In USA and UK at least unauthorised access or use of a computer is criminalised. On some situations you can argue for assumed consent, the law doesn't operate on "if I can do it then it's authorised". Unless you can show you have permission then it's not authorised, ergo not legal.
But the premise was to circumvent crap such as captive portals. Doing that on your own computer (mostly in a public wlan), I don't see any reason against it.
Who is the "someone else" in your case? Where does the someone else's hardware come from? OP mentioned this to get rid off e.g captive portals.
Iodine requires a client and a server. Both belong to you, what is the problem here? That I use a network to transmit packets? We are not talking about installing iodine on someone else's computer!
Not sure if you're trolling, but the network is being accessed by bypassing the captive portal. The network is being accessed in a way that isn't permitted.
So the network is not password protected, DNS (or ICMP) works normally, but somehow using it in a particular way is not permitted? Then why does it work at all?
Maybe I'm not understanding this correctly, but if a coffee shop has wifi and you need to enter info into a captive portal before you can use their network, by circumventing it, the "Someone else" is the coffee shop owner, and the hardware is their router.
"Please get off my router if you don't agree to my conditions". "Nah I'm just using DNS, it's fine" probably is not an admissible excuse.
Do you dispute that a coffee shop providing WiFi with a captive portal only intends to provide web access through that portal? Just as they only intend customers to take sugar packets for use in their coffee, etc..
If the shop don't intend the use its not authorised. Your ethical framework may not put any value on that lack of authorisation, but you see the action is unauthorised, surely?
It's unfit for general use and abuses the DNS protocol to stealthily convey data, hence the shadiness. You're right, it needn't be used in a negative way. DNS tunneling is slow, needs polling for incoming traffic (due to the way dns works over udp) and is usually used to circumvent firewalls for both good (censorship) and bad reasons (exfiltrating data).
It's clearly to evade a security control..
As if you approached a door, to find it locked, but then discovered the front window was unlocked and let yourself in.. Clearly the occupant didn't want you to enter, and just failed to secure the entire building. Pretty sure nobody would ever suggest it was okay for you to enter in such a way.
