//字典排序拼接字符串
function getWxPaySignature($arr){ksort($arr);$str = '';foreach ($arr as $k=>$a){$str .= $k;$str .= '='.$a.'&';}$str = trim($str,'&');return $str;
}
//微信回调验证
function weCallbackCheck($xml){$sign = $xml->sign;$appid = $xml->appid;$bank_type = $xml->bank_type;$cash_fee = $xml->cash_fee;$fee_type = $xml->fee_type;$is_subscribe = $xml->is_subscribe;$mch_id = $xml->mch_id;$nonce_str = $xml->nonce_str;$openid = $xml->openid;$out_trade_no = $xml->out_trade_no;$result_code = $xml->result_code;$return_code = $xml->return_code;$time_end = $xml->time_end;$total_fee = $xml->total_fee;$trade_type = $xml->trade_type;$transaction_id = $xml->transaction_id;$device_info = $xml->device_info;$signArr = array('appid' => "$appid",'bank_type' => "$bank_type",'cash_fee' => "$cash_fee",'device_info' => "$device_info",'fee_type' => "$fee_type",'is_subscribe' => "$is_subscribe",'mch_id' => "$mch_id",'nonce_str' => "$nonce_str",'openid' => "$openid",'out_trade_no' => "$out_trade_no",'result_code' => "$result_code",'return_code' => "$return_code",'time_end' => "$time_end",'total_fee' => "$total_fee",'trade_type' => "$trade_type",'transaction_id' => "$transaction_id");foreach ($signArr as $key => $value) {if($value == ''){unset($signArr[$key]);}}$stringA = getWxPaySignature($signArr);//数组字典排序拼接字符串$stringSignTemp = $stringA.'&key=???';//设置的key$signValue = md5($stringSignTemp);$signValue = strtoupper($signValue);if($signValue == $sign){return 'success';//支付成功}else{file_put_contents('failure.txt',json_encode($signArr).PHP_EOL,FILE_APPEND);return 'failure';}}
$xmlstr = file_get_contents("php://input");
$xml=simplexml_load_string($xmlstr, 'SimpleXMLElement', LIBXML_NOCDATA);
if(weCallbackCheck($xml)=="success"){echo "支付成功";
}