Strange ORA-942 when using DBMS_CRYPTO but table exists - oracle

Question

This is very strange, and not easy to explain, so please bear with me.
Oracle 12.2.0.1 on Linux x86_64.
We have a user called BATCH who has minimal privileges.
CREATE USER batch IDENTIFIED BY batch
DEFAULT TABLESPACE users
QUOTA UNLIMITED ON users;
GRANT CREATE SESSION TO batch;
GRANT EXECUTE ON DBMS_CRYPTO TO batch;
The is a PLSQL package in a schema called ATLED which is :
CREATE OR REPLACE PACKAGE ALTED.the_pkh AUTHID current_user AS
PROCEDURE crttab;
END;
/
CREATE OR REPLACE PACKAGE BODY ALTED.the_pkh AS
PROCEDURE crttab IS
BEGIN
EXECUTE IMMEDIATE 'CREATE TABLE atled.the_tab AS SELECT id, DBMS_CRYPTO.HASH(cc,2) AS cc FROM ARCHIVE.table_b';
END crttab;
END;
/
We are using Code Based Access Control (CBAC - 12c feature) to restrict/control/allow certain canned actions to an otherwise toothless user, so we create a wrapper procedure, grant that a high priv role, and grant execute on that to the batch user:
CREATE OR REPLACE PROCEDURE ALTED.wrapper_crttab AS
PROCEDURE p1 IS
CURSOR c1 is SELECT * FROM SESSION_PRIVS;
BEGIN
FOR r1 IN c1 LOOP
DBMS_OUTPUT.PUT_LINE( r1.privilege );
END LOOP;
END;
BEGIN
p1;
ALTED.the_pkh.crttab;
END;
/
GRANT IMP_FULL_DATABASE TO ALTED;
GRANT IMP_FULL_DATABASE ALTED.wrapper_crttab;
GRANT EXECUTE ON ALTED.wrapper_crttab TO batch;
Now let's run it:
CONN batch/batch
SET SERVEROUTPUT ON
EXEC ALTED.wrapper_crttab;
This causes the error:
Error at line 1:
ORA-00942: table or view does not exist
The tables referenced do exist.
The call to the p1 proc confirms that all the privileges bundled with IMP_FULL_DATABASE are present, including CREATE ANY TABLE, DROP ANY TABLE, EXECUTE ANY PROCEDURE.
If I do this:
GRANT CREATE ANY TABLE TO batch;
GRANT SELECT ANY TABLE TO batch;
CONN batch/batch
EXEC EXECUTE IMMEDIATE 'CREATE TABLE atled.the_tab AS SELECT id, DBMS_CRYPTO.HASH(cc,2) AS cc FROM ARCHIVE.table_b;
This works.
If I change the CREATE TABLE stmt to remove the DBMS_CRYPTO call, it works as well.
The actual package/proc that is called creates a number of tables fine when run as above, but fails on the case when DBMS_CRYPTO is called in any CREATE TABLE stmt.
If I grant the batch user the CREATE ANY TABLE, SELECT ANY TABLE and EXECUTE ANY PROCEDURE privs directly and run the CREATE TABLE command as batch directly then that works too.
So this is not (I think) a straight ORA-942 error, but something related to a chain of privileges to DBMS_CRYPTO, and only when executed in a package stored procedure, but what exactly I do not know.
UPDATE 1
If I create a wrapper for DBMS_CRYPTO.HASH as follows:
CREATE OR REPLACE FUNCTION batch.crypto_hash ( pcc IN CLOB ) RETURN VARCHAR2 IS
BEGIN
RETURN DBMS_CRYPTO.HASH(pcc,2);
END;
/
Then replace the DBMS_CRYPTO.HASH(cc,2) in the CREATE TABLE stmt with batch.crypto_hash(cc) then it works!!!
So, DEFINITELY not a issue with grants on teh tables being referenced, but more likely something internal with the way DBMS_CRYPTO works. Perhaps it reads a look up table somewhere. I tried GRANT EXECUTE ON UTL_I18N to batch as well before this but that didn't work.
So I have a workaround, but woudl still like to know why this happens.

Answer 1

You're doing this:
... FROM ARCHIVE.table_b
User, who is supposed to select from that table, has to have SELECT privileges on it. It can be granted
via role
directly
If you granted the privilege via role, it works - but not in named PL/SQL procedures. It will work in anonymous PL/SQL, but not in procedures, function, packages, so - check that and, possibly, grant SELECT on table_b directly to that user.