HSIntro supports protocol versions 3 and 4: ``` The "HSIntro" protocol handles introduction points. "3" -- supports authentication as of proposal 121 in Tor 0.2.1.6-alpha. "4" -- support ed25519 authentication keys which is defined by the HS v3 protocol as part of proposal 224 in Tor 0.3.0.4-alpha. ``` But rend_service_update_descriptor() says "intro protocols 2 and 3": ``` /* Support intro protocols 2 and 3. */ d->protocols = (1 << 2) + (1 << 3); ``` I think we need to delete "2" here. And rend_service_descriptor_t says "introduce/rendezvous" 0-3: ``` /** Bitmask: which introduce/rendezvous protocols are supported? * (We allow bits '0', '1', '2' and '3' to be set.) */ unsigned protocols : REND_PROTOCOL_VERSION_BITMASK_WIDTH; ``` I think we need to delete "/rendezvous" and 0-2 here. This seems to be a bug in 496fe68 in 0.2.5.3-alpha.