Hello Thiabault,

...

native wired xp 802.1X client with PEAP (mschapv2) tries to authenticate via freeradius against openldap with an md4 encoded utf-16e password hash.

This is just not possible. PEAP (mschapv2) requires you can read the user password either as a cleartext password or as a NTLM-hashed password in your DB.

it was a bit ambiguous. The term "md4 encoded utf-16e password hash" should express, that it is an NTLM Hash. Sorry for the confusion. Best Regards, Michael