service-wechat/app/service/weixin.js

'use strict';

const assert = require('assert');
const uuid = require('uuid');
const _ = require('lodash');
const { BusinessError, ErrorCode } = require('naf-core').Error;
const crypto = require('crypto');
const Service = require('egg').Service;

class WeixinAuthService extends Service {
  constructor(ctx) {
    super(ctx, {});
  }

  // 取得微信AccessToken
  async accesstoken({ appid }) {
    assert(appid, '缺少appid参数项');
    const key = `visit:auth:accesstoken:${appid}`;
    const val = await this.app.redis.get(key);
    const data = {};
    if (val) {
      const { access_token } = JSON.parse(val);
      data.access_token = access_token;
    } else {
      const { wxapi } = this.app.config;
      const appidlist = wxapi;
      const wxapp = _.find(appidlist, { appid });
      const feturl = `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${appid}&secret=${wxapp.appSecret}`;
      const result = await this.ctx.curl(feturl, {
        method: 'get',
        headers: {
          'content-type': 'application/json',
        },
        dataType: 'json',
      });
        if (result) {
        // console.log(result);
        const val = JSON.stringify(result.data);
        await this.app.redis.set(key, val, 'EX', 7200);
        data.access_token = result.data.access_token;
      }
    }
    return data;
  }

  // 取得微信jsapiticket
  async jsapiticket({ appid }) {
    assert(appid, '缺少appid参数项');
    const result = await this.accesstoken({ appid });
    const accesstoken = result.access_token;
    assert(accesstoken, '缺少access_token参数项');
    const key = `visit:auth:jsapiticket:${appid}`;
    const val = await this.app.redis.get(key);
    const data = {};
    if (val) {
      const { ticket } = JSON.parse(val);
      data.ticket = ticket;
    } else {
      const feturl = `https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=${accesstoken}&type=jsapi`;
      const result = await this.ctx.curl(feturl, {
        method: 'get',
        headers: {
          'content-type': 'application/json',
        },
        dataType: 'json',
      });
      if (result) {
        if (result.data.errcode === 0) {
          const val = JSON.stringify(result.data);
          await this.app.redis.set(key, val, 'EX', 7200);
          data.ticket = result.data.ticket;
        }

      }
    }
    return data;
  }

  // 签名算法
  async getsign({ appid, url }) {
    assert(appid, '缺少appid参数项');
    assert(url, '缺少url参数项');
    const result = await this.jsapiticket({ appid });
    // const { wxapi } = this.app.config;
    // const appidlist = wxapi;
    // const wxapp = _.find(appidlist, { appid });
    const noncestr = await this.createNonceStr();
    const timestamp = await this.createTimestamp();
    const ret = {
      jsapi_ticket: result.ticket,
      noncestr,
      timestamp,
      url,
    };
    const string = await this.raw(ret);
    ret.sign = await this.sha1(string);
    ret.appid = appid;
    return ret;
  }

  // sha1加密
  async sha1(str) {
    const shasum = crypto.createHash('sha1');
    shasum.update(str);
    str = shasum.digest('hex');
    return str;
  }

  // 生成签名的时间戳
  async createTimestamp() {
    return parseInt(new Date().getTime() / 1000) + '';
  }

  // 生成签名的随机串
  async createNonceStr() {
    return Math.random().toString(36).substr(2, 15);
  }

  // 对参数对象进行字典排序
  // @param  {对象} args 签名所需参数对象
  // @return {字符串}    排序后生成字符串
  async raw(args) {
    let keys = Object.keys(args);
    keys = keys.sort();
    const newArgs = {};
    keys.forEach(function(key) {
      newArgs[key.toLowerCase()] = args[key];
    });

    let string = '';
    for (const k in newArgs) {
      string += '&' + k + '=' + newArgs[k];
    }
    string = string.substr(1);
    return string;
  }

}

module.exports = WeixinAuthService;