[FIX] mass_mailing: improve opened traces tracking

Purpose of this commit is to improve tracking of opened traces. Notably
a token is added to ensure we do not mess with traces and have unique
tracking URLs.

MIGRATION REMARK

Emails sent before the migration will not be marked as opened anymore after
migration. We recommend to avoid sending statistically important mass mailings
about one week before migrating database. Indeed statistics show that most of
open emails happen within the first week after being sent.

Task 2223146

closes odoo/odoo#49139

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

4 files changed, 36 insertions, 6 deletions

diff --git a/addons/mass_mailing/controllers/main.py b/addons/mass_mailing/controllers/main.py
index 02ffe4609c3..b5ef9b9faca 100644
--- a/addons/mass_mailing/controllers/main.py
+++ b/addons/mass_mailing/controllers/main.py
@@ -7,6 +7,7 @@ import werkzeug
 from odoo import _, exceptions, http, tools
 from odoo.http import request
 from odoo.tools import consteq
+from werkzeug.exceptions import BadRequest
 
 
 class MassMailController(http.Controller):
@@ -91,9 +92,12 @@ class MassMailController(http.Controller):
             return True
         return 'error'
 
-    @http.route('/mail/track/<int:mail_id>/blank.gif', type='http', auth='public')
-    def track_mail_open(self, mail_id, **post):
+    @http.route('/mail/track/<int:mail_id>/<string:token>/blank.gif', type='http', auth='public')
+    def track_mail_open(self, mail_id, token, **post):
         """ Email tracking. """
+        if not consteq(token, tools.hmac(request.env(su=True), 'mass_mailing-mail_mail-open', mail_id)):
+            raise BadRequest()
+
         request.env['mailing.trace'].sudo().set_opened(mail_mail_ids=[mail_id])
         response = werkzeug.wrappers.Response()
         response.mimetype = 'image/gif'
diff --git a/addons/mass_mailing/models/mail_mail.py b/addons/mass_mailing/models/mail_mail.py
index b92b6f1e478..4c627234c27 100644
--- a/addons/mass_mailing/models/mail_mail.py
+++ b/addons/mass_mailing/models/mail_mail.py
@@ -26,8 +26,8 @@ class MailMail(models.Model):
 
     def _get_tracking_url(self):
         base_url = self.env['ir.config_parameter'].sudo().get_param('web.base.url')
-        track_url = werkzeug.urls.url_join(base_url, 'mail/track/%s/blank.gif' % self.id)
-        return '<img src="%s" alt=""/>' % track_url
+        token = tools.hmac(self.env(su=True), 'mass_mailing-mail_mail-open', self.id)
+        return werkzeug.urls.url_join(base_url, 'mail/track/%s/%s/blank.gif' % (self.id, token))
 
     def _get_unsubscribe_url(self, email_to):
         base_url = self.env['ir.config_parameter'].sudo().get_param('web.base.url')
@@ -64,8 +64,11 @@ class MailMail(models.Model):
 
             # generate tracking URL
             tracking_url = self._get_tracking_url()
-            if tracking_url:
-                body = tools.append_content_to_html(body, tracking_url, plaintext=False, container_tag='div')
+            body = tools.append_content_to_html(
+                body,
+                '<img src="%s"/>' % tracking_url,
+                plaintext=False,
+            )
 
         body = self.env['mail.render.mixin']._replace_local_links(body)
 
diff --git a/addons/mass_mailing/tests/__init__.py b/addons/mass_mailing/tests/__init__.py
index 49ff0a87784..ddc9e161eec 100644
--- a/addons/mass_mailing/tests/__init__.py
+++ b/addons/mass_mailing/tests/__init__.py
@@ -4,3 +4,4 @@
 from . import common
 from . import test_mailing_internals
 from . import test_mailing_list
+from . import test_mailing_controllers
diff --git a/addons/mass_mailing/tests/test_mailing_controllers.py b/addons/mass_mailing/tests/test_mailing_controllers.py
new file mode 100644
index 00000000000..eb1ecd60178
--- /dev/null
+++ b/addons/mass_mailing/tests/test_mailing_controllers.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+import werkzeug
+
+from odoo.addons.mass_mailing.tests.common import TestMassMailCommon
+from odoo.tests.common import HttpCase
+
+
+class TestMassMailingControllers(TestMassMailCommon, HttpCase):
+
+    def test_tracking_url_token(self):
+        mail_mail = self.env['mail.mail'].create({})
+
+        response = self.url_open(mail_mail._get_tracking_url())
+        self.assertEqual(response.status_code, 200)
+
+        base_url = self.env['ir.config_parameter'].sudo().get_param('web.base.url')
+        url = werkzeug.urls.url_join(base_url, 'mail/track/%s/fake_token/blank.gif' % mail_mail.id)
+
+        response = self.url_open(url)
+        self.assertEqual(response.status_code, 400)