if (!(bin = driver_alloc_binary(len))) {
if (!(bin = driver_alloc_binary(16))) {
static void md4drv_from_erlang(ErlDrvData drv_data, char *buf, int len){    MD4_CTX context;    unsigned char digest[16];    t_md4drv *md4 = (t_md4drv *) drv_data;    ErlDrvBinary *bin = NULL;    MD4Init(&context);    MD4Update(&context, buf, len);    MD4Final(digest, &context);    if (!(bin = driver_alloc_binary(len))) {	driver_send_error(md4, &am_enomem);    }    else {	memcpy(bin->orig_bytes, digest, 16);	driver_send_bin(md4, bin, 16);	driver_free_binary(bin);    }    return;}