stream_socket_client（）：无法在php中设置ios推送通知的私钥

我正在使用php作为后端向ios应用程序发送推送通知。这是我的密码：

  $deviceToken = "XXXX";
  $ctx = stream_context_create();
  // ck.pem is your certificate file
  stream_context_set_option($ctx, 'ssl', 'local_cert', $_SERVER['DOCUMENT_ROOT'] . '/uploads/ck.pem');
  stream_context_set_option($ctx, 'ssl', 'passphrase', 'xxxx');
  // Open a connection to the APNS server
  $fp = stream_socket_client('ssl://gateway.sandbox.push.apple.com:2195', $err, $errstr, 60, STREAM_CLIENT_CONNECT|STREAM_CLIENT_PERSISTENT, $ctx);
  if (!$fp)
        exit("Failed to connect: $err $errstr" . PHP_EOL);
    // Create the payload body
    $body['aps'] = array(
        'alert' => array(
            'title' => "haia",
            'body' => "how are you",
         ),
        'sound' => 'default'
    );
    // Encode the payload as JSON
    $payload = json_encode($body);
    // Build the binary notification
    $msg = chr(0) . pack('n', 32) . pack('H*', $deviceToken) . pack('n', strlen($payload)) . $payload;
    // Send it to the server
    $result = fwrite($fp, $msg, strlen($msg));

    // Close the connection to the server
    fclose($fp);
    if (!$result)
        return 'Message not delivered' . PHP_EOL;
    else
        return 'Message successfully delivered' . PHP_EOL;

在上面的代码中，我得到了这个错误

  Message: stream_socket_client(): Unable to set private key file `/home/developer/workspace/codeigniter/Ekattor/uploads/ck.pem'
  Message: stream_socket_client(): failed to create an SSL handle
  Message: stream_socket_client(): Failed to enable crypto
  Message: stream_socket_client(): unable to connect to ssl://gateway.sandbox.push.apple.com:2195 (Unknown error)

---

但是，当我从stream\u socket\u client（）函数中删除ssl时，它不会显示任何错误。如果我在stream_socket_client（）中包含ssl，则会显示上述错误。我看到了已经解决的答案，但我没有得到任何运气。请有人帮助我解决此问题

检查ck.pem文件权限并确保文件存在查看我重新创建了pem文件，但仍然只有相同的错误。在流\u socket\u client（）中删除ssl时，我没有收到错误。当我只使用ssl时，我得到了这个错误。是否有必要在stream_socket_client（）中使用ssl？