[pptp-server] Security: rollback to MS-chapv1

[Pascal Fremaux]

Is PoPToP/PPP protected from the 'bug' of Windows implementation: when
you ask the PoPToP/PPP server to accept only MS-chapv2, tho PPP protocol
authorize to downgrade to MS-chapv1 if the client doesn't know V2 ?
I put 'require Ms-chapv2' in my PPP option file. Is it sufficient ?
Should I put also 'refuse Ms-chapv1' ?

--
 Pascal Fremaux, SSII Alten
 Study Engineer at Alcatel Telecom
 R&D, Illkirch, France