UnrealIRCd 4.0.14 released

News about the UnrealIRCd project, including release announcements
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UnrealIRCd head coder
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UnrealIRCd 4.0.14 released

Post by Syzop » Fri Sep 15, 2017 9:00 am

Hi everyone,

UnrealIRCd 4.0.14 (stable) is now available for download. This release consists of several SSL/TLS related improvements.

There's now a tutorial called Using Let's Encrypt with UnrealIRCd which should help people get a "proper" SSL certificate.

You may also be interested in my blog post Improving IRC Security Step By Step which tells the journey that IRC has taken so far with regards to SSL/TLS deployment. It includes UnrealIRCd's perspective and recent improvements like draft/sts (4.0.13) and plaintext-policy (4.0.14).

  • New set::plaintext-policy configuration settings. This defines what happens to users/ircops/servers that are not using SSL/TLS.

    Code: Select all

    The default settings are:
    set {
      plaintext-policy {
        user allow; /* allow any user to connect */
        oper warn; /* warn on /OPER if not using SSL/TLS */
        server deny; /* deny servers without SSL/TLS, except localhost */
    You can change each of the three classes to allow, warn or deny. More information: https://www.unrealircd.org/docs/Set_blo ... ext-policy
    If your services do not run on localhost and link without SSL/TLS then you may get an error during linking. In such a case check out this FAQ item.
  • You can now ask UnrealIRCd to verify certificates of server links by:

    Code: Select all

    link irc1.test.net {
        verify-certificate yes;
    This will verify the certificate of the link, making sure the certificate is valid, issued for the specified name (irc1.test.net) and given out by a trusted Certificate Authority (like Let's Encrypt).
    Obviously, if you use self-signed certificates then you can't use this.
  • Introduce a concept called link security level. This will rate the security of your network from 0 to 2.
    Whenever security is degraded due to a new server link UnrealIRCd will print a warning about it.
    See https://www.unrealircd.org/docs/Link_security for more information.
    This also adds a new command /LINKSECURITY (IRCop-only).
  • The plaintext-policy and link-security is shown in "CAP LS".
Major issues fixed
  • None
Minor issues fixed
  • If you had a link block named irc1.example.net and did an outgoing connect to that server, then the server could introduce himself under a different name, such as irc1.other.net. Not a security issue since all authentication has to be passed, but this could cause confusing autoconnect attempts.
  • password::sslclientcert did not accept relative paths
  • Compile problem with LibreSSL (regarding SSL_CTX_get0_param)
  • set::modes-on-connect: was refusing certain (old) modes like +N
Other changes:
  • The ssl options 'verify-certificate' and 'no-self-signed' have been removed. Use link::verify-certificate instead. It makes no sense to verify certificates or prevent self signed certificates elsewhere such as in vhost or oper, since there is no hostname to match against.
  • Weak cipher suites such as 3DES and RC4 are disabled by default but previously you could still enable them through set::ssl::ciphers. Now you can no longer, since there is no legitimate reason to do so.
  • Update cipher suite to work with TLS 1.3. This ensures you can use TLS 1.3 in UnrealIRCd 4.0.14+ when OpenSSL supports it (in the future).
  • Bump MODDATA_MAX_CLIENT from 8 to 12: needed if you have a lot of 3rd party modules loaded. Also moved MODDATA_MAX_* to include/config.h
Module coders:
  • You can now attach ModData to server objects as well (including &me).
  • Please do not use UmodeDel, CmdoverrideDel and any other *Del() functions from MOD_UNLOAD. These undocumented functions are unnecessary since 2008 or so. UnrealIRCd takes care of unloading all module objects. It can cause a crash if someone unloads the module in UnrealIRCd 4 (more specifically: double free if unloading modules which use ModData). Attempts to use these functions in future UnrealIRCd versions may result in a compile error.
As always, you can download UnrealIRCd from www.unrealircd.org.

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