Enhance security for alias and resize operations (elastic/x-pack-elasticsearch#3302)

This commit adds additional checks around resize operations and alias creation operations to
add an extra layer of security around these APIs.

Original commit: elastic/x-pack-elasticsearch@b79f16673c

plugin/src/main/java/org/elasticsearch/xpack/security/Security.java

@@ -82,7 +82,9 @@ import org.elasticsearch.xpack.extensions.XPackExtension;
 import org.elasticsearch.xpack.extensions.XPackExtensionsService;
 import org.elasticsearch.xpack.security.action.filter.SecurityActionFilter;
 import org.elasticsearch.xpack.security.action.interceptor.BulkShardRequestInterceptor;
+import org.elasticsearch.xpack.security.action.interceptor.IndicesAliasesRequestInterceptor;
 import org.elasticsearch.xpack.security.action.interceptor.RequestInterceptor;
+import org.elasticsearch.xpack.security.action.interceptor.ResizeRequestInterceptor;
 import org.elasticsearch.xpack.security.action.interceptor.SearchRequestInterceptor;
 import org.elasticsearch.xpack.security.action.interceptor.UpdateRequestInterceptor;
 import org.elasticsearch.xpack.security.action.realm.ClearRealmCacheAction;
@@ -433,10 +435,12 @@ public class Security implements ActionPlugin, IngestPlugin, NetworkPlugin, Clus
 
         final Set<RequestInterceptor> requestInterceptors;
         if (XPackSettings.DLS_FLS_ENABLED.get(settings)) {
-            requestInterceptors = Sets.newHashSet(
+            requestInterceptors = Collections.unmodifiableSet(Sets.newHashSet(
                     new SearchRequestInterceptor(settings, threadPool, licenseState),
                     new UpdateRequestInterceptor(settings, threadPool, licenseState),
-                    new BulkShardRequestInterceptor(settings, threadPool, licenseState));
+                    new BulkShardRequestInterceptor(settings, threadPool, licenseState),
+                    new ResizeRequestInterceptor(settings, threadPool, licenseState, auditTrailService),
+                    new IndicesAliasesRequestInterceptor(threadPool.getThreadContext(), licenseState, auditTrailService)));
         } else {
             requestInterceptors = Collections.emptySet();
         }

plugin/src/main/java/org/elasticsearch/xpack/security/action/filter/SecurityActionFilter.java

@@ -18,7 +18,6 @@ import org.elasticsearch.action.support.ActionFilterChain;
 import org.elasticsearch.action.support.ContextPreservingActionListener;
 import org.elasticsearch.action.support.DestructiveOperations;
 import org.elasticsearch.common.component.AbstractComponent;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 import org.elasticsearch.license.LicenseUtils;
@@ -56,7 +55,6 @@ public class SecurityActionFilter extends AbstractComponent implements ActionFil
     private final SecurityContext securityContext;
     private final DestructiveOperations destructiveOperations;
 
-    @Inject
     public SecurityActionFilter(Settings settings, AuthenticationService authcService, AuthorizationService authzService,
                                 XPackLicenseState licenseState, Set<RequestInterceptor> requestInterceptors, ThreadPool threadPool,
                                 SecurityContext securityContext, DestructiveOperations destructiveOperations) {
@@ -172,7 +170,7 @@ public class SecurityActionFilter extends AbstractComponent implements ActionFil
                          */
                         for (RequestInterceptor interceptor : requestInterceptors) {
                             if (interceptor.supports(request)) {
-                                interceptor.intercept(request, user);
+                                interceptor.intercept(request, user, runAsRoles != null ? runAsRoles : userRoles, securityAction);
                             }
                         }
                         listener.onResponse(null);

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/BulkShardRequestInterceptor.java

@@ -10,7 +10,6 @@ import org.elasticsearch.action.bulk.BulkItemRequest;
 import org.elasticsearch.action.bulk.BulkShardRequest;
 import org.elasticsearch.action.update.UpdateRequest;
 import org.elasticsearch.common.component.AbstractComponent;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 import org.elasticsearch.license.XPackLicenseState;
@@ -19,6 +18,7 @@ import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportRequest;
 import org.elasticsearch.xpack.security.authz.AuthorizationService;
 import org.elasticsearch.xpack.security.authz.accesscontrol.IndicesAccessControl;
+import org.elasticsearch.xpack.security.authz.permission.Role;
 import org.elasticsearch.xpack.security.user.User;
 
 /**
@@ -29,14 +29,13 @@ public class BulkShardRequestInterceptor extends AbstractComponent implements Re
     private final ThreadContext threadContext;
     private final XPackLicenseState licenseState;
 
-    @Inject
     public BulkShardRequestInterceptor(Settings settings, ThreadPool threadPool, XPackLicenseState licenseState) {
         super(settings);
         this.threadContext = threadPool.getThreadContext();
         this.licenseState = licenseState;
     }
 
-    public void intercept(BulkShardRequest request, User user) {
+    public void intercept(BulkShardRequest request, User user, Role userPermissions, String action) {
         if (licenseState.isDocumentAndFieldLevelSecurityAllowed() == false) {
             return;
         }

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/FieldAndDocumentLevelSecurityRequestInterceptor.java

@@ -12,6 +12,7 @@ import org.elasticsearch.common.util.concurrent.ThreadContext;
 import org.elasticsearch.license.XPackLicenseState;
 import org.elasticsearch.xpack.security.authz.AuthorizationService;
 import org.elasticsearch.xpack.security.authz.accesscontrol.IndicesAccessControl;
+import org.elasticsearch.xpack.security.authz.permission.Role;
 import org.elasticsearch.xpack.security.user.User;
 
 /**
@@ -31,7 +32,7 @@ abstract class FieldAndDocumentLevelSecurityRequestInterceptor<Request extends I
         this.licenseState = licenseState;
     }
 
-    public void intercept(Request request, User user) {
+    public void intercept(Request request, User user, Role userPermissions, String action) {
         if (licenseState.isDocumentAndFieldLevelSecurityAllowed() == false) {
             return;
         }

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/IndicesAliasesRequestInterceptor.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.security.action.interceptor;
+
+import org.apache.lucene.util.automaton.Automaton;
+import org.apache.lucene.util.automaton.Operations;
+import org.elasticsearch.ElasticsearchSecurityException;
+import org.elasticsearch.action.admin.indices.alias.IndicesAliasesRequest;
+import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.license.XPackLicenseState;
+import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.transport.TransportRequest;
+import org.elasticsearch.xpack.security.audit.AuditTrailService;
+import org.elasticsearch.xpack.security.authz.AuthorizationService;
+import org.elasticsearch.xpack.security.authz.accesscontrol.IndicesAccessControl;
+import org.elasticsearch.xpack.security.authz.permission.Role;
+import org.elasticsearch.xpack.security.support.Exceptions;
+import org.elasticsearch.xpack.security.user.User;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public final class IndicesAliasesRequestInterceptor implements RequestInterceptor<IndicesAliasesRequest> {
+
+    private final ThreadContext threadContext;
+    private final XPackLicenseState licenseState;
+    private final AuditTrailService auditTrailService;
+
+    public IndicesAliasesRequestInterceptor(ThreadContext threadContext, XPackLicenseState licenseState,
+                                            AuditTrailService auditTrailService) {
+        this.threadContext = threadContext;
+        this.licenseState = licenseState;
+        this.auditTrailService = auditTrailService;
+    }
+
+    @Override
+    public void intercept(IndicesAliasesRequest request, User user, Role userPermissions, String action) {
+        if (licenseState.isDocumentAndFieldLevelSecurityAllowed()) {
+            IndicesAccessControl indicesAccessControl = threadContext.getTransient(AuthorizationService.INDICES_PERMISSIONS_KEY);
+            for (IndicesAliasesRequest.AliasActions aliasAction : request.getAliasActions()) {
+                if (aliasAction.actionType() == IndicesAliasesRequest.AliasActions.Type.ADD) {
+                    for (String index : aliasAction.indices()) {
+                        IndicesAccessControl.IndexAccessControl indexAccessControl = indicesAccessControl.getIndexPermissions(index);
+                        if (indexAccessControl != null) {
+                            final boolean fls = indexAccessControl.getFieldPermissions().hasFieldLevelSecurity();
+                            final boolean dls = indexAccessControl.getQueries() != null;
+                            if (fls || dls) {
+                                throw new ElasticsearchSecurityException("Alias requests are not allowed for users who have " +
+                                        "field or document level security enabled on one of the indices", RestStatus.BAD_REQUEST);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        Map<String, Automaton> permissionsMap = new HashMap<>();
+        for (IndicesAliasesRequest.AliasActions aliasAction : request.getAliasActions()) {
+            if (aliasAction.actionType() == IndicesAliasesRequest.AliasActions.Type.ADD) {
+                for (String index : aliasAction.indices()) {
+                    Automaton indexPermissions = permissionsMap.computeIfAbsent(index, userPermissions.indices()::allowedActionsMatcher);
+                    for (String alias : aliasAction.aliases()) {
+                        Automaton aliasPermissions =
+                                permissionsMap.computeIfAbsent(alias, userPermissions.indices()::allowedActionsMatcher);
+                        if (Operations.subsetOf(aliasPermissions, indexPermissions) == false) {
+                            // TODO we've already audited a access granted event so this is going to look ugly
+                            auditTrailService.accessDenied(user, action, request, userPermissions.names());
+                            throw Exceptions.authorizationError("Adding an alias is not allowed when the alias " +
+                                    "has more permissions than any of the indices");
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Override
+    public boolean supports(TransportRequest request) {
+        return request instanceof IndicesAliasesRequest;
+    }
+}

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/RequestInterceptor.java

@@ -5,6 +5,7 @@
  */
 package org.elasticsearch.xpack.security.action.interceptor;
 
+import org.elasticsearch.xpack.security.authz.permission.Role;
 import org.elasticsearch.xpack.security.user.User;
 import org.elasticsearch.transport.TransportRequest;
 
@@ -17,7 +18,7 @@ public interface RequestInterceptor<Request> {
      * If {@link #supports(TransportRequest)} returns <code>true</code> this interceptor will introspect the request
      * and potentially modify it.
      */
-    void intercept(Request request, User user);
+    void intercept(Request request, User user, Role userPermissions, String action);
 
     /**
      * Returns whether this request interceptor should intercept the specified request.

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/ResizeRequestInterceptor.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.security.action.interceptor;
+
+import org.apache.lucene.util.automaton.Automaton;
+import org.apache.lucene.util.automaton.Operations;
+import org.elasticsearch.ElasticsearchSecurityException;
+import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
+import org.elasticsearch.common.component.AbstractComponent;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.license.XPackLicenseState;
+import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.TransportRequest;
+import org.elasticsearch.xpack.security.audit.AuditTrailService;
+import org.elasticsearch.xpack.security.authz.AuthorizationService;
+import org.elasticsearch.xpack.security.authz.accesscontrol.IndicesAccessControl;
+import org.elasticsearch.xpack.security.authz.permission.Role;
+import org.elasticsearch.xpack.security.support.Exceptions;
+import org.elasticsearch.xpack.security.user.User;
+
+public final class ResizeRequestInterceptor extends AbstractComponent implements RequestInterceptor<ResizeRequest> {
+
+    private final ThreadContext threadContext;
+    private final XPackLicenseState licenseState;
+    private final AuditTrailService auditTrailService;
+
+    public ResizeRequestInterceptor(Settings settings, ThreadPool threadPool, XPackLicenseState licenseState,
+                                    AuditTrailService auditTrailService) {
+        super(settings);
+        this.threadContext = threadPool.getThreadContext();
+        this.licenseState = licenseState;
+        this.auditTrailService = auditTrailService;
+    }
+
+    @Override
+    public void intercept(ResizeRequest request, User user, Role userPermissions, String action) {
+        if (licenseState.isDocumentAndFieldLevelSecurityAllowed()) {
+            IndicesAccessControl indicesAccessControl = threadContext.getTransient(AuthorizationService.INDICES_PERMISSIONS_KEY);
+            IndicesAccessControl.IndexAccessControl indexAccessControl = indicesAccessControl.getIndexPermissions(request.getSourceIndex());
+            if (indexAccessControl != null) {
+                final boolean fls = indexAccessControl.getFieldPermissions().hasFieldLevelSecurity();
+                final boolean dls = indexAccessControl.getQueries() != null;
+                if (fls || dls) {
+                    throw new ElasticsearchSecurityException("Resize requests are not allowed for users when " +
+                            "field or document level security is enabled on the source index", RestStatus.BAD_REQUEST);
+                }
+            }
+        }
+
+        // ensure that the user would have the same level of access OR less on the target index
+        final Automaton sourceIndexPermissions = userPermissions.indices().allowedActionsMatcher(request.getSourceIndex());
+        final Automaton targetIndexPermissions = userPermissions.indices().allowedActionsMatcher(request.getTargetIndexRequest().index());
+        if (Operations.subsetOf(targetIndexPermissions, sourceIndexPermissions) == false) {
+            // TODO we've already audited a access granted event so this is going to look ugly
+            auditTrailService.accessDenied(user, action, request, userPermissions.names());
+            throw Exceptions.authorizationError("Resizing an index is not allowed when the target index " +
+                    "has more permissions than the source index");
+        }
+    }
+
+    @Override
+    public boolean supports(TransportRequest request) {
+        return request instanceof ResizeRequest;
+    }
+}

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/SearchRequestInterceptor.java

@@ -7,7 +7,6 @@ package org.elasticsearch.xpack.security.action.interceptor;
 
 import org.elasticsearch.ElasticsearchSecurityException;
 import org.elasticsearch.action.search.SearchRequest;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.license.XPackLicenseState;
 import org.elasticsearch.rest.RestStatus;
@@ -19,7 +18,6 @@ import org.elasticsearch.transport.TransportRequest;
  */
 public class SearchRequestInterceptor extends FieldAndDocumentLevelSecurityRequestInterceptor<SearchRequest> {
 
-    @Inject
     public SearchRequestInterceptor(Settings settings, ThreadPool threadPool, XPackLicenseState licenseState) {
         super(settings, threadPool.getThreadContext(), licenseState);
     }

plugin/src/main/java/org/elasticsearch/xpack/security/action/interceptor/UpdateRequestInterceptor.java

@@ -7,7 +7,6 @@ package org.elasticsearch.xpack.security.action.interceptor;
 
 import org.elasticsearch.ElasticsearchSecurityException;
 import org.elasticsearch.action.update.UpdateRequest;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.license.XPackLicenseState;
 import org.elasticsearch.rest.RestStatus;
@@ -23,7 +22,6 @@ import org.elasticsearch.transport.TransportRequest;
  */
 public class UpdateRequestInterceptor extends FieldAndDocumentLevelSecurityRequestInterceptor<UpdateRequest> {
 
-    @Inject
     public UpdateRequestInterceptor(Settings settings, ThreadPool threadPool, XPackLicenseState licenseState) {
         super(settings, threadPool.getThreadContext(), licenseState);
     }

plugin/src/main/java/org/elasticsearch/xpack/security/authz/permission/IndicesPermission.java

@@ -5,6 +5,7 @@
  */
 package org.elasticsearch.xpack.security.authz.permission;
 
+import org.apache.lucene.util.automaton.Automaton;
 import org.elasticsearch.cluster.metadata.AliasOrIndex;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.MetaData;
@@ -90,6 +91,16 @@ public final class IndicesPermission implements Iterable<IndicesPermission.Group
         return false;
     }
 
+    public Automaton allowedActionsMatcher(String index) {
+        List<Automaton> automatonList = new ArrayList<>();
+        for (Group group : groups) {
+            if (group.indexNameMatcher.test(index)) {
+                automatonList.add(group.privilege.getAutomaton());
+            }
+        }
+        return automatonList.isEmpty() ? Automatons.EMPTY : Automatons.unionAndMinimize(automatonList);
+    }
+
     /**
      * Authorizes the provided action against the provided indices, given the current cluster metadata
      */

plugin/src/test/java/org/elasticsearch/xpack/security/action/interceptor/IndicesAliasesRequestInterceptorTests.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.security.action.interceptor;
+
+import org.elasticsearch.ElasticsearchSecurityException;
+import org.elasticsearch.action.admin.indices.alias.IndicesAliasesAction;
+import org.elasticsearch.action.admin.indices.alias.IndicesAliasesRequest;
+import org.elasticsearch.common.bytes.BytesArray;
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.license.XPackLicenseState;
+import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.xpack.security.audit.AuditTrailService;
+import org.elasticsearch.xpack.security.authz.AuthorizationService;
+import org.elasticsearch.xpack.security.authz.accesscontrol.IndicesAccessControl;
+import org.elasticsearch.xpack.security.authz.permission.FieldPermissions;
+import org.elasticsearch.xpack.security.authz.permission.FieldPermissionsDefinition;
+import org.elasticsearch.xpack.security.authz.permission.Role;
+import org.elasticsearch.xpack.security.authz.privilege.IndexPrivilege;
+import org.elasticsearch.xpack.security.user.User;
+
+import java.util.Collections;
+import java.util.Set;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class IndicesAliasesRequestInterceptorTests extends ESTestCase {
+
+    public void testInterceptorThrowsWhenFLSDLSEnabled() {
+        XPackLicenseState licenseState = mock(XPackLicenseState.class);
+        when(licenseState.isAuditingAllowed()).thenReturn(true);
+        when(licenseState.isDocumentAndFieldLevelSecurityAllowed()).thenReturn(true);
+        ThreadContext threadContext = new ThreadContext(Settings.EMPTY);
+        AuditTrailService auditTrailService = new AuditTrailService(Settings.EMPTY, Collections.emptyList(), licenseState);
+        User user = new User("john", "role");
+        final FieldPermissions fieldPermissions;
+        final boolean useFls = randomBoolean();
+        if (useFls) {
+            fieldPermissions = new FieldPermissions(new FieldPermissionsDefinition(new String[] { "foo" }, null));
+        } else {
+            fieldPermissions = new FieldPermissions();
+        }
+        final boolean useDls = (useFls == false) || randomBoolean();
+        final Set<BytesReference> queries;
+        if (useDls) {
+            queries = Collections.singleton(new BytesArray(randomAlphaOfLengthBetween(2, 8)));
+        } else {
+            queries = null;
+        }
+        Role role = Role.builder().add(fieldPermissions, queries, IndexPrivilege.ALL, "foo").build();
+        final String action = IndicesAliasesAction.NAME;
+        IndicesAccessControl accessControl = new IndicesAccessControl(true, Collections.singletonMap("foo",
+                new IndicesAccessControl.IndexAccessControl(true, fieldPermissions, queries)));
+        threadContext.putTransient(AuthorizationService.INDICES_PERMISSIONS_KEY, accessControl);
+
+        IndicesAliasesRequestInterceptor interceptor =
+                new IndicesAliasesRequestInterceptor(threadContext, licenseState, auditTrailService);
+
+        IndicesAliasesRequest indicesAliasesRequest = new IndicesAliasesRequest();
+        if (randomBoolean()) {
+            indicesAliasesRequest.addAliasAction(IndicesAliasesRequest.AliasActions.remove().index("bar").alias(randomAlphaOfLength(4)));
+        }
+        indicesAliasesRequest.addAliasAction(IndicesAliasesRequest.AliasActions.add().index("foo").alias(randomAlphaOfLength(4)));
+        if (randomBoolean()) {
+            indicesAliasesRequest.addAliasAction(IndicesAliasesRequest.AliasActions.removeIndex().index("foofoo"));
+        }
+        ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
+                () -> interceptor.intercept(indicesAliasesRequest, user, role, action));
+        assertEquals("Alias requests are not allowed for users who have field or document level security enabled on one of the indices",
+                securityException.getMessage());
+    }
+
+    public void testInterceptorThrowsWhenTargetHasGreaterPermissions() throws Exception {
+        XPackLicenseState licenseState = mock(XPackLicenseState.class);
+        when(licenseState.isAuditingAllowed()).thenReturn(true);
+        when(licenseState.isDocumentAndFieldLevelSecurityAllowed()).thenReturn(true);
+        ThreadContext threadContext = new ThreadContext(Settings.EMPTY);
+        AuditTrailService auditTrailService = new AuditTrailService(Settings.EMPTY, Collections.emptyList(), licenseState);
+        User user = new User("john", "role");
+        Role role = Role.builder()
+                .add(IndexPrivilege.ALL, "alias")
+                .add(IndexPrivilege.READ, "index")
+                .build();
+        final String action = IndicesAliasesAction.NAME;
+        IndicesAccessControl accessControl = new IndicesAccessControl(true, Collections.emptyMap());
+        threadContext.putTransient(AuthorizationService.INDICES_PERMISSIONS_KEY, accessControl);
+        IndicesAliasesRequestInterceptor interceptor =
+                new IndicesAliasesRequestInterceptor(threadContext, licenseState, auditTrailService);
+
+        final IndicesAliasesRequest indicesAliasesRequest = new IndicesAliasesRequest();
+        if (randomBoolean()) {
+            indicesAliasesRequest.addAliasAction(IndicesAliasesRequest.AliasActions.remove().index("bar").alias(randomAlphaOfLength(4)));
+        }
+        indicesAliasesRequest.addAliasAction(IndicesAliasesRequest.AliasActions.add().index("index").alias("alias"));
+        if (randomBoolean()) {
+            indicesAliasesRequest.addAliasAction(IndicesAliasesRequest.AliasActions.removeIndex().index("foofoo"));
+        }
+
+        ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
+                () -> interceptor.intercept(indicesAliasesRequest, user, role, action));
+        assertEquals("Adding an alias is not allowed when the alias has more permissions than any of the indices",
+                securityException.getMessage());
+
+        // swap target and source for success
+        final IndicesAliasesRequest successRequest = new IndicesAliasesRequest();
+        if (randomBoolean()) {
+            successRequest.addAliasAction(IndicesAliasesRequest.AliasActions.remove().index("bar").alias(randomAlphaOfLength(4)));
+        }
+        successRequest.addAliasAction(IndicesAliasesRequest.AliasActions.add().index("alias").alias("index"));
+        if (randomBoolean()) {
+            successRequest.addAliasAction(IndicesAliasesRequest.AliasActions.removeIndex().index("foofoo"));
+        }
+        interceptor.intercept(successRequest, user, role, action);
+    }
+}

plugin/src/test/java/org/elasticsearch/xpack/security/action/interceptor/ResizeRequestInterceptorTests.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.security.action.interceptor;
+
+import org.elasticsearch.ElasticsearchSecurityException;
+import org.elasticsearch.action.admin.indices.shrink.ResizeAction;
+import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
+import org.elasticsearch.action.admin.indices.shrink.ShrinkAction;
+import org.elasticsearch.common.bytes.BytesArray;
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.license.XPackLicenseState;
+import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.xpack.security.audit.AuditTrailService;
+import org.elasticsearch.xpack.security.authz.AuthorizationService;
+import org.elasticsearch.xpack.security.authz.accesscontrol.IndicesAccessControl;
+import org.elasticsearch.xpack.security.authz.permission.FieldPermissions;
+import org.elasticsearch.xpack.security.authz.permission.FieldPermissionsDefinition;
+import org.elasticsearch.xpack.security.authz.permission.Role;
+import org.elasticsearch.xpack.security.authz.privilege.IndexPrivilege;
+import org.elasticsearch.xpack.security.user.User;
+
+import java.util.Collections;
+import java.util.Set;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class ResizeRequestInterceptorTests extends ESTestCase {
+
+    public void testResizeRequestInterceptorThrowsWhenFLSDLSEnabled() {
+        XPackLicenseState licenseState = mock(XPackLicenseState.class);
+        when(licenseState.isAuditingAllowed()).thenReturn(true);
+        when(licenseState.isDocumentAndFieldLevelSecurityAllowed()).thenReturn(true);
+        ThreadPool threadPool = mock(ThreadPool.class);
+        ThreadContext threadContext = new ThreadContext(Settings.EMPTY);
+        when(threadPool.getThreadContext()).thenReturn(threadContext);
+        AuditTrailService auditTrailService = new AuditTrailService(Settings.EMPTY, Collections.emptyList(), licenseState);
+        User user = new User("john", "role");
+        final FieldPermissions fieldPermissions;
+        final boolean useFls = randomBoolean();
+        if (useFls) {
+            fieldPermissions = new FieldPermissions(new FieldPermissionsDefinition(new String[] { "foo" }, null));
+        } else {
+            fieldPermissions = new FieldPermissions();
+        }
+        final boolean useDls = (useFls == false) || randomBoolean();
+        final Set<BytesReference> queries;
+        if (useDls) {
+            queries = Collections.singleton(new BytesArray(randomAlphaOfLengthBetween(2, 8)));
+        } else {
+            queries = null;
+        }
+        Role role = Role.builder().add(fieldPermissions, queries, IndexPrivilege.ALL, "foo").build();
+        final String action = randomFrom(ShrinkAction.NAME, ResizeAction.NAME);
+        IndicesAccessControl accessControl = new IndicesAccessControl(true, Collections.singletonMap("foo",
+                        new IndicesAccessControl.IndexAccessControl(true, fieldPermissions, queries)));
+        threadContext.putTransient(AuthorizationService.INDICES_PERMISSIONS_KEY, accessControl);
+
+        ResizeRequestInterceptor resizeRequestInterceptor =
+                new ResizeRequestInterceptor(Settings.EMPTY, threadPool, licenseState, auditTrailService);
+
+        ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
+                () -> resizeRequestInterceptor.intercept(new ResizeRequest("bar", "foo"), user, role, action));
+        assertEquals("Resize requests are not allowed for users when field or document level security is enabled on the source index",
+                securityException.getMessage());
+    }
+
+    public void testResizeRequestInterceptorThrowsWhenTargetHasGreaterPermissions() throws Exception {
+        XPackLicenseState licenseState = mock(XPackLicenseState.class);
+        when(licenseState.isAuditingAllowed()).thenReturn(true);
+        when(licenseState.isDocumentAndFieldLevelSecurityAllowed()).thenReturn(true);
+        ThreadPool threadPool = mock(ThreadPool.class);
+        ThreadContext threadContext = new ThreadContext(Settings.EMPTY);
+        when(threadPool.getThreadContext()).thenReturn(threadContext);
+        AuditTrailService auditTrailService = new AuditTrailService(Settings.EMPTY, Collections.emptyList(), licenseState);
+        User user = new User("john", "role");
+        Role role = Role.builder()
+                .add(IndexPrivilege.ALL, "target")
+                .add(IndexPrivilege.READ, "source")
+                .build();
+        final String action = randomFrom(ShrinkAction.NAME, ResizeAction.NAME);
+        IndicesAccessControl accessControl = new IndicesAccessControl(true, Collections.emptyMap());
+        threadContext.putTransient(AuthorizationService.INDICES_PERMISSIONS_KEY, accessControl);
+        ResizeRequestInterceptor resizeRequestInterceptor =
+                new ResizeRequestInterceptor(Settings.EMPTY, threadPool, licenseState, auditTrailService);
+        ElasticsearchSecurityException securityException = expectThrows(ElasticsearchSecurityException.class,
+                () -> resizeRequestInterceptor.intercept(new ResizeRequest("target", "source"), user, role, action));
+        assertEquals("Resizing an index is not allowed when the target index has more permissions than the source index",
+                securityException.getMessage());
+
+        // swap target and source for success
+        resizeRequestInterceptor.intercept(new ResizeRequest("source", "target"), user, role, action);
+    }
+}