//Create 1 file Stego from input
public void CreateStegoFile(string inPath1, string message, string password, string inPath2)
{
//Checking input
if (inPath1 == "")
{
throw new Exception("You have not selected the image yet");
}
if (inPath2 == "")
{
throw new Exception("You have not defined where the image will be saved");
}
if (message == "")
{
throw new Exception("Message doesn't be allowed to be empty");
}
if (password == "")
{
throw new Exception("Password doesn't be allowed to be empty");
}
// Mo file dau vao
FileStream inStream = new FileStream(inPath1, FileMode.Open, FileAccess.Read);
// kiem tra xem co phai anh bitmap 24 bits khong
char b = (char)inStream.ReadByte();
char m = (char)inStream.ReadByte();
if (!(b == 'B' && m == 'M'))
{
throw new Exception("Image must be bitmap format");
}
// kiem tra xem co phai la anh 24 bit hay k
inStream.Seek(28, 0); // dua con tro ve vi tri byte thu 28
byte[] temp = new byte[2];
inStream.Read(temp, 0, 2); // so bit/1pixel duoc luu bang 2 byte
Int16 nBit = BitConverter.ToInt16(temp, 0); // chuyen mang byte temp[] ve so nguyen 16 bit
if (nBit != 24)
{
throw new Exception("It's not a 24 bit image");
}
// Doc 54 byte phan header roi dua vao trong outStream
int offset = 54;
inStream.Seek(0, 0);
byte[] header = new byte[offset];
inStream.Read(header, 0, offset);
//viet 54 byte nay vao trong file stego ( file dau ra)
FileStream outStream = new FileStream(inPath2, FileMode.Create, FileAccess.Write);
outStream.Write(header, 0, offset);
// ma hoa thong diep va mat khau thanh 1 thong diep duy nhat
UnicodeEncoding unicode = new UnicodeEncoding();
byte[] newMessageByte = AddMessLengthToAhead(unicode.GetBytes(message));// them 4 byte do dai cua message vao dau cua thong diep
// thuc hien tron
newMessageByte = Crypto.Encrypt(newMessageByte, password);
// thuc hien giau thong diep nay vao trong anh
inStream.Seek(offset, 0); // dua con tro ve noi bat dau cua Data o vi tri thu 54 (offset=54)
LSB.Encode(inStream, newMessageByte, outStream); //thay tung bit cua thong diep vao LSB cua inStream va ghi ra outStream
inStream.Close(); // dong file anh dau vao
outStream.Close();
}
