Filter to block old REST API for specified client versions

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

@@ -141,6 +141,7 @@ import org.whispersystems.textsecuregcm.filters.ExternalRequestFilter;
 import org.whispersystems.textsecuregcm.filters.RemoteAddressFilter;
 import org.whispersystems.textsecuregcm.filters.RemoteDeprecationFilter;
 import org.whispersystems.textsecuregcm.filters.RequestStatisticsFilter;
+import org.whispersystems.textsecuregcm.filters.RestDeprecationFilter;
 import org.whispersystems.textsecuregcm.filters.TimestampResponseFilter;
 import org.whispersystems.textsecuregcm.geo.MaxMindDatabaseManager;
 import org.whispersystems.textsecuregcm.grpc.AccountsAnonymousGrpcService;
@@ -1001,7 +1002,12 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
     metricsHttpChannelListener.configure(environment);
     final MessageMetrics messageMetrics = new MessageMetrics();
 
+    // BufferingInterceptor is needed on the base environment but not the WebSocketEnvironment,
+    // because we handle serialization of http responses on the websocket on our own and can
+    // compute content lengths without it
     environment.jersey().register(new BufferingInterceptor());
+    environment.jersey().register(new RestDeprecationFilter(dynamicConfigurationManager, experimentEnrollmentManager));
+
     environment.jersey().register(new VirtualExecutorServiceProvider("managed-async-virtual-thread-"));
     environment.jersey().register(new RateLimitByIpFilter(rateLimiters));
     environment.jersey().register(new RequestStatisticsFilter(TrafficSource.HTTP));

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

@@ -6,6 +6,7 @@
 package org.whispersystems.textsecuregcm.configuration.dynamic;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.vdurmont.semver4j.Semver;
 import jakarta.validation.Valid;
 import java.util.Collections;
 import java.util.HashMap;
@@ -13,6 +14,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import org.whispersystems.textsecuregcm.limits.RateLimiterConfig;
+import org.whispersystems.textsecuregcm.util.ua.ClientPlatform;
 
 public class DynamicConfiguration {
 
@@ -72,6 +74,10 @@ public class DynamicConfiguration {
   @Valid
   List<String> svrStatusCodesToIgnoreForAccountDeletion = Collections.emptyList();
 
+  @JsonProperty
+  @Valid
+  Map<ClientPlatform, Semver> minimumRestFreeVersion = Map.of();
+
   public Optional<DynamicExperimentEnrollmentConfiguration> getExperimentEnrollmentConfiguration(
       final String experimentName) {
     return Optional.ofNullable(experiments.get(experimentName));
@@ -130,4 +136,8 @@ public class DynamicConfiguration {
     return svrStatusCodesToIgnoreForAccountDeletion;
   }
 
+  public Map<ClientPlatform, Semver> minimumRestFreeVersion() {
+    return minimumRestFreeVersion;
+  }
+
 }

service/src/main/java/org/whispersystems/textsecuregcm/filters/RestDeprecationFilter.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.filters;
+
+import com.google.common.net.HttpHeaders;
+import com.vdurmont.semver4j.Semver;
+import io.micrometer.core.instrument.Metrics;
+import io.micrometer.core.instrument.Tags;
+import jakarta.ws.rs.WebApplicationException;
+import jakarta.ws.rs.container.ContainerRequestContext;
+import jakarta.ws.rs.container.ContainerRequestFilter;
+import jakarta.ws.rs.core.SecurityContext;
+import java.io.IOException;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.whispersystems.textsecuregcm.auth.AuthenticatedDevice;
+import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
+import org.whispersystems.textsecuregcm.experiment.ExperimentEnrollmentManager;
+import org.whispersystems.textsecuregcm.metrics.MetricsUtil;
+import org.whispersystems.textsecuregcm.storage.DynamicConfigurationManager;
+import org.whispersystems.textsecuregcm.util.ua.ClientPlatform;
+import org.whispersystems.textsecuregcm.util.ua.UnrecognizedUserAgentException;
+import org.whispersystems.textsecuregcm.util.ua.UserAgent;
+import org.whispersystems.textsecuregcm.util.ua.UserAgentUtil;
+
+public class RestDeprecationFilter implements ContainerRequestFilter {
+
+  private static final String EXPERIMENT_NAME = "restDeprecation";
+  private static final String DEPRECATED_REST_COUNTER_NAME = MetricsUtil.name(RestDeprecationFilter.class, "blockedRestRequest");
+
+  private static final Logger log = LoggerFactory.getLogger(RestDeprecationFilter.class);
+
+  final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager;
+  final ExperimentEnrollmentManager experimentEnrollmentManager;
+
+  public RestDeprecationFilter(
+      final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager,
+      final ExperimentEnrollmentManager experimentEnrollmentManager) {
+    this.dynamicConfigurationManager = dynamicConfigurationManager;
+    this.experimentEnrollmentManager = experimentEnrollmentManager;
+  }
+
+  @Override
+  public void filter(final ContainerRequestContext requestContext) throws IOException {
+
+    final SecurityContext securityContext = requestContext.getSecurityContext();
+
+    if (securityContext == null || securityContext.getUserPrincipal() == null) {
+      // We can't check if an unauthenticated request is in the experiment
+      return;
+    }
+
+    if (securityContext.getUserPrincipal() instanceof AuthenticatedDevice ad) {
+      if (!experimentEnrollmentManager.isEnrolled(ad.getAccount().getUuid(), EXPERIMENT_NAME)) {
+        return;
+      }
+    } else {
+      log.error("Security context was not null but user principal was of type {}", securityContext.getUserPrincipal().getClass().getName());
+      return;
+    }
+
+    final Map<ClientPlatform, Semver> minimumRestFreeVersion = dynamicConfigurationManager.getConfiguration().minimumRestFreeVersion();
+    final String userAgentString = requestContext.getHeaderString(HttpHeaders.USER_AGENT);
+
+    try {
+      final UserAgent userAgent = UserAgentUtil.parseUserAgentString(userAgentString);
+      final ClientPlatform platform = userAgent.getPlatform();
+      final Semver version = userAgent.getVersion();
+      if (!minimumRestFreeVersion.containsKey(platform)) {
+        return;
+      }
+      if (version.isGreaterThanOrEqualTo(minimumRestFreeVersion.get(platform))) {
+        Metrics.counter(
+            DEPRECATED_REST_COUNTER_NAME, Tags.of("platform", platform.name().toLowerCase(), "version", version.toString()))
+            .increment();
+        throw new WebApplicationException("use websockets", 498);
+      }
+    } catch (final UnrecognizedUserAgentException e) {
+      return;                   // at present we're only interested in experimenting on known clients
+    }
+  }
+}