php-jwt-token

<?php

class JWT
{

    //使用HMAC生成信息摘要时所使用的密钥
    private static $key = 'key';
    private static $expireTime = 24 * 3600 * 7;


    //头部
    private static $header = array(
        'alg' => 'HS256', //生成signature的算法
        'typ' => 'JWT'    //类型
    );


    /**
     * 获取jwt token
     * @param array $payload jwt载荷   格式如下非必须
     * [
     *  'iss'=>'jwt_admin',  //该JWT的签发者
     *  'iat'=>time(),  //签发时间
     *  'exp'=>time()+7200,  //过期时间
     *  'nbf'=>time()+60,  //该时间之前不接收处理该Token
     *  'sub'=>'www.admin.com',  //面向的用户
     *  'jti'=>md5(uniqid('JWT').time())  //该Token唯一标识
     * ]
     * @return bool|string
     */
    public static function getToken(array $payload)
    {
        $payloadCommon = array('iss' => 'admin', 'iat' => time(), 'exp' => time() + 7200, 'nbf' => time(), 'sub' => 'www.baidu.com', 'jti' => md5(uniqid('JWT') . time()));

        foreach($payload as $key=>$item){
            if(in_array($key,['iss','admin','iat','exp','nbf','sub','jti'])){
                unset($payloadCommon[$key]);
            }
        }

        $payload = array_merge($payload, $payloadCommon);
        $base64header = self::base64UrlEncode(json_encode(self::$header, JSON_UNESCAPED_UNICODE));
        $base64payload = self::base64UrlEncode(json_encode($payload, JSON_UNESCAPED_UNICODE));
        return $base64header . '.' . $base64payload . '.' . self::signature($base64header . '.' . $base64payload, self::$key, self::$header['alg']);
    }

    /**
     * 验证token是否有效,默认验证exp,nbf,iat时间
     * @param string $Token 需要验证的token
     * @return bool|string
     */
    public static function verifyToken(string $Token)
    {
        $tokens = explode('.', $Token);
        if (count($tokens) != 3)
            return false;

        list($base64header, $base64payload, $sign) = $tokens;

        //获取jwt算法
        $base64decodeheader = json_decode(self::base64UrlDecode($base64header), JSON_OBJECT_AS_ARRAY);
        if (empty($base64decodeheader['alg']))
            return false;

        //签名验证
        if (self::signature($base64header . '.' . $base64payload, self::$key, $base64decodeheader['alg']) !== $sign)
            return false;

        $payload = json_decode(self::base64UrlDecode($base64payload), JSON_OBJECT_AS_ARRAY);

        //签发时间大于当前服务器时间验证失败
        if (isset($payload['iat']) && $payload['iat'] > time())
            return false;

        //过期时间小宇当前服务器时间验证失败
        if (isset($payload['exp']) && $payload['exp'] < time())
            return false;

        //该nbf时间之前不接收处理该Token
        if (isset($payload['nbf']) && $payload['nbf'] > time())
            return false;

        return $payload;
    }

    /**
     * HMACSHA256签名   https://jwt.io/  中HMACSHA256签名实现
     * @param string $input 为base64UrlEncode(header).".".base64UrlEncode(payload)
     * @param string $key
     * @param string $alg 算法方式
     * @return mixed
     */
    private static function signature(string $input, string $key, string $alg = 'HS256')
    {
        $alg_config = array(
            'HS256' => 'sha256'
        );
        // https://www.php.net/manual/zh/function.hash-hmac.php
        return self::base64UrlEncode(hash_hmac($alg_config[$alg], $input, $key, true));
    }


    /**
     * Encodes to base64url
     *
     * @param string $data
     * @return string
     */
    public static function base64UrlEncode($data)
    {
        return str_replace('=', '', strtr(base64_encode($data), '+/', '-_'));
    }

    /**
     * Decodes from base64url
     *
     * @param string $data
     * @return string
     */
    public static function base64UrlDecode($data)
    {
        if ($remainder = strlen($data) % 4) {
            $data .= str_repeat('=', 4 - $remainder);
        }

        return base64_decode(strtr($data, '-_', '+/'));
    }
}

//***********测试和官网是否匹配begin****************************
$payload = array('sub' => '1234567890', 'name' => 'Brady wang', 'iat' => time(), 'exp' => time() + 3600);
$jwt = new Jwt;
$token = $jwt->getToken($payload);
echo "<pre>";
echo $token;


//对token进行验证签名
$getPayload = $jwt->verifyToken($token);
echo "<br><br>";
var_dump($getPayload);
echo "<br><br>";


//自己使用测试begin
$payload_test = array('iss' => 'admin', 'iat' => time(), 'exp' => time() + 7200, 'nbf' => time(), 'sub' => 'www.admin.com', 'jti' => md5(uniqid('JWT') . time()));;
$token_test = Jwt::getToken($payload_test);
echo "<pre>";
echo $token_test;

//对token进行验证签名
$getPayload_test = Jwt::verifyToken($token_test);
echo "<br><br>";
var_dump($getPayload_test);
echo "<br><br>";


//自己使用测试begin
$payload_test = array('user_name'=>'brady');;
$token_test = Jwt::getToken($payload_test);
echo "<pre>";
echo $token_test;

//对token进行验证签名
$getPayload_test = Jwt::verifyToken($token_test);
echo "<br><br>";
var_dump($getPayload_test);
echo "<br><br>";