解密的时候报错:
javax.crypto.BadPaddingException: Given final block not properly padded
该异常是在解密的时候抛出的,加密的方法没有问题。
但是两个方法的唯一差别是Cipher对象的模式不一样,这就排除了程序写错的可能性。再看一下异常的揭示信息,大概的意思是:提供的字块不符合填补的。原来在用DES加密的时候,最后一位长度不足64的,它会自动填补到64,那么在我们进行字节数组到字串的转化过程中,可以把它填补的不可见字符改变了,所以引发系统抛出异常。大家还记得邮件传输通常会把一些信息编码保存,就是Base64,那样保证了信息的完整性,所以我们就是利用一下下了。为了方便使用,再写一个新的方法封装一下原来的方法: 1. DataDecrypt 2. DataEncrypt
加密:
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
public class DescryptCoder {
private final static String DES = "DES";
/**
*
* @param src 数据源
* @param key 密钥,长度必须是8的倍数
* @return
* @throws Exception
*/
public static byte[] decrypt(byte[] src, byte[] key) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
// 从原始密匙数据创建一个DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);
// 创建一个密匙工厂,然后用它把DESKeySpec对象转换成一个SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
SecretKey securekey = keyFactory.generateSecret(dks);
// Cipher对象实际完成解密操作
Cipher cipher = Cipher.getInstance(DES);
// 用密匙初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
// 正式执行解密操作
return cipher.doFinal(src);
}
public final static String decrypt(String data, String key) {
try {
//这里就没走
return new String(decrypt(String2byte(data.getBytes()), key.getBytes()));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static byte[] String2byte(byte[] b) {
if ((b.length % 2) != 0)
throw new IllegalArgumentException("长度不是偶数");
byte[] b2 = new byte[b.length / 2];
for (int n = 0; n < b.length; n += 2) {
String item = new String(b, n, 2);
b2[n / 2] = (byte) Integer.parseInt(item, 16);
}
return b2;
}
public static String DataDecrypt(String str,byte[] key){
String decrypt = null;
try{
byte[] ret = decrypt(Base64.decode(str),key);
decrypt = new String(ret,"UTF-8");
}catch(Exception e){
System.out.print(e);
decrypt = str;
}
return decrypt;
}
public static void main(String[] args){
String desencryptString = decrypt("B00542E93695F4CFCE34FC4393C2F4BF","test中英文杂七烂八混搭@123654{");
System.out.println(desencryptString);
}
//输出:is张三丰
}
解密:
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
public class EncryptCoder {
private final static String DES = "DES";
public static byte[] encrypt(byte[] src, byte[] key) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
// 从原始密匙数据创建DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);
// 创建一个密匙工厂,然后用它把DESKeySpec转换成一个SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
SecretKey securekey = keyFactory.generateSecret(dks);
// Cipher对象实际完成加密操作
Cipher cipher = Cipher.getInstance(DES);
// 用密匙初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
// 正式执行加密操作
return cipher.doFinal(src);
}
/**
*
* @param password 密码
* @param key 加密字符串
* @return
*/
public final static String encrypt(String password, String key) {
try {
return byte2String(encrypt(password.getBytes(), key.getBytes()));
} catch (Exception e) {
}
return null;
}
public static String byte2String(byte[] b) {
String hs = "";
String stmp = "";
for (int n = 0; n < b.length; n++) {
stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
if (stmp.length() == 1)
hs = hs + "0" + stmp;
else
hs = hs + stmp;
}
return hs.toUpperCase();
}
public static String DataEncrypt(String str,byte[] key){
String encrypt = null;
try{
byte[] ret = encrypt(str.getBytes("UTF-8"),key);
encrypt = new String(Base64.encode(ret));
}catch(Exception e){
System.out.print(e);
encrypt = str;
}
return encrypt;
}
public static void main(String[] args){
String encryptString = EncryptCoder.encrypt("is张三丰","test中英文杂七烂八混搭@123654{");
System.out.println("加密后:"+encryptString);
}
//输出:B00542E93695F4CFCE34FC4393C2F4BF
}