ImportError: dynamic module does not define init function (init_constant_time)

[harrisnb]

I get the following error:

libs/cryptography/hazmat/primitives/constant_time.py", line 9, in
from cryptography.hazmat.bindings._constant_time import lib
ImportError: dynamic module does not define init function (init_constant_time)

and could do with a little help. Any ideas where to start?

[alex]

What platform are you on? How did you install cryptography?

[harrisnb]

Name: cryptography
Version: 1.1.2

pip installed in virtual env on Mac OSX 10.11.2
Copied and running on GoogleAppEngine

[alex]

I think you may be out of luck, my reading of the AppEngine FAQ is that libraries with extension modules are not supported: https://cloud.google.com/appengine/kb/#libraries

I think your best bet would be to ask a GAE forum for help.

[harrisnb]

oh no! ok, if I learn differently I'll come back here.

Anyway, thank you for your help.

[tjerkw]

Appengine supports pycrypto. So you should use that.

Its so crappy the python libs that require these native libraries. It didnt compile on my macos box due to compiler issues.

[reaperhulk]

@tjerkw You can't safely do cryptographic operations in pure Python in many scenarios, so the requirement for native libs can't be wished away. Additionally, if you are on an up-to-date pip cryptography supplies precompiled wheels for macOS. This allows you to install cryptography without a compiler or even an up-to-date copy of OpenSSL (which is statically linked in the wheel). The pip team continues to work to make it easier to install Python packages even when they have complex requirements like cryptographic packages do, but I'm sure they'd be quite welcoming of any new ideas you might have.

It is unfortunate that GAE can't support this project at this time, especially as pycrypto has several known CVEs, doesn't have some modern algorithms, uses its own bespoke C that has not undergone significant review, and is generally largely unsupported but this is the world we live in. Software interdependencies can be very complex (especially with a PaaS like GAE).

If you have a legitimate issue installing or using this project that isn't covered by our existing documentation please feel free to file a new issue.

[goginenir6]

Hey , Any one tell me please is this problem solved or not. I stuck here. "dynamic module does not define init function (init_constant_time)" Getting Error in GAE. I want to do Oauth login with Office 365. The back end modules using cryptography for decode. I don't know what I have to do.

[reaperhulk]

There is still no support for cryptography on GAE. Rumor has it that may change with some new GAE features in the next 6 months, but at this time you're out of luck.