[Feature Request] [L] MSAL.NET supports Prompt.Create so that customers can implement self-service sign-up

Is your feature request related to a problem? Please describe. When developers want to implement self-service sign up for their apps, they can use a prompt=create, triggered by a “Sign-up” link in their app. The end user can then enter the ‘create account’ experience.

Describe the solution you’d like MSAL.NET should propose a new property named Create in the Prompt class. When using this property, MSAL.NET would send ‘prompt=create’ to the authorize endpoint, which will trigger the sign-up experience.

Additional context

Example URL: https://login.microsoftonline.com/d014fd44-d398-4813-a3a9-8cd725f7f356/oauth2/authorize? client_id=da53de5a-636b-425f-ad57-0f62d6f974c7 &response_type=id_token &resource=da53de5a-636b-425f-ad57-0f62d6f974c7 &scope=openid &nonce=default_nonce &redirect_uri=https://jwt.ms &prompt=create

The draft OIDC spec for this is here: https://openid.net/specs/openid-connect-prompt-create-1_0.html

Work to do

• Expose a new Create property in Prompt.
• Wire-up the prompt so that ‘prompt=create’ is sent to the authorize endpoint when this prompt is used.
• Update the wiki page, or better redirect it to the docs.ms page, which would, however need to be synced Update after release
• Update the docs.ms AcquireToken desktop scenario page. MS Docs PR Merge after release
• Update Microsoft.Identity.Web documentation to explain how to trigger a sign-up experience Updated: Web Apps / Enabling sign-up experience

Out of scope for this work item:

• Update the desktop sample to showcase this new prompt.
• Update the Xamarin sample to showcase this new prompt
• Update the desktop tutorial to showcase this new prompt

[jmprieur]

@pmaytak : I don’t think so … this is only for external identities …

[pmaytak]

@jmprieur @jennyf19 For Identity Web, I updated Web Apps / Enabling sign-up experience wiki. Would it be useful to add that SignUp action to Identity.Web.UI AccountController?