Authentication types

At various places in the configuration file, for example the Oper block, Vhost block, Link block and Allow block you can authenticate clients by password or other means. You can specify the password as plaintext, but you can also use other authentication types, such as a hashed password or TLS certificate fingerprint.

For passwords, we recommend using argon2, see the example argon2 password in vhost block on how to generate password hashes and use them in the config file (it works for oper passwords too).

Available auth-types

The following auth-types are available:

Auth-type	Description	Security level	How to generate
none	Plaintext / cleartext password	Bad	Plaintext password directly in the config. Not recommended.
crypt	UNIX crypt. The exact hashing algorithm depends on the type of crypt, therefore the security can range from bad to reasonable.	Bad or reasonable	Not recommended.
bcrypt	Blowfish crypt with salt and many rounds [1]	Reasonable (still good for long strong passwords)	On IRC: /MKPASSWD bcrypt <password> On *NIX shell: ./unrealircd mkpasswd bcrypt On Windows: unrealircdctl mkpasswd bcrypt passwdhere
argon2	Argon2 hashing algorithm. Many rounds, anti-GPU cracking measures, etc. [2]	Good	On IRC: /MKPASSWD argon2 <password> On *NIX shell: ./unrealircd mkpasswd argon2 On Windows: unrealircdctl mkpasswd argon2 passwdhere
cert	SSL/TLS Client certificate file Note that most people use certfp or spkifp instead of this.	Excellent	Path to a public SSL/TLS certificate (.pem file)
certfp	SSL/TLS Client certificate fingerprint (SHA256)	Excellent	For a given SSL/TLS certificate such as client.pem, run: openssl x509 -in client.pem -sha256 -noout -fingerprint and copy the AA:BB:CC:DD:etc... fingerprint.
spkifp	SPKI Fingerprint. This is similar to an SSL/TLS Client certificate fingerprint but is usually only used for server linking. The benefit of spkifp over certfp is that the spkifp stays the same as long as the key stays the same.	Excellent	For a given SSL/TLS certificate: On *NIX: ./unrealircd spkifp conf/ssl/server.cert.pem On Windows: unrealircdctl spkifp conf\ssl\server.cert.pem Or, alternatively, these openssl commands

The auth-type argon2 is the best one if you want to authenticate using a password. It's slow to crack. The algorithm bcrypt is fine too, if you use long strong passwords, say 16+ characters of mixed UPPERCASE, lowercase and digits.

The types cert and certfp require a bit more work and expertise, as the user must generate their own SSL/TLS Certificate and then use it to connect to the server via SSL/TLS. We suggest to use this auth-type for /OPER (in the Oper block), see the 2nd example below. Finally the type spkifp is usually only used for linking servers.

Example 1: argon2 password in vhost block

Say, you want to use the password test and want to use argon2 hashed passwords (the best password hashing method available).

• Create the password hash (choose 1 of these 3 methods):
  • As IRCOp (or unless you have set set::options::mkpasswd-for-everyone block) run:

    /MKPASSWD argon2 test

  • Or on the *NIX command line run:

    irc@system:~/unrealircd$ ./unrealircd mkpasswd
    Enter password to hash:
    Encrypted password is: $argon2id$v=19$m=8192,t=3,p=2$hDpgvcBOUVAJMQcJITTLnQ$fL5lg/3tZ0VgTXn61EQ6Rnxhl5j+MvESBBGpg1mZqWM
    

  • Or on Windows:

    C:\Program Files\UnrealIRCd 6\bin> unrealircdctl mkpasswd test
    Encrypted password is: $argon2id$v=19$m=8192,t=3,p=2$ZMPmFokpauGUQmz8xhxY+A$KARb6fJb0b9QOi95Ts1xAGgfmY5STkwlGiheNG1JvwU

• You should get back a string that starts with $ followed by a lot of characters.
• Put this string in your vhost block (or any other block) like this:

  vhost {
      vhost I.love.Tux;
      mask *@*;
      login Tux;
      password "$argon2id$v=19$m=8192,t=3,p=2$hDpgvcBOUVAJMQcJITTLnQ$fL5lg/3tZ0VgTXn61EQ6Rnxhl5j+MvESBBGpg1mZqWM";
  };
  

/REHASH your IRCd server configuration (Execute /REHASH as an IRCop on IRC)

Try to use the new vhost by typing /VHOST Tux test

Example 2: Oper by SSL/TLS Client certificates

cert and certfp are exceptional auth-types which can be used to authenticate SSL/TLS users by their client certificate. With these authentication methods you can be sure the user is using SSL/TLS and is using the specified client certificate. It's very secure but is a slightly advanced feature.

See Certificate fingerprint on how to get your client certificate fingerprint. Then, put your certfp in the unrealircd.conf like this:

oper test {
     password "e74d46f19ff468f5e8e349cc285df96585ba4f16b64902e334e6e76afe76a798" { certfp; };
[..]
};

• Rehash your server
• Now oper up through /OPER test. When you try this, make sure that you are not already an IRCOp.
• You should now have IRC Operator rights.
• Congratulations, you are now using the most secure authentication method available in UnrealIRCd!

Example 3: spkifp when linking servers

When you are linking servers via the Link block we highly suggest you follow the Tutorial: Linking servers. It uses the spkifp method which is based on the SSL/TLS client certificate (or key, actually).