Using OAuth 2 I need to limit user access to permitted resources only, where the connection to the API is made through an ext.js REST proxy. The ext.js proxy takes care of data retrieval and maintaining the model relationships. I haven't found an elegant way to make different calls from the proxy to the backend depending on the user logged in.
I am wondering if the proxy has to be different for each user logged in to my application because each user has their own access token.
Another option would be to make the proxy know about the logged in user during the proxy initialisation process and save this information in a persistent way.
Has anyone solved a similar situation before?
The article gives a detailed explanation on how to use OAuth2 with Sencha Touch.
http://www.sencha.com/blog/meetcha-using-sencha-touch-to-build-a-mobile-app-for-meetup-com/
There are several ways to use OAuth. One uses redirects after the initial authentication (for this you might use an iFrame inside a Sencha login view). The other uses your backend server as an intermediary to the OAuth server that can avoid the iFrame solution but requires more logic on your server.
You can then use a session cookie which will be resent with all HTTP requests including your REST calls. Most back ends support session cookies and so all you need to do then is look up the user ID you stored in the session object as part of your REST API code.
Another option is to set a custom HTTP header in each REST call that requires authentication. To avoid duplicate code, create a derived class from the Sencha proxy class to set the header containing the access token. You can store the access token in a Store or on the Application object or as a static value on the proxy. I've done this for both REST proxy calls and Sencha Direct proxy calls.
AJAX Proxy header property:
http://docs.sencha.com/touch/2.3.1/#!/api/Ext.data.proxy.Ajax-cfg-headers
Related
I've got an application where back-end and front-end are served from different hosts and are two different applications (both Symfony 3 based).
One of them (back-end ofc) handles business logic and keeps users and their roles in it's DB. Back-end provides REST API to be used by front-end. I have no possibility to modify back-end code as it's not my project - I just want to create a front-end for it.
Currently, I'm trying to create front-end app in Symfony 3 but I'm not sure how to make the front-end app authenticate against a remote API and keep no user data (or as little as possible) on its side.
After passing credentials to the backend via REST API a token is sent to front-end application and following API requests (e.g. data the front-end app would present to the user are to be sent with token received after successful authentication).
My question again: How can I authenticate against remote custom (non-OAuth) API from Symfony 3?
And additionally: How to handle token properly later? (it has to be used while making every request after successful authentication). What is the easiest way to achieve this?
I've been struggling to find decent info (maybe a tutorial?) I'm a noob in Symfony :(
Most articles describe providing an API which allows clients to connect to it, not making a client app in Symfony.
What I found:
Symfony2 authentication via 3rd Party REST API - most relevant, though it describes a flow for Symfony 2 and the accepted answer describes what should be done only briefly
https://blog.vandenbrand.org/2012/06/19/symfony2-authentication-provider-authenticate-against-webservice/ - concerning Symfony 2
http://symfony.com/doc/current/security/custom_authentication_provider.html - probably the most on topic, however, I don't understand where will app keep it's users (is writing a custom user provider necessary in this example?)
You've already found the answer on your question. That's custom authentication provider. You can keep the tokens in your frontend app storage, and just authenticate them. On login, you should create the token via request to backend app, save it in your token storage and that's all. Then you only need to authenticate the token (just see an example of auth provider).
Regarding keeping user data in your frontend app, it's up to you. You don't have to keep any data, therefore if you'd like to show some details (i.e. user name and so on) you have to store that details too (or retrieve it each request - but that will impact the performance). At least you can use caching for that.
So the possible approach is:
On login(with login form or elsewhere), just authenticate user in login handler (create your own auth provider as described there - don't worry about Symfony 2, security component is almost the same - there are some incompatibilities, but the direction is correct). After successful authentication, store token in your frontend storage (also you can store some user details you need like name and so on).
On each request, authenticate the user using the token that's kept in your frontend app storage (that's another auth provider) - you don't need to send request to your backend app.
Someone to explain please (hopefully with simple words for newbies) why a web application built upon a RESTful API can be CSRF exempt?
I received such assertion after asking: Serializing FormView data in JSON, but honnestly I can't figure out why?
Thanks in advance
CSRF or Cross Site Request Forgery, in layman terms, is meant to allow only selected sources(your own website) to submit data to particular url. It prevents misuse of your functionality by other websites or robots.
Say, I have an url for registration, /registration/, but I don't want to allow external submission of POST data to /registration/. So, I would provide a crsf cookie(depending on host and other stuff) when GET request is issued for /registration/, and ensure that same cookie is provided with POST request. This will ensure that users who have requested the registration form(i.e. genuine web users, not robots), would be able to register. It is not completely full-proof, but ensures some level of security.
Now, We don't use CSRF in API's due to following:-
Technically, CSRF is stored as cookie, since browser is not the intended client of API's, it is of no use.
Secondly, API's are supposed to use specialized client and user authentication, thereby eliminating the need for using any CSRF protection.
Thirdly, Restful api's are supposed to be stateless, therefore the order of API calls should not matter, which is essential for working of CSRF.
Note:-
If you have frontend framework like Angular or intend to use api's on browser too, then it is perfectly ok to use CSRF. In that case you are suppose to write two types of authentication for your apis.
Token Based Authentication - for non-browser clients
Session Authentication - for browser based clients (With csrf)
In this case, any request to api must authenticate with atleast one of the authentication.
According to owasp.org:
Cross-Site Request Forgery (CSRF) is a type of attack that occurs when a malicious Web site, email, blog, instant message, or program causes a user's Web browser to perform an unwanted action on a trusted site for which the user is currently authenticated.
This is not an issue for REST Web services because either:
1) you usually want your service to be accessible from multiple applications (Mobile app, browser, etc.)
2) you have to provide a direct authentication for each request, so this kind of attack is not applicable for REST services. The authentication is done by your application (let's say javascript) and no directly by your browser (sending the session id), so even if a malicious application redirect the user to your webpage, it cannot automatically trigger your javascript function to perform the request (and the authentication).
I am building a RESTful API application with Symfony2.
The app will consist of two parts.
JavaScript front-end - everything the user will ever be able to see and do will reside here.
Symfony2 back-end API - every resource and data the user will be able to reach from front-end will be served in standard JSON via endpoints.
I have never built a fully RESTful application before. My main concern is how to authenticate users.
I imagine REST authentication like this:
A user enters his credentials in a form generated in the front end, then the request is sent to the server where authentication logic happens and if the user is authenticated, a response with "token" is sent back to user, that he will add that token to every request url or authorization header (I don't know which of these options is preferable).
Then with every request, the server will check if the user token is valid and if the user is authorized to access that data (roles) and if so serves request data. (I don't want to allow users login with Google, Facebook or anything like that. I want my users logging in to other application using my app)
Now this seems quite simple, but then there's OAuth2 that got me confused because I jumped into developing without research. I downloaded FOSOAuthServerBundle and started messing around when I started to get a feeling that something is not right.
What I would like to know is the difference between RESTful authentication and OAuth.
What are the recommendations for implementing the described login mechanism?
You've got it pretty spot on. You use OAuth just for the authentication and all the following requests will have to provide that HTTP-Authorization header. You would need to create your custom authentication provider to handle that. Also use something like FOSRestBundle to create your resources.
I'm developing a mobile app, the server side is REST using Spring 3 MVC.
I was trying to integrate Spring Security with it to secure resources. I've read through a lot of material to get information on how to do it. I understand the architecture, however, when it comes to implementation I am still confused.
I referred a SO question; I have the same requirements. I understand the code, however, I am confused about when the first authenticate request comes in; at that time a token will not be present as the part of the header, so the same filter won't work.
So I was wondering how should I implement it. I was thinking of implementing it as follows:
A separate filter that authenticates user using username password from the request
After authentication the filter sets the authentication info in the context
And another filter that works with tokens for authentication for all API URLs
Is this the correct way to implement it?
No need to add another filter. Whatever the authentication result, the system will try to call handler for corresponding mapping, as you have chain.doFilter() outside if(validate_token).
You must tell Spring security that your request /login MUST NOT BE AUTHENTICATED. You can configure it in xml/java config.
First, let me describe the application: we are working on a web-based software which is some kind of custom help desk application. It requires the user to login (we use FOSUserBundle). After login the user is redirected to the dashboard. From the dashboard there is no more page reload, the frontend is build on Angularjs and the user can get anywhere within the application without page reload. You could speak of a single page application.
So the data that is presented to the user, is fetched from a rest api (we use FOSRestBundle). This works quite well at this point.
There is some kind of dilemma. Only our staff will access this application (for now). So a staff member needs to login to access the helpdesk. The data that is pushed to the frontend via angularjs is called via api, so the user that has just logged in needs to authenticate again on every request because of rest.
Problem: Since the backend runs on symfony2 let us just try to get the user object of the currently logged in user when an api call is made:
$this->get('security.context')->getToken()->getUser()
returns anon. that stands for anonymous, or
$this->getUser();
returns just null.
So the authenticated context seems to be gone when using the rest api. However when I call an action directly without rest, I can get user information.
So what we need is to secure our rest api and get user information on every api call. We don't want third party people to access our application, just staff. I am not familar with OAuth, but the user will be redirected to a third party page to Allow/Deny access to his data? This would not be an option for us.
Based on that information, do you have any suggestions or ideas how to secure the api and transport the user data so that getUser does not return null or anon. but the actuall logged in user?
there's another way to resolve your problem.
It's by using Certificates.
you can generate certificates then use Http tunneling (https obviousley), the server will ask for a certificate (you've to configure Apache for that but it's not a big challenge).
with this in place, you've to add a CertificateManageron the server side to ensure that the certificate is valid and to know who's calling the service (to be able to authenticate the user at each request), the CertificateManager(or what ever you'll call it) will probably have to be configured within you filters chaine (as known in the java world), et voilà
Hop that help you,
Abderrazak
REST is stateless so you will have to send some kind of authentication/authorization in each request. You can use HTTP BASIC AUTH or something like OAuth.
Have a look at https://github.com/FriendsOfSymfony/FOSOAuthServerBundle
I'm kind of building our application in exactly the same architecture (RESTful API with Symfony2 back-end and AngularJS frontend.
Another way is to duplicate the api routes, so that you have the api routes protected by OAUTH and the api routes protected by the session, both of them pointing to the same controllers. The method was explained here: https://stackoverflow.com/a/22964736/435026