c0d3 :: j0rg3

A collection of tips, tricks and snips. A proud Blosxom weblog. All code. No cruft.

Tue, 18 Mar 2014

Random datums with Random.org

I was reading about the vulnerability in the ‘random’ number generator in iOS 7 (http://threatpost.com/weak-random-number-generator-threatens-ios-7-kernel-exploit-mitigations/104757) and thought I would share a method that I’ve used. Though, I certainly was not on any version of iOS but, at least, I can help in GNU/Linux and BSDs.

What if we want to get some random numbers or strings? We need a salt or something and, in the interest of best practices, we’re trying to restrain the trust given to any single participant in the chain. That is, we do not want to generate the random data from the server that we are on. Let’s make it somewhere else!

YEAH! I know, right? Where to get a random data can be a headache-inducing challenge. Alas! The noble people at Random.org are using atmospheric noise to provide randomness for us regular folk!

Let’s head over and ask for some randomness:
https://www.random.org/strings/?num=1&len=16&digits=on&loweralpha=on&unique=on&format=html&rnd=new

Great! Still feels a little plain. What if big brother saw the string coming over and knew what I was doing? I mean, aside from the fact that I could easily wrap the string with other data of my choosing.

Random.org is really generous with the random data, so why don’t we take advantage of that? Instead of asking for a single string, let’s ask for several. Nobunny will know which one I picked, except for me!

We’ll do that by increasing the 'num' part of the request that we’re sending:
https://www.random.org/strings/?num=25&len=16&digits=on&loweralpha=on&unique=on&format=html&rnd=new

They were also thinking of CLI geeks like us with the 'format' variable. We set that to 'plain' and all the fancy formatting for human eyes is dropped and we get a simple list that we don’t need to use any clever tricks to parse!
curl -s 'https://www.random.org/strings/?num=25&len=16&digits=on&loweralpha=on&unique=on&format=plain&rnd=new'

Now we’ve got 25 strings at the CLI. We can pick one to copy and paste. But what if we don’t want to do the picking? Well, we can use the local system to do that. We’ll have it pick a number between 1 and 25. It’s zero-indexed, so we’re going to increment by 1 so that our number is really between 1 and 25.
echo $(( (RANDOM % 25)+1 ))

Next, we’ll send our list to head with our random number. Head is going to give us the first X lines of what we send to it. So if our random number is 17, then it will give us the first 17 lines from Random.org
curl -s 'https://www.random.org/strings/?num=25&len=16&digits=on&loweralpha=on&unique=on&format=plain&rnd=new' | head -$(( (RANDOM % 25)+1 ))

After that, we’ll use the friend of head: tail. We’ll tell tail that we want only the last record of the list, of psuedo-random length, of strings that are random.
curl -s 'https://www.random.org/strings/?num=25&len=16&digits=on&loweralpha=on&unique=on&format=plain&rnd=new' | head -$(( (RANDOM % 25)+1 )) | tail -1

And we can walk away feeling pretty good about having gotten some properly random data for our needs!


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Permalink: 20140318.random.data

Sun, 09 Jun 2013

ixquick link maker

In an effort to promote practical privacy measures, when I send people links to search engines, I choose ixquick. However, my personal settings submit my search terms via POST data rather than GET, meaning that the search terms aren’t in the URL.

Recently, I’ve found myself hand-crafting links for people and then I paste the link into a new tab, to make sure I didn’t fat-finger anything. Not a problem per se, but the technique leaves room for a bit more efficiency. So I’ve taken the ‘A Search Box on Your Website’ tool offered by ixquick and slightly modified the code it offers, to use GET variables, in a new tab where I can then copy the URL and provide the link to others.

You can test, or use, it here — I may add it (or a variant that just provides you the link) to the navigation bar above. First, though, I’m going to mention the need to the outstanding minds at ixquick because it would make a LOT more sense on their page than on mine.


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Permalink: 20130609.ixquick.search

Thu, 30 May 2013

Making ixquick your default search engine

In this writer’s opinion, it is vitally important that we take reasonable measures now to help insure anonymity, lest we create a situation where privacy no longer exists, and the simple want of, becomes suspicious.

Here’s how to configure your browser to automatically use a search engine that respects your privacy.

Chrome:

  1. Click Settings.
  2. Click “Set pages” in the “On startup” section.
  3. Enter https://ixquick.com/eng/ in the “Add a new page” text field.
  4. Click OK.
  5. Click “Manage search engines…”
  6. At the bottom of the “Search Engines” dialog, click in the “Add a new search engine” field.
  7. Enter
    ixquick
    ixquick.com
    https://ixquick.com/do/search?lui=english&language=english&cat=web&query=%s
  8. Click “Make Default”.
  9. Click “Done”.

Firefox:

  1. Click the Tools Menu.
  2. Click Options.
  3. Click the General tab.
  4. In “When Firefox Starts” dropdown, select “Show my home page”.
  5. Enter https://ixquick.com/eng/ in the “Home Page” text field.
  6. Click one of the English options here.
  7. Check box for “Start using it right away.”
  8. Click “Add”.

Opera:

  1. Click “Manage Search Engines
  2. Click “Add”
  3. Enter
    Name: ixquick
    Keyword: x
    Address: https://ixquick.com/do/search?lui=english&language=english&cat=web&query=%s
  4. Check “Use as default search engine”
  5. Click “OK”

Internet Explorer:

      _     ___  _ __        ___   _ _____ ___ 
     | |   / _ \| |\ \      / / | | |_   _|__ \
     | |  | | | | | \ \ /\ / /| | | | | |   / /
     | |__| |_| | |__\ V  V / | |_| | | |  |_| 
     |_____\___/|_____\_/\_/   \___/  |_|  (_) 
    
    
    (This is not a good strategy for privacy.)

Congratulations!

\o/

You are now one step closer to not having every motion on the Internet recorded.

This is a relatively small measure, though. You can improve your resistance to prying eyes (e.g., browser fingerprinting) by using the Torbrowser Bundle, or even better, Tails, and routing your web usage through Tor, i2p, or FreeNet.

If you would like more on subjects like anonymyzing, privacy and security then drop me a line via email or Bitmessage me: BM-2D9tDkYEJSTnEkGDKf7xYA5rUj2ihETxVR


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Permalink: 20130530.hey.you.get.offa.my.data

Tue, 07 May 2013

Welcome, traveler.

Thanks for visiting my little spot on the web. This is a Blosxom ‘blog which, for those who don’t know, is a CGI written in Perl using the file-system (rather than a database).

To the CLI-addicted, this is an awesome little product. Accepting, of course, that you’re going to get under the hood if you’re going to make it the product you want. After some modules and hacking, I’m pleased with the result.

My posts are just text files, meaning I start a new one like: vim ~posts/`date +%Y%m%d`.brief.subject.txt

Note: the back-ticks (`) tell the system that you want to execute the command between ticks, and dynamically insert its output into the command. In this case, the command date with these parameters:
  1. (+) we’re going to specify a format
  2. (%Y) four-digit year
  3. (%m) two-digit month
  4. (%d) two-digit day
That means the command above will use Vim to edit a text file named ‘20130507.brief.subject.txt’ in the directory I have assigned to the hash of ‘posts’. (using hash this way is a function of Zsh that I’ll cover in another post)

In my CLI-oriented ‘blog, I can sprinkle in my own HTML or use common notation like wrapping a word in underscores to have it underlined, forward-slashes for italics and asterisks for bold.

Toss in a line that identifies tags and, since Perl is the beast of Regex, we pick up the tags and make them links, meta-tags, etc.

Things here are likely to change a lot at first, while I twiddle with CSS and hack away at making a Blosxom that perfectly fits my tastes — so don’t be too alarmed if you visit and things look a tad wonky. It just means that I’m tinkering.

Once the saw-horses have been tucked away, I’m going to take the various notes I’ve made during my years in IT and write them out, in a very simple breakdown, aimed at sharing these with people who know little about how to negotiate the command line. The assumption here is that you have an interest in *nix/BSD. If you’ve that and the CLI is not a major part of your computing experience, it probably will be at some point. If you’re working on systems remotely, graphical interfaces often just impede you.

Once you’ve started working on remote machines, the rest is inevitable. You can either remember how to do everything two ways, through a graphical interface and CLI — or just start using the CLI for everything.

So let’s take a little journey through the kinds of things that make me love the CLI.


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Permalink: 20130507.greetings