function print_layout()
{
$php_self = $_SERVER['PHP_SELF'];
$public_key = get_session_var('public_key', true);
$private_key = get_session_var('private_key', true);
$document = get_session_var('document', true);
$signature = get_session_var('signature', true);
$plain_text = get_session_var('plain_text', true);
$enc_text = get_session_var('enc_text', true);
$is_sign_valid = get_session_var('is_sign_valid', true);
echo <<<END
<html>
<head>
<title>Crypt_RSA example of usage</title>
<style type="text/css">
form { margin: 10px; padding: 10px; background: #ccc; border: 1px solid; }
textarea { margin-bottom: 10px; }
</style>
</head>
<body>
<h1>Crypt_RSA example of usage</h1>
<form action="{$php_self}?task=generate_key_pair" method="POST">
<div>
<h1>Key generation</h1>
Select key length:
<select name="key_length">
<option value="32">32 bit</option>
<option value="64">64 bit</option>
<option value="128">128 bit</option>
<option value="256">256 bit</option>
<option value="512">512 bit</option>
<option value="1024">1024 bit</option>
<option value="2048">2048 bit</option>
</select><br/>
Public key:<br/>
<textarea style="height:100px;width:90%">{$public_key}</textarea><br/>
Private key:<br/>
<textarea style="height:100px;width:90%">{$private_key}</textarea><br/>
<input type="submit" value="Start">
</div>
</form>
<form action="{$php_self}?task=create_sign" method="POST">
<div>
<h1>Signing document</h1>
Document:<br/>
<textarea style="height:100px;width:90%" name="document">{$document}</textarea><br/>
Private key:<br/>
<textarea style="height:100px;width:90%" name="private_key">{$private_key}</textarea><br/>
Signature:<br/>
<textarea style="height:100px;width:90%">{$signature}</textarea><br/>
<input type="submit" value="Sign">
</div>
</form>
<form action="{$php_self}?task=validate_sign" method="POST">
<div>
<h1>Validating document sign</h1>
Document:<br/>
<textarea style="height:100px;width:90%" name="document">{$document}</textarea><br/>
Signature:<br/>
<textarea style="height:100px;width:90%" name="signature">{$signature}</textarea><br/>
Public key:<br/>
<textarea style="height:100px;width:90%" name="public_key">{$public_key}</textarea><br/>
Result: <span style="font-size:2em">{$is_sign_valid}</span><br/>
<input type="submit" value="Validate">
</div>
</form>
<form action="{$php_self}?task=encrypt" method="POST">
<div>
<h1>Encrypting</h1>
Plain text:<br/>
<textarea style="height:100px;width:90%" name="plain_text">{$plain_text}</textarea><br/>
Public key:<br/>
<textarea style="height:100px;width:90%" name="public_key">{$public_key}</textarea><br/>
Encrypted text:<br/>
<textarea style="height:100px;width:90%">{$enc_text}</textarea><br/>
<input type="submit" value="Encrypt">
</div>
</form>
<form action="{$php_self}?task=decrypt" method="POST">
<div>
<h1>Decrypting</h1>
Encrypted text:<br/>
<textarea style="height:100px;width:90%" name="enc_text">{$enc_text}</textarea><br/>
Private key:<br/>
<textarea style="height:100px;width:90%" name="private_key">{$private_key}</textarea><br/>
Plain text:<br/>
<textarea style="height:100px;width:90%">{$plain_text}</textarea><br/>
<input type="submit" value="Decrypt">
</div>
</form>
END;
}
/**
* Validate CSRF tokens, POST and GET.
* User will get logged out in case error reporting does not stop script.
*
* @access public
* @param string $token_prefix (default: 'csrf_')
* @return void
*/
function validate_csrf_tokens($token_prefix = 'csrf_')
{
if ($_SERVER['REQUEST_METHOD'] === 'POST' && count($_POST)) {
if (empty($_POST[$token_prefix . 'token_name']) || empty($_POST[$token_prefix . 'token_value'])) {
trigger_error('No CSRF token found, probable invalid request.', E_USER_ERROR);
logout_user('csrf-post-invalid', 'danger');
}
if (!validate_session_token($_POST[$token_prefix . 'token_name'], $_POST[$token_prefix . 'token_value'])) {
trigger_error('Validating the CSRF token failed, probable an outdated request.', E_USER_ERROR);
logout_user('csrf-post-failed', 'danger');
}
} else {
validate_csrf_get_token('csrftoken');
}
// Purge cached tokens
if ($cached_tokens = get_session_var('cached_unique_tokens')) {
$now = time();
$timespan = 60 * 15;
// 15 Minutes
foreach ($cached_tokens as $unique_name => $time) {
if ($time < $now - $timespan) {
unset_session_var($unique_name);
unset_cached_token($unique_name);
}
}
}
}
