1 files changed, 39 insertions, 0 deletions
diff --git a/toolkit/components/resistfingerprinting/RelativeTimeline.cpp b/toolkit/components/resistfingerprinting/RelativeTimeline.cpp
new file mode 100644
index 0000000000..eca7fca975
--- /dev/null
+++ b/toolkit/components/resistfingerprinting/RelativeTimeline.cpp
@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsCOMPtr.h"
+#include "nsIRandomGenerator.h"
+#include "nsServiceManagerUtils.h"
+
+#include "RelativeTimeline.h"
+
+namespace mozilla {
+
+int64_t RelativeTimeline::GetRandomTimelineSeed() {
+  if (mRandomTimelineSeed == 0) {
+    nsresult rv;
+    nsCOMPtr<nsIRandomGenerator> randomGenerator =
+        do_GetService("@mozilla.org/security/random-generator;1", &rv);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      mRandomTimelineSeed = rand();
+      return mRandomTimelineSeed;
+    }
+
+    uint8_t* buffer = nullptr;
+    rv = randomGenerator->GenerateRandomBytes(sizeof(mRandomTimelineSeed),
+                                              &buffer);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      mRandomTimelineSeed = rand();
+      return mRandomTimelineSeed;
+    }
+
+    memcpy(&mRandomTimelineSeed, buffer, sizeof(mRandomTimelineSeed));
+    MOZ_ASSERT(buffer);
+    free(buffer);
+  }
+  return mRandomTimelineSeed;
+}
+
+}  // namespace mozilla