Rearrange sources (#4997)

src/libxrpl/crypto/csprng.cpp

@@ -0,0 +1,105 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 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 <ripple/basics/contract.h>
+#include <ripple/crypto/csprng.h>
+#include <array>
+#include <cassert>
+#include <openssl/rand.h>
+#include <random>
+#include <stdexcept>
+
+namespace ripple {
+
+csprng_engine::csprng_engine()
+{
+    // This is not strictly necessary
+    if (RAND_poll() != 1)
+        Throw<std::runtime_error>("CSPRNG: Initial polling failed");
+}
+
+csprng_engine::~csprng_engine()
+{
+    // This cleanup function is not needed in newer versions of OpenSSL
+#if (OPENSSL_VERSION_NUMBER < 0x10100000L)
+    RAND_cleanup();
+#endif
+}
+
+void
+csprng_engine::mix_entropy(void* buffer, std::size_t count)
+{
+    std::array<std::random_device::result_type, 128> entropy;
+
+    {
+        // On every platform we support, std::random_device
+        // is non-deterministic and should provide some good
+        // quality entropy.
+        std::random_device rd;
+
+        for (auto& e : entropy)
+            e = rd();
+    }
+
+    std::lock_guard lock(mutex_);
+
+    // We add data to the pool, but we conservatively assume that
+    // it contributes no actual entropy.
+    RAND_add(
+        entropy.data(),
+        entropy.size() * sizeof(std::random_device::result_type),
+        0);
+
+    if (buffer != nullptr && count != 0)
+        RAND_add(buffer, count, 0);
+}
+
+void
+csprng_engine::operator()(void* ptr, std::size_t count)
+{
+    // RAND_bytes is thread-safe on OpenSSL 1.1.0 and later when compiled
+    // with thread support, so we don't need to grab a mutex.
+    // https://mta.openssl.org/pipermail/openssl-users/2020-November/013146.html
+#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || !defined(OPENSSL_THREADS)
+    std::lock_guard lock(mutex_);
+#endif
+
+    auto const result =
+        RAND_bytes(reinterpret_cast<unsigned char*>(ptr), count);
+
+    if (result != 1)
+        Throw<std::runtime_error>("CSPRNG: Insufficient entropy");
+}
+
+csprng_engine::result_type
+csprng_engine::operator()()
+{
+    result_type ret;
+    (*this)(&ret, sizeof(result_type));
+    return ret;
+}
+
+csprng_engine&
+crypto_prng()
+{
+    static csprng_engine engine;
+    return engine;
+}
+
+}  // namespace ripple