PHP实现支付宝支付的方法

/**
 * 将要参与签名的参数按要求拼接
 * @param $data
 * author 江南极客
 * @return string
 */
function signQueryString($data){
 // 去空
 $data = array_filter($data);
 //签名步骤一：按字典序排序参数
 ksort($data);
 $string_a = http_build_query($data);
 $string_a = urldecode($string_a);
 return $string_a;
}
 
/**
 * 支付宝RSA签名加密
 * @param $data 要参与加密的参数
 * @param $private_key 应用私钥
 * author 江南极客
 * @return array|string
 */
function RSASign($data,$private_key){
 //要签名的参数字符串
 $query_string = signQueryString($data);
 //应用私钥
 $private_key = chunk_split($private_key, , "
");
 $private_key = "-----BEGIN RSA PRIVATE KEY-----
$private_key-----END RSA PRIVATE KEY-----
";
 $private_key_id = openssl_pkey_get_private($private_key);
 if ($private_key_id === false){
 return array(-1,'提供的私钥格式不对');
 }
 $rsa_sign = false;
 if($data['sign_type'] == 'RSA'){
 $rsa_sign = openssl_sign($query_string, $sign, $private_key_id,OPENSSL_ALGO_SHA1);
 }else if($data['sign_type'] == 'RSA2'){
 $rsa_sign = openssl_sign($query_string, $sign, $private_key_id,OPENSSL_ALGO_SHA256);
 }
 //释放资源
 openssl_free_key($private_key_id);
 if ($rsa_sign === false){
 return array(-1,'签名失败');
 }
 $signature = base_encode($sign);
 return $signature;
}
 
/**
 * 支付宝支付
 * @param array $params 构造好的支付参数
 * author 江南极客
 * @return array|string
 */
function aliPay(array $params){
 $public = [
 'app_id' => $params['app_id'],
 'method' => $params['method'],
 'sign_type' => $params['sign_type'],
 'format' => 'JSON',
 'charset' => 'utf-8',
 'version' => '1.0',
 'timestamp' => date('Y-m-d H:i:s'),
 'biz_content' => $params['biz_content'],
 ];
 if(!empty($params['notify_url'])){
 $public['notify_url'] = $params['notify_url'];
 }
 if(!empty($params['return_url'])){
 $public['return_url'] = $params['return_url'];
 }
 $sign = RSASign($public,$params['private_key']);
 if(is_array($sign)){
 return $sign;
 }
 $public['sign'] = $sign;
 $url = 'https://mapi.alipay.com/gateway.do?'. http_build_query($public,'', '&');
 return $url;
}

$biz_content = [
 'body' => '测试商品x1',
 'subject' => '测试商品',
 'out_trade_no' => date('YmdHis').rand(1000,9999),
 'product_code' => 'QUICK_WAP_WAY',
 'total_amount' => 0.01,
];
$notify_url = "https://xxxxxxxx/notify.php";//通知回调地址(必须是可以无障碍访问没有登录验证的地址)
$params = [
 'app_id' => '2017xxxxxxxxx6554',//appid
 'method' => 'alipay.trade.wap.pay',//接口名称
 'sign_type' => 'RSA2',//签名加密方式
 'notify_url' => $notify_url,
 'biz_content' => json_encode($biz_content),//请求参数
];
$params['private_key'] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";//应用私钥
$data = aliPay($params);
print_r($data);

/**
 * 支付宝验证签名
 * @param $return_data 支付宝服务器推送给notify_url的数据
 * @param $public_key 支付宝公钥
 * author 江南极客
 * @return bool|int
 */
function RSAVerify($return_data, $public_key){
 if(empty($return_data) || !is_array($return_data)){
 return false;
 }
 //支付宝公钥
 $public_key = wordwrap($public_key, , "
", true);
 $public_key = "-----BEGIN PUBLIC KEY-----
$public_key
-----END PUBLIC KEY-----
";
 $public_key_id = openssl_pkey_get_public($public_key);
 if($public_key_id === false){
 return false;
 }
 //除去sign、sign_type两个参数外，凡是通知返回回来的参数皆是待验签的参数。
 $sign = $return_data['sign'];
 $sign_type = trim($return_data['sign_type'],'"');
 unset($return_data['sign'], $return_data['sign_type']);
 
 $query_string = signQueryString($return_data);
 $sign = base_decode($sign);
 $rsa_verify = 0;
 if($sign_type == 'RSA'){
 $rsa_verify = openssl_verify($query_string, $sign, $public_key_id,OPENSSL_ALGO_SHA1);
 }else if($sign_type == 'RSA2'){
 $rsa_verify = openssl_verify($query_string, $sign, $public_key_id,OPENSSL_ALGO_SHA256);
 }
 openssl_free_key($public_key_id);
 if($rsa_verify == 0 || $rsa_verify == -1){
 //Returns 1 if the signature is correct, 0 if it is incorrect, and -1 on error.
 return false;
 }
 return $rsa_verify;
}