private void btnExtract_Click(object sender, System.EventArgs e)
{
Bitmap bitmap = (Bitmap)picImage.Image;
//empty stream for the extracted message
Stream messageStream = new MemoryStream();
//get a stream for the key
Stream keyStream = GetKeyStream();
if (keyStream.Length == 0)
{
MessageBox.Show("Please enter a password or select a key file.");
txtKeyText.Focus();
}
else
{
try{
//extract the hidden message from the bitmap
CryptUtility.ExtractMessageFromBitmap(bitmap, keyStream, ref messageStream);
//save the message, if a filename is available
if (txtExtractedMsgFile.Text.Length > 0)
{
messageStream.Seek(0, SeekOrigin.Begin);
FileStream fs = new FileStream(txtExtractedMsgFile.Text, FileMode.Create);
byte[] streamContent = new Byte[messageStream.Length];
messageStream.Read(streamContent, 0, streamContent.Length);
fs.Write(streamContent, 0, streamContent.Length);
}
//display the message - displays chaos, if it's no unicode text
messageStream.Seek(0, SeekOrigin.Begin);
StreamReader reader = new StreamReader(messageStream, UnicodeEncoding.Unicode);
String readerContent = reader.ReadToEnd();
if (readerContent.Length > txtExtractedMsgText.MaxLength)
{
readerContent = readerContent.Substring(0, txtExtractedMsgText.MaxLength);
}
txtExtractedMsgText.Text = readerContent;
}catch (Exception ex) {
MessageBox.Show("Exception:\r\n" + ex.Message);
}
}
//close the streams
messageStream.Close();
keyStream.Close();
bitmap = null;
}
private void btnHide_Click(object sender, System.EventArgs e)
{
Bitmap bitmap = (Bitmap)picImage.Image;
//get a stream for the message to hide
Stream messageStream = GetMessageStream();
if (messageStream.Length == 0)
{
MessageBox.Show("Please enter a message or select a file.");
txtMessageText.Focus();
}
else
{
//get a stream fot the key
Stream keyStream = GetKeyStream();
if (keyStream.Length == 0)
{
MessageBox.Show("Please enter a password or select a key file.");
txtKeyText.Focus();
}
else
{
try{
//hide the message
CryptUtility.HideMessageInBitmap(messageStream, bitmap, keyStream, chkGrayscale.Checked);
//display result
picImage.Image = bitmap;
btnSaveBitmap.Enabled = true;
MessageBox.Show("Hide the message successfull !");
}catch (Exception ex) {
MessageBox.Show("Exception:\r\n" + ex.Message);
}
}
keyStream.Close();
}
messageStream.Close();
bitmap = null;
}
