# $EPIC: ircuser,v 1.5 2001/11/28 09:13:09 anders Exp $
Synopsis:
   ircuser <username>

About usernames, registration, and identd:
   Whenever you connect to an irc server, the client sends some information
   about you to the server (``registration'').  One of the pieces of infor-
   mation it sends is your "username".  This is supposed to be the name of
   the account you are logged into.  The server treats this username as
   nothing more than a fallback value; a hint.  The server does not trust
   the client to send trustworthy data (and why should it?  The user has
   control over the client. ;-)

   By default, the server always queries your username by asking the ident
   (auth) service that is running on your machine (using RFC 1413).  If your
   host is running identd, then the value returned by identd will be used as
   your username and the "hint" provided at registration time is ignored.
   If your host is not running identd, then the value provided at registration
   time is used, but is prepended with a ~ (tilde) to warn other irc users 
   that the username was not authenticated.

   It is a good idea to be running an identd, and many servers on large public
   networks absolutely require that you be running identd before they will 
   accept your registration.  This is for your protection, rather than being
   an annoyance...

   In the modern irc world, most of the irc users are running windows, where
   this is no concept of a username, and hence the username you see for them
   is ultimately provided by the client.  Most reputable windows clients
   provide their own identd server which just returns the same username that
   the client provided at registration time.  Therefore, the username that 
   you get for a user is not really of much value at all, even if it is 
   "authenticated".

   One of the features of the identd service is that if you ask it for the
   username of a connection that does not exist, it will return an error 
   code.  A popular irc attack is to forge many irc connections (and 
   registration attempts) from a victim's ip address so many times as to 
   annoy an operator enough into falsely K-lining the victim for running
   clonebots.  

   Every time a connection is made to an irc server, the server asks the
   identd service on the connecting host what the username is for the new
   connection.  If the connection is fraudulent (forged), identd will return
   an error, and the server will consider the connection non-authenticated.

   Thus, if a server forbids all non-authenticated users, then by rule all
   connections on the server have been positively confirmed by an identd 
   service running on the connecting host to be valid and truthful.  It is
   therefore possible to hold responsible people who do rude things to others
   since it is not possible to forge connections with others' addresses.

   There are three lessons here:
   1) DO run an identd service, even if it is one that lets you control
      what it returns as your username.  The server isn't interested in 
      what your username is, only that the connection actually came from
      you.  Running an identd service is your first line of defense from 
      others who would try to get you in trouble.
   1) DON'T run an identd service that returns a dummy username for all
      requests valid or invalid.  That will make it look like you really 
      *are* running clonebots and will get you in trouble.
   2) DON'T run an identd service that returns an error for all requests
      valid or invalid.  That makes it look like your (valid) connections
      are actually forgeries and many large public servers don't want any
      forged connections.

   Do your part.  Run identd for the good of IRC.

Description:
   You can use this command to change the default "hint" that is sent by
   EPIC to the server every time you establish a new server connection.
   This "hint" is overridden by whatever your identd server returns, and
   you are running an identd server, right? ;-)  Because the "hint" is
   generally discarded, being able to set the "hint" is a moot point.

   You must, of course, reconnect after you use ircuser before your
   new username will be seen to other users (if at all).

See Also:
   reconnect(1)
