PyCryptoPlus

Differences with pycrypto

ciphers from pycrypto are being used with the python chaining modes and not the original pycrypto ones
=> plaintext can be supplied in arbitrary sizes instead of multiples of the blocksize like in pycrypto: the new chaining modes keep a cache to encrypt/decrypt data once the cachesize holds at least a blocksize of data
new possibilities:
- Rijndael, Serpent, Twofish
  - Rijndael is limited to blocksizes of 128, 192 and 256 bits
- CMAC, XTS, CTR
  - XTS is usable for ciphers with blocksizes of 16 bytes => XTS-AES, Serpent, Twofish
  - XTS encrypts the given input at once while all other chain modes encrypt only when a block plaintext is available in the cache
  - CMAC is usable for blocksizes of 8 and 16 bytes
- OFB,CFB and CTR can be accessed as a stream cipher (you get the encrypted message immediately, you don't have to wait until a complete block of plaintext has been provided to the cipher)
test functions are available via doctests and extensive tests that loop through dictionary of test vectors
- new pycrypto version will have it's own test bench for ciphers, this is not implemented yet

add chaining modes: ~~CMAC~~, CTR mod?
~~further importing of pycrypto~~
~~make test vectors available as variables~~
add tests:
- CBC for serpent, twofish, blowfish
- XTS ~~is only tested by comparing deciphered ciphertext, not by checking ciphertext~~: XTS-AES doctest done
check other implementation of Blowfish
~~final() method of chains~~
- ~~add a cipher.final() method? pycrypto doesn't have it, but it doesn't really conflict with the pycrypto API. It will just extend it~~
- ~~final() method should use padding. Choose padding function at initialization of the cipher => again: extending the API~~
XTS
- make other blocksizes available besides 16 bytes?
CMAC
- make other blocksizes available besides 8 and 16 bytes?
- ~~supply XTS keys by splitting 1 big key or by supplying two keys?~~
~~add rijndael instead of only AES~~
add docstring to every "new" function of every module, explaining what should be passed as arguments (probably the same for every function)
Move doctests there so they are easily viewable
check GF2 in XTS + can it be replaced by Sage's implementation of GF2 ( -> [1]? ) ?
use unittest for test functions
check development of pycrypto:
- Util.Counter & Util._counter
- SelfTest: usable to perform the test for python algo's in CryptoPlus if testvectors are in right format?

Doctests
- Blowfish: ECB, CBC, CFB, OFB
- all chain modes in AES
Extensive external test (via tester.py)
- DES,TDES2,TDES3: ECB
- Serpent 128/192/256: ECB
- CMAC: AES128/192/256
- XTS: AES128/256 and plaintext multiples and non-multiples of 16 bytes

used from python truecrypt implementation
all original code is under MIT license (much freedom according to [2])
- pyTwofish (untouched)
  python truecrypt author isn't the original author = > extra copyright notice that should be left in place
- pyserpent (untouched)
  python truecrypt author isn't the original author = > extra copyright notice that should be left in place
- XTS (modified)
  python truecrypt author is the original author => only MIT License
- GF2n.py(untouched)
  python truecrypt author is the original author => only MIT License
pyblowfish (untouched)
gpl or artistic license
To not affect the rest of the distribution we've to redistribute it only under Artistic license terms
rijndael.py (untouched)
using tls lite (public domain) implementation which uses code from Bram Cohen (public domain)
pyDes (untouched)
public domain according to its homepage
blockciphers CBC, ECB, CTR from [3] (modified)
keep copyright notice in place?
CMAC: omac.py
GPL but not really used it, just used as a starting point

setup.py
- creating a distribution tar.gz: "python setup.py sdist"
- installing the source distribution (sdist):
  - untar .tar.gz: "cd dist && tar zxfv CryptoPlus-1.0.tar.gz -C ~/"
  - "cd ~/CryptoPlus-1.0 && python setup.py install"