AES加密

2023-06-25,

package com.edu.hpu;

import java.math.BigInteger;

import java.security.MessageDigest;

import java.security.SecureRandom;

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.spec.SecretKeySpec;

import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;

public class No14 {

public static void main(String[] args) throws Exception {

String content = "***";

System.out.println("加密前:" + content);

String key = "123";

System.out.println("加密密钥和解密密钥:" + (int)'1' + " " + (int)'2' + " " + (int)'3' );

String encrypt = aesEncrypt(content, key);

System.out.println("密文:" + encrypt);

String decrypt = aesDecrypt(encrypt, key);

System.out.println("解密后:" + decrypt);

}

/**

* 将byte[]转为各种进制的字符串

* @param bytes byte[]

* @param radix 可以转换进制的范围,从Character.MIN_RADIX到Character.MAX_RADIX,超出范围后变为10进制

* @return 转换后的字符串

*/

public static String binary(byte[] bytes, int radix){

return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数

}

/**

* base 64 encode

* @param bytes 待编码的byte[]

* @return 编码后的base 64 code

*/

public static String base64Encode(byte[] bytes){

return new BASE64Encoder().encode(bytes);

}

/**

* base 64 decode

* @param base64Code 待解码的base 64 code

* @return 解码后的byte[]

* @throws Exception

*/

public static byte[] base64Decode(String base64Code) throws Exception{

return QStringUtil.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);

}

/**

* 获取byte[]的md5值

* @param bytes byte[]

* @return md5

* @throws Exception

*/

public static byte[] md5(byte[] bytes) throws Exception {

MessageDigest md = MessageDigest.getInstance("MD5");

md.update(bytes);

return md.digest();

}

/**

* 获取字符串md5值

* @param msg

* @return md5

* @throws Exception

*/

public static byte[] md5(String msg) throws Exception {

return QStringUtil.isEmpty(msg) ? null : md5(msg.getBytes());

}

/**

* 结合base64实现md5加密

* @param msg 待加密字符串

* @return 获取md5后转为base64

* @throws Exception

*/

public static String md5Encrypt(String msg) throws Exception{

return QStringUtil.isEmpty(msg) ? null : base64Encode(md5(msg));

}

/**

* AES加密

* @param content 待加密的内容

* @param encryptKey 加密密钥

* @return 加密后的byte[]

* @throws Exception

*/

public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {

//加密解密时都加上,否则不同机器加密结果不一致

KeyGenerator kgen = KeyGenerator.getInstance("AES");

SecureRandom random=SecureRandom.getInstance("SHA1PRNG");

random.setSeed(encryptKey.getBytes());

kgen.init(128, random);

//一般写法

//KeyGenerator kgen = KeyGenerator.getInstance("AES");

//kgen.init(128, new SecureRandom(encryptKey.getBytes()));

Cipher cipher = Cipher.getInstance("AES");

cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));

return cipher.doFinal(content.getBytes("utf-8"));

}

/**

* AES加密为base 64 code

* @param content 待加密的内容

* @param encryptKey 加密密钥

* @return 加密后的base 64 code

* @throws Exception

*/

public static String aesEncrypt(String content, String encryptKey) throws Exception {

return base64Encode(aesEncryptToBytes(content, encryptKey));

}

/**

* AES解密

* @param encryptBytes 待解密的byte[]

* @param decryptKey 解密密钥

* @return 解密后的String

* @throws Exception

*/

public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {

//加密解密时都加上,否则不同机器加密结果不一致

KeyGenerator kgen = KeyGenerator.getInstance("AES");

SecureRandom random=SecureRandom.getInstance("SHA1PRNG");

random.setSeed(decryptKey.getBytes());

kgen.init(128, random);

//一般写法

//KeyGenerator kgen = KeyGenerator.getInstance("AES");

//kgen.init(128, new SecureRandom(decryptKey.getBytes()));

Cipher cipher = Cipher.getInstance("AES");

cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));

byte[] decryptBytes = cipher.doFinal(encryptBytes);

return new String(decryptBytes);

}

/**

* 将base 64 code AES解密

* @param encryptStr 待解密的base 64 code

* @param decryptKey 解密密钥

* @return 解密后的string

* @throws Exception

*/

public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {

return QStringUtil.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);

}

}

class QStringUtil {

public static boolean isEmpty(String str){

if(str==null){

return true;

}else{

return false;

}

}

}

AES加密的相关教程结束。

《AES加密.doc》

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