From 52e6ff7c5602ef93210aaa679666d8336bedda4a Mon Sep 17 00:00:00 2001
From: Guido Vranken <guidovranken@gmail.com>
Date: Tue, 6 Apr 2021 01:34:09 +0200
Subject: [PATCH] Account for sp_sqr failure in _sp_exptmod_nct

ZD 12039
---
 wolfcrypt/src/sp_int.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index d22dd82bc..bd94e9d00 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -8874,7 +8874,7 @@ static int _sp_exptmod_nct(sp_int* b, sp_int* e, sp_int* m, sp_int* r)
                 /* Sqaure until we find bit that is 1 or there's less than a
                  * window of bits left.
                  */
-                while ((i >= 0) || (c >= winBits)) {
+                while (err == MP_OKAY && ((i >= 0) || (c >= winBits))) {
                     sp_digit n2 = n;
                     int c2 = c;
                     int i2 = i;