/*
  
  
  
 * Copyright (C) 2018 Baidu, Inc. All Rights Reserved.
  
  
  
 */
  
  
  
/*
  
  
  
 * Copyright (C) 2018 Baidu, Inc. All Rights Reserved.
  
  
  
 */
  
  
  
package com.baidu.utils.secruity;
  
  
  

  
  
  
import java.nio.charset.Charset;
  
  
  
import java.util.Arrays;
  
  
  
import javax.crypto.Cipher;
  
  
  
import javax.crypto.spec.IvParameterSpec;
  
  
  
import javax.crypto.spec.SecretKeySpec;
  
  
  
import org.apache.commons.codec.binary.Base64;
  
  
  

  
  
  
public class Demo {
  
  
  
 private static Charset CHARSET = Charset.forName("utf-8");
  
  
  

  
  
  
 /**
  
  
  
 * 對密文進(jìn)行解密
  
  
  
 *
  
  
  
 * @param text 需要解密的密文
  
  
  
 *
  
  
  
 * @return 解密得到的明文
  
  
  
 *
  
  
  
 * @throws Exception 異常錯誤信息
  
  
  
 */
  
  
  
 public String decrypt(String text, String sessionKey,String ivStr) throws Exception {
  
  
  
 byte[] aesKey = Base64.decodeBase64(sessionKey + "=");
  
  
  
 byte[] original;
  
  
  
 try {
  
  
  
 Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
  
  
  
 SecretKeySpec keySpec = new SecretKeySpec(aesKey, "AES");
  
  
  
 byte[] ivBytes = Base64.decodeBase64(ivStr);
  
  
  
 IvParameterSpec iv = new IvParameterSpec(ivBytes);
  
  
  
 cipher.init(Cipher.DECRYPT_MODE, keySpec, iv);
  
  
  
 byte[] encrypted = Base64.decodeBase64(text);
  
  
  
 original = cipher.doFinal(encrypted);
  
  
  
 } catch (Exception e) {
  
  
  
 throw new Exception(e);
  
  
  
 }
  
  
  
 String xmlContent;
  
  
  
 String fromClientId;
  
  
  
 try {
  
  
  
 // 去除補(bǔ)位字符
  
  
  
 byte[] bytes = PKCS7Encoder.decode(original);
  
  
  
 // 分離16位隨機(jī)字符串,網(wǎng)絡(luò)字節(jié)序和ClientId
  
  
  
 byte[] networkOrder = Arrays.copyOfRange(bytes, 16, 20);
  
  
  
 int xmlLength = recoverNetworkBytesOrder(networkOrder);
  
  
  
 xmlContent = new String(Arrays.copyOfRange(bytes, 20, 20 + xmlLength), CHARSET);
  
  
  
 fromClientId = new String(Arrays.copyOfRange(bytes, 20 + xmlLength, bytes.length), CHARSET);
  
  
  
 } catch (Exception e) {
  
  
  
 throw new Exception(e);
  
  
  
 }
  
  
  
 return xmlContent;
  
  
  
 }
  
  
  

  
  
  
 public static String getType(Object test) {
  
  
  
 return test.getClass().getName().toString();
  
  
  

  
  
  
 }
  
  
  

  
  
  
 /**
  
  
  
 * 還原4個(gè)字節(jié)的網(wǎng)絡(luò)字節(jié)序
  
  
  
 *
  
  
  
 * @param orderBytes 字節(jié)碼
  
  
  
 *
  
  
  
 * @return sourceNumber
  
  
  
 */
  
  
  
 private int recoverNetworkBytesOrder(byte[] orderBytes) {
  
  
  
 int sourceNumber = 0;
  
  
  
 int length = 4;
  
  
  
 int number = 8;
  
  
  
 for (int i = 0; i < length; i++) {
  
  
  
 sourceNumber <<= number;
  
  
  
 sourceNumber |= orderBytes[i] & 0xff;
  
  
  
 }
  
  
  
 return sourceNumber;
  
  
  
 }
  
  
  

  
  
  
 /**
  
  
  
 * 加密解密demo
  
  
  
 * 
  
  
  
 * @param args
  
  
  
 * @throws Exception
  
  
  
 */
  
  
  
 public static void main(String[] args) throws Exception {
  
  
  
 String dy = "toMIrTrp2WovaM4RUoqsrBX4kR7p5JThrzY8bW4ZTBKm4YPRr0CfxY8ZZFwk0RJIPEVCVNebRuN3h6zOIHrHrjdvz5hcKkRfX3VO4OfoHJ3LiZv5uVRl6056iLBgNm+x2HY6T07A40aKeYJQDT3kmgdaAi3UB7NUlrEFUpAuZ2Tsm5B+bF3lnbmUzhskTCFE";
  
  
  

  
  
  
 String sessionKey = "a28bea08d86e426f8d51e024194eae6f";
  
  
  
 String iv = "a28bea08d86e426f8d51ew==";
  
  
  

  
  
  
 Demo demo = new Demo();
  
  
  
 String dd = demo.decrypt(dy, sessionKey, iv);
  
  
  
 System.out.println(dd);
  
  
  
 }
  
  
  
}
  
  
  
class PKCS7Encoder {
  
  
  

  
  
  
 static Charset CHARSET = Charset.forName("utf-8");
  
  
  
 static int BLOCK_SIZE = 32;
  
  
  

  
  
  
 /**
  
  
  
 * 獲得對明文進(jìn)行補(bǔ)位填充的字節(jié).
  
  
  
 *
  
  
  
 * @param count 需要進(jìn)行填充補(bǔ)位操作的明文字節(jié)個(gè)數(shù)
  
  
  
 *
  
  
  
 * @return 補(bǔ)齊用的字節(jié)數(shù)組
  
  
  
 */
  
  
  
 static byte[] encode(int count) {
  
  
  
 // 計(jì)算需要填充的位數(shù)
  
  
  
 int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE);
  
  
  
 if (amountToPad == 0) {
  
  
  
 amountToPad = BLOCK_SIZE;
  
  
  
 }
  
  
  
 // 獲得補(bǔ)位所用的字符
  
  
  
 char padChr = chr(amountToPad);
  
  
  
 String tmp = new String();
  
  
  
 for (int index = 0; index < amountToPad; index++) {
  
  
  
 tmp += padChr;
  
  
  
 }
  
  
  
 return tmp.getBytes(CHARSET);
  
  
  
 }
  
  
  

  
  
  
 /**
  
  
  
 * 刪除解密后明文的補(bǔ)位字符
  
  
  
 *
  
  
  
 * @param decrypted 解密后的明文
  
  
  
 *
  
  
  
 * @return 刪除補(bǔ)位字符后的明文
  
  
  
 */
  
  
  
 static byte[] decode(byte[] decrypted) {
  
  
  
 int pad = (int) decrypted[decrypted.length - 1];
  
  
  
 if (pad < 1 || pad > 32) {
  
  
  
 pad = 0;
  
  
  
 }
  
  
  
 return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad);
  
  
  
 }
  
  
  

  
  
  
 /**
  
  
  
 * 將數(shù)字轉(zhuǎn)化成ASCII碼對應(yīng)的字符，用于對明文進(jìn)行補(bǔ)碼
  
  
  
 *
  
  
  
 * @param a 需要轉(zhuǎn)化的數(shù)字
  
  
  
 *
  
  
  
 * @return 轉(zhuǎn)化得到的字符
  
  
  
 */
  
  
  
 static char chr(int a) {
  
  
  
 byte target = (byte) (a & 0xFF);
  
  
  
 return (char) target;
  
  
  
 }
  
  
  

  
  
  
}
 
 
 

涉及加解密的開放數(shù)據(jù)接口

各場景解密獲取的數(shù)據(jù)結(jié)構(gòu)請參照相應(yīng)功能的接口文檔說明
獲取用戶信息 - button 組件方式、獲取用戶手機(jī)號

解密常見問題

java 解密報(bào) OOM 錯誤解決辦法：受美國軟件出口限制，JDK 默認(rèn)使用的 AES 算法最高只能支持 128 位。如需要更高位的支持需要從 oracle 官網(wǎng)下載 Java 密碼技術(shù)擴(kuò)展（JCE）更換 JAVA_HOME/jre/lib/security 目錄下的：local_policy.jar 和 US_export_policy.jar。

下載地址：https://www.oracle.com/technetwork/java/javase/downloads/jce-all-download-5170447.html