【以下内容是在thinkphp框架中编写的，做简单修改就可使用】
一、扩展
1-1、支付扩展
扩展路径：extend/wxpay/Wx.php，根据项目实际情况修改。
<?php
/*** User: Lee* Date: 2025/2/23* Time: 22:23*/namespace extend\wxpay;class Wx
{private $appid=''; // 小程序idprivate $mch_id=''; // 商户号private $serial_no=''; // 商户证书序列号private $private_key=''; // 商户私钥private $api_key=''; // API密钥private $notify_url='https://*******/callback.html'; // 支付结果通知地址private $apiclient_cert_url = ''; // apiclient_cert.pem文件在服务器的磁盘路径private $apiclient_key_url = ''; // apiclient_key.pem文件在服务器的磁盘路径/*** 构造函数** @param string $mch_id 商户号* @param string $serial_no 商户证书序列号* @param string $private_key 商户私钥* @param string $api_key API密钥* @param string $notify_url 支付结果通知地址*/public function __construct(){$serial_no = $this->getSerialNoFromCert($this->apiclient_cert_url);$this->serial_no = $serial_no;$this->private_key = file_get_contents($this->apiclient_key_url);}/*** 统一下单接口** @param string $openid 用户openid* @param string $out_trade_no 商户订单号* @param string $description 商品描述* @param int $amount 订单金额（单位：分）* @return array 返回统一下单结果*/public function unifiedOrder($openid, $out_trade_no, $description, $amount){// 统一下单接口URL$url = "https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi";// 请求参数$params = ['appid' => $this->appid, // 小程序或公众号的appid'mchid' => $this->mch_id,'description' => $description,'out_trade_no' => $out_trade_no,'notify_url' => $this->notify_url,'amount' => ['total' => $amount, // 订单金额（单位：分）'currency' => 'CNY', // 货币类型],'payer' => ['openid' => $openid, // 用户openid],];// 生成签名$authorization = $this->generateAuthorization('POST', $url, $params);// 发送HTTP请求$response = $this->httpPost($url, json_encode($params), ['Authorization: ' . $authorization,'Content-Type: application/json','Accept: application/json','User-Agent:yaode/1.0',]);// 解析响应return json_decode($response, true);}/*** 生成签名** @param string $method HTTP方法（GET/POST等）* @param string $url 请求URL* @param array $body 请求体* @return string 返回Authorization头*/private function generateAuthorization($method, $url, $body){// 1. 生成随机字符串$nonce_str = $this->generateNonceStr();// 2. 生成时间戳$timestamp = time();// 3. 生成签名原文$signature = $this->generateSignature($method, $url, $timestamp, $nonce_str, $body);// 4. 生成Authorization头return sprintf('WECHATPAY2-SHA256-RSA2048 mchid="%s",nonce_str="%s",timestamp="%d",serial_no="%s",signature="%s"',$this->mch_id,$nonce_str,$timestamp,$this->serial_no,$signature);}/*** 生成签名** @param string $method HTTP方法* @param string $url 请求URL* @param int $timestamp 时间戳* @param string $nonce_str 随机字符串* @param array $body 请求体* @return string 返回签名*/private function generateSignature($method, $url, $timestamp, $nonce_str, $body){// 1. 拼接签名原文$message = sprintf("%s\n%s\n%d\n%s\n%s\n",$method,parse_url($url, PHP_URL_PATH),$timestamp,$nonce_str,json_encode($body));// 2. 使用私钥生成签名openssl_sign($message, $signature, $this->private_key, OPENSSL_ALGO_SHA256);// 3. 返回Base64编码的签名return base64_encode($signature);}/*** 生成随机字符串*/private function generateNonceStr($length = 32){$chars = "abcdefghijklmnopqrstuvwxyz0123456789";$str = "";for ($i = 0; $i < $length; $i++) {$str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);}return $str;}/*** 发送HTTP POST请求*/private function httpPost($url, $data, $headers = []){$ch = curl_init();curl_setopt($ch, CURLOPT_URL, $url);curl_setopt($ch, CURLOPT_POST, true);curl_setopt($ch, CURLOPT_POSTFIELDS, $data);curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // 不验证SSL证书$response = curl_exec($ch);curl_close($ch);return $response;}public function getSerialNoFromCert($certPath) {$cert = file_get_contents($certPath);$ssl = openssl_x509_parse($cert);return $ssl['serialNumberHex'];}/*** 生成小程序调起支付所需的参数** @param string $prepay_id 统一下单接口返回的prepay_id* @return array 返回小程序调起支付所需的参数*/public function getPaymentParams($prepay_id){// 参数$params = ['appId' => $this->appid, // 小程序或公众号的appid'timeStamp' => (string)time(), // 时间戳'nonceStr' => $this->generateNonceStr(), // 随机字符串'package' => 'prepay_id=' . $prepay_id, // 预支付交易会话标识'signType' => 'RSA', // 签名类型];// 生成签名$params['paySign'] = $this->generateSignature_($params);return $params;}private function generateSignature_($params){$stringToSign = sprintf("%s\n%s\n%s\n%s\n",$params['appId'],$params['timeStamp'],$params['nonceStr'],$params['package']);// 3. 使用商户私钥生成签名openssl_sign($stringToSign, $signature, $this->private_key, OPENSSL_ALGO_SHA256);// 4. 返回 Base64 编码的签名return base64_encode($signature);}}1-2、回调扩展
路径：extend/wxpay/AesUtil.php，根据项目实际情况修改。
下面代码是微信支付文档给的代码示例，可用。
<?php
/*** User: Lee* Date: 2025/2/28* Time: 17:10*/namespace extend\api\wxpay;class AesUtil
{public $aesKey = 'API密钥';const KEY_LENGTH_BYTE = 32;const AUTH_TAG_LENGTH_BYTE = 16;/*** Constructor*/publicfunction __construct(){$aesKey = 'IAMpnZCXj70oRGuS5gA4N00fHVcCXJJp';if (strlen($aesKey) != self::KEY_LENGTH_BYTE) {throw new InvalidArgumentException('无效的ApiV3Key，长度应为32个字节');}$this->aesKey = $aesKey;}/*** Decrypt AEAD_AES_256_GCM ciphertext** @param string $associatedData AES GCM additional authentication data* @param string $nonceStr AES GCM nonce* @param string $ciphertext AES GCM cipher text** @return string|bool Decrypted string on success or FALSE on failure*/publicfunction decryptToString($associatedData, $nonceStr, $ciphertext){$ciphertext = \base64_decode($ciphertext);if (strlen($ciphertext) <= self::AUTH_TAG_LENGTH_BYTE) {return false;}// ext-sodium (default installed on >= PHP 7.2)if (function_exists('\sodium_crypto_aead_aes256gcm_is_available') && \sodium_crypto_aead_aes256gcm_is_available()) {return \sodium_crypto_aead_aes256gcm_decrypt($ciphertext, $associatedData, $nonceStr, $this->aesKey);}// ext-libsodium (need install libsodium-php 1.x via pecl)if (function_exists('\Sodium\crypto_aead_aes256gcm_is_available') && \Sodium\crypto_aead_aes256gcm_is_available()) {return \Sodium\crypto_aead_aes256gcm_decrypt($ciphertext, $associatedData, $nonceStr, $this->aesKey);}// openssl (PHP >= 7.1 support AEAD)if (PHP_VERSION_ID >= 70100 && in_array('aes-256-gcm', \openssl_get_cipher_methods())) {$ctext = substr($ciphertext, 0, -self::AUTH_TAG_LENGTH_BYTE);$authTag = substr($ciphertext, -self::AUTH_TAG_LENGTH_BYTE);return \openssl_decrypt($ctext, 'aes-256-gcm', $this->aesKey, \OPENSSL_RAW_DATA, $nonceStr,$authTag, $associatedData);}throw new \RuntimeException('AEAD_AES_256_GCM需要PHP 7.1以上或者安装libsodium-php');}
}二、controller文件
controller文件路径：app/api/controoler/Pay.php，根据项目实际情况修改。
<?php
/*** User: Lee* Date: 2025/2/23* Time: 17:05*/namespace app\api\controller;use extend\api\wxpay\Wx;class Pay extends BaseApi
{public function pay(){// 订单编号$out_trade_no = $this->params['out_trade_no'];$token = $this->checkToken();if ($token['code'] < 0) return $this->response($token);// 这里写业务逻辑$total_fee = 1; // 订单金额（单位：分）$openid = '用户openid';$body = '描述';$Wx = new Wx();$res = $Wx->unifiedOrder($openid, $out_trade_no, $body, $total_fee);if (isset($res['prepay_id'])) {// 生成小程序调起支付所需的参数$paymentParams = $Wx->getPaymentParams($res['prepay_id']);// 根据项目情况修改返回信息格式及参数return json(['data'=>array_merge($res,$paymentParams)]);}else{// 根据项目情况修改返回信息格式及参数return json();}}
}三、回调
<?php
/*** User: Lee* Date: 2025/2/23* Time: 15:21*/namespace app\api\controller;use extend\wxpay\AesUtil;class Callback
{public $appid='';public $mch_id=''; // 商户号public $serial_no=''; // 商户证书序列号public $private_key=''; // 商户私钥public $public_key=''; // 商户公钥public $api_key=''; // API密钥const AUTH_TAG_LENGTH_BYTE = 16;private $notify_url='https://*******/callback.html'; // 支付结果通知地址private $apiclient_cert_url = ''; // apiclient_cert.pem文件在服务器的磁盘路径private $apiclient_key_url = ''; // apiclient_key.pem文件在服务器的磁盘路径public function __construct(){$serial_no = $this->getSerialNoFromCert($this->apiclient_cert_url);$this->serial_no = $serial_no;$this->private_key = file_get_contents($this->apiclient_key_url);}public function getSerialNoFromCert($certPath) {$cert = file_get_contents($certPath);$ssl = openssl_x509_parse($cert);return $ssl['serialNumberHex'];}public function index(){$return = file_get_contents('php://input');if(!empty($return)){$return = json_decode($return, true);$all = getallheaders();if($return['event_type']!='TRANSACTION.SUCCESS' || empty($return['resource'])){return json(['code'=>"FAIL",'message'=>"失败-3"]);}$associatedData = $return['resource']['associated_data']; //获取associated_data数据,附加数据$nonceStr = $return['resource']['nonce']; //获取nonce数据,加密使用的随机串$ciphertext = $return['resource']['ciphertext']; //获取ciphertext数据,base64编码后的数据密文$aes = new AesUtil();$res = $aes->decryptToString($associatedData,$nonceStr,$ciphertext);if(!empty($res)){$res = json_decode($res,true);if(!empty($res)){$out_trade_no = $res['out_trade_no'];// 这里写业务逻辑return json();}else{return json(['code'=>"FAIL",'message'=>"失败-2"]);}}}return json(['code'=>"FAIL",'message'=>"失败-1"]);}
}