SSL: support for TLSv1.3 early data with BoringSSL.

Early data AKA 0-RTT mode is enabled as long as "ssl_early_data on" is
specified in the configuration (default is off).

The $ssl_early_data variable evaluates to "1" if the SSL handshake
isn't yet completed, and can be used to set the Early-Data header as
per draft-ietf-httpbis-replay-04.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
index 7e9544127..9e243ea05 100644
--- a/src/http/modules/ngx_http_ssl_module.c
+++ b/src/http/modules/ngx_http_ssl_module.c
@@ -239,6 +239,13 @@ static ngx_command_t  ngx_http_ssl_commands[] = {
       offsetof(ngx_http_ssl_srv_conf_t, stapling_verify),
       NULL },
 
+    { ngx_string("ssl_early_data"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_HTTP_SRV_CONF_OFFSET,
+      offsetof(ngx_http_ssl_srv_conf_t, early_data),
+      NULL },
+
       ngx_null_command
 };
 
@@ -294,6 +301,10 @@ static ngx_http_variable_t  ngx_http_ssl_vars[] = {
     { ngx_string("ssl_session_reused"), NULL, ngx_http_ssl_variable,
       (uintptr_t) ngx_ssl_get_session_reused, NGX_HTTP_VAR_CHANGEABLE, 0 },
 
+    { ngx_string("ssl_early_data"), NULL, ngx_http_ssl_variable,
+      (uintptr_t) ngx_ssl_get_early_data,
+      NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE, 0 },
+
     { ngx_string("ssl_server_name"), NULL, ngx_http_ssl_variable,
       (uintptr_t) ngx_ssl_get_server_name, NGX_HTTP_VAR_CHANGEABLE, 0 },
 
@@ -552,6 +563,7 @@ ngx_http_ssl_create_srv_conf(ngx_conf_t *cf)
 
     sscf->enable = NGX_CONF_UNSET;
     sscf->prefer_server_ciphers = NGX_CONF_UNSET;
+    sscf->early_data = NGX_CONF_UNSET;
     sscf->buffer_size = NGX_CONF_UNSET_SIZE;
     sscf->verify = NGX_CONF_UNSET_UINT;
     sscf->verify_depth = NGX_CONF_UNSET_UINT;
@@ -594,6 +606,8 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
     ngx_conf_merge_value(conf->prefer_server_ciphers,
                          prev->prefer_server_ciphers, 0);
 
+    ngx_conf_merge_value(conf->early_data, prev->early_data, 0);
+
     ngx_conf_merge_bitmask_value(conf->protocols, prev->protocols,
                          (NGX_CONF_BITMASK_SET|NGX_SSL_TLSv1
                           |NGX_SSL_TLSv1_1|NGX_SSL_TLSv1_2));
@@ -809,6 +823,10 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
 
     }
 
+    if (ngx_ssl_early_data(cf, &conf->ssl, conf->early_data) != NGX_OK) {
+        return NGX_CONF_ERROR;
+    }
+
     return NGX_CONF_OK;
 }