var auth = "116asd1f2341dfas2f"
//this is executed always before somone calls a request
app.use(function (req, res, next) {
var header=req.headers['authorization']; // get the header
if(header != auth)
{
res.status(401) // HTTP status 404: NotFound
.send('401 Unauthorized');
return
}
next();
});
Is this a safe way to protect an API? I am new to node.js
No, absolutely not. You have written a basic middleware that might offer some protection but isn't remotely secure.
There are a lot of things that go into ensuring the protection of an API. I would suggest you learn more about middlewares, token-based authentication and how does it work (JWT AUTHENTICATION is quite popular with node.js), Passport Authentication strategies etc.
We can't write the code for you but can surely guide you to correct way of doing things. There are a lot of excellent tutorials out there that can surely help you.
Remember, doing it yourself is the only way to learn.
I'm wondering how to control/restrict access from different users to their content stored in mongodb (accessed via mongoose). Let's say there is a data-model to store last wills for users.
My approach would be:
Login: authenticate via username and password, store username in session.
Middleware: Check Login-Status, query user-model for the stored username and return the user id, attach it to req-object (req.userId)
When hitting the route to get actual content (the last-will-model): query the will-model with two conditions: matching willId and matching userId (which is also stored in will-model)
Is this in any way reasonable or even save? Couldn't find any best-practises, all the examples basically end with authentication.
Steps 1 and 2 can be covered by using passport-local, although it's not too hard to implement manually.
Step 3 is reasonable, given that a will belongs to a user and both willId and userId are required to determine if that user should have access to a particular will document.
Since security is based on session id's, you should obviously use HTTPS and use httpOnly and secure session cookies.
With any of the three ways you can implement authorization, IMO the option I would choose is to use a Middleware.
It would be a cleaner option, with little impact on the code
functionality and easy to maintain for future changes, also separates
the concept of authentication and authorization.
I've never used, but have in mind to use this package in a project that I have to make. You can define your rules and then use it on specific routes.
app.get('/', *user.can('access home page'), function (req, res) {
res.render('private');
});
app.get('/private', *user.can('access private page'), function (req, res) {
res.render('private');
});
app.get('/admin', *user.can('access admin page'), function (req, res) {
res.render('admin');
});
*Predefined rules
I am currently using node.js, express, and mongodb for an instagram app. I have found that many times I would like to know whether or not a user is already logged into instagram (be it through my app via the instagram-node authentication or through instagram's actual website).
Is there an easy way to do this?
I ended up using passport to solve this problem. Passport conveniently takes care of handling instagram authorization and they even include an example app to see how it all works. https://github.com/jaredhanson/passport-instagram/blob/master/examples/login/app.js
function ensureAuthenticated(req, res, next) {
if (req.isAuthenticated()) { return next(); }
res.redirect('/login')
}
Is especially useful since it can be placed at the top of your routing file and all the routes underneath it will first check to see if the user is authenticated.
If I have a user to a web application with id=555, how do I give him access to URLs only under:
www.example.com/users/555/home
and prevent him from getting to
www.example.com/users/554/home
etc?
what is the best way to do that? I am currently using Passport.js for authentication.
In Express 4, use() can take a path. So, very loosely ( and likely with errors) put this before your app,get(), app.put() etc...
app.use('/users/:id/:dir', function(req, res, next){
if (checkAuth(lots of args)). // you have an id, dir, etc...
next(); // user is o.k. to proceed
else
send a 400 or whatever; and don't call next!
});
Unlike the JimmyRare answer, this covers all the HTTP verbs and all users.
Added: I'm not familiar with passport.js so that part needs to be filled in by somebody else. Passport experts, please feel free to edit this answer.
app.get('/users/:id/home', function(req, res) {
if(req.params.id == 554) {
res.send('Thy art not allowed!');
}
};
What are good strategies for role-based authorization in express.js? Especially with express-resource?
With Express-resource there are no handlers, so I think there are three options:
Use a middleware
Pass the authorization function to the resource and check each resource request separately
Check authorization with every request right after authentication
Are there any other solutions?
Group/Role-based authorization is a pretty antique approach. Are there newer methods of access control? If not, how can role-based authorization be applied to node.js? Where to store group-rule relationships (with NoSQL/CouchDB/Redis)?
As an example, the structure:
/
/forums
/forums/threads
Each resource with index, new, create, show, edit update and destroy. Some people can edit/delete etc. threads and forums, some people shouldn't.
I would say that it's hard to solve this in a clean manner using express-resource, since it doesn't allow for route-specific middleware (at least not in a clean way).
I would opt for a similar layout as an express-resource module, but route it with plain old express. Something like this:
// Resource
var forum = {
index: // ...
show: // ...
create: // ...
update: // ...
destroy: // ...
};
// Middleware
var requireRole = function(role) {
return function(req, res, next) {
if('user' in req.session && req.session.user.role === role)
next();
else
res.send(403);
}
};
// Routing
app.get('/forums', forum.index);
app.get('/forums/:id', forum.show);
app.post('/forums', requireRole('moderator'), forum.create); // Only moderators can create forums
app.delete('/forums/:id', requireRole('admin'), forum.destroy); // Only admins can delete forums
UPDATE: There have been ongoing discussions regarding route-specific middleware in express-resource, e.g. here. The prevailing view seems to be to have an array per action, e.g.:
var forums = {
index: [ requireRole('foo'), function(req, res, next) { ... } ]
};
You could take a look through the pull requests and see if there is anything you could use. I totally understand it, of course, if you don't feel comfortable with that. I'm pretty sure we will see something like this in express-resource in the future.
The only other solution I can think of is along the lines of Jan Jongboom's answer, which would be to mount the resources with express-resource, but have middleware attached "outside" of that, something like:
app.delete('*', requireRole('admin')); // Only admins are allowed to delete anything
app.put('/forums/*', requireRole('moderator')); // Only moderators are allowed to update forums
But I regret that this leaks URLs all over the place.
I have been researching the same question and have come across a few good modules. I have been focusing on the node-acl package that can be found here. https://github.com/optimalbits/node_acl.
This package seems to have implemented the ACL pattern in a very understandable way and has provided ways to easily integrate it into your node/express application.
Firstly, you'll want to define your resources, roles, and permissions.
For example, the resources can be:
/
/forums
/forums/threads
The roles can be
public
admin
user
john
jane
In this example, the roles john and jane can map to actual user accounts, but they will inherit all the permissions of the user role.
The permissions on the resources
create
show
update
destroy
Or your standard CRUD operations.
Now that those have been defined, we can take a look at how it would look to set up the acl using node-acl. These notes are derived from the documentation
import the package
var acl = require('acl');
Set up your backend. My app is using mongodb, but the node-acl package does support other storage mechanisms
acl = new acl(new acl.mongodbBackend(dbInstance, prefix));
My app is using mongoose so dbInstance would be replaced with mongoose.connection.db
Now lets add our roles to the ACL. In node-acl, roles are created by giving them permissions. Its like killing two birds with one stone (no birds are actually harmed)
acl.allow('admin', ['/', '/forum', '/forum/threads'], '*');
acl.allow('public', ['/', '/forum', '/forum/threads'], 'show');
acl.allow('user', ['/', '/forum', '/forum/threads'], ['create', 'show']);
Lets assume a new resource is created by john, we will add a new record that allows john to also update and delete that resource.
acl.allow('john', ['/forum/threads/abc123'], ['update', 'delete']);
My application is also using express, so I will use the routing middleware approach to check routes. In my routing configuration, I would add the line
In most express configurations, this looks like for the pos
app.post('/', acl.middleware(), function(req, res, next) {...});
app.post('/forums', acl.middleware(), function(req, res, next) {...});
app.post('/forums/:forumId', acl.middleware(), function(req, res, next) {...});
app.post('/forums/threads', acl.middleware(), function(req, res, next) {...});
app.post('/forums/threads/:threadId', acl.middleware(), function(req, res, next) {...});
When no parameters are passed, this will check if the role defined in req.userId is allowed to execute the http method on the resource identified but the route.
In this example the http method is post, but it will do the same thing for each http idenitified in your configuration.
This raises the question, about the permissions defined earlier. To answer those questions, we would have to change the permissions from
create
show
update
destroy
To the conventional
post
get
put
delete
Although this example shows everything hardcoded, the better practice is to have a management interface for your permissions so they can be created, read, updated, and deleted dynamically without having to modify your code.
I like the node-acl plugins approach as it allows for very fine grained permission-role assignments using a very straight forward and flexible api. There is a lot more in their documentation, my example shows were I am with the package.
Hopefully this helps.
Connect-roles is quite good, simple and the documentation is also very clear.
var user = roles;
app.get('/profile/:id', user.can('edit profile'), function (req, res) {
req.render('profile-edit', { id: req.params.id });
})
app.get('/admin', user.is('admin'), function (req, res) {
res.render('admin');
}
In express you can add a handler that hooks into every operator (http://expressjs.com/guide.html#passing-route control) where you can do precondition validation. Here you can retrieve the role for the user and restrict access based on the HTTP verb (PUT, DELETE, etc.) or the URL (param('op') is 'edit' or so).
app.all('/user/:id/:op?', function(req, res, next){
req.user = users[req.params.id];
if (req.user) {
next();
} else {
next(new Error('cannot find user ' + req.params.id));
}
});
I wrote a module as non-explicit routing middleware. Works well with express-routes.
Gandalf on GitHub
You can try Casbin: https://casbin.org/, it has a Node.js version. It also has a Express.js middleware called express-authz: https://casbin.org/docs/en/middlewares