Migrate from legacy "Microsoft.IdentityModel.Clients.ActiveDirectory" (ADAL) to "Microsoft.Identity.Client" (MSAL)

[Kiechlus]

What would you like to be added:

We found out that KeyVault checks (and possibly others) still use the deprecated ADAL authentication library.

Why is this needed:

We are currently investigating SSL Heartbleed issues and detected that ADAL is using System.Security.Cryptography.OpenSsl version 4.3.0 from 2016. We are not sure if this is causing the issue, but it is still quite old. The new MSAL does not contain this package (tested on .Net 6).

[sungam3r]

PR is welcome.

[Kiechlus]

I don't even understand why this package is needed. I checked all files in the HealthChecks.AzureKeyVault namespace on master and don't find any reference to that package.

[WillemRB]

Both Microsoft.Azure.Services.AppAuthentication and Microsoft.IdentityModel.Clients.ActiveDirectory aren't needed in the project.

[sungam3r]

@Kiechlus I see no Microsoft.IdentityModel.Clients.ActiveDirectory references in master. Please try the latest preview packages.