Authentication for new Twitter API 1.1 - api

I have an application that needs to display number of followers and following (users/show.json) for a random user on a public page (authentication is not required).
With the Twitter API 1.0 it was quite easy as authentication is not needed for the request. With the new Twitter API 1.1 is no more possible, so I need to authenticate the request (via OAuth).
Is it possible only "authenticate" the application and not the user too?
I mean: can I avoid to ask user to login and only authenticate with application key/secret? Or everytime I need to create a token with user credentials too, creating callback, etc.?

Yes, it is possible! If your application doesn't need to do things like post statuses or send direct messages on behalf of a user, you should be able to retrieve all of a user's public information with a single hardcoded set of Twitter OAuth credentials, and not require the user to authenticate.
Login to Twitter and go to the developer dashboard at https://dev.twitter.com/apps
Register a new application; after the application is registered, view the application details. You'll see an "OAuth Tool" tab, where you'll find all the relevant OAuth values for that application: Consumer Key, Consumer Secret, Access Token, and Access Token Secret.
Using these credentials, you'll be able to make requests to the new Twitter API.
If you're not comfortable using the Twitter API directly, there are a number of good API wrappers out there for various languages -- among others, the Temboo SDK, which will give you code snippets for calling various methods (and also gives you a place to securely store your Twitter credentials, so you don't need to bake them into your application).
Take a look at:
UserTimeline
GetFollowersByID
(Full disclosure: I work at Temboo.)

The easiest way to do what you're asking is to use Twitter API 1.1's 'application-only authentication' feature, which works for much of the API. See Application-only authentication. You can see a Python example of it in get_bearer_token.py.
Once you have a bearer token, you only need to include that in your request authorization header - signing is not necessary.

Related

Who generates JWT when using Google OpenID Connect authnentication for my ASP.NET Core Web API app?

I am building an ASP.NET Core 6 Web API application for mobile clients (and maybe later SPA JS app). The application should have sign-in with Google option. I also want to add my own app's custom sign up and sign in options that would also be based on JWT authentication and not cookie.
I understand that for my custom sign in flow my app will generated JWT that will be sent to the client.
But I have few questions how that works when user signs-in with its Google account:
who's responsibility is to generate the JWT when user signs-in with its Google account? Is that responsibility of Google or mine application? I don't want Google to return JWT to the client in the cookie.
Then when client is authenticated with Google, and sends requests to my application, how can my application validate JWT token it gets?
When user signs in with Google for the first time, should I automatically register that user in my application (I am using Identity framework) by taking claim values (email) from the JWT? What is the general practice here?
I am trying to understand these processes and flows so sample code is not necessary (but I do welcome it).
Ad.1. Normally, in a larger system, you would have an authorization server (AS) that would handle user authentication and the issuance of tokens. Your clients would contact only the AS, and the AS will be able to provide the user with different forms of authentication: e.g., through your website's password or through Google. The AS is the single point of issuing tokens to your clients. It can issue tokens regardless of the authentication method used. So it then doesn't matter whether the user authenticated with Google or a password, the client will still get the same access token.
Ad.2. When the AS issues token to your client, then you don't have any problems validating that token. The client doesn't care if the user authenticated with Google or not, it's not relevant in this case.
If you decide to skip using an AS and let the client receive tokens directly from Google, then you can still verify them. An ID token is a JWT and can be easily validated with a JWT library using verification keys provided by Google. Access tokens returned by Google are opaque tokens (If I remember correctly), and you need to check whether Google exposes an endpoint to verify them.
Ad.3. That is the general practice. When the user authenticates with Google and you notice that you don't have that user's data in your system, then you take the information from Google's ID token and create a user entry in your system.

Can RestSharp obtain an oauth2 access token from IdentityServer/DuendeServer for a user programmatically if given username/password?

We have Duende server for our UI and users provide their username and password and obtain an access token that is then used by our SPA app to call api's with the access token issued by our identity server.
I'm in a situation where I need to call the same API from a script and was wondering if RestSharp has some capability to obtain an access token if provided certain information (perhaps the users email/password etc that are typically entered into an interactive website) ?
I see that the RestSharp has some OAuth related "authenticators" but the documentation is unclear exactly what they achieve. I also dont see it mentioning anything about an email address and password.
I'm wondering if theres an option that is different than me generating a JWT elsewhere and supplying it directly to restsharp. I'd love if there was a programmatic way to generate the token directly from the IDP.
RestSharp documentation doesn't make it secret about how authenticators work. Both OAuth2 authenticators only add the necessary header or query string using the token you provide, but they don't request the token.
Duende server documentation explains in detail how to get a token based on the password grant (which is using the username and password).
Although the OAuth2 spec is stable, each API vendor has its own limitations. For example, Twitter API v2 only supports the client_credentials grant type. Therefore, it's not easy to create a generic OAuth2 client.
Still, it's quite easy to amend the Twitter authenticator sample from the docs and extend both request and response models to support the Duende server token request endpoint.

Single Signon Tokens usage in multiple applications

I am currently working on a small SingleSignon application. This way, I can save time whenever i make a new project, because the login process is mostly in place from the beginning.
To start with i think I should mention that many off my applications are build on Angular, so I often have multiple applications in one project:
The Angular app (HTML / Javascript)
The REST API (Either PHP or .NET (doesnt really matter))
I have been reading up on OAuth2, JWT and so on, and I understand that:
1) the application authorizes with the SSO API.
2) the SSO API responds (if successful) with an access token.
3) Add the access token to the header, and i have now access to the SSO APIs
BUT
What about my own API that belongs to the application itself? (See the image below for better understanding).
The API for the application knows nothing about the token I recieved from the SSO API, and would of course reject it...
SingleSignon Authorization flow
How would you normally implement this?
Should the application API also ask the SSO api on every request, to validate the token, or how? What would be best practice?`
Thanks
/Dennis
After studying Auth0, I found out that if you are using Opaque tokens (croptographically random string, with no meaning), the token is being verified against the authorization server from the API, as I mentioned in my original post. If you are using JsonWebToken on the other hand, there is no need to contact the authorization server, but check validity of the token by its expiration and signature, AND audience should match the domain of the custom API
So therefore; If you have a custom resource / API, you can benefit from a selfsigned token like JWT, and define the custom resource url in the AUD grant of the token.
Then the resource can validate against the AUD grant.

Twitter Oauth authorization code

I am building a REST API.
For registering a user, he needs to authenticate on Twitter.
Normally, I would use an Authorization code provided by an OAuth2 server but it seems like Twitter does not implement this type of authorization.
I don't want my mobile app to send the Twitter token to the API to register the user. I see this as a security flaw.
I checked OAuth echo (https://dev.twitter.com/oauth/echo) which seems okay. The user passes the credentials to my API, and my API checks the user against the twitter API. Twitter then returns a user object. It does not return a access token though.
Is it the only way to do this?
Thanks for your help.
Yes you are correct. Using OAuth Echo will use you as the third party for that individual without exposing your Access token/key and Credentials.
Just be aware that you're under a different rate limit from Twitter's API when you're going through that route. In some cases it's an increase in limit while it's a decrease in other.

Twitter authentication URL

Which URL I should user for authentication user in the Twitter?
For example, in the Instagram token for user can be received when user click on the following link
https://api.instagram.com/oauth/authorize/?client_id=XXX&redirect_uri=XXX&response_type=XXX
After this its return token and I can work with user profile.
How to build such link for twitter?
Twitter API has several ways to authorize and it depends on what you want to do for determining which approach to take.
The OAuth2 approach that instagram takes is called application-only in Twitter API. The thing about application-only is that you can only use it on endpoints that aren't associated with a user. e.g. it's great for search, but doesn't work well for tweeting (which is something a user would do).
A couple other approaches are Single User Authorization, which is good if your app only needs one set of credentials. e.g. a server app. Another is Pin Authorization which is a work-around for devices that can't manage Web callbacks. These use OAuth 1.0A.
There are a few other OAuth options, but this was just to give you an idea about the available choices and the need to think about what you want to accomplish and match that with what the Twitter API offers. Here's the Twitter docs for more info:
Authentication and Authorization