public byte[] Update(byte[] b, int off, int len)
{
if (aes)
{
if (initiated)
{
return(cipher.Update(b, off, len));
}
else
{
int left = Math.Min(iv.Length - ivptr, len);
System.Array.Copy(b, off, iv, ivptr, left);
off += left;
len -= left;
ivptr += left;
if (ivptr == iv.Length)
{
cipher = new AESCipher(false, key, iv);
initiated = true;
if (len > 0)
{
return(cipher.Update(b, off, len));
}
}
return(null);
}
}
else
{
byte[] b2 = new byte[len];
arcfour.EncryptARCFOUR(b, off, len, b2, 0);
return(b2);
}
}
/**
* Gets a random initialization vector.
* @param len the length of the initialization vector
* @return a random initialization vector
*/
public static byte[] GetIV(int len) {
byte[] b = new byte[len];
lock (rc4) {
rc4.EncryptARCFOUR(b);
}
return b;
}
