Restrict direct use of ApplicationPrivilege constructor (#91176)

The canonical way to construct application privileges is to use
ApplicationPrivilege::get which accounts for stored privilege look-up.
This PR restricts and reduces the direct usage of the
ApplicationPrivilege constructor, to enforce this. To ease testing, the
PR introduces a new utility function that matches the constructor's
signature.

Author: n1v0lg

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/authz/privilege/ApplicationPrivilege.java

@@ -43,16 +43,13 @@ public final class ApplicationPrivilege extends Privilege {
      */
     private static final Pattern VALID_NAME_OR_ACTION = Pattern.compile("^\\p{Graph}*$");
 
-    public static final Function<String, ApplicationPrivilege> NONE = app -> new ApplicationPrivilege(app, "none", new String[0]);
+    public static final Function<String, ApplicationPrivilege> NONE = app -> new ApplicationPrivilege(app, Collections.singleton("none"));
 
     private final String application;
     private final String[] patterns;
 
-    public ApplicationPrivilege(String application, String privilegeName, String... patterns) {
-        this(application, Collections.singleton(privilegeName), patterns);
-    }
-
-    public ApplicationPrivilege(String application, Set<String> name, String... patterns) {
+    // TODO make this private once ApplicationPrivilegeTests::createPrivilege uses ApplicationPrivilege::get
+    ApplicationPrivilege(String application, Set<String> name, String... patterns) {
         super(name, patterns);
         this.application = application;
         this.patterns = patterns;

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/authz/permission/ApplicationPermissionTests.java

@@ -11,6 +11,7 @@
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilege;
 import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilegeDescriptor;
+import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilegeTests;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -40,7 +41,7 @@ public class ApplicationPermissionTests extends ESTestCase {
 
     private ApplicationPrivilege storePrivilege(String app, String name, String... patterns) {
         store.add(new ApplicationPrivilegeDescriptor(app, name, Sets.newHashSet(patterns), Collections.emptyMap()));
-        return new ApplicationPrivilege(app, name, patterns);
+        return ApplicationPrivilegeTests.createPrivilege(app, name, patterns);
     }
 
     public void testCheckSimplePermission() {

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/authz/permission/LimitedRoleTests.java

@@ -28,6 +28,7 @@
 import org.elasticsearch.xpack.core.security.authz.accesscontrol.IndicesAccessControl;
 import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilege;
 import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilegeDescriptor;
+import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilegeTests;
 import org.elasticsearch.xpack.core.security.authz.privilege.ClusterPrivilegeResolver;
 import org.elasticsearch.xpack.core.security.authz.privilege.IndexPrivilege;
 import org.elasticsearch.xpack.core.security.support.Automatons;
@@ -873,7 +874,7 @@ private ApplicationPrivilege defineApplicationPrivilege(String app, String name,
         applicationPrivilegeDescriptors.add(
             new ApplicationPrivilegeDescriptor(app, name, Sets.newHashSet(actions), Collections.emptyMap())
         );
-        return new ApplicationPrivilege(app, name, actions);
+        return ApplicationPrivilegeTests.createPrivilege(app, name, actions);
     }
 
     private static MapBuilder<String, ResourcePrivileges> mapBuilder() {

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/authz/permission/SimpleRoleTests.java

@@ -11,8 +11,8 @@
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.core.security.authz.AuthorizationEngine;
 import org.elasticsearch.xpack.core.security.authz.RoleDescriptor;
-import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilege;
 import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilegeDescriptor;
+import org.elasticsearch.xpack.core.security.authz.privilege.ApplicationPrivilegeTests;
 
 import java.util.Arrays;
 import java.util.List;
@@ -102,7 +102,7 @@ public void testBuildFromRoleDescriptorWithApplicationPrivileges() {
             "expected grant for role with application privilege to be: " + applicationPrivilege,
             role.application()
                 .grants(
-                    new ApplicationPrivilege(
+                    ApplicationPrivilegeTests.createPrivilege(
                         wildcardApplication ? randomAlphaOfLengthBetween(1, 10) : applicationPrivilege.getApplication(),
                         wildcardPrivileges ? Set.of(randomAlphaOfLengthBetween(1, 10)) : Set.of(applicationPrivilege.getPrivileges()),
                         wildcardPrivileges ? randomAlphaOfLengthBetween(1, 10) : allowedApplicationActionPattern
@@ -117,7 +117,7 @@ public void testBuildFromRoleDescriptorWithApplicationPrivileges() {
             "expected grant for role with application privilege to be: " + applicationPrivilege,
             role.application()
                 .grants(
-                    new ApplicationPrivilege(
+                    ApplicationPrivilegeTests.createPrivilege(
                         false == wildcardApplication
                             ? randomValueOtherThan(applicationPrivilege.getApplication(), () -> randomAlphaOfLengthBetween(1, 10))
                             : randomAlphaOfLengthBetween(1, 10),

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/authz/privilege/ApplicationPrivilegeTests.java

@@ -19,9 +19,7 @@
 
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.Locale;
-import java.util.Map;
 import java.util.Set;
 import java.util.function.Supplier;
 
@@ -35,6 +33,19 @@
 
 public class ApplicationPrivilegeTests extends ESTestCase {
 
+    public static ApplicationPrivilege createPrivilege(final String applicationName, final String privilegeName, final String... patterns) {
+        return createPrivilege(applicationName, Collections.singleton(privilegeName), patterns);
+    }
+
+    public static ApplicationPrivilege createPrivilege(
+        final String applicationName,
+        final Set<String> privilegeNames,
+        final String... patterns
+    ) {
+        // TODO rewrite this to use `ApplicationPrivilege.get()`
+        return new ApplicationPrivilege(applicationName, privilegeNames, patterns);
+    }
+
     public void testValidationOfApplicationName() {
         final String specialCharacters = ":;$#%()+='.{}[]!@^&'";
         final Supplier<Character> specialCharacter = () -> specialCharacters.charAt(randomInt(specialCharacters.length() - 1));
@@ -203,7 +214,7 @@ public void testEqualsAndHashCode() {
         final EqualsHashCodeTestUtils.MutateFunction<ApplicationPrivilege> mutate = randomFrom(
             orig -> createPrivilege("x" + orig.getApplication(), getPrivilegeName(orig), orig.getPatterns()),
             orig -> createPrivilege(orig.getApplication(), "x" + getPrivilegeName(orig), orig.getPatterns()),
-            orig -> new ApplicationPrivilege(orig.getApplication(), getPrivilegeName(orig), "*")
+            orig -> createPrivilege(orig.getApplication(), getPrivilegeName(orig), "*")
         );
         EqualsHashCodeTestUtils.checkEqualsAndHashCode(
             privilege,
@@ -212,10 +223,6 @@ public void testEqualsAndHashCode() {
         );
     }
 
-    private ApplicationPrivilege createPrivilege(String applicationName, String privilegeName, String... patterns) {
-        return new ApplicationPrivilege(applicationName, privilegeName, patterns);
-    }
-
     private String getPrivilegeName(ApplicationPrivilege privilege) {
         if (privilege.name.size() == 1) {
             return privilege.name.iterator().next();
@@ -257,10 +264,6 @@ private ApplicationPrivilege randomPrivilege() {
             patterns[i] = randomAlphaOfLengthBetween(2, 5) + "/" + suffix;
         }
 
-        final Map<String, Object> metadata = new HashMap<>();
-        for (int i = randomInt(3); i > 0; i--) {
-            metadata.put(randomAlphaOfLengthBetween(2, 5), randomFrom(randomBoolean(), randomInt(10), randomAlphaOfLength(5)));
-        }
         return createPrivilege(applicationName, privilegeName, patterns);
     }