move policy enforcing code to a new file, include basic test

3 files changed, 124 insertions, 13 deletions

diff --git a/test/unit/test_policy_enforcing.py b/test/unit/test_policy_enforcing.py
new file mode 100644
index 0000000..2f7bc80
--- /dev/null
+++ b/test/unit/test_policy_enforcing.py
@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: CC0-1.0
+
+"""
+Haketilo unit tests - enforcing script blocking policy from content script
+"""
+
+# This file is part of Haketilo
+#
+# Copyright (C) 2022 Wojtek Kosior <koszko@koszko.org>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the CC0 1.0 Universal License as published by
+# the Creative Commons Corporation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# CC0 1.0 Universal License for more details.
+
+import pytest
+import json
+import urllib.parse
+from selenium.webdriver.support.ui import WebDriverWait
+
+from ..script_loader import load_script
+from .utils import are_scripts_allowed
+
+# For simplicity, we'll use one nonce in all test cases.
+nonce = 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'
+
+allow_policy = {'allow': True}
+block_policy = {
+    'allow': False,
+    'csp': f"prefetch-src 'none'; script-src-attr 'none'; script-src 'none'; script-src-elem 'none'; frame-src http://* https://*;"
+}
+payload_policy = {
+    'mapping': 'somemapping',
+    'payload': {'identifier': 'someresource'},
+    'csp': f"prefetch-src 'none'; script-src-attr 'none'; script-src 'nonce-{nonce}'; script-src-elem 'nonce-{nonce}';"
+}
+
+content_script = load_script('content/policy_enforcing.js') + ''';{
+const smuggled_what_to_do = /^[^#]*#?(.*)$/.exec(document.URL)[1];
+const what_to_do = smuggled_what_to_do === "" ? {allow: true} :
+                   JSON.parse(decodeURIComponent(smuggled_what_to_do));
+
+if (what_to_do.csp_off) {
+    const orig_DOMParser = window.DOMParser;
+    window.DOMParser = function() {
+        parser = new orig_DOMParser();
+        this.parseFromString = () => parser.parseFromString('', 'text/html');
+    }
+}
+
+if (what_to_do.onbeforescriptexecute_off)
+    prevent_script_execution = () => {};
+
+if (what_to_do.sanitize_script_off) {
+    sanitize_script = () => {};
+    desanitize_script = () => {};
+}
+
+enforce_blocking(what_to_do.policy);
+}'''
+
+def get(driver, page, what_to_do):
+    driver.get(page + '#' + urllib.parse.quote(json.dumps(what_to_do)))
+    driver.execute_script('window.before_reload = true; location.reload();')
+    done = lambda _: not driver.execute_script('return window.before_reload;')
+    WebDriverWait(driver, 10).until(done)
+
+@pytest.mark.ext_data({'content_script': content_script})
+@pytest.mark.usefixtures('webextension')
+def test_policy_enforcing(driver, execute_in_page):
+    """
+    A test case of sanitizing <script>s and <meta>s in pages.
+    """
+    # First, see if scripts run when not blocked.
+    get(driver, 'https://gotmyowndoma.in/scripts_to_block_1.html', {
+        'policy': allow_policy
+    })
+
+    for i in range(1, 3):
+        driver.find_element_by_id(f'clickme{i}').click()
+
+    assert set(driver.execute_script('return window.__run || [];')) == \
+        {'inline', 'on', 'href', 'src', 'data'}
+
+    # Now, verify scripts don't run when blocked.
+    get(driver, 'https://gotmyowndoma.in/scripts_to_block_1.html', {
+        'policy': block_policy
+    })
+
+    for i in range(1, 3):
+        driver.find_element_by_id(f'clickme{i}').click()
+
+    assert set(driver.execute_script('return window.__run || [];')) == set()
+    assert not are_scripts_allowed(driver)
+
+    # Now, verify only scripts with nonce can run when payload is injected.
+    get(driver, 'https://gotmyowndoma.in/scripts_to_block_1.html', {
+        'policy': payload_policy
+    })
+
+    for i in range(1, 3):
+        driver.find_element_by_id(f'clickme{i}').click()
+
+    assert set(driver.execute_script('return window.__run || [];')) == set()
+    assert not are_scripts_allowed(driver)
+    assert are_scripts_allowed(driver, nonce)
diff --git a/test/unit/test_webrequest.py b/test/unit/test_webrequest.py
index ae617aa..598f43b 100644
--- a/test/unit/test_webrequest.py
+++ b/test/unit/test_webrequest.py
@@ -22,6 +22,7 @@ from hashlib import sha256
 import pytest
 
 from ..script_loader import load_script
+from .utils import are_scripts_allowed
 
 def webrequest_js():
     return (load_script('background/webrequest.js',
@@ -50,19 +51,6 @@ def webrequest_js():
             start("somesecret");
             ''')
 
-def are_scripts_allowed(driver, nonce=None):
-        return driver.execute_script(
-            '''
-            document.scripts_allowed = false;
-            const script = document.createElement("script");
-            script.innerHTML = "document.scripts_allowed = true;";
-            if (arguments[0])
-                script.setAttribute("nonce", arguments[0]);
-            document.head.append(script);
-            return document.scripts_allowed;
-            ''',
-            nonce)
-
 @pytest.mark.ext_data({'background_script': webrequest_js})
 @pytest.mark.usefixtures('webextension')
 def test_on_headers_received(driver, execute_in_page):
diff --git a/test/unit/utils.py b/test/unit/utils.py
index 96ebf60..8e04d91 100644
--- a/test/unit/utils.py
+++ b/test/unit/utils.py
@@ -187,3 +187,16 @@ def is_prime(n):
     return n > 1 and all([n % i != 0 for i in range(2, n)])
 
 broker_js = lambda: load_script('background/broadcast_broker.js') + ';start();'
+
+def are_scripts_allowed(driver, nonce=None):
+        return driver.execute_script(
+            '''
+            document.scripts_allowed = false;
+            const script = document.createElement("script");
+            script.innerHTML = "document.scripts_allowed = true;";
+            if (arguments[0])
+                script.setAttribute("nonce", arguments[0]);
+            document.head.append(script);
+            return document.scripts_allowed;
+            ''',
+            nonce)