ScoDoc/app/api/auth.py

# -*- coding: UTF-8 -*
# Authentication code borrowed from Miguel Grinberg's Mega Tutorial
# (see https://github.com/miguelgrinberg/microblog)
# and modified for ScoDoc

# Under The MIT License (MIT)

# Copyright (c) 2017 Miguel Grinberg

# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
# the Software, and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

from functools import wraps

from flask import g
from flask_httpauth import HTTPBasicAuth, HTTPTokenAuth
import flask_login
from flask_login import current_user

from app import log
from app.auth.models import User
from app.api.errors import error_response

basic_auth = HTTPBasicAuth()
token_auth = HTTPTokenAuth()


@basic_auth.verify_password
def verify_password(username, password):
    "Verify password for this user"
    user = User.query.filter_by(user_name=username).first()
    if user and user.check_password(password):
        g.current_user = user
        # note: est aussi basic_auth.current_user()
        return user


@basic_auth.error_handler
def basic_auth_error(status):
    "error response (401 for invalid auth.)"
    return error_response(status)


@token_auth.verify_token
def verify_token(token) -> User:
    """Retrouve l'utilisateur à partir du jeton.
    Si la requête n'a pas de jeton, token == "".
    """

    user = User.check_token(token) if token else None
    if user is not None:
        flask_login.login_user(user)
    g.current_user = user
    return user


@token_auth.error_handler
def token_auth_error(status):
    "Réponse en cas d'erreur d'auth."
    return error_response(status)


@token_auth.get_user_roles
def get_user_roles(user):
    return user.roles


def token_permission_required(permission):
    "Décorateur pour les fonctions de l'API ScoDoc"

    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            # token_auth.login_required()
            current_user = basic_auth.current_user()
            if not current_user or not current_user.has_permission(permission, None):
                if current_user:
                    message = f"API permission denied (user {current_user})"
                else:
                    message = f"API permission denied (no user supplied)"
                log(message)
                # raise werkzeug.exceptions.Forbidden(description=message)
                return error_response(403, message=None)
            return f(*args, **kwargs)

        # return decorated_function(token_auth.login_required())
        return decorated_function

    return decorator


def permission_required_api(permission_web, permission_api):
    """Décorateur pour les fonctions de l'API accessibles en mode jeton
    ou en mode web.
    Si cookie d'authentification web, utilise pour se logger et calculer les
    permissions.
    Sinon, tente le jeton jwt.
    """

    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            scodoc_dept = getattr(g, "scodoc_dept", None)
            if not current_user.has_permission(permission_web, scodoc_dept):
                # try API
                return token_auth.login_required(
                    token_permission_required(permission_api)(f)
                )(*args, **kwargs)
            return f(*args, **kwargs)

        return decorated_function

    return decorator