Aside: in pursuit of helping Jake register “.onion” as a "special name” in an RFC, I am currently being beaten-up on the IETF discussion mail-list regards the potential future length of onion addresses, and that they may possibly exceed the bounds of DNS’ maximum label length of 63 characters:
https://www.ietf.org/mail-archive/web/ietf/current/msg94332.html https://www.ietf.org/mail-archive/web/ietf/current/msg94332.html
The examples in Proposal 224 are a mere 53 characters long leaving 10 to play with for padding-hyphens and possibly checksum characters.
Nick: Is this likely to need to change? Or might there be a need to encode > 315 bits / 63 chars total?
-a
— Alec Muffett Security Infrastructure Facebook Engineering London