I am a fan of Steve Gibson and his weekly Security Now audio talks.
His website has a password generation page which generates "long, high-quality random passwords" and in the spirit of self defense I copied about 30 characters [half of the generated alpha-numeric password] and paste it into password box of a web application I use. Although the number of '*' characters in the password box was less than the length of password I pasted, I continued and clicked on the 'change password' button. The password change confirmation text appeared and I promptly saved this new long password into Password Minder [my password remembering application].
When I tried to login with the new long password, I got the 'invalid password' message!
After a few tries I came to the conclusion that the password I put in was probably truncated. However, I had no idea what the maximum password length for the web application was! I looked up the documentation, FAQ etc. but couldn't find the maximum length of the password. It was frustrating.
The way you enter password is through the browser's User Name and Password prompt so it does not limit the no. of characters you can enter which means I cannot use the built in 'Maximum Length' feature that many textboxes have to find the limit.
The generated password I had was 30 characters long.
Guessing that the web application had a 16 character limit for the password, I copied the first 16 characters of the generated password into the password box and tried. No luck.
Remaining locked out was not an option and the obvious 'brute force' approach of trying different lengths from 5 to 30 one by one did not appeal to me.
The key was to find out the password character limit and I resumed on that path. Remembering that the change password box was showing lesser '*' than I had pasted I started searching for any documentation or page which would show me the no. of '*' in the change password page, alas I found it on their FAQ page:-
It looked like the following
I thanked my stars and counted them. It was an odd number 15.
So, I copied the first 15 characters of the generated password that I had and it worked! problem solved, lesson learned.
[A long post to describe a simple stupid mistake and lesson learned. I am not even sure I got the story across but I enjoyed every bit of the writing process. Live Writer does make blog writing easier]