diff --git a/epp/start_epp.php b/epp/start_epp.php
index 61af31c..b3d17bc 100644
--- a/epp/start_epp.php
+++ b/epp/start_epp.php
@@ -64,15 +64,18 @@ $server->set([
     'tcp_defer_accept' => true,
     'tcp_fastopen' => true,
     'tcp_user_timeout' => 30000,
-    'ssl_handshake_timeout' => 2,
+    'ssl_handshake_timeout' => 15,
     'heartbeat_check_interval' => 60,
     'heartbeat_idle_time' => 120,
     'buffer_output_size' => 2 * 1024 * 1024,
     'send_yield' => true,
     'open_ssl' => true,
+    'ssl_client_cert_depth' => 1,
     'ssl_cert_file' => $c['ssl_cert'],
     'ssl_key_file' => $c['ssl_key'],
     'ssl_verify_peer' => false,
+    'ssl_verify_depth' => 3,
+    'ssl_client_cert_file' => '/etc/ssl/certs/ca-certificates.crt',
     'ssl_allow_self_signed' => false,
     'ssl_protocols' => SWOOLE_SSL_TLSv1_2 | SWOOLE_SSL_TLSv1_3,
     'ssl_ciphers' => 'ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE+AESGCM:ECDHE+AES256:ECDHE+AES128:DHE+AES256:DHE+AES128:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK',