java使用AES 工具类 加解密解决数据保密性问题

Posted 2021-10-30 BBinChina

场景：

请求权限时，将请求的返回值进行AES加密成token，用户通过临时token请求权限时，解密获取请求的数据，避免请求数据被拦截解析。

密文返回十六进制，解决 前端可能通过url请求时，将token设置为url参数会导致url格式不正确（包含’/’ '+'等特殊符号）

package com.digquant.util;

import org.apache.commons.lang3.StringUtils;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

public class EncryptUtil {

    private static final String KEY_ALGORITHM = "AES";
    private static final String CHAR_SET = "UTF-8";

    /**
     * AES的密钥长度
     */
    private static final Integer SECRET_KEY_LENGTH = 128;
    /**
     * 加解密算法/工作模式/填充方式
     */
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";


    /**
     * AES加密操作
     *
     * @param content  待加密内容
     * @param password 加密密码
     * @return 返回Base64转码后的加密数据
     */
    public static String encrypt(String content, String password) {
        if (StringUtils.isAnyEmpty(content, password)) {
            return null;
        }
        try {
            //创建密码器
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            byte[] byteContent = content.getBytes(CHAR_SET);
            //初始化为加密密码器
            cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(password));
            byte[] encryptByte = cipher.doFinal(byteContent);
            return parseByte2HexStr(encryptByte);
        } catch (Exception e) {

        }
        return null;
    }

    /**
     * AES解密操作
     *
     * @param encryptContent 加密的密文
     * @param password       解密的密钥
     * @return
     */
    public static String decrypt(String encryptContent, String password) {
        if (StringUtils.isAnyEmpty(encryptContent, password)) {
            return null;
        }
        Cipher cipher = null;
        try {
            cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            //设置为解密模式
            cipher.init(Cipher.DECRYPT_MODE, getSecretKey(password));
            //执行解密操作
            parseHexStr2Byte(encryptContent);

            byte[] result = cipher.doFinal(parseHexStr2Byte(encryptContent));
            return new String(result, CHAR_SET);
        } catch (Exception e) {
        }
        return null;
    }

    private static SecretKeySpec getSecretKey(final String password) throws NoSuchAlgorithmException {
        //生成指定算法密钥的生成器
        KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM);
        //linux系统下填充
        SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
        random.setSeed(password.getBytes());
       
        keyGenerator.init(SECRET_KEY_LENGTH, random);
        
        //生成密钥
        SecretKey secretKey = keyGenerator.generateKey();
        //转换成AES的密钥
        return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);
    }

    /**
     * 将二进制转换成16进制
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        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
     */
    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;
    }
}

PS:

javax.crypto.BadPaddingException: Given final block not properly padded

这是在linux上的AES key需要填充