[Bug] user_realm_discovery_failed exception does not provide reason for failure

[bgavrilMS]

Which version of MSAL.NET are you using?
4.35.1

What authentication flow has the issue?

• Desktop / Mobile
  • Interactive
  • Integrated Windows Authentication
  • Username Password
  • Device code flow (browserless)
• Web app
  • Authorization code
  • On-Behalf-Of
• Daemon app
  • Service to Service calls

Other?

Is this a new or existing app? Existing

Expected behavior
HTTP errors while discovering the user realm are not exposed to the user. MSAL should use the standard error handling mechanism here (i.e. MsalServiceExceptionFactory.FromHttpResponse)

Actual behavior
Error root cause is hidden and a generic "user_realm_discovery_failed" exception is presented.

Possible solution

microsoft-authentication-library-for-dotnet/src/client/Microsoft.Identity.Client/WsTrust/CommonNonInteractiveHandler.cs

Line 52 in b406142

if (userRealmResponse == null)

[pmaytak]

Included in MSAL.NET 4.36.0 release.