diff options
Diffstat (limited to 'synapse/api/auth.py')
| -rw-r--r-- | synapse/api/auth.py | 188 |
1 files changed, 145 insertions, 43 deletions
diff --git a/synapse/api/auth.py b/synapse/api/auth.py index 2474a1453b..0db26fcfd7 100644 --- a/synapse/api/auth.py +++ b/synapse/api/auth.py @@ -13,23 +13,22 @@ # See the License for the specific language governing permissions and # limitations under the License. -"""This module contains classes for authenticating the user.""" +import logging + +import pymacaroons from canonicaljson import encode_canonical_json from signedjson.key import decode_verify_key_bytes from signedjson.sign import verify_signed_json, SignatureVerifyException - from twisted.internet import defer +from unpaddedbase64 import decode_base64 +import synapse.types from synapse.api.constants import EventTypes, Membership, JoinRules from synapse.api.errors import AuthError, Codes, SynapseError, EventSizeError -from synapse.types import Requester, UserID, get_domain_from_id -from synapse.util.logutils import log_function +from synapse.types import UserID, get_domain_from_id from synapse.util.logcontext import preserve_context_over_fn +from synapse.util.logutils import log_function from synapse.util.metrics import Measure -from unpaddedbase64 import decode_base64 - -import logging -import pymacaroons logger = logging.getLogger(__name__) @@ -42,13 +41,20 @@ AuthEventTypes = ( class Auth(object): - + """ + FIXME: This class contains a mix of functions for authenticating users + of our client-server API and authenticating events added to room graphs. + """ def __init__(self, hs): self.hs = hs self.clock = hs.get_clock() self.store = hs.get_datastore() self.state = hs.get_state_handler() self.TOKEN_NOT_FOUND_HTTP_STATUS = 401 + # Docs for these currently lives at + # https://github.com/matrix-org/matrix-doc/blob/master/drafts/macaroons_caveats.rst + # In addition, we have type == delete_pusher which grants access only to + # delete pushers. self._KNOWN_CAVEAT_PREFIXES = set([ "gen = ", "guest = ", @@ -57,7 +63,7 @@ class Auth(object): "user_id = ", ]) - def check(self, event, auth_events): + def check(self, event, auth_events, do_sig_check=True): """ Checks if this event is correctly authed. Args: @@ -73,6 +79,13 @@ class Auth(object): if not hasattr(event, "room_id"): raise AuthError(500, "Event has no room_id: %s" % event) + + sender_domain = get_domain_from_id(event.sender) + + # Check the sender's domain has signed the event + if do_sig_check and not event.signatures.get(sender_domain): + raise AuthError(403, "Event not signed by sending server") + if auth_events is None: # Oh, we don't know what the state of the room was, so we # are trusting that this is allowed (at least for now) @@ -80,6 +93,12 @@ class Auth(object): return True if event.type == EventTypes.Create: + room_id_domain = get_domain_from_id(event.room_id) + if room_id_domain != sender_domain: + raise AuthError( + 403, + "Creation event's room_id domain does not match sender's" + ) # FIXME return True @@ -102,6 +121,22 @@ class Auth(object): # FIXME: Temp hack if event.type == EventTypes.Aliases: + if not event.is_state(): + raise AuthError( + 403, + "Alias event must be a state event", + ) + if not event.state_key: + raise AuthError( + 403, + "Alias event must have non-empty state_key" + ) + sender_domain = get_domain_from_id(event.sender) + if event.state_key != sender_domain: + raise AuthError( + 403, + "Alias event's state_key does not match sender's domain" + ) return True logger.debug( @@ -120,6 +155,24 @@ class Auth(object): return allowed self.check_event_sender_in_room(event, auth_events) + + # Special case to allow m.room.third_party_invite events wherever + # a user is allowed to issue invites. Fixes + # https://github.com/vector-im/vector-web/issues/1208 hopefully + if event.type == EventTypes.ThirdPartyInvite: + user_level = self._get_user_power_level(event.user_id, auth_events) + invite_level = self._get_named_level(auth_events, "invite", 0) + + if user_level < invite_level: + raise AuthError( + 403, ( + "You cannot issue a third party invite for %s." % + (event.content.display_name,) + ) + ) + else: + return True + self._can_send_event(event, auth_events) if event.type == EventTypes.PowerLevels: @@ -323,6 +376,10 @@ class Auth(object): if Membership.INVITE == membership and "third_party_invite" in event.content: if not self._verify_third_party_invite(event, auth_events): raise AuthError(403, "You are not invited to this room.") + if target_banned: + raise AuthError( + 403, "%s is banned from the room" % (target_user_id,) + ) return True if Membership.JOIN != membership: @@ -507,15 +564,13 @@ class Auth(object): return default @defer.inlineCallbacks - def get_user_by_req(self, request, allow_guest=False): + def get_user_by_req(self, request, allow_guest=False, rights="access"): """ Get a registered user's ID. Args: request - An HTTP request with an access_token query parameter. Returns: - tuple of: - UserID (str) - Access token ID (str) + defer.Deferred: resolves to a ``synapse.types.Requester`` object Raises: AuthError if no user by that token exists or the token is invalid. """ @@ -524,16 +579,18 @@ class Auth(object): user_id = yield self._get_appservice_user_id(request.args) if user_id: request.authenticated_entity = user_id - defer.returnValue( - Requester(UserID.from_string(user_id), "", False) - ) + defer.returnValue(synapse.types.create_requester(user_id)) access_token = request.args["access_token"][0] - user_info = yield self.get_user_by_access_token(access_token) + user_info = yield self.get_user_by_access_token(access_token, rights) user = user_info["user"] token_id = user_info["token_id"] is_guest = user_info["is_guest"] + # device_id may not be present if get_user_by_access_token has been + # stubbed out. + device_id = user_info.get("device_id") + ip_addr = self.hs.get_ip_from_request(request) user_agent = request.requestHeaders.getRawHeaders( "User-Agent", @@ -545,7 +602,8 @@ class Auth(object): user=user, access_token=access_token, ip=ip_addr, - user_agent=user_agent + user_agent=user_agent, + device_id=device_id, ) if is_guest and not allow_guest: @@ -555,7 +613,8 @@ class Auth(object): request.authenticated_entity = user.to_string() - defer.returnValue(Requester(user, token_id, is_guest)) + defer.returnValue(synapse.types.create_requester( + user, token_id, is_guest, device_id)) except KeyError: raise AuthError( self.TOKEN_NOT_FOUND_HTTP_STATUS, "Missing access token.", @@ -590,7 +649,7 @@ class Auth(object): defer.returnValue(user_id) @defer.inlineCallbacks - def get_user_by_access_token(self, token): + def get_user_by_access_token(self, token, rights="access"): """ Get a registered user's ID. Args: @@ -601,47 +660,61 @@ class Auth(object): AuthError if no user by that token exists or the token is invalid. """ try: - ret = yield self.get_user_from_macaroon(token) + ret = yield self.get_user_from_macaroon(token, rights) except AuthError: # TODO(daniel): Remove this fallback when all existing access tokens # have been re-issued as macaroons. + if self.hs.config.expire_access_token: + raise ret = yield self._look_up_user_by_access_token(token) + defer.returnValue(ret) @defer.inlineCallbacks - def get_user_from_macaroon(self, macaroon_str): + def get_user_from_macaroon(self, macaroon_str, rights="access"): try: macaroon = pymacaroons.Macaroon.deserialize(macaroon_str) - self.validate_macaroon(macaroon, "access", self.hs.config.expire_access_token) + user_id = self.get_user_id_from_macaroon(macaroon) + user = UserID.from_string(user_id) + + self.validate_macaroon( + macaroon, rights, self.hs.config.expire_access_token, + user_id=user_id, + ) - user_prefix = "user_id = " - user = None guest = False for caveat in macaroon.caveats: - if caveat.caveat_id.startswith(user_prefix): - user = UserID.from_string(caveat.caveat_id[len(user_prefix):]) - elif caveat.caveat_id == "guest = true": + if caveat.caveat_id == "guest = true": guest = True - if user is None: - raise AuthError( - self.TOKEN_NOT_FOUND_HTTP_STATUS, "No user caveat in macaroon", - errcode=Codes.UNKNOWN_TOKEN - ) - if guest: ret = { "user": user, "is_guest": True, "token_id": None, + "device_id": None, + } + elif rights == "delete_pusher": + # We don't store these tokens in the database + ret = { + "user": user, + "is_guest": False, + "token_id": None, + "device_id": None, } else: - # 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. + # This codepath exists for several reasons: + # * so that we can actually return a token ID, which is used + # in some parts of the schema (where we probably ought to + # use device IDs instead) + # * the only way we currently have to invalidate an + # access_token is by removing it from the database, so we + # have to check here that it is still in the db + # * some attributes (notably device_id) aren't stored in the + # macaroon. They probably should be. + # TODO: build the dictionary from the macaroon once the + # above are fixed ret = yield self._look_up_user_by_access_token(macaroon_str) if ret["user"] != user: logger.error( @@ -661,21 +734,46 @@ class Auth(object): errcode=Codes.UNKNOWN_TOKEN ) - def validate_macaroon(self, macaroon, type_string, verify_expiry): + def get_user_id_from_macaroon(self, macaroon): + """Retrieve the user_id given by the caveats on the macaroon. + + Does *not* validate the macaroon. + + Args: + macaroon (pymacaroons.Macaroon): The macaroon to validate + + Returns: + (str) user id + + Raises: + AuthError if there is no user_id caveat in the macaroon + """ + user_prefix = "user_id = " + for caveat in macaroon.caveats: + if caveat.caveat_id.startswith(user_prefix): + return caveat.caveat_id[len(user_prefix):] + raise AuthError( + self.TOKEN_NOT_FOUND_HTTP_STATUS, "No user caveat in macaroon", + errcode=Codes.UNKNOWN_TOKEN + ) + + def validate_macaroon(self, macaroon, type_string, verify_expiry, user_id): """ validate that a Macaroon is understood by and was signed by this server. Args: macaroon(pymacaroons.Macaroon): The macaroon to validate - type_string(str): The kind of token this is (e.g. "access", "refresh") + type_string(str): The kind of token required (e.g. "access", "refresh", + "delete_pusher") verify_expiry(bool): Whether to verify whether the macaroon has expired. This should really always be True, but no clients currently implement token refresh, so we can't enforce expiry yet. + user_id (str): The user_id required """ v = pymacaroons.Verifier() v.satisfy_exact("gen = 1") v.satisfy_exact("type = " + type_string) - v.satisfy_general(lambda c: c.startswith("user_id = ")) + v.satisfy_exact("user_id = %s" % user_id) v.satisfy_exact("guest = true") if verify_expiry: v.satisfy_general(self._verify_expiry) @@ -714,10 +812,14 @@ class Auth(object): self.TOKEN_NOT_FOUND_HTTP_STATUS, "Unrecognised access token.", errcode=Codes.UNKNOWN_TOKEN ) + # we use ret.get() below because *lots* of unit tests stub out + # get_user_by_access_token in a way where it only returns a couple of + # the fields. user_info = { "user": UserID.from_string(ret.get("name")), "token_id": ret.get("token_id", None), "is_guest": False, + "device_id": ret.get("device_id"), } defer.returnValue(user_info) |