Partager le code de décryptage php de la version v3 du paiement WeChat

//微信原生支付
class Wxpay
{
    /*
     * 支付(小程序支付)
     * @param type $sn        订单编号
     * @param type $money  金额
     * @param type $openid  用户小程序openid
     * @return type
     */
    public static function getPayParam($sn, $money, $openid)
    {
        $url = 'https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi';
        $notify_url = url('/api/weixin/notify');
        $data = [];
        $data['appid'] = Action::config(CONFIG_WXXCX, 'app_id');
        $data['mchid'] = Action::config(CONFIG_WXXCX, 'mchid'); //商户号
        $data['description'] = 'xxx'; //描述？
        $data['out_trade_no'] = $sn; //商户系统内部订单号
        $data['time_expire'] = date('Y-m-d') . 'T' . date('H:i:s', (time() + 1800)) . '+08:00'; //订单失效时间2018-06-08T10:34:56+08:00
        $data['notify_url'] = $notify_url; //异步通知接口地址
        $data['amount'] = ['total' => $money * 100, 'currency' => 'CNY']; //金额
        $data['payer'] = ['openid' => $openid]; //用户
        $re = self::wxCurl($url, $data, 'POST');
        if (!isset($re['prepay_id'])) {
            api_fail('参数获取失败');
        }
        $result = [];
        $result['appId'] = Action::config(CONFIG_WXXCX, 'app_id');
        $result['timeStamp'] = (string)time();
        $result['nonceStr'] = uniqid();
        $result['package'] = 'prepay_id=' . $re['prepay_id'];
        $result['signType'] = 'RSA';
        $result['paySign'] = self::getPaySign($result);
        return $result;
    }
    /**
     * 查询订单
     * @param type $sn
     */
    public static function select($sn, $return = false)
    {
        $mchid = Action::config(CONFIG_WXXCX, 'mchid'); //商户号
        $url = 'https://api.mch.weixin.qq.com/v3/pay/transactions/out-trade-no/' . $sn . '?mchid=' . $mchid;
        $re = self::wxCurl($url, [], 'GET');
        if ($return) {
            return $re;
        }
        if (isset($re['trade_state']) && $re['trade_state'] == 'SUCCESS') {
            return true;
        }
        return false;
    }
    /**
     * 关闭订单
     * @param type $sn
     */
    public static function close($sn)
    {
        $mchid = Action::config(CONFIG_WXXCX, 'mchid'); //商户号
        $url = 'https://api.mch.weixin.qq.com/v3/pay/transactions/out-trade-no/' . $sn . '/close';
        $re = self::wxCurl($url, ['mchid'=>$mchid], 'POST');
        return true;
    }
    /**
     * 退款
     * @param type $sn
     */
    public static function refund($order_sn,$refund_sn,$total,$refund,$msg='退款')
    {
        $url='https://api.mch.weixin.qq.com/v3/refund/domestic/refunds';
        $data=[];
        $data['notify_url']=url('ag/weixin/notify_refund');
        $data['out_trade_no']=$order_sn;//订单号
        $data['out_refund_no']=$refund_sn;//退款单号
        $data['reason']=$msg;
        $data['amount']=['refund'=>$refund*100,'total'=>$total*100,'currency'=>'CNY'];
        $re = self::wxCurl($url, $data, 'POST');
        return $re;
    }
    //请求
    public static function wxCurl($url, $data = [], $method = 'GET')
    {
        $Authorization = self::getReSign($url, $data, $method);
        $header = [
            'Content-Type: application/json',
            'Accept: application/json',
            'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36 Edg/89.0.774.63',
            'Authorization: ' . $Authorization
        ];
        $redata = $data ? json_encode($data) : '';
        $res = reCurl($url, $redata, $header);
        return $res ? json_decode($res, true) : [];
    }
    //后端请求签名
    public static function getReSign($url, $data, $method = 'GET')
    {
        $url_parts = parse_url($url);
        $canonical_url = ($url_parts['path'] . (!empty($url_parts['query']) ? "?${url_parts['query']}" : ""));
        $http_method = $method;
        $timestamp = time();
        $nonce = uniqid();
        $body = $data ? json_encode($data) : '';
        $mchid = Action::config(CONFIG_WXXCX, 'mchid'); //商户id
        $serial_no = Action::config(CONFIG_WXXCX, 'serial_no'); //证书编号
        $private_key = self::getPrivateKey(BASE_PATH . 'cert/apiclient_key.pem'); //商户私钥
        $message = $http_method . "\n" .
            $canonical_url . "\n" .
            $timestamp . "\n" .
            $nonce . "\n" .
            $body . "\n";
        openssl_sign($message, $raw_sign, $private_key, 'sha256WithRSAEncryption');
        $sign = base64_encode($raw_sign);
        $token = sprintf('mchid="%s",nonce_str="%s",timestamp="%d",serial_no="%s",signature="%s"', $mchid, $nonce, $timestamp, $serial_no, $sign);
        return 'WECHATPAY2-SHA256-RSA2048 ' . $token;
    }
    //前端小程序签名
    public static function getPaySign($result)
    {
        $private_key = self::getPrivateKey(BASE_PATH . 'cert/apiclient_key.pem'); //商户私钥
        $message = $result['appId'] . "\n" .
            $result['timeStamp'] . "\n" .
            $result['nonceStr'] . "\n" .
            $result['package'] . "\n";
        openssl_sign($message, $raw_sign, $private_key, 'sha256WithRSAEncryption');
        $sign = base64_encode($raw_sign);
        return $sign;
    }
    //验证签名
    public static function checkSign()
    {
        $header = Context::get('header');
        $serial_no = $header['wechatpay-serial'] ?? ''; //微信平台序列号
        $timeStamp = $header['wechatpay-timestamp'] ?? '';
        $nonce = $header['wechatpay-nonce'] ?? '';
        $body = Context::get('raw');
        $wx_sign = $header['wechatpay-signature'] ?? '';
        $wx_serial_no = Action::config(CONFIG_WXXCX, 'wx_serial_no');//保存的序列号
        if (!$serial_no || $wx_serial_no != $serial_no) {
            \sff\Log::write('签名过期');
            return false;
        }
        $message = $timeStamp . "\n" .
            $nonce . "\n" .
            $body . "\n";
        
        $wx_sign = base64_decode($wx_sign);
        $public_key = self::getPublicKey(BASE_PATH . 'cert/wx_public_cert.pem'); //平台公钥
        $res = openssl_verify($message, $wx_sign, $public_key, OPENSSL_ALGO_SHA256);
        if ($res == 1) {
            return true;
        }
        \sff\Log::write('验签失败');
        return false;
    }
    //获取私钥
    public static function getPrivateKey($filepath)
    {
        return openssl_get_privatekey(file_get_contents($filepath));
    }
    //获取公钥
    public static function getPublicKey($filepath)
    {
        return openssl_pkey_get_public(file_get_contents($filepath));
    }
    //加密数据
    public static function getEncrypt($str)
    {
//$str是待加密字符串 
        $public_key_path = BASE_PATH . 'cert/wx_public_cert.pem'; //'平台证书路径';
        $public_key = file_get_contents($public_key_path);
        $encrypted = '';
        if (openssl_public_encrypt($str, $encrypted, $public_key, OPENSSL_PKCS1_OAEP_PADDING)) {
            //base64编码 
            $sign = base64_encode($encrypted);
        } else {
            throw new Exception('encrypt failed');
        }
        return $sign;
    }
    //解密数据
    public static function decryptToString($ciphertext, $associatedData, $nonceStr)
    {
        $aesKey = Action::config(CONFIG_WXXCX, 'mch_keyv3'); //商户apiv3密钥解密
        $str = base64_decode($ciphertext);
        if (strlen($str) <= 16) {
            return &#39;&#39;;
        }
        // ext-sodium (default installed on >= PHP 7.2)
        return \sodium_crypto_aead_aes256gcm_decrypt($str, $associatedData, $nonceStr, $aesKey);
    }
    //下载平台证书
    public static function downCert()
    {
        $url = &#39;https://api.mch.weixin.qq.com/v3/certificates&#39;;
        $re = self::wxCurl($url, [], &#39;GET&#39;);
        if (!isset($re[&#39;data&#39;])) {
            api_fail(&#39;获取证书失败&#39;);
        }
        $ciphertext = $re[&#39;data&#39;][0][&#39;encrypt_certificate&#39;][&#39;ciphertext&#39;];
        $associatedData = $re[&#39;data&#39;][0][&#39;encrypt_certificate&#39;][&#39;associated_data&#39;];
        $nonceStr = $re[&#39;data&#39;][0][&#39;encrypt_certificate&#39;][&#39;nonce&#39;];
        $data = self::decryptToString($ciphertext, $associatedData, $nonceStr);
        if (!$data) {
            api_fail(&#39;获取证书解密失败&#39;);
        }
        file_put_contents(BASE_PATH . &#39;/cert/wx_public_cert.pem&#39;, $data);
        return $data;
    }
}