I want to use mechanize to log into a page and retrieve some information. But however I try to authenticate It just fails with Error code **HTTP 401**, as you can see below:

```
r = br.open('http://intra')
File "bui...e\_mechanize.py", line 203, in open
File "bui...g\mechanize\_mechanize.py", line 255,
in _mech_openmechanize._response.httperror_seek_wrapper: HTTP Error 401: Unauthorized

```

This is my code so far:

```
import mechanize
import cookielib

# Browser
br = mechanize.Browser()

# Cookie Jar
cj = cookielib.LWPCookieJar()
br.set_cookiejar(cj)

# Browser options
br.set_handle_equiv(True)
# br.set_handle_gzip(True)
br.set_handle_redirect(True)
br.set_handle_referer(True)
br.set_handle_robots(False)

# Follows refresh 0 but not hangs on refresh > 0
br.set_handle_refresh(mechanize._http.HTTPRefreshProcessor(), max_time=1)

# If the protected site didn't receive the authentication data you would
# end up with a 410 error in your face
br.add_password('http://intra', 'myusername', 'mypassword')

# User-Agent (this is cheating, ok?)
br.addheaders = [('User-agent', 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1')]
# Open some site, let's pick a random one, the first that pops in mind:
# r = br.open('http://google.com')
r = br.open('http://intra')
html = r.read()

# Show the source
print html

```

What am I doing wrong? visiting `http://intra` (internal page) with e.g. chrome, it pops open a windows and asks for username/password once and then all is good.

The dialogue which pops open looks like this:

![enter image description here](https://i.stack.imgur.com/JTb7M.png)
['https://Stackoverflow.com/questions/22224840', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/576671/']
After tons of reaserch I managed to find out the reason behind this.

Find of all the site uses a so called [NTLM authentication](http://hc.apache.org/httpclient-legacy/authentication.html#Authentication_Schemes), which is not supported by mechanize.
This can help to find out the authentication mechanism of a site:

```
wget -O /dev/null -S http://www.the-site.com/

```

So the code was modified a little bit:

```
import sys
import urllib2
import mechanize
from ntlm import HTTPNtlmAuthHandler

print("LOGIN...")
user = sys.argv[1]
password = sys.argv[2]
url = sys.argv[3]

passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
passman.add_password(None, url, user, password)
# create the NTLM authentication handler
auth_NTLM = HTTPNtlmAuthHandler.HTTPNtlmAuthHandler(passman)

browser = mechanize.Browser()
handlersToKeep = []

for handler in browser.handlers:
    if not isinstance(handler,
    (mechanize._http.HTTPRobotRulesProcessor)):
        handlersToKeep.append(handler)

browser.handlers = handlersToKeep
browser.add_handler(auth_NTLM)

response = browser.open(url)
response = browser.open("http://www.the-site.com")
print(response.read())

```

and finally mechanize needs to be patched, as mentioned [here](https://stackoverflow.com/questions/13649964/python-mechanize-with-ntlm-getting-attributeerror-httpresponse-instance-has-no):

```
--- _response.py.old    2013-02-06 11:14:33.208385467 +0100
+++ _response.py    2013-02-06 11:21:41.884081708 +0100
@@ -350,8 +350,13 @@
             self.fileno = self.fp.fileno
         else:
             self.fileno = lambda: None
-        self.__iter__ = self.fp.__iter__
-        self.next = self.fp.next
+
+        if hasattr(self.fp, "__iter__"):
+            self.__iter__ = self.fp.__iter__
+            self.next = self.fp.next
+        else:
+            self.__iter__ = lambda self: self
+            self.next = lambda self: self.fp.readline()

     def __repr__(self):
         return '<%s at %s whose fp = %r>' % (

```
@theAlse : did you need to separately handle session cookies? I used your approach to authenticate against the SSO server but when I access the main site (ServiceNow) on the second "browser.open" call I still get a 401:Unauthorized error.

I tacked on a debug message on the mechanize \_response.py file to show the URL being visited and I was surprised that there is a secondary SSO server. 

```
$ python s3.py
LOGIN...
[_DEBUG] Visiting  https://sso.intra.client.com
[_DEBUG] Got past the first open statement.
[_DEBUG] Visiting  https://clienteleitsm.service-now.com
[_DEBUG] Visiting  <Request for https://ssointra.web.ipc.us.client.com/ssofedi/public/saml2sso?SAMLRequest=lVLB--snipped--&RelayState=https%3a%2f%2fclienteleitsm.service-now.com%2fnavpage.do>
[_DEBUG] Visiting  <Request for https://ssointra.web.ipc.us.client.com/ssofedi/redirectjsp/FederationRedirectWDA.jsp?SAMLRequest=lVLBb--snipped--&SMPORTALURL=https%3A%2F%2Fssointra.web.ipc.us.client.com%2Fssofedi%2Fpublic%2Fsaml2sso>
[_DEBUG] Visiting  <Request for https://ssointra.web.ipc.us.client.com/SSOI/ntlm/RedirectToWDA.jsp?TYPE=33554433&REALMOID=--snipped--%3D%26RelayState%3dhttps$%3a$%2f$%2fclienteleitsm%2eservice-now%2ecom$%2fnavpage%2edo%26SMPORTALURL%3dhttps$%3A$%2F$%2Fssointra%2eweb%2eipc%2eus%2eclient%2ecom$%2Fssofedi$%2Fpublic$%2Fsaml2sso>
[_DEBUG] Visiting  <Request for https://ssointra.web.ipc.us.client.com/SSOI/ntlm/WDAProtectedPage.jsp?Target=HTTPS://ssointra.--snipped--&RelayState=https%3A%2F%2Fclienteleitsm.service-now.com%2Fnavpage.do&SMPORTALURL=https%3A%2F%2Fssointra.web.ipc.us.client.com%2Fssofedi%2Fpublic%2Fsaml2sso>
[_DEBUG] Visiting  <Request for https://sso.intra.client.com/siteminderagent/ntlm/creds.ntc?CHALLENGE=&SMAGENTNAME=--snipped--https$%3A$%2F$%2Fssointra%2eweb%2eipc%2eus%2eclient%2ecom$%2Fssofedi$%2Fpublic$%2Fsaml2sso>

[Client-specific page about invalid username and password credential combination follows]
<HTML>
...
</HTML>

```

I already snipped a lot of the redirect URLS after the third debug line. The random strings are actually unique as when I put them in a browser I get an error page. However if I do it in an IE browser I dont even see the redirect pages.

Thanks.