Use EpochSecondSerializer for UserRemoteConfigList.serverEpochTime

service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java

@@ -822,7 +822,8 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
             config.getRemoteConfigConfiguration().requiredHostedDomain(),
             config.getRemoteConfigConfiguration().audiences(),
             new GoogleIdTokenVerifier.Builder(new ApacheHttpTransport(), new GsonFactory()),
-            config.getRemoteConfigConfiguration().globalConfig()),
+            config.getRemoteConfigConfiguration().globalConfig(),
+            clock),
         new SecureStorageController(storageCredentialsGenerator),
         new SecureValueRecovery2Controller(svr2CredentialsGenerator, accountsManager),
         new StickerController(rateLimiters, config.getCdnConfiguration().accessKey().value(),

service/src/main/java/org/whispersystems/textsecuregcm/controllers/RemoteConfigController.java

@@ -61,11 +61,14 @@ public class RemoteConfigController {
 
   private final GoogleIdTokenVerifier googleIdTokenVerifier;
 
+  private final Clock clock;
+
   private static final String GLOBAL_CONFIG_PREFIX = "global.";
 
   public RemoteConfigController(RemoteConfigsManager remoteConfigsManager, AdminEventLogger adminEventLogger,
       Set<String> configAuthUsers, String requiredHostedDomain, List<String> audience,
-      final GoogleIdTokenVerifier.Builder googleIdTokenVerifierBuilder, Map<String, String> globalConfig) {
+      final GoogleIdTokenVerifier.Builder googleIdTokenVerifierBuilder, Map<String, String> globalConfig,
+      final Clock clock) {
     this.remoteConfigsManager = remoteConfigsManager;
     this.adminEventLogger = Objects.requireNonNull(adminEventLogger);
     this.configAuthUsers = configAuthUsers;
@@ -73,6 +76,8 @@ public class RemoteConfigController {
 
     this.requiredHostedDomain = requiredHostedDomain;
     this.googleIdTokenVerifier = googleIdTokenVerifierBuilder.setAudience(audience).build();
+
+    this.clock = clock;
   }
 
   @GET
@@ -90,7 +95,7 @@ public class RemoteConfigController {
             config.getUuids());
         return new UserRemoteConfig(config.getName(), inBucket,
             inBucket ? config.getValue() : config.getDefaultValue());
-      }), globalConfigStream).collect(Collectors.toList()), Clock.systemUTC().instant());
+      }), globalConfigStream).collect(Collectors.toList()), clock.instant());
     } catch (NoSuchAlgorithmException e) {
       throw new AssertionError(e);
     }

service/src/main/java/org/whispersystems/textsecuregcm/entities/UserRemoteConfigList.java

@@ -7,10 +7,10 @@ package org.whispersystems.textsecuregcm.entities;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.annotation.JsonProperty;
-
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import java.time.Instant;
-import java.time.temporal.ChronoUnit;
 import java.util.List;
+import org.whispersystems.textsecuregcm.util.InstantAdapter;
 
 public class UserRemoteConfigList {
 
@@ -18,6 +18,7 @@ public class UserRemoteConfigList {
   private List<UserRemoteConfig> config;
 
   @JsonProperty
+  @JsonSerialize(using = InstantAdapter.EpochSecondSerializer.class)
   @JsonFormat(shape = JsonFormat.Shape.NUMBER_INT)
   private Instant serverEpochTime;
 
@@ -25,7 +26,7 @@ public class UserRemoteConfigList {
 
   public UserRemoteConfigList(List<UserRemoteConfig> config, Instant serverEpochTime) {
     this.config = config;
-    this.serverEpochTime = serverEpochTime != null ? serverEpochTime.truncatedTo(ChronoUnit.SECONDS) : null;
+    this.serverEpochTime = serverEpochTime;
   }
 
   public List<UserRemoteConfig> getConfig() {

service/src/main/java/org/whispersystems/textsecuregcm/util/InstantAdapter.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.util;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import java.io.IOException;
+import java.time.Instant;
+
+public class InstantAdapter {
+
+  public static class EpochSecondSerializer extends JsonSerializer<Instant> {
+
+    @Override
+    public void serialize(final Instant value, final JsonGenerator gen, final SerializerProvider serializers)
+        throws IOException {
+
+      gen.writeNumber(value.getEpochSecond());
+    }
+  }
+
+}

service/src/test/java/org/whispersystems/textsecuregcm/controllers/RemoteConfigControllerTest.java

@@ -23,6 +23,7 @@ import io.dropwizard.testing.junit5.DropwizardExtensionsSupport;
 import io.dropwizard.testing.junit5.ResourceExtension;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -34,6 +35,8 @@ import java.util.Set;
 import javax.ws.rs.client.Entity;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
+import org.assertj.core.api.Assertions;
+import org.assertj.core.api.InstanceOfAssertFactory;
 import org.glassfish.jersey.test.grizzly.GrizzlyWebTestContainerFactory;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -49,6 +52,7 @@ import org.whispersystems.textsecuregcm.mappers.DeviceLimitExceededExceptionMapp
 import org.whispersystems.textsecuregcm.storage.RemoteConfig;
 import org.whispersystems.textsecuregcm.storage.RemoteConfigsManager;
 import org.whispersystems.textsecuregcm.tests.util.AuthHelper;
+import org.whispersystems.textsecuregcm.util.TestClock;
 
 @ExtendWith(DropwizardExtensionsSupport.class)
 class RemoteConfigControllerTest {
@@ -67,6 +71,10 @@ class RemoteConfigControllerTest {
     when(googleIdVerificationTokenBuilder.build()).thenReturn(googleIdTokenVerifier);
   }
 
+  private static final long PINNED_EPOCH_SECONDS = 1701287216L;
+  private static final TestClock TEST_CLOCK = TestClock.pinned(Instant.ofEpochSecond(PINNED_EPOCH_SECONDS));
+
+
   private static final ResourceExtension resources = ResourceExtension.builder()
       .addProvider(AuthHelper.getAuthFilter())
       .addProvider(new PolymorphicAuthValueFactoryProvider.Binder<>(
@@ -75,7 +83,7 @@ class RemoteConfigControllerTest {
       .addProvider(new DeviceLimitExceededExceptionMapper())
       .addResource(new RemoteConfigController(remoteConfigsManager, new NoOpAdminEventLogger(), remoteConfigsUsers,
           requiredHostedDomain, Collections.singletonList("aud.example.com"),
-          googleIdVerificationTokenBuilder, Map.of("maxGroupSize", "42")))
+          googleIdVerificationTokenBuilder, Map.of("maxGroupSize", "42"), TEST_CLOCK))
       .build();
 
 
@@ -153,6 +161,20 @@ class RemoteConfigControllerTest {
     assertThat(configuration.getConfig().get(10).getName()).isEqualTo("global.maxGroupSize");
   }
 
+  @Test
+  void testServerEpochTime() {
+    Object serverEpochTime = resources.getJerseyTest()
+        .target("/v1/config/")
+        .request()
+        .header("Authorization", AuthHelper.getAuthHeader(AuthHelper.VALID_UUID, AuthHelper.VALID_PASSWORD))
+        .get(Map.class)
+        .get("serverEpochTime");
+
+    assertThat(serverEpochTime).asInstanceOf(new InstanceOfAssertFactory<>(Number.class, Assertions::assertThat))
+        .extracting(Number::longValue)
+        .isEqualTo(PINNED_EPOCH_SECONDS);
+  }
+
   @Test
   void testRetrieveConfigNotSpecial() {
     UserRemoteConfigList configuration = resources.getJerseyTest()