text: #!/usr/bin/env python
  #
  # Copyright 2007 Google Inc.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  
  """Tool for performing authenticated RPCs against App Engine."""
  
  
  import google
  
  import cookielib
  import fancy_urllib
  import logging
  import os
  import re
  import socket
  import sys
  import urllib
  import urllib2
  
  from google.appengine.tools import dev_appserver_login
  
  
  logger = logging.getLogger('google.appengine.tools.appengine_rpc')
  
  def GetPlatformToken(os_module=os, sys_module=sys, platform=sys.platform):
    """Returns a 'User-agent' token for the host system platform.
  
    Args:
      os_module, sys_module, platform: Used for testing.
  
    Returns:
      String containing the platform token for the host system.
    """
    if hasattr(sys_module, "getwindowsversion"):
      windows_version = sys_module.getwindowsversion()
      version_info = ".".join(str(i) for i in windows_version[:4])
      return platform + "/" + version_info
    elif hasattr(os_module, "uname"):
      uname = os_module.uname()
      return "%s/%s" % (uname[0], uname[2])
    else:
      return "unknown"
  
  def HttpRequestToString(req, include_data=True):
    """Converts a urllib2.Request to a string.
  
    Args:
      req: urllib2.Request
    Returns:
      Multi-line string representing the request.
    """
  
    headers = ""
    for header in req.header_items():
      headers += "%s: %s\n" % (header[0], header[1])
  
    template = ("%(method)s %(selector)s %(type)s/1.1\n"
                "Host: %(host)s\n"
                "%(headers)s")
    if include_data:
      template = template + "\n%(data)s"
  
    return template % {
        'method' : req.get_method(),
        'selector' : req.get_selector(),
        'type' : req.get_type().upper(),
        'host' : req.get_host(),
        'headers': headers,
        'data': req.get_data(),
        }
  
  class ClientLoginError(urllib2.HTTPError):
    """Raised to indicate there was an error authenticating with ClientLogin."""
  
    def __init__(self, url, code, msg, headers, args):
      urllib2.HTTPError.__init__(self, url, code, msg, headers, None)
      self.args = args
      self.reason = args["Error"]
  
    def read(self):
      return '%d %s: %s' % (self.code, self.msg, self.reason)
  
  
  class AbstractRpcServer(object):
    """Provides a common interface for a simple RPC server."""
  
    def __init__(self, host, auth_function, user_agent, source,
                 host_override=None, extra_headers=None, save_cookies=False,
                 auth_tries=3, account_type=None, debug_data=True, secure=True):
      """Creates a new HttpRpcServer.
  
      Args:
        host: The host to send requests to.
        auth_function: A function that takes no arguments and returns an
          (email, password) tuple when called. Will be called if authentication
          is required.
        user_agent: The user-agent string to send to the server. Specify None to
          omit the user-agent header.
        source: The source to specify in authentication requests.
        host_override: The host header to send to the server (defaults to host).
        extra_headers: A dict of extra headers to append to every request. Values
          supplied here will override other default headers that are supplied.
        save_cookies: If True, save the authentication cookies to local disk.
          If False, use an in-memory cookiejar instead.  Subclasses must
          implement this functionality.  Defaults to False.
        auth_tries: The number of times to attempt auth_function before failing.
        account_type: One of GOOGLE, HOSTED_OR_GOOGLE, or None for automatic.
        debug_data: Whether debugging output should include data contents.
      """
      if secure:
        self.scheme = "https"
      else:
        self.scheme = "http"
      self.host = host
      self.host_override = host_override
      self.auth_function = auth_function
      self.source = source
      self.authenticated = False
      self.auth_tries = auth_tries
      self.debug_data = debug_data
  
      self.account_type = account_type
  
      self.extra_headers = {}
      if user_agent:
        self.extra_headers["User-Agent"] = user_agent
      if extra_headers:
        self.extra_headers.update(extra_headers)
  
      self.save_cookies = save_cookies
      self.cookie_jar = cookielib.MozillaCookieJar()
      self.opener = self._GetOpener()
      if self.host_override:
        logger.info("Server: %s; Host: %s", self.host, self.host_override)
      else:
        logger.info("Server: %s", self.host)
  
      if ((self.host_override and self.host_override == "localhost") or
          self.host == "localhost" or self.host.startswith("localhost:")):
        self._DevAppServerAuthenticate()
  
    def _GetOpener(self):
      """Returns an OpenerDirector for making HTTP requests.
  
      Returns:
        A urllib2.OpenerDirector object.
      """
      raise NotImplemented()
  
    def _CreateRequest(self, url, data=None):
      """Creates a new urllib request."""
      req = fancy_urllib.FancyRequest(url, data=data)
      if self.host_override:
        req.add_header("Host", self.host_override)
      for key, value in self.extra_headers.iteritems():
        req.add_header(key, value)
      return req
  
    def _GetAuthToken(self, email, password):
      """Uses ClientLogin to authenticate the user, returning an auth token.
  
      Args:
        email:    The user's email address
        password: The user's password
  
      Raises:
        ClientLoginError: If there was an error authenticating with ClientLogin.
        HTTPError: If there was some other form of HTTP error.
  
      Returns:
        The authentication token returned by ClientLogin.
      """
      account_type = self.account_type
      if not account_type:
        if (self.host.split(':')[0].endswith(".google.com")
            or (self.host_override
                and self.host_override.split(':')[0].endswith(".google.com"))):
          account_type = "HOSTED_OR_GOOGLE"
        else:
          account_type = "GOOGLE"
      data = {
          "Email": email,
          "Passwd": password,
          "service": "ah",
          "source": self.source,
          "accountType": account_type
      }
  
      req = self._CreateRequest(
          url="https://www.google.com/accounts/ClientLogin",
          data=urllib.urlencode(data))
      try:
        response = self.opener.open(req)
        response_body = response.read()
        response_dict = dict(x.split("=")
                             for x in response_body.split("\n") if x)
        return response_dict["Auth"]
      except urllib2.HTTPError, e:
        if e.code == 403:
          body = e.read()
          response_dict = dict(x.split("=", 1) for x in body.split("\n") if x)
          raise ClientLoginError(req.get_full_url(), e.code, e.msg,
                                 e.headers, response_dict)
        else:
          raise
  
    def _GetAuthCookie(self, auth_token):
      """Fetches authentication cookies for an authentication token.
  
      Args:
        auth_token: The authentication token returned by ClientLogin.
  
      Raises:
        HTTPError: If there was an error fetching the authentication cookies.
      """
      continue_location = "http://localhost/"
      args = {"continue": continue_location, "auth": auth_token}
      login_path = os.environ.get("APPCFG_LOGIN_PATH", "/_ah")
      req = self._CreateRequest("%s://%s%s/login?%s" %
                                (self.scheme, self.host, login_path,
                                 urllib.urlencode(args)))
      try:
        response = self.opener.open(req)
      except urllib2.HTTPError, e:
        response = e
      if (response.code != 302 or
          response.info()["location"] != continue_location):
        raise urllib2.HTTPError(req.get_full_url(), response.code, response.msg,
                                response.headers, response.fp)
      self.authenticated = True
  
    def _Authenticate(self):
      """Authenticates the user.
  
      The authentication process works as follows:
       1) We get a username and password from the user
       2) We use ClientLogin to obtain an AUTH token for the user
          (see http://code.google.com/apis/accounts/AuthForInstalledApps.html).
       3) We pass the auth token to /_ah/login on the server to obtain an
          authentication cookie. If login was successful, it tries to redirect
          us to the URL we provided.
  
      If we attempt to access the upload API without first obtaining an
      authentication cookie, it returns a 401 response and directs us to
      authenticate ourselves with ClientLogin.
      """
      for unused_i in range(self.auth_tries):
        credentials = self.auth_function()
        try:
          auth_token = self._GetAuthToken(credentials[0], credentials[1])
        except ClientLoginError, e:
          if e.reason == "BadAuthentication":
            print >>sys.stderr, "Invalid username or password."
            continue
          if e.reason == "CaptchaRequired":
            print >>sys.stderr, (
                "Please go to\n"
                "https://www.google.com/accounts/DisplayUnlockCaptcha\n"
                "and verify you are a human.  Then try again.")
            break
          if e.reason == "NotVerified":
            print >>sys.stderr, "Account not verified."
            break
          if e.reason == "TermsNotAgreed":
            print >>sys.stderr, "User has not agreed to TOS."
            break
          if e.reason == "AccountDeleted":
            print >>sys.stderr, "The user account has been deleted."
            break
          if e.reason == "AccountDisabled":
            print >>sys.stderr, "The user account has been disabled."
            break
          if e.reason == "ServiceDisabled":
            print >>sys.stderr, ("The user's access to the service has been "
                                 "disabled.")
            break
          if e.reason == "ServiceUnavailable":
            print >>sys.stderr, "The service is not available; try again later."
            break
          raise
        self._GetAuthCookie(auth_token)
        return
  
    def _DevAppServerAuthenticate(self):
      """Authenticates the user on the dev_appserver."""
      credentials = self.auth_function()
      value = dev_appserver_login.CreateCookieData(credentials[0], True)
      self.extra_headers["Cookie"] = ('dev_appserver_login="%s"; Path=/;' % value)
  
    def Send(self, request_path, payload="",
             content_type="application/octet-stream",
             timeout=None,
             **kwargs):
      """Sends an RPC and returns the response.
  
      Args:
        request_path: The path to send the request to, eg /api/appversion/create.
        payload: The body of the request, or None to send an empty request.
        content_type: The Content-Type header to use.
        timeout: timeout in seconds; default None i.e. no timeout.
          (Note: for large requests on OS X, the timeout doesn't work right.)
        kwargs: Any keyword arguments are converted into query string parameters.
  
      Returns:
        The response body, as a string.
      """
      old_timeout = socket.getdefaulttimeout()
      socket.setdefaulttimeout(timeout)
      try:
        tries = 0
        auth_tried = False
        while True:
          tries += 1
          args = dict(kwargs)
          url = "%s://%s%s?%s" % (self.scheme, self.host, request_path,
                                  urllib.urlencode(args))
          req = self._CreateRequest(url=url, data=payload)
          req.add_header("Content-Type", content_type)
          req.add_header("X-appcfg-api-version", "1")
          try:
            logger.debug('Sending HTTP request:\n%s',
                         HttpRequestToString(req, include_data=self.debug_data))
            f = self.opener.open(req)
            response = f.read()
            f.close()
            return response
          except urllib2.HTTPError, e:
            logger.debug("Got http error, this is try #%s", tries)
            if tries > self.auth_tries:
              raise
            elif e.code == 401:
              if auth_tried:
                raise
              auth_tried = True
              self._Authenticate()
            elif e.code >= 500 and e.code < 600:
              continue
            elif e.code == 302:
              if auth_tried:
                raise
              auth_tried = True
              loc = e.info()["location"]
              logger.debug("Got 302 redirect. Location: %s", loc)
              if loc.startswith("https://www.google.com/accounts/ServiceLogin"):
                self._Authenticate()
              elif re.match(r"https://www.google.com/a/[a-z0-9.-]+/ServiceLogin",
                            loc):
                self.account_type = os.getenv("APPENGINE_RPC_HOSTED_LOGIN_TYPE",
                                              "HOSTED")
                self._Authenticate()
              elif loc.startswith("http://%s/_ah/login" % (self.host,)):
                self._DevAppServerAuthenticate()
              else:
                raise
            else:
              raise
      finally:
        socket.setdefaulttimeout(old_timeout)
  
  
  class HttpRpcServer(AbstractRpcServer):
    """Provides a simplified RPC-style interface for HTTP requests."""
  
    DEFAULT_COOKIE_FILE_PATH = "~/.appcfg_cookies"
  
    def __init__(self, *args, **kwargs):
      self.certpath = os.path.normpath(os.path.join(
          os.path.dirname(__file__), '..', '..', '..', 'lib', 'cacerts',
          'cacerts.txt'))
      self.cert_file_available = os.path.exists(self.certpath)
      super(HttpRpcServer, self).__init__(*args, **kwargs)
  
    def _CreateRequest(self, url, data=None):
      """Creates a new urllib request."""
      req = super(HttpRpcServer, self)._CreateRequest(url, data)
      if self.cert_file_available and fancy_urllib.can_validate_certs():
        req.set_ssl_info(ca_certs=self.certpath)
      return req
  
    def _Authenticate(self):
      """Save the cookie jar after authentication."""
      if self.cert_file_available and not fancy_urllib.can_validate_certs():
        logger.warn("""ssl module not found.
  Without the ssl module, the identity of the remote host cannot be verified, and
  connections may NOT be secure. To fix this, please install the ssl module from
  http://pypi.python.org/pypi/ssl .
  To learn more, see http://code.google.com/appengine/kb/general.html#rpcssl .""")
      super(HttpRpcServer, self)._Authenticate()
      if self.cookie_jar.filename is not None and self.save_cookies:
        logger.info("Saving authentication cookies to %s",
                    self.cookie_jar.filename)
        self.cookie_jar.save()
  
    def _GetOpener(self):
      """Returns an OpenerDirector that supports cookies and ignores redirects.
  
      Returns:
        A urllib2.OpenerDirector object.
      """
      opener = urllib2.OpenerDirector()
      opener.add_handler(fancy_urllib.FancyProxyHandler())
      opener.add_handler(urllib2.UnknownHandler())
      opener.add_handler(urllib2.HTTPHandler())
      opener.add_handler(urllib2.HTTPDefaultErrorHandler())
      opener.add_handler(fancy_urllib.FancyHTTPSHandler())
      opener.add_handler(urllib2.HTTPErrorProcessor())
  
      if self.save_cookies:
        self.cookie_jar.filename = os.path.expanduser(
            HttpRpcServer.DEFAULT_COOKIE_FILE_PATH)
  
        if os.path.exists(self.cookie_jar.filename):
          try:
            self.cookie_jar.load()
            self.authenticated = True
            logger.info("Loaded authentication cookies from %s",
                        self.cookie_jar.filename)
          except (OSError, IOError, cookielib.LoadError), e:
            logger.debug("Could not load authentication cookies; %s: %s",
                         e.__class__.__name__, e)
            self.cookie_jar.filename = None
        else:
          try:
            fd = os.open(self.cookie_jar.filename, os.O_CREAT, 0600)
            os.close(fd)
          except (OSError, IOError), e:
            logger.debug("Could not create authentication cookies file; %s: %s",
                         e.__class__.__name__, e)
            self.cookie_jar.filename = None
  
      opener.add_handler(urllib2.HTTPCookieProcessor(self.cookie_jar))
      return opener
  