api_middleware_post_2.py

import json

from flask import current_app, request, g
from werkzeug.wrappers import Response
from werkzeug.exceptions import HTTPException

from star_wars.models import User, Client

from .utils import  decode_client_token, get_token_from_request


def check_auth(auth):
    un = current_app.config['BASIC_AUTH_USERNAME']
    pw = current_app.config['BASIC_AUTH_PASSWORD']
    return auth.username == un and auth.password == pw


def basic_auth(endpoint):

    auth = request.authorization
    if not auth or not check_auth(auth):
        resp = Response(
            response=json.dumps({'message': 'Not Authorized', 'error': True}),
            headers = {
                'WWW-Authenticate': 'Basic realm="Login Required"'
            },
            mimetype='application/json',
            status=401
        )
        raise HTTPException('Api Error', response=resp)


def get_api_client_from_request(endpoint):
    """Ensure a valid api_key query param was provided with the request and store the
    client on `g.api_client`
    """
    api_key = request.args.get('api_key', None)
    if not api_key:
        payload = {'message': 'Missing required ?api_key param'}
        endpoint.return_error(422, payload=payload)

    client = Client.query.filter_by(client_id=api_key).one_or_none()
    if client is None:
        payload = {'message': 'API Client not found'}
        endpoint.return_error(404, payload=payload)

    g.api_client = client
    return client



def get_client_token(endpoint):
    """Validate the request has a valid JWT token.  If the provided api_key and token
    a valid the JWT will be decoded and stored on g.token for use later on.
    """
    token = get_token_from_request()
    if not token:
        payload = {'message': 'Request does not contain token'}
        endpoint.return_error(
            401,
            payload=payload
        )

    payload = decode_client_token(client, token)
    if not payload:
        payload = {'message': 'Invalid token'}
        endpoint.return_error(
            401,
            payload=payload,
        )

    g.token = payload


def get_client_user_from_token(endpoint):
    """Using the provided sub field of a JWT, query the database to find the user by ID
    and validate that the provided client has permissions to access this user.
    """

    # The subject is matched against User.user_id and must be owned by the api_client.
    user = User.query.filter_by(id=token['sub'], client_id=client.id).one_or_none()
    if not user:
        current_app.logger.debug('User not found')
        endpoint.return_error(message='User not found.', status=404)

g.user = user