Secure Chat with YTalk and SSH
Pages: 1, 2

Exploiting the Full Power of YTalk While Online

YTalk can become quite cool when its options are used properly. Press Escape for a menu:

###########################
#        Main Menu
#
#a: add a user
#d: delete a user
#k: kill all unconnected
#o: options
#s: shell
#u: user list
#w: output user to file
#q: quit
###########################

I won't repeat details that can be found in the man pages. The menu allows you to know who's on the talk server, react to new users, reply to talk requests, connect and disconnect, as well as output everything to a file.

Suppose salt@www.munchies.org and vinegar@www.munchies.org are chatting away. Suddenly ketchup wants to join in and talk to vinegar. Here's what vinegar will see:

----------= YTalk version 3.1.1 =----------

       ######################################
       # Talk to ketchup@www.munchies.org?  #
       ######################################

----------= salt@www.munchies.org =----------

All vinegar has to do is type y for yes. He will now see:

----------= YTalk version 3.1.1 =----------


----------= salt@www.munchies.org =----------


----------= ketchup@www.munchies.org =----------

If salt@www.munchies.org wants to talk to ketchup@www.munchies.org, all he has to do is to select a: add a user from the YTalk main menu. He will see:

###########################
#        Main Menu        
#                         
# a: add a user           
######################################
# Add Which User?                                       
# >                                                   
#######################################
# u: user list            
# w: output user to file  
# q: quit                 
###########################

All salt has to do is type ketchup to add him to the conversation. Deleting a user is just as simple.

Setting Options Before Going Online with .ytalkrc

There are a number of useful options that give power and flexibility to YTalk, but let's stick to the basics for the sake of brevity and simplicity. Options may be set in the .ytalkrc file located in your home directory. Otherwise, the system wide defaults are in /usr/local/etc/ytalkrc. Here a typical .ytalkrc:

################
#  a user's window will scroll when he reaches the bottom 
#  instead of wrapping back around to the top.
turn scrolling on

# re-ring any user who does not respond to your
# invitation within 30 seconds.
turn rering on

# re-rings a user without asking permission.
turn prompt-rering off

# any word which would overextend the right margin will
# be automatically moved to the next line on your screen.
turn word-wrap on

# will add these users to your session 
# automatically, without asking you for verification.
turn auto-import on

# will automatically accept any connection
# requested by another user and add 
# them to your session. You will not be asked for verification.
turn auto-invite on
#################

Remember to look at the man page for further referencing.

Extra Tricks

One of the unfortunate aspects of your garden variety chat lines and instant messaging systems is the inability to navigate up or down one or more lines to retype a letter, word or phrase, much less copy and paste something you may have said 10 minutes earlier. You are condemned to retype. However, if salt@www.munchies.org were to use the shell command and activate vi (or, my preference, vim), he would have the control and versatility of this powerful editor within YTalk. For the truly enterprising, you can't go wrong using emacs; just think of all those horizontal and vertical screens you can generate.

Most of my explorations were involved figuring out YTalk but there was a lot I could have done with SSH. We could have set up public key authentication, for example, but remember it is only available on SSH protocol version 2. A simple SSH contact would have resulted in an immediate login without typing a password. This is great for the typing handicapped among us.

Simplifying and securing the login process can be further enhanced by restricting the login profile and default account shell--bash in my case. Everybody can use the same account and when YTalk is automatically invoked in the script it will look for certain terminals to log into.

Conclusions

Are there limitations? YTalk works best when there are no more than 3 users. Why? Terminal size: the more people log in, the less space each user receives. Are there nifty features that could be incorporated? The X version of YTalk, although primitive, is going in the right direction. Wouldn't it be great if somebody could look at the code and incorporate X11 forwarding so as to allow graphical utilities to be tunneled through it, say, xpaint? Now that I think of it SSH already has X11 port forwarding...

References

• YTalk
• Ssh
• Ssh public key authentication
• Ssh X11 authentication

Robert Bernier is the PostgreSQL business intelligence analyst for SRA America, a subsidiary of Software Research America (SRA).

---

Return to the Linux DevCenter.