[pyOpenSSL] How to read information from X509v3 extensions of certificate using pyOpenSSL?

[Taras P. I. <nap...@gm...>]

Hello, list!

I use pyopenssl for checking SSL certificates.
And one of such checks is if given certificate is self-signed.
I can do it using values of X509v3 extensions: the subject key identifier and
the authority key id:
X509v3 Subject Key Identifier:
	    0E:D4:AA:B1:09:91:7C:36:60:EA:56:4E:9C:57:00:AF:9C:4D:02:00
X509v3 Authority Key Identifier:
	    keyid:0E:D4:AA:B1:09:91:7C:36:60:EA:56:4E:9C:57:00:AF:9C:4D:02:00

I read documentation of pyOpenSSL but I didn't find way how to grub this information 
from certificate using, for example, methods of X509 object.

-- 
Тарас Иващенко (Taras Ivashchenko), OSCP
www.securityaudit.ru
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"Software is like sex: it's better when it's free." - Linus Torvalds