[DERBY-3929] SQL roles: tighten up check for existing user name collision when creating a role

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: SQL
• Labels: derby_triage10_10
• Urgency: Normal
• Assignee: Unassigned
• Reporter: Dag H. Wanvik
• Created: 29/Oct/08 12:24
• Updated: 30/Sep/12 02:03

Description

Cf section 6.2 "The authorization identifier name space issue" in
spec.html (rev 9) attached to DERBY-2207.

One more check to avoid collision could be attempted (this is the last
loophole that I am aware of), but is currently not being performed:
Even if there is no trace of a user in the dictionary (as schema owner
or grantee for privileges or roles), there could still be a user
connected with the proposed name of the role being created. This could
be checked by maintaining a list of connected users with reference
counts, but would impose a cost (synchronize, hash name and check
table) at connection time.

Even if this scenario could unfold; I can't (yet) see any serious
consequences of it happening (CURRENT_USER would still work as
expected). The next time the user connects she would be denied, sicne
there is a role by that name.

Issue Links

• is related to: DERBY-2207 Improve usability of Derby's client/server security by implementing ANSI Roles