Reviewed-by: Marcelo Henrique Cerri <marcelo.ce...@canonical.com> Tested-by: Marcelo Henrique Cerri <marcelo.ce...@canonical.com>
On Sun, Jul 12, 2020 at 06:40:57PM +0200, Stephan Müller wrote:
> After the generation of a local public key, SP800-56A rev 3 section
> 5.6.2.1.3 mandates a validation of that key with a full validation
> compliant to section 5.6.2.3.1.
>
> Only if the full validation passes, the key is allowed to be used.
>
> Signed-off-by: Stephan Mueller <smuel...@chronox.de>
> ---
> crypto/dh.c | 59 ++++++++++++++++++++++++++++++-----------------------
> 1 file changed, 34 insertions(+), 25 deletions(-)
>
> diff --git a/crypto/dh.c b/crypto/dh.c
> index f84fd50ec79b..cd4f32092e5c 100644
> --- a/crypto/dh.c
> +++ b/crypto/dh.c
> @@ -180,32 +180,41 @@ static int dh_compute_value(struct kpp_request *req)
> if (ret)
> goto err_free_base;
>
> - /* SP800-56A rev3 5.7.1.1 check: Validation of shared secret */
> - if (fips_enabled && req->src) {
> - MPI pone;
> -
> - /* z <= 1 */
> - if (mpi_cmp_ui(val, 1) < 1) {
> - ret = -EBADMSG;
> - goto err_free_base;
> - }
> -
> - /* z == p - 1 */
> - pone = mpi_alloc(0);
> -
> - if (!pone) {
> - ret = -ENOMEM;
> - goto err_free_base;
> + if (fips_enabled) {
> + /* SP800-56A rev3 5.7.1.1 check: Validation of shared secret */
> + if (req->src) {
> + MPI pone;
> +
> + /* z <= 1 */
> + if (mpi_cmp_ui(val, 1) < 1) {
> + ret = -EBADMSG;
> + goto err_free_base;
> + }
> +
> + /* z == p - 1 */
> + pone = mpi_alloc(0);
> +
> + if (!pone) {
> + ret = -ENOMEM;
> + goto err_free_base;
> + }
> +
> + ret = mpi_sub_ui(pone, ctx->p, 1);
> + if (!ret && !mpi_cmp(pone, val))
> + ret = -EBADMSG;
> +
> + mpi_free(pone);
> +
> + if (ret)
> + goto err_free_base;
> +
> + /* SP800-56A rev 3 5.6.2.1.3 key check */
> + } else {
> + if (dh_is_pubkey_valid(ctx, val)) {
> + ret = -EAGAIN;
> + goto err_free_val;
> + }
> }
> -
> - ret = mpi_sub_ui(pone, ctx->p, 1);
> - if (!ret && !mpi_cmp(pone, val))
> - ret = -EBADMSG;
> -
> - mpi_free(pone);
> -
> - if (ret)
> - goto err_free_base;
> }
>
> ret = mpi_write_to_sgl(val, req->dst, req->dst_len, &sign);
> --
> 2.26.2
>
>
>
>
--
Regards,
Marcelo
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