Is it possible to create local user in Juniper SA Series and generates certificate on each user for authentication purpose? If yes, will it be possible also that the user can enroll to juniper Appliance to generate and get their certificate remotely?
Can it also provide user expiration option?
Technically you could login as each user and create their certificate for them, yes; however, that will not be of any benefit to you as you would still need to distribute the certificates to users.
The Juniper appliance does not do any certificate enrollment; you would need to allow users to connect to your certificate server and create the certificates through the appliance.
There is no timer for user expiration other than a one-time-use only option.
Does Juniper have any type of certificate enrollment device / services that could be utilized? If not, what are others doing in such a situation?
no, there is nothing like this from juniper.
most of the environments i have worked with over the years that use certificates utilize MS certificate services.
I have run across a few that use their own openSSL-based option; public PKI a l verisign (or similar); and i'm sure there are others available that i have not run across
If you have a windows domain, then the easiest way is to auto-enroll your domain computers using group policy. You add the CA (certificate authority) role to a server in your enterprise. Then you create the group policy that will auto-enroll all your domian computers.
http://technet.microsoft.com/en-us/library/cc947849%28v=ws.10%29.aspx
The the SA then you will add your enterprise CA to the certificate authorities. And then you can use it for authentication.