从零开始的Spring Security Oauth2(二)
本文开始从源码的层面,讲解一些spring Security Oauth2的认证流程。本文较长,适合在空余时间段观看。且涉及了较多的源码,非关键性代码以…代替。
获取token
上一篇博客中我们尝试使用了password模式和client模式,有一个比较关键的endpoint:/oauth/token。从这个入口开始分析,spring security oauth2内部是如何生成token的。
首先开启debug信息:
logging: level: org.springframework: DEBUG |
可以完整的看到内部的运转流程。
client模式稍微简单一些,使用client模式获取tokenhttp://localhost:8080/oauth/token? client_id=client_1&client_secret=123456&scope=select&grant_type=client_credentials
由于debug信息太多了,我简单按照顺序列了一下关键的几个类:
ClientCredentialsTokenEndpointFilter DaoAuthenticationProvider TokenEndpoint TokenGranter |
ClientCredentialsTokenEndpointFilter和DaoAuthenticationProvider
截取关键的代码,可以分析出大概的流程
在请求到达/oauth/token之前经过了ClientCredentialsTokenEndpointFilter这个过滤器,关键方法如下
public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException, IOException, ServletException { ... String clientId = request.getParameter("client_id"); String clientSecret = request.getParameter("client_secret"); ... clientId = clientId.trim(); UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(clientId, clientSecret); return this.getAuthenticationManager().authenticate(authRequest); } |
用来从请求中获取client_id,client_secret,组装成一个UsernamePasswordAuthenticationToken作为身份标识,使用容器中的*身份管理器AuthenticationManager去进行身份认证(AuthenticationManager的实现类一般是ProviderManager。而ProviderManager内部维护了一个List,真正的身份认证是由一系列AuthenticationProvider去完成。而AuthenticationProvider的常用实现类则是DaoAuthenticationProvider,DaoAuthenticationProvider内部又聚合了一个UserDetailsService接口,UserDetailsService才是获取用户详细信息的最终接口,而我们上一篇文章中在内存中配置用户,就是使用了UserDetailsService的一个实现类InMemoryUserDetailsManager)。UML类图可以大概理解下这些类的关系,省略了授权部分。
可能机智的读者会发现一个问题,我前面一片文章已经提到了client模式是不存在“用户”的概念的,那么这里的身份认证是在认证什么呢?debug可以发现UserDetailsService的实现被适配成了ClientDetailsUserDetailsService,这个设计是将client客户端的信息(client_id,client_secret)适配成用户的信息(username,password),这样我们的认证流程就不需要修改了。
经过ClientCredentialsTokenEndpointFilter之后,身份信息已经得到了AuthenticationManager的验证。接着便到达了
TokenEndpoint。
TokenEndpoint
前面的两个ClientCredentialsTokenEndpointFilter和DaoAuthenticationProvider可以理解为一些前置校验,和身份封装,而这个类一看名字就知道和我们的token是密切相关的。
@FrameworkEndpoint public class TokenEndpoint extends AbstractEndpoint { @RequestMapping(value = "/oauth/token", method=RequestMethod.POST) public ResponseEntity<OAuth2AccessToken> postAccessToken(Principal principal, @RequestParam Map<String, String> parameters) throws HttpRequestMethodNotSupportedException { ... String clientId = getClientId(principal); ClientDetails authenticatedClient = getClientDetailsService().loadClientByClientId(clientId); ... TokenRequest tokenRequest = getOAuth2RequestFactory().createTokenRequest(parameters, authenticatedClient); ... OAuth2AccessToken token = getTokenGranter().grant(tokenRequest.getGrantType(), tokenRequest); ... return getResponse(token); } private TokenGranter tokenGranter; } |
省略了一些校验代码之后,真正的/oauth/token端点暴露在了我们眼前,其中方法参数中的Principal经过之前的过滤器,已经被填充了相关的信息,而方法的内部则是依赖了一个TokenGranter 来颁发token。其中OAuth2AccessToken的实现类DefaultOAuth2AccessToken就是最终在控制台得到的token序列化之前的原始类:
public class DefaultOAuth2AccessToken implements Serializable, OAuth2AccessToken { private static final long serialVersionUID = 914967629530462926L; private String value; private Date expiration; private String tokenType = BEARER_TYPE.toLowerCase(); private OAuth2RefreshToken refreshToken; private Set<String> scope; private Map<String, Object> additionalInformation = Collections.emptyMap(); //getter,setter } @org.codehaus.jackson.map.annotate.JsonSerialize(using = OAuth2AccessTokenJackson1Serializer.class) @org.codehaus.jackson.map.annotate.JsonDeserialize(using = OAuth2AccessTokenJackson1Deserializer.class) @com.fasterxml.jackson.databind.annotation.JsonSerialize(using = OAuth2AccessTokenJackson2Serializer.class) @com.fasterxml.jackson.databind.annotation.JsonDeserialize(using = OAuth2AccessTokenJackson2Deserializer.class) public interface OAuth2AccessToken { public static String BEARER_TYPE = "Bearer"; public static String OAUTH2_TYPE = "OAuth2"; /** * The access token issued by the authorization server. This value is REQUIRED. */ public static String ACCESS_TOKEN = "access_token"; /** * The type of the token issued as described in <a * href="http://tools.ietf.org/html/draft-ietf-oauth-v2-22#section-7.1">Section 7.1</a>. Value is case insensitive. * This value is REQUIRED. */ public static String TOKEN_TYPE = "token_type"; /** * The lifetime in seconds of the access token. For example, the value "3600" denotes that the access token will * expire in one hour from the time the response was generated. This value is OPTIONAL. */ public static String EXPIRES_IN = "expires_in"; /** * The refresh token which can be used to obtain new access tokens using the same authorization grant as described * in <a href="http://tools.ietf.org/html/draft-ietf-oauth-v2-22#section-6">Section 6</a>. This value is OPTIONAL. */ public static String REFRESH_TOKEN = "refresh_token"; /** * The scope of the access token as described by <a * href="http://tools.ietf.org/html/draft-ietf-oauth-v2-22#section-3.3">Section 3.3</a> */ public static String SCOPE = "scope"; ... } |
一个典型的样例token响应,如下所示,就是上述类序列化后的结果:
{ "access_token":"950a7cc9-5a8a-42c9-a693-40e817b1a4b0", "token_type":"bearer", "refresh_token":"773a0fcd-6023-45f8-8848-e141296cb3cb", "expires_in":27036, "scope":"select" } |
TokenGranter
先从UML类图对TokenGranter接口的设计有一个宏观的认识
TokenGranter的设计思路是使用CompositeTokenGranter管理一个List列表,每一种grantType对应一个具体的真正授权者,在debug过程中可以发现CompositeTokenGranter 内部就是在循环调用五种TokenGranter实现类的grant方法,而granter内部则是通过grantType来区分是否是各自的授权类型。
public class CompositeTokenGranter implements TokenGranter { private final List<TokenGranter> tokenGranters; public CompositeTokenGranter(List<TokenGranter> tokenGranters) { this.tokenGranters = new ArrayList<TokenGranter>(tokenGranters); } public OAuth2AccessToken grant(String grantType, TokenRequest tokenRequest) { for (TokenGranter granter : tokenGranters) { OAuth2AccessToken grant = granter.grant(grantType, tokenRequest); if (grant!=null) { return grant; } } return null; } } |
五种类型分别是:
- ResourceOwnerPasswordTokenGranter ==> password密码模式
- AuthorizationCodeTokenGranter ==> authorization_code授权码模式
- ClientCredentialsTokenGranter ==> client_credentials客户端模式
- ImplicitTokenGranter ==> implicit简化模式
- RefreshTokenGranter ==>refresh_token 刷新token专用
以客户端模式为例,思考如何产生token的,则需要继续研究5种授权者的抽象类:AbstractTokenGranter
public abstract class AbstractTokenGranter implements TokenGranter { protected final Log logger = LogFactory.getLog(getClass()); //与token相关的service,重点 private final AuthorizationServerTokenServices tokenServices; //与clientDetails相关的service,重点 private final ClientDetailsService clientDetailsService; //创建oauth2Request的工厂,重点 private final OAuth2RequestFactory requestFactory; private final String grantType; ... public OAuth2AccessToken grant(String grantType, TokenRequest tokenRequest) { ... String clientId = tokenRequest.getClientId(); ClientDetails client = clientDetailsService.loadClientByClientId(clientId); validateGrantType(grantType, client); logger.debug("Getting access token for: " + clientId); return getAccessToken(client, tokenRequest); } protected OAuth2AccessToken getAccessToken(ClientDetails client, TokenRequest tokenRequest) { return tokenServices.createAccessToken(getOAuth2Authentication(client, tokenRequest)); } protected OAuth2Authentication getOAuth2Authentication(ClientDetails client, TokenRequest tokenRequest) { OAuth2Request storedOAuth2Request = requestFactory.createOAuth2Request(client, tokenRequest); return new OAuth2Authentication(storedOAuth2Request, null); } ... } |
回过头去看TokenEndpoint中,正是调用了这里的三个重要的类变量的相关方法。由于篇幅限制,不能延展太多,不然没完没了,所以重点分析下AuthorizationServerTokenServices是何方神圣。
AuthorizationServerTokenServices
public interface AuthorizationServerTokenServices { //创建token OAuth2AccessToken createAccessToken(OAuth2Authentication authentication) throws AuthenticationException; //刷新token OAuth2AccessToken refreshAccessToken(String refreshToken, TokenRequest tokenRequest) throws AuthenticationException; //获取token OAuth2AccessToken getAccessToken(OAuth2Authentication authentication); } |
在默认的实现类DefaultTokenServices中,可以看到token是如何产生的,并且了解了框架对token进行哪些信息的关联。
@Transactional public OAuth2AccessToken createAccessToken(OAuth2Authentication authentication) throws AuthenticationException { OAuth2AccessToken existingAccessToken = tokenStore.getAccessToken(authentication); OAuth2RefreshToken refreshToken = null; if (existingAccessToken != null) { if (existingAccessToken.isExpired()) { if (existingAccessToken.getRefreshToken() != null) { refreshToken = existingAccessToken.getRefreshToken(); // The token store could remove the refresh token when the // access token is removed, but we want to // be sure... tokenStore.removeRefreshToken(refreshToken); } tokenStore.removeAccessToken(existingAccessToken); } else { // Re-store the access token in case the authentication has changed tokenStore.storeAccessToken(existingAccessToken, authentication); return existingAccessToken; } } // Only create a new refresh token if there wasn't an existing one // associated with an expired access token. // Clients might be holding existing refresh tokens, so we re-use it in // the case that the old access token // expired. if (refreshToken == null) { refreshToken = createRefreshToken(authentication); } // But the refresh token itself might need to be re-issued if it has // expired. else if (refreshToken instanceof ExpiringOAuth2RefreshToken) { ExpiringOAuth2RefreshToken expiring = (ExpiringOAuth2RefreshToken) refreshToken; if (System.currentTimeMillis() > expiring.getExpiration().getTime()) { refreshToken = createRefreshToken(authentication); } } OAuth2AccessToken accessToken = createAccessToken(authentication, refreshToken); tokenStore.storeAccessToken(accessToken, authentication); // In case it was modified refreshToken = accessToken.getRefreshToken(); if (refreshToken != null) { tokenStore.storeRefreshToken(refreshToken, authentication); } return accessToken; } |
简单总结一下AuthorizationServerTokenServices的作用,他提供了创建token,刷新token,获取token的实现。在创建token时,他会调用tokenStore对产生的token和相关信息存储到对应的实现类中,可以是Redis,数据库,内存,jwt。
总结
本篇总结了使用客户端模式获取Token时,spring security oauth2内部的运作流程,其他模式有一定的不同,但抽象功能是固定的,只是具体的实现类会被响应地替换。阅读spring的源码,会发现它的设计中出现了非常多的抽象接口,这对我们理清楚内部工作流程产生了不小的困扰,我的方式是可以借助UML类图,先从宏观理清楚作者的设计思路,这会让我们的分析事半功倍。
下一篇文章重点分析用户携带token访问受限资源时,spring security oauth2内部的工作流程。