added xauth scenarios

testing/tests/ikev1/xauth-psk/description.txt

@@ -0,0 +1,9 @@
+The roadwarriors <b>carol</b> and <b>dave</b> set up a connection to gateway <b>moon</b>.
+The authentication is based on Pre-Shared Keys (<b>PSK</b>)
+followed by extended authentication (<b>XAUTH</b>) of <b>carol</b> and <b>dave</b>
+based on user names and passwords.
+<p>
+Upon the successful establishment of the IPsec tunnel, leftfirewall=yes automatically
+inserts iptables-based firewall rules that let pass the tunneled traffic.
+In order to test both tunnel and firewall, <b>carol</b> and <b>dave</b> ping the client
+<b>alice</b> behind the gateway <b>moon</b>.