SSL: automatic rotation of session ticket keys.

As long as ssl_session_cache in shared memory is configured, session ticket
keys are now automatically generated in shared memory, and rotated
periodically.  This can be beneficial from forward secrecy point of view,
and also avoids increased CPU usage after configuration reloads.

This also helps BoringSSL to properly resume sessions in configurations
with multiple worker processes and no ssl_session_ticket_key directives,
as BoringSSL tries to automatically rotate session ticket keys and does
this independently in different worker processes, thus breaking session
resumption between worker processes.

1 files changed, 11 insertions, 12 deletions

diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
index 936662127..45d8b78a7 100644
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h
@@ -147,23 +147,22 @@ struct ngx_ssl_sess_id_s {
 
 
 typedef struct {
-    ngx_rbtree_t                session_rbtree;
-    ngx_rbtree_node_t           sentinel;
-    ngx_queue_t                 expire_queue;
-    time_t                      fail_time;
-} ngx_ssl_session_cache_t;
-
-
-#ifdef SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB
-
-typedef struct {
-    size_t                      size;
     u_char                      name[16];
     u_char                      hmac_key[32];
     u_char                      aes_key[32];
+    time_t                      expire;
+    unsigned                    size:8;
+    unsigned                    shared:1;
 } ngx_ssl_ticket_key_t;
 
-#endif
+
+typedef struct {
+    ngx_rbtree_t                session_rbtree;
+    ngx_rbtree_node_t           sentinel;
+    ngx_queue_t                 expire_queue;
+    ngx_ssl_ticket_key_t        ticket_keys[2];
+    time_t                      fail_time;
+} ngx_ssl_session_cache_t;
 
 
 #define NGX_SSL_SSLv2    0x0002