Technology Insights

Secure /tmp And /var/tmp Directories On CentOS Linux

A couple days ago a CentOS Linux server that I took over administration on had some mysterious files show up in the /tmp and /var/tmp directories. The files were placed in /tmp and /var/tmp by the apache user meaning there is some form of security hole in Apache, PHP, or one of the virtual hosts has an insecure application installed. Before looking into where the issue is I needed to lock things down so no applications could be executed from these directories in the future regardless of a security flaw in the future. Below are instructions on how to secure /tmp and /var/tmp.

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Technology Insights

Disable Geo Tagging on the HTC Evo

I recently learned that most common smart phones do something called geotagging. As people who regularly follow this site will know I have recently been doing a lot of work with a new HTC Evo so I was really interested in this. Geotagging, also called geocoding, is the process of assigning geographic location metadata to a photo. The geographic information can include details such as the latitude and longitude coordinates or city and state details for the geographic location of the photo. I may write a later article on how to actually extract the metadata from a picture however for this post I will just show how to turn it off.

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Technology Errors

iTunes Could Not Sync Calendars To The iPhone Because The Sync Server Failed

I typically charge my iPhone using a USB cable that attaches to my computer but recently I have been using the wall charger because my computer wasn’t always close. After using the wall charger for a week or so without ever actually syncing my iPhone to iTunes on my Windows 7 computer I attempted to synchronize my iPhone to my computer but received an error related to synchronizing the calendar during the process. I hadn’t modified any settings that I was aware of on the iPhone or within iTunes on the Windows 7 computer so I wasn’t exactly sure what caused the issue to begin with. Below is more information related to the calendar synchronization error and how I was able to resolve the error with one simple setting in iTunes.

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Information Security

Hash Collisions: World’s First Triple Hash Collision In MySQL(64)

In this article, I’ll try to explain as much as I can about hashes and collisions and my latest discovery of a triple hash collision while keeping things as simple as possible.

What Is A Hash:

It’s a cryptographic function, which takes some data as input, and generates a string, usually composed of hex characters.¬†Now, hash differs from a checksum.¬†Checksums are mostly made for files, to verify they’re integrity, while a hash can be both used for files and passwords(or plaintext data).

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Technology Insights

Obtain Dell Express Service Code & Dell Service Tag From Dell Server Running Linux

I wrote a previous article about obtaining the BIOS version on a Dell Poweredge 650 server which had the end goal of updating the BIOS version on the server if a new BIOS version was available. So after obtaining the BIOS version of the Poweredge 650 server I needed the Dell Service Tag from the server so I could use Dell’s web site to see if a new BIOS version was available. Below is information on how to obtain the Dell Service Tag as well as the Dell Express Service code for the server if it is running a Linux operating system.

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