Allow setting the mode of log files

This also sets the appropriate flags in glog

docs/wiki/installation/cli-flags.md

@@ -266,6 +266,12 @@ Enable verbose informational messages.
 
 Directory path for ERROR/WARN/INFO and results logging.
 
+`--logger_mode=640`
+
+File mode for output log files (provided as an octal string).  Note that this
+affects both the query result log and the status logs.
+**Warning**: If run as root, log files may contain sensitive information!
+
 `--value_max=512`
 
 Maximum returned row value size.

osquery/logger/plugins/filesystem.cpp

@@ -18,12 +18,22 @@
 namespace pt = boost::property_tree;
 namespace fs = boost::filesystem;
 
+// This is the mode that glog uses for logfiles.  Must be at the top level
+// (i.e. outside of the `osquery` namespace).
+DECLARE_int32(logfile_mode);
+
 namespace osquery {
 
 FLAG(string,
      logger_path,
      "/var/log/osquery/",
      "Directory path for ERROR/WARN/INFO and results logging");
+
+FLAG(int32,
+     logger_mode,
+     0640,
+     "Mode for log files (default '0640')");
+
 /// Legacy, backward compatible "osquery_log_dir" CLI option.
 FLAG_ALIAS(std::string, osquery_log_dir, logger_path);
 
@@ -51,6 +61,16 @@ REGISTER(FilesystemLoggerPlugin, "logger", "filesystem");
 
 Status FilesystemLoggerPlugin::setUp() {
   log_path_ = fs::path(FLAGS_logger_path);
+
+  // Ensure that the glog status logs use the same mode as our results log.
+  FLAGS_logfile_mode = FLAGS_logger_mode;
+
+  // Ensure that we create the results log here.
+  auto status = logString("");
+  if (!status.ok()) {
+    return status;
+  }
+
   return Status(0, "OK");
 }
 
@@ -62,8 +82,7 @@ Status FilesystemLoggerPlugin::logStringToFile(const std::string& s,
                                                const std::string& filename) {
   std::lock_guard<std::mutex> lock(filesystemLoggerPluginMutex);
   try {
-    // The results log may contain sensitive information if run as root.
-    auto status = writeTextFile((log_path_ / filename).string(), s, 0640, true);
+    auto status = writeTextFile((log_path_ / filename).string(), s, FLAGS_logger_mode, true);
     if (!status.ok()) {
       return status;
     }

third-party

@@ -1 +1 @@
-Subproject commit f5a91963fab9e7b1481c58d55671390e12ce7757
+Subproject commit c9d9d4e7ec1e80a43ee86316ca2fab6ef2fd332c

tools/tests/test_osqueryd.py

@@ -93,5 +93,39 @@ class DaemonTests(test_base.ProcessGenerator, unittest.TestCase):
         acceptable_retcodes = [-1, -2, -1 * signal.SIGINT]
         self.assertTrue(daemon.retcode in acceptable_retcodes)
 
+    def test_6_logger_mode(self):
+        logger_path = os.path.join(test_base.CONFIG_DIR, "logger-mode-tests")
+        os.makedirs(logger_path)
+
+        test_mode = 0754        # Strange mode that should never exist
+        daemon = self._run_daemon({
+            "disable_watchdog": True,
+            "disable_extensions": True,
+            "disable_logging": False,
+        },
+        options_only={
+            "logger_path": logger_path,
+            "logger_mode": test_mode,
+            "verbose": True,
+        })
+        info_path = os.path.join(logger_path, "osqueryd.INFO")
+        self.assertTrue(daemon.isAlive())
+
+        def info_exists():
+            return os.path.exists(info_path)
+        # Wait for the daemon to flush to GLOG.
+        test_base.expectTrue(info_exists)
+
+        # Both log files should exist and have the given mode.
+        for fname in ['osqueryd.INFO', 'osqueryd.results.log']:
+            pth = os.path.join(logger_path, fname)
+            self.assertTrue(os.path.exists(pth))
+
+            rpath = os.path.realpath(info_path)
+            mode = os.stat(rpath).st_mode & 0777
+            self.assertEqual(mode, test_mode)
+
+        daemon.kill()
+
 if __name__ == '__main__':
     test_base.Tester().run()