private void button_Encoder_Click(object sender, EventArgs e)
{
// Field fill check
if (textBox_OriginalMessage.Text.Length <= 0 || textBox_OriginalSymmetricKey.Text.Length <= 0 ||
textBox_P.Text.Length <= 0 || textBox_Q.Text.Length <= 0)
{
MessageBox.Show("Fields are not filled");
return;
}
string message = textBox_OriginalMessage.Text; // Message A
string codedMessage; // Encrypted message A
string symKey = textBox_OriginalSymmetricKey.Text; // Session key
List <string> codedSymKey; // Encrypted session key
// A: create session key
byte[] keyByte = ASCIIEncoding.ASCII.GetBytes(symKey);
RC4 symEncode = new RC4(keyByte);
// A: Encoding message A using a symmetric algorithm
byte[] messageBytes = ASCIIEncoding.ASCII.GetBytes(message);
byte[] codedMessageByte = symEncode.Encode(messageBytes, messageBytes.Length);
codedMessage = Convert.ToBase64String(codedMessageByte);
label_CodedMessage.Text = codedMessage;
// B: Generate and display RSA public key
Int64 p = Convert.ToInt64(textBox_P.Text);
Int64 q = Convert.ToInt64(textBox_Q.Text);
if (!asymEncoderDecoder.GeneratePublicAndPrivateKey(p, q))
{
//MessageBox.Show("Symmetric key is not encoded");
return;
}
Int64 N = asymEncoderDecoder.GetN();
label_N_public.Text = Convert.ToString("N: " + N);
Int64 E = asymEncoderDecoder.GetE();
label_E.Text = Convert.ToString("E: " + E);
// A: Encrypt symmetric key with RSA public key
codedSymKey = asymEncoderDecoder.Encrypt(symKey);
label_CodedSymmetricalKey.ResetText();
foreach (string item in codedSymKey)
{
label_CodedSymmetricalKey.Text += item + " ";
}
button_Decoder.Enabled = true;
}
private void button_Decoder_Click(object sender, EventArgs e)
{
// Q: Print the private key
Int64 N = asymEncoderDecoder.GetN();
label_N_private.Text = Convert.ToString("N: " + N);
Int64 d = asymEncoderDecoder.GetD();
label_D.Text = Convert.ToString("D: " + d);
// B: Read and decrypt the symmetric key using the RSA private key
List <string> codedSymKey = new List <string>();
string[] tmp = label_CodedSymmetricalKey.Text.Split(' ');
for (int i = 0; i < tmp.Length; i++)
{
codedSymKey.Add(tmp[i]);
}
string origKey = asymEncoderDecoder.Decrypt(codedSymKey);
label_DecodedSymmetricalKey.Text = origKey;
// Q: decode message A with the decrypted symmetric key
byte[] origKeyByte = ASCIIEncoding.ASCII.GetBytes(origKey);
RC4 decoder = new RC4(origKeyByte);
string codedMessage = label_CodedMessage.Text;
byte[] codedMessageByte = Convert.FromBase64String(codedMessage);
byte[] origMessageByte = decoder.Decode(codedMessageByte, codedMessageByte.Length);
string origMessage = ASCIIEncoding.ASCII.GetString(origMessageByte);
label_DecodedMessage.Text = origMessage;
button_Decoder.Enabled = false;
}
public void CreateDec(byte[] key)
{
dec = new RC4();
dec.Shuffle(key);
}
public void CreateEnc(byte[] key)
{
enc = new RC4();
enc.Shuffle(key);
mppc = new MPPC();
}