jwt是什么?
JWTs是JSON对象的编码表示。JSON对象由零或多个名称/值对组成，其中名称为字符串，值为任意JSON值。
JWT有助于在clear(例如在URL中)发送这样的信息，可以被信任为不可读(即加密的)、不可修改的(即签名)和URL - safe(即Base64编码的)。
jwt的组成
Header: 标题包含了令牌的元数据，并且在最小包含签名和/或加密算法的类型
Claims: Claims包含您想要签署的任何信息
JSON Web Signature (JWS): 在header中指定的使用该算法的数字签名和声明
例如：
Header: { "alg": "HS256", "typ": "JWT" } Claims: { "sub": "1234567890", "name": "John Doe", "admin": true } Signature: base64UrlEncode(Header) + "." + base64UrlEncode(Claims),
加密生成的token：
如何保证 JWT 安全
有很多库可以帮助您创建和验证JWT，但是当使用JWT时，仍然可以做一些事情来限制您的安全风险。在您信任JWT中的任何信息之前，请始终验证签名。这应该是给定的。
换句话说，如果您正在传递一个秘密签名密钥到验证签名的方法，并且签名算法被设置为“none”，那么它应该失败验证。
确保签名的秘密签名，用于计算和验证签名。秘密签名密钥只能由发行者和消费者访问，不能在这两方之外访问。
不要在JWT中包含任何敏感数据。这些令牌通常是用来防止操作(未加密)的，因此索赔中的数据可以很容易地解码和读取。
如果您担心重播攻击，包括一个nonce(jti索赔)、过期时间(exp索赔)和创建时间(iat索赔)。这些在JWT规范中定义得很好。
jwt的框架：JJWT
JJWT是一个提供端到端的JWT创建和验证的Java库。永远免费和开源(Apache License，版本2.0)，JJWT很容易使用和理解。它被设计成一个以建筑为中心的流畅界面，隐藏了它的大部分复杂性。
JJWT的目标是最容易使用和理解用于在JVM上创建和验证JSON Web令牌(JWTs)的库。
JJWT是基于JWT、JWS、JWE、JWK和JWA RFC规范的Java实现。
JJWT还添加了一些不属于规范的便利扩展，比如JWT压缩和索赔强制。
规范兼容:
创建和解析明文压缩JWTs
创建、解析和验证所有标准JWS算法的数字签名紧凑JWTs(又称JWSs):
HS256: HMAC using SHA-256
HS384: HMAC using SHA-384
HS512: HMAC using SHA-512
RS256: RSASSA-PKCS-v1_5 using SHA-256
RS384: RSASSA-PKCS-v1_5 using SHA-384
RS512: RSASSA-PKCS-v1_5 using SHA-512
PS256: RSASSA-PSS using SHA-256 and MGF1 with SHA-256
PS384: RSASSA-PSS using SHA-384 and MGF1 with SHA-384
PS512: RSASSA-PSS using SHA-512 and MGF1 with SHA-512
ES256: ECDSA using P-256 and SHA-256
ES384: ECDSA using P-384 and SHA-384
ES512: ECDSA using P-521 and SHA-512
这里以github上的demo演示，理解原理，集成到自己项目中即可。
应用采用 spring boot + angular + jwt
结构图
Maven 引进 : pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.nibado.example</groupId> <artifactId>jwt-angular-spring</artifactId> <version>0.0.2-SNAPSHOT</version> <properties> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <commons.io.version>2.4</commons.io.version> <jjwt.version>0.6.0</jjwt.version> <junit.version>4.12</junit.version> <spring.boot.version>1.5.3.RELEASE</spring.boot.version> </properties> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>${spring.boot.version}</version> <executions> <execution> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>${spring.boot.version}</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>${commons.io.version}</version> </dependency> <dependency> <groupId>io.jsonwebtoken</groupId> <artifactId>jjwt</artifactId> <version>${jjwt.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> </dependency> </dependencies> </project>
WebApplication.java
package com.nibado.example.jwtangspr; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.web.servlet.FilterRegistrationBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; @EnableAutoConfiguration @ComponentScan @Configuration public class WebApplication { //过滤器 @Bean public FilterRegistrationBean jwtFilter() { final FilterRegistrationBean registrationBean = new FilterRegistrationBean(); registrationBean.setFilter(new JwtFilter()); registrationBean.addUrlPatterns("/api/*"); return registrationBean; } public static void main(final String[] args) throws Exception { SpringApplication.run(WebApplication.class, args); } }
JwtFilter.java
package com.nibado.example.jwtangspr; import java.io.IOException; import javax.servlet.FilterChain; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import org.springframework.web.filter.GenericFilterBean; import io.jsonwebtoken.Claims; import io.jsonwebtoken.Jwts; import io.jsonwebtoken.SignatureException; public class JwtFilter extends GenericFilterBean { @Override public void doFilter(final ServletRequest req, final ServletResponse res, final FilterChain chain) throws IOException, ServletException { final HttpServletRequest request = (HttpServletRequest) req; //客户端将token封装在请求头中，格式为（Bearer后加空格）：Authorization：Bearer +token final String authHeader = request.getHeader("Authorization"); if (authHeader == null || !authHeader.startsWith("Bearer ")) { throw new ServletException("Missing or invalid Authorization header."); } //去除Bearer 后部分 final String token = authHeader.substring(7); try { //解密token，拿到里面的对象claims final Claims claims = Jwts.parser().setSigningKey("secretkey") .parseClaimsJws(token).getBody(); //将对象传递给下一个请求 request.setAttribute("claims", claims); } catch (final SignatureException e) { throw new ServletException("Invalid token."); } chain.doFilter(req, res); } }
UserController.java
package com.nibado.example.jwtangspr; import java.util.Arrays; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.servlet.ServletException; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; import io.jsonwebtoken.Jwts; import io.jsonwebtoken.SignatureAlgorithm; @RestController @RequestMapping("/user") public class UserController { //这里模拟数据库 private final Map<String, List<String>> userDb = new HashMap<>(); @SuppressWarnings("unused") private static class UserLogin { public String name; public String password; } public UserController() { userDb.put("tom", Arrays.asList("user")); userDb.put("wen", Arrays.asList("user", "admin")); } /*以上是模拟数据库，并往数据库插入tom和sally两条记录*/ @RequestMapping(value = "login", method = RequestMethod.POST) public LoginResponse login(@RequestBody final UserLogin login) throws ServletException { if (login.name == null || !userDb.containsKey(login.name)) { throw new ServletException("Invalid login"); } //加密生成token return new LoginResponse(Jwts.builder().setSubject(login.name) .claim("roles", userDb.get(login.name)).setIssuedAt(new Date()) .signWith(SignatureAlgorithm.HS256, "secretkey").compact()); } @SuppressWarnings("unused") private static class LoginResponse { public String token; public LoginResponse(final String token) { this.token = token; } } }
ApiController.java
package com.nibado.example.jwtangspr; import io.jsonwebtoken.Claims; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/api") public class ApiController { @SuppressWarnings("unchecked") @RequestMapping(value = "role/{role}", method = RequestMethod.GET) public Boolean login(@PathVariable final String role, final HttpServletRequest request) throws ServletException { final Claims claims = (Claims) request.getAttribute("claims"); return ((List<String>) claims.get("roles")).contains(role); } }
index.html
<!doctype html> <html ng-app="myApp"> <head> <meta charset="utf-8"/> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/> <title>JSON Web Token / AngularJS / Spring Boot example</title> <meta name="description" content=""> <meta name="viewport" content="width=device-width"> <link rel="stylesheet" href="libs/bootstrap/css/bootstrap.css"> <script src="libs/jquery/jquery.js"></script> <script src="libs/bootstrap/js/bootstrap.js"></script> <script src="libs/angular/angular.js"></script> <script src="app.js"></script> </head> <body> <div class="container" ng-controller='MainCtrl'> <h1>{{greeting}}</h1> <div ng-show="!loggedIn()"> Please log in (tom and sally are valid names)</br> <form ng-submit="login()"> Username: <input type="text" ng-model="userName"/><span><input type="submit" value="Login"/> </form> </div> <div class="alert alert-danger" role="alert" ng-show="error.data.message"> <span class="glyphicon glyphicon-exclamation-sign" aria-hidden="true"></span> <span class="sr-only">Error:</span> {{error.data.message}} </div> <div ng-show="loggedIn()"> <div class="row"> <div class="col-md-6"> <h3><span class="label label-success">Success!</span> Welcome {{userName}}</h3> <a href ng-click="logout()">(logout)</a> </div> <div class="col-md-4"> <div class="row header"> <div class="col-sm-4">{{userName}} is a</div> </div> <div class="row"> <div class="col-sm-2">User</div> <div class="col-sm-2"><span class="glyphicon glyphicon-ok" aria-hidden="true" ng-show="roleUser"></span></div> </div> <div class="row"> <div class="col-sm-2">Admin</div> <div class="col-sm-2"><span class="glyphicon glyphicon-ok" aria-hidden="true" ng-show="roleAdmin"></span></div> </div> <div class="row"> <div class="col-sm-2">Foo</div> <div class="col-sm-2"><span class="glyphicon glyphicon-ok" aria-hidden="true" ng-show="roleFoo"></span></div> </div> </div> </div> </div> </div> </body> </html>
app.js
var appModule = angular.module('myApp', []); appModule.controller('MainCtrl', ['mainService','$scope','$http', function(mainService, $scope, $http) { $scope.greeting = 'Welcome to the JSON Web Token / AngularJR / Spring example!'; $scope.token = null; $scope.error = null; $scope.roleUser = false; $scope.roleAdmin = false; $scope.roleFoo = false; $scope.login = function() { $scope.error = null; mainService.login($scope.userName).then(function(token) { $scope.token = token; $http.defaults.headers.common.Authorization = 'Bearer ' + token; $scope.checkRoles(); }, function(error){ $scope.error = error $scope.userName = ''; }); } $scope.checkRoles = function() { mainService.hasRole('user').then(function(user) {$scope.roleUser = user}); mainService.hasRole('admin').then(function(admin) {$scope.roleAdmin = admin}); mainService.hasRole('foo').then(function(foo) {$scope.roleFoo = foo}); } $scope.logout = function() { $scope.userName = ''; $scope.token = null; $http.defaults.headers.common.Authorization = ''; } $scope.loggedIn = function() { return $scope.token !== null; } } ]); appModule.service('mainService', function($http) { return { login : function(username) { return $http.post('/user/login', {name: username}).then(function(response) { return response.data.token; }); }, hasRole : function(role) { return $http.get('/api/role/' + role).then(function(response){ console.log(response); return response.data; }); } }; });
运行应用
效果