Warning: Input variables exceeded 1000

I found out that the right way to handle json data directly in PHP (via file_get_contents('php://input')) is to make sure the request sets the right content-type i.e. Content-type: application/json in the HTTP request header.

In my case I'm requesting pages from php using curl with to this code:

function curl_post($url, array $post = NULL, array $options = array()) {
  $defaults = array(
    CURLOPT_POST => 1,
    CURLOPT_HEADER => 0,
    CURLOPT_URL => $url,
    CURLOPT_FRESH_CONNECT => 1,
    CURLOPT_RETURNTRANSFER => 1,
    CURLOPT_FORBID_REUSE => 1,
    CURLOPT_TIMEOUT => 600
  );
  if(!is_null($post))
    $defaults['CURLOPT_POSTFIELDS'] = http_build_query($post);
  $ch = curl_init();
  curl_setopt_array($ch, ($options + $defaults));
  if(($result = curl_exec($ch)) === false) {
    throw new Exception(curl_error($ch) . "\n $url");
  }
  if(curl_getinfo($ch, CURLINFO_HTTP_CODE) != 200) {
    throw new Exception("Curl error: ". 
      curl_getinfo($ch, CURLINFO_HTTP_CODE) ."\n".$result . "\n");
  }
  curl_close($ch);
  return $result;
}

$curl_result = curl_post(URL, NULL,
    array(CURLOPT_HTTPHEADER => array('Content-Type: application/json'),
      CURLOPT_POSTFIELDS => json_encode($out))
    );

Do note the CURLOPT_HTTPHEADER => array('Content-Type: application/json') part.

On the receiving side I'm using the following code:

$rawData = file_get_contents('php://input');
$postedJson = json_decode($rawData,true);
if(json_last_error() != JSON_ERROR_NONE) {
  error_log('Last JSON error: '. json_last_error(). 
    json_last_error_msg() . PHP_EOL. PHP_EOL,0);
}

Do not change the max_input_vars variable. Since changing the request to set right headers my issue with max_input_vars went away. Apparently does not PHP evaluate the post variables with certain Content-type is set.

Change this

; max_input_vars = 1000

To this

max_input_vars = 3000

Comment line in php.ini file is

;

Something is wrong, you do not need 1000 variables. Recode your program to accept 1 variable array with 1000 keys. This is error is there to warn you that you are not doing things the recommended way. Do not disable it, extend it, or hide it in any way.