Enabling configure TLS sessions.

To support TLS sessions, Unit uses the OpenSSL built-in session cache; the
cache_size option defines the number sessions to store.  To disable the feather,
the option must be zero.

5 files changed, 142 insertions, 22 deletions

diff --git a/docs/changes.xml b/docs/changes.xml
index 68db823d..2aa9bb65 100644
--- a/docs/changes.xml
+++ b/docs/changes.xml
@@ -33,6 +33,12 @@ NGINX Unit updated to 1.25.0.
 
 <change type="feature">
 <para>
+TLS sessions cache.
+</para>
+</change>
+
+<change type="feature">
+<para>
 process and thread lifecycle hooks in Ruby.
 </para>
 </change>
diff --git a/src/nxt_conf_validation.c b/src/nxt_conf_validation.c
index a16c955c..fd57a983 100644
--- a/src/nxt_conf_validation.c
+++ b/src/nxt_conf_validation.c
@@ -95,6 +95,10 @@ static nxt_int_t nxt_conf_vldt_object_conf_commands(nxt_conf_validation_t *vldt,
 #endif
 static nxt_int_t nxt_conf_vldt_certificate_element(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value);
+static nxt_int_t nxt_conf_vldt_tls_cache_size(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data);
+static nxt_int_t nxt_conf_vldt_tls_timeout(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data);
 #endif
 static nxt_int_t nxt_conf_vldt_action(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
@@ -206,6 +210,7 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_websocket_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_static_members[];
 #if (NXT_TLS)
 static nxt_conf_vldt_object_t  nxt_conf_vldt_tls_members[];
+static nxt_conf_vldt_object_t  nxt_conf_vldt_session_members[];
 #endif
 static nxt_conf_vldt_object_t  nxt_conf_vldt_match_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_python_target_members[];
@@ -378,11 +383,65 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_tls_members[] = {
         .validator  = nxt_conf_vldt_unsupported,
         .u.string   = "conf_commands",
 #endif
+    }, {
+        .name       = nxt_string("session"),
+        .type       = NXT_CONF_VLDT_OBJECT,
+        .validator  = nxt_conf_vldt_object,
+        .u.members  = nxt_conf_vldt_session_members,
     },
 
     NXT_CONF_VLDT_END
 };
 
+
+static nxt_conf_vldt_object_t  nxt_conf_vldt_session_members[] = {
+    {
+        .name       = nxt_string("cache_size"),
+        .type       = NXT_CONF_VLDT_INTEGER,
+        .validator  = nxt_conf_vldt_tls_cache_size,
+    }, {
+        .name       = nxt_string("timeout"),
+        .type       = NXT_CONF_VLDT_INTEGER,
+        .validator  = nxt_conf_vldt_tls_timeout,
+    },
+
+    NXT_CONF_VLDT_END
+};
+
+
+static nxt_int_t
+nxt_conf_vldt_tls_cache_size(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data)
+{
+    int64_t  cache_size;
+
+    cache_size = nxt_conf_get_number(value);
+
+    if (cache_size < 0) {
+        return nxt_conf_vldt_error(vldt, "The \"cache_size\" number must not "
+                                         "be negative.");
+    }
+
+    return NXT_OK;
+}
+
+
+static nxt_int_t
+nxt_conf_vldt_tls_timeout(nxt_conf_validation_t *vldt, nxt_conf_value_t *value,
+    void *data)
+{
+    int64_t  timeout;
+
+    timeout = nxt_conf_get_number(value);
+
+    if (timeout <= 0) {
+        return nxt_conf_vldt_error(vldt, "The \"timeout\" number must be "
+                                         "greater than zero.");
+    }
+
+    return NXT_OK;
+}
+
 #endif
 
 
diff --git a/src/nxt_openssl.c b/src/nxt_openssl.c
index 2fd5d1bf..3b5d4fda 100644
--- a/src/nxt_openssl.c
+++ b/src/nxt_openssl.c
@@ -42,15 +42,16 @@ static void nxt_openssl_lock(int mode, int type, const char *file, int line);
 static unsigned long nxt_openssl_thread_id(void);
 static void nxt_openssl_locks_free(void);
 #endif
-static nxt_int_t nxt_openssl_server_init(nxt_task_t *task,
-    nxt_tls_conf_t *conf, nxt_mp_t *mp, nxt_conf_value_t *conf_cmds,
-    nxt_bool_t last);
+static nxt_int_t nxt_openssl_server_init(nxt_task_t *task, nxt_mp_t *mp,
+    nxt_tls_init_t *tls_init, nxt_bool_t last);
 static nxt_int_t nxt_openssl_chain_file(nxt_task_t *task, SSL_CTX *ctx,
     nxt_tls_conf_t *conf, nxt_mp_t *mp, nxt_bool_t single);
 #if (NXT_HAVE_OPENSSL_CONF_CMD)
 static nxt_int_t nxt_ssl_conf_commands(nxt_task_t *task, SSL_CTX *ctx,
     nxt_conf_value_t *value, nxt_mp_t *mp);
 #endif
+static void nxt_ssl_session_cache(SSL_CTX *ctx, size_t cache_size,
+    time_t timeout);
 static nxt_uint_t nxt_openssl_cert_get_names(nxt_task_t *task, X509 *cert,
     nxt_tls_conf_t *conf, nxt_mp_t *mp);
 static nxt_int_t nxt_openssl_bundle_hash_test(nxt_lvlhsh_query_t *lhq,
@@ -265,11 +266,12 @@ nxt_openssl_locks_free(void)
 
 
 static nxt_int_t
-nxt_openssl_server_init(nxt_task_t *task, nxt_tls_conf_t *conf,
-    nxt_mp_t *mp, nxt_conf_value_t *conf_cmds, nxt_bool_t last)
+nxt_openssl_server_init(nxt_task_t *task, nxt_mp_t *mp,
+    nxt_tls_init_t *tls_init, nxt_bool_t last)
 {
     SSL_CTX                *ctx;
     const char             *ciphers, *ca_certificate;
+    nxt_tls_conf_t         *conf;
     STACK_OF(X509_NAME)    *list;
     nxt_tls_bundle_conf_t  *bundle;
 
@@ -279,6 +281,8 @@ nxt_openssl_server_init(nxt_task_t *task, nxt_tls_conf_t *conf,
         return NXT_ERROR;
     }
 
+    conf = tls_init->conf;
+
     bundle = conf->bundle;
     nxt_assert(bundle != NULL);
 
@@ -337,13 +341,15 @@ nxt_openssl_server_init(nxt_task_t *task, nxt_tls_conf_t *conf,
     }
 
 #if (NXT_HAVE_OPENSSL_CONF_CMD)
-    if (conf_cmds != NULL
-        && nxt_ssl_conf_commands(task, ctx, conf_cmds, mp) != NXT_OK)
+    if (tls_init->conf_cmds != NULL
+        && nxt_ssl_conf_commands(task, ctx, tls_init->conf_cmds, mp) != NXT_OK)
     {
         goto fail;
     }
 #endif
 
+    nxt_ssl_session_cache(ctx, tls_init->cache_size, tls_init->timeout);
+
     SSL_CTX_set_options(ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
 
     if (conf->ca_certificate != NULL) {
@@ -582,6 +588,22 @@ fail:
 #endif
 
 
+static void
+nxt_ssl_session_cache(SSL_CTX *ctx, size_t cache_size, time_t timeout)
+{
+    if (cache_size == 0) {
+        SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
+        return;
+    }
+
+    SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_SERVER);
+
+    SSL_CTX_sess_set_cache_size(ctx, cache_size);
+
+    SSL_CTX_set_timeout(ctx, (long) timeout);
+}
+
+
 static nxt_uint_t
 nxt_openssl_cert_get_names(nxt_task_t *task, X509 *cert, nxt_tls_conf_t *conf,
     nxt_mp_t *mp)
diff --git a/src/nxt_router.c b/src/nxt_router.c
index 409f88a1..1156edb8 100644
--- a/src/nxt_router.c
+++ b/src/nxt_router.c
@@ -44,10 +44,10 @@ typedef struct {
     nxt_str_t               name;
     nxt_socket_conf_t       *socket_conf;
     nxt_router_temp_conf_t  *temp_conf;
-    nxt_conf_value_t        *conf_cmds;
+    nxt_tls_init_t          *tls_init;
     nxt_bool_t              last;
 
-    nxt_queue_link_t   link;  /* for nxt_socket_conf_t.tls */
+    nxt_queue_link_t        link;  /* for nxt_socket_conf_t.tls */
 } nxt_router_tlssock_t;
 
 #endif
@@ -123,8 +123,8 @@ static void nxt_router_listen_socket_error(nxt_task_t *task,
 static void nxt_router_tls_rpc_handler(nxt_task_t *task,
     nxt_port_recv_msg_t *msg, void *data);
 static nxt_int_t nxt_router_conf_tls_insert(nxt_router_temp_conf_t *tmcf,
-    nxt_conf_value_t *value, nxt_socket_conf_t *skcf,
-    nxt_conf_value_t * conf_cmds, nxt_bool_t last);
+    nxt_conf_value_t *value, nxt_socket_conf_t *skcf, nxt_tls_init_t *tls_init,
+    nxt_bool_t last);
 #endif
 static void nxt_router_app_rpc_create(nxt_task_t *task,
     nxt_router_temp_conf_t *tmcf, nxt_app_t *app);
@@ -1341,7 +1341,8 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
     nxt_router_t                *router;
     nxt_app_joint_t             *app_joint;
 #if (NXT_TLS)
-    nxt_conf_value_t            *certificate, *conf_cmds;
+    nxt_tls_init_t              *tls_init;
+    nxt_conf_value_t            *certificate;
 #endif
     nxt_conf_value_t            *conf, *http, *value, *websocket;
     nxt_conf_value_t            *applications, *application;
@@ -1363,6 +1364,8 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
 #if (NXT_TLS)
     static nxt_str_t  certificate_path = nxt_string("/tls/certificate");
     static nxt_str_t  conf_commands_path = nxt_string("/tls/conf_commands");
+    static nxt_str_t  conf_cache_path = nxt_string("/tls/session/cache_size");
+    static nxt_str_t  conf_timeout_path = nxt_string("/tls/session/timeout");
 #endif
     static nxt_str_t  static_path = nxt_string("/settings/http/static");
     static nxt_str_t  websocket_path = nxt_string("/settings/http/websocket");
@@ -1741,7 +1744,26 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
             certificate = nxt_conf_get_path(listener, &certificate_path);
 
             if (certificate != NULL) {
-                conf_cmds = nxt_conf_get_path(listener, &conf_commands_path);
+                tls_init = nxt_mp_get(tmcf->mem_pool, sizeof(nxt_tls_init_t));
+                if (nxt_slow_path(tls_init == NULL)) {
+                    return NXT_ERROR;
+                }
+
+                tls_init->cache_size = 0;
+                tls_init->timeout = 300;
+
+                value = nxt_conf_get_path(listener, &conf_cache_path);
+                if (value != NULL) {
+                    tls_init->cache_size = nxt_conf_get_number(value);
+                }
+
+                value = nxt_conf_get_path(listener, &conf_timeout_path);
+                if (value != NULL) {
+                    tls_init->timeout = nxt_conf_get_number(value);
+                }
+
+                tls_init->conf_cmds = nxt_conf_get_path(listener,
+                                                        &conf_commands_path);
 
                 if (nxt_conf_type(certificate) == NXT_CONF_ARRAY) {
                     n = nxt_conf_array_elements_count(certificate);
@@ -1752,7 +1774,7 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
                         nxt_assert(value != NULL);
 
                         ret = nxt_router_conf_tls_insert(tmcf, value, skcf,
-                                                         conf_cmds, i == 0);
+                                                         tls_init, i == 0);
                         if (nxt_slow_path(ret != NXT_OK)) {
                             goto fail;
                         }
@@ -1761,7 +1783,7 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
                 } else {
                     /* NXT_CONF_STRING */
                     ret = nxt_router_conf_tls_insert(tmcf, certificate, skcf,
-                                                     conf_cmds, 1);
+                                                     tls_init, 1);
                     if (nxt_slow_path(ret != NXT_OK)) {
                         goto fail;
                     }
@@ -1856,7 +1878,7 @@ fail:
 static nxt_int_t
 nxt_router_conf_tls_insert(nxt_router_temp_conf_t *tmcf,
     nxt_conf_value_t *value, nxt_socket_conf_t *skcf,
-    nxt_conf_value_t *conf_cmds, nxt_bool_t last)
+    nxt_tls_init_t *tls_init, nxt_bool_t last)
 {
     nxt_router_tlssock_t  *tls;
 
@@ -1865,8 +1887,8 @@ nxt_router_conf_tls_insert(nxt_router_temp_conf_t *tmcf,
         return NXT_ERROR;
     }
 
+    tls->tls_init = tls_init;
     tls->socket_conf = skcf;
-    tls->conf_cmds = conf_cmds;
     tls->temp_conf = tmcf;
     tls->last = last;
     nxt_conf_get_string(value, &tls->name);
@@ -2467,6 +2489,8 @@ nxt_router_tls_rpc_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg,
         tlscf = tls->socket_conf->tls;
     }
 
+    tls->tls_init->conf = tlscf;
+
     bundle = nxt_mp_get(mp, sizeof(nxt_tls_bundle_conf_t));
     if (nxt_slow_path(bundle == NULL)) {
         goto fail;
@@ -2480,8 +2504,8 @@ nxt_router_tls_rpc_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg,
     bundle->next = tlscf->bundle;
     tlscf->bundle = bundle;
 
-    ret = task->thread->runtime->tls->server_init(task, tlscf, mp,
-                                                  tls->conf_cmds, tls->last);
+    ret = task->thread->runtime->tls->server_init(task, mp, tls->tls_init,
+                                                  tls->last);
     if (nxt_slow_path(ret != NXT_OK)) {
         goto fail;
     }
diff --git a/src/nxt_tls.h b/src/nxt_tls.h
index 63c49ee4..a92f1c21 100644
--- a/src/nxt_tls.h
+++ b/src/nxt_tls.h
@@ -28,14 +28,14 @@
 
 typedef struct nxt_tls_conf_s         nxt_tls_conf_t;
 typedef struct nxt_tls_bundle_conf_s  nxt_tls_bundle_conf_t;
+typedef struct nxt_tls_init_s         nxt_tls_init_t;
 
 typedef struct {
     nxt_int_t                     (*library_init)(nxt_task_t *task);
     void                          (*library_free)(nxt_task_t *task);
 
-    nxt_int_t                     (*server_init)(nxt_task_t *task,
-                                      nxt_tls_conf_t *conf, nxt_mp_t *mp,
-                                      nxt_conf_value_t *conf_cmds,
+    nxt_int_t                     (*server_init)(nxt_task_t *task, nxt_mp_t *mp,
+                                      nxt_tls_init_t *tls_init,
                                       nxt_bool_t last);
     void                          (*server_free)(nxt_task_t *task,
                                       nxt_tls_conf_t *conf);
@@ -78,6 +78,15 @@ struct nxt_tls_conf_s {
 };
 
 
+struct nxt_tls_init_s {
+    size_t                        cache_size;
+    nxt_time_t                    timeout;
+    nxt_conf_value_t              *conf_cmds;
+
+    nxt_tls_conf_t                *conf;
+};
+
+
 #if (NXT_HAVE_OPENSSL)
 extern const nxt_tls_lib_t        nxt_openssl_lib;