[refactor] creates a common.blobs with preamble

Refactor suggested from !105 review.

1 files changed, 0 insertions, 88 deletions

diff --git a/src/leap/soledad/common/preamble.py b/src/leap/soledad/common/preamble.py
deleted file mode 100644
index d4065c38..00000000
--- a/src/leap/soledad/common/preamble.py
+++ /dev/null
@@ -1,88 +0,0 @@
-# -*- coding: utf-8 -*-
-# preamble.py
-# Copyright (C) 2017 LEAP Encryption Access Project
-#
-# 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/>.
-"""
-Preamble is a binary packed metadata payload present on encrypted documents. It
-holds data about encryption scheme, iv, document id and sync related data.
-   MAGIC, -> used to differentiate from other data formats
-   ENC_SCHEME, -> cryptographic scheme (symmetric or asymmetric)
-   ENC_METHOD, -> cipher used, such as AES-GCM or AES-CTR or GPG
-   current_time, -> time.time()
-   self.iv, -> initialization vector if any, or 0 when not applicable
-   str(self.doc_id), -> document id
-   str(self.rev), -> current revision
-   self._content_size) -> size, rounded to ceiling
-"""
-import warnings
-import struct
-import time
-from collections import namedtuple
-PACMAN = struct.Struct('2sbbQ16s255p255pQ')
-LEGACY_PACMAN = struct.Struct('2sbbQ16s255p255p')  # DEPRECATED
-MAGIC = '\x13\x37'
-ENC_SCHEME = namedtuple('SCHEME', 'symkey external')(1, 2)
-ENC_METHOD = namedtuple('METHOD', 'aes_256_ctr aes_256_gcm pgp')(1, 2, 3)
-
-
-class InvalidPreambleException(Exception):
-    pass
-
-
-class Preamble(object):
-
-    def __init__(self, doc_id, rev, scheme, method,
-                 timestamp=0, iv='', magic=None, content_size=0):
-        self.doc_id = doc_id
-        self.rev = rev
-        self.scheme = scheme
-        self.method = method
-        self.iv = iv
-        self.timestamp = int(timestamp) or int(time.time())
-        self.magic = magic or MAGIC
-        self.content_size = int(content_size)
-
-    def encode(self):
-        preamble = PACMAN.pack(
-            self.magic,
-            self.scheme,
-            self.method,
-            self.timestamp,
-            self.iv,
-            str(self.doc_id),
-            str(self.rev),
-            self.content_size)
-        return preamble
-
-
-def decode_preamble(encoded_preamble):
-    preamble_size = len(encoded_preamble)
-    try:
-        if preamble_size == LEGACY_PACMAN.size:
-            unpacked_data = LEGACY_PACMAN.unpack(encoded_preamble)
-            magic, sch, meth, ts, iv, doc_id, rev = unpacked_data
-            warnings.warn("Decoding a legacy preamble without size. " +
-                          "This will be deprecated in 0.12. Doc was: " +
-                          "doc_id: %s rev: %s" % (doc_id, rev), Warning)
-            return Preamble(doc_id, rev, sch, meth, ts, iv, magic)
-        elif preamble_size == PACMAN.size:
-            unpacked_data = PACMAN.unpack(encoded_preamble)
-            magic, sch, meth, ts, iv, doc_id, rev, size = unpacked_data
-            return Preamble(doc_id, rev, sch, meth, ts, iv, magic, int(size))
-        else:
-            raise InvalidPreambleException("Unexpected preamble size %d",
-                                           preamble_size)
-    except struct.error as e:
-        raise InvalidPreambleException(e)