Workshops / Background reports / Book introductions
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Workshops / Background reports / Book introductions
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The master of remote control - part 3
A Telnet daemon on the Amiga
In the article on VNCS on the last issue of Amiga aktuell, the Amiga was acting as a server, making its screen output available over an Intranet or even worldwide through the Internet, if desired.
This required an Amiga well equipped with RAM and processing power. But as you will learn now, a much more modest configuration can be remote-controlled via TCP/IP, even if it is a little more inconvenient for an Amiga user who is used to intuitive mouse control.
We are talking about the old and honored telnet. Clients for controlling other computers can be found in vast amounts on the Aminet and are usable without much installation. Let's see if this is also true for telnet daemons...
The program package of our choice will be "Telnetd 2.0" [1] from Peter Simons and Steve Holland. The requirements are quite humble. All you need is an Amiga with a TCP/IP stack. Telnetd was written for use with AmiTCP, but, as you will see, it also works well with Miami.
After unarchiving the file extracted either from Aminet or the Aminet CD-ROM No. 15, you'll find several subdirectories.
All files from the directories "c", "devs" and "s" have to be copied to the corresponding directories on the system partitions. Then move the directory "serv" into the Miami drawer and the manual anywhere you want. That's all.
Start up Miami, go to the database section and select the entry InetD. Add the following: service "telnet", socket "stream", protocol "TCP" and "nowait", the user will be "root", the server is "Miami:/serv/telnetd" and the name can be left blank.
4.2 Users The user to login later is configured in the same database module in the section "users". Probably there are already some existing users from earlier configurations. All potential users who want access through telnet will need a password and a shell, because the complete telnet access is handled in this shell. The user in our example will be called "uwep". He gets a password and under 'Shell' the entry "*NewShell * from s:remote-startup". This is to make sure that the output of the Shell will be sent to the remote computer.
This completes the configuration. Save it under a telling name. Now it is time to go online.
From now on, all users defined in Miami can log into the Amiga and manipulate it as they wish. Of course, we are going to test that right now. Almost every operating system includes a telnet client. Under Linux, you can evoke telnet by entering "telnet hostname" or "telnet IP address" into a shell. Of course you have to give the correct hostname or IP address of the Amiga we prepared earlier. The Amiga in this example can be reached under the name "amiga.xwing.de" or the IP "192.168.0.2".
Under Windows, you can use the MS-DOS prompt to start telnet. The syntax is the same as under Linux. You will then be requested to enter a username and the password. If this information was correct, you will find yourself in a Shell on the Amiga. You can check the logon on the Amiga itself, because Miami keeps an entry in its Log window.
As easy as installation and usage of a telnet daemon may be, you should be aware that all information is transferred unencrypted over telnet. This includes passwords and other valuable data. This might be acceptable for use in an Intranet, but if you want to control the Amiga over an Internet connection, this is a serious security issue. In these cases, SSH is a safer method, since it encrypts the transferred information.
You should also never forget that the Amiga is a single user operating system.
Every user who is logged in via telnet or another service can do serious harm to your system. This can be helped by using the MultiUser-Filessystem [2] from Geert Uytterhoeven, but this takes some effort.
[1] im Aminet unter /comm/tcp/telnetd2_0.lha
[2] im Aminet unter /util/misc/MultiUser**.lha
Uwe Pannecke <Uwe.Pannecke@t-online.de>
