based on patch from andreas@oetken.name:
http://patchwork.ozlabs.org/patch/294318/
commit message:
I currently need support for rsa-sha256 signatures in u-boot and found out that
the code for signatures is not very generic. Thus adding of different
hash-algorithms for rsa-signatures is not easy to do without copy-pasting the
rsa-code. I attached a patch for how I think it could be better and included
support for rsa-sha256. This is a fast first shot.
aditionally work:
- removed checkpatch warnings
- removed compiler warnings
- rebased against current head
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: andreas@oetken.name
Cc: Simon Glass <sjg@chromium.org>
While signing images is useful, it does not provide complete protection
against several types of attack. For example, it it possible to create a
FIT with the same signed images, but with the configuration changed such
that a different one is selected (mix and match attack). It is also possible
to substitute a signed image from an older FIT version into a newer FIT
(roll-back attack).
Add support for signing of FIT configurations using the libfdt's region
support.
Please see doc/uImage.FIT/signature.txt for more information.
Signed-off-by: Simon Glass <sjg@chromium.org>
RSA provides a public key encryption facility which is ideal for image
signing and verification.
Images are signed using a private key by mkimage. Then at run-time, the
images are verified using a private key.
This implementation uses openssl for the host part (mkimage). To avoid
bringing large libraries into the U-Boot binary, the RSA public key
is encoded using a simple numeric representation in the device tree.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add support for signing images using a new signature node. The process
is handled by fdt_add_verification_data() which now takes parameters to
provide the keys and related information.
Signed-off-by: Simon Glass <sjg@chromium.org>
Heiko Schocher
Wolfgang Denk
Simon Glass