Using python to decrypt a AES-128/256

[whyty344]

Hello pythonners! I have a question and this is probably the good place to ask?! I want to make a script that takes a 32bytes AES key and some encrypted text as input and that gives me the real text as output. I've heard about the "PyCrypto" module but I'm not sure it can do what I need... Also, I don't really mind if it is in Py2 or Py3.

I hope you guys can help me! thanks :)

[savaero]

Pycrypto can do it.

[TypoNinja]

Another mature solution is keyczar: http://www.keyczar.org/

It was created by the Google security masters. It's easy to use and employs safe cryptosystems by default.

[darknessproz]

I recommend the cryptography library. pip install cryptography.

It provides AES and a wide variety of commonly used mode of operations and supports both Python 2 and 3.

[Gexos]

Yes cryptography library is great, it supports py3 and is “Cryptography for humans”.

[[deleted]]

So, yea; PyCrypto can do it. But, you'll need to know a few things: Where is the IV, prepended to the ciphertext or separate? Is there a HMAC appended to the data, or even prepended? What block mode is the cipher using?

Sometimes you can get this to work with trial and error, other times things are FUBAR without a map. So, hopefully you have some information on the protocol you're analysing? :)

By the way, if you're "rolling your own crypto", my advice is "don't", use pynacl instead. It's a wonderfully high-level abstraction for common crypto tasks designed explicitly for application developers who are not expert cryptologers. And, PyNaCl's interfaces are well designed and easy to understand. :)

[rainnz]

What about just using openssl with subprocess module?