"; */ ?>

network

linux / network / ubuntu — Comments Off on Connect to Wireless Network at Startup
20
Aug 10

Connect to Wireless Network at Startup

Assuming WPA/WPA2 security is used, first thing to do is to get a hash/hex of the password. Below “myssid” is the wireless network’s SSID, and “mypassword” is the password for this network.

Step 1 Generate a WPA password hash to be used later when setting up network interfaces:

$ wpa_passphrase myssid
# reading passphrase from stdin
mypassword
network={
	ssid="myssid"
	#psk="mypassword"
	psk=2f0568b3492812bd56b946dbaf3fd7dd669b9a4602a09aa6462ff057949b025c
}

Step 2 Configure a wireless network interface using the password hash from Step 1:

$ vi /etc/network/interfaces
   auto wlan0
 
   # configuring a static IP
 
   iface wlan0 inet static
   address 192.168.0.34
   gateway 192.168.0.1
   network  192.168.0.0
   broadcast 192.168.0.255
   netmask 255.255.255.0
 
   #  OR if static IP is not needed ignore above 6 lines and uncomment the one below
   #  iface wlan0 inet dhcp   
 
   # configure WPA/WPA2 security
   wpa-ssid myssid
   wpa-psk 2f0568b3492812bd56b946dbaf3fd7dd669b9a4602a09aa6462ff057949b025c
howto / linux / network / tutorials / ubuntu — 17 Comments
17
Nov 08

Configure iwl3945 Driver on Ubuntu

It is quite frustrating when you have a wireless card built in, but you cannot use it – don’t you agree? That seems to be the case for wifi cards that are served by “iwl3945” driver. One of such examples can be “Intel Corporation PRO/Wireless 3945ABG” card.

Before, ( e.g. Feisty and earlier ) “ipw3945” driver was used instead, and worked beautifully with Intel cards. However the active development of this driver has stopped a couple of years ago, which means that security risks that were identified in the last couple of years were not patched. Therefore Ubuntu community switched to a more recent and supported “iwl3945” driver.

However that created a problem with NetworkManager that is used as a default network user interface in (Gnome) Ubuntu. It appears that in order “to be compatible with NetworkManager, a wireless driver must support both hardware and software scanning. Currently, hardware scanning is faster and more reliable and so is recommended for use with NetworkManager“. But unfortunately “iwl3945” driver does not support hardware scanning very well, however it is a default behaviour that NetworkManager expects.

But usually, and that is what I love Ubuntu for, if there is a problem, there is 99.9999% a solution to this problem. So this how to will help you solve it, and enjoy your Intel Wireless card with Ubuntu, despite of inconsiderate (in this case) NetworkManager.

1. Remove the bad guy

sudo apt-get remove network-manager

2. Disable “iwl3945” hardware scan

sudo vi /etc/modrobe.d/iwl3945

enter:

	alias wlan0 iwl3945
	options iwl3945 disable_hw_scan=1   # <-- enables software scanning

and save it (:wq).

At this you might want to restart or (optinal) just re-insert the module like this:

sudo modprobe -r iwl3945
sudo modprobe iwl3945

3. Install the good guy

Here you’ll install “the good guy” – his/her name is WICD:

Add wicd’s repository to Ubuntu sources:

sudo vi /etc/apt/sources.list
	 deb http://apt.wicd.net intrepid extras

(if you have Hardy Heron, then add “deb http://apt.wicd.net hardy extras” instead)

Update repositories

   sudo apt-get update

Install wicd “the normal Ubuntu way”:

   sudo apt-get install wicd

4. Run the good guy

   wicd-client

or restart, it should run automatically.

Happy wifying!

howto / interesting / linux / network / security / tutorials — 3 Comments
10
Nov 08

Configure Simp Server to Encrypt IM clients in Linux

Recently many companies started to inject their security policies with securing IM communication. It makes sense, since everything you type in that chat window to your buddy flies over the network in a clear text. That does not sound to bad, you think, but what it really means, is if anybody wanted to see what you are talking to your colleague, or even to your wife, about, s/he can see it easily by reading your network packets – which is a very easy thing to do now days.

Another example could be the client whose policy is to monitor all the incoming/outgoing network request, and you want to talk over IM to your colleague about something that you do not want your client to see.

Below I’ll show you how to secure you IM communication with SimpServer: http://www.secway.fr/us/products/simpserver/ on Unix client/server boxes. I am going to use Ubuntu here as an example, but it should work for most if not for all Unix flavours.

1. Get the SimpServer.

According to the liink above “SimpServer is currently beta software and is free for any use”, hence let’s get it for free from here:

wget http://download.secway.com/public/products/simpserver/simpserver-2.1.5c-linux-x86.tgz

2. Install the SimpServer.

Before untarring it, let’s make sure the standard C++ libraries that SimpServer uses are installed:

sudo apt-get install libstdc++5

Now let’s untar it and move to “/usr/local” – that is where it will search for its binary files, so make sure you do that:

tar -xvzf simpserver-2.1.5c-linux-x86.tgz
 
sudo mv simp/ /usr/local/

Go to “/usr/local/simp/bin/”, and run the SimpServer:

cd /usr/local/simp/bin/
 
./simpserver
 
----------------------------------------------------------------------------------
SimpServer Linux 2.2.1.5c - (c) Copyright Secway 2000-2005
All rights reserved
 
Visit http://www.secway.com/products/simpserver/ for updates.
Visit http://www.secway.com/support/ for support.
 
MSN Service on 0.0.0.0:11863, mode 1
MSN Service on 0.0.0.0:1863, mode 0
AIM Service on 0.0.0.0:15191, mode 1
ICQ Service on 0.0.0.0:15190, mode 1
YAHOO Service on 0.0.0.0:15050, mode 1
Admin Service on 127.0.0.1:10023, mode 0
 
----------------------------------------------------------------------------------

If there are any problems, grab the simpserver version that is offered here: http://www.secway.fr/us/products/simpserver/download.php

3. Configure the SimpServer.

While SimpServer is running, telnet to it (port 10023). Default “username/password” are “admin/admin”:

$ telnet localhost 10023
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
SimpServer Linux 2.2.1.5c - (c) Copyright Secway 2000-2005
All rights reserved
 
Visit http://www.secway.com/products/simpserver/ for updates.
Visit http://www.secway.com/support/ for support.
 
Login: admin
Password: admin

Let’s see what it is capable of by asking for “help”:

> help
SimpServer Linux 2.2.1.5c - (c) Copyright Secway 2000-2005
All rights reserved
 
Visit http://www.secway.com/products/simpserver/ for updates.
Visit http://www.secway.com/support/ for support.
 
 ?,        help                  print this help
 list,     list_keys             [all, public, private]
 generate, generate_private_key  [-e<account>] [-s<service>] [-c<cipher>] [-b<size>] [-n<name>] [-p
<password>]
 load,     load_private_key      -i<keyid> [-e<account>] [-s<service>] [-c<cipher>] [-p
<password>]
 unload,   unload_private_key    -i<keyid> [-e<account>] [-s<service>] [-c<cipher>]
 change,   change_password       -i<keyid> [-e<account>] [-s<service>] [-c<cipher>] [-o
<old_password>] [-p<new_password>]
 delete,   delete_key            -i<keyid> [-e<account>] [-s<service>] [-c<cipher>] [-force] [-pendinf]
 accept,   accept_pending_key    -i<keyid> [-e<account>] [-s<service>] [-c<cipher>]
 quit,     exit                  exit

4. Create private/public certificates.

Notice that the “list” command, from the above help, shows all/public/private keys, including your public/private key, and all your IM buddies that you are talking to.

Let’s try to see what keys we have right away (without doing anything yet):

> list
Prv  Loaded KeyId             SHA-1 fingerprint                                   Date        Type         Srv  Name
--------------------------------------------------------------------------------------------------------------------

As you can see, we have no keys – because for now we have neither “secure/encrypted” IM buddies, nor our public/private key pair.

Hence start by by running a “generate” command that would create your the key pair (link to certificates article) that will be used:

> generate
generating the new key pair, please wait... done!
new key: 278dc025d92cdbc4  b14e 7b16 6415 e88f 2a67 2fe6 2e31 579b 580e 1a89   2008-10-16  RSA-2048  [admin] KeyPair

Now let’s “list” the keys again:

> list
Prv  Loaded KeyId             SHA-1 fingerprint                                   Date        Type         Srv  Name
--------------------------------------------------------------------------------------------------------------------
Yes  Yes    278dc025d92cdbc4  b14e 7b16 6415 e88f 2a67 2fe6 2e31 579b 580e 1a89   2008-10-16     RSA-2048    *  [admin] KeyPair

Perfect – you have your own “KeyPair”, that will be used to authenticate and encrypt communication from your IM buddies.

5. Connect IM clients to the SimpServer.

Next, let’s connect to our SimpPro / SimpLight / etc.. IM buddies. Here is an example on how to configure “Pidgin” to use a SimpServer:

For example you’d like your work AIM account to “follow the company standards” and use encryption via simp server. Here is what you should do

Go to "Accounts" -> (Choose your AIM account) "Edit Account" -> "Advanced"
 
Choose "SOCKS4" in "Proxy Options"
 
type "127.0.0.1" in Host
type "15191" in Port

Pidgin SOCKS4 settings

Why “127.0.0.1”? Because you have started the SimpServer on your local box. By the way, you can start the server on one box, and use it from many other PCs by entering IP address of that box to the “host” field for the proxy settings of the account in your IM client.

Why “15191”? Let’s look at the server output once again:

MSN Service on 0.0.0.0:11863, mode 1
MSN Service on 0.0.0.0:1863, mode 0
AIM Service on 0.0.0.0:15191, mode 1
ICQ Service on 0.0.0.0:15190, mode 1
YAHOO Service on 0.0.0.0:15050, mode 1
Admin Service on 127.0.0.1:10023, mode 0

We see that “AIM Service” listens on the port “15191”.

6. Start using the SimpServer with your IM client(s).

Now when you send an IM to anybody who runs SimpPro / SimpLight / or just a Simp Server, they would get a pop up asking them to accept your message. After they do accept it, your public key ( one of the keys that was generated by the “generate” command ) will be added to their Simp database. Same thing will happen when they ping you or respond to your IM encrypted message – their public key will be added to the simpserver:

Here is an example of what happens initially, when there is a new “Simp-Oriented” buddy pings you:

(2008-10-16 15:16:09) BuddyName: *** (*) SimpServer Linux 2.2.1.5c - Encrypted and Authenticated (*) ***
(2008-10-16 15:16:09) BuddyName: Hey, that is cool - so now our messages are encrypted...!

And now you can go back to your “telnet” session and “list” the keys again:

> list
Prv  Loaded KeyId             SHA-1 fingerprint                                   Date        Type         Srv  Name
--------------------------------------------------------------------------------------------------------------------
Yes  Yes    278dc025d92cdbc4  b14e 7b16 6415 e88f 2a67 2fe6 2e31 579b 580e 1a89   2008-10-16     RSA-2048    *  [admin] KeyPair
 No  N/A    0f2292a9d40c2f90  ab1d 6f78 6bff a03e 892a 34df 2b3a 26e7 16ff cbb9   2008-10-16     RSA-2048  AIM   <buddy1Name>
 No  N/A    62f02d7e858e0139  c315 616f 8518 d9c8 9827 e4c4 d8b4 2448 06f7 4278   2008-10-16     RSA-2048  AIM   <buddy2Name>

Notice that now you have your own “KeyPair”, a public key for “Buddy1Name”, and a public key for “Buddy2Name”.

Happy Secure IMing, and don’t abuse your secrecy :)

hardware / howto / linux / network / tutorials / ubuntu — 9 Comments
29
Sep 08

Sure Way to Restart a Wireless Network

linux penguin is watching windows fly

While wireless signal is good, the network is dead – why is that? Many reasons, of course. You can spend time to figure out the reason and then try to fix, which is a good approach, but requires some time. Or you can restart the network to see if it resolves the issue, and if it does – forget that the problem ever existed.

However the way to restart a wireless network is not always “black and white”. Sometimes it is possible using GUI, and sometimes by typing something that means “network service restart”. And yes these ways are “clean”, but have a drawback – they rely on operating system to do what it suppose to do and restart the network.

However, OS does not always behave (yes, Linux does not always behave, along with Mac, and Windows, and “any” OS.. ). But here is a sure way to restart it – you would need to get down to the driver level though – to be less OS (or distribution) specific. But I’ll guide you through, don’t worry..

So, the signal is full/good/strong:

wireless signal is good
but there is no network:

$ ping -c 4 google.com
ping: unknown host google.com

First thing to do is to see what wireless card you are using:

$ lspci | grep -i network
08:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG Network Connection (rev 02)

In my case it is Intel 3945ABG. Next, check what driver is used for this card. I did a simple google search, and saw that the driver is “ipw”something.

Let’s see what ipw-like modules/drivers are currently running/loaded:

$ modprobe -l | grep ipw
/lib/modules/2.6.20-17-generic/kernel/ubuntu/wireless/ipw3945/ipw3945.ko
/lib/modules/2.6.20-17-generic/kernel/drivers/usb/serial/ipw.ko
/lib/modules/2.6.20-17-generic/kernel/drivers/net/wireless/ipw2200.ko
/lib/modules/2.6.20-17-generic/kernel/drivers/net/wireless/ipw2100.ko

Here it is “ipw3945”. Let’s kill it (-r stands for “remove”):

$ sudo modprobe -r ipw3945

Let’s start it back up:

$ sudo modprobe ipw3945

Checking connectivity:

$ ping -c 4 google.com
 
PING google.com (64.233.187.99) 56(84) bytes of data.
64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=1 ttl=238 time=43.3 ms
64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=2 ttl=238 time=28.9 ms
64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=3 ttl=238 time=27.7 ms
64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=4 ttl=238 time=34.7 ms
 
--- google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3005ms
rtt min/avg/max/mdev = 27.742/33.685/43.323/6.165 ms

Perfect!

howto / linux / network / ubuntu — Comments Off on Connect to Wireless Network on Startup
3
Jun 08

Connect to Wireless Network on Startup

Make sure to have only one “auto” interface, as it will be the main one
If you have “auto eth0” as well, then once “eth0” is unplugged “eth1” will be also unreachable

edit network interfaces configuration:

vi /etc/network/interfaces

here is what to put in:

auto eth1
iface eth1 inet dhcp
wireless-essid YourESSIDName
wireless-channel 10
wireless-key ##########################

to make it get a static IP, do this instead of the above:

 
# The primary network interface
# connect to wirless network on startup
auto eth1
 
# eth1 Interface
iface eth1 inet static
address  10.7.1.99
netmask  255.255.255.0
network  10.7.1.0
broadcast 10.7.1.255
gateway  10.7.1.1
wireless-essid YourESSIDName
wireless-channel 10
wireless-key ##########################