diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/api/auth.py | 104 |
1 files changed, 95 insertions, 9 deletions
diff --git a/synapse/api/auth.py b/synapse/api/auth.py index 65ee1452ce..f8ea1e2c69 100644 --- a/synapse/api/auth.py +++ b/synapse/api/auth.py @@ -23,6 +23,7 @@ from synapse.util.logutils import log_function from synapse.types import UserID import logging +import pymacaroons logger = logging.getLogger(__name__) @@ -40,6 +41,12 @@ class Auth(object): self.store = hs.get_datastore() self.state = hs.get_state_handler() self.TOKEN_NOT_FOUND_HTTP_STATUS = 401 + self._KNOWN_CAVEAT_PREFIXES = set([ + "gen = ", + "type = ", + "time < ", + "user_id = ", + ]) def check(self, event, auth_events): """ Checks if this event is correctly authed. @@ -359,8 +366,8 @@ class Auth(object): except KeyError: pass # normal users won't have the user_id query parameter set. - user_info = yield self.get_user_by_access_token(access_token) - user = user_info["user"] + user_info = yield self._get_user_by_access_token(access_token) + user_id = user_info["user_id"] token_id = user_info["token_id"] ip_addr = self.hs.get_ip_from_request(request) @@ -368,17 +375,17 @@ class Auth(object): "User-Agent", default=[""] )[0] - if user and access_token and ip_addr: + if user_id and access_token and ip_addr: self.store.insert_client_ip( - user=user, + user=user_id, access_token=access_token, ip=ip_addr, user_agent=user_agent ) - request.authenticated_entity = user.to_string() + request.authenticated_entity = user_id.to_string() - defer.returnValue((user, token_id,)) + defer.returnValue((user_id, token_id,)) except KeyError: raise AuthError( self.TOKEN_NOT_FOUND_HTTP_STATUS, "Missing access token.", @@ -386,7 +393,7 @@ class Auth(object): ) @defer.inlineCallbacks - def get_user_by_access_token(self, token): + def _get_user_by_access_token(self, token): """ Get a registered user's ID. Args: @@ -396,6 +403,86 @@ class Auth(object): Raises: AuthError if no user by that token exists or the token is invalid. """ + try: + ret = yield self._get_user_from_macaroon(token) + except AuthError: + # TODO(daniel): Remove this fallback when all existing access tokens + # have been re-issued as macaroons. + ret = yield self._look_up_user_by_access_token(token) + defer.returnValue(ret) + + @defer.inlineCallbacks + def _get_user_from_macaroon(self, macaroon_str): + try: + macaroon = pymacaroons.Macaroon.deserialize(macaroon_str) + self._validate_macaroon(macaroon) + + user_prefix = "user_id = " + for caveat in macaroon.caveats: + if caveat.caveat_id.startswith(user_prefix): + user_id = UserID.from_string(caveat.caveat_id[len(user_prefix):]) + # This codepath exists so that we can actually return a + # token ID, because we use token IDs in place of device + # identifiers throughout the codebase. + # TODO(daniel): Remove this fallback when device IDs are + # properly implemented. + ret = yield self._look_up_user_by_access_token(macaroon_str) + if ret["user_id"] != user_id: + logger.error( + "Macaroon user (%s) != DB user (%s)", + user_id, + ret["user_id"] + ) + raise AuthError( + self.TOKEN_NOT_FOUND_HTTP_STATUS, + "User mismatch in macaroon", + errcode=Codes.UNKNOWN_TOKEN + ) + defer.returnValue(ret) + raise AuthError( + self.TOKEN_NOT_FOUND_HTTP_STATUS, "No user caveat in macaroon", + errcode=Codes.UNKNOWN_TOKEN + ) + except (pymacaroons.exceptions.MacaroonException, TypeError, ValueError): + raise AuthError( + self.TOKEN_NOT_FOUND_HTTP_STATUS, "Invalid macaroon passed.", + errcode=Codes.UNKNOWN_TOKEN + ) + + def _validate_macaroon(self, macaroon): + v = pymacaroons.Verifier() + v.satisfy_exact("gen = 1") + v.satisfy_exact("type = access") + v.satisfy_general(lambda c: c.startswith("user_id = ")) + v.satisfy_general(self._verify_expiry) + v.verify(macaroon, self.hs.config.macaroon_secret_key) + + v = pymacaroons.Verifier() + v.satisfy_general(self._verify_recognizes_caveats) + v.verify(macaroon, self.hs.config.macaroon_secret_key) + + def _verify_expiry(self, caveat): + prefix = "time < " + if not caveat.startswith(prefix): + return False + # TODO(daniel): Enable expiry check when clients actually know how to + # refresh tokens. (And remember to enable the tests) + return True + expiry = int(caveat[len(prefix):]) + now = self.hs.get_clock().time_msec() + return now < expiry + + def _verify_recognizes_caveats(self, caveat): + first_space = caveat.find(" ") + if first_space < 0: + return False + second_space = caveat.find(" ", first_space + 1) + if second_space < 0: + return False + return caveat[:second_space + 1] in self._KNOWN_CAVEAT_PREFIXES + + @defer.inlineCallbacks + def _look_up_user_by_access_token(self, token): ret = yield self.store.get_user_by_access_token(token) if not ret: raise AuthError( @@ -403,10 +490,9 @@ class Auth(object): errcode=Codes.UNKNOWN_TOKEN ) user_info = { - "user": UserID.from_string(ret.get("name")), + "user_id": UserID.from_string(ret.get("name")), "token_id": ret.get("token_id", None), } - defer.returnValue(user_info) @defer.inlineCallbacks |