From e252b1014880b1a49f5fd85b8932e204e324f1fd Mon Sep 17 00:00:00 2001
From: cyliangtw <cyliang@nuvoton.com>
Date: Thu, 9 Nov 2017 16:01:14 +0800
Subject: [PATCH] [M487/NUC472] zeroize random data on the stack memory

---
 targets/TARGET_NUVOTON/TARGET_M480/trng_api.c   | 2 +-
 targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/targets/TARGET_NUVOTON/TARGET_M480/trng_api.c b/targets/TARGET_NUVOTON/TARGET_M480/trng_api.c
index 82e5227d46..87f124801b 100644
--- a/targets/TARGET_NUVOTON/TARGET_M480/trng_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M480/trng_api.c
@@ -92,10 +92,10 @@ int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_l
         output += 32;
     }     
     if( length > *output_length ) {
-        trng_zeroize(tmpBuff, sizeof(tmpBuff));
         trng_get(tmpBuff);
         memcpy(output, &tmpBuff, (length - *output_length));
         *output_length = length;
+        trng_zeroize(tmpBuff, sizeof(tmpBuff));
     }
 
     return 0;
diff --git a/targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c b/targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c
index a8a9498284..a4210e2910 100644
--- a/targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c
@@ -97,10 +97,10 @@ int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_l
         output += 32;
     }     
     if( length > *output_length ) {
-        trng_zeroize(tmpBuff, sizeof(tmpBuff));
         trng_get(tmpBuff);
         memcpy(output, &tmpBuff, (length - *output_length));
         *output_length = length;
+        trng_zeroize(tmpBuff, sizeof(tmpBuff));
     }
 
     return 0;