TEST_F(ConfigTests, test_config_parser) {
// Register a config parser plugin.
Registry::add<TestConfigParserPlugin>("config_parser", "test");
Registry::get("config_parser", "test")->setUp();
{
// Access the parser's data without having updated the configuration.
ConfigDataInstance config;
const auto& test_data = config.getParsedData("test");
// Expect the setUp method to have run and set blank defaults.
// Accessing an invalid property tree key will abort.
ASSERT_EQ(test_data.get_child("dictionary").count(""), 0);
}
// Update or load the config, expect the parser to be called.
Config::update(
{{"source1",
"{\"dictionary\": {\"key1\": \"value1\"}, \"list\": [\"first\"]}"}});
ASSERT_TRUE(TestConfigParserPlugin::update_called);
{
// Now access the parser's data AFTER updating the config (no longer blank)
ConfigDataInstance config;
const auto& test_data = config.getParsedData("test");
// Expect a value that existed in the configuration.
EXPECT_EQ(test_data.count("dictionary"), 1);
EXPECT_EQ(test_data.get("dictionary.key1", ""), "value1");
// Expect a value for every key the parser requested.
// Every requested key will be present, event if the key's tree is empty.
EXPECT_EQ(test_data.count("dictionary2"), 1);
// Expect the parser-created data item.
EXPECT_EQ(test_data.count("dictionary3"), 1);
EXPECT_EQ(test_data.get("dictionary3.key2", ""), "value2");
}
// Update from a secondary source into a dictionary.
// Expect that the keys in the top-level dictionary are merged.
Config::update({{"source2", "{\"dictionary\": {\"key3\": \"value3\"}}"}});
// Update from a third source into a list.
// Expect that the items from each source in the top-level list are merged.
Config::update({{"source3", "{\"list\": [\"second\"]}"}});
{
ConfigDataInstance config;
const auto& test_data = config.getParsedData("test");
EXPECT_EQ(test_data.count("dictionary"), 1);
EXPECT_EQ(test_data.get("dictionary.key1", ""), "value1");
EXPECT_EQ(test_data.get("dictionary.key3", ""), "value3");
EXPECT_EQ(test_data.count("list"), 1);
EXPECT_EQ(test_data.get_child("list").count(""), 2);
}
}
Status YARAEventSubscriber::init() {
Status status;
ConfigDataInstance config;
const auto& yara_config = config.getParsedData("yara");
if (yara_config.count("file_paths") == 0)
return Status(0, "OK");
const auto& yara_paths = yara_config.get_child("file_paths");
const auto& file_map = config.files();
for (const auto& yara_path_element : yara_paths) {
// Subscribe to each file for the given key (category).
if (file_map.count(yara_path_element.first) == 0) {
VLOG(1) << "Key in yara.file_paths not found in file_paths: "
<< yara_path_element.first;
continue;
}
for (const auto& file : file_map.at(yara_path_element.first)) {
VLOG(1) << "Added YARA listener to: " << file;
auto mc = createSubscriptionContext();
mc->path = file;
mc->mask = FILE_CHANGE_MASK;
mc->recursive = true;
subscribe(&YARAEventSubscriber::Callback,
mc,
(void*)(&yara_path_element.first));
}
}
return Status(0, "OK");
}
Status YARAEventSubscriber::Callback(const FileEventContextRef& ec,
const void* user_data) {
if (user_data == nullptr) {
return Status(1, "No YARA category string provided");
}
if (ec->action != "UPDATED" && ec->action != "CREATED") {
return Status(1, "Invalid action");
}
Row r;
r["action"] = ec->action;
r["target_path"] = ec->path;
r["category"] = *(std::string*)user_data;
// Only FSEvents transactions updates (inotify is a no-op).
r["transaction_id"] = INTEGER(ec->transaction_id);
// These are default values, to be updated in YARACallback.
r["count"] = INTEGER(0);
r["matches"] = std::string("");
r["strings"] = std::string("");
r["tags"] = std::string("");
ConfigDataInstance config;
const auto& parser = config.getParser("yara");
if (parser == nullptr)
return Status(1, "ConfigParser unknown.");
const auto& yaraParser = std::static_pointer_cast<YARAConfigParserPlugin>(parser);
auto rules = yaraParser->rules();
// Use the category as a lookup into the yara file_paths. The value will be
// a list of signature groups to scan with.
auto category = r.at("category");
const auto& yara_config = config.getParsedData("yara");
const auto& yara_paths = yara_config.get_child("file_paths");
const auto& sig_groups = yara_paths.find(category);
for (const auto& rule : sig_groups->second) {
const std::string group = rule.second.data();
int result = yr_rules_scan_file(rules[group],
ec->path.c_str(),
SCAN_FLAGS_FAST_MODE,
YARACallback,
(void*)&r,
0);
if (result != ERROR_SUCCESS) {
return Status(1, "YARA error: " + std::to_string(result));
}
}
if (ec->action != "" && r.at("matches").size() > 0) {
add(r, ec->time);
}
return Status(0, "OK");
}
