From b30640d74939a93ec5f3e218aa5c89f3210c2f67 Mon Sep 17 00:00:00 2001
From: Starlet <gpyron@mail.com>
Date: Tue, 3 Jul 2018 12:10:35 -0400
Subject: [PATCH] Implement CSRNG (Cryptographically Secure Random Bytes)

---
 Ryujinx.HLE/OsHle/Services/ServiceFactory.cs  |  4 ++
 .../OsHle/Services/Spl/IRandomInterface.cs    | 38 +++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 Ryujinx.HLE/OsHle/Services/Spl/IRandomInterface.cs

diff --git a/Ryujinx.HLE/OsHle/Services/ServiceFactory.cs b/Ryujinx.HLE/OsHle/Services/ServiceFactory.cs
index 914c84490d..b69fc9f884 100644
--- a/Ryujinx.HLE/OsHle/Services/ServiceFactory.cs
+++ b/Ryujinx.HLE/OsHle/Services/ServiceFactory.cs
@@ -18,6 +18,7 @@ using Ryujinx.HLE.OsHle.Services.Prepo;
 using Ryujinx.HLE.OsHle.Services.Set;
 using Ryujinx.HLE.OsHle.Services.Sfdnsres;
 using Ryujinx.HLE.OsHle.Services.Sm;
+using Ryujinx.HLE.OsHle.Services.Spl;
 using Ryujinx.HLE.OsHle.Services.Ssl;
 using Ryujinx.HLE.OsHle.Services.Vi;
 using System;
@@ -66,6 +67,9 @@ namespace Ryujinx.HLE.OsHle.Services
                 case "caps:ss":
                     return new IScreenshotService();
 
+                case "csrng":
+                    return new IRandomInterface();
+
                 case "friend:a":
                     return new IServiceCreator();
 
diff --git a/Ryujinx.HLE/OsHle/Services/Spl/IRandomInterface.cs b/Ryujinx.HLE/OsHle/Services/Spl/IRandomInterface.cs
new file mode 100644
index 0000000000..b534f150fa
--- /dev/null
+++ b/Ryujinx.HLE/OsHle/Services/Spl/IRandomInterface.cs
@@ -0,0 +1,38 @@
+using Ryujinx.HLE.OsHle.Ipc;
+using System.Collections.Generic;
+using System.Security.Cryptography;
+
+namespace Ryujinx.HLE.OsHle.Services.Spl
+{
+    class IRandomInterface : IpcService
+    {
+        private Dictionary<int, ServiceProcessRequest> m_Commands;
+
+        public override IReadOnlyDictionary<int, ServiceProcessRequest> Commands => m_Commands;
+
+        private RNGCryptoServiceProvider CspRnd;
+
+        public IRandomInterface()
+        {
+            m_Commands = new Dictionary<int, ServiceProcessRequest>()
+            {
+                { 0, GetRandomBytes }
+            };
+
+            CspRnd = new RNGCryptoServiceProvider();
+        }
+
+        public long GetRandomBytes(ServiceCtx Context)
+        {
+            (long Position, long Size) = Context.Request.GetBufferType0x21();
+
+            byte[] BytesBuffer = new byte[Size];
+
+            CspRnd.GetBytes(BytesBuffer);
+
+            Context.Memory.WriteBytes(Position, BytesBuffer);
+
+            return 0;
+        }
+    }
+}
\ No newline at end of file