keygeneration: psp verstagebl: refactor key gen & csr generation

We want to separate the stages of creating the key & using the key as
our HSM tools use different commands for these.

This also means we no longer need a passphrase at all.

BUG=b:166095736
TEST=ran script before & after and made sure output (largely) looked the same
BRANCH=None

Change-Id: Id488789f83c21ffb6263489e3c22531878ceb1f2
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2391219
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
1 file changed