Is there a way to decrypt AES this with Python?

Question

So i am able to get this to work in javascript with CryptoJS

var key = CryptoJS.enc.Latin1.parse("m6h6dTeZavubd74U");
var oldData = CryptoJS.enc.Hex.parse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
var nextData = CryptoJS.AES.decrypt( { ciphertext: oldData}, key, { iv: key })
var plaintext = nextData.toString(CryptoJS.enc.Utf8);

Which gives me a JSON output of

{"widget": {    "debug": "on",    "window": {        "title": "Sample Konfabulator Widget",        "name": "main_window",        "width": 500,        "height": 500    },    "image": {         "src": "Images/Sun.png",        "name": "sun1",        "hOffset": 250,        "vOffset": 250,        "alignment": "center"    },    "text": {        "data": "Click Here",        "size": 36,        "style": "bold",        "name": "text1",        "hOffset": 250,        "vOffset": 100,        "alignment": "center",        "onMouseUp": "sun1.opacity = (sun1.opacity / 100) * 90;"    }}}

Howevery I am not too familiar with Python but I am wondering if it is possible to do the same type of AES decrypting in python. Thanks

gelonida · Answer 1 · 2019-09-15T07:36:40.007

This is an almost answer and might be the starting point for your solution.

You have to install the cryptography module with:

pip install cryptography

The message decrypts almost correctly.

I have a decryption error with the first few bytes though. Perhaps somebody else can pinpoint a crypto setting, that will fix this issue. Perhaps somebody else has an idea what is wrong.

import codecs

from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend

backend = default_backend()

key = "m6h6dTeZavubd74U"

msg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


def decrypt(key_aslatin1, msg_as_ascii_hex):
    msg = codecs.decode(msg_as_ascii_hex, "hex")
    key = key_aslatin1.encode("latin1")

    iv = key

    cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
    decryptor = cipher.decryptor()
    rslt_bytes = decryptor.update(msg) + decryptor.finalize()
    rslt = rslt_bytes.decode("utf8")
    return rslt


print(decrypt(key, msg))

The shown output is:

_3.CLUnu "debug": "on",
    "window": {
        "title": "Sample Konfabulator Widget",
        "name": "main_window",
        "width": 500,
        "height": 500
    },
    "image": { 
        "src": "Images/Sun.png",
        "name": "sun1",
        "hOffset": 250,
        "vOffset": 250,
        "alignment": "center"
    },
    "text": {
        "data": "Click Here",
        "size": 36,
        "style": "bold",
        "name": "text1",
        "hOffset": 250,
        "vOffset": 100,
        "alignment": "center",
        "onMouseUp": "sun1.opacity = (sun1.opacity / 100) * 90;"
    }
}}

great that the answer is working. As others pointed out. This question has already been answered. However they do not use the module cryptography. So my answer might still be interesting for cryptography adepts. @Zeebon44 Can you decode the message completely or do you also have a few erroneous bytes. — gelonida, Sep 15 '19 at 19:58

Is there a way to decrypt AES this with Python?

1 Answers1