From 12f6ec16fb5d528bb8b58f0b385fbc741ca96dae Mon Sep 17 00:00:00 2001
From: Piotr Gankiewicz <piotr.gankiewicz@gmail.com>
Date: Fri, 23 Aug 2019 14:56:19 +0200
Subject: [PATCH] Added Blake2Fast lib #816

---
 src/Nethermind/Nethermind.Evm/Metrics.cs      |  1 +
 .../Nethermind.Evm/Nethermind.Evm.csproj      |  1 +
 .../Precompiles/Blake2BPrecompiledContract.cs | 44 +++++++++++++++++++
 .../Nethermind.Evm/VirtualMachine.cs          |  3 +-
 4 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 src/Nethermind/Nethermind.Evm/Precompiles/Blake2BPrecompiledContract.cs

diff --git a/src/Nethermind/Nethermind.Evm/Metrics.cs b/src/Nethermind/Nethermind.Evm/Metrics.cs
index 48c93772bd5..d06428b88e6 100644
--- a/src/Nethermind/Nethermind.Evm/Metrics.cs
+++ b/src/Nethermind/Nethermind.Evm/Metrics.cs
@@ -34,5 +34,6 @@ public class Metrics
         public static long ModExpPrecompile { get; set; }
         public static long Ripemd160Precompile { get; set; }
         public static long Sha256Precompile { get; set; }
+        public static long Blake2BPrecompile { get; set; }
     }
 }
\ No newline at end of file
diff --git a/src/Nethermind/Nethermind.Evm/Nethermind.Evm.csproj b/src/Nethermind/Nethermind.Evm/Nethermind.Evm.csproj
index 7048bab7558..b03f86303a6 100644
--- a/src/Nethermind/Nethermind.Evm/Nethermind.Evm.csproj
+++ b/src/Nethermind/Nethermind.Evm/Nethermind.Evm.csproj
@@ -13,6 +13,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="1.2.2" />
+    <PackageReference Include="SauceControl.Blake2Fast" Version="1.0.0" />
     <PackageReference Include="System.Buffers" Version="4.5.0" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/Nethermind/Nethermind.Evm/Precompiles/Blake2BPrecompiledContract.cs b/src/Nethermind/Nethermind.Evm/Precompiles/Blake2BPrecompiledContract.cs
new file mode 100644
index 00000000000..c1423b0ef0e
--- /dev/null
+++ b/src/Nethermind/Nethermind.Evm/Precompiles/Blake2BPrecompiledContract.cs
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2018 Demerzel Solutions Limited
+ * This file is part of the Nethermind library.
+ *
+ * The Nethermind library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Nethermind library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+using Nethermind.Core;
+using Nethermind.Core.Crypto.ZkSnarks;
+using Nethermind.Core.Extensions;
+using Nethermind.Core.Specs;
+using SauceControl.Blake2Fast;
+
+namespace Nethermind.Evm.Precompiles
+{
+    public class Blake2BPrecompiledContract : IPrecompiledContract
+    {
+        public static readonly IPrecompiledContract Instance = new Blake2BPrecompiledContract();
+        
+        public Address Address { get; } = Address.FromNumber(9);
+
+        public long BaseGasCost(IReleaseSpec releaseSpec) => 0;
+
+        public long DataGasCost(byte[] inputData, IReleaseSpec releaseSpec) => 12;
+
+        public (byte[], bool) Run(byte[] inputData)
+        {
+            Metrics.Blake2BPrecompile++;
+
+            return (inputData, true);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Nethermind/Nethermind.Evm/VirtualMachine.cs b/src/Nethermind/Nethermind.Evm/VirtualMachine.cs
index 3e68ffe5b6a..e87e07e9f4c 100644
--- a/src/Nethermind/Nethermind.Evm/VirtualMachine.cs
+++ b/src/Nethermind/Nethermind.Evm/VirtualMachine.cs
@@ -395,7 +395,8 @@ private void InitializePrecompiledContracts()
                 [Bn128AddPrecompiledContract.Instance.Address] = Bn128AddPrecompiledContract.Instance,
                 [Bn128MulPrecompiledContract.Instance.Address] = Bn128MulPrecompiledContract.Instance,
                 [Bn128PairingPrecompiledContract.Instance.Address] = Bn128PairingPrecompiledContract.Instance,
-                [ModExpPrecompiledContract.Instance.Address] = ModExpPrecompiledContract.Instance
+                [ModExpPrecompiledContract.Instance.Address] = ModExpPrecompiledContract.Instance,
+                [Blake2BPrecompiledContract.Instance.Address] = Blake2BPrecompiledContract.Instance,
             };
         }