微信支付已上线企业付款至银行卡功能。商户可以将商户号余额付款至指定的收款银行账户。通过指定收款银行账户户名、卡号，以及收款银行信息即可实现付款。功能目前为灰度开放，已灰度新资金流直连普通商户及普通受理模式子商户，其他商户类型将在后续开放。

一、微信商户号须开通此功能；

二、应用环境TP5+Mysql+Centos

三、编写代码

3.1、Model层，Wechat.php

<?php
namespace app\home\model;
use think\Cache;

class Wechat extends Model
{
 private $appid; //公众号APPID
 private $appsecret; //公众号appsecret
 private $mchid; //商户号
 private $key; //支付密钥
 private $sslcert; //证书保存的绝对路径
 private $sslkey; //证书保存的绝对路径
 
 public function __construct($appid,$appsecret,$mchid,$key,$sslcert,$sslkey)
 {
 parent::__construct();
 $this->appid = $appid;
 $this->appsecret = $appsecret;
 $this->mchid = $mchid;
 $this->key = $key;
 $this->sslcert = $sslcert;
 $this->sslkey = $sslkey;
 }
 /*
 * 企业付款到银行卡接口
 * @params string $out_trade_no : 商户订单号
 * @params int $amount : 付款金额，单位分
 * @params string $enc_bank_no : 收款方银行卡号
 * @params string $enc_true_name : 收款方用户名
 * @params string $bank_name : 收款方开户行,根据银行名称获取银行编号bank_code
 * @params string $desc : 付款备注
 * return string $payment_no ：支付成功的订单号
 */
 public function payForBank($out_trade_no,$amount,$enc_bank_no,$enc_true_name,$bank_name,$desc='企业付款到银行卡')
 {
 $data['amount'] = $amount;
 $data['bank_code'] = $this->getBankCode($bank_code);
 $data['desc'] = $desc;
 $data['enc_bank_no'] = $this->publicEncrypt($enc_bank_no);
 $data['enc_true_name'] = $this->publicEncrypt($enc_true_name);
 $data['mch_id'] = $this->mchid;
 $data['nonce_str'] = $this->random(12);
 $data['partner_trade_no'] = $out_trade_no;
 $sign = $this->getParam($data);

 $dataXML="<xml>
 <amount>".$data['amount']."</amount>
 <bank_code>".$data['bank_code']."</bank_code>
 <desc>".$data['desc']."</desc>
 <enc_bank_no>".$data['enc_bank_no']."</enc_bank_no>
 <enc_true_name>".$data['enc_true_name']."</enc_true_name>
 <mch_id>".$data['mch_id']."</mch_id>
 <nonce_str>".$data['nonce_str']."</nonce_str>
 <partner_trade_no>".$data['partner_trade_no']."</partner_trade_no>
 <sign>".$sign."</sign>
 </xml>";

 $url = 'https://api.mch.weixin.qq.com/mmpaysptrans/pay_bank';
 $ret = $this->httpsPost($url,$dataXML,true);
 if($ret['return_code'] == 'SUCCESS' && $ret['result_code'] == 'SUCCESS' && $ret['err_code'] == 'SUCCESS'){
 return $ret['payment_no'];
 }else{
 $this->errorLog('微信付款到银行卡失败，appid：'.$this->appid,$ret);
 return false;
 }
 }
 /*
 * 查询付款到银行卡状态
 * @params string $out_trade_no : 商户订单号
 * return array $ret：查询状态
 * */
 public function queryBank($out_trade_no)
 {
 $data['mch_id'] = $this->mchid;
 $data['nonce_str'] = $this->random(12);
 $data['partner_trade_no'] = $out_trade_no;
 $sign = $this->getParam($data);
 $dataXML="<xml>
 <mch_id>".$data['mch_id']."</mch_id>
 <nonce_str>".$data['nonce_str']."</nonce_str>
 <partner_trade_no>".$data['partner_trade_no']."</partner_trade_no>
 <sign>".$sign."</sign>
 </xml>";
 $url = 'https://api.mch.weixin.qq.com/mmpaysptrans/query_bank';
 $ret = $this->httpsPost($url,$dataXML,true);
 if($ret['return_code'] == 'SUCCESS' && $ret['result_code'] == 'SUCCESS' && $ret['err_code'] == 'SUCCESS'){
 return $ret;
 }else{
 $this->errorLog('查询微信付款到银行卡失败，appid：'.$this->appid.'，订单号：'.$out_trade_no,$ret);
 return false;
 }
 }
 /*
 * 银行编号列表，详情参考：https://pay.weixin.qq.com/wiki/doc/api/tools/mch_pay.php?chapter=24_4
 * @params string $bank_name : 银行名称，4个汉字
 * return int $bank_code : 银行编码
 * */
 private function getBankCode($bank_name)
 {
 $bank_code = 0;
 switch ($bank_name){
 case '工商银行': $bank_code = 1002; break;
 case '农业银行': $bank_code = 1005; break;
 case '中国银行': $bank_code = 1026; break;
 case '建设银行': $bank_code = 1003; break;
 case '招商银行': $bank_code = 1001; break;
 case '邮储银行': $bank_code = 1066; break;
 case '交通银行': $bank_code = 1020; break;
 case '浦发银行': $bank_code = 1004; break;
 case '民生银行': $bank_code = 1006; break;
 case '兴业银行': $bank_code = 1009; break;
 case '平安银行': $bank_code = 1010; break;
 case '中信银行': $bank_code = 1021; break;
 case '华夏银行': $bank_code = 1025; break;
 case '广发银行': $bank_code = 1027; break;
 case '光大银行': $bank_code = 1022; break;
 case '北京银行': $bank_code = 1032; break;
 case '宁波银行': $bank_code = 1056; break;
 }
 return $bank_code;
 }
 /**
 * 公钥加密，银行卡号和姓名需要RSA算法加密
 * @param string $data 需要加密的字符串，银行卡/姓名
 * @return null|string 加密后的字符串
 */
 private function publicEncrypt($data)
 {
 // 进行加密
 $pubkey = openssl_pkey_get_public(file_get_contents(ROOT_PATH.'data/cert/public_pkcs8.pem'));
 $encrypt_data = '';
 $encrypted = '';
 $r = openssl_public_encrypt($data,$encrypt_data,$pubkey,OPENSSL_PKCS1_OAEP_PADDING);
 if($r){//加密成功，返回base编码的字符串
 return base_encode($encrypted.$encrypt_data);
 }else{
 return false;
 }
 }
 /*
 * 获取公钥,格式为PKCS#1 转PKCS#8
 * openssl rsa -RSAPublicKey_in -in <filename> -out <out_put_filename>
 * */
 private function get_pub_key()
 {
 $rsafile = ROOT_PATH.'data/cert/'.$this->appid.'_publicrsa.pem';
 if(!is_file($rsafile)){
 $data['mch_id'] = $this->mchid;
 $data['nonce_str'] = $this->random(12);
 $sign = $this->getParam($data);
 $dataXML="<xml>
 <mch_id>".$data['mch_id']."</mch_id>
 <nonce_str>".$data['nonce_str']."</nonce_str>
 <sign>".$sign."</sign>
 </xml>";
 $url = 'https://fraud.mch.weixin.qq.com/risk/getpublickey';
 $ret = $this->httpsPost($url,$dataXML,true);
 if($ret['return_code'] == 'SUCCESS' && isset($ret['pub_key'])){
 file_put_contents($rsafile,$ret['pub_key']);
 return $ret['pub_key'];
 }else{
 return null;
 }
 }else{
 return file_get_contents($rsafile);
 }
 }
 /*
 * 发起POST网络请求
 * @params string $url : 请求的url链接地址
 * @params string $data : 数据包
 * @params bool $ssl : 是否加载证书
 * return array $result : 返回的数据结果 
 */
 private function httpsPost($url,$data,$ssl = false)
 {
 $ch = curl_init ();
 curl_setopt ( $ch, CURLOPT_URL, $url );
 curl_setopt ( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
 curl_setopt ( $ch, CURLOPT_SSL_VERIFYPEER, FALSE );
 curl_setopt ( $ch, CURLOPT_SSL_VERIFYHOST, FALSE );
 if($ssl) {
 curl_setopt ( $ch,CURLOPT_SSLCERT,$this->sslcert);
 curl_setopt ( $ch,CURLOPT_SSLKEY,$this->sslkey);
 }
 curl_setopt ( $ch, CURLOPT_FOLLOWLOCATION, 1 );
 curl_setopt ( $ch, CURLOPT_AUTOREFERER, 1 );
 curl_setopt ( $ch, CURLOPT_POSTFIELDS, $data );
 curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );
 $result = curl_exec($ch);
 if (curl_errno($ch)) {
 return 'Errno: '.curl_error($ch);
 }
 curl_close($ch);
 return $this->xmlToArray($result);
 }
 //对参数排序，生成MD5加密签名
 private function getParam($paramArray, $isencode=false)
 {
 $paramStr = '';
 ksort($paramArray);
 $i = 0;
 foreach ($paramArray as $key => $value)
 {
 if ($key == 'Signature'){
 continue;
 }
 if ($i == 0){
 $paramStr .= '';
 }else{
 $paramStr .= '&';
 }
 $paramStr .= $key . '=' . ($isencode?urlencode($value):$value);
 ++$i;
 }
 $stringSignTemp=$paramStr."&key=".$this->key;
 $sign=strtoupper(md5($stringSignTemp));
 return $sign;
 }
 /*
 * 将xml转换成数组
 * @params xml $xml : xml数据
 * return array $data : 返回数组
 */
 private function xmlToArray($xml)
 {
 //禁止引用外部xml实体
 libxml_disable_entity_loader(true);
 $xmlstring = simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA);
 $val = json_decode(json_encode($xmlstring),true);
 return $val;
 }
 /*
 * 随机字符串
 * @param int $length 长度
 * @param string $type 类型
 * @param int $convert 转换大小写 1大写 0小写
 * @return string
 */
 private function random($length=10,$type='letter',$convert=false)
 {
 $config = array(
 'number'=>'12345670',
 'letter'=>'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
 'string'=>'abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ234567',
 'all'=>'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ12345670'
 );
 
 if(!isset($config[$type])) $type = 'letter';
 $string = $config[$type];
 
 $code = '';
 $strlen = strlen($string) -1;
 for($i = 0; $i < $length; $i++){
 $code .= $string{mt_rand(0, $strlen)};
 }
 if(!empty($convert)){
 $code = ($convert > 0)? strtoupper($code) : strtolower($code);
 }
 return $code;
 }
 /*
 * 日志记录
 * @params string $msg : 文字描述
 * @params array $ret : 调用接口返回的数组
 */
 private function errorLog($msg,$ret)
 {
 $path = ROOT_PATH.'runtime/error/';
 if(!is_dir($path)) mkdir($path,0777);
 file_put_contents(ROOT_PATH . 'runtime/error/wxpay.log', "[" . date('Y-m-d H:i:s') . "] ".$msg."," .json_encode($ret).PHP_EOL, FILE_APPEND);
 }
}

3.2、Controller控制层调用，Wxpay.php

<?php
namespace app\home\controller;
use app\home\model\Wechat;
class Wxpay extends Controller
{
 //企业付款到银行卡
 public function payBank()
 {
 $appid = 'wx****d4';
 $appsecret = '37***f0';
 $mchid = '13***2';
 $key = '53***e8';
 $sslcert = ROOT_PATH.'data/cert/apiclient_cert.pem';
 $sslkey = ROOT_PATH.'data/cert/apiclient_key.pem';
 $out_trade_no = date('Ymdhis', time()).substr(floor(microtime()*1000),0,1).rand(0,9);
 $money = 100;
 $enc_bank_no = '62***44';
 $enc_true_name = '张**';
 $bank_name = '中国银行';
 $desc = '企业付款到银行卡测试';
 $wxapi = new Wechat($appid,$appsecret,$mchid,$key,$sslcert,$sslkey);
 $payment_no = $wxapi->payForBank($out_trade_no,$money,$enc_bank_no,$enc_true_name,$bank_name,$desc);
 if($payment_no){
 echo '微信付款到银行卡操作成功，微信订单号：'.$payment_no;
 } else {
 echo '微信付款到银行卡操作失败，请检查日记';
 }
 }
}

四、付款截图

五、注意事项

1、获取的rsa为PKCS1格式需要转成PKCS8，需要执行以下命令

$filename : 从微信服务器上获取的公钥数组

$out_put_filename ：转换成PKCS8后的文件保存路径

openssl rsa -RSAPublicKey_in -in <filename> -out <out_put_filename>