/*
* Algorithm decryption and encryption
*/
private void deAndenCryption(byte[] source, operationTypeEnum operationType)
{
if (operationType == operationTypeEnum.Encryption)
{
buttonEncryption.Enabled = false;
buttonDecryption.Enabled = true;
}
else if (operationType == operationTypeEnum.Decryption)
{
buttonEncryption.Enabled = true;
buttonDecryption.Enabled = false;
}
byte[] key = Encoding.UTF8.GetBytes(textBoxKey.Text); //key
ushort[] numKey = new ushort[key.Length]; //number key
ushort keyLength = (ushort)key.Length; //Counter
ushort maxCharVal = 0; //Max char value
ushort ind = 0; //current index
/*string key to number key*/
for (ushort i = 0; i < key.Length; i++)
{
for (ushort j = 0; j < key.Length; j++)
{
if (maxCharVal < key[j] && numKey[j] == 0)
{
maxCharVal = key[j];
ind = j;
}
}
numKey[ind] = keyLength--;
maxCharVal = 0;
ind = 0;
}
/*encryption*/
byte[] result = new byte[source.Length];
uint sizeEncrpttion = (uint)((source.Length / numKey.Length) * numKey.Length);
uint remainder = (uint)(source.Length - sizeEncrpttion);
for (uint i = 0; i < sizeEncrpttion; i += (uint)numKey.Length)
{
for (uint j = 0; j < numKey.Length; j++)
{
if (operationType == operationTypeEnum.Encryption)
{
result[i + j] = source[i + numKey[j] - 1];
}
else if (operationType == operationTypeEnum.Decryption)
{
result[i + numKey[j] - 1] = source[i + j];
}
}
}
/*end of the array without encryption*/
Array.Copy(source, sizeEncrpttion, result, sizeEncrpttion, remainder);
/*Show to richEditor*/
currentFile = result;
richTextBoxFile.Text = Encoding.UTF8.GetString(result);
}
/*
* Algorithm decryption and encryption
*/
private void deAndenCryption(operationTypeEnum operationType, byte[] source)
{
/*
* Warning about wrong a one-time notepad
*/
if ((oneTimeNotepad.Length != currentFile.Length) && operationType == operationTypeEnum.Encryption)
{
DialogResult result;
// Displays the MessageBox.
result = MessageBox.Show(
this,
"The length of a one-time notepad does not equal the source file. Do you want to continue this encryption?",
"Warning",
MessageBoxButtons.YesNo,
MessageBoxIcon.Question,
MessageBoxDefaultButton.Button1,
MessageBoxOptions.RightAlign
);
if (result == DialogResult.No)
{
return;
}
}
byte[] newSource = new byte[source.Length];
for (int i = 0, j = 0; i < source.Length; i++, j++)
{
if (j < oneTimeNotepad.Length)
{
j = 0;
}
newSource[i] = (byte)(source[i] ^ oneTimeNotepad[j]);
}
currentFile = newSource;
richTextBoxFile.Text = Encoding.UTF8.GetString(newSource);
}
