44 lines
1.1 KiB
Python
44 lines
1.1 KiB
Python
import sys
|
|
|
|
# python2/3 compatibility
|
|
if sys.version > '3':
|
|
byte2int = lambda x: x
|
|
else:
|
|
byte2int = ord
|
|
|
|
|
|
def remove_pkcs5_padding(data):
|
|
padding_length = byte2int(data[-1])
|
|
return data[:-padding_length]
|
|
|
|
|
|
def add_pkcs5_padding(data, blocksize):
|
|
last_block_len = len(data) % blocksize
|
|
padding_length = blocksize - last_block_len
|
|
if padding_length == 0:
|
|
padding_length = blocksize
|
|
return data + bytes(bytearray([padding_length] * padding_length))
|
|
|
|
|
|
# algorithm taken from msdn documentation for CryptDeriveKey
|
|
def derive_key_3des_aes(hash_alg):
|
|
from wincrypto.api import CryptCreateHash
|
|
|
|
buf1 = bytearray(b'\x36' * 64)
|
|
hash_val = bytearray(hash_alg.get_hash_val())
|
|
for x in range(len(hash_val)):
|
|
buf1[x] ^= hash_val[x]
|
|
buf2 = bytearray(b'\x5c' * 64)
|
|
for x in range(len(hash_val)):
|
|
buf2[x] ^= hash_val[x]
|
|
hash1 = CryptCreateHash(hash_alg.alg_id)
|
|
hash1.hash_data(bytes(buf1))
|
|
hash2 = CryptCreateHash(hash_alg.alg_id)
|
|
hash2.hash_data(bytes(buf2))
|
|
derived_key = hash1.get_hash_val() + hash2.get_hash_val()
|
|
return derived_key
|
|
|
|
|
|
def GET_ALG_CLASS(x):
|
|
return x & (7 << 13)
|