Developers , Developers , Developers

No its not Steve Balmer. Its DS. I would like to welcome 3 new web developers .

Fausto Piovesan from Brazil who respects open source. Local boy Peter, badminton champion of the world and lastly Michael Dravnieks who play drums in Norwich based band, GPD.

Vehicle Sales CMS

We have recently developed a CMS (Content Management System) which is targeted specifically at the vehicle sales sector.

The system was designed to be very easy to use.

Features

• Add Vehicles
• Add Categories
• Add Photos
• Add Vehicle Details

2 companies who are already using the system are:

Becks Motor Homes

Manorfield Cars

MySQL binary log rotation

We are running a MySQL replication setup, and find that the binary logs get very large, very quickly. Since MySQL didn’t come with a log rotation script, we rolled our own. Usage is simple:

At the top of the script are some definitions that you need to change for your setup:

1. MYSQL_USER MYSQL_PASS - You will need to create a user in MySQL that has the RELOAD and SUPER privileges
2. MYSQL_HOST - Where your MySQL server is located
3. MYSQL_LOG_PATH MYSQL_LOG_NAME - where your binary logs are kept, and what they are called
4. MYSQL_SLOW_LOG_NAME - the name of your slow log file
5. MAX_LOG_DAYS - the number of days worth of old logs that you want to keep

Once you’ve configured these values, whack the script into cron and run it daily.

Download the script (1.6Kb)

Apple QuickTime RTSP Buffer Overflow

A vulnerability has been found in the way QuickTime handles Real Time Streaming Protocol URL’s. Until Apple release a Software Update for this, it is recommended that users disable QuickTime support in their browsers. This is simple to do:

1. Navigate to /Library/Internet Plug-Ins
2. Drag the QuickTime Plugin.plugin and QuickTime Plugin.webplugin files to a temporary location, perhaps into your Documents folder
3. Restart any open browsers, i.e. Safari, Firefox, Opera etc.

More information on this vulnerability can be found here:

US-CERT Vulnerability Note VU#442497

Preventing Apache DOS attacks

We’ve recently come under attack from denial-of-service (DOS) attacks. In order to alleviate this situation, we are currently testing out the mod_evasive Apache module.

mod_evasive v1.10.1

The install was simple. After downloading and unpacking the source code…

/usr/sbin/apxs -i -a -c mod_evasive20.c

This will compile the module, copy it to the correct directory and enable the module in your Apache config. In addition, we added the following options to our httpd.conf:


<IfModule mod_evasive20.c>
DOSHashTableSize 3097
DOSPageCount 2
DOSSiteCount 50
DOSPageInterval 1
DOSSiteInterval 1
DOSBlockingPeriod 10
DOSEmailNotify glen@designsolution.co.uk
</IfModule>


Now, if too many requests come in from an IP address, the server will respond with a HTTP 403 response. This helps to save on bandwidth and reduce CPU load. Ideally, we would like to hook this into our firewall… our investigations are on-going!

Make text PHP safe

Have you ever copied and pasted some text from somewhere for use in a PHP string? You have? Well, you know that there can be some problems if the text contains single or double quotes. That’s where this little tool will come in handy:

PHP String Quoter

Just enter your text, and it will return a version of it ready to use in either single or double quoted PHP strings.

Optimizing MailScanner

Our MailScanner installation is pretty heavily utilised, scanning 20,000+ messages a day. I’m always looking for ways of improving it’s performance, so the following document has proved useful:

Optimization tips

1. Use a ramdisk (tmpfs) for MailScanner’s working directory.
2. Make sure you have enough ram
3. Set the noatime flag on your spool and log partitions
4. Use a local DNS caching nameserver
5. No syncs on logs
6. Use DCC as a daemon
7. Tweak your # of max child processes
8. Running your own copy of RBLs, and servers for DCC, Pyzor and Razor
9. Consider dropping unknown recipient emails on the inbound MailScanner MTA

Perfect Harmony?

Perfect Harmony?, originally uploaded by lonesome cowboy glen.

The latest version of Parallels Desktop for Mac offers a feature called Coherence which means that you can run Windows apps on your Mac desktop. It’s really handy, especially when you need to do some browser testing. Also, it means Windows XP is hidden from your view which is a nice bonus

Sending encrypted mail with Apple Mail

Apple Mail has a nice feature that allows you to digitally sign and encrypt your messages. This is extremely important if you are sending sensitive information via e-mail because messages are usually sent over an unencrypted channel. This means that there is the potential of your message being intercepted by a third-party. By encrypting your messages, it means that only the recipient of the message can read them.

The process of setting this up is fairly straightforward. First you need a Secure Email Signing Certificate (Digital ID). The good news is that you can get one for free:

Personal E-mail Certificates - secure e-mail communications

Once you’ve gone through the fairly lengthy registration process, you will be able to request a certificate.

Select the Mozilla Firefox option and go through the request process. Eventually your browser will download your certificate, and if you are using Safari, import it into Keychain Access.

When you now use Apple Mail, your outgoing messages will be signed by default. When you receive signed messages from other people, their public certificates will be automatically imported into Keychain Access allowing you to send them encypted messages. Just click the lock icon when you create a new mail! Bingo!

For more information:

Mac OS X 10.3: Mail - How to Use a Secure Email Signing Certificate (Digital ID)

Run multiple versions of Internet Explorer on Windows

Windows has always been a bit of a pain when it comes to Internet Explorer versions: it only allows you to have one installed. This makes testing problematic: it means, for instance, that I have to have several Windows XP installations in Parallels Desktop and load them up when needed. However, there now seems to be a solution:

Run IE5, IE6, and IE7 at the Same Time - Even On a Mac

Just three installs and you are done! IE3, 4, 5, 5.5, 6 and 7 on one copy of Windows! Lovely!