微信小程序后台获取openid (解密encryptedData)_openidcipher

微信前台调用后台，传CODE 还有加密的文本

 其中unionid 这个是需要在平台绑定的， 一个公司的小程序员，公众号等都 是同一个unionid 需要先绑定

            1.需要微信前端调用wx.login接口获取code。 然后再调用wx.getuserInfo接口获取用户的信息。           
            2. 前端调用服务器接口，将获取到的code，以及encryptedData，和iv一起发送到后端。      
            3. 服务器在解密encryptedData之前，需要调用微信接口获取sessionkey. 有了encryptedData才能解密。

  wx.login({
        success: function (res_login) {
          if (res_login.code){
            wx.getUserInfo({
              success:function(res){
                console.log(res)
                var jsonData = {
                  code: res_login.code,
                  encryptedData: res.encryptedData,
                  iv: res.iv
                };
               wx.request({
                 url: 'http://com.testwechat.comlogin/userinfo',
                 header: { 'Content-Type': 'application/json' },
                 method:'POST',
                 data: jsonData,
                 success: res => {
                   console.log(res.data)
                   wx.hideLoading()
                   this.setData({
                     projectlist: res.data.content
                   })
                 }
               })
              }
            })
       
          }
        }
      })

前台参数至少包含这三个参数

	JSONObject dataObj = JSONObject.parseObject(infoData);
		String  code =  (String) dataObj.get("code");
		String  encryptedData =  (String) dataObj.get("encryptedData");
		String  iv =  (String) dataObj.get("iv");

 private static final String APP_SECRET="";   //写上自己的的
 private static final String APP_ID = "";   //写上自己的的APPID
 
	public JSONObject getSessionKey(String code) {
		String url = "https://api.weixin.qq.com/sns/jscode2session?appid=" + APP_ID + "&secret="
				+ APP_SECRET + "&js_code=" + code + "&grant_type=authorization_code";
		String reusult = GET(url);
		JSONObject oppidObj = JSONObject.parseObject(reusult);
		String openid = (String) oppidObj.get("openid");
		String session_key = (String) oppidObj.get("session_key");
		oppidObj.put("openid", openid);
		oppidObj.put("session_key", session_key);
		if (oppidObj.containsKey("unionid")) {
			oppidObj.put("unionid", (String) oppidObj.get("unionid"));
		}else{
			oppidObj.put("unionid", "");
		}
		return oppidObj;
	}

解密用户传过来的信息

	/**
     * 获取信息
     */
    public JSONObject getUserInfo(String encryptedData,String sessionkey,String iv){
        // 被加密的数据
        byte[] dataByte = Base64.decode(encryptedData);
        // 加密秘钥
        byte[] keyByte = Base64.decode(sessionkey);
        // 偏移量
        byte[] ivByte = Base64.decode(iv);
        try {
               // 如果密钥不足16位，那么就补足.  这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                return JSONObject.parseObject(result);
            }
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidParameterSpecException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
        } catch (NoSuchProviderException e) {
            e.printStackTrace();
        }
        return null;
    }

下面是HPPT请求发送方式了

//发起get请求的方法。
		public static String GET(String url) {
			String result = "";
			BufferedReader in = null;
			InputStream is = null;
			InputStreamReader isr = null;
			try {
				URL realUrl = new URL(url);
				URLConnection conn = realUrl.openConnection();
				conn.connect();
				Map<String, List<String>> map = conn.getHeaderFields();
				is = conn.getInputStream();
				isr = new InputStreamReader(is);
				in = new BufferedReader(isr);
				String line;
				while ((line = in.readLine()) != null) {
					result += line;
				}
			} catch (Exception e) {
				// 异常记录
			} finally {
				try {
					if (in != null) {
						in.close();
					}
					if (is != null) {
						is.close();
					}
					if (isr != null) {
						isr.close();
					}
				} catch (Exception e2) {
					// 异常记录
				}
			}
			return result;
		}

需要的解密加密数据包

  <!-- 注：微信小程序加密解密包 xfire-core, bcprov-jdk1-->
	<dependency>
		    <groupId>org.codehaus.xfire</groupId>
		    <artifactId>xfire-core</artifactId>
		    <version>1.2.6</version>
		</dependency>
		<dependency>
		    <groupId>org.bouncycastle</groupId>
		    <artifactId>bcprov-jdk16</artifactId>
		    <version>1.46</version>
		</dependency>

这些流程配下来，基本可以走通微信接口登录，然后做自己想做的事情