It's not about "where to direct the SSL request". It's about selecting the correct server certificate. The handshake goes something like this: the client opens

It's not about "where to direct the SSL request". It's about selecting the correct server certificate. The handshake goes something like this: the client opens the connection and sends several parameters (in the clear). The server replies with its parameters (in the clear) and its certificate (in the clear, and it includes the domain name). Both sides exchange the key to be used (encrypted), switch to encrypted mode, and verify the handshake. Notice that, even without SNI, the hostname is already sent by the server, in the clear, within the certificate. That poses a chicken-and-egg dilemma: the hostname is sent to the server after the handshake is finished, but the server has to present the correct certificate before the handshake is finished. The solution was to send the hostname (and only the hostname) at the start of the handshake. It's no big deal because the certificate hostname is already visible in the next handshake step. For Tor, it's no big issue: it just manufactures a random hostname and presents it. Tor would have to do it (in the certificate) even without SNI. When using Tor, this does not compromise the domains requested by the browser, since they are sent directly to the exits within the triple-encrypted tunnel; only the chosen exits can see them.