90 lines
2.1 KiB
PHP
Executable File
90 lines
2.1 KiB
PHP
Executable File
<?php
|
|
|
|
namespace Vn\Web;
|
|
|
|
use Exception;
|
|
|
|
/**
|
|
* Basic class to encode, decode and verify JWT tokens. It implements the HS256
|
|
* algorithm from the RFC 7519 standard.
|
|
*/
|
|
class Jwt
|
|
{
|
|
/**
|
|
* Creates a new JWT token with the passed $payload and $key.
|
|
*
|
|
* @param {Array} $payload The data to encode
|
|
* @param {string} $key The key used to sign the token
|
|
* @return {string} The new JWT token
|
|
*/
|
|
static function encode ($payload, $key)
|
|
{
|
|
$header = [
|
|
'alg' => 'HS256',
|
|
'typ' => 'JWT'
|
|
];
|
|
|
|
$b64Header = self::jsonB64Encode ($header);
|
|
$b64Payload = self::jsonB64Encode ($payload);
|
|
$b64Signature = self::getSignature ($b64Header, $b64Payload, $key);
|
|
|
|
return "$b64Header.$b64Payload.$b64Signature";
|
|
}
|
|
|
|
/**
|
|
* Validates and extracts the data from a JWT token.
|
|
*
|
|
* @param {Array} $token The JWT token
|
|
* @param {string} $key The key used to validate the token
|
|
* @return {string} The JWT validated and decoded data
|
|
*/
|
|
static function decode ($token, $key)
|
|
{
|
|
$parts = explode ('.', $token);
|
|
|
|
if (count($parts) !== 3)
|
|
throw new Exception ('Bad JWT token');
|
|
|
|
$b64Header = $parts[0];
|
|
$b64Payload = $parts[1];
|
|
$b64Signature = $parts[2];
|
|
|
|
$header = self::jsonB64Decode ($b64Header);
|
|
$payload = self::jsonB64Decode ($b64Payload);
|
|
|
|
if ($b64Signature != self::getSignature ($b64Header, $b64Payload, $key))
|
|
throw new Exception ('Bad token signature');
|
|
|
|
return $payload;
|
|
}
|
|
|
|
static function getSignature ($b64Header, $b64Payload, $key)
|
|
{
|
|
$signature = hash_hmac ('sha256', "$b64Header.$b64Payload", $key, TRUE);
|
|
return self::base64UrlEncode ($signature);
|
|
}
|
|
|
|
static function jsonB64Encode ($data)
|
|
{
|
|
return self::base64UrlEncode (json_encode ($data));
|
|
}
|
|
|
|
static function jsonB64Decode ($data)
|
|
{
|
|
return json_decode (self::base64UrlDecode ($data), TRUE);
|
|
}
|
|
|
|
static function base64UrlEncode ($data)
|
|
{
|
|
return rtrim (strtr (base64_encode ($data), '+/', '-_'), '=');
|
|
}
|
|
|
|
static function base64UrlDecode ($data)
|
|
{
|
|
$remainder = strlen ($data) % 4;
|
|
$data = strtr ($data, '-_', '+/');
|
|
return base64_decode (str_pad ($data, $remainder, '=', STR_PAD_RIGHT));
|
|
}
|
|
}
|
|
|