If I understand correctly, new NT authentication is implemented as only taking the password from active directory.
I wonder, why it was not implemented completely, i.e. auto-logging into vault as logged-in NT user - like it is in Exchange and sql server.
Authentication in v.3
Moderator: SourceGear
Authentication in v.3
Vadim Rapp
It doesn't work well for Vault's remote nature. In the standard use case, you can't depend on the client machine and server machine both seeing the same domain controller to verify the user's credentials. We wanted to give people the ability to use Active Directory to handle enforcing tough passwords and expiring passwords, and still give that benefit to remote users. In the near future, I would like to include the passing of Active Directory credentials from client to server for local users, and also Passport credentials, which makes more sense in the internet world.