Implement user searching in the community auth system

This lets downstream systems securely search for users that are in
the system, so they can populate their local database with users
before they have logged in if necessary. This can be used for example
for the commitfest management system to be able to flag users as
authors and reviewers even before they have logged in.

tools/communityauth/sample/django/auth.py

@@ -6,7 +6,7 @@
 #
 # To integrate with django, you need the following:
 # * Make sure the view "login" from this module is used for login
-# * Map an url somwehere (typicall /auth_receive/) to the auth_receive
+# * Map an url somwehere (typically /auth_receive/) to the auth_receive
 #   view.
 # * In settings.py, set AUTHENTICATION_BACKENDS to point to the class
 #   AuthBackend in this module.
@@ -26,6 +26,8 @@ from django.contrib.auth import logout as django_logout
 from django.conf import settings
 
 import base64
+import simplejson
+import socket
 import urlparse
 import urllib
 from Crypto.Cipher import AES
@@ -168,3 +170,36 @@ We apologize for the inconvenience.
 	if hasattr(settings, 'PGAUTH_REDIRECT_SUCCESS'):
 		return HttpResponseRedirect(settings.PGAUTH_REDIRECT_SUCCESS)
 	raise Exception("Authentication successful, but don't know where to redirect!")
+
+
+# Perform a search in the central system. Note that the results are returned as an
+# array of dicts, and *not* as User objects. To be able to for example reference the
+# user through a ForeignKey, a User object must be materialized locally. We don't do
+# that here, as this search might potentially return a lot of unrelated users since
+# it's a wildcard match.
+# Unlike the authentication, searching does not involve the browser - we just make
+# a direct http call.
+def user_search(searchterm=None, userid=None):
+	# If upsteam isn't responding quickly, it's not going to respond at all, and
+	# 10 seconds is already quite long.
+	socket.setdefaulttimeout(10)
+	if userid:
+		q = {'u': userid}
+	else:
+		q = {'s': searchterm}
+
+	u = urllib.urlopen('%ssearch/?%s' % (
+		settings.PGAUTH_REDIRECT,
+		urllib.urlencode(q),
+		))
+	(ivs, datas) = u.read().split('&')
+	u.close()
+
+	# Decryption time
+	decryptor = AES.new(base64.b64decode(settings.PGAUTH_KEY),
+						AES.MODE_CBC,
+						base64.b64decode(ivs, "-_"))
+	s = decryptor.decrypt(base64.b64decode(datas, "-_")).rstrip(' ')
+	j = simplejson.loads(s)
+
+	return j