public void HideBytesInPng(Image innocuousBmp, string outputImageFileName, byte[] hiddenBytes)
{
hiddenBytes = ByteEncryptionUtil.EncryptSalsa20(hiddenBytes, _key);
byte[] hiddenLengthBytes = BitConverter.GetBytes(hiddenBytes.Length);
byte[] hiddenCombinedBytes = PngUtils.Combine(hiddenLengthBytes, hiddenBytes);
byte[] rgbComponents = PngUtils.RgbComponentsToBytes(innocuousBmp);
byte[] encodedRgbComponents = EncodeBytes(hiddenCombinedBytes, rgbComponents);
Bitmap encodedBmp = PngUtils.ByteArrayToBitmap(encodedRgbComponents, innocuousBmp.Width, innocuousBmp.Height);
encodedBmp.Save(outputImageFileName, ImageFormat.Png);
encodedBmp.Dispose();
innocuousBmp.Dispose();
}
public byte[] ReadHiddenBytesFromPng(string imageFileName)
{
Bitmap loadedEncodedBmp = new Bitmap(imageFileName);
byte[] loadedEncodedRgbComponents = PngUtils.RgbComponentsToBytes(loadedEncodedBmp);
const int bytesInInt = 4;
byte[] loadedHiddenLengthBytes = DecodeBytes(loadedEncodedRgbComponents, 0, bytesInInt);
int loadedHiddenLength = BitConverter.ToInt32(loadedHiddenLengthBytes, 0);
byte[] loadedHiddenBytes = DecodeBytes(loadedEncodedRgbComponents, bytesInInt, loadedHiddenLength);
loadedEncodedBmp.Dispose();
return(ByteEncryptionUtil.DecryptSalsa20(loadedHiddenBytes, _key));
}
