Support UI Authentication for OpenID Connect accounts (#7457)

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Patrick Cloke 2020-05-15 12:26:02 -04:00 committed by GitHub
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commit a3cf36f76e
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6 changed files with 105 additions and 41 deletions

1
changelog.d/7457.feature Normal file
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@ -0,0 +1 @@
Add OpenID Connect login/registration support. Contributed by Quentin Gliech, on behalf of [les Connecteurs](https://connecteu.rs).

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@ -80,7 +80,9 @@ class AuthHandler(BaseHandler):
self.hs = hs # FIXME better possibility to access registrationHandler later?
self.macaroon_gen = hs.get_macaroon_generator()
self._password_enabled = hs.config.password_enabled
self._sso_enabled = hs.config.saml2_enabled or hs.config.cas_enabled
self._sso_enabled = (
hs.config.cas_enabled or hs.config.saml2_enabled or hs.config.oidc_enabled
)
# we keep this as a list despite the O(N^2) implication so that we can
# keep PASSWORD first and avoid confusing clients which pick the first

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@ -311,7 +311,7 @@ class OidcHandler:
``ClientAuth`` to authenticate with the client with its ID and secret.
Args:
code: The autorization code we got from the callback.
code: The authorization code we got from the callback.
Returns:
A dict containing various tokens.
@ -497,11 +497,14 @@ class OidcHandler:
return UserInfo(claims)
async def handle_redirect_request(
self, request: SynapseRequest, client_redirect_url: bytes
) -> None:
self,
request: SynapseRequest,
client_redirect_url: bytes,
ui_auth_session_id: Optional[str] = None,
) -> str:
"""Handle an incoming request to /login/sso/redirect
It redirects the browser to the authorization endpoint with a few
It returns a redirect to the authorization endpoint with a few
parameters:
- ``client_id``: the client ID set in ``oidc_config.client_id``
@ -511,24 +514,32 @@ class OidcHandler:
- ``state``: a random string
- ``nonce``: a random string
In addition to redirecting the client, we are setting a cookie with
In addition generating a redirect URL, we are setting a cookie with
a signed macaroon token containing the state, the nonce and the
client_redirect_url params. Those are then checked when the client
comes back from the provider.
Args:
request: the incoming request from the browser.
We'll respond to it with a redirect and a cookie.
client_redirect_url: the URL that we should redirect the client to
when everything is done
ui_auth_session_id: The session ID of the ongoing UI Auth (or
None if this is a login).
Returns:
The redirect URL to the authorization endpoint.
"""
state = generate_token()
nonce = generate_token()
cookie = self._generate_oidc_session_token(
state=state, nonce=nonce, client_redirect_url=client_redirect_url.decode(),
state=state,
nonce=nonce,
client_redirect_url=client_redirect_url.decode(),
ui_auth_session_id=ui_auth_session_id,
)
request.addCookie(
SESSION_COOKIE_NAME,
@ -541,7 +552,7 @@ class OidcHandler:
metadata = await self.load_metadata()
authorization_endpoint = metadata.get("authorization_endpoint")
uri = prepare_grant_uri(
return prepare_grant_uri(
authorization_endpoint,
client_id=self._client_auth.client_id,
response_type="code",
@ -550,8 +561,6 @@ class OidcHandler:
state=state,
nonce=nonce,
)
request.redirect(uri)
finish_request(request)
async def handle_oidc_callback(self, request: SynapseRequest) -> None:
"""Handle an incoming request to /_synapse/oidc/callback
@ -625,7 +634,11 @@ class OidcHandler:
# Deserialize the session token and verify it.
try:
nonce, client_redirect_url = self._verify_oidc_session_token(session, state)
(
nonce,
client_redirect_url,
ui_auth_session_id,
) = self._verify_oidc_session_token(session, state)
except MacaroonDeserializationException as e:
logger.exception("Invalid session")
self._render_error(request, "invalid_session", str(e))
@ -678,6 +691,11 @@ class OidcHandler:
return
# and finally complete the login
if ui_auth_session_id:
await self._auth_handler.complete_sso_ui_auth(
user_id, ui_auth_session_id, request
)
else:
await self._auth_handler.complete_sso_login(
user_id, request, client_redirect_url
)
@ -687,6 +705,7 @@ class OidcHandler:
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.
@ -702,6 +721,8 @@ class OidcHandler:
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.
@ -718,12 +739,19 @@ class OidcHandler:
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: str, state: str) -> Tuple[str, str]:
def _verify_oidc_session_token(
self, session: str, 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
@ -734,7 +762,7 @@ class OidcHandler:
state: The state the OIDC provider gave back
Returns:
The nonce and the client_redirect_url for this session
The nonce, client_redirect_url, and ui_auth_session_id for this session
"""
macaroon = pymacaroons.Macaroon.deserialize(session)
@ -744,17 +772,27 @@ class OidcHandler:
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` and `client_redirect_url` from the token
# 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
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.
@ -773,7 +811,7 @@ class OidcHandler:
for caveat in macaroon.caveats:
if caveat.caveat_id.startswith(prefix):
return caveat.caveat_id[len(prefix) :]
raise Exception("No %s caveat in macaroon" % (key,))
raise ValueError("No %s caveat in macaroon" % (key,))
def _verify_expiry(self, caveat: str) -> bool:
prefix = "time < "

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@ -401,19 +401,22 @@ class BaseSSORedirectServlet(RestServlet):
PATTERNS = client_patterns("/login/(cas|sso)/redirect", v1=True)
def on_GET(self, request: SynapseRequest):
async def on_GET(self, request: SynapseRequest):
args = request.args
if b"redirectUrl" not in args:
return 400, "Redirect URL not specified for SSO auth"
client_redirect_url = args[b"redirectUrl"][0]
sso_url = self.get_sso_url(client_redirect_url)
sso_url = await self.get_sso_url(request, client_redirect_url)
request.redirect(sso_url)
finish_request(request)
def get_sso_url(self, client_redirect_url: bytes) -> bytes:
async def get_sso_url(
self, request: SynapseRequest, client_redirect_url: bytes
) -> bytes:
"""Get the URL to redirect to, to perform SSO auth
Args:
request: The client request to redirect.
client_redirect_url: the URL that we should redirect the
client to when everything is done
@ -428,7 +431,9 @@ class CasRedirectServlet(BaseSSORedirectServlet):
def __init__(self, hs):
self._cas_handler = hs.get_cas_handler()
def get_sso_url(self, client_redirect_url: bytes) -> bytes:
async def get_sso_url(
self, request: SynapseRequest, client_redirect_url: bytes
) -> bytes:
return self._cas_handler.get_redirect_url(
{"redirectUrl": client_redirect_url}
).encode("ascii")
@ -465,11 +470,13 @@ class SAMLRedirectServlet(BaseSSORedirectServlet):
def __init__(self, hs):
self._saml_handler = hs.get_saml_handler()
def get_sso_url(self, client_redirect_url: bytes) -> bytes:
async def get_sso_url(
self, request: SynapseRequest, client_redirect_url: bytes
) -> bytes:
return self._saml_handler.handle_redirect_request(client_redirect_url)
class OIDCRedirectServlet(RestServlet):
class OIDCRedirectServlet(BaseSSORedirectServlet):
"""Implementation for /login/sso/redirect for the OIDC login flow."""
PATTERNS = client_patterns("/login/sso/redirect", v1=True)
@ -477,12 +484,12 @@ class OIDCRedirectServlet(RestServlet):
def __init__(self, hs):
self._oidc_handler = hs.get_oidc_handler()
async def on_GET(self, request):
args = request.args
if b"redirectUrl" not in args:
return 400, "Redirect URL not specified for SSO auth"
client_redirect_url = args[b"redirectUrl"][0]
await self._oidc_handler.handle_redirect_request(request, client_redirect_url)
async def get_sso_url(
self, request: SynapseRequest, client_redirect_url: bytes
) -> bytes:
return await self._oidc_handler.handle_redirect_request(
request, client_redirect_url
)
def register_servlets(hs, http_server):

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@ -131,14 +131,19 @@ class AuthRestServlet(RestServlet):
self.registration_handler = hs.get_registration_handler()
# SSO configuration.
self._saml_enabled = hs.config.saml2_enabled
if self._saml_enabled:
self._saml_handler = hs.get_saml_handler()
self._cas_enabled = hs.config.cas_enabled
if self._cas_enabled:
self._cas_handler = hs.get_cas_handler()
self._cas_server_url = hs.config.cas_server_url
self._cas_service_url = hs.config.cas_service_url
self._saml_enabled = hs.config.saml2_enabled
if self._saml_enabled:
self._saml_handler = hs.get_saml_handler()
self._oidc_enabled = hs.config.oidc_enabled
if self._oidc_enabled:
self._oidc_handler = hs.get_oidc_handler()
self._cas_server_url = hs.config.cas_server_url
self._cas_service_url = hs.config.cas_service_url
async def on_GET(self, request, stagetype):
session = parse_string(request, "session")
@ -172,11 +177,17 @@ class AuthRestServlet(RestServlet):
)
elif self._saml_enabled:
client_redirect_url = ""
client_redirect_url = b""
sso_redirect_url = self._saml_handler.handle_redirect_request(
client_redirect_url, session
)
elif self._oidc_enabled:
client_redirect_url = b""
sso_redirect_url = await self._oidc_handler.handle_redirect_request(
request, client_redirect_url, session
)
else:
raise SynapseError(400, "Homeserver not configured for SSO.")

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@ -292,11 +292,10 @@ class OidcHandlerTestCase(HomeserverTestCase):
@defer.inlineCallbacks
def test_redirect_request(self):
"""The redirect request has the right arguments & generates a valid session cookie."""
req = Mock(spec=["addCookie", "redirect", "finish"])
yield defer.ensureDeferred(
req = Mock(spec=["addCookie"])
url = yield defer.ensureDeferred(
self.handler.handle_redirect_request(req, b"http://client/redirect")
)
url = req.redirect.call_args[0][0]
url = urlparse(url)
auth_endpoint = urlparse(AUTHORIZATION_ENDPOINT)
@ -382,7 +381,10 @@ class OidcHandlerTestCase(HomeserverTestCase):
nonce = "nonce"
client_redirect_url = "http://client/redirect"
session = self.handler._generate_oidc_session_token(
state=state, nonce=nonce, client_redirect_url=client_redirect_url,
state=state,
nonce=nonce,
client_redirect_url=client_redirect_url,
ui_auth_session_id=None,
)
request.getCookie.return_value = session
@ -472,7 +474,10 @@ class OidcHandlerTestCase(HomeserverTestCase):
# Mismatching session
session = self.handler._generate_oidc_session_token(
state="state", nonce="nonce", client_redirect_url="http://client/redirect",
state="state",
nonce="nonce",
client_redirect_url="http://client/redirect",
ui_auth_session_id=None,
)
request.args = {}
request.args[b"state"] = [b"mismatching state"]