1. A method comprising: determining, by a processing device, whether a computer system is able to access an authentication server; in response to a determination that the computer system is able to access the authentication server, requesting a first set of credentials; authenticating the first set of credentials; and assigning a user a first role for performing operations on the computer system in view of the first set of credentials; and in response to a determination that the computer system is unable to access the authentication server; requesting another set of credentials different from the first set of credentials; authenticating one or more credentials provided by the user; assigning the user another role for performing operations on the computer system in view of the one or more credentials, wherein the first role specifies a first type of access to at least one object on the computer system, and the other role specifies another type of access to the at least one object, wherein the first type of access is different from the other type of access; detecting that the computer system is able to access the authentication server; requesting an additional credential, wherein the first set of credentials comprises the additional credential and the other set of credentials does not comprise the additional credential; authenticating the additional credential; and assigning the user the first role for access to the computer system in view of the additional credential.