Extending Security Through Site Security Exits › TSSINSTX Characteristics

TSSINSTX Characteristics

TSSINSTX is a single load module with a single entry point. There are 26 different processing routines which are entered based upon the function code passed on entry. The load module must reside in a LINKLST library and must be named TSSINSTX. The link‑edit must specify AMODE(31),RMODE(ANY).

To link edit the sample exit provided in the AAKOSRC0 file as member TSSINST1, the SYSLIB concatenation should include the following data sets:

SYS1.MACLIB

z/OS target macro library.

SYS1.HASPSRC

JES2 distribution macro library.

SYS1.AMODGEN

z/OS distribution macro library.

cai.AAKOSRC0

CA Top Secret for z/OS optional materials file.

With the exception of the COMMAND exit, TSSINSTX normally runs in the user address space under the security SVC. In the case of the COMMAND exit, TSSINSTX runs in the CA Top Secret address space. The exit is entered in supervisor state, key 0. The exit can issue any SVC and perform I/O unless otherwise noted in the list above.

TSSINSTX is protected by an error recovery routine (in most cases). In the event of an abend, an SVC dump is taken and the exit is disabled with a message issued to the security and master consoles. Any variations to this rule are noted in the list above.

CA Top Secret loads the installation exit (TSSINSTX) as specified on the module's linkedit attributes. The installation exit should be linked as RMODE(ANY), so that it is loaded above the line. Because most parameters passed to the exit now exist above the line, RACROUTE calls must be issued for all security checks. TSSINST1, supplied in CAI.AAKOSRC0, contains examples of proper coding of RACROUTE requests.

Because the exit can issue any SVC and perform I/O, different exits are called when in cross memory mode. A FASTAUTH call that would ordinarily call the RESOURCE, RESOURCE POST VALIDATION, MESSAGE, or VIOLATION exit points instead calls CROSS MEMORY versions of these exits if the FASTAUTH is issued in cross memory mode. These exit points may not issue SVC's or perform I/O.

If a validation is processed for a facility with resource translation, the translation of resource classes occurs before an exit point is invoked. The values communicated to TSSINSTX for TXA#RTYP and TXARTYP2 correspond to the translated resource type.