逆向解析 1688 商品详情接口：自主构建 Sign 签名算法实战

https://detail.1688.com/offer/{商品ID}.html

https://m.1688.com/offer/{商品ID}.html?sign={签名值}&...

import hashlib
import time
import random
import string
from urllib.parse import urlencode

class SignGenerator:
    def __init__(self):
        # 固定密钥，通过逆向JS代码获得
        self.secret_key = "your_secret_key_from_js"
        
    def generate_random_str(self, length=6):
        """生成随机字符串"""
        return ''.join(random.choices(string.ascii_letters + string.digits, k=length))
    
    def get_timestamp(self):
        """获取当前时间戳（毫秒）"""
        return int(time.time() * 1000)
    
    def sort_params(self, params):
        """按参数名ASCII码从小到大排序"""
        return sorted(params.items(), key=lambda x: x[0])
    
    def generate_sign(self, offer_id):
        """生成sign签名"""
        # 1. 准备基础参数
        params = {
            "offerId": str(offer_id),
            "timestamp": self.get_timestamp(),
            "nonce": self.generate_random_str(),
            "appKey": "12574478",  # 固定appKey
            "dataType": "json"
        }
        
        # 2. 参数排序
        sorted_params = self.sort_params(params)
        
        # 3. 拼接参数为字符串
        param_str = ""
        for key, value in sorted_params:
            param_str += f"{key}{value}"
        
        # 4. 拼接密钥
        sign_str = f"{param_str}{self.secret_key}"
        
        # 5. MD5加密
        md5 = hashlib.md5()
        md5.update(sign_str.encode('utf-8'))
        sign = md5.hexdigest().upper()  # 转为大写
        
        # 6. 添加sign到参数中
        params["sign"] = sign
        
        return params
    
    def generate_url(self, offer_id):
        """生成完整的商品详情接口URL"""
        base_url = "https://m.1688.com/offer/{}.html"
        params = self.generate_sign(offer_id)
        url = base_url.format(offer_id) + "?" + urlencode(params)
        return url

# 使用示例
if __name__ == "__main__":
    generator = SignGenerator()
    offer_id = "610877411453"  # 示例商品ID
    url = generator.generate_url(offer_id)
    print(f"生成的1688商品详情接口URL：\n{url}")

import requests
import json
from 1688_sign_generator import SignGenerator

class ProductFetcher:
    def __init__(self):
        self.sign_generator = SignGenerator()
        self.headers = {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36",
            "Referer": "https://www.1688.com/",
            "Accept-Language": "zh-CN,zh;q=0.9"
        }
        
    def fetch_product_detail(self, offer_id):
        """获取商品详情数据"""
        try:
            # 生成带签名的URL
            url = self.sign_generator.generate_url(offer_id)
            
            # 发送请求
            response = requests.get(url, headers=self.headers, timeout=10)
            response.raise_for_status()  # 抛出HTTP错误
            
            # 解析响应
            data = response.json()
            
            # 提取关键信息
            if data.get("success"):
                product_info = {
                    "offer_id": offer_id,
                    "title": data.get("data", {}).get("title"),
                    "price": data.get("data", {}).get("price"),
                    "seller": data.get("data", {}).get("seller", {}).get("name"),
                    "location": data.get("data", {}).get("seller", {}).get("location"),
                    "sales_count": data.get("data", {}).get("tradeCount")
                }
                return product_info
            else:
                print(f"获取商品详情失败: {data.get('errorMessage')}")
                return None
                
        except Exception as e:
            print(f"请求发生错误: {str(e)}")
            return None

# 使用示例
if __name__ == "__main__":
    fetcher = ProductFetcher()
    offer_id = "610877411453"  # 示例商品ID
    product_detail = fetcher.fetch_product_detail(offer_id)
    
    if product_detail:
        print("商品详情:")
        print(json.dumps(product_detail, ensure_ascii=False, indent=2))