Remove obsolete security settings (#40496)

Removes the deprecated accept_default_password setting.
This setting become redundant when default passwords were removed
from 6.0, but the setting was kept for BWC.

Removes native role store cache settings.
These have been unused since 5.2 but were kept for BWC.

Author: tvernum

docs/reference/migration/migrate_8_0.asciidoc

@@ -15,6 +15,7 @@ coming[8.0.0]
 * <<breaking_80_discovery_changes>>
 * <<breaking_80_mappings_changes>>
 * <<breaking_80_snapshots_changes>>
+* <<breaking_80_security_changes>>
 
 //NOTE: The notable-breaking-changes tagged regions are re-used in the
 //Installation and Upgrade Guide
@@ -41,3 +42,4 @@ include::migrate_8_0/analysis.asciidoc[]
 include::migrate_8_0/discovery.asciidoc[]
 include::migrate_8_0/mappings.asciidoc[]
 include::migrate_8_0/snapshots.asciidoc[]
+include::migrate_8_0/security.asciidoc[]

docs/reference/migration/migrate_8_0/security.asciidoc

@@ -0,0 +1,18 @@
+[float]
+[[breaking_80_security_changes]]
+=== Security changes
+
+[float]
+==== The `accept_default_password` setting has been removed
+
+The `xpack.security.authc.accept_default_password` setting has not had any affect
+since the 6.0 release of {es}. It has been removed and cannot be used.
+
+[float]
+==== The `roles.index.cache.*` settings have been removed
+
+The `xpack.security.authz.store.roles.index.cache.max_size` and
+`xpack.security.authz.store.roles.index.cache.ttl` settings have
+been removed. These settings have been redundant and deprecated
+since the 5.2 release of {es}.
+

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

@@ -618,7 +618,6 @@ public static List<Setting<?>> getSettings(boolean transportClientMode, List<Sec
         // authentication and authorization settings
         AnonymousUser.addSettings(settingsList);
         settingsList.addAll(InternalRealmsSettings.getSettings());
-        NativeRolesStore.addSettings(settingsList);
         ReservedRealm.addSettings(settingsList);
         AuthenticationService.addSettings(settingsList);
         AuthorizationService.addSettings(settingsList);

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/esnative/ReservedRealm.java

@@ -17,7 +17,6 @@
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.xpack.core.XPackSettings;
-import org.elasticsearch.xpack.core.security.SecurityField;
 import org.elasticsearch.xpack.core.security.authc.AuthenticationResult;
 import org.elasticsearch.xpack.core.security.authc.RealmConfig;
 import org.elasticsearch.xpack.core.security.authc.esnative.ClientReservedRealm;
@@ -51,9 +50,6 @@ public class ReservedRealm extends CachingUsernamePasswordRealm {
     public static final String TYPE = "reserved";
 
     private final ReservedUserInfo bootstrapUserInfo;
-    public static final Setting<Boolean> ACCEPT_DEFAULT_PASSWORD_SETTING = Setting.boolSetting(
-            SecurityField.setting("authc.accept_default_password"), true, Setting.Property.NodeScope, Setting.Property.Filtered,
-            Setting.Property.Deprecated);
     public static final Setting<SecureString> BOOTSTRAP_ELASTIC_PASSWORD = SecureSetting.secureString("bootstrap.password",
             KeyStoreWrapper.SEED_SETTING);
 
@@ -250,7 +246,6 @@ private Version getDefinedVersion(String username) {
     }
 
     public static void addSettings(List<Setting<?>> settingsList) {
-        settingsList.add(ACCEPT_DEFAULT_PASSWORD_SETTING);
         settingsList.add(BOOTSTRAP_ELASTIC_PASSWORD);
     }
 }

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

@@ -26,10 +26,7 @@
 import org.elasticsearch.client.Client;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.bytes.BytesReference;
-import org.elasticsearch.common.settings.Setting;
-import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -69,7 +66,6 @@
 import static org.elasticsearch.xpack.core.ClientHelper.SECURITY_ORIGIN;
 import static org.elasticsearch.xpack.core.ClientHelper.executeAsyncWithOrigin;
 import static org.elasticsearch.xpack.core.ClientHelper.stashWithOrigin;
-import static org.elasticsearch.xpack.core.security.SecurityField.setting;
 import static org.elasticsearch.xpack.core.security.authz.RoleDescriptor.ROLE_TYPE;
 import static org.elasticsearch.xpack.security.support.SecurityIndexManager.SECURITY_INDEX_NAME;
 
@@ -83,11 +79,6 @@
  */
 public class NativeRolesStore implements BiConsumer<Set<String>, ActionListener<RoleRetrievalResult>> {
 
-    // these are no longer used, but leave them around for users upgrading
-    private static final Setting<Integer> CACHE_SIZE_SETTING =
-            Setting.intSetting(setting("authz.store.roles.index.cache.max_size"), 10000, Property.NodeScope, Property.Deprecated);
-    private static final Setting<TimeValue> CACHE_TTL_SETTING = Setting.timeSetting(setting("authz.store.roles.index.cache.ttl"),
-            TimeValue.timeValueMinutes(20), Property.NodeScope, Property.Deprecated);
     private static final Logger logger = LogManager.getLogger(NativeRolesStore.class);
 
     private final Settings settings;
@@ -413,11 +404,6 @@ static RoleDescriptor transformRole(String id, BytesReference sourceBytes, Logge
         }
     }
 
-    public static void addSettings(List<Setting<?>> settings) {
-        settings.add(CACHE_SIZE_SETTING);
-        settings.add(CACHE_TTL_SETTING);
-    }
-
     /**
      * Gets the document's id field for the given role name.
      */