public static extern unsafe NTSTATUS BCryptDecrypt(SafeKeyHandle hKey, byte* pbInput, int cbInput, IntPtr paddingInfo, [In, Out] byte[] pbIV, int cbIV, byte* pbOutput, int cbOutput, out int cbResult, int dwFlags);
public static extern NTSTATUS BCryptImportKey(SafeAlgorithmHandle hAlgorithm, IntPtr hImportKey, String pszBlobType, out SafeKeyHandle hKey, IntPtr pbKeyObject, int cbKeyObject, byte[] pbInput, int cbInput, int dwFlags);
public static extern NTSTATUS BCryptImportKey(SafeAlgorithmHandle hAlgorithm, IntPtr hImportKey, string pszBlobType, out SafeKeyHandle hKey, IntPtr pbKeyObject, int cbKeyObject, byte[] pbInput, int cbInput, int dwFlags);
public static extern unsafe NTSTATUS BCryptDecrypt(SafeKeyHandle hKey, byte *pbInput, int cbInput, IntPtr paddingInfo, [In, Out] byte[] pbIV, int cbIV, byte *pbOutput, int cbOutput, out int cbResult, int dwFlags);
internal static int DecryptDataCp(SafeKeyHandle hKey,
byte[] data, int ib, int cb, ref byte[] outputBuffer,
int outputOffset, PaddingMode PaddingMode, bool fDone)
{
int dwDataLen = (int)cb; // ebp+0x5C
if (ib < 0)
{
throw new ArgumentOutOfRangeException("ib", SR.ArgumentOutOfRange_NeedNonNegNum);
}
if (cb < 0)
{
throw new ArgumentOutOfRangeException("cb", SR.ArgumentOutOfRange_NeedNonNegNum);
}
if ((ib > data.Length) || (ib + cb > data.Length))
{
throw new ArgumentException(SR.Argument_InvalidValue);
}
// CryptDecrypt использует один буфер с данными,
// поэтому от new не избавиться.
byte[] tmpBuffer = new byte[dwDataLen]; // ebp + 0x50
Array.Copy(data, ib, tmpBuffer, 0, dwDataLen);
if (!Interop.Advapi32.CryptDecrypt(
hKey, SafeHashHandle.InvalidHandle,
false, 0, tmpBuffer, ref dwDataLen))
{
throw new CryptographicException(Interop.CPError.GetLastWin32Error());
}
int realLength = (int)dwDataLen; // ebp + 0x34
if (fDone)
{
byte fill = 0;
if (PaddingMode == PaddingMode.PKCS7
// [data] [length..length]
|| PaddingMode == PaddingMode.ANSIX923
// [data] [0..0] [length]
|| PaddingMode == PaddingMode.ISO10126
// [data] [random] [length]
)
{
if (dwDataLen < 8)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
fill = tmpBuffer[dwDataLen - 1]; // ebp + 0x4C
if (fill > 8)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
if (PaddingMode == PaddingMode.PKCS7)
{
for (int i = dwDataLen - fill; i < dwDataLen - 1; i++)
{
if (tmpBuffer[i] != fill)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
}
}
else if (PaddingMode == PaddingMode.ANSIX923)
{
for (int i = dwDataLen - fill; i < dwDataLen - 1; i++)
{
if (tmpBuffer[i] != 0)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
}
}
}
else if (PaddingMode != PaddingMode.None && // [data]
PaddingMode != PaddingMode.Zeros) // [data] [0..0]
{
throw new ArgumentException(SR.Cryptography_InvalidPaddingMode);
}
realLength -= fill;
}
if (outputBuffer == null)
{
outputBuffer = new byte[realLength];
Array.Copy(tmpBuffer, 0, outputBuffer, 0, realLength);
}
else
{
if (outputOffset < 0)
{
throw new ArgumentOutOfRangeException("outputOffset", SR.ArgumentOutOfRange_NeedNonNegNum);
}
if ((outputBuffer.Length < realLength) ||
(outputBuffer.Length - realLength < outputOffset))
{
throw new ArgumentException(SR.Argument_InvalidValue);
}
Array.Copy(tmpBuffer, 0, outputBuffer, outputOffset, realLength);
}
return(realLength);
}
internal static int EncryptDataCp(SafeProvHandle hProv, SafeKeyHandle hKey, byte[] data,
int ib, int cb, ref byte[] outputBuffer, int outputOffset,
PaddingMode paddingMode, bool fDone, bool isStream)
{
int dwDataLen = (int)cb; // ebp+0x58
int bufLength = cb; // ebp+0x34
if (fDone)
{
// Мы не используем в отличии от MS реализации Final
// поэтому на 8 байт CAPI Padding меньше
bufLength += 8;
}
int remainder = cb & 7; // ebp+0x30
if (cb < 0)
{
throw new ArgumentOutOfRangeException("cb", SR.ArgumentOutOfRange_NeedNonNegNum);
}
if (ib < 0)
{
throw new ArgumentOutOfRangeException("ib", SR.ArgumentOutOfRange_NeedNonNegNum);
}
if (ib > data.Length)
{
throw new ArgumentException(SR.Argument_InvalidValue, "ib");
}
byte[] tmpBuffer = new byte[bufLength]; // ebp + 0x4c
Array.Clear(tmpBuffer, 0, bufLength);
Array.Copy(data, ib, tmpBuffer, 0, cb);
if (fDone)
{
byte fill = (byte)(8 - remainder); // ebp - 0x28;
switch (paddingMode)
{
case PaddingMode.None: // [data]
if (remainder == 0)
{
break;
}
if (isStream)
{
break;
}
throw new CryptographicException(
SR.Cryptography_InvalidPaddingMode);
case PaddingMode.PKCS7: // [data] [length..length]
{
int c = cb; // ebp+0x44;
dwDataLen += fill;
while (c < dwDataLen)
{
tmpBuffer[c++] = fill;
}
}
break;
case PaddingMode.Zeros: // [data] [0..0]
if (remainder == 0)
{
break;
}
dwDataLen += fill;
break;
case PaddingMode.ANSIX923: // [data] [0..0] [length]
{
int c = cb; // ebp+0x48;
dwDataLen += fill;
// без while: итак 0.
tmpBuffer[dwDataLen - 1] = fill;
break;
}
case PaddingMode.ISO10126: // [data] [random] [length]
{
byte[] tmpBuf = new byte[fill - 1];
if (hProv == null || hProv.IsInvalid)
{
CspParameters gostParameters = new CspParameters(GostConstants.PROV_GOST_2001_DH);
using (var rng = new GostRngCryptoServiceProvider(gostParameters))
{
rng.GetBytes(tmpBuf);
}
}
else
{
using (var rng = new GostRngCryptoServiceProvider(hProv))
{
rng.GetBytes(tmpBuf);
}
}
tmpBuf.CopyTo(tmpBuffer, cb);
dwDataLen += fill;
tmpBuffer[dwDataLen - 1] = fill;
break;
}
default:
throw new ArgumentException(
SR.Cryptography_InvalidPaddingMode
);
}
}
// Утверждалось, что "Это похоже ошибка CSP. Не дает шифровать 0 байт в конце."
// if (dwDataLen != 0)
//
// Не используем CAPI Padding!
bool ret = Interop.Advapi32.CryptEncrypt(hKey, SafeHashHandle.InvalidHandle,
false, 0, tmpBuffer,
ref dwDataLen, (int)bufLength);
if (!ret)
{
throw new CryptographicException(Interop.CPError.GetLastWin32Error());
}
if (outputBuffer == null)
{
outputBuffer = new byte[dwDataLen];
Array.Copy(tmpBuffer, 0, outputBuffer, 0, dwDataLen);
}
else
{
if (outputOffset < 0)
{
throw new ArgumentOutOfRangeException("outputOffset", SR.ArgumentOutOfRange_NeedNonNegNum);
}
if (outputBuffer.Length < dwDataLen)
{
throw new ArgumentException(SR.Argument_InvalidValue);
}
if (outputBuffer.Length - dwDataLen < outputOffset)
{
throw new ArgumentException(SR.Argument_InvalidValue);
}
Array.Copy(tmpBuffer, 0, outputBuffer, outputOffset, dwDataLen);
}
return((int)dwDataLen);
}
