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PHP: Codeigniter CSRF functionality does not support putting the CSRF token in the HTTP headers for the purposes of the double submit cookie method. It also only runs the CSRF check on POST and not on PUT or DELETE. This drop in MY_Security.php makes sure CSRF runs on POST, PUT or DELETE and checks the HTTP headers for X-XSRF-TOKEN recommended b…
<?php
class MY_Security extends CI_Security{
//overriding the normal csrf_verify, this gets automatically called in the Input library's constructor
//verifying on POST and PUT and DELETE
public function csrf_verify(){
$request_method = strtoupper($_SERVER['REQUEST_METHOD']);
//If it is GET, ignore the rest
if($request_method == 'GET' OR $request_method == 'HEAD' OR $request_method == 'OPTIONS'){
return $this->csrf_set_cookie();
}
// Check if URI has been whitelisted from CSRF checks
if($exclude_uris = config_item('csrf_exclude_uris')){
$uri = load_class('URI', 'core');
if(in_array($uri->uri_string(), $exclude_uris)){
return $this;
}
}
//Double submit cookie method: COOKIE needs to exist and at least either POST or SERVER needs to exist and at least one of the POST or SERVER must match the COOKIE
if(
!isset($_COOKIE[$this->_csrf_cookie_name])
OR
(
!isset($_POST[$this->_csrf_cookie_name])
AND
!isset($_SERVER['HTTP_X_XSRF_TOKEN'])
)
){
$this->csrf_show_error();
}
//if CSRF token was in the POST, then it needs to match the cookie
if(isset($_POST[$this->_csrf_token_name])){
if($_POST[$this->_csrf_token_name] !== $_COOKIE[$this->_csrf_cookie_name]){
$this->csrf_show_error();
}
}
//if CSRF token was in the SERVER (headers), then it needs to match the cookie
if(isset($_SERVER['HTTP_X_XSRF_TOKEN'])){
if($_SERVER['HTTP_X_XSRF_TOKEN'] !== $_COOKIE[$this->_csrf_cookie_name]){
$this->csrf_show_error();
}
}
// We kill this since we're done and we don't want to polute the _POST array
unset($_POST[$this->_csrf_token_name]);
if(config_item('csrf_regenerate')){
unset($_COOKIE[$this->_csrf_cookie_name]);
$this->_csrf_hash = '';
}
$this->_csrf_set_hash();
$this->csrf_set_cookie();
log_message('debug', 'CSRF token verified');
return $this;
}
}
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