Sharing key 8/9 storage in [E]CSA presents a security risk. The only secure way 
to share memory is with shared private memory. 

There are several issues that appear to be relevant for shared private storage, 
any one of which is simple to deal with. A solution that deals adequately with 
all of the issues concurrently would take much more work, ugh IMHO it would be 
worth it. If your installation needs it, I suggest building a business case and 
submitting an RFE.


--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3

________________________________________
From: IBM Mainframe Assembler List [[email protected]] on behalf 
of Wendell Lovewell [[email protected]]
Sent: Monday, December 6, 2021 7:13 PM
To: [email protected]
Subject: Is it possible to update CSA from an unauthorized user-key program?

Hello Listers,

I'd like to be able to update a common storage area across all CICS and batch 
regions.  I've looked at IARV64 REQUEST=GETCOMMON, but it seems that it 
requires supervisor state and/or key 0-7.

It seems that something like issuing a STORAGE macro similar to:

STORAGE OBTAIN LENGTH=32768,SP=241,KEY=x,LOC=31,OWNER=SYSTEM

...from an authorized program would allocate the storage needed.   But I don't 
know the rules for accessing it from "user-mode" (unauthorized, key 8) programs 
like a CICS application.

a) Given the address of the storage obtained like that, can any user-mode 
program read that storage?
b) Could a user-mode program update that storage?
c) Should the KEY parameter be specified, and if so, what value should I use.  
Afaik it has to be 0-7 since User-key CSA was outlawed.
d) Am I correct that there isn't an IRAV64 option that will allow a user-mode 
program to update the storage?

Thanks for your help!

Wendell

(Cross-posted to the CICS list.)

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