Not sure how to go about doing this; I'm not looking for B2C, I don't want my users to sign in. I just want my Xamarin app to be able to access an Azure AAD protected API. In other words, I want to authenticate the app itself with the Azure Active Directory, to access an Azure AAD protected API. From what I've found on the internets, service principal to service principal auth is discouraged when using mobile apps and I've not really found a way to do it service to service anyhow.
Any suggestions on how to properly do this? Links with tutorials would be great.
Thanks!
Azure does provide the ability to generate a client ID which you could have sent from your application and checked. Microsoft talk about this in this article. You will want to be careful with how you store this ID in your app as if someone were to steal this they would be able to access your API. Along with that you'd also want to make sure that your connection between your app and server is secured with a pinned SSL certificate so it cannot be man-in-the-middle'd.
Another interesting approach is software attestation where some service checks various aspects of your app to ensure that it is your app. Full disclosure, I work for a company which does this. See Approov. We take a fingerprint of your app and our SAAS checks that this matches at run time. We then issue a token which your app can use to prove that it is the real app.
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I have checked many sample examples even by Microsoft on Azure ADB2C Authentication. All examples showing how to implement Azure ADB2C in Asp.Net Core Web App and Web Api together.
In Azure Portal, while registering Web App/Api, there is an option to generate App Key. My question is:
Do we really need to generate App Key and use it in Asp.Net Web App? I tried many samples and everything is fine but when I set invalid key in AzureAdB2COptions, its still working with no problem and not throwing any error. I removed the key from Azure Portal and its still working. Can anyone explain why?
The sample I used is here
Is this App Key for Web Api authentication?
As juunas mentioned, client secret is needed if your application exchanges a code for a token. It is used to prove Azure AD app's identity when requesting a token.
And implicit flow will not use a client secret to get the token.
Besides, if you use native/public client app, it would not be able to protect a secret. So generally we don't need client secret in native app.
I have tested the sample you shared. When I modify the ClientSecret in appsettings.json file and run this project, it will give an error requires me to correct the secret. You could have a quick test in an incognito window.
I'm trying to setup an application to validate identity using Azure AD and acquire a token to allow access to a secure api. The front end application is written in angular and allows anonymous access. What can I use to access AAD authenticate and return an access token?
This will be an angular 6+ UI that is communicating to a secure .Net api using Azure AD for authentication. I have done a couple days research and everything points to a user logging in to authenticate using the login page. I need it to be by app and open the login page. I tried a couple examples where it utilized authentication/authorization and that didn't work because the app needs to authorization the user to talk to the api. I have seen where people were using Microsoft graph but once again it was user based and they were redirected to an azure login. I am looking for a solution that will allow me to setup an account in azure ad and authenticate the app on start to get an access token to allow communication to my secure api. If I have missed something somewhere in my research and test attempts let me know. This is my first Azure AD auth attempt and I feel like I am missing something for application authorization.
The problem is an Angular app is what we call a public client.
It cannot hold secrets and thus cannot prove its identity.
So, only user-based authentication flows should be used by public clients.
Confidential clients on the other hand can hold secrets as they run on servers that you control.
So for example, a back-end Web application or API would be a confidential client.
Those can use the client credentials flow to acquire access tokens and call APIs as themselves without a user being involved.
There is a bit of a fundamental issue in your question.
Your API requires authentication, but you want functionality to be available to anonymous users.
So you want to bypass authentication.
If you really want to bypass authentication for parts of the API, you could just make those endpoints available anonymously without a token.
Be warned possibly noob question ahead.
I'm a little unsure where exactly Azure AD or IdentityServer is supposed to fit in in the overall communication flow.
Here is a scenario that I often face.
Some "dumb" client (e.g. a Windows App that can't use external assemblies or some JavaScript in a web app) has to contact my Web API which will then contact other APIs or other resources.
If I want to try and implement either Azure AD or IdentityServer as a means of authentication and authorization in the Web API, I don't see that this can be done in any other way, than it has to be the Web API that communicates with Azure AD or IdentityServer as the client doesn't have the ability to do so due to the lack of required assemblies.
If this assumption is not correct, then how would I do this?
If it is correct however, then what means of security is there between the client and the Web API other than communicating over HTTPS when the client has to send it's credentials to the Web API, so the Web API can authenticate and authorize the user against either Azure AD or IdentityServer?
If I understand your requirements correctly, then you are able to change the client Windows app, but unable to add external assemblies to it? So you would not be able to add the ADAL NuGet package to it.
You can still use Azure AD authentication - it is possible, but not trivial, to implement the client code yourself.
Or you can, as you already mentioned, pass the user's credentials to the Web API somehow, and then use that to have the Web API do authentication towards Azure AD on behalf of the user. There is a sample app which shows how to use username/password credentials.
This however, goes against the whole OAuth/OpenIdConnect mindset, where your app should never know the user's credentials.
Here:
https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/active-directory/develop/active-directory-v2-protocols-oidc.md
Be careful with trying to use the most recent version of the Azure AD endpoint (just don't use version 2.0, they shot themselves in the foot by excluding all Azure AD webapp registrations & by "securing" web APIs by making them only available to apps with the same appid - as far as I'm concerned, it's unusable until they fix those two issues) - see the "[!NOTE]" near the top of that linked page for the v2.0 limitations.
I've successfully built a ruby script and a mac app that use service account credentials to authenticate (without user interaction) to google cloud storage and upload/download objects.
I now need to perform similar actions on an iOS device. Is it possible to use installed application credentials to authenticate still without user interaction?
If it's possible or has been done, can you please provide an example or point me in the right direction.
Thanks!
You need the private key for the service account to get the access token for the application. Please bear in mind that some hacker may steal that private key for both mac and iOS app. If the data is per user and you have a backend server, you may authenticate the user on the backend and then use the private key on the server to access the storage. If the data is per app, seems there is no good way to prevent the private key abuse.
I recently started a new project using different carefully-chosen technologies, my project is built as follow :
The approach is API-Centric, which means I'm building a website and an iOS app communicating with an API written using Symfony2. I've successfully managed to write my API, and it is perfectly working.
To gain access to the services provided by the API, the main actors (the website users, the iOS app users and the developers) can authenticate theirself in several ways :
Clients can gain access with a login/password couple through the website interface which is communicating directly with the API through AJAX to validate the provided credentials and set a session. So, when someones logs in our website, they have automatically access to the API as well.
Developers can authenticate theirself through the API using HTTP-Basic over SSL, which will as well generate a session and give them access to the services they are authorized to call.
Also, Developers and clients can gain access to the website and the API using their facebook account through the Facebook Connect functionality. This deletes the step where each actor has to create an account on our website.
So basically, the credentials are provided either through HTTP-Basic or using the Facebook Login functionality.
Now that my authentication system is working and that my clients are able to access the website, I would like them to connect to a real-time server when they log in. Like in Facebook or Google+ if you want where the real-time server manages chat and push informations.
In this case i'm using Node.js and the powerfull socket.io library to manage everything that deals with the real-time side.
Of course, the real-time service will need some credentials to authenticate the user since he is authenticated to the Symfony security system with a session but is not authenticated against the real-time server.
A solution I've been thinking about would be to use the PdoSessionStorage in my API (Symfony side) and store all the active sessions in a database such as MySQL or PostgreSQL. Doing so, I would be able to send to my real-time server the session id generated by symfony and check on the database if the session id provided is correct or not. If he is I'll let the user access the services provided by my real-time server and associate his session with an identity.
But I really don;t know if this is a good solution and I would like some more experienced advices on this and on how to deal with this issue.
Note : For some reasons, I cannot implement OAuth even if it could be a solution to solve this issue using a Single Sign On approach.