Java 使用AES-128 ECB PKCS7Padding解密，如何操作

Question

近期在和终端设备协议对接，遇到了这种加解密问题，有没有哪位道友遇见过，先谢过了

Answer 1

楼主我给你找了答案，我没分了，平时又经常要下载，有用就给分！

JAVA实现“AES/ECB/PKCS7Padding”对称加解密，尤其是 AES256的加解密需要注意两点：

技术出口限制，国内的JDK 默认不支持；


PKCS7Padding JAVA默认不支持PKCS7Padding填充模式，需借助第三方提供者。

解决出口限制问题，下载以下两个包替换jdk安装路径下： jre\lib\security 的同名文件

jdk1.7：http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html

jdk1.8：http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html

解决无提供者的问题，maven工程pom.xml文件中添加以下配置：

org.bouncycastle
bcprov-jdk15
1.44

完成以上步骤，在类初始化时添加如下代码：

static{ if (Security.getProvider("BC") == null) { Security .addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider()); } else { Security.removeProvider("BC"); Security .addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider()); }}

完整的工具类：

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Base64;

/**

• @program: featureapp
• @description:
• @author: Mr.Li

• @create: 2018-09-13 22:14
  **/
  public class AES256 {
  public static byte[] encrypt(String content, String password) {
  try {
  //"AES"：请求的密钥算法的标准名称
  KeyGenerator kgen = KeyGenerator.getInstance("AES");
  //256：密钥生成参数；securerandom：密钥生成器的随机源
  SecureRandom securerandom = new SecureRandom(tohash256Deal(password));
  kgen.init(256, securerandom);
  //生成秘密（对称）密钥
  SecretKey secretKey = kgen.generateKey();
  //返回基本编码格式的密钥
  byte[] enCodeFormat = secretKey.getEncoded();
  //根据给定的字节数组构造一个密钥。enCodeFormat：密钥内容；"AES"：与给定的密钥内容相关联的密钥算法的名称
  SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
  //将提供程序添加到下一个可用位置
  Security.addProvider(new BouncyCastleProvider());
  //创建一个实现指定转换的 Cipher对象，该转换由指定的提供程序提供。
  //"AES/ECB/PKCS7Padding"：转换的名称；"BC"：提供程序的名称
  Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");

  cipher.init(Cipher.ENCRYPT_MODE, key);
  byte[] byteContent = content.getBytes("utf-8");
  byte[] cryptograph = cipher.doFinal(byteContent);
  return Base64.encode(cryptograph);
  

  } catch (Exception e) {
  e.printStackTrace();
  }
  return null;
  }

  public static String decrypt(byte[] cryptograph, String password) {
  try {
  KeyGenerator kgen = KeyGenerator.getInstance("AES");
  SecureRandom securerandom = new SecureRandom(tohash256Deal(password));
  kgen.init(256, securerandom);
  SecretKey secretKey = kgen.generateKey();
  byte[] enCodeFormat = secretKey.getEncoded();
  SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
  Security.addProvider(new BouncyCastleProvider());
  Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");

      cipher.init(Cipher.DECRYPT_MODE, key);
      byte[] content = cipher.doFinal(Base64.decode(cryptograph));
      return new String(content);
  } catch (Exception e) {
      e.printStackTrace();
  }
  return null;
  

  }

  private 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();
  }

  /*private 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;
  }*/

  private static byte[] tohash256Deal(String datastr) {
  try {
  MessageDigest digester=MessageDigest.getInstance("SHA-256");
  digester.update(datastr.getBytes());
  byte[] hex=digester.digest();
  return hex;
  } catch (NoSuchAlgorithmException e) {
  throw new RuntimeException(e.getMessage());
  }
  }

  public static void main(String[] args) {

  String content = "0f607264fc6318a92b9e13c65db7cd3c";
  String password = "zsyy";
  System.out.println("明文：" + content);
  System.out.println("key：" + password);
  
  byte[] encryptResult = AES256.encrypt(content, password);
  System.out.println("密文：" + AES256.parseByte2HexStr(encryptResult));
  
  String decryptResult = AES256.decrypt(encryptResult, password);
  System.out.println("解密：" + decryptResult);
  

  }
  }
  ————————————————
  版权声明：本文为CSDN博主「李君的csdn」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
  原文链接：https://blog.csdn.net/lijun169/article/details/82736103