This is an installable version of the 64-bit Windows M2Crypto binaries for Python made available by grr.
This package is available on PyPI as M2CryptoWin64.
See M2CryptoWindows for more information.
If you see an error like the following during install, then you [allegedly] have an old version of setuptools:
error: option --single-version-externally-managed not recognized
This seems to happen consistently for me, under Windows, even though it pip seems to download the latest version of setuptools when you install it.
To get around this, use the --egg option:
C:\>pip install --egg M2CryptoWin64