For some system initialization parameters, the default is now changed, or the values that you can specify are changed, or the scope of the system initialization parameter is changed. You might need to modify your system initialization table (SIT) or CICS® startup JCL because of these changes.
APAR PI28039 update
The default setting for the ENCRYPTION system initialization parameter, ENCRYPTION=STRONG, no longer allows the use of the SSL version 3.0 security protocol. The minimum security protocol allowed with ENCRYPTION=STRONG is now TLS version 1.0.
If you have clients that still require the SSL version 3.0 protocol, you can enable support for that protocol by specifying the system initialization parameter ENCRYPTION=SSLV3 for the CICS region. SSL 3.0 should only be used for a migration period while clients that still require this protocol are upgraded. Any connections that require encryption automatically use the TLS protocol, unless the client specifically requires SSL 3.0.
System initialization parameters changed in CICS Transaction Server for z/OS, Version 5 Release 2
- ENCRYPTION={ALL|TLS12|STRONG|SSLV3}
Before CICS TS for z/OS®, Version 5.2, the ENCRYPTION system initialization parameter supported these values: STRONG, ALL, and TLS12FIPS.
The value TLS12FIPS is no longer supported. The new value TLS12 is added. To obtain the same result as using the old TLS12FIPS option, use TLS12, and also code the new system initialization parameter NISTSP800131A=CHECK.If your system initialization table contains an invalid value, the default value, STRONG, is used instead. If you specify an override with an invalid value in your CICS JCL, CICS pauses during startup and prompts you to respecify the override. To avoid these occurrences, update any system initialization tables or JCL overrides to specify a valid value.
- JVMPROFILEDIR={/usr/lpp/cicsts/cicsts52/JVMProfiles|directory}
From CICS TS for z/OS, Version 5.2, JVM servers can be defined in CICS bundles. For these JVM servers, the JVM profile is packaged in the CICS bundle with the JVMSERVER resource definition. CICS does not load these JVM profiles from the directory that is specified by JVMPROFILEDIR. Instead, they are stored in a suitable directory for the CICS bundle, and the location is specified by the CICS bundle.
- MXT={250|number}
Before CICS TS for z/OS, Version 5.1, the minimum, default, and maximum values of the MXT parameter were 1, 5, and 999. In CICS TS for z/OS, Version 5.1, the minimum, default, and maximum values were changed to 10, 500, and 2000. From CICS TS for z/OS, Version 5.2, the minimum value is 10, the default value is 250, and the maximum value is 2000. These adjustments were made to ensure that CICS regions operate efficiently with the default setting and can process more workload.
