Java/Security/JCE

Материал из Java эксперт
Версия от 18:01, 31 мая 2010; (обсуждение)
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Encrypting and Decrypting with the JCE

import java.awt.Point;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.HashSet;
import java.util.Random;
import java.util.Set;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
public class TestCipher {
  // Password must be at least 8 characters
  private static final String password = "zukowski";
  public static void main(String args[]) throws Exception {
    Set set = new HashSet();
    Random random = new Random();
    for (int i = 0; i < 10; i++) {
      Point point = new Point(random.nextInt(1000), random.nextInt(2000));
      set.add(point);
    }
    int last = random.nextInt(5000);
    // Create Key
    byte key[] = password.getBytes();
    DESKeySpec desKeySpec = new DESKeySpec(key);
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
    SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
    // Create Cipher
    Cipher desCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
    desCipher.init(Cipher.ENCRYPT_MODE, secretKey);
    // Create stream
    FileOutputStream fos = new FileOutputStream("out.des");
    BufferedOutputStream bos = new BufferedOutputStream(fos);
    CipherOutputStream cos = new CipherOutputStream(bos, desCipher);
    ObjectOutputStream oos = new ObjectOutputStream(cos);
    // Write objects
    oos.writeObject(set);
    oos.writeInt(last);
    oos.flush();
    oos.close();
    // Change cipher mode
    desCipher.init(Cipher.DECRYPT_MODE, secretKey);
    // Create stream
    FileInputStream fis = new FileInputStream("out.des");
    BufferedInputStream bis = new BufferedInputStream(fis);
    CipherInputStream cis = new CipherInputStream(bis, desCipher);
    ObjectInputStream ois = new ObjectInputStream(cis);
    // Read objects
    Set set2 = (Set) ois.readObject();
    int last2 = ois.readInt();
    ois.close();
    // Compare original with what was read back
    int count = 0;
    if (set.equals(set2)) {
      System.out.println("Set1: " + set);
      System.out.println("Set2: " + set2);
      System.out.println("Sets are okay.");
      count++;
    }
    if (last == last2) {
      System.out.println("int1: " + last);
      System.out.println("int2: " + last2);
      System.out.println("ints are okay.");
      count++;
    }
    if (count != 2) {
      System.out.println("Problem during encryption/decryption");
    }
  }
}