testserver.py

#!/usr/bin/python2.4
# Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""This is a simple HTTP server used for testing Chrome.

It supports several test URLs, as specified by the handlers in TestPageHandler.
It defaults to living on localhost:8888.
It can use https if you specify the flag --https=CERT where CERT is the path
to a pem file containing the certificate and private key that should be used.
To shut it down properly, visit localhost:8888/kill.
"""

import base64
import BaseHTTPServer
import cgi
import optparse
import os
import re
import shutil
import SocketServer
import sys
import time
import tlslite
import tlslite.api
import pyftpdlib.ftpserver

try:
  import hashlib
  _new_md5 = hashlib.md5
except ImportError:
  import md5
  _new_md5 = md5.new

SERVER_HTTP = 0
SERVER_FTP = 1

debug_output = sys.stderr
def debug(str):
  debug_output.write(str + "\n")
  debug_output.flush()

class StoppableHTTPServer(BaseHTTPServer.HTTPServer):
  """This is a specialization of of BaseHTTPServer to allow it
  to be exited cleanly (by setting its "stop" member to True)."""

  def serve_forever(self):
    self.stop = False
    self.nonce_time = None
    while not self.stop:
      self.handle_request()
    self.socket.close()

class HTTPSServer(tlslite.api.TLSSocketServerMixIn, StoppableHTTPServer):
  """This is a specialization of StoppableHTTPerver that add https support."""

  def __init__(self, server_address, request_hander_class, cert_path):
    s = open(cert_path).read()
    x509 = tlslite.api.X509()
    x509.parse(s)
    self.cert_chain = tlslite.api.X509CertChain([x509])
    s = open(cert_path).read()
    self.private_key = tlslite.api.parsePEMKey(s, private=True)

    self.session_cache = tlslite.api.SessionCache()
    StoppableHTTPServer.__init__(self, server_address, request_hander_class)

  def handshake(self, tlsConnection):
    """Creates the SSL connection."""
    try:
      tlsConnection.handshakeServer(certChain=self.cert_chain,
                                    privateKey=self.private_key,
                                    sessionCache=self.session_cache)
      tlsConnection.ignoreAbruptClose = True
      return True
    except tlslite.api.TLSError, error:
      print "Handshake failure:", str(error)
      return False

class ForkingHTTPServer(SocketServer.ForkingMixIn, StoppableHTTPServer):
  """This is a specialization of of StoppableHTTPServer which serves each
  request in a separate process"""
  pass

class ForkingHTTPSServer(SocketServer.ForkingMixIn, HTTPSServer):
  """This is a specialization of of HTTPSServer which serves each
  request in a separate process"""
  pass

class TestPageHandler(BaseHTTPServer.BaseHTTPRequestHandler):

  def __init__(self, request, client_address, socket_server):
    self._connect_handlers = [
      self.RedirectConnectHandler,
      self.ServerAuthConnectHandler,
      self.DefaultConnectResponseHandler]
    self._get_handlers = [
      self.KillHandler,
      self.NoCacheMaxAgeTimeHandler,
      self.NoCacheTimeHandler,
      self.CacheTimeHandler,
      self.CacheExpiresHandler,
      self.CacheProxyRevalidateHandler,
      self.CachePrivateHandler,
      self.CachePublicHandler,
      self.CacheSMaxAgeHandler,
      self.CacheMustRevalidateHandler,
      self.CacheMustRevalidateMaxAgeHandler,
      self.CacheNoStoreHandler,
      self.CacheNoStoreMaxAgeHandler,
      self.CacheNoTransformHandler,
      self.DownloadHandler,
      self.DownloadFinishHandler,
      self.EchoHeader,
      self.EchoHeaderOverride,
      self.EchoAllHandler,
      self.FileHandler,
      self.RealFileWithCommonHeaderHandler,
      self.RealBZ2FileWithCommonHeaderHandler,
      self.SetCookieHandler,
      self.AuthBasicHandler,
      self.AuthDigestHandler,
      self.SlowServerHandler,
      self.ContentTypeHandler,
      self.ServerRedirectHandler,
      self.ClientRedirectHandler,
      self.MultipartHandler,
      self.DefaultResponseHandler]
    self._post_handlers = [
      self.WriteFile,
      self.EchoTitleHandler,
      self.EchoAllHandler,
      self.EchoHandler] + self._get_handlers
    self._put_handlers = [
      self.WriteFile,
      self.EchoTitleHandler,
      self.EchoAllHandler,
      self.EchoHandler] + self._get_handlers

    self._mime_types = {
      'gif': 'image/gif',
      'jpeg' : 'image/jpeg',
      'jpg' : 'image/jpeg',
      'xml' : 'text/xml'
    }
    self._default_mime_type = 'text/html'

    BaseHTTPServer.BaseHTTPRequestHandler.__init__(self, request,
                                                   client_address,
                                                   socket_server)

  def _ShouldHandleRequest(self, handler_name):
    """Determines if the path can be handled by the handler.

    We consider a handler valid if the path begins with the
    handler name. It can optionally be followed by "?*", "/*".
    """

    pattern = re.compile('%s($|\?|/).*' % handler_name)
    return pattern.match(self.path)

  def GetMIMETypeFromName(self, file_name):
    """Returns the mime type for the specified file_name. So far it only looks
    at the file extension."""

    (shortname, extension) = os.path.splitext(file_name)
    if len(extension) == 0:
      # no extension.
      return self._default_mime_type

    # extension starts with a dot, so we need to remove it
    return self._mime_types.get(extension[1:], self._default_mime_type)

  def KillHandler(self):
    """This request handler kills the server, for use when we're done"
    with the a particular test."""

    if (self.path.find("kill") < 0):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=0')
    self.end_headers()
    if options.never_die:
      self.wfile.write('I cannot die!! BWAHAHA')
    else:
      self.wfile.write('Goodbye cruel world!')
      self.server.stop = True

    return True

  def NoCacheMaxAgeTimeHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and no caching requested."""

    if not self._ShouldHandleRequest("/nocachetime/maxage"):
      return False

    self.send_response(200)
    self.send_header('Cache-Control', 'max-age=0')
    self.send_header('Content-type', 'text/html')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def NoCacheTimeHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and no caching requested."""

    if not self._ShouldHandleRequest("/nocachetime"):
      return False

    self.send_response(200)
    self.send_header('Cache-Control', 'no-cache')
    self.send_header('Content-type', 'text/html')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheTimeHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and allows caching for one minute."""

    if not self._ShouldHandleRequest("/cachetime"):
      return False

    self.send_response(200)
    self.send_header('Cache-Control', 'max-age=60')
    self.send_header('Content-type', 'text/html')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheExpiresHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and set the page to expire on 1 Jan 2099."""

    if not self._ShouldHandleRequest("/cache/expires"):
      return False

    self.send_response(200)
    self.send_header('Expires', 'Thu, 1 Jan 2099 00:00:00 GMT')
    self.send_header('Content-type', 'text/html')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheProxyRevalidateHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and allows caching for 60 seconds"""

    if not self._ShouldHandleRequest("/cache/proxy-revalidate"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=60, proxy-revalidate')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CachePrivateHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and allows caching for 5 seconds."""

    if not self._ShouldHandleRequest("/cache/private"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=3, private')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CachePublicHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and allows caching for 5 seconds."""

    if not self._ShouldHandleRequest("/cache/public"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=3, public')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheSMaxAgeHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and does not allow for caching."""

    if not self._ShouldHandleRequest("/cache/s-maxage"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'public, s-maxage = 60, max-age = 0')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheMustRevalidateHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and does not allow caching."""

    if not self._ShouldHandleRequest("/cache/must-revalidate"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'must-revalidate')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheMustRevalidateMaxAgeHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and does not allow caching event though max-age of 60
    seconds is specified."""

    if not self._ShouldHandleRequest("/cache/must-revalidate/max-age"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=60, must-revalidate')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheNoStoreHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and does not allow the page to be stored."""

    if not self._ShouldHandleRequest("/cache/no-store"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'no-store')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def CacheNoStoreMaxAgeHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and does not allow the page to be stored even though max-age
    of 60 seconds is specified."""

    if not self._ShouldHandleRequest("/cache/no-store/max-age"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=60, no-store')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True


  def CacheNoTransformHandler(self):
    """This request handler yields a page with the title set to the current
    system time, and does not allow the content to transformed during
    user-agent caching"""

    if not self._ShouldHandleRequest("/cache/no-transform"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'no-transform')
    self.end_headers()

    self.wfile.write('<html><head><title>%s</title></head></html>' %
                     time.time())

    return True

  def EchoHeader(self):
    """This handler echoes back the value of a specific request header."""
    """The only difference between this function and the EchoHeaderOverride"""
    """function is in the parameter being passed to the helper function"""
    return self.EchoHeaderHelper("/echoheader")

  def EchoHeaderOverride(self):
    """This handler echoes back the value of a specific request header."""
    """The UrlRequest unit tests also execute for ChromeFrame which uses"""
    """IE to issue HTTP requests using the host network stack."""
    """The Accept and Charset tests which expect the server to echo back"""
    """the corresponding headers fail here as IE returns cached responses"""
    """The EchoHeaderOverride parameter is an easy way to ensure that IE"""
    """treats this request as a new request and does not cache it."""
    return self.EchoHeaderHelper("/echoheaderoverride")

  def EchoHeaderHelper(self, echo_header):
    """This function echoes back the value of the request header passed in."""
    if not self._ShouldHandleRequest(echo_header):
      return False

    query_char = self.path.find('?')
    if query_char != -1:
      header_name = self.path[query_char+1:]

    self.send_response(200)
    self.send_header('Content-type', 'text/plain')
    self.send_header('Cache-control', 'max-age=60000')
    # insert a vary header to properly indicate that the cachability of this
    # request is subject to value of the request header being echoed.
    if len(header_name) > 0:
      self.send_header('Vary', header_name)
    self.end_headers()

    if len(header_name) > 0:
      self.wfile.write(self.headers.getheader(header_name))

    return True

  def EchoHandler(self):
    """This handler just echoes back the payload of the request, for testing
    form submission."""

    if not self._ShouldHandleRequest("/echo"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    length = int(self.headers.getheader('content-length'))
    request = self.rfile.read(length)
    self.wfile.write(request)
    return True

  def WriteFile(self):
    """This is handler dumps the content of POST/PUT request to a disk file
    into the data_dir/dump. Sub-directories are not supported."""

    prefix='/writefile/'
    if not self.path.startswith(prefix):
      return False

    file_name = self.path[len(prefix):]

    # do not allow fancy chars in file name
    re.sub('[^a-zA-Z0-9_.-]+', '', file_name)
    if len(file_name) and file_name[0] != '.':
      path = os.path.join(self.server.data_dir, 'dump', file_name);
      length = int(self.headers.getheader('content-length'))
      request = self.rfile.read(length)
      f = open(path, "wb")
      f.write(request);
      f.close()

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    self.wfile.write('<html>%s</html>' % file_name)
    return True

  def EchoTitleHandler(self):
    """This handler is like Echo, but sets the page title to the request."""

    if not self._ShouldHandleRequest("/echotitle"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    length = int(self.headers.getheader('content-length'))
    request = self.rfile.read(length)
    self.wfile.write('<html><head><title>')
    self.wfile.write(request)
    self.wfile.write('</title></head></html>')
    return True

  def EchoAllHandler(self):
    """This handler yields a (more) human-readable page listing information
    about the request header & contents."""

    if not self._ShouldHandleRequest("/echoall"):
      return False

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    self.wfile.write('<html><head><style>'
      'pre { border: 1px solid black; margin: 5px; padding: 5px }'
      '</style></head><body>'
      '<div style="float: right">'
      '<a href="http://localhost:8888/echo">back to referring page</a></div>'
      '<h1>Request Body:</h1><pre>')

    if self.command == 'POST' or self.command == 'PUT':
      length = int(self.headers.getheader('content-length'))
      qs = self.rfile.read(length)
      params = cgi.parse_qs(qs, keep_blank_values=1)

      for param in params:
        self.wfile.write('%s=%s\n' % (param, params[param][0]))

    self.wfile.write('</pre>')

    self.wfile.write('<h1>Request Headers:</h1><pre>%s</pre>' % self.headers)

    self.wfile.write('</body></html>')
    return True

  def DownloadHandler(self):
    """This handler sends a downloadable file with or without reporting
    the size (6K)."""

    if self.path.startswith("/download-unknown-size"):
      send_length = False
    elif self.path.startswith("/download-known-size"):
      send_length = True
    else:
      return False

    #
    # The test which uses this functionality is attempting to send
    # small chunks of data to the client.  Use a fairly large buffer
    # so that we'll fill chrome's IO buffer enough to force it to
    # actually write the data.
    # See also the comments in the client-side of this test in
    # download_uitest.cc
    #
    size_chunk1 = 35*1024
    size_chunk2 = 10*1024

    self.send_response(200)
    self.send_header('Content-type', 'application/octet-stream')
    self.send_header('Cache-Control', 'max-age=0')
    if send_length:
      self.send_header('Content-Length', size_chunk1 + size_chunk2)
    self.end_headers()

    # First chunk of data:
    self.wfile.write("*" * size_chunk1)
    self.wfile.flush()

    # handle requests until one of them clears this flag.
    self.server.waitForDownload = True
    while self.server.waitForDownload:
      self.server.handle_request()

    # Second chunk of data:
    self.wfile.write("*" * size_chunk2)
    return True

  def DownloadFinishHandler(self):
    """This handler just tells the server to finish the current download."""

    if not self._ShouldHandleRequest("/download-finish"):
      return False

    self.server.waitForDownload = False
    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Cache-Control', 'max-age=0')
    self.end_headers()
    return True

  def FileHandler(self):
    """This handler sends the contents of the requested file.  Wow, it's like
    a real webserver!"""

    prefix = self.server.file_root_url
    if not self.path.startswith(prefix):
      return False

    # Consume a request body if present.
    if self.command == 'POST' or self.command == 'PUT' :
      self.rfile.read(int(self.headers.getheader('content-length')))

    file = self.path[len(prefix):]
    if file.find('?') > -1:
      # Ignore the query parameters entirely.
      url, querystring = file.split('?')
    else:
      url = file
    entries = url.split('/')
    path = os.path.join(self.server.data_dir, *entries)
    if os.path.isdir(path):
      path = os.path.join(path, 'index.html')

    if not os.path.isfile(path):
      print "File not found " + file + " full path:" + path
      self.send_error(404)
      return True

    f = open(path, "rb")
    data = f.read()
    f.close()

    # If file.mock-http-headers exists, it contains the headers we
    # should send.  Read them in and parse them.
    headers_path = path + '.mock-http-headers'
    if os.path.isfile(headers_path):
      f = open(headers_path, "r")

      # "HTTP/1.1 200 OK"
      response = f.readline()
      status_code = re.findall('HTTP/\d+.\d+ (\d+)', response)[0]
      self.send_response(int(status_code))

      for line in f:
        header_values = re.findall('(\S+):\s*(.*)', line)
        if len(header_values) > 0:
          # "name: value"
          name, value = header_values[0]
          self.send_header(name, value)
      f.close()
    else:
      # Could be more generic once we support mime-type sniffing, but for
      # now we need to set it explicitly.
      self.send_response(200)
      self.send_header('Content-type', self.GetMIMETypeFromName(file))
      self.send_header('Content-Length', len(data))
    self.end_headers()

    self.wfile.write(data)

    return True

  def RealFileWithCommonHeaderHandler(self):
    """This handler sends the contents of the requested file without the pseudo
    http head!"""

    prefix='/realfiles/'
    if not self.path.startswith(prefix):
      return False

    file = self.path[len(prefix):]
    path = os.path.join(self.server.data_dir, file)

    try:
      f = open(path, "rb")
      data = f.read()
      f.close()

      # just simply set the MIME as octal stream
      self.send_response(200)
      self.send_header('Content-type', 'application/octet-stream')
      self.end_headers()

      self.wfile.write(data)
    except:
      self.send_error(404)

    return True

  def RealBZ2FileWithCommonHeaderHandler(self):
    """This handler sends the bzip2 contents of the requested file with
     corresponding Content-Encoding field in http head!"""

    prefix='/realbz2files/'
    if not self.path.startswith(prefix):
      return False

    parts = self.path.split('?')
    file = parts[0][len(prefix):]
    path = os.path.join(self.server.data_dir, file) + '.bz2'

    if len(parts) > 1:
      options = parts[1]
    else:
      options = ''

    try:
      self.send_response(200)
      accept_encoding = self.headers.get("Accept-Encoding")
      if accept_encoding.find("bzip2") != -1:
        f = open(path, "rb")
        data = f.read()
        f.close()
        self.send_header('Content-Encoding', 'bzip2')
        self.send_header('Content-type', 'application/x-bzip2')
        self.end_headers()
        if options == 'incremental-header':
          self.wfile.write(data[:1])
          self.wfile.flush()
          time.sleep(1.0)
          self.wfile.write(data[1:])
        else:
          self.wfile.write(data)
      else:
        """client do not support bzip2 format, send pseudo content
        """
        self.send_header('Content-type', 'text/html; charset=ISO-8859-1')
        self.end_headers()
        self.wfile.write("you do not support bzip2 encoding")
    except:
      self.send_error(404)

    return True

  def SetCookieHandler(self):
    """This handler just sets a cookie, for testing cookie handling."""

    if not self._ShouldHandleRequest("/set-cookie"):
      return False

    query_char = self.path.find('?')
    if query_char != -1:
      cookie_values = self.path[query_char + 1:].split('&')
    else:
      cookie_values = ("",)
    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    for cookie_value in cookie_values:
      self.send_header('Set-Cookie', '%s' % cookie_value)
    self.end_headers()
    for cookie_value in cookie_values:
      self.wfile.write('%s' % cookie_value)
    return True

  def AuthBasicHandler(self):
    """This handler tests 'Basic' authentication.  It just sends a page with
    title 'user/pass' if you succeed."""

    if not self._ShouldHandleRequest("/auth-basic"):
      return False

    username = userpass = password = b64str = ""

    set_cookie_if_challenged = self.path.find('?set-cookie-if-challenged') > 0

    auth = self.headers.getheader('authorization')
    try:
      if not auth:
        raise Exception('no auth')
      b64str = re.findall(r'Basic (\S+)', auth)[0]
      userpass = base64.b64decode(b64str)
      username, password = re.findall(r'([^:]+):(\S+)', userpass)[0]
      if password != 'secret':
        raise Exception('wrong password')
    except Exception, e:
      # Authentication failed.
      self.send_response(401)
      self.send_header('WWW-Authenticate', 'Basic realm="testrealm"')
      self.send_header('Content-type', 'text/html')
      if set_cookie_if_challenged:
        self.send_header('Set-Cookie', 'got_challenged=true')
      self.end_headers()
      self.wfile.write('<html><head>')
      self.wfile.write('<title>Denied: %s</title>' % e)
      self.wfile.write('</head><body>')
      self.wfile.write('auth=%s<p>' % auth)
      self.wfile.write('b64str=%s<p>' % b64str)
      self.wfile.write('username: %s<p>' % username)
      self.wfile.write('userpass: %s<p>' % userpass)
      self.wfile.write('password: %s<p>' % password)
      self.wfile.write('You sent:<br>%s<p>' % self.headers)
      self.wfile.write('</body></html>')
      return True

    # Authentication successful.  (Return a cachable response to allow for
    # testing cached pages that require authentication.)
    if_none_match = self.headers.getheader('if-none-match')
    if if_none_match == "abc":
      self.send_response(304)
      self.end_headers()
    else:
      self.send_response(200)
      self.send_header('Content-type', 'text/html')
      self.send_header('Cache-control', 'max-age=60000')
      self.send_header('Etag', 'abc')
      self.end_headers()
      self.wfile.write('<html><head>')
      self.wfile.write('<title>%s/%s</title>' % (username, password))
      self.wfile.write('</head><body>')
      self.wfile.write('auth=%s<p>' % auth)
      self.wfile.write('You sent:<br>%s<p>' % self.headers)
      self.wfile.write('</body></html>')

    return True

  def GetNonce(self, force_reset=False):
   """Returns a nonce that's stable per request path for the server's lifetime.

   This is a fake implementation. A real implementation would only use a given
   nonce a single time (hence the name n-once). However, for the purposes of
   unittesting, we don't care about the security of the nonce.

   Args:
     force_reset: Iff set, the nonce will be changed. Useful for testing the
         "stale" response.
   """
   if force_reset or not self.server.nonce_time:
     self.server.nonce_time = time.time()
   return _new_md5('privatekey%s%d' %
                   (self.path, self.server.nonce_time)).hexdigest()

  def AuthDigestHandler(self):
    """This handler tests 'Digest' authentication.

    It just sends a page with title 'user/pass' if you succeed.

    A stale response is sent iff "stale" is present in the request path.
    """
    if not self._ShouldHandleRequest("/auth-digest"):
      return False

    stale = 'stale' in self.path
    nonce = self.GetNonce(force_reset=stale)
    opaque = _new_md5('opaque').hexdigest()
    password = 'secret'
    realm = 'testrealm'

    auth = self.headers.getheader('authorization')
    pairs = {}
    try:
      if not auth:
        raise Exception('no auth')
      if not auth.startswith('Digest'):
        raise Exception('not digest')
      # Pull out all the name="value" pairs as a dictionary.
      pairs = dict(re.findall(r'(\b[^ ,=]+)="?([^",]+)"?', auth))

      # Make sure it's all valid.
      if pairs['nonce'] != nonce:
        raise Exception('wrong nonce')
      if pairs['opaque'] != opaque:
        raise Exception('wrong opaque')

      # Check the 'response' value and make sure it matches our magic hash.
      # See http://www.ietf.org/rfc/rfc2617.txt
      hash_a1 = _new_md5(
          ':'.join([pairs['username'], realm, password])).hexdigest()
      hash_a2 = _new_md5(':'.join([self.command, pairs['uri']])).hexdigest()
      if 'qop' in pairs and 'nc' in pairs and 'cnonce' in pairs:
        response = _new_md5(':'.join([hash_a1, nonce, pairs['nc'],
            pairs['cnonce'], pairs['qop'], hash_a2])).hexdigest()
      else:
        response = _new_md5(':'.join([hash_a1, nonce, hash_a2])).hexdigest()

      if pairs['response'] != response:
        raise Exception('wrong password')
    except Exception, e:
      # Authentication failed.
      self.send_response(401)
      hdr = ('Digest '
             'realm="%s", '
             'domain="/", '
             'qop="auth", '
             'algorithm=MD5, '
             'nonce="%s", '
             'opaque="%s"') % (realm, nonce, opaque)
      if stale:
        hdr += ', stale="TRUE"'
      self.send_header('WWW-Authenticate', hdr)
      self.send_header('Content-type', 'text/html')
      self.end_headers()
      self.wfile.write('<html><head>')
      self.wfile.write('<title>Denied: %s</title>' % e)
      self.wfile.write('</head><body>')
      self.wfile.write('auth=%s<p>' % auth)
      self.wfile.write('pairs=%s<p>' % pairs)
      self.wfile.write('You sent:<br>%s<p>' % self.headers)
      self.wfile.write('We are replying:<br>%s<p>' % hdr)
      self.wfile.write('</body></html>')
      return True

    # Authentication successful.
    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    self.wfile.write('<html><head>')
    self.wfile.write('<title>%s/%s</title>' % (pairs['username'], password))
    self.wfile.write('</head><body>')
    self.wfile.write('auth=%s<p>' % auth)
    self.wfile.write('pairs=%s<p>' % pairs)
    self.wfile.write('</body></html>')

    return True

  def SlowServerHandler(self):
    """Wait for the user suggested time before responding. The syntax is
    /slow?0.5 to wait for half a second."""
    if not self._ShouldHandleRequest("/slow"):
      return False
    query_char = self.path.find('?')
    wait_sec = 1.0
    if query_char >= 0:
      try:
        wait_sec = int(self.path[query_char + 1:])
      except ValueError:
        pass
    time.sleep(wait_sec)
    self.send_response(200)
    self.send_header('Content-type', 'text/plain')
    self.end_headers()
    self.wfile.write("waited %d seconds" % wait_sec)
    return True

  def ContentTypeHandler(self):
    """Returns a string of html with the given content type.  E.g.,
    /contenttype?text/css returns an html file with the Content-Type
    header set to text/css."""
    if not self._ShouldHandleRequest("/contenttype"):
      return False
    query_char = self.path.find('?')
    content_type = self.path[query_char + 1:].strip()
    if not content_type:
      content_type = 'text/html'
    self.send_response(200)
    self.send_header('Content-Type', content_type)
    self.end_headers()
    self.wfile.write("<html>\n<body>\n<p>HTML text</p>\n</body>\n</html>\n");
    return True

  def ServerRedirectHandler(self):
    """Sends a server redirect to the given URL. The syntax is
    '/server-redirect?http://foo.bar/asdf' to redirect to
    'http://foo.bar/asdf'"""

    test_name = "/server-redirect"
    if not self._ShouldHandleRequest(test_name):
      return False

    query_char = self.path.find('?')
    if query_char < 0 or len(self.path) <= query_char + 1:
      self.sendRedirectHelp(test_name)
      return True
    dest = self.path[query_char + 1:]

    self.send_response(301)  # moved permanently
    self.send_header('Location', dest)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    self.wfile.write('<html><head>')
    self.wfile.write('</head><body>Redirecting to %s</body></html>' % dest)

    return True

  def ClientRedirectHandler(self):
    """Sends a client redirect to the given URL. The syntax is
    '/client-redirect?http://foo.bar/asdf' to redirect to
    'http://foo.bar/asdf'"""

    test_name = "/client-redirect"
    if not self._ShouldHandleRequest(test_name):
      return False

    query_char = self.path.find('?');
    if query_char < 0 or len(self.path) <= query_char + 1:
      self.sendRedirectHelp(test_name)
      return True
    dest = self.path[query_char + 1:]

    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    self.wfile.write('<html><head>')
    self.wfile.write('<meta http-equiv="refresh" content="0;url=%s">' % dest)
    self.wfile.write('</head><body>Redirecting to %s</body></html>' % dest)

    return True

  def MultipartHandler(self):
    """Send a multipart response (10 text/html pages)."""
    test_name = "/multipart"
    if not self._ShouldHandleRequest(test_name):
      return False

    num_frames = 10
    bound = '12345'
    self.send_response(200)
    self.send_header('Content-type',
                     'multipart/x-mixed-replace;boundary=' + bound)
    self.end_headers()

    for i in xrange(num_frames):
      self.wfile.write('--' + bound + '\r\n')
      self.wfile.write('Content-type: text/html\r\n\r\n')
      self.wfile.write('<title>page ' + str(i) + '</title>')
      self.wfile.write('page ' + str(i))

    self.wfile.write('--' + bound + '--')
    return True

  def DefaultResponseHandler(self):
    """This is the catch-all response handler for requests that aren't handled
    by one of the special handlers above.
    Note that we specify the content-length as without it the https connection
    is not closed properly (and the browser keeps expecting data)."""

    contents = "Default response given for path: " + self.path
    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header("Content-Length", len(contents))
    self.end_headers()
    self.wfile.write(contents)
    return True

  def RedirectConnectHandler(self):
    """Sends a redirect to the CONNECT request for www.redirect.com. This
    response is not specified by the RFC, so the browser should not follow
    the redirect."""

    if (self.path.find("www.redirect.com") < 0):
      return False

    dest = "http://www.destination.com/foo.js"

    self.send_response(302)  # moved temporarily
    self.send_header('Location', dest)
    self.send_header('Connection', 'close')
    self.end_headers()
    return True

  def ServerAuthConnectHandler(self):
    """Sends a 401 to the CONNECT request for www.server-auth.com. This
    response doesn't make sense because the proxy server cannot request
    server authentication."""

    if (self.path.find("www.server-auth.com") < 0):
      return False

    challenge = 'Basic realm="WallyWorld"'

    self.send_response(401)  # unauthorized
    self.send_header('WWW-Authenticate', challenge)
    self.send_header('Connection', 'close')
    self.end_headers()
    return True

  def DefaultConnectResponseHandler(self):
    """This is the catch-all response handler for CONNECT requests that aren't
    handled by one of the special handlers above.  Real Web servers respond
    with 400 to CONNECT requests."""

    contents = "Your client has issued a malformed or illegal request."
    self.send_response(400)  # bad request
    self.send_header('Content-type', 'text/html')
    self.send_header("Content-Length", len(contents))
    self.end_headers()
    self.wfile.write(contents)
    return True

  def do_CONNECT(self):
    for handler in self._connect_handlers:
      if handler():
        return

  def do_GET(self):
    for handler in self._get_handlers:
      if handler():
        return

  def do_POST(self):
    for handler in self._post_handlers:
      if handler():
        return

  def do_PUT(self):
    for handler in self._put_handlers:
      if handler():
        return

  # called by the redirect handling function when there is no parameter
  def sendRedirectHelp(self, redirect_name):
    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.end_headers()
    self.wfile.write('<html><body><h1>Error: no redirect destination</h1>')
    self.wfile.write('Use <pre>%s?http://dest...</pre>' % redirect_name)
    self.wfile.write('</body></html>')

def MakeDumpDir(data_dir):
  """Create directory named 'dump' where uploaded data via HTTP POST/PUT
  requests will be stored. If the directory already exists all files and
  subdirectories will be deleted."""
  dump_dir = os.path.join(data_dir, 'dump');
  if os.path.isdir(dump_dir):
    shutil.rmtree(dump_dir)
  os.mkdir(dump_dir)

def MakeDataDir():
  if options.data_dir:
    if not os.path.isdir(options.data_dir):
      print 'specified data dir not found: ' + options.data_dir + ' exiting...'
      return None
    my_data_dir = options.data_dir
  else:
    # Create the default path to our data dir, relative to the exe dir.
    my_data_dir = os.path.dirname(sys.argv[0])
    my_data_dir = os.path.join(my_data_dir, "..", "..", "..", "..",
                                   "test", "data")

    #TODO(ibrar): Must use Find* funtion defined in google\tools
    #i.e my_data_dir = FindUpward(my_data_dir, "test", "data")

  return my_data_dir

def main(options, args):
  # redirect output to a log file so it doesn't spam the unit test output
  logfile = open('testserver.log', 'w')
  sys.stderr = sys.stdout = logfile

  port = options.port

  if options.server_type == SERVER_HTTP:
    if options.cert:
      # let's make sure the cert file exists.
      if not os.path.isfile(options.cert):
        print 'specified cert file not found: ' + options.cert + ' exiting...'
        return
      if options.forking:
        server_class = ForkingHTTPSServer
      else:
        server_class = HTTPSServer
      server = server_class(('127.0.0.1', port), TestPageHandler, options.cert)
      print 'HTTPS server started on port %d...' % port
    else:
      if options.forking:
        server_class = ForkingHTTPServer
      else:
        server_class = StoppableHTTPServer
      server = server_class(('127.0.0.1', port), TestPageHandler)
      print 'HTTP server started on port %d...' % port

    server.data_dir = MakeDataDir()
    server.file_root_url = options.file_root_url
    MakeDumpDir(server.data_dir)

  # means FTP Server
  else:
    my_data_dir = MakeDataDir()

    def line_logger(msg):
      if (msg.find("kill") >= 0):
        server.stop = True
        print 'shutting down server'
        sys.exit(0)

    # Instantiate a dummy authorizer for managing 'virtual' users
    authorizer = pyftpdlib.ftpserver.DummyAuthorizer()

    # Define a new user having full r/w permissions and a read-only
    # anonymous user
    authorizer.add_user('chrome', 'chrome', my_data_dir, perm='elradfmw')

    authorizer.add_anonymous(my_data_dir)

    # Instantiate FTP handler class
    ftp_handler = pyftpdlib.ftpserver.FTPHandler
    ftp_handler.authorizer = authorizer
    pyftpdlib.ftpserver.logline = line_logger

    # Define a customized banner (string returned when client connects)
    ftp_handler.banner = ("pyftpdlib %s based ftpd ready." %
                          pyftpdlib.ftpserver.__ver__)

    # Instantiate FTP server class and listen to 127.0.0.1:port
    address = ('127.0.0.1', port)
    server = pyftpdlib.ftpserver.FTPServer(address, ftp_handler)
    print 'FTP server started on port %d...' % port

  try:
    server.serve_forever()
  except KeyboardInterrupt:
    print 'shutting down server'
    server.stop = True

if __name__ == '__main__':
  option_parser = optparse.OptionParser()
  option_parser.add_option("-f", '--ftp', action='store_const',
                           const=SERVER_FTP, default=SERVER_HTTP,
                           dest='server_type',
                           help='FTP or HTTP server: default is HTTP.')
  option_parser.add_option('--forking', action='store_true', default=False,
                           dest='forking',
                           help='Serve each request in a separate process.')
  option_parser.add_option('', '--port', default='8888', type='int',
                           help='Port used by the server.')
  option_parser.add_option('', '--data-dir', dest='data_dir',
                           help='Directory from which to read the files.')
  option_parser.add_option('', '--https', dest='cert',
                           help='Specify that https should be used, specify '
                           'the path to the cert containing the private key '
                           'the server should use.')
  option_parser.add_option('', '--file-root-url', default='/files/',
                           help='Specify a root URL for files served.')
  option_parser.add_option('', '--never-die', default=False,
                           action="store_true",
                           help='Prevent the server from dying when visiting '
                           'a /kill URL. Useful for manually running some '
                           'tests.')
  options, args = option_parser.parse_args()

  sys.exit(main(options, args))