I was looking into using OpenID for an upcoming project I was going to be working on. After reading through some tutorials on Janrain's PHP implementation of OpenID and looking through the source code I uploaded it to my server and tested out the example script included with my Google ID and I was getting some errors about the Auth_OpenID_RAND_SOURCE in CryptUtil.php not being set properly. I found an answer through Google to define it as null instead of the default /dev/urandom. My question is, this obviously isn't safe right? and is /dev/urandom a random number generator in linux? What would be some good alternatives to using /dev/urandom on my home windows machine for messing around with the implementation?