ("user_id", "project_id", "id") if is_valid_uuid(id) else ("username", "project_name", "name")
 509         uid = "user_id" if is_valid_uuid(item_id) else "username"
 510         if (role_permission in ["projects:get", "projects:id:get", "roles:get", "roles:id:get", "users:get"]) \
 511                 or (role_permission == "users:id:get" and item_id == token_info[uid]):
 512             # or (role_permission == "projects:id:get" and item_id == token_info[pid]) \
 513             # or (role_permission == "roles:id:get" and item_id in [role[rid] for role in token_info["roles"]]):
 514             return False
 515
 516         if not operation_allowed:
 517             raise AuthExceptionUnauthorized("Access denied: lack of permissions.")
 518         else:
 519             raise AuthExceptionUnauthorized("Access denied: You have not permissions to use these admin query string")
 520
 521     def get_user_list(self):
 522         return self.backend.get_user_list()
 523
 524     def _normalize_url(self, url, method):
 525         # DEPRECATED !!!
 526         # Removing query strings
 527         normalized_url = url if '?' not in url else url[:url.find("?")]
 528         normalized_url_splitted = normalized_url.split("/")
 529         parameters = {}
 530
 531         filtered_keys = [key for key in self.resources_to_operations_mapping.keys()
 532                          if method in key.split()[0]]
 533
 534         for idx, path_part in enumerate(normalized_url_splitted):
 535             tmp_keys = []
 536             for tmp_key in filtered_keys:
 537                 splitted = tmp_key.split()[1].split("/")
 538                 if idx >= len(splitted):
 539                     continue
 540                 elif "<" in splitted[idx] and ">" in splitted[idx]:
 541                     if splitted[idx] == "<artifactPath>":
 542                         tmp_keys.append(tmp_key)
 543                         continue
 544                     elif idx == len(normalized_url_splitted) - 1 and \
 545                             len(normalized_url_splitted) != len(splitted):
 546                         continue
 547                     else:
 548                         tmp_keys.append(tmp_key)
 549                 elif splitted[idx] == path_part:
 550                     if idx == len(normalized_url_splitted) - 1 and \
 551                             len(normalized_url_splitted) != len(splitted):
 552                         continue
 553                     else:
 554                         tmp_keys.append(tmp_key)
 555             filtered_keys = tmp_keys
 556             if len(filtered_keys) == 1 and \
 557                     filtered_keys[0].split("/")[-1] == "<artifactPath>":
 558                 break
 559
 560         if len(filtered_keys) == 0:
 561             raise AuthException("Cannot make an authorization decision. URL not found. URL: {0}".format(url))
 562         elif len(filtered_keys) > 1:
 563             raise AuthException("Cannot make an authorization decision. Multiple URLs found. URL: {0}".format(url))
 564
 565         filtered_key = filtered_keys[0]
 566
 567         for idx, path_part in enumerate(filtered_key.split()[1].split("/")):
 568             if "<" in path_part and ">" in path_part:
 569                 if path_part == "<artifactPath>":
 570                     parameters[path_part[1:-1]] = "/".join(normalized_url_splitted[idx:])
 571                 else:
 572                     parameters[path_part[1:-1]] = normalized_url_splitted[idx]
 573
 574         return filtered_key, parameters
 575
 576     def _internal_get_token_list(self, token_info):
 577         now = time()
 578         token_list = self.db.get_list("tokens", {"username": token_info["username"], "expires.gt": now})
 579         return token_list
 580
 581     def _internal_get_token(self, token_info, token_id):
 582         token_value = self.db.get_one("tokens", {"_id": token_id}, fail_on_empty=False)
 583         if not token_value:
 584             raise AuthException("token not found", http_code=HTTPStatus.NOT_FOUND)
 585         if token_value["username"] != token_info["username"] and not token_info["admin"]:
 586             raise AuthException("needed admin privileges", http_code=HTTPStatus.UNAUTHORIZED)
 587         return token_value
 588
 589     def _internal_tokens_prune(self, now=None):
 590         now = now or time()
 591         if not self.next_db_prune_time or self.next_db_prune_time >= now:
 592             self.db.del_list("tokens", {"expires.lt": now})
 593             self.next_db_prune_time = self.periodin_db_pruning + now
 594             # self.tokens_cache.clear()  # not required any more
 595
 596     def remove_token_from_cache(self, token=None):
 597         if token:
 598             self.tokens_cache.pop(token, None)
 599         else:
 600             self.tokens_cache.clear()
 601         self.msg.write("admin", "revoke_token", {"_id": token} if token else None)