root/lang/csharp/Misuzilla.Build.Tasks.Hash/Misuzilla.Build.Tasks.Hash/HashTask.cs

// $Id$
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Build.Framework;
using System.Security.Cryptography;
using System.IO;

namespace Misuzilla.Build.Tasks.Hash
{
    public abstract class HashTask : Microsoft.Build.Utilities.Task
    {
        private ITaskItem[] _files;

        public abstract HashAlgorithm HashAlgorithm { get; }
        public abstract String HashAlgorithmName { get; }

        [Required]
        public ITaskItem[] Files
        {
            get { return _files; }
            set { _files = value; }
        }

        public override bool Execute()
        {
            foreach (ITaskItem item in _files)
            {
                if (item.ItemSpec.Length > 0)
                {
                    try
                    {
                        Log.LogMessage("Generate " + Path.GetFileName(item.ItemSpec + "." + HashAlgorithmName.ToLower()));
                        WriteHash(item.ItemSpec);
                    }
                    catch (IOException e)
                    {
                        Log.LogError(e.Message);
                        return false;
                    }
                }
            }
            return true;
        }

        private void WriteHash(String path)
        {
            using (FileStream fsTarget = new FileStream(path, FileMode.Open, FileAccess.Read))
            using (StreamWriter swHash = new StreamWriter(path + "." + HashAlgorithmName.ToLower(), false))
            {
                Byte[] hash = HashAlgorithm.ComputeHash(fsTarget);
                swHash.Write("{0}({1})= ", HashAlgorithmName, Path.GetFileName(path));
                foreach (Byte b in hash)
                    swHash.Write("{0:x2}", b);
            }
        }
    }
}