When Db2 cannot provide an ACEE
Sometimes Db2 cannot provide an ACEE. This happens, for example, when you do not use external security in CICS® and CICS does not pass an ACEE to the CICS attachment facility.
When Db2 does not have an ACEE, it passes
zeros in the XAPLACEE field. If this happens, your routine can return
a 4 in the EXPLRC1 field, and let Db2 handle
the authorization check.
Db2 does not pass the ACEE address for IMS transactions. The ACEE address is passed for CICS transactions, if available.
Db2 does pass the ACEE address when it is available for Db2 commands that are issued from a logged on z/OS® console. Db2 does not pass the ACEE address for Db2 commands that are issued from a console that is not logged on, or for the START DB2 command, or commands issued automatically during Db2 startup.
An ACEE is available to Db2 for an IMS transaction if IMS is configured to use either APPC/OTMA security full or the IMS Build Security Environment exit (DFSBSEX0). You need to code DFSBSEX0 to return RC4 in register 15, which will instruct IMS to create the ACEE in the dependent region.