> On 03.05.2020, at 13:26, Heiko Stuebner <he...@sntech.de> wrote:
>
> From: Heiko Stuebner <heiko.stueb...@theobroma-systems.com>
>
> To fill the exponent field of the rsa_public_key struct, rsa_mod_exp_sw
> did a cast to uint64_t of the key_prop->public_exponent field.
> But that alignment is not guaranteed in all cases.
>
> This came to light when in my spl-fit-signature the key-name exceeded
> a certain length and with it the verification then started failing.
> (naming it "integrity" worked fine, "integrity-uboot" failed)
>
> key_prop.public_exponent itself is actually a void-pointer, fdt_getprop()
> also just returns such a void-pointer and inside the devicetree the 64bit
> exponent is represented as 2 32bit numbers, so assuming a 64bit alignment
> can lead to false reads.
>
> So just use the already existing rsa_convert_big_endian() to do the actual
> conversion from the dt's big-endian to the needed uint64 value.
>
> Fixes: fc2f4246b4b3 ("rsa: Split the rsa-verify to separate the modular
> exponentiation")
> Signed-off-by: Heiko Stuebner <heiko.stueb...@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.toms...@theobroma-systems.com>
