Normally, multiple public keys can be provided and U-Boot is not
required to use all of them for verification. This is because some
images may not be signed, or may be optionally signed.

But we still need a mechanism to determine when a key must be used.
This feature cannot be implemented in the FIT itself, since anyone
could change it to mark a key as optional. The requirement for
key verification must go in with the public keys, in a place that
is protected from modification.

Add a -r option which tells mkimage to mark all keys that it uses
for signing as 'required'.

If some keys are optional and some are required, run mkimage several
times (perhaps with different key directories if some keys are very
secret) using the -F flag to update an existing FIT.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMarek Vasut <marex@denx.de>

When signing an image, it is useful to add some details about which tool
or person is authorising the signing. Add a comment field which can take
care of miscellaneous requirements.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMarek Vasut <marex@denx.de>

When signing images it is sometimes necessary to sign with different keys
at different times, or make the signer entirely separate from the FIT
creation to avoid needing the private keys to be publicly available in
the system.

Add a -F option so that key signing can be a separate step, and possibly
done multiple times as different keys are avaiable.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMarek Vasut <marex@denx.de>

FIT image verification requires public keys. Add a convenient option to
mkimage to write the public keys to an FDT blob when it uses then for
signing an image. This allows us to use:

   mkimage -f test.its -K dest.dtb -k keys test.fit

and have the signatures written to test.fit and the corresponding public
keys written to dest.dtb. Then dest.dtb can be used as the control FDT
for U-Boot (CONFIG_OF_CONTROL), thus providing U-Boot with access to the
public keys it needs.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMarek Vasut <marex@denx.de>

Keys required for signing images will be in a specific directory. Add a
-k option to specify that directory.

Also update the mkimage man page with this information and a clearer list
of available commands.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de> (v1)

Signed-off-by: NHorst Kronstorfer <hkronsto@frequentis.com>

Signed-off-by: NHorst Kronstorfer <hkronsto@frequentis.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>

By default, "-" chars are interpreted as hyphens (U+2010) by groff, not
as minus signs (U+002D). Since options to programs use minus signs
(U+002D), this means for example in UTF-8 locales that you cannot cut
and paste options, nor search for them easily.

(Reported by lintian.)
Signed-off-by: NLoc Minier <loic.minier@linaro.org>

Some Linux distributions include the "mkimage" as a package.
This commit provides a manual page for mkimage.
Signed-off-by: NNobuhiro Iwamatsu <iwamatsu@nigauri.org>

Added documentation for FIT images and examples.
Moved to doc/ directory.
Signed-off-by: NWolfgang Denk <wd@denx.de>