From 83169f91e9f0db88633ac1d1cfb60d1b71c0c68e Mon Sep 17 00:00:00 2001
From: jordan <jordan@wolfssl.com>
Date: Sat, 3 Feb 2024 17:36:26 -0600
Subject: [PATCH] Fix ShaFinal overrun.

---
 wolfcrypt/src/sha.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/wolfcrypt/src/sha.c b/wolfcrypt/src/sha.c
index 1f4439f0f..69990791f 100644
--- a/wolfcrypt/src/sha.c
+++ b/wolfcrypt/src/sha.c
@@ -841,7 +841,10 @@ int wc_ShaFinal(wc_Sha* sha, byte* hash)
 
     /* pad with zeros */
     if (sha->buffLen > WC_SHA_PAD_SIZE) {
-        XMEMSET(&local[sha->buffLen], 0, WC_SHA_BLOCK_SIZE - sha->buffLen);
+        if (sha->buffLen < WC_SHA_BLOCK_SIZE) {
+            XMEMSET(&local[sha->buffLen], 0, WC_SHA_BLOCK_SIZE - sha->buffLen);
+        }
+
         sha->buffLen += WC_SHA_BLOCK_SIZE - sha->buffLen;
 
     #if defined(WOLFSSL_USE_ESP32_CRYPT_HASH_HW)