I'm able to validate user credentials when Active directory server is reachable with below code:
using(PrincipalContext pc = new PrincipalContext(ContextType.Domain, "DOMAIN"))
{
// validate the credentials
bool isValid = pc.ValidateCredentials("myuser", "mypassword");
}
However when AD server is down isValid is false. But I can login to computer, which is most probably because Cached domain logon information provided by MS.
https://support.microsoft.com/en-us/kb/172931
So my question is how can I check also cached passwords? Because I want user to be able to enter my app when he's able to login to his computer.