--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto.py	Tue Feb 16 10:33:48 2010 +0100
@@ -0,0 +1,35 @@
+"""Simple cryptographic routines, based on python-crypto.
+
+:organization: Logilab
+:copyright: 2009-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
+:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
+:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
+"""
+__docformat__ = "restructuredtext en"
+
+from pickle import dumps, loads
+from base64 import b64encode, b64decode
+
+from Crypto.Cipher import Blowfish
+
+
+_CYPHERERS = {}
+def _cypherer(seed):
+    try:
+        return _CYPHERERS[seed]
+    except KeyError:
+        _CYPHERERS[seed] = Blowfish.new(seed, Blowfish.MODE_ECB)
+        return _CYPHERERS[seed]
+
+
+def encrypt(data, seed):
+    string = dumps(data)
+    string = string + '*' * (8 - len(string) % 8)
+    string = b64encode(_cypherer(seed).encrypt(string))
+    return unicode(string)
+
+
+def decrypt(string, seed):
+    # pickle ignores trailing characters so we do not need to strip them off
+    string = _cypherer(seed).decrypt(b64decode(string))
+    return loads(string)