DeDRM_tools/DeDRM_plugin/alfcrypto.py
NoDRM 410e086d08 Remove AlfCrypto libraries and perform everything in Python
The old AlfCrypto DLL, SO and DYLIB files are ancient,
I don't have the systems to recompile them all, they
cause issues on ARM Macs, and I doubt with all the Python
improvements over the last years that they have a significant
performance advantage. And even if that's the case, nobody is
importing hundreds of DRM books at the same time so it shouldn't
hurt if some decryptions might take a bit longer.
2022-08-06 20:13:19 +02:00

134 lines
4.1 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# crypto library mainly by some_updates
# pbkdf2.py pbkdf2 code taken from pbkdf2.py
# pbkdf2.py Copyright © 2004 Matt Johnston <matt @ ucc asn au>
# pbkdf2.py Copyright © 2009 Daniel Holth <dholth@fastmail.fm>
# pbkdf2.py This code may be freely used and modified for any purpose.
import hmac
from struct import pack
import hashlib
import aescbc
class Pukall_Cipher(object):
def __init__(self):
self.key = None
def PC1(self, key, src, decryption=True):
sum1 = 0;
sum2 = 0;
keyXorVal = 0;
if len(key)!=16:
raise Exception("PC1: Bad key length")
wkey = []
for i in range(8):
wkey.append(key[i*2]<<8 | key[i*2+1])
dst = bytearray(len(src))
for i in range(len(src)):
temp1 = 0;
byteXorVal = 0;
for j in range(8):
temp1 ^= wkey[j]
sum2 = (sum2+j)*20021 + sum1
sum1 = (temp1*346)&0xFFFF
sum2 = (sum2+sum1)&0xFFFF
temp1 = (temp1*20021+1)&0xFFFF
byteXorVal ^= temp1 ^ sum2
curByte = src[i]
if not decryption:
keyXorVal = curByte * 257;
curByte = ((curByte ^ (byteXorVal >> 8)) ^ byteXorVal) & 0xFF
if decryption:
keyXorVal = curByte * 257;
for j in range(8):
wkey[j] ^= keyXorVal;
dst[i] = curByte
return bytes(dst)
class Topaz_Cipher(object):
def __init__(self):
self._ctx = None
def ctx_init(self, key):
ctx1 = 0x0CAFFE19E
if isinstance(key, str):
key = key.encode('latin-1')
for keyByte in key:
ctx2 = ctx1
ctx1 = ((((ctx1 >>2) * (ctx1 >>7))&0xFFFFFFFF) ^ (keyByte * keyByte * 0x0F902007)& 0xFFFFFFFF )
self._ctx = [ctx1, ctx2]
return [ctx1,ctx2]
def decrypt(self, data, ctx=None):
if ctx == None:
ctx = self._ctx
ctx1 = ctx[0]
ctx2 = ctx[1]
plainText = ""
if isinstance(data, str):
data = data.encode('latin-1')
for dataByte in data:
m = (dataByte ^ ((ctx1 >> 3) &0xFF) ^ ((ctx2<<3) & 0xFF)) &0xFF
ctx2 = ctx1
ctx1 = (((ctx1 >> 2) * (ctx1 >> 7)) &0xFFFFFFFF) ^((m * m * 0x0F902007) &0xFFFFFFFF)
plainText += chr(m)
return plainText
class AES_CBC(object):
def __init__(self):
self._key = None
self._iv = None
self.aes = None
def set_decrypt_key(self, userkey, iv):
self._key = userkey
self._iv = iv
self.aes = aescbc.AES_CBC(userkey, aescbc.noPadding(), len(userkey))
def decrypt(self, data):
iv = self._iv
cleartext = self.aes.decrypt(iv + data)
return cleartext
class KeyIVGen(object):
# this only exists in openssl so we will use pure python implementation instead
# PKCS5_PBKDF2_HMAC_SHA1 = F(c_int, 'PKCS5_PBKDF2_HMAC_SHA1',
# [c_char_p, c_ulong, c_char_p, c_ulong, c_ulong, c_ulong, c_char_p])
def pbkdf2(self, passwd, salt, iter, keylen):
def xorbytes( a, b ):
if len(a) != len(b):
raise Exception("xorbytes(): lengths differ")
return bytes([x ^ y for x, y in zip(a, b)])
def prf( h, data ):
hm = h.copy()
hm.update( data )
return hm.digest()
def pbkdf2_F( h, salt, itercount, blocknum ):
U = prf( h, salt + pack('>i',blocknum ) )
T = U
for i in range(2, itercount+1):
U = prf( h, U )
T = xorbytes( T, U )
return T
sha = hashlib.sha1
digest_size = sha().digest_size
# l - number of output blocks to produce
l = keylen // digest_size
if keylen % digest_size != 0:
l += 1
h = hmac.new( passwd, None, sha )
T = b""
for i in range(1, l+1):
T += pbkdf2_F( h, salt, iter, i )
return T[0: keylen]