KNOX-3317: Fixed NPE when no token-metadata-headers are declared for ICEBERG-REST

gateway-service-restcatalog/src/main/java/org/apache/knox/gateway/service/restcatalog/TokenMetadataHeaderHandler.java

@@ -88,11 +88,13 @@ private Set<String> getMetadataHeaderConfig(final FilterConfig filterConfig) {
         // Add the default metadata element to be included in the outbound request headers
         metadataForHeaders.add("userName");
 
-        // Parse the configured token metadata elements which should be included as outbound request headers
+        // Parse the configured token metadata elements, if any, which should be included as outbound request headers
         String tokenMetadataHeadersConfig = filterConfig.getInitParameter(TOKEN_METADATA_PARAM);
-        String[] tokenMetadataHeaderNames = tokenMetadataHeadersConfig.split(",");
-        for (String metadataName : tokenMetadataHeaderNames) {
-            metadataForHeaders.add(metadataName.trim());
+        if (tokenMetadataHeadersConfig != null) {
+            String[] tokenMetadataHeaderNames = tokenMetadataHeadersConfig.split(",");
+            for (String metadataName : tokenMetadataHeaderNames) {
+                metadataForHeaders.add(metadataName.trim());
+            }
         }
         return metadataForHeaders;
     }

gateway-service-restcatalog/src/test/java/org/apache/knox/gateway/service/restcatalog/TokenMetadataHeaderHandlerTest.java

@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.knox.gateway.service.restcatalog;
+
+import org.apache.http.client.methods.HttpRequestBase;
+import org.apache.knox.gateway.security.CommonTokenConstants;
+import org.apache.knox.gateway.services.GatewayServices;
+import org.apache.knox.gateway.services.ServiceType;
+import org.apache.knox.gateway.services.security.token.TokenMetadata;
+import org.apache.knox.gateway.services.security.token.TokenStateService;
+import org.easymock.EasyMock;
+import org.eclipse.jetty.http.HttpMethod;
+import org.junit.Test;
+
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import java.util.Base64;
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+public class TokenMetadataHeaderHandlerTest {
+
+    @Test
+    public void testNullTokenMetadataHeadersConfig() throws Exception {
+        FilterConfig filterConfig = createFilterConfig(null, null, null, null);
+        // This should not throw NPE
+        TokenMetadataHeaderHandler handler = new TokenMetadataHeaderHandler(filterConfig);
+        assertNotNull(handler);
+    }
+
+    @Test
+    public void testEmptyTokenMetadataHeadersConfig() throws Exception {
+        FilterConfig filterConfig = createFilterConfig("", null, null, null);
+        TokenMetadataHeaderHandler handler = new TokenMetadataHeaderHandler(filterConfig);
+        assertNotNull(handler);
+    }
+
+    @Test
+    public void testApplyHeaders() throws Exception {
+        final String clientId = "test-client-id";
+        Map<String, String> metadataMap = new HashMap<>();
+        metadataMap.put("userName", "test-user");
+        metadataMap.put("custom-meta", "custom-value");
+        metadataMap.put("another-meta", "another-value");
+
+        FilterConfig filterConfig = createFilterConfig("custom-meta, another-meta", null, clientId, metadataMap);
+        TokenMetadataHeaderHandler handler = new TokenMetadataHeaderHandler(filterConfig);
+
+        HttpServletRequest inboundRequest = createInboundRequest(clientId);
+        TestHttpUriRequest outboundRequest = new TestHttpUriRequest();
+        handler.applyHeadersToRequest(inboundRequest, outboundRequest);
+
+        assertEquals("test-user", outboundRequest.getFirstHeader("X-Knox-Meta-userName").getValue());
+        assertEquals("custom-value", outboundRequest.getFirstHeader("X-Knox-Meta-custom-meta").getValue());
+        assertEquals("another-value", outboundRequest.getFirstHeader("X-Knox-Meta-another-meta").getValue());
+    }
+
+    @Test
+    public void testApplyHeadersCustomPrefix() throws Exception {
+        final String clientId = "test-client-id";
+        Map<String, String> metadataMap = new HashMap<>();
+        metadataMap.put("userName", "test-user");
+
+        FilterConfig filterConfig = createFilterConfig(null, "Custom-Prefix-", clientId, metadataMap);
+        TokenMetadataHeaderHandler handler = new TokenMetadataHeaderHandler(filterConfig);
+
+        HttpServletRequest inboundRequest = createInboundRequest(clientId);
+        TestHttpUriRequest outboundRequest = new TestHttpUriRequest();
+        handler.applyHeadersToRequest(inboundRequest, outboundRequest);
+
+        assertEquals("test-user", outboundRequest.getFirstHeader("Custom-Prefix-userName").getValue());
+    }
+
+    @Test
+    public void testApplyHeadersMissingMetadata() throws Exception {
+        final String clientId = "test-client-id";
+        Map<String, String> metadataMap = new HashMap<>(); // Empty metadata
+
+        FilterConfig filterConfig = createFilterConfig("custom-meta", null, clientId, metadataMap);
+        TokenMetadataHeaderHandler handler = new TokenMetadataHeaderHandler(filterConfig);
+
+        HttpServletRequest inboundRequest = createInboundRequest(clientId);
+        TestHttpUriRequest outboundRequest = new TestHttpUriRequest();
+        handler.applyHeadersToRequest(inboundRequest, outboundRequest);
+
+        assertNull("userName header should be null if metadata is missing", outboundRequest.getFirstHeader("X-Knox-Meta-userName"));
+        assertNull("custom-meta header should be null if metadata is missing", outboundRequest.getFirstHeader("X-Knox-Meta-custom-meta"));
+    }
+
+    private FilterConfig createFilterConfig(String tokenMetadataHeaders, String headerPrefix, String clientId, Map<String, String> metadataMap) throws Exception {
+        FilterConfig filterConfig = EasyMock.createNiceMock(FilterConfig.class);
+        ServletContext servletContext = EasyMock.createNiceMock(ServletContext.class);
+        GatewayServices gatewayServices = EasyMock.createNiceMock(GatewayServices.class);
+        TokenStateService tss = EasyMock.createNiceMock(TokenStateService.class);
+
+        EasyMock.expect(filterConfig.getServletContext()).andReturn(servletContext).anyTimes();
+        EasyMock.expect(servletContext.getAttribute(GatewayServices.GATEWAY_SERVICES_ATTRIBUTE)).andReturn(gatewayServices).anyTimes();
+        EasyMock.expect(gatewayServices.getService(ServiceType.TOKEN_STATE_SERVICE)).andReturn(tss).anyTimes();
+        EasyMock.expect(filterConfig.getInitParameter(TokenMetadataHeaderHandler.TOKEN_METADATA_PARAM)).andReturn(tokenMetadataHeaders).anyTimes();
+        EasyMock.expect(filterConfig.getInitParameter(TokenMetadataHeaderHandler.METADATA_HEADER_PREFIX_PARAM)).andReturn(headerPrefix).anyTimes();
+
+        if (clientId != null && metadataMap != null) {
+            TokenMetadata tokenMetadata = EasyMock.createNiceMock(TokenMetadata.class);
+            EasyMock.expect(tss.getTokenMetadata(clientId)).andReturn(tokenMetadata).anyTimes();
+            EasyMock.expect(tokenMetadata.getMetadataMap()).andReturn(metadataMap).anyTimes();
+            EasyMock.replay(tokenMetadata);
+        }
+
+        EasyMock.replay(filterConfig, servletContext, gatewayServices, tss);
+        return filterConfig;
+    }
+
+    private HttpServletRequest createInboundRequest(String clientId) {
+        final String clientSecret = Base64.getEncoder().encodeToString(
+                (Base64.getEncoder().encodeToString(clientId.getBytes(UTF_8)) + "::" +
+                 Base64.getEncoder().encodeToString("secret".getBytes(UTF_8))).getBytes(UTF_8));
+
+        HttpServletRequest inboundRequest = EasyMock.createNiceMock(HttpServletRequest.class);
+        EasyMock.expect(inboundRequest.getParameter(CommonTokenConstants.GRANT_TYPE)).andReturn(CommonTokenConstants.CLIENT_CREDENTIALS).anyTimes();
+        EasyMock.expect(inboundRequest.getParameter(CommonTokenConstants.CLIENT_SECRET)).andReturn(clientSecret).anyTimes();
+        EasyMock.replay(inboundRequest);
+        return inboundRequest;
+    }
+
+    private static class TestHttpUriRequest extends HttpRequestBase {
+        @Override
+        public String getMethod() {
+            return HttpMethod.GET.asString();
+        }
+    }
+}