OSCrypt for POSIX uses libsecret to store a randomised encryption key.

components/os_crypt/libsecret_util_linux.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_OS_CRYPT_LIBSECRET_UTIL_POSIX_H_
-#define COMPONENTS_OS_CRYPT_LIBSECRET_UTIL_POSIX_H_
+#ifndef COMPONENTS_OS_CRYPT_LIBSECRET_UTIL_LINUX_H_
+#define COMPONENTS_OS_CRYPT_LIBSECRET_UTIL_LINUX_H_
 
 #include <libsecret/secret.h>
 
 #include <list>
 #include <string>
 
 #include "base/macros.h"
 
 // Utility for dynamically loading libsecret.
 class LibsecretLoader {
  public:
+  static decltype(&::secret_item_get_attributes) secret_item_get_attributes;
+  static decltype(&::secret_item_get_secret) secret_item_get_secret;
+  static decltype(&::secret_item_load_secret_sync) secret_item_load_secret_sync;
+  static decltype(&::secret_password_clear_sync) secret_password_clear_sync;
   static decltype(&::secret_password_store_sync) secret_password_store_sync;
+  static decltype(&::secret_service_lookup_sync) secret_service_lookup_sync;
   static decltype(&::secret_service_search_sync) secret_service_search_sync;
-  static decltype(&::secret_password_clear_sync) secret_password_clear_sync;
-  static decltype(&::secret_item_get_secret) secret_item_get_secret;
   static decltype(&::secret_value_get_text) secret_value_get_text;
-  static decltype(&::secret_item_get_attributes) secret_item_get_attributes;
-  static decltype(&::secret_item_load_secret_sync) secret_item_load_secret_sync;
   static decltype(&::secret_value_unref) secret_value_unref;
 
   // Loads the libsecret library and checks that it responds to queries.
   // Returns false if either step fails.
   // Repeated calls check the responsiveness every time, but do not load the
   // the library again if already successful.
   static bool EnsureLibsecretLoaded();
 
  protected:
   static bool libsecret_loaded_;
@@ skipping 38 matching lines @@
   // TODO(crbug.com/607950): Make implementation more robust by not depending on
   // the implementation details of containers. External objects keep references
   // to the objects stored in this container. Using a vector here will fail the
   // ASan tests, because it may move the objects and break the references.
   std::list<std::string> name_values_;
   GHashTable* attrs_;
 
   DISALLOW_COPY_AND_ASSIGN(LibsecretAttributesBuilder);
 };
 
-#endif  // COMPONENTS_OS_CRYPT_LIBSECRET_UTIL_POSIX_H_
+#endif  // COMPONENTS_OS_CRYPT_LIBSECRET_UTIL_LINUX_H_