sbc - Use SSH Like a Boss!

Introduction

sbc stands for Secure Back Channel and is a little tool to help you using SSH sessions. It looks like bcvi but is more secure in the command execution process (it uses SSH and not a new non-crypted non-authenticated protocol) and is very flexible for plugin creation (you can create your plugin easily, using your preferred programming language). It is tested on GNU/Linux and Mac OS X as client machines and any UNIX-like server, with any shell.

Example use case: sometimes when you are in a local-machine and connects via SSH to a remote-machine you need to copy some files between two machines, run some time-consuming commands and other things. sbc helps you in these tasks so you don't need to open other terminal windows/SSH sessions to do it or you can be notified when some tasks are done, for example.

Are you lazy? Watch the sbc screencast and learn how it works (note that the screencast is not up-to-date to to current code version).

Usage

First, you need to install sbc in your local and remote machines - you don't need root access in either machines, but need to run SSH daemon in both machines. After installing in both machines, let's setup sbc SSH key in the remote one:

user@local-machine:~$ sbc setup other-user@remote-machine
[sbc] Generating SSH RSA key without password (/home/user/.ssh/sbc_rsa)... [OK]
[sbc] Copying private key and sbc executables to remote server... [OK]
[sbc] Executing sbc setup... [OK]
[sbc] Updating local authorized_keys (if needed)... [OK]

Now your server is configured to run sbc! Let's copy a file (/tmp/some-file.txt) from the remote machine to the local machine, executing a command in the remote machine - this command is just calling sbc with the cp plugin.

First, let's check if there is no file called /tmp/some-file.txt on local machine:

user@local-machine:~$ ls /tmp/some-file.txt
ls: cannot access /tmp/some-file.txt: No such file or directory

Ok, now we'll connect to remote server using sbc ssh and list files in remote home directory:

user@local-machine:~$ sbc ssh other-user@remote-machine
[sbc] Creating back-channel and connecting... [OK]
other-user@remote-machine:~$ ls
some-file.txt

Now, copy the file to local machine's /tmp and disconnect:

other-user@remote-machine:~$ sbc cp some-file.txt /tmp/
some-file.txt                                 100%  545     0.5KB/s   00:01
other-user@remote-machine:~$ exit
[sbc] Closing back-channel... [OK]
Connection to remote-machine closed.

...and check if the file was copied to local machine:

user@local-machine:~$ ls /tmp/some-file.txt
/tmp/some-file.txt

When we execute sbc ssh it creates a back-channel so the remote machine can connect to the local machine through SSH. This back-channel is used to call sbc plugins in local machine when you run sbc plugin_name in remote machine. All plugins are stored and run in your local machine - they are in $HOME/.sbc/plugins and a plugin is just an executable file (yes, of course you can use your preferred language to write one! ;-).

cp is only one of other cool plugins shipped by default with sbc. For example, if you want to edit a file stored in remote machine using an editor running in your local machine (so you can use your own configuration files, for example), you can use the plugins vim, gvim or gedit. Let's see an example with gvim:

other-user@remote-machine:~$ sbc gvim some-file.txt

It'll run gvim in your local machine editing the file /home/other-user/some-file.txt that is stored in the remote machine - and you'll execute the command to call gvim in the remote machine (mind blowing? ;).

Now let's see another great plugin: notify - it shows in your local machine (generally near the clock) a notification sent by the remote machine. It is handy in cases when you need to run time-consuming commands on remote machine and don't want to "watch" every minute if the command finished. A command is worth a thousand of words:

other-user@remote-machine:~$ tar -zcf /tmp/myhome.tar.gz ~/; sbc notify "hey, your targz was created!"

Installation

Copy the executable script sbc to some directory in your $PATH and the entire directory plugins to $HOME/.sbc/. The following commands do it for you (please read the commands before executing):

wget https://github.com/turicas/sbc/tarball/develop -O /tmp/sbc.tar.gz
cd /tmp
tar xfz sbc.tar.gz

mkdir -p $HOME/bin $HOME/.sbc
mv /tmp/turicas-sbc-*/sbc $HOME/bin/
mv /tmp/turicas-sbc-*/plugins $HOME/.sbc/
rm -rf /tmp/sbc.tar.gz /tmp/turicas-sbc-*
chmod +x $HOME/bin/sbc

line_to_add='PATH=$PATH:$HOME/bin'
if [ -z "$(grep $line_to_add $HOME/.profile)" ]; then
    echo $line_to_add >> $HOME/.profile
    source $HOME/.profile
fi

Author

The core idea of this software was stolen from bcvi and the rest (flexibility + security) was idealized and coded by Álvaro Justen (with much help from Flávio Amieiro, Kretcheu and KurtKraut).

Copying

sbc is licensed under the terms of the GNU General Public License version 3 as published by the Free Software Foundation.