Posted inWeb application security

Cracking PHP rand()

Webapps occasionaly need to create tokens that are hard to guess. For example for session tokens or CSRF tokens, or in forgot password functionality where you get a token mailed to reset your password. These tokens should be cryptographically secure, but are often made by calling rand() multiple times and transforming the output to a string. This post will explore how hard it is to predict a token made with rand().
15/02/2016Posted inWeb application security
Recursive scp and symlinks
Posted inGNU Linux

Recursive scp and symlinks

Recursive scp without following symbolic links. When using recursive scp, symbolic links aren't preserved and are copied as if they are normal directories. So you have to look for another solution to recursively transfer symlinks over ssh. Here is one: Tar over ssh!
04/02/2016Posted inGNU Linux
Install Varnish Cache on CentOS 6.7
Posted inGNU Linux

Install Varnish Cache on CentOS 6.7

How to install and configure Varnish Cache on CentOS. Varnish is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Because Varnish Cache is really, really fast, web applications like WordPress, Drupal and Joomla can greatly benefit from Varnish Cache.
29/12/2015Posted inGNU Linux
Elasticsearch logo
Posted inGNU Linux

Install Elasticsearch on CentOS 6.7

Elasticsearch is a highly scalable open-source full-text search and analytics engine. It allows you to store, search, and analyze big volumes of data quickly and in near real time. In this article we'll go over the steps to install Elasticsearch on CentOS 6.7.
29/12/2015Posted inGNU Linux
Posted inWindows Server

SQL Server versions list

An unofficial build chart lists all of the known SQL Server Service Packs (SP), Cumulative Updates (CU), patches, hotfixes and other builds, including builds of MS SQL Server 2019, 2017, 2016, 2014, 2012, 2008 R2, 2008, 2005, 2000, 7.0, 6.5 and 6.0 that have been released.
11/12/2015Posted inWindows Server
Posted inWindows Server

RewriteProxy with .htaccess in IIS

Rewrite and proxy HTTP requests in IIS using a .htaccess. In my case scenario, I had to proxy requests in IIS, because a website was moved from web server A to B, and the DNS wasn't updated yet. All HTTP requests for the moved website are handled in IIS' Default Web Site; that's the wildcard host, and the original host no longer existed there. We needed to match our website and proxy those requests to the new IIS web server. This can either be done using a proxy with IIS URL Rewrite, IIS Application Request Routing (ARR), or a .htaccess file handled by Helicon Ape.
08/10/2015Posted inWindows Server
Posted inWordPress

How to add conditional analytics tracking code in WordPress Multisite

In my WordPress multisite, I use one theme for three sites and a tracking code for analytics on my websites. Whether it is Google Analytics or Piwik doesn't matter. Here is how you can conditionally add tracking codes to your WordPress Multisite: Use a condition in functions.php to add the tracking code for Piwik/Matomo Analytics or Google Analytics.
11/07/2015Posted inWordPress