Azure Active Directory - Authentication without a browser window

Is it possible to achieve Azure Active Directory authentication without going to a browser window? I will have a username and password through the mobile app login interface.

I need to execute the below script:

• Use an open mobile app (ios / android)
• Enter your Azure AD username and password on the app login screen - eg. user@tenant.onmicrosoft.com and password
• I am passing this information to a .net web service that needs to call some Apache Azure AD to validate the user's credentials before doing any other business logic / making database calls.

Any recommendation? I do NOT want the user to be redirected to any login window / page, as this would not be a good user experience.

I have already checked several different articles but not a satisfactory answer yet.

Thank you for your time.