How to configure Squid with for authentication but skip it for local requests?

Question

My Squid HTTP proxy works fine with authentication. Here is the config:

auth_param basic program /usr/lib/squid/pam_auth
auth_param basic children 5
auth_param basic realm test-proxy
auth_param basic credentialsttl 4 hours
auth_param basic casesensitive off

But I want that my locally running applications which use the proxy don't have to authenticate. How to disable authentication for requests from localhost?

Answer 1

Something like

acl localhost src 127.0.0.1
acl auth proxy_auth REQUIRED
http_access allow localhost auth

should do the trick.

Answer 2

Better still - don't proxy for local requests - this is easily set up in browser config, group policy, proxy.pac etc. - there is generally no real case for local proxying.