[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>

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'

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)
 

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

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)

odoo/tools/misc.py

@@ -8,6 +8,8 @@ Miscellaneous tools used by OpenERP.
 import cProfile
 import collections
 import datetime
+import hmac as hmac_lib
+import hashlib
 import io
 import os
 import pickle as pickle_
@@ -1530,3 +1532,24 @@ def traverse_containers(val, type_):
     elif isinstance(val, collections.abc.Sequence):
         for v in val:
             yield from traverse_containers(v, type_)
+
+
+def hmac(env, scope, message, hash_function=hashlib.sha256):
+    """Compute HMAC with `database.secret` config parameter as key.
+
+    :param env: sudo environment to use for retrieving config parameter
+    :param message: message to authenticate
+    :param scope: scope of the authentication, to have different signature for the same
+        message in different usage
+    :param hash_function: hash function to use for HMAC (default: SHA-256)
+    """
+    if not scope:
+        raise ValueError('Non-empty scope required')
+
+    secret = env['ir.config_parameter'].get_param('database.secret')
+    message = repr((scope, message))
+    return hmac_lib.new(
+        secret.encode(),
+        message.encode(),
+        hash_function,
+    ).hexdigest()