[Enhancement] Setup auth token utils for obo

src/main/java/org/opensearch/security/authtoken/jwt/JwtVendor.java

@@ -16,7 +16,6 @@
 import java.util.Optional;
 import java.util.function.LongSupplier;
 
-import com.google.common.base.Strings;
 import org.apache.cxf.jaxrs.json.basic.JsonMapObjectReaderWriter;
 import org.apache.cxf.rs.security.jose.jwk.JsonWebKey;
 import org.apache.cxf.rs.security.jose.jwk.KeyType;
@@ -32,6 +31,8 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.security.ssl.util.ExceptionUtils;
 
+import static org.opensearch.security.util.AuthTokenUtils.isKeyNull;
+
 public class JwtVendor {
     private static final Logger logger = LogManager.getLogger(JwtVendor.class);
 
@@ -53,7 +54,7 @@ public JwtVendor(final Settings settings, final Optional<LongSupplier> timeProvi
             throw ExceptionUtils.createJwkCreationException(e);
         }
         this.jwtProducer = jwtProducer;
-        if (settings.get("encryption_key") == null) {
+        if (isKeyNull(settings, "encryption_key")) {
             throw new IllegalArgumentException("encryption_key cannot be null");
         } else {
             this.claimsEncryptionKey = settings.get("encryption_key");
@@ -73,9 +74,8 @@ public JwtVendor(final Settings settings, final Optional<LongSupplier> timeProvi
      *   Encryption Algorithm: HS512
      * */
     static JsonWebKey createJwkFromSettings(Settings settings) throws Exception {
-        String signingKey = settings.get("signing_key");
-
-        if (!Strings.isNullOrEmpty(signingKey)) {
+        if (!isKeyNull(settings, "signing_key")) {
+            String signingKey = settings.get("signing_key");
 
             JsonWebKey jwk = new JsonWebKey();
 

src/main/java/org/opensearch/security/http/OnBehalfOfAuthenticator.java

@@ -43,13 +43,12 @@
 
 import static org.opensearch.security.OpenSearchSecurityPlugin.LEGACY_OPENDISTRO_PREFIX;
 import static org.opensearch.security.OpenSearchSecurityPlugin.PLUGINS_PREFIX;
+import static org.opensearch.security.util.AuthTokenUtils.isAccessToRestrictedEndpoints;
 
 public class OnBehalfOfAuthenticator implements HTTPAuthenticator {
 
     private static final String REGEX_PATH_PREFIX = "/(" + LEGACY_OPENDISTRO_PREFIX + "|" + PLUGINS_PREFIX + ")/" + "(.*)";
     private static final Pattern PATTERN_PATH_PREFIX = Pattern.compile(REGEX_PATH_PREFIX);
-    private static final String ON_BEHALF_OF_SUFFIX = "api/generateonbehalfoftoken";
-    private static final String ACCOUNT_SUFFIX = "api/account";
 
     protected final Logger log = LogManager.getLogger(this.getClass());
 
@@ -233,8 +232,7 @@ private void logDebug(String message, Object... args) {
     public Boolean isRequestAllowed(final RestRequest request) {
         Matcher matcher = PATTERN_PATH_PREFIX.matcher(request.path());
         final String suffix = matcher.matches() ? matcher.group(2) : null;
-        if (request.method() == RestRequest.Method.POST && ON_BEHALF_OF_SUFFIX.equals(suffix)
-            || request.method() == RestRequest.Method.PUT && ACCOUNT_SUFFIX.equals(suffix)) {
+        if (isAccessToRestrictedEndpoints(request, suffix)) {
             final OpenSearchException exception = ExceptionUtils.invalidUsageOfOBOTokenException();
             log.error(exception.toString());
             return false;

src/main/java/org/opensearch/security/securityconf/DynamicConfigModelV7.java

@@ -67,6 +67,8 @@
 import org.opensearch.security.securityconf.impl.v7.ConfigV7.AuthzDomain;
 import org.opensearch.security.support.ReflectionHelper;
 
+import static org.opensearch.security.util.AuthTokenUtils.*;
+
 public class DynamicConfigModelV7 extends DynamicConfigModel {
 
     private final ConfigV7 config;
@@ -383,7 +385,7 @@ private void buildAAA() {
          * order: -1 - prioritize the OBO authentication when it gets enabled
          */
         Settings oboSettings = getDynamicOnBehalfOfSettings();
-        if (oboSettings.get("signing_key") != null && oboSettings.get("encryption_key") != null) {
+        if (!isKeyNull(oboSettings, "signing_key") && !isKeyNull(oboSettings, "encryption_key")) {
             final AuthDomain _ad = new AuthDomain(
                 new NoOpAuthenticationBackend(Settings.EMPTY, null),
                 new OnBehalfOfAuthenticator(getDynamicOnBehalfOfSettings(), this.cih.getClusterName()),

src/main/java/org/opensearch/security/util/AuthTokenUtils.java

@@ -0,0 +1,41 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.security.util;
+
+import org.opensearch.common.settings.Settings;
+import org.opensearch.rest.RestRequest;
+
+import static org.opensearch.rest.RestRequest.Method.POST;
+import static org.opensearch.rest.RestRequest.Method.PUT;
+
+public class AuthTokenUtils {
+    private static final String ON_BEHALF_OF_SUFFIX = "api/generateonbehalfoftoken";
+    private static final String ACCOUNT_SUFFIX = "api/account";
+
+    public static Boolean isAccessToRestrictedEndpoints(final RestRequest request, final String suffix) {
+        if (suffix == null) {
+            return false;
+        }
+        switch (suffix) {
+            case ON_BEHALF_OF_SUFFIX:
+                return request.method() == POST;
+            case ACCOUNT_SUFFIX:
+                return request.method() == PUT;
+            default:
+                return false;
+        }
+    }
+
+    public static Boolean isKeyNull(Settings settings, String key) {
+        return settings.get(key) == null;
+    }
+}