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Gadgets, Technology, Public speaking and IT from an undergraduate's perspective.
Protect Your Wireless Network with MAC Address Filtering…A Bad Idea
To secure your wireless network, you can use a variety of means, and one of which is by selecting only what MAC addresses are allowed. This is known as MAC filtering, and it can serve as a basic deterrent against most opportunistic attackers.
However, just using MAC filtering alone will probably be a bad idea. It doesn’t take much determination or knowledge at all to spoof a MAC address. In fact, it’s actually quite easy to spoof a MAC address, and can be done within 2 steps.
Step 1. Download and run any freely available security tool, for example Nmap. Set it to listen in on network traffic and pick out the MAC address.
Step 2. Change your MAC address to the one you picked out.
In fact, Nmap even allows you to spoof your MAC address by running the “-spoof-mac” command line option. This was originally intended to hide the true source of Nmap probes.
If you don’t have Nmap, you can just spoof your MAC address with the software that comes with most operating systems.
Here are some examples:
1. Linux: ifconfig eth0 hw ether 02:a1:13:d4:00:12
2. MS Windows: the MAC address is stored in a registry key (location of that key varies from one MS Windows version to the next, but you can easily find that and just edit it yourself). Alternatively, download a free tool such as Macshift to help you change your MAC address.
Now that you know how easy it is to spoof your MAC address, start worrying even more, because these simple steps are run automatically and very, very quickly by malware. This means that if you are using MAC filtering to protect your wireless network, you should seriously consider something a little more robust.
Tags: cool inventions, mac address, mac filtering, PHP, protect wireless, Technology, Tips, wifi routerRelated posts
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26 Apr 08 | Edit .htaccess to increase PHP’s max file upload
To increase the upload file size limit on your website, you need to edit PHP’s configuration settings. Unfortunately, not everyone has their own web server, so most of the time people are constrained by the limits of shared hosting. But you can still modify your base php.ini file by creating your own php.ini with the edits that you want.
Your php.ini file needs to be in every folder that’s going to be affected, or at least in the folder where the php script is being called from. Unfortunately if you have dozens of folders that need this edit, then you’ll need dozens of php.ini files.
An alternative is to then use .htaccess. By just placing a.htaccess file in your root folder, all folders beneath it will also have the change. The code to change your PHP max file upload size is:
RewriteEngine On
php_value post_max_size 1000M
php_value upload_max_filesize 1000M
php_value max_execution_time 6000000
You can edit it to suit your needs. 1000M = 1GB, so edit accordingly. Do note that your host will need to allow PHP edits though.
Tags: alternative, base, change, code, configuration, everyone, execution, folder, htaccess, ini, limit, max, max file size, max file size upload, max upload size, PHP, php.ini, post, RewriteEngine, root, server, shared hosting, size, time, upload, vps, websiteRelated posts
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Convert PDF to Doc with Free Software Download
I use a Treo 650 smartphone, and it’s been one of the best investments that I’ve made because of how it has allowed me to make use of idle time to read. With so much to read and so little time, every moment counts, and I love reading ebooks on my Treo. There’s no need to carry around an extra book, because everything is loaded in the memory of my Treo, and there’s no worry about low light because I can read in any kind of lighting condition with the Treo’s lighted screen.
The only problem I found is that documents must be in plaintext for best results. I’ve tried loading in PDF files, but the PDF reader doesn’t load as fast as the eReader software, and the process doesn’t seem as smooth. So I convert my PDFs to DOC format, and then convert them to PDB with the easyPDB software. Here’s a screenshot of how the PDF to DOC converter looks like - simple and efficient!
The great thing is, both these software are free!
Dowload the free PDF to Doc software
Download the free easyPDB software
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How To Edit .htaccess So That SSI Include Code Will Run
If you have tried adding in SSI include codes into your HTML files, but find that it doesn’t work, the problem may be that you might not have enabled SSI yet.
The easier way to do so is to edit your .htaccess file to have these lines of code:
AddHandler server-parsed .html
Options Indexes FollowSymLinks Includes
By setting this, you are telling your server to parse all HTML files. There’s a drawback though — ALL HTML files are parsed — even if they don’t have SSI or include code in them. So, there’s a bit of an overhead. Otherwise, this is fine.
Tags: edit htaccess, html, html include files, include files, includes, PHP, server configuration, ssiRelated posts
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How To Solve “No available system font while editing PDF in Adobe Acrobat” Problem
If you’ve tried editing PDF documents using Adobe Acrobat (using the Acrobat Touch Up Text Tool), then you’ve most probably come across this problem that says “No available system font”. Bummer.
Now some of you might legitimately have the font when you created the PDF, but might have switched computers, went through an upgrade, or anything of that sort that caused you to not have that particular system font now.
The conventional way was to go out there and buy that font again, so that you edit your PDF document in Adobe Acrobat right? Well — that will work, but it’s not a very scalable solution. Imagine having multiple fonts that you had to buy, or perhaps you only had to edit the document, and having the exact same font didn’t matter at all to you.
That was the problem I faced — the fonts that I used were pretty, but it wasn’t crucial that I continued using them. In fact, I would have been happy with just Arial or even Times New Roman. So the main thing is to get the editing operation to work.
So I gave it some thought, and I realised that I could actually masquerade some fonts as the required fonts by Adobe Acrobat. However, it wasn’t as easy as I thought. I discovered that just changing the font’s filename wouldn’t work, so I searched around this software download site for a solution, and found it in the form of FontCreator, a font software created by High-Logic.
FontCreator is, in essence, a very powerful font-creation tool that even professional typographers and graphic designers use. But it’s simple and user-friendly, and best of all, affordable enough for home users to buy.
The font editor allows you to easily select and modify the entire character set of any TrueType® font and fonts based on OpenType® font technology. You can even convert images to outlines! I tried scanning in my signature, and made a font with my own signature. Then I tried the same process with my handwriting! So now I can select “My Handwriting” as the font in any application (such as Microsoft Word), and have my documents written in my signature, digitally!
Most importantly though, it allowed me to edit the property of an existing font. So I made a copy of an existing font in my system (I can’t remember which!), and then used FontCreator to change the name of the font to the one that was embedded in my PDF document. Next, I opened up Adobe Acrobat again to edit my font, and viola! IT WORKED.
So if you’re looking for a long-term solution that’s infinitely more scalable than always having to buy individual fonts again and again, try out FontCreator. It’s a great piece of software to add to your collection, and you get to have added functionality like creating a customised font to mimic your handwriting!
Update: Ah! I found a coupon for 10% off…but only after I made my purchase! 
If anyone wants the 10% discount coupon for FontCreator, it’s “VGHK-D515″ (without the quotes).
Tags: adobe acrobat, download fonts, downloads, edit, editing pdf, font editing software, font problem, font software, free font solution, Main, no available system font, PHP, software, TechnologyRelated posts
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About AlvinMy blog covers areas covering mainly IT, technology, and public speaking. My posts are usually about any useful things that I think are worth sharing, and of my research that I do. |
