varbin / xtea Goto Github PK

A python version of XTEA

Python 88.12% C 8.41% Batchfile 3.46%

xtea's Introduction

Python XTEA

This is an XTEA-Cipher implementation in Python (eXtended Tiny Encryption Algorithm).

XTEA is a blockcipher with 8 bytes blocksize and 16 bytes Keysize (128-Bit). The algorithm is secure at 2014 with the recommend 64 rounds (32 cycles). This implementation supports following modes of operation: ECB, CBC, CFB, OFB, CTR

Example:

>>> from xtea import * >>> key = b" "16 # Never use this key >>> text = b"This is a text. "8 >>> x = new(key, mode=MODE_OFB, IV=b"12345678") # IV's must be unpredictable >>> c = x.encrypt(text) >>> text == new(key, mode=MODE_OFB, IV=b"12345678").decrypt(c) True

Resources

PyPi: https://pypi.org/project/xtea
Docs: http://xtea.readthedocs.io/
Source code: https://github.com/varbin/xtea
Issue tracker: https://github.com/varbin/xtea/issues

xtea's People

Contributors

Stargazers

Watchers

Forkers

schelv tgates42 wiemerjan areyal

xtea's Issues

Counter module is not correctly installed.

Getting 'False' after running example in init_.py code

Bug in the decrypt() of version 0.7.1 but not in 0.4.1

Hi,

The follow is my test code when using Xtea 0.7.1 with python3:

import xtea, struct

from binascii import hexlify


msg = b"This is a text. "
key = b' '*16
ivv = b"12345678"
tea = xtea.new(key, mode=xtea.MODE_OFB, IV=ivv)


enc = tea.encrypt(msg)
clr = tea.decrypt(enc)

print (msg == clr)
print (f' IV: {hexlify(ivv).decode()} LEN:{len(ivv)}')
print (f' KEY: {hexlify(key).decode()} LEN:{len(key)}')
print (f' MSG: {hexlify(msg).decode()} LEN:{len(msg)}')
print (f' ENC: {hexlify(enc).decode()} LEN:{len(enc)}')
print (f' CLR: {hexlify(clr).decode()} LEN:{len(clr)}')

Output when I ran it against version 0.7.1

 IV: 3132333435363738 LEN:8
 KEY: 20202020202020202020202020202020 LEN:16
 MSG: 54686973206973206120746578742e20 LEN:16
 ENC: fa66ec11b82e38bc77c14be093bb8aa0 LEN:16
 CLR: 79f08adb7eab4acbb4cc1aca058c0a29 LEN:16

Test code when ran with 0.4.1 and Python2.7

import xtea, struct

from binascii import hexlify


msg = b"This is a text. "
key = b' '*16
ivv = b"12345678"
tea = xtea.new(key, mode=xtea.MODE_OFB, IV=ivv)


enc = tea.encrypt(msg)
clr = tea.decrypt(enc)


print msg == clr
print "IV: {} LEN:{}".format(hexlify(ivv).decode(),len(ivv))
print "KEY: {} LEN:{}".format(hexlify(key).decode(),len(key))
print "MSG: {} LEN:{}".format(hexlify(msg).decode(),len(msg))
print "ENC: {} LEN:{}".format(hexlify(enc).decode(),len(enc))
print "CLR: {} LEN:{}".format(hexlify(clr).decode(),len(clr))

Output:

IV: 3132333435363738 LEN:8
KEY: 20202020202020202020202020202020 LEN:16
MSG: 54686973206973206120746578742e20 LEN:16
ENC: fa66ec11b82e38bc77c14be093bb8aa0 LEN:16
CLR: 54686973206973206120746578742e20 LEN:16

Why is rounds divided by 2?

All other implementations that I've seen define the default # of rounds to be 64, and they do 64 iterations in the encrypt. This implementation defines a round as 2 cycles, so 64 rounds = 32 iterations. This makes it not act the same as most of the other implementations of XTEA unless you set rounds=128.

Python 3 support with xtea3

CCM-Mode

Add CCM-Mode to the modes, beeing compitable for PyCrypto

XTea on PyPi seems to have not been updated

Is this the right PyPi package location - https://pypi.org/project/xtea/ the version on it seems much older than the version in use on GitHub and it lacks some of the recent fixes. Is it possible to publish an update?

CBCMAC implementation

CBCMAC implementation is insecure because of following, fix will come soon. Try to not use it before next patch.

MAC(Message1)+MAC(Message2) = MAC(Message1+Message2)