This is a demonstration video on how to test the strength of your passwords on an Ubuntu system against the John the Ripper password cracker. It is important to know how fast these tools can actually work to crack passwords and how to protect yourself against them finding your password. In my example password, password1 and elephant were all found in under 20 seconds and I don’t have a fast machine. Btw… these were test accounts I removed immediately after making the video 🙂
Guide by Jean-Francois Theroux (Installation / Configuration):
Background can be found here:
Most authentication is still based on username and password, personally I feel this is adequate for most of my personal accounts as long as I use a strong password. I do wish MY Bank offered two factor authentication, but alas it does not yet.
So, if a strong password is ALL you have to protect yourself how do you create one and more importantly how do you remember it? Let’s start with creating a strong password…
CREATING A STRONG PASSWORD
- Pick two or three words that are 10 or more letters in length.
- Use unrelated words
- Substitute at least one letter for a number, such as 4 for A or 3 for E. Do not substitute ALL possible letters for numbers.
- Add a punctuation.
- Capitalize at least one letter.
Sound doable? Now, the real challenge is remembering it. If you absolutely cannot remember passwords then I suggest using the Password Safe, just make sure your password to access the safe is VERY secure. This allows you to remember only one password and have access to all your other passwords contained in the safe. For those of you that feel up to the challenge try running an installation of TeamPass. It is what I personally use. Just make sure to back it up and NEVER change the salt. You should be able to but it is not supported yet and you will lose ALL of your passwords as well as all passwords for all others. I suggest not putting this site on the internet.
- picture leaf
- pictur3 l3af
Now what you have to remember….
- picture#leaf with e’s substituted for 3’s and the first and last letters capitalized.
- space manhole
- sp4ce m4nhole
Now what you have to remember….
- space.manhole with a’s substituted for 4’s and the last letter of the first word and first letter of the last word capitalized.
What is clear text? Basically it is sending information between machines (many times over the internet) with out using encryption. Why is this still a bad idea?
Here is a sample packet capture from a test site I used that does not require encryption for a login for demonstration purposes. Here is the URL as shown in Chrome. It does not have the padlock and is running unsecured over port 80.
Here is the actual test login form. This form alone does not mean the login is unsecured, however in this case it is.
I did attempt to login with a bogus username and password. I recorded a packet capture when I did. As you can see below unencrypted logins are not secure. Pay special attention to:
As you can see my username and password is viewable by a simple packet capture. The one thing to note is that NotMyPassWord%3F is actually NotMyPassWord?
You might wonder why ‘%3F’ is translated to ‘?’. This is because characters like ‘?’ need to be translated to HEX before transmitting to the server.
To see a full ASCII to HEX table; http://www.asciitable.com/
Great! So now you can see how easy it is to capture a packet and see usernames and passwords sent in clear text. So now you might wonder, how hard is this to do? I’ll tell you, it is very simple. While the chances of someone intercepting might be low because someone actually has to be looking, if they are looking they have captured your password easily. The most common way to do this is through a man in the middle attack where a ‘hacker’ tricks you into sending the data to them, then they route it to the intended machine, capture your password and never know the difference. The less common way but still highly effective is to just be in the path of the communication. Given you don’t know who owns the routers and communication channels between yourself and the server you are trying to login to the communication cannot be considered safe.
If that seems to far fetched to you consider this, your ISP can see the contents of ALL Clear Text transmissions if they wanted to.
Most people now know how important it is to secure your home wireless, however many still don’t know all the steps available to protect your wireless beyond setting a password. Here some tips to provide advanced security to your home wireless network.
- Change the administrative password. Use a strong password.
- Set your wireless name to something that would not be easily associated with you. Do not use your address, name, car make, etc.
- Turn off broadcasting of your SSID (name of the wireless connection setup in step number two above). Some devices require broadcasting to setup and connect the first time, if this is the case turn on broadcasting of your SSID, connect the device, then disable it again.
- Use WPA2 Encryption. Again, use a strong password as you did to setup your administrative password. Do not use the same passwords.
- Use MAC Security. What is MAC security? Each system (network card) has a virtually unique MAC address. Much like an IP address, however it is an address provided by the maker of the network card and not dynamic. Setting up your wireless to only allow specific MAC Addresses (your MAC Addresses) further reduces the chances an unauthorized individual could use your wireless. You can find your MAC address for any device generally fairly easily by Goggling “how do i find the MAC address for”…
- Turn off DHCP. DHCP is a service provided by your wireless router that provides an IP address to each machine that is allowed on the wireless network. Turning off DHCP and setting the IP addresses manually for each device is the safest, however I find it to be quite a pain so instead I limit the DHCP scope (range) to only the number of IP addresses of devices I will have connecting and then assign each one to a device. This then associates an IP address with a MAC address and eliminates the need to manually set IP addresses on each device.
- If you have the option and do not need your wireless devices (such as a laptop) talking to other devices (such as a wireless printer) then disable communication between devices. Many home wireless routers do not support this option, so you may not be able to enable it.
- If you have options to limit the range (strength) of your wireless signal set it to the level that ensures it works for you but not higher. Setting it higher than is needed makes your wireless network available in ranges you would not need it, thus increasing the chances that someone else might try to use it.