Flask login using Linux System Credentials

Question

I am creating a simple web app using flask. I will be hosting it on my linux server.

The web-app does multiple user specific things. Like list directories in Users home, add ssh-keys for user and stuff like that.

I would like to know if there is a way for flask to open a login page, and the user-name and password be validated based on system user-name and password. (i.e that users system credentials). If yes, then how. If no then what else can I do?

Answer 1

Using ’simplepam’ python package you can authenticate against PAM system on linux. Here is flask basic example which I have modifed to use simplepam:

from flask import Flask, session, redirect, url_for, escape, request
from simplepam import authenticate


app = Flask(__name__)

@app.route('/')
def index():
    if 'username' in session:
        return 'Logged in as %s' % escape(session['username'])
    return 'You are not logged in'

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        if authenticate(str(username), str(password)):
            session['username'] = request.form['username']
            return redirect(url_for('index'))
        else:
            return 'Invalid username/password'
    return '''
        <form action="" method="post">
            <p><input type=text name=username>
            <p><input type=password name=password>
            <p><input type=submit value=Login>
        </form>
    '''

@app.route('/logout')
def logout():
    # remove the username from the session if it's there
    session.pop('username', None)
    return redirect(url_for('index'))

# set the secret key.  keep this really secret:
app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'

if __name__ == '__main__':
    app.run(debug='True')