shiro源码(三)-认证过滤器原理

  简单研究下对于需要登陆的请求,后端的处理逻辑。

1. 前提条件

  继续访问/test 接口,按照我们下面的配置,该请求会被authc 过滤器拦截到。

        /**
         *  路径 -> 过滤器名称1[参数1,参数2,参数3...],过滤器名称2[参数1,参数2...]...
         * 自定义配置(前面是路径, 后面是具体的过滤器名称加参数,多个用逗号进行分割,过滤器参数也多个之间也是用逗号分割))
         * 有的过滤器不需要参数,比如anon, authc, shiro 在解析的时候接默认解析一个数组为 [name, null]
         */
        FILTER_CHAIN_DEFINITION_MAP.put("/test2", "anon"); // 测试地址
        FILTER_CHAIN_DEFINITION_MAP.put("/user/**", "roles[系统管理员,用户管理员],perms['user:manager:*']");
        FILTER_CHAIN_DEFINITION_MAP.put("/**", "authc"); // 所有资源都需要经过验证

前提条件回顾

1. org.apache.shiro.spring.web.ShiroFilterFactoryBean.SpringShiroFilter 注册到Spring 中,默认是拦截所有请求。

2. /test 请求进入该拦截器。

3. 调用 org.apache.shiro.web.servlet.OncePerRequestFilter#doFilter

4. 调用org.apache.shiro.web.servlet.AbstractShiroFilter#doFilterInternal。

5. 调用org.apache.shiro.web.servlet.AbstractShiroFilter#executeChain

6. 调用org.apache.shiro.web.servlet.AbstractShiroFilter#getExecutionChain 生成代理FilterChain (逻辑是根据请求的URI, 和自己配置的路径进行正则匹配,如果满足条件,则获取到匹配到路径对应的NameFilterList, 然后生成ProxiedFilterChain(该代理对象内部包含NameFilterList和原来的FApplicationFilterChain))

7. 调用代理FilterChain 的doFilter方法。 该代理对象的方法会先走NameFilterList 的doFilter,然后走ApplicationFilterChain 的doFilter 方法。

2. org.apache.shiro.web.filter.authc.FormAuthenticationFilter 原理

  上面根据路径获取到的代理FilterChain 如下:

1. ProxiedFilterChai.doFilter 方法会调用到FormAuthenticationFilter .doFilter 方法。该方法是父类方法:org.apache.shiro.web.servlet.OncePerRequestFilter#doFilter

    public final void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String alreadyFilteredAttributeName = this.getAlreadyFilteredAttributeName();
        if (request.getAttribute(alreadyFilteredAttributeName) != null) {
            log.trace("Filter '{}' already executed.  Proceeding without invoking this filter.", this.getName());
            filterChain.doFilter(request, response);
        } else if (this.isEnabled(request, response) && !this.shouldNotFilter(request)) {
            log.trace("Filter '{}' not yet executed.  Executing now.", this.getName());
            request.setAttribute(alreadyFilteredAttributeName, Boolean.TRUE);

            try {
                this.doFilterInternal(request, response, filterChain);
            } finally {
                request.removeAttribute(alreadyFilteredAttributeName);
            }
        } else {
            log.debug("Filter '{}' is not enabled for the current request.  Proceeding without invoking this filter.", this.getName());
            filterChain.doFilter(request, response);
        }

    }

2. 继续调用到org.apache.shiro.web.servlet.AdviceFilter#doFilterInternal

    public void doFilterInternal(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
        Exception exception = null;

        try {
            boolean continueChain = this.preHandle(request, response);
            if (log.isTraceEnabled()) {
                log.trace("Invoked preHandle method.  Continuing chain?: [" + continueChain + "]");
            }

            if (continueChain) {
                this.executeChain(request, response, chain);
            }

            this.postHandle(request, response);
            if (log.isTraceEnabled()) {
                log.trace("Successfully invoked postHandle method");
            }
        } catch (Exception var9) {
            exception = var9;
        } finally {
            this.cleanup(request, response, exception);
        }

    }

这里面可分为三步:

第一步:this.preHandle(request, response); 前置处理

第二步:如果前置处理返回true,则调用this.executeChain(request, response, chain); 链条继续执行

第三步:this.postHandle(request, response); 后置处理

3. 前置处理逻辑:

调用org.apache.shiro.web.filter.PathMatchingFilter#preHandle

    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        if (this.appliedPaths != null && !this.appliedPaths.isEmpty()) {
            Iterator var3 = this.appliedPaths.keySet().iterator();

            String path;
            do {
                if (!var3.hasNext()) {
                    return true;
                }

                path = (String)var3.next();
            } while(!this.pathsMatch(path, request));

            log.trace("Current requestURI matches pattern '{}'.  Determining filter chain execution...", path);
            Object config = this.appliedPaths.get(path);
            return this.isFilterChainContinued(request, response, path, config);
        } else {
            if (log.isTraceEnabled()) {
                log.trace("appliedPaths property is null or empty.  This Filter will passthrough immediately.");
            }

            return true;
        }
    }

    private boolean isFilterChainContinued(ServletRequest request, ServletResponse response, String path, Object pathConfig) throws Exception {
        if (this.isEnabled(request, response, path, pathConfig)) {
            if (log.isTraceEnabled()) {
                log.trace("Filter '{}' is enabled for the current request under path '{}' with config [{}].  Delegating to subclass implementation for 'onPreHandle' check.", new Object[]{this.getName(), path, pathConfig});
            }

            return this.onPreHandle(request, response, pathConfig);
        } else {
            if (log.isTraceEnabled()) {
                log.trace("Filter '{}' is disabled for the current request under path '{}' with config [{}].  The next element in the FilterChain will be called immediately.", new Object[]{this.getName(), path, pathConfig});
            }

            return true;
        }
    }

1》this.isEnabled(request, response, path, pathConfig) 这一步默认都是true,也就是会进下面的onPreHandle 方法。 如果返回false,那么直接返回去。进行下一个链条执行。

2》 调用到org.apache.shiro.web.filter.AccessControlFilter#onPreHandle: 这里逻辑理解为逻辑与运算,如果某一个返回true 则返回true, 那么执行下一个链条。也就是如果允许访问或者拒绝访问都会走下一个链条。只有当isAccessAllowed 返回false, 并且onAccessDenied 也返回false, 才会跳过链条。

    public boolean onPreHandle(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
        return this.isAccessAllowed(request, response, mappedValue) || this.onAccessDenied(request, response, mappedValue);
    }

这里又有两步:

第一步: 调用isAccessAllowed 判断请求是否允许访问(mappedValue 是配置的请求的参数)。如果已经认证或者不是登陆地址,并且配置的参数包含permissive 则允许访问

会调用到:org.apache.shiro.web.filter.authc.AuthenticatingFilter#isAccessAllowed

    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
        return super.isAccessAllowed(request, response, mappedValue) ||
                (!isLoginRequest(request, response) && isPermissive(mappedValue));
    }

    protected boolean isPermissive(Object mappedValue) {
        if(mappedValue != null) {
            String[] values = (String[]) mappedValue;
            return Arrays.binarySearch(values, PERMISSIVE) >= 0;
        }
        return false;
    }
  • super.isAccessAllowed 继续调用到:org.apache.shiro.web.filter.authc.AuthenticationFilter#isAccessAllowed 判断请求是否已经授权(关于认证之后如何进行标记之后研究)
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
        Subject subject = this.getSubject(request, response);
        return subject.isAuthenticated() && subject.getPrincipal() != null;
    }

getSubject 实际调org.apache.shiro.SecurityUtils#getSubject:(实际是从ThreadLocal 中获取对象)

    public static Subject getSubject() {
        Subject subject = ThreadContext.getSubject();
        if (subject == null) {
            subject = (new Subject.Builder()).buildSubject();
            ThreadContext.bind(subject);
        }
        return subject;
    }
  • 判断是否是登陆地址:org.apache.shiro.web.filter.AccessControlFilter#isLoginRequest
    protected boolean isLoginRequest(ServletRequest request, ServletResponse response) {
        return this.pathsMatch(this.getLoginUrl(), request);
    }

第二步:onAccessDenied 判断是否拒绝访问

  • org.apache.shiro.web.filter.AccessControlFilter#onAccessDenied(javax.servlet.ServletRequest, javax.servlet.ServletResponse, java.lang.Object)
    protected boolean onAccessDenied(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
        return onAccessDenied(request, response);
    }
  • org.apache.shiro.web.filter.authc.FormAuthenticationFilter#onAccessDenied
    protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
        if (isLoginRequest(request, response)) {
            if (isLoginSubmission(request, response)) {
                if (log.isTraceEnabled()) {
                    log.trace("Login submission detected.  Attempting to execute login.");
                }
                return executeLogin(request, response);
            } else {
                if (log.isTraceEnabled()) {
                    log.trace("Login page view.");
                }
                //allow them to see the login page ;)
                return true;
            }
        } else {
            if (log.isTraceEnabled()) {
                log.trace("Attempting to access a path which requires authentication.  Forwarding to the " +
                        "Authentication url [" + getLoginUrl() + "]");
            }

            saveRequestAndRedirectToLogin(request, response);
            return false;
        }
    }

    protected boolean isLoginSubmission(ServletRequest request, ServletResponse response) {
        return (request instanceof HttpServletRequest) && WebUtils.toHttp(request).getMethod().equalsIgnoreCase(POST_METHOD);
    }

    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
        AuthenticationToken token = createToken(request, response);
        if (token == null) {
            String msg = "createToken method implementation returned null. A valid non-null AuthenticationToken " +
                    "must be created in order to execute a login attempt.";
            throw new IllegalStateException(msg);
        }
        try {
            Subject subject = getSubject(request, response);
            subject.login(token);
            return onLoginSuccess(token, subject, request, response);
        } catch (AuthenticationException e) {
            return onLoginFailure(token, e, request, response);
        }
    }

首先判断是否是登陆请求:

1》如果是:

  判断是否是提交登陆请求,返回执行登陆请求;如果不是则返回true。返回true 的话链条就可以继续执行。执行登录也比较简单:

    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
        AuthenticationToken token = createToken(request, response);
        if (token == null) {
            String msg = "createToken method implementation returned null. A valid non-null AuthenticationToken " +
                    "must be created in order to execute a login attempt.";
            throw new IllegalStateException(msg);
        }
        try {
            Subject subject = getSubject(request, response);
            subject.login(token);
            return onLoginSuccess(token, subject, request, response);
        } catch (AuthenticationException e) {
            return onLoginFailure(token, e, request, response);
        }
    }

org.apache.shiro.web.filter.authc.FormAuthenticationFilter#createToken 创建Token :(实际就是以默认的username 和 password 为参数去request 获取参数)

    public static final String DEFAULT_USERNAME_PARAM = "username";
    public static final String DEFAULT_PASSWORD_PARAM = "password";
    public static final String DEFAULT_REMEMBER_ME_PARAM = "rememberMe";

    protected AuthenticationToken createToken(ServletRequest request, ServletResponse response) {
        String username = getUsername(request);
        String password = getPassword(request);
        return createToken(username, password, request, response);
    }

    protected String getUsername(ServletRequest request) {
        return WebUtils.getCleanParam(request, getUsernameParam());
    }

    protected String getPassword(ServletRequest request) {
        return WebUtils.getCleanParam(request, getPasswordParam());
    }

2》如果不是:

  调用saveRequestAndRedirectToLogin(request, response); 然后返回false, 返回false,那么请求链条不会继续执行。

org.apache.shiro.web.filter.AccessControlFilter#saveRequestAndRedirectToLogin 就是保存请求并且重定向到登陆地址

    protected void saveRequestAndRedirectToLogin(ServletRequest request, ServletResponse response) throws IOException {
        saveRequest(request);
        redirectToLogin(request, response);
    }

    protected void saveRequest(ServletRequest request) {
        WebUtils.saveRequest(request);
    }

    protected void redirectToLogin(ServletRequest request, ServletResponse response) throws IOException {
        String loginUrl = getLoginUrl();
        WebUtils.issueRedirect(request, response, loginUrl);
    }

WebUtils 工具类如下:

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.shiro.web.util;

import org.apache.shiro.SecurityUtils;
import org.apache.shiro.session.Session;
import org.apache.shiro.subject.Subject;
import org.apache.shiro.subject.support.DefaultSubjectContext;
import org.apache.shiro.util.StringUtils;
import org.apache.shiro.web.env.EnvironmentLoader;
import org.apache.shiro.web.env.WebEnvironment;
import org.apache.shiro.web.filter.AccessControlFilter;
import org.owasp.encoder.Encode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.Map;

/**
 * Simple utility class for operations used across multiple class hierarchies in the web framework code.
 * <p/>
 * Some methods in this class were copied from the Spring Framework so we didn't have to re-invent the wheel,
 * and in these cases, we have retained all license, copyright and author information.
 *
 * @since 0.9
 */
public class WebUtils {

    //TODO - complete JavaDoc

    private static final Logger log = LoggerFactory.getLogger(WebUtils.class);

    public static final String SERVLET_REQUEST_KEY = ServletRequest.class.getName() + "_SHIRO_THREAD_CONTEXT_KEY";
    public static final String SERVLET_RESPONSE_KEY = ServletResponse.class.getName() + "_SHIRO_THREAD_CONTEXT_KEY";

    /**
     * {@link org.apache.shiro.session.Session Session} key used to save a request and later restore it, for example when redirecting to a
     * requested page after login, equal to {@code shiroSavedRequest}.
     */
    public static final String SAVED_REQUEST_KEY = "shiroSavedRequest";

    /**
     * Standard Servlet 2.3+ spec request attributes for include URI and paths.
     * <p>If included via a RequestDispatcher, the current resource will see the
     * originating request. Its own URI and paths are exposed as request attributes.
     */
    public static final String INCLUDE_REQUEST_URI_ATTRIBUTE = "javax.servlet.include.request_uri";
    public static final String INCLUDE_CONTEXT_PATH_ATTRIBUTE = "javax.servlet.include.context_path";
    public static final String INCLUDE_SERVLET_PATH_ATTRIBUTE = "javax.servlet.include.servlet_path";
    public static final String INCLUDE_PATH_INFO_ATTRIBUTE = "javax.servlet.include.path_info";
    public static final String INCLUDE_QUERY_STRING_ATTRIBUTE = "javax.servlet.include.query_string";

    /**
     * Standard Servlet 2.4+ spec request attributes for forward URI and paths.
     * <p>If forwarded to via a RequestDispatcher, the current resource will see its
     * own URI and paths. The originating URI and paths are exposed as request attributes.
     */
    public static final String FORWARD_REQUEST_URI_ATTRIBUTE = "javax.servlet.forward.request_uri";
    public static final String FORWARD_CONTEXT_PATH_ATTRIBUTE = "javax.servlet.forward.context_path";
    public static final String FORWARD_SERVLET_PATH_ATTRIBUTE = "javax.servlet.forward.servlet_path";
    public static final String FORWARD_PATH_INFO_ATTRIBUTE = "javax.servlet.forward.path_info";
    public static final String FORWARD_QUERY_STRING_ATTRIBUTE = "javax.servlet.forward.query_string";

    /**
     * Default character encoding to use when <code>request.getCharacterEncoding</code>
     * returns <code>null</code>, according to the Servlet spec.
     *
     * @see javax.servlet.ServletRequest#getCharacterEncoding
     */
    public static final String DEFAULT_CHARACTER_ENCODING = "ISO-8859-1";

    /**
     * Return the path within the web application for the given request.
     * Detects include request URL if called within a RequestDispatcher include.
     * <p/>
     * For example, for a request to URL
     * <p/>
     * <code>http://www.somehost.com/myapp/my/url.jsp</code>,
     * <p/>
     * for an application deployed to <code>/mayapp</code> (the application's context path), this method would return
     * <p/>
     * <code>/my/url.jsp</code>.
     *
     * @param request current HTTP request
     * @return the path within the web application
     */
    public static String getPathWithinApplication(HttpServletRequest request) {
        return normalize(removeSemicolon(getServletPath(request) + getPathInfo(request)));
    }

    /**
     * Return the request URI for the given request, detecting an include request
     * URL if called within a RequestDispatcher include.
     * <p>As the value returned by <code>request.getRequestURI()</code> is <i>not</i>
     * decoded by the servlet container, this method will decode it.
     * <p>The URI that the web container resolves <i>should</i> be correct, but some
     * containers like JBoss/Jetty incorrectly include ";" strings like ";jsessionid"
     * in the URI. This method cuts off such incorrect appendices.
     *
     * @param request current HTTP request
     * @return the request URI
     * @deprecated use getPathWithinApplication() to get the path minus the context path, or call HttpServletRequest.getRequestURI() directly from your code.
     */
    @Deprecated
    public static String getRequestUri(HttpServletRequest request) {
        String uri = (String) request.getAttribute(INCLUDE_REQUEST_URI_ATTRIBUTE);
        if (uri == null) {
            uri = request.getRequestURI();
        }
        return normalize(decodeAndCleanUriString(request, uri));
    }

    private static String getServletPath(HttpServletRequest request) {
        String servletPath = (String) request.getAttribute(INCLUDE_SERVLET_PATH_ATTRIBUTE);
        return servletPath != null ? servletPath : valueOrEmpty(request.getServletPath());
    }

    private static String getPathInfo(HttpServletRequest request) {
        String pathInfo = (String) request.getAttribute(INCLUDE_PATH_INFO_ATTRIBUTE);
        return pathInfo != null ? pathInfo : valueOrEmpty(request.getPathInfo());
    }

    private static String valueOrEmpty(String input) {
        if (input == null) {
            return "";
        }
        return input;
    }

    /**
     * Normalize a relative URI path that may have relative values ("/./",
     * "/../", and so on ) it it.  <strong>WARNING</strong> - This method is
     * useful only for normalizing application-generated paths.  It does not
     * try to perform security checks for malicious input.
     * Normalize operations were was happily taken from org.apache.catalina.util.RequestUtil in
     * Tomcat trunk, r939305
     *
     * @param path Relative path to be normalized
     * @return normalized path
     */
    public static String normalize(String path) {
        return normalize(path, true);
    }

    /**
     * Normalize a relative URI path that may have relative values ("/./",
     * "/../", and so on ) it it.  <strong>WARNING</strong> - This method is
     * useful only for normalizing application-generated paths.  It does not
     * try to perform security checks for malicious input.
     * Normalize operations were was happily taken from org.apache.catalina.util.RequestUtil in
     * Tomcat trunk, r939305
     *
     * @param path             Relative path to be normalized
     * @param replaceBackSlash Should '\' be replaced with '/'
     * @return normalized path
     */
    private static String normalize(String path, boolean replaceBackSlash) {

        if (path == null)
            return null;

        // Create a place for the normalized path
        String normalized = path;

        if (replaceBackSlash && normalized.indexOf('\') >= 0)
            normalized = normalized.replace('\', '/');

        if (normalized.equals("/."))
            return "/";

        // Add a leading "/" if necessary
        if (!normalized.startsWith("/"))
            normalized = "/" + normalized;

        // Resolve occurrences of "//" in the normalized path
        while (true) {
            int index = normalized.indexOf("//");
            if (index < 0)
                break;
            normalized = normalized.substring(0, index) +
                    normalized.substring(index + 1);
        }

        // Resolve occurrences of "/./" in the normalized path
        while (true) {
            int index = normalized.indexOf("/./");
            if (index < 0)
                break;
            normalized = normalized.substring(0, index) +
                    normalized.substring(index + 2);
        }

        // Resolve occurrences of "/../" in the normalized path
        while (true) {
            int index = normalized.indexOf("/../");
            if (index < 0)
                break;
            if (index == 0)
                return (null);  // Trying to go outside our context
            int index2 = normalized.lastIndexOf('/', index - 1);
            normalized = normalized.substring(0, index2) +
                    normalized.substring(index + 3);
        }

        // Return the normalized path that we have completed
        return (normalized);

    }


    /**
     * Decode the supplied URI string and strips any extraneous portion after a ';'.
     *
     * @param request the incoming HttpServletRequest
     * @param uri     the application's URI string
     * @return the supplied URI string stripped of any extraneous portion after a ';'.
     */
    private static String decodeAndCleanUriString(HttpServletRequest request, String uri) {
        uri = decodeRequestString(request, uri);
        return removeSemicolon(uri);
    }

    private static String removeSemicolon(String uri) {
        int semicolonIndex = uri.indexOf(';');
        return (semicolonIndex != -1 ? uri.substring(0, semicolonIndex) : uri);
    }

    /**
     * Return the context path for the given request, detecting an include request
     * URL if called within a RequestDispatcher include.
     * <p>As the value returned by <code>request.getContextPath()</code> is <i>not</i>
     * decoded by the servlet container, this method will decode it.
     *
     * @param request current HTTP request
     * @return the context path
     */
    public static String getContextPath(HttpServletRequest request) {
        String contextPath = (String) request.getAttribute(INCLUDE_CONTEXT_PATH_ATTRIBUTE);
        if (contextPath == null) {
            contextPath = request.getContextPath();
        }
        contextPath = normalize(decodeRequestString(request, contextPath));
        if ("/".equals(contextPath)) {
            // the normalize method will return a "/" and includes on Jetty, will also be a "/".
            contextPath = "";
        }
        return contextPath;
    }

    /**
     * Find the Shiro {@link WebEnvironment} for this web application, which is typically loaded via the
     * {@link org.apache.shiro.web.env.EnvironmentLoaderListener}.
     * <p/>
     * This implementation rethrows an exception that happened on environment startup to differentiate between a failed
     * environment startup and no environment at all.
     *
     * @param sc ServletContext to find the web application context for
     * @return the root WebApplicationContext for this web app
     * @throws IllegalStateException if the root WebApplicationContext could not be found
     * @see org.apache.shiro.web.env.EnvironmentLoader#ENVIRONMENT_ATTRIBUTE_KEY
     * @since 1.2
     */
    public static WebEnvironment getRequiredWebEnvironment(ServletContext sc)
            throws IllegalStateException {

        WebEnvironment we = getWebEnvironment(sc);
        if (we == null) {
            throw new IllegalStateException("No WebEnvironment found: no EnvironmentLoaderListener registered?");
        }
        return we;
    }

    /**
     * Find the Shiro {@link WebEnvironment} for this web application, which is typically loaded via
     * {@link org.apache.shiro.web.env.EnvironmentLoaderListener}.
     * <p/>
     * This implementation rethrows an exception that happened on environment startup to differentiate between a failed
     * environment startup and no environment at all.
     *
     * @param sc ServletContext to find the web application context for
     * @return the root WebApplicationContext for this web app, or <code>null</code> if none
     * @see org.apache.shiro.web.env.EnvironmentLoader#ENVIRONMENT_ATTRIBUTE_KEY
     * @since 1.2
     */
    public static WebEnvironment getWebEnvironment(ServletContext sc) {
        return getWebEnvironment(sc, EnvironmentLoader.ENVIRONMENT_ATTRIBUTE_KEY);
    }

    /**
     * Find the Shiro {@link WebEnvironment} for this web application.
     *
     * @param sc       ServletContext to find the web application context for
     * @param attrName the name of the ServletContext attribute to look for
     * @return the desired WebEnvironment for this web app, or <code>null</code> if none
     * @since 1.2
     */
    public static WebEnvironment getWebEnvironment(ServletContext sc, String attrName) {
        if (sc == null) {
            throw new IllegalArgumentException("ServletContext argument must not be null.");
        }
        Object attr = sc.getAttribute(attrName);
        if (attr == null) {
            return null;
        }
        if (attr instanceof RuntimeException) {
            throw (RuntimeException) attr;
        }
        if (attr instanceof Error) {
            throw (Error) attr;
        }
        if (attr instanceof Exception) {
            throw new IllegalStateException((Exception) attr);
        }
        if (!(attr instanceof WebEnvironment)) {
            throw new IllegalStateException("Context attribute is not of type WebEnvironment: " + attr);
        }
        return (WebEnvironment) attr;
    }


    /**
     * Decode the given source string with a URLDecoder. The encoding will be taken
     * from the request, falling back to the default "ISO-8859-1".
     * <p>The default implementation uses <code>URLDecoder.decode(input, enc)</code>.
     *
     * @param request current HTTP request
     * @param source  the String to decode
     * @return the decoded String
     * @see #DEFAULT_CHARACTER_ENCODING
     * @see javax.servlet.ServletRequest#getCharacterEncoding
     * @see java.net.URLDecoder#decode(String, String)
     * @see java.net.URLDecoder#decode(String)
     */
    @SuppressWarnings({"deprecation"})
    public static String decodeRequestString(HttpServletRequest request, String source) {
        String enc = determineEncoding(request);
        try {
            return URLDecoder.decode(source, enc);
        } catch (UnsupportedEncodingException ex) {
            if (log.isWarnEnabled()) {
                log.warn("Could not decode request string [" + Encode.forHtml(source) + "] with encoding '" + Encode.forHtml(enc) +
                        "': falling back to platform default encoding; exception message: " + ex.getMessage());
            }
            return URLDecoder.decode(source);
        }
    }

    /**
     * Determine the encoding for the given request.
     * Can be overridden in subclasses.
     * <p>The default implementation checks the request's
     * {@link ServletRequest#getCharacterEncoding() character encoding}, and if that
     * <code>null</code>, falls back to the {@link #DEFAULT_CHARACTER_ENCODING}.
     *
     * @param request current HTTP request
     * @return the encoding for the request (never <code>null</code>)
     * @see javax.servlet.ServletRequest#getCharacterEncoding()
     */
    protected static String determineEncoding(HttpServletRequest request) {
        String enc = request.getCharacterEncoding();
        if (enc == null) {
            enc = DEFAULT_CHARACTER_ENCODING;
        }
        return enc;
    }

    /*
     * Returns {@code true} IFF the specified {@code SubjectContext}:
     * <ol>
     * <li>A {@link WebSubjectContext} instance</li>
     * <li>The {@code WebSubjectContext}'s request/response pair are not null</li>
     * <li>The request is an {@link HttpServletRequest} instance</li>
     * <li>The response is an {@link HttpServletResponse} instance</li>
     * </ol>
     *
     * @param context the SubjectContext to check to see if it is HTTP compatible.
     * @return {@code true} IFF the specified context has HTTP request/response objects, {@code false} otherwise.
     * @since 1.0
     */

    public static boolean isWeb(Object requestPairSource) {
        return requestPairSource instanceof RequestPairSource && isWeb((RequestPairSource) requestPairSource);
    }

    public static boolean isHttp(Object requestPairSource) {
        return requestPairSource instanceof RequestPairSource && isHttp((RequestPairSource) requestPairSource);
    }

    public static ServletRequest getRequest(Object requestPairSource) {
        if (requestPairSource instanceof RequestPairSource) {
            return ((RequestPairSource) requestPairSource).getServletRequest();
        }
        return null;
    }

    public static ServletResponse getResponse(Object requestPairSource) {
        if (requestPairSource instanceof RequestPairSource) {
            return ((RequestPairSource) requestPairSource).getServletResponse();
        }
        return null;
    }

    public static HttpServletRequest getHttpRequest(Object requestPairSource) {
        ServletRequest request = getRequest(requestPairSource);
        if (request instanceof HttpServletRequest) {
            return (HttpServletRequest) request;
        }
        return null;
    }

    public static HttpServletResponse getHttpResponse(Object requestPairSource) {
        ServletResponse response = getResponse(requestPairSource);
        if (response instanceof HttpServletResponse) {
            return (HttpServletResponse) response;
        }
        return null;
    }

    private static boolean isWeb(RequestPairSource source) {
        ServletRequest request = source.getServletRequest();
        ServletResponse response = source.getServletResponse();
        return request != null && response != null;
    }

    private static boolean isHttp(RequestPairSource source) {
        ServletRequest request = source.getServletRequest();
        ServletResponse response = source.getServletResponse();
        return request instanceof HttpServletRequest && response instanceof HttpServletResponse;
    }

    /**
     * Returns {@code true} if a session is allowed to be created for a subject-associated request, {@code false}
     * otherwise.
     * <p/>
     * <b>This method exists for Shiro's internal framework needs and should never be called by Shiro end-users.  It
     * could be changed/removed at any time.</b>
     *
     * @param requestPairSource a {@link RequestPairSource} instance, almost always a
     *                          {@link org.apache.shiro.web.subject.WebSubject WebSubject} instance.
     * @return {@code true} if a session is allowed to be created for a subject-associated request, {@code false}
     *         otherwise.
     */
    public static boolean _isSessionCreationEnabled(Object requestPairSource) {
        if (requestPairSource instanceof RequestPairSource) {
            RequestPairSource source = (RequestPairSource) requestPairSource;
            return _isSessionCreationEnabled(source.getServletRequest());
        }
        return true; //by default
    }

    /**
     * Returns {@code true} if a session is allowed to be created for a subject-associated request, {@code false}
     * otherwise.
     * <p/>
     * <b>This method exists for Shiro's internal framework needs and should never be called by Shiro end-users.  It
     * could be changed/removed at any time.</b>
     *
     * @param request incoming servlet request.
     * @return {@code true} if a session is allowed to be created for a subject-associated request, {@code false}
     *         otherwise.
     */
    public static boolean _isSessionCreationEnabled(ServletRequest request) {
        if (request != null) {
            Object val = request.getAttribute(DefaultSubjectContext.SESSION_CREATION_ENABLED);
            if (val != null && val instanceof Boolean) {
                return (Boolean) val;
            }
        }
        return true; //by default
    }

    /**
     * A convenience method that merely casts the incoming <code>ServletRequest</code> to an
     * <code>HttpServletRequest</code>:
     * <p/>
     * <code>return (HttpServletRequest)request;</code>
     * <p/>
     * Logic could be changed in the future for logging or throwing an meaningful exception in
     * non HTTP request environments (e.g. Portlet API).
     *
     * @param request the incoming ServletRequest
     * @return the <code>request</code> argument casted to an <code>HttpServletRequest</code>.
     */
    public static HttpServletRequest toHttp(ServletRequest request) {
        return (HttpServletRequest) request;
    }

    /**
     * A convenience method that merely casts the incoming <code>ServletResponse</code> to an
     * <code>HttpServletResponse</code>:
     * <p/>
     * <code>return (HttpServletResponse)response;</code>
     * <p/>
     * Logic could be changed in the future for logging or throwing an meaningful exception in
     * non HTTP request environments (e.g. Portlet API).
     *
     * @param response the outgoing ServletResponse
     * @return the <code>response</code> argument casted to an <code>HttpServletResponse</code>.
     */
    public static HttpServletResponse toHttp(ServletResponse response) {
        return (HttpServletResponse) response;
    }

    /**
     * Redirects the current request to a new URL based on the given parameters.
     *
     * @param request          the servlet request.
     * @param response         the servlet response.
     * @param url              the URL to redirect the user to.
     * @param queryParams      a map of parameters that should be set as request parameters for the new request.
     * @param contextRelative  true if the URL is relative to the servlet context path, or false if the URL is absolute.
     * @param http10Compatible whether to stay compatible with HTTP 1.0 clients.
     * @throws java.io.IOException if thrown by response methods.
     */
    public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams, boolean contextRelative, boolean http10Compatible) throws IOException {
        RedirectView view = new RedirectView(url, contextRelative, http10Compatible);
        view.renderMergedOutputModel(queryParams, toHttp(request), toHttp(response));
    }

    /**
     * Redirects the current request to a new URL based on the given parameters and default values
     * for unspecified parameters.
     *
     * @param request  the servlet request.
     * @param response the servlet response.
     * @param url      the URL to redirect the user to.
     * @throws java.io.IOException if thrown by response methods.
     */
    public static void issueRedirect(ServletRequest request, ServletResponse response, String url) throws IOException {
        issueRedirect(request, response, url, null, true, true);
    }

    /**
     * Redirects the current request to a new URL based on the given parameters and default values
     * for unspecified parameters.
     *
     * @param request     the servlet request.
     * @param response    the servlet response.
     * @param url         the URL to redirect the user to.
     * @param queryParams a map of parameters that should be set as request parameters for the new request.
     * @throws java.io.IOException if thrown by response methods.
     */
    public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams) throws IOException {
        issueRedirect(request, response, url, queryParams, true, true);
    }

    /**
     * Redirects the current request to a new URL based on the given parameters and default values
     * for unspecified parameters.
     *
     * @param request         the servlet request.
     * @param response        the servlet response.
     * @param url             the URL to redirect the user to.
     * @param queryParams     a map of parameters that should be set as request parameters for the new request.
     * @param contextRelative true if the URL is relative to the servlet context path, or false if the URL is absolute.
     * @throws java.io.IOException if thrown by response methods.
     */
    public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams, boolean contextRelative) throws IOException {
        issueRedirect(request, response, url, queryParams, contextRelative, true);
    }

    /**
     * <p>Checks to see if a request param is considered true using a loose matching strategy for
     * general values that indicate that something is true or enabled, etc.</p>
     * <p/>
     * <p>Values that are considered "true" include (case-insensitive): true, t, 1, enabled, y, yes, on.</p>
     *
     * @param request   the servlet request
     * @param paramName @return true if the param value is considered true or false if it isn't.
     * @return true if the given parameter is considered "true" - false otherwise.
     */
    public static boolean isTrue(ServletRequest request, String paramName) {
        String value = getCleanParam(request, paramName);
        return value != null &&
                (value.equalsIgnoreCase("true") ||
                        value.equalsIgnoreCase("t") ||
                        value.equalsIgnoreCase("1") ||
                        value.equalsIgnoreCase("enabled") ||
                        value.equalsIgnoreCase("y") ||
                        value.equalsIgnoreCase("yes") ||
                        value.equalsIgnoreCase("on"));
    }

    /**
     * Convenience method that returns a request parameter value, first running it through
     * {@link StringUtils#clean(String)}.
     *
     * @param request   the servlet request.
     * @param paramName the parameter name.
     * @return the clean param value, or null if the param does not exist or is empty.
     */
    public static String getCleanParam(ServletRequest request, String paramName) {
        return StringUtils.clean(request.getParameter(paramName));
    }

    public static void saveRequest(ServletRequest request) {
        Subject subject = SecurityUtils.getSubject();
        Session session = subject.getSession();
        HttpServletRequest httpRequest = toHttp(request);
        SavedRequest savedRequest = new SavedRequest(httpRequest);
        session.setAttribute(SAVED_REQUEST_KEY, savedRequest);
    }

    public static SavedRequest getAndClearSavedRequest(ServletRequest request) {
        SavedRequest savedRequest = getSavedRequest(request);
        if (savedRequest != null) {
            Subject subject = SecurityUtils.getSubject();
            Session session = subject.getSession();
            session.removeAttribute(SAVED_REQUEST_KEY);
        }
        return savedRequest;
    }

    public static SavedRequest getSavedRequest(ServletRequest request) {
        SavedRequest savedRequest = null;
        Subject subject = SecurityUtils.getSubject();
        Session session = subject.getSession(false);
        if (session != null) {
            savedRequest = (SavedRequest) session.getAttribute(SAVED_REQUEST_KEY);
        }
        return savedRequest;
    }

    /**
     * Redirects the to the request url from a previously
     * {@link #saveRequest(javax.servlet.ServletRequest) saved} request, or if there is no saved request, redirects the
     * end user to the specified {@code fallbackUrl}.  If there is no saved request or fallback url, this method
     * throws an {@link IllegalStateException}.
     * <p/>
     * This method is primarily used to support a common login scenario - if an unauthenticated user accesses a
     * page that requires authentication, it is expected that request is
     * {@link #saveRequest(javax.servlet.ServletRequest) saved} first and then redirected to the login page. Then,
     * after a successful login, this method can be called to redirect them back to their originally requested URL, a
     * nice usability feature.
     *
     * @param request     the incoming request
     * @param response    the outgoing response
     * @param fallbackUrl the fallback url to redirect to if there is no saved request available.
     * @throws IllegalStateException if there is no saved request and the {@code fallbackUrl} is {@code null}.
     * @throws IOException           if there is an error redirecting
     * @since 1.0
     */
    public static void redirectToSavedRequest(ServletRequest request, ServletResponse response, String fallbackUrl)
            throws IOException {
        String successUrl = null;
        boolean contextRelative = true;
        SavedRequest savedRequest = WebUtils.getAndClearSavedRequest(request);
        if (savedRequest != null && savedRequest.getMethod().equalsIgnoreCase(AccessControlFilter.GET_METHOD)) {
            successUrl = savedRequest.getRequestUrl();
            contextRelative = false;
        }

        if (successUrl == null) {
            successUrl = fallbackUrl;
        }

        if (successUrl == null) {
            throw new IllegalStateException("Success URL not available via saved request or via the " +
                    "successUrlFallback method parameter. One of these must be non-null for " +
                    "issueSuccessRedirect() to work.");
        }

        WebUtils.issueRedirect(request, response, successUrl, null, contextRelative);
    }

}
View Code

  至此完成了未登录访问的拦截,并且重定向到登陆地址。 以及对登陆地址的放行。

3. 登陆原理

  查看登陆是如何从Controller 调用到realm的,以及是如何维护登陆状态的。

1. 前置修改

1. 增加登陆地址

    @GetMapping("/login2")
    public String login2() {
        Subject subject = SecurityUtils.getSubject();
        AuthenticationToken generateToken = new UsernamePasswordToken("zs", "111222");
        subject.login(generateToken);
        return "success";
    }

2. ShiroConfig 配置该地址允许匿名访问

        /**
         *  路径 -> 过滤器名称1[参数1,参数2,参数3...],过滤器名称2[参数1,参数2...]...
         * 自定义配置(前面是路径, 后面是具体的过滤器名称加参数,多个用逗号进行分割,过滤器参数也多个之间也是用逗号分割))
         * 有的过滤器不需要参数,比如anon, authc, shiro 在解析的时候接默认解析一个数组为 [name, null]
         */
        FILTER_CHAIN_DEFINITION_MAP.put("/test2", "anon"); // 测试地址
        FILTER_CHAIN_DEFINITION_MAP.put("/login2", "anon"); // 登陆地址
        FILTER_CHAIN_DEFINITION_MAP.put("/user/**", "roles[系统管理员,用户管理员],perms['user:manager:*']");
        FILTER_CHAIN_DEFINITION_MAP.put("/**", "authc"); // 所有资源都需要经过验证

3. 修改自定义realm 认证方法

    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authenticationToken)
            throws AuthenticationException {
        User user = new User();
        user.setPassword("111222");
        return new SimpleAuthenticationInfo(user, user.getPassword(), this.getName());
    }

2. 测试登陆

1. 访问测试地址 /login2

2. 首先经过shiro的anon 过滤器会放行,然后进入后面的controller 方法。

3. org.apache.shiro.SecurityUtils#getSubject 获取subject, 实际也就是从ThreadLocal 中获取

    public static Subject getSubject() {
        Subject subject = ThreadContext.getSubject();
        if (subject == null) {
            subject = (new Subject.Builder()).buildSubject();
            ThreadContext.bind(subject);
        }
        return subject;
    }

4. 调用org.apache.shiro.subject.support.DelegatingSubject#login 进行认证流程如下:

    public void login(AuthenticationToken token) throws AuthenticationException {
        clearRunAsIdentitiesInternal();
        Subject subject = securityManager.login(this, token);

        PrincipalCollection principals;

        String host = null;

        if (subject instanceof DelegatingSubject) {
            DelegatingSubject delegating = (DelegatingSubject) subject;
            //we have to do this in case there are assumed identities - we don't want to lose the 'real' principals:
            principals = delegating.principals;
            host = delegating.host;
        } else {
            principals = subject.getPrincipals();
        }

        if (principals == null || principals.isEmpty()) {
            String msg = "Principals returned from securityManager.login( token ) returned a null or " +
                    "empty value.  This value must be non null and populated with one or more elements.";
            throw new IllegalStateException(msg);
        }
        this.principals = principals;
        this.authenticated = true;
        if (token instanceof HostAuthenticationToken) {
            host = ((HostAuthenticationToken) token).getHost();
        }
        if (host != null) {
            this.host = host;
        }
        Session session = subject.getSession(false);
        if (session != null) {
            this.session = decorate(session);
        } else {
            this.session = null;
        }
    }

  核心都在securityManager.login(this, token) 调用内部, 传递subject 对象和 usernamePasswordToken。 认证成功之后会验证一些 信息并保存到当前对象, 也就是将当前subject 标记为已经认证。

5. org.apache.shiro.mgt.DefaultSecurityManager#login 

    /**
     * First authenticates the {@code AuthenticationToken} argument, and if successful, constructs a
     * {@code Subject} instance representing the authenticated account's identity.
     * <p/>
     * Once constructed, the {@code Subject} instance is then {@link #bind bound} to the application for
     * subsequent access before being returned to the caller.
     *
     * @param token the authenticationToken to process for the login attempt.
     * @return a Subject representing the authenticated user.
     * @throws AuthenticationException if there is a problem authenticating the specified {@code token}.
     */
    public Subject login(Subject subject, AuthenticationToken token) throws AuthenticationException {
        AuthenticationInfo info;
        try {
            info = authenticate(token);
        } catch (AuthenticationException ae) {
            try {
                onFailedLogin(token, ae, subject);
            } catch (Exception e) {
                if (log.isInfoEnabled()) {
                    log.info("onFailedLogin method threw an " +
                            "exception.  Logging and propagating original AuthenticationException.", e);
                }
            }
            throw ae; //propagate
        }

        Subject loggedIn = createSubject(token, info, subject);

        onSuccessfulLogin(token, info, loggedIn);

        return loggedIn;
    }

(1) 调用org.apache.shiro.mgt.AuthenticatingSecurityManager#authenticate进行认证

    /**
     * Delegates to the wrapped {@link org.apache.shiro.authc.Authenticator Authenticator} for authentication.
     */
    public AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
        return this.authenticator.authenticate(token);
    }

1》继续调用:org.apache.shiro.authc.AbstractAuthenticator#authenticate

    public final AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {

        if (token == null) {
            throw new IllegalArgumentException("Method argument (authentication token) cannot be null.");
        }

        log.trace("Authentication attempt received for token [{}]", token);

        AuthenticationInfo info;
        try {
            info = doAuthenticate(token);
            if (info == null) {
                String msg = "No account information found for authentication token [" + token + "] by this " +
                        "Authenticator instance.  Please check that it is configured correctly.";
                throw new AuthenticationException(msg);
            }
        } catch (Throwable t) {
            AuthenticationException ae = null;
            if (t instanceof AuthenticationException) {
                ae = (AuthenticationException) t;
            }
            if (ae == null) {
                //Exception thrown was not an expected AuthenticationException.  Therefore it is probably a little more
                //severe or unexpected.  So, wrap in an AuthenticationException, log to warn, and propagate:
                String msg = "Authentication failed for token submission [" + token + "].  Possible unexpected " +
                        "error? (Typical or expected login exceptions should extend from AuthenticationException).";
                ae = new AuthenticationException(msg, t);
                if (log.isWarnEnabled())
                    log.warn(msg, t);
            }
            try {
                notifyFailure(token, ae);
            } catch (Throwable t2) {
                if (log.isWarnEnabled()) {
                    String msg = "Unable to send notification for failed authentication attempt - listener error?.  " +
                            "Please check your AuthenticationListener implementation(s).  Logging sending exception " +
                            "and propagating original AuthenticationException instead...";
                    log.warn(msg, t2);
                }
            }


            throw ae;
        }

        log.debug("Authentication successful for token [{}].  Returned account [{}]", token, info);

        notifySuccess(token, info);

        return info;
    }

2》继续调用到org.apache.shiro.authc.pam.ModularRealmAuthenticator#doAuthenticate: (这里实际就是将请求转交给realm)

    protected AuthenticationInfo doAuthenticate(AuthenticationToken authenticationToken) throws AuthenticationException {
        assertRealmsConfigured();
        Collection<Realm> realms = getRealms();
        if (realms.size() == 1) {
            return doSingleRealmAuthentication(realms.iterator().next(), authenticationToken);
        } else {
            return doMultiRealmAuthentication(realms, authenticationToken);
        }
    }

  从这里可以看出可以支持多种realm 认证方式。 这里研究单realm 认证方式。 多realm 认证之后研究。

3》继续调用org.apache.shiro.authc.pam.ModularRealmAuthenticator#doSingleRealmAuthentication:

    protected AuthenticationInfo doSingleRealmAuthentication(Realm realm, AuthenticationToken token) {
        if (!realm.supports(token)) {
            String msg = "Realm [" + realm + "] does not support authentication token [" +
                    token + "].  Please ensure that the appropriate Realm implementation is " +
                    "configured correctly or that the realm accepts AuthenticationTokens of this type.";
            throw new UnsupportedTokenException(msg);
        }
        AuthenticationInfo info = realm.getAuthenticationInfo(token);
        if (info == null) {
            String msg = "Realm [" + realm + "] was unable to find account data for the " +
                    "submitted AuthenticationToken [" + token + "].";
            throw new UnknownAccountException(msg);
        }
        return info;
    }
  • 首先调用org.apache.shiro.realm.AuthenticatingRealm#supports 判断是否支持该token (也就是判断是否是类型相匹配)
    public boolean supports(AuthenticationToken token) {
        return token != null && getAuthenticationTokenClass().isAssignableFrom(token.getClass());
    }
  • 调用realm.getAuthenticationInfo(token); 进行获取认证信息, 如果获取的微null, 那么抛出UnknownAccountException(msg); 异常

4》 继续研究获取认证信息org.apache.shiro.realm.AuthenticatingRealm#getAuthenticationInfo

    public final AuthenticationInfo getAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {

        AuthenticationInfo info = getCachedAuthenticationInfo(token);
        if (info == null) {
            //otherwise not cached, perform the lookup:
            info = doGetAuthenticationInfo(token);
            log.debug("Looked up AuthenticationInfo [{}] from doGetAuthenticationInfo", info);
            if (token != null && info != null) {
                cacheAuthenticationInfoIfPossible(token, info);
            }
        } else {
            log.debug("Using cached authentication info [{}] to perform credentials matching.", info);
        }

        if (info != null) {
            assertCredentialsMatch(token, info);
        } else {
            log.debug("No AuthenticationInfo found for submitted AuthenticationToken [{}].  Returning null.", token);
        }

        return info;
    }
  • 首先根据 org.apache.shiro.authc.UsernamePasswordToken#getPrincipal 也就是根据用户的唯一身份标识(内部是getUsername()), 获取缓存。 如果获取到直接验证密码; 获取不到就调realm 进行获取
  • 调用realm 获取认证信息,这里调用到: com.zd.bx.config.shiro.CustomRealm#doGetAuthenticationInfo(也就是自己的realm)
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authenticationToken)
            throws AuthenticationException {
        User user = new User();
        user.setPassword("111222");
        return new SimpleAuthenticationInfo(user, user.getPassword(), this.getName());
    }

org.apache.shiro.authc.SimpleAuthenticationInfo#SimpleAuthenticationInfo(java.lang.Object, java.lang.Object, java.lang.String) 构造如下:

    public SimpleAuthenticationInfo(Object principal, Object credentials, String realmName) {
        // 身份信息
        this.principals = new SimplePrincipalCollection(principal, realmName);
    // 凭证信息,可以理解为密码(用户数据库的秘密,不是token 里面的密码)
        this.credentials = credentials;
    }

org.apache.shiro.subject.SimplePrincipalCollection#SimplePrincipalCollection(java.lang.Object, java.lang.String) 相当于缓存相关细腻些:

private Map<String, Set> realmPrincipals;

    public SimplePrincipalCollection(Object principal, String realmName) {
        if (principal instanceof Collection) {
            addAll((Collection) principal, realmName);
        } else {
            add(principal, realmName);
        }
    }

    public void add(Object principal, String realmName) {
        if (realmName == null) {
            throw new NullPointerException("realmName argument cannot be null.");
        }
        if (principal == null) {
            throw new NullPointerException("principal argument cannot be null.");
        }
        this.cachedToString = null;
        getPrincipalsLazy(realmName).add(principal);
    }

    protected Collection getPrincipalsLazy(String realmName) {
        if (realmPrincipals == null) {
            realmPrincipals = new LinkedHashMap<String, Set>();
        }
        Set principals = realmPrincipals.get(realmName);
        if (principals == null) {
            principals = new LinkedHashSet();
            realmPrincipals.put(realmName, principals);
        }
        return principals;
    }
  • 获取到认证信息之后缓存起来。org.apache.shiro.realm.AuthenticatingRealm#cacheAuthenticationInfoIfPossible
    private void cacheAuthenticationInfoIfPossible(AuthenticationToken token, AuthenticationInfo info) {
        if (!isAuthenticationCachingEnabled(token, info)) {
            log.debug("AuthenticationInfo caching is disabled for info [{}].  Submitted token: [{}].", info, token);
            //return quietly, caching is disabled for this token/info pair:
            return;
        }

        Cache<Object, AuthenticationInfo> cache = getAvailableAuthenticationCache();
        if (cache != null) {
            Object key = getAuthenticationCacheKey(token);
            cache.put(key, info);
            log.trace("Cached AuthenticationInfo for continued authentication.  key=[{}], value=[{}].", key, info);
        }
    }

  核心逻辑是如果开启缓存,就根据token 生成缓存的key(默认就是根据username 生成唯一key), 然后缓存起来。

  • 如果认证信息不为null, 进行身份凭证信息匹配,也就是验证密码

org.apache.shiro.realm.AuthenticatingRealm#assertCredentialsMatch 验证凭证信息, 不匹配的话就抛出异常

    protected void assertCredentialsMatch(AuthenticationToken token, AuthenticationInfo info) throws AuthenticationException {
        CredentialsMatcher cm = getCredentialsMatcher();
        if (cm != null) {
            if (!cm.doCredentialsMatch(token, info)) {
                //not successful - throw an exception to indicate this:
                String msg = "Submitted credentials for token [" + token + "] did not match the expected credentials.";
                throw new IncorrectCredentialsException(msg);
            }
        } else {
            throw new AuthenticationException("A CredentialsMatcher must be configured in order to verify " +
                    "credentials during authentication.  If you do not wish for credentials to be examined, you " +
                    "can configure an " + AllowAllCredentialsMatcher.class.getName() + " instance.");
        }
    }

继续调用到:org.apache.shiro.authc.credential.SimpleCredentialsMatcher#doCredentialsMatch 实际就是根据token 的凭证信息和认证信息的凭证信息进行匹配。

    public boolean doCredentialsMatch(AuthenticationToken token, AuthenticationInfo info) {
        Object tokenCredentials = getCredentials(token);
        Object accountCredentials = getCredentials(info);
        return equals(tokenCredentials, accountCredentials);
    }

    protected Object getCredentials(AuthenticationToken token) {
        return token.getCredentials();
    }

    protected Object getCredentials(AuthenticationInfo info) {
        return info.getCredentials();
    }

(2) createSubject(token, info, subject) 创建Subject

1》调用org.apache.shiro.mgt.DefaultSecurityManager#createSubject(org.apache.shiro.authc.AuthenticationToken, org.apache.shiro.authc.AuthenticationInfo, org.apache.shiro.subject.Subject)

    protected Subject createSubject(AuthenticationToken token, AuthenticationInfo info, Subject existing) {
        SubjectContext context = createSubjectContext();
        context.setAuthenticated(true);
        context.setAuthenticationToken(token);
        context.setAuthenticationInfo(info);
        context.setSecurityManager(this);
        if (existing != null) {
            context.setSubject(existing);
        }
        return createSubject(context);
    }

继续调用:org.apache.shiro.mgt.DefaultSecurityManager#createSubject(org.apache.shiro.subject.SubjectContext)

    public Subject createSubject(SubjectContext subjectContext) {
        //create a copy so we don't modify the argument's backing map:
        SubjectContext context = copy(subjectContext);

        //ensure that the context has a SecurityManager instance, and if not, add one:
        context = ensureSecurityManager(context);

        //Resolve an associated Session (usually based on a referenced session ID), and place it in the context before
        //sending to the SubjectFactory.  The SubjectFactory should not need to know how to acquire sessions as the
        //process is often environment specific - better to shield the SF from these details:
        context = resolveSession(context);

        //Similarly, the SubjectFactory should not require any concept of RememberMe - translate that here first
        //if possible before handing off to the SubjectFactory:
        context = resolvePrincipals(context);

        Subject subject = doCreateSubject(context);

        //save this subject for future reference if necessary:
        //(this is needed here in case rememberMe principals were resolved and they need to be stored in the
        //session, so we don't constantly rehydrate the rememberMe PrincipalCollection on every operation).
        //Added in 1.2:
        save(subject);

        return subject;
    }
  • 继续调用org.apache.shiro.web.mgt.DefaultWebSubjectFactory#createSubject 创建Subject (实际就是解析属性然后创建对象)
    public Subject createSubject(SubjectContext context) {
        //SHIRO-646
        //Check if the existing subject is NOT a WebSubject. If it isn't, then call super.createSubject instead.
        //Creating a WebSubject from a non-web Subject will cause the ServletRequest and ServletResponse to be null, which wil fail when creating a session.
        boolean isNotBasedOnWebSubject = context.getSubject() != null && !(context.getSubject() instanceof WebSubject);
        if (!(context instanceof WebSubjectContext) || isNotBasedOnWebSubject) {
            return super.createSubject(context);
        }
        WebSubjectContext wsc = (WebSubjectContext) context;
        SecurityManager securityManager = wsc.resolveSecurityManager();
        Session session = wsc.resolveSession();
        boolean sessionEnabled = wsc.isSessionCreationEnabled();
        PrincipalCollection principals = wsc.resolvePrincipals();
        boolean authenticated = wsc.resolveAuthenticated();
        String host = wsc.resolveHost();
        ServletRequest request = wsc.resolveServletRequest();
        ServletResponse response = wsc.resolveServletResponse();

        return new WebDelegatingSubject(principals, authenticated, host, session, sessionEnabled,
                request, response, securityManager);
    }
  • org.apache.shiro.mgt.DefaultSecurityManager#save保存subject
    protected void save(Subject subject) {
        this.subjectDAO.save(subject);
    }

继续调用:org.apache.shiro.mgt.DefaultSubjectDAO#saveToSession

    protected void saveToSession(Subject subject) {
        //performs merge logic, only updating the Subject's session if it does not match the current state:
        mergePrincipals(subject);
        mergeAuthenticationState(subject);
    }

  org.apache.shiro.mgt.DefaultSubjectDAO#mergePrincipals: 保存身份信息到session

    protected void mergePrincipals(Subject subject) {
        //merge PrincipalCollection state:

        PrincipalCollection currentPrincipals = null;

        //SHIRO-380: added if/else block - need to retain original (source) principals
        //This technique (reflection) is only temporary - a proper long term solution needs to be found,
        //but this technique allowed an immediate fix that is API point-version forwards and backwards compatible
        //
        //A more comprehensive review / cleaning of runAs should be performed for Shiro 1.3 / 2.0 +
        if (subject.isRunAs() && subject instanceof DelegatingSubject) {
            try {
                Field field = DelegatingSubject.class.getDeclaredField("principals");
                field.setAccessible(true);
                currentPrincipals = (PrincipalCollection)field.get(subject);
            } catch (Exception e) {
                throw new IllegalStateException("Unable to access DelegatingSubject principals property.", e);
            }
        }
        if (currentPrincipals == null || currentPrincipals.isEmpty()) {
            currentPrincipals = subject.getPrincipals();
        }

        Session session = subject.getSession(false);

        if (session == null) {
            if (!isEmpty(currentPrincipals)) {
                session = subject.getSession();
                session.setAttribute(DefaultSubjectContext.PRINCIPALS_SESSION_KEY, currentPrincipals);
            }
            // otherwise no session and no principals - nothing to save
        } else {
            PrincipalCollection existingPrincipals =
                    (PrincipalCollection) session.getAttribute(DefaultSubjectContext.PRINCIPALS_SESSION_KEY);

            if (isEmpty(currentPrincipals)) {
                if (!isEmpty(existingPrincipals)) {
                    session.removeAttribute(DefaultSubjectContext.PRINCIPALS_SESSION_KEY);
                }
                // otherwise both are null or empty - no need to update the session
            } else {
                if (!currentPrincipals.equals(existingPrincipals)) {
                    session.setAttribute(DefaultSubjectContext.PRINCIPALS_SESSION_KEY, currentPrincipals);
                }
                // otherwise they're the same - no need to update the session
            }
        }
    }

  org.apache.shiro.mgt.DefaultSubjectDAO#mergeAuthenticationState 保存认证信息到session

    protected void mergeAuthenticationState(Subject subject) {

        Session session = subject.getSession(false);

        if (session == null) {
            if (subject.isAuthenticated()) {
                session = subject.getSession();
                session.setAttribute(DefaultSubjectContext.AUTHENTICATED_SESSION_KEY, Boolean.TRUE);
            }
            //otherwise no session and not authenticated - nothing to save
        } else {
            Boolean existingAuthc = (Boolean) session.getAttribute(DefaultSubjectContext.AUTHENTICATED_SESSION_KEY);

            if (subject.isAuthenticated()) {
                if (existingAuthc == null || !existingAuthc) {
                    session.setAttribute(DefaultSubjectContext.AUTHENTICATED_SESSION_KEY, Boolean.TRUE);
                }
                //otherwise authc state matches - no need to update the session
            } else {
                if (existingAuthc != null) {
                    //existing doesn't match the current state - remove it:
                    session.removeAttribute(DefaultSubjectContext.AUTHENTICATED_SESSION_KEY);
                }
                //otherwise not in the session and not authenticated - no need to update the session
            }
        }
    }

(3) 当前subject 记录principals 登录存的身份信息、登陆成功状态、登陆主机信息等然后结束login 方法

6. 上面登录完成之后我们再访问另一个请求查看其如何维护登录状态,subject 如何获取登录状态

(1) 第一个创建Subject 并且记录到ThreadLocal 是在org.apache.shiro.web.servlet.AbstractShiroFilter#doFilterInternal

(2) 继续调用org.apache.shiro.web.servlet.AbstractShiroFilter#createSubject

    protected WebSubject createSubject(ServletRequest request, ServletResponse response) {
        return new WebSubject.Builder(getSecurityManager(), request, response).buildWebSubject();
    }

(3) 最后会调用到org.apache.shiro.mgt.DefaultSecurityManager#createSubject(org.apache.shiro.subject.SubjectContext)

    public Subject createSubject(SubjectContext subjectContext) {
        //create a copy so we don't modify the argument's backing map:
        SubjectContext context = copy(subjectContext);

        //ensure that the context has a SecurityManager instance, and if not, add one:
        context = ensureSecurityManager(context);

        //Resolve an associated Session (usually based on a referenced session ID), and place it in the context before
        //sending to the SubjectFactory.  The SubjectFactory should not need to know how to acquire sessions as the
        //process is often environment specific - better to shield the SF from these details:
        context = resolveSession(context);

        //Similarly, the SubjectFactory should not require any concept of RememberMe - translate that here first
        //if possible before handing off to the SubjectFactory:
        context = resolvePrincipals(context);

        Subject subject = doCreateSubject(context);

        //save this subject for future reference if necessary:
        //(this is needed here in case rememberMe principals were resolved and they need to be stored in the
        //session, so we don't constantly rehydrate the rememberMe PrincipalCollection on every operation).
        //Added in 1.2:
        save(subject);

        return subject;
    }

重要方法:

1》 org.apache.shiro.mgt.DefaultSecurityManager#resolveSession 解析session

    protected SubjectContext resolveSession(SubjectContext context) {
        if (context.resolveSession() != null) {
            log.debug("Context already contains a session.  Returning.");
            return context;
        }
        try {
            //Context couldn't resolve it directly, let's see if we can since we have direct access to 
            //the session manager:
            Session session = resolveContextSession(context);
            if (session != null) {
                context.setSession(session);
            }
        } catch (InvalidSessionException e) {
            log.debug("Resolved SubjectContext context session is invalid.  Ignoring and creating an anonymous " +
                    "(session-less) Subject instance.", e);
        }
        return context;
    }

最终解析到的session 如下: (可以看到有关于登录后的相关信息)

 2》org.apache.shiro.mgt.DefaultSecurityManager#resolvePrincipals 解析登录后的身份信息

    protected SubjectContext resolvePrincipals(SubjectContext context) {

        PrincipalCollection principals = context.resolvePrincipals();

        if (isEmpty(principals)) {
            log.trace("No identity (PrincipalCollection) found in the context.  Looking for a remembered identity.");

            principals = getRememberedIdentity(context);

            if (!isEmpty(principals)) {
                log.debug("Found remembered PrincipalCollection.  Adding to the context to be used " +
                        "for subject construction by the SubjectFactory.");

                context.setPrincipals(principals);

                // The following call was removed (commented out) in Shiro 1.2 because it uses the session as an
                // implementation strategy.  Session use for Shiro's own needs should be controlled in a single place
                // to be more manageable for end-users: there are a number of stateless (e.g. REST) applications that
                // use Shiro that need to ensure that sessions are only used when desirable.  If Shiro's internal
                // implementations used Subject sessions (setting attributes) whenever we wanted, it would be much
                // harder for end-users to control when/where that occurs.
                //
                // Because of this, the SubjectDAO was created as the single point of control, and session state logic
                // has been moved to the DefaultSubjectDAO implementation.

                // Removed in Shiro 1.2.  SHIRO-157 is still satisfied by the new DefaultSubjectDAO implementation
                // introduced in 1.2
                // Satisfies SHIRO-157:
                // bindPrincipalsToSession(principals, context);

            } else {
                log.trace("No remembered identity found.  Returning original context.");
            }
        }

        return context;
    }

接续调用:org.apache.shiro.subject.support.DefaultSubjectContext#resolvePrincipals(可以看到有从session 中拿登录用户的信息,所以可以拿到principals3)

    public PrincipalCollection resolvePrincipals() {
        PrincipalCollection principals = getPrincipals();

        if (isEmpty(principals)) {
            //check to see if they were just authenticated:
            AuthenticationInfo info = getAuthenticationInfo();
            if (info != null) {
                principals = info.getPrincipals();
            }
        }

        if (isEmpty(principals)) {
            Subject subject = getSubject();
            if (subject != null) {
                principals = subject.getPrincipals();
            }
        }

        if (isEmpty(principals)) {
            //try the session:
            Session session = resolveSession();
            if (session != null) {
                principals = (PrincipalCollection) session.getAttribute(PRINCIPALS_SESSION_KEY);
            }
        }

        return principals;
    }

3》 调用org.apache.shiro.web.mgt.DefaultWebSubjectFactory#createSubject 创建Subject

    public Subject createSubject(SubjectContext context) {
        //SHIRO-646
        //Check if the existing subject is NOT a WebSubject. If it isn't, then call super.createSubject instead.
        //Creating a WebSubject from a non-web Subject will cause the ServletRequest and ServletResponse to be null, which wil fail when creating a session.
        boolean isNotBasedOnWebSubject = context.getSubject() != null && !(context.getSubject() instanceof WebSubject);
        if (!(context instanceof WebSubjectContext) || isNotBasedOnWebSubject) {
            return super.createSubject(context);
        }
        WebSubjectContext wsc = (WebSubjectContext) context;
        SecurityManager securityManager = wsc.resolveSecurityManager();
        Session session = wsc.resolveSession();
        boolean sessionEnabled = wsc.isSessionCreationEnabled();
        PrincipalCollection principals = wsc.resolvePrincipals();
        boolean authenticated = wsc.resolveAuthenticated();
        String host = wsc.resolveHost();
        ServletRequest request = wsc.resolveServletRequest();
        ServletResponse response = wsc.resolveServletResponse();

        return new WebDelegatingSubject(principals, authenticated, host, session, sessionEnabled,
                request, response, securityManager);
    }

获取属性然后创建Subject,是否认证属性 authenticated 调用org.apache.shiro.subject.support.DefaultSubjectContext#resolveAuthenticated 解析

    public boolean resolveAuthenticated() {
        Boolean authc = getTypedValue(AUTHENTICATED, Boolean.class);
        if (authc == null) {
            //see if there is an AuthenticationInfo object.  If so, the very presence of one indicates a successful
            //authentication attempt:
            AuthenticationInfo info = getAuthenticationInfo();
            authc = info != null;
        }
        if (!authc) {
            //fall back to a session check:
            Session session = resolveSession();
            if (session != null) {
                Boolean sessionAuthc = (Boolean) session.getAttribute(AUTHENTICATED_SESSION_KEY);
                authc = sessionAuthc != null && sessionAuthc;
            }
        }

        return authc;
    }

4》这样就从Session 中拿到认证的信息,然后创建Subject 之后放到ThreadLocal 对象中。

org.apache.shiro.web.servlet.AbstractShiroFilter#doFilterInternal 调用 org.apache.shiro.subject.support.DelegatingSubject#sessionStopped。 会调用到:org.apache.shiro.subject.support.SubjectCallable#call

    public V call() throws Exception {
        try {
            threadState.bind();
            return doCall(this.callable);
        } finally {
            threadState.restore();
        }
    }

org.apache.shiro.subject.support.SubjectThreadState#bind 就是绑定线程相关到ThreadLocal:

    public void bind() {
        SecurityManager securityManager = this.securityManager;
        if ( securityManager == null ) {
            //try just in case the constructor didn't find one at the time:
            securityManager = ThreadContext.getSecurityManager();
        }
        this.originalResources = ThreadContext.getResources();
        ThreadContext.remove();

        ThreadContext.bind(this.subject);
        if (securityManager != null) {
            ThreadContext.bind(securityManager);
        }
    }
【当你用心写完每一篇博客之后,你会发现它比你用代码实现功能更有成就感!】
原文地址:https://www.cnblogs.com/qlqwjy/p/15456027.html