Zeroday 01100100011010010

While digging through youtube html for another project I came upon this interesting error message.

msg[“koreaFail”] = “본인확인제로 인해 한국 국가 설정시 동영상/댓글 업로드 기능을자발적으로 비활성화합니다. We have voluntarily disabled this functionality on kr.youtube.com because of the Korean real-name verification law.”;

I looked into this a bit more and South Korea seems to have rallied around the death of a popular actress who killed herself due to online comments about her. The new “anti bully” law requires all sites with at least 100,000 users to verify the posters real name.

“The Cyber Defamation Law, as it’s called, went into effect on April 1st. According
to officials at the Korea Communications Commission (KCC), the country’s
broadcasting and telecommunications regulator, the law is an attempt to
quell the cyber-bullying and spread of misinformation on the internet.”

source: readwriteweb

Google is unwilling to collect this kind of data about its users and instead has opted to disable upload (and I assume comment) capabilities from South Korean IP addresses.

I’ve decided to step down from the Advisory Board of the SourceBoston conference. I still think that it is a fantastic project but I have been so busy with academic projects and class work that I couldn’t give them enough time.

I’m also not going to be a regular columnist at SecurityFocus after this month. This was more a decision on their part than mine however I am not going to fight it. I could use the extra time to focus on two very exciting academic papers I have lined up for this year.

A recent project has me thinking about storing of IP addresses in mysql. The natural tendency is to store it as text. My first attempt stored the address as char(16) with a normal index to help speed searches against it. After some reading about high performance MySQL techniques I was reminded that IP addresses in dotted quad form are the least efficient. Instead of storing as a string of characters I could instead convert the dotted quad into a 32 bit integer.

The magic of converting it is pretty easy to find online however if you are using ruby simply install the IPAddr gem.

>> ip = IPAddr.new(‘255.255.255.255’)
=> #
>> puts ip.to_i
4294967295
=> nil

Reversing the process isn’t quite as easy and the documentation fails to mention this possibility. A little digging online will unearth this additional parameter that is needed:

>> ipnum = 4294967295
=> 4294967295
>> ip = IPAddr.new(ipnum, Socket::AF_INET).to_s
=> “255.255.255.255”

When I first tried to store this in MySQL I ran into another problem. In my haste I created the column ip_num as an int(11). The code I ran didn’t raise an exception and converted all the ip addresses in the database. However when I viewed the results a large number of ip addresses came back as 127.255.255.255. This ip address converts to 2147483647 as an integer.

If this number looks familiar it is because it is exactly half of the value of 255.255.255.255. It is also the limit of a signed integer.
“The signed range is -2147483648 to 2147483647”

Ensure that you create an unsigned int column for ip addresses to hold the max value of 4294967295.
The unsigned range is 0 to 4294967295.