If you are creating a KVM host you can sometimes get the error such XML error: expected unicast mac address. Basically, you if you have manually entered a mac address which meets the Unicast standard then it will cause problems.
Here is a quick way of generating a proper MAC Address:
openssl rand 6 | xxd -p | sed 's/\(..\)/\1:/g; s/:$//'
This is the settings that worked for me when running gource
xvfb-run -a -s “-screen 0 1280x720x24” gource -s 0.4 -p 0.01 -1280×720 –auto-skip-seconds .4 –multi-sampling –stop-at-end –highlight-users –hide mouse,progress,filenames,dirnames –file-idle-time 0 –background-colour 111111 –font-size 20 –title “Omlet Lib 4_1” –output-ppm-stream – –output-framerate 60 | avconv -y -r 60 -f image2pipe -vcodec ppm -i – -b 8192K movie.mp4
There is a method of hacking php using a security flaw in php in how it handles exif meta data embedded in jpeg, png or gif images. You describe this as an EXIF injection attack. As a precaution it is a good idea to strip all EXIF information from any images that are uploaded to your website.
I have found these two tools really useful to do this and this is a quick outline of how we used them:
Removing EXIF meta data from .jpg on Ubuntu / PHP
There is a really good tool called exiftool. There is a version in the Ubuntu repositories – so it is super easy to install.
apt-get install libimage-exiftool-perl
You can then strip exif meta from a jpeg using the command:
exiftool -all= filename.jpg
So in php this would look like this:
$output = exec(sprintf("exiftool -all= %s", escapeshellarg($_image_path)));
Removing EXIF meta data from .png images on Ubuntu / PHP
The best tool for removing exif information from .pngs is Optipng. You can install optipng on Ubuntu from source using this recipe.
apt-get install optipng
and so again in php it would look something like this:
$output = exec(sprintf('optipng -strip all %s', escapeshellarg($_image_path)));
I hope this helps someone.
Optipng is in the Ubuntu repositories but is you want an up to date version then it can be worth installing Optipng from source. This is essentially a script but you can use the commands on there own if you want.
wget --quiet http://downloads.sourceforge.net/project/optipng/OptiPNG/optipng-0.7.3/optipng-0.7.3.tar.gz tar xf optipng-0.7.3.tar.gz cd /root/scripts/optipng-0.7.3 ./configure > /dev/null 2>&1 make > /dev/null 2>&1 cp /root/scripts/optipng-0.7.3/src/optipng/optipng /usr/bin/ ln -s /usr/local/bin/optipng /usr/bin/optipng rm /root/scripts/optipng-0.7.3.tar.gz rm -rf /root/scripts/optipng-0.7.3