[comp.unix.wizards] Preventing date rollback

barmar@think.com (Barry Margolin) (12/05/90)

In article <RICHARD.90Dec3143525@dataspan.dataspan.UUCP> richard@dataspan.dataspan.UUCP (Richard "Tiger" Melville) writes:
>Is there a reliable way to test if the date on a machine has been rolled
>back ?  (System files which have modified dates in the future might do the
>trick.)

No, there isn't.  Anyone who has access to change the date would also have
access to change anything that the program might look at to verify the
date.  The Unix superuser is all-powerful within that system.  If he's
clever enough, he could patch the executable file so that it would skip
over the date checks.
--
Barry Margolin, Thinking Machines Corp.

barmar@think.com
{uunet,harvard}!think!barmar

brnstnd@kramden.acf.nyu.edu (Dan Bernstein) (12/05/90)

In article <RICHARD.90Dec3143525@dataspan.dataspan.UUCP> richard@dataspan.dataspan.UUCP (Richard "Tiger" Melville) writes:
> Is there a reliable way to test if the date on a machine has been rolled
> back ?

No, there is not.

---Dan