Certifi: Python SSL Certificates

Certifi_ provides Mozilla's carefully curated collection of Root Certificates for validating the trustworthiness of SSL certificates while verifying the identity of TLS hosts. It has been extracted from the Requests_ project.

Installation

certifi is available on PyPI. Simply install it with pip::

$ pip install certifi

Usage

To reference the installed certificate authority (CA) bundle, you can use the built-in function::

>>> import certifi

>>> certifi.where()
'/usr/local/lib/python3.7/site-packages/certifi/cacert.pem'

Or from the command line::

$ python -m certifi
/usr/local/lib/python3.7/site-packages/certifi/cacert.pem

Enjoy!

1024-bit Root Certificates ~~~~~~~~~~~~~~~~~~~~~~~~~~

Browsers and certificate authorities have concluded that 1024-bit keys are unacceptably weak for certificates, particularly root certificates. For this reason, Mozilla has removed any weak (i.e. 1024-bit key) certificate from its bundle, replacing it with an equivalent strong (i.e. 2048-bit or greater key) certificate from the same CA. Because Mozilla removed these certificates from its bundle, certifi removed them as well.

In previous versions, certifi provided the certifi.old_where() function to intentionally re-add the 1024-bit roots back into your bundle. This was not recommended in production and therefore was removed at the end of 2018.

.. _Certifi: https://certifiio.readthedocs.io/en/latest/ .. _Requests: https://requests.readthedocs.io/en/master/

Addition/Removal of Certificates

Certifi does not support any addition/removal or other modification of the CA trust store content. This project is intended to provide a reliable and highly portable root of trust to python deployments. Look to upstream projects for methods to use alternate trust.