Add m.login.terms to the registration flow

changelog.d/4004.feature

@@ -0,0 +1 @@
+Add `m.login.terms` to the registration flow when consent tracking is enabled. **This makes the template arguments conditionally optional on a new `public_version` variable - update your privacy templates to support this.**

docs/consent_tracking.md

@@ -31,7 +31,7 @@ Note that the templates must be stored under a name giving the language of the
 template - currently this must always be `en` (for "English");
 internationalisation support is intended for the future.
 
-The template for the policy itself should be versioned and named according to 
+The template for the policy itself should be versioned and named according to
 the version: for example `1.0.html`. The version of the policy which the user
 has agreed to is stored in the database.
 
@@ -81,9 +81,9 @@ should be a matter of `pip install Jinja2`. On debian, try `apt-get install
 python-jinja2`.
 
 Once this is complete, and the server has been restarted, try visiting
-`https://<server>/_matrix/consent`. If correctly configured, this should give
-an error "Missing string query parameter 'u'". It is now possible to manually
-construct URIs where users can give their consent.
+`https://<server>/_matrix/consent`. If correctly configured, you should see a
+default policy document. It is now possible to manually construct URIs where
+users can give their consent.
 
 ### Constructing the consent URI
 
@@ -106,6 +106,11 @@ query parameters:
    `https://<server>/_matrix/consent?u=<user>&h=68a152465a4d...`.
 
 
+Note that not providing a `u` parameter will be interpreted as wanting to view
+the document from an unauthenticated perspective, such as prior to registration.
+Therefore, the `h` parameter is not required in this scenario.
+
+
 Sending users a server notice asking them to agree to the policy
 ----------------------------------------------------------------
 

docs/privacy_policy_templates/en/1.0.html

@@ -12,12 +12,15 @@
     <p>
       All your base are belong to us.
     </p>
-    <form method="post" action="consent">
-      <input type="hidden" name="v" value="{{version}}"/>
-      <input type="hidden" name="u" value="{{user}}"/>
-      <input type="hidden" name="h" value="{{userhmac}}"/>
-      <input type="submit" value="Sure thing!"/>
-    </form>
+    {% if not public_version %}
+      <!-- The variables used here are only provided when the 'u' param is given to the homeserver -->
+      <form method="post" action="consent">
+        <input type="hidden" name="v" value="{{version}}"/>
+        <input type="hidden" name="u" value="{{user}}"/>
+        <input type="hidden" name="h" value="{{userhmac}}"/>
+        <input type="submit" value="Sure thing!"/>
+      </form>
+    {% endif %}
   {% endif %}
   </body>
 </html>

synapse/api/constants.py

@@ -51,6 +51,7 @@ class LoginType(object):
     EMAIL_IDENTITY = u"m.login.email.identity"
     MSISDN = u"m.login.msisdn"
     RECAPTCHA = u"m.login.recaptcha"
+    TERMS = u"m.login.terms"
     DUMMY = u"m.login.dummy"
 
     # Only for C/S API v1

synapse/handlers/auth.py

@@ -59,6 +59,7 @@ def __init__(self, hs):
             LoginType.EMAIL_IDENTITY: self._check_email_identity,
             LoginType.MSISDN: self._check_msisdn,
             LoginType.DUMMY: self._check_dummy_auth,
+            LoginType.TERMS: self._check_terms_auth,
         }
         self.bcrypt_rounds = hs.config.bcrypt_rounds
 
@@ -431,6 +432,9 @@ def _check_msisdn(self, authdict, _):
     def _check_dummy_auth(self, authdict, _):
         return defer.succeed(True)
 
+    def _check_terms_auth(self, authdict, _):
+        return defer.succeed(True)
+
     @defer.inlineCallbacks
     def _check_threepid(self, medium, authdict):
         if 'threepid_creds' not in authdict:
@@ -462,13 +466,30 @@ def _check_threepid(self, medium, authdict):
     def _get_params_recaptcha(self):
         return {"public_key": self.hs.config.recaptcha_public_key}
 
+    def _get_params_terms(self):
+        return {
+            "policies": {
+                "privacy_policy": {
+                    "version": self.hs.config.user_consent_version,
+                    "en": {
+                        "name": "Privacy Policy",
+                        "url": "%s/_matrix/consent?v=%s" % (
+                            self.hs.config.public_baseurl,
+                            self.hs.config.user_consent_version,
+                        ),
+                    },
+                },
+            },
+        }
+
     def _auth_dict_for_flows(self, flows, session):
         public_flows = []
         for f in flows:
             public_flows.append(f)
 
         get_params = {
             LoginType.RECAPTCHA: self._get_params_recaptcha,
+            LoginType.TERMS: self._get_params_terms,
         }
 
         params = {}

synapse/rest/client/v2_alpha/auth.py

@@ -68,6 +68,29 @@
 </html>
 """
 
+TERMS_TEMPLATE = """
+<html>
+<head>
+<title>Authentication</title>
+<meta name='viewport' content='width=device-width, initial-scale=1,
+    user-scalable=no, minimum-scale=1.0, maximum-scale=1.0'>
+<link rel="stylesheet" href="/_matrix/static/client/register/style.css">
+</head>
+<body>
+<form id="registrationForm" method="post" action="%(myurl)s">
+    <div>
+        <p>
+            Please click the button below if you agree to the
+            <a href="%(terms_url)s">privacy policy of this homeserver.</a>
+        </p>
+        <input type="hidden" name="session" value="%(session)s" />
+        <input type="submit" value="Agree" />
+    </div>
+</form>
+</body>
+</html>
+"""
+
 SUCCESS_TEMPLATE = """
 <html>
 <head>
@@ -130,6 +153,27 @@ def on_GET(self, request, stagetype):
             request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
             request.setHeader(b"Content-Length", b"%d" % (len(html_bytes),))
 
+            request.write(html_bytes)
+            finish_request(request)
+            defer.returnValue(None)
+        elif stagetype == LoginType.TERMS:
+            session = request.args['session'][0]
+
+            html = TERMS_TEMPLATE % {
+                'session': session,
+                'terms_url': "%s/_matrix/consent?v=%s" % (
+                    self.hs.config.public_baseurl,
+                    self.hs.config.user_consent_version,
+                ),
+                'myurl': "%s/auth/%s/fallback/web" % (
+                    CLIENT_V2_ALPHA_PREFIX, LoginType.TERMS
+                ),
+            }
+            html_bytes = html.encode("utf8")
+            request.setResponseCode(200)
+            request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
+            request.setHeader(b"Content-Length", b"%d" % (len(html_bytes),))
+
             request.write(html_bytes)
             finish_request(request)
             defer.returnValue(None)
@@ -139,7 +183,7 @@ def on_GET(self, request, stagetype):
     @defer.inlineCallbacks
     def on_POST(self, request, stagetype):
         yield
-        if stagetype == "m.login.recaptcha":
+        if stagetype == LoginType.RECAPTCHA:
             if ('g-recaptcha-response' not in request.args or
                     len(request.args['g-recaptcha-response'])) == 0:
                 raise SynapseError(400, "No captcha response supplied")
@@ -178,6 +222,41 @@ def on_POST(self, request, stagetype):
             request.write(html_bytes)
             finish_request(request)
 
+            defer.returnValue(None)
+        elif stagetype == LoginType.TERMS:
+            if ('session' not in request.args or
+                    len(request.args['session'])) == 0:
+                raise SynapseError(400, "No session supplied")
+
+            session = request.args['session'][0]
+            authdict = {'session': session}
+
+            success = yield self.auth_handler.add_oob_auth(
+                LoginType.TERMS,
+                authdict,
+                self.hs.get_ip_from_request(request)
+            )
+
+            if success:
+                html = SUCCESS_TEMPLATE
+            else:
+                html = TERMS_TEMPLATE % {
+                    'session': session,
+                    'terms_url': "%s/_matrix/consent?v=%s" % (
+                        self.hs.config.public_baseurl,
+                        self.hs.config.user_consent_version,
+                    ),
+                    'myurl': "%s/auth/%s/fallback/web" % (
+                        CLIENT_V2_ALPHA_PREFIX, LoginType.TERMS
+                    ),
+                }
+            html_bytes = html.encode("utf8")
+            request.setResponseCode(200)
+            request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
+            request.setHeader(b"Content-Length", b"%d" % (len(html_bytes),))
+
+            request.write(html_bytes)
+            finish_request(request)
             defer.returnValue(None)
         else:
             raise SynapseError(404, "Unknown auth stage type")

synapse/rest/client/v2_alpha/register.py

@@ -359,6 +359,13 @@ def on_POST(self, request):
                     [LoginType.MSISDN, LoginType.EMAIL_IDENTITY]
                 ])
 
+        # Append m.login.terms to all flows if we're requiring consent
+        if self.hs.config.block_events_without_consent_error is not None:
+            new_flows = []
+            for flow in flows:
+                flow.append(LoginType.TERMS)
+            flows.extend(new_flows)
+
         auth_result, params, session_id = yield self.auth_handler.check_auth(
             flows, body, self.hs.get_ip_from_request(request)
         )
@@ -445,6 +452,12 @@ def on_POST(self, request):
                 params.get("bind_msisdn")
             )
 
+        if auth_result and LoginType.TERMS in auth_result:
+            logger.info("%s has consented to the privacy policy" % registered_user_id)
+            yield self.store.user_set_consent_version(
+                registered_user_id, self.hs.config.user_consent_version,
+            )
+
         defer.returnValue((200, return_dict))
 
     def on_OPTIONS(self, _):

synapse/rest/consent/consent_resource.py

@@ -137,27 +137,31 @@ def _async_render_GET(self, request):
             request (twisted.web.http.Request):
         """
 
-        version = parse_string(request, "v",
-                               default=self._default_consent_version)
-        username = parse_string(request, "u", required=True)
-        userhmac = parse_string(request, "h", required=True, encoding=None)
-
-        self._check_hash(username, userhmac)
-
-        if username.startswith('@'):
-            qualified_user_id = username
-        else:
-            qualified_user_id = UserID(username, self.hs.hostname).to_string()
-
-        u = yield self.store.get_user_by_id(qualified_user_id)
-        if u is None:
-            raise NotFoundError("Unknown user")
+        version = parse_string(request, "v", default=self._default_consent_version)
+        username = parse_string(request, "u", required=False, default="")
+        userhmac = None
+        has_consented = False
+        public_version = username != ""
+        if not public_version:
+            userhmac = parse_string(request, "h", required=True, encoding=None)
+
+            self._check_hash(username, userhmac)
+
+            if username.startswith('@'):
+                qualified_user_id = username
+            else:
+                qualified_user_id = UserID(username, self.hs.hostname).to_string()
+
+            u = yield self.store.get_user_by_id(qualified_user_id)
+            if u is None:
+                raise NotFoundError("Unknown user")
+            has_consented = u["consent_version"] == version
 
         try:
             self._render_template(
                 request, "%s.html" % (version,),
                 user=username, userhmac=userhmac, version=version,
-                has_consented=(u["consent_version"] == version),
+                has_consented=has_consented, public_version=public_version,
             )
         except TemplateNotFound:
             raise NotFoundError("Unknown policy version")