一个es模块友好的简化版本的jwt-decode.js

function b64DecodeUnicode(str) {
  return decodeURIComponent(
    atob(str).replace(/(.)/g, function (m, p) {
      var code = p.charCodeAt(0).toString(16).toUpperCase();
      if (code.length < 2) {
        code = "0" + code;
      }
      return "%" + code;
    })
  );
}

function base64_url_decode(str) {
  var output = str.replace(/-/g, "+").replace(/_/g, "/");
  switch (output.length % 4) {
    case 0:
      break;
    case 2:
      output += "==";
      break;
    case 3:
      output += "=";
      break;
    default:
      throw "Illegal base64url string!";
  }

  try {
    return b64DecodeUnicode(output);
  } catch (err) {
    return atob(output);
  }
}

export function jwtDecode(token, options) {
  options = options || {};
  var pos = options.header === true ? 0 : 1;
  try {
    return JSON.parse(base64_url_decode(token.split(".")[pos]));
  } catch (e) {
    console.log(e.message);
  }
}

由于nodejs环境中没有“window”对象， 我们可以使用以下代码行:

let base64Url = token.split('.')[1]; // token you get
let base64 = base64Url.replace('-', '+').replace('_', '/');
let decodedData = JSON.parse(Buffer.from(base64, 'base64').toString('binary'));

它非常适合我。希望能有所帮助。

我在jwt找到了这个代码。IO，它工作得很好。

//this is used to parse base64
function url_base64_decode(str) {
  var output = str.replace(/-/g, '+').replace(/_/g, '/');
  switch (output.length % 4) {
    case 0:
      break;
    case 2:
      output += '==';
      break;
    case 3:
      output += '=';
      break;
    default:
      throw 'Illegal base64url string!';
  }
  var result = window.atob(output); //polifyll https://github.com/davidchambers/Base64.js
  try{
    return decodeURIComponent(escape(result));
  } catch (err) {
    return result;
  }
}

在某些情况下(某些开发平台)， 最好的答案(目前)面临一个base64长度无效的问题。 所以，我需要一种更稳定的方法。

我希望这对你有所帮助。

你可以使用jwt-decode，这样你就可以这样写:

import jwt_decode from 'jwt-decode';

var token = 'eyJ0eXAiO.../// jwt token';

var decoded = jwt_decode(token);
console.log(decoded);
/*{exp: 10012016 name: john doe, scope:['admin']}*/

如果你正在使用Typescript或普通JavaScript，这里有一个零依赖，准备复制粘贴到你的项目简单函数(基于@Rajan Maharjan的回答)。

This answer is particularly good, not only because it does not depend on any npm module, but also because it does not depend an any node.js built-in module (like Buffer) that some other solutions here are using and of course would fail in the browser (unless polyfilled, but there's no reason to do that in the first place). Additionally JSON.parse can fail at runtime and this version (especially in Typescript) will force handling of that. The JSDoc annotations will make future maintainers of your code thankful. :)

/**
 * Returns a JS object representation of a Javascript Web Token from its common encoded
 * string form.
 *
 * @template T the expected shape of the parsed token
 * @param {string} token a Javascript Web Token in base64 encoded, `.` separated form
 * @returns {(T | undefined)} an object-representation of the token
 * or undefined if parsing failed
 */
export function getParsedJwt<T extends object = { [k: string]: string | number }>(
  token: string,
): T | undefined {
  try {
    return JSON.parse(atob(token.split('.')[1]))
  } catch {
    return undefined
  }
}

为了完成，这里还有一个普通的javascript版本:

/**
 * Returns a JS object representation of a Javascript Web Token from its common encoded
 * string form.
 *
 * @param {string} token a Javascript Web Token in base64 encoded, `.` separated form
 * @returns {(object | undefined)} an object-representation of the token
 * or undefined if parsing failed
 */
export function getParsedJwt(token) {
  try {
    return JSON.parse(atob(token.split('.')[1]))
  } catch (error) {
    return undefined
  }
}

注意:这并不验证签名，它只是从令牌中提取JSON有效负载，这可能已经被篡改了。

浏览器

unicode文本JWT解析器功能:

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

    return JSON.parse(jsonPayload);
}

JWT使用base64url (RFC 4648§5)，因此仅使用atob(使用base64)是不够的。

node . js

function parseJwt (token) {
    return JSON.parse(Buffer.from(token.split('.')[1], 'base64').toString());
}