I have a webforms app running on .net 4.7.2, currently being hosted on Azure as a SaaS. It is a single software for multiple clients, each one with its own database.
Currently the user authentication is manually handled by us, but we are trying to implement a multi tenant strategy, using the AzureAD and OWIN tools.
The app service has an Identity Provider configured, from a test AAD. We can login with the provided credentials, but I can only configure a single microsoft identity provider.
I'm not sure where to go from here... After hours reading the multiple docs from microsoft, i'm still stuck.
By default, web app/API registrations in Azure AD are single tenant. You can make your registration multi-tenant by finding the Supported account types switch on the Authentication pane of your application registration in the Azure portal and setting it to Accounts in any organizational directory. So that people from other azure ad tenants will login. multi-tenant SaaS web application sample
If in case if you want to use other identity providers, You can federate with IdPs that use the SAML protocol. SAML/WS-Fed IdP federation allows external users to redeem invitations from you by signing into your apps with their existing social or enterprise accounts. Federation with SAML/WS-Fed identity providers
And we have azure ADB2C, Azure Active Directory B2C provides business-to-customer identity as a service. Your customers use their preferred social, enterprise, or local account identities to get single sign-on access to your applications and APIs.
Reference Docs: Sign in any Azure Active Directory user using the multi-tenant application pattern