如何实施Custom Spring Security ACL？

Question

我正在使用Spring开发应用程序。 在“访问控制访问”部分，我想使用Spring Security Acl（我是Acl的新手）。 我想基于两点在我的应用程序中实现ACL：

1. 应用程序应具有五个权限，即read ， create ， modify ， delete和Administrator 。
2. 权限是分层的，当用户拥有create权限时，它应该能够read ，或者当拥有modify权限时，它应该能够read ， create和modify等。

可能吗？ 怎么样？

更新 ：
我的应用程序基于Spring MVC RESTFUL。 当用户想要修改自己的信息时，他使用Ajax发送一些json数据。 json数据的示例如下：

{
  "id": 1,//user Id
  "name": "my name",
  "password": "my password",
  "email": "email@email.com",
   ...
}

现在，恶意用户可以登录自己的帐户。 该用户可以像其他所有用户一样modify其数据。 在他发送数据之前，请更改其ID，然后modify另一个帐户用户信息。 我想使用ACL来防止这种颠覆性工作。 用户可以访问其他用户，其他人可以修改其信息。

Answer 1

您可以使用spring安全性实现一个简单的解决方案。 这个想法是创建一个实现org.springframework.security.access.PermissionEvaluator的类，并重写hasPermission方法。 看下一个例子：

@Component("permissionEvaluator")
public class PermissionEvaluator implements org.springframework.security.access.PermissionEvaluator {

    /**
     * @param authentication     represents the user in question. Should not be null.
     * @param targetDomainObject the domain object for which permissions should be
     *                           checked. May be null in which case implementations should return false, as the null
     *                           condition can be checked explicitly in the expression.
     * @param permission         a representation of the permission object as supplied by the
     *                           expression system. Not null.
     * @return true if the permission is granted, false otherwise
     */
    @Override
    public boolean hasPermission(Authentication authentication, Object targetDomainObject, Object permission) {
        if (authentication != null && permission instanceof String) {
            User loggedUser = (User) authentication.getPrincipal();
            String permissionToCheck = (String) permission;
            // in this part of the code you need to check if the loggedUser has the "permission" over the
            // targetDomainObject. In this implementation the "permission" is a string, for example "read", or "update"
            // The targetDomainObject is an actual object, for example a object of UserProfile class (a class that
            // has the profile information for a User)

            // You can implement the permission to check over the targetDomainObject in the way that suits you best
            // A naive approach:
            if (targetDomainObject.getClass().getSimpleName().compareTo("UserProfile") == 0) {
                if ((UserProfile) targetDomainObject.getId() == loggedUser.getId())
                    return true;
            }
            // A more robust approach: you can have a table in your database holding permissions to each user over
            // certain targetDomainObjects
            List<Permission> userPermissions = permissionRepository.findByUserAndObject(loggedUser,
                targetDomainObject.getClass().getSimpleName());
            // now check if in userPermissions list we have the "permission" permission.

            // ETC...
        }
        //access denied
        return false;
    }

}

现在，通过此实现，您可以在服务层中使用@PreAuthorize注释，如下所示：

@PreAuthorize("hasPermission(#profile, 'update')")
public void updateUserProfileInASecureWay(UserProfile profile) {
    //code to update user profile
}

@PreAuthorize批注中的“ hasPermission”从updateUserProfileInASecureWay方法的参数中接收targetDomainObject #profile，并且我们还传递了所需的权限（在本例中为“ update”）。

该解决方案通过实现“小型” ACL避免了ACL的所有复杂性。 也许它可以为您工作。

Answer 2

您可以使用以下示例中使用的角色层次结构组合。Spring acl具有基本权限，如果要实现自定义权限，则需要创建一个自定义Permission类，以扩展api中的Base Permissions类。 我们可以为每种权限定义角色，并如下定义角色层次结构。

<bean id="expressionHandler"
    class="org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler">
    <property name="permissionEvaluator" ref="permissionEvaluator" />
    <property name="roleHierarchy" ref="roleHierarchy" />
</bean>

<!-- A customized PermissionEvaluator that evaluates permissions via the ACL module -->
<bean class="org.springframework.security.acls.AclPermissionEvaluator" id="permissionEvaluator">
    <!-- Reference to the ACL service which performs JDBC calls to an ACL database -->
    <constructor-arg ref="aclService"/>
     <property name="permissionFactory" ref="customPermissionFactory" /> 
</bean>
<bean id="customPermissionFactory" class="org.krams.tutorial.security.CustomPermissionFactory"></bean>

<!-- A customized ACL service which provides default JDBC implementation -->
<bean class="org.springframework.security.acls.jdbc.JdbcMutableAclService" id="aclService">
    <constructor-arg ref="dataSource"/>
    <constructor-arg ref="lookupStrategy"/>
    <constructor-arg ref="aclCache"/>
</bean>

<!-- A lookup strategy for optimizing database queries -->
<bean id="lookupStrategy" class="org.springframework.security.acls.jdbc.BasicLookupStrategy">
    <constructor-arg ref="dataSource"/>
    <constructor-arg ref="aclCache"/>
    <constructor-arg ref="aclAuthorizationStrategy"/>
    <constructor-arg ref="auditLogger"/>
    <property name="permissionFactory" ref="customPermissionFactory"/>
</bean>

<!-- A MySQL datasource with pooling capabalities for the ACL module -->
<!-- <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
     destroy-method="close"
     p:driverClass="com.mysql.jdbc.Driver"
     p:jdbcUrl="jdbc:mysql://localhost/acl"
     p:user="root"
     p:password=""
     p:acquireIncrement="5"
     p:idleConnectionTestPeriod="60"
     p:maxPoolSize="100"
     p:maxStatements="50"
     p:minPoolSize="10" /> -->




<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="org.h2.Driver" />
    <property name="url" value="jdbc:h2:tcp://localhost/~/springsecurity" />

    <!--<property name="url" value="jdbc:h2:tcp://ggk-wrl-win1/~/dev" /> -->
    <property name="username" value="sa" />
    <property name="password" value="" />
</bean>

<!-- An ACL cache to minimize calls to the ACL database -->   
<bean id="aclCache" class="org.springframework.security.acls.domain.EhCacheBasedAclCache">
    <constructor-arg>
        <bean class="org.springframework.cache.ehcache.EhCacheFactoryBean">
            <property name="cacheManager">
                <bean class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean"/>
            </property>
            <property name="cacheName" value="aclCache"/>
        </bean>
    </constructor-arg>
</bean>

<!-- An ACL authorization strategy to determine whether a principal is permitted to call administrative methods -->
<bean id="aclAuthorizationStrategy" class="org.springframework.security.acls.domain.AclAuthorizationStrategyImpl">
    <constructor-arg>
        <list>
            <bean class="org.springframework.security.core.authority.GrantedAuthorityImpl">
                <constructor-arg value="ROLE_USER"/>
            </bean>
            <bean class="org.springframework.security.core.authority.GrantedAuthorityImpl">
                <constructor-arg value="ROLE_USER"/>
            </bean>
            <bean class="org.springframework.security.core.authority.GrantedAuthorityImpl">
                <constructor-arg value="ROLE_USER"/>
            </bean>
        </list>
    </constructor-arg>
</bean>

<!-- An audit logger used to log audit events -->
<bean id="auditLogger" class="org.springframework.security.acls.domain.ConsoleAuditLogger"/>

<!-- Defines the role order -->
<!-- http://static.springsource.org/spring-security/site/docs/3.0.x/apidocs/org/springframework/security/access/hierarchicalroles/RoleHierarchyImpl.html -->
<bean id="roleHierarchy"  class="org.springframework.security.access.hierarchicalroles.RoleHierarchyImpl">
    <property name="hierarchy">
        <value>
            ROLE_ADMIN > ROLE_USER
            ROLE_USER > ROLE_VISITOR
        </value>
    </property>
</bean>