Connecting Using SSH

What is SSH?

ssh, the "secure shell", is a set of programs which provide the facility to log into a remote machine, execute commands on a remote machine, or copy files from one machine to another, in a manner that provides strong authentication and which encrypts any data passing between machines.

Why SSH?

Many of the traditional protocols such as TELNET and FTP are inherently insecure as passwords are transmitted unencrypted over the network. This poses considerable security risks to both our servers and your data. By using a secure protocol the risk of unauthorised access is much reduced.

Which Version?

2020Media mostly uses SSH1 protocol for connecting.
Quicklink to this page: http://www.2020media.com/index.php?option=com_content&task=view&id=63&Itemid=38

Connecting Using SSH

Rather than using the traditional username / password combination to validate users, there is an alternative system using 'keys' that provides better security. A 'key' consists of two parts, a public part and a private part.

The public part of they key is given to 2020Media and installed on our servers. The private part is kept on your computer and should not be given to anyone else.

When you attempt to connect to our servers, our server checks that the computer connecting has the 'private' part of the key, and only then will allow the connection.

For further security there is an additional 'passphrase' that is requested each time the private key is used.

Before connecting for the first time you will need to generate your own public / private key pair and send the public key to us. Details of how to do this using various programs are below.

SSH on Macintosh

SSH on Windows

There are a number of implementations of SSH for windows.

You can download a trial version of SecureCRT here

First you need to generate your public / private key pair.

Open the program and you will be presented with the following screen as shown in below. Select the new session button as highlighted.

A new screen will now open asking you to enter some session settings. Select ssh1 as the protocol. Replace 'yourhostname'with your hostname and replace 'username-x' with your tomcat username in the spaces provided. This information can be obtained from your account letter. Lastly select RSA as the authentication method as shown below.

Now select 'Public Key' and untick the box marked 'Use global identity file'. The 'create identity file' button will now become active as shown below.

Press this button to begin create your public / private key pair. Click next on the screen that appears and you will then be presented with Key generation wizard. Enter in a passphrase and a comment. You should make a note of the passphrase. This screen when then look as shown below once you have done so.

Now select next and you will be asked to specify the length of your key pair. By default it will have 1024 written in this bar. This is the recommended amount so you do not need to change this. Click next

Now you have to generate the key pair. The keys are generated through the movement of your mouse. Randomly move your mouse over the screen until the bar fills up as shown below.

To save your private key pair choose a location. The public key will be saved in the same file with the same filename but will have a .pub extension. This screen looks as shown below

Now go to the directory where you saved these files and open the .pub file with notepad. A series of numbers should appear. They should look something like
1024 65537 15852769953865678248595021177432773703698441430689480942563605478862813901667095
82252313716196314574979084639327521589001616543937412214325820304892480167192585
19750231407958905448052396056261391600691073971143911372612455069140250054555351
297317339851369049929979997124305646589350885768284052300239330306659
Copy the public key from the window into an email and send it to support. Please also be sure to include your Tomcat username and the server host name of your website. This information should all be obtainable from your account letter. If you omit this information we won't be able to match up your key with your account and it will delay your access.

After you have received an email back from us confirming your public key has been installed, you are ready to connect. Next under the connection setting select 'public key. This will bring up the folowing screen as shown below

Untick, the 'global identity' box and in the identity file box, select the browse icon on the right and locate your private key file. Click ok to return to the main connection screen.
Your new connection should now appear in the list. Click connect to login. This should look as shown below

If you have entered all of your information correctly the following screen should appear asking you for your passphrase. This is the passphrase that you created when you created your public/private key pair. Enter your passphrase in the space provided. The screen should look as shown below

Click ok to make the connection. If you have entered this correctly you should now be logged in securely and the screen should look as shown below

IF YOU HAVE ANY PROBLEMS WITH THESE INSTRUCTIONS, FOR INSTANCE IF THE SOFTWARE VERSION OF SECURECRT HAS CHANGED, PLEASE CONTACT THE SOFTWARE PROVIDER, NOT 2020MEDIA.

WE PROVIDE THESE INSTRUCTIONS IN GOOD FAITH. HOWEVER WE ARE NOT RESPONSIBLE FOR CLIENT APPLICATION SET UP.

OpenSSH on Windows

There is a good version of OpenSSH available for Windows. You can download it from http://sshwindows.sourceforge.net. You can then follow the instructions below for SSH on Unix.

SSH on UNIX

There are various implementations available. You can download them from here.

To generate the public / private key pair you need to execute a command like

ssh-keygen -1 -t rsa1 username -P passphrase

where username is found on your account letter, and passphase is some sentence choosen at random by you. This will generate two files, one called - which contains your private key, and another called username.pub - which contains the public key.

Email the username.pub file, together with your username to Support so that we can install it on the server.

The key you send should look something like

1024 37 123544354354354352432543543254354325434354353454354543534325354 ....32434324 rsa-key-435435435

If the directory '.ssh' does not exist in your home directory create it.

Copy the username file to '.ssh/identity'

cp username .ssh/identity

After you have received an email back from us confirming your public key, you are ready to connect.

ssh -l username hostname

where username and hostname are found in your account details letter.

SSH on Macintosh

Useful commands

Here are a few useful commands you can use, if you have appropriate permissions:

sh ./startup.sh      Start Tomcat
sh ./shutdown.sh     Stop Tomcat
tail -f logs/catalina.out   View live Catalina log
rm -R -f work/Standalone/_ Remove worker files
or rm -R -f work/Standalone/
ps auxwww|grep X     Check what tomcat processes are running (where X is your username)
history              View command history
exit                 Logout