private static byte[] CryptoTransform(
string fileName, CryptoTransformOperationsEnum operation, SymmetricAlgorithm algo)
{
byte[] orignalFile = File.ReadAllBytes(fileName);
byte[] processedFile;
ICryptoTransform cryptoTransform;
switch (operation)
{
case CryptoTransformOperationsEnum.Encrypt:
cryptoTransform = algo.CreateEncryptor();
break;
case CryptoTransformOperationsEnum.Decrypt:
cryptoTransform = algo.CreateDecryptor();
break;
default:
throw new Exception();
}
using (MemoryStream memoryStream = new MemoryStream())
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoTransform, CryptoStreamMode.Write))
{
cryptoStream.Write(orignalFile, 0, orignalFile.Length);
}
algo.Dispose();
processedFile = memoryStream.ToArray();
}
return(processedFile);
}
private static void StartCryptoProcessing(
string fileName, CryptoTransformOperationsEnum operation, SymetricAlgorithmsEnum algorithm)
{
SymmetricAlgorithm algo;
switch (algorithm)
{
case SymetricAlgorithmsEnum.AES:
algo = new AesManaged();
break;
case SymetricAlgorithmsEnum.DES:
algo = new DESCryptoServiceProvider();
break;
case SymetricAlgorithmsEnum.RC2:
algo = new RC2CryptoServiceProvider();
break;
default:
throw new Exception();
}
byte[] key = GetCredencial("Key", algo.BlockSize);
byte[] iv = GetCredencial("IV", algo.BlockSize);
algo.IV = iv;
algo.Key = key;
byte[] transformedFile = CryptoTransform(fileName, operation, algo);
string newFileName = "";
if (operation == CryptoTransformOperationsEnum.Decrypt)
{
newFileName = Path.Combine(
Path.GetDirectoryName(fileName),
Path.GetFileNameWithoutExtension(fileName));
newFileName = GetNextFileName(newFileName);
}
else if (operation == CryptoTransformOperationsEnum.Encrypt)
{
newFileName = fileName + ".enc";
}
File.WriteAllBytes(newFileName, transformedFile);
}
