golang版微信小程序登录和ase解码微信公开数据

• 虽然微信提供了很多版语言的代码,但是没有go版,很简单的,大家想偷个懒就直接copy我的代码就好了
  

1. 首选用code登录微信服务器,返回openID和session_key

   type RespWXSmall struct {
   	Openid     string `json:"openid"`      //用户唯一标识
   	Sessionkey string `json:"session_key"` //会话**
   	Unionid    string `json:"unionid"`     //用户在开放平台的唯一标识符，在满足 UnionID 下发条件的情况下会返回，详见 UnionID 机制说明。
   	Errcode    int    `json:"errcode"`     //错误码
   	ErrMsg     string `json:"errMsg"`      //错误信息
   }
   
   func loginWXSmall(code string) (wxInfo RespWXSmall, err error) {
   	//https://api.weixin.qq.com/sns/jscode2session?appid=APPID&secret=SECRET&js_code=JSCODE&grant_type=authorization_code
   	appId := "******"
   	appSecret := "***************"
   	url := "https://api.weixin.qq.com/sns/jscode2session?appid=%s&secret=%s&js_code=%s&grant_type=authorization_code"
   	resp, err := http.Get(fmt.Sprintf(url, appId, appSecret, code))
   	if err != nil {
   		return wxInfo, err
   	}
   	defer resp.Body.Close()
   
   	err = tools.BindJson(resp.Body, &wxInfo)
   	if err != nil {
   		return wxInfo, err
   	}
   	if wxInfo.Errcode != 0 {
   		return wxInfo, errors.New(fmt.Sprintf("code: %d, errmsg: %s", wxInfo.Errcode, wxInfo.ErrMsg))
   	}
   	return wxInfo, nil
   }
   
   

2. 获得放回结果了,进入的业务代码,处理自己的逻辑后,在给小程序返回

• aes解码微信的公开数据,我参考python的代码

  func DecryptWXOpenData(sessionKey, encryptData, iv string) (map[string]interface{}, error) {
  	decodeBytes, err := base64.StdEncoding.DecodeString(encryptData)
  	if err != nil {
  		return nil, err
  	}
  	sessionKeyBytes, err := base64.StdEncoding.DecodeString(sessionKey)
  	if err != nil {
  		return nil, err
  	}
  	ivBytes, err := base64.StdEncoding.DecodeString(iv)
  	if err != nil {
  		return nil, err
  	}
  	dataBytes, err := AesDecrypt(decodeBytes, sessionKeyBytes, ivBytes)
  	fmt.Println(string(dataBytes))
  	m := make(map[string]interface{})
  	err = json.Unmarshal(dataBytes, &m)
  	if err != nil {
  		fmt.Println(err)
  		return nil, err
  	}
  	temp := m["watermark"].(map[string]interface{})
  	appid := temp["appid"].(string)
  	if appid != setting.WxSmallConf.Appid {
  		return nil, fmt.Errorf("invalid appid, get !%s!", appid)
  	}
  	if err != nil {
  		return nil, err
  	}
  	return m, nil
  
  }
  
  func AesDecrypt(crypted, key, iv []byte) ([]byte, error) {
  	block, err := aes.NewCipher(key)
  	if err != nil {
  		return nil, err
  	}
  	//blockSize := block.BlockSize()
  	blockMode := cipher.NewCBCDecrypter(block, iv)
  	origData := make([]byte, len(crypted))
  	blockMode.CryptBlocks(origData, crypted)
  	//获取的数据尾端有'/x0e'占位符,去除它
  	for i, ch := range origData {
  		if ch == '\x0e' {
  			origData[i] = ' '
  		}
  	}
  	//{"phoneNumber":"15082726017","purePhoneNumber":"15082726017","countryCode":"86","watermark":{"timestamp":1539657521,"appid":"wx4c6c3ed14736228c"}}//<nil>
  	return origData, nil
  }