python/google/appengine/tools/dev_appserver_login.py

   1 #!/usr/bin/env python
   2 #
   3 # Copyright 2007 Google Inc.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16 #
  17 """Helper CGI for logins/logout in the development application server.
  18
  19 This CGI has these parameters:
  20
  21   continue: URL to redirect to after a login or logout has completed.
  22   email: Email address to set for the client.
  23   admin: If 'True', the client should be logged in as an admin.
  24   action: What action to take ('Login' or 'Logout').
  25
  26 To view the current user information and a form for logging in and out,
  27 supply no parameters.
  28 """
  29
  30
  31
  32 import cgi
  33 import Cookie
  34 import os
  35 import sys
  36 import urllib
  37 import hashlib
  38
  39
  40
  41
  42 CONTINUE_PARAM = 'continue'
  43 EMAIL_PARAM = 'email'
  44 ADMIN_PARAM = 'admin'
  45 ACTION_PARAM = 'action'
  46
  47
  48 LOGOUT_ACTION = 'Logout'
  49 LOGIN_ACTION = 'Login'
  50
  51
  52 LOGOUT_PARAM = 'action=%s' % LOGOUT_ACTION
  53
  54
  55 COOKIE_NAME = 'dev_appserver_login'
  56
  57
  58
  59 def GetUserInfo(http_cookie, cookie_name=COOKIE_NAME):
  60   """Get the requestor's user info from the HTTP cookie in the CGI environment.
  61
  62   Args:
  63     http_cookie: Value of the HTTP_COOKIE environment variable.
  64     cookie_name: Name of the cookie that stores the user info.
  65
  66   Returns:
  67     Tuple (email, admin, user_id) where:
  68       email: The user's email address, if any.
  69       admin: True if the user is an admin; False otherwise.
  70       user_id: The user ID, if any.
  71   """
  72   try:
  73     cookie = Cookie.SimpleCookie(http_cookie)
  74   except Cookie.CookieError:
  75     return '', False, ''
  76
  77   cookie_value = ''
  78   if cookie_name in cookie:
  79     cookie_value = cookie[cookie_name].value
  80
  81   email, admin, user_id = (cookie_value.split(':') + ['', '', ''])[:3]
  82   return email, (admin == 'True'), user_id
  83
  84
  85 def CreateCookieData(email, admin):
  86   """Creates cookie payload data.
  87
  88   Args:
  89     email, admin: Parameters to incorporate into the cookie.
  90
  91   Returns:
  92     String containing the cookie payload.
  93   """
  94   admin_string = 'False'
  95   if admin:
  96     admin_string = 'True'
  97   if email:
  98     user_id_digest = hashlib.md5(email.lower()).digest()
  99     user_id = '1' + ''.join(['%02d' % ord(x) for x in user_id_digest])[:20]
 100   else:
 101     user_id = ''
 102   return '%s:%s:%s' % (email, admin_string, user_id)
 103
 104
 105 def SetUserInfoCookie(email, admin, cookie_name=COOKIE_NAME):
 106   """Creates a cookie to set the user information for the requestor.
 107
 108   Args:
 109     email: Email to set for the user.
 110     admin: True if the user should be admin; False otherwise.
 111     cookie_name: Name of the cookie that stores the user info.
 112
 113   Returns:
 114     'Set-Cookie' header for setting the user info of the requestor.
 115   """
 116   cookie_value = CreateCookieData(email, admin)
 117   set_cookie = Cookie.SimpleCookie()
 118   set_cookie[cookie_name] = cookie_value
 119   set_cookie[cookie_name]['path'] = '/'
 120   return '%s\r\n' % set_cookie
 121
 122
 123 def ClearUserInfoCookie(cookie_name=COOKIE_NAME):
 124   """Clears the user info cookie from the requestor, logging them out.
 125
 126   Args:
 127     cookie_name: Name of the cookie that stores the user info.
 128
 129   Returns:
 130     'Set-Cookie' header for clearing the user info of the requestor.
 131   """
 132   set_cookie = Cookie.SimpleCookie()
 133   set_cookie[cookie_name] = ''
 134   set_cookie[cookie_name]['path'] = '/'
 135   set_cookie[cookie_name]['max-age'] = '0'
 136   return '%s\r\n' % set_cookie
 137
 138
 139
 140 LOGIN_TEMPLATE = """<html>
 141 <head>
 142   <title>Login</title>
 143 </head>
 144 <body>
 145
 146 <form method="get" action="%(login_url)s"
 147       style="text-align:center; font: 13px sans-serif">
 148   <div style="width: 20em; margin: 1em auto;
 149               text-align:left;
 150               padding: 0 2em 1.25em 2em;
 151               background-color: #d6e9f8;
 152               border: 2px solid #67a7e3">
 153     <h3>%(login_message)s</h3>
 154     <p style="padding: 0; margin: 0">
 155       <label for="email" style="width: 3em">Email:</label>
 156       <input name="email" type="text" value="%(email)s" id="email"/>
 157     </p>
 158     <p style="margin: .5em 0 0 3em; font-size:12px">
 159       <input name="admin" type="checkbox" value="True"
 160        %(admin_checked)s id="admin"/>
 161         <label for="admin">Sign in as Administrator</label>
 162     </p>
 163     <p style="margin-left: 3em">
 164       <input name="action" value="Login" type="submit"
 165              id="submit-login" />
 166       <input name="action" value="Logout" type="submit"
 167              id="submit-logout" />
 168     </p>
 169   </div>
 170   <input name="continue" type="hidden" value="%(continue_url)s"/>
 171 </form>
 172
 173 </body>
 174 </html>
 175 """
 176
 177
 178 def RenderLoginTemplate(login_url, continue_url, email, admin):
 179   """Renders the login page.
 180
 181   Args:
 182     login_url, continue_url, email, admin: Parameters passed to
 183       LoginCGI.
 184
 185   Returns:
 186     String containing the contents of the login page.
 187   """
 188   login_message = 'Not logged in'
 189   if email:
 190     login_message = 'Logged in'
 191   admin_checked = ''
 192   if admin:
 193     admin_checked = 'checked'
 194
 195   template_dict = {
 196
 197
 198     'email': (cgi.escape(email, quote=1) or 'test\x40example.com'),
 199     'admin_checked': admin_checked,
 200     'login_message': login_message,
 201     'login_url': cgi.escape(login_url, quote=1),
 202     'continue_url': cgi.escape(continue_url, quote=1)
 203   }
 204
 205   return LOGIN_TEMPLATE % template_dict
 206
 207
 208
 209 def LoginRedirect(login_url,
 210                   hostname,
 211                   port,
 212                   relative_url,
 213                   outfile):
 214   """Writes a login redirection URL to a user.
 215
 216   Args:
 217     login_url: Relative URL which should be used for handling user logins.
 218     hostname: Name of the host on which the webserver is running.
 219     port: Port on which the webserver is running.
 220     relative_url: String containing the URL accessed.
 221     outfile: File-like object to which the response should be written.
 222   """
 223   dest_url = "http://%s:%s%s" % (hostname, port, relative_url)
 224   redirect_url = 'http://%s:%s%s?%s=%s' % (hostname,
 225                                            port,
 226                                            login_url,
 227                                            CONTINUE_PARAM,
 228                                            urllib.quote(dest_url))
 229   outfile.write('Status: 302 Requires login\r\n')
 230   outfile.write('Location: %s\r\n\r\n' % redirect_url)
 231
 232
 233 def LoginCGI(login_url,
 234              email,
 235              admin,
 236              action,
 237              set_email,
 238              set_admin,
 239              continue_url,
 240              outfile):
 241   """Runs the login CGI.
 242
 243   This CGI does not care about the method at all. For both POST and GET the
 244   client will be redirected to the continue URL.
 245
 246   Args:
 247     login_url: URL used to run the CGI.
 248     email: Current email address of the requesting user.
 249     admin: True if the requesting user is an admin; False otherwise.
 250     action: The action used to run the CGI; 'Login' for a login action, 'Logout'
 251       for when a logout should occur.
 252     set_email: Email to set for the user; Empty if no email should be set.
 253     set_admin: True if the user should be an admin; False otherwise.
 254     continue_url: URL to which the user should be redirected when the CGI
 255       finishes loading; defaults to the login_url with no parameters (showing
 256       current status) if not supplied.
 257     outfile: File-like object to which all output data should be written.
 258   """
 259   redirect_url = ''
 260   output_headers = []
 261
 262   if action:
 263     if action.lower() == LOGOUT_ACTION.lower():
 264       output_headers.append(ClearUserInfoCookie())
 265     elif set_email:
 266       output_headers.append(SetUserInfoCookie(set_email, set_admin))
 267
 268     redirect_url = continue_url or login_url
 269
 270   if redirect_url:
 271     outfile.write('Status: 302 Redirecting to continue URL\r\n')
 272     for header in output_headers:
 273       outfile.write(header)
 274     outfile.write('Location: %s\r\n' % redirect_url)
 275     outfile.write('\r\n')
 276   else:
 277     outfile.write('Status: 200\r\n')
 278     outfile.write('Content-Type: text/html\r\n')
 279     outfile.write('\r\n')
 280     outfile.write(RenderLoginTemplate(login_url,
 281                                       continue_url,
 282                                       email,
 283                                       admin))
 284
 285
 286
 287 def main():
 288   """Runs the login and logout CGI script."""
 289   form = cgi.FieldStorage(environ=os.environ)
 290   login_url = os.environ['PATH_INFO']
 291   email = os.environ.get('USER_EMAIL', '')
 292   admin = os.environ.get('USER_IS_ADMIN', '0') == '1'
 293
 294   action = form.getfirst(ACTION_PARAM)
 295   set_email = form.getfirst(EMAIL_PARAM, '')
 296   set_admin = form.getfirst(ADMIN_PARAM, '') == 'True'
 297   continue_url = form.getfirst(CONTINUE_PARAM, '')
 298
 299   LoginCGI(login_url,
 300            email,
 301            admin,
 302            action,
 303            set_email,
 304            set_admin,
 305            continue_url,
 306            sys.stdout)
 307   return 0
 308
 309
 310
 311 if __name__ == '__main__':
 312   main()