AuthorizedKeysCommand /usr/bin/auth
AuthorizedKeysCommandUser root

#!/bin/bash

cn=$1
server=ldap.myad.net #Put your server IP
basedn=dc=mydomain,dc=net #Put your basedn
port=389
bindUser=myBindUser
bindPass=myBindUserPassword
#cn=mathieu

ldapsearch -LLL -o ldif-wrap=no -x -h $server -p $port -b $basedn -D $bindUser -w $bindPass -s sub "(sAMAccountName=$cn)" | sed -n 's/^[ t]*odiSSHPubKeys:[ t]*(.*)/1/p'

Apr 18 11:56:26 MLL-HV-UBU-16 sshd[9103]: Invalid user mathieu from 192.168.0.114
Apr 18 11:56:26 MLL-HV-UBU-16 sshd[9103]: input_userauth_request: invalid user mathieu [preauth]
Apr 18 11:56:26 MLL-HV-UBU-16 sshd[9103]: Connection closed by 192.168.0.114 port 50152 [preauth]