Improving performance of --show #1

[mohemiv]

Related: #3988

Let's take a look into src/hashcat.c file:

    while (!hc_feof (&fp))
    {
      const size_t line_len = fgetl (&fp, line_buf, HCBUFSIZ_LARGE);

      if (line_len == 0) continue;

      char *hash_buf = NULL;
      int   hash_len = 0;

      hlfmt_hash (hashcat_ctx, hashlist_format, line_buf, line_len, &hash_buf, &hash_len);

      bool hash_fmt_error = false;

      if (hash_len < 1)     hash_fmt_error = true;
      if (hash_buf == NULL) hash_fmt_error = true;

      if (hash_fmt_error) continue;

      int parser_status = module_ctx->module_hash_decode (hashconfig, digest, salt, esalt, hook_salt, hash_info, hash_buf, hash_len);

This code uses module_hash_decode in a loop and doesn't memset salt, esalt, or hook_salt. Therefore, we can conclude that it's safe to use module_hash_decode without memsetting the buffers.