* Expose X509_V_* constants.

* Switch to strategy where cryptography 40.0.2 exposes the constants.

* Fix bad merge.

* Fix flake.

* Link to PR.

* Check availability, rather than versions.

* Add namespacing.

* Add success code to namespace.

* Fix lint.

* Remove unnecessary conditional.

* Update CHANGELOG.rst

Co-authored-by: Alex Gaynor <alex.gaynor@gmail.com>

---------

Co-authored-by: Itamar Turner-Trauring <itamar@pythonspeed.com>
Co-authored-by: Alex Gaynor <alex.gaynor@gmail.com>

* remove X509StoreFlags.NOTIFY_POLICY

fixes #1212

* also fix twisted

* more CI fixes, sigh

* Reject invalid versions in X509Req.set_version

* Update CHANGELOG.rst

Co-authored-by: Paul Kehrer <paul.l.kehrer@gmail.com>

---------

Co-authored-by: Paul Kehrer <paul.l.kehrer@gmail.com>

* port changelog

* forward port the nid2sn workaround

Add support for DTLS timeouts

When performing a DTLS handshake, the DTLS state machine may need to be
updated based on the passage of time, for instance in response to packet
loss.

OpenSSL supports this by means of the `DTLSv1_get_timeout` and
`DTLSv1_handle_timeout` methods, both of which are included in
cryptography's bindings. This change adds Python wrappers for these
methods in the `Connection` class.

* Reformat code using black 23.x

* fix compat with tox 4