lib: Remove some unneeded zeroizing of memory.

Author: besser82

lib/alg-gost3411-2012-hmac.c

@@ -29,15 +29,9 @@ void
 gost_hash256 (const uint8_t *t, size_t n, uint8_t *out32,
               GOST34112012Context *ctx)
 {
-  /* Clear the context state. */
-  explicit_bzero (ctx, sizeof (GOST34112012Context));
-
   GOST34112012Init (ctx, GOSTR3411_2012_BITS);
   GOST34112012Update (ctx, t, n);
   GOST34112012Final (ctx, out32);
-
-  /* Clear the context state. */
-  explicit_bzero (ctx, sizeof (GOST34112012Context));
 }
 
 /* HMAC_GOSTR3411_2012_256 */
@@ -47,9 +41,6 @@ gost_hmac256 (const uint8_t *k, size_t n, const uint8_t *t, size_t len,
 {
   size_t i;
 
-  /* Clear the context state. */
-  explicit_bzero (gostbuf, sizeof (gost_hmac_256_t));
-
   /* R 50.1.113-2016 only allowed N to be in range 256..512 bits */
   assert (n >= GOSTR3411_2012_L && n <= GOSTR3411_2012_B);
 

lib/alg-hmac-sha1.c

@@ -81,9 +81,6 @@ hmac_sha1_process_data (const uint8_t *text, size_t text_len,
       sha1_process_bytes (key, &tctx, key_len);
       sha1_finish_ctx(&tctx, &tk);
 
-      /* Clean the stack. */
-      explicit_bzero (&tctx, sizeof (struct sha1_ctx));
-
       key = tk;
       key_len = HASH_LENGTH;
     }
@@ -124,7 +121,6 @@ hmac_sha1_process_data (const uint8_t *text, size_t text_len,
   sha1_finish_ctx(&ctx, resbuf);
 
   /* Clean the stack. */
-  explicit_bzero (&ctx, sizeof (struct sha1_ctx));
   explicit_bzero (k_ipad, HMAC_BLOCKSZ);
 
   /*
@@ -138,7 +134,6 @@ hmac_sha1_process_data (const uint8_t *text, size_t text_len,
   sha1_finish_ctx(&ctx, resbuf);
 
   /* Clean the stack. */
-  explicit_bzero (&ctx, sizeof (struct sha1_ctx));
   explicit_bzero (k_opad, HMAC_BLOCKSZ);
 }