From 83fe87cc13b4dd6285fbc15465c7bd39fdadb53d Mon Sep 17 00:00:00 2001
From: Jack Lloyd <lloyd@randombit.net>
Date: Thu, 15 Oct 2015 09:28:25 -0400
Subject: Add System_RNG which is an instantiatable RNG that uses the system
 RNG

Previously you couldn't have an unique_ptr<RNG> that might point to
either a system rng or an autoseed rng depending on availability. That
was already needed in ffi and is useful elsewhere.
---
 src/lib/ffi/ffi.cpp                   | 17 +----------------
 src/lib/rng/system_rng/system_rng.cpp | 16 ++++++++--------
 src/lib/rng/system_rng/system_rng.h   | 25 ++++++++++++++++++++++++-
 3 files changed, 33 insertions(+), 25 deletions(-)

(limited to 'src/lib')

diff --git a/src/lib/ffi/ffi.cpp b/src/lib/ffi/ffi.cpp
index 27dcc6015..978a76c0f 100644
--- a/src/lib/ffi/ffi.cpp
+++ b/src/lib/ffi/ffi.cpp
@@ -228,21 +228,6 @@ int botan_hex_encode(const uint8_t* in, size_t len, char* out, uint32_t flags)
 
 int botan_rng_init(botan_rng_t* rng_out, const char* rng_type)
    {
-   // Just gives unique_ptr something to delete, really
-   class RNG_Wrapper : public Botan::RandomNumberGenerator
-      {
-      public:
-         RNG_Wrapper(Botan::RandomNumberGenerator& rng) : m_rng(rng) {}
-         void randomize(Botan::byte out[], size_t len) override { m_rng.randomize(out, len); }
-         bool is_seeded() const override { return m_rng.is_seeded(); }
-         void clear() override { m_rng.clear(); }
-         std::string name() const override { return m_rng.name(); }
-         void reseed(size_t poll_bits = 256) override { m_rng.reseed(poll_bits); }
-         void add_entropy(const Botan::byte in[], size_t len) override { m_rng.add_entropy(in, len); }
-      private:
-         Botan::RandomNumberGenerator& m_rng;
-      };
-
    try
       {
       BOTAN_ASSERT_ARG_NON_NULL(rng_out);
@@ -255,7 +240,7 @@ int botan_rng_init(botan_rng_t* rng_out, const char* rng_type)
       std::unique_ptr<Botan::RandomNumberGenerator> rng;
 
       if(rng_type_s == "system")
-         rng.reset(new RNG_Wrapper(Botan::system_rng()));
+         rng.reset(new Botan::System_RNG);
       else if(rng_type_s == "user")
          rng.reset(new Botan::AutoSeeded_RNG);
 
diff --git a/src/lib/rng/system_rng/system_rng.cpp b/src/lib/rng/system_rng/system_rng.cpp
index 1ab80669b..8b949d071 100644
--- a/src/lib/rng/system_rng/system_rng.cpp
+++ b/src/lib/rng/system_rng/system_rng.cpp
@@ -1,6 +1,6 @@
 /*
 * System RNG
-* (C) 2014 Jack Lloyd
+* (C) 2014,2015 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -28,11 +28,11 @@ namespace Botan {
 
 namespace {
 
-class System_RNG : public RandomNumberGenerator
+class System_RNG_Impl : public RandomNumberGenerator
    {
    public:
-      System_RNG();
-      ~System_RNG();
+      System_RNG_Impl();
+      ~System_RNG_Impl();
 
       void randomize(byte buf[], size_t len) override;
 
@@ -51,7 +51,7 @@ class System_RNG : public RandomNumberGenerator
 #endif
    };
 
-System_RNG::System_RNG()
+System_RNG_Impl::System_RNG_Impl()
    {
 #if defined(BOTAN_TARGET_OS_HAS_CRYPTGENRANDOM)
 
@@ -66,7 +66,7 @@ System_RNG::System_RNG()
 #endif
    }
 
-System_RNG::~System_RNG()
+System_RNG_Impl::~System_RNG_Impl()
    {
 #if defined(BOTAN_TARGET_OS_HAS_CRYPTGENRANDOM)
    ::CryptReleaseContext(m_prov, 0);
@@ -76,7 +76,7 @@ System_RNG::~System_RNG()
 #endif
    }
 
-void System_RNG::randomize(byte buf[], size_t len)
+void System_RNG_Impl::randomize(byte buf[], size_t len)
    {
 #if defined(BOTAN_TARGET_OS_HAS_CRYPTGENRANDOM)
    ::CryptGenRandom(m_prov, static_cast<DWORD>(len), buf);
@@ -104,7 +104,7 @@ void System_RNG::randomize(byte buf[], size_t len)
 
 RandomNumberGenerator& system_rng()
    {
-   static System_RNG g_system_rng;
+   static System_RNG_Impl g_system_rng;
    return g_system_rng;
    }
 
diff --git a/src/lib/rng/system_rng/system_rng.h b/src/lib/rng/system_rng/system_rng.h
index cac861618..0f4b94725 100644
--- a/src/lib/rng/system_rng/system_rng.h
+++ b/src/lib/rng/system_rng/system_rng.h
@@ -1,6 +1,6 @@
 /*
 * System RNG interface
-* (C) 2014 Jack Lloyd
+* (C) 2014,2015 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -19,6 +19,29 @@ namespace Botan {
 */
 BOTAN_DLL RandomNumberGenerator& system_rng();
 
+/*
+* Instantiatable reference to the system RNG.
+*/
+class BOTAN_DLL System_RNG : public RandomNumberGenerator
+   {
+   public:
+      System_RNG() : m_rng(system_rng()) {}
+
+      void randomize(Botan::byte out[], size_t len) override { m_rng.randomize(out, len); }
+
+      bool is_seeded() const override { return m_rng.is_seeded(); }
+
+      void clear() override { m_rng.clear(); }
+
+      std::string name() const override { return m_rng.name(); }
+
+      void reseed(size_t poll_bits = 256) override { m_rng.reseed(poll_bits); }
+
+      void add_entropy(const byte in[], size_t len) override { m_rng.add_entropy(in, len); }
+   private:
+      Botan::RandomNumberGenerator& m_rng;
+   };
+
 }
 
 #endif
-- 
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