matrix-registration/app.py

import logging
import os
import uuid
from logging.config import dictConfig
from urllib.parse import urlparse, urljoin

import flask
from flask import Flask, redirect, render_template, request, g, flash, url_for
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address
from flask_login import (LoginManager,
                         login_required,
                         login_user,
                         logout_user,
                         UserMixin)
from flask_wtf import CSRFProtect
from werkzeug.contrib.fixers import ProxyFix

from db import (
    get_db,
    get_registration_codes,
    add_registration_code,
    expire_registration_code,
    delete_registration_code,
    get_registered_users,
    add_registered_user)
from forms import (RegistrationForm,
                   LoginForm,
                   RegistrationCodeForm,
                   ExpireRegistrationCodeForm)
from register_new_matrix_user import register_new_user

csrf = CSRFProtect()
login_manager = LoginManager()

dictConfig({
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {'default': {
        'format': '[%(asctime)s] %(levelname)s in %(module)s: %(message)s',
    }},
    'handlers': {
        'wsgi': {
            'class': 'logging.StreamHandler',
            'stream': 'ext://flask.logging.wsgi_errors_stream',
            'formatter': 'default'
        }
    },
    'root': {
        'level': 'INFO',
        'handlers': ['wsgi']
    }
})

log = logging.getLogger(__name__)


def init_db(flask_app):
    with flask_app.app_context():
        log.info("Initializing DB")
        db = get_db()
        with flask_app.open_resource('schema.sql', mode='r') as f:
            db.cursor().executescript(f.read())
            log.info("Initialized DB")
        db.commit()


def create_app():
    flask_app = Flask(__name__)

    flask_app.config.update(dict(
        APPLICATION_ROOT=os.getenv("APPLICATION_ROOT", "/"),
        ADMIN_TOKEN=os.getenv("ADMIN_TOKEN", uuid.uuid4().__str__()),
        SECRET_KEY=os.getenv("SECRET_KEY", "changeme"),
        WTF_CSRF_SECRET_KEY=os.getenv("CSRF_SECRET_KEY", "csrf_changeme"),
        MATRIX_HOMESERVER=os.getenv("MATRIX_HOMESERVER"),
        MATRIX_SHARED_SECRET=os.getenv("MATRIX_SHARED_SECRET"),
        REGISTRATION_SUCCESS_REDIRECT=os.getenv("REGISTRATION_SUCCESS_REDIRECT")
    ))

    log.info("Admin Token: %s" % flask_app.config.get("ADMIN_TOKEN"))

    csrf.init_app(flask_app)

    login_manager.init_app(flask_app)
    login_manager.login_view = "admin_login"

    init_db(flask_app)

    log.info("Application ready")

    return flask_app


app = create_app()
app.wsgi_app = ProxyFix(app.wsgi_app, num_proxies=1)
limiter = Limiter(app, key_func=get_remote_address)

log.info("Bound reverse proxy wsgi app")


def flash_form_errors(form):
    if hasattr(form, 'errors') and len(form.errors) > 0:
        for error in form.errors.items():
            flash("%s: %s" % (form[error[0]].label.text, error[1]), 'error')


class User(UserMixin):
    username: str
    token: str
    authenticated: bool = False

    def __init__(self, username: str, token: str):
        self.username = username
        self.token = token

    def is_authenticated(self):
        return self.authenticated

    def get_id(self):
        return self.username


def is_safe_url(target):
    ref_url = urlparse(request.host_url)
    test_url = urlparse(urljoin(request.host_url, target))
    return test_url.scheme in (
        'http', 'https') and ref_url.netloc == test_url.netloc


def get_successful_registration_redirect():
    target = app.config.get('REGISTRATION_SUCCESS_REDIRECT')
    if target is None or not target.startswith('http'):
        return url_for('index', _external=True)
    return target


@login_manager.user_loader
def load_user(user_id):
    if user_id == "admin":
        user = User("admin", app.config.get("ADMIN_TOKEN"))
        g.user = user
        return user
    else:
        return None


@app.route('/')
def index():
    return redirect(url_for('registration'))


@app.route('/register', methods=('GET', 'POST'))
@limiter.limit("2/minute")
def registration():
    form = RegistrationForm()
    if form.validate_on_submit():
        if app.config.get("MATRIX_HOMESERVER") is None:
            flash(
                "Matrix Homeserver Currently Unavailable. Please Try Again Later!")
            return render_template('register.html', form=form)
        else:
            if app.config.get("MATRIX_SHARED_SECRET") is None:
                flash(
                    "Registration Configuration Is Invalid. Contact Administrator!")
                return render_template('register.html', form=form)
            else:
                response = register_new_user(
                    form.username.data,
                    form.password.data,
                    app.config.get("MATRIX_HOMESERVER"),
                    app.config.get("MATRIX_SHARED_SECRET")
                )
                if response is not None:
                    registered_user_id = response['user_id']
                    add_registered_user(
                        form.registration_code.data,
                        form.username.data,
                        registered_user_id)
                    return redirect(get_successful_registration_redirect())
                else:
                    flash("Registration Failure. Contact Administrator!")
                    return render_template('register.html', form=form)

    flash_form_errors(form)

    if 'registrationCode' in request.values:
        form.registration_code.data = request.values['registrationCode']

    return render_template('register.html', form=form)


@app.route('/admin')
@login_required
def admin_index():
    context = {
        'add_registration_code_form': RegistrationCodeForm(),
        'registration_codes': get_registration_codes(),
        'registered_users': get_registered_users()
    }
    return render_template('admin.html', **context)


@app.route('/admin/add_registration_code', methods=['POST'])
@login_required
def admin_add_registration_code():
    form = RegistrationCodeForm()
    if form.validate_on_submit():
        expiration_time = form.expiration_time.data
        max_usages = form.max_usages.data
        add_registration_code(expiration_time, max_usages)
        redirect(url_for('admin_index', _external=True))

    flash_form_errors(form)

    return redirect(url_for('admin_index', _external=True))


@app.route('/admin/expire_registration_code', methods=['POST'])
@login_required
def admin_expire_registration_code():
    form = ExpireRegistrationCodeForm()
    if form.validate_on_submit():
        if form.expire.data:
            expire_registration_code(form.registration_code.data)
        elif form.delete.data:
            delete_registration_code(form.registration_code.data)
        redirect(url_for('admin_index', _external=True))

    flash_form_errors(form)

    return redirect(url_for('admin_index', _external=True))


@app.route('/admin/login', methods=('GET', 'POST'))
@limiter.limit("2/minute")
def admin_login():
    form = LoginForm()
    if form.validate_on_submit():
        user = load_user(form.username.data)
        if user is not None:
            if form.token.data == user.token:
                user.authenticated = True
                login_user(user)
                flask.flash('Logged in successfully.')
                next_loc = flask.request.args.get('next')
                if not is_safe_url(next_loc):
                    return flask.abort(400)
                else:
                    if next_loc is not None:
                        return redirect(next_loc)
                    else:
                        return redirect(url_for('admin_index', _external=True))

    flash_form_errors(form)

    return render_template('login.html', form=form)


@app.route("/admin/logout")
@login_required
def admin_logout():
    logout_user()
    flask.flash('Logged out successfully.')
    return redirect(url_for('index', _external=True))


@app.teardown_appcontext
def close_connection(exception):
    db = getattr(g, '_database', None)
    if db is not None:
        db.close()


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