生成JWT格式的token

JWT简介

• JWT是json web token缩写
• 它将用户信息加密到token里，服务器不保存任何用户信息
• 服务器通过使用保存的密钥验证token的正确性，只要正确即通过验证
• 于token的身份验证可以替代传统的cookie+session身份验证方法

JWT组成

header部分

{
  "alg": "HS256",
  "typ": "JWT"
}
//对应base64UrlEncode编码为：eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9
//说明：该字段为json格式。alg字段指定了生成signature的算法，默认值为HS256，typ默认值为JWT

payload部分

{
  "sub": "1234567890",
  "name": "John Doe",
  "iat": 1516239022
}
//对应base64UrlEncode编码为：eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ
//说明：该字段为json格式，表明用户身份的数据，可以自己自定义字段，很灵活。sub 面向的用户，name 姓名 ,iat 签发时间。例如可自定义示例如下：
{
    "iss": "admin",          //该JWT的签发者
    "iat": 1535967430,        //签发时间
    "exp": 1535974630,        //过期时间
    "nbf": 1535967430,         //该时间之前不接收处理该Token
    "sub": "www.admin.com",   //面向的用户
    "jti": "9f10e796726e332cec401c569969e13e"   //该Token唯一标识
}

signature部分

HMACSHA256(
  base64UrlEncode(header) + "." +
  base64UrlEncode(payload),
  123456
) 
//对应的签名为：keH6T3x1z7mmhKL1T3r9sQdAxxdzB6siemGMr_6ZOwU

//最终得到的JWT的json为(header.payload.signature)：eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.keH6T3x1z7mmhKL1T3r9sQdAxxdzB6siemGMr_6ZOwU
//说明：对header和payload进行base64UrlEncode编码后进行拼接。通过key（这里是123456）进行HS256算法签名。

JWT使用流程

• 初次登录：用户初次登录，输入用户名密码
• 密码验证：服务器从数据库取出用户名和密码进行验证
• 生成JWT：服务器端验证通过，根据从数据库返回的信息，以及预设规则，生成JWT
• 返还JWT：服务器的HTTP RESPONSE中将JWT返还
• 带JWT的请求：以后客户端发起请求，HTTP REQUEST
• HEADER中的Authorizatio字段都要有值，为JWT
• 服务器验证JWT

 'HS256', 'typ' => 'JWT'];

    //使用HMAC生成信息摘要时所使用的密钥
    private static $key = '123456';

    /**
     * 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 $payload)
    {
        if (is_array($payload)) {
            echo "开始生成token\n
";
            $base64header = self::base64UrlEncode(json_encode(self::$header, JSON_UNESCAPED_UNICODE));
            echo "header部分\n";
            echo "$base64header
";
            $base64payload = self::base64UrlEncode(json_encode($payload, JSON_UNESCAPED_UNICODE));
            echo "payload部分\n";
            echo "$base64payload
";
            $token = $base64header . '.' . $base64payload . '.' . self::signature($base64header . '.' . $base64payload, self::$key, self::$header['alg']);
            echo "token整体\n";
            echo "$token
";
            return $token;
        } else {
            return false;
        }
    }


    /**
     * 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)
    {
        echo "开始对签名验证\n
";
        $tokens = explode('.', $Token);
        echo "得到header payload 及第三部分\n";
        var_dump($tokens);
        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;
    }


    /**
     * base64UrlEncode   https://jwt.io/  中base64UrlEncode编码实现
     * @param string $input 需要编码的字符串
     * @return string
     */
    private static function base64UrlEncode(string $input)
    {
        return str_replace('=', '', strtr(base64_encode($input), '+/', '-_'));
    }

    /**
     * base64UrlEncode  https://jwt.io/  中base64UrlEncode解码实现
     * @param string $input 需要解码的字符串
     * @return bool|string
     */
    private static function base64UrlDecode(string $input)
    {
        $remainder = strlen($input) % 4;
        if ($remainder) {
            $addlen = 4 - $remainder;
            $input  .= str_repeat('=', $addlen);
        }
        return base64_decode(strtr($input, '-_', '+/'));
    }

    /**
     * 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')
    {
        $alg_config = ['HS256' => 'sha256'];
        return self::base64UrlEncode(hash_hmac($alg_config[$alg], $input, $key, true));
    }
}

//测试和官网是否匹配begin
//$payload = ['sub' => '1234567890', 'name' => 'John Doe', 'iat' => 1516239022];
//$jwt     = new Jwt;
//echo "
";
//$token = $jwt->getToken($payload);
//
//对token进行验证签名
//$getPayload = $jwt->verifyToken($token);
//echo "

";
//var_dump($getPayload);
//echo "

";
//测试和官网是否匹配end


//自己使用测试begin
$payload_test = [
    'iss'    => 'admin',
    'iat'    => time(),
    'exp'    => time() + 7200,
    'nbf'    => time(),
    'sub'    => 'www.admin.com',
    'jti'    => md5(uniqid('JWT') . time()),
    'mtoken' => '0854089c8fa538ab3dd3d2e311b32c92',
    'btoken' => '50329e02db492b461120c25a212413c2',
    'utoken' => '8f5a5312acb94c5885f932795c710922'
];
$token_test   = Jwt::getToken($payload_test);
echo "
";
//echo $token_test;

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

";
var_dump($getPayload_test);
echo "

";
//自己使用时候end
 
  
开始生成token
header部分 eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9
payload部分 eyJpc3MiOiJhZG1pbiIsImlhdCI6MTU0ODEyNjkyMCwiZXhwIjoxNTQ4MTM0MTIwLCJuYmYiOjE1NDgxMjY5MjAsInN1YiI6Ind3dy5hZG1pbi5jb20iLCJqdGkiOiJkYjYyZDMxZmEyNzJiY2JhM2JkNzYzYjUzY2I3MjRlYyIsIm10b2tlbiI6IjA4NTQwODljOGZhNTM4YWIzZGQzZDJlMzExYjMyYzkyIiwiYnRva2VuIjoiNTAzMjllMDJkYjQ5MmI0NjExMjBjMjVhMjEyNDEzYzIiLCJ1dG9rZW4iOiI4ZjVhNTMxMmFjYjk0YzU4ODVmOTMyNzk1YzcxMDkyMiJ9
token整体 eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJhZG1pbiIsImlhdCI6MTU0ODEyNjkyMCwiZXhwIjoxNTQ4MTM0MTIwLCJuYmYiOjE1NDgxMjY5MjAsInN1YiI6Ind3dy5hZG1pbi5jb20iLCJqdGkiOiJkYjYyZDMxZmEyNzJiY2JhM2JkNzYzYjUzY2I3MjRlYyIsIm10b2tlbiI6IjA4NTQwODljOGZhNTM4YWIzZGQzZDJlMzExYjMyYzkyIiwiYnRva2VuIjoiNTAzMjllMDJkYjQ5MmI0NjExMjBjMjVhMjEyNDEzYzIiLCJ1dG9rZW4iOiI4ZjVhNTMxMmFjYjk0YzU4ODVmOTMyNzk1YzcxMDkyMiJ9.iUCC9QSk_HlRCvm8B7BAyOyxpgwCa-OwAhhbvHMRpyk
开始对签名验证
得到header payload 及第三部分
D:\WebServer\www\jwtDemo\Jwt.php:57:
array (size=3)
  0 => string 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9' (length=36)
  1 => string 'eyJpc3MiOiJhZG1pbiIsImlhdCI6MTU0ODEyNjkyMCwiZXhwIjoxNTQ4MTM0MTIwLCJuYmYiOjE1NDgxMjY5MjAsInN1YiI6Ind3dy5hZG1pbi5jb20iLCJqdGkiOiJkYjYyZDMxZmEyNzJiY2JhM2JkNzYzYjUzY2I3MjRlYyIsIm10b2tlbiI6IjA4NTQwODljOGZhNTM4YWIzZGQzZDJlMzExYjMyYzkyIiwiYnRva2VuIjoiNTAzMjllMDJkYjQ5MmI0NjExMjBjMjVhMjEyNDEzYzIiLCJ1dG9rZW4iOiI4ZjVhNTMxMmFjYjk0YzU4ODVmOTMyNzk1YzcxMDkyMiJ9' (length=348)
  2 => string 'iUCC9QSk_HlRCvm8B7BAyOyxpgwCa-OwAhhbvHMRpyk' (length=43)


D:\WebServer\www\jwtDemo\Jwt.php:161:
array (size=9)
  'iss' => string 'admin' (length=5)
  'iat' => int 1548126920
  'exp' => int 1548134120
  'nbf' => int 1548126920
  'sub' => string 'www.admin.com' (length=13)
  'jti' => string 'db62d31fa272bcba3bd763b53cb724ec' (length=32)
  'mtoken' => string '0854089c8fa538ab3dd3d2e311b32c92' (length=32)
  'btoken' => string '50329e02db492b461120c25a212413c2' (length=32)
  'utoken' => string '8f5a5312acb94c5885f932795c710922' (length=32)