release of the toolkit , used to organize the operation of the anonymous Tor network. Tor 0.4.2.5 is recognized as the first stable release of the 0.4.2 branch, which has been in development for the past four months. At the same time, updates have been offered for older branches 0.4.1.7, 0.4.0.6, and 0.3.5.9. The 0.4.2 branch will be accompanied within the standard support cycle — the release of updates will cease in 9 months or 3 months after the release of the 0.4.3.x branch. Long-term support (LTS) is provided for the 0.3.5 branch, with updates being released until February 1, 2022. Support for the 0.4.0.x and 0.2.9.x branches will be discontinued early next year.
Key innovations:
- Node directory servers have included of connections from nodes running outdated Tor releases, for which support has been discontinued (all nodes not running the current branches 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2 will be blocked). This blocking will allow for the automatic exclusion of nodes from the network that fail to transition to the latest software as support for additional branches is phased out.
The presence of nodes with outdated software negatively impacts stability and creates additional security risks. If an administrator does not monitor the updates for Tor, it suggests a careless attitude towards updating the system and other server applications, which increases the risk of control being seized over the node due to targeted attacks. Nodes running unsupported releases also hinder the fixing of critical bugs, impede the introduction of new protocol features, and decrease network efficiency. Operators of outdated systems were notified about the planned blocking back in September.
- For hidden services to protect against DoS attacks. Introduction points can now limit the intensity of client requests, using parameters sent by the hidden service in the ESTABLISH_INTRO cell. If the new extension is not used by the hidden service, the introduction point will follow the parameters of reaching consensus.
- Direct single-hop connections for clients used with the now-defunct Tor2web service are prohibited at the connection selection points. This blocking will help reduce network load from spam clients.
- A generic token bucket has been implemented for hidden services, utilizing a single counter that can be used to combat DoS attacks.
- The 'BEST' mode in the ADD_ONION command now defaults to using ED25519-V3 (v3) services instead of RSA1024 (v2).
- The configuration settings code now includes the capability for splitting configuration data among multiple objects.
- Significant code cleanup has been conducted.
Source: opennet.ru
