SEC-525: [PATCH] Add AccessCheckerTag based on URL resource access permissions. Added functionality to "authorize" tag to allow evaluation of whether a particual url is accessible to the user. Uses a WebInvocationPrivilegeEvaluator registered in the application context.

taglibs/src/main/java/org/springframework/security/taglibs/authz/AuthorizeTag.java

@@ -8,6 +8,7 @@ import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
 import javax.servlet.jsp.JspException;
 
 import org.springframework.context.ApplicationContext;
@@ -17,31 +18,43 @@ import org.springframework.security.access.expression.ExpressionUtils;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.web.FilterInvocation;
+import org.springframework.security.web.access.WebInvocationPrivilegeEvaluator;
 import org.springframework.security.web.access.expression.WebSecurityExpressionHandler;
 import org.springframework.web.context.support.WebApplicationContextUtils;
 
 /**
- * Expression-based access control tag.
- *
+ * Access control tag which evaluates its body based either on
+ * <ul>
+ * <li>an access expression (the "access" attribute), or</li>
+ * <li>by evaluating the current user's right to access a particular URL (set using the "url" attribute).</li>
+ * </ul>
  * @author Luke Taylor
  * @version $Id$
  * @since 3.0
  */
 public class AuthorizeTag extends LegacyAuthorizeTag {
     private String access;
+    private String url;
+    private String method;
 
     // If access expression evaluates to "true" return
     public int doStartTag() throws JspException {
-        if (access == null || access.length() == 0) {
-            return super.doStartTag();
-        }
-
         Authentication currentUser = SecurityContextHolder.getContext().getAuthentication();
 
         if (currentUser == null) {
             return SKIP_BODY;
         }
 
+        if (access != null && access.length() > 0) {
+            return authorizeUsingAccessExpression(currentUser);
+        } else if (url != null && url.length() > 0) {
+            return authorizeUsingUrlCheck(currentUser);
+        }
+
+        return super.doStartTag();
+    }
+
+    private int authorizeUsingAccessExpression(Authentication currentUser) throws JspException {
         // Get web expression
         WebSecurityExpressionHandler handler = getExpressionHandler();
 
@@ -62,10 +75,23 @@ public class AuthorizeTag extends LegacyAuthorizeTag {
         return SKIP_BODY;
     }
 
+    private int authorizeUsingUrlCheck(Authentication currentUser) throws JspException {
+        return getPrivilegeEvaluator().isAllowed(((HttpServletRequest)pageContext.getRequest()).getContextPath(),
+                url, method, currentUser) ? EVAL_BODY_INCLUDE : SKIP_BODY;
+    }
+
     public void setAccess(String access) {
         this.access = access;
     }
 
+    public void setUrl(String url) {
+        this.url = url;
+    }
+
+    public void setMethod(String method) {
+        this.method = method;
+    }
+
     WebSecurityExpressionHandler getExpressionHandler() throws JspException {
         ServletContext servletContext = pageContext.getServletContext();
         ApplicationContext ctx = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
@@ -73,12 +99,25 @@ public class AuthorizeTag extends LegacyAuthorizeTag {
 
         if (expressionHdlrs.size() == 0) {
             throw new JspException("No visible WebSecurityExpressionHandler instance could be found in the application " +
-                    "context. There must be at least one in order to use expressions with taglib support.");
+                    "context. There must be at least one in order to support expressions in JSP 'authorize' tags.");
         }
 
         return (WebSecurityExpressionHandler) expressionHdlrs.values().toArray()[0];
     }
 
+    WebInvocationPrivilegeEvaluator getPrivilegeEvaluator() throws JspException {
+        ServletContext servletContext = pageContext.getServletContext();
+        ApplicationContext ctx = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
+        Map<String, WebInvocationPrivilegeEvaluator> wipes = ctx.getBeansOfType(WebInvocationPrivilegeEvaluator.class);
+
+        if (wipes.size() == 0) {
+            throw new JspException("No visible WebInvocationPrivilegeEvaluator instance could be found in the application " +
+                    "context. There must be at least one in order to support the use of URL access checks in 'authorize' tags.");
+        }
+
+        return (WebInvocationPrivilegeEvaluator) wipes.values().toArray()[0];
+    }
+
     private static final FilterChain DUMMY_CHAIN = new FilterChain() {
         public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
            throw new UnsupportedOperationException();

taglibs/src/main/resources/META-INF/security.tld

@@ -30,6 +30,28 @@
             </description>
         </attribute>
 
+        <attribute>
+            <name>url</name>
+            <required>false</required>
+            <rtexprvalue>false</rtexprvalue>
+            <description>
+                A URL within the application. If the user has access to this URL (as determined by
+                the AccessDecisionManager), the tag body will be evaluated. If not, it will
+                be skipped.
+            </description>
+        </attribute>
+
+        <attribute>
+            <name>method</name>
+            <required>false</required>
+            <rtexprvalue>false</rtexprvalue>
+            <description>
+                Can optionally be used to narrow down the HTTP method (typically GET or POST) to which the URL
+                applies to. Only has any meaning when used in combination with the "url" attribute.
+            </description>
+        </attribute>
+
+
         <attribute>
             <name>ifNotGranted</name>
             <required>false</required>