DeDRM_tools/DeDRM_plugin/alfcrypto.py
Apprentice Harper afa4ac5716 Starting on Version 7.0 using the work done by others. Completely untested. I will be testing things, but I thought I'd get this base version up for others to give pull requests.
THIS IS ON THE MASTER BRANCH. The Master branch will be Python 3.0 from now on. While Python 2.7 support will not be deliberately broken, all efforts should now focus on Python 3.0 compatibility.

I can see a lot of work has been done. There's more to do. I've bumped the version number of everything I came across to the next major number for Python 3.0 compatibility indication.

Thanks everyone. I hope to update here at least once a week until we have a stable 7.0 release for calibre 5.0
2020-09-26 21:22:47 +01:00

303 lines
9.8 KiB
Python

#!/usr/bin/env python
# -*- 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.
from __future__ import print_function
import sys, os
import hmac
from struct import pack
import hashlib
# interface to needed routines libalfcrypto
def _load_libalfcrypto():
import ctypes
from ctypes import CDLL, byref, POINTER, c_void_p, c_char_p, c_int, c_long, \
Structure, c_ulong, create_string_buffer, addressof, string_at, cast, sizeof
pointer_size = ctypes.sizeof(ctypes.c_voidp)
name_of_lib = None
if sys.platform.startswith('darwin'):
name_of_lib = 'libalfcrypto.dylib'
elif sys.platform.startswith('win'):
if pointer_size == 4:
name_of_lib = 'alfcrypto.dll'
else:
name_of_lib = 'alfcrypto64.dll'
else:
if pointer_size == 4:
name_of_lib = 'libalfcrypto32.so'
else:
name_of_lib = 'libalfcrypto64.so'
# hard code to local location for libalfcrypto
libalfcrypto = os.path.join(sys.path[0],name_of_lib)
if not os.path.isfile(libalfcrypto):
libalfcrypto = os.path.join(sys.path[0], 'lib', name_of_lib)
if not os.path.isfile(libalfcrypto):
libalfcrypto = os.path.join('.',name_of_lib)
if not os.path.isfile(libalfcrypto):
raise Exception('libalfcrypto not found at %s' % libalfcrypto)
libalfcrypto = CDLL(libalfcrypto)
c_char_pp = POINTER(c_char_p)
c_int_p = POINTER(c_int)
def F(restype, name, argtypes):
func = getattr(libalfcrypto, name)
func.restype = restype
func.argtypes = argtypes
return func
# aes cbc decryption
#
# struct aes_key_st {
# unsigned long rd_key[4 *(AES_MAXNR + 1)];
# int rounds;
# };
#
# typedef struct aes_key_st AES_KEY;
#
# int AES_set_decrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key);
#
#
# void AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
# const unsigned long length, const AES_KEY *key,
# unsigned char *ivec, const int enc);
AES_MAXNR = 14
class AES_KEY(Structure):
_fields_ = [('rd_key', c_long * (4 * (AES_MAXNR + 1))), ('rounds', c_int)]
AES_KEY_p = POINTER(AES_KEY)
AES_cbc_encrypt = F(None, 'AES_cbc_encrypt',[c_char_p, c_char_p, c_ulong, AES_KEY_p, c_char_p, c_int])
AES_set_decrypt_key = F(c_int, 'AES_set_decrypt_key',[c_char_p, c_int, AES_KEY_p])
# Pukall 1 Cipher
# unsigned char *PC1(const unsigned char *key, unsigned int klen, const unsigned char *src,
# unsigned char *dest, unsigned int len, int decryption);
PC1 = F(c_char_p, 'PC1', [c_char_p, c_ulong, c_char_p, c_char_p, c_ulong, c_ulong])
# Topaz Encryption
# typedef struct _TpzCtx {
# unsigned int v[2];
# } TpzCtx;
#
# void topazCryptoInit(TpzCtx *ctx, const unsigned char *key, int klen);
# void topazCryptoDecrypt(const TpzCtx *ctx, const unsigned char *in, unsigned char *out, int len);
class TPZ_CTX(Structure):
_fields_ = [('v', c_long * 2)]
TPZ_CTX_p = POINTER(TPZ_CTX)
topazCryptoInit = F(None, 'topazCryptoInit', [TPZ_CTX_p, c_char_p, c_ulong])
topazCryptoDecrypt = F(None, 'topazCryptoDecrypt', [TPZ_CTX_p, c_char_p, c_char_p, c_ulong])
class AES_CBC(object):
def __init__(self):
self._blocksize = 0
self._keyctx = None
self._iv = 0
def set_decrypt_key(self, userkey, iv):
self._blocksize = len(userkey)
if (self._blocksize != 16) and (self._blocksize != 24) and (self._blocksize != 32) :
raise Exception('AES CBC improper key used')
return
keyctx = self._keyctx = AES_KEY()
self._iv = iv
rv = AES_set_decrypt_key(userkey, len(userkey) * 8, keyctx)
if rv < 0:
raise Exception('Failed to initialize AES CBC key')
def decrypt(self, data):
out = create_string_buffer(len(data))
mutable_iv = create_string_buffer(self._iv, len(self._iv))
rv = AES_cbc_encrypt(data, out, len(data), self._keyctx, mutable_iv, 0)
if rv == 0:
raise Exception('AES CBC decryption failed')
return out.raw
class Pukall_Cipher(object):
def __init__(self):
self.key = None
def PC1(self, key, src, decryption=True):
self.key = key
out = create_string_buffer(len(src))
de = 0
if decryption:
de = 1
rv = PC1(key, len(key), src, out, len(src), de)
return out.raw
class Topaz_Cipher(object):
def __init__(self):
self._ctx = None
def ctx_init(self, key):
tpz_ctx = self._ctx = TPZ_CTX()
topazCryptoInit(tpz_ctx, key, len(key))
return tpz_ctx
def decrypt(self, data, ctx=None):
if ctx == None:
ctx = self._ctx
out = create_string_buffer(len(data))
topazCryptoDecrypt(ctx, data, out, len(data))
return out.raw
print(u"Using Library AlfCrypto DLL/DYLIB/SO")
return (AES_CBC, Pukall_Cipher, Topaz_Cipher)
def _load_python_alfcrypto():
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('Pukall_Cipher: Bad key length.')
wkey = []
for i in range(8):
wkey.append(ord(key[i*2])<<8 | ord(key[i*2+1]))
dst = ""
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 = ord(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+=chr(curByte)
return dst
class Topaz_Cipher(object):
def __init__(self):
self._ctx = None
def ctx_init(self, key):
ctx1 = 0x0CAFFE19E
for keyChar in key:
keyByte = ord(keyChar)
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 = ""
for dataChar in data:
dataByte = ord(dataChar)
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
print(u"Using Library AlfCrypto Python")
return (AES_CBC, Pukall_Cipher, Topaz_Cipher)
def _load_crypto():
AES_CBC = Pukall_Cipher = Topaz_Cipher = None
cryptolist = (_load_libalfcrypto, _load_python_alfcrypto)
for loader in cryptolist:
try:
AES_CBC, Pukall_Cipher, Topaz_Cipher = loader()
break
except (ImportError, Exception):
pass
return AES_CBC, Pukall_Cipher, Topaz_Cipher
AES_CBC, Pukall_Cipher, Topaz_Cipher = _load_crypto()
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 xorstr( a, b ):
if len(a) != len(b):
raise Exception("xorstr(): lengths differ")
return ''.join((chr(ord(x)^ord(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 = xorstr( 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 = ""
for i in range(1, l+1):
T += pbkdf2_F( h, salt, iter, i )
return T[0: keylen]