How to use both CSRF and auth Token in Flask-Security
以前学习的《Flask Web开发：基于Python的Web应用开发实战》，用到了
Flask-Login，管理用户Session、Cookie
我们的应用：Vue 2.0 起步(4) 轻量级后端Flask用户认证 – 微信公众号RSS，用到了Flask-JWT，管理REST访问用的Token
用户权限管理，像Admin/User/Editor，是用Flask-Principal
当然，还有E-mail验证、密码修改。。。
如果我们的应用，即想管理Session（网页），又想要管理Token（REST访问），是不是两者不能兼得？抑或很繁琐呢？
幸好，Flask用于鉴权管理，有个集大成者：Flask-Security
Flask-Security.png
功能
先浏览一下Flask-Security官网所列的功能：
会话管理 Session Based Authentication
Session based authentication is fulfilled entirely by the Flask-Login
extension. Also uses Flask-Login’s alternative token feature for remembering users when their session has expired.权限分类 Role/Identity Based Access
you can associate a high level role or multiple roles to any user.密码加密 Password Encryption
Password encryption is enabled with passlib.基本网页HTTP鉴权 Basic HTTP Authentication
use e-mail as ‘username’Token鉴权 Token Authentication
Token based authentication is enabled by retrieving the user auth token by performing an HTTP POST with the authentication details as JSON data。
- Last login date
- Current login date
- Last login IP address
- Current login IP address
- Total login count
JSON/Ajax Support
Flask-Security supports JSON/Ajax requests where appropriate. Just remember that all endpoints require a CSRF token just like HTML views.
JSON is supported for the following operations:- Login requests
- Registration requests
- Change password requests
- Confirmation requests
- Forgot password requests
- Passwordless login requests
是不是眼花缭乱了？哈哈，你能想到的和想不到的，Flask-Security都帮你做到了。
注意看功能列表最后一段：JSON访问必须也带上CSRF。这跟我们以前用的Flask-JWT是不一样的哦！
下面我们来使用Flask-Security，实现Session CSRF和REST Token兼得的效果！
CSRF跨站请求伪造（Cross-site request forgery）
也被称为one-click attack 或者session riding，通常缩写为CSRF或者XSRF， 是一种挟制用户在当前已登录的Web应用程序上，执行非本意的操作的攻击方法。
因为表单登录以后，会保存session信息到用户电脑。如果使用了“Remember me”功能，会保存session_token到用户cookie到用户电脑，那更加危险！攻击者拿到这个cookie，就能直接访问了。
对于web站点，将持久化的授权方法（例如cookie或者HTTP授权）切换为瞬时的授权方法（一般是在每个form中提供隐藏csrf_token field），这将帮助网站防止这些攻击。
步骤：
1. get csrf_token
正常浏览器登录，都会用到表单(Forms)，表单里带有隐藏的CSRF。所以，如果REST访问，我们先拿到这个CSRF
# ajax send request:
GET http://localhost:5000/login
# Server response:
<h1>Login</h1>
<form action="/login" method="POST" name="login_user_form">
<input id="csrf_token" name="csrf_token" type="hidden" value="34c942cc61f0bxxx">
...
# javascript fetch "csrf_token"
document.getElementById("csrf_token").value
2. post email/password
REST访问，使用POST，带上email, password和上一步的csrf_token
# ajax send request:
POST http://localhost:5000/login
Headers: Content-Type application/json
Body:
{
"email":"aaa@bbb.com",
"password":"password",
"csrf_token":"34c942cc61f0bxxx"
}
3. get auth_token
服务器检查CSRF是否有效，以及email/password是否匹配。成功则返回auth_token：
# Server response:
{
"meta": {
"code": 200
},
"response": {
"user": {
"authentication_token": "WyIxIiwiNWY0ZGNjM2I1Yxxx",
"id": "1"
}
}
}
4. access views with @auth_token_required
终于拿到auth_token了！
下面的REST访问，带上它，就能访问服务器端@auth_token_required保护的所有路由了
# ajax send request:
GET http://localhost:5000/token_protected
Headers: Authentication-Token WyIxIiwiNWY0ZGNjM2I1Yxxx
到此，我们Server端，即可以管理Session（网页），又可以管理Token（REST访问）了！
Quickstart源码
源码很短，60来行
- 保存为app.py，然后运行
python app.py - 浏览器Session尝试：http://localhost:5000/login、http://localhost:5000/logout、http://localhost:5000/register
- JSON Token尝试：使用Curl或浏览器REST插件，来模拟Ajax GET/POST
# encoding: utf-8
from flask import Flask, render_template
from flask_sqlalchemy import SQLAlchemy
from flask_security import Security, SQLAlchemyUserDatastore, \
UserMixin, RoleMixin, login_required, auth_token_required, http_auth_required
# Create app
app = Flask(__name__)
app.config['DEBUG'] = True
app.config['SECRET_KEY'] = 'super-secret'
app.config['SECURITY_TRACKABLE'] = True
app.config['SECURITY_REGISTERABLE'] = True
app.config['SECURITY_SEND_REGISTER_EMAIL'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///.security-dev.sqlite'
# Create database connection object
db = SQLAlchemy(app)
# Define models
roles_users = db.Table('roles_users',
db.Column('user_id', db.Integer(), db.ForeignKey('user.id')),
db.Column('role_id', db.Integer(), db.ForeignKey('role.id')))
class Role(db.Model, RoleMixin):
id = db.Column(db.Integer(), primary_key=True)
name = db.Column(db.String(80), unique=True)
description = db.Column(db.String(255))
class User(db.Model, UserMixin):
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(255), unique=True)
password = db.Column(db.String(255))
active = db.Column(db.Boolean())
confirmed_at = db.Column(db.DateTime())
last_login_at = db.Column(db.DateTime())
current_login_at = db.Column(db.DateTime())
last_login_ip = db.Column(db.String(63))
current_login_ip = db.Column(db.String(63))
login_count = db.Column(db.Integer)
roles = db.relationship('Role', secondary=roles_users,
backref=db.backref('users', lazy='dynamic'))
def __repr__(self):
return '<User %r>' % self.email
# Setup Flask-Security
user_datastore = SQLAlchemyUserDatastore(db, User, Role)
security = Security(app, user_datastore)
# Create a user to test with
@app.before_first_request
def create_user():
db.create_all()
if not User.query.first():
user_datastore.create_user(email='aaa@bbb.com', password='password')
db.session.commit()
# Views
@app.route('/')
@login_required
def home():
return 'you\'re logged in!'
@app.route('/api')
#@http_auth_required
@auth_token_required
def token_protected():
return 'you\'re logged in by Token!'
if __name__ == '__main__':
app.run()
TODO:
后台管理，一般用Flask-Admin。它也可以由Flask-Security来保护
My source code
参考：
Flask-Admin Use Flask-Security to authenticate users
Token Based Authentication with Flask-Security
