微信支付：小微商户申请入驻第一步：平台证书序列号的获取

文档地址

申请入驻文档：https://pay.weixin.qq.com/wiki/doc/api/xiaowei.php?chapter=19_2

平台证书获取文档：https://pay.weixin.qq.com/wiki/doc/api/xiaowei.php?chapter=19_11

1. 微信支付商户平台升级API证书，升级后才可成功调用本接口。

具体操作看：http://kf.qq.com/faq/180824BrQnQB180824m6v2yA.html
需要注意的问题，不要着急关闭软件，等全部完成之后再关闭。

2. 平台证书获取(不需要证书)

查看文档，得知我们需要的参数

1. mch_id ： 商户号
2. nonce_str：随机字符串，不大于32位
3. sign：签名
4. sign_type：签名类型
5. mch_key：签名参数

为了方便，首先，导入jar

• 解析xml 需要dom4j
• 由于我们需要从后台调用微信的接口，需要httpclient

         <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>
        <dependency>
            <groupId>jaxen</groupId>
            <artifactId>jaxen</artifactId>
            <version>1.1.6</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.6</version>
        </dependency>  

这边需要注意的，就是加密，暂只支持HMAC-SHA256,下面提供工具类

Java代码

package com.li.utils;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

/**
 * 签名加密工具类
 *
 * @author bertonlee
 */
@Slf4j
public class SignUtil {

    /**
     * 微信证书HMAC-SHA256签名
     *
     * @param params
     * @param secret
     * @return
     */
    public static String wechatCertficatesSignBySHA256(Map<String, String> params, String secret) {
        // 需要保证排序
        SortedMap<String, String> sortedMap = new TreeMap<>(params);
        // 将参数拼接成字符串
        StringBuilder toSign = new StringBuilder();
        for (String key : sortedMap.keySet()) {
            String value = params.get(key);
            if (StringUtils.isNotEmpty(value) && !"sign".equals(key) && !"key".equals(key)) {
                toSign.append(key).append("=").append(value).append("&");
            }
        }
        toSign.append("key=").append(secret);

        return sha256_HMAC(toSign.toString(), secret);
    }

    /**
     * 加密HMAC-SHA256
     *
     * @param message
     * @param secret
     * @return
     */
    private static String sha256_HMAC(String message, String secret) {
        try {
            Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
            SecretKeySpec secret_key = new SecretKeySpec(secret.getBytes(), "HmacSHA256");
            sha256_HMAC.init(secret_key);
            byte[] bytes = sha256_HMAC.doFinal(message.getBytes());
            String sign = byteArrayToHexString(bytes);
            sign = sign.toUpperCase();
            return sign;
        } catch (Exception e) {
            log.error("sha256_HMAC加密异常", e);
        }
        return null;
    }

    /**
     * 加密后的字节转字符串
     *
     * @param b
     * @return
     */
    private static String byteArrayToHexString(byte[] b) {
        StringBuilder hs = new StringBuilder();
        String stmp = null;
        for (int n = 0; b != null && n < b.length; n++) {
            stmp = Integer.toHexString(b[n] & 0XFF);
            if (stmp.length() == 1)
                hs.append('0');
            hs.append(stmp);
        }
        return hs.toString().toLowerCase();
    }
}

• 其中主要方法wechatCertficatesSignBySHA256
• 将参数排序后进行拼接，规则查看微信官方的加密规则
• 然后进行加密
• secret 也就是我们的API 密钥

实现代码

package com.li.getcertficates.service.impl;

import com.li.getcertficates.service.CertFicatesService;
import com.li.utils.SignUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.HttpHeaders;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

@Service
@Slf4j
public class CertFicatesServiceImpl implements CertFicatesService {
    @Override
    public String getCertFicates() {
        // 初始化一个HttpClient
        CloseableHttpClient httpClient = HttpClients.createDefault();
        // Post请求
        HttpPost httpPost = new HttpPost("https://api.mch.weixin.qq.com/risk/getcertficates");
        /**
         * 这边需要您提供微信分配的商户号跟API密钥
         */
        Map<String, String> param = new HashMap<>(4);
        param.put("mch_id", "微信分配的商户号");
        param.put("nonce_str", UUID.randomUUID().toString().replace("-", ""));
        // 暂只支持HMAC-SHA256 加密
        param.put("sign_type", "HMAC-SHA256");
        // 对你的参数进行加密处理
        param.put("sign", SignUtil.wechatCertficatesSignBySHA256(param, "API密钥(mch_key)"));
        httpPost.setEntity(new StringEntity(map2Xml(param), "UTF-8"));
        httpPost.setHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_XML.getMimeType());
        try {
            HttpResponse httpResponse = httpClient.execute(httpPost);
            log.info("获取平台证书响应 {}", httpResponse);
            if (httpResponse != null && httpResponse.getStatusLine().getStatusCode() == 200) {
                String responseEntity = EntityUtils.toString(httpResponse.getEntity());
                Document document = DocumentHelper.parseText(responseEntity);
                if ("SUCCESS".equalsIgnoreCase(document.selectSingleNode("//return_code").getStringValue())
                        && "SUCCESS".equalsIgnoreCase(document.selectSingleNode("//result_code").getStringValue())) {
                    return document.selectSingleNode("//certificates").getStringValue();
                }
                log.error("请求平台证书序号响应异常 {}", document.selectSingleNode("//return_msg").getStringValue());
            }
        } catch (Exception e) {
            log.error("执行httpclient请求平台证书序号错误 {}", e);
        }
        return null;
    }
    /**
     * map对象转xml
     *
     * @param map
     * @return
     */
    private String map2Xml(Map<String, String> map) {
        StringBuilder result = new StringBuilder();
        result.append("<xml>");
        if (map != null && map.keySet().size() > 0) {
            map.forEach((key, value) -> {
                result.append("<" + key + "><![CDATA[");
                result.append(value);
                result.append("]]></" + key + ">");
            });
        }
        result.append("</xml>");
        return result.toString();
    }
}

• 具体逻辑不难，单纯调个接口，响应结果

可以自己写个main方法，也可以写个单元测试

最终请求参数

<xml>
<sign_type>HMAC-SHA256</sign_type>
<nonce_str>qazwsxedcrfvtgbyhnujmiklopasdwefka</nonce_str>
<mch_id>商户号</mch_id>
<sign>FD29B578B31C509B45B7C2779803D9E41B68E6B84AEB1EBDE47DCA00049B649B</sign>
</xml>

响应结果

<xml> 
<return_code><![CDATA[SUCCESS]]></return_code> 
<return_msg><![CDATA[OK]]></return_msg> 
<result_code><![CDATA[SUCCESS]]></result_code> 
<nonce_str><![CDATA[PnDRNZSFzpp2ieUq]]></nonce_str> 
<sign><![CDATA[AD5919F5FE6D77C308ABEE1A4021CB9839C3F04D7C2FE68FC765011EA3BBEB0F]]></sign> 
<mch_id><![CDATA[1900006511]]></mch_id> 
<certificates><![CDATA[{"data":[{"serial_no":"42A5C4F7F70D57D0576BBEDA0E0928D6E5C4F003","effective_time":"2017-08-18 14:52:04","expire_time":"2022-08-17 14:52:04","encrypt_certificate":{"algorithm":"AEAD_AES_256_GCM","nonce":"bfcb2bd59c97","associated_data":"certificate","ciphertext":"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"}}]}]]></certificates> 
</xml>

如上，其他基础响应外，多了个certificates

1. data里面的serial_no，我们申请入驻需要的参数就是这个
2. 其次是encrypt_certificate，主要用来平台证书解密成密钥，为申请入驻接口敏感信息加密处理,后面申请入驻时详细讲解

第一步完成，欲知后事如何，且听下回分解

版权声明：本文为不会代码的小白原创文章，转载需添加小白地址 ： https://www.ccode.live/bertonlee/list/10?from=art

源代码：https://github.com/bertonlee/micro-merchant/tree/getcertficates 分支：getcertficates

欢迎Star

欢迎关注

欢迎关注公众号“码上开发”，每天分享最新技术资讯