Faster crypto by using libssl (closes #199)

This commit is contained in:
Christian Stemmle 2017-08-20 01:21:11 +02:00 committed by Lonami
parent afcddfd7c1
commit ffb1cf483d
2 changed files with 90 additions and 1 deletions

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@ -1,6 +1,6 @@
import os
import pyaes
from . import libssl
class AES:
@staticmethod
@ -71,3 +71,7 @@ class AES:
cipher_text.extend(cipher_text_block)
return bytes(cipher_text)
# use libssl if available
if libssl.libssl:
AES = libssl.AES

85
telethon/crypto/libssl.py Normal file
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@ -0,0 +1,85 @@
import os
import ctypes
from ctypes.util import find_library
# search and load libssl.so
lib = find_library('ssl')
if not lib:
libssl = None
else:
libssl = ctypes.cdll.LoadLibrary(lib)
""" <aes.h>
# define AES_ENCRYPT 1
# define AES_DECRYPT 0
# define AES_MAXNR 14
struct aes_key_st {
# ifdef AES_LONG
unsigned long rd_key[4 * (AES_MAXNR + 1)];
# else
unsigned int rd_key[4 * (AES_MAXNR + 1)];
# endif
int rounds;
};
typedef struct aes_key_st AES_KEY;
int AES_set_encrypt_key(const unsigned char *userKey, const int bits,
AES_KEY *key);
int AES_set_decrypt_key(const unsigned char *userKey, const int bits,
AES_KEY *key);
void AES_ige_encrypt(const unsigned char *in, unsigned char *out,
size_t length, const AES_KEY *key,
unsigned char *ivec, const int enc);
"""
AES_MAXNR = 14
AES_ENCRYPT = ctypes.c_int(1)
AES_DECRYPT = ctypes.c_int(0)
class AES_KEY(ctypes.Structure):
_fields_ = [
('rd_key', ctypes.c_uint32 * (4*(AES_MAXNR + 1))),
('rounds', ctypes.c_uint),
]
class AES:
@staticmethod
def decrypt_ige(cipher_text, key, iv):
# declare types
aeskey = AES_KEY()
ckey = (ctypes.c_ubyte * len(key))(*key)
cklen = ctypes.c_int(len(key)*8)
cin = (ctypes.c_ubyte * len(cipher_text))(*cipher_text)
ctlen = ctypes.c_size_t(len(cipher_text))
cout = (ctypes.c_ubyte * len(cipher_text))()
civ = (ctypes.c_ubyte * len(iv))(*iv)
# decrypt
libssl.AES_set_decrypt_key(ckey, cklen, ctypes.byref(aeskey))
libssl.AES_ige_encrypt(ctypes.byref(cin), ctypes.byref(cout), ctlen, ctypes.byref(aeskey), ctypes.byref(civ), AES_DECRYPT)
return bytes(cout)
@staticmethod
def encrypt_ige(plain_text, key, iv):
# Add random padding if and only if it's not evenly divisible by 16 already
if len(plain_text) % 16 != 0:
padding_count = 16 - len(plain_text) % 16
plain_text += os.urandom(padding_count)
# declare types
aeskey = AES_KEY()
ckey = (ctypes.c_ubyte * len(key))(*key)
cklen = ctypes.c_int(len(key)*8)
cin = (ctypes.c_ubyte * len(plain_text))(*plain_text)
ctlen = ctypes.c_size_t(len(plain_text))
cout = (ctypes.c_ubyte * len(plain_text))()
civ = (ctypes.c_ubyte * len(iv))(*iv)
# encrypt
libssl.AES_set_encrypt_key(ckey, cklen, ctypes.byref(aeskey))
libssl.AES_ige_encrypt(ctypes.byref(cin), ctypes.byref(cout), ctlen, ctypes.byref(aeskey), ctypes.byref(civ), AES_ENCRYPT)
return bytes(cout)