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https://issues.apache.org/jira/browse/DERBY-6429?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13845426#comment-13845426
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Rick Hillegas commented on DERBY-6429:
--------------------------------------
Thanks again for the feedback, Dag. Let me continue the discussion of
privileges related to foreign keys.
-----------------------------
>> "have" meaning have a privilege granted (to user of PUBLIC), or
>> granted to the current role, right?
Part 2, section 11.8 (referential constraint definition), access rule 1 is all
I have to go on:
"The applicable privileges for the owner of T shall include REFERENCES for each
referenced column."
Note that the Standard is talking about the privileges of the owner of T, not
the privileges of the person issuing the DDL. So consider the following
statements issued by the DBO:
create table alice.primaryTable
(
a int primary key
);
grant references ( a ) on table alice.primary to ref_role;
grant ref_role to fred;
Now suppose that the DBO issues the following statement:
create table fred.foreignTable
(
b int references alice.primaryTable( a )
);
I don't think that FRED has a meaningful default role here which can be used to
supplement the privileges needed for this statement. I think that the CREATE
TABLE statement should fail. The following GRANT is needed to make it succeed:
grant references ( a ) on table alice.primary to fred;
-----------------------------
>> Hmm.. this seems wrong to me. I'd expect this dependency to be
>> tracked, and Derby to barf (with RESTRICT semantics by default) when
>> that privilege was revoked (or cascades as the case might be)...
Yes, I agree with you. The following statement will fail...
revoke references ( a ) on table alice.primary from fred restrict;
...if the foreign key was created. The following statement will drop the
foreign key...
revoke references ( a ) on table alice.primary from fred cascade;
That, at least, is my reading of the extensive general rules in part 2, section
12.7 (revoke statement).
Note that all of this is orthogonal to the privileges required for an UPDATE of
fred.foreignTable. If there is a foreign key, it imposes no privilege-checking
burden on an UPDATE statement. The UPDATE statement may need to be re-compiled
if a foreign key is added or dropped, but the foreign key does not add any
privilege checks to the UPDATE statement.
Thanks,
-Rick
> Privilege checks for UPDATE statements are wrong.
> -------------------------------------------------
>
> Key: DERBY-6429
> URL: https://issues.apache.org/jira/browse/DERBY-6429
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.11.0.0
> Reporter: Rick Hillegas
>
> UPDATE statements confuse SELECT and UPDATE privileges. Consider the
> following SET clause:
> SET updateColumn = selectColumn
> According to part 2 of the 2011 edition of the SQL Standard, that SET clause
> requires the following privileges:
> 1) UPDATE privilege on updateColumn. Privileges for the left side of a SET
> clause are described by section 14.14 (update statement: searched), access
> rule 1b.
> 2) SELECT privilege on selectColumn. Privileges for the right side of a SET
> clause are described by section 14.15 (set clause list) and the various
> productions underneath value expression. In this case, we have a column
> reference, whose privileges are governed by section 6.7 (column reference),
> access rule 2.
> However, Derby requires the following:
> 1') UPDATE privilege on both updateColumn and selectColumn
> When we address this bug, we should make corresponding changes to the MERGE
> statement.
> The following script shows the current behavior:
> connect 'jdbc:derby:memory:db;user=test_dbo;create=true';
> call syscs_util.syscs_create_user( 'TEST_DBO', 'test_dbopassword' );
> call syscs_util.syscs_create_user( 'RUTH', 'ruthpassword' );
> connect 'jdbc:derby:memory:db;shutdown=true';
> connect 'jdbc:derby:memory:db;user=test_dbo;password=test_dbopassword' as dbo;
> create table t1_025
> (
> a int primary key,
> updateColumn int,
> selectColumn int,
> privateColumn int
> );
> grant update ( updateColumn ) on t1_025 to ruth;
> grant select ( selectColumn ) on t1_025 to ruth;
> insert into t1_025 values ( 1, 100, 1000, 10000 );
> connect 'jdbc:derby:memory:db;user=ruth;password=ruthpassword' as ruth;
> -- correctly succeeds because ruth has UPDATE privilege on updateColumn
> update test_dbo.t1_025 set updateColumn = 17;
> -- the error message incorrectly states that the missing privilege
> -- is UPDATE privilege on privateColumn
> update test_dbo.t1_025 set updateColumn = privateColumn;
> -- incorrectly fails.
> -- ruth does have UPDATE privilege on updateColumn
> -- and SELECT privilege on selectColumn, which should be good enough.
> -- however, the error message incorrectly states that the missing privilege
> -- is UPDATE privilege on selectColumn.
> update test_dbo.t1_025 set updateColumn = selectColumn;
> -- incorrectly succeeds even though ruth does not have SELECT privilege on
> updateColumn
> update test_dbo.t1_025 set updateColumn = 2 * updateColumn;
> set connection dbo;
> select * from t1_025 order by a;
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