Azure Active Directory B2C user signup without redirect (non interactive)

Question

I am building a native iOS application and want to use AADB2C as identity provider where users login, signup, reset their passwords etc.

I cannot figure out a way to let users signup with AADB2C (or regular AAD for that matter) without redirecting them to a (customizable, but still) microsoft website. To be perfectly clear: I want to let customers create user accounts on AAD from a native iOS form without redirecting them to a website, preferably via REST request. (Like here under "Create consumer user accounts": https://docs.microsoft.com/en-us/azure/active-directory-b2c/active-directory-b2c-devquickstarts-graph-dotnet)

Answer 1

Can you create users from an iOS app? Yes, using the Graph API as per the article you showed. You can only create local accounts at this time though.

However you need to be very careful about how you do it given that currently, the ability to create users requires Directory.ReadWrite.All permission, which also allows all other sorts of operations. You should NOT put the client ID and client secret for an app with these permissions in your iOS app. Rather, you would need to create a backend service that exposes an API for your iOS app to call for user creation.

However, more importantly, what you WON'T be able to do is SIGN IN the users without a redirect (which is what the B2C sign up policy does). In order to do this from your own UI without redirects, you would need Azure AD B2C to support Resource Owner Password Credentials Flow so that you can, after creating the user, use this flow to sign them in and get a token.

Note: You would also need to disable Email Verification so that you can leverage the user account right after user creation. You can set this in the Sign-up policy or Sign-up/Sign-in policy via Page UI customization > Local account sign-up page > Email Address > Require Verification > No

Lastly, as an FYI, there's a feature in the works in Azure AD B2C: Customer Owned Domains, which, paired up with UI customization, would allow you to have sign-up/sign-in pages that you can look like your own and have a URL of your own, with no trace of Microsoft for your end users to see.