tls: fix the case of sp_256_mont_tpl_10() leaving striay high bits

It has no effect on correctness, but interferes with compating internal state
of different implementations.

function                                             old     new   delta
sp_256_proj_point_dbl_10                             443     451      +8
static.sp_256_mont_sub_10                             46      49      +3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 11/0)               Total: 11 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/networking/tls.h b/networking/tls.h
index 215e92b02..eb0fdd4cf 100644
--- a/networking/tls.h
+++ b/networking/tls.h
@@ -117,3 +117,7 @@ void curve_x25519_compute_pubkey_and_premaster(
 void curve_P256_compute_pubkey_and_premaster(
                 uint8_t *pubkey2x32, uint8_t *premaster32,
                 const uint8_t *peerkey2x32) FAST_FUNC;
+
+void curve_P256_compute_pubkey_and_premaster_NEW(
+                uint8_t *pubkey2x32, uint8_t *premaster32,
+                const uint8_t *peerkey2x32) FAST_FUNC;