Google Checkout, OpenId, and downloadable products

I going to use Google Checkout to process orders to purchase downloadable content. When the order process is completed via Google Checkout I'd like for the user to be able come back to my site, authenticate using their 开发者_StackOverflowGoogle credentials (OpenID?) that they purchased the item with linked back end, and download the goods. The site is written using C# and ASP.NET MVC.

Is this possible or how should I rethink this? Are there open-source libraries to get me started?

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I don't know anything about Google Checkout, but I know that No.1 library for OpenId is DotNetOpenAuth.

See project project home page, authors blog or search stackoverflow for details. There are also examples in the library download to get you started.

Cheers!

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Google Checkout offers a Digital Delivery service to sell downloadable content.

See the document below for more info on digital delivery options, specific Checkout API requests and the buyer's experience in completing an order for digitally delivered goods:

http://code.google.com/apis/checkout/developer/Google_Checkout_Digital_Delivery.html