Include role names in access denied errors

This commit adds a User's list of current role names to access denied
error messages to aid in diagnostics.
This allows an administrator to know whether the correct course of
action is to add another role to the user (e.g. by fixing incorrect
role mappings) or by modifying a role to add more privileges.

Resolves: elastic#42166

x-pack/plugin/ilm/qa/with-security/src/javaRestTest/java/org/elasticsearch/xpack/security/PermissionsIT.java

@@ -146,6 +146,7 @@ public void testCanManageIndexWithNoPermissions() throws Exception {
                 assertThat(stepInfo.get("type"), equalTo("security_exception"));
                 assertThat(stepInfo.get("reason"), equalTo("action [indices:monitor/stats] is unauthorized" +
                     " for user [test_ilm]" +
+                    " with roles [ilm]" +
                     " on indices [not-ilm]," +
                     " this action is granted by the index privileges [monitor,manage,all]"));
             }

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authz/AuthorizationService.java

@@ -28,6 +28,7 @@
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Nullable;
+import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
@@ -630,6 +631,9 @@ private ElasticsearchSecurityException denialException(Authentication authentica
             final String apiKeyId = (String) authentication.getMetadata().get(ApiKeyService.API_KEY_ID_KEY);
             assert apiKeyId != null : "api key id must be present in the metadata";
             userText = "API key id [" + apiKeyId + "] of " + userText;
+        } else {
+            // Don't print roles for API keys because they're not meaningful
+            userText = userText + " with roles [" + Strings.arrayToCommaDelimitedString(authentication.getUser().roles()) + "]";
         }
 
         String message = "action [" + action + "] is unauthorized for " + userText;

x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authz/AuthorizationServiceTests.java

@@ -677,8 +677,11 @@ public void testUnknownRoleCausesDenial() throws IOException {
 
         ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
             () -> authorize(authentication, action, request));
-        assertThat(securityException,
-            throwableWithMessage(containsString("[" + action + "] is unauthorized for user [test user] on indices [")));
+        assertThat(securityException, throwableWithMessage(containsString(
+            "[" + action + "] is unauthorized" +
+                " for user [test user]" +
+                " with roles [non-existent-role]" +
+                " on indices [")));
         assertThat(securityException, throwableWithMessage(containsString("this action is granted by the index privileges [read,all]")));
 
         verify(auditTrail).accessDenied(eq(requestId), eq(authentication), eq(action), eq(request), authzInfoRoles(Role.EMPTY.names()));
@@ -716,8 +719,11 @@ public void testThatRoleWithNoIndicesIsDenied() throws IOException {
 
         ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
             () -> authorize(authentication, action, request));
-        assertThat(securityException,
-            throwableWithMessage(containsString("[" + action + "] is unauthorized for user [test user] on indices [")));
+        assertThat(securityException, throwableWithMessage(containsString(
+            "[" + action + "] is unauthorized" +
+                " for user [test user]" +
+                " with roles [no_indices]" +
+                " on indices [")));
         assertThat(securityException, throwableWithMessage(containsString("this action is granted by the index privileges [read,all]")));
 
         verify(auditTrail).accessDenied(eq(requestId), eq(authentication), eq(action), eq(request),
@@ -888,23 +894,28 @@ public void testCreateIndexWithAlias() throws IOException {
     }
 
     public void testDenialErrorMessagesForSearchAction() throws IOException {
-        RoleDescriptor role = new RoleDescriptor("some_indices_" + randomAlphaOfLengthBetween(3, 6), null, new IndicesPrivileges[]{
+        RoleDescriptor indexRole = new RoleDescriptor("some_indices_" + randomAlphaOfLengthBetween(3, 6), null, new IndicesPrivileges[]{
             IndicesPrivileges.builder().indices("all*").privileges("all").build(),
             IndicesPrivileges.builder().indices("read*").privileges("read").build(),
             IndicesPrivileges.builder().indices("write*").privileges("write").build()
         }, null);
-        User user = new User(randomAlphaOfLengthBetween(6, 8), role.getName());
+        RoleDescriptor emptyRole = new RoleDescriptor("empty_role_" +  randomAlphaOfLengthBetween(1,4), null, null, null);
+        User user = new User(randomAlphaOfLengthBetween(6, 8), indexRole.getName(), emptyRole.getName());
         final Authentication authentication = createAuthentication(user);
-        roleMap.put(role.getName(), role);
+        roleMap.put(indexRole.getName(), indexRole);
+        roleMap.put(emptyRole.getName(), emptyRole);
 
         AuditUtil.getOrGenerateRequestId(threadContext);
 
         TransportRequest request = new SearchRequest("all-1", "read-2", "write-3", "other-4");
 
         ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
             () -> authorize(authentication, SearchAction.NAME, request));
-        assertThat(securityException, throwableWithMessage(
-            containsString("[" + SearchAction.NAME + "] is unauthorized for user [" + user.principal() + "] on indices [")));
+        assertThat(securityException, throwableWithMessage(containsString(
+            "[" + SearchAction.NAME + "] is unauthorized" +
+                " for user [" + user.principal() + "]" +
+                " with roles [" + indexRole.getName() + "," + emptyRole.getName() + "]" +
+                " on indices [")));
         assertThat(securityException, throwableWithMessage(containsString("write-3")));
         assertThat(securityException, throwableWithMessage(containsString("other-4")));
         assertThat(securityException, throwableWithMessage(not(containsString("all-1"))));

x-pack/plugin/src/test/resources/rest-api-spec/test/api_key/11_invalidation.yml

@@ -126,7 +126,8 @@ teardown:
               "username": "api_key_manager"
             }
   - match: { "error.type": "security_exception" }
-  - match: { "error.reason": "action [cluster:admin/xpack/security/api_key/invalidate] is unauthorized for user [api_key_user_1], this action is granted by the cluster privileges [manage_api_key,manage_security,all]" }
+  - match:
+      "error.reason": "action [cluster:admin/xpack/security/api_key/invalidate] is unauthorized for user [api_key_user_1] with roles [user_role], this action is granted by the cluster privileges [manage_api_key,manage_security,all]"
 
   - do:
       headers:
@@ -189,7 +190,8 @@ teardown:
               "realm_name": "default_native"
             }
   - match: { "error.type": "security_exception" }
-  - match: { "error.reason": "action [cluster:admin/xpack/security/api_key/invalidate] is unauthorized for user [api_key_user_1], this action is granted by the cluster privileges [manage_api_key,manage_security,all]" }
+  - match:
+      "error.reason": "action [cluster:admin/xpack/security/api_key/invalidate] is unauthorized for user [api_key_user_1] with roles [user_role], this action is granted by the cluster privileges [manage_api_key,manage_security,all]"
 
   - do:
       headers: