diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/handlers/oidc_handler.py | 304 |
1 files changed, 163 insertions, 141 deletions
diff --git a/synapse/handlers/oidc_handler.py b/synapse/handlers/oidc_handler.py index 6835c6c462..88097639ef 100644 --- a/synapse/handlers/oidc_handler.py +++ b/synapse/handlers/oidc_handler.py @@ -14,7 +14,7 @@ # limitations under the License. import inspect import logging -from typing import TYPE_CHECKING, Dict, Generic, List, Optional, Tuple, TypeVar +from typing import TYPE_CHECKING, Dict, Generic, List, Optional, TypeVar from urllib.parse import urlencode import attr @@ -35,7 +35,6 @@ from typing_extensions import TypedDict from twisted.web.client import readBody from synapse.config import ConfigError -from synapse.handlers._base import BaseHandler from synapse.handlers.sso import MappingException, UserAttributes from synapse.http.site import SynapseRequest from synapse.logging.context import make_deferred_yieldable @@ -85,12 +84,15 @@ class OidcError(Exception): return self.error -class OidcHandler(BaseHandler): +class OidcHandler: """Handles requests related to the OpenID Connect login flow. """ def __init__(self, hs: "HomeServer"): - super().__init__(hs) + self._store = hs.get_datastore() + + self._token_generator = OidcSessionTokenGenerator(hs) + self._callback_url = hs.config.oidc_callback_url # type: str self._scopes = hs.config.oidc_scopes # type: List[str] self._user_profile_method = hs.config.oidc_user_profile_method # type: str @@ -116,7 +118,6 @@ class OidcHandler(BaseHandler): self._http_client = hs.get_proxied_http_client() self._server_name = hs.config.server_name # type: str - self._macaroon_secret_key = hs.config.macaroon_secret_key # identifier for the external_ids table self.idp_id = "oidc" @@ -519,11 +520,13 @@ class OidcHandler(BaseHandler): if not client_redirect_url: client_redirect_url = b"" - cookie = self._generate_oidc_session_token( + cookie = self._token_generator.generate_oidc_session_token( state=state, - nonce=nonce, - client_redirect_url=client_redirect_url.decode(), - ui_auth_session_id=ui_auth_session_id, + session_data=OidcSessionData( + nonce=nonce, + client_redirect_url=client_redirect_url.decode(), + ui_auth_session_id=ui_auth_session_id, + ), ) request.addCookie( SESSION_COOKIE_NAME, @@ -628,11 +631,9 @@ class OidcHandler(BaseHandler): # Deserialize the session token and verify it. try: - ( - nonce, - client_redirect_url, - ui_auth_session_id, - ) = self._verify_oidc_session_token(session, state) + session_data = self._token_generator.verify_oidc_session_token( + session, state + ) except MacaroonDeserializationException as e: logger.exception("Invalid session") self._sso_handler.render_error(request, "invalid_session", str(e)) @@ -674,14 +675,14 @@ class OidcHandler(BaseHandler): else: logger.debug("Extracting userinfo from id_token") try: - userinfo = await self._parse_id_token(token, nonce=nonce) + userinfo = await self._parse_id_token(token, nonce=session_data.nonce) except Exception as e: logger.exception("Invalid id_token") self._sso_handler.render_error(request, "invalid_token", str(e)) return # first check if we're doing a UIA - if ui_auth_session_id: + if session_data.ui_auth_session_id: try: remote_user_id = self._remote_id_from_userinfo(userinfo) except Exception as e: @@ -690,7 +691,7 @@ class OidcHandler(BaseHandler): return return await self._sso_handler.complete_sso_ui_auth_request( - self.idp_id, remote_user_id, ui_auth_session_id, request + self.idp_id, remote_user_id, session_data.ui_auth_session_id, request ) # otherwise, it's a login @@ -698,133 +699,12 @@ class OidcHandler(BaseHandler): # Call the mapper to register/login the user try: await self._complete_oidc_login( - userinfo, token, request, client_redirect_url + userinfo, token, request, session_data.client_redirect_url ) except MappingException as e: logger.exception("Could not map user") self._sso_handler.render_error(request, "mapping_error", str(e)) - def _generate_oidc_session_token( - self, - state: str, - nonce: str, - client_redirect_url: str, - ui_auth_session_id: Optional[str], - duration_in_ms: int = (60 * 60 * 1000), - ) -> str: - """Generates a signed token storing data about an OIDC session. - - When Synapse initiates an authorization flow, it creates a random state - and a random nonce. Those parameters are given to the provider and - should be verified when the client comes back from the provider. - It is also used to store the client_redirect_url, which is used to - complete the SSO login flow. - - Args: - state: The ``state`` parameter passed to the OIDC provider. - nonce: The ``nonce`` parameter passed to the OIDC provider. - client_redirect_url: The URL the client gave when it initiated the - flow. - ui_auth_session_id: The session ID of the ongoing UI Auth (or - None if this is a login). - duration_in_ms: An optional duration for the token in milliseconds. - Defaults to an hour. - - Returns: - A signed macaroon token with the session information. - """ - macaroon = pymacaroons.Macaroon( - location=self._server_name, identifier="key", key=self._macaroon_secret_key, - ) - macaroon.add_first_party_caveat("gen = 1") - macaroon.add_first_party_caveat("type = session") - macaroon.add_first_party_caveat("state = %s" % (state,)) - macaroon.add_first_party_caveat("nonce = %s" % (nonce,)) - macaroon.add_first_party_caveat( - "client_redirect_url = %s" % (client_redirect_url,) - ) - if ui_auth_session_id: - macaroon.add_first_party_caveat( - "ui_auth_session_id = %s" % (ui_auth_session_id,) - ) - now = self.clock.time_msec() - expiry = now + duration_in_ms - macaroon.add_first_party_caveat("time < %d" % (expiry,)) - - return macaroon.serialize() - - def _verify_oidc_session_token( - self, session: bytes, state: str - ) -> Tuple[str, str, Optional[str]]: - """Verifies and extract an OIDC session token. - - This verifies that a given session token was issued by this homeserver - and extract the nonce and client_redirect_url caveats. - - Args: - session: The session token to verify - state: The state the OIDC provider gave back - - Returns: - The nonce, client_redirect_url, and ui_auth_session_id for this session - """ - macaroon = pymacaroons.Macaroon.deserialize(session) - - v = pymacaroons.Verifier() - v.satisfy_exact("gen = 1") - v.satisfy_exact("type = session") - v.satisfy_exact("state = %s" % (state,)) - v.satisfy_general(lambda c: c.startswith("nonce = ")) - v.satisfy_general(lambda c: c.startswith("client_redirect_url = ")) - # Sometimes there's a UI auth session ID, it seems to be OK to attempt - # to always satisfy this. - v.satisfy_general(lambda c: c.startswith("ui_auth_session_id = ")) - v.satisfy_general(self._verify_expiry) - - v.verify(macaroon, self._macaroon_secret_key) - - # Extract the `nonce`, `client_redirect_url`, and maybe the - # `ui_auth_session_id` from the token. - nonce = self._get_value_from_macaroon(macaroon, "nonce") - client_redirect_url = self._get_value_from_macaroon( - macaroon, "client_redirect_url" - ) - try: - ui_auth_session_id = self._get_value_from_macaroon( - macaroon, "ui_auth_session_id" - ) # type: Optional[str] - except ValueError: - ui_auth_session_id = None - - return nonce, client_redirect_url, ui_auth_session_id - - def _get_value_from_macaroon(self, macaroon: pymacaroons.Macaroon, key: str) -> str: - """Extracts a caveat value from a macaroon token. - - Args: - macaroon: the token - key: the key of the caveat to extract - - Returns: - The extracted value - - Raises: - Exception: if the caveat was not in the macaroon - """ - prefix = key + " = " - for caveat in macaroon.caveats: - if caveat.caveat_id.startswith(prefix): - return caveat.caveat_id[len(prefix) :] - raise ValueError("No %s caveat in macaroon" % (key,)) - - def _verify_expiry(self, caveat: str) -> bool: - prefix = "time < " - if not caveat.startswith(prefix): - return False - expiry = int(caveat[len(prefix) :]) - now = self.clock.time_msec() - return now < expiry - async def _complete_oidc_login( self, userinfo: UserInfo, @@ -901,8 +781,8 @@ class OidcHandler(BaseHandler): # and attempt to match it. attributes = await oidc_response_to_user_attributes(failures=0) - user_id = UserID(attributes.localpart, self.server_name).to_string() - users = await self.store.get_users_by_id_case_insensitive(user_id) + user_id = UserID(attributes.localpart, self._server_name).to_string() + users = await self._store.get_users_by_id_case_insensitive(user_id) if users: # If an existing matrix ID is returned, then use it. if len(users) == 1: @@ -954,6 +834,148 @@ class OidcHandler(BaseHandler): return str(remote_user_id) +class OidcSessionTokenGenerator: + """Methods for generating and checking OIDC Session cookies.""" + + def __init__(self, hs: "HomeServer"): + self._clock = hs.get_clock() + self._server_name = hs.hostname + self._macaroon_secret_key = hs.config.key.macaroon_secret_key + + def generate_oidc_session_token( + self, + state: str, + session_data: "OidcSessionData", + duration_in_ms: int = (60 * 60 * 1000), + ) -> str: + """Generates a signed token storing data about an OIDC session. + + When Synapse initiates an authorization flow, it creates a random state + and a random nonce. Those parameters are given to the provider and + should be verified when the client comes back from the provider. + It is also used to store the client_redirect_url, which is used to + complete the SSO login flow. + + Args: + state: The ``state`` parameter passed to the OIDC provider. + session_data: data to include in the session token. + duration_in_ms: An optional duration for the token in milliseconds. + Defaults to an hour. + + Returns: + A signed macaroon token with the session information. + """ + macaroon = pymacaroons.Macaroon( + location=self._server_name, identifier="key", key=self._macaroon_secret_key, + ) + macaroon.add_first_party_caveat("gen = 1") + macaroon.add_first_party_caveat("type = session") + macaroon.add_first_party_caveat("state = %s" % (state,)) + macaroon.add_first_party_caveat("nonce = %s" % (session_data.nonce,)) + macaroon.add_first_party_caveat( + "client_redirect_url = %s" % (session_data.client_redirect_url,) + ) + if session_data.ui_auth_session_id: + macaroon.add_first_party_caveat( + "ui_auth_session_id = %s" % (session_data.ui_auth_session_id,) + ) + now = self._clock.time_msec() + expiry = now + duration_in_ms + macaroon.add_first_party_caveat("time < %d" % (expiry,)) + + return macaroon.serialize() + + def verify_oidc_session_token( + self, session: bytes, state: str + ) -> "OidcSessionData": + """Verifies and extract an OIDC session token. + + This verifies that a given session token was issued by this homeserver + and extract the nonce and client_redirect_url caveats. + + Args: + session: The session token to verify + state: The state the OIDC provider gave back + + Returns: + The data extracted from the session cookie + """ + macaroon = pymacaroons.Macaroon.deserialize(session) + + v = pymacaroons.Verifier() + v.satisfy_exact("gen = 1") + v.satisfy_exact("type = session") + v.satisfy_exact("state = %s" % (state,)) + v.satisfy_general(lambda c: c.startswith("nonce = ")) + v.satisfy_general(lambda c: c.startswith("client_redirect_url = ")) + # Sometimes there's a UI auth session ID, it seems to be OK to attempt + # to always satisfy this. + v.satisfy_general(lambda c: c.startswith("ui_auth_session_id = ")) + v.satisfy_general(self._verify_expiry) + + v.verify(macaroon, self._macaroon_secret_key) + + # Extract the `nonce`, `client_redirect_url`, and maybe the + # `ui_auth_session_id` from the token. + nonce = self._get_value_from_macaroon(macaroon, "nonce") + client_redirect_url = self._get_value_from_macaroon( + macaroon, "client_redirect_url" + ) + try: + ui_auth_session_id = self._get_value_from_macaroon( + macaroon, "ui_auth_session_id" + ) # type: Optional[str] + except ValueError: + ui_auth_session_id = None + + return OidcSessionData( + nonce=nonce, + client_redirect_url=client_redirect_url, + ui_auth_session_id=ui_auth_session_id, + ) + + def _get_value_from_macaroon(self, macaroon: pymacaroons.Macaroon, key: str) -> str: + """Extracts a caveat value from a macaroon token. + + Args: + macaroon: the token + key: the key of the caveat to extract + + Returns: + The extracted value + + Raises: + Exception: if the caveat was not in the macaroon + """ + prefix = key + " = " + for caveat in macaroon.caveats: + if caveat.caveat_id.startswith(prefix): + return caveat.caveat_id[len(prefix) :] + raise ValueError("No %s caveat in macaroon" % (key,)) + + def _verify_expiry(self, caveat: str) -> bool: + prefix = "time < " + if not caveat.startswith(prefix): + return False + expiry = int(caveat[len(prefix) :]) + now = self._clock.time_msec() + return now < expiry + + +@attr.s(frozen=True, slots=True) +class OidcSessionData: + """The attributes which are stored in a OIDC session cookie""" + + # The `nonce` parameter passed to the OIDC provider. + nonce = attr.ib(type=str) + + # The URL the client gave when it initiated the flow. ("" if this is a UI Auth) + client_redirect_url = attr.ib(type=str) + + # The session ID of the ongoing UI Auth (None if this is a login) + ui_auth_session_id = attr.ib(type=Optional[str], default=None) + + UserAttributeDict = TypedDict( "UserAttributeDict", {"localpart": Optional[str], "display_name": Optional[str]} ) |