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 "base/strings/string_util.h"
10 #include "testing/gtest/include/gtest/gtest.h"
11 
12 // Basic functionality tests. Does NOT test the security of the random data.
13 
14 // Ensures we don't have all trivial data, i.e. that the data is indeed random.
15 // Currently, that means the bytes cannot be all the same (e.g. all zeros).
IsTrivial(const std::string & bytes)16 bool IsTrivial(const std::string& bytes) {
17   for (size_t i = 0; i < bytes.size(); i++) {
18     if (bytes[i] != bytes[0]) {
19       return false;
20     }
21   }
22   return true;
23 }
24 
TEST(RandBytes,RandBytes)25 TEST(RandBytes, RandBytes) {
26   std::string bytes(16, '\0');
27   crypto::RandBytes(base::WriteInto(&bytes, bytes.size()), bytes.size());
28   EXPECT_TRUE(!IsTrivial(bytes));
29 }
30