private static void EncriptFile(X509Certificate2 sert, string sourceFile, string encFile)
{
var publicKey = (Gost3410_2012_256CryptoServiceProvider)sert.PublicKey.Key;
var asymmetricAlg = publicKey as Gost3410_2012_256;
if (asymmetricAlg == null)
{
throw new CryptographicException("Not a gost certificate");
}
var symmetricKey = Gost28147.Create();
Gost3410_2012_256 senderRndKey = Gost3410_2012_256.Create();
Gost3410Parameters senderRndKeyParameters = senderRndKey.ExportParameters(false);
GostSharedSecretAlgorithm agreeKey = senderRndKey.CreateAgree(asymmetricAlg.ExportParameters(false));
var encodedSymmetricKey = agreeKey.Wrap(symmetricKey, GostKeyWrapMethod.CryptoProKeyWrap);
ICryptoTransform transform = symmetricKey.CreateEncryptor();
using (FileStream writer = new FileStream(encFile, FileMode.Create))
{
BinaryWriter binaryWriter = new BinaryWriter(writer);
binaryWriter.Write(encodedSymmetricKey.Length);
binaryWriter.Write(encodedSymmetricKey);
binaryWriter.Write(symmetricKey.IV.Length);
binaryWriter.Write(symmetricKey.IV);
BinaryFormatter binaryFormatter = new BinaryFormatter();
binaryFormatter.Serialize(writer, senderRndKeyParameters);
using (CryptoStream cryptoStream = new CryptoStream(writer, transform, CryptoStreamMode.Write))
{
var buffer = new byte[100];
using (FileStream reader = new FileStream(sourceFile, FileMode.Open, FileAccess.Read))
{
var length = reader.Read(buffer, 0, buffer.Length);
while (length > 0)
{
cryptoStream.Write(buffer, 0, buffer.Length);
length = reader.Read(buffer, 0, buffer.Length);
}
}
}
}
}
/// <summary>
/// Инициализирует новый экземпляр класса <c>GostKeyValue</c> с новым,
/// сгенерированным случайным образом открытым ключом ГОСТ 34.10-2012 256.
/// </summary>
/// <remarks>При создании нового ключа ГОСТ 34.10-2012 256 этот конструктор
/// использует реализацию <see cref="Gost3410_2012_256"/> по
/// умолчанию, как определено классом
/// <see cref="System.Security.Cryptography.CryptoConfig"/>.</remarks>
public Gost2012_256KeyValue()
{
_key = (Gost3410_2012_256)Gost3410_2012_256.Create();
}