crypt.java

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package com.richeninfo.crypt;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: </p>
 * @author xiaolie
 * @version 1.0
 */
import java.security.*;
import javax.crypto.*;
import java.io.*;

public class Crypt {
    //static {
    //    Security.addProvider(new com.sun.crypto.provider.SunJCE());
    //}

    private SecretKey deskey;
    private String algorithm = "Blowfish";
    Cipher c1;
    private static Crypt crypt = null;

    public static Crypt getCrypt(String keyFileName, String algorithm)
            throws FileNotFoundException, IOException, ClassNotFoundException, NoSuchAlgorithmException, NoSuchPaddingException {
        //Security.addProvider(new com.sun.crypto.provider.SunJCE());
        if (crypt == null) {
            return new Crypt(keyFileName, algorithm);
        } else {
            return crypt;
        }
    }

    public static Crypt getCrypt(String keyFileName)
            throws FileNotFoundException, IOException, ClassNotFoundException, NoSuchAlgorithmException, NoSuchPaddingException {
        //Security.addProvider(new com.sun.crypto.provider.SunJCE());
        if (crypt == null) {
            return new Crypt(keyFileName);
        } else {
            return crypt;
        }
    }

    private Crypt(String keyFileName, String algorithm)
            throws FileNotFoundException, IOException, ClassNotFoundException, NoSuchAlgorithmException, NoSuchPaddingException {
        this.algorithm = algorithm;
        ObjectInputStream in = new java.io.ObjectInputStream(new java.io.FileInputStream(keyFileName));
        deskey = (SecretKey) in.readObject();
        in.close();
        c1 = Cipher.getInstance(algorithm);
    }

    private Crypt(String keyFileName)
            throws FileNotFoundException, IOException, ClassNotFoundException, NoSuchAlgorithmException, NoSuchPaddingException {
        ObjectInputStream in = new java.io.ObjectInputStream(new java.io.FileInputStream(keyFileName));
        deskey = (SecretKey) in.readObject();
        in.close();
        c1 = Cipher.getInstance(algorithm);
    }

    public byte[] encrypt(byte[] data, int offset, int len) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        c1.init(Cipher.ENCRYPT_MODE, deskey);
        return c1.doFinal(data, offset, len);
    }

    public byte[] encrypt(byte[] data) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        c1.init(Cipher.ENCRYPT_MODE, deskey);
        return c1.doFinal(data);
    }

    public byte[] decrypt(byte[] data, int offset, int len) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        c1.init(Cipher.DECRYPT_MODE, deskey);
        return c1.doFinal(data, offset, len);
    }

    public byte[] decrypt(byte[] data) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        c1.init(Cipher.DECRYPT_MODE, deskey);
        return c1.doFinal(data);
    }
}