public byte[] Decrypt(byte[] chiphertext)
{
byte[] res = new byte[chiphertext.Length];
int currpos = 0;
byte[] pi = new byte[BLOCK_SIZE]; //P(i)
byte[] ci = new byte[BLOCK_SIZE]; //C(i)
byte[] oi = new byte[BLOCK_SIZE]; //O(i)
byte[] oim = new byte[BLOCK_SIZE]; //O(i-1)
Array.Copy(iv, 0, oim, 0, BLOCK_SIZE);
while (currpos < chiphertext.Length)
{
Array.Copy(chiphertext, currpos, ci, 0, BLOCK_SIZE);
oi = aes.Encrypt(oim);
Array.Copy(oi, 0, oim, 0, BLOCK_SIZE);
arrXOR(ci, oi);
Array.Copy(ci, 0, res, currpos, BLOCK_SIZE);
currpos += BLOCK_SIZE;
}
return(res);
}
public byte[] Decrypt(byte[] chiphertext)
{
byte[] res = new byte[chiphertext.Length];
int currpos = 0;
byte[] pi = new byte[BLOCK_SIZE]; //P(i)
byte[] ci = new byte[BLOCK_SIZE]; //C(i)
byte[] ctr = new byte[BLOCK_SIZE];
Array.Copy(iv, 0, ctr, 0, BLOCK_SIZE);
while (currpos < chiphertext.Length)
{
Array.Copy(chiphertext, currpos, ci, 0, BLOCK_SIZE);
pi = aes.Encrypt(ctr);
arrXOR(pi, ci);
Array.Copy(pi, 0, res, currpos, BLOCK_SIZE);
currpos += BLOCK_SIZE;
IncrCTR(ctr);
}
return(res);
}
public byte[] Encrypt(byte[] plaintext)
{
byte[] res = new byte[plaintext.Length];
int currpos = 0;
byte[] inpBlock = new byte[BLOCK_SIZE];
byte[] outpBlock = new byte[BLOCK_SIZE];
while (currpos < plaintext.Length)
{
Array.Copy(plaintext, currpos, inpBlock, 0, BLOCK_SIZE);
outpBlock = aes.Encrypt(inpBlock);
Array.Copy(outpBlock, 0, res, currpos, BLOCK_SIZE);
currpos += BLOCK_SIZE;
}
return(res);
}