Merge branch 'develop' into babolivier/mark_unread

1 files changed, 146 insertions, 204 deletions

diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 25a1b67092..dceb2792fa 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -14,12 +14,6 @@
 # limitations under the License.
 
 import logging
-import xml.etree.ElementTree as ET
-
-from six.moves import urllib
-
-from twisted.internet import defer
-from twisted.web.client import PartialDownloadError
 
 from synapse.api.errors import Codes, LoginError, SynapseError
 from synapse.api.ratelimiting import Ratelimiter
@@ -29,9 +23,10 @@ from synapse.http.servlet import (
     parse_json_object_from_request,
     parse_string,
 )
+from synapse.http.site import SynapseRequest
 from synapse.rest.client.v2_alpha._base import client_patterns
 from synapse.rest.well_known import WellKnownBuilder
-from synapse.types import UserID, map_username_to_mxid_localpart
+from synapse.types import UserID
 from synapse.util.msisdn import phone_number_to_msisdn
 
 logger = logging.getLogger(__name__)
@@ -88,29 +83,42 @@ class LoginRestServlet(RestServlet):
         self.jwt_algorithm = hs.config.jwt_algorithm
         self.saml2_enabled = hs.config.saml2_enabled
         self.cas_enabled = hs.config.cas_enabled
+        self.oidc_enabled = hs.config.oidc_enabled
         self.auth_handler = self.hs.get_auth_handler()
         self.registration_handler = hs.get_registration_handler()
         self.handlers = hs.get_handlers()
         self._well_known_builder = WellKnownBuilder(hs)
-        self._address_ratelimiter = Ratelimiter()
+        self._address_ratelimiter = Ratelimiter(
+            clock=hs.get_clock(),
+            rate_hz=self.hs.config.rc_login_address.per_second,
+            burst_count=self.hs.config.rc_login_address.burst_count,
+        )
+        self._account_ratelimiter = Ratelimiter(
+            clock=hs.get_clock(),
+            rate_hz=self.hs.config.rc_login_account.per_second,
+            burst_count=self.hs.config.rc_login_account.burst_count,
+        )
+        self._failed_attempts_ratelimiter = Ratelimiter(
+            clock=hs.get_clock(),
+            rate_hz=self.hs.config.rc_login_failed_attempts.per_second,
+            burst_count=self.hs.config.rc_login_failed_attempts.burst_count,
+        )
 
     def on_GET(self, request):
         flows = []
         if self.jwt_enabled:
             flows.append({"type": LoginRestServlet.JWT_TYPE})
-        if self.saml2_enabled:
-            flows.append({"type": LoginRestServlet.SSO_TYPE})
-            flows.append({"type": LoginRestServlet.TOKEN_TYPE})
-        if self.cas_enabled:
-            flows.append({"type": LoginRestServlet.SSO_TYPE})
 
+        if self.cas_enabled:
             # we advertise CAS for backwards compat, though MSC1721 renamed it
             # to SSO.
             flows.append({"type": LoginRestServlet.CAS_TYPE})
 
+        if self.cas_enabled or self.saml2_enabled or self.oidc_enabled:
+            flows.append({"type": LoginRestServlet.SSO_TYPE})
             # While its valid for us to advertise this login type generally,
             # synapse currently only gives out these tokens as part of the
-            # CAS login flow.
+            # SSO login flow.
             # Generally we don't want to advertise login flows that clients
             # don't know how to implement, since they (currently) will always
             # fall back to the fallback API if they don't understand one of the
@@ -126,26 +134,19 @@ class LoginRestServlet(RestServlet):
     def on_OPTIONS(self, request):
         return 200, {}
 
-    @defer.inlineCallbacks
-    def on_POST(self, request):
-        self._address_ratelimiter.ratelimit(
-            request.getClientIP(),
-            time_now_s=self.hs.clock.time(),
-            rate_hz=self.hs.config.rc_login_address.per_second,
-            burst_count=self.hs.config.rc_login_address.burst_count,
-            update=True,
-        )
+    async def on_POST(self, request):
+        self._address_ratelimiter.ratelimit(request.getClientIP())
 
         login_submission = parse_json_object_from_request(request)
         try:
             if self.jwt_enabled and (
                 login_submission["type"] == LoginRestServlet.JWT_TYPE
             ):
-                result = yield self.do_jwt_login(login_submission)
+                result = await self.do_jwt_login(login_submission)
             elif login_submission["type"] == LoginRestServlet.TOKEN_TYPE:
-                result = yield self.do_token_login(login_submission)
+                result = await self.do_token_login(login_submission)
             else:
-                result = yield self._do_other_login(login_submission)
+                result = await self._do_other_login(login_submission)
         except KeyError:
             raise SynapseError(400, "Missing JSON keys.")
 
@@ -154,8 +155,7 @@ class LoginRestServlet(RestServlet):
             result["well_known"] = well_known_data
         return 200, result
 
-    @defer.inlineCallbacks
-    def _do_other_login(self, login_submission):
+    async def _do_other_login(self, login_submission):
         """Handle non-token/saml/jwt logins
 
         Args:
@@ -201,28 +201,43 @@ class LoginRestServlet(RestServlet):
                 # (See add_threepid in synapse/handlers/auth.py)
                 address = address.lower()
 
+            # We also apply account rate limiting using the 3PID as a key, as
+            # otherwise using 3PID bypasses the ratelimiting based on user ID.
+            self._failed_attempts_ratelimiter.ratelimit((medium, address), update=False)
+
             # Check for login providers that support 3pid login types
-            canonical_user_id, callback_3pid = (
-                yield self.auth_handler.check_password_provider_3pid(
-                    medium, address, login_submission["password"]
-                )
+            (
+                canonical_user_id,
+                callback_3pid,
+            ) = await self.auth_handler.check_password_provider_3pid(
+                medium, address, login_submission["password"]
             )
             if canonical_user_id:
                 # Authentication through password provider and 3pid succeeded
-                result = yield self._register_device_with_callback(
+
+                result = await self._complete_login(
                     canonical_user_id, login_submission, callback_3pid
                 )
                 return result
 
             # No password providers were able to handle this 3pid
             # Check local store
-            user_id = yield self.hs.get_datastore().get_user_id_by_threepid(
+            user_id = await self.hs.get_datastore().get_user_id_by_threepid(
                 medium, address
             )
             if not user_id:
-                logger.warn(
+                logger.warning(
                     "unknown 3pid identifier medium %s, address %r", medium, address
                 )
+                # We mark that we've failed to log in here, as
+                # `check_password_provider_3pid` might have returned `None` due
+                # to an incorrect password, rather than the account not
+                # existing.
+                #
+                # If it returned None but the 3PID was bound then we won't hit
+                # this code path, which is fine as then the per-user ratelimit
+                # will kick in below.
+                self._failed_attempts_ratelimiter.can_do_action((medium, address))
                 raise LoginError(403, "", errcode=Codes.FORBIDDEN)
 
             identifier = {"type": "m.id.user", "user": user_id}
@@ -234,32 +249,71 @@ class LoginRestServlet(RestServlet):
         if "user" not in identifier:
             raise SynapseError(400, "User identifier is missing 'user' key")
 
-        canonical_user_id, callback = yield self.auth_handler.validate_login(
-            identifier["user"], login_submission
+        if identifier["user"].startswith("@"):
+            qualified_user_id = identifier["user"]
+        else:
+            qualified_user_id = UserID(identifier["user"], self.hs.hostname).to_string()
+
+        # Check if we've hit the failed ratelimit (but don't update it)
+        self._failed_attempts_ratelimiter.ratelimit(
+            qualified_user_id.lower(), update=False
         )
 
-        result = yield self._register_device_with_callback(
+        try:
+            canonical_user_id, callback = await self.auth_handler.validate_login(
+                identifier["user"], login_submission
+            )
+        except LoginError:
+            # The user has failed to log in, so we need to update the rate
+            # limiter. Using `can_do_action` avoids us raising a ratelimit
+            # exception and masking the LoginError. The actual ratelimiting
+            # should have happened above.
+            self._failed_attempts_ratelimiter.can_do_action(qualified_user_id.lower())
+            raise
+
+        result = await self._complete_login(
             canonical_user_id, login_submission, callback
         )
         return result
 
-    @defer.inlineCallbacks
-    def _register_device_with_callback(self, user_id, login_submission, callback=None):
-        """ Registers a device with a given user_id. Optionally run a callback
-        function after registration has completed.
+    async def _complete_login(
+        self, user_id, login_submission, callback=None, create_non_existent_users=False
+    ):
+        """Called when we've successfully authed the user and now need to
+        actually login them in (e.g. create devices). This gets called on
+        all succesful logins.
+
+        Applies the ratelimiting for succesful login attempts against an
+        account.
 
         Args:
             user_id (str): ID of the user to register.
             login_submission (dict): Dictionary of login information.
             callback (func|None): Callback function to run after registration.
+            create_non_existent_users (bool): Whether to create the user if
+                they don't exist. Defaults to False.
 
         Returns:
             result (Dict[str,str]): Dictionary of account information after
                 successful registration.
         """
+
+        # Before we actually log them in we check if they've already logged in
+        # too often. This happens here rather than before as we don't
+        # necessarily know the user before now.
+        self._account_ratelimiter.ratelimit(user_id.lower())
+
+        if create_non_existent_users:
+            canonical_uid = await self.auth_handler.check_user_exists(user_id)
+            if not canonical_uid:
+                canonical_uid = await self.registration_handler.register_user(
+                    localpart=UserID.from_string(user_id).localpart
+                )
+            user_id = canonical_uid
+
         device_id = login_submission.get("device_id")
         initial_display_name = login_submission.get("initial_device_display_name")
-        device_id, access_token = yield self.registration_handler.register_device(
+        device_id, access_token = await self.registration_handler.register_device(
             user_id, device_id, initial_display_name
         )
 
@@ -271,23 +325,21 @@ class LoginRestServlet(RestServlet):
         }
 
         if callback is not None:
-            yield callback(result)
+            await callback(result)
 
         return result
 
-    @defer.inlineCallbacks
-    def do_token_login(self, login_submission):
+    async def do_token_login(self, login_submission):
         token = login_submission["token"]
         auth_handler = self.auth_handler
-        user_id = (
-            yield auth_handler.validate_short_term_login_token_and_get_user_id(token)
+        user_id = await auth_handler.validate_short_term_login_token_and_get_user_id(
+            token
         )
 
-        result = yield self._register_device_with_callback(user_id, login_submission)
+        result = await self._complete_login(user_id, login_submission)
         return result
 
-    @defer.inlineCallbacks
-    def do_jwt_login(self, login_submission):
+    async def do_jwt_login(self, login_submission):
         token = login_submission.get("token", None)
         if token is None:
             raise LoginError(
@@ -311,15 +363,8 @@ class LoginRestServlet(RestServlet):
             raise LoginError(401, "Invalid JWT", errcode=Codes.UNAUTHORIZED)
 
         user_id = UserID(user, self.hs.hostname).to_string()
-
-        registered_user_id = yield self.auth_handler.check_user_exists(user_id)
-        if not registered_user_id:
-            registered_user_id = yield self.registration_handler.register_user(
-                localpart=user
-            )
-
-        result = yield self._register_device_with_callback(
-            registered_user_id, login_submission
+        result = await self._complete_login(
+            user_id, login_submission, create_non_existent_users=True
         )
         return result
 
@@ -329,24 +374,27 @@ class BaseSSORedirectServlet(RestServlet):
 
     PATTERNS = client_patterns("/login/(cas|sso)/redirect", v1=True)
 
-    def on_GET(self, request):
+    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):
+    async def get_sso_url(
+        self, request: SynapseRequest, client_redirect_url: bytes
+    ) -> bytes:
         """Get the URL to redirect to, to perform SSO auth
 
         Args:
-            client_redirect_url (bytes): the URL that we should redirect the
+            request: The client request to redirect.
+            client_redirect_url: the URL that we should redirect the
                 client to when everything is done
 
         Returns:
-            bytes: URL to redirect to
+            URL to redirect to
         """
         # to be implemented by subclasses
         raise NotImplementedError()
@@ -354,19 +402,14 @@ class BaseSSORedirectServlet(RestServlet):
 
 class CasRedirectServlet(BaseSSORedirectServlet):
     def __init__(self, hs):
-        super(CasRedirectServlet, self).__init__()
-        self.cas_server_url = hs.config.cas_server_url.encode("ascii")
-        self.cas_service_url = hs.config.cas_service_url.encode("ascii")
+        self._cas_handler = hs.get_cas_handler()
 
-    def get_sso_url(self, client_redirect_url):
-        client_redirect_url_param = urllib.parse.urlencode(
-            {b"redirectUrl": client_redirect_url}
+    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")
-        hs_redirect_url = self.cas_service_url + b"/_matrix/client/r0/login/cas/ticket"
-        service_param = urllib.parse.urlencode(
-            {b"service": b"%s?%s" % (hs_redirect_url, client_redirect_url_param)}
-        ).encode("ascii")
-        return b"%s/login?%s" % (self.cas_server_url, service_param)
 
 
 class CasTicketServlet(RestServlet):
@@ -374,80 +417,25 @@ class CasTicketServlet(RestServlet):
 
     def __init__(self, hs):
         super(CasTicketServlet, self).__init__()
-        self.cas_server_url = hs.config.cas_server_url
-        self.cas_service_url = hs.config.cas_service_url
-        self.cas_required_attributes = hs.config.cas_required_attributes
-        self._sso_auth_handler = SSOAuthHandler(hs)
-        self._http_client = hs.get_simple_http_client()
-
-    @defer.inlineCallbacks
-    def on_GET(self, request):
-        client_redirect_url = parse_string(request, "redirectUrl", required=True)
-        uri = self.cas_server_url + "/proxyValidate"
-        args = {
-            "ticket": parse_string(request, "ticket", required=True),
-            "service": self.cas_service_url,
-        }
-        try:
-            body = yield self._http_client.get_raw(uri, args)
-        except PartialDownloadError as pde:
-            # Twisted raises this error if the connection is closed,
-            # even if that's being used old-http style to signal end-of-data
-            body = pde.response
-        result = yield self.handle_cas_response(request, body, client_redirect_url)
-        return result
+        self._cas_handler = hs.get_cas_handler()
 
-    def handle_cas_response(self, request, cas_response_body, client_redirect_url):
-        user, attributes = self.parse_cas_response(cas_response_body)
+    async def on_GET(self, request: SynapseRequest) -> None:
+        client_redirect_url = parse_string(request, "redirectUrl")
+        ticket = parse_string(request, "ticket", required=True)
 
-        for required_attribute, required_value in self.cas_required_attributes.items():
-            # If required attribute was not in CAS Response - Forbidden
-            if required_attribute not in attributes:
-                raise LoginError(401, "Unauthorized", errcode=Codes.UNAUTHORIZED)
+        # Maybe get a session ID (if this ticket is from user interactive
+        # authentication).
+        session = parse_string(request, "session")
 
-            # Also need to check value
-            if required_value is not None:
-                actual_value = attributes[required_attribute]
-                # If required attribute value does not match expected - Forbidden
-                if required_value != actual_value:
-                    raise LoginError(401, "Unauthorized", errcode=Codes.UNAUTHORIZED)
+        # Either client_redirect_url or session must be provided.
+        if not client_redirect_url and not session:
+            message = "Missing string query parameter redirectUrl or session"
+            raise SynapseError(400, message, errcode=Codes.MISSING_PARAM)
 
-        return self._sso_auth_handler.on_successful_auth(
-            user, request, client_redirect_url
+        await self._cas_handler.handle_ticket(
+            request, ticket, client_redirect_url, session
         )
 
-    def parse_cas_response(self, cas_response_body):
-        user = None
-        attributes = {}
-        try:
-            root = ET.fromstring(cas_response_body)
-            if not root.tag.endswith("serviceResponse"):
-                raise Exception("root of CAS response is not serviceResponse")
-            success = root[0].tag.endswith("authenticationSuccess")
-            for child in root[0]:
-                if child.tag.endswith("user"):
-                    user = child.text
-                if child.tag.endswith("attributes"):
-                    for attribute in child:
-                        # ElementTree library expands the namespace in
-                        # attribute tags to the full URL of the namespace.
-                        # We don't care about namespace here and it will always
-                        # be encased in curly braces, so we remove them.
-                        tag = attribute.tag
-                        if "}" in tag:
-                            tag = tag.split("}")[1]
-                        attributes[tag] = attribute.text
-            if user is None:
-                raise Exception("CAS response does not contain user")
-        except Exception:
-            logger.error("Error parsing CAS response", exc_info=1)
-            raise LoginError(401, "Invalid CAS response", errcode=Codes.UNAUTHORIZED)
-        if not success:
-            raise LoginError(
-                401, "Unsuccessful CAS response", errcode=Codes.UNAUTHORIZED
-            )
-        return user, attributes
-
 
 class SAMLRedirectServlet(BaseSSORedirectServlet):
     PATTERNS = client_patterns("/login/sso/redirect", v1=True)
@@ -455,74 +443,26 @@ class SAMLRedirectServlet(BaseSSORedirectServlet):
     def __init__(self, hs):
         self._saml_handler = hs.get_saml_handler()
 
-    def get_sso_url(self, client_redirect_url):
+    async def get_sso_url(
+        self, request: SynapseRequest, client_redirect_url: bytes
+    ) -> bytes:
         return self._saml_handler.handle_redirect_request(client_redirect_url)
 
 
-class SSOAuthHandler(object):
-    """
-    Utility class for Resources and Servlets which handle the response from a SSO
-    service
+class OIDCRedirectServlet(BaseSSORedirectServlet):
+    """Implementation for /login/sso/redirect for the OIDC login flow."""
 
-    Args:
-        hs (synapse.server.HomeServer)
-    """
+    PATTERNS = client_patterns("/login/sso/redirect", v1=True)
 
     def __init__(self, hs):
-        self._hostname = hs.hostname
-        self._auth_handler = hs.get_auth_handler()
-        self._registration_handler = hs.get_registration_handler()
-        self._macaroon_gen = hs.get_macaroon_generator()
-
-    @defer.inlineCallbacks
-    def on_successful_auth(
-        self, username, request, client_redirect_url, user_display_name=None
-    ):
-        """Called once the user has successfully authenticated with the SSO.
-
-        Registers the user if necessary, and then returns a redirect (with
-        a login token) to the client.
-
-        Args:
-            username (unicode|bytes): the remote user id. We'll map this onto
-                something sane for a MXID localpath.
-
-            request (SynapseRequest): the incoming request from the browser. We'll
-                respond to it with a redirect.
-
-            client_redirect_url (unicode): the redirect_url the client gave us when
-                it first started the process.
-
-            user_display_name (unicode|None): if set, and we have to register a new user,
-                we will set their displayname to this.
+        self._oidc_handler = hs.get_oidc_handler()
 
-        Returns:
-            Deferred[none]: Completes once we have handled the request.
-        """
-        localpart = map_username_to_mxid_localpart(username)
-        user_id = UserID(localpart, self._hostname).to_string()
-        registered_user_id = yield self._auth_handler.check_user_exists(user_id)
-        if not registered_user_id:
-            registered_user_id = yield self._registration_handler.register_user(
-                localpart=localpart, default_display_name=user_display_name
-            )
-
-        login_token = self._macaroon_gen.generate_short_term_login_token(
-            registered_user_id
+    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
         )
-        redirect_url = self._add_login_token_to_redirect_url(
-            client_redirect_url, login_token
-        )
-        request.redirect(redirect_url)
-        finish_request(request)
-
-    @staticmethod
-    def _add_login_token_to_redirect_url(url, token):
-        url_parts = list(urllib.parse.urlparse(url))
-        query = dict(urllib.parse.parse_qsl(url_parts[4]))
-        query.update({"loginToken": token})
-        url_parts[4] = urllib.parse.urlencode(query)
-        return urllib.parse.urlunparse(url_parts)
 
 
 def register_servlets(hs, http_server):
@@ -532,3 +472,5 @@ def register_servlets(hs, http_server):
         CasTicketServlet(hs).register(http_server)
     elif hs.config.saml2_enabled:
         SAMLRedirectServlet(hs).register(http_server)
+    elif hs.config.oidc_enabled:
+        OIDCRedirectServlet(hs).register(http_server)