hadoop/hadoop-common-project/hadoop-auth/README.txt

Hadoop Alfredo, Java HTTP SPNEGO

Hadoop Alfredo is a Java library consisting of a client and a server
components to enable Kerberos SPNEGO authentication for HTTP.

The client component is the AuthenticatedURL class.

The server component is the AuthenticationFilter servlet filter class.

Authentication mechanisms support is pluggable in both the client and
the server components via interfaces.

In addition to Kerberos SPNEGO, Alfredo also supports Pseudo/Simple
authentication (trusting the value of the query string parameter
'user.name').