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<?php |
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class csrf_lib extends Library { |
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public function __construct() { |
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if (session_status() == PHP_SESSION_NONE) { |
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session_start(); |
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} |
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} |
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/** |
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* Generates a new CSRF token |
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* @return string Base64 encoded token |
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*/ |
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public static function generate_token() { |
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return base64_encode(openssl_random_pseudo_bytes(12)); |
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} |
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/** |
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* Generates a new CSRF token and sets it as the current token |
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* @return string The token |
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*/ |
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public function new_csrf_token() { |
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if (! isset($_SESSION['csrf_token'])) { |
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$_SESSION['csrf_token'] = self::generate_token(); |
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} |
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return $_SESSION['csrf_token']; |
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} |
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/** |
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* Resets the CSRF token saved in session |
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*/ |
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public function reset_csrf_token() { |
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unset($_SESSION['csrf_token']); |
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} |
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/** |
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* Checks whether CSRF is set and whether the current CSRF token from |
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* the POST data is correct. If not, returns a 400 HTTP response code, |
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* loads the 400 view and quits. |
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*/ |
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public function check_csrf_token($value) { |
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if (! isset($_SESSION['csrf_token']) |
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|| $value !== $_SESSION['csrf_token'] |
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) { |
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// If no CSRF token is set, or the $value does not match it, error |
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$this->load_library('http_lib', 'http'); |
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$this->http->response_code(400); |
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return false; |
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} |
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return true; |
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} |
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} |
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