Move source files to subfolder.

1 files changed, 163 insertions, 0 deletions

diff --git a/soledad/backends/sqlcipher.py b/soledad/backends/sqlcipher.py
new file mode 100644
index 00000000..5d2569bf
--- /dev/null
+++ b/soledad/backends/sqlcipher.py
@@ -0,0 +1,163 @@
+"""A U1DB backend that uses SQLCipher as its persistence layer."""
+
+import os
+from pysqlcipher import dbapi2
+import time
+
+from leap import util
+from u1db.backends import sqlite_backend
+util.logger.debug(
+    "Monkey-patching u1db.backends.sqlite_backend with pysqlcipher.dbapi2..."
+)
+sqlite_backend.dbapi2 = dbapi2
+
+from u1db import (
+    errors,
+)
+
+from leap.soledad.backends.leap_backend import LeapDocument
+
+
+def open(path, password, create=True, document_factory=None, soledad=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.
+    """
+    return SQLCipherDatabase.open_database(
+        path, password, create=create, document_factory=document_factory,
+        soledad=soledad)
+
+
+class DatabaseIsNotEncrypted(Exception):
+    """
+    Exception raised when trying to open non-encrypted databases.
+    """
+    pass
+
+
+class SQLCipherDatabase(sqlite_backend.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,
+                 soledad=None):
+        """Create a new sqlcipher file."""
+        self._check_if_db_is_encrypted(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._soledad = soledad
+
+        def factory(doc_id=None, rev=None, json='{}', has_conflicts=False,
+                    encrypted_json=None, syncable=True):
+            return LeapDocument(doc_id=doc_id, rev=rev, json=json,
+                                has_conflicts=has_conflicts,
+                                encrypted_json=encrypted_json,
+                                syncable=syncable, soledad=self._soledad)
+        self.set_document_factory(factory)
+
+    def _check_if_db_is_encrypted(self, sqlite_file):
+        if not os.path.exists(sqlite_file):
+            return
+        else:
+            try:
+                # try to open an encrypted database with the regular u1db
+                # backend should raise a DatabaseError exception.
+                sqlite_backend.SQLitePartialExpandDatabase(sqlite_file)
+                raise DatabaseIsNotEncrypted()
+            except dbapi2.DatabaseError:
+                pass
+
+    @classmethod
+    def _open_database(cls, sqlite_file, password, document_factory=None,
+                       soledad=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,
+            soledad=soledad)
+
+    @classmethod
+    def open_database(cls, sqlite_file, password, create, backend_cls=None,
+                      document_factory=None, soledad=None):
+        """Open U1DB database using SQLCipher as backend."""
+        try:
+            return cls._open_database(sqlite_file, password,
+                                      document_factory=document_factory,
+                                      soledad=soledad)
+        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,
+                               soledad=soledad)
+
+    def sync(self, url, creds=None, autocreate=True):
+        """
+        Synchronize encrypted documents with remote replica exposed at url.
+        """
+        from u1db.sync import Synchronizer
+        from leap.soledad.backends.leap_backend import LeapSyncTarget
+        return Synchronizer(
+            self,
+            LeapSyncTarget(url,
+                           creds=creds,
+                           soledad=self._soledad)).sync(autocreate=autocreate)
+
+    def _extra_schema_init(self, c):
+        c.execute(
+            'ALTER TABLE document '
+            'ADD COLUMN syncable BOOL NOT NULL DEFAULT TRUE')
+
+    def _put_and_update_indexes(self, old_doc, doc):
+        super(SQLCipherDatabase, self)._put_and_update_indexes(old_doc, doc)
+        c = self._db_handle.cursor()
+        c.execute('UPDATE document SET syncable=? WHERE doc_id=?',
+                  (doc.syncable, doc.doc_id))
+
+    def _get_doc(self, doc_id, check_for_conflicts=False):
+        doc = super(SQLCipherDatabase, self)._get_doc(doc_id,
+                                                      check_for_conflicts)
+        if doc:
+            c = self._db_handle.cursor()
+            c.execute('SELECT syncable FROM document WHERE doc_id=?',
+                      (doc.doc_id,))
+            doc.syncable = bool(c.fetchone()[0])
+        return doc
+
+sqlite_backend.SQLiteDatabase.register_implementation(SQLCipherDatabase)