_gnutls_encrypt (gnutls_session_t session, const opaque * headers,
		 size_t headers_size, const opaque * data,
		 size_t data_size, opaque * ciphertext,
		 size_t ciphertext_size, content_type_t type, int random_pad)
{
  gnutls_datum_t plain;
  gnutls_datum_t comp;
  int ret;
  int free_comp = 1;

  plain.data = (opaque *) data;
  plain.size = data_size;

  if (plain.size == 0 || is_write_comp_null (session) == 0)
    {
      comp = plain;
      free_comp = 0;
    }
  else
    {
      /* Here comp is allocated and must be 
       * freed.
       */
      ret = _gnutls_m_plaintext2compressed (session, &comp, &plain);
      if (ret < 0)
	{
	  gnutls_assert ();
	  return ret;
	}
    }

  ret = _gnutls_compressed2ciphertext (session, &ciphertext[headers_size],
				       ciphertext_size - headers_size,
				       comp, type, random_pad);

  if (free_comp)
    _gnutls_free_datum (&comp);

  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }


  /* copy the headers */
  memcpy (ciphertext, headers, headers_size);
  _gnutls_write_uint16 (ret, &ciphertext[3]);

  return ret + headers_size;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.