"Rejecting truncated ESTABLISH_INTRO cell" warns

[Roger Dingledine <arma@xxxxxxx>]

Hi folks,

A number of server operators have been reporting seeing these lines
in their logs lately:

Sep 25 04:59:13.165 [warn] Rejecting truncated ESTABLISH_INTRO cell.
Sep 25 05:31:56.838 [warn] Rejecting truncated ESTABLISH_INTRO cell.
Sep 25 05:57:53.254 [warn] Rejecting truncated ESTABLISH_INTRO cell.
Sep 25 06:28:13.560 [warn] Rejecting truncated ESTABLISH_INTRO cell.
Sep 25 08:06:53.230 [warn] Rejecting truncated ESTABLISH_INTRO cell.
Sep 25 08:28:56.614 [warn] Rejecting truncated ESTABLISH_INTRO cell.
...

Two notes:

A) This is not a problem with your server, it's a problem with a Tor
client somewhere behaving in a way we didn't expect. So there's no need
to shut down your server, worry about security issues from this, etc. :)
If the warnings continue, we'll make them quieter in the next release.
Which leads me to:

B) Somewhere in the world somebody is working on a new implementation
of Tor hidden services, but it's currently making malformed requests
when trying to set up introduction circuits. Perhaps even somebody on
this list. Let us know if you need help making it work. ;)

--Roger