GuilhermeTome / jwt

src/Jwt.php

<?php

namespace GuilhermeTome;

/*
 *
 * class Jwt
 * 
 * used to encode and decode jwt
 * pass the secret in global var
 * 
 */

class Jwt
{

    /**
     * The secret to encode and decode the JWT
     * 
     * @var string;
     */
    private static string $secret = JWT_SECRET;

The constant GuilhermeTome\JWT_SECRET was not found. Maybe you did not declare it correctly or list all dependencies?

    /**
     * JWT hash to use
     * 
     * @var string
     */
    private static string $hash = JWT_HASH;

The constant GuilhermeTome\JWT_HASH was not found. Maybe you did not declare it correctly or list all dependencies?

    /**
     * JWT alg to put in header
     * 
     * @var string
     */
    private static string $alg = JWT_ALG;

The constant GuilhermeTome\JWT_ALG was not found. Maybe you did not declare it correctly or list all dependencies?

    /**
     * Create a jwt token
     * 
     * @param array $data
     * @return string
     */
    public static function encode(array $data): string
    {

        // Header json
        $header = json_encode(["alg" => self::$alg, "typ" => "JWT"]);

        // Payload json
        $payload = json_encode($data);

        // Convert then to base64
        $header = self::base64url_encode($header);
        $payload = self::base64url_encode($payload);

        // Creating and converting signature with key
        $signature = hash_hmac(self::$hash, $header . "." . $payload, self::$secret, true);
        $signature = self::base64url_encode($signature);

        return $header . "." . $payload . "." . $signature;
    }

    /**
     * Validate a jwt token
     * 
     * @param string $token
     * @return bool|array
     */
    public static function decode(string $token)
    {
        if (!empty($token)) {
            $split = explode('.', $token);
            if (count($split) == 3) {

                $signature = hash_hmac(self::$hash, $split[0] . "." . $split[1], self::$secret, true);
                $bsig = self::base64url_encode($signature);

                if ($bsig == $split[2]) {
                    return json_decode(self::base64url_decode($split[1]));
                }
            }
        }
        return false;
    }

    /**
     * Private function to encode url base64
     *
     * @param string $data
     * @return string
     */
    private static function base64url_encode(string $data): string
    {
        return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
    }

    /**
     * Private function to decode url base64
     *
     * @param string $data
     * @return string
     */
    private static function base64url_decode(string $data): string
    {
        return base64_decode(strtr($data, '-_', '+/') . str_repeat('=', 3 - (3 + strlen($data)) % 4));
    }
}