public static string encryptpw(string pw)
{
byte[] pwba = Encoding.Unicode.GetBytes(pw);
dataBlob dataIn = new dataBlob();
dataBlob dataOut = new dataBlob();
StringBuilder epwsb = new StringBuilder();
try
{
try
{
InitBLOB(pwba, ref dataIn);
}
catch (Exception ex)
{
throw new Exception("Cannot initialize dataIn BLOB.", ex);
}
bool success = CryptProtectData(
ref dataIn,
"psw",
nullPtr,
nullPtr,
nullPtr,
CryptprotectUiForbidden,
ref dataOut);
if (!success)
{
int errCode = Marshal.GetLastWin32Error();
throw new Exception("CryptProtectData failed.", new Win32Exception(errCode));
}
byte[] epwba = new byte[dataOut.cbData];
Marshal.Copy(dataOut.pbData, epwba, 0, dataOut.cbData);
// Convert hex data to hex characters (suitable for a string)
for (int i = 0; i < dataOut.cbData; i++)
{
epwsb.Append(Convert.ToString(epwba[i], 16).PadLeft(2, '0').ToUpper());
}
}
catch (Exception ex)
{
throw new Exception("unable to encrypt data.", ex);
}
finally
{
if (dataIn.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataIn.pbData);
}
if (dataOut.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataOut.pbData);
}
}
return(epwsb.ToString());
}
private static extern bool CryptProtectData(
ref dataBlob pPlainText,
[MarshalAs(UnmanagedType.LPWStr)] string szDescription,
IntPtr pEntroy,
IntPtr pReserved,
IntPtr pPrompt,
int dwFlags,
ref dataBlob pCipherText);
private static void InitBLOB(byte[] data, ref dataBlob blob)
{
blob.pbData = Marshal.AllocHGlobal(data.Length);
if (blob.pbData == IntPtr.Zero)
{
throw new Exception("Unable to allocate buffer for BLOB data.");
}
blob.cbData = data.Length;
Marshal.Copy(data, 0, blob.pbData, data.Length);
}
