微信退款回调信息解密笔记

解密步骤：

（1）对加密串A做base64解码，得到加密串B

（3）用key*对加密串B做AES-256-ECB解密（PKCS7Padding）

import java.util.Base64;

public class Base64Util {
	/**
	 * 解码
	 * @param encodedText
	 * @return
	 */
	 public static byte[] decode(String encodedText){
	        final Base64.Decoder decoder = Base64.getDecoder();
	        return decoder.decode(encodedText);
	    }
	    /**
	     * 编码
	     * @param data
	     * @return
	     */
	    public static String encode(byte[] data){
	        final Base64.Encoder encoder = Base64.getEncoder();
	        return encoder.encodeToString(data);
	    }
}

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


public class AESUtil {
	/** 
     * 密钥算法 
     */  
    private static final String ALGORITHM = "AES";  
    /** 
     * 加解密算法/工作模式/填充方式 
     */  
    private static final String ALGORITHM_MODE_PADDING = "AES/ECB/PKCS5Padding";  
 
    /** 
     * AES加密 
     * 
     * @param data 
     * @return 
     * @throws Exception 
     */  
    public static String encryptData(String data,String password) throws Exception {  
        // 创建密码器  
        Cipher cipher = Cipher.getInstance(ALGORITHM_MODE_PADDING);
        SecretKeySpec key = new SecretKeySpec(MD5.MD5Encode(password).toLowerCase().getBytes(), ALGORITHM);
        // 初始化  
        cipher.init(Cipher.ENCRYPT_MODE, key);  
        return Base64Util.encode(cipher.doFinal(data.getBytes()));  
    }  
  
    /** 
     * AES解密 
     *  
     * @param base64Data 
     * @return 
     * @throws Exception 
     */  
    public static String decryptData(String base64Data,String password) throws Exception {  
        Cipher cipher = Cipher.getInstance(ALGORITHM_MODE_PADDING);  
        SecretKeySpec key = new SecretKeySpec(MD5.MD5Encode(password).toLowerCase().getBytes(), ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, key);  
        byte[] decode = Base64Util.decode(base64Data);
        byte[] doFinal = cipher.doFinal(decode);
        return new String(doFinal,"utf-8");  
    }  
}

/**
	 * InputStream流转换成String字符串
	 * @param inStream InputStream流
	 * @param encoding 编码格式
	 * @return String字符串
	 */
	public static String inputStreamToString(InputStream inStream, String encoding){
	 String result = null;
	 try {
	 if(inStream != null){
	  ByteArrayOutputStream outStream = new ByteArrayOutputStream();
	  byte[] tempBytes = new byte[1024];
	  int count = -1;
	  while((count = inStream.read(tempBytes, 0, 1024)) != -1){
	    outStream.write(tempBytes, 0, count);
	  }
	  tempBytes = null;
	  outStream.flush();
	  result = new String(outStream.toByteArray(), encoding);
	 }
	 } catch (Exception e) {
	 result = null;
	 }
	 return result;
	}
	/**
	 * xml转换成map
	 * @param xml
	 * @return
	 */
	public static Map<String, String> readStringXmlOut(String xml) {
		Map<String, String> map = new HashMap<String, String>();
		Document doc = null;
		try {
			doc = DocumentHelper.parseText(xml); // 将字符串转为XML
			Element rootElt = doc.getRootElement(); // 获取根节点
			List<Element> list = rootElt.elements();// 获取根节点下所有节点
			for (Element element : list) { // 遍历节点
				map.put(element.getName(), element.getText()); // 节点的name为map的key，text为map的value
			}
		} catch (DocumentException e) {
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return map;
	}

测试方法

打印结果: