feat: detour region-restriction

[iomz]

https://github.com/jackyzy823/rajiko detours the region restriction and even allows downloading a stream from any region.
Investigate the mechanism and allow radicron to save fetch a program from anywhere.

[iomz]

This feature would be somewhat policy-violating: jackyzy823/rajiko#6

I'm fine with paying the radiko premium fee then, although I am technically interested.

[garret1317]

the mechanism is:
extract key from mobile app
used to be enormous pain with the old app apparently, but it's just sitting there in the v8 apk (/assets/flutter_assets/assets/key/android.jpg, verify with mitmproxy script)
now you can pretend to be the mobile app
mobile app gets region locked by telling auth2 its physical location in X-Radiko-Location
since we're just pretending to be the app, we can tell it whatever we want

fwiw yeah it is policy violating, but i prefer being able to listen to the stuff i want over not being able to lol
like you, wouldnt mind paying, but only if it gives me legitimate access from outside japan

[iomz]

Thanks for your comment @garret1317

Yeah you are right. Right after commented above, I came to know the payment requires a Japanese address, so after all figured out how it's done by rajiko and secretly implemented it: https://github.com/iomz/radicron/blob/6d2a46e35036f8ab7a5664b8d48c5aeefbdf8cc8/auth.go#LL39C2-L39C2

I guess it'll be just alright as long as keeping a "low profile" 😂