- Rotate tls-level connections -- make new ones, expire old ones. Nick, can you remember why we wanted to do this? Legend: SPEC!! - Not specified SPEC - Spec not finalized NICK - nick claims ARMA - arma claims - Not done * Top priority . Partially done o Done D Deferred X Abandoned Short-term: - Make tls connections tls_close intentionally o Rename ACI to circID . integrate rep_ok functions, see what breaks - update tor faq o obey SocksBindAddress, ORBindAddress - warn if we're running as root o make connection_flush_buf() more obviously obsolete .* let hup reread the config file, eg so we can get new exit policies without restarting - use times(2) rather than gettimeofday to measure how long it takes to process a cell - Separate trying to rebuild a circuit because you have none from trying to rebuild a circuit because the current one is stale - Continue reading from socks port even while waiting for connect. .* Exit policies o Spec how to write the exit policies -* More flexible policies (18.*, 18.0.0.0/8) -* Path selection algorithms -* Choose path more incrementally -* Let user request first/last node - And disallow certain nodes D Choose path by jurisdiction, etc? . Make relay end cells have failure status and payload attached -* Streams that fail due to exit policy must reextend to new node -* Add extend_wait state to edge connections, thumb through them when the AP get an extended cell. -* let non-approved routers handshake. -* just list approved routers in directory. - Dirserver shouldn't put you in running-routers list if you haven't uploaded a descriptor recently . migrate to using nickname rather than addr:port for routers o decide_aci_type - generate onion skins - circuit_send_next_onion_skin - circuit_extend - onion_generate_cpath - get_unique_aci_by_addr_port - circ->n_addr and circ->n_port - circuit_enumerate_by_naddr_nport - cpath layers - connection_or_connect - connection_exact_get_by_addr_port - connection_twin_get_by_addr_port - router_get_by_addr_port - connection_or_init_conn_from_router - tag_pack, tag_unpack, connection_cpu_process_inbuf - directory_initiate_command .* Move from onions to ephemeral DH o incremental path building o transition circuit-level sendmes to hop-level sendmes o implement truncate, truncated o move from 192byte DH to 128byte DH, so it isn't so damn slow -* exiting from not-last hop -* OP logic to decide to extend/truncate a path -* make sure exiting from the not-last hop works -* logic to find last *open* hop, not last hop, in cpath -* choose exit nodes by exit policies o Remember address and port when beginning. - Extend by nickname/hostname/something, not by IP. - Need a relay teardown cell, separate from one-way ends. On-going . Better comments for functions! . Go through log messages, reduce confusing error messages. . make the logs include more info (fd, etc) . Unit tests Mid-term: - Are there anonymity issues with sequential streamIDs? Sequential circIDs? Eg an attacker can learn how many there have been. - Look at having smallcells and largecells . Redo scheduler o fix SSL_read bug for buffered records - make round-robining more fair - What happens when a circuit's length is 1? What breaks? . streams / circuits o Implement streams o Rotate circuits after N minutes? X Circuits should expire when circuit->expire triggers NICK . Handle half-open connections o openssh is an application that uses half-open connections o Figure out what causes connections to close, standardize when we mark a connection vs when we tear it down o Look at what ssl does to keep from mutating data streams ARMA - Reduce streamid footprint from 7 bytes to 2 bytes - Check for collisions in streamid (now possible with just 2 bytes), and back up & replace with padding if so - Use the 3 saved bytes to put pseudorandomness in each relay cell - Use the 4 reserved bytes in each cell header to keep 1/5 of a sha1 of the relay payload (move into stream header) - Move length into the stream header too - Spec the stream_id stuff. Clarify that nobody on the backward stream should look at stream_id. . Put CPU workers in separate processes o Handle multiple cpu workers (one for each cpu, plus one) o Queue for pending tasks if all workers full o Support the 'process this onion' task D Merge dnsworkers and cpuworkers to some extent - Handle cpuworkers dying . Scrubbing proxies - Find an smtp proxy? - Check the old smtp proxy code o Find an ftp proxy? wget --passive D Wait until there are packet redirectors for Linux . Get socks4a support into Mozilla . Develop rendezvous points SPEC!! - Handle socks commands other than connect, eg, bind? o Design - Spec - Implement - Tests o Testing harness/infrastructure D System tests (how?) - Performance tests, so we know when we've improved . webload infrastructure (Bruce) . httperf infrastructure (easy to set up) . oprofile (installed in RH >8.0) NICK . Daemonize and package o Teach it to fork and background - Red Hat spec file - Debian spec file equivalent . Portability . Which .h files are we actually using? . Port to: o Linux o BSD . Solaris o Cygwin . Win32 o OS X - deal with pollhup / reached_eof on all platforms o openssl randomness o inet_ntoa . stdint.h - Make a script to set up a local network on your machine - More flexibility in node addressing D Support IPv6 rather than just 4 - Handle multihomed servers (config variable to set IP) In the distant future: D Load balancing between router twins D Keep track of load over links/nodes, to know who's hosed SPEC!! D Non-clique topologies D Implement our own memory management, at least for common structs (Not ever necessary?) D Advanced directory servers D Automated reputation management SPEC!! D Figure out how to do threshold directory servers D jurisdiction info in dirserver entries? other info? Older (done) todo stuff: o Get tor to act like a socks server o socks4, socks4a o socks5 o routers have identity key, link key, onion key. o link key certs are D signed by identity key D not in descriptor o not in config D not on disk o identity and onion keys are in descriptor (and disk) o upon boot, if it doesn't find identity key, generate it and write it. o also write a file with the identity key fingerprint in it o router generates descriptor: flesh out router_get_my_descriptor() o Routers sign descriptors with identity key o routers put version number in descriptor o routers should maybe have `uname -a` in descriptor? o Give nicknames to routers o in config o in descriptors o router posts descriptor o when it boots D when it changes o change tls stuff so certs don't get written to disk, or read from disk o make directory.c 'thread'safe o dirserver parses descriptor o dirserver checks signature D client checks signature? o dirserver writes directory to file o reads that file upon boot o directory includes all routers, up and down o add "up" line to directory, listing nicknames o instruments ORs to report stats o average cell fullness o average bandwidth used o configure log files. separate log file, separate severities. o what assumptions break if we fclose(0) when we daemonize? o make buffer struct elements opaque outside buffers.c o add log convention to the HACKING file o make 'make install' do the right thing o change binary name to tor o change config files so you look at commandline, else look in /etc/torrc. no cascading. o have an absolute datadir with fixed names for files, and fixed-name keydir under that with fixed names o Move (most of) the router/directory code out of main.c o Simple directory servers o Include key in source; sign directories o Signed directory backend o Document o Integrate o Add versions to code o Have directories list recommended-versions o Include line in directories o Check for presence of line. o Quit if running the wrong version o Command-line option to override quit o Add more information to directory server entries o Exit policies o Clearer bandwidth management o Do we want to remove bandwidth from OR handshakes? o What about OP handshakes? X Move away from openssl o Abstract out crypto calls X Look at nss, others? Just include code? o Use a stronger cipher o aes now, by including the code ourselves X On the fly compression of each stream o Clean up the event loop (optimize and sanitize) o Remove that awful concept of 'roles' o Terminology o Circuits, topics, cells stay named that o 'Connection' gets divided, or renamed, or something? o DNS farm o Distribute queries onto the farm, get answers o Preemptively grow a new worker before he's needed o Prune workers when too many are idle o DNS cache o Clear DNS cache over time D Honor DNS TTL info (how??) o Have strategy when all workers are busy o Keep track of which connections are in dns_wait o Need to cache positives/negatives on the tor side o Keep track of which queries have been asked o Better error handling when o An address doesn't resolve o We have max workers running o Consider taking the master out of the loop? X Implement reply onions o Total rate limiting o Look at OR handshake in more detail o Spec it o Merge OR and OP handshakes o rearrange connection_or so it doesn't suck so much to read D Periodic link key rotation. Spec? o wrap malloc with something that explodes when it fails o Clean up the number of places that get to look at prkey