Тег <keygen />

Этот тег создает пары ключей.

index.php

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<?php
if($_SERVER['REQUEST_METHOD'] == 'POST') {
$a = (string)trim(htmlspecialchars($_POST['a'], ENT_QUOTES));
if($_REQUEST['clear']) {
$a = null;
}
}
?>
<form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="post">
<fieldset>
<legend>This data will send into a server</legend>
<input type="text" name="a" value="<?php echo $a; ?>" />
   
<label>Enter a text</label>
<br />
<br />
<keygen name="keygen1" />
   
<label>Encryption</label>
<br />
<br />
<input type="submit" name="perform" value="Perform" />
   
<input type="submit" name="clear" value="   Clear   " />
</fieldset>
<br />
<fieldset>
<legend>Reading data from a server</legend>
<?php
if($_SERVER['REQUEST_METHOD']=='POST' && $_REQUEST['perform'] && !$_REQUEST['clear']) {
echo $a;
}
else {
echo null;
}
?>
<br />
</fieldset>
</form>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<?php
if($_SERVER['REQUEST_METHOD'] == 'POST') {
$a = (string)trim(htmlspecialchars($_POST['a'], ENT_QUOTES));
if($_REQUEST['clear']) {
$a = null;
}
}
?>
<form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="post">
<fieldset>
<legend>This data will send into a server</legend>
<input type="text" name="a" value="<?php echo $a; ?>" />
   
<label>Enter a text</label>
<br />
<br />
<keygen name="keygen1" />
   
<label>Encryption</label>
<br />
<br />
<input type="submit" name="perform" value="Perform" />
   
<input type="submit" name="clear" value="   Clear   " />
</fieldset>
<br />
<fieldset>
<legend>Reading data from a server</legend>
<?php
if($_SERVER['REQUEST_METHOD']=='POST' && $_REQUEST['perform'] && !$_REQUEST['clear']) {
echo $a;
}
else {
echo null;
}
?>
<br />
</fieldset>
</form>
</body>
</html>