OASIS Open

QuintessenceLabs Pty Ltd.

server must return an answer for each attribute in the request, including repeated attributes

Returning an answer for each attribute in the request, including repeated attributes, is consistent with many deployed protocols and applications. Examples of these include SQL SELECT statement, SNMP GetRequest-PDU, and the Unix programs "ls" and "df".

The KMIP get_attributes query is similar in purpose to SQL SELECT, and SNMP GetRequest-PDU. In some implementations, SQL and/or SNMP may even be used to provide the data for the KMIP response. Given the similarity of the operations, and the potential use of these operations in implementations, it seems sensible to support the same behaviour.

This does lead to the question of whether the returned repeated attributes, if dynamic (such as time-based, or modifiable by other concurrent activities on the server during the operation), can be different. And if so, is some order required. I would recommend that dynamic attributes SHOULD NOT be allowed to be different (note: not SHALL NOT), and that order is not guaranteed.

As far as I am aware, SQL SELECT always returns equal values for repeated items (each row in the database is locked to ensure consistency), but SNMP GetRequest-PDU can return different values for repeated items.