Spring Security Oauth - Custom format for OAuth2Exceptions - spring

Question

The error format of spring security oauth conforms with the OAuth spec and looks like this.
{
"error":"insufficient_scope",
"error_description":"Insufficient scope for this resource",
"scope":"do.something"
}
Especially on a resource server I find it a bit strange to get a different error format for authentication issues. So I would like to change the way this exception is rendered.
The documentation says
Error handling in an Authorization Server uses standard Spring MVC
features, namely #ExceptionHandler methods
So I tried something like this to customize the format of the error:
#ControllerAdvice
#Order(Ordered.HIGHEST_PRECEDENCE)
public class MyErrorHandler {
#ExceptionHandler(value = {InsufficientScopeException.class})
ResponseEntity<MyErrorRepresentation> handle(RuntimeException ex, HttpServletRequest request) {
return errorResponse(HttpStatus.FORBIDDEN,
MyErrorRepresentation.builder()
.errorId("insufficient.scope")
.build(),
request);
}
}
But this does not work.
Looking at the code, all the error rendering seems to be done in DefaultWebResponseExceptionTranslator#handleOAuth2Exception. But implementing a custom WebResponseExceptionTranslator would not allow changing the format.
Any hints?

Answer 1

First of all，some knowledge for Spring Security OAuth2.
OAuth2 has two main parts
AuthorizationServer : /oauth/token, get token
ResourceServer : url resource priviledge management
Spring Security add filter to the filter chains of server container, so the exception of Spring Security will not reach #ControllerAdvice
Then, custom OAuth2Exceptions should consider for AuthorizationServer and ResourceServer.
This is configuration
#Configuration
#EnableAuthorizationServer
public class OAuthSecurityConfig extends AuthorizationServerConfigurerAdapter {
#Override
public void configure(AuthorizationServerEndpointsConfigurer endpoints) throws Exception {
//for custom
endpoints.exceptionTranslator(new MyWebResponseExceptionTranslator());
}
}
#Configuration
#EnableResourceServer
public class ResourceServerConfiguration extends ResourceServerConfigurerAdapter {
#Override
public void configure(ResourceServerSecurityConfigurer resources) {
// format message
resources.authenticationEntryPoint(new MyAuthenticationEntryPoint());
resources.accessDeniedHandler(new MyAccessDeniedHandler());
}
}
MyWebResponseExceptionTranslator is translate the exception to ourOAuthException and we custom ourOAuthException serializer by jackson, which way is same by default the OAuth2 use.
#JsonSerialize(using = OAuth2ExceptionJackson1Serializer.class)
public class OAuth2Exception extends RuntimeException {
other custom handle class stuff
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.oauth2.common.exceptions.OAuth2Exception;
import org.springframework.security.oauth2.provider.error.WebResponseExceptionTranslator;
/**
* #author qianggetaba
* #date 2019/6/21
*/
public class MyWebResponseExceptionTranslator implements WebResponseExceptionTranslator {
#Override
public ResponseEntity<OAuth2Exception> translate(Exception exception) throws Exception {
if (exception instanceof OAuth2Exception) {
OAuth2Exception oAuth2Exception = (OAuth2Exception) exception;
return ResponseEntity
.status(oAuth2Exception.getHttpErrorCode())
.body(new CustomOauthException(oAuth2Exception.getMessage()));
}else if(exception instanceof AuthenticationException){
AuthenticationException authenticationException = (AuthenticationException) exception;
return ResponseEntity
.status(HttpStatus.UNAUTHORIZED)
.body(new CustomOauthException(authenticationException.getMessage()));
}
return ResponseEntity
.status(HttpStatus.OK)
.body(new CustomOauthException(exception.getMessage()));
}
}
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import org.springframework.security.oauth2.common.exceptions.OAuth2Exception;
/**
* #author qianggetaba
* #date 2019/6/21
*/
#JsonSerialize(using = CustomOauthExceptionSerializer.class)
public class CustomOauthException extends OAuth2Exception {
public CustomOauthException(String msg) {
super(msg);
}
}
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;
import java.io.IOException;
import java.util.Arrays;
import java.util.Map;
/**
* #author qianggetaba
* #date 2019/6/21
*/
public class CustomOauthExceptionSerializer extends StdSerializer<CustomOauthException> {
public CustomOauthExceptionSerializer() {
super(CustomOauthException.class);
}
#Override
public void serialize(CustomOauthException value, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
jsonGenerator.writeStartObject();
jsonGenerator.writeNumberField("code4444", value.getHttpErrorCode());
jsonGenerator.writeBooleanField("status", false);
jsonGenerator.writeObjectField("data", null);
jsonGenerator.writeObjectField("errors", Arrays.asList(value.getOAuth2ErrorCode(),value.getMessage()));
if (value.getAdditionalInformation()!=null) {
for (Map.Entry<String, String> entry : value.getAdditionalInformation().entrySet()) {
String key = entry.getKey();
String add = entry.getValue();
jsonGenerator.writeStringField(key, add);
}
}
jsonGenerator.writeEndObject();
}
}
for custom ResourceServer exception
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
/**
* #author qianggetaba
* #date 2019/6/21
*/
public class MyAuthenticationEntryPoint implements AuthenticationEntryPoint {
#Override
public void commence(HttpServletRequest request, HttpServletResponse response,
AuthenticationException authException)
throws ServletException {
Map map = new HashMap();
map.put("errorentry", "401");
map.put("message", authException.getMessage());
map.put("path", request.getServletPath());
map.put("timestamp", String.valueOf(new Date().getTime()));
response.setContentType("application/json");
response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
try {
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(response.getOutputStream(), map);
} catch (Exception e) {
throw new ServletException();
}
}
}
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.web.access.AccessDeniedHandler;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
/**
* #author qianggetaba
* #date 2019/6/21
*/
public class MyAccessDeniedHandler implements AccessDeniedHandler{
#Override
public void handle(HttpServletRequest request, HttpServletResponse response, AccessDeniedException accessDeniedException) throws IOException, ServletException {
response.setContentType("application/json;charset=UTF-8");
Map map = new HashMap();
map.put("errorauth", "400");
map.put("message", accessDeniedException.getMessage());
map.put("path", request.getServletPath());
map.put("timestamp", String.valueOf(new Date().getTime()));
response.setContentType("application/json");
response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
try {
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(response.getOutputStream(), map);
} catch (Exception e) {
throw new ServletException();
}
}
}

Answer 2

I found a similar question with answers that really helped my solving this - Handle spring security authentication exceptions with #ExceptionHandler
But my question is specifically about spring-security-oauth2 - so I think it is still worth stating the answer specific to spring-security-oauth2. My solution was picked from different answers to the question mentioned above.
My samples work for spring-security-oauth2 2.0.13
So the solution for me to achieve a different custom error structure for oauth2 errors on resource server resources was to register a custom OAuth2AuthenticationEntryPoint and OAuth2AccessDeniedHandler that I register using a ResourceServerConfigurerAdapter. It is worth mentioning that this is only changing the format for ResourceServer endpoints - and not the AuthorizationServer endpoints like the TokenEndpoint.
class MyCustomOauthErrorConversionConfigurerAdapter extends ResourceServerConfigurerAdapter {
#Override
public void configure(ResourceServerSecurityConfigurer configurer) throws Exception {
configurer.authenticationEntryPoint(new MyCustomOauthErrorOAuth2AuthenticationEntryPoint());
configurer.accessDeniedHandler(new MyCustomOauthErrorOAuth2AccessDeniedHandler());
}
}
I could not reuse the functionality in OAuth2AuthenticationEntryPoint and OAuth2AccessDeniedHandler because the relevant methods translate the exception and flush it in the same method. So I needed to copy some code:
public class MyCustomOauthErrorOAuth2AccessDeniedHandler extends OAuth2AccessDeniedHandler {
private final MyCustomOauthErrorOAuth2SecurityExceptionHandler oAuth2SecurityExceptionHandler = new MyCustomOauthErrorOAuth2SecurityExceptionHandler();
/**
* Does exactly what OAuth2AccessDeniedHandler does only that the body is transformed to {#link MyCustomOauthError} before rendering the exception
*/
#Override
public void handle(HttpServletRequest request, HttpServletResponse response, org.springframework.security.access.AccessDeniedException authException)
throws IOException, ServletException {
oAuth2SecurityExceptionHandler.handle(request, response, authException, this::enhanceResponse);
}
}
public class ExceptionMessageOAuth2AuthenticationEntryPoint extends OAuth2AuthenticationEntryPoint {
private final MyCustomOauthErrorOAuth2SecurityExceptionHandler oAuth2SecurityExceptionHandler = new MyCustomOauthErrorOAuth2SecurityExceptionHandler();
/**
* Does exactly what OAuth2AuthenticationEntryPoint does only that the body is transformed to {#link MyCustomOauthError} before rendering the exception
*/
#Override
public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException) throws IOException, ServletException {
oAuth2SecurityExceptionHandler.handle(request, response, authException, this::enhanceResponse);
}
}
#RequiredArgsConstructor
public class MyCustomOauthErrorOAuth2SecurityExceptionHandler {
private final WebResponseExceptionTranslator exceptionTranslator = new DefaultWebResponseExceptionTranslator();
private final OAuth2ExceptionRenderer exceptionRenderer = new DefaultOAuth2ExceptionRenderer();
private final HandlerExceptionResolver handlerExceptionResolver = new DefaultHandlerExceptionResolver();
/**
* This is basically what {#link org.springframework.security.oauth2.provider.error.AbstractOAuth2SecurityExceptionHandler#doHandle(HttpServletRequest, HttpServletResponse, Exception)} does.
*/
public void handle(HttpServletRequest request, HttpServletResponse response, RuntimeException authException,
BiFunction<ResponseEntity<OAuth2Exception>, Exception, ResponseEntity<OAuth2Exception>> oauthExceptionEnhancer)
throws IOException, ServletException {
try {
ResponseEntity<OAuth2Exception> defaultErrorResponse = exceptionTranslator.translate(authException);
defaultErrorResponse = oauthExceptionEnhancer.apply(defaultErrorResponse, authException);
//this is the actual translation of the error
final MyCustomOauthError customErrorPayload =
MyCustomOauthError.builder()
.errorId(defaultErrorResponse.getBody().getOAuth2ErrorCode())
.message(defaultErrorResponse.getBody().getMessage())
.details(defaultErrorResponse.getBody().getAdditionalInformation() == null ? emptyMap() : defaultErrorResponse.getBody().getAdditionalInformation())
.build();
final ResponseEntity<MyCustomOauthError> responseEntity = new ResponseEntity<>(customErrorPayload, defaultErrorResponse.getHeaders(), defaultErrorResponse.getStatusCode());
exceptionRenderer.handleHttpEntityResponse(responseEntity, new ServletWebRequest(request, response));
response.flushBuffer();
} catch (ServletException e) {
// Re-use some of the default Spring dispatcher behaviour - the exception came from the filter chain and
// not from an MVC handler so it won't be caught by the dispatcher (even if there is one)
if (handlerExceptionResolver.resolveException(request, response, this, e) == null) {
throw e;
}
} catch (IOException | RuntimeException e) {
throw e;
} catch (Exception e) {
// Wrap other Exceptions. These are not expected to happen
throw new RuntimeException(e);
}
}
}

Answer 3

Spring Boot version: 2.2.5
You really don't have to write that much code. All you need to do create a custom AuthenticationEntryPoint by extending OAuth2AuthenticationEntryPoint, override enhanceResponse method of it and register it via Resource Server configuration.
First part:
#Configuration
#EnableResourceServer
public class ResourceServerConfiguration extends ResourceServerConfigurerAdapter {
#Override
public void configure(ResourceServerSecurityConfigurer config) {
config.authenticationEntryPoint(new CustomOauth2AuthenticationEntryPoint());
}
}
Second part:
public class CustomOauth2AuthenticationEntryPoint extends OAuth2AuthenticationEntryPoint {
#Override
protected ResponseEntity<String> enhanceResponse(ResponseEntity<?> response, Exception exception) {
return ResponseEntity.status(response.getStatusCode()).body("My custom response body.");
}
}
Keep in mind that according to spec 401 response must send WWW-Authenticate header. The enhanceResponse that we override sends that header. Take a look at the implementation and send that header if you return 401.

Answer 4

You have to setAuthenticationEntryPoint in TokenEndpointAuthenticationFilter Bean if you config by AuthorizationServer
#Bean
public TokenEndpointAuthenticationFilter tokenEndpointAuthenticationFilter() {
CustomOauth2AuthenticationEntryPoint entryPoint = new CustomOauth2AuthenticationEntryPoint();
TokenEndpointAuthenticationFilter filter = new TokenEndpointAuthenticationFilter(authenticationManager, requestFactory());
filter.setAuthenticationEntryPoint(entryPoint);
return filter;
}