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Sunday, February 2, 2020

User eXperience fixes for "Smart card ATR parsing"

Smart card ATR parsing

My web site/service "Smart card ATR parsing" is used to parse smart card ATR. You can read the previous article "Parsing an ATR: new web site URL" to get some background history.

If you have an ATR I do not already have in my database you can submit it with a description of the corresponding smart card.


I sometimes receive strange ATR to be added the list. For example I just received these 2 ATRs:
What is strange with these 2 ATRs is that:
  1. I already have a shorter version in my list
  2. they have 4 extra bytes at the end
  3. these 4 extra bytes "3B 02 14 50" look like another ATR
At first I thought of a corrupted ATR or a bogus reader or driver that mixes 2 ATRs.
But then I realised that the value "3B 02 14 50" is the default value I use for the ATR input field. So if you copy & paste a new ATR value without removing the default value then the default value is appended to your ATR.


The solution is now obvious. The problem is with my web site.
The value "3B 02 14 50" is now a placeholder= and not a value=. You can copy & paste a new ATR in the input field and the "3B 02 14 50" will disappear.


I was aware of this problem. I used to first select the default value "3B 02 14 50" to replace it with the real ATR. I thought every body would do the same as me. I was wrong and the User eXperience was bad.

The web site should now be more useful to my users and also easier to use.
Do not hesitate to complain if you find a bug or want to suggest a UX improvement.