arch-wiki-md-repo/wiki/_content/english/Identd Setup.md

All arch-wiki articles in markdown format, updated every two days.

The Ident service as specified by RFC 1413 is mostly used by various IRC networks and the occasional old FTP server to ask a remote server which user is making a connection. This method is quite untrustworthy, as the remote host can simply choose to lie.

So you have two choices:

1.  Tell the truth (see [#oidentd](#oidentd) below)
2.  Tell a little white lie (see nullidentmod or nullidentd below)

## Contents

*   [1 oidentd](#oidentd)
*   [2 nullIdentdMod](#nullIdentdMod)
    *   [2.1 Customization](#Customization)
*   [3 nullIdent](#nullIdent)
    *   [3.1 systemd activation](#systemd_activation)

## oidentd

See [oidentd](/index.php/Oidentd "Oidentd").

If all went well, you should have the auth service running on port 113\. A good way of checking this is by installing [nmap](https://www.archlinux.org/packages/?name=nmap) (if you do not have it already) and typing

```
$ nmap localhost

```

## nullIdentdMod

**1.** [Install](/index.php/Install "Install") the [nullidentdmod-git](https://aur.archlinux.org/packages/nullidentdmod-git/) package.

**2.** [Enable](/index.php/Enable "Enable") `nullidentdmod.socket` on systemd.

**3.** [Start](/index.php/Start "Start") `nullidentdmod.socket` on systemd.

**4.** Check if is working [here](http://acidhub.click/NullidentdMod/).

As is, nullidentdmod will return a random userid.

### Customization

**1.** [Edit](/index.php/Edit "Edit") the unit with systemctl command:

```
# systemctl edit --full nullidentdmod@.service

```

At line 6, write desired userid

```
[Unit]                                   
Description=NullidentdMod service        

[Service]                                
User=nobody                              
ExecStart=/usr/bin/nullidentdmod **<userid>**
StandardInput=socket                     
StandardOutput=socket                    

[Install]                                
WantedBy=multi-user.target               

```

Obviously where <userid> you put your custom userid.

**4.** Check if is working [here](http://acidhub.click/NullidentdMod/)

## nullIdent

This Ident server is capable of only returning the same name for any query. With a quick change to a single line of code, it can be customized to return any name you can think. One use for such a simple service would be for IRC client connections to ensure a degree of privacy (remote IRC server and users do not know your username) as well as allowing a small degree of 'vanity plating' for use in IRC channels.

The original code suffered link rot, but may now be found on github, at this address [https://github.com/dxtr/nullidentd](https://github.com/dxtr/nullidentd).

**1.** clone the source to a directory of your choice using git.

```
git clone https://github.com/dxtr/nullidentd

```

**2.** Edit line 86 of nullidentd.c to your liking. use any text editor of your choice

example:

```
nano nullidentd.c

```

**3.** Compile the binary.

```
make

```

**4.** Install Binary You can move it to any location of your choice of course, but the FileSystem Hierarchy states the nullidentd binary should live in `/usr/local/sbin`

```
# mv nullidentd /usr/local/sbin

```

### systemd activation

Below are two files you need to create under `/etc/systemd/system/`

**1.** identd@.service

```
[Unit]
Description=per connection null identd

[Service]
User=nobody
ExecStart=/usr/local/sbin/nullidentd
StandardInput=socket
StandardOutput=socket

```

**2.** ident.socket

```
[Unit]
Description=socket for ident

[Socket]
ListenStream=113
Accept=yes

[Install]
WantedBy=sockets.target

```

**3.** inform SystemD of the new files

```
# systemctl daemon-reload

```

**4.** Test that the socket is listening sucessfully

```
$ systemctl status ident.socket

```

this should yield output similar to the below

```
ident.socket - socket for ident
   Loaded: loaded (/etc/systemd/system/ident.socket; enabled)
   Active: active (listening) since Fri 2014-01-24 02:30:53 WST; 30 seconds ago
   Listen: [::]:113 (Stream)
 Accepted: 0; Connected: 0

Jan 24 02:30:53 HOSTNAME systemd[1]: Listening on socket for ident.

```