From be2ad82e6d5b31db143531c8c5d81666b5b6a2bf Mon Sep 17 00:00:00 2001
From: elms <jeff@wolfssl.com>
Date: Wed, 25 Aug 2021 14:59:51 -0700
Subject: [PATCH] sp_math: error on multiplier larger than curve order

zd 12674
---
 wolfcrypt/src/ecc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/wolfcrypt/src/ecc.c b/wolfcrypt/src/ecc.c
index c5be45d08..0ff14a63d 100644
--- a/wolfcrypt/src/ecc.c
+++ b/wolfcrypt/src/ecc.c
@@ -3121,6 +3121,11 @@ exit:
 
    (void)a;
 
+   /* k can't have more bits than modulus count plus 1 */
+   if (mp_count_bits(k) > mp_count_bits(modulus) + 1) {
+       return ECC_OUT_OF_RANGE_E;
+   }
+
 #ifdef WOLFSSL_HAVE_SP_ECC
 #ifndef WOLFSSL_SP_NO_256
    if (mp_count_bits(modulus) == 256) {