php curl结果无效

This is my first time posting here! :) I have made a php license generation and validation system. The server end communicates with the mysql database and outputs a json result like the following:

{"valid":"true","info":{"id":"1","expire":"1421811123"}}

The problem is on the client server where i have the following script:

<?php


$key_info['key'] = "KEY"];
$serverurl = "http://URLTOSERVER";

$ch = curl_init ($serverurl);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

curl_setopt ($ch, CURLOPT_POST, true);

curl_setopt ($ch, CURLOPT_POSTFIELDS, $key_info);

$result = curl_exec ($ch);
$result = json_decode($result, true);

if($result['valid'] == true){

        echo "valid";
}
else {
        die("Invalid Key!");

}


?>

When i run this i get "valid" every time, even when i enter the wrong key - i have tried printing the output and i can confirm that.

Please advise.

Thanks.

Your JSON contains a string true, not a boolean true. Any string in there will pass == true.

if($result['valid'] == 'true'){