public static void EndDecrypt(ProviderType providerType, SafeKeyHandleImpl symKeyHandle)
{
uint dataLength = 0;
var data = new byte[0];
var success = CryptoApi.CryptDecrypt(symKeyHandle, SafeHashHandleImpl.InvalidHandle, true, 0, data, ref dataLength) || providerType.IsVipNet();
if (!success)
{
throw CreateWin32Error();
}
}
public static void EndCrypt(SafeKeyHandleImpl symKeyHandle, Gost28147CryptoTransformMode transformMode)
{
bool success;
uint dataLength = 0;
if (transformMode == Gost28147CryptoTransformMode.Encrypt)
{
var data = new byte[32];
success = CryptoApi.CryptEncrypt(symKeyHandle, SafeHashHandleImpl.InvalidHandle, true, 0, data, ref dataLength, (uint)data.Length);
}
else
{
var data = new byte[0];
success = CryptoApi.CryptDecrypt(symKeyHandle, SafeHashHandleImpl.InvalidHandle, true, 0, data, ref dataLength) || (GostCryptoConfig.ProviderType == ProviderTypes.VipNet);
}
if (!success)
{
throw CreateWin32Error();
}
}
public static int DecryptData(SafeKeyHandleImpl symKeyHandle, byte[] data, int dataOffset, int dataLength, ref byte[] decryptedData, int decryptedDataOffset, PaddingMode paddingMode, bool isDone)
{
if (dataOffset < 0)
{
throw ExceptionUtility.ArgumentOutOfRange(nameof(dataOffset));
}
if (dataLength < 0)
{
throw ExceptionUtility.ArgumentOutOfRange(nameof(dataLength));
}
if ((dataOffset > data.Length) || ((dataOffset + dataLength) > data.Length))
{
throw ExceptionUtility.ArgumentOutOfRange(nameof(dataOffset), Resources.InvalidDataOffset);
}
// Выровненные данные
var dataAlignLength = (uint)dataLength;
var dataAlign = new byte[dataAlignLength];
Array.Copy(data, dataOffset, dataAlign, 0L, dataAlignLength);
// Расшифровка данных
if (!CryptoApi.CryptDecrypt(symKeyHandle, SafeHashHandleImpl.InvalidHandle, false, 0, dataAlign, ref dataAlignLength))
{
throw CreateWin32Error();
}
var length = (int)dataAlignLength;
if (isDone)
{
byte dataPaddingSize = 0;
// Удаление дополнения данных в зависимости от настроек
if (((paddingMode == PaddingMode.PKCS7) || (paddingMode == PaddingMode.ANSIX923)) || (paddingMode == PaddingMode.ISO10126))
{
if (dataAlignLength < 8)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
// Размер дополнения находится в последнем байте
dataPaddingSize = dataAlign[(int)((IntPtr)(dataAlignLength - 1))];
if (dataPaddingSize > 8)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
// Проверка корректности дополнения данных
if (paddingMode == PaddingMode.PKCS7)
{
for (var paddingIndex = dataAlignLength - dataPaddingSize; paddingIndex < (dataAlignLength - 1); paddingIndex++)
{
if (dataAlign[paddingIndex] != dataPaddingSize)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
}
}
else if (paddingMode == PaddingMode.ANSIX923)
{
for (var paddingIndex = dataAlignLength - dataPaddingSize; paddingIndex < (dataAlignLength - 1); paddingIndex++)
{
if (dataAlign[paddingIndex] != 0)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
}
}
}
else if ((paddingMode != PaddingMode.None) && (paddingMode != PaddingMode.Zeros))
{
throw ExceptionUtility.Argument(nameof(paddingMode), Resources.InvalidPaddingMode);
}
length -= dataPaddingSize;
}
if (decryptedData == null)
{
decryptedData = new byte[length];
Array.Copy(dataAlign, 0, decryptedData, 0, length);
}
else
{
if (decryptedDataOffset < 0)
{
throw ExceptionUtility.ArgumentOutOfRange(nameof(decryptedDataOffset));
}
if ((decryptedData.Length < length) || ((decryptedData.Length - length) < decryptedDataOffset))
{
throw ExceptionUtility.ArgumentOutOfRange(nameof(decryptedData), Resources.InvalidDataOffset);
}
Array.Copy(dataAlign, 0, decryptedData, decryptedDataOffset, length);
}
return(length);
}
