1 files changed, 115 insertions, 0 deletions
diff --git a/src/leap/bitmask/core/uuid_map.py b/src/leap/bitmask/core/uuid_map.py
new file mode 100644
index 00000000..5edc7216
--- /dev/null
+++ b/src/leap/bitmask/core/uuid_map.py
@@ -0,0 +1,115 @@
+# -*- coding: utf-8 -*-
+# uuid_map.py
+# Copyright (C) 2015,2016 LEAP
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+"""
+UUID Map: a persistent mapping between user-ids and uuids.
+"""
+
+import base64
+import os
+import re
+
+import scrypt
+
+from leap.common.config import get_path_prefix
+
+
+MAP_PATH = os.path.join(get_path_prefix(), 'leap', 'uuids')
+
+
+class UserMap(object):
+
+    """
+    A persistent mapping between user-ids and uuids.
+    """
+
+    # TODO Add padding to the encrypted string
+
+    def __init__(self):
+        self._d = {}
+        self._lines = set([])
+        if os.path.isfile(MAP_PATH):
+            self.load()
+
+    def add(self, userid, uuid, passwd):
+        """
+        Add a new userid-uuid mapping, and encrypt the record with the user
+        password.
+        """
+        self._add_to_cache(userid, uuid)
+        self._lines.add(_encode_uuid_map(userid, uuid, passwd))
+        self.dump()
+
+    def _add_to_cache(self, userid, uuid):
+        self._d[userid] = uuid
+
+    def load(self):
+        """
+        Load a mapping from a default file.
+        """
+        with open(MAP_PATH, 'r') as infile:
+            lines = infile.readlines()
+            self._lines = set(lines)
+
+    def dump(self):
+        """
+        Dump the mapping to a default file.
+        """
+        with open(MAP_PATH, 'w') as out:
+            out.write('\n'.join(self._lines))
+
+    def lookup_uuid(self, userid, passwd=None):
+        """
+        Lookup the uuid for a given userid.
+
+        If no password is given, try to lookup on cache.
+        Else, try to decrypt all the records that we know about with the
+        passed password.
+        """
+        if not passwd:
+            return self._d.get(userid)
+
+        for line in self._lines:
+            guess = _decode_uuid_line(line, passwd)
+            if guess:
+                record_userid, uuid = guess
+                if record_userid == userid:
+                    self._add_to_cache(userid, uuid)
+                    return uuid
+
+    def lookup_userid(self, uuid):
+        """
+        Get the userid for the given uuid from cache.
+        """
+        rev_d = {v: k for (k, v) in self._d.items()}
+        return rev_d.get(uuid)
+
+
+def _encode_uuid_map(userid, uuid, passwd):
+    data = 'userid:%s:uuid:%s' % (userid, uuid)
+    encrypted = scrypt.encrypt(data, passwd, maxtime=0.05)
+    return base64.encodestring(encrypted).replace('\n', '')
+
+
+def _decode_uuid_line(line, passwd):
+    decoded = base64.decodestring(line)
+    try:
+        maybe_decrypted = scrypt.decrypt(decoded, passwd, maxtime=0.1)
+    except scrypt.error:
+        return None
+    match = re.findall("userid\:(.+)\:uuid\:(.+)", maybe_decrypted)
+    if match:
+        return match[0]