src/code/kalter/longflight/crypto/CIStream.java

   1 package code.kalter.longflight.crypto;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5
   6 /**
   7  * Шифровальный входной поток (обёртка для InputStream). Дешифровка:
   8  * xor -> xchgb
   9  *
  10  * @author KalterFive
  11  */
  12 public class CIStream extends InputStream {
  13
  14     private final InputStream istream;
  15     private final Random random;
  16
  17     // key - ключ для ГПСЧ
  18     public CIStream(InputStream istream, int key) {
  19         this.istream = istream;
  20         this.random = new Random(key);
  21     }
  22
  23     public int read() throws IOException {
  24         int b = istream.read();
  25         b ^= random.random(0xFF);
  26         b = (b << 4) | (b >> 4);
  27         return b;
  28     }
  29
  30     public int available() throws IOException {
  31         return istream.available();
  32     }
  33
  34     public void close() throws IOException {
  35         istream.close();
  36     }
  37 }