gh-95231: Disable md5 & crypt modules if FIPS is enabled (GH-94742)

If kernel fips is enabled, we get permission error upon doing
`import crypt`. So, if kernel fips is enabled, disable the
unallowed hashing methods.

Python 3.9.1 (default, May 10 2022, 11:36:26)
[GCC 10.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import crypt
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.9/crypt.py", line 117, in <module>
    _add_method('MD5', '1', 8, 34)
  File "/usr/lib/python3.9/crypt.py", line 94, in _add_method
    result = crypt('', salt)
  File "/usr/lib/python3.9/crypt.py", line 82, in crypt
    return _crypt.crypt(word, salt)
PermissionError: [Errno 1] Operation not permitted

Signed-off-by: Shreenidhi Shedi <sshedi@vmware.com>
(cherry picked from commit 2fa03b1b0708d5d74630c351ec9abd2aac7550da)

Co-authored-by: Shreenidhi Shedi <53473811+sshedi@users.noreply.github.com>

diff --git a/Lib/crypt.py b/Lib/crypt.py
index 33dbc46bb3e96bed9f32f7919c81cfda069b65ce..b296c3edb0f511e11b442b7f1dc9cd8b670c7c33 100644 (file)
--- a/Lib/crypt.py
+++ b/Lib/crypt.py
@@ -94,7 +94,7 @@ def _add_method(name, *args, rounds=None):
         result = crypt('', salt)
     except OSError as e:
         # Not all libc libraries support all encryption methods.
-        if e.errno == errno.EINVAL:
+        if e.errno in {errno.EINVAL, errno.EPERM, errno.ENOSYS}:
             return False
         raise
     if result and len(result) == method.total_size:

diff --git a/Misc/NEWS.d/next/Library/2022-07-25-15-45-06.gh-issue-95231.i807-g.rst b/Misc/NEWS.d/next/Library/2022-07-25-15-45-06.gh-issue-95231.i807-g.rst
new file mode 100644 (file)
index 0000000..aa53f29
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-07-25-15-45-06.gh-issue-95231.i807-g.rst
@@ -0,0 +1,3 @@
+Fail gracefully if :data:`~errno.EPERM` or :data:`~errno.ENOSYS` is raised when loading
+:mod:`crypt` methods. This may happen when trying to load ``MD5`` on a Linux kernel
+with :abbr:`FIPS (Federal Information Processing Standard)` enabled.