Programmatically purchase from a website in C# or javascript

Hey guys, I'm trying to create a website that can help a user purchase items from other websites. What would be the best way to go about doing this?

I know most of the sites I'm using are sending their information using FORM:POST, but I'm having trouble finding the exact POST packet in fiddler (I'm assuming it's encrypted?), and know that a lot of the sites are using login credentials, so that complicates th开发者_JS百科ings a bit.

Is there any way I could use webkit or something to handle all the http stuff, and just pass javascript to fill in the forms? Or is there an even simpler way to create proper POST packets and use a WebRequest?

Thank you!

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1) get permission
2) use their published API

If the sites do not have an API and allow you to use their server process, copy their forms to your site and use post. You can post from your server with credentials using for example CURL

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Usually shopping cart and credit-card transaction use SSL and you have to login in the site. So I think it's not so simple to bridge with a javascript or a simple webrequest.

There's not a statndard-simple-way way to do this!

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You're heading for a world of hurt.

First, you should check if what you're trying to do is legal. Does the web site allow "proxy orders"? Or are they forbidden by their EULA?

Second, you'll have to handle the user's confidential data (username, password, credit card number), and especially credit card numbers are calling for troubles.

Third, how are you planning to implement payment methods like PayPal? You're going to collect the user's PayPal credentials in order to make payments on their behalf? (See point number two if answer is yes.)

Fourth, since you have to fake HTTP requests, as soon as the web site changes a single field, your tool will break, how are you planning to handle this?

Or you're trying to automate only the first steps of the orders and not the payment?