"""
Fetches a URL from a web-server supporting NTLM authentication
eg, IIS.

If no arguments are specified, a default of http://localhost/localstart.asp
is used.  This script does follow simple 302 redirections, so pointing at the
root of an IIS server is should work.
"""

import sys
import urllib.request, urllib.parse, urllib.error
import http.client
import urllib.parse
from base64 import encodestring, decodestring

from sspi import ClientAuth

import optparse # sorry, this demo needs 2.3+

options = None # set to optparse options object

def open_url(host, url):
    h = http.client.HTTPConnection(host)
#    h.set_debuglevel(9)
    h.putrequest('GET', url)
    h.endheaders()
    resp = h.getresponse()
    print("Initial response is", resp.status, resp.reason)
    body = resp.read()
    if resp.status == 302: # object moved
        url = "/" + resp.msg["location"]
        resp.close()
        h.putrequest('GET', url)
        h.endheaders()
        resp = h.getresponse()
        print("After redirect response is", resp.status, resp.reason)
    if options.show_headers:
        print("Initial response headers:")
        for name, val in list(resp.msg.items()):
            print(" %s: %s" % (name, val))
    if options.show_body:
        print(body)
    if resp.status == 401:
        # 401: Unauthorized - here is where the real work starts
        auth_info = None
        if options.user or options.domain or options.password:
            auth_info = options.user, options.domain, options.password
        ca = ClientAuth("NTLM", auth_info=auth_info)
        auth_scheme = ca.pkg_info['Name']
        data = None
        while 1:
            err, out_buf = ca.authorize(data)
            data = out_buf[0].Buffer
            # Encode it as base64 as required by HTTP
            auth = encodestring(data).replace("\012", "")
            h.putrequest('GET', url)
            h.putheader('Authorization', auth_scheme + ' ' + auth)
            h.putheader('Content-Length', '0')
            h.endheaders()
            resp = h.getresponse()
            if options.show_headers:
                print("Token dance headers:")
                for name, val in list(resp.msg.items()):
                    print(" %s: %s" % (name, val))

            if err==0:
                break
            else:
                if resp.status != 401:
                    print("Eeek - got response", resp.status)
                    cl = resp.msg.get("content-length")
                    if cl:
                        print(repr(resp.read(int(cl))))
                    else:
                        print("no content!")

                assert resp.status == 401, resp.status

            assert not resp.will_close, "NTLM is per-connection - must not close"
            schemes = [s.strip() for s in resp.msg.get("WWW-Authenticate", "").split(",")]
            for scheme in schemes:
                if scheme.startswith(auth_scheme):
                    data = decodestring(scheme[len(auth_scheme)+1:])
                    break
            else:
                print("Could not find scheme '%s' in schemes %r" % (auth_scheme, schemes))
                break
        
            resp.read()
    print("Final response status is", resp.status, resp.reason)
    if resp.status == 200:
        # Worked!
        # Check we can read it again without re-authenticating.
        if resp.will_close:
            print("EEEK - response will close, but NTLM is per connection - it must stay open")
        body = resp.read()
        if options.show_body:
            print("Final response body:")
            print(body)
        h.putrequest('GET', url)
        h.endheaders()
        resp = h.getresponse()
        print("Second fetch response is", resp.status, resp.reason)
        if options.show_headers:
            print("Second response headers:")
            for name, val in list(resp.msg.items()):
                print(" %s: %s" % (name, val))
        
        resp.read(int(resp.msg.get("content-length", 0)))
    elif resp.status == 500:
        print("Error text")
        print(resp.read())
    else:
        if options.show_body:
            cl = resp.msg.get("content-length")
            print(resp.read(int(cl)))

if __name__=='__main__':
    parser = optparse.OptionParser(description=__doc__)
    
    parser.add_option("", "--show-body", action="store_true",
                      help="print the body of each response as it is received")

    parser.add_option("", "--show-headers", action="store_true",
                      help="print the headers of each response as it is received")

    parser.add_option("", "--user", action="store",
                      help="The username to login with")

    parser.add_option("", "--password", action="store",
                      help="The password to login with")

    parser.add_option("", "--domain", action="store",
                      help="The domain to login to")

    options, args = parser.parse_args()
    if not args:
        print("Run with --help for usage details")
        args = ["http://localhost/localstart.asp"]
    for url in args:
        scheme, netloc, path, params, query, fragment = urllib.parse.urlparse(url)
        if (scheme != "http") or params or query or fragment:
            parser.error("Scheme must be http, URL must be simple")
    
        print("Opening '%s' from '%s'" % (path, netloc))
        r = open_url(netloc, path)