JAVA 实现AES加密的两种方法

原创
2018/03/15 15:48
阅读数 3.4K
/**
 *AES加密解密工具类
 *@author M-Y
 */
public class AESUtil {
      private static final Logger logger = Logger.getLogger(AESUtil.class);
      private static final String defaultCharset = "UTF-8";
      private static final String KEY_AES = "AES";
      private static final String KEY = "123456";
    /**
     * 加密
     *
     * @param data 需要加密的内容
     * @param key 加密密码
     * @return
     */
    public static String encrypt(String data, String key) {
        return doAES(data, key, Cipher.ENCRYPT_MODE);
    }

    /**
     * 解密
     *
     * @param data 待解密内容
     * @param key 解密密钥
     * @return
     */
    public static String decrypt(String data, String key) {
        return doAES(data, key, Cipher.DECRYPT_MODE);
    }

    /**
     * 加解密
     *
     * @param data 待处理数据
     * @param password  密钥
     * @param mode 加解密mode
     * @return
     */
    private static String doAES(String data, String key, int mode) {
        try {
            if (StringUtils.isBlank(data) || StringUtils.isBlank(key)) {
                return null;
            }
            //判断是加密还是解密
            boolean encrypt = mode == Cipher.ENCRYPT_MODE;
            byte[] content;
            //true 加密内容 false 解密内容
            if (encrypt) {
                content = data.getBytes(defaultCharset);
            } else {
                content = parseHexStr2Byte(data);
            }
            //1.构造密钥生成器,指定为AES算法,不区分大小写
            KeyGenerator kgen = KeyGenerator.getInstance(KEY_AES);
            //2.根据ecnodeRules规则初始化密钥生成器
            //生成一个128位的随机源,根据传入的字节数组
            kgen.init(128, new SecureRandom(key.getBytes()));
            //3.产生原始对称密钥
            SecretKey secretKey = kgen.generateKey();
            //4.获得原始对称密钥的字节数组
            byte[] enCodeFormat = secretKey.getEncoded();
            //5.根据字节数组生成AES密钥
            SecretKeySpec keySpec = new SecretKeySpec(enCodeFormat, KEY_AES);
            //6.根据指定算法AES自成密码器
            Cipher cipher = Cipher.getInstance(KEY_AES);// 创建密码器
            //7.初始化密码器,第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作,第二个参数为使用的KEY
            cipher.init(mode, keySpec);// 初始化
            byte[] result = cipher.doFinal(content);
            if (encrypt) {
                //将二进制转换成16进制
                return parseByte2HexStr(result);
            } else {
                return new String(result, defaultCharset);
            }
        } catch (Exception e) {
            logger.error("AES 密文处理异常", e);
        }
        return null;
    }
    /**
     * 将二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }
    /**
     * 将16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }
    public static void main(String[] args) throws Exception {  
        String content = "{'repairPhone':'18547854787','customPhone':'12365478965','captchav':'58m7'}";  
        System.out.println("加密前:" + content);  
        System.out.println("加密密钥和解密密钥:" + KEY);  
        String encrypt = encrypt(content, KEY);  
        System.out.println("加密后:" + encrypt);  
        String decrypt = decrypt(encrypt, KEY);  
        System.out.println("解密后:" + decrypt);  
    }  
}
加密前:{'repairPhone':'18547854787','customPhone':'12365478965','captchav':'58m7'}
加密密钥和解密密钥:123456
加密后:2A3D75862E69BF61DFAD94017E930227A715C8E533AA1A12361D6BE6E190EC5EE77AA66CAC8005A643BFB26134EE60398C30104B1F7FB3CC6B78795368A86D8215B88A5C80D9C2E4936EEEB0DECA7A88
解密后:{'repairPhone':'18547854787','customPhone':'12365478965','captchav':'58m7'}

方法二:替换AESUtil 类中的doAES方法并加上以下成员   

    private static final String KEY_MD5 = "MD5";
    private static MessageDigest md5Digest;

    static {
        try {
            md5Digest = MessageDigest.getInstance(KEY_MD5);
        } catch (NoSuchAlgorithmException e) {
            //
        }
    }
/**
     * 加解密
     *
     * @param data
     * @param key
     * @param mode
     * @return
     */
    private static String doAES(String data, String key, int mode) {
        try {
            if (StringUtils.isBlank(data) || StringUtils.isBlank(key)) {
                return null;
            }
            boolean encrypt = mode == Cipher.ENCRYPT_MODE;
            byte[] content;
            //true 加密内容 false 解密内容
            if (encrypt) {
                content = data.getBytes(defaultCharset);
            } else {
                 content = parseHexStr2Byte(data);
            }
            SecretKeySpec keySpec = new SecretKeySpec(md5Digest.digest(key.getBytes(defaultCharset)), KEY_AES);//构造一个密钥
            Cipher cipher = Cipher.getInstance(KEY_AES);// 创建密码器
            cipher.init(mode, keySpec);// 初始化
            byte[] result = cipher.doFinal(content);//加密或解密
            if (encrypt) {
                return parseByte2HexStr(result);
            } else {
                return new String(result, defaultCharset);
            }
        } catch (Exception e) {
            logger.error("AES 密文处理异常", e);
        }
        return null;
    }

 

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