View source for Shell in a box

<metadesc>How to set up shellinabox, make sure it restarts after reboot and is reachable from a browser (port 80 or 443). Tested on SUSE and Ubuntu.</metadesc>
Shell in a Box allows you to [[control a computer over the network]] using a Linux console in a web page. 

= Install it =
== Get it ==
* [[open a console]] as root.

* Download shell in a box from google
 wget http://shellinabox.googlecode.com/files/shellinabox-2.14.tar.gz

* [[unpack]] it
 [[tar]] xvzf shellinabox-2.14.tar.gz

<ul>
<li />[[find out your distribution]] and [[install]] some [[dependencies]],
<ul>
<li /> for SUSE Linux:
 [[yast]] -i make gcc
<li /> for Ubuntu: 
 apt-get update
 apt-get install make gcc
</ul>
</ul>

* [[build]] it
 [[cd]] shellinabox-2.14
 ./configure && make && make install

* make sure the firewall is open, here is an example for SUSE Linux:
 rcSuSEfirewall2 stop

* you are not allowed to log in as root, so make sure you have at least one ordinary user. Add a user name ''user'' like this:
 useradd -m ''user''
 passwd ''user''

* call shell in a box
 cd /tmp
 shellinaboxd &

* test it by surfing to your computer: http://localhost:4200

== Make it persistent ==
You want the shell in a box daemon shellinaboxd to be started when booting your machine, so 

=== for SUSE Linux ===
* add the following line to /etc/init.d/boot.local:
 shellinaboxd &
* configure the firewall to always open up port 80 or stop it persistantly:
 [[chkconfig]] SuSEfirewall2_setup off
 chkconfig SuSEfirewall2_init off
* configure apache to start on boot
 chkconfig apache2 on

=== for Ubuntu ===
To start the shellinabox daemon after reboot add the following line to /etc/crontab:
 @reboot root /usr/local/bin/shellinaboxd &
This will start the daemon only on reboot as a background job.

== Use in a web server ==
You probably want shell in a box to be reachable via port 80 (so you can use it from within a typical corporate network) and you may want to run a web server on the same machine. So here is how you integrate shell in a box into an Apache2 web server

=== for SUSE Linux ===
* install apache2, in this example for SUSE Linux 12.1:
 yast -i apache2

* enable a reverse proxy. To do this, edit /etc/sysconfig/apache2 and add the following words to APACHE_MODULES: proxy proxy_http. In the end your line may read like this:
 APACHE_MODULES="actions alias auth_basic proxy proxy_http authn_file authz_host authz_groupfile authz_default authz_user autoindex cgi dir env expires include log_config mime negotiation setenvif ssl userdir php5"

* tell apache that if someone calls http://yourserver.yourdomain/shell this is forwarded to http://yourserver.yourdomain:4200 internally. To do this, edit /etc/apache2/default-server.conf, add a block 
 <IfModule mod_proxy.c>
 <Location /shell>
     ProxyPass http://127.0.0.1:4200
 </Location>
 </IfModule>

* now [[set up apache for https]] so your passwords are not transmitted unencrypted over the internet

=== for Ubuntu ===
* install apache2
 apt-get install apache2
* enable apache's proxy module:
 a2enmod proxy
* do
 ln -s /etc/apache2/mods-available/proxy_http.load /etc/apache2/mods-enabled/proxy_http.load
* tell apache that if someone calls http://yourserver.yourdomain/shell this is forwarded to http://yourserver.yourdomain:4200 internally. To do this, edit /etc/apache2/sites-enabled/000-default, add a block:
 <Location /shell>
     ProxyPass http://127.0.0.1:4200
     Allow from 127.0.0.1
 </Location>
* restart apache
 /etc/init.d/apache2 restart
* test if the module has indeed been loaded:
 # apache2ctl -t -D DUMP_MODULES 2>&1 | grep proxy_http
  proxy_http_module (shared)

* now [[set up apache for https]] so your passwords are not transmitted unencrypted over the internet

= TroubleShooting =

== cannot read valid certificate ==
'''Symptom:''' ShellInABoxD does not start, it tells the [[error message]]:
 Cannot read valid certificate from "certificate.pem". Check file permissions and file format.

'''Reason:''' See http://code.google.com/p/shellinabox/issues/detail?id=59. ShellInABoxD tries to create a file certificate.pem in the folder where it is started as user nobody:
 /tmp # ll certificate.pem 
 -rw------- 1 nobody nogroup 2794 Aug  5 07:53 certificate.pem

'''Solution:''' Start shellinaboxd in a directory that every user can access, e.g. /tmp:
 cd /tmp
 shellinaboxd &

== forkpty() failed ==
;Symptom: When you surf to the shellinabox page you see an error message
 forkpty() failed

;Solution: Kill all shellinaboxd processes and start them with root privileges:
 killall shellinaboxd
 shellinaboxd --user=0 & disown

== minus sign ==
;Symptom: The minus sign does not work if you type it on the keypad.

;Solution: I could fix this by using Safari instead of [[FireFox]]

= See also =
* [[guacAMole]]
* http://code.google.com/p/shellinabox/

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