Many payment gateways, like PayPal and Stripe, offer a client side
Form where you input the sale data (price, amount, buyer address, etc), and it’s being sent to the gateway (e.g PayPal) from the client side.
But, at this point when i fill the form using
I know things has to be validated on my server, but validation means that the server is sending back to client a response saying this price is good or not good, but this respond can also be manipulated.
So how is it that companies allow client side payment anyway using a form ? How/where the actual sale data is being passed to the payment gateway ? client? server?