Using multiple authentication schemes

We can configure Squid to use multiple authentication schemes by using the auth_param directive for each authentication scheme. If we use multiple authentication schemes, then Squid will present the clients with a list of available authentication schemes. According to RFC 2617 (http://www.ietf.org/rfc/rfc2617), a client must select the strongest authentication scheme that it understands. However, due to bugs in various user agents, they generally pick the first one.

So, while adding the configuration lines with the auth_param directive in our configuration file, we should consider the following order (strongest first) for the different authentication schemes:

1. Negotiate/Kerberos Authentication

2. Microsoft NTLM Authentication

3. Digest Authentication

4. Basic Authentication

Also, it's not compulsory to use configure helpers for all authentication schemes. We can configure helpers for any number of authentication schemes. All we need to do is preserve the aforementioned...