Support conditional access policy in obo flow.

eng/versioning/external_dependencies.txt

@@ -132,6 +132,7 @@ org.springframework:spring-messaging;5.2.10.RELEASE
 org.springframework:spring-tx;5.2.10.RELEASE
 org.springframework:spring-web;5.2.10.RELEASE
 org.springframework:spring-webmvc;5.2.10.RELEASE
+org.springframework:spring-webflux;5.2.10.RELEASE
 
 # spring-boot-starter-parent is not managed by spring-boot-dependencies or spring-cloud-dependencies.
 org.springframework.boot:spring-boot-starter-parent;2.3.7.RELEASE

sdk/spring/azure-spring-boot-samples/azure-spring-boot-sample-active-directory-resource-server-obo/src/main/java/com/azure/spring/sample/aad/configuration/AADSampleConfiguration.java

@@ -15,25 +15,13 @@
 public class AADSampleConfiguration {
 
     @Bean
-    public OAuth2AuthorizedClientManager authorizedClientManager(
-        ClientRegistrationRepository clientRegistrationRepository,
-        OAuth2AuthorizedClientRepository authorizedClientRepository) {
-        OAuth2AuthorizedClientProvider authorizedClientProvider =
-            OAuth2AuthorizedClientProviderBuilder.builder()
-                                                 .refreshToken()
-                                                 .build();
-        DefaultOAuth2AuthorizedClientManager authorizedClientManager =
-            new DefaultOAuth2AuthorizedClientManager(clientRegistrationRepository, authorizedClientRepository);
-        authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);
-        return authorizedClientManager;
-    }
-
-    @Bean
-    public WebClient webClient(OAuth2AuthorizedClientManager authorizedClientManager) {
-        ServletOAuth2AuthorizedClientExchangeFilterFunction oauth2Client =
-            new ServletOAuth2AuthorizedClientExchangeFilterFunction(authorizedClientManager);
+    public static WebClient webClient(ClientRegistrationRepository clientRegistrationRepository,
+                                      OAuth2AuthorizedClientRepository authorizedClientRepository) {
+        ServletOAuth2AuthorizedClientExchangeFilterFunction function =
+            new ServletOAuth2AuthorizedClientExchangeFilterFunction(clientRegistrationRepository,
+                authorizedClientRepository);
         return WebClient.builder()
-                        .apply(oauth2Client.oauth2Configuration())
+                        .apply(function.oauth2Configuration())
                         .build();
     }
 }

sdk/spring/azure-spring-boot-samples/azure-spring-boot-sample-active-directory-resource-server-obo/src/main/java/com/azure/spring/sample/aad/controller/SampleController.java

@@ -28,7 +28,7 @@ public class SampleController {
 
     private static final String GRAPH_ME_ENDPOINT = "https://graph.microsoft.com/v1.0/me";
 
-    private static final String CUSTOM_LOCAL_FILE_ENDPOINT = "http://localhost:8080/file";
+    private static final String CUSTOM_LOCAL_FILE_ENDPOINT = "http://localhost:8082/file";
 
     @Autowired
     private WebClient webClient;

sdk/spring/azure-spring-boot-samples/azure-spring-boot-sample-active-directory-resource-server/src/main/resources/application.yml

@@ -2,6 +2,9 @@
 # In v2.0 tokens, this is always the client ID of the API, while in v1.0 tokens it can be the client ID or the resource URI used in the request.
 # If you are using v1.0 tokens, configure both to properly complete the audience validation.
 
+server:
+  port: 8082
+
 #azure:
 #  activedirectory:
 #    client-id: <client-id>

sdk/spring/azure-spring-boot-samples/azure-spring-boot-sample-active-directory-webapp/src/main/java/com/azure/spring/sample/aad/config/WebClientConfig.java

@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.spring.sample.aad.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
+import org.springframework.security.oauth2.client.web.OAuth2AuthorizedClientRepository;
+import org.springframework.security.oauth2.client.web.reactive.function.client.ServletOAuth2AuthorizedClientExchangeFilterFunction;
+import org.springframework.web.reactive.function.client.WebClient;
+
+
+@Configuration
+public class WebClientConfig {
+
+    @Bean
+    public static WebClient webClient(ClientRegistrationRepository clientRegistrationRepository,
+                                      OAuth2AuthorizedClientRepository authorizedClientRepository) {
+        ServletOAuth2AuthorizedClientExchangeFilterFunction function =
+            new ServletOAuth2AuthorizedClientExchangeFilterFunction(clientRegistrationRepository,
+                authorizedClientRepository);
+        return WebClient.builder()
+                        .apply(function.oauth2Configuration())
+                        .build();
+    }
+}

sdk/spring/azure-spring-boot-samples/azure-spring-boot-sample-active-directory-webapp/src/main/java/com/azure/spring/sample/aad/controller/CallOboServerController.java

@@ -0,0 +1,60 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.spring.sample.aad.controller;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
+import org.springframework.security.oauth2.client.annotation.RegisteredOAuth2AuthorizedClient;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.reactive.function.client.WebClient;
+
+
+import static org.springframework.security.oauth2.client.web.reactive.function.client.ServletOAuth2AuthorizedClientExchangeFilterFunction.oauth2AuthorizedClient;
+
+@Controller
+public class CallOboServerController {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(CallOboServerController.class);
+
+    private static final String CUSTOM_LOCAL_FILE_ENDPOINT = "http://localhost:8081/call-custom";
+
+    @Autowired
+    private WebClient webClient;
+
+    /**
+     * Call obo server, combine all the response and return.
+     * @param obo authorized client for Custom
+     * @return Response Graph and Custom data.
+     */
+    @GetMapping("/obo")
+    @ResponseBody
+    public String callOboServer(@RegisteredOAuth2AuthorizedClient("obo") OAuth2AuthorizedClient obo) {
+        return callOboEndpoint(obo);
+    }
+
+    /**
+     * Call obo local file endpoint
+     * @param obo Authorized Client
+     * @return Response string data.
+     */
+    private String callOboEndpoint(OAuth2AuthorizedClient obo) {
+        if (null != obo) {
+            String body = webClient
+                .get()
+                .uri(CUSTOM_LOCAL_FILE_ENDPOINT)
+                .attributes(oauth2AuthorizedClient(obo))
+                .retrieve()
+                .bodyToMono(String.class)
+                .block();
+            LOGGER.info("Response from obo server: {}", body);
+            return "Obo server response " + (null != body ? "success." : "failed.");
+        } else {
+            return "Obo server response failed.";
+        }
+    }
+}

sdk/spring/azure-spring-boot-samples/azure-spring-boot-sample-active-directory-webapp/src/main/resources/templates/index.html

@@ -34,6 +34,7 @@ <h1>Azure Active Directory OAuth 2.0 Login with Spring Security</h1>
     <a href="/group2" >Group2 Message</a> |
     <a href="/graph" >Graph Client</a> |
     <a href="/arm" >Arm Client</a> |
+    <a href="/obo" >Obo Client</a> |
 </div>
 </body>
 </html>

sdk/spring/azure-spring-boot/pom.xml

@@ -270,6 +270,12 @@
       <artifactId>spring-core</artifactId>
       <version>5.2.10.RELEASE</version> <!-- {x-version-update;org.springframework:spring-core;external_dependency} -->
     </dependency>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-webflux</artifactId>
+      <version>5.2.10.RELEASE</version> <!-- {x-version-update;org.springframework:spring-webflux;external_dependency} -->
+      <optional>true</optional>
+    </dependency>
     <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpclient</artifactId>
@@ -302,6 +308,7 @@
                 <include>org.springframework:spring-core:[5.2.10.RELEASE]</include> <!-- {x-include-update;org.springframework:spring-core;external_dependency} -->
                 <include>org.springframework:spring-web:[5.2.10.RELEASE]</include> <!-- {x-include-update;org.springframework:spring-web;external_dependency} -->
                 <include>org.springframework:spring-jms:[5.2.10.RELEASE]</include> <!-- {x-include-update;org.springframework:spring-jms;external_dependency} -->
+                <include>org.springframework:spring-webflux:[5.2.10.RELEASE]</include> <!-- {x-include-update;org.springframework:spring-webflux;external_dependency} -->
                 <include>org.springframework.boot:spring-boot-actuator-autoconfigure:[2.3.5.RELEASE]</include> <!-- {x-include-update;org.springframework.boot:spring-boot-actuator-autoconfigure;external_dependency} -->
                 <include>org.springframework.boot:spring-boot-autoconfigure-processor:[2.3.5.RELEASE]</include> <!-- {x-include-update;org.springframework.boot:spring-boot-autoconfigure-processor;external_dependency} -->
                 <include>org.springframework.boot:spring-boot-autoconfigure:[2.3.5.RELEASE]</include> <!-- {x-include-update;org.springframework.boot:spring-boot-autoconfigure;external_dependency} -->

sdk/spring/azure-spring-boot/src/main/java/com/azure/spring/aad/webapi/AADOAuth2OboAuthorizedClientRepository.java

@@ -3,28 +3,42 @@
 
 package com.azure.spring.aad.webapi;
 
+import com.azure.spring.autoconfigure.aad.Constants;
 import com.microsoft.aad.msal4j.ClientCredentialFactory;
 import com.microsoft.aad.msal4j.ConfidentialClientApplication;
 import com.microsoft.aad.msal4j.IClientSecret;
+import com.microsoft.aad.msal4j.MsalInteractionRequiredException;
 import com.microsoft.aad.msal4j.OnBehalfOfParameters;
 import com.microsoft.aad.msal4j.UserAssertion;
 import com.nimbusds.jwt.JWT;
 import com.nimbusds.jwt.JWTParser;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
 import org.springframework.security.oauth2.client.registration.ClientRegistration;
 import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
 import org.springframework.security.oauth2.client.web.OAuth2AuthorizedClientRepository;
 import org.springframework.security.oauth2.core.OAuth2AccessToken;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
 import org.springframework.security.oauth2.server.resource.authentication.AbstractOAuth2TokenAuthenticationToken;
+import org.springframework.util.Assert;
+import org.springframework.web.context.request.RequestContextHolder;
+import org.springframework.web.context.request.ServletRequestAttributes;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.net.MalformedURLException;
+import java.text.ParseException;
 import java.time.Instant;
 import java.util.Date;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ExecutionException;
 
 /**
  * <p>
@@ -86,8 +100,18 @@ public <T extends OAuth2AuthorizedClient> T loadAuthorizedClient(String registra
                 oAuth2AccessToken);
             request.setAttribute(oboAuthorizedClientAttributeName, (T) oAuth2AuthorizedClient);
             return (T) oAuth2AuthorizedClient;
-        } catch (Throwable throwable) {
-            LOGGER.error("Failed to load authorized client.", throwable);
+        } catch (ExecutionException exception) {
+            // Handle conditional access policy for obo flow.
+            // A user interaction is required, but we are in a web API, and therefore, we need to report back to the
+            // client through a 'WWW-Authenticate' header https://tools.ietf.org/html/rfc6750#section-3.1
+            Optional.of(exception)
+                    .map(Throwable::getCause)
+                    .filter(e -> e instanceof MsalInteractionRequiredException)
+                    .map(e -> (MsalInteractionRequiredException) e)
+                    .ifPresent(this::replyForbiddenWithWwwAuthenticateHeader);
+            LOGGER.error("Failed to load authorized client.", exception);
+        } catch (InterruptedException | ParseException exception) {
+            LOGGER.error("Failed to load authorized client.", exception);
         }
         return null;
     }
@@ -130,4 +154,18 @@ private String interceptAuthorizationUri(String authorizationUri) {
         }
         return null;
     }
+
+    void replyForbiddenWithWwwAuthenticateHeader(MsalInteractionRequiredException exception) {
+        ServletRequestAttributes attr =
+            (ServletRequestAttributes) RequestContextHolder.currentRequestAttributes();
+        HttpServletResponse response = attr.getResponse();
+        Assert.notNull(response, "HttpServletResponse should not be null.");
+        response.setStatus(HttpStatus.FORBIDDEN.value());
+        Map<String, Object> parameters = new LinkedHashMap<>();
+        parameters.put(Constants.CONDITIONAL_ACCESS_POLICY_CLAIMS, exception.claims());
+        parameters.put(OAuth2ParameterNames.ERROR, OAuth2ErrorCodes.INVALID_TOKEN);
+        parameters.put(OAuth2ParameterNames.ERROR_DESCRIPTION, "The resource server requires higher privileges than "
+            + "provided by the access token");
+        response.addHeader(HttpHeaders.WWW_AUTHENTICATE, Constants.BEARER_PREFIX + parameters.toString());
+    }
 }