1 files changed, 127 insertions, 0 deletions
diff --git a/src/leap/soledad/backends/sqlcipher.py b/src/leap/soledad/backends/sqlcipher.py
new file mode 100644
index 00000000..6fd6e619
--- /dev/null
+++ b/src/leap/soledad/backends/sqlcipher.py
@@ -0,0 +1,127 @@
+# Copyright 2011 Canonical Ltd.
+#
+# This file is part of u1db.
+#
+# u1db is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3
+# as published by the Free Software Foundation.
+#
+# u1db 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with u1db.  If not, see <http://www.gnu.org/licenses/>.
+
+"""A U1DB implementation that uses SQLCipher as its persistence layer."""
+
+import errno
+import os
+try:
+    import simplejson as json
+except ImportError:
+    import json  # noqa
+from sqlite3 import dbapi2
+import sys
+import time
+import uuid
+
+import pkg_resources
+
+from u1db.backends import CommonBackend, CommonSyncTarget
+from u1db.backends.sqlite_backend import SQLitePartialExpandDatabase
+from u1db import (
+    Document,
+    errors,
+    query_parser,
+    vectorclock,
+    )
+
+
+def open(path, create, document_factory=None, password=None):
+    """Open a database at the given location.
+
+    Will raise u1db.errors.DatabaseDoesNotExist if create=False and the
+    database does not already exist.
+
+    :param path: The filesystem path for the database to open.
+    :param create: True/False, should the database be created if it doesn't
+        already exist?
+    :param document_factory: A function that will be called with the same
+        parameters as Document.__init__.
+    :return: An instance of Database.
+    """
+    from u1db.backends import sqlite_backend
+    return sqlite_backend.SQLCipherDatabase.open_database(
+        path, password, create=create, document_factory=document_factory)
+
+
+class SQLCipherDatabase(SQLitePartialExpandDatabase):
+    """A U1DB implementation that uses SQLCipher as its persistence layer."""
+
+    _index_storage_value = 'expand referenced encrypted'
+
+
+    @classmethod
+    def set_pragma_key(cls, db_handle, key):
+       db_handle.cursor().execute("PRAGMA key = '%s'" % key)
+
+    def __init__(self, sqlite_file, password, document_factory=None):
+        """Create a new sqlite file."""
+        self._db_handle = dbapi2.connect(sqlite_file)
+        SQLCipherDatabase.set_pragma_key(self._db_handle, password)
+        self._real_replica_uid = None
+        self._ensure_schema()
+        self._factory = document_factory or Document
+
+    @classmethod
+    def _open_database(cls, sqlite_file, password, document_factory=None):
+        if not os.path.isfile(sqlite_file):
+            raise errors.DatabaseDoesNotExist()
+        tries = 2
+        while True:
+            # Note: There seems to be a bug in sqlite 3.5.9 (with python2.6)
+            #       where without re-opening the database on Windows, it
+            #       doesn't see the transaction that was just committed
+            db_handle = dbapi2.connect(sqlite_file)
+            SQLCipherDatabase.set_pragma_key(db_handle, password)
+            c = db_handle.cursor()
+            v, err = cls._which_index_storage(c)
+            db_handle.close()
+            if v is not None:
+                break
+            # possibly another process is initializing it, wait for it to be
+            # done
+            if tries == 0:
+                raise err  # go for the richest error?
+            tries -= 1
+            time.sleep(cls.WAIT_FOR_PARALLEL_INIT_HALF_INTERVAL)
+        return SQLCipherDatabase._sqlite_registry[v](
+            sqlite_file, password, document_factory=document_factory)
+
+    @classmethod
+    def open_database(cls, sqlite_file, password, create, backend_cls=None,
+                      document_factory=None):
+        try:
+            return cls._open_database(sqlite_file, password,
+                                      document_factory=document_factory)
+        except errors.DatabaseDoesNotExist:
+            if not create:
+                raise
+            if backend_cls is None:
+                # default is SQLCipherPartialExpandDatabase
+                backend_cls = SQLCipherDatabase
+            return backend_cls(sqlite_file, password,
+                               document_factory=document_factory)
+
+    @staticmethod
+    def register_implementation(klass):
+        """Register that we implement an SQLCipherDatabase.
+
+        The attribute _index_storage_value will be used as the lookup key.
+        """
+        SQLCipherDatabase._sqlite_registry[klass._index_storage_value] = klass
+
+
+SQLCipherDatabase.register_implementation(SQLCipherDatabase)