futility: Add create command to make keypairs from RSA files

This command reads a single .pem file and emits the public and
private keys generated from it. It can produce both the old-style
vboot 1.0 keys (.vbpubk and .vbprivk), or the new vboot 2.1
format keys (.vbpubk2 and .vbprik2). The default is the new
format, but you can give futility the --vb1 arg to force the old
format.

A test is included.

BUG=chromium:231547
BRANCH=ToT
TEST=make runtests

Change-Id: I4713dc5bf34151052870f88ba52ddccf9d4dab50
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/246766
Reviewed-by: Randall Spangler <rspangler@chromium.org>
17 files changed