Basic Challenge-Response authentication

This is a perl5 module implementing basic MD5-based challenge/response.
The authentication method provided, allows for mutual authentications
of the endpoints of a communication channel provided that a shared
secret known only to them has been exchanged prior to the session.

If the secret is known to a third party, this authentication mechanism
is useless (ie, this situation can lead to a man-in-the-middle-attack)
so its secrecy is very important.

Note that this module does NOT provide security agains eavesdropping or
hijacking. A positive identification can be followed by an attacker
stealing the connection or sniffing. Both situations can be detrimental
to the security.

This module allows for the detection of date-synch issues, such as the
ones ussually present when an attacker drifts the clock of one of the
peers to influence other authentication schemes. At run-time, the user
of the module can define a time-sync-tolerance. Host dates when the
challenge and response were generated must match to within this
specified tolerance to be acceptable.

The user can also define a lifespan for the challenge/response
transaction.

This code is subject to the same restrictions and warranties than
perl itself.

This implementation depends on MD5.pm to be correctly installed
on your system. It has been tested on FreeBSD 2.2.5-RELEASE and
2.2.6-RELEASE as well as on Digital Unix 3.0B. It should work on
any system where perl's MD5() works correctly.

Installing Auth::Challenge::Basic should be as easy as unpacking the 
gzipped file and doing

		perl Makefile.PL
		make
		make test
		make install

The tests are very simple. Essentially, if the MD5 module works, 
this one *should* also work :)

It would be very nice to have more challenge/response methods
available. They can be created bellow Auth::Challenge.

Please send bugs, queries, suggestions to

Luis E. Munoz, lem@cantv.net

Good luck.






