Function fxBigInt_mod_exp_LR

modules/crypt/arith/xsBigIntEx.c:369–392

}

txBigInt *fxBigInt_mod_exp_LR(txMachine *the, txBigInt *r, txBigInt *b, txBigInt *e, txBigInt *m)
{
	int i;
	txBigInt *t, *t2 = NULL;
	pool_t pool;
	
	pool_init(&pool);
	if (r == NULL)
		r = fxBigInt_alloc(the, m->size);
	t = pool_get(the, m->size, &pool);
	t = mod_exp_init(the, t, m);
	if (fxBigInt_ucomp(b, m) > 0) {
		t2 = pool_get(the, m->size, &pool);
		b = fxBigInt_mod(the, t2, b, m);
	}
	for (i = fxBigInt_bitsize(e); --i >= 0;) {
		fxBigInt_mod_square(the, t, t, m, &pool);
		if (fxBigInt_isset(e, i))
			fxBigInt_mod_mul(the, t, t, b, m,&pool);
	}
	fxBigInt_copy(r, t);
	pool_dispose(the, &pool);
	return r;
}

/*
 * Montgomery method