python 微信v3支付接口 签名 Native支付

微信支付需要用到微信公众平台账号、微信商户账号。
注册完成后，我们需要在平台找到 appid、mchid、证书等
具体操作：微信支付接入前准备(Native支付)
这里仅演示 签名的生成方法、Authorization的传递以及出现401 Unauthorized的解决方案。

# _*_ coding: utf-8 _*_
"""
Time:     2022/2/28 14:33
Author:   Jyun
Version:  V 0.1
File:     wxpay.py
Blog:     https://ctrlcv.blog.youkuaiyun.com
"""
import time
import json
import random
import string
import requests

from base64 import b64encode
from urllib.parse import urlparse
from Cryptodome.PublicKey import RSA
from Cryptodome.Signature import pkcs1_15
from Cryptodome.Hash import SHA256


# 生成二维码
def to_qr(text):
    import qrcode
    img = qrcode.make(text)
    with open('pay.png', 'wb') as f:
        img.save(f)


class WXPay:
    """ 微信 Native支付
    """

    def __init__(self):
        self.appid = "wx1fxxxxxc0eeexxx" # APPID
        self.mchid = "100000001"  # 商户号
        self.payment_url = 'https://api.mch.weixin.qq.com/v3/pay/transactions/native'  # Native支付下单接口
        self.refund_url = 'https://api.mch.weixin.qq.com/v3/refund/domestic/refunds'  # 退款接口
        self.notify_url = "https://weixin.qq.com/"  # 通知url
        self.serial_no = '48757XXXX9D9CD835841B45969B0XXXXXXXXXXXX'  # 商户证书序列号
        self.apiclient_key = './apiclient_key.pem'  # 本地证书路径

    # 生成签名
    def get_sign(self, sign_str):
        rsa_key = RSA.importKey(open(self.apiclient_key).read())
        signer = pkcs1_15.new(rsa_key)
        digest = SHA256.new(sign_str.encode('utf8'))
        sign = b64encode(signer.sign(digest)).decode('utf-8')
        return sign

    def request(self, url: str, method: str, data: dict = None):
        data = json.dumps(data) if data else ''
        random_str = ''.join(random.choice(string.ascii_uppercase + string.digits) for _ in range(32))
        timestamp = str(int(time.time()))
        sign_str = '\n'.join([
            method.upper(),  # HTTP请求方法
            url.split(urlparse(url).netloc)[-1],  # path+args
            timestamp,  # 时间戳
            random_str,  # 请求随机串
            data, ''  # 请求报文主体
        ])  # 结尾空窜仅用于让后面多一个\n
        sign = self.get_sign(sign_str)

        headers = {
            'Content-Type': 'application/json; charset=UTF-8',
            'Authorization': f'WECHATPAY2-SHA256-RSA2048 mchid="{self.mchid}",nonce_str="{random_str}",signature="{sign}",timestamp="{timestamp}",serial_no="{self.serial_no}"'
        }
        response = requests.request(url=url, method=method, data=data, headers=headers)
        return response

    # 支付
    def payment(self, order_no, total, description):
        data = {
            "mchid": self.mchid,
            "out_trade_no": order_no,  # 订单号
            "appid": self.appid,
            "description": description,  # 商品描述
            "notify_url": self.notify_url,
            "amount": {
                "total": total,  # 总金额(分)
                "currency": "CNY"
            }
        }
        return self.request(self.payment_url, 'POST', data)

    # 退款
    def refund(self, transaction_id, out_refund_no, refund, reason):
        data = {
            "transaction_id": transaction_id,  # 微信支付订单号(交易单号)
            "out_refund_no": out_refund_no,  # 商户退款单号(商户单号)
            "reason": reason,  # 退款原因
            "notify_url": self.notify_url,  # 通知Url
            "amount": {
                "total": refund,  # 订单金额
                "refund": refund,  # 退款金额(分)
                "currency": "CNY"
            }
        }
        return self.request(self.refund_url, 'POST', data)

    def application_bill(self):
        url = 'https://api.mch.weixin.qq.com/v3/bill/tradebill?bill_date=2022-02-28&bill_type=ALL'
        return self.request(url, 'GET')


if __name__ == "__main__":
    wx = WXPay()
    resp = wx.payment("80000000018", 1, "订单支付-测试")
    print(resp.text)
    to_qr(resp.json()['code_url'])

    # resp = wx.refund('4200002222222222000000000000', 'T80000000018', 1, '商品已售完')
    # print(resp.text)