Tor 0.0.2pre17 prerelease is out

[Roger Dingledine]

This release provides actual security and design improvements. It breaks
backward compatibility again (you will need to upgrade); but hopefully
I won't do it again for a while.

http://freehaven.net/tor/dist/tor-0.0.2pre17.tar.gz

Note that 'make install' will clobber your torrc, so back it up if you've
changed it.

Improvements since 0.0.2pre16:

Bugfixes:
  - Made --debuglogfile (or any second log file, actually) work.
  - Resolved an edge case in get_unique_circ_id_by_conn where a smart
    adversary could force us into an infinite loop.

Features:
  - Each onionskin handshake now includes a hash of the computed key,
    to prove the server's identity and help perfect forward secrecy.
  - Changed cell size from 256 to 512 bytes (working toward compatibility
    with MorphMix).
  - Changed cell length to 2 bytes, and moved it to the relay header.
  - Implemented end-to-end integrity checking for the payloads of
    relay cells.
  - Separated streamid from 'recognized' (otherwise circuits will get
    messed up when we try to have streams exit from the middle). We
    use the integrity-checking to confirm that a cell is addressed to
    this hop.
  - Randomize the initial circid and streamid values, so an adversary who
    breaks into a node can't learn how many circuits or streams have
    been made so far.