Added thirdparty: boost library

thirdparty/include/boost/beast/websocket/detail/prng.ipp

@@ -0,0 +1,151 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_WEBSOCKET_DETAIL_PRNG_IPP
+#define BOOST_BEAST_WEBSOCKET_DETAIL_PRNG_IPP
+
+#include <boost/beast/websocket/detail/prng.hpp>
+#include <boost/beast/core/detail/chacha.hpp>
+#include <boost/beast/core/detail/pcg.hpp>
+#include <atomic>
+#include <cstdlib>
+#include <mutex>
+#include <random>
+
+namespace boost {
+namespace beast {
+namespace websocket {
+namespace detail {
+
+//------------------------------------------------------------------------------
+
+std::uint32_t const*
+prng_seed(std::seed_seq* ss)
+{
+    struct data
+    {
+        std::uint32_t v[8];
+
+        explicit
+        data(std::seed_seq* pss)
+        {
+            if(! pss)
+            {
+                std::random_device g;
+                std::seed_seq ss{
+                    g(), g(), g(), g(),
+                    g(), g(), g(), g()};
+                ss.generate(v, v+8);
+            }
+            else
+            {
+                pss->generate(v, v+8);
+            }
+        }
+    };
+    static data const d(ss);
+    return d.v;
+}
+
+//------------------------------------------------------------------------------
+
+inline
+std::uint32_t
+make_nonce()
+{
+    static std::atomic<std::uint32_t> nonce{0};
+    return ++nonce;
+}
+
+inline
+beast::detail::pcg make_pcg()
+{
+    auto const pv = prng_seed();
+    return beast::detail::pcg{
+        ((static_cast<std::uint64_t>(pv[0])<<32)+pv[1]) ^
+        ((static_cast<std::uint64_t>(pv[2])<<32)+pv[3]) ^
+        ((static_cast<std::uint64_t>(pv[4])<<32)+pv[5]) ^
+        ((static_cast<std::uint64_t>(pv[6])<<32)+pv[7]), make_nonce()};
+}
+
+#ifdef BOOST_NO_CXX11_THREAD_LOCAL
+
+inline
+std::uint32_t
+secure_generate()
+{
+    struct generator
+    {
+        std::uint32_t operator()()
+        {
+            std::lock_guard<std::mutex> guard{mtx};
+            return gen();
+        }
+
+        beast::detail::chacha<20> gen;
+        std::mutex mtx;
+    };
+    static generator gen{beast::detail::chacha<20>{prng_seed(), make_nonce()}};
+    return gen();
+}
+
+inline
+std::uint32_t
+fast_generate()
+{
+    struct generator
+    {
+        std::uint32_t operator()()
+        {
+            std::lock_guard<std::mutex> guard{mtx};
+            return gen();
+        }
+
+        beast::detail::pcg gen;
+        std::mutex mtx;
+    };
+    static generator gen{make_pcg()};
+    return gen();
+}
+
+#else
+
+inline
+std::uint32_t
+secure_generate()
+{
+    thread_local static beast::detail::chacha<20> gen{prng_seed(), make_nonce()};
+    return gen();
+}
+
+inline
+std::uint32_t
+fast_generate()
+{
+    thread_local static beast::detail::pcg gen{make_pcg()};
+    return gen();
+}
+
+#endif
+
+generator
+make_prng(bool secure)
+{
+    if (secure)
+        return &secure_generate;
+    else
+        return &fast_generate;
+}
+
+} // detail
+} // websocket
+} // beast
+} // boost
+
+#endif