springboot 调用32位动态链接库DLL springboot url为动态的

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技术领航探索者 2024-02-22 20:24:00

本文介绍的spring security动态配置url权限认证基于的是spring-boot-2.0.0、spring-security 5.X来编写的。

笔者浏览完spring security官方文档之后，发现并没有详细的介绍说明如何动态的配置我们的url权限认证。spring security默认的权限配置确只会在启动工程的时候初始化一次url权限配置。但是实际情况我们项目的权限会随时动态的更改，这样我们就需要重新启动项目以便新配置的权限生效。这样的处理显然不合理。当然spring是具有非常好的拓展性，我们就抓主spring的这个特性，模仿默认的认证方式来拓展我们需要的认证规则。
在spring security的官方文档的Spring Security FAQ里有这么一个问题解答44.4.6. How do I define the secured URLs within an application dynamically? 这里的解答非常重要
1.需要提供认证数据规则源数据(类似默认配置在代码里的url权限数据)
2.自定义一个拦截器然后把它添加到spring security的filterChain中
通过这两个主要思路，在逐步通过来代码来实现我们的动态url权限配置

具体步骤

1.配置认证数据源

public class MyFilterSecurityMetadataSource implements FilterInvocationSecurityMetadataSource {

    private final Map<RequestMatcher, Collection<ConfigAttribute>> requestMap;

    /*
     * 这个例子放在构造方法里初始化url权限数据，我们只要保证在 getAttributes()之前初始好数据就可以了
     */
    public MyFilterSecurityMetadataSource() {
        Map<RequestMatcher, Collection<ConfigAttribute>> map = new HashMap<>();

        AntPathRequestMatcher matcher = new AntPathRequestMatcher("/home");
        SecurityConfig config = new SecurityConfig("ROLE_ADMIN");
        ArrayList<ConfigAttribute> configs = new ArrayList<>();
        configs.add(config);
        map.put(matcher,configs);

        AntPathRequestMatcher matcher2 = new AntPathRequestMatcher("/");
        SecurityConfig config2 = new SecurityConfig("ROLE_ADMIN");
        ArrayList<ConfigAttribute> configs2 = new ArrayList<>();
        configs2.add(config2);
        map.put(matcher2,configs2);

        this.requestMap = map;
    }


    /**
     * 在我们初始化的权限数据中找到对应当前url的权限数据
     *
     * @param object
     * @return
     * @throws IllegalArgumentException
     */
    @Override
    public Collection<ConfigAttribute> getAttributes(Object object) throws IllegalArgumentException {
        FilterInvocation fi = (FilterInvocation) object;
        HttpServletRequest request = fi.getRequest();
        String url = fi.getRequestUrl();
        String httpMethod = fi.getRequest().getMethod();

        // Lookup your database (or other source) using this information and populate the
        // list of attributes (这里初始话你的权限数据)
        //List<ConfigAttribute> attributes = new ArrayList<ConfigAttribute>();

        //遍历我们初始化的权限数据，找到对应的url对应的权限
        for (Map.Entry<RequestMatcher, Collection<ConfigAttribute>> entry : requestMap
                .entrySet()) {
            if (entry.getKey().matches(request)) {
                return entry.getValue();
            }
        }
        return null;
    }

    @Override
    public Collection<ConfigAttribute> getAllConfigAttributes() {
        return null;
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return FilterInvocation.class.isAssignableFrom(clazz);
    }

这里使用不了WebExpressionConfigAttribute这个类配置ConfigAttribute，应为它只能在package中使用，这也导致了在认证管理器中，我们不能使用对应WebExpressionVoter来解析我们使用的SecurityConfig加载的数据。具体原因如下:

springboot 调用32位动态链接库DLL springboot url为动态的_数据

image.png

这里做了一个类的实例检查。所以在后面使用了RoleVoter来做认证数据的解析。

2.自定义动态数据拦截器

public class DynamicallyUrlInterceptor extends AbstractSecurityInterceptor implements Filter {

    //标记自定义的url拦截器已经加载
    private static final String FILTER_APPLIED = "__spring_security_filterSecurityInterceptor_filterApplied_dynamically";

    private FilterInvocationSecurityMetadataSource securityMetadataSource;
    private boolean observeOncePerRequest = true;


    @Override
    public Class<?> getSecureObjectClass() {
        return FilterInvocation.class;
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        FilterInvocation fi = new FilterInvocation(request, response, chain);
        invoke(fi);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void destroy() {
    }

    public FilterInvocationSecurityMetadataSource getSecurityMetadataSource() {
        return this.securityMetadataSource;
    }

    public SecurityMetadataSource obtainSecurityMetadataSource() {
        return this.securityMetadataSource;
    }

    public void setSecurityMetadataSource(FilterInvocationSecurityMetadataSource newSource) {
        this.securityMetadataSource = newSource;
    }

    @Override
    public void setAccessDecisionManager(AccessDecisionManager accessDecisionManager) {
        super.setAccessDecisionManager(accessDecisionManager);
    }

    public void invoke(FilterInvocation fi) throws IOException, ServletException {

        if ((fi.getRequest() != null)
                && (fi.getRequest().getAttribute(FILTER_APPLIED) != null)
                && observeOncePerRequest) {
            // filter already applied to this request and user wants us to observe
            // once-per-request handling, so don't re-do security checking
            fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
        }
        else {
            // first time this request being called, so perform security checking
            if (fi.getRequest() != null) {
                fi.getRequest().setAttribute(FILTER_APPLIED, Boolean.TRUE);
            }

            InterceptorStatusToken token = super.beforeInvocation(fi);

            try {
                fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
            }
            finally {
                super.finallyInvocation(token);
            }

            super.afterInvocation(token, null);
        }
    }

这个类参考的是FilterSecurityInterceptor这个类写的，只是修改了FILTER_APPLIED的值。主要是重写了父类的方法，添加认证数据源值的设置。使父类在调用方法是能找到对应的数据。

3.提供一个认证管理器

public class DynamicallyUrlAccessDecisionManager extends AbstractAccessDecisionManager {

    public DynamicallyUrlAccessDecisionManager(List<AccessDecisionVoter<?>> decisionVoters) {
        super(decisionVoters);
    }

    @Override
    public void decide(Authentication authentication, Object object, Collection<ConfigAttribute> configAttributes)
            throws AccessDeniedException, InsufficientAuthenticationException {
        int deny = 0;

        for (AccessDecisionVoter voter : getDecisionVoters()) {
            int result = voter.vote(authentication, object, configAttributes);

            if (logger.isDebugEnabled()) {
                logger.debug("Voter: " + voter + ", returned: " + result);
            }

            switch (result) {
                case AccessDecisionVoter.ACCESS_GRANTED:
                    return;

                case AccessDecisionVoter.ACCESS_DENIED:
                    deny++;

                    break;

                default:
                    break;
            }
        }

        if (deny > 0) {
            throw new AccessDeniedException(messages.getMessage(
                    "AbstractAccessDecisionManager.accessDenied", "Access is denied"));
        }

        // To get this far, every AccessDecisionVoter abstained
        checkAllowIfAllAbstainDecisions();
    }
}

spring security默认提供了

springboot 调用32位动态链接库DLL springboot url为动态的_ide_02

image.png

有这么几种具体的认证决策，这里最终使用的是RoleVoter这个决策认证类。

4.配置filter

@Bean
    public DynamicallyUrlInterceptor dynamicallyUrlInterceptor(){
        DynamicallyUrlInterceptor interceptor = new DynamicallyUrlInterceptor();
        interceptor.setSecurityMetadataSource(new MyFilterSecurityMetadataSource());

        //配置RoleVoter决策
        List<AccessDecisionVoter<? extends Object>> decisionVoters = new ArrayList<AccessDecisionVoter<? extends Object>>();
        decisionVoters.add(new RoleVoter());
        //设置认证决策管理器
        interceptor.setAccessDecisionManager(new DynamicallyUrlAccessDecisionManager(decisionVoters));
        return interceptor;
    }

然后在把我们的filter添加到spring security的filter中

springboot 调用32位动态链接库DLL springboot url为动态的_数据_03