Pario TechnoBlob » ssh

Secure browsing with Firefox and SOCKS v5

Hans-Henry Jakobsen — Thu, 04 Sep 2008 22:43:22 +0000

This post describes how you can setup secure web browsing using Firefox3 and by setting up a SSH tunnel from your PC/host to a remote PC/host. Your PC will then act as a local SOCKS proxy and all applications that supports SOCKS5 interface to this port. This is a handy solution if you are on a untrusted net like a wireless connection. The solution can also be used in Thunderbird if you would like.
Note
It is important to note that it’s only the connection between your host and the remote host that is secure. It is also important to note that Firefox will do DNS queries to the untrusted netwoork. This can be fixed by opening the about:config page and change network.proxy.socks_remote_dns to true.

Start a SSH connection to a host that you want to proxy through. Use the -D option to specify a SOCKS5 port on your localhost. The port doesn’t really matter. Just make sure you use the same port in your SOCKS client application.

# ssh -D 3333 username@example.com

In Firefox select “Tools | Options… | Advanced | Network |Settings… button”.

Then select “Manual proxy configuration”. All you need to fill out is “SOCKS Host: Localhost”, “Port: 3333″, then select “SOCKS v5″.

Type in “localhost” in the SOCKS host field and press the OK button.

You are now ready to surf using Firefox3 and SOCKS5 througt a SSH tunnel.

Configure a secure tunnel using Putty

You can also use Putty if you are a Windows user. The configuration is then as follows:

Fix slow SSH login

Hans-Henry Jakobsen — Wed, 28 May 2008 23:49:51 +0000

Add the following line if your SSH login takes a long time on your SSH server.

File /etc/ssh/sshd_config:

UseDNS no

Restart the SSH daemon to activate this change.

Mounting remote filesystems using SSH and Debian

Hans-Henry Jakobsen — Wed, 20 Feb 2008 20:50:40 +0000

This post describes how to mount a remote filesystem through SSH using the shfs kernel module on a Debian Etch server. By doing this I can access the remote filesystem as if it was a local filesystem and also use my local tools and software.
This is a short description of how I made a remote filesystem accessible on my private server.

Download the needed software

# apt-get install shfs-source shfs-utils module-assistant

This step might not be needed on your system, but I didn’t have the needed software to build the kernel module

# module-assistant prepare

Use the module assistant to build the kernel module to match your local system (I use a 2.6 kernel but this whould work on a 2.4 kernel also)

module-assistant build shfs

Now you can install it

# module-assistant install shfs
Selecting previously deselected package shfs-module-2.6.18-5-686.
(Reading database ... 78212 files and directories currently installed.)
Unpacking shfs-module-2.6.18-5-686 (from .../shfs-module-2.6.18-5-686_0.35-6.2+2.6.18.dfsg.1-17_i386.deb) ...
Setting up shfs-module-2.6.18-5-686 (0.35-6.2+2.6.18.dfsg.1-17) ...

You might see some error messages but those are mostly harmless :) and can be ignored.
Now we can try to mount the remote filesystem

# mkdir /export/remotefs
# shfsmount user@remotesystem.com /export/remotefs
Password:

The remote filesystem should now be available after typing your password.

# cd /export/remotefs
# ls

You will now see all your files in the remote filesystem as if they were on your local machine.
To unmount your filesystem

# cd /
# umount /export/remotefs

This post could have been extended to use passwordless

My custom putty settings

Hans-Henry Jakobsen — Wed, 13 Feb 2008 11:52:27 +0000

This is a quick note of my custom putty settings in Windows

Category: Session
Connection type: SSH

Category: Window
Lines of scrollback: 20000

Category: Window > Appearance
Font: Lucida Console, 9-point
Font quality: ClearType
Gap between text and window edge: 3

Category: Window > Translation
Character set: UTF-8
Handling of line drawing characters: Unicode

Category: Window > Selection
Action of mouse buttons: xterm
Paste to clipboard in RTF as well as plain text: enabled

Category: Window > Colours
ANSI Blue: Red:74 Green:74 Blue:255
ANSI Blue Bold: Red:140: Green:140 Blue:255

Category: Connection
Seconds between keepalives (0 to turn off): 30

Category: Connection > SSH > X11
Enable X11 forwarding: enabled

X11 forwarding is enabled to to let me access remote X applications in Windows using Xming.

Use ssh on multiple servers simultaneous

Hans-Henry Jakobsen — Sun, 20 Jan 2008 01:32:29 +0000

If you have many servers to manage and want to perform the same tasks on each of the machine every day, then you should look at the package named clusterssh.

Install the clusterssh package

apt-get install clusterssh

Perform the same command on the three servers server1 server2 and server3

cssh server1 server2 server3

This opens three ssh consoles, one for each server, and a little console for you to type your commands.