DES是一种对称加密算法,所谓对称加密算法:加密和解密使用相同的秘钥的算法。
示例:
public class DESUtil {
private static Key key;
//设置秘钥key
private static String KEY_STR="myKey";
private static String CHARSETNAME="UTF-8";
private static String ALGORITHM="DES";
static{
try{
//生成DES算法对象
KeyGenerator generator=KeyGenerator.getInstance(ALGORITHM);
//运用SHA1安全策略
SecureRandom secureRandom=SecureRandom.getInstance("SHA1PRNG");
//设置上密钥种子
secureRandom.setSeed(KEY_STR.getBytes());
//初始化基于SHA1的算法对象
generator.init(secureRandom);
//生成密钥对象
key=generator.generateKey();
generator=null;
}catch(Exception e){
throw new RuntimeException(e);
}
}
/**
* 获取加密的信息
* @param str
* @return
*/
public static String getEncryptString(String str){
//基于BASE64编码,接收byte[]并转换成String
BASE64Encoder base64Encoder=new BASE64Encoder();
try {
// 按UTF8编码
byte[] bytes = str.getBytes(CHARSETNAME);
// 获取加密对象
Cipher cipher = Cipher.getInstance(ALGORITHM);
// 初始化密码信息
cipher.init(Cipher.ENCRYPT_MODE, key);
// 加密
byte[] doFinal = cipher.doFinal(bytes);
// byte[]to encode好的String并返回
return base64Encoder.encode(doFinal);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 获取解密之后的信息
*
* @param str
* @return
*/
public static String getDecryptString(String str) {
// 基于BASE64编码,接收byte[]并转换成String
BASE64Decoder base64decoder = new BASE64Decoder();
try {
// 将字符串decode成byte[]
byte[] bytes = base64decoder.decodeBuffer(str);
// 获取解密对象
Cipher cipher = Cipher.getInstance(ALGORITHM);
// 初始化解密信息
cipher.init(Cipher.DECRYPT_MODE, key);
// 解密
byte[] doFinal = cipher.doFinal(bytes);
// 返回解密之后的信息
return new String(doFinal, CHARSETNAME);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public static void main(String[] args) {
//加密
String encode = getEncryptString("zhangsan");
System.out.println(encode);
//解密
String decode = getDecryptString(encode);
System.out.println(decode);
}
}