[tor-talk] Tor 0.4.6.1-alpha is released
nickm at torproject.org
Thu Mar 18 18:31:01 UTC 2021
There's a new alpha Tor release! Because it's an alpha, you should
only run it if you're ready to find more bugs than usual, and report
them on gitlab.torproject.org.
The source code is available from the download page at
https://www.torproject.org/download/tor/ ; if you build Tor from
source, why not give it a try? And if you don't build Tor from source,
packages should be ready over the coming days, with a Tor Browser
alpha release likely some time next week.
Here's what's new:
Changes in version 0.4.6.1-alpha - 2021-03-18
Tor 0.4.6.1-alpha is the first alpha release in the 0.4.6.x series. It
improves client circuit performance, adds missing features, and
improves some of our DoS handling and statistics reporting. It also
includes numerous smaller bugfixes.
Below are the changes since 0.4.5.7. (Note that this release DOES
include the fixes for the security bugs already fixed in 0.4.5.7.)
o Major features (control port, onion services):
- Add controller support for creating version 3 onion services with
client authorization. Previously, only v2 onion services could be
created with client authorization. Closes ticket 40084. Patch by
o Major features (directory authorityl):
- When voting on a relay with a Sybil-like appearance, add the Sybil
flag when clearing out the other flags. This lets a relay operator
know why their relay hasn't been included in the consensus. Closes
ticket 40255. Patch by Neel Chauhan.
o Major features (metrics):
- Relays now report how overloaded they are in their extrainfo
documents. This information is controlled with the
OverloadStatistics torrc option, and it will be used to improve
decisions about the network's load balancing. Implements proposal
328; closes ticket 40222.
o Major features (relay, denial of service):
- Add a new DoS subsystem feature to control the rate of client
connections for relays. Closes ticket 40253.
o Major features (statistics):
- Relays now publish statistics about the number of v3 onion
services and volume of v3 onion service traffic, in the same
manner they already do for v2 onions. Closes ticket 23126.
o Major bugfixes (circuit build timeout):
- Improve the accuracy of our circuit build timeout calculation for
60%, 70%, and 80% build rates for various guard choices. We now
use a maximum likelihood estimator for Pareto parameters of the
circuit build time distribution, instead of a "right-censored
estimator". This causes clients to ignore circuits that never
finish building in their timeout calculations. Previously, clients
were counting such unfinished circuits as having the highest
possible build time value, when in reality these circuits most
likely just contain relays that are offline. We also now wait a
bit longer to let circuits complete for measurement purposes,
lower the minimum possible effective timeout from 1.5 seconds to
10ms, and increase the resolution of the circuit build time
histogram from 50ms bin widths to 10ms bin widths. Additionally,
we alter our estimate Xm by taking the maximum of the top 10 most
common build time values of the 10ms histogram, and compute Xm as
the average of these. Fixes bug 40168; bugfix on 0.2.2.14-alpha.
- Remove max_time calculation and associated warning from circuit
build timeout 'alpha' parameter estimation, as this is no longer
needed by our new estimator from 40168. Fixes bug 34088; bugfix
o Major bugfixes (signing key):
- In the tor-gencert utility, give an informative error message if
the passphrase given in `--create-identity-key` is too short.
Fixes bug 40189; bugfix on 0.2.0.1-alpha. Patch by Neel Chauhan.
o Minor features (bridge):
- We now announce the URL to Tor's new bridge status at
https://bridges.torproject.org/ when Tor is configured to run as a
bridge relay. Closes ticket 30477.
o Minor features (build system):
- New "make lsp" command to auto generate the compile_commands.json
file used by the ccls server. The "bear" program is needed for
this. Closes ticket 40227.
o Minor features (command-line interface):
- Add build informations to `tor --version` in order to ease
reproducible builds. Closes ticket 32102.
- When parsing command-line flags that take an optional argument,
treat the argument as absent if it would start with a '-'
character. Arguments in that form are not intelligible for any of
our optional-argument flags. Closes ticket 40223.
- Allow a relay operator to list the ed25519 keys on the command
line by adding the `rsa` and `ed25519` arguments to the
--list-fingerprint flag to show the respective RSA and ed25519
relay fingerprint. Closes ticket 33632. Patch by Neel Chauhan.
o Minor features (control port, stream handling):
- Add the stream ID to the event line in the ADDRMAP control event.
Closes ticket 40249. Patch by Neel Chauhan.
o Minor features (dormant mode):
- Add a new 'DormantTimeoutEnabled' option for coarse-grained
control over whether the client can become dormant from
inactivity. Most people won't need this. Closes ticket 40228.
o Minor features (logging):
- Change the DoS subsystem heartbeat line format to be more clear on
what has been detected/rejected, and which option is disabled (if
any). Closes ticket 40308.
- In src/core/mainloop/mainloop.c and src/core/mainloop/connection.c,
put brackets around IPv6 addresses in log messages. Closes ticket
40232. Patch by Neel Chauhan.
o Minor features (performance, windows):
- Use SRWLocks to implement locking on Windows. Replaces the
"critical section" locking implementation with the faster
SRWLocks, available since Windows Vista. Closes ticket 17927.
Patch by Daniel Pinto.
o Minor features (protocol, proxy support, defense in depth):
- Close HAProxy connections if they somehow manage to send us data
before we start reading. Closes another case of ticket 40017.
o Minor features (tests, portability):
- Port the hs_build_address.py test script to work with recent
versions of python. Closes ticket 40213. Patch from
o Minor features (vote document):
- Add a "stats" line to directory authority votes, to report various
statistics that authorities compute about the relays. This will
help us diagnose the network better. Closes ticket 40314.
o Minor bugfixes (build):
- The configure script now shows whether or not lzma and zstd have
been used, not just if the enable flag was passed in. Fixes bug
40236; bugfix on 0.4.3.1-alpha.
o Minor bugfixes (compatibility):
- Fix a failure in the test cases when running on the "hppa"
architecture, along with a related test that might fail on other
architectures in the future. Fixes bug 40274; bugfix
o Minor bugfixes (controller):
- Fix a "BUG" warning that would appear when a controller chooses
the first hop for a circuit, and that circuit completes. Fixes bug
40285; bugfix on 0.3.2.1-alpha.
o Minor bugfixes (directory authorities, voting):
- Add a new consensus method (31) to support any future changes that
authorities decide to make to the value of bwweightscale or
maxunmeasuredbw. Previously, there was a bug that prevented the
authorities from parsing these consensus parameters correctly under
most circumstances. Fixes bug 19011; bugfix on 0.2.2.10-alpha.
o Minor bugfixes (ipv6):
- Allow non-SOCKSPorts to disable IPv4, IPv6, and PreferIPv4. Some
rare configurations might break, but in this case you can disable
NoIPv4Traffic and NoIPv6Traffic as needed. Fixes bug 33607; bugfix
on 0.4.1.1-alpha. Patch by Neel Chauhan.
o Minor bugfixes (key generation):
- Do not require a valid torrc when using the `--keygen` argument to
generate a signing key. This allows us to generate keys on systems
or users which may not run Tor. Fixes bug 40235; bugfix on
0.2.7.2-alpha. Patch by Neel Chauhan.
o Minor bugfixes (onion services, logging):
- Downgrade the severity of a few rendezvous circuit-related
warnings from warning to info. Fixes bug 40207; bugfix on
0.3.2.1-alpha. Patch by Neel Chauhan.
o Minor bugfixes (relay):
- Reduce the compression level for data streaming from HIGH to LOW.
This should reduce the CPU and memory burden for directory caches.
Fixes bug 40301; bugfix on 0.3.5.1-alpha.
o Code simplification and refactoring:
- Remove the orconn_ext_or_id_map structure and related functions.
(Nothing outside of unit tests used them.) Closes ticket 33383.
Patch by Neel Chauhan.
o Code simplification and refactoring (metrics, DoS):
- Move the DoS subsystem into the subsys manager, including its
configuration options. Closes ticket 40261.
o Removed features (relay):
- Because DirPorts are only used on authorities, relays no longer
advertise them. Similarly, self-testing for DirPorts has been
disabled, since an unreachable DirPort is no reason for a relay
not to advertise itself. (Configuring a DirPort will still work,
for now.) Closes ticket 40282.
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