ERROR: 'OpenSSL.crypto' has no attribute 'sign'

Author: Rodrigo-NovasCreated Jan 24, 2025Updated Apr 7, 2026
Labelstype: bugpriority: p3

Environment details

  • OS type and version: ubuntu:20.04 and macOs 14.7.1
  • Python version: 3.11
  • pip version: I dont use pip y use Poetry 1.5.1
  • google-api-python-client version: 2.159.0

Steps to reproduce

  1. Install google-api-python-client with pip, pdm, poetry, hatch... it doesn't matter
  2. Use the method oauth to authenticate from oauth2client.service_account import ServiceAccountCredentials
  3. use .execute() method of any googleapi method
  4. this retrieves the error 'OpenSSL.crypto' has no attribute 'sign'

Why does this happen?

Because you are importing oauth2client on the line https://github.com/googleapis/google-api-python-client/blob/main/googleapiclient/_auth.py#L33 and it is deprecated, oauth2client uses openssl with the method sign and openssl removed the method sign on the version 24.3.0.

So if you install openssl >= 24.3.0, and if you use the oauth2client.service_account from googleapiclient this will retrieves you the error

ERROR: module 'OpenSSL.crypto' has no attribute 'sign'

How to solves this?

Set a constraint of openssl >= 24.3.0 on googleapiclient or dont import oauth2client on googleapi anymore.

Source: googleapis/google-api-python-client