From 2c84eee2df3cc64c137e57a3d8be650de27b0ec6 Mon Sep 17 00:00:00 2001
From: John Blixt <jblixt@wolfssl.com>
Date: Wed, 7 Jun 2017 11:55:55 -0600
Subject: [PATCH] Fix wc_SetKeyUsage() value error.

---
 wolfcrypt/src/asn.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c
index f615728d8..7669fda90 100644
--- a/wolfcrypt/src/asn.c
+++ b/wolfcrypt/src/asn.c
@@ -9082,7 +9082,9 @@ int wc_SetKeyUsage(Cert *cert, const char *value)
     XSTRNCPY(str, value, XSTRLEN(value));
 
     /* parse value, and set corresponding Key Usage value */
-    token = XSTRTOK(str, ",", &ptr);
+    if ((token = XSTRTOK(str, ",", &ptr)) == NULL) {
+        return KEYUSAGE_E;
+    }
     while (token != NULL)
     {
         len = (word32)XSTRLEN(token);