Squid transparent authentication

[bekirk]

I have configured squid to use samba and windows authentication, transparent to the user, but now want to take this further. Not everyone here requires Internet access, so when someone tries to go to the Internet, but isn't in a security group in AD, how can I tell squid to prompt for authentication. Some systems have multiple users, but just one windows login, so those systems need to ask the user for authentication, where the majority of the workstations, can use the windows authentication.

Any help would be great.

Thank you,
Brian

squid.conf
------------------------------------
# Changed the default to port 8080
http_port 8080

icp_port 0

# added for our firewall http proxy as the next hop
cache_peer firewall.mydomain.com parent 8080 0 no-query default

hierarchy_stoplist cgi-bin ?
acl QUERY urlpath_regex cgi-bin \?
no_cache deny QUERY
emulate_httpd_log on

# added for smartfilter and authorization
smartfilter_state on
smartfilter_config /usr/local/squid/etc/config.txt
smartfilter_userinfo_program /usr/local/squid/libexec/sf_userinfo -f /usr/local/squid/etc/config.txt
smartfilter_userinfo_children 5

# added for our dns server
dns_nameservers xxx.yyy.zzz.14 xxx.yyy.zzz.15

# added for AD authentication
auth_param ntlm program /usr/local/samba/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp
auth_param ntlm children 30
auth_param ntlm max_challenge_reuses 0
auth_param ntlm max_challenge_lifetime 2 minutes
auth_param basic program /usr/local/samba/bin/ntlm_auth --helper-protocol=squid-2.5-basic
auth_param basic children 5
auth_param basic realm Squid proxy-caching web server
auth_param basic credentialsttl 2 hours

refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern . 0 20% 4320
acl all src 0.0.0.0/0.0.0.0

# added for our firewall http proxy
never_direct allow all

acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl to_localhost dst 127.0.0.0/8
acl SSL_ports port 443 563
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 563 # https, snews
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl CONNECT method CONNECT

# added for AD authentication
acl AuthorizedUsers proxy_auth REQUIRED
http_access allow all AuthorizedUsers

http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access deny all
http_reply_access allow all
icp_access allow all
coredump_dir /var/spool/squid

[jledhead]

I was under the impression that squid wasn't able to prompt for authentication when running in transparent mode. prompting for auth and being transparent don't really go together.

as for restricting certain people, is this in a shared computer situation or could you block a whole computer from accessing the internet, if its not a shared situation then blocking based on hostname or IP will probably be the best if you are running squid transparent.

at least that was the assumptions I have been under

***edit***

maybe I read that wrong, you aren't running a transparent proxy but are trying to use windows credentials transparent to the user.

I am not sure if squid can read AD permission, but I have used msntauth for authenticating against AD and it has 2 files where you can allow and deny access. not sure how much that helps but it does give you another direction to look

[bekirk]

I am not really running squid in transparent mode, I am however trying to make it easier on the user so they don't have to authenticate to the Internet if they are in a "standard internet" security group, I have been able to verify if a user is a member of the group using squid_ldap_group helper, but don't have it in the squid.conf at the moment. I think you have given me some direction though.

The computers that I am talking about are shared so the host or IP blocking won't work.

I will let everyone know if I get this working the way I want.

Thank you,
Brian