public byte[] decrypt()
{
//form shift register
byte[] register = Encoding.ASCII.GetBytes(this.iv);
byte[] ikey = new byte[register.Length];
//start decryption
Enkripsi enkripsi = new Enkripsi();
Int32 blok = Encoding.ASCII.GetBytes(this.key).Length;
byte[] cbyte = this.cipher;
byte[] pbyte = new byte[cbyte.Length];
for (int i = 0; i <= (cbyte.Length / blok); i++)
{
//get internal key
ikey = enkripsi.encrypt(Encoding.ASCII.GetBytes(key), register);
//get block-sized plaintext
byte[] ci;
byte[] pi;
//ci = cbyte.Skip(i * blok).Take(cbyte.Length - (i * blok)).ToArray();
//pi = xor(ci, ikey);
if (cbyte.Length - (i * blok) >= blok)
{
ci = new byte[blok];
pi = new byte[blok];
ci = cbyte.Skip(i * blok).Take(blok).ToArray();
}
else
{
pi = new byte[cbyte.Length - (i * blok)];
ci = new byte[cbyte.Length - (i * blok)];
ci = cbyte.Skip(i * blok).Take(cbyte.Length - (i * blok)).ToArray();
}
ikey = ikey.Skip(0).Take(ci.Length).ToArray();
pi = xor(ci, ikey);
for (int m = 0; m < pi.Length; m++)
{
pbyte[i * blok + m] = pi[m];
}
//wrap register
register = ikey;
}
//this.plain = Encoding.ASCII.GetString(pbyte);
this.plain = new byte[pbyte.Length];
this.plain = pbyte;
return this.plain;
}
public byte[] encrypt()
{
Enkripsi enkripsi = new Enkripsi();
int leftover = plain.Length % key.Length;
int blockTotal = plain.Length / key.Length;
cipher = new byte[plain.Length + ((key.Length - leftover) % key.Length)];
for (int i = 0; i < blockTotal; i++)
{
byte[] blockPlain = new byte [key.Length];
for (int j = 0; j < key.Length; j++)
{
blockPlain[j] = plain[i * key.Length + j];
}
blockPlain = enkripsi.encrypt(blockPlain, Encoding.ASCII.GetBytes(key));
for (int j = 0; j < key.Length; j++)
{
this.cipher[i * key.Length + j] = blockPlain[j];
}
}
if (leftover > 0)
{
byte[] blockPlain = new byte[key.Length];
byte paddingByte = 0;
for (int i = 0; i < key.Length; i++)
{
if (i < leftover)
blockPlain[i] = plain[blockTotal * key.Length + i];
else
blockPlain[i] = paddingByte;
}
blockPlain = enkripsi.encrypt(blockPlain, Encoding.ASCII.GetBytes(key));
for (int i = 0; i < key.Length; i++)
{
this.cipher[blockTotal * key.Length + i] = blockPlain[i];
}
}
return this.cipher;
}