[U-Boot] [PATCH] rsa: Return immediately if required-key verification fails

[Simon Glass]

Hi Daniele,

On Sat, 14 Sep 2019 at 04:37, Daniele Alessandrelli
<daniele.alessandrelli at gmail.com> wrote:
>
> Currently, if image verification with a required key fails, rsa_verify()
> code tries to find another key to verify the FIT image. This however, is
> not the intended behavior as the documentation says that required keys
> "must be verified for the image / configuration to be considered valid".
>
> This patch fixes the issue by making rsa_verify() return immediately if
> the verification of a required key fails.
>
> Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli at gmail.com>
> ---
>  lib/rsa/rsa-verify.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
> index 287fcc4d23..82dc513260 100644
> --- a/lib/rsa/rsa-verify.c
> +++ b/lib/rsa/rsa-verify.c
> @@ -437,8 +437,7 @@ int rsa_verify(struct image_sign_info *info,
>         if (info->required_keynode != -1) {
>                 ret = rsa_verify_with_keynode(info, hash, sig, sig_len,
>                         info->required_keynode);
> -               if (!ret)
> -                       return ret;
> +               return ret;
>         }
>
>         /* Look for a key that matches our hint */
> --
> 2.21.0
>

Thanks for the patch.

Unfortunately I don't think it is worth taking a patch in this area
without updating the test. Will see if someone has time to do that.

Regards,
Simon