private static void EncodeMessageLinear(ref Bitmap img, string text)
{
int maxLinear = img.Width * img.Height;
string pass = string.Format("{0}x{1}={2}", img.Width, img.Height, maxLinear);
AESEncrypt encrypt = new AESEncrypt();
int c = 0;
string encrypted = encrypt.EncryptString(text, pass);
OutputConsole.Write(string.Format("Text encrypted \n{0}", encrypted));
OutputConsole.Write("Processing image...");
if (encrypted.Length < maxLinear)
{
for (int i = 0; i < encrypted.Length; i++)
{
Point point = LinearIndexToPoint(i, img.Width, img.Height);
Color pixel = img.GetPixel(point.X, point.Y);
char letter = encrypted[i];
int value = Convert.ToInt32(letter);
Color n = EncodePixel(pixel, value);
img.SetPixel(point.X, point.Y, n);
c = i;
}
//Null value placed at the end to indicate end of text - or using 255 for better hiding
Point pointEnd = LinearIndexToPoint(c, img.Width, img.Height);
Color pixelEnd = img.GetPixel(pointEnd.X, pointEnd.Y);
img.SetPixel(pointEnd.X, pointEnd.Y, EncodePixel(pixelEnd, 0));
OutputConsole.Write("Finished embedding encrypted text");
}
else
{
OutputConsole.Write("Error: Image size doesn't support encrypted text size");
img = null;
}
}
public static string GetDecryptedTextFromImageLinear(Image image)
{
Bitmap img = new Bitmap(image);
int maxLinear = image.Width * image.Height;
string pass = string.Format("{0}x{1}={2}", image.Width, image.Height, maxLinear);
AESEncrypt encrypt = new AESEncrypt();
string text = string.Empty;
int value = 0;
int i = 0;
OutputConsole.Write("Processing image...");
do
{
Point point = LinearIndexToPoint(i, image.Width, image.Height);
Color pixel = img.GetPixel(point.X, point.Y);
value = DecodePixel(pixel);
i++;
if (value != 255)
{
text += Convert.ToChar(value);
}
} while (value != 255);
try
{
OutputConsole.Write(string.Format("String found: \n{0}", text));
OutputConsole.Write("Decrypting text...");
return(encrypt.DecryptString(text, pass));
}
catch (Exception e)
{
OutputConsole.Write("Error: Text not found");
Console.WriteLine(e.Message);
return(null);
}
}
public static byte[] EncryptTextLinear(byte[] wav, string text)
{
WavAudio audio = new WavAudio(wav);
uint value = 0;
string pass = string.Format(audio.bitsPerSample.ToString());
AESEncrypt encrypt = new AESEncrypt();
string encrypted = encrypt.EncryptString(text, pass);
OutputConsole.Write(string.Format("Text encrypted \n{0}", encrypted));
if (encrypted.Length <= Math.Floor((double)(audio.totalSamples / 8)))
{
uint n = 0;
OutputConsole.Write("Seed generated");
OutputConsole.Write("Processing wav file...");
for (int i = 0; i < encrypted.Length; i++)
{
value = encrypted[i];
for (int x = 0; x < 8; x++)
{
uint sample = n;
uint sampleValue = audio.samples[sample];
sampleValue = (sampleValue & 0xFFFFFFFE) | ((value >> x) & 1);
audio.samples[sample] = sampleValue;
n++;
}
}
value = 0;
for (int x = 0; x < 8; x++)
{
uint sample = n;
uint sampleValue = audio.samples[sample];
sampleValue = (sampleValue & 0xFFFFFFFE) | ((value >> x) & 1);
audio.samples[sample] = sampleValue;
n++;
}
audio.Save();
OutputConsole.Write(string.Format("Text encrypted... used {0} samples", encrypted.Length * 8));
OutputConsole.Write("Saving wav file");
return(audio.data);
}
else
{
return(null);
}
}
public static string DecryptTextLinear(byte[] wav)
{
WavAudio audio = new WavAudio(wav);
string text = string.Empty;
uint n = 0;
uint value = 0;
string pass = string.Format(audio.bitsPerSample.ToString());
AESEncrypt encrypt = new AESEncrypt();
OutputConsole.Write("Processing wav file...");
do
{
value = 0;
for (int x = 0; x < 8; x++)
{
uint sample = n;
uint sampleValue = audio.samples[sample];
value = value | ((sampleValue & 1) << x);
n++;
}
if (value != 0)
{
text += Convert.ToChar(value);
}
} while (value != 0);
OutputConsole.Write("Decrypting text...");
try
{
return(encrypt.DecryptString(text, pass));
}
catch (Exception e)
{
OutputConsole.Write("Error: Text not found");
Console.WriteLine(e.Message);
return(null);
}
}
