SSL: save sessions for upstream peers using a callback function.

In TLSv1.3, NewSessionTicket messages arrive after the handshake and
can come at any time.  Therefore we use a callback to save the session
when we know about it.  This approach works for < TLSv1.3 as well.
The callback function is set once per location on merge phase.

Since SSL_get_session() in BoringSSL returns an unresumable session for
TLSv1.3, peer save_session() methods have been updated as well to use a
session supplied within the callback.  To preserve API, the session is
cached in c->ssl->session.  It is preferably accessed in save_session()
methods by ngx_ssl_get_session() and ngx_ssl_get0_session() wrappers.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
index 623d851dc..22350d54b 100644
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h
@@ -77,6 +77,9 @@ struct ngx_ssl_connection_s {
 
     ngx_connection_handler_pt   handler;
 
+    ngx_ssl_session_t          *session;
+    ngx_connection_handler_pt   save_session;
+
     ngx_event_handler_pt        saved_read_handler;
     ngx_event_handler_pt        saved_write_handler;
 
@@ -168,6 +171,8 @@ RSA *ngx_ssl_rsa512_key_callback(ngx_ssl_conn_t *ssl_conn, int is_export,
 ngx_array_t *ngx_ssl_read_password_file(ngx_conf_t *cf, ngx_str_t *file);
 ngx_int_t ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *file);
 ngx_int_t ngx_ssl_ecdh_curve(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *name);
+ngx_int_t ngx_ssl_client_session_cache(ngx_conf_t *cf, ngx_ssl_t *ssl,
+    ngx_uint_t enable);
 ngx_int_t ngx_ssl_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
     ssize_t builtin_session_cache, ngx_shm_zone_t *shm_zone, time_t timeout);
 ngx_int_t ngx_ssl_session_ticket_keys(ngx_conf_t *cf, ngx_ssl_t *ssl,
@@ -178,7 +183,8 @@ ngx_int_t ngx_ssl_create_connection(ngx_ssl_t *ssl, ngx_connection_t *c,
 
 void ngx_ssl_remove_cached_session(SSL_CTX *ssl, ngx_ssl_session_t *sess);
 ngx_int_t ngx_ssl_set_session(ngx_connection_t *c, ngx_ssl_session_t *session);
-#define ngx_ssl_get_session(c)      SSL_get1_session(c->ssl->connection)
+ngx_ssl_session_t *ngx_ssl_get_session(ngx_connection_t *c);
+ngx_ssl_session_t *ngx_ssl_get0_session(ngx_connection_t *c);
 #define ngx_ssl_free_session        SSL_SESSION_free
 #define ngx_ssl_get_connection(ssl_conn)                                      \
     SSL_get_ex_data(ssl_conn, ngx_ssl_connection_index)