I want to setup squid on my home pc where many people uses the same pc. What can i do to verify users based on their account on the pc ?
You can setup authentication (of varying levels and complexity) in Squid to prompt for user/pass by the person browsing. For such a small implementation, I'd maybe recommend using basic authentication, but your decision.
You can review the documentation here: https://wiki.squid-cache.org/Features/Authentication
But essentially, for Basic Authentication you'll need to install the apache2-utils package. Then follow this:
sudo touch /etc/squid/passwd sudo chown proxy: /etc/squid/passwd sudo htpasswd /etc/squid/passwd user1
Now we need to edit the squid.conf for authentication. Towards the bottom and before you http_access allow none, you'll want this:
auth_param basic program /usr/lib64/squid/basic_ncsa_auth /etc/squid/passwd auth_param basic children 5 auth_param basic realm Authentication for Squid Proxy auth_param basic credentialsttl 6 hours acl auth_users proxy_auth REQUIRED http_access allow auth_users
Now restart squid and when you access the proxy you'll be prompted for user/pass. There are helper applications that allow the user to modify their own password after the fact, but for a single instance, it probably isn't necessary.