Alex Gaynor
2014-07-01 18:26:27 UTC
Hi all,
I wanted to bring everyone up to speed on the status of PEP 466, what's been
completed, and what's left to do.
First the completed stuff:
* hmac.compare_digest
* hashlib.pbkdf2_hmac
Are both backported, and I've added support to use them in Django, so users
should start seeing these benefits just as soon as we get a Python release into
their hands.
Now the uncompleted stuff:
* Persistent file descriptor for ``os.urandom``
* SSL module
It's the SSL module that I'll spend the rest of this email talking about.
Backporting the features from the Python3 version of this module has proven
more difficult than I had expected. This is primarily because the stdlib took a
maintenance strategy that was different from what most Python projects have
done for their 2/3 support: multiple independent codebases.
I've tried a few different strategies for the backport, none of which has
worked:
* Copying the ``ssl.py``, ``test_ssl.py``, and ``_ssl.c`` files from Python3
and trying to port all the code.
* Coping just ``test_ssl.py`` and then copying individual chunks/functions as
necessary to get stuff to pass.
* Manually doing stuff.
All of these proved to be a massive undertaking, and made it too easy to
accidentally introduce breaking changes.
I've come up with a new approach, which I believe is most likely to be
successful, but I'll need help to implement it.
The idea is to find the most recent commit which is a parent of both the
``2.7`` and ``default`` branches. Then take every single change to an ``ssl``
related file on the ``default`` branch, and attempt to replay it on the ``2.7``
branch. Require manual review on each commit to make sure it compiles, and to
ensure it doesn't make any backwards incompatible changes.
I think this provides the most iterative and guided approach to getting this
done.
I can do all the work of reviewing each commit, but I need some help from a
mercurial expert to automate the cherry-picking/rebasing of every single
commit.
What do folks think? Does this approach make sense? Anyone willing to help with
the mercurial scripting?
Cheers,
Alex
I wanted to bring everyone up to speed on the status of PEP 466, what's been
completed, and what's left to do.
First the completed stuff:
* hmac.compare_digest
* hashlib.pbkdf2_hmac
Are both backported, and I've added support to use them in Django, so users
should start seeing these benefits just as soon as we get a Python release into
their hands.
Now the uncompleted stuff:
* Persistent file descriptor for ``os.urandom``
* SSL module
It's the SSL module that I'll spend the rest of this email talking about.
Backporting the features from the Python3 version of this module has proven
more difficult than I had expected. This is primarily because the stdlib took a
maintenance strategy that was different from what most Python projects have
done for their 2/3 support: multiple independent codebases.
I've tried a few different strategies for the backport, none of which has
worked:
* Copying the ``ssl.py``, ``test_ssl.py``, and ``_ssl.c`` files from Python3
and trying to port all the code.
* Coping just ``test_ssl.py`` and then copying individual chunks/functions as
necessary to get stuff to pass.
* Manually doing stuff.
All of these proved to be a massive undertaking, and made it too easy to
accidentally introduce breaking changes.
I've come up with a new approach, which I believe is most likely to be
successful, but I'll need help to implement it.
The idea is to find the most recent commit which is a parent of both the
``2.7`` and ``default`` branches. Then take every single change to an ``ssl``
related file on the ``default`` branch, and attempt to replay it on the ``2.7``
branch. Require manual review on each commit to make sure it compiles, and to
ensure it doesn't make any backwards incompatible changes.
I think this provides the most iterative and guided approach to getting this
done.
I can do all the work of reviewing each commit, but I need some help from a
mercurial expert to automate the cherry-picking/rebasing of every single
commit.
What do folks think? Does this approach make sense? Anyone willing to help with
the mercurial scripting?
Cheers,
Alex