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-rw-r--r--src/leap/soledad/client/_crypto.py7
-rw-r--r--src/leap/soledad/client/_preamble.py88
2 files changed, 5 insertions, 90 deletions
diff --git a/src/leap/soledad/client/_crypto.py b/src/leap/soledad/client/_crypto.py
index d0fb6e7f..998b70fa 100644
--- a/src/leap/soledad/client/_crypto.py
+++ b/src/leap/soledad/client/_crypto.py
@@ -86,8 +86,11 @@ from cryptography.hazmat.backends import default_backend
from zope.interface import implementer
-from ._preamble import InvalidPreambleException, decode_preamble, Preamble
-from ._preamble import ENC_SCHEME, ENC_METHOD, BLOB_SIGNATURE_MAGIC
+from leap.soledad.common.preamble import InvalidPreambleException
+from leap.soledad.common.preamble import decode_preamble
+from leap.soledad.common.preamble import Preamble
+from leap.soledad.common.preamble import ENC_SCHEME, ENC_METHOD
+from leap.soledad.common.preamble import BLOB_SIGNATURE_MAGIC
SECRET_LENGTH = 64
diff --git a/src/leap/soledad/client/_preamble.py b/src/leap/soledad/client/_preamble.py
deleted file mode 100644
index 262d70ce..00000000
--- a/src/leap/soledad/client/_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 metadata payload present on encrypted documents. It holds data
-about encryption scheme, iv, document id and sync related data.
- BLOB_SIGNATURE_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
-BLOB_SIGNATURE_MAGIC = '\x13\x37'
-ENC_SCHEME = namedtuple('SCHEME', 'symkey')(1)
-ENC_METHOD = namedtuple('METHOD', 'aes_256_ctr aes_256_gcm')(1, 2)
-
-
-class InvalidPreambleException(Exception):
- pass
-
-
-class Preamble:
-
- 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 BLOB_SIGNATURE_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)