[RFC PATCH v3 7/8] mkimage: add public key for image pre-load stage

Philippe REYNES philippe.reynes at softathome.com
Fri Dec 3 11:29:43 CET 2021

Hi Simon,

Le 25/11/2021 à 01:13, Simon Glass a écrit :
> Hi Philippe,
> On Wed, 17 Nov 2021 at 10:52, Philippe Reynes
> <philippe.reynes at softathome.com> wrote:
>> This commit enhances mkimage to update the node
>> /image/pre-load/sig with the public key.
>> Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
>> ---
>>   include/image.h    |  15 ++++++
>>   tools/fit_image.c  |   3 ++
>>   tools/image-host.c | 116 +++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 134 insertions(+)
> I'm a bit unsure about the format of the key here. Is it different
> from the normal one used by U-Boot?
The format used by pkey is the der format without the first 24 bytes.
For example, to create this key in a shell, I use the following commands :

openssl rsa -in private.pem -pubout -outform der -out public.der
dd if=public.der of=public.raw bs=24 skip=1

As described in the comment line 340 in the file test/lib/asn1.c.

> Regards,
> Simon

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