cURL错误(58）:无法设置私钥文件:'/var/www/work/xml/keys/client.pem

我在使用私钥和公钥连接到服务器时遇到此错误。

cURL错误（58）：无法设置私钥文件：'/var/www/work/xml/keys/client.pem'类型pem

我的私钥包含密钥和证书。它还有密码。

我当前的代码在这里：

    $url="https://example.website.com";
    $pemfile = "/var/www/work/xml/keys/server.pem";
    $keyfile = "/var/www/work/xml/keys/client.pem";
    $requestXml = file_get_contents("net.xml");
    $ch = curl_init(); 
    curl_setopt($ch, CURLOPT_URL, $url); 
    curl_setopt($ch, CURLOPT_HTTP_VERSION, 1.1); 
    curl_setopt($ch, CURLOPT_PORT, 443); 
    curl_setopt($ch, CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
    curl_setopt($ch, CURLOPT_VERBOSE, 1); 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); 
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); 
    curl_setopt($ch, CURLOPT_FAILONERROR, 0); 
    curl_setopt($ch, CURLOPT_SSLCERT, $pemfile); 
    curl_setopt($ch, CURLOPT_SSLCERTTYPE, 'PEM'); 
    curl_setopt($ch, CURLOPT_SSLCERTPASSWD, 'PASSWORD'); 

    curl_setopt($ch, CURLOPT_SSLKEY, $keyfile); 
    curl_setopt($ch, CURLOPT_SSLKEYPASSWD, "PASSWORD");

    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));
    curl_setopt($ch, CURLOPT_POSTFIELDS, $requestXml);
    $data = curl_exec($ch);
    $curl_errno = curl_errno($ch);
    $curl_error = curl_error($ch);
    if ($curl_errno > 0) 
    {
        echo "cURL Error ($curl_errno): $curl_error'n";
    }
    else 
    {
        header("Content-Type: text/xml");
        print_r($data);
    }
    curl_close($ch);