private void bgwCrypto_DoWork(object sender, DoWorkEventArgs eventArgs)
{
bool encTask = (bool)eventArgs.Argument;
if (encTask) // encryption
{
List <byte> bytes = new List <byte>();
int block_size = (n.BitLength() - 1) / 8;
int nIter = currentFileContents.Length / block_size;
byte[] subArr = new byte[block_size];
for (int i = 0; i < nIter; i++)
{
Buffer.BlockCopy(currentFileContents, i * block_size, subArr, 0, block_size);
BigInteger m = Util.ArrToUnsignedBigInt(ref subArr);
BigInteger c = MyRSA.Encrypt(m, e, n);
byte[] cip = Util.BigIntToFixedLenArr(ref c, block_size + 1);
bytes.AddRange(cip);
(sender as BackgroundWorker).ReportProgress(100 * i / nIter);
}
int rem = currentFileContents.Length % block_size;
if (rem > 0)
{
subArr = new byte[rem];
Buffer.BlockCopy(currentFileContents, nIter * block_size, subArr, 0, rem);
BigInteger m = Util.ArrToUnsignedBigInt(ref subArr);
BigInteger c = MyRSA.Encrypt(m, e, n);
byte[] cip = Util.BigIntToFixedLenArr(ref c, block_size + 1);
bytes.AddRange(cip);
}
bytes.AddRange(Encoding.UTF8.GetBytes(new BigInteger(rem).ToString()));
currentFileContents = bytes.ToArray();
(sender as BackgroundWorker).ReportProgress(100);
}
else // decrypt
{
List <byte> bytes = new List <byte>();
int block_size = (n.BitLength() - 1) / 8 + 1;
int nIter = currentFileContents.Length / block_size;
byte[] subArr = new byte[block_size];
for (int i = 0; i < nIter - 1; i++)
{
Buffer.BlockCopy(currentFileContents, i * block_size, subArr, 0, block_size);
BigInteger c = Util.ArrToUnsignedBigInt(ref subArr);
BigInteger m = MyRSA.Decrypt(ref c, ref d, ref n);
byte[] msg = Util.BigIntToFixedLenArr(ref m, block_size - 1);
bytes.AddRange(msg);
(sender as BackgroundWorker).ReportProgress(100 * i / nIter);
}
{
int rem = currentFileContents.Length % block_size;
subArr = new byte[rem];
Buffer.BlockCopy(currentFileContents, nIter * block_size, subArr, 0, rem);
int lastIterByteCount = (int)BigInteger.Parse(Encoding.UTF8.GetString(subArr));
subArr = new byte[block_size];
Buffer.BlockCopy(currentFileContents, (nIter - 1) * block_size, subArr, 0, block_size);
BigInteger c = Util.ArrToUnsignedBigInt(ref subArr);
BigInteger m = MyRSA.Decrypt(ref c, ref d, ref n);
byte[] msg = Util.BigIntToFixedLenArr(ref m, lastIterByteCount);
bytes.AddRange(msg);
}
currentFileContents = bytes.ToArray();
(sender as BackgroundWorker).ReportProgress(100);
}
eventArgs.Result = encTask;
}
private void btnRegister_Click(object sender, EventArgs e)
{
string u = txtUsername.Text.Trim();
string p = txtPassword.Text;
string r = txtRetype.Text;
Regex uPattern = new Regex("^[a-zA-Z_][a-zA-Z0-9_]*$");
if (!uPattern.IsMatch(u) ||
p.Length < 1 ||
p != r)
{
MessageBox.Show("Username and password must be at least 1 character long\nPassword and Confirm passwords must match",
"Incorrect information",
MessageBoxButtons.OK,
MessageBoxIcon.Exclamation);
return;
}
if (!Directory.Exists(Config.AppDataFolderPath))
{
Directory.CreateDirectory(Config.AppDataFolderPath);
}
if (!File.Exists(Config.AppDataFilePath))
{
var fs = File.Create(Config.AppDataFilePath);
fs.Close();
}
if (!File.Exists(Path.Combine(Config.AppDataFolderPath, u)))
{
var fs = File.Create(Config.GetAppDataUserFile(u));
fs.Close();
}
string[] lines = File.ReadAllLines(Config.AppDataFilePath);
foreach (string line in lines)
{
if (u == line.Split(new char[] { ' ' })[0])
{
MessageBox.Show("This username is already taken. Please use a different username.", "Username already taken", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
return;
}
}
string hp = Util.Hash(p);
BigInteger ke, kd, kn;
MyRSA.KeyGen(Config.CryptoKeySize, out ke, out kd, out kn);
string eStr = Convert.ToBase64String(Util.XOREncDec(ke.ToByteArray()));
string dStr = Convert.ToBase64String(Util.XOREncDec(kd.ToByteArray()));
string nStr = Convert.ToBase64String(Util.XOREncDec(kn.ToByteArray()));
StringBuilder sb = new StringBuilder();
sb.Append(u);
sb.Append(" ");
sb.Append(hp);
sb.Append(" ");
sb.Append(eStr);
sb.Append(" ");
sb.Append(dStr);
sb.Append(" ");
sb.Append(nStr);
File.AppendAllLines(Config.AppDataFilePath, new string[] { sb.ToString() });
if (!Directory.Exists(Path.Combine(Config.AppDataFolderPath, u)))
{
Directory.CreateDirectory(Path.Combine(Config.AppDataFolderPath, u));
}
this.Username = u;
this.E = ke;
this.D = kd;
this.N = kn;
this.DialogResult = DialogResult.OK;
MessageBox.Show("Registration successful.", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
this.Close();
}