#!/usr/bin/env python import sys import threading import urlparse import urllib2 import BaseHTTPServer import unittest import md5 from test import test_support # Loopback http server infrastructure class LoopbackHttpServer(BaseHTTPServer.HTTPServer): """HTTP server w/ a few modifications that make it useful for loopback testing purposes. """ def __init__(self, server_address, RequestHandlerClass): BaseHTTPServer.HTTPServer.__init__(self, server_address, RequestHandlerClass) # Set the timeout of our listening socket really low so # that we can stop the server easily. self.socket.settimeout(1.0) def get_request(self): """BaseHTTPServer method, overridden.""" request, client_address = self.socket.accept() # It's a loopback connection, so setting the timeout # really low shouldn't affect anything, but should make # deadlocks less likely to occur. request.settimeout(1.0) return (request, client_address) class LoopbackHttpServerThread(threading.Thread): """Stoppable thread that runs a loopback http server.""" def __init__(self, port, RequestHandlerClass): threading.Thread.__init__(self) self._RequestHandlerClass = RequestHandlerClass self._stop = False self._port = port self._server_address = ('127.0.0.1', self._port) self.ready = threading.Event() def stop(self): """Stops the webserver if it's currently running.""" # Set the stop flag. self._stop = True self.join() def run(self): protocol = "HTTP/1.0" self._RequestHandlerClass.protocol_version = protocol httpd = LoopbackHttpServer(self._server_address, self._RequestHandlerClass) sa = httpd.socket.getsockname() #print "Serving HTTP on", sa[0], "port", sa[1], "..." self.ready.set() while not self._stop: httpd.handle_request() # Authentication infrastructure class DigestAuthHandler: """Handler for performing digest authentication.""" def __init__(self): self._request_num = 0 self._nonces = [] self._users = {} self._realm_name = "Test Realm" self._qop = "auth" def set_qop(self, qop): self._qop = qop def set_users(self, users): assert isinstance(users, dict) self._users = users def set_realm(self, realm): self._realm_name = realm def _generate_nonce(self): self._request_num += 1 nonce = md5.md5(str(self._request_num)).hexdigest() self._nonces.append(nonce) return nonce def _create_auth_dict(self, auth_str): first_space_index = auth_str.find(" ") auth_str = auth_str[first_space_index+1:] parts = auth_str.split(",") auth_dict = {} for part in parts: name, value = part.split("=") name = name.strip() if value[0] == '"' and value[-1] == '"': value = value[1:-1] else: value = value.strip() auth_dict[name] = value return auth_dict def _validate_auth(self, auth_dict, password, method, uri): final_dict = {} final_dict.update(auth_dict) final_dict["password"] = password final_dict["method"] = method final_dict["uri"] = uri HA1_str = "%(username)s:%(realm)s:%(password)s" % final_dict HA1 = md5.md5(HA1_str).hexdigest() HA2_str = "%(method)s:%(uri)s" % final_dict HA2 = md5.md5(HA2_str).hexdigest() final_dict["HA1"] = HA1 final_dict["HA2"] = HA2 response_str = "%(HA1)s:%(nonce)s:%(nc)s:" \ "%(cnonce)s:%(qop)s:%(HA2)s" % final_dict response = md5.md5(response_str).hexdigest() return response == auth_dict["response"] def _return_auth_challenge(self, request_handler): request_handler.send_response(407, "Proxy Authentication Required") request_handler.send_header("Content-Type", "text/html") request_handler.send_header( 'Proxy-Authenticate', 'Digest realm="%s", ' 'qop="%s",' 'nonce="%s", ' % \ (self._realm_name, self._qop, self._generate_nonce())) # XXX: Not sure if we're supposed to add this next header or # not. #request_handler.send_header('Connection', 'close') request_handler.end_headers() request_handler.wfile.write("Proxy Authentication Required.") return False def handle_request(self, request_handler): """Performs digest authentication on the given HTTP request handler. Returns True if authentication was successful, False otherwise. If no users have been set, then digest auth is effectively disabled and this method will always return True. """ if len(self._users) == 0: return True if not request_handler.headers.has_key('Proxy-Authorization'): return self._return_auth_challenge(request_handler) else: auth_dict = self._create_auth_dict( request_handler.headers['Proxy-Authorization'] ) if self._users.has_key(auth_dict["username"]): password = self._users[ auth_dict["username"] ] else: return self._return_auth_challenge(request_handler) if not auth_dict.get("nonce") in self._nonces: return self._return_auth_challenge(request_handler) else: self._nonces.remove(auth_dict["nonce"]) auth_validated = False # MSIE uses short_path in its validation, but Python's # urllib2 uses the full path, so we're going to see if # either of them works here. for path in [request_handler.path, request_handler.short_path]: if self._validate_auth(auth_dict, password, request_handler.command, path): auth_validated = True if not auth_validated: return self._return_auth_challenge(request_handler) return True # Proxy test infrastructure class FakeProxyHandler(BaseHTTPServer.BaseHTTPRequestHandler): """This is a 'fake proxy' that makes it look like the entire internet has gone down due to a sudden zombie invasion. It main utility is in providing us with authentication support for testing. """ digest_auth_handler = DigestAuthHandler() def log_message(self, format, *args): # Uncomment the next line for debugging. #sys.stderr.write(format % args) pass def do_GET(self): (scm, netloc, path, params, query, fragment) = urlparse.urlparse( self.path, 'http') self.short_path = path if self.digest_auth_handler.handle_request(self): self.send_response(200, "OK") self.send_header("Content-Type", "text/html") self.end_headers() self.wfile.write("You've reached %s!
" % self.path) self.wfile.write("Our apologies, but our server is down due to " "a sudden zombie invasion.") # Test cases class ProxyAuthTests(unittest.TestCase): URL = "http://www.foo.com" def setUp(self): PORT = 8080 USER = "tester" PASSWD = "test123" REALM = "TestRealm" FakeProxyHandler.digest_auth_handler.set_users({ USER : PASSWD }) FakeProxyHandler.digest_auth_handler.set_realm(REALM) self.server = LoopbackHttpServerThread(PORT, FakeProxyHandler) self.server.start() self.server.ready.wait() proxyUrl = "http://127.0.0.1:%d" % PORT handler = urllib2.ProxyHandler({"http" : proxyUrl}) digest_auth_handler = urllib2.ProxyDigestAuthHandler() digest_auth_handler.add_password(REALM, self.URL, USER, PASSWD) self.opener = urllib2.build_opener(handler, digest_auth_handler) def tearDown(self): self.server.stop() def test_proxy_qop_auth(self): FakeProxyHandler.digest_auth_handler.set_qop("auth") result = self.opener.open(self.URL) def test_proxy_qop_auth_int(self): FakeProxyHandler.digest_auth_handler.set_qop("auth-int") try: result = self.opener.open(self.URL) except urllib2.URLError: # It's okay if we don't support auth-int, but we certainly # shouldn't receive any kind of exception here other than # a URLError. pass def test_main(): # We will NOT depend on the network resource flag # (Lib/test/regrtest.py -u network) since all tests here are only # localhost. However, if this is a bad rationale, then uncomment # the next line. #test_support.requires("network") test_support.run_unittest(ProxyAuthTests) if __name__ == "__main__": test_main()