Which node(s), if any, in the circuit for a hidden service, can see the URI of a request to a hidden service?

Question

I understand that all of the communication between a client and a hidden service (.onion) takes place within the Tor network and is therefore end-to-end encrypted. What I am wondering, however, is how the URL / URI of a given request is handled. If in my Tor Browser I see this;

http://hiddenservxxxxxx.onion/index.php?page=someidentifyinginformation

Are there nodes within the Tor circuit that can see that I am attempting to access a page with some potentially identifying information in it?

Is the whole URL obscured from leaking sensitive info? Or even part of it?

Answer 1

(Assuming the URL is http://X.onion?foo=bar)

One relay (HSDir) knows that someone (but not who) wanted to look up the record for where to leave a message to request to talk to "X".

Another relay (Introduction Point) knows that someone (but not who) left a message asking to talk to "Y" (see note.) at some location that it doesn't know.

(Note: "Y" is not the same as "X", it is actually a distinct key that it published for each Introduction Point in the Hidden Service descriptor. If the Introduction Point has a descriptor for "X", it knows "Y" is "X" and therefor it is serving "X", otherwise it knows nothing about either party.)

Yet another relay (Rendezvous Point) know that someone (but not who) is talking to some hidden service (but not which).

No single relay knows with certainty that they ever did talk or who either of the participants were nor what they spoke about.

At most the value of "X" is known by some HSDir(s).

Answer 2

http://

and

/index.php?page=someidentifyinginformation

Only you and HS, because end-to-end encryption takes place. Encryption hides the protocol you use and thus its payload (in this case /index.php?page=someidentifyinginformation).

hiddenservxxxxxx.onion

Introduction points, you and HS. The guard and the last hop of the HS circuit and rendezvous points may also know this through some sort of attacks (actually all nodes can know if the attack is 'strong' enough).