1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "crypto/random.h"
6 
7 #include <stddef.h>
8 
9 #include <string>
10 
11 #include "base/strings/string_util.h"
12 #include "testing/gtest/include/gtest/gtest.h"
13 
14 // Basic functionality tests. Does NOT test the security of the random data.
15 
16 // Ensures we don't have all trivial data, i.e. that the data is indeed random.
17 // Currently, that means the bytes cannot be all the same (e.g. all zeros).
18 bool IsTrivial(const std::string& bytes) {
19   for (size_t i = 0; i < bytes.size(); i++) {
20     if (bytes[i] != bytes[0]) {
21       return false;
22     }
23   }
24   return true;
25 }
26 
27 TEST(RandBytes, RandBytes) {
28   std::string bytes(16, '\0');
29   crypto::RandBytes(base::WriteInto(&bytes, bytes.size()), bytes.size());
30   EXPECT_TRUE(!IsTrivial(bytes));
31 }
32