From 31d23f226d073d142b10e290ac8ec68e872d7b4e Mon Sep 17 00:00:00 2001
From: Rob Reynolds <ferventcoder@gmail.com>
Date: Sun, 3 May 2015 15:43:12 -0500
Subject: [PATCH] (GH-121) Add hash provider

To compute hashes in files, add a hash provider that can determine
hashes of files.
---
 src/chocolatey/chocolatey.csproj              |  2 +
 .../registration/ContainerBinding.cs          |  3 ++
 .../cryptography/IHashProvider.cs             | 30 +++++++++++++
 .../cryptography/Md5HashProvider.cs           | 42 +++++++++++++++++++
 4 files changed, 77 insertions(+)
 create mode 100644 src/chocolatey/infrastructure/cryptography/IHashProvider.cs
 create mode 100644 src/chocolatey/infrastructure/cryptography/Md5HashProvider.cs

diff --git a/src/chocolatey/chocolatey.csproj b/src/chocolatey/chocolatey.csproj
index 18b9ede0fa..fcb6693aec 100644
--- a/src/chocolatey/chocolatey.csproj
+++ b/src/chocolatey/chocolatey.csproj
@@ -166,6 +166,8 @@
     <Compile Include="infrastructure\commandline\InteractivePrompt.cs" />
     <Compile Include="infrastructure\commands\ICommandExecutor.cs" />
     <Compile Include="infrastructure\commands\PowershellExecutor.cs" />
+    <Compile Include="infrastructure\cryptography\IHashProvider.cs" />
+    <Compile Include="infrastructure\cryptography\Md5HashProvider.cs" />
     <Compile Include="infrastructure\guards\Ensure.cs" />
     <Compile Include="infrastructure\information\ProcessInformation.cs" />
     <Compile Include="infrastructure\logging\ChocolateyLoggers.cs" />
diff --git a/src/chocolatey/infrastructure.app/registration/ContainerBinding.cs b/src/chocolatey/infrastructure.app/registration/ContainerBinding.cs
index 28fde79390..762607914c 100644
--- a/src/chocolatey/infrastructure.app/registration/ContainerBinding.cs
+++ b/src/chocolatey/infrastructure.app/registration/ContainerBinding.cs
@@ -20,6 +20,7 @@ namespace chocolatey.infrastructure.app.registration
     using SimpleInjector;
     using adapters;
     using commands;
+    using cryptography;
     using events;
     using filesystem;
     using infrastructure.commands;
@@ -28,6 +29,7 @@ namespace chocolatey.infrastructure.app.registration
     using nuget;
     using services;
     using IFileSystem = filesystem.IFileSystem;
+    using IHashProvider = cryptography.IHashProvider;
 
     // ReSharper disable InconsistentNaming
 
@@ -54,6 +56,7 @@ public void RegisterComponents(Container container)
             container.Register<IShimGenerationService, ShimGenerationService>(Lifestyle.Singleton);
             container.Register<IRegistryService, RegistryService>(Lifestyle.Singleton);
             container.Register<IFilesService, FilesService>(Lifestyle.Singleton);
+            container.Register<IHashProvider, Md5HashProvider>(Lifestyle.Singleton);
             container.Register<ITemplateService, TemplateService>(Lifestyle.Singleton);
             container.Register<IChocolateyConfigSettingsService, ChocolateyConfigSettingsService>(Lifestyle.Singleton);
             container.Register<IChocolateyPackageService, ChocolateyPackageService>(Lifestyle.Singleton);
diff --git a/src/chocolatey/infrastructure/cryptography/IHashProvider.cs b/src/chocolatey/infrastructure/cryptography/IHashProvider.cs
new file mode 100644
index 0000000000..5356a05097
--- /dev/null
+++ b/src/chocolatey/infrastructure/cryptography/IHashProvider.cs
@@ -0,0 +1,30 @@
+// Copyright © 2011 - Present RealDimensions Software, LLC
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// 
+// You may obtain a copy of the License at
+// 
+// 	http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+namespace chocolatey.infrastructure.cryptography
+{
+    /// <summary>
+    /// A hash provider for hashing files
+    /// </summary>
+    public interface IHashProvider
+    {
+        /// <summary>
+        /// Returns a hash of the specified file path.
+        /// </summary>
+        /// <param name="filePath">The file path.</param>
+        /// <returns>A computed hash of the file, based on the contents.</returns>
+        string hash_file(string filePath);
+    }
+}
\ No newline at end of file
diff --git a/src/chocolatey/infrastructure/cryptography/Md5HashProvider.cs b/src/chocolatey/infrastructure/cryptography/Md5HashProvider.cs
new file mode 100644
index 0000000000..e15004bc57
--- /dev/null
+++ b/src/chocolatey/infrastructure/cryptography/Md5HashProvider.cs
@@ -0,0 +1,42 @@
+// Copyright © 2011 - Present RealDimensions Software, LLC
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// 
+// You may obtain a copy of the License at
+// 
+// 	http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+namespace chocolatey.infrastructure.cryptography
+{
+    using System;
+    using System.Security.Cryptography;
+    using filesystem;
+
+    public sealed class Md5HashProvider : IHashProvider
+    {
+        private readonly IFileSystem _fileSystem;
+        private readonly MD5 _cryptoProvider;
+
+        public Md5HashProvider(IFileSystem fileSystem)
+        {
+            _fileSystem = fileSystem;
+            _cryptoProvider = MD5.Create();
+        }
+
+        public string hash_file(string filePath)
+        {
+            if (!_fileSystem.file_exists(filePath)) return string.Empty;
+
+            var hash = _cryptoProvider.ComputeHash(_fileSystem.read_file_bytes(filePath));
+
+            return BitConverter.ToString(hash).Replace("-", string.Empty);
+        }
+    }
+}
\ No newline at end of file