code.grnet.gr Git - pithos-ms-client/blob - trunk/NetSparkle/NetSparkleDSAVerificator.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Linq;
   4 using System.Text;
   5 using System.IO;
   6 using System.Reflection;
   7 using System.Security.Cryptography;
   8
   9 namespace AppLimit.NetSparkle
  10 {
  11     public class NetSparkleDSAVerificator
  12     {
  13         private DSACryptoServiceProvider _provider;
  14
  15         public static Boolean ExistsPublicKey(String publicKey)
  16         {
  17                 // 1. try to load this from resource
  18             Stream data = TryGetResourceStream(publicKey);
  19             if (data == null )
  20                 data = TryGetFileResource(publicKey, data);
  21
  22             // 2. check the resource
  23             if (data == null)
  24                 return false;
  25             else
  26                 return true;
  27         }
  28
  29         public NetSparkleDSAVerificator(String publicKey)
  30         {
  31             // 1. try to load this from resource
  32             Stream data = TryGetResourceStream(publicKey);
  33             if (data == null )
  34                 data = TryGetFileResource(publicKey, data);
  35
  36             // 2. check the resource
  37             if ( data == null )
  38                 throw new Exception("Couldn't find public key for verification");
  39
  40             // 3. read out the key value
  41             using (StreamReader reader = new StreamReader(data))
  42             {
  43                     String key = reader.ReadToEnd();
  44                     _provider = new DSACryptoServiceProvider();
  45                     _provider.FromXmlString(key);
  46             }
  47         }
  48
  49         public Boolean VerifyDSASignature(String signature, String binaryPath)
  50         {
  51             if (_provider == null)
  52                 return false;
  53
  54             // convert signature
  55             Byte[] bHash = Convert.FromBase64String(signature);
  56
  57             // read the data
  58             byte[] bData = null;
  59             using (Stream inputStream = File.OpenRead(binaryPath))
  60             {
  61                 bData = new Byte[inputStream.Length];
  62                 inputStream.Read(bData, 0, bData.Length);
  63             }
  64
  65             // verify
  66             return _provider.VerifyData(bData, bHash);
  67         }
  68
  69         private static Stream TryGetFileResource(String publicKey, Stream data)
  70         {
  71             if (File.Exists(publicKey))
  72             {
  73                 data = File.OpenRead(publicKey);
  74             }
  75             return data;
  76         }
  77
  78         private static Stream TryGetResourceStream(String publicKey)
  79         {
  80             Stream data = null;
  81
  82             foreach (Assembly asm in AppDomain.CurrentDomain.GetAssemblies())
  83             {
  84                 var resourceName = asm.GetManifestResourceNames().FirstOrDefault(s => s.IndexOf(publicKey, StringComparison.OrdinalIgnoreCase) > -1);
  85                 if (!string.IsNullOrEmpty(resourceName))
  86                 {
  87                   data = asm.GetManifestResourceStream(resourceName);
  88                   if (data != null)
  89                     break;
  90                 }
  91             }
  92             return data;
  93         }
  94     }
  95 }