[JWT] 인증 토큰 Decrypt

• JSON Web Tokens

Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJnb29kcy1kb25hdGlvbiIsImV4cCI6MTYyNDMyMDU1OCwiaWQiOiJjdzAxMTExQGJlYXV0aWZ1bHN0b3JlLm9LWRvbmF0aW9uIiwibmJmIjoxNjI0MjMzODU4LCJyb2xlcyI6Im1lbWJlciJ9.z6wT-CB3r-ba038swVEFYOLxlakYb1p2smxgc1_ch40

위처럼 정신 없는 장문 텍스트가 json 형식으로 깔끔하게 변환된다!

• How to decode jwt token in javascript without using a library?

function parseJwt (token) {
    var base64Url = token.split('.')[1];
    var base64 = base64Url.replace(/-/g, '+').replace(/_/g, '/');
    var jsonPayload = decodeURIComponent(atob(base64).split('').map(function(c) {
        return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
    }).join(''));
    return JSON.parse(jsonPayload);
};