如何在django上传之前加密文件

Question

Im building a project secure file sharing.which encrypts a file before uploading into local computer and decrypts while downloading if the user has the decryption key.I was stuck how to encrypt a file before uploading into my pc

I'm following this approach which is mentioned below.

https://ruddra.com/documentation-of-django-encrypt-file/#basic-usage

but i dont't know how to link with my code. can anyone help me

views.py

def upload(request):
    context={}
    if request.method == 'POST':
        upload_file= request.FILES["document"]
        fs=FileSystemStorage()
        name=fs.save(upload_file.name, upload_file)
        context['url'] = fs.url(name)
    return render(request, 'accounts/upload.html',context)

upload.html

{% include 'accounts/main.html'%}

<pre>
Upload your files for sharing
</pre>


{% block content %}

  <form method="post" enctype="multipart/form-data">
    {% csrf_token %}
    <input type="file" name="document">
    <button type="submit">Upload</button>
  </form>
  {% if url %}

  <p> Uploaded file:<a href="{{ url }}">{{ url }}</a></p>
  {% endif %}

{% endblock %}

settings.py

MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
MEDIA_URL= '/media/'

Answer 1

To encrypt a file BEFORE uploading to the server, it means you need to encrypt it within the browser - eg using JavaScript. Here's a thread that can help you to encrypt stuff in JS: JavaScript AES encryption and decryption (Advanced Encryption Standard)

If you're feeling up to the challenge, look into running AES in WASM to speed up encryption (important for large files).

Note that in Django, all python code is executed ON THE SERVER. The linked example in the question shows how to encrypt files on the server AFTER uploading them: https://ruddra.com/documentation-of-django-encrypt-file/#basic-usage

Note that encrypting the file on the browser before uploading is only a small portion of the whole problem. To have a secure file sharing service, you would probably want to have a way to share the key with the other users who need to decrypt it. For that you'd probably need to use asymmetric encryption, eg, wrap (encrypt) the key using other users' public keys before uploading it.