Pass carrier data from lookup services to registration service

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

@@ -1118,7 +1118,7 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
             config.getCdnConfiguration().bucket()),
         new VerificationController(registrationServiceClient, new VerificationSessionManager(verificationSessions),
             pushNotificationManager, registrationCaptchaManager, registrationRecoveryPasswordsManager,
-            phoneNumberIdentifiers, rateLimiters, accountsManager, registrationFraudChecker,
+            phoneNumberIdentifiers, rateLimiters, accountsManager, carrierDataProvider, registrationFraudChecker,
             dynamicConfigurationManager, clock)
     );
     if (config.getSubscription() != null && config.getOneTimeDonations() != null) {

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicCarrierDataLookupConfiguration.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.configuration.dynamic;
+
+import jakarta.validation.constraints.NotNull;
+import java.time.Duration;
+
+public record DynamicCarrierDataLookupConfiguration(boolean enabled, @NotNull Duration maxCacheAge) {
+
+  public static Duration DEFAULT_MAX_CACHE_AGE = Duration.ofDays(7);
+
+  public DynamicCarrierDataLookupConfiguration() {
+    this(false, DEFAULT_MAX_CACHE_AGE);
+  }
+
+  public DynamicCarrierDataLookupConfiguration {
+    if (maxCacheAge == null) {
+      maxCacheAge = DEFAULT_MAX_CACHE_AGE;
+    }
+  }
+}

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicConfiguration.java

@@ -68,6 +68,10 @@ public class DynamicConfiguration {
   @Valid
   private DynamicBackupConfiguration backup = new DynamicBackupConfiguration();
 
+  @JsonProperty
+  @Valid
+  private DynamicCarrierDataLookupConfiguration carrierDataLookup = new DynamicCarrierDataLookupConfiguration();
+
   public Optional<DynamicExperimentEnrollmentConfiguration> getExperimentEnrollmentConfiguration(
       final String experimentName) {
     return Optional.ofNullable(experiments.get(experimentName));
@@ -121,4 +125,8 @@ public class DynamicConfiguration {
   public DynamicBackupConfiguration getBackupConfiguration() {
     return backup;
   }
+
+  public DynamicCarrierDataLookupConfiguration getCarrierDataLookupConfiguration() {
+    return carrierDataLookup;
+  }
 }

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

@@ -94,6 +94,9 @@ import org.whispersystems.textsecuregcm.storage.DynamicConfigurationManager;
 import org.whispersystems.textsecuregcm.storage.PhoneNumberIdentifiers;
 import org.whispersystems.textsecuregcm.storage.RegistrationRecoveryPasswordsManager;
 import org.whispersystems.textsecuregcm.storage.VerificationSessionManager;
+import org.whispersystems.textsecuregcm.telephony.CarrierData;
+import org.whispersystems.textsecuregcm.telephony.CarrierDataException;
+import org.whispersystems.textsecuregcm.telephony.CarrierDataProvider;
 import org.whispersystems.textsecuregcm.util.ExceptionUtils;
 import org.whispersystems.textsecuregcm.util.ObsoletePhoneNumberFormatException;
 import org.whispersystems.textsecuregcm.util.Pair;
@@ -129,6 +132,7 @@ public class VerificationController {
   private final PhoneNumberIdentifiers phoneNumberIdentifiers;
   private final RateLimiters rateLimiters;
   private final AccountsManager accountsManager;
+  private final CarrierDataProvider carrierDataProvider;
   private final RegistrationFraudChecker registrationFraudChecker;
   private final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager;
   private final Clock clock;
@@ -141,6 +145,7 @@ public class VerificationController {
       final PhoneNumberIdentifiers phoneNumberIdentifiers,
       final RateLimiters rateLimiters,
       final AccountsManager accountsManager,
+      final CarrierDataProvider carrierDataProvider,
       final RegistrationFraudChecker registrationFraudChecker,
       final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager,
       final Clock clock) {
@@ -152,6 +157,7 @@ public class VerificationController {
     this.phoneNumberIdentifiers = phoneNumberIdentifiers;
     this.rateLimiters = rateLimiters;
     this.accountsManager = accountsManager;
+    this.carrierDataProvider = carrierDataProvider;
     this.registrationFraudChecker = registrationFraudChecker;
     this.dynamicConfigurationManager = dynamicConfigurationManager;
     this.clock = clock;
@@ -187,14 +193,29 @@ public class VerificationController {
       throw new ServerErrorException("could not parse already validated number", Response.Status.INTERNAL_SERVER_ERROR);
     }
 
+    Optional<CarrierData> maybeCarrierData;
+
+    if (dynamicConfigurationManager.getConfiguration().getCarrierDataLookupConfiguration().enabled()) {
+      try {
+        maybeCarrierData = carrierDataProvider.lookupCarrierData(phoneNumber,
+            dynamicConfigurationManager.getConfiguration().getCarrierDataLookupConfiguration().maxCacheAge());
+      } catch (final IOException | CarrierDataException e) {
+        logger.warn("Failed to retrieve carrier data", e);
+        maybeCarrierData = Optional.empty();
+      }
+    } else {
+      maybeCarrierData = Optional.empty();
+    }
+
     final RegistrationServiceSession registrationServiceSession;
     try {
       final String sourceHost = (String) requestContext.getProperty(RemoteAddressFilter.REMOTE_ADDRESS_ATTRIBUTE_NAME);
 
-      registrationServiceSession = registrationServiceClient.createRegistrationSession(phoneNumber, sourceHost,
+      registrationServiceSession = registrationServiceClient.createRegistrationSession(phoneNumber,
+          sourceHost,
           accountsManager.getByE164(request.number()).isPresent(),
-          request.updateVerificationSessionRequest().mcc(),
-          request.updateVerificationSessionRequest().mnc(),
+          maybeCarrierData.flatMap(CarrierData::mcc).orElse(null),
+          maybeCarrierData.flatMap(CarrierData::mnc).orElse(null),
           REGISTRATION_RPC_TIMEOUT).join();
     } catch (final CancellationException e) {
 

service/src/main/proto/RegistrationService.proto

@@ -47,12 +47,12 @@ message CreateRegistrationSessionRequest {
   string rate_limit_collation_key = 3;
 
   /**
-   * The MCC for the given `e164` as reported by the client.
+   * The MCC for the given `e164` as reported by a number lookup service.
    */
   string mcc = 4;
 
   /**
-   * The MNC for the given `e164` as reported by the client.
+   * The MNC for the given `e164` as reported by a number lookup service.
    */
   string mnc = 5;
 }

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

@@ -58,6 +58,7 @@ import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.ArgumentCaptor;
 import org.whispersystems.textsecuregcm.captcha.AssessmentResult;
 import org.whispersystems.textsecuregcm.captcha.RegistrationCaptchaManager;
+import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicCarrierDataLookupConfiguration;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicRegistrationConfiguration;
 import org.whispersystems.textsecuregcm.entities.RegistrationServiceSession;
@@ -83,6 +84,7 @@ import org.whispersystems.textsecuregcm.storage.DynamicConfigurationManager;
 import org.whispersystems.textsecuregcm.storage.PhoneNumberIdentifiers;
 import org.whispersystems.textsecuregcm.storage.RegistrationRecoveryPasswordsManager;
 import org.whispersystems.textsecuregcm.storage.VerificationSessionManager;
+import org.whispersystems.textsecuregcm.telephony.CarrierDataProvider;
 import org.whispersystems.textsecuregcm.util.SystemMapper;
 import org.whispersystems.textsecuregcm.util.TestRemoteAddressFilterProvider;
 
@@ -106,6 +108,7 @@ class VerificationControllerTest {
   private final PhoneNumberIdentifiers phoneNumberIdentifiers = mock(PhoneNumberIdentifiers.class);
   private final RateLimiters rateLimiters = mock(RateLimiters.class);
   private final AccountsManager accountsManager = mock(AccountsManager.class);
+  private final CarrierDataProvider carrierDataProvider = mock(CarrierDataProvider.class);
   private final Clock clock = Clock.systemUTC();
 
   private final RateLimiter captchaLimiter = mock(RateLimiter.class);
@@ -127,7 +130,7 @@ class VerificationControllerTest {
       .addResource(
           new VerificationController(registrationServiceClient, verificationSessionManager, pushNotificationManager,
               registrationCaptchaManager, registrationRecoveryPasswordsManager, phoneNumberIdentifiers, rateLimiters, accountsManager,
-              RegistrationFraudChecker.noop(), dynamicConfigurationManager, clock))
+              carrierDataProvider, RegistrationFraudChecker.noop(), dynamicConfigurationManager, clock))
       .build();
 
   @BeforeEach
@@ -140,6 +143,8 @@ class VerificationControllerTest {
         .thenReturn(Optional.empty());
     when(dynamicConfiguration.getRegistrationConfiguration())
         .thenReturn(new DynamicRegistrationConfiguration(false));
+    when(dynamicConfiguration.getCarrierDataLookupConfiguration())
+        .thenReturn(new DynamicCarrierDataLookupConfiguration());
     when(dynamicConfigurationManager.getConfiguration())
         .thenReturn(dynamicConfiguration);
     when(phoneNumberIdentifiers.getPhoneNumberIdentifier(NUMBER))