/**
* Converts and signs a PHP object or array into a JWT string.
*
* @param object|array $payload PHP object or array
* @param string $key The secret key.
* If the algorithm used is asymmetric, this is the private key
* @param string $alg The signing algorithm.
* Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256'
* @param array $head An array with header elements to attach
*
* @return string A signed JWT
*
* @uses jsonEncode
* @uses urlsafeB64Encode
*/
public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null)
{
$header = array('typ' => 'JWT', 'alg' => $alg);
if ($keyId !== null) {
$header['kid'] = $keyId;
}
if (isset($head) && is_array($head)) {
$header = array_merge($head, $header);
}
$segments = array();
$segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header));
$segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload));
$signing_input = implode('.', $segments);
$signature = JWT::sign($signing_input, $key, $alg);
$segments[] = JWT::urlsafeB64Encode($signature);
return implode('.', $segments);
}
