xds: Implement GcpAuthenticationFilter

xds/BUILD.bazel

@@ -37,6 +37,7 @@ java_library(
         "//:auto_value_annotations",
         "//alts",
         "//api",
+        "//auth",
         "//context",
         "//core:internal",
         "//netty",
@@ -47,6 +48,7 @@ java_library(
         "@com_google_googleapis//google/rpc:rpc_java_proto",
         "@com_google_protobuf//:protobuf_java",
         "@com_google_protobuf//:protobuf_java_util",
+        "@maven//:com_google_auth_google_auth_library_oauth2_http",
         artifact("com.google.code.findbugs:jsr305"),
         artifact("com.google.code.gson:gson"),
         artifact("com.google.errorprone:error_prone_annotations"),
@@ -84,6 +86,7 @@ java_proto_library(
         "@envoy_api//envoy/extensions/clusters/aggregate/v3:pkg",
         "@envoy_api//envoy/extensions/filters/common/fault/v3:pkg",
         "@envoy_api//envoy/extensions/filters/http/fault/v3:pkg",
+        "@envoy_api//envoy/extensions/filters/http/gcp_authn/v3:pkg",
         "@envoy_api//envoy/extensions/filters/http/rbac/v3:pkg",
         "@envoy_api//envoy/extensions/filters/http/router/v3:pkg",
         "@envoy_api//envoy/extensions/filters/network/http_connection_manager/v3:pkg",

xds/src/main/java/io/grpc/xds/GcpAuthenticationFilter.java

@@ -0,0 +1,222 @@
+/*
+ * Copyright 2021 The gRPC Authors
+ *
+ * Licensed 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 io.grpc.xds;
+
+import com.google.auth.oauth2.ComputeEngineCredentials;
+import com.google.auth.oauth2.IdTokenCredentials;
+import com.google.common.primitives.UnsignedLongs;
+import com.google.protobuf.Any;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import io.envoyproxy.envoy.extensions.filters.http.gcp_authn.v3.GcpAuthnFilterConfig;
+import io.envoyproxy.envoy.extensions.filters.http.gcp_authn.v3.TokenCacheConfig;
+import io.grpc.CallCredentials;
+import io.grpc.CallOptions;
+import io.grpc.Channel;
+import io.grpc.ClientCall;
+import io.grpc.ClientInterceptor;
+import io.grpc.CompositeCallCredentials;
+import io.grpc.LoadBalancer.PickSubchannelArgs;
+import io.grpc.Metadata;
+import io.grpc.MethodDescriptor;
+import io.grpc.Status;
+import io.grpc.auth.MoreCallCredentials;
+import io.grpc.xds.Filter.ClientInterceptorBuilder;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.function.Function;
+import javax.annotation.Nullable;
+
+/**
+ * A {@link Filter} that injects a {@link CallCredentials} to handle
+ * authentication for xDS credentials.
+ */
+final class GcpAuthenticationFilter implements Filter, ClientInterceptorBuilder {
+
+  static final String TYPE_URL =
+      "type.googleapis.com/envoy.extensions.filters.http.gcp_authn.v3.GcpAuthnFilterConfig";
+
+  @Override
+  public String[] typeUrls() {
+    return new String[] { TYPE_URL };
+  }
+
+  @Override
+  public ConfigOrError<? extends FilterConfig> parseFilterConfig(Message rawProtoMessage) {
+    GcpAuthnFilterConfig gcpAuthnProto;
+    if (!(rawProtoMessage instanceof Any)) {
+      return ConfigOrError.fromError("Invalid config type: " + rawProtoMessage.getClass());
+    }
+    Any anyMessage = (Any) rawProtoMessage;
+
+    try {
+      gcpAuthnProto = anyMessage.unpack(GcpAuthnFilterConfig.class);
+    } catch (InvalidProtocolBufferException e) {
+      return ConfigOrError.fromError("Invalid proto: " + e);
+    }
+
+    long cacheSize = 10;
+    // Validate cache_config
+    TokenCacheConfig cacheConfig = gcpAuthnProto.getCacheConfig();
+    if (cacheConfig != null) {
+      cacheSize = cacheConfig.getCacheSize().getValue();
+      if (cacheSize == 0) {
+        return ConfigOrError.fromError(
+            "cache_config.cache_size must be greater than zero");
+      }
+      // LruCache's size is an int and briefly exceeds its maximum size before evicting entries
+      cacheSize = UnsignedLongs.min(cacheSize, Integer.MAX_VALUE - 1);
+    }
+
+    GcpAuthenticationConfig config = new GcpAuthenticationConfig((int) cacheSize);
+    return ConfigOrError.fromConfig(config);
+  }
+
+  @Override
+  public ConfigOrError<? extends FilterConfig> parseFilterConfigOverride(Message rawProtoMessage) {
+    return parseFilterConfig(rawProtoMessage);
+  }
+
+  @Nullable
+  @Override
+  public ClientInterceptor buildClientInterceptor(FilterConfig config,
+      @Nullable FilterConfig overrideConfig, PickSubchannelArgs args,
+      ScheduledExecutorService scheduler) {
+
+    ComputeEngineCredentials credentials = ComputeEngineCredentials.create();
+    LruCache<String, CallCredentials> callCredentialsCache =
+        new LruCache<>(((GcpAuthenticationConfig) config).getCacheSize());
+    return new ClientInterceptor() {
+      @Override
+      public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
+          MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) {
+
+        /*String clusterName = callOptions.getOption(InternalXdsAttributes.ATTR_CLUSTER_NAME);
+        if (clusterName == null) {
+          return next.newCall(method, callOptions);
+        }*/
+
+        // TODO: Fetch the CDS resource for the cluster.
+        // If the CDS resource is not available, fail the RPC with Status.UNAVAILABLE.
+
+        // TODO: Extract the audience from the CDS resource metadata.
+        // If the audience is not found or is in the wrong format, fail the RPC.
+        String audience = "TEST_AUDIENCE";
+
+        try {
+          CallCredentials existingCallCredentials = callOptions.getCredentials();
+          CallCredentials newCallCredentials =
+              getCallCredentials(callCredentialsCache, audience, credentials);
+          if (existingCallCredentials != null) {
+            callOptions = callOptions.withCallCredentials(
+                new CompositeCallCredentials(existingCallCredentials, newCallCredentials));
+          } else {
+            callOptions = callOptions.withCallCredentials(newCallCredentials);
+          }
+        }
+        catch (Exception e) {
+          // If we fail to attach CallCredentials due to any reason, return a FailingClientCall
+          return new FailingClientCall<>(Status.UNAUTHENTICATED
+              .withDescription("Failed to attach CallCredentials.")
+              .withCause(e));
+        }
+        return next.newCall(method, callOptions);
+      }
+    };
+  }
+
+  private CallCredentials getCallCredentials(LruCache<String, CallCredentials> cache,
+      String audience, ComputeEngineCredentials credentials) {
+
+    synchronized (cache) {
+      return cache.getOrInsert(audience, key -> {
+        IdTokenCredentials creds = IdTokenCredentials.newBuilder()
+            .setIdTokenProvider(credentials)
+            .setTargetAudience(audience)
+            .build();
+        return MoreCallCredentials.from(creds);
+      });
+    }
+  }
+
+  static final class GcpAuthenticationConfig implements FilterConfig {
+
+    private final int cacheSize;
+
+    public GcpAuthenticationConfig(int cacheSize) {
+      this.cacheSize = cacheSize;
+    }
+
+    public int getCacheSize() {
+      return cacheSize;
+    }
+
+    @Override
+    public String typeUrl() {
+      return GcpAuthenticationFilter.TYPE_URL;
+    }
+  }
+
+  /** An implementation of {@link ClientCall} that fails when started. */
+  private static final class FailingClientCall<ReqT, RespT> extends ClientCall<ReqT, RespT> {
+
+    private final Status error;
+
+    public FailingClientCall(Status error) {
+      this.error = error;
+    }
+
+    @Override
+    public void start(ClientCall.Listener<RespT> listener, Metadata headers) {
+      listener.onClose(error, new Metadata());
+    }
+
+    @Override
+    public void request(int numMessages) {}
+
+    @Override
+    public void cancel(String message, Throwable cause) {}
+
+    @Override
+    public void halfClose() {}
+
+    @Override
+    public void sendMessage(ReqT message) {}
+  }
+
+  private static final class LruCache<K, V> {
+
+    private final Map<K, V> cache;
+
+    LruCache(int maxSize) {
+      this.cache = new LinkedHashMap<K, V>(
+          maxSize,
+          0.75f,
+          true) {
+        @Override
+        protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
+          return size() > maxSize;
+        }
+      };
+    }
+
+    V getOrInsert(K key, Function<K, V> create) {
+      return cache.computeIfAbsent(key, create);
+    }
+  }
+}

xds/src/test/java/io/grpc/xds/GcpAuthenticationFilterTest.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed 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 io.grpc.xds;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.eq;
+
+import com.google.protobuf.Any;
+import com.google.protobuf.Empty;
+import com.google.protobuf.Message;
+import com.google.protobuf.UInt64Value;
+import io.envoyproxy.envoy.extensions.filters.http.gcp_authn.v3.GcpAuthnFilterConfig;
+import io.envoyproxy.envoy.extensions.filters.http.gcp_authn.v3.TokenCacheConfig;
+import io.grpc.CallOptions;
+import io.grpc.Channel;
+import io.grpc.ClientInterceptor;
+import io.grpc.MethodDescriptor;
+import io.grpc.testing.TestMethodDescriptors;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mockito;
+
+@RunWith(JUnit4.class)
+public class GcpAuthenticationFilterTest {
+
+  @Test
+  public void testParseFilterConfig_withValidConfig() {
+    GcpAuthnFilterConfig config = GcpAuthnFilterConfig.newBuilder()
+        .setCacheConfig(TokenCacheConfig.newBuilder().setCacheSize(UInt64Value.of(20)))
+        .build();
+    Any anyMessage = Any.pack(config);
+
+    GcpAuthenticationFilter filter = new GcpAuthenticationFilter();
+    ConfigOrError<? extends Filter.FilterConfig> result = filter.parseFilterConfig(anyMessage);
+
+    assertNotNull(result.config);
+    assertNull(result.errorDetail);
+    assertEquals(20L,
+        ((GcpAuthenticationFilter.GcpAuthenticationConfig) result.config).getCacheSize());
+  }
+
+  @Test
+  public void testParseFilterConfig_withZeroCacheSize() {
+    GcpAuthnFilterConfig config = GcpAuthnFilterConfig.newBuilder()
+        .setCacheConfig(TokenCacheConfig.newBuilder().setCacheSize(UInt64Value.of(0)))
+        .build();
+    Any anyMessage = Any.pack(config);
+
+    GcpAuthenticationFilter filter = new GcpAuthenticationFilter();
+    ConfigOrError<? extends Filter.FilterConfig> result = filter.parseFilterConfig(anyMessage);
+
+    assertNull(result.config);
+    assertNotNull(result.errorDetail);
+    assertTrue(result.errorDetail.contains("cache_config.cache_size must be greater than zero"));
+  }
+
+  @Test
+  public void testParseFilterConfig_withInvalidMessageType() {
+    GcpAuthenticationFilter filter = new GcpAuthenticationFilter();
+    Message invalidMessage = Empty.getDefaultInstance();
+    ConfigOrError<? extends Filter.FilterConfig> result = filter.parseFilterConfig(invalidMessage);
+
+    assertNull(result.config);
+    assertThat(result.errorDetail).contains("Invalid config type");
+  }
+
+  @Test
+  public void testClientInterceptor_createsAndReusesCachedCredentials() {
+    GcpAuthenticationFilter.GcpAuthenticationConfig config =
+        new GcpAuthenticationFilter.GcpAuthenticationConfig(10);
+    GcpAuthenticationFilter filter = new GcpAuthenticationFilter();
+
+    // Create interceptor
+    ClientInterceptor interceptor = filter.buildClientInterceptor(config, null, null, null);
+    MethodDescriptor<Void, Void> methodDescriptor = TestMethodDescriptors.voidMethod();
+
+    // Mock channel and capture CallOptions
+    Channel mockChannel = Mockito.mock(Channel.class);
+    ArgumentCaptor<CallOptions> callOptionsCaptor = ArgumentCaptor.forClass(CallOptions.class);
+
+    // Execute interception twice to check caching
+    interceptor.interceptCall(methodDescriptor, CallOptions.DEFAULT, mockChannel);
+    interceptor.interceptCall(methodDescriptor, CallOptions.DEFAULT, mockChannel);
+
+    // Capture and verify CallOptions for CallCredentials presence
+    Mockito.verify(mockChannel, Mockito.times(2))
+        .newCall(eq(methodDescriptor), callOptionsCaptor.capture());
+
+    // Retrieve the CallOptions captured from both calls
+    CallOptions firstCapturedOptions = callOptionsCaptor.getAllValues().get(0);
+    CallOptions secondCapturedOptions = callOptionsCaptor.getAllValues().get(1);
+
+    // Ensure that CallCredentials was added
+    assertNotNull(firstCapturedOptions.getCredentials());
+    assertNotNull(secondCapturedOptions.getCredentials());
+
+    // Ensure that the CallCredentials from both calls are the same, indicating caching
+    assertSame(firstCapturedOptions.getCredentials(), secondCapturedOptions.getCredentials());
+  }
+}

xds/third_party/envoy/import.sh

@@ -75,6 +75,7 @@ envoy/extensions/clusters/aggregate/v3/cluster.proto
 envoy/extensions/filters/common/fault/v3/fault.proto
 envoy/extensions/filters/http/fault/v3/fault.proto
 envoy/extensions/filters/http/rate_limit_quota/v3/rate_limit_quota.proto
+envoy/extensions/filters/http/gcp_authn/v3/gcp_authn.proto
 envoy/extensions/filters/http/rbac/v3/rbac.proto
 envoy/extensions/filters/http/router/v3/router.proto
 envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto