John's blog

Talking about technology (mostly)

About Jay Jay

Hi there. My name is John Elliot V. My friends call me Jay Jay. I talk about technology on my blog at blog.jj5.net and make videos about electronics on my YouTube channel @InTheLabWithJayJay.

IDN homograph attacks and confusable characters

Posted on 2012-03-20 [Tuesday] by Jay Jay

Today I read about IDN homograph attacks. Basically it’s where Unicode characters that look like ASCII characters are put into a link so the link seems to go to a genuine/trusted site. In related news I found a list of confusable characters via stackoverflow. Also found a list of confusable symbols.

Punycode

Posted on 2012-03-20 [Tuesday] by Jay Jay

Today I learned about Punycode, which is a system for reversibly encoding Unicode in ASCII.

PHP Number Base Conversion

Posted on 2012-03-20 [Tuesday] by Jay Jay

I was doing some research into base conversion and so far have found a function, dec2base, which looks like it might come in handy. There’s an online demo of the function.

New bcmod JavaScript function at jsphp.co

Posted on 2012-03-20 [Tuesday] by Jay Jay

I was working on some code the other evening and found myself needing a version of PHP’s bcmod function in JavaScript. It wasn’t already available at jsphp.co so I implemented it and posted about it to the ProgClub programming list.

The Most Common OpenSSL Commands and viewing a CRL

Posted on 2012-03-19 [Monday] by Jay Jay

Found a helpful article today, The Most Common OpenSSL Commands.

The particular command I needed wasn’t listed there though. What I needed to do was examine the contents of my Certificate Revocation List (CRL) certificate. I had a problem connecting to my website because it was complaining about an expired certificate and the culprit was indeed the CRL as I discovered when I ran:

 $ openssl crl -inform CER -in ca.crl -text -noout

Clearing SSL session state in Firefox

Posted on 2012-03-16 [Friday] by Jay Jay

Sometimes I have a problem where I connect to my server without using a certificate, and then later need to connect using a certificate. But if I’ve already selected not to use a certificate then Firefox doesn’t prompt again so I have been having to restart my browser when that happens, which was a real pain, until now!

To clear your SSL session state in Firefox choose History -> Clear Recent History… and then select “Active Logins” and click “Clear Now”. Then the next time you connect to your SSL server Firefox will prompt for which certificate to use.