Allow hs to do CAS login completely and issue the client with a login token that can be redeemed for the usual successful login response

1 files changed, 144 insertions, 1 deletions

diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 4ea06c1434..5a2cedacb0 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -22,6 +22,7 @@ from base import ClientV1RestServlet, client_path_pattern
 
 import simplejson as json
 import urllib
+import urlparse
 
 import logging
 from saml2 import BINDING_HTTP_POST
@@ -39,6 +40,7 @@ class LoginRestServlet(ClientV1RestServlet):
     PASS_TYPE = "m.login.password"
     SAML2_TYPE = "m.login.saml2"
     CAS_TYPE = "m.login.cas"
+    TOKEN_TYPE = "m.login.token"
 
     def __init__(self, hs):
         super(LoginRestServlet, self).__init__(hs)
@@ -58,6 +60,7 @@ class LoginRestServlet(ClientV1RestServlet):
             flows.append({"type": LoginRestServlet.CAS_TYPE})
         if self.password_enabled:
             flows.append({"type": LoginRestServlet.PASS_TYPE})
+        flows.append({"type": LoginRestServlet.TOKEN_TYPE})
         return (200, {"flows": flows})
 
     def on_OPTIONS(self, request):
@@ -83,6 +86,7 @@ class LoginRestServlet(ClientV1RestServlet):
                     "uri": "%s%s" % (self.idp_redirect_url, relay_state)
                 }
                 defer.returnValue((200, result))
+            # TODO Delete this after all CAS clients switch to token login instead
             elif self.cas_enabled and (login_submission["type"] ==
                                        LoginRestServlet.CAS_TYPE):
                 # TODO: get this from the homeserver rather than creating a new one for
@@ -96,6 +100,9 @@ class LoginRestServlet(ClientV1RestServlet):
                 body = yield http_client.get_raw(uri, args)
                 result = yield self.do_cas_login(body)
                 defer.returnValue(result)
+            elif login_submission["type"] == LoginRestServlet.TOKEN_TYPE:
+                result = yield self.do_token_login(login_submission)
+                defer.returnValue(result)
             else:
                 raise SynapseError(400, "Bad login type.")
         except KeyError:
@@ -132,6 +139,26 @@ class LoginRestServlet(ClientV1RestServlet):
         defer.returnValue((200, result))
 
     @defer.inlineCallbacks
+    def do_token_login(self, login_submission):
+        token = login_submission['token']
+        auth_handler = self.handlers.auth_handler
+        user_id = (
+            yield auth_handler.validate_short_term_login_token_and_get_user_id(token)
+        )
+        user_id, access_token, refresh_token = (
+            yield auth_handler.login_with_user_id(user_id)
+        )
+        result = {
+            "user_id": user_id,  # may have changed
+            "access_token": access_token,
+            "refresh_token": refresh_token,
+            "home_server": self.hs.hostname,
+        }
+
+        defer.returnValue((200, result))
+
+    # TODO Delete this after all CAS clients switch to token login instead
+    @defer.inlineCallbacks
     def do_cas_login(self, cas_response_body):
         user, attributes = self.parse_cas_response(cas_response_body)
 
@@ -152,7 +179,7 @@ class LoginRestServlet(ClientV1RestServlet):
         user_exists = yield auth_handler.does_user_exist(user_id)
         if user_exists:
             user_id, access_token, refresh_token = (
-                yield auth_handler.login_with_cas_user_id(user_id)
+                yield auth_handler.login_with_user_id(user_id)
             )
             result = {
                 "user_id": user_id,  # may have changed
@@ -173,6 +200,7 @@ class LoginRestServlet(ClientV1RestServlet):
 
         defer.returnValue((200, result))
 
+    # TODO Delete this after all CAS clients switch to token login instead
     def parse_cas_response(self, cas_response_body):
         root = ET.fromstring(cas_response_body)
         if not root.tag.endswith("serviceResponse"):
@@ -243,6 +271,7 @@ class SAML2RestServlet(ClientV1RestServlet):
         defer.returnValue((200, {"status": "not_authenticated"}))
 
 
+# TODO Delete this after all CAS clients switch to token login instead
 class CasRestServlet(ClientV1RestServlet):
     PATTERN = client_path_pattern("/login/cas")
 
@@ -254,6 +283,118 @@ class CasRestServlet(ClientV1RestServlet):
         return (200, {"serverUrl": self.cas_server_url})
 
 
+class CasRedirectServlet(ClientV1RestServlet):
+    PATTERN = client_path_pattern("/login/cas/redirect")
+
+    def __init__(self, hs):
+        super(CasRedirectServlet, self).__init__(hs)
+        self.cas_server_url = hs.config.cas_server_url
+        self.cas_service_url = hs.config.cas_service_url
+
+    def on_GET(self, request):
+        args = request.args
+        if "redirectUrl" not in args:
+            return (400, "Redirect URL not specified for CAS auth")
+        clientRedirectUrlParam = urllib.urlencode({
+            "redirectUrl": args["redirectUrl"][0]
+        })
+        hsRedirectUrl = self.cas_service_url + "/_matrix/client/api/v1/login/cas/ticket"
+        serviceParam = urllib.urlencode({
+            "service": "%s?%s" % (hsRedirectUrl, clientRedirectUrlParam)
+        })
+        request.redirect("%s?%s" % (self.cas_server_url, serviceParam))
+        request.finish()
+        defer.returnValue(None)
+
+
+class CasTicketServlet(ClientV1RestServlet):
+    PATTERN = client_path_pattern("/login/cas/ticket")
+
+    def __init__(self, hs):
+        super(CasTicketServlet, self).__init__(hs)
+        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
+
+    @defer.inlineCallbacks
+    def on_GET(self, request):
+        clientRedirectUrl = request.args["redirectUrl"][0]
+        # TODO: get this from the homeserver rather than creating a new one for
+        # each request
+        http_client = SimpleHttpClient(self.hs)
+        uri = self.cas_server_url + "/proxyValidate"
+        args = {
+            "ticket": request.args["ticket"],
+            "service": self.cas_service_url
+        }
+        body = yield http_client.get_raw(uri, args)
+        result = yield self.handle_cas_response(request, body, clientRedirectUrl)
+        defer.returnValue(result)
+
+    @defer.inlineCallbacks
+    def handle_cas_response(self, request, cas_response_body, clientRedirectUrl):
+        user, attributes = self.parse_cas_response(cas_response_body)
+
+        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)
+
+            # 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)
+
+        user_id = UserID.create(user, self.hs.hostname).to_string()
+        auth_handler = self.handlers.auth_handler
+        user_exists = yield auth_handler.does_user_exist(user_id)
+        if not user_exists:
+            user_id, ignored = (
+                yield self.handlers.registration_handler.register(localpart=user)
+            )
+
+        login_token = auth_handler.generate_short_term_login_token(user_id)
+        redirectUrl = self.add_login_token_to_redirect_url(clientRedirectUrl, login_token)
+        request.redirect(redirectUrl)
+        request.finish()
+        defer.returnValue(None)
+
+    def add_login_token_to_redirect_url(self, url, token):
+        url_parts = list(urlparse.urlparse(url))
+        query = dict(urlparse.parse_qsl(url_parts[4]))
+        query.update({"loginToken": token})
+        url_parts[4] = urllib.urlencode(query)
+        return urlparse.urlunparse(url_parts)
+
+    def parse_cas_response(self, cas_response_body):
+        root = ET.fromstring(cas_response_body)
+        if not root.tag.endswith("serviceResponse"):
+            raise LoginError(401, "Invalid CAS response", errcode=Codes.UNAUTHORIZED)
+        if not root[0].tag.endswith("authenticationSuccess"):
+            raise LoginError(401, "Unsuccessful CAS response", errcode=Codes.UNAUTHORIZED)
+        for child in root[0]:
+            if child.tag.endswith("user"):
+                user = child.text
+            if child.tag.endswith("attributes"):
+                attributes = {}
+                for attribute in child:
+                    # ElementTree library expands the namespace in attribute tags
+                    # to the full URL of the namespace.
+                    # See (https://docs.python.org/2/library/xml.etree.elementtree.html)
+                    # We don't care about namespace here and it will always be encased in
+                    # curly braces, so we remove them.
+                    if "}" in attribute.tag:
+                        attributes[attribute.tag.split("}")[1]] = attribute.text
+                    else:
+                        attributes[attribute.tag] = attribute.text
+        if user is None or attributes is None:
+            raise LoginError(401, "Invalid CAS response", errcode=Codes.UNAUTHORIZED)
+
+        return (user, attributes)
+
+
 def _parse_json(request):
     try:
         content = json.loads(request.content.read())
@@ -269,5 +410,7 @@ def register_servlets(hs, http_server):
     if hs.config.saml2_enabled:
         SAML2RestServlet(hs).register(http_server)
     if hs.config.cas_enabled:
+        CasRedirectServlet(hs).register(http_server)
+        CasTicketServlet(hs).register(http_server)
         CasRestServlet(hs).register(http_server)
     # TODO PasswordResetRestServlet(hs).register(http_server)