From 25cba9eea702336e82f75faf829873987c72dd33 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philipp=20H=C3=B6rist?= <philipp@hoerist.com>
Date: Fri, 14 Feb 2020 17:10:37 +0100
Subject: [PATCH] [omemo] Switch to 12 byte IV
---
omemo/backend/aes.py | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/omemo/backend/aes.py b/omemo/backend/aes.py
index 175eac9a..49d288a5 100644
--- a/omemo/backend/aes.py
+++ b/omemo/backend/aes.py
@@ -28,6 +28,7 @@ log = logging.getLogger('gajim.p.omemo')
EncryptionResult = namedtuple('EncryptionResult', 'payload key iv')
+IV_SIZE = 12
def _decrypt(key, iv, tag, data):
decryptor = Cipher(
@@ -60,7 +61,7 @@ def aes_decrypt_file(key, iv, payload):
return _decrypt(key, iv, tag, data)
-def _encrypt(data, key_size, iv_size):
+def _encrypt(data, key_size, iv_size=IV_SIZE):
if isinstance(data, str):
data = data.encode()
key = os.urandom(key_size)
@@ -75,13 +76,13 @@ def _encrypt(data, key_size, iv_size):
def aes_encrypt(plaintext):
- key, iv, tag, payload = _encrypt(plaintext, 16, 16)
+ key, iv, tag, payload = _encrypt(plaintext, 16)
key += tag
return EncryptionResult(payload=payload, key=key, iv=iv)
def aes_encrypt_file(data):
- key, iv, tag, payload, = _encrypt(data, 32, 16)
+ key, iv, tag, payload, = _encrypt(data, 32)
payload += tag
return EncryptionResult(payload=payload, key=key, iv=iv)
@@ -91,4 +92,4 @@ def get_new_key():
def get_new_iv():
- return os.urandom(16)
+ return os.urandom(IV_SIZE)
--
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