Time for action – configuring Negotiate authentication

Negotiate/Kerberos authentication is provided by the negotiate_kerberos_auth authentication helper. Next, we'll learn to configure the system running Squid to enable Negotiate authentication.

1. First of all, we need to generate a keytab file using the ktpass utility on a Windows machine, as shown:

   ktpass -princ HTTP/proxy.example.com@REALM -mapuser proxy.example.com -crypto rc4-hmac-nt pass s3cr3t -ptype KRB5_NT_SRV_HST -out squid.keytab
   

   We should make sure that we have a proxy.example.com user account on our Windows machine before generating the keytab file. Once the keytab file is generated, move it to an appropriate location on the Squid server, for example, /opt/squid/etc/squid.keytab. We should make sure that only the Squid user has access to the keytab file on our system.

2. Now, we need to configure Kerberos on our Squid proxy server. For that, we need to change the libdefaults section in our Kerberos configuration file, which is generally...