From 621f4f14afe83d15d04c5aae2f3290e51ff84bce Mon Sep 17 00:00:00 2001
From: Marco Oliverio <marco@wolfssl.com>
Date: Thu, 16 Jun 2022 13:51:39 +0200
Subject: [PATCH] kdf: fix clang uninitialized.Assign

commit f1ce0cc95d22569640bc522354025fbc16c88e43 tigger static analyzer warnings
about unitialized assign.
---
 wolfcrypt/src/kdf.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/wolfcrypt/src/kdf.c b/wolfcrypt/src/kdf.c
index 18b02c16f..a10c734bd 100644
--- a/wolfcrypt/src/kdf.c
+++ b/wolfcrypt/src/kdf.c
@@ -150,6 +150,11 @@ int wc_PRF(byte* result, word32 resLen, const byte* secret,
     if (lastLen)
         times += 1;
 
+    /* times == 0 iif resLen == 0, but times == 0 abides clang static analyzer
+       while resLen == 0 doesn't */
+    if (times == 0)
+        return BAD_FUNC_ARG;
+
     lastTime = times - 1;
 
     ret = wc_HmacInit(hmac, heap, devId);