AaronFiore/electrum
1
0
Fork 0
Code Activity

crypto: fix pkcs7 padding check

Browse Source 
related: ricmoo/pyaes#22

in practice, the only strings we would incorrectly accept are
(certain length of) all zero bytes
This commit is contained in:
SomberNight
2018-11-22 18:21:19 +01:00
parent a8e6eaa247
commit f04e5fbed6
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
electrum/crypto.py
View File

@@ -55,8 +55,8 @@ def strip_PKCS7_padding(data: bytes) -> bytes:
if len(data) % 16 != 0 or len(data) == 0:
raise InvalidPadding("invalid length")
padlen = data[-1]
if padlen > 16:
raise InvalidPadding("invalid padding byte (large)")
if not (0 < padlen <= 16):
raise InvalidPadding("invalid padding byte (out of range)")
for i in data[-padlen:]:
if i != padlen:
raise InvalidPadding("invalid padding byte (inconsistent)")