有没有使用java.security类来加密文本(不是数字签名)的程序?可否给我看看.我不会用那个类.最好是用RSA和DES算法的.

Question

我发给你一个吧，你的e-mail是？

Answer 1

用java.security包是不能进行加密操作的，只能用 javax.crypto　的。至于例子，你可以看一个jce的文档和例子，（jce在jdk1.3以前是单独的扩展包，在jdk1.4才被加入，就是那个crypto包了）。可以在java.sun.com找到相关资料，有文档、教程和例子。

Answer 2

确实要用到javax.crypto.*, 我这里有一些例程，但愿对你有帮助：
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import java.security.Security;
import java.security.NoSuchAlgorithmException;
public class DESCipherGenerator {
    public static void main(String[] args) {
        Security.addProvider(new com.sun.crypto.provider.SunJCE());
        try {
            Cipher cipher = Cipher.getInstance("DES");
            System.out.println("Cipher provider: " + cipher.getProvider());
            System.out.println("Cipher algorithm: " + cipher.getAlgorithm());
        }
        catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }
    }
}
 //--------------------------------------import javax.crypto.KeyGenerator;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.Security;
public class DESKeyGenerator {
    public static void main(String[] args) {
        Security.addProvider(new com.sun.crypto.provider.SunJCE());
        try {
            KeyGenerator kg = KeyGenerator.getInstance("DES");
            Key key = kg.generateKey();
            System.out.println("Key format: " + key.getFormat());
            System.out.println("Key algorithm: " + key.getAlgorithm());
        }
        catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
    }
}//-----------------------------------------import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.BadPaddingException;
import java.security.Key;
import java.security.Security;
import java.security.NoSuchAlgorithmException;
import java.security.InvalidKeyException;
public class DESCryptoTest {
    public static void main(String[] args) {
        Security.addProvider(new com.sun.crypto.provider.SunJCE());
        try {
            KeyGenerator kg = KeyGenerator.getInstance("DES");
            Key key = kg.generateKey();
            Cipher cipher = Cipher.getInstance("DES");
 
            byte[] data = "Hello World!".getBytes();
            System.out.println("Original data : " + new String(data));
 
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] result = cipher.doFinal(data);
            System.out.println("Encrypted data: " + new String(result));
 
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] original = cipher.doFinal(result);
            System.out.println("Decrypted data: " + new String(original));
        }
        catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }
        catch (InvalidKeyException e) {
            e.printStackTrace();
        }
        catch (IllegalStateException e) {
            e.printStackTrace();
        }
        catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        }
        catch (BadPaddingException e) {
            e.printStackTrace();
        }
    }
}
 

Answer 3

Kevin 给我发一个好吗？ [email protected]