For non-RACF users — the ESM parameter list

CICS® (or another caller) passes information to your external security manager in the ESM parameter list, the address of which can be calculated using field SAFPRACP of the MVS™ router parameter list.

When the caller is CICS, the “INSTLN” field of the ESM parameter list points to the installation data parameter list, which contains CICS-related information that can be used by ESM exit programs.

The format of the ESM parameter list, and the actual name of the “INSTLN” field, vary, depending on which CICS security event is being processed. (The “request type” field (SAFPREQT) of the router parameter list shows why the ESM is being called by indicating the RACROUTE REQUEST type.) Table 1 shows how some formats of the ESM parameter list can be mapped using MVS macros.

Table 1. Mapping the ESM parameter list
RACROUTE REQUEST type	Parameter list mapping macro	INSTLN field name
VERIFY	IRRPRIPL	INITIPTR (X'10')
AUTH	ICHACHKL	ACHKIN31 (X'20')
FASTAUTH	Not available	Offset X'18'
LIST	Not available	Offset X'0C'
EXTRACT	Not available	None

Note: The INSTLN field points to the installation parameter list only if you specify INSTLN on the ESMEXITS system initialization parameter. The default value of this parameter is NOINSTLN, which means that no installation data is passed.