[Answered ]-How to read pcks#7 personal digital certificates with python?

You’ve tagged your question with “django” and you’ve mentioned logging in users using certificates. Sorry to say the rest of your question doesn’t make much sense to me.

If your question is “How to I authenticate users in my Django website using SSL certificate authentication?“

Then my suggestion would be to use apache to handle the authentication:
http://httpd.apache.org/docs/2.0/ssl/ssl_howto.html#accesscontrol

And write yourself custom authentication backend to hook this up with Django.
http://docs.djangoproject.com/en/dev/topics/auth/#authentication-backends

Not tried it myself, I presume it’s possible to get mod_ssl to place something useful in the request environment.