Reject unknown UI auth sessions (instead of silently generating a new one) (#7268)
Patrick Cloke
GitHub
parent
0f8f02bc39
commit
f5ea8b48bd
|
|
@ -0,0 +1 @@
|
|||
Reject unknown session IDs during user interactive authentication instead of silently creating a new session.
|
||||
|
|
@ -257,10 +257,6 @@ class AuthHandler(BaseHandler):
|
|||
Takes a dictionary sent by the client in the login / registration
|
||||
protocol and handles the User-Interactive Auth flow.
|
||||
|
||||
As a side effect, this function fills in the 'creds' key on the user's
|
||||
session with a map, which maps each auth-type (str) to the relevant
|
||||
identity authenticated by that auth-type (mostly str, but for captcha, bool).
|
||||
|
||||
If no auth flows have been completed successfully, raises an
|
||||
InteractiveAuthIncompleteError. To handle this, you can use
|
||||
synapse.rest.client.v2_alpha._base.interactive_auth_handler as a
|
||||
|
|
@ -304,50 +300,47 @@ class AuthHandler(BaseHandler):
|
|||
del clientdict["auth"]
|
||||
if "session" in authdict:
|
||||
sid = authdict["session"]
|
||||
session = self._get_session_info(sid)
|
||||
|
||||
if len(clientdict) > 0:
|
||||
# This was designed to allow the client to omit the parameters
|
||||
# and just supply the session in subsequent calls so it split
|
||||
# auth between devices by just sharing the session, (eg. so you
|
||||
# could continue registration from your phone having clicked the
|
||||
# email auth link on there). It's probably too open to abuse
|
||||
# because it lets unauthenticated clients store arbitrary objects
|
||||
# on a homeserver.
|
||||
# Revisit: Assuming the REST APIs do sensible validation, the data
|
||||
# isn't arbintrary.
|
||||
session["clientdict"] = clientdict
|
||||
self._save_session(session)
|
||||
elif "clientdict" in session:
|
||||
clientdict = session["clientdict"]
|
||||
|
||||
# Ensure that the queried operation does not vary between stages of
|
||||
# the UI authentication session. This is done by generating a stable
|
||||
# comparator based on the URI, method, and body (minus the auth dict)
|
||||
# and storing it during the initial query. Subsequent queries ensure
|
||||
# that this comparator has not changed.
|
||||
comparator = (request.uri, request.method, clientdict)
|
||||
if "ui_auth" not in session:
|
||||
session["ui_auth"] = comparator
|
||||
self._save_session(session)
|
||||
elif session["ui_auth"] != comparator:
|
||||
raise SynapseError(
|
||||
403,
|
||||
"Requested operation has changed during the UI authentication session.",
|
||||
# If there's no session ID, create a new session.
|
||||
if not sid:
|
||||
session = self._create_session(
|
||||
clientdict, (request.uri, request.method, clientdict), description
|
||||
)
|
||||
session_id = session["id"]
|
||||
|
||||
# Add a human readable description to the session.
|
||||
if "description" not in session:
|
||||
session["description"] = description
|
||||
self._save_session(session)
|
||||
else:
|
||||
session = self._get_session_info(sid)
|
||||
session_id = sid
|
||||
|
||||
if not clientdict:
|
||||
# This was designed to allow the client to omit the parameters
|
||||
# and just supply the session in subsequent calls so it split
|
||||
# auth between devices by just sharing the session, (eg. so you
|
||||
# could continue registration from your phone having clicked the
|
||||
# email auth link on there). It's probably too open to abuse
|
||||
# because it lets unauthenticated clients store arbitrary objects
|
||||
# on a homeserver.
|
||||
# Revisit: Assuming the REST APIs do sensible validation, the data
|
||||
# isn't arbitrary.
|
||||
clientdict = session["clientdict"]
|
||||
|
||||
# Ensure that the queried operation does not vary between stages of
|
||||
# the UI authentication session. This is done by generating a stable
|
||||
# comparator based on the URI, method, and body (minus the auth dict)
|
||||
# and storing it during the initial query. Subsequent queries ensure
|
||||
# that this comparator has not changed.
|
||||
comparator = (request.uri, request.method, clientdict)
|
||||
if session["ui_auth"] != comparator:
|
||||
raise SynapseError(
|
||||
403,
|
||||
"Requested operation has changed during the UI authentication session.",
|
||||
)
|
||||
|
||||
if not authdict:
|
||||
raise InteractiveAuthIncompleteError(
|
||||
self._auth_dict_for_flows(flows, session)
|
||||
self._auth_dict_for_flows(flows, session_id)
|
||||
)
|
||||
|
||||
if "creds" not in session:
|
||||
session["creds"] = {}
|
||||
creds = session["creds"]
|
||||
|
||||
# check auth type currently being presented
|
||||
|
|
@ -387,9 +380,9 @@ class AuthHandler(BaseHandler):
|
|||
list(clientdict),
|
||||
)
|
||||
|
||||
return creds, clientdict, session["id"]
|
||||
return creds, clientdict, session_id
|
||||
|
||||
ret = self._auth_dict_for_flows(flows, session)
|
||||
ret = self._auth_dict_for_flows(flows, session_id)
|
||||
ret["completed"] = list(creds)
|
||||
ret.update(errordict)
|
||||
raise InteractiveAuthIncompleteError(ret)
|
||||
|
|
@ -407,8 +400,6 @@ class AuthHandler(BaseHandler):
|
|||
raise LoginError(400, "", Codes.MISSING_PARAM)
|
||||
|
||||
sess = self._get_session_info(authdict["session"])
|
||||
if "creds" not in sess:
|
||||
sess["creds"] = {}
|
||||
creds = sess["creds"]
|
||||
|
||||
result = await self.checkers[stagetype].check_auth(authdict, clientip)
|
||||
|
|
@ -448,7 +439,7 @@ class AuthHandler(BaseHandler):
|
|||
value: The data to store
|
||||
"""
|
||||
sess = self._get_session_info(session_id)
|
||||
sess.setdefault("serverdict", {})[key] = value
|
||||
sess["serverdict"][key] = value
|
||||
self._save_session(sess)
|
||||
|
||||
def get_session_data(
|
||||
|
|
@ -463,7 +454,7 @@ class AuthHandler(BaseHandler):
|
|||
default: Value to return if the key has not been set
|
||||
"""
|
||||
sess = self._get_session_info(session_id)
|
||||
return sess.setdefault("serverdict", {}).get(key, default)
|
||||
return sess["serverdict"].get(key, default)
|
||||
|
||||
async def _check_auth_dict(
|
||||
self, authdict: Dict[str, Any], clientip: str
|
||||
|
|
@ -519,7 +510,7 @@ class AuthHandler(BaseHandler):
|
|||
}
|
||||
|
||||
def _auth_dict_for_flows(
|
||||
self, flows: List[List[str]], session: Dict[str, Any]
|
||||
self, flows: List[List[str]], session_id: str,
|
||||
) -> Dict[str, Any]:
|
||||
public_flows = []
|
||||
for f in flows:
|
||||
|
|
@ -538,28 +529,71 @@ class AuthHandler(BaseHandler):
|
|||
params[stage] = get_params[stage]()
|
||||
|
||||
return {
|
||||
"session": session["id"],
|
||||
"session": session_id,
|
||||
"flows": [{"stages": f} for f in public_flows],
|
||||
"params": params,
|
||||
}
|
||||
|
||||
def _get_session_info(self, session_id: Optional[str]) -> dict:
|
||||
def _create_session(
|
||||
self,
|
||||
clientdict: Dict[str, Any],
|
||||
ui_auth: Tuple[bytes, bytes, Dict[str, Any]],
|
||||
description: str,
|
||||
) -> dict:
|
||||
"""
|
||||
Gets or creates a session given a session ID.
|
||||
Creates a new user interactive authentication session.
|
||||
|
||||
The session can be used to track data across multiple requests, e.g. for
|
||||
interactive authentication.
|
||||
|
||||
Each session has the following keys:
|
||||
|
||||
id:
|
||||
A unique identifier for this session. Passed back to the client
|
||||
and returned for each stage.
|
||||
clientdict:
|
||||
The dictionary from the client root level, not the 'auth' key.
|
||||
ui_auth:
|
||||
A tuple which is checked at each stage of the authentication to
|
||||
ensure that the asked for operation has not changed.
|
||||
creds:
|
||||
A map, which maps each auth-type (str) to the relevant identity
|
||||
authenticated by that auth-type (mostly str, but for captcha, bool).
|
||||
serverdict:
|
||||
A map of data that is stored server-side and cannot be modified
|
||||
by the client.
|
||||
description:
|
||||
A string description of the operation that the current
|
||||
authentication is authorising.
|
||||
Returns:
|
||||
The newly created session.
|
||||
"""
|
||||
session_id = None
|
||||
while session_id is None or session_id in self.sessions:
|
||||
session_id = stringutils.random_string(24)
|
||||
|
||||
self.sessions[session_id] = {
|
||||
"id": session_id,
|
||||
"clientdict": clientdict,
|
||||
"ui_auth": ui_auth,
|
||||
"creds": {},
|
||||
"serverdict": {},
|
||||
"description": description,
|
||||
}
|
||||
|
||||
return self.sessions[session_id]
|
||||
|
||||
def _get_session_info(self, session_id: str) -> dict:
|
||||
"""
|
||||
Gets a session given a session ID.
|
||||
|
||||
The session can be used to track data across multiple requests, e.g. for
|
||||
interactive authentication.
|
||||
"""
|
||||
if session_id not in self.sessions:
|
||||
session_id = None
|
||||
|
||||
if not session_id:
|
||||
# create a new session
|
||||
while session_id is None or session_id in self.sessions:
|
||||
session_id = stringutils.random_string(24)
|
||||
self.sessions[session_id] = {"id": session_id}
|
||||
|
||||
return self.sessions[session_id]
|
||||
try:
|
||||
return self.sessions[session_id]
|
||||
except KeyError:
|
||||
raise SynapseError(400, "Unknown session ID: %s" % (session_id,))
|
||||
|
||||
async def get_access_token_for_user_id(
|
||||
self, user_id: str, device_id: Optional[str], valid_until_ms: Optional[int]
|
||||
|
|
@ -1030,11 +1064,8 @@ class AuthHandler(BaseHandler):
|
|||
The HTML to render.
|
||||
"""
|
||||
session = self._get_session_info(session_id)
|
||||
# Get the human readable operation of what is occurring, falling back to
|
||||
# a generic message if it isn't available for some reason.
|
||||
description = session.get("description", "modify your account")
|
||||
return self._sso_auth_confirm_template.render(
|
||||
description=description, redirect_url=redirect_url,
|
||||
description=session["description"], redirect_url=redirect_url,
|
||||
)
|
||||
|
||||
def complete_sso_ui_auth(
|
||||
|
|
@ -1050,8 +1081,6 @@ class AuthHandler(BaseHandler):
|
|||
"""
|
||||
# Mark the stage of the authentication as successful.
|
||||
sess = self._get_session_info(session_id)
|
||||
if "creds" not in sess:
|
||||
sess["creds"] = {}
|
||||
creds = sess["creds"]
|
||||
|
||||
# Save the user who authenticated with SSO, this will be used to ensure
|
||||
|
|
|
|||
Loading…
Reference in New Issue