Control #RestController availability programmatically - spring

Is it possible to control a #RestController programmatically to enable it or disable it? I don't want to just write code in each #RequestMapping method to do some kind of if (!enabled) { return 404Exception; }
I've seen this question but that works only at startup time. What I need is really something that would allow me to enable or disable the controller multiple times.
I've thought of different ways but don't know which are doable in spring.
Actually control the container (jetty in my case) so requests to that particular endpoint are disabled
Somehow control RequestMappingHandlerMapping since it seems to be that class that does the mapping between urls and controllers
control the lifecycle of the #RestController component so that i can create it and destroy it at will, but then i'm not sure how to trigger the mapping to the endpoint

If the end result is that you want to respond with a 404 when you decide that a specific endpoint should be disabled then you could write an interceptor which checks whether your enabled condition is false and, if so, sets the response accordingly.
For example:
#Component
public class ConditionalRejectionInterceptor extends HandlerInterceptorAdapter {
#Override
public boolean preHandle(HttpServletRequest request,
HttpServletResponse response, Object handler) throws Exception {
String requestUri = request.getRequestURI();
if (shouldReject(requestUri)) {
response.setStatus(HttpStatus.NOT_FOUND.value());
return false;
}
return super.preHandle(request, response, handler);
}
private boolean shouldReject(String requestUri) {
// presumably you have some mechanism of inferring or discovering whether
// the endpoint represented by requestUri should be allowed or disallowed
return ...;
}
}
In Spring Boot, registering your own interceptor just involves implementing a WebMvcConfigurerAdapter. For example:
#Configuration
public class CustomWebMvcConfigurer extends WebMvcConfigurerAdapter {
#Autowired
private HandlerInterceptor conditionalRejectionInterceptor;
#Override
public void addInterceptors(InterceptorRegistry registry) {
// you can use .addPathPatterns(...) here to limit this interceptor to specific endpoints
// this could be used to replace any 'conditional on the value of requestUri' code in the interceptor
registry.addInterceptor(conditionalRejectionInterceptor);
}
}

Related

Controller interceptor that process endpoint annotation in WebFlux

My team is in the middle of migrating our Spring MVC extensions to WebFlux.
We've got a feature that lets our clients customize metric of controller method. To do that we've created our annotation that is processed by HandlerInterceptorAdapter.
The problem is that I can't see any equivalent of this in Spring WebFlux. I can't use WebFilter because Spring does not know yet which endpoint will be called. How can I implement that?
The closest workaround I found is to use RequestMappingHandlerMapping and somehow build a map of Map<String(path), HandlerMethod>, but this is cumbersome and error prone in my opinion.
Is there any better way to solve this?
Edit:
It goes like this
public class MeteredHandlerInterceptor extends HandlerInterceptorAdapter {
public MeteredHandlerInterceptor() {
}
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
// I save start time of method
return true;
}
#Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
// I read endpoint method from the HandlerMethod, I apply any customisation by our custom #MeteredEndpoint annotation (for example custom name) and I save it in MeterRegistry
}
}
I haven't coded workaround yet because I didn't want to invest time in it, but I see that I could obtain HandlerMethod for path, but I'm not sure I will receive same HandlerMethod as I normally would when the controller is called.
Maybe little bit late, but it can still be useful for someone...
I have not found an easy way to do that, the best I was able to create is a HandlerAdapter bean that intercepts handling in the following way:
#Bean
#Order(Ordered.HIGHEST_PRECEDENCE)
public HandlerAdapter handlerAdapter(RequestMappingHandlerAdapter requestMappingHandlerAdapter) {
return new HandlerAdapter() {
#Override
public boolean supports(Object handler) {
return handler instanceof HandlerMethod;
}
#Override
public Mono<HandlerResult> handle(ServerWebExchange exchange, Object handler) {
// your stuff here...
// e.g. ((HandlerMethod) handler).getMethod().getAnnotations()...
return requestMappingHandlerAdapter.handle(exchange, handler);
}
};
}
The idea is that this adapter is used for all HandlerMethod handlers (those are the ones created by collecting annotated methods from #Controllers) and delegates the handling to the RequestMappingHandlerAdapter (that would be used directly for HandlerMethod handlers in normal case, notice the #Order annotation here).
The point is you can put your code before/after the invocation of the handle method and you are aware of the method being invoked at this point.
Solution:
#Component
class AuditWebFilter(
private val requestMapping: RequestMappingHandlerMapping
): WebFilter {
override fun filter(exchange: ServerWebExchange, chain: WebFilterChain): Mono<Void> {
// if not to call - then exchange.attributes will be empty
// so little early initialize exchange.attributes by calling next line
requestMapping.getHandler(exchange)
val handlerFunction = exchange.attributes.get(HandlerMapping.BEST_MATCHING_HANDLER_ATTRIBUTE) as HandlerMethod
val annotationMethod = handlerFunction.method.getAnnotation(MyAnnotation::class.java)
// annotationMethod proccesing here
}
}

Spring MVC accessing Spring Security ConfigAttributes?

I want to produce HTTP Response Body with an error message referencing something like _"missing ... 'CUSTOM_AUTHORITY'"_ in addition to a 403 Forbidden HTTP Status code.
My application is Spring Boot with a Spring-Security-Secured #PreAuthorize method within a Spring-MVC-REST #Controller:
MyController
#Controller
#RequestMapping("/foo")
public FooController{
#PreAuthorize("hasAuthority('CUSTOM_AUTHORITY')")
public Object getSomething(){ ... }
}
GlobalExceptionHandlerResolver
#ControllerAdvice
public class GlobalExceptionHandler {
#ExceptionHandler(AccessDeniedException.class)
#ResponseStatus(HttpStatus.FORBIDDEN)
public Object forbidden(AccessDeniedException exception){ ... }
}
What I want is to expose/inject Collection<ConfigAttribute>. The Spring Security docs reference it.
There doesn't seem to be a straightforward way of accomplishing this. The AccessDecisionManager (which is AffirmativeBased) throws the AccessDeniedException with none of the information you want. So if you want to "expose/inject" the Collection<ConfigAttribute>, you'll want to provide your own AccessDecisionManager that throws a custom exception that holds the ConfigAttributes.
The easiest way to do this could be to wrap the default AccessDecisionManager with your own and delegate method calls to it:
#Configuration
#EnableGlobalMethodSecurity(prePostEnabled=true)
CustomMethodSecurityConfig extends GlobalMethodSecurityConfiguration
#Override
protected AccessDecisionManager accessDecisionManager() {
AccessDecisionManager default = super.accessDecisionManager();
MyCustomDecisionManager custom = new CustomDecisionManager(default);
}
}
You could define your custom AccessDecisionManager as follows:
public class MyCustomDecisionManager implements AccessDecisionManager {
private AccessDecisionManager default;
public MyCustomDecisionManager(AccessDecisionManager acm) {
this.default = acm;
}
#Override
public void decide(Authentication authentication, Object object, Collection<ConfigAttribute> configAttributes) throws AccessDeniedException, InsufficientAuthenticationException{
try {
default.decide(authentication, object, configAttributes)
} catch(AccessDeniedException ex) {
throw new CustomAccessDeniedException(ex.getMessage(), configAttributes);
}
}
// other methods delegate to default
}
Now whenever access is denied, you will get an exception that holds the Collection<ConfigAttribute>.
Your custom exception could look like this:
public class CustomAccessDeniedException extends AccessDeniedException {
private Collection<ConfigAttribute> attributes;
public CustomAccessDeniedException(String message, Collection<ConfigAttribute> attr) {
super(message);
this.attributes = attr;
}
public Collection<ConfigAttribute> getAttributes() {
return this.attributes;
}
}
Now your #ExceptionHandler could handle your CustomAccessDeniedException and have access to the ConfigAttributes.
HOWEVER...
I am not sure that will provide you with the error message you wanted. The ConfigAttribute interface only has one method:
String getAttribute();
And the javadoc states:
If the ConfigAttribute cannot be expressed with sufficient precision as a String, null should be returned.
Since we can't rely on the interface method, how you deal with each ConfigAttribute will be heavily dependent on the type of the particular object you're dealing with.
For example, the ConfigAttribute that corresponds to #PreAuthorize("hasAuthority('CUSTOM_AUTHORITY')") is PreInvocationExpressionAttribute, and to print something that resembles what you want, you could do:
PreInvocationExpressionAttribute attr = (PreInvocationExpressionAttribute)configAttribute;
String expressionString = attr.getAuthorizeExpression().getExpressionString();
System.out.println(expressionString); // "hasAuthority('CUSTOM_AUTHORITY')"
That's the major drawback. Also, you would get ALL the ConfigAttributes, not necessarily the ones that failed.

How to check security acess (#Secured or #PreAuthorize) before validation (#Valid) in my Controller?

here is my Controller code :
#PreAuthorize("hasRole('CREATE_USER')")
#RequestMapping(method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE, consumes = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public UserReturnRO createUser(#Valid #RequestBody UserRO userRO) throws BadParameterException{
return userService.createUser(userRO);
}
My need is when a client without the appropriate role tries to create a user, the controller responds "Not authorized" even if the data sent are not valid. Instead of that, if the client (without the appropriate role) tries to create a user with wrong data, my controller responds with the #Valid message (ex : "password cannot be empty"), while I want it responds "not authorized".
In the PreAuthorized Interface we can find this sentence :
Annotation for specifying a method access-control expression which will be evaluated to decide whether a method invocation is allowed or not.
but it seems that it's not the case.
You can not do this directly, since #Valid is processed before an actual method call and as a result before #PreAuthorize.
But what you can do instead is to inject BindingResult just right after your model (userRO) and in doing so - take control of validation process. Then check if BindingResult has some errors and if so return bad request response (similar to what spring does).
Example:
#ResponseBody
#RequestMapping(method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE, consumes = MediaType.APPLICATION_JSON_VALUE)
#PreAuthorize("hasRole('CREATE_USER')")
public ResponseEntity<?> createUser(#RequestBody #Valid UserRO userRO, BindingResult result) {
if (result.hasErrors()) {
return ResponseEntity.badRequest().body(result.getAllErrors());
}
return ResponseEntity.ok(userService.createUser(userRO));
}
As already stated, Spring Security's #PreAuthorize is method advice, which means that it does not get to participate until the method and its arguments have already been resolved.
Aside from the answer already given, there are a few ways to move authorization before argument resolution, instead.
Filter Security
First, Spring Security checks URLs before the request is mapped to a method. And since this is a #Controller, it's reasonable to suppose that you could instead map the request to the role at that level instead of #PreAuthorize:
http
.authorizeRequests()
.mvcMatchers(POST, "/somepath").hasRole("CREATE_USER")
Handler Interceptor
Second, Spring MVC does ship with limited support for checking authorities before parsing method arguments. For example, you can do:
#EnableWebMvc
public static class MvcConfig implements WebMvcConfigurer {
#Override
public void addInterceptors(InterceptorRegistry registry) {
UserRoleAuthorizationInterceptor userRole =
new UserRoleAuthorizationInterceptor();
userRole.setAuthorizedRoles("CREATE_USER");
registry.addInterceptor(userRole);
}
}
This is much more basic than #PreAuthorize since it's a global setting, but I've included it for completeness.
Handler Interceptor, Part 2
Third (warning, some inelegance ahead), you can create your own HandlerInterceptor.
The flow is:
FilterSecurityInterceptor <== where .mvcMatchers(...).hasRole(...) lives
Then HandlerInterceptors
Then argument validation
Then MethodSecurityInterceptor <== where #PreAuthorize lives
So, your HandlerInterceptor would check before arguments are resolved. It doesn't have to be as involved as MethodSecurityInterceptor, though. It could, for example, simply be:
static class AuthorizationInterceptor extends HandlerInterceptorAdapter {
SecurityMetadataSource securityMetadataSource;
AccessDecisionManager accessDecisionManager;
#Override
public void preHandle(HttpServletRequest request,
HttpServletResponse response, Object handler) {
Authentication authenticated = (Authentication) request.getUserPrincipal();
MethodInvocation mi = convert(handler);
Collection<ConfigAttribute> attributes =
this.securityMetadataSource.getAttributes(mi);
// throws AccessDeniedException
this.accessDecisionManager.decide(authenticated, mi, attributes);
return true;
}
}
Then you wire it together with:
#EnableGlobalMethodSecurity(prePostEnabled = true)
static class MethodConfig extends GlobalMethodSecurityConfiguration {
#Bean
HandlerInterceptor preAuthorize() throws Exception {
return new AuthorizationInterceptor(
accessDecisionManager(), methodSecurityMetadataSource());
}
}
#EnableWebMvc
public static class MvcConfig implements WebMvcConfigurer {
#Autowired
AuthorizationInterceptor authorizationInterceptor;
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(authorizationInterceptor);
}
}
It's inelegant because MethodSecurityInterceptor would still participate in authorized requests, which would ostensibly be the majority.

Custom default headers for REST API only using Spring Data REST

I have a use case where my application hosts REST API and web application and we need to add custom header to REST APIs only. REST APIs are enabled through Spring Data REST. Typically we could use Servlet Filter to achieve this but we need code the logic of isolating requests to our REST API and add the custom headers. It would be nice if Spring Data REST API allows to add a default header to all the responses it generates. What are your thoughts? Don't say I am lazy :)
For folks looking for actual implementation details..
Interceptor
public class CustomInterceptor extends HandlerInterceptorAdapter {
#Override
public boolean preHandle(HttpServletRequest request,
HttpServletResponse response, Object handler) throws Exception {
System.out.println("adding CORS headers.....");
response.addHeader("HEADER-NAME", "HEADER-VALUE");
return true;
}
}
Java Configuration
#Configuration
public class RepositoryConfig extends
RepositoryRestMvcConfiguration {
#Override
public RequestMappingHandlerMapping repositoryExporterHandlerMapping() {
RequestMappingHandlerMapping mapping = super
.repositoryExporterHandlerMapping();
mapping.setInterceptors(new Object[] { new CustomInterceptor() });
return mapping;
}
}
As Spring Data REST is built on top of Spring MVC, the easiest way is to configure a custom HandlerInterceptor as described in the reference documentation.
With Spring Data REST the easiest way is to extend RepositoryRestMvcConfiguration and override repositoryExporterHandlerMapping, call the parent method and then invoke ….setInterceptors(…) on it.
Finally I managed to make the setup of custom interceptor working also on spring-data-rest 2.4.1.RELEASE.
#Configuration
public class RestMvcConfig extends RepositoryRestMvcConfiguration {
#Autowired UserInterceptor userInterceptor;
#Autowired ApplicationContext applicationContext;
#Override
public DelegatingHandlerMapping restHandlerMapping() {
RepositoryRestHandlerMapping repositoryMapping = new RepositoryRestHandlerMapping(resourceMappings(), config());
repositoryMapping.setInterceptors(new Object[] { userInterceptor }); // FIXME: not nice way of defining interceptors
repositoryMapping.setJpaHelper(jpaHelper());
repositoryMapping.setApplicationContext(applicationContext);
repositoryMapping.afterPropertiesSet();
BasePathAwareHandlerMapping basePathMapping = new BasePathAwareHandlerMapping(config());
basePathMapping.setApplicationContext(applicationContext);
basePathMapping.afterPropertiesSet();
List<HandlerMapping> mappings = new ArrayList<HandlerMapping>();
mappings.add(basePathMapping);
mappings.add(repositoryMapping);
return new DelegatingHandlerMapping(mappings);
}
}
I had to override the restHandlerMapping method, copy-paste it's content and add a line repositoryMapping.setInterceptors for adding custom interceptor, in my case the UserInterceptor.
Is there any better way?

Spring security - Access to a controller method based on an attribute

I'm configuring Spring Security across all my controllers.
I want some method executions to start only when "my system is enabled". This information is accessible from all over the controllers via a specific static method (I can make it non-static).
My point is that I want to avoid making an explicit check in java code at the beginning of every method.
How can I get there via Spring Security?
One approach is to use a handler interceptor.
Here is general idea:
(1) Configure url patterns which you want to block:
<util:list id="sysEnableCheckUrlPatterns" value-type="java.lang.String">
<beans:value>/module1/**</beans:value>
<beans:value>/module2/**</beans:value>
</util:list>
(2) Write an interceptor:
public class SysEnableCheckInterceptor extends HandlerInterceptorAdapter {
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
/*
If system enabled then return true. Otherwise return false (and optionally write something in response)
*/
}
}
(3) Configure that interceptor. In 3.1 you can do it as follows:
#Configuration
public class AppConfig extends WebMvcConfigurerAdapter {
#Resource(name="sysEnableCheckUrlPatterns")
/* or use #Autowired or #Inject if you like */
private String[] sysEnableCheckUrlPatterns;
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new SysEnableCheckInterceptor()).addPathPatterns(sysEnableCheckUrlPatterns);
}
}
You can use SPEL (Spring Expression Language) in a security annotation.
See http://static.springsource.org/spring-security/site/docs/3.0.x/reference/el-access.html

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