Update: It seems we are on z13 boxes at the moment, and they do not have the Message-Security-Assist Extension 7 feature necessary to use the TRNG functions of PRNO. I could try the DRNG functions of PRNO but they seem to be a lot of work to use the right way (seeding, parameter blocks, etc.). It would be far easier to use the COBOL RANDOM intrinsic, but that only returns a fraction between 0 and 1, which could be useful but quite a bit more work to incorporate into the application function at issue.
Lacking the COBOL UUID4 function here, the KISS principle says STCKE it will be for now. Thanks all for the discussion and recommendations. Peter -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Farley, Peter x23353 Sent: Friday, March 19, 2021 4:21 AM To: [email protected] Subject: Re: Contents of TOD Programmable Field under z/OS? Thanks Ed, I hadn't actually looked at the RNG capabilities in CPACF in recent times. From an initial once-over of the TRNG capability described in the latest PoOP, it may be a better source of data than STCKE for my application. I will need to make some performance measurements to make sure I am not slowing the application process flow too much. The COBOL UUID4 function may be the "future state" version for my application requirements, once we are up to date enough to use it. That will need some performance measuring too once we are there. Peter -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Ed Jaffe Sent: Thursday, March 18, 2021 10:06 PM To: [email protected] Subject: Re: Contents of TOD Programmable Field under z/OS? On 3/18/2021 6:38 PM, Paul Gilmartin wrote: > > Using clock values as a source of entropy is discouraged. If a > (fe)malefactor can make a good guess at an interval during which the > clock is sampled there's little entropy available. IBM Z was recently enhanced with a true random source in CPACF. For all the many decades before that, all "random" numbers on the mainframe were actually pseudo-random... -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
