1、生成(验证)签名的代码(安装包：pycryptodomex==3.9.4。有个sdk：python-alipay-sdk)，密钥类型RSA 用SHA。苹果手机验证通过，Android手机应该也一样

import binascii
import json
import urllib
from Cryptodome.Hash import SHA, SHA256
from Cryptodome.PublicKey import RSA
from Cryptodome.Signature import PKCS1_v1_5
from myapp.alipay.configs import alipay_public_key_begin_end, alipay_merchant_private_key_begin_end, sign_type
from utils.helper import SimException


class SignRSA(object):
    MAXLINESIZE = 76  # Excluding the CRLF
    MAXBINSIZE = (MAXLINESIZE // 4) * 3

    def __init__(self, **kwargs):
        self.kwargs = kwargs
        self.sign_type = sign_type  # rsa 用sha, rsa2方式用SHA256
        self.private_key = alipay_merchant_private_key_begin_end
        self.public_key = alipay_public_key_begin_end  # alipay_sand_public_key_begin_end

        if sign_type not in ("RSA", "RSA2"):
            raise SimException("Unsupported sign type {}".format(sign_type))

    @staticmethod
    def get_ordered_data(data: dict):
        #  还没生成签名 前不能传 sign 和 sign_type 进行排序
        complex_keys = [k for k, v in data.items() if isinstance(v, dict)]

        # 将字典类型的数据dump出来
        for key in complex_keys:
            data[key] = json.dumps(data[key], separators=(',', ':'))

        return sorted([(k, v) for k, v in data.items()])

    @staticmethod
    def encode_for_sign(ordered_items):
        unsigned_str = "&".join('''{}="{}"'''.format(k, v) for k, v in ordered_items)
        return unsigned_str.encode('utf-8').decode('unicode_escape')

    def verify_with_public_key(self, sign):
        """
        :parameter sign:
            The signature that needs to be validated.
        :type sign: byte string
        """
        ordered_item = self.get_ordered_data(self.kwargs)
        params = "&".join(u"{}={}".format(k, v) for k, v in ordered_item)

        # 公钥验签
        signer = PKCS1_v1_5.new(RSA.importKey(self.public_key))

        if self.sign_type == 'RSA':
            msg_hash = SHA.new()
        else:
            msg_hash = SHA256.new()
        msg_hash.update(params.encode("utf8"))

        # sign = urllib.parse.unquote_plus(sign)
        # sign = self.decodebytes(sign.encode())  # 反操作：base64 编码，转换为unicode表示并移除回车
        return signer.verify(msg_hash, self.decodebytes(sign.encode("utf8")))  # true / false

    def sign_with_private_key(self):
        ordered_item = self.get_ordered_data(self.kwargs)
        unsigned_str = self.encode_for_sign(ordered_item)

        signer = PKCS1_v1_5.new(RSA.importKey(self.private_key))

        # rsa 用sha, rsa2方式用SHA256
        if self.sign_type == 'RSA':
            rand_hash = SHA.new()
        else:
            rand_hash = SHA256.new()
        rand_hash.update(unsigned_str.encode())
        signature = signer.sign(rand_hash)

        # base64 编码，转换为unicode表示并移除回车
        sign = self.encodebytes(signature).decode("utf8").replace("\n", "")

        # app支付中，对于参数sign，需要进行urlencode
        sign = urllib.parse.quote_plus(sign)

        data = self.kwargs
        data['sign'] = sign
        data['sign_type'] = self.sign_type
        ordered_data = self.get_ordered_data(data)

        return f'''{self.encode_for_sign(ordered_data)}'''

    def encodebytes(self, s):
        """Encode a bytestring into a bytes object containing multiple lines
        of base-64 data."""
        self._input_type_check(s)
        pieces = []
        for i in range(0, len(s), self.MAXBINSIZE):
            chunk = s[i: i + self.MAXBINSIZE]
            pieces.append(binascii.b2a_base64(chunk))
        return b"".join(pieces)

    def decodebytes(self, byte_str):
        """Decode a bytestring of base-64 data into a bytes object."""
        self._input_type_check(byte_str)
        return binascii.a2b_base64(byte_str)

    @staticmethod
    def _input_type_check(s):
        try:
            m = memoryview(s)
        except TypeError as err:
            msg = "expected bytes-like object, not %s" % s.__class__.__name__
            raise TypeError(msg) from err
        if m.format not in ('c', 'b', 'B'):
            msg = ("expected single byte elements, not %r from %s" %
                   (m.format, s.__class__.__name__))
            raise TypeError(msg)
        if m.ndim != 1:
            msg = ("expected 1-D data, not %d-D data from %s" %
                   (m.ndim, s.__class__.__name__))
            raise TypeError(msg)



class SimException(Exception):

    def __init__(self, *args, **kwargs):
        super(SimException, self).__init__(*args, **kwargs)


2）生成签名：partner、seller_id一样；境外收单不能用 CNY 且 网站、移动端都是申请(New Cross-border Online Payment(PC/WAP))；移动端使用NEW_WAP_OVERSEAS_SELLER，网站用WAP_OVERSEAS_SELLER；移动端和网站支付宝接口对应下面的data需要的参数也有所不同
data = {
	'service': 'mobile.securitypay.pay',
	'partner': '2088621948283543',
	'_input_charset': 'UTF-8',
	'subject': 'WT(随便取？)',
	'out_trade_no': '自己系统生成的订单号',
	'currency': 'USD',
	"forex_biz": "FP",
	"seller_id": '2088621948283543',
	'total_fee': '0.01',
	'refer_url': "http://www.wtf.com/",
	'payment_type': 1,
	'product_code': 'NEW_WAP_OVERSEAS_SELLER',
	'trade_information': {
		'business_type': '1',
		'other_business_type': '嗯哼..'
	},
	'return_url': '自己系统后端 同步接口',
	'notify_url': '自己系统后端 异步接口'
}

sign_rsa = SignRSA(**data)
order_info = sign_rsa.sign_with_private_key()
移动端将order_info通过sdk调用就可以唤醒支付宝并支付了

2、支付宝工具：

1）、支付宝签名调试工具：
https://isandbox.alipaydev.com/melitigo/Test_083.html

2）支付宝在线服务(要人工服务就回复 人工)
https://cschannel.alipay.com/mada.htm?scene=ef678de5d81cff29&envType=3

3）支付宝公私钥生成工具
https://isandbox.alipaydev.com/melitigo/Test_085.html

4）官方文档
https://global.alipay.com/doc/global/mobile_securitypay_pay

3、支付宝的通知(异步通知)

3、调用(python3)，除了sign_type、sign两个参数，其余都要参与签名过程

    data = request.POST.dict()
    sign = data.pop('sign', None)
    data.pop('sign_type', None)

    trade_status = data.get('trade_status', None)
    out_trade_no = data.get('out_trade_no', None)
    total_fee = data.get('total_fee', None)
    trade_no = data.get('trade_no', None)

    # 首先验签
    sign_rsa = SignRSA(**data)
    sign_rsa.verify_with_public_key(sign) # 返回 true 或 false

4、支付宝通知(同步通知。SDK返回的信息，移动端可以通过sdk收到)，即就是同步通知不需要进行验签直接关闭支付宝app就可以了？是的吧应该