root/torment/trunk/ChangeLog

Changes in version 0.1.1.23 - 2006-07-30
  o Major bugfixes:
    - Fast Tor servers, especially exit nodes, were triggering asserts
      due to a bug in handling the list of pending DNS resolves. Some
      bugs still remain here; we're hunting them.
    - Entry guards could crash clients by sending unexpected input.
    - More fixes on reachability testing: if you find yourself reachable,
      then don't ever make any client requests (so you stop predicting
      circuits), then hup or have your clock jump, then later your IP
      changes, you won't think circuits are working, so you won't try to
      test reachability, so you won't publish.

  o Minor bugfixes:
    - Avoid a crash if the controller does a resetconf firewallports
      and then a setconf fascistfirewall=1.
    - Avoid an integer underflow when the dir authority decides whether
      a router is stable: we might wrongly label it stable, and compute
      a slightly wrong median stability, when a descriptor is published
      later than now.
    - Fix a place where we might trigger an assert if we can't build our
      own server descriptor yet.


Changes in version 0.1.1.22 - 2006-07-05
  o Major bugfixes:
    - Fix a big bug that was causing servers to not find themselves
      reachable if they changed IP addresses. Since only 0.1.1.22+
      servers can do reachability testing correctly, now we automatically
      make sure to test via one of these.
    - Fix to allow clients and mirrors to learn directory info from
      descriptor downloads that get cut off partway through.
    - Directory authorities had a bug in deciding if a newly published
      descriptor was novel enough to make everybody want a copy -- a few
      servers seem to be publishing new descriptors many times a minute.
  o Minor bugfixes:
    - Fix a rare bug that was causing some servers to complain about
      "closing wedged cpuworkers" and skip some circuit create requests.
    - Make the Exit flag in directory status documents actually work.
    - Add a preliminary OSX binary un-installer, and fix permissions.


Changes in version 0.1.1.21 - 2006-06-10
  o Crash and assert fixes from 0.1.1.20:
    - Fix a rare crash on Tor servers that have enabled hibernation.
    - Fix a seg fault on startup for Tor networks that use only one
      directory authority.
    - Fix an assert from a race condition that occurs on Tor servers
      while exiting, where various threads are trying to log that they're
      exiting, and delete the logs, at the same time.
    - Make our unit tests pass again on certain obscure platforms.

  o Other fixes:
    - Add support for building SUSE RPM packages.
    - Speed up initial bootstrapping for clients: if we are making our
      first ever connection to any entry guard, then don't mark it down
      right after that.
    - When only one Tor server in the network is labelled as a guard,
      and we've already picked him, we would cycle endlessly picking him
      again, being unhappy about it, etc. Now we specifically exclude
      current guards when picking a new guard.
    - Servers send create cells more reliably after the TLS connection
      is established: we were sometimes forgetting to send half of them
      when we had more than one pending.
    - If we get a create cell that asks us to extend somewhere, but the
      Tor server there doesn't match the expected digest, we now send
      a destroy cell back, rather than silently doing nothing.
    - Make options->RedirectExit work again.
    - Make cookie authentication for the controller work again.
    - Stop being picky about unusual characters in the arguments to
      mapaddress. It's none of our business.
    - Add a new config option "TestVia" that lets you specify preferred
      middle hops to use for test circuits. Perhaps this will let me
      debug the reachability problems better.

  o Log / documentation fixes:
    - If we're a server and some peer has a broken TLS certificate, don't
      log about it unless ProtocolWarnings is set, i.e., we want to hear
      about protocol violations by others.
    - Fix spelling of VirtualAddrNetwork in man page.
    - Add a better explanation at the top of the autogenerated torrc file
      about what happened to our old torrc.


Changes in version 0.1.1.20 - 2006-05-23
  o Crash and assert fixes from 0.1.0.17:
    - Fix assert bug in close_logs() on exit: when we close and delete
      logs, remove them all from the global "logfiles" list.
    - Fix an assert error when we're out of space in the connection_list
      and we try to post a hidden service descriptor (reported by Peter
      Palfrader).
    - Fix a rare assert error when we've tried all intro points for
      a hidden service and we try fetching the service descriptor again:
      "Assertion conn->state != AP_CONN_STATE_RENDDESC_WAIT failed".
    - Setconf SocksListenAddress kills Tor if it fails to bind. Now back
      out and refuse the setconf if it would fail.
    - If you specify a relative torrc path and you set RunAsDaemon in
      your torrc, then it chdir()'s to the new directory. If you then
      HUP, it tries to load the new torrc location, fails, and exits.
      The fix: no longer allow a relative path to torrc when using -f.
    - Check for integer overflows in more places, when adding elements
      to smartlists. This could possibly prevent a buffer overflow
      on malicious huge inputs.

  o Security fixes, major:
    - When we're printing strings from the network, don't try to print
      non-printable characters. Now we're safer against shell escape
      sequence exploits, and also against attacks to fool users into
      misreading their logs.
    - Implement entry guards: automatically choose a handful of entry
      nodes and stick with them for all circuits. Only pick new guards
      when the ones you have are unsuitable, and if the old guards
      become suitable again, switch back. This will increase security
      dramatically against certain end-point attacks. The EntryNodes
      config option now provides some hints about which entry guards you
      want to use most; and StrictEntryNodes means to only use those.
      Fixes CVE-2006-0414.
    - Implement exit enclaves: if we know an IP address for the
      destination, and there's a running Tor server at that address
      which allows exit to the destination, then extend the circuit to
      that exit first. This provides end-to-end encryption and end-to-end
      authentication. Also, if the user wants a .exit address or enclave,
      use 4 hops rather than 3, and cannibalize a general circ for it
      if you can.
    - Obey our firewall options more faithfully:
      . If we can't get to a dirserver directly, try going via Tor.
      . Don't ever try to connect (as a client) to a place our
        firewall options forbid.
      . If we specify a proxy and also firewall options, obey the
        firewall options even when we're using the proxy: some proxies
        can only proxy to certain destinations.
    - Make clients regenerate their keys when their IP address changes.
    - For the OS X package's modified privoxy config file, comment
      out the "logfile" line so we don't log everything passed
      through privoxy.
    - Our TLS handshakes were generating a single public/private
      keypair for the TLS context, rather than making a new one for
      each new connection. Oops. (But we were still rotating them
      periodically, so it's not so bad.)
    - When we were cannibalizing a circuit with a particular exit
      node in mind, we weren't checking to see if that exit node was
      already present earlier in the circuit. Now we are.
    - Require server descriptors to list IPv4 addresses -- hostnames
      are no longer allowed. This also fixes potential vulnerabilities
      to servers providing hostnames as their address and then
      preferentially resolving them so they can partition users.
    - Our logic to decide if the OR we connected to was the right guy
      was brittle and maybe open to a mitm for invalid routers.

  o Security fixes, minor:
    - Adjust tor-spec.txt to parameterize cell and key lengths. Now
      Ian Goldberg can prove things about our handshake protocol more
      easily.
    - Make directory authorities generate a separate "guard" flag to
      mean "would make a good entry guard". Clients now honor the
      is_guard flag rather than looking at is_fast or is_stable.
    - Try to list MyFamily elements by key, not by nickname, and warn
      if we've not heard of a server.
    - Start using RAND_bytes rather than RAND_pseudo_bytes from
      OpenSSL. Also, reseed our entropy every hour, not just at
      startup. And add entropy in 512-bit chunks, not 160-bit chunks.
    - Refuse server descriptors where the fingerprint line doesn't match
      the included identity key. Tor doesn't care, but other apps (and
      humans) might actually be trusting the fingerprint line.
    - We used to kill the circuit when we receive a relay command we
      don't recognize. Now we just drop that cell.
    - Fix a bug found by Lasse Overlier: when we were making internal
      circuits (intended to be cannibalized later for rendezvous and
      introduction circuits), we were picking them so that they had
      useful exit nodes. There was no need for this, and it actually
      aids some statistical attacks.
    - Start treating internal circuits and exit circuits separately.
      It's important to keep them separate because internal circuits
      have their last hops picked like middle hops, rather than like
      exit hops. So exiting on them will break the user's expectations.
    - Fix a possible way to DoS dirservers.
    - When the client asked for a rendezvous port that the hidden
      service didn't want to provide, we were sending an IP address
      back along with the end cell. Fortunately, it was zero. But stop
      that anyway.

  o Packaging improvements:
    - Implement --with-libevent-dir option to ./configure. Improve
      search techniques to find libevent, and use those for openssl too.
    - Fix a couple of bugs in OpenSSL detection. Deal better when
      there are multiple SSLs installed with different versions.
    - Avoid warnings about machine/limits.h on Debian GNU/kFreeBSD.
    - On non-gcc compilers (e.g. Solaris's cc), use "-g -O" instead of
      "-Wall -g -O2".
    - Make unit tests (and other invocations that aren't the real Tor)
      run without launching listeners, creating subdirectories, and so on.
    - The OS X installer was adding a symlink for tor_resolve but
      the binary was called tor-resolve (reported by Thomas Hardly).
    - Now we can target arch and OS in rpm builds (contributed by
      Phobos). Also make the resulting dist-rpm filename match the
      target arch.
    - Apply Matt Ghali's --with-syslog-facility patch to ./configure
      if you log to syslog and want something other than LOG_DAEMON.
    - Fix the torify (tsocks) config file to not use Tor for localhost
      connections.
    - Start shipping socks-extensions.txt, tor-doc-unix.html,
      tor-doc-server.html, and stylesheet.css in the tarball.
    - Stop shipping tor-doc.html, INSTALL, and README in the tarball.
      They are useless now.
    - Add Peter Palfrader's contributed check-tor script. It lets you
      easily check whether a given server (referenced by nickname)
      is reachable by you.
    - Add BSD-style contributed startup script "rc.subr" from Peter
      Thoenen.

  o Directory improvements -- new directory protocol:
    - See tor/doc/dir-spec.txt for all the juicy details. Key points:
    - Authorities and caches publish individual descriptors (by
      digest, by fingerprint, by "all", and by "tell me yours").
    - Clients don't download or use the old directory anymore. Now they
      download network-statuses from the directory authorities, and
      fetch individual server descriptors as needed from mirrors.
    - Clients don't download descriptors of non-running servers.
    - Download descriptors by digest, not by fingerprint. Caches try to
      download all listed digests from authorities; clients try to
      download "best" digests from caches. This avoids partitioning
      and isolating attacks better.
    - Only upload a new server descriptor when options change, 18
      hours have passed, uptime is reset, or bandwidth changes a lot.
    - Directory authorities silently throw away new descriptors that
      haven't changed much if the timestamps are similar. We do this to
      tolerate older Tor servers that upload a new descriptor every 15
      minutes. (It seemed like a good idea at the time.)
    - Clients choose directory servers from the network status lists,
      not from their internal list of router descriptors. Now they can
      go to caches directly rather than needing to go to authorities
      to bootstrap the first set of descriptors.
    - When picking a random directory, prefer non-authorities if any
      are known.
    - Add a new flag to network-status indicating whether the server
      can answer v2 directory requests too.
    - Directory mirrors now cache up to 16 unrecognized network-status
      docs, so new directory authorities will be cached too.
    - Stop parsing, storing, or using running-routers output (but
      mirrors still cache and serve it).
    - Clients consider a threshold of "versioning" directory authorities
      before deciding whether to warn the user that he's obsolete.
    - Authorities publish separate sorted lists of recommended versions
      for clients and for servers.
    - Change DirServers config line to note which dirs are v1 authorities.
    - Put nicknames on the DirServer line, so we can refer to them
      without requiring all our users to memorize their IP addresses.
    - Remove option when getting directory cache to see whether they
      support running-routers; they all do now. Replace it with one
      to see whether caches support v2 stuff.
    - Stop listing down or invalid nodes in the v1 directory. This
      reduces its bulk by about 1/3, and reduces load on mirrors.
    - Mirrors no longer cache the v1 directory as often.
    - If we as a directory mirror don't know of any v1 directory
      authorities, then don't try to cache any v1 directories.

  o Other directory improvements:
    - Add lefkada.eecs.harvard.edu and tor.dizum.com as fourth and
      fifth authoritative directory servers.
    - Directory authorities no longer require an open connection from
      a server to consider him "reachable". We need this change because
      when we add new directory authorities, old servers won't know not
      to hang up on them.
    - Dir authorities now do their own external reachability testing
      of each server, and only list as running the ones they found to
      be reachable. We also send back warnings to the server's logs if
      it uploads a descriptor that we already believe is unreachable.
    - Spread the directory authorities' reachability testing over the
      entire testing interval, so we don't try to do 500 TLS's at once
      every 20 minutes.
    - Make the "stable" router flag in network-status be the median of
      the uptimes of running valid servers, and make clients pay
      attention to the network-status flags. Thus the cutoff adapts
      to the stability of the network as a whole, making IRC, IM, etc
      connections more reliable.
    - Make the v2 dir's "Fast" flag based on relative capacity, just
      like "Stable" is based on median uptime. Name everything in the
      top 7/8 Fast, and only the top 1/2 gets to be a Guard.
    - Retry directory requests if we fail to get an answer we like
      from a given dirserver (we were retrying before, but only if
      we fail to connect).
    - Return a robots.txt on our dirport to discourage google indexing.

  o Controller protocol improvements:
    - Revised controller protocol (version 1) that uses ascii rather
      than binary: tor/doc/control-spec.txt. Add supporting libraries
      in python and java and c# so you can use the controller from your
      applications without caring how our protocol works.
    - Allow the DEBUG controller event to work again. Mark certain log
      entries as "don't tell this to controllers", so we avoid cycles.
    - New controller function "getinfo accounting", to ask how
      many bytes we've used in this time period.
    - Add a "resetconf" command so you can set config options like
      AllowUnverifiedNodes and LongLivedPorts to "". Also, if you give
      a config option in the torrc with no value, then it clears it
      entirely (rather than setting it to its default).
    - Add a "getinfo config-file" to tell us where torrc is. Also
      expose guard nodes, config options/names.
    - Add a "quit" command (when when using the controller manually).
    - Add a new signal "newnym" to "change pseudonyms" -- that is, to
      stop using any currently-dirty circuits for new streams, so we
      don't link new actions to old actions. This also occurs on HUP
      or "signal reload".
    - If we would close a stream early (e.g. it asks for a .exit that
      we know would refuse it) but the LeaveStreamsUnattached config
      option is set by the controller, then don't close it.
    - Add a new controller event type "authdir_newdescs" that allows
      controllers to get all server descriptors that were uploaded to
      a router in its role as directory authority.
    - New controller option "getinfo desc/all-recent" to fetch the
      latest server descriptor for every router that Tor knows about.
    - Fix the controller's "attachstream 0" command to treat conn like
      it just connected, doing address remapping, handling .exit and
      .onion idioms, and so on. Now we're more uniform in making sure
      that the controller hears about new and closing connections.
    - Permit transitioning from ORPort==0 to ORPort!=0, and back, from
      the controller. Also, rotate dns and cpu workers if the controller
      changes options that will affect them; and initialize the dns
      worker cache tree whether or not we start out as a server.
    - Add a new circuit purpose 'controller' to let the controller ask
      for a circuit that Tor won't try to use. Extend the "extendcircuit"
      controller command to let you specify the purpose if you're starting
      a new circuit.  Add a new "setcircuitpurpose" controller command to
      let you change a circuit's purpose after it's been created.
    - Let the controller ask for "getinfo dir/server/foo" so it can ask
      directly rather than connecting to the dir port. "getinfo
      dir/status/foo" also works, but currently only if your DirPort
      is enabled.
    - Let the controller tell us about certain router descriptors
      that it doesn't want Tor to use in circuits. Implement
      "setrouterpurpose" and modify "+postdescriptor" to do this.
    - If the controller's *setconf commands fail, collect an error
      message in a string and hand it back to the controller -- don't
      just tell them to go read their logs.

  o Scalability, resource management, and performance:
    - Fix a major load balance bug: we were round-robin reading in 16 KB
      chunks, and servers with bandwidthrate of 20 KB, while downloading
      a 600 KB directory, would starve their other connections. Now we
      try to be a bit more fair.
    - Be more conservative about whether to advertise our DirPort.
      The main change is to not advertise if we're running at capacity
      and either a) we could hibernate ever or b) our capacity is low
      and we're using a default DirPort.
    - We weren't cannibalizing circuits correctly for
      CIRCUIT_PURPOSE_C_ESTABLISH_REND and
      CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, so we were being forced to
      build those from scratch. This should make hidden services faster.
    - Predict required circuits better, with an eye toward making hidden
      services faster on the service end.
    - Compress exit policies even more: look for duplicate lines and
      remove them.
    - Generate 18.0.0.0/8 address policy format in descs when we can;
      warn when the mask is not reducible to a bit-prefix.
    - There used to be two ways to specify your listening ports in a
      server descriptor: on the "router" line and with a separate "ports"
      line. Remove support for the "ports" line.
    - Reduce memory requirements in our structs by changing the order
      of fields. Replace balanced trees with hash tables. Inline
      bottleneck smartlist functions. Add a "Map from digest to void*"
      abstraction so we can do less hex encoding/decoding, and use it
      in router_get_by_digest(). Many other CPU and memory improvements.
    - Allow tor_gzip_uncompress to extract as much as possible from
      truncated compressed data. Try to extract as many
      descriptors as possible from truncated http responses (when
      purpose is DIR_PURPOSE_FETCH_ROUTERDESC).
    - Make circ->onionskin a pointer, not a static array. moria2 was using
      125000 circuit_t's after it had been up for a few weeks, which
      translates to 20+ megs of wasted space.
    - The private half of our EDH handshake keys are now chosen out
      of 320 bits, not 1024 bits. (Suggested by Ian Goldberg.)
    - Stop doing the complex voodoo overkill checking for insecure
      Diffie-Hellman keys. Just check if it's in [2,p-2] and be happy.
    - Do round-robin writes for TLS of at most 16 kB per write. This
      might be more fair on loaded Tor servers.
    - Do not use unaligned memory access on alpha, mips, or mipsel.
      It *works*, but is very slow, so we treat them as if it doesn't.

  o Other bugfixes and improvements:
    - Start storing useful information to $DATADIR/state, so we can
      remember things across invocations of Tor. Retain unrecognized
      lines so we can be forward-compatible, and write a TorVersion line
      so we can be backward-compatible.
    - If ORPort is set, Address is not explicitly set, and our hostname
      resolves to a private IP address, try to use an interface address
      if it has a public address. Now Windows machines that think of
      themselves as localhost can guess their address.
    - Regenerate our local descriptor if it's dirty and we try to use
      it locally (e.g. if it changes during reachability detection).
      This was causing some Tor servers to keep publishing the same
      initial descriptor forever.
    - Tor servers with dynamic IP addresses were needing to wait 18
      hours before they could start doing reachability testing using
      the new IP address and ports. This is because they were using
      the internal descriptor to learn what to test, yet they were only
      rebuilding the descriptor once they decided they were reachable.
    - It turns out we couldn't bootstrap a network since we added
      reachability detection in 0.1.0.1-rc. Good thing the Tor network
      has never gone down. Add an AssumeReachable config option to let
      servers and authorities bootstrap. When we're trying to build a
      high-uptime or high-bandwidth circuit but there aren't enough
      suitable servers, try being less picky rather than simply failing.
    - Newly bootstrapped Tor networks couldn't establish hidden service
      circuits until they had nodes with high uptime. Be more tolerant.
    - Really busy servers were keeping enough circuits open on stable
      connections that they were wrapping around the circuit_id
      space. (It's only two bytes.) This exposed a bug where we would
      feel free to reuse a circuit_id even if it still exists but has
      been marked for close. Try to fix this bug. Some bug remains.
    - When we fail to bind or listen on an incoming or outgoing
      socket, we now close it before refusing, rather than just
      leaking it. (Thanks to Peter Palfrader for finding.)
    - Fix a file descriptor leak in start_daemon().
    - On Windows, you can't always reopen a port right after you've
      closed it. So change retry_listeners() to only close and re-open
      ports that have changed.
    - Workaround a problem with some http proxies that refuse GET
      requests that specify "Content-Length: 0". Reported by Adrian.
    - Recover better from TCP connections to Tor servers that are
      broken but don't tell you (it happens!); and rotate TLS
      connections once a week.
    - Fix a scary-looking but apparently harmless bug where circuits
      would sometimes start out in state CIRCUIT_STATE_OR_WAIT at
      servers, and never switch to state CIRCUIT_STATE_OPEN.
    - Check for even more Windows version flags when writing the platform
      string in server descriptors, and note any we don't recognize.
    - Add reasons to DESTROY and RELAY_TRUNCATED cells, so clients can
      get a better idea of why their circuits failed. Not used yet.
    - Add TTLs to RESOLVED, CONNECTED, and END_REASON_EXITPOLICY cells.
      We don't use them yet, but maybe one day our DNS resolver will be
      able to discover them.
    - Let people type "tor --install" as well as "tor -install" when they
      want to make it an NT service.
    - Looks like we were never delivering deflated (i.e. compressed)
      running-routers lists, even when asked. Oops.
    - We were leaking some memory every time the client changed IPs.
    - Clean up more of the OpenSSL memory when exiting, so we can detect
      memory leaks better.
    - Never call free() on tor_malloc()d memory. This will help us
      use dmalloc to detect memory leaks.
    - Some Tor servers process billions of cells per day. These
      statistics are now uint64_t's.
    - Check [X-]Forwarded-For headers in HTTP requests when generating
      log messages. This lets people run dirservers (and caches) behind
      Apache but still know which IP addresses are causing warnings.
    - Fix minor integer overflow in calculating when we expect to use up
      our bandwidth allocation before hibernating.
    - Lower the minimum required number of file descriptors to 1000,
      so we can have some overhead for Valgrind on Linux, where the
      default ulimit -n is 1024.
    - Stop writing the "router.desc" file, ever. Nothing uses it anymore,
      and its existence is confusing some users.

  o Config option fixes:
    - Add a new config option ExitPolicyRejectPrivate which defaults
      to on. Now all exit policies will begin with rejecting private
      addresses, unless the server operator explicitly turns it off.
    - Bump the default bandwidthrate to 3 MB, and burst to 6 MB.
    - Add new ReachableORAddresses and ReachableDirAddresses options
      that understand address policies. FascistFirewall is now a synonym
      for "ReachableORAddresses *:443", "ReachableDirAddresses *:80".
    - Start calling it FooListenAddress rather than FooBindAddress,
      since few of our users know what it means to bind an address
      or port.
    - If the user gave Tor an odd number of command-line arguments,
      we were silently ignoring the last one. Now we complain and fail.
      This wins the oldest-bug prize -- this bug has been present since
      November 2002, as released in Tor 0.0.0.
    - If you write "HiddenServicePort 6667 127.0.0.1 6668" in your
      torrc rather than "HiddenServicePort 6667 127.0.0.1:6668",
      it would silently ignore the 6668.
    - If we get a linelist or linelist_s config option from the torrc,
      e.g. ExitPolicy, and it has no value, warn and skip rather than
      silently resetting it to its default.
    - Setconf was appending items to linelists, not clearing them.
    - Add MyFamily to torrc.sample in the server section, so operators
      will be more likely to learn that it exists.
    - Make ContactInfo mandatory for authoritative directory servers.
    - MaxConn has been obsolete for a while now. Document the ConnLimit
      config option, which is a *minimum* number of file descriptors
      that must be available else Tor refuses to start.
    - Get rid of IgnoreVersion undocumented config option, and make us
      only warn, never exit, when we're running an obsolete version.
    - Make MonthlyAccountingStart config option truly obsolete now.
    - Correct the man page entry on TrackHostExitsExpire.
    - Let directory authorities start even if they don't specify an
      Address config option.
    - Change "AllowUnverifiedNodes" to "AllowInvalidNodes", to
      reflect the updated flags in our v2 dir protocol.

  o Config option features:
    - Add a new config option FastFirstHopPK (on by default) so clients
      do a trivial crypto handshake for their first hop, since TLS has
      already taken care of confidentiality and authentication.
    - Let the user set ControlListenAddress in the torrc. This can be
      dangerous, but there are some cases (like a secured LAN) where it
      makes sense.
    - New config options to help controllers: FetchServerDescriptors
      and FetchHidServDescriptors for whether to fetch server
      info and hidserv info or let the controller do it, and
      PublishServerDescriptor and PublishHidServDescriptors.
    - Also let the controller set the __AllDirActionsPrivate config
      option if you want all directory fetches/publishes to happen via
      Tor (it assumes your controller bootstraps your circuits).
    - Add "HardwareAccel" config option: support for crypto hardware
      accelerators via OpenSSL. Off by default, until we find somebody
      smart who can test it for us. (It appears to produce seg faults
      in at least some cases.)
    - New config option "AuthDirRejectUnlisted" for directory authorities
      as a panic button: if we get flooded with unusable servers we can
      revert to only listing servers in the approved-routers file.
    - Directory authorities can now reject/invalidate by key and IP,
      with the config options "AuthDirInvalid" and "AuthDirReject", or
      by marking a fingerprint as "!reject" or "!invalid" (as its
      nickname) in the approved-routers file. This is useful since
      currently we automatically list servers as running and usable
      even if we know they're jerks.
    - Add a new config option TestSocks so people can see whether their
      applications are using socks4, socks4a, socks5-with-ip, or
      socks5-with-fqdn. This way they don't have to keep mucking
      with tcpdump and wondering if something got cached somewhere.
    - Add "private:*" as an alias in configuration for policies. Now
      you can simplify your exit policy rather than needing to list
      every single internal or nonroutable network space.
    - Accept "private:*" in routerdesc exit policies; not generated yet
      because older Tors do not understand it.
    - Add configuration option "V1AuthoritativeDirectory 1" which
      moria1, moria2, and tor26 have set.
    - Implement an option, VirtualAddrMask, to set which addresses
      get handed out in response to mapaddress requests. This works
      around a bug in tsocks where 127.0.0.0/8 is never socksified.
    - Add a new config option FetchUselessDescriptors, off by default,
      for when you plan to run "exitlist" on your client and you want
      to know about even the non-running descriptors.
    - SocksTimeout: How long do we let a socks connection wait
      unattached before we fail it?
    - CircuitBuildTimeout: Cull non-open circuits that were born
      at least this many seconds ago.
    - CircuitIdleTimeout: Cull open clean circuits that were born
      at least this many seconds ago.
    - New config option SafeSocks to reject all application connections
      using unsafe socks protocols. Defaults to off.

  o Improved and clearer log messages:
    - Reduce clutter in server logs. We're going to try to make
      them actually usable now. New config option ProtocolWarnings that
      lets you hear about how _other Tors_ are breaking the protocol. Off
      by default.
    - Divide log messages into logging domains. Once we put some sort
      of interface on this, it will let people looking at more verbose
      log levels specify the topics they want to hear more about.
    - Log server fingerprint on startup, so new server operators don't
      have to go hunting around their filesystem for it.
    - Provide dire warnings to any users who set DirServer manually;
      move it out of torrc.sample and into torrc.complete.
    - Make the log message less scary when all the dirservers are
      temporarily unreachable.
    - When tor_socketpair() fails in Windows, give a reasonable
      Windows-style errno back.
    - Improve tor_gettimeofday() granularity on windows.
    - We were printing the number of idle dns workers incorrectly when
      culling them.
    - Handle duplicate lines in approved-routers files without warning.
    - We were whining about using socks4 or socks5-with-local-lookup
      even when it's an IP address in the "virtual" range we designed
      exactly for this case.
    - Check for named servers when looking them up by nickname;
      warn when we're calling a non-named server by its nickname;
      don't warn twice about the same name.
    - Downgrade the dirserver log messages when whining about
      unreachability.
    - Correct "your server is reachable" log entries to indicate that
      it was self-testing that told us so.
    - If we're trying to be a Tor server and running Windows 95/98/ME
      as a server, explain that we'll likely crash.
    - Provide a more useful warn message when our onion queue gets full:
      the CPU is too slow or the exit policy is too liberal.
    - Don't warn when we receive a 503 from a dirserver/cache -- this
      will pave the way for them being able to refuse if they're busy.
    - When we fail to bind a listener, try to provide a more useful
      log message: e.g., "Is Tor already running?"
    - Only start testing reachability once we've established a
      circuit. This will make startup on dir authorities less noisy.
    - Don't try to upload hidden service descriptors until we have
      established a circuit.
    - Tor didn't warn when it failed to open a log file.
    - Warn when listening on a public address for socks. We suspect a
      lot of people are setting themselves up as open socks proxies,
      and they have no idea that jerks on the Internet are using them,
      since they simply proxy the traffic into the Tor network.
    - Give a useful message when people run Tor as the wrong user,
      rather than telling them to start chowning random directories.
    - Fix a harmless bug that was causing Tor servers to log
      "Got an end because of misc error, but we're not an AP. Closing."
    - Fix wrong log message when you add a "HiddenServiceNodes" config
      line without any HiddenServiceDir line (reported by Chris Thomas).
    - Directory authorities now stop whining so loudly about bad
      descriptors that they fetch from other dirservers. So when there's
      a log complaint, it's for sure from a freshly uploaded descriptor.
    - When logging via syslog, include the pid whenever we provide
      a log entry. Suggested by Todd Fries.
    - When we're shutting down and we do something like try to post a
      server descriptor or rendezvous descriptor, don't complain that
      we seem to be unreachable. Of course we are, we're shutting down.
    - Change log line for unreachability to explicitly suggest /etc/hosts
      as the culprit. Also make it clearer what IP address and ports we're
      testing for reachability.
    - Put quotes around user-supplied strings when logging so users are
      more likely to realize if they add bad characters (like quotes)
      to the torrc.
    - NT service patch from Matt Edman to improve error messages on Win32.


Changes in version 0.1.0.17 - 2006-02-17
  o Crash bugfixes on 0.1.0.x:
    - When servers with a non-zero DirPort came out of hibernation,
      sometimes they would trigger an assert.

  o Other important bugfixes:
    - On platforms that don't have getrlimit (like Windows), we were
      artificially constraining ourselves to a max of 1024
      connections. Now just assume that we can handle as many as 15000
      connections. Hopefully this won't cause other problems.

  o Backported features:
    - When we're a server, a client asks for an old-style directory,
      and our write bucket is empty, don't give it to him. This way
      small servers can continue to serve the directory *sometimes*,
      without getting overloaded.
    - Whenever you get a 503 in response to a directory fetch, try
      once more. This will become important once servers start sending
      503's whenever they feel busy.
    - Fetch a new directory every 120 minutes, not every 40 minutes.
      Now that we have hundreds of thousands of users running the old
      directory algorithm, it's starting to hurt a lot.
    - Bump up the period for forcing a hidden service descriptor upload
      from 20 minutes to 1 hour.


Changes in version 0.1.0.16 - 2006-01-02
  o Crash bugfixes on 0.1.0.x:
    - On Windows, build with a libevent patch from "I-M Weasel" to avoid
      corrupting the heap, losing FDs, or crashing when we need to resize
      the fd_sets. (This affects the Win32 binaries, not Tor's sources.)
    - It turns out sparc64 platforms crash on unaligned memory access
      too -- so detect and avoid this.
    - Handle truncated compressed data correctly (by detecting it and
      giving an error).
    - Fix possible-but-unlikely free(NULL) in control.c.
    - When we were closing connections, there was a rare case that
      stomped on memory, triggering seg faults and asserts.
    - Avoid potential infinite recursion when building a descriptor. (We
      don't know that it ever happened, but better to fix it anyway.)
    - We were neglecting to unlink marked circuits from soon-to-close OR
      connections, which caused some rare scribbling on freed memory.
    - Fix a memory stomping race bug when closing the joining point of two
      rendezvous circuits.
    - Fix an assert in time parsing found by Steven Murdoch.

  o Other bugfixes on 0.1.0.x:
    - When we're doing reachability testing, provide more useful log
      messages so the operator knows what to expect.
    - Do not check whether DirPort is reachable when we are suppressing
      advertising it because of hibernation.
    - When building with -static or on Solaris, we sometimes needed -ldl.
    - One of the dirservers (tor26) changed its IP address.
    - When we're deciding whether a stream has enough circuits around
      that can handle it, count the freshly dirty ones and not the ones
      that are so dirty they won't be able to handle it.
    - When we're expiring old circuits, we had a logic error that caused
      us to close new rendezvous circuits rather than old ones.
    - Give a more helpful log message when you try to change ORPort via
      the controller: you should upgrade Tor if you want that to work.
    - We were failing to parse Tor versions that start with "Tor ".
    - Tolerate faulty streams better: when a stream fails for reason
      exitpolicy, stop assuming that the router is lying about his exit
      policy. When a stream fails for reason misc, allow it to retry just
      as if it was resolvefailed. When a stream has failed three times,
      reset its failure count so we can try again and get all three tries.


Changes in version 0.1.0.15 - 2005-09-23
  o Bugfixes on 0.1.0.x:
    - Reject ports 465 and 587 (spam targets) in default exit policy.
    - Don't crash when we don't have any spare file descriptors and we
      try to spawn a dns or cpu worker.
    - Get rid of IgnoreVersion undocumented config option, and make us
      only warn, never exit, when we're running an obsolete version.
    - Don't try to print a null string when your server finds itself to
      be unreachable and the Address config option is empty.
    - Make the numbers in read-history and write-history into uint64s,
      so they don't overflow and publish negatives in the descriptor.
    - Fix a minor memory leak in smartlist_string_remove().
    - We were only allowing ourselves to upload a server descriptor at
      most every 20 minutes, even if it changed earlier than that.
    - Clean up log entries that pointed to old URLs.


Changes in version 0.1.0.14 - 2005-08-08
  o Bugfixes on 0.1.0.x:
      - Fix the other half of the bug with crypto handshakes
        (CVE-2005-2643).
      - Fix an assert trigger if you send a 'signal term' via the
        controller when it's listening for 'event info' messages.


Changes in version 0.1.0.13 - 2005-08-04
  o Bugfixes on 0.1.0.x:
    - Fix a critical bug in the security of our crypto handshakes.
    - Fix a size_t underflow in smartlist_join_strings2() that made
      it do bad things when you hand it an empty smartlist.
    - Fix Windows installer to ship Tor license (thanks to Aphex for
      pointing out this oversight) and put a link to the doc directory
      in the start menu.
    - Explicitly set no-unaligned-access for sparc: it turns out the
      new gcc's let you compile broken code, but that doesn't make it
      not-broken.


Changes in version 0.1.0.12 - 2005-07-18
  o New directory servers:
      - tor26 has changed IP address.

  o Bugfixes on 0.1.0.x:
    - Fix a possible double-free in tor_gzip_uncompress().
    - When --disable-threads is set, do not search for or link against
      pthreads libraries.
    - Don't trigger an assert if an authoritative directory server
      claims its dirport is 0.
    - Fix bug with removing Tor as an NT service: some people were
      getting "The service did not return an error." Thanks to Matt
      Edman for the fix.


Changes in version 0.1.0.11 - 2005-06-30
  o Bugfixes on 0.1.0.x:
    - Fix major security bug: servers were disregarding their
      exit policies if clients behaved unexpectedly.
    - Make OS X init script check for missing argument, so we don't
      confuse users who invoke it incorrectly.
    - Fix a seg fault in "tor --hash-password foo".
    - The MAPADDRESS control command was broken.


Changes in version 0.1.0.10 - 2005-06-14
  o Fixes on Win32:
    - Make NT services work and start on startup on Win32 (based on
      patch by Matt Edman). See the FAQ entry for details.
    - Make 'platform' string in descriptor more accurate for Win32
      servers, so it's not just "unknown platform".
    - REUSEADDR on normal platforms means you can rebind to the port
      right after somebody else has let it go. But REUSEADDR on Win32
      means you can bind to the port _even when somebody else already
      has it bound_! So, don't do that on Win32.
    - Clean up the log messages when starting on Win32 with no config
      file.
    - Allow seeding the RNG on Win32 even when you're not running as
      Administrator. If seeding the RNG on Win32 fails, quit.

  o Assert / crash bugs:
    - Refuse relay cells that claim to have a length larger than the
      maximum allowed. This prevents a potential attack that could read
      arbitrary memory (e.g. keys) from an exit server's process
      (CVE-2005-2050).
    - If unofficial Tor clients connect and send weird TLS certs, our
      Tor server triggers an assert. Stop asserting, and start handling
      TLS errors better in other situations too.
    - Fix a race condition that can trigger an assert when we have a
      pending create cell and an OR connection attempt fails.

  o Resource leaks:
    - Use pthreads for worker processes rather than forking. This was
      forced because when we forked, we ended up wasting a lot of
      duplicate ram over time.
      - Also switch to foo_r versions of some library calls to allow
        reentry and threadsafeness.
      - Implement --disable-threads configure option. Disable threads on
        netbsd and openbsd by default, because they have no reentrant
        resolver functions (!), and on solaris since it has other
        threading issues.
    - Fix possible bug on threading platforms (e.g. win32) which was
      leaking a file descriptor whenever a cpuworker or dnsworker died.
    - Fix a minor memory leak when somebody establishes an introduction
      point at your Tor server.
    - Fix possible memory leak in tor_lookup_hostname(). (Thanks to
      Adam Langley.)
    - Add ./configure --with-dmalloc option, to track memory leaks.
    - And try to free all memory on closing, so we can detect what
      we're leaking.

  o Protocol correctness:
    - When we've connected to an OR and handshaked but didn't like
      the result, we were closing the conn without sending destroy
      cells back for pending circuits. Now send those destroys.
    - Start sending 'truncated' cells back rather than destroy cells
      if the circuit closes in front of you. This means we won't have
      to abandon partially built circuits.
    - Handle changed router status correctly when dirserver reloads
      fingerprint file. We used to be dropping all unverified descriptors
      right then. The bug was hidden because we would immediately
      fetch a directory from another dirserver, which would include the
      descriptors we just dropped.
    - Revise tor-spec to add more/better stream end reasons.
    - Revise all calls to connection_edge_end to avoid sending 'misc',
      and to take errno into account where possible.
    - Client now retries when streams end early for 'hibernating' or
      'resource limit' reasons, rather than failing them.
    - Try to be more zealous about calling connection_edge_end when
      things go bad with edge conns in connection.c.

  o Robustness improvements:
    - Better handling for heterogeneous / unreliable nodes:
      - Annotate circuits with whether they aim to contain high uptime
        nodes and/or high capacity nodes. When building circuits, choose
        appropriate nodes.
      - This means that every single node in an intro rend circuit,
        not just the last one, will have a minimum uptime.
      - New config option LongLivedPorts to indicate application streams
        that will want high uptime circuits.
      - Servers reset uptime when a dir fetch entirely fails. This
        hopefully reflects stability of the server's network connectivity.
      - If somebody starts his tor server in Jan 2004 and then fixes his
        clock, don't make his published uptime be a year.
      - Reset published uptime when we wake up from hibernation.
    - Introduce a notion of 'internal' circs, which are chosen without
      regard to the exit policy of the last hop. Intro and rendezvous
      circs must be internal circs, to avoid leaking information. Resolve
      and connect streams can use internal circs if they want.
    - New circuit pooling algorithm: keep track of what destination ports
      we've used recently (start out assuming we'll want to use 80), and
      make sure to have enough circs around to satisfy these ports. Also
      make sure to have 2 internal circs around if we've required internal
      circs lately (and with high uptime if we've seen that lately too).
    - Turn addr_policy_compare from a tristate to a quadstate; this should
      help address our "Ah, you allow 1.2.3.4:80. You are a good choice
      for google.com" problem.
    - When a client asks us for a dir mirror and we don't have one,
      launch an attempt to get a fresh one.
    - First cut at support for "create-fast" cells. Clients can use
      these when extending to their first hop, since the TLS already
      provides forward secrecy and authentication. Not enabled on
      clients yet.

  o Reachability testing.
    - Your Tor server will automatically try to see if its ORPort and
      DirPort are reachable from the outside, and it won't upload its
      descriptor until it decides at least ORPort is reachable (when
      DirPort is not yet found reachable, publish it as zero).
    - When building testing circs for ORPort testing, use only
      high-bandwidth nodes, so fewer circuits fail.
    - Notice when our IP changes, and reset stats/uptime/reachability.
    - Authdirservers don't do ORPort reachability detection, since
      they're in clique mode, so it will be rare to find a server not
      already connected to them.
    - Authdirservers now automatically approve nodes running 0.1.0.2-rc
      or later.

  o Dirserver fixes:
    - Now we allow two unverified servers with the same nickname
      but different keys. But if a nickname is verified, only that
      nickname+key are allowed.
    - If you're an authdirserver connecting to an address:port,
      and it's not the OR you were expecting, forget about that
      descriptor. If he *was* the one you were expecting, then forget
      about all other descriptors for that address:port.
    - Allow servers to publish descriptors from 12 hours in the future.
      Corollary: only whine about clock skew from the dirserver if
      he's a trusted dirserver (since now even verified servers could
      have quite wrong clocks).
    - Require servers that use the default dirservers to have public IP
      addresses. We have too many servers that are configured with private
      IPs and their admins never notice the log entries complaining that
      their descriptors are being rejected.

  o Efficiency improvements:
    - Use libevent. Now we can use faster async cores (like epoll, kpoll,
      and /dev/poll), and hopefully work better on Windows too.
      - Apple's OS X 10.4.0 ships with a broken kqueue API, and using
        kqueue on 10.3.9 causes kernel panics. Don't use kqueue on OS X.
      - Find libevent even if it's hiding in /usr/local/ and your
        CFLAGS and LDFLAGS don't tell you to look there.
      - Be able to link with libevent as a shared library (the default
        after 1.0d), even if it's hiding in /usr/local/lib and even
        if you haven't added /usr/local/lib to your /etc/ld.so.conf,
        assuming you're running gcc. Otherwise fail and give a useful
        error message.
    - Switch to a new buffer management algorithm, which tries to avoid
      reallocing and copying quite as much. In first tests it looks like
      it uses *more* memory on average, but less cpu.
    - Switch our internal buffers implementation to use a ring buffer,
      to hopefully improve performance for fast servers a lot.
    - Reenable the part of the code that tries to flush as soon as an
      OR outbuf has a full TLS record available. Perhaps this will make
      OR outbufs not grow as huge except in rare cases, thus saving lots
      of CPU time plus memory.
    - Improve performance for dirservers: stop re-parsing the whole
      directory every time you regenerate it.
    - Keep a big splay tree of (circid,orconn)->circuit mappings to make
      it much faster to look up a circuit for each relay cell.
    - Remove most calls to assert_all_pending_dns_resolves_ok(),
      since they're eating our cpu on exit nodes.
    - Stop wasting time doing a case insensitive comparison for every
      dns name every time we do any lookup. Canonicalize the names to
      lowercase when you first see them.

  o Hidden services:
    - Handle unavailable hidden services better. Handle slow or busy
      hidden services better.
    - Cannibalize GENERAL circs to be C_REND, C_INTRO, S_INTRO, and S_REND
      circ as necessary, if there are any completed ones lying around
      when we try to launch one.
    - Make hidden services try to establish a rendezvous for 30 seconds
      after fetching the descriptor, rather than for n (where n=3)
      attempts to build a circuit.
    - Adjust maximum skew and age for rendezvous descriptors: let skew
      be 48 hours rather than 90 minutes.
    - Reject malformed .onion addresses rather then passing them on as
      normal web requests.

  o Controller:
    - More Tor controller support. See
      http://tor.eff.org/doc/control-spec.txt for all the new features,
      including signals to emulate unix signals from any platform;
      redirectstream; extendcircuit; mapaddress; getinfo; postdescriptor;
      closestream; closecircuit; etc.
    - Encode hashed controller passwords in hex instead of base64,
      to make it easier to write controllers.
    - Revise control spec and implementation to allow all log messages to
      be sent to controller with their severities intact (suggested by
      Matt Edman). Disable debug-level logs while delivering a debug-level
      log to the controller, to prevent loop. Update TorControl to handle
      new log event types.

  o New config options/defaults:
    - Begin scrubbing sensitive strings from logs by default. Turn off
      the config option SafeLogging if you need to do debugging.
    - New exit policy: accept most low-numbered ports, rather than
      rejecting most low-numbered ports.
    - Put a note in the torrc about abuse potential with the default
      exit policy.
    - Add support for CONNECTing through https proxies, with "HttpsProxy"
      config option.
    - Add HttpProxyAuthenticator and HttpsProxyAuthenticator support
      based on patch from Adam Langley (basic auth only).
    - Bump the default BandwidthRate from 1 MB to 2 MB, to accommodate
      the fast servers that have been joining lately. (Clients are now
      willing to load balance over up to 2 MB of advertised bandwidth
      capacity too.)
    - New config option MaxAdvertisedBandwidth which lets you advertise
      a low bandwidthrate (to not attract as many circuits) while still
      allowing a higher bandwidthrate in reality.
    - Require BandwidthRate to be at least 20kB/s for servers.
    - Add a NoPublish config option, so you can be a server (e.g. for
      testing running Tor servers in other Tor networks) without
      publishing your descriptor to the primary dirservers.
    - Add a new AddressMap config directive to rewrite incoming socks
      addresses. This lets you, for example, declare an implicit
      required exit node for certain sites.
    - Add a new TrackHostExits config directive to trigger addressmaps
      for certain incoming socks addresses -- for sites that break when
      your exit keeps changing (based on patch from Mike Perry).
    - Split NewCircuitPeriod option into NewCircuitPeriod (30 secs),
      which describes how often we retry making new circuits if current
      ones are dirty, and MaxCircuitDirtiness (10 mins), which describes
      how long we're willing to make use of an already-dirty circuit.
    - Change compiled-in SHUTDOWN_WAIT_LENGTH from a fixed 30 secs to
      a config option "ShutdownWaitLength" (when using kill -INT on
      servers).
    - Fix an edge case in parsing config options: if they say "--"
      on the commandline, it's not a config option (thanks weasel).
    - New config option DirAllowPrivateAddresses for authdirservers.