3.2.1 Abstract Data Model
This section describes a conceptual model of possible data organization that an implementation maintains to participate in this protocol. The described organization is provided to facilitate the explanation of how the protocol behaves. This document does not mandate that implementations adhere to this model as long as their external behavior is consistent with that described in this document.
To support all functionality of SFU, the account database MUST be extended to support the following additional information for each principal:
DelegationNotAllowed: A Boolean setting to prevent PROXIABLE or FORWARDABLE ticket flags ([RFC4120] sections 2.5 and 2.6) in tickets for the principal. KILE implementations that use an Active Directory for the account database SHOULD use the userAccountControl attribute ([MS-ADTS] section 2.2.16) ND flag. The default is FALSE.
ServicesAllowedToReceiveForwardedTicketsFrom: A SECURITY_DESCRIPTOR ([MS-DTYP] section 2.4.6) which specifies from which services a service will accept forwarded service tickets. SFU implementations that use an Active Directory for the configuration database SHOULD<15> use the msDS-AllowedToActOnBehalfOfOtherIdentity attribute ([MS-ADA2] section 2.210).
ServicesAllowedToSendForwardedTicketsTo: A list of services to which a service will be allowed to forward tickets to support constrained delegation. SFU implementations that use an Active Directory for the configuration database SHOULD use the msDS-AllowedToDelegateTo attribute ([MS-ADA2] section 2.211).
TrustedToAuthenticationForDelegation: A Boolean setting to control whether the KDC sets the FORWARDABLE ticket flag ([RFC4120] section 2.6) in S4U2self service tickets for principals for the service. SFU implementations that use an Active Directory for the account database SHOULD use the userAccountControl attribute ([MS-ADTS] section 2.2.16) TA flag. The default is FALSE.