[Feature] Support DKIM signing in Lua plugins

diff --git a/src/plugins/dkim_check.c b/src/plugins/dkim_check.c
index 7c00f4e90850524b2a26d9b81ec960c574b04a29..039c12c3f3abe6f556fa1c47b4af21ed029e1da7 100644 (file)
--- a/src/plugins/dkim_check.c
+++ b/src/plugins/dkim_check.c
@@ -88,6 +88,8 @@ static struct dkim_ctx *dkim_module_ctx = NULL;
 static void dkim_symbol_callback (struct rspamd_task *task, void *unused);
 static void dkim_sign_callback (struct rspamd_task *task, void *unused);
 
+static gint lua_dkim_sign_handler (lua_State *L);
+
 /* Initialization */
 gint dkim_module_init (struct rspamd_config *cfg, struct module_ctx **ctx);
 gint dkim_module_config (struct rspamd_config *cfg);
@@ -271,6 +273,22 @@ dkim_module_init (struct rspamd_config *cfg, struct module_ctx **ctx)
                        NULL,
                        0);
 
+        /* Register global methods */
+       lua_getglobal (cfg->lua_state, "rspamd_plugins");
+
+       if (lua_type (cfg->lua_state, -1) == LUA_TTABLE) {
+               lua_pushstring (cfg->lua_state, "dkim");
+               lua_createtable (cfg->lua_state, 0, 1);
+               /* Set methods */
+               lua_pushstring (cfg->lua_state, "sign");
+               lua_pushcfunction (cfg->lua_state, lua_dkim_sign_handler);
+               lua_settable (cfg->lua_state, -3);
+                /* Finish dkim key */
+               lua_settable (cfg->lua_state, -3);
+       }
+
+       lua_pop (cfg->lua_state, 1); /* Remove global function */
+
        return 0;
 }
 
@@ -475,8 +493,8 @@ dkim_module_config (struct rspamd_config *cfg)
 
                if (lua_script) {
                        if (luaL_dostring (cfg->lua_state, lua_script) != 0) {
-                               msg_err_config ("cannot execute lua script for fuzzy "
-                                               "learn condition: %s", lua_tostring (cfg->lua_state, -1));
+                               msg_err_config ("cannot execute lua script for dkim "
+                                               "sign condition: %s", lua_tostring (cfg->lua_state, -1));
                        }
                        else {
                                if (lua_type (cfg->lua_state, -1) == LUA_TFUNCTION) {
@@ -522,6 +540,87 @@ dkim_module_config (struct rspamd_config *cfg)
        return res;
 }
 
+gint
+lua_dkim_sign_handler (lua_State *L)
+{
+       struct rspamd_task *task = lua_check_task (L, 1);
+       luaL_argcheck (L, lua_type (L, 2) == LUA_TTABLE, 2, "'table' expected");
+
+       GError *err = NULL;
+       GString *hdr;
+       const gchar *selector = NULL, *domain = NULL, *key = NULL;
+       rspamd_dkim_sign_context_t *ctx;
+       rspamd_dkim_sign_key_t *dkim_key;
+       /*
+        * Get the following elements:
+        * - selector
+        * - domain
+        * - key
+        */
+       if (!rspamd_lua_parse_table_arguments (L, 2, &err,
+                       "*key=S;*domain=S;*selector=S",
+                       &key, &domain, &selector)) {
+               msg_err_task ("invalid return value from sign condition: %e",
+                               err);
+               g_error_free (err);
+
+               lua_pushboolean (L, FALSE);
+               return 1;
+       }
+
+       if (dkim_module_ctx->dkim_sign_hash == NULL) {
+               dkim_module_ctx->dkim_sign_hash = rspamd_lru_hash_new (
+                               128,
+                               g_free, /* Keys are just C-strings */
+                               (GDestroyNotify)rspamd_dkim_sign_key_unref);
+       }
+
+       dkim_key = rspamd_lru_hash_lookup (dkim_module_ctx->dkim_sign_hash,
+                       key, time (NULL));
+
+       if (dkim_key == NULL) {
+               dkim_key = rspamd_dkim_sign_key_load (key, &err);
+
+               if (dkim_key == NULL) {
+                       msg_err_task ("cannot load dkim key %s: %e",
+                                       key, err);
+                       g_error_free (err);
+
+                       lua_pushboolean (L, FALSE);
+                       return 1;
+               }
+
+               rspamd_lru_hash_insert (dkim_module_ctx->dkim_sign_hash,
+                               g_strdup (key), dkim_key,
+                               time (NULL), 0);
+       }
+
+       ctx = rspamd_create_dkim_sign_context (task, dkim_key,
+                       DKIM_CANON_RELAXED, DKIM_CANON_RELAXED,
+                       dkim_module_ctx->sign_headers, &err);
+
+       if (ctx == NULL) {
+               msg_err_task ("cannot create sign context: %e",
+                               err);
+               g_error_free (err);
+
+               lua_pushboolean (L, FALSE);
+               return 1;
+       }
+
+       hdr = rspamd_dkim_sign (task, selector, domain, 0, 0, ctx);
+
+       if (hdr) {
+               rspamd_mempool_set_variable (task->task_pool, "dkim-signature",
+                               hdr, rspamd_gstring_free_hard);
+               lua_pushboolean (L, TRUE);
+               return 1;
+       }
+
+       lua_pushboolean (L, FALSE);
+       return 1;
+}
+
 gint
 dkim_module_reconfig (struct rspamd_config *cfg)
 {