企业用户使用备案资源包进行网站备案ICP并开通微信H5支付（附API V3版本支付nodejs代码）

//APIV3支付
const { Wechatpay } = require('wechatpay-axios-plugin');
const { readFileSync } = require('fs');
// 商户号，支持「普通商户/特约商户」或「服务商商户」
const merchantId = ''; //商户号
const appid = '' // APPID
// 「商户API证书」的「证书序列号」， 通过网页查看
const merchantCertificateSerial = '';
// 从本地文件中加载「商户API私钥」
const merchantPrivateKeyFilePath = '/key/apiclient_key.pem';
const merchantPrivateKeyInstance = readFileSync(merchantPrivateKeyFilePath);
// 「微信支付平台证书」的「证书序列号」，下载器下载后有提示`serial`序列号字段
const platformCertificateSerial = '';
// 从本地文件中加载「微信支付平台证书」，用来验证微信支付请求响应体的签名

const platformCertificateFilePath = '/key/wechatpay_573AB99XXXXXXXXXXXXXX.pem';

const platformCertificateInstance = readFileSync(platformCertificateFilePath);
// 创建支付实例

const wxpay = new Wechatpay({

mchid: merchantId,

serial: merchantCertificateSerial,

privateKey: merchantPrivateKeyInstance,

certs: { [platformCertificateSerial]: platformCertificateInstance, },

});
// 云函数入口函数

exports.main = async (event, context) => {

wxpay.v3.pay.transactions.h5

.post({

appid:appid,

mchid:merchantId,

description:"此处为唤起支付后的页面抬头，商户自拟",

out_trade_no:"AABBCC"+Date.now().toString(),//此处为商户端的订单号，自拟

notify_url:"XXXXX",// 此处为支付通知回调，非常重要，不要填错

amount:{

total:1,// 此处为消费金额，应由前端传入

currency:'CNY'

},

scene_info:{

payer_client_ip:"127.0.0.1",

h5_info:{

type:'Wap'

}

}

})

.then(({data: {h5_url}}) => console.info(h5_url))

.catch(console.error)

}

//nodejs解密

const crypto = require('crypto');

//APIV3 nodejs模块

const { Wechatpay } = require('wechatpay-axios-plugin');

const { readFileSync } = require('fs');

//npm install wechatpay-axios-plugin

// 商户号

const merchantId = '';

// 商户证书序列号

const merchantCertificateSerial = '';

// 商户私钥路径

const merchantPrivateKeyFilePath = './merchant/apiclient_key.pem';

// 商户API私钥 PEM格式的文本字符串或者文件buffer

const merchantPrivateKeyInstance = readFileSync(merchantPrivateKeyFilePath);

// 平台证书

const platformCertificateFilePath = './merchant/wechatpay_XXXXX.pem';

const platformCertificateInstance = readFileSync(platformCertificateFilePath);

//平台证书公钥

const platformPubKeyFilePath = './merchant/wechatpay_XXXXXXXX.pem';

const platformPubKeyInstance = readFileSync(platformPubKeyFilePath);

// 平台证书序列号，下载器下载后有提示序列号字段，也可由命令行

const platformCertificateSerial = '';

//初始化

const wxpay = new Wechatpay({

mchid: merchantId,

serial: merchantCertificateSerial,

privateKey: merchantPrivateKeyInstance,

certs: { [platformCertificateSerial]: platformCertificateInstance, },

});

exports.main = async (event, context) => {

//接收支付通知结果

var body = JSON.parse(event.body);

// 解密 ciphertext字符  AEAD_AES_256_GCM算法，验证消息来源

let ciphertext = body.resource.ciphertext;

let nonce = body.resource.nonce;

let associated_data = body.resource.associated_data;

let apiv3key = "";//商户端的APIV3密钥，在网页中设置

ciphertext = Buffer.from(ciphertext, 'base64');

let authTag = ciphertext.slice(ciphertext.length - 16);

let data = ciphertext.slice(0, ciphertext.length - 16);

let decipher = crypto.createDecipheriv('aes-256-gcm', apiv3key, nonce);

decipher.setAuthTag(authTag);

decipher.setAAD(Buffer.from(associated_data));

let decoded = decipher.update(data, null, 'utf8');

decipher.final();

let payData = JSON.parse(decoded); //解密后的数据

console.log(payData)

var sub_mchid =payData.sub_mchid;

var transaction_id = payData.transaction_id;

var out_trade_no = payData.out_trade_no;
// 商户自行拟定后续逻辑
// TODO

// 收到回调后必须返回如下字段，否则通知会持续进行
return {   
    "code": "SUCCESS",
    "message": "成功"
}

};