Add unit test for crypto_prng class

Builds/VisualStudio2015/RippleD.vcxproj

@@ -4415,6 +4415,10 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='debug|x64'">True</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='release|x64'">True</ExcludedFromBuild>
     </ClCompile>
+    <ClCompile Include="..\..\src\test\core\CryptoPRNG_test.cpp">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='debug|x64'">True</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='release|x64'">True</ExcludedFromBuild>
+    </ClCompile>
     <ClCompile Include="..\..\src\test\core\DeadlineTimer_test.cpp">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='debug|x64'">True</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='release|x64'">True</ExcludedFromBuild>

Builds/VisualStudio2015/RippleD.vcxproj.filters

@@ -5160,6 +5160,9 @@
     <ClCompile Include="..\..\src\test\core\Coroutine_test.cpp">
       <Filter>test\core</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\test\core\CryptoPRNG_test.cpp">
+      <Filter>test\core</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\test\core\DeadlineTimer_test.cpp">
       <Filter>test\core</Filter>
     </ClCompile>

src/test/core/CryptoPRNG_test.cpp

@@ -0,0 +1,125 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012-2017 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <test/jtx/Env.h>
+#include <ripple/beast/utility/temp_dir.h>
+#include <ripple/crypto/csprng.h>
+#include <boost/filesystem.hpp>
+#include <fstream>
+#include <streambuf>
+
+namespace ripple {
+
+class CryptoPRNG_test : public beast::unit_test::suite
+{
+    void
+    testGetValues()
+    {
+        testcase ("Get Values");
+        try
+        {
+            auto& engine = crypto_prng();
+            auto rand_val = engine();
+            BEAST_EXPECT(rand_val >= engine.min());
+            BEAST_EXPECT(rand_val <= engine.max());
+
+            uint16_t twoByte {0};
+            engine(&twoByte, sizeof(uint16_t));
+            pass();
+        }
+        catch(std::exception&)
+        {
+            fail();
+        }
+    }
+
+    void
+    testSaveLoad()
+    {
+        testcase ("Save/Load State");
+        try
+        {
+            // create a temporary path to write crypto state files
+            beast::temp_dir td;
+
+            auto stateFile = boost::filesystem::path {td.file("cryptostate")};
+            auto& engine = crypto_prng();
+            engine.save_state(stateFile.string());
+
+            size_t size_before_load;
+            std::string data_before_load, data_after_load;
+
+            {
+                boost::system::error_code ec;
+                size_before_load = file_size(stateFile, ec);
+                if(! BEAST_EXPECTS(!ec, ec.message()))
+                    return;
+                if(! BEAST_EXPECT(size_before_load > 0))
+                    return;
+
+                std::ifstream ifs(
+                    stateFile.string(),
+                    std::ios::in | std::ios::binary);
+                data_before_load =
+                    std::string{std::istreambuf_iterator<char>{ifs}, {}};
+                BEAST_EXPECT(data_before_load.size() == size_before_load);
+            }
+
+            engine.load_state(stateFile.string());
+
+            // load_state actually causes a new state file to be written
+            // ...verify it has changed
+
+            {
+                boost::system::error_code ec;
+                size_t size_after_load = file_size(stateFile, ec);
+                if(! BEAST_EXPECTS(!ec, ec.message()))
+                    return;
+                BEAST_EXPECT(size_after_load == size_before_load);
+
+                std::ifstream ifs(
+                    stateFile.string(),
+                    std::ios::in | std::ios::binary);
+                data_after_load =
+                    std::string{std::istreambuf_iterator<char>{ifs}, {}};
+                BEAST_EXPECT(data_after_load.size() == size_after_load);
+                BEAST_EXPECT(data_after_load != data_before_load);
+            }
+
+            // verify the loaded engine works
+            engine();
+            pass();
+        }
+        catch(std::exception&)
+        {
+            fail();
+        }
+    }
+
+public:
+    void run ()
+    {
+        testGetValues();
+        testSaveLoad();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE (CryptoPRNG, core, ripple);
+
+}  // ripple

src/test/unity/core_test_unity.cpp

@@ -20,6 +20,7 @@
 
 #include <test/core/Config_test.cpp>
 #include <test/core/Coroutine_test.cpp>
+#include <test/core/CryptoPRNG_test.cpp>
 #include <test/core/DeadlineTimer_test.cpp>
 #include <test/core/JobCounter_test.cpp>
 #include <test/core/SociDB_test.cpp>