[SOLVED] Tell me what this line does please

[webref.eu]

Hi All

 

Please could you explain to me what this line of code does, i.e. translate the code into English please:

 

$AuthCode = md5(rand(0,55)."{$password}{$username}");

 

Many thanks 

[Mchl]

Assign to a variable called $AuthCode an output of md5 function, whose argument is a random number from 0 to 55 followed by a $password and a $username variables.

[webref.eu]

OK thanks, that's what I thought ... The reason I asked is because I had noticed in testing the same AuthCode cropping up every now and again, which clearly should not have been happening.  I have now realised the problem was that I had a case sensitivity issue, i.e. I should have been using $Password and not $password. 

 

Thanks for your help. 

[webref.eu]

Am I right in saying that provided whatever I provide to the md5 function is unique, the resulting md5 hash will be unique?  i.e. it is impossible for the same md5 hash to be produced from two different input strings? 

 

Thanks

[Mchl]

You are not right. MD5 is not collision-resistant. With computing power available today it's relatively easy to find two strings that result in same hash.

 

See http://www.win.tue.nl/hashclash/Nostradamus/

for an impressive example.