JAVA对称加密算法

[转：http://liulang203.iteye.com/blog/1028257]

一、DES算法 
   设置算法及参数 

//算法名称
public static final String KEY_ALGORITHM = "DES";
//算法名称/加密模式/填充方式
public static final String CIPHER_ALGORITHM = "DES/ECB/PKCS5Padding";

   生成密钥 

KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM);
keyGenerator.init(56);
SecretKey secretKey = keyGenerator.generateKey();
return secretKey.getEncoded();

   还原密钥 

private static Key toKey(byte[] key) {
    DESKeySpec des = new DESKeySpec(key);
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_ALGORITHM);
    SecretKey secretKey = keyFactory.generateSecret(des);
    return secretKey;
}

    加密 

public static byte[] encrypt(byte[] data ,byte[] key) {
    Key k = toKey(key);
    Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
    cipher.init(Cipher.ENCRYPT_MODE, k);
    return cipher.doFinal();
}

     解密 

Key k = toKey(key);
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, k);
return cipher.doFinal();

注：加密和解密的区别在于init初始化时模式 
二、三重DES---DESede 
    其过程同上只需把变声明算法改变一下,Java6支持的密钥长度为112或168 

//算法名称
public static final String KEY_ALGORITHM = "DESede";
//算法名称/加密模式/填充方式
public static final String CIPHER_ALGORITHM = "DESede/ECB/PKCS5Padding";

   还原密钥 

DESedeKeySpec des = new DESedeKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_ALGORITHM);
        SecretKey secretKey = keyFactory.generateSecret(des);

三、AES算法 
   同DES基本一致。 

public static final String KEY_ALGORITHM = "AES";
public static final String CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";
private static Key toKey(byte[] key){
    SecretKey secretKey = new SecretKeySpec(key, KEY_ALGORITHM);
    return secretKey;
}

四、IDEA 同AES算法一致。 

public static final String KEY_ALGORITHM = "IDEA";
public static final String CIPHER_ALGORITHM = "IDEA/ECB/PKCS5Padding";
private static Key toKey(byte[] key){
    SecretKey secretKey = new SecretKeySpec(key, KEY_ALGORITHM);
    return secretKey;
}

五、基本口令加密---PBE 

import java.security.Key;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;

public class PBECode {
    public static final String ALGORITHM = "PBEWITHMD5andDES";
    //迭代次数
    public static final int ITERATION_COUNT = 100;
    /**
     * 盐初始化<br>
     * 盐长度必须为8字节
     * @return byte[] 盐
     */
    public static byte[] initSalt(){
        //实例化安全随机数
        SecureRandom random = new SecureRandom();
        //生产盐
        return random.generateSeed(8);
    }
    /**
     * 转换密钥
     * @param password 密码
     * @return key 密钥
     * @throws Exception
     */
    private static Key toKey(String password)throws Exception{
        //密钥材料转换
        PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray());
        //实例化
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
        SecretKey secretKey = keyFactory.generateSecret(keySpec);
        return secretKey;
    }
    /**
     * 加密
     * @param data 数据
     * @param password 密码
     * @param salt 盐
     * @return byte[] 加密数据
     * @throws Exception
     */
    public static byte[] encrypt(byte[] data,String password,byte[] salt) throws Exception{
        Key key = toKey(password);
        //实例化PBE参数材料
        PBEParameterSpec parameterSpec = new PBEParameterSpec(salt, ITERATION_COUNT);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, key,parameterSpec);
        return cipher.doFinal(data);
    }
    public static byte[] decrypt(byte[] data, String password,byte[] salt) throws Exception{
        Key key = toKey(password);
        //实例化PBE参数材料
        PBEParameterSpec parameterSpec = new PBEParameterSpec(salt, ITERATION_COUNT);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, key,parameterSpec);
        return cipher.doFinal(data);
    }
}