Django AES Encryption : how encrypt user-uploaded files before they are saved?

Question

I want to encrypt user uploaded files in django before saving them.

When user send files through POST requests, I get a "InMemoryUploadedFile" type object.

How can I encrypt the files before saving them ? I currently use pyAesCrypt to encrypt files but I can't manage to pass in it the "InMemoryUploadedFile" objects. I manage to only encrypt them after they are saved with :

import pyAesCrypt

with open("*FileName*", "rb") as InputFile:
    with open("*OutputFileName*", "wb+") as OutputFile:
        pyAesCrypt.encryptStream(InputFile, OutputFile, Password, BufferSize)

Answer 1

I recently asked this questions and a user told me to use a package with better community support. It is pyca/cryptography . I was stuck in the same thing and I found a solution. Mind that, I use Django Rest Framework.

from cryptography.fernet import Fernet
# Generate a key and store safely
key = Fernet.generate_key()
f = Fernet(key)

I'll take an excel file for example but you could actually use any file.

import pandas as pd
import io
from django.core.files.uploadedfile import SimpleUploadedFile

# Request file from user and load the file into a dataframe
df = pd.read_excel(request.FILES('file_name'))
# Create BytesIO
output = io.BytesIO()
# Output df to BytesIO
df.to_excel(output, index=False)
# Encrypt data (BytesIO)
encrypted_out = f.encrypt(output.getvalue())
# Export encrypted file
output_file = SimpleUploadedFile('<some_file_name.extension>',encrypted_out)
# Typically you would pass this through a serializer.

To decrypt the file before you can serve the user. Read the file and write it to BytesIO and then you can serve the file to the user.