[thelist] download complete verification

[Hassan Schroeder]

> This is what my client has asked me:
> 
> "As a general prudent measure we need to know when every download has
> been successfully downloaded and completed.  This is absolutely
> essential for any goods/items that are delivered as a result of the
> customer making a payment to us.  We need irrefutable proof that a
> customer has received the goods/item (could include serial number
> deliverd by email) that they have paid for.  One instance where this is
> essential is in regard to charge backs - we need to prove that they have
> in fact received the goods/serial number.  We don't have a leg to stand
> on if we can't prove that the customer has received the goods.  I assume
> and hope that this isn't a problem - based on the principle that our
> server is talking to their pc whilst it is downloading and all it needs
> to do is send a "I've definitely completed the download" message once it
> has successfully completed.  Tell me if it's not that simple."

This is where you say "it's not that simple"  :-)

Your client is banking on the actions of an unknown and *untrusted*
user-agent (FTP client) to confirm the completion of a transaction.

Bad idea.

One possibility is to require the customer to download your own
tailored downloader which then handles the entire process, and will
return confirmation if the download completes successfully.

FWIW!
-- 
Hassan Schroeder ----------------------------- hassan at webtuitive.com
Webtuitive Design ===  (+1) 408-938-0567   === http://webtuitive.com

                           dream.  code.