1 files changed, 68 insertions, 0 deletions
diff --git a/horizon/utils/secret_key.py b/horizon/utils/secret_key.py
new file mode 100644
index 00000000..6eba25eb
--- /dev/null
+++ b/horizon/utils/secret_key.py
@@ -0,0 +1,68 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2012 Nebula, 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.
+
+
+from __future__ import with_statement  # Python 2.5 compliance
+
+import lockfile
+import random
+import string
+import tempfile
+import os
+
+
+class FilePermissionError(Exception):
+    """The key file permissions are insecure."""
+    pass
+
+
+def generate_key(key_length=64):
+    """Secret key generator.
+
+    The quality of randomness depends on operating system support,
+    see http://docs.python.org/library/random.html#random.SystemRandom.
+    """
+    if hasattr(random, 'SystemRandom'):
+        choice = random.SystemRandom().choice
+    else:
+        choice = random.choice
+    return ''.join(map(lambda x: choice(string.digits + string.letters),
+                   range(key_length)))
+
+
+def generate_or_read_from_file(key_file='.secret_key', key_length=64):
+    """Multiprocess-safe secret key file generator.
+
+    Useful to replace the default (and thus unsafe) SECRET_KEY in settings.py
+    upon first start. Save to use, i.e. when multiple Python interpreters
+    serve the dashboard Django application (e.g. in a mod_wsgi + daemonized
+    environment).  Also checks if file permissions are set correctly and
+    throws an exception if not.
+    """
+    lock = lockfile.FileLock(key_file)
+    with lock:
+        if not os.path.exists(key_file):
+            key = generate_key(key_length)
+            old_umask = os.umask(0177)  # Use '0600' file permissions
+            with open(key_file, 'w') as f:
+                f.write(key)
+            os.umask(old_umask)
+        else:
+            if oct(os.stat(key_file).st_mode & 0777) != '0600':
+                raise FilePermissionError("Insecure key file permissions!")
+            with open(key_file, 'r') as f:
+                key = f.readline()
+        return key