Synnefo » Pithos MS Client

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.IO;

using System.Reflection;

using System.Security.Cryptography;

namespace AppLimit.NetSparkle

{

    public class NetSparkleDSAVerificator

    {

        private DSACryptoServiceProvider _provider;

        public static Boolean ExistsPublicKey(String publicKey)

        {

                // 1. try to load this from resource

            Stream data = TryGetResourceStream(publicKey);

            if (data == null )

                data = TryGetFileResource(publicKey, data);

            // 2. check the resource

            if (data == null)

                return false;

            else

                return true;

        }

        public NetSparkleDSAVerificator(String publicKey)

        {

            // 1. try to load this from resource

            Stream data = TryGetResourceStream(publicKey);

            if (data == null )

                data = TryGetFileResource(publicKey, data);

            // 2. check the resource

            if ( data == null )

                throw new Exception("Couldn't find public key for verification");

            // 3. read out the key value

            using (StreamReader reader = new StreamReader(data))

            {

                    String key = reader.ReadToEnd();

                    _provider = new DSACryptoServiceProvider();

                    _provider.FromXmlString(key);

            }            

        }

        public Boolean VerifyDSASignature(String signature, String binaryPath)

        {

            if (_provider == null)

                return false;

            // convert signature

            Byte[] bHash = Convert.FromBase64String(signature);

            // read the data

            byte[] bData = null;

            using (Stream inputStream = File.OpenRead(binaryPath))

            {

                bData = new Byte[inputStream.Length];

                inputStream.Read(bData, 0, bData.Length);

            }

            // verify

            return _provider.VerifyData(bData, bHash);            

        }

        private static Stream TryGetFileResource(String publicKey, Stream data)

        {

            if (File.Exists(publicKey))

            {

                data = File.OpenRead(publicKey);

            }

            return data;

        }

        private static Stream TryGetResourceStream(String publicKey)

        {

            Stream data = null;

            foreach (Assembly asm in AppDomain.CurrentDomain.GetAssemblies())

            {

                var resourceName = asm.GetManifestResourceNames().FirstOrDefault(s => s.IndexOf(publicKey, StringComparison.OrdinalIgnoreCase) > -1);

                if (!string.IsNullOrEmpty(resourceName))

                {

                  data = asm.GetManifestResourceStream(resourceName);

                  if (data != null)

                    break;

                }

            }

            return data;

        }

    }

}