desencrypter.java

是一个专门设计用于触摸屏的POS(point of sales)应用软件

/* From the java almanac */

package net.adrianromero.tpv.util;

import java.io.*;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;

public class DesEncrypter {
    
    private Cipher ecipher;
    private Cipher dcipher;

    // 8-byte Salt
    private static final byte[] salt = {
        (byte)0xA9, (byte)0x9B, (byte)0xC8, (byte)0x32,
        (byte)0x56, (byte)0x35, (byte)0xE3, (byte)0x03
    };

    // Iteration count
    private static final int iterationCount = 19;

    public DesEncrypter(String passPhrase) {
        try {
            // Create the key
            KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
            SecretKey key = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(keySpec);
            ecipher = Cipher.getInstance(key.getAlgorithm());
            dcipher = Cipher.getInstance(key.getAlgorithm());

            // Prepare the parameter to the ciphers
            AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);

            // Create the ciphers
            ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
            dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
        } catch (InvalidAlgorithmParameterException e) {
        } catch (InvalidKeySpecException e) {
        } catch (NoSuchPaddingException e) {
        } catch (NoSuchAlgorithmException e) {
        } catch (InvalidKeyException e) {
        }
    }

    public String encrypt(String str) {
        try {
            return StringUtils.byte2hex(ecipher.doFinal(str.getBytes("UTF8")));
        } catch (BadPaddingException e) {
        } catch (IllegalBlockSizeException e) {
        } catch (UnsupportedEncodingException e) {
        } catch (IOException e) {
        }
        return null;
    }

    public String decrypt(String str) {
        try {
            return new String(dcipher.doFinal(StringUtils.hex2byte(str)), "UTF8");
        } catch (BadPaddingException e) {
        } catch (IllegalBlockSizeException e) {
        } catch (UnsupportedEncodingException e) {
        } catch (IOException e) {
        }
        return null;
    }
}