{{tag>csp webbrowser security python reporting}}

====== Content security policy report uri endpoint in python ======
The content policy can also be enforced in app code. The below is for using the web server to send appropriate headers.

This assumes that the python app will run on the same server where the web server is.

The content policy is set up only to send warnings it will not block anything. Use the directive
''Content-Security-Policy'' to actually enforce it. But TEST FIRST!

===== Setup =====
  apt install python3-venv
  pip install Flask
  source venv/bin/activate

==== Add the webserver configuration ====
**apache**:

<code apache>
<VirtualHost *:443>
  ...
  ProxyPass /csp http://localhost:5000/
  ...
  Header set Content-Security-Policy-Report-Only "default-src 'self';script-src 'unsafe-inline' 'unsafe-eval';report-uri csp;"
  ...
</code>

**nginx**:
<code nginx>
  ...
  location / {
  ...
  add_header Content-Security-Policy-Report-Only "default-src 'self';script-src 'unsafe-inline' 'unsafe-eval';report-uri csp;";
  ...
</code>
===== Create json consumer that the CSP will send to =====
<file python csp.py>
from flask import Flask, request

app = Flask(__name__)

@app.route("/", methods=['GET', 'POST'])
def hello_world():
    # we need to force the detection of csp payload as json
    content = request.get_json(force=True)
    print(f"Got json {content}")
    if content:
        return content
    else:
        return "Nothing received"


</file>

Export name:
  export FLASK_APP=csp

and run:
  flask run

You should now get the printed json from CSP when you refresh your website page.

====== Tested on ======
  * Debian 10.11
  * Ubuntu 20.04.3

====== See also ======

====== References ======
  * https://stackoverflow.com/questions/20001229/how-to-get-posted-json-in-flask
  * https://flask.palletsprojects.com/en/2.0.x/quickstart/
  * https://content-security-policy.com/
  * https://dropbox.tech/security/on-csp-reporting-and-filtering
  * https://blog.rapidsec.com/10-tips-to-build-a-content-security-policy-csp-without-breaking-your-site/