Python 3 urllib with self-signed certificates

Question

I'm attempting to download some data from an internal server using Python. Since it's internal, it uses a self-signed certificate. (We don't want to pay Verisign for servers that will never appear "in the wild.") The Python 2.6 version of the code worked fine.

response = urllib2.urlopen(URL)
data = csv.reader(response)

I'm now trying to update to Python 3.4 (long story, don't ask.) However, using Python 3's urllib fails:

response = urllib.request.urlopen(URL)

It throws a CERTIFICATE_VERIFY_FAILED error.

urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:600)>

In reading around the web, apparently Python 2.6 urllib2 doesn't bother to verify certificates. Some versions of urllib allow "verify=False" to be passed to the method signature, but that doesn't appear to work in Python 3.4.

Does anyone know how I can get around this? I'd like to avoid using the Requests package because of corporate security guidelines.

Answer 1

urllib.request.urlopen has a context keyword parameter that accepts an SSLContext object. So, passing a SSLContext object with .verify_mode set to ssl.CERT_NONE i.e. SSLContext.verify_mode = ssl.CERT_NONE should be equal to verify=False

Answer 2

Use following for disabling SSL certificate validation for a URL

import ssl
myssl = ssl.create_default_context();
myssl.check_hostname=False
myssl.verify_mode=ssl.CERT_NONE
urlopen("URL",context=myssl)

Use following to disable SSL certificate validations for all URLs

 ssl._create_default_https_context = ssl._create_unverified_context
 urlopen("URL");