diff options
| -rw-r--r-- | common/src/leap/soledad/common/couch/state.py | 46 | ||||
| -rw-r--r-- | common/src/leap/soledad/common/tests/test_server.py | 31 | ||||
| -rw-r--r-- | server/src/leap/soledad/server/auth.py | 52 |
3 files changed, 79 insertions, 50 deletions
diff --git a/common/src/leap/soledad/common/couch/state.py b/common/src/leap/soledad/common/couch/state.py index 39d49fa0..40c0d55b 100644 --- a/common/src/leap/soledad/common/couch/state.py +++ b/common/src/leap/soledad/common/couch/state.py @@ -19,11 +19,14 @@ Server state using CouchDatabase as backend. """ import re import logging +import time from urlparse import urljoin +from hashlib import sha512 from u1db.remote.server_state import ServerState from leap.soledad.common.command import exec_validated_cmd from leap.soledad.common.couch import CouchDatabase +from leap.soledad.common.couch import couch_server from u1db.errors import Unauthorized @@ -50,6 +53,12 @@ class CouchServerState(ServerState): Inteface of the WSGI server with the CouchDB backend. """ + TOKENS_DB_PREFIX = "tokens_" + TOKENS_DB_EXPIRE = 30 * 24 * 3600 # 30 days in seconds + TOKENS_TYPE_KEY = "type" + TOKENS_TYPE_DEF = "Token" + TOKENS_USER_ID_KEY = "user_id" + def __init__(self, couch_url, create_cmd=None): """ Initialize the couch server state. @@ -112,3 +121,40 @@ class CouchServerState(ServerState): delete databases. """ raise Unauthorized() + + def verify_token(self, uuid, token): + """ + Query couchdb to decide if C{token} is valid for C{uuid}. + + @param uuid: The user uuid. + @type uuid: str + @param token: The token. + @type token: str + """ + with couch_server(self.couch_url) as server: + # the tokens db rotates every 30 days, and the current db name is + # "tokens_NNN", where NNN is the number of seconds since epoch divided + # by the rotate period in seconds. When rotating, old and new tokens + # db coexist during a certain window of time and valid tokens are + # replicated from the old db to the new one. See: + # https://leap.se/code/issues/6785 + dbname = self._tokens_dbname() + db = server[dbname] + # lookup key is a hash of the token to prevent timing attacks. + token = db.get(sha512(token).hexdigest()) + if token is None: + return False + # we compare uuid hashes to avoid possible timing attacks that + # might exploit python's builtin comparison operator behaviour, + # which fails immediatelly when non-matching bytes are found. + couch_uuid_hash = sha512(token[self.TOKENS_USER_ID_KEY]).digest() + req_uuid_hash = sha512(uuid).digest() + if token[self.TOKENS_TYPE_KEY] != self.TOKENS_TYPE_DEF \ + or couch_uuid_hash != req_uuid_hash: + return False + return True + + def _tokens_dbname(self): + dbname = self.TOKENS_DB_PREFIX + \ + str(int(time.time() / self.TOKENS_DB_EXPIRE)) + return dbname diff --git a/common/src/leap/soledad/common/tests/test_server.py b/common/src/leap/soledad/common/tests/test_server.py index d75275d6..e1129a9f 100644 --- a/common/src/leap/soledad/common/tests/test_server.py +++ b/common/src/leap/soledad/common/tests/test_server.py @@ -24,6 +24,7 @@ import time import binascii from pkg_resources import resource_filename from uuid import uuid4 +from hashlib import sha512 from urlparse import urljoin from twisted.internet import defer @@ -46,6 +47,36 @@ from leap.soledad.server import LockResource from leap.soledad.server import load_configuration from leap.soledad.server import CONFIG_DEFAULTS from leap.soledad.server.auth import URLToAuthorization +from leap.soledad.server.auth import SoledadTokenAuthMiddleware + + +class ServerAuthenticationMiddlewareTestCase(CouchDBTestCase): + + def setUp(self): + super(ServerAuthenticationMiddlewareTestCase, self).setUp() + app = mock.Mock() + self._state = CouchServerState(self.couch_url) + app.state = self._state + self.auth_middleware = SoledadTokenAuthMiddleware(app) + self._authorize('valid-uuid', 'valid-token') + + def _authorize(self, uuid, token): + token_doc = {} + token_doc['_id'] = sha512(token).hexdigest() + token_doc[self._state.TOKENS_USER_ID_KEY] = uuid + token_doc[self._state.TOKENS_TYPE_KEY] = \ + self._state.TOKENS_TYPE_DEF + dbname = self._state._tokens_dbname() + db = self.couch_server.create(dbname) + db.save(token_doc) + self.addCleanup(self.delete_db, db.name) + + def test_authorized_user(self): + is_authorized = self.auth_middleware._verify_authentication_data + self.assertTrue(is_authorized('valid-uuid', 'valid-token')) + self.assertFalse(is_authorized('valid-uuid', 'invalid-token')) + self.assertFalse(is_authorized('invalid-uuid', 'valid-token')) + self.assertFalse(is_authorized('eve', 'invalid-token')) class ServerAuthorizationTestCase(BaseSoledadTest): diff --git a/server/src/leap/soledad/server/auth.py b/server/src/leap/soledad/server/auth.py index 02b54cca..01baf1ce 100644 --- a/server/src/leap/soledad/server/auth.py +++ b/server/src/leap/soledad/server/auth.py @@ -21,20 +21,16 @@ Authentication facilities for Soledad Server. """ -import time import httplib import json from u1db import DBNAME_CONSTRAINTS, errors as u1db_errors from abc import ABCMeta, abstractmethod from routes.mapper import Mapper -from couchdb.client import Server from twisted.python import log -from hashlib import sha512 from leap.soledad.common import SHARED_DB_NAME from leap.soledad.common import USER_DB_PREFIX -from leap.soledad.common.errors import InvalidAuthTokenError class URLToAuthorization(object): @@ -193,6 +189,7 @@ class SoledadAuthMiddleware(object): @type prefix: str """ self._app = app + self._state = app.state def _error(self, start_response, status, description, message=None): """ @@ -351,12 +348,6 @@ class SoledadTokenAuthMiddleware(SoledadAuthMiddleware): Token based authentication. """ - TOKENS_DB_PREFIX = "tokens_" - TOKENS_DB_EXPIRE = 30 * 24 * 3600 # 30 days in seconds - TOKENS_TYPE_KEY = "type" - TOKENS_TYPE_DEF = "Token" - TOKENS_USER_ID_KEY = "user_id" - TOKEN_AUTH_ERROR_STRING = "Incorrect address or token." def _verify_authentication_scheme(self, scheme): @@ -391,50 +382,11 @@ class SoledadTokenAuthMiddleware(SoledadAuthMiddleware): """ token = auth_data # we expect a cleartext token at this point try: - return self._verify_token_in_couch(uuid, token) - except InvalidAuthTokenError: - raise + return self._state.verify_token(uuid, token) except Exception as e: log.err(e) return False - def _verify_token_in_couch(self, uuid, token): - """ - Query couchdb to decide if C{token} is valid for C{uuid}. - - @param uuid: The user uuid. - @type uuid: str - @param token: The token. - @type token: str - - @raise InvalidAuthTokenError: Raised when token received from user is - either missing in the tokens db or is - invalid. - """ - server = Server(url=self._app.state.couch_url) - # the tokens db rotates every 30 days, and the current db name is - # "tokens_NNN", where NNN is the number of seconds since epoch divided - # by the rotate period in seconds. When rotating, old and new tokens - # db coexist during a certain window of time and valid tokens are - # replicated from the old db to the new one. See: - # https://leap.se/code/issues/6785 - dbname = self.TOKENS_DB_PREFIX + \ - str(int(time.time() / self.TOKENS_DB_EXPIRE)) - db = server[dbname] - # lookup key is a hash of the token to prevent timing attacks. - token = db.get(sha512(token).hexdigest()) - if token is None: - raise InvalidAuthTokenError() - # we compare uuid hashes to avoid possible timing attacks that - # might exploit python's builtin comparison operator behaviour, - # which fails immediatelly when non-matching bytes are found. - couch_uuid_hash = sha512(token[self.TOKENS_USER_ID_KEY]).digest() - req_uuid_hash = sha512(uuid).digest() - if token[self.TOKENS_TYPE_KEY] != self.TOKENS_TYPE_DEF \ - or couch_uuid_hash != req_uuid_hash: - raise InvalidAuthTokenError() - return True - def _get_auth_error_string(self): """ Get the error string for token auth. |