diff --git a/modules/ssl/ssl_engine_init.c b/modules/ssl/ssl_engine_init.c

index b286053..8b6c34f 100644

--- a/modules/ssl/ssl_engine_init.c

+++ b/modules/ssl/ssl_engine_init.c

@@ -824,6 +824,13 @@ static apr_status_t ssl_init_ctx_protocol(server_rec *s,

         SSL_CTX_set_keylog_callback(ctx, modssl_callback_keylog);

     }

 #endif

+

+#ifdef SSL_OP_NO_RENEGOTIATION

+    /* For server-side SSL_CTX, disable renegotiation by default.. */

+    if (!mctx->pkp) {

+        SSL_CTX_set_options(ctx, SSL_OP_NO_RENEGOTIATION);

+    }

+#endif

     return APR_SUCCESS;

 }

@@ -845,6 +852,14 @@ static void ssl_init_ctx_session_cache(server_rec *s,

     }

 }

+#ifdef SSL_OP_NO_RENEGOTIATION

+/* OpenSSL-level renegotiation protection. */

+#define MODSSL_BLOCKS_RENEG (0)

+#else

+/* mod_ssl-level renegotiation protection. */

+#define MODSSL_BLOCKS_RENEG (1)

+#endif

+

 static void ssl_init_ctx_callbacks(server_rec *s,

                                    apr_pool_t *p,

                                    apr_pool_t *ptemp,

@@ -854,7 +869,13 @@ static void ssl_init_ctx_callbacks(server_rec *s,

     SSL_CTX_set_tmp_dh_callback(ctx,  ssl_callback_TmpDH);

-    SSL_CTX_set_info_callback(ctx, ssl_callback_Info);

+    /* The info callback is used for debug-level tracing.  For OpenSSL

+     * versions where SSL_OP_NO_RENEGOTIATION is not available, the

+     * callback is also used to prevent use of client-initiated

+     * renegotiation.  Enable it in either case. */

+    if (APLOGdebug(s) || MODSSL_BLOCKS_RENEG) {

+        SSL_CTX_set_info_callback(ctx, ssl_callback_Info);

+    }

 #ifdef HAVE_TLS_ALPN

     SSL_CTX_set_alpn_select_cb(ctx, ssl_callback_alpn_select, NULL);

diff --git a/modules/ssl/ssl_engine_io.c b/modules/ssl/ssl_engine_io.c

index 836bfdb..0958135 100644

--- a/modules/ssl/ssl_engine_io.c

+++ b/modules/ssl/ssl_engine_io.c

@@ -200,11 +200,13 @@ static int bio_filter_out_write(BIO *bio, const char *in, int inl)

     apr_bucket *e;

     int need_flush;

+#ifndef SSL_OP_NO_RENEGOTIATION

     /* Abort early if the client has initiated a renegotiation. */

     if (outctx->filter_ctx->config->reneg_state == RENEG_ABORT) {

         outctx->rc = APR_ECONNABORTED;

         return -1;

     }

+#endif

     /* when handshaking we'll have a small number of bytes.

      * max size SSL will pass us here is about 16k.

@@ -458,11 +460,13 @@ static int bio_filter_in_read(BIO *bio, char *in, int inlen)

     if (!in)

         return 0;

+#ifndef SSL_OP_NO_RENEGOTIATION

     /* Abort early if the client has initiated a renegotiation. */

     if (inctx->filter_ctx->config->reneg_state == RENEG_ABORT) {

         inctx->rc = APR_ECONNABORTED;

         return -1;

     }

+#endif

     BIO_clear_retry_flags(bio);

diff --git a/modules/ssl/ssl_engine_kernel.c b/modules/ssl/ssl_engine_kernel.c

index e217b9d..21f701f 100644

--- a/modules/ssl/ssl_engine_kernel.c

+++ b/modules/ssl/ssl_engine_kernel.c

@@ -992,7 +992,7 @@ static int ssl_hook_Access_classic(request_rec *r, SSLSrvConfigRec *sc, SSLDirCo

             /* Toggle the renegotiation state to allow the new

              * handshake to proceed. */

-            sslconn->reneg_state = RENEG_ALLOW;

+            modssl_set_reneg_state(sslconn, RENEG_ALLOW);

             SSL_renegotiate(ssl);

             SSL_do_handshake(ssl);

@@ -1019,7 +1019,7 @@ static int ssl_hook_Access_classic(request_rec *r, SSLSrvConfigRec *sc, SSLDirCo

              */

             SSL_peek(ssl, peekbuf, 0);

-            sslconn->reneg_state = RENEG_REJECT;

+            modssl_set_reneg_state(sslconn, RENEG_REJECT);

             if (!SSL_is_init_finished(ssl)) {

                 ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02261)

@@ -1078,7 +1078,7 @@ static int ssl_hook_Access_modern(request_rec *r, SSLSrvConfigRec *sc, SSLDirCon

         (sc->server->auth.verify_mode != SSL_CVERIFY_UNSET)) {

         int vmode_inplace, vmode_needed;

         int change_vmode = FALSE;

-        int old_state, n, rc;

+        int n, rc;

         vmode_inplace = SSL_get_verify_mode(ssl);

         vmode_needed = SSL_VERIFY_NONE;

@@ -1180,8 +1180,6 @@ static int ssl_hook_Access_modern(request_rec *r, SSLSrvConfigRec *sc, SSLDirCon

                 return HTTP_FORBIDDEN;

             }

-            old_state = sslconn->reneg_state;

-            sslconn->reneg_state = RENEG_ALLOW;

             modssl_set_app_data2(ssl, r);

             SSL_do_handshake(ssl);

@@ -1191,7 +1189,6 @@ static int ssl_hook_Access_modern(request_rec *r, SSLSrvConfigRec *sc, SSLDirCon

              */

             SSL_peek(ssl, peekbuf, 0);

-            sslconn->reneg_state = old_state;

             modssl_set_app_data2(ssl, NULL);

             /*

@@ -2271,8 +2268,8 @@ static void log_tracing_state(const SSL *ssl, conn_rec *c,

 /*

  * This callback function is executed while OpenSSL processes the SSL

  * handshake and does SSL record layer stuff.  It's used to trap

- * client-initiated renegotiations, and for dumping everything to the

- * log.

+ * client-initiated renegotiations (where SSL_OP_NO_RENEGOTIATION is

+ * not available), and for dumping everything to the log.

  */

 void ssl_callback_Info(const SSL *ssl, int where, int rc)

 {

@@ -2284,14 +2281,12 @@ void ssl_callback_Info(const SSL *ssl, int where, int rc)

         return;

     }

-    /* With TLS 1.3 this callback may be called multiple times on the first

-     * negotiation, so the below logic to detect renegotiations can't work.

-     * Fortunately renegotiations are forbidden starting with TLS 1.3, and

-     * this is enforced by OpenSSL so there's nothing to be done here.

-     */

-#if SSL_HAVE_PROTOCOL_TLSV1_3

-    if (SSL_version(ssl) < TLS1_3_VERSION)

-#endif

+#ifndef SSL_OP_NO_RENEGOTIATION

+    /* With OpenSSL < 1.1.1 (implying TLS v1.2 or earlier), this

+     * callback is used to block client-initiated renegotiation.  With

+     * TLSv1.3 it is unnecessary since renegotiation is forbidden at

+     * protocol level.  Otherwise (TLSv1.2 with OpenSSL >=1.1.1),

+     * SSL_OP_NO_RENEGOTIATION is used to block renegotiation. */

     {

         SSLConnRec *sslconn;

@@ -2316,6 +2311,7 @@ void ssl_callback_Info(const SSL *ssl, int where, int rc)

             sslconn->reneg_state = RENEG_REJECT;

         }

     }

+#endif

     s = mySrvFromConn(c);

     if (s && APLOGdebug(s)) {

diff --git a/modules/ssl/ssl_private.h b/modules/ssl/ssl_private.h

index 2514407..f4e5ac9 100644

--- a/modules/ssl/ssl_private.h

+++ b/modules/ssl/ssl_private.h

@@ -508,6 +508,16 @@ typedef struct {

     apr_time_t     source_mtime;

 } ssl_asn1_t;

+typedef enum {

+    RENEG_INIT = 0, /* Before initial handshake */

+    RENEG_REJECT,   /* After initial handshake; any client-initiated

+                     * renegotiation should be rejected */

+    RENEG_ALLOW,    /* A server-initiated renegotiation is taking

+                     * place (as dictated by configuration) */

+    RENEG_ABORT     /* Renegotiation initiated by client, abort the

+                     * connection */

+} modssl_reneg_state;

+

 /**

  * Define the mod_ssl per-module configuration structure

  * (i.e. the global configuration for each httpd process)

@@ -540,18 +550,13 @@ typedef struct {

         NON_SSL_SET_ERROR_MSG  /* Need to set the error message */

     } non_ssl_request;

-    /* Track the handshake/renegotiation state for the connection so

-     * that all client-initiated renegotiations can be rejected, as a

-     * partial fix for CVE-2009-3555. */

-    enum {

-        RENEG_INIT = 0, /* Before initial handshake */

-        RENEG_REJECT,   /* After initial handshake; any client-initiated

-                         * renegotiation should be rejected */

-        RENEG_ALLOW,    /* A server-initiated renegotiation is taking

-                         * place (as dictated by configuration) */

-        RENEG_ABORT     /* Renegotiation initiated by client, abort the

-                         * connection */

-    } reneg_state;

+#ifndef SSL_OP_NO_RENEGOTIATION

+    /* For OpenSSL < 1.1.1, track the handshake/renegotiation state

+     * for the connection to block client-initiated renegotiations.

+     * For OpenSSL >=1.1.1, the SSL_OP_NO_RENEGOTIATION flag is used in

+     * the SSL * options state with equivalent effect. */

+    modssl_reneg_state reneg_state;

+#endif

     server_rec *server;

     SSLDirConfigRec *dc;

@@ -1130,6 +1135,9 @@ int ssl_is_challenge(conn_rec *c, const char *servername,

  * the configured ENGINE. */

 int modssl_is_engine_id(const char *name);

+/* Set the renegotation state for connection. */

+void modssl_set_reneg_state(SSLConnRec *sslconn, modssl_reneg_state state);

+

 #endif /* SSL_PRIVATE_H */

 /** @} */

diff --git a/modules/ssl/ssl_util_ssl.c b/modules/ssl/ssl_util_ssl.c

index 4fa089b..3413d83 100644

--- a/modules/ssl/ssl_util_ssl.c

+++ b/modules/ssl/ssl_util_ssl.c

@@ -504,3 +504,19 @@ char *modssl_SSL_SESSION_id2sz(IDCONST unsigned char *id, int idlen,

     return str;

 }

+

+void modssl_set_reneg_state(SSLConnRec *sslconn, modssl_reneg_state state)

+{

+#ifdef SSL_OP_NO_RENEGOTIATION

+    switch (state) {

+    case RENEG_ALLOW:

+        SSL_clear_options(sslconn->ssl, SSL_OP_NO_RENEGOTIATION);

+        break;

+    default:

+        SSL_set_options(sslconn->ssl, SSL_OP_NO_RENEGOTIATION);

+        break;

+    }

+#else

+    sslconn->reneg_state = state;

+#endif

+}