From b8eccec62dc7662d2c69aa129cfe5423c36ade5b Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Sat, 8 Sep 2018 19:10:59 +0900
Subject: [PATCH] nghttpx: Disable OpenSSL anti-replay

---
 src/shrpx_tls.cc | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/shrpx_tls.cc b/src/shrpx_tls.cc
index 1b701fdf..c9ea5fc5 100644
--- a/src/shrpx_tls.cc
+++ b/src/shrpx_tls.cc
@@ -770,7 +770,17 @@ SSL_CTX *create_ssl_context(const char *private_key_file, const char *cert_file,
       (SSL_OP_ALL & ~SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS) | SSL_OP_NO_SSLv2 |
       SSL_OP_NO_SSLv3 | SSL_OP_NO_COMPRESSION |
       SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | SSL_OP_SINGLE_ECDH_USE |
-      SSL_OP_SINGLE_DH_USE | SSL_OP_CIPHER_SERVER_PREFERENCE;
+      SSL_OP_SINGLE_DH_USE |
+      SSL_OP_CIPHER_SERVER_PREFERENCE
+#if OPENSSL_1_1_1_API
+      // The reason for disabling built-in anti-replay in OpenSSL is
+      // that it only works if client gets back to the same server.
+      // The freshness check described in
+      // https://tools.ietf.org/html/rfc8446#section-8.3 is still
+      // performed.
+      | SSL_OP_NO_ANTI_REPLAY
+#endif // OPENSSL_1_1_1_API
+      ;
 
   auto config = mod_config();
   auto &tlsconf = config->tls;