v4 Overview

This page contains an overview of the biggest changes in InspIRCd v4.

Cloaking

The cloaking and hostchange modules have been combined and modularised to form one consistent cloaking system. Users of the cloaking module will not need to do anything to upgrade but users of the hostchange module will need to update their configuration.

Core cloaking functionality like user mode x (cloak), the /CLOAK command, the <cloak> configuration tag, and the cloaks metadata is now provided by the cloak module.

The cloak_md5 module has been added to provide the v3 full and half cloaking methods which were previously part of the cloaking module. These methods are now deprecated because they use salted MD5 which is no longer considered secure. As with v3 they can be used as a secondary cloak system to prevent breaking bans.

The cloak_sha256 module has been added to provide the modern hmac-sha256 and hmac-sha256-addr cloaking systems which cloaks user IP addresses, hostnames, and UNIX socket paths using the standard HMAC-SHA256 algorithm.

The cloak_user module has been added to provide the ability to cloak users with their userdata. This userdata can be their account name, their account identifier, their nickname, their TLS fingerprint, or their real username. This replaces the addnick and addaccount action from the v3 hostchange module.

The cloak_static module has been added to provide the ability to cloak users with a static value. This replaces the set action from the v3 hostchange module.

Extended Bans

Extended bans are now a first class feature and have support for match inversion (!m:R:CoolPerson) and can be added using their full names instead of a character (e.g. mute instead of m).

To help migrate over to named extbans you can set <options:extbanformat> to name to rewrite entries to the new format.

Extended ban letters are now configurable via the <extbans> tag.

ISupport

Connect class level settings (e.g. CHANLIMIT) are now correctly reflected in the ISupport output.

When server features change (e.g. modules with new modes being loaded) a diff of the changes will now be sent to clients.

Logging

Logging has been rewritten in InspIRCd v4 and now has support for support for time-based log rotation, more sensible log levels, and support for logging to:

• JSON (requires the log_json module)
• SQL (requires the log_sql module)
• Standard error & output streams (core)
• syslog (requires the log_syslog module)

The --debug option no longer enables raw I/O logging. To enable raw I/O logging the new --protocoldebug option must be used.

Modes

Numeric mode characters can now be used by modules. This alleviates the lack of free mode characters for contrib modules.

Mode letters are now configurable via the <modes> tag.

Operators

Autologin support is now provided by the core and can match on more fields than just the user's TLS client fingerprint. It now also supports only authenticating a user if their nick matches an account name.

Operator accounts can now opt-out of having a password to push security onto other fields such as a services account name (requires the account module) or a TLS client fingerprint (requires the sslinfo module).

Operator accounts and types can now specify fields directly instead of inheriting them from an operator type or class.

Operator MOTDs can now be customised depending on the type of the operator.

Operator privileges are now synchronised over the network so remote servers can check them.

Services can now grant server operator privileges to users remotely (requires the services module).

Regex

Regular expression support has been entirely rewritten with support for captures and flags.

The regex_pcre and regex_tre modules have been moved to inspircd-contrib as their dependencies are deprecated. It is recommended that you migrate to the regex_pcre2 and regex_stdlib modules respectively.

The regex_stdlib module is now always built on all platforms. This is now the recommended regex module.

Services

Channel mode r (registered) and user mode r (u_registered) are now optional as they no longer have a use at the IRCd level.

Services can now synchronise the nicknames that belong to an user when they log in. This replaces the behaviour of user mode r (u_registered).

Services servers now have to opt-in to receiving channel history messages when no pseudoclient is present. This improves the privacy of channel history and lowers the amount of messages that services have to process.

Spam protection

The opmoderated module has been imported from inspircd-contrib. This module allows you to make unprivileged users messages only visible to channel operators.

The securelist module can now show a fake /LIST output to users. It can also hide small channels that may not have an active channel operator from the /LIST output.

TLS

InspIRCd now has stricter requirements regarding TLS. At least one TLS module must now be enabled at build time and servers which link over the public internet must now be linked via TLS.

Using multiple hash algorithms for client fingerprints is now supported. This allows migrating away from old, insecure algorithms like md5. You can also use a Subject Public Key Info (SPKI) fingerprint instead of a client certificate fingerprint.

Other

Modules can now synchronise channel membership metadata between servers.

Support for incremental backoff has been added to the filter, permchannels, and xline_db modules.

The setter and set time of list modes will now be preserved across network bursts and in the permanent channel database.

Various anti-flood modes have been extended to support more methods of punishment.