The nntpd daemon provides a simple authorization scheme.
If you capitalize any of the access tokens in the
nntp_access file, nntpd requires
authorization from the client for the respective operation. For instance,
when specifying a permission of Xfer or
XFER, (as opposed to
xfer), nntpd will not
let the client transfer articles to your site unless it passes authorization.
The authorization procedure is implemented by means of a new NNTP command
named AUTHINFO. Using this command, the
client transmits a username and a password to the NNTP server.
nntpd validates them by checking them against the
/etc/passwd database and verifies that the user belongs to
the nntp group.
The current implementation of NNTP authorization is only experimental
and has therefore not been implemented very portably. The result of
this is that it works only with plain-style password databases; shadow
passwords are not recognized. If you are compiling from source and
have the PAM package installed, the password check is fairly simple to
change.
