FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

[3.14] gh-90309: Base64-encode cookie values embedded in JS by miss-islington · Pull Request #148889 · python/cpython · GitHub

  1. python
  2. cpython

Repository navigation

[3.14] gh-90309: Base64-encode cookie values embedded in JS #148889

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
encukou merged 1 commit into from
Apr 23, 2026
+27 −13
Conversation 0 Commits 1 Checks 47 Files changed 3
Merged

[3.14] gh-90309: Base64-encode cookie values embedded in JS #148889

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension .py  (2) .rst  (1) All 2 file types selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
8 changes: 6 additions & 2 deletions Lib/http/cookies.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -391,17 +391,21 @@ def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self.OutputString())

def js_output(self, attrs=None):
import base64
# Print javascript
output_string = self.OutputString(attrs)
if _has_control_character(output_string):
raise CookieError("Control characters are not allowed in cookies")
# Base64-encode value to avoid template
# injection in cookie values.
output_encoded = base64.b64encode(output_string.encode('utf-8')).decode("ascii")
return """
<script type="text/javascript">
<!-- begin hiding
document.cookie = \"%s\";
document.cookie = atob(\"%s\");
// end hiding -->
</script>
""" % (output_string.replace('"', r'\"'))
""" % (output_encoded,)

def OutputString(self, attrs=None):
# Build up our result
Expand Down
29 changes: 18 additions & 11 deletions Lib/test/test_http_cookies.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
# Simple test suite for http/cookies.py

import base64
import copy
import unittest
import doctest
Expand Down Expand Up @@ -152,17 +152,19 @@ def test_load(self):

self.assertEqual(C.output(['path']),
'Set-Cookie: Customer="WILE_E_COYOTE"; Path=/acme')
self.assertEqual(C.js_output(), r"""
cookie_encoded = base64.b64encode(b'Customer="WILE_E_COYOTE"; Path=/acme; Version=1').decode('ascii')
self.assertEqual(C.js_output(), fr"""
<script type="text/javascript">
<!-- begin hiding
document.cookie = "Customer=\"WILE_E_COYOTE\"; Path=/acme; Version=1";
document.cookie = atob("{cookie_encoded}");
// end hiding -->
</script>
""")
self.assertEqual(C.js_output(['path']), r"""
cookie_encoded = base64.b64encode(b'Customer="WILE_E_COYOTE"; Path=/acme').decode('ascii')
self.assertEqual(C.js_output(['path']), fr"""
<script type="text/javascript">
<!-- begin hiding
document.cookie = "Customer=\"WILE_E_COYOTE\"; Path=/acme";
document.cookie = atob("{cookie_encoded}");
// end hiding -->
</script>
""")
Expand Down Expand Up @@ -267,17 +269,19 @@ def test_quoted_meta(self):

self.assertEqual(C.output(['path']),
'Set-Cookie: Customer="WILE_E_COYOTE"; Path=/acme')
self.assertEqual(C.js_output(), r"""
expected_encoded_cookie = base64.b64encode(b'Customer=\"WILE_E_COYOTE\"; Path=/acme; Version=1').decode('ascii')
self.assertEqual(C.js_output(), fr"""
<script type="text/javascript">
<!-- begin hiding
document.cookie = "Customer=\"WILE_E_COYOTE\"; Path=/acme; Version=1";
document.cookie = atob("{expected_encoded_cookie}");
// end hiding -->
</script>
""")
self.assertEqual(C.js_output(['path']), r"""
expected_encoded_cookie = base64.b64encode(b'Customer=\"WILE_E_COYOTE\"; Path=/acme').decode('ascii')
self.assertEqual(C.js_output(['path']), fr"""
<script type="text/javascript">
<!-- begin hiding
document.cookie = "Customer=\"WILE_E_COYOTE\"; Path=/acme";
document.cookie = atob("{expected_encoded_cookie}");
// end hiding -->
</script>
""")
Expand Down Expand Up @@ -368,13 +372,16 @@ def test_setter(self):
self.assertEqual(
M.output(),
"Set-Cookie: %s=%s; Path=/foo" % (i, "%s_coded_val" % i))
expected_encoded_cookie = base64.b64encode(
("%s=%s; Path=/foo" % (i, "%s_coded_val" % i)).encode("ascii")
).decode('ascii')
expected_js_output = """
<script type="text/javascript">
<!-- begin hiding
document.cookie = "%s=%s; Path=/foo";
document.cookie = atob("%s");
// end hiding -->
</script>
""" % (i, "%s_coded_val" % i)
""" % (expected_encoded_cookie,)
self.assertEqual(M.js_output(), expected_js_output)
for i in ["foo bar", "foo@bar"]:
# Try some illegal characters
Expand Down
3 changes: 3 additions & 0 deletions Misc/NEWS.d/next/Security/2026-04-21-13-46-30.gh-issue-90309.srvj9q.rst
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Base64-encode values when embedding cookies to JavaScript using the
:meth:`http.cookies.BaseCookie.js_output` method to avoid injection
and escaping.
Loading
Back | FazBrowse Home | New Git URL