Add basic auth.

handler.py

@@ -1,5 +1,7 @@
 #!/usr/bin/env python2.5
 
+import base64
+import logging
 import os
 
 from google.appengine.ext import webapp
@@ -17,10 +19,45 @@
 else:
   HOST_NAME = os.environ['SERVER_NAME']
 
+# Inspired by mox's MoxMetaTestBase.
+class RequestHandlerMetaClass(type):
+  """Metaclass to do auth checks at the beginning of get and post methods."""
+
+  def __init__(cls, name, bases, d):
+    type.__init__(cls, name, bases, d)
+    # Also get all of the attributes from base classes to account for a case
+    # when the handler class is not the immediate child of RequestHandler.
+    for base in bases:
+      for attr_name in dir(base):
+        if attr_name not in d:
+          d[attr_name] = getattr(base, attr_name)
+
+      for func_name, func in d.items():
+        if callable(func) and (func_name == 'get' or func_name == 'post'):
+          setattr(cls, func_name, RequestHandlerMetaClass.wrap_with_auth(
+              cls, func))
+
+  @staticmethod
+  def wrap_with_auth(cls, func):
+    def new_method(self, *args, **kwargs):
+      if self.check_basic_auth():
+        func(self, *args, **kwargs)
+    new_method.__name__ = func.__name__
+    new_method.__doc__ = func.__doc__
+    new_method.__module__ = func.__module__
+    return new_method
+
+
 class RequestHandler(webapp.RequestHandler):
+
+  __metaclass__ = RequestHandlerMetaClass
+
   COOKIE_NAME = 'hq_username'
   NOBODY = 'nobody'
 
+  BASIC_AUTH_USER = 'nugget'
+  BASIC_AUTH_PASSWORD = 'hotdog'
+
   def initialize(self, *args, **kwds):
     super(RequestHandler, self).initialize(*args, **kwds)
 
@@ -34,6 +71,30 @@ def set_username(self, username):
         '%s=%s; path=/; expires=Fri, 31-Dec-2020 23:59:59 GMT' \
           % (self.COOKIE_NAME, username.encode()))
 
+  def check_basic_auth(self):
+    auth_header = self.request.headers.get('Authorization')
+    if auth_header:
+      try:
+        (scheme, base64_raw) = auth_header.split(' ')
+        if scheme != 'Basic':
+          raise ValueError, 'scheme is not Basic!'
+        (username, password) = base64.b64decode(base64_raw).split(':')
+      except (ValueError, TypeError), err:
+        username = password = ''
+        logging.warn(type(err))
+      finally:
+        if (username == self.BASIC_AUTH_USER and
+            password == self.BASIC_AUTH_PASSWORD):
+          return True
+        else:
+          self.error(401)
+          self.response.headers['WWW-Authenticate'] = 'Basic realm="CIC"'
+          return False
+    else:
+      self.error(401)
+      self.response.headers['WWW-Authenticate'] = 'Basic realm="CIC"'
+      return False
+
   def render_template(self, template_name, params, **kwds):
     params['usernames'] = model.Username.all()
     params['current_user'] = self.username