diff options
Diffstat (limited to 'client/src/leap/soledad/client/sqlcipher.py')
| -rw-r--r-- | client/src/leap/soledad/client/sqlcipher.py | 220 |
1 files changed, 197 insertions, 23 deletions
diff --git a/client/src/leap/soledad/client/sqlcipher.py b/client/src/leap/soledad/client/sqlcipher.py index 894c6f97..3aea340d 100644 --- a/client/src/leap/soledad/client/sqlcipher.py +++ b/client/src/leap/soledad/client/sqlcipher.py @@ -43,16 +43,19 @@ So, as the statements above were introduced for backwards compatibility with SLCipher 1.1 databases, we do not implement them as all SQLCipher databases handled by Soledad should be created by SQLCipher >= 2.0. """ +import httplib import logging import os -import time import string import threading +import time - -from u1db.backends import sqlite_backend from pysqlcipher import dbapi2 +from u1db.backends import sqlite_backend +from u1db.sync import Synchronizer from u1db import errors as u1db_errors + +from leap.soledad.client.target import SoledadSyncTarget from leap.soledad.common.document import SoledadDocument logger = logging.getLogger(__name__) @@ -88,10 +91,10 @@ def open(path, password, create=True, document_factory=None, crypto=None, database does not already exist. :param path: The filesystem path for the database to open. - :param type: str + :type path: str :param create: True/False, should the database be created if it doesn't already exist? - :param type: bool + :param create: bool :param document_factory: A function that will be called with the same parameters as Document.__init__. :type document_factory: callable @@ -144,25 +147,30 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): _index_storage_value = 'expand referenced encrypted' k_lock = threading.Lock() + create_doc_lock = threading.Lock() + update_indexes_lock = threading.Lock() + _syncer = None def __init__(self, sqlcipher_file, password, document_factory=None, crypto=None, raw_key=False, cipher='aes-256-cbc', kdf_iter=4000, cipher_page_size=1024): """ - Create a new sqlcipher file. + Connect to an existing SQLCipher database, creating a new sqlcipher + database file if needed. :param sqlcipher_file: The path for the SQLCipher file. :type sqlcipher_file: str :param password: The password that protects the SQLCipher db. :type password: str :param document_factory: A function that will be called with the same - parameters as Document.__init__. + parameters as Document.__init__. :type document_factory: callable :param crypto: An instance of SoledadCrypto so we can encrypt/decrypt - document contents when syncing. + document contents when syncing. :type crypto: soledad.crypto.SoledadCrypto - :param raw_key: Whether C{password} is a raw 64-char hex string or a - passphrase that should be hashed to obtain the encyrption key. + :param raw_key: Whether password is a raw 64-char hex string or a + passphrase that should be hashed to obtain the + encyrption key. :type raw_key: bool :param cipher: The cipher and mode to use. :type cipher: str @@ -186,6 +194,13 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): self._set_crypto_pragmas( self._db_handle, password, raw_key, cipher, kdf_iter, cipher_page_size) + if os.environ.get('LEAP_SQLITE_NOSYNC'): + self._pragma_synchronous_off(self._db_handle) + else: + self._pragma_synchronous_normal(self._db_handle) + if os.environ.get('LEAP_SQLITE_MEMSTORE'): + self._pragma_mem_temp_store(self._db_handle) + self._pragma_write_ahead_logging(self._db_handle) self._real_replica_uid = None self._ensure_schema() self._crypto = crypto @@ -336,13 +351,46 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): :return: The local generation before the synchronisation was performed. :rtype: int """ - from u1db.sync import Synchronizer - from leap.soledad.client.target import SoledadSyncTarget - return Synchronizer( - self, - SoledadSyncTarget(url, - creds=creds, - crypto=self._crypto)).sync(autocreate=autocreate) + if not self.syncer: + self._create_syncer(url, creds=creds) + + try: + res = self.syncer.sync(autocreate=autocreate) + except httplib.CannotSendRequest: + # raised when you reuse httplib.HTTP object for new request + # while you havn't called its getresponse() + # this catch works for the current connclass used + # by our HTTPClientBase, since it uses httplib. + # we will have to replace it if it changes. + logger.info("Replacing connection and trying again...") + self._syncer = None + self._create_syncer(url, creds=creds) + res = self.syncer.sync(autocreate=autocreate) + return res + + @property + def syncer(self): + """ + Accesor for synchronizer. + """ + return self._syncer + + def _create_syncer(self, url, creds=None): + """ + Creates a synchronizer + + :param url: The url of the target replica to sync with. + :type url: str + :param creds: optional dictionary giving credentials. + to authorize the operation with the server. + :type creds: dict + """ + if self._syncer is None: + self._syncer = Synchronizer( + self, + SoledadSyncTarget(url, + creds=creds, + crypto=self._crypto)) def _extra_schema_init(self, c): """ @@ -359,6 +407,22 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): 'ALTER TABLE document ' 'ADD COLUMN syncable BOOL NOT NULL DEFAULT TRUE') + def create_doc(self, content, doc_id=None): + """ + Create a new document in the local encrypted database. + + :param content: the contents of the new document + :type content: dict + :param doc_id: an optional identifier specifying the document id + :type doc_id: str + + :return: the new document + :rtype: SoledadDocument + """ + with self.create_doc_lock: + return sqlite_backend.SQLitePartialExpandDatabase.create_doc( + self, content, doc_id=doc_id) + def _put_and_update_indexes(self, old_doc, doc): """ Update a document and all indexes related to it. @@ -368,12 +432,13 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): :param doc: The new version of the document. :type doc: u1db.Document """ - sqlite_backend.SQLitePartialExpandDatabase._put_and_update_indexes( - self, old_doc, doc) - c = self._db_handle.cursor() - c.execute('UPDATE document SET syncable=? ' - 'WHERE doc_id=?', - (doc.syncable, doc.doc_id)) + with self.update_indexes_lock: + sqlite_backend.SQLitePartialExpandDatabase._put_and_update_indexes( + self, 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): """ @@ -697,6 +762,115 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): # XXX change passphrase param! db_handle.cursor().execute('PRAGMA rekey = "x\'%s"' % passphrase) + @classmethod + def _pragma_synchronous_off(cls, db_handle): + """ + Change the setting of the "synchronous" flag to OFF. + """ + logger.debug("SQLCIPHER: SETTING SYNCHRONOUS OFF") + db_handle.cursor().execute('PRAGMA synchronous=OFF') + + @classmethod + def _pragma_synchronous_normal(cls, db_handle): + """ + Change the setting of the "synchronous" flag to NORMAL. + """ + logger.debug("SQLCIPHER: SETTING SYNCHRONOUS NORMAL") + db_handle.cursor().execute('PRAGMA synchronous=NORMAL') + + @classmethod + def _pragma_mem_temp_store(cls, db_handle): + """ + Use a in-memory store for temporary tables. + """ + logger.debug("SQLCIPHER: SETTING TEMP_STORE MEMORY") + db_handle.cursor().execute('PRAGMA temp_store=MEMORY') + + @classmethod + def _pragma_write_ahead_logging(cls, db_handle): + """ + Enable write-ahead logging, and set the autocheckpoint to 50 pages. + + Setting the autocheckpoint to a small value, we make the reads not + suffer too much performance degradation. + + From the sqlite docs: + + "There is a tradeoff between average read performance and average write + performance. To maximize the read performance, one wants to keep the + WAL as small as possible and hence run checkpoints frequently, perhaps + as often as every COMMIT. To maximize write performance, one wants to + amortize the cost of each checkpoint over as many writes as possible, + meaning that one wants to run checkpoints infrequently and let the WAL + grow as large as possible before each checkpoint. The decision of how + often to run checkpoints may therefore vary from one application to + another depending on the relative read and write performance + requirements of the application. The default strategy is to run a + checkpoint once the WAL reaches 1000 pages" + """ + logger.debug("SQLCIPHER: SETTING WRITE-AHEAD LOGGING") + db_handle.cursor().execute('PRAGMA journal_mode=WAL') + # The optimum value can still use a little bit of tuning, but we favor + # small sizes of the WAL file to get fast reads, since we assume that + # the writes will be quick enough to not block too much. + + # TODO + # As a further improvement, we might want to set autocheckpoint to 0 + # here and do the checkpoints manually in a separate thread, to avoid + # any blocks in the main thread (we should run a loopingcall from here) + db_handle.cursor().execute('PRAGMA wal_autocheckpoint=50') + + # Extra query methods: extensions to the base sqlite implmentation. + + def get_count_from_index(self, index_name, *key_values): + """ + Returns the count for a given combination of index_name + and key values. + + Extension method made from similar methods in u1db version 13.09 + + :param index_name: The index to query + :type index_name: str + :param key_values: values to match. eg, if you have + an index with 3 fields then you would have: + get_from_index(index_name, val1, val2, val3) + :type key_values: tuple + :return: count. + :rtype: int + """ + c = self._db_handle.cursor() + definition = self._get_index_definition(index_name) + + if len(key_values) != len(definition): + raise u1db_errors.InvalidValueForIndex() + tables = ["document_fields d%d" % i for i in range(len(definition))] + novalue_where = ["d.doc_id = d%d.doc_id" + " AND d%d.field_name = ?" + % (i, i) for i in range(len(definition))] + exact_where = [novalue_where[i] + + (" AND d%d.value = ?" % (i,)) + for i in range(len(definition))] + args = [] + where = [] + for idx, (field, value) in enumerate(zip(definition, key_values)): + args.append(field) + where.append(exact_where[idx]) + args.append(value) + + tables = ["document_fields d%d" % i for i in range(len(definition))] + statement = ( + "SELECT COUNT(*) FROM document d, %s WHERE %s " % ( + ', '.join(tables), + ' AND '.join(where), + )) + try: + c.execute(statement, tuple(args)) + except dbapi2.OperationalError, e: + raise dbapi2.OperationalError( + str(e) + '\nstatement: %s\nargs: %s\n' % (statement, args)) + res = c.fetchall() + return res[0][0] + def __del__(self): """ Closes db_handle upon object destruction. |