Added crypto random-number generator

crypto/random_unittest.cc

+// Copyright (c) 2012 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.
+
+#include "crypto/random.h"
+
+#include "base/string_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Basic functionality tests. Does NOT test the security of the random data.
+
+// Ensures we don't have all trivial data, i.e. that the data is indeed random.
+// Currently, that means the bytes cannot be all the same (e.g. all zeros).
+bool IsTrivial(const std::string& bytes) {
+  for (size_t i = 0; i < bytes.size(); i++) {
+    if (bytes[i] != bytes[0]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+TEST(RandBytes, RandBytes) {
+  std::string bytes(16, '\0');
+  crypto::RandBytes(WriteInto(&bytes, bytes.size()), bytes.size());
+  EXPECT_TRUE(!IsTrivial(bytes));
+}