Revert XMEMSET 0 after free in copy process for digest/hashing functions

Author: night1rider

wolfcrypt/src/md5.c

@@ -540,8 +540,6 @@ int wc_Md5Copy(wc_Md5* src, wc_Md5* dst)
     /* Free dst resources before copy to prevent memory leaks (e.g.,
      * hardware contexts). XMEMCPY overwrites dst. */
     wc_Md5Free(dst);
-    XMEMSET(dst, 0, sizeof(wc_Md5));
-
     XMEMCPY(dst, src, sizeof(wc_Md5));
 
 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_MD5)

wolfcrypt/src/sha.c

@@ -1175,8 +1175,6 @@ int wc_ShaCopy(wc_Sha* src, wc_Sha* dst)
     /* Free dst resources before copy to prevent memory leaks (e.g., msg
      * buffer, W cache, hardware contexts). XMEMCPY overwrites dst. */
     wc_ShaFree(dst);
-    XMEMSET(dst, 0, sizeof(wc_Sha));
-
     XMEMCPY(dst, src, sizeof(wc_Sha));
 
 #if defined(WOLFSSL_SILABS_SE_ACCEL) && defined(WOLFSSL_SILABS_SE_ACCEL_3)

wolfcrypt/src/sha256.c

@@ -2585,8 +2585,6 @@ int wc_Sha224_Grow(wc_Sha224* sha224, const byte* in, int inSz)
         /* Free dst resources before copy to prevent memory leaks (e.g., msg
          * buffer, W cache, hardware contexts). XMEMCPY overwrites dst. */
         wc_Sha224Free(dst);
-        XMEMSET(dst, 0, sizeof(wc_Sha224));
-
         XMEMCPY(dst, src, sizeof(wc_Sha224));
 
     #ifdef WOLFSSL_SMALL_STACK_CACHE
@@ -2736,8 +2734,6 @@ int wc_Sha256Copy(wc_Sha256* src, wc_Sha256* dst)
     /* Free dst resources before copy to prevent memory leaks (e.g., msg
      * buffer, W cache, hardware contexts). XMEMCPY overwrites dst. */
     wc_Sha256Free(dst);
-    XMEMSET(dst, 0, sizeof(wc_Sha256));
-
     XMEMCPY(dst, src, sizeof(wc_Sha256));
 
 #ifdef WOLFSSL_MAXQ10XX_CRYPTO

wolfcrypt/src/sha3.c

@@ -1309,8 +1309,6 @@ static int wc_Sha3Copy(wc_Sha3* src, wc_Sha3* dst)
     /* Free dst resources before copy to prevent memory leaks (e.g.,
      * hardware contexts). XMEMCPY overwrites dst. */
     wc_Sha3Free(dst);
-    XMEMSET(dst, 0, sizeof(wc_Sha3));
-
     XMEMCPY(dst, src, sizeof(wc_Sha3));
 
 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_SHA3)

wolfcrypt/src/sha512.c

@@ -2252,8 +2252,6 @@ int wc_Sha512Copy(wc_Sha512* src, wc_Sha512* dst)
     /* Free dst resources before copy to prevent memory leaks (e.g., msg
      * buffer, W cache, hardware contexts). XMEMCPY overwrites dst. */
     wc_Sha512Free(dst);
-    XMEMSET(dst, 0, sizeof(wc_Sha512));
-
     XMEMCPY(dst, src, sizeof(wc_Sha512));
 #ifdef WOLFSSL_SMALL_STACK_CACHE
     /* This allocation combines the customary W buffer used by
@@ -2695,8 +2693,6 @@ int wc_Sha384Copy(wc_Sha384* src, wc_Sha384* dst)
     /* Free dst resources before copy to prevent memory leaks (e.g., msg
      * buffer, W cache, hardware contexts). XMEMCPY overwrites dst. */
     wc_Sha384Free(dst);
-    XMEMSET(dst, 0, sizeof(wc_Sha384));
-
     XMEMCPY(dst, src, sizeof(wc_Sha384));
 
 #ifdef WOLFSSL_SMALL_STACK_CACHE