Hosane Hosane - 9 months ago 78
Python Question

Custom urllib opener that uses client certificates

I have got an API that I have to work with. The API is secured by HTTPS and uses mutual authentication/client certificates. I have a PEM file and a CRT file.

When I connect to the server regularly, using PyOpenSSL I have no problem, here is the code:

import settings
from OpenSSL import SSL
import socket

def verify(conn, cert, errnum, depth, ok):
# This obviously has to be updated
print 'Got certificate: %s' % cert.get_subject()
return ok

def password_callback(maxlen, verify, extra):
print (maxlen, verify, extra)
return settings.DEPOSIT_CODE

context = SSL.Context(SSL.SSLv23_METHOD)
context.set_verify(SSL.VERIFY_NONE, verify)
context.set_passwd_cb(password_callback)
context.use_certificate_file(settings.CLIENT_CERT_FILE)
context.use_privatekey_file(settings.PEM_FILE)

sock = SSL.Connection(context, socket.socket(socket.AF_INET, socket.SOCK_STREAM))
sock.connect(("someserver.com",443))

http_get_request = """
GET / HTTP/1.1

"""
sock.write(http_get_request)
print sock.recv(1000)


But, because this is an HTTPS API with client certificate, I have implemented an opener for it, the code somehow modified is here:

import settings
import socket
import urllib2

def verify(conn, cert, errnum, depth, ok):
# This obviously has to be updated
print 'Got certificate: %s' % cert.get_subject()
return ok

def password_callback(maxlen, verify, extra):
print (maxlen, verify, extra)
return settings.DEPOSIT_CODE

class MyHTTPSConnection(httplib.HTTPSConnection):
def connect(self):
context = SSL.Context(SSL.SSLv23_METHOD)
context.set_passwd_cb(password_callback)
context.use_certificate_file(settings.CLIENT_CERT_FILE)
context.set_verify(SSL.VERIFY_NONE, verify)
context.use_privatekey_file(settings.PEM_FILE)
self.sock = SSL.Connection(context, socket.socket(socket.AF_INET, socket.SOCK_STREAM))

class MyHTTPSHandler(urllib2.HTTPSHandler):
def https_open(self,req):
return self.do_open(MyHTTPSConnection,req)

opener = urllib2.build_opener(urllib2.HTTPHandler,MyCHTTPSHandler)
urllib2.install_opener(opener)

f = urllib2.urlopen("https://sampleapiserver.com")
print f.code


but when I run the second code, I get the following error:

File "/usr/lib/python2.6/urllib2.py", line 126, in urlopen
return _opener.open(url, data, timeout)
File "/usr/lib/python2.6/urllib2.py", line 391, in open
response = self._open(req, data)
File "/usr/lib/python2.6/urllib2.py", line 409, in _open
'_open', req)
File "/usr/lib/python2.6/urllib2.py", line 369, in _call_chain
result = func(*args)
File "network.py", line 37, in https_open
return self.do_open(IRNICHTTPSConnection,req)
File "/usr/lib/python2.6/urllib2.py", line 1142, in do_open
h.request(req.get_method(), req.get_selector(), req.data, headers)
File "/usr/lib/python2.6/httplib.py", line 914, in request
self._send_request(method, url, body, headers)
File "/usr/lib/python2.6/httplib.py", line 951, in _send_request
self.endheaders()
File "/usr/lib/python2.6/httplib.py", line 908, in endheaders
self._send_output()
File "/usr/lib/python2.6/httplib.py", line 780, in _send_output
self.send(msg)
File "/usr/lib/python2.6/httplib.py", line 759, in send
self.sock.sendall(str)
OpenSSL.SSL.Error: [('SSL routines', 'SSL_write', 'uninitialized')]


Finally, am I doing something wrong? If not, please help me understand the error...

Cheers.

Answer Source

I'm not sure - but it looks to me like you are missing doing the connect() call in the connect() method:

self.sock.connect(("someserver.com",443))

Also httplib's https handling has wrapper classes for the SSL socket, so maybe those are required for it to work?

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