Java实现AES256加解密

时间:2023-01-14 18:29:36
一.代码 package com.handler;import java.io.UnsupportedEncodingException;import java.security.Key; import java.security.Security;import javax.crypto.Cipher; import javax.crypto.KeyGenerator;import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; 
public class AES256Encryption{ 
public static final String KEY_ALGORITHM="AES";          
public static final String CIPHER_ALGORITHM="AES/ECB/PKCS7Padding";          public static byte[] initkey() throws Exception{           //实例化密钥生成器           Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());          KeyGenerator kg=KeyGenerator.getInstance(KEY_ALGORITHM, "BC");           kg.init(256);           kg.init(128);               SecretKey secretKey=kg.generateKey();              return secretKey.getEncoded();      }
public static byte[] initRootKey() throws Exception{ 
          return new byte[] { 0x08, 0x08, 0x04, 0x0b, 0x02, 0x0f, 0x0b, 0x0c,              0x01, 0x03, 0x09, 0x07, 0x0c, 0x03, 0x07, 0x0a, 0x04, 0x0f,               0x06, 0x0f, 0x0e, 0x09, 0x05, 0x01, 0x0a, 0x0a, 0x01, 0x09,             0x06, 0x07, 0x09, 0x0d };   }
public static Key toKey(byte[] key) throws Exception{ 
SecretKey secretKey=new SecretKeySpec(key,KEY_ALGORITHM);            return secretKey;     }          public static byte[] encrypt(byte[] data,byte[] key) throws Exception{        Key k=toKey(key);    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());   Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM, "BC"); 
   cipher.init(Cipher.ENCRYPT_MODE, k); 
   return cipher.doFinal(data);     } 
public static byte[] decrypt(byte[] data,byte[] key) throws Exception{ 
        Key k =toKey(key); 
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());        Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM, "BC"); 
        cipher.init(Cipher.DECRYPT_MODE, k); 
        return cipher.doFinal(data);     }    public static void main(String[] args) throws UnsupportedEncodingException{                   String str="芸sweet";                   //打印原文         System.out.println("原文:"+str); 
         //密钥         byte[] key;                     try {                 //生成随机密钥              key = AES256Encryption.initkey();                          //打印密钥             System.out.print("密钥:");              for(int i = 0;i                System.out.printf("%x", key[i]);             }             System.out.print("\n");                         //加密             byte[] data=AES256Encryption.encrypt(str.getBytes(), key);                         //打印密文             System.out.print("加密后:");                       for(int i = 0;i                System.out.printf("%x", data[i]);             }             System.out.print("\n");                         //解密密文data=AES256Encryption.decrypt(data, key); //打印原文  System.out.println("解密后:"+new String(data));
         } catch (Exception e) {                    e.printStackTrace();        }                    }

二.注意 1.需要在工程中引入 bcprov-jdk15-133.jar 下载链接:http://pan.baidu.com/s/1dDBY9xB 2.替换\jre\lib\security下的local_policy.jar 和 US_export_policy.jar 下载链接:http://pan.baidu.com/s/1dDBY9xB 1)如果程序使用是系统jdk,则替换系统环境变量的jdk中\jre\lib\security下jar包。 2)如果程序是在MyEclipse中运行,则找到MyEclipse使用的jdk(方法:在MyEclipse里面进入window->Preferences->java选项里面有一个Installed JREs的选项,点击右边会出现一个列表,里面有你现在用到的JDK版本及路径),替换该jdk中\jre\lib\security下jar包。 可以解决:java.security.InvalidKeyException: Illegal key size or default parameters异常
三.如果密钥需要存入数据库,则需要对密钥进行base64编码,即将密钥(byte数组)通过base64编码转换成密钥(String类型);从数据库中读取密钥时,则使用base64解码,即将密钥(String类型)转换成密钥(byte数组)。详见《Java实现base64编码》