Implement CSRNG (Cryptographically Secure Random Bytes) (#216)

* Implement CSRNG (Cryptographically Secure Random Bytes)

* Compliant with review.

* Dispose Rng

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();
 

Ryujinx.HLE/OsHle/Services/Spl/IRandomInterface.cs

@@ -0,0 +1,50 @@
+using Ryujinx.HLE.OsHle.Ipc;
+using System;
+using System.Collections.Generic;
+using System.Security.Cryptography;
+
+namespace Ryujinx.HLE.OsHle.Services.Spl
+{
+    class IRandomInterface : IpcService, IDisposable
+    {
+        private Dictionary<int, ServiceProcessRequest> m_Commands;
+
+        public override IReadOnlyDictionary<int, ServiceProcessRequest> Commands => m_Commands;
+
+        private RNGCryptoServiceProvider Rng;
+
+        public IRandomInterface()
+        {
+            m_Commands = new Dictionary<int, ServiceProcessRequest>()
+            {
+                { 0, GetRandomBytes }
+            };
+
+            Rng = new RNGCryptoServiceProvider();
+        }
+
+        public long GetRandomBytes(ServiceCtx Context)
+        {
+            byte[] RandomBytes = new byte[Context.Request.ReceiveBuff[0].Size];
+
+            Rng.GetBytes(RandomBytes);
+
+            Context.Memory.WriteBytes(Context.Request.ReceiveBuff[0].Position, RandomBytes);
+
+            return 0;
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        protected virtual void Dispose(bool Disposing)
+        {
+            if (Disposing)
+            {
+                Rng.Dispose();
+            }
+        }
+    }
+}