Using client certificates with urllib2 - python

I need to create a secure channel between my server and a remote web service. I'll be using HTTPS with a client certificate. I'll also need to validate the certificate presented by the remote service.
How can I use my own client certificate with urllib2?
What will I need to do in my code to ensure that the remote certificate is correct?

Because alex's answer is a link, and the code on that page is poorly formatted, I'm just going to put this here for posterity:
import urllib2, httplib
class HTTPSClientAuthHandler(urllib2.HTTPSHandler):
def __init__(self, key, cert):
urllib2.HTTPSHandler.__init__(self)
self.key = key
self.cert = cert
def https_open(self, req):
# Rather than pass in a reference to a connection class, we pass in
# a reference to a function which, for all intents and purposes,
# will behave as a constructor
return self.do_open(self.getConnection, req)
def getConnection(self, host, timeout=300):
return httplib.HTTPSConnection(host, key_file=self.key, cert_file=self.cert)
opener = urllib2.build_opener(HTTPSClientAuthHandler('/path/to/file.pem', '/path/to/file.pem.') )
response = opener.open("https://example.org")
print response.read()

Here's a bug in the official Python bugtracker that looks relevant, and has a proposed patch.

Per Antoine Pitrou's response to the issue linked in Hank Gay's answer, this can be simplified somewhat (as of 2011) by using the included ssl library:
import ssl
import urllib.request
context = ssl.create_default_context()
context.load_cert_chain('/path/to/file.pem', '/path/to/file.key')
opener = urllib.request.build_opener(urllib.request.HTTPSHandler(context=context))
response = opener.open('https://example.org')
print(response.read())
(Python 3 code, but the ssl library is also available in Python 2).
The load_cert_chain function also accepts an optional password parameter, allowing the private key to be encrypted.

check http://www.osmonov.com/2009/04/client-certificates-with-urllib2.html

Related

Use python to access a site with PKI security

I have a site that has PKI security enabled. Each client used either a card reader to load their certificate, or the certificate is installed in the IE certificate storage on their box.
So my question are:
How can I use either the card reader certificate or the certificate stored on the system to verify the system?
How do I pass the credentials onto the site to say, hey I'm me and I can access the service? They example can be using soft certificates. I can figure out the card reader part later.
I've been searching around, and I haven't come up with anything to help me in this situation. Django has a bunch of modules, but this isn't an option because I'm only concerned of the client side of things. I'm not creating a site to host the service. I need to just access these services.
I have this code working sort of. I just do not know how to handle the redirect I am getting:
import httplib
KEYFILE = r"C:\cert\my.key"
CERTFILE = r"c:\cert\my.pem"
HOSTNAME = 'machine.com'
conn = httplib.HTTPSConnection(
HOSTNAME,
key_file = KEYFILE,
cert_file = CERTFILE
)
conn.putrequest('GET', '/arcgis/sharing/rest?f=json')
conn.endheaders()
response = conn.getresponse()
print response.read()
The result of all of this is:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved here.</p>
</body></html>
Any help provided would be great!
Software specs: python 2.7.8, Windows 2012 R2
I created a PKI handler to handle the requests so I can use it work urllib2 library.
import httplib, urllib2
class HTTPSClientAuthHandler(urllib2.HTTPSHandler):
def __init__(self, key, cert):
urllib2.HTTPSHandler.__init__(self)
self.key = key
self.cert = cert
def https_open(self, req):
#Rather than pass in a reference to a connection class, we pass in
# a reference to a function which, for all intents and purposes,
# will behave as a constructor
return self.do_open(self.getConnection, req)
def getConnection(self, host, timeout=300):
return httplib.HTTPSConnection(host,
key_file=self.key,
cert_file=self.cert,
timeout=timeout)
To use this, you will need to use a cookiejar with the handler.
from cookielib import CookieJar
cookiejar = CookieJay()
handlers = []
handlers.append(HTTPSClientAuthHandler(somekey, somecert))
handlers.append(urllib2.HTTPCookieProcessor(cookiejar))
opener = urllib2.build_opener(*handlers)
... do other urllib2 calls ....
Hope this helps everyone!
Try this code
#!/usr/bin/env python
import httplib
CERTFILE = '/home/robr/mycert'
HOSTNAME = 'localhost'
conn = httplib.HTTPSConnection(
HOSTNAME,
key_file = CERTFILE,
cert_file = CERTFILE
)
conn.putrequest('GET', '/ssltest/')
conn.endheaders()
response = conn.getresponse()
print response.read()

How to retain cookies for xmlrpc.client in Python 3?

The default Python xmlrpc.client.Transport (can be used with xmlrpc.client.ServerProxy) does not retain cookies, which are sometimes needed for cookie based logins.
For example, the following proxy, when used with the TapaTalk API (for which the login method uses cookies for authentication), will give a permission error when trying to modify posts.
proxy = xmlrpc.client.ServerProxy(URL, xmlrpc.client.Transport())
There are some solutions for Python 2 on the net, but they aren't compatible with Python 3.
How can I use a Transport that retains cookies?
Existing answer from GermainZ works only for HTTP. After a lot of time fighting with it, there is HTTPS adaptation. Note the context option which is crucial.
class CookiesTransport(xmlrpc.client.SafeTransport):
"""A SafeTransport (HTTPS) subclass that retains cookies over its lifetime."""
# Note context option - it's required for success
def __init__(self, context=None):
super().__init__(context=context)
self._cookies = []
def send_headers(self, connection, headers):
if self._cookies:
connection.putheader("Cookie", "; ".join(self._cookies))
super().send_headers(connection, headers)
def parse_response(self, response):
# This check is required if in some responses we receive no cookies at all
if response.msg.get_all("Set-Cookie"):
for header in response.msg.get_all("Set-Cookie"):
cookie = header.split(";", 1)[0]
self._cookies.append(cookie)
return super().parse_response(response)
The reason for it is that ServerProxy doesn't respect context option related to transport, if transport is specified, so we need to use it directly in Transport constructor.
Usage:
import xmlrpc.client
import ssl
transport = CookiesTransport(context=ssl._create_unverified_context())
# Note the closing slash in address as well, very important
server = xmlrpc.client.ServerProxy("https://<api_link>/", transport=transport)
# do stuff with server
server.myApiFunc({'param1': 'x', 'param2': 'y'})
This is a simple Transport subclass that will retain all cookies:
class CookiesTransport(xmlrpc.client.Transport):
"""A Transport subclass that retains cookies over its lifetime."""
def __init__(self):
super().__init__()
self._cookies = []
def send_headers(self, connection, headers):
if self._cookies:
connection.putheader("Cookie", "; ".join(self._cookies))
super().send_headers(connection, headers)
def parse_response(self, response):
for header in response.msg.get_all("Set-Cookie"):
cookie = header.split(";", 1)[0]
self._cookies.append(cookie)
return super().parse_response(response)
Usage:
proxy = xmlrpc.client.ServerProxy(URL, CookiesTransport())
Since xmlrpc.client in Python 3 has better suited hooks for this, it's much simpler than an equivalent Python 2 version.

403 when retrieving a WSDL via Python SUDS

I can't seem to get SUDS to download a WSDL that requires Basic auth credentials. My code is simple:
wsdl_url = 'https://example.com/ChangeRequest.do?WSDL'
self.client = Client(wsdl_url, username=username, password=password)
I've also tried:
from suds.transport.https import HttpAuthenticated
wsdl_url = 'https://example.com/ChangeRequest.do?WSDL'
credentials = dict(username=username, password=password)
t = HttpAuthenticated(**credentials)
self.client = Client(url=wsdl_url, transport=t)
In both cases, the service returns a 403 Forbidden error. I can go down into the SUDS code in http.py and add this line to the call:
u2request.add_header('Authorization','Basic xxxxxxxxxxxxxxxxxxxx')
This works. What am I doing wrong to get SUDS to pass my credentials when downloading the WSDL?
Note: I try to connect to the WSDL directly using both Chrome's Postman plugin and SoapUI, and the service works as well. So I know the credentials are correct.
I encountered a similar issue (suds v0.4, wsdl, 403), and found out that it was because the server I'm trying to access blocks any requests with the header User-Agent set like Python-urllib* (suds is using urllib2, hence the default header). Explicitly change the header solves the issue.
Particular to my solution: I overrode the open method of a transport class, and set client options, like the following code snippet. Note that we need to explicitly set for open and subsequent requests separately. Please advice better ways to circumvent this if you know any. And hope this post could help save someone's time in the future.
import urllib2
import suds
from suds.transport.https import HttpAuthenticated
from suds.transport import TransportError
URL = 'https://example.com/ChangeRequest.do?WSDL'
class HttpHeaderModify(HttpAuthenticated):
def open(self, request):
try:
url = request.url
u2request = urllib2.Request(url, headers={'User-Agent': 'Mozilla'})
self.proxy = self.options.proxy
return self.u2open(u2request)
except urllib2.HTTPError, e:
raise TransportError(str(e), e.code, e.fp)
transport = HttpHeaderModify()
client = Client(URL, transport=transport, timeout=10)
# Subsequent requests' header needs to be set again here. The overridden transport
# class only handles opening of the client.
client.set_options(headers={'User-Agent': 'Mozilla'})
P.S. Though my problem may not be the same, searching for "403 suds" pops up this SO question, so I decide just post my solution here.
reference post that gave me the right direction: https://bitbucket.org/jurko/suds/issues/27/client-request-for-wsdl-does-not-use-given
I used to have this issue before and compare with the soap UI header.
Found that suds missing to include the header (Host).
client.set_options(headers={'Host': 'value'})
And issue fixed.

Modifying Python code to use SSL for a REST call

I have Python code to call a REST service that is something like this:
import urllib
import urllib2
username = 'foo'
password = 'bar'
passwordManager = urllib2.HTTPPasswordMgrWithDefaultRealm()
passwordManager .add_password(None, MY_APP_PATH, username, password)
authHandler = urllib2.HTTPBasicAuthHandler(passwordManager)
opener = urllib2.build_opener(authHandler)
urllib2.install_opener(opener)
params= { "param1" : param1,
"param2" : param2,
"param3" : param3 }
xmlResults = urllib2.urlopen(MY_APP_PATH, urllib.urlencode(params)).read()
results = MyResponseParser.parse(xmlResults)
MY_APP_PATH is currently an HTTP url. I would like to change it to use SSL ("HTTPS"). How would I go about changing this code to use https in the simplest way possible?
Unfortunately, urllib2 and httplib, at least up to Python 2.7 don't do any certificate verification for when using HTTPS. The result is that you're exchanging information with a server you haven't necessarily identified (it's a bit like exchanging a secret with someone whose identity you haven't verified): this defeats the security purpose of HTTPS.
See this quote from httplib (in Python 2.7):
Note: This does not do any certificate
verification.
(This is independent of httplib.HTTPSConnection being able to send a client-certificate: that's what its key and cert parameters are for.)
There are ways around this, for example:
http://thejosephturner.com/blog/post/https-certificate-verification-in-python-with-urllib2/
http://code.google.com/p/python-httpclient/ (not using urllib2, so possibly not the shortest way for you)
Just using HTTPS:// instead of HTTP:// in the URL you are calling should work, at least if you are trying to reach a known/verified server. If necessary, you can use your client-side SSL certificate to secure the API transaction:
mykey = '/path/to/ssl_key_file'
mycert = '/path/to/ssl_cert_file'
opener = urllib2.build_opener(HTTPSClientAuthHandler(mykey, mycert))
opener.add_handler(urllib2.HTTPBasicAuthHandler()) # add HTTP Basic Authentication information...
opener.add_password(user=settings.USER_ID, passwd=settings.PASSWD)

python http request with token

how and with which python library is it possible to make an httprequest (https) with a user:password or a token?
basically the equivalent to curl -u user:pwd https://www.mysite.com/
thank you
use python requests : Http for Humans
import requests
requests.get("https://www.mysite.com/", auth=('username','pwd'))
you can also use digest auth...
If you need to make thread-safe requests, use pycurl (the python interface to curl):
import pycurl
from StringIO import StringIO
response_buffer = StringIO()
curl = pycurl.Curl()
curl.setopt(curl.URL, "https://www.yoursite.com/")
# Setup the base HTTP Authentication.
curl.setopt(curl.USERPWD, '%s:%s' % ('youruser', 'yourpassword'))
curl.setopt(curl.WRITEFUNCTION, response_buffer.write)
curl.perform()
curl.close()
response_value = response_buffer.getvalue()
Otherwise, use urllib2 (see other responses for more info) as it's builtin and the interface is much cleaner.
class urllib2.HTTPSHandler
A class to handle opening of HTTPS URLs.
21.6.7. HTTPPasswordMgr Objects
These methods are available on HTTPPasswordMgr and HTTPPasswordMgrWithDefaultRealm objects.
HTTPPasswordMgr.add_password(realm, uri, user, passwd)
uri can be either a single URI, or a sequence of URIs. realm, user and passwd must be strings. This causes (user, passwd) to be used as authentication tokens when authentication for realm and a super-URI of any of the given URIs is given.
HTTPPasswordMgr.find_user_password(realm, authuri)
Get user/password for given realm and URI, if any. This method will return (None, None) if there is no matching user/password.
For HTTPPasswordMgrWithDefaultRealm objects, the realm None will be searched if the given realm has no matching user/password.
Check our urllib2. The examples at the bottom will probably be of interest.
http://docs.python.org/library/urllib2.html

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