PHPDeveloper.org

Etienne Kneuss' Blog: SPL Datastructures updated

Tue, 13 May 2008 09:31:24 -0500

Etienne Kneuss has posted about some updates to the data structures functionality in the Standard PHP Library (SPL), specifically some new additions.

There finally is documentation for SplDoublyLinkedList, SplStack and SplQueue and some "new" classes: SplHeap (abstract), SplMaxHeap, SplMinHeap and SplPriorityQueue, documentation of those classes is in progress.

An example of the new functionality (for SplPriorityQueue) is included in the post showing the insertion of a value into a pre-existing array (without having to slice or splice!).

Hardened-PHP Project: PHP HTML Entity Encoder Heap Overflow Vulnerability

Fri, 03 Nov 2006 12:58:00 -0600

The Hardened-PHP Project has put out another advisory for the PHP distribution itself, versions 5.1.6/4.4.4 and below dealing with the HTML entity encoder heap.

While we were searching for a hole in htmlspecialchars() and htmlentities() to bypass the encoding of certain chars to exploit a possible eval() injection hole in another application we discovered that the implementation contains a possible bufferoverflow that can be triggered when the UTF-8 charset is selected.

The issue has been corrected in the latest PHP 5 release - version 5.2 - but is still present in the PHP 4.4 series (they have a recommended patch until the new version is posted). You can get complete information about this issue from the full vulnerability listing.

DevShed: Collections and Sorting Continued

Wed, 05 Apr 2006 07:13:17 -0500

Previously from DevShed, they started a series on collections and sorting in PHP. Today, they've posted part two of the series that builds on that and looks at sorting algorithm examples.

This article will examine the primary sorting algorithms with code examples, and some empirical data regarding how they perform in relation to one another, as well as the size of the data set in question.

We will also create a function to fill up our collection with random data in order to test the sort algorithms with a sufficiently large data set. The sort algorithms listed above are the ones that every computer science student learns in college and are the primary sort algorithms found in real-world applications.

The sorting styles they cover include: bubble sort, heap sort, merge sort, quick sort, and shell sort. For each, they provide the code, making it a simple matter of cut and paste to make it work in your script. There's not a whole lot of documentation going along with the code in this article, but the sorting code is simple enough to understand without it.