This may be a long shot since it's been a while since this thread was active, but I'm trying to get the same scenario working. How are you generating the signature? I am sha1 hashing a string version of the access policy, and then rsa signing it. I'm getting an "Access Denied" error every time. I was not able to get the signature right with URL signing either. I always got "Access Denied" with that as well. I am able to use
Amazon's URL-signing perl script to sign URLs and get temporary access to my content, but I can't run perl code in my Roku channel... Unfortunately, the hashing/signing process I do in brightscript doesn't come up with a working signature.
