BN_BYTES
#if BN_BYTES == 8
if (bytes > (INT_MAX - BN_BYTES + 1))
words = (bytes + BN_BYTES - 1) / BN_BYTES;
#if BN_BYTES == 8
if (BN_num_bytes(bn) <= BN_BYTES)
if (BN_is_zero(bn) || BN_num_bytes(bn) > BN_BYTES)
if (BN_num_bytes(bn) <= BN_BYTES)
#if BN_BYTES == 8