I'm implementing a login auth in my app. For now I'm using an IOC interface which stores my email and password in the device storage (It uses the SharedPreferences in Android and the NSUserDefault class in iOS). When I go to the login screen I must put my email and my password, then I send that data to the server API. The server response is an authentication token, set in the request "Set-Cookie" header. I must set this auth token in every request that I make to the server API. The token expires after certain amount of time, value which comes also in the request header. Basically everything is working OK now, but the issue is that as we know, saving sensitive data like the user email and password in the SharedPreferences/NSUserDefaults is not a good idea. So I was wondering if I can achieve this using Xamarin.Auth. AFAIK Xamarin.Auth only works with identity providers such as Facebook, Google, OAuth, etc.
Is this possible? Can I user Xamarin.Auth to securely save this values?
This should definitely work, take a look at the GitHub repository of Xamarin.Auth.
The "getting started" page states that you can easily extend/customize Xamarin.Auth to work with your endpoint:
Xamarin.Auth includes OAuth 1.0 and OAuth 2.0 authenticators,
providing support for thousands of popular services. For services that
use traditional username/password authentication, you can roll your
own authenticator by deriving from FormAuthenticator.
If you want to authenticate against an ostensibly unsupported service,
fear not – Xamarin.Auth is extensible! It's very easy to create your
own authenticators – just derive from any of the existing
authenticators and start overriding methods.
Related
I'm working on an Absinthe GraphQL API for my app. I'm still learning the procedure(so please go easy on me).
I've a Absinthe/GraphQL MyAppWeb.schema.ex file in which I use for my queries and mutations. My question is how do I use this API for authenticating the user on both Mobile and Web app?
How do set a cookie(httpOnly & secure) in my web app and access/refresh tokens in a single Absinthe API to serve my website and mobile app. Basically what I'm trying to learn is how do I authenticate the user based on specific platform.
If my question sounds bit confusing, I would be happy to provide more information related to my question. I would really be grateful if someone could explain the procedure, I've been very stuck on this for a while.
I would avoid using authentication mechanisms provided by absinthe(if there are any). Depending on what front-end you are using, I would go with JSON API authentication. The flow on server goes the following way:
Create a endpoint for login that will receive a user and password and will return a refresh token.
Create a endpoint for exchanging refresh token for access token.
Use a library like guardian to generate your refresh/access tokens.
Create a phoenix plug for authentication that will check your tokens, guardian has some built-in plugs for this.
Now on device you have to implement:
Ability to save refresh and access token on device.
Have a global handler for injecting access token on authorized requests.
Have a global handler for case when access token is expired. (you usually check if your request returns Unauthorized, then you should request a new access token from the server using your refresh token)
This seems like a crude implementation, however I would advise in implementing your system instead of using a black box library that you have no idea how it works under the hood.
I don't want to roll my own security anymore and am looking at using OpenID Connect with my c# API and AngularJS app. I can get all that to work just fine. However, my brain cannot seem to understand how to secure my API correctly for both use cases:
Use Case 1: AngularJS SPA
My AngularJS app connects to my API and sends a bearer token identifying the user and includes user claims. This one is easy and there is tons of documentation on it.
Use Case 2: API to API
Some customers want to access my API directly instead of going through my AngularJS app. In this case, I thought I could use a Client ID/Secret for toen-based authentication which is great except then I know nothing about the user that's using the client id/secret. There could be 10 users using the same custom API that is calling my API. How do I get user info via the API call? I've seen others use API keys that they then lookup the user and create a JWT but I thought there might be an easier way. Any ideas?
The whole point of API to API authentication is that there is no user context. Or well, the user in that case is the machine trying to access your API. You would then need to design your authorization logic around that and implement scope based permissions. Alternatively, your options are to use api keys as you mentioned or if you want OAuth protocol with user context in the api to api scenario - then ResourceOwnerCredentials flow is an option.
API to API communcation
You can use Client Credentials Grant defined through OAuth 2.0. This won't require you to have end user credentials. Now this won't be OpenID Connect. OpenID Connect require the involvement of an end user and bound to authentication. OAuth 2.0 on the other hand is about authorization, checking whether the entity can access the resource.
With Client Credential Grant, your identity server will issue tokens for a specific client. So one of your API becomes the client (resource consumer). From request handling API endpoint, you can accept valid tokens and respond back with resource.
If you require fine grained access control from request handling API, you will require to use token introspection to identify to whom this token was issued. In this case, it will be identification of specific client identity and execute a logic on top of it. You can check the token introspection response to identify such details.
Alternatively, access tokens can be come in form of a JWT. If this is the case, they can be considered as self contained tokens so validation is straightforward.
I am working on Xamarin Forms application and new to providing login authentication of the application. I have completed the design part of the application with using Entries for user id and password and button for Submit. Also, i am having web API and for authentication. Now how to connect that Web API in xamarin forms application for login.
Please guide or provide some use full samples...
Thanks in advance...!
I assume you've built out your authentication API already, and that you can make Fiddler or Postman calls directly to your controller, pass in a set of credentials, and return back a JWT / bearer token that you can then use for authenticated calls?
At this point, it's relatively simple then as you'll want to use build a proxy layer / API layer to make calls out to your API. These calls will simply mirror the ones you've made in Fiddler/Postman/your proxy of choice.
I used Refit to achieve this:
https://github.com/reactiveui/refit
Specifically, you can see on the "Setting request headers" section how they easily encapsulate it for you to pass your token.
Of course, your initial call should be to login, and then once logged in, take the JWT response back from your controller, set the token in your Keychain, and then pull it out of Keychain to set in the header.
Let me know specific questions you have? For example, which of the following do you need more info on?
Sending and parsing a response (serializing the response) from your Login action to set/assign a token in keychain?
Saving the token, and setting it in a header for subsequent calls?
Building a proxy layer using a framework like Refit to make generic outbound calls?
I have a webapi running on a self hosted app, security provided via oauth, and I'm setting the authorisation header for calling the API. This works great, we have a user identity on all calls.
Now I can pass the same authorization token by query string or cookie (or header on some connection types) to signalr (self hosted in the same app).
The token gets to the server for signalr, I can can add it into context.cookie, or into the headers.
but..nowhere can I get it to create an authenticated user, I seem to be plagued by 401 errors
I assume I am missing a key piece of code thats supposed to take the token and create an authenticated user for signalr (even though webapi/owin does it itself).
does anybody have any pointers, or examples where signalr works with oauth on self-host?
You are correct that you need to setup a way to authenticate and set the user when wanting to use SignalR with OAuth.
You can create a customer AuthorizeAttribute for SignalR.
In it you can basically get the query string to get hold of the token, once you have the token, you can unprotect it and start validating it and setting the user context in the request.
I have an example at
https://github.com/louislewis2/AngularJSAuthentication/blob/master/AngularJSAuthentication.API/SignalRHelpers/QueryStringBearerAuthorizeAttribute.cs
Once that has been implemented, you simply decorate your hub with [QueryStringBearerAuthorize]
The github link has a full working example for this and might provide some valuable insight.
I’m trying to get my head around how I would introduce token-based (key-based?) authentication to a web API (currently looking at Sinatra, but maybe Rails too) that would be used by a mobile client and how OAuth would fit into the picture.
So, let’s say I want to create a web service that uses Facebook for authentication and grabbing basic user data. Here, my API would be a client to Facebook’s OAuth Server, requesting an access token upon a user’s successful login to Facebook. This would then grant me access to the user’s data which I would use to create an entry in my database, storing this user-specific token with any other application information I would like linked to them.
I think I got that part right so far, but here’s where I’m a bit confused.
I think that my API would also need some form of API key to grant access to a mobile user, since I wouldn’t want to transmit and store the Facebook key on their device. Would I have to have a separate store of keys which I provide to the client to access my service? Are there any ‘best practice’ ways of doing this?
Would I have to have a separate store of keys which I provide to the client to access my service?
yes.
Are there any ‘best practice’ ways of doing this?
The simplest way would be to generate a separate authentication token on every User creation and expose that to the mobile client. Then send it with every subsequent request header.
Devise provides a simple example how to achieve that. You don't need devise for that, just provide some token generation mechanism.
#Devise.friendly_token
def self.friendly_token
SecureRandom.urlsafe_base64(15).tr('lIO0', 'sxyz')
end
This mechanism can be extended to provide more security in following ways
Being an oauth2 provider itself.
On successfull login with facebook, you would generate an :authorization_code which the client can exchange for your own Oauth2 Bearer or MAC token within a next step. Then you can send your own Oauth2 token with every request for user authentication.
See rack-oauth2
Implement HMAC token encryption.
Generate and expose a secret_key to every client after singning in. Use this secret to sign messages along with a unique client id. The server can then lookup the secret_key for the specific client_id and verify the message.
See api-auth