From 4b4f883aef8fbc4f8a8b6c842df61eb0d5253f45 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 11 Nov 2018 22:33:31 -0500
Subject: csrng: Use std::mt19937 engine for random number generation

---
 src/core/hle/service/spl/module.cpp | 9 +++++++--
 src/core/hle/service/spl/module.h   | 4 ++++
 2 files changed, 11 insertions(+), 2 deletions(-)

(limited to 'src/core')

diff --git a/src/core/hle/service/spl/module.cpp b/src/core/hle/service/spl/module.cpp
index 44a6717d0..69c260408 100644
--- a/src/core/hle/service/spl/module.cpp
+++ b/src/core/hle/service/spl/module.cpp
@@ -3,18 +3,23 @@
 // Refer to the license.txt file included.
 
 #include <algorithm>
+#include <chrono>
 #include <cstdlib>
+#include <ctime>
+#include <functional>
 #include <vector>
 #include "common/logging/log.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/service/spl/csrng.h"
 #include "core/hle/service/spl/module.h"
 #include "core/hle/service/spl/spl.h"
+#include "core/settings.h"
 
 namespace Service::SPL {
 
 Module::Interface::Interface(std::shared_ptr<Module> module, const char* name)
-    : ServiceFramework(name), module(std::move(module)) {}
+    : ServiceFramework(name), module(std::move(module)),
+      rng(Settings::values.rng_seed.value_or(std::time(nullptr))) {}
 
 Module::Interface::~Interface() = default;
 
@@ -24,7 +29,7 @@ void Module::Interface::GetRandomBytes(Kernel::HLERequestContext& ctx) {
     std::size_t size = ctx.GetWriteBufferSize();
 
     std::vector<u8> data(size);
-    std::generate(data.begin(), data.end(), std::rand);
+    std::generate(data.begin(), data.end(), rng);
 
     ctx.WriteBuffer(data);
 
diff --git a/src/core/hle/service/spl/module.h b/src/core/hle/service/spl/module.h
index 48fda6099..afa1f0295 100644
--- a/src/core/hle/service/spl/module.h
+++ b/src/core/hle/service/spl/module.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <random>
 #include "core/hle/service/service.h"
 
 namespace Service::SPL {
@@ -19,6 +20,9 @@ public:
 
     protected:
         std::shared_ptr<Module> module;
+
+    private:
+        std::mt19937 rng;
     };
 };
 
-- 
cgit v1.2.3


From 2a16fd7ffc1ec4e2dc90480c04f9867fdeec6a98 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 11 Nov 2018 22:34:23 -0500
Subject: settings: Add config option to set RNG seed

---
 src/core/settings.h | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'src/core')

diff --git a/src/core/settings.h b/src/core/settings.h
index a8954647f..83a1a7069 100644
--- a/src/core/settings.h
+++ b/src/core/settings.h
@@ -6,6 +6,7 @@
 
 #include <array>
 #include <atomic>
+#include <optional>
 #include <string>
 #include "common/common_types.h"
 
@@ -114,6 +115,7 @@ struct Values {
     // System
     bool use_docked_mode;
     bool enable_nfc;
+    std::optional<u64> rng_seed;
     s32 current_user;
     s32 language_index;
 
-- 
cgit v1.2.3


From cb1e63ef09a5cd775e916f6f4482cde3ea256f44 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Mon, 12 Nov 2018 21:46:21 -0500
Subject: svc: Return random seed for svcGetInfo RandomEntropy

---
 src/core/hle/kernel/svc.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'src/core')

diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index 7e8e87c33..0bfe1e3be 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -34,6 +34,7 @@
 #include "core/hle/lock.h"
 #include "core/hle/result.h"
 #include "core/hle/service/service.h"
+#include "core/settings.h"
 
 namespace Kernel {
 namespace {
@@ -558,7 +559,7 @@ static ResultCode GetInfo(u64* result, u64 info_id, u64 handle, u64 info_sub_id)
         *result = 0;
         break;
     case GetInfoType::RandomEntropy:
-        *result = 0;
+        *result = Settings::values.rng_seed.value_or(0);
         break;
     case GetInfoType::ASLRRegionBaseAddr:
         *result = vm_manager.GetASLRRegionBaseAddress();
-- 
cgit v1.2.3