Where can I download Windows 8 legally, from Microsoft?

I obtained a licence key for Windows 8 through DreamSpark. Is there a way to download a Windows 8 ISO image like you could for Windows 7? I am on a non-Windows machine, so I cannot use the Secure Download Manager to download Windows 8 directly using DreamSpark.

Solution:

My order confirmation says:

 

If you need to download Windows, write down your new product key and enter it here.

And it links to the Windows Setup.exe.

Additionally, there’s this option:

1. Go to https://www.mswos.com/

2. Fill out the details of your order.

   

3. You’ll find the download link at the bottom of the page.