ngircd/debian/ngircd.README.Debian

TLS-based server connection, wheezy/jessie interoperability
===========================================================

There might be a problem when linking two ngircd servers running
the wheezy and the jessie version respectively. If you see
| gnutls_handshake: Could not negotiate a supported cipher suite.
on the wheezy and
| SSL error: The TLS connection was non-properly terminated. [gnutls_handshake].
on the jessie side: As a workaround, set "Passive = yes" in jessie's
[Server] section so the connection is always initiated by wheezy.
This way around the negotiation will succeed.


TLS support
===========

Some things to take into account when configuring TLS/SSL support:

* The irc user must be able to read the key file.
* ngIRCd will run without a DH parameters file but that's a bad idea.
* A certificate exchange requires restart.


Certificate location
--------------------
* If your certificate and key are for ngIRCd only: Simply place them in
  /etc/ngircd, set KeyFile and CertFile accordingly. To secure the key
  file (server.key):

    chown irc:irc server.key
    chmod 600 server.key

* If however you offer several TLS-based services that using the same
  certificate and key: Consider installing the ssl-cert package which
  provides the ssl-cert group. Place the certificate file (server.crt)
  in /etc/ssl/certs/ and the key file (server.key) in /etc/ssl/private/,
  and make sure ngIRCd can read it:

	chown root:ssl-cert /etc/ssl/private/server.key
	chmod 640 /etc/ssl/private/server.key
	adduser irc ssl-cert

  Repeat the last step for all users that run a daemon providing TLS.


TLS-based server-server links
-----------------------------
When linking two ngircd servers, the connection should be TLS-based for
obvious reasons. To do so, edit ngircd.conf:

* Enable SSLConnect in each [Server] stanza.
* Define CAFile in the [SSL] stanza. Note that by default *no*
  certificate is trusted.
  If the peers's certificate was signed by one of the well-known
  certificate authorities: Use the suggested value
  "/etc/ssl/certs/ca-certificates.crt" and install the ca-certificate
  package.
  Else set the value to the respective CA's certificate file.

Verfication can be disabled entirely on a per-link base by setting
SSLVerify to false. This is strongly discouraged as you will lose all
security by that.


DH parameters file
------------------
It is suggested to create a DH params file. If missing, ngIRCd will
create one on the fly but this will prolong each startup.

To create that file:

* using gnutls (from gnutls-cli package):

    certtool --generate-dh-params --bits 2048 >/etc/ngircd/dhparams.pem

* using openssl:

    openssl dhparam -2 -out /etc/ngircd/dhparams.pem 2048

This has to be done only once. Don't forget to enable the DHFile
setting in /etc/ngircd/ngircd.conf.


Certificate exchange
--------------------
Due to limitations of GnuTLS, a re-start of ngIRCd is required if the
certificates were changed. A reload is not sufficient.