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classification
Title: SSLContext._load_windows_store_certs fails with PermissionError
Type: behavior Stage: resolved
Components: Windows Versions: Python 3.6, Python 3.5, Python 2.7
process
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: steve.dower Nosy List: paul.moore, python-dev, steve.dower, tim.golden, zach.ware
Priority: normal Keywords: patch

Created on 2016-05-24 22:24 by steve.dower, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Files
File name Uploaded Description Edit
27114_1.patch steve.dower, 2016-05-24 22:30
Messages (5)
msg266285 - (view) Author: Steve Dower (steve.dower) * (Python committer) Date: 2016-05-24 22:24
In some restricted server scenarios, it is not possible to enumerate the Windows machine certificate store. A PermissionError is raised and the operation aborted.

Instead, we should simply return no certificates from _load_windows_store_certs. This will most likely cause the SSL request to fail (as the certificate cannot be verified), but it allows the use of SSL_CERT_FILE to use certificates from a local file. Without handling the PermissionError, it doesn't matter whether the environment variable is set or not - we simply fail every time.
msg266286 - (view) Author: Steve Dower (steve.dower) * (Python committer) Date: 2016-05-24 22:30
Added a patch against 3.5 that handles PermissionError and warns about the failure.

I think this should be applied against 2.7, 3.5 and 3.6, and that it's unfortunately untestable (without adding extra API to force it to fail). Any concerns?
msg266448 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2016-05-26 19:18
New changeset 40f3f2b27112 by Steve Dower in branch '2.7':
Issue #27114: Fix SSLContext._load_windows_store_certs fails with PermissionError
https://hg.python.org/cpython/rev/40f3f2b27112
msg266449 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2016-05-26 19:20
New changeset 29f163db229e by Steve Dower in branch '3.5':
Issue #27114: Fix SSLContext._load_windows_store_certs fails with PermissionError
https://hg.python.org/cpython/rev/29f163db229e

New changeset eaee5aed6fbc by Steve Dower in branch 'default':
Issue #27114: Fix SSLContext._load_windows_store_certs fails with PermissionError
https://hg.python.org/cpython/rev/eaee5aed6fbc
msg266450 - (view) Author: Steve Dower (steve.dower) * (Python committer) Date: 2016-05-26 19:26
One slight change to the patch for 2.7 - has to catch OSError.

Just realised that I forgot to mention the reason we shouldn't just let the exception propagate out is that we then never load certificates specified by the SSL_CERT_FILE variable. Handling the exception allows a workaround.

If the exception occurs and no other certificates have been provided, it seems certain that a later operation is going to fail with a much more useful message (i.e. unverifiable connection, or whatever it says). There are also libraries (I think urllib is the one that was causing me actual trouble) that keep retrying the call when it fails, and all of those would need to be updated to handle this error.

The docs don't specify potential exceptions, so I see only good by not raising an exception here.
History
Date User Action Args
2022-04-11 14:58:31adminsetgithub: 71301
2016-05-26 19:28:09steve.dowersetstatus: open -> closed
resolution: fixed
stage: commit review -> resolved
2016-05-26 19:26:06steve.dowersetmessages: + msg266450
stage: patch review -> commit review
2016-05-26 19:20:11python-devsetmessages: + msg266449
2016-05-26 19:18:25python-devsetnosy: + python-dev
messages: + msg266448
2016-05-24 22:30:39steve.dowersetfiles: + 27114_1.patch
keywords: + patch
messages: + msg266286

stage: needs patch -> patch review
2016-05-24 22:24:35steve.dowercreate