Express-Authz

Express-Authz is an authorization middleware for Express, it's based on Node-Casbin: https://github.com/casbin/node-casbin.

Installation

use casbin v2.x

npm install casbin@2 casbin-express-authz@1 --save

use casbin v3.x

npm install casbin@3 casbin-express-authz@2 --save

Simple Example

const { newEnforcer } = require('casbin')
const express = require('express')
const authz = require('casbin-express-authz')

const app = express()

// set userinfo
app.use((req, res, next) => {
  const username = req.get('Authorization') || 'anonymous'
  req.user = {username}
  next()
})

// use authz middleware
app.use(authz(async() => {
  // load the casbin model and policy from files, database is also supported.
  const enforcer = await newEnforcer('authz_model.conf', 'authz_policy.csv')
  return enforcer
}))

// response
app.use((req, res, next) => {
  res.status(200).json({status: 'OK'})
})

app.listen(3000)

How to control the access

The authorization determines a request based on {subject, object, action}, which means what subject can perform what action on what object. In this plugin, the meanings are:

1. subject: the logged-on user name
2. object: the URL path for the web resource like "dataset1/item1"
3. action: HTTP method like GET, POST, PUT, DELETE, or the high-level actions you defined like "read-file", "write-blog"

For how to write authorization policy and other details, please refer to the Casbin's documentation.

Getting Help

• Node-Casbin

License

This project is licensed under the Apache 2.0 license.