SSL: added support for TLSv1.3 in ssl_protocols directive. Support for the TLSv1.3 protocol will be introduced in OpenSSL 1.1.1.

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 8c7c677..eb41831 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c

@@ -323,6 +323,12 @@
         SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_TLSv1_2);
     }
 #endif
+#ifdef SSL_OP_NO_TLSv1_3
+    SSL_CTX_clear_options(ssl->ctx, SSL_OP_NO_TLSv1_3);
+    if (!(protocols & NGX_SSL_TLSv1_3)) {
+        SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_TLSv1_3);
+    }
+#endif
 
 #ifdef SSL_OP_NO_COMPRESSION
     SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_COMPRESSION);

diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
index e093e10..607ee90 100644
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h

@@ -131,6 +131,7 @@
 #define NGX_SSL_TLSv1    0x0008
 #define NGX_SSL_TLSv1_1  0x0010
 #define NGX_SSL_TLSv1_2  0x0020
+#define NGX_SSL_TLSv1_3  0x0040
 
 
 #define NGX_SSL_BUFFER   1

diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index e594d06..0fee2c2 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c

@@ -235,6 +235,7 @@
     { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
     { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
     { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
+    { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 },
     { ngx_null_string, 0 }
 };
 

diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
index 2771ac1..b466e5d 100644
--- a/src/http/modules/ngx_http_ssl_module.c
+++ b/src/http/modules/ngx_http_ssl_module.c

@@ -57,6 +57,7 @@
     { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
     { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
     { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
+    { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 },
     { ngx_null_string, 0 }
 };
 

diff --git a/src/http/modules/ngx_http_uwsgi_module.c b/src/http/modules/ngx_http_uwsgi_module.c
index b7e7c12..26443bb 100644
--- a/src/http/modules/ngx_http_uwsgi_module.c
+++ b/src/http/modules/ngx_http_uwsgi_module.c

@@ -129,6 +129,7 @@
     { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
     { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
     { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
+    { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 },
     { ngx_null_string, 0 }
 };
 

diff --git a/src/mail/ngx_mail_ssl_module.c b/src/mail/ngx_mail_ssl_module.c
index fbc9bc7..aebd179 100644
--- a/src/mail/ngx_mail_ssl_module.c
+++ b/src/mail/ngx_mail_ssl_module.c

@@ -42,6 +42,7 @@
     { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
     { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
     { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
+    { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 },
     { ngx_null_string, 0 }
 };
 

diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index 81a0891..fe52cb6 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c

@@ -103,6 +103,7 @@
     { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
     { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
     { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
+    { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 },
     { ngx_null_string, 0 }
 };
 

diff --git a/src/stream/ngx_stream_ssl_module.c b/src/stream/ngx_stream_ssl_module.c
index 2f242b6..593776b 100644
--- a/src/stream/ngx_stream_ssl_module.c
+++ b/src/stream/ngx_stream_ssl_module.c

@@ -45,6 +45,7 @@
     { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
     { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
     { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
+    { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 },
     { ngx_null_string, 0 }
 };