I'm writing this question + answer because I struggled a lot (maybe because of a lack of experience), got lost in many different ways of encrypting/decrypting things with node or python.
I thought maybe my case could help people in the future.
What I needed to do:
- Get data from a form, encrypt them using Crypto (node-js)
- Pass the encrypted data in Python and decrypt it using PyCrypto.
I chose to use the AES encryption.
Here is how I started (I'm not gonna go through everything I tried):
I followed the example at the end of this page
Which gave in my case:
(this might be a very bad mix between javascript and coffeescript)
crypto = require "crypto" [...] key = "mykeywhatever" cipher = crypto.createCipher('aes192', key) cipher.update('string i want to encode', 'binary', 'hex') encoded_string = cipher.final('hex') [...]
This worked pretty fine to encode my string.
Then I wrote my python script to decrypt this string, using the readme on PyCrypto's github's page:
from Crypto.Cipher import AES [...] my_string = data_coming_from_rabbitmq obj = AES.new('mykeywhatever', AES.MODE_CBC) obj.decrypt(ciphertext) [...]
This obviously didn't work: in the readme there is an IV but since I didn't gave one in the node script, why would I give one in the python one?
After more googling, I learnt that node's Crypto uses OpenSSL, while PyCrypto apparently doesn't. So I looked into that and found those pages:
- How can I decrypt something with PyCrypto that was encrypted using OpenSSL?
- Is AES the same in libraries PyCrypto & Node.JS Crypto
- and a lot more...
So things got complicated, no one is doing the same thing to decrypt data, I got lost, and asked for help.
The answer is what my coworker and I came up with (well, mostly my corworker).
See Question&Answers more detail:os