saltbundlepy-paramiko/CVE-2022-24302-race-condition.patch

103 lines
4.1 KiB
Diff

Index: paramiko-2.4.2/paramiko/pkey.py
===================================================================
--- paramiko-2.4.2.orig/paramiko/pkey.py
+++ paramiko-2.4.2/paramiko/pkey.py
@@ -519,7 +519,18 @@ class PKey(object):
:raises: ``IOError`` -- if there was an error writing the file.
"""
- with open(filename, "w") as f:
+ # Ensure that we create new key files directly with a user-only mode,
+ # instead of opening, writing, then chmodding, which leaves us open to
+ # CVE-2022-24302.
+ # NOTE: O_TRUNC is a noop on new files, and O_CREAT is a noop on
+ # existing files, so using all 3 in both cases is fine. Ditto the use
+ # of the 'mode' argument; it should be safe to give even for existing
+ # files (though it will not act like a chmod in that case).
+ # TODO 3.0: turn into kwargs again
+ args = [os.O_WRONLY | os.O_TRUNC | os.O_CREAT, o600]
+ # NOTE: yea, you still gotta inform the FLO that it is in "write" mode
+ with os.fdopen(os.open(filename, *args), "w") as f:
+ # TODO 3.0: remove the now redundant chmod
os.chmod(filename, o600)
self._write_private_key(f, key, format, password=password)
Index: paramiko-2.4.2/tests/test_pkey.py
===================================================================
--- paramiko-2.4.2.orig/tests/test_pkey.py
+++ paramiko-2.4.2/tests/test_pkey.py
@@ -23,11 +23,15 @@ Some unit tests for public/private key o
import unittest
import os
+import stat
from binascii import hexlify
from hashlib import md5
from paramiko import RSAKey, DSSKey, ECDSAKey, Ed25519Key, Message, util
from paramiko.py3compat import StringIO, byte_chr, b, bytes, PY2
+from paramiko.common import o600
+
+from mock import patch, Mock
from .util import _support
@@ -567,3 +571,57 @@ class KeyTest(unittest.TestCase):
key1.load_certificate,
_support("test_rsa.key-cert.pub"),
)
+
+ @patch("paramiko.pkey.os")
+ def _test_keyfile_race(self, os_, exists):
+ # Re: CVE-2022-24302
+ password = "television"
+ newpassword = "radio"
+ source = _support("test_ecdsa_384.key")
+ new = source + ".new"
+ # Mock setup
+ os_.path.exists.return_value = exists
+ # Attach os flag values to mock
+ for attr, value in vars(os).items():
+ if attr.startswith("O_"):
+ setattr(os_, attr, value)
+ # Load fixture key
+ key = ECDSAKey(filename=source, password=password)
+ key._write_private_key = Mock()
+ # Write out in new location
+ key.write_private_key_file(new, password=newpassword)
+ # Expected open via os module
+ os_.open.assert_called_once_with(new, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, o600)
+ os_.fdopen.assert_called_once_with(os_.open.return_value, "w")
+ # Old chmod still around for backwards compat
+ os_.chmod.assert_called_once_with(new, o600)
+ assert (
+ key._write_private_key.call_args[0][0]
+ == os_.fdopen.return_value.__enter__.return_value
+ )
+
+ def test_new_keyfiles_avoid_file_descriptor_race_on_chmod(self):
+ self._test_keyfile_race(exists=False)
+
+ def test_existing_keyfiles_still_work_ok(self):
+ self._test_keyfile_race(exists=True)
+
+ def test_new_keyfiles_avoid_descriptor_race_integration(self):
+ # Integration-style version of above
+ password = "television"
+ newpassword = "radio"
+ source = _support("test_ecdsa_384.key")
+ new = source + ".new"
+ # Load fixture key
+ key = ECDSAKey(filename=source, password=password)
+ try:
+ # Write out in new location
+ key.write_private_key_file(new, password=newpassword)
+ # Test mode
+ assert stat.S_IMODE(os.stat(new).st_mode) == o600
+ # Prove can open with new password
+ reloaded = ECDSAKey(filename=new, password=newpassword)
+ assert reloaded == key
+ finally:
+ if os.path.exists(new):
+ os.unlink(new)