1 files changed, 2 insertions, 0 deletions

diff --git a/qmail-smtpd.c b/qmail-smtpd.c
index c4b498e..d97dfc5 100644
--- a/qmail-smtpd.c
+++ b/qmail-smtpd.c
@@ -1334,6 +1334,8 @@ void tls_init()
   SSL_CTX_set_min_proto_version(ctx, min_ssl_version);
   SSL_CTX_set_options(ctx, SSL_OP_CIPHER_SERVER_PREFERENCE |
                            SSL_OP_PRIORITIZE_CHACHA);
+  /* TLS renegotiation is possible cpu resource attack */
+  SSL_CTX_set_options(ctx, SSL_OP_NO_RENEGOTIATION);
 
   /* set the callback here; SSL_set_verify didn't work before 0.9.6c */
   SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, verify_cb);