crypto: Fix possible stack out-of-bound error

BugLink: https://bugs.launchpad.net/bugs/1931727



Adding fix to check the upper limit on the length
of the destination array while copying elements
from source address to avoid stack out of bound error.

Change-Id: I39d5768fa97f9d269cfb101a389bb771d13c7538
Signed-off-by: Monika Singh <monising@codeaurora.org>
(cherry picked from commit ba9d8be6d5935f1dc3ed1066c000db8b9430e82e)
Signed-off-by: Shrirang Bagul <shrirang.bagul@canonical.com>