Clarify guarantees around remote channnel/request attribute presence

service/src/main/java/org/whispersystems/textsecuregcm/auth/grpc/AbstractAuthenticationInterceptor.java

@@ -1,34 +1,22 @@
 package org.whispersystems.textsecuregcm.auth.grpc;
 
-import io.grpc.Grpc;
-import io.grpc.Metadata;
 import io.grpc.ServerCall;
 import io.grpc.ServerInterceptor;
-import io.grpc.Status;
-import io.netty.channel.local.LocalAddress;
-import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
 import java.util.Optional;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
+import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
 
 abstract class AbstractAuthenticationInterceptor implements ServerInterceptor {
 
   private final GrpcClientConnectionManager grpcClientConnectionManager;
 
-  private static final Metadata EMPTY_TRAILERS = new Metadata();
-
   AbstractAuthenticationInterceptor(final GrpcClientConnectionManager grpcClientConnectionManager) {
     this.grpcClientConnectionManager = grpcClientConnectionManager;
   }
 
-  protected Optional<AuthenticatedDevice> getAuthenticatedDevice(final ServerCall<?, ?> call) {
+  protected Optional<AuthenticatedDevice> getAuthenticatedDevice(final ServerCall<?, ?> call)
-    if (call.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR) instanceof LocalAddress localAddress) {
+      throws ChannelNotFoundException {
-      return grpcClientConnectionManager.getAuthenticatedDevice(localAddress);
-    } else {
-      throw new AssertionError("Unexpected channel type: " + call.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR));
-    }
-  }
 
-  protected <ReqT, RespT> ServerCall.Listener<ReqT> closeAsUnauthenticated(final ServerCall<ReqT, RespT> call) {
+    return grpcClientConnectionManager.getAuthenticatedDevice(call);
-    call.close(Status.UNAUTHENTICATED, EMPTY_TRAILERS);
-    return new ServerCall.Listener<>() {};
   }
 }

service/src/main/java/org/whispersystems/textsecuregcm/auth/grpc/ProhibitAuthenticationInterceptor.java

@@ -3,12 +3,17 @@ package org.whispersystems.textsecuregcm.auth.grpc;
 import io.grpc.Metadata;
 import io.grpc.ServerCall;
 import io.grpc.ServerCallHandler;
+import io.grpc.Status;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
+import org.whispersystems.textsecuregcm.grpc.ServerInterceptorUtil;
 import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
 
 /**
  * A "prohibit authentication" interceptor ensures that requests to endpoints that should be invoked anonymously do not
  * originate from a channel that is associated with an authenticated device. Calls with an associated authenticated
- * device are closed with an {@code UNAUTHENTICATED} status.
+ * device are closed with an {@code UNAUTHENTICATED} status. If a call's authentication status cannot be determined
+ * (i.e. because the underlying remote channel closed before the {@code ServerCall} started), the interceptor will
+ * reject the call with a status of {@code UNAVAILABLE}.
  */
 public class ProhibitAuthenticationInterceptor extends AbstractAuthenticationInterceptor {
 
@@ -21,8 +26,15 @@ public class ProhibitAuthenticationInterceptor extends AbstractAuthenticationInt
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
 
-    return getAuthenticatedDevice(call)
+    try {
-        .map(ignored -> closeAsUnauthenticated(call))
+      return getAuthenticatedDevice(call)
-        .orElseGet(() -> next.startCall(call, headers));
+          // Status.INTERNAL may seem a little surprising here, but if a caller is reaching an authentication-prohibited
+          // service via an authenticated connection, then that's actually a server configuration issue and not a
+          // problem with the client's request.
+          .map(ignored -> ServerInterceptorUtil.closeWithStatus(call, Status.INTERNAL))
+          .orElseGet(() -> next.startCall(call, headers));
+    } catch (final ChannelNotFoundException e) {
+      return ServerInterceptorUtil.closeWithStatus(call, Status.UNAVAILABLE);
+    }
   }
 }

service/src/main/java/org/whispersystems/textsecuregcm/auth/grpc/RequireAuthenticationInterceptor.java

@@ -5,12 +5,16 @@ import io.grpc.Contexts;
 import io.grpc.Metadata;
 import io.grpc.ServerCall;
 import io.grpc.ServerCallHandler;
+import io.grpc.Status;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
+import org.whispersystems.textsecuregcm.grpc.ServerInterceptorUtil;
 import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
 
 /**
  * A "require authentication" interceptor requires that requests be issued from a connection that is associated with an
  * authenticated device. Calls without an associated authenticated device are closed with an {@code UNAUTHENTICATED}
- * status.
+ * status. If a call's authentication status cannot be determined (i.e. because the underlying remote channel closed
+ * before the {@code ServerCall} started), the interceptor will reject the call with a status of {@code UNAVAILABLE}.
  */
 public class RequireAuthenticationInterceptor extends AbstractAuthenticationInterceptor {
 
@@ -23,10 +27,17 @@ public class RequireAuthenticationInterceptor extends AbstractAuthenticationInte
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
 
-    return getAuthenticatedDevice(call)
+    try {
-        .map(authenticatedDevice -> Contexts.interceptCall(Context.current()
+      return getAuthenticatedDevice(call)
-                .withValue(AuthenticationUtil.CONTEXT_AUTHENTICATED_DEVICE, authenticatedDevice),
+          .map(authenticatedDevice -> Contexts.interceptCall(Context.current()
-            call, headers, next))
+                  .withValue(AuthenticationUtil.CONTEXT_AUTHENTICATED_DEVICE, authenticatedDevice),
-        .orElseGet(() -> closeAsUnauthenticated(call));
+              call, headers, next))
+          // Status.INTERNAL may seem a little surprising here, but if a caller is reaching an authentication-required
+          // service via an unauthenticated connection, then that's actually a server configuration issue and not a
+          // problem with the client's request.
+          .orElseGet(() -> ServerInterceptorUtil.closeWithStatus(call, Status.INTERNAL));
+    } catch (final ChannelNotFoundException e) {
+      return ServerInterceptorUtil.closeWithStatus(call, Status.UNAVAILABLE);
+    }
   }
 }

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

@@ -81,7 +81,16 @@ public class RemoteDeprecationFilter implements Filter, ServerInterceptor {
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
 
-    if (shouldBlock(RequestAttributesUtil.getUserAgent().orElse(null))) {
+    @Nullable final UserAgent userAgent = RequestAttributesUtil.getUserAgent()
+        .map(userAgentString -> {
+          try {
+            return UserAgentUtil.parseUserAgentString(userAgentString);
+          } catch (final UnrecognizedUserAgentException e) {
+            return null;
+          }
+        }).orElse(null);
+
+    if (shouldBlock(userAgent)) {
       call.close(StatusConstants.UPGRADE_NEEDED_STATUS, new Metadata());
       return new ServerCall.Listener<>() {};
     } else {

service/src/main/java/org/whispersystems/textsecuregcm/grpc/ChannelNotFoundException.java

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.grpc;
+
+/**
+ * Indicates that a remote channel was not found for a given server call or remote address.
+ */
+public class ChannelNotFoundException extends Exception {
+}

service/src/main/java/org/whispersystems/textsecuregcm/grpc/MessagesAnonymousGrpcService.java

@@ -253,7 +253,7 @@ public class MessagesAnonymousGrpcService extends SimpleMessagesAnonymousGrpc.Me
           story,
           ephemeral,
           urgent,
-          RequestAttributesUtil.getRawUserAgent().orElse(null));
+          RequestAttributesUtil.getUserAgent().orElse(null));
 
       final SendMultiRecipientMessageResponse.Builder responseBuilder = SendMultiRecipientMessageResponse.newBuilder();
 

service/src/main/java/org/whispersystems/textsecuregcm/grpc/MessagesGrpcHelper.java

@@ -55,7 +55,7 @@ public class MessagesGrpcHelper {
           messagesByDeviceId,
           registrationIdsByDeviceId,
           syncMessageSenderDeviceId,
-          RequestAttributesUtil.getRawUserAgent().orElse(null));
+          RequestAttributesUtil.getUserAgent().orElse(null));
 
       return SEND_MESSAGE_SUCCESS_RESPONSE;
     } catch (final MismatchedDevicesException e) {

service/src/main/java/org/whispersystems/textsecuregcm/grpc/RequestAttributes.java

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.grpc;
+
+import java.net.InetAddress;
+import java.util.List;
+import java.util.Locale;
+import javax.annotation.Nullable;
+
+public record RequestAttributes(InetAddress remoteAddress,
+                                @Nullable String userAgent,
+                                List<Locale.LanguageRange> acceptLanguage) {
+}

service/src/main/java/org/whispersystems/textsecuregcm/grpc/RequestAttributesInterceptor.java

@@ -2,28 +2,25 @@ package org.whispersystems.textsecuregcm.grpc;
 
 import io.grpc.Context;
 import io.grpc.Contexts;
-import io.grpc.Grpc;
 import io.grpc.Metadata;
 import io.grpc.ServerCall;
 import io.grpc.ServerCallHandler;
 import io.grpc.ServerInterceptor;
 import io.grpc.Status;
-import io.netty.channel.local.LocalAddress;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
-import org.whispersystems.textsecuregcm.util.ua.UserAgent;
-import java.net.InetAddress;
-import java.util.List;
-import java.util.Locale;
-import java.util.Optional;
 
+/**
+ * The request attributes interceptor makes request attributes from the underlying remote channel available to service
+ * implementations by attaching them to a {@link Context} attribute that can be read via {@link RequestAttributesUtil}.
+ * All server calls should have request attributes, and calls will be rejected with a status of {@code UNAVAILABLE} if
+ * request attributes are unavailable (i.e. the underlying channel closed before the {@code ServerCall} started).
+ *
+ * @see RequestAttributesUtil
+ */
 public class RequestAttributesInterceptor implements ServerInterceptor {
 
   private final GrpcClientConnectionManager grpcClientConnectionManager;
 
-  private static final Logger log = LoggerFactory.getLogger(RequestAttributesInterceptor.class);
-
   public RequestAttributesInterceptor(final GrpcClientConnectionManager grpcClientConnectionManager) {
     this.grpcClientConnectionManager = grpcClientConnectionManager;
   }
@@ -33,52 +30,12 @@ public class RequestAttributesInterceptor implements ServerInterceptor {
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
 
-    if (call.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR) instanceof LocalAddress localAddress) {
+    try {
-      Context context = Context.current();
+      return Contexts.interceptCall(Context.current()
-
+              .withValue(RequestAttributesUtil.REQUEST_ATTRIBUTES_CONTEXT_KEY,
-      {
+                  grpcClientConnectionManager.getRequestAttributes(call)), call, headers, next);
-        final Optional<InetAddress> maybeRemoteAddress = grpcClientConnectionManager.getRemoteAddress(localAddress);
+    } catch (final ChannelNotFoundException e) {
-
+      return ServerInterceptorUtil.closeWithStatus(call, Status.UNAVAILABLE);
-        if (maybeRemoteAddress.isEmpty()) {
-          // We should never have a call from a party whose remote address we can't identify
-          log.warn("No remote address available");
-
-          call.close(Status.INTERNAL, new Metadata());
-          return new ServerCall.Listener<>() {};
-        }
-
-        context = context.withValue(RequestAttributesUtil.REMOTE_ADDRESS_CONTEXT_KEY, maybeRemoteAddress.get());
-      }
-
-      {
-        final Optional<List<Locale.LanguageRange>> maybeAcceptLanguage =
-            grpcClientConnectionManager.getAcceptableLanguages(localAddress);
-
-        if (maybeAcceptLanguage.isPresent()) {
-          context = context.withValue(RequestAttributesUtil.ACCEPT_LANGUAGE_CONTEXT_KEY, maybeAcceptLanguage.get());
-        }
-      }
-
-      {
-        final Optional<String> maybeRawUserAgent =
-            grpcClientConnectionManager.getRawUserAgent(localAddress);
-
-        if (maybeRawUserAgent.isPresent()) {
-          context = context.withValue(RequestAttributesUtil.RAW_USER_AGENT_CONTEXT_KEY, maybeRawUserAgent.get());
-        }
-      }
-
-      {
-        final Optional<UserAgent> maybeUserAgent = grpcClientConnectionManager.getUserAgent(localAddress);
-
-        if (maybeUserAgent.isPresent()) {
-          context = context.withValue(RequestAttributesUtil.USER_AGENT_CONTEXT_KEY, maybeUserAgent.get());
-        }
-      }
-
-      return Contexts.interceptCall(context, call, headers, next);
-    } else {
-      throw new AssertionError("Unexpected channel type: " + call.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR));
     }
   }
 }

service/src/main/java/org/whispersystems/textsecuregcm/grpc/RequestAttributesUtil.java

@@ -3,18 +3,13 @@ package org.whispersystems.textsecuregcm.grpc;
 import io.grpc.Context;
 import java.net.InetAddress;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
-import org.whispersystems.textsecuregcm.util.ua.UserAgent;
 
 public class RequestAttributesUtil {
 
-  static final Context.Key<List<Locale.LanguageRange>> ACCEPT_LANGUAGE_CONTEXT_KEY = Context.key("accept-language");
+  static final Context.Key<RequestAttributes> REQUEST_ATTRIBUTES_CONTEXT_KEY = Context.key("request-attributes");
-  static final Context.Key<InetAddress> REMOTE_ADDRESS_CONTEXT_KEY = Context.key("remote-address");
-  static final Context.Key<String> RAW_USER_AGENT_CONTEXT_KEY = Context.key("unparsed-user-agent");
-  static final Context.Key<UserAgent> USER_AGENT_CONTEXT_KEY = Context.key("parsed-user-agent");
 
   private static final List<Locale> AVAILABLE_LOCALES = Arrays.asList(Locale.getAvailableLocales());
 
@@ -23,8 +18,8 @@ public class RequestAttributesUtil {
    *
    * @return the acceptable languages listed by the remote client; may be empty if unparseable or not specified
    */
-  public static Optional<List<Locale.LanguageRange>> getAcceptableLanguages() {
+  public static List<Locale.LanguageRange> getAcceptableLanguages() {
-    return Optional.ofNullable(ACCEPT_LANGUAGE_CONTEXT_KEY.get());
+    return REQUEST_ATTRIBUTES_CONTEXT_KEY.get().acceptLanguage();
   }
 
   /**
@@ -35,9 +30,7 @@ public class RequestAttributesUtil {
    * @return a list of distinct locales acceptable to the remote client and available in this JVM
    */
   public static List<Locale> getAvailableAcceptedLocales() {
-    return getAcceptableLanguages()
+    return Locale.filter(getAcceptableLanguages(), AVAILABLE_LOCALES);
-        .map(languageRanges -> Locale.filter(languageRanges, AVAILABLE_LOCALES))
-        .orElseGet(Collections::emptyList);
   }
 
   /**
@@ -46,16 +39,7 @@ public class RequestAttributesUtil {
    * @return the remote address of the remote client
    */
   public static InetAddress getRemoteAddress() {
-    return REMOTE_ADDRESS_CONTEXT_KEY.get();
+    return REQUEST_ATTRIBUTES_CONTEXT_KEY.get().remoteAddress();
-  }
-
-  /**
-   * Returns the parsed user-agent of the remote client in the current gRPC request context.
-   *
-   * @return the parsed user-agent of the remote client; may be empty if unparseable or not specified
-   */
-  public static Optional<UserAgent> getUserAgent() {
-    return Optional.ofNullable(USER_AGENT_CONTEXT_KEY.get());
   }
 
   /**
@@ -63,7 +47,7 @@ public class RequestAttributesUtil {
    *
    * @return the unparsed user-agent of the remote client; may be empty if not specified
    */
-  public static Optional<String> getRawUserAgent() {
+  public static Optional<String> getUserAgent() {
-    return Optional.ofNullable(RAW_USER_AGENT_CONTEXT_KEY.get());
+    return Optional.ofNullable(REQUEST_ATTRIBUTES_CONTEXT_KEY.get().userAgent());
   }
 }

service/src/main/java/org/whispersystems/textsecuregcm/grpc/ServerInterceptorUtil.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.grpc;
+
+import io.grpc.Metadata;
+import io.grpc.ServerCall;
+import io.grpc.Status;
+
+public class ServerInterceptorUtil {
+
+  @SuppressWarnings("rawtypes")
+  private static final ServerCall.Listener NO_OP_LISTENER = new ServerCall.Listener<>() {};
+
+  private static final Metadata EMPTY_TRAILERS = new Metadata();
+
+  private ServerInterceptorUtil() {
+  }
+
+  /**
+   * Closes the given server call with the given status, returning a no-op listener.
+   *
+   * @param call the server call to close
+   * @param status the status with which to close the call
+   *
+   * @return a no-op server call listener
+   *
+   * @param <ReqT> the type of request object handled by the server call
+   * @param <RespT> the type of response object returned by the server call
+   */
+  public static <ReqT, RespT> ServerCall.Listener<ReqT> closeWithStatus(final ServerCall<ReqT, RespT> call, final Status status) {
+    call.close(status, EMPTY_TRAILERS);
+
+    //noinspection unchecked
+    return NO_OP_LISTENER;
+  }
+}

service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/EstablishLocalGrpcConnectionHandler.java

@@ -12,8 +12,10 @@ import io.netty.handler.codec.http.websocketx.WebSocketCloseStatus;
 import io.netty.util.ReferenceCountUtil;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
 
 /**
  * An "establish local connection" handler waits for a Noise handshake to complete upstream in the pipeline, buffering
@@ -48,12 +50,12 @@ class EstablishLocalGrpcConnectionHandler extends ChannelInboundHandlerAdapter {
 
   @Override
   public void userEventTriggered(final ChannelHandlerContext remoteChannelContext, final Object event) {
-    if (event instanceof NoiseIdentityDeterminedEvent noiseIdentityDeterminedEvent) {
+    if (event instanceof NoiseIdentityDeterminedEvent(final Optional<AuthenticatedDevice> authenticatedDevice)) {
       // We assume that we'll only get a completed handshake event if the handshake met all authentication requirements
       // for the requested service. If the handshake doesn't have an authenticated device, we assume we're trying to
       // connect to the anonymous service. If it does have an authenticated device, we assume we're aiming for the
       // authenticated service.
-      final LocalAddress grpcServerAddress = noiseIdentityDeterminedEvent.authenticatedDevice().isPresent()
+      final LocalAddress grpcServerAddress = authenticatedDevice.isPresent()
           ? authenticatedGrpcServerAddress
           : anonymousGrpcServerAddress;
 
@@ -72,7 +74,7 @@ class EstablishLocalGrpcConnectionHandler extends ChannelInboundHandlerAdapter {
             if (localChannelFuture.isSuccess()) {
               grpcClientConnectionManager.handleConnectionEstablished((LocalChannel) localChannelFuture.channel(),
                   remoteChannelContext.channel(),
-                  noiseIdentityDeterminedEvent.authenticatedDevice());
+                  authenticatedDevice);
 
               // Close the local connection if the remote channel closes and vice versa
               remoteChannelContext.channel().closeFuture().addListener(closeFuture -> localChannelFuture.channel().close());

service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/GrpcClientConnectionManager.java

@@ -1,6 +1,8 @@
 package org.whispersystems.textsecuregcm.grpc.net;
 
 import com.google.common.annotations.VisibleForTesting;
+import io.grpc.Grpc;
+import io.grpc.ServerCall;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.local.LocalAddress;
@@ -23,15 +25,25 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.auth.DisconnectionRequestListener;
 import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
-import org.whispersystems.textsecuregcm.util.ua.UnrecognizedUserAgentException;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
-import org.whispersystems.textsecuregcm.util.ua.UserAgent;
+import org.whispersystems.textsecuregcm.grpc.RequestAttributes;
-import org.whispersystems.textsecuregcm.util.ua.UserAgentUtil;
 
 /**
  * A client connection manager associates a local connection to a local gRPC server with a remote connection through a
- * Noise-over-WebSocket tunnel. It provides access to metadata associated with the remote connection, including the
+ * Noise tunnel. It provides access to metadata associated with the remote connection, including the authenticated
- * authenticated identity of the device that opened the connection (for non-anonymous connections). It can also close
+ * identity of the device that opened the connection (for non-anonymous connections). It can also close connections
- * connections associated with a given device if that device's credentials have changed and clients must reauthenticate.
+ * associated with a given device if that device's credentials have changed and clients must reauthenticate.
+ * <p>
+ * In general, all {@link ServerCall}s <em>must</em> have a local address that in turn <em>should</em> be resolvable to
+ * a remote channel, which <em>must</em> have associated request attributes and authentication status. It is possible
+ * that a server call's local address may not be resolvable to a remote channel if the remote channel closed in the
+ * narrow window between a server call being created and the start of call execution, in which case accessor methods
+ * in this class will throw a {@link ChannelNotFoundException}.
+ * <p>
+ * A gRPC client connection manager's methods for getting request attributes accept {@link ServerCall} entities to
+ * identify connections. In general, these methods should only be called from {@link io.grpc.ServerInterceptor}s.
+ * Methods for requesting connection closure accept an {@link AuthenticatedDevice} to identify the connection and may
+ * be called from any application code.
  */
 public class GrpcClientConnectionManager implements DisconnectionRequestListener {
 
@@ -43,94 +55,56 @@ public class GrpcClientConnectionManager implements DisconnectionRequestListener
       AttributeKey.valueOf(GrpcClientConnectionManager.class, "authenticatedDevice");
 
   @VisibleForTesting
-  static final AttributeKey<InetAddress> REMOTE_ADDRESS_ATTRIBUTE_KEY =
+  public static final AttributeKey<RequestAttributes> REQUEST_ATTRIBUTES_KEY =
-      AttributeKey.valueOf(WebsocketHandshakeCompleteHandler.class, "remoteAddress");
+      AttributeKey.valueOf(GrpcClientConnectionManager.class, "requestAttributes");
-
-  @VisibleForTesting
-  static final AttributeKey<String> RAW_USER_AGENT_ATTRIBUTE_KEY =
-      AttributeKey.valueOf(WebsocketHandshakeCompleteHandler.class, "rawUserAgent");
-
-  @VisibleForTesting
-  static final AttributeKey<UserAgent> PARSED_USER_AGENT_ATTRIBUTE_KEY =
-      AttributeKey.valueOf(WebsocketHandshakeCompleteHandler.class, "userAgent");
-
-  @VisibleForTesting
-  static final AttributeKey<List<Locale.LanguageRange>> ACCEPT_LANGUAGE_ATTRIBUTE_KEY =
-      AttributeKey.valueOf(WebsocketHandshakeCompleteHandler.class, "acceptLanguage");
 
   private static final Logger log = LoggerFactory.getLogger(GrpcClientConnectionManager.class);
 
   /**
-   * Returns the authenticated device associated with the given local address, if any. An authenticated device is
+   * Returns the authenticated device associated with the given server call, if any. If the connection is anonymous
-   * available if and only if the given local address maps to an active local connection and that connection is
+   * (i.e. unauthenticated), the returned value will be empty.
-   * authenticated (i.e. not anonymous).
    *
-   * @param localAddress the local address for which to find an authenticated device
+   * @param serverCall the gRPC server call for which to find an authenticated device
    *
    * @return the authenticated device associated with the given local address, if any
+   *
+   * @throws ChannelNotFoundException if the server call is not associated with a known channel; in practice, this
+   * generally indicates that the channel has closed while request processing is still in progress
    */
-  public Optional<AuthenticatedDevice> getAuthenticatedDevice(final LocalAddress localAddress) {
+  public Optional<AuthenticatedDevice> getAuthenticatedDevice(final ServerCall<?, ?> serverCall)
-    return getAuthenticatedDevice(remoteChannelsByLocalAddress.get(localAddress));
+      throws ChannelNotFoundException {
+
+    return getAuthenticatedDevice(getRemoteChannel(serverCall));
   }
 
-  private Optional<AuthenticatedDevice> getAuthenticatedDevice(@Nullable final Channel remoteChannel) {
+  @VisibleForTesting
-    return Optional.ofNullable(remoteChannel)
+  Optional<AuthenticatedDevice> getAuthenticatedDevice(final Channel remoteChannel) {
-        .map(channel -> channel.attr(AUTHENTICATED_DEVICE_ATTRIBUTE_KEY).get());
+    return Optional.ofNullable(remoteChannel.attr(AUTHENTICATED_DEVICE_ATTRIBUTE_KEY).get());
   }
 
   /**
-   * Returns the parsed acceptable languages associated with the given local address, if any. Acceptable languages may
+   * Returns the request attributes associated with the given server call.
-   * be unavailable if the local connection associated with the given local address has already closed, if the client
-   * did not provide a list of acceptable languages, or the list provided by the client could not be parsed.
    *
-   * @param localAddress the local address for which to find acceptable languages
+   * @param serverCall the gRPC server call for which to retrieve request attributes
    *
-   * @return the acceptable languages associated with the given local address, if any
+   * @return the request attributes associated with the given server call
+   *
+   * @throws ChannelNotFoundException if the server call is not associated with a known channel; in practice, this
+   * generally indicates that the channel has closed while request processing is still in progress
    */
-  public Optional<List<Locale.LanguageRange>> getAcceptableLanguages(final LocalAddress localAddress) {
+  public RequestAttributes getRequestAttributes(final ServerCall<?, ?> serverCall) throws ChannelNotFoundException {
-    return Optional.ofNullable(remoteChannelsByLocalAddress.get(localAddress))
+    return getRequestAttributes(getRemoteChannel(serverCall));
-        .map(remoteChannel -> remoteChannel.attr(ACCEPT_LANGUAGE_ATTRIBUTE_KEY).get());
   }
 
-  /**
+  @VisibleForTesting
-   * Returns the remote address associated with the given local address, if any. A remote address may be unavailable if
+  RequestAttributes getRequestAttributes(final Channel remoteChannel) {
-   * the local connection associated with the given local address has already closed.
+    final RequestAttributes requestAttributes = remoteChannel.attr(REQUEST_ATTRIBUTES_KEY).get();
-   *
-   * @param localAddress the local address for which to find a remote address
-   *
-   * @return the remote address associated with the given local address, if any
-   */
-  public Optional<InetAddress> getRemoteAddress(final LocalAddress localAddress) {
-    return Optional.ofNullable(remoteChannelsByLocalAddress.get(localAddress))
-        .map(remoteChannel -> remoteChannel.attr(REMOTE_ADDRESS_ATTRIBUTE_KEY).get());
-  }
 
-  /**
+    if (requestAttributes == null) {
-   * Returns the unparsed user agent provided by the client that opened the connection associated with the given local
+      throw new IllegalStateException("Channel does not have request attributes");
-   * address. This method may return an empty value if no active local connection is associated with the given local
+    }
-   * address.
-   *
-   * @param localAddress the local address for which to find a User-Agent string
-   *
-   * @return the user agent string associated with the given local address
-   */
-  public Optional<String> getRawUserAgent(final LocalAddress localAddress) {
-    return Optional.ofNullable(remoteChannelsByLocalAddress.get(localAddress))
-        .map(remoteChannel -> remoteChannel.attr(RAW_USER_AGENT_ATTRIBUTE_KEY).get());
-  }
 
-  /**
+    return requestAttributes;
-   * Returns the parsed user agent provided by the client that opened the connection associated with the given local
-   * address. This method may return an empty value if no active local connection is associated with the given local
-   * address or if the client's user-agent string was not recognized.
-   *
-   * @param localAddress the local address for which to find a User-Agent string
-   *
-   * @return the user agent associated with the given local address
-   */
-  public Optional<UserAgent> getUserAgent(final LocalAddress localAddress) {
-    return Optional.ofNullable(remoteChannelsByLocalAddress.get(localAddress))
-        .map(remoteChannel -> remoteChannel.attr(PARSED_USER_AGENT_ATTRIBUTE_KEY).get());
   }
 
   /**
@@ -156,11 +130,32 @@ public class GrpcClientConnectionManager implements DisconnectionRequestListener
     return remoteChannelsByAuthenticatedDevice.get(authenticatedDevice);
   }
 
+  private Channel getRemoteChannel(final ServerCall<?, ?> serverCall) throws ChannelNotFoundException {
+    return getRemoteChannel(getLocalAddress(serverCall));
+  }
+
   @VisibleForTesting
-  Channel getRemoteChannelByLocalAddress(final LocalAddress localAddress) {
+  Channel getRemoteChannel(final LocalAddress localAddress) throws ChannelNotFoundException {
+    final Channel remoteChannel = remoteChannelsByLocalAddress.get(localAddress);
+
+    if (remoteChannel == null) {
+      throw new ChannelNotFoundException();
+    }
+
     return remoteChannelsByLocalAddress.get(localAddress);
   }
 
+  private static LocalAddress getLocalAddress(final ServerCall<?, ?> serverCall) {
+    // In this server, gRPC's "remote" channel is actually a local channel that proxies to a distinct Noise channel.
+    // The gRPC "remote" address is the "local address" for the proxy connection, and the local address uniquely maps to
+    // a proxied Noise channel.
+    if (!(serverCall.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR) instanceof LocalAddress localAddress)) {
+      throw new IllegalArgumentException("Unexpected channel type: " + serverCall.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR));
+    }
+
+    return localAddress;
+  }
+
   /**
    * Handles successful completion of a WebSocket handshake and associates attributes and headers from the handshake
    * request with the channel via which the handshake took place.
@@ -171,30 +166,23 @@ public class GrpcClientConnectionManager implements DisconnectionRequestListener
    * @param acceptLanguageHeader the value of the Accept-Language header provided in the handshake request; may be
    * {@code null}
    */
-  static void handleWebSocketHandshakeComplete(final Channel channel,
+  static void handleHandshakeComplete(final Channel channel,
       final InetAddress preferredRemoteAddress,
       @Nullable final String userAgentHeader,
       @Nullable final String acceptLanguageHeader) {
 
-    channel.attr(GrpcClientConnectionManager.REMOTE_ADDRESS_ATTRIBUTE_KEY).set(preferredRemoteAddress);
+    @Nullable List<Locale.LanguageRange> acceptLanguages = Collections.emptyList();
-
-    if (StringUtils.isNotBlank(userAgentHeader)) {
-      channel.attr(GrpcClientConnectionManager.RAW_USER_AGENT_ATTRIBUTE_KEY).set(userAgentHeader);
-
-      try {
-        channel.attr(GrpcClientConnectionManager.PARSED_USER_AGENT_ATTRIBUTE_KEY)
-            .set(UserAgentUtil.parseUserAgentString(userAgentHeader));
-      } catch (final UnrecognizedUserAgentException ignored) {
-      }
-    }
 
     if (StringUtils.isNotBlank(acceptLanguageHeader)) {
       try {
-        channel.attr(GrpcClientConnectionManager.ACCEPT_LANGUAGE_ATTRIBUTE_KEY).set(Locale.LanguageRange.parse(acceptLanguageHeader));
+        acceptLanguages = Locale.LanguageRange.parse(acceptLanguageHeader);
       } catch (final IllegalArgumentException e) {
         log.debug("Invalid Accept-Language header from User-Agent {}: {}", userAgentHeader, acceptLanguageHeader, e);
       }
     }
+
+    channel.attr(REQUEST_ATTRIBUTES_KEY)
+        .set(new RequestAttributes(preferredRemoteAddress, userAgentHeader, acceptLanguages));
   }
 
   /**

service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/WebsocketHandshakeCompleteHandler.java

@@ -74,7 +74,7 @@ class WebsocketHandshakeCompleteHandler extends ChannelInboundHandlerAdapter {
         preferredRemoteAddress = maybePreferredRemoteAddress.get();
       }
 
-      GrpcClientConnectionManager.handleWebSocketHandshakeComplete(context.channel(),
+      GrpcClientConnectionManager.handleHandshakeComplete(context.channel(),
           preferredRemoteAddress,
           handshakeCompleteEvent.requestHeaders().getAsString(HttpHeaderNames.USER_AGENT),
           handshakeCompleteEvent.requestHeaders().getAsString(HttpHeaderNames.ACCEPT_LANGUAGE));

service/src/test/java/org/whispersystems/textsecuregcm/auth/grpc/ProhibitAuthenticationInterceptorTest.java

@@ -3,6 +3,7 @@ package org.whispersystems.textsecuregcm.auth.grpc;
 import io.grpc.Status;
 import org.junit.jupiter.api.Test;
 import org.signal.chat.rpc.GetAuthenticatedDeviceResponse;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
 import org.whispersystems.textsecuregcm.grpc.GrpcTestUtils;
 import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
 import org.whispersystems.textsecuregcm.storage.Device;
@@ -22,7 +23,7 @@ class ProhibitAuthenticationInterceptorTest extends AbstractAuthenticationInterc
   }
 
   @Test
-  void interceptCall() {
+  void interceptCall() throws ChannelNotFoundException {
     final GrpcClientConnectionManager grpcClientConnectionManager = getClientConnectionManager();
 
     when(grpcClientConnectionManager.getAuthenticatedDevice(any())).thenReturn(Optional.empty());
@@ -34,6 +35,10 @@ class ProhibitAuthenticationInterceptorTest extends AbstractAuthenticationInterc
     final AuthenticatedDevice authenticatedDevice = new AuthenticatedDevice(UUID.randomUUID(), Device.PRIMARY_ID);
     when(grpcClientConnectionManager.getAuthenticatedDevice(any())).thenReturn(Optional.of(authenticatedDevice));
 
-    GrpcTestUtils.assertStatusException(Status.UNAUTHENTICATED, this::getAuthenticatedDevice);
+    GrpcTestUtils.assertStatusException(Status.INTERNAL, this::getAuthenticatedDevice);
+
+    when(grpcClientConnectionManager.getAuthenticatedDevice(any())).thenThrow(ChannelNotFoundException.class);
+
+    GrpcTestUtils.assertStatusException(Status.UNAVAILABLE, this::getAuthenticatedDevice);
   }
 }

service/src/test/java/org/whispersystems/textsecuregcm/auth/grpc/RequireAuthenticationInterceptorTest.java

@@ -9,6 +9,7 @@ import java.util.Optional;
 import java.util.UUID;
 import org.junit.jupiter.api.Test;
 import org.signal.chat.rpc.GetAuthenticatedDeviceResponse;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
 import org.whispersystems.textsecuregcm.grpc.GrpcTestUtils;
 import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
 import org.whispersystems.textsecuregcm.storage.Device;
@@ -22,12 +23,12 @@ class RequireAuthenticationInterceptorTest extends AbstractAuthenticationInterce
   }
 
   @Test
-  void interceptCall() {
+  void interceptCall() throws ChannelNotFoundException {
     final GrpcClientConnectionManager grpcClientConnectionManager = getClientConnectionManager();
 
     when(grpcClientConnectionManager.getAuthenticatedDevice(any())).thenReturn(Optional.empty());
 
-    GrpcTestUtils.assertStatusException(Status.UNAUTHENTICATED, this::getAuthenticatedDevice);
+    GrpcTestUtils.assertStatusException(Status.INTERNAL, this::getAuthenticatedDevice);
 
     final AuthenticatedDevice authenticatedDevice = new AuthenticatedDevice(UUID.randomUUID(), Device.PRIMARY_ID);
     when(grpcClientConnectionManager.getAuthenticatedDevice(any())).thenReturn(Optional.of(authenticatedDevice));
@@ -35,5 +36,9 @@ class RequireAuthenticationInterceptorTest extends AbstractAuthenticationInterce
     final GetAuthenticatedDeviceResponse response = getAuthenticatedDevice();
     assertEquals(UUIDUtil.toByteString(authenticatedDevice.accountIdentifier()), response.getAccountIdentifier());
     assertEquals(authenticatedDevice.deviceId(), response.getDeviceId());
+
+    when(grpcClientConnectionManager.getAuthenticatedDevice(any())).thenThrow(ChannelNotFoundException.class);
+
+    GrpcTestUtils.assertStatusException(Status.UNAVAILABLE, this::getAuthenticatedDevice);
   }
 }

service/src/test/java/org/whispersystems/textsecuregcm/filters/ExternalRequestFilterTest.java

@@ -7,6 +7,7 @@ package org.whispersystems.textsecuregcm.filters;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import com.google.common.net.InetAddresses;
 import com.google.protobuf.ByteString;
 import io.dropwizard.core.Application;
 import io.dropwizard.core.Configuration;
@@ -24,7 +25,6 @@ import jakarta.ws.rs.GET;
 import jakarta.ws.rs.Path;
 import jakarta.ws.rs.client.Client;
 import jakarta.ws.rs.core.Response;
-import java.net.InetAddress;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.Set;
@@ -39,6 +39,7 @@ import org.signal.chat.rpc.EchoServiceGrpc;
 import org.whispersystems.textsecuregcm.grpc.EchoServiceImpl;
 import org.whispersystems.textsecuregcm.grpc.GrpcTestUtils;
 import org.whispersystems.textsecuregcm.grpc.MockRequestAttributesInterceptor;
+import org.whispersystems.textsecuregcm.grpc.RequestAttributes;
 import org.whispersystems.textsecuregcm.util.InetAddressRange;
 
 @ExtendWith(DropwizardExtensionsSupport.class)
@@ -157,7 +158,7 @@ class ExternalRequestFilterTest {
       @BeforeEach
       void setUp() throws Exception {
         final MockRequestAttributesInterceptor mockRequestAttributesInterceptor = new MockRequestAttributesInterceptor();
-        mockRequestAttributesInterceptor.setRemoteAddress(InetAddress.getByName("127.0.0.1"));
+        mockRequestAttributesInterceptor.setRequestAttributes(new RequestAttributes(InetAddresses.forString("127.0.0.1"), null, null));
 
         testServer = InProcessServerBuilder.forName("ExternalRequestFilterTest")
             .directExecutor()

service/src/test/java/org/whispersystems/textsecuregcm/filters/RemoteDeprecationFilterTest.java

@@ -15,6 +15,7 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.google.common.net.HttpHeaders;
+import com.google.common.net.InetAddresses;
 import com.google.protobuf.ByteString;
 import com.vdurmont.semver4j.Semver;
 import io.grpc.ManagedChannel;
@@ -40,11 +41,10 @@ import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfigurati
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicRemoteDeprecationConfiguration;
 import org.whispersystems.textsecuregcm.grpc.EchoServiceImpl;
 import org.whispersystems.textsecuregcm.grpc.MockRequestAttributesInterceptor;
+import org.whispersystems.textsecuregcm.grpc.RequestAttributes;
 import org.whispersystems.textsecuregcm.grpc.StatusConstants;
 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.UserAgentUtil;
 
 class RemoteDeprecationFilterTest {
 
@@ -130,11 +130,7 @@ class RemoteDeprecationFilterTest {
   @MethodSource(value="testFilter")
   void testGrpcFilter(final String userAgentString, final boolean expectDeprecation) throws IOException, InterruptedException {
     final MockRequestAttributesInterceptor mockRequestAttributesInterceptor = new MockRequestAttributesInterceptor();
-
+    mockRequestAttributesInterceptor.setRequestAttributes(new RequestAttributes(InetAddresses.forString("127.0.0.1"), userAgentString, null));
-    try {
-      mockRequestAttributesInterceptor.setUserAgent(UserAgentUtil.parseUserAgentString(userAgentString));
-    } catch (UnrecognizedUserAgentException ignored) {
-    }
 
     final Server testServer = InProcessServerBuilder.forName("RemoteDeprecationFilterTest")
         .directExecutor()

service/src/test/java/org/whispersystems/textsecuregcm/grpc/AccountsAnonymousGrpcServiceTest.java

@@ -72,7 +72,8 @@ class AccountsAnonymousGrpcServiceTest extends
 
     when(rateLimiter.validateReactive(anyString())).thenReturn(Mono.empty());
 
-    getMockRequestAttributesInterceptor().setRemoteAddress(InetAddresses.forString("127.0.0.1"));
+    getMockRequestAttributesInterceptor().setRequestAttributes(
+        new RequestAttributes(InetAddresses.forString("127.0.0.1"), null, null));
 
     return new AccountsAnonymousGrpcService(accountsManager, rateLimiters);
   }

service/src/test/java/org/whispersystems/textsecuregcm/grpc/MockRequestAttributesInterceptor.java

@@ -5,6 +5,7 @@
 
 package org.whispersystems.textsecuregcm.grpc;
 
+import com.google.common.net.InetAddresses;
 import io.grpc.Context;
 import io.grpc.Contexts;
 import io.grpc.Metadata;
@@ -19,25 +20,10 @@ import org.whispersystems.textsecuregcm.util.ua.UserAgent;
 
 public class MockRequestAttributesInterceptor implements ServerInterceptor {
 
-  @Nullable
+  private RequestAttributes requestAttributes = new RequestAttributes(InetAddresses.forString("127.0.0.1"), null, null);
-  private InetAddress remoteAddress;
 
-  @Nullable
+  public void setRequestAttributes(final RequestAttributes requestAttributes) {
-  private UserAgent userAgent;
+    this.requestAttributes = requestAttributes;
-
-  @Nullable
-  private List<Locale.LanguageRange> acceptLanguage;
-
-  public void setRemoteAddress(@Nullable final InetAddress remoteAddress) {
-    this.remoteAddress = remoteAddress;
-  }
-
-  public void setUserAgent(@Nullable final UserAgent userAgent) {
-    this.userAgent = userAgent;
-  }
-
-  public void setAcceptLanguage(@Nullable final List<Locale.LanguageRange> acceptLanguage) {
-    this.acceptLanguage = acceptLanguage;
   }
 
   @Override
@@ -45,20 +31,7 @@ public class MockRequestAttributesInterceptor implements ServerInterceptor {
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
 
-    Context context = Context.current();
+    return Contexts.interceptCall(Context.current()
-
+        .withValue(RequestAttributesUtil.REQUEST_ATTRIBUTES_CONTEXT_KEY, requestAttributes), serverCall, headers, next);
-    if (remoteAddress != null) {
-      context = context.withValue(RequestAttributesUtil.REMOTE_ADDRESS_CONTEXT_KEY, remoteAddress);
-    }
-
-    if (userAgent != null) {
-      context = context.withValue(RequestAttributesUtil.USER_AGENT_CONTEXT_KEY, userAgent);
-    }
-
-    if (acceptLanguage != null) {
-      context = context.withValue(RequestAttributesUtil.ACCEPT_LANGUAGE_CONTEXT_KEY, acceptLanguage);
-    }
-
-    return Contexts.interceptCall(context, serverCall, headers, next);
   }
 }

service/src/test/java/org/whispersystems/textsecuregcm/grpc/ProfileAnonymousGrpcServiceTest.java

@@ -15,6 +15,7 @@ import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 import static org.whispersystems.textsecuregcm.grpc.GrpcTestUtils.assertStatusException;
 
+import com.google.common.net.InetAddresses;
 import com.google.protobuf.ByteString;
 import io.grpc.Status;
 import java.nio.charset.StandardCharsets;
@@ -75,8 +76,6 @@ import org.whispersystems.textsecuregcm.tests.util.AuthHelper;
 import org.whispersystems.textsecuregcm.tests.util.ProfileTestHelper;
 import org.whispersystems.textsecuregcm.util.TestRandomUtil;
 import org.whispersystems.textsecuregcm.util.UUIDUtil;
-import org.whispersystems.textsecuregcm.util.ua.UnrecognizedUserAgentException;
-import org.whispersystems.textsecuregcm.util.ua.UserAgentUtil;
 
 public class ProfileAnonymousGrpcServiceTest extends SimpleBaseGrpcTest<ProfileAnonymousGrpcService, ProfileAnonymousGrpc.ProfileAnonymousBlockingStub> {
 
@@ -96,13 +95,9 @@ public class ProfileAnonymousGrpcServiceTest extends SimpleBaseGrpcTest<ProfileA
 
   @Override
   protected ProfileAnonymousGrpcService createServiceBeforeEachTest() {
-    getMockRequestAttributesInterceptor().setAcceptLanguage(Locale.LanguageRange.parse("en-us"));
+    getMockRequestAttributesInterceptor().setRequestAttributes(new RequestAttributes(InetAddresses.forString("127.0.0.1"),
-
+        "Signal-Android/1.2.3",
-    try {
+        Locale.LanguageRange.parse("en-us")));
-      getMockRequestAttributesInterceptor().setUserAgent(UserAgentUtil.parseUserAgentString("Signal-Android/1.2.3"));
-    } catch (final UnrecognizedUserAgentException e) {
-      throw new IllegalArgumentException(e);
-    }
 
     return new ProfileAnonymousGrpcService(
         accountsManager,

service/src/test/java/org/whispersystems/textsecuregcm/grpc/ProfileGrpcServiceTest.java

@@ -24,6 +24,7 @@ import static org.mockito.Mockito.when;
 import static org.whispersystems.textsecuregcm.grpc.GrpcTestUtils.assertRateLimitExceeded;
 import static org.whispersystems.textsecuregcm.grpc.GrpcTestUtils.assertStatusException;
 
+import com.google.common.net.InetAddresses;
 import com.google.i18n.phonenumbers.PhoneNumberUtil;
 import com.google.i18n.phonenumbers.Phonenumber;
 import com.google.protobuf.ByteString;
@@ -108,8 +109,6 @@ import org.whispersystems.textsecuregcm.tests.util.ProfileTestHelper;
 import org.whispersystems.textsecuregcm.util.MockUtils;
 import org.whispersystems.textsecuregcm.util.TestRandomUtil;
 import org.whispersystems.textsecuregcm.util.UUIDUtil;
-import org.whispersystems.textsecuregcm.util.ua.UnrecognizedUserAgentException;
-import org.whispersystems.textsecuregcm.util.ua.UserAgentUtil;
 import reactor.core.publisher.Mono;
 import software.amazon.awssdk.services.s3.S3AsyncClient;
 import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
@@ -177,13 +176,9 @@ public class ProfileGrpcServiceTest extends SimpleBaseGrpcTest<ProfileGrpcServic
         PhoneNumberUtil.getInstance().getExampleNumber("US"),
         PhoneNumberUtil.PhoneNumberFormat.E164);
 
-    getMockRequestAttributesInterceptor().setAcceptLanguage(Locale.LanguageRange.parse("en-us"));
+    getMockRequestAttributesInterceptor().setRequestAttributes(new RequestAttributes(InetAddresses.forString("127.0.0.1"),
-
+        "Signal-Android/1.2.3",
-    try {
+        Locale.LanguageRange.parse("en-us")));
-      getMockRequestAttributesInterceptor().setUserAgent(UserAgentUtil.parseUserAgentString("Signal-Android/1.2.3"));
-    } catch (final UnrecognizedUserAgentException e) {
-      throw new IllegalArgumentException(e);
-    }
 
     when(rateLimiters.getProfileLimiter()).thenReturn(rateLimiter);
     when(rateLimiter.validateReactive(any(UUID.class))).thenReturn(Mono.empty());

service/src/test/java/org/whispersystems/textsecuregcm/grpc/RequestAttributesServiceImpl.java

@@ -1,13 +1,11 @@
 package org.whispersystems.textsecuregcm.grpc;
 
 import io.grpc.stub.StreamObserver;
-import org.apache.commons.lang3.StringUtils;
 import org.signal.chat.rpc.GetAuthenticatedDeviceRequest;
 import org.signal.chat.rpc.GetAuthenticatedDeviceResponse;
 import org.signal.chat.rpc.GetRequestAttributesRequest;
 import org.signal.chat.rpc.GetRequestAttributesResponse;
 import org.signal.chat.rpc.RequestAttributesGrpc;
-import org.signal.chat.rpc.UserAgent;
 import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
 import org.whispersystems.textsecuregcm.auth.grpc.AuthenticationUtil;
 import org.whispersystems.textsecuregcm.util.UUIDUtil;
@@ -20,21 +18,15 @@ public class RequestAttributesServiceImpl extends RequestAttributesGrpc.RequestA
 
     final GetRequestAttributesResponse.Builder responseBuilder = GetRequestAttributesResponse.newBuilder();
 
-    RequestAttributesUtil.getAcceptableLanguages().ifPresent(acceptableLanguages ->
+    RequestAttributesUtil.getAcceptableLanguages()
-        acceptableLanguages.forEach(languageRange -> responseBuilder.addAcceptableLanguages(languageRange.toString())));
+        .forEach(languageRange -> responseBuilder.addAcceptableLanguages(languageRange.toString()));
 
     RequestAttributesUtil.getAvailableAcceptedLocales().forEach(locale ->
         responseBuilder.addAvailableAcceptedLocales(locale.toLanguageTag()));
 
     responseBuilder.setRemoteAddress(RequestAttributesUtil.getRemoteAddress().getHostAddress());
 
-    RequestAttributesUtil.getUserAgent().ifPresent(userAgent -> responseBuilder.setUserAgent(UserAgent.newBuilder()
+    RequestAttributesUtil.getUserAgent().ifPresent(responseBuilder::setUserAgent);
-            .setPlatform(userAgent.platform().toString())
-            .setVersion(userAgent.version().toString())
-            .setAdditionalSpecifiers(StringUtils.stripToEmpty(userAgent.additionalSpecifiers()))
-        .build()));
-
-    RequestAttributesUtil.getRawUserAgent().ifPresent(responseBuilder::setRawUserAgent);
 
     responseObserver.onNext(responseBuilder.build());
     responseObserver.onCompleted();

service/src/test/java/org/whispersystems/textsecuregcm/grpc/RequestAttributesUtilTest.java

@@ -3,172 +3,84 @@ package org.whispersystems.textsecuregcm.grpc;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 import com.google.common.net.InetAddresses;
-import io.grpc.ManagedChannel;
+import io.grpc.Context;
-import io.grpc.Server;
+import java.net.InetAddress;
-import io.grpc.Status;
+import java.util.Collections;
-import io.grpc.netty.NettyChannelBuilder;
-import io.grpc.netty.NettyServerBuilder;
-import io.netty.channel.DefaultEventLoopGroup;
-import io.netty.channel.local.LocalAddress;
-import io.netty.channel.local.LocalChannel;
-import io.netty.channel.local.LocalServerChannel;
-import java.io.IOException;
 import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
-import org.junit.jupiter.api.AfterAll;
+import java.util.concurrent.Callable;
-import org.junit.jupiter.api.AfterEach;
+import javax.annotation.Nullable;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.signal.chat.rpc.GetRequestAttributesRequest;
-import org.signal.chat.rpc.GetRequestAttributesResponse;
-import org.signal.chat.rpc.RequestAttributesGrpc;
-import org.whispersystems.textsecuregcm.grpc.net.GrpcClientConnectionManager;
-import org.whispersystems.textsecuregcm.util.ua.UnrecognizedUserAgentException;
-import org.whispersystems.textsecuregcm.util.ua.UserAgent;
-import org.whispersystems.textsecuregcm.util.ua.UserAgentUtil;
 
 class RequestAttributesUtilTest {
 
-  private static DefaultEventLoopGroup eventLoopGroup;
+  private static final InetAddress REMOTE_ADDRESS = InetAddresses.forString("127.0.0.1");
 
-  private GrpcClientConnectionManager grpcClientConnectionManager;
+  @Test
+  void getAcceptableLanguages() throws Exception {
+    assertEquals(Collections.emptyList(),
+        callWithRequestAttributes(buildRequestAttributes(Collections.emptyList()),
+            RequestAttributesUtil::getAcceptableLanguages));
 
-  private Server server;
+    assertEquals(Locale.LanguageRange.parse("en,ja"),
-  private ManagedChannel managedChannel;
+        callWithRequestAttributes(buildRequestAttributes(Locale.LanguageRange.parse("en,ja")),
-
+            RequestAttributesUtil::getAcceptableLanguages));
-  @BeforeAll
-  static void setUpBeforeAll() {
-    eventLoopGroup = new DefaultEventLoopGroup();
-  }
-
-  @BeforeEach
-  void setUp() throws IOException {
-    final LocalAddress serverAddress = new LocalAddress("test-request-metadata-server");
-
-    grpcClientConnectionManager = mock(GrpcClientConnectionManager.class);
-
-    when(grpcClientConnectionManager.getRemoteAddress(any()))
-        .thenReturn(Optional.of(InetAddresses.forString("127.0.0.1")));
-
-    // `RequestAttributesInterceptor` operates on `LocalAddresses`, so we need to do some slightly fancy plumbing to make
-    // sure that we're using local channels and addresses
-    server = NettyServerBuilder.forAddress(serverAddress)
-        .channelType(LocalServerChannel.class)
-        .bossEventLoopGroup(eventLoopGroup)
-        .workerEventLoopGroup(eventLoopGroup)
-        .intercept(new RequestAttributesInterceptor(grpcClientConnectionManager))
-        .addService(new RequestAttributesServiceImpl())
-        .build()
-        .start();
-
-    managedChannel = NettyChannelBuilder.forAddress(serverAddress)
-        .channelType(LocalChannel.class)
-        .eventLoopGroup(eventLoopGroup)
-        .usePlaintext()
-        .build();
-  }
-
-  @AfterEach
-  void tearDown() {
-    managedChannel.shutdown();
-    server.shutdown();
-  }
-
-  @AfterAll
-  static void tearDownAfterAll() throws InterruptedException {
-    eventLoopGroup.shutdownGracefully().await();
   }
 
   @Test
-  void getAcceptableLanguages() {
+  void getAvailableAcceptedLocales() throws Exception {
-    when(grpcClientConnectionManager.getAcceptableLanguages(any()))
+    assertEquals(Collections.emptyList(),
-        .thenReturn(Optional.empty());
+        callWithRequestAttributes(buildRequestAttributes(Collections.emptyList()),
+            RequestAttributesUtil::getAvailableAcceptedLocales));
 
-    assertTrue(getRequestAttributes().getAcceptableLanguagesList().isEmpty());
+    final List<Locale> availableAcceptedLocales =
+        callWithRequestAttributes(buildRequestAttributes(Locale.LanguageRange.parse("en,ja")),
+            RequestAttributesUtil::getAvailableAcceptedLocales);
 
-    when(grpcClientConnectionManager.getAcceptableLanguages(any()))
+    assertFalse(availableAcceptedLocales.isEmpty());
-        .thenReturn(Optional.of(Locale.LanguageRange.parse("en,ja")));
 
-    assertEquals(List.of("en", "ja"), getRequestAttributes().getAcceptableLanguagesList());
+    availableAcceptedLocales.forEach(locale ->
+        assertTrue("en".equals(locale.getLanguage()) || "ja".equals(locale.getLanguage())));
   }
 
   @Test
-  void getAvailableAcceptedLocales() {
+  void getRemoteAddress() throws Exception {
-    when(grpcClientConnectionManager.getAcceptableLanguages(any()))
+    assertEquals(REMOTE_ADDRESS,
-        .thenReturn(Optional.empty());
+        callWithRequestAttributes(new RequestAttributes(REMOTE_ADDRESS, null, null),
-
+            RequestAttributesUtil::getRemoteAddress));
-    assertTrue(getRequestAttributes().getAvailableAcceptedLocalesList().isEmpty());
-
-    when(grpcClientConnectionManager.getAcceptableLanguages(any()))
-        .thenReturn(Optional.of(Locale.LanguageRange.parse("en,ja")));
-
-    final GetRequestAttributesResponse response = getRequestAttributes();
-
-    assertFalse(response.getAvailableAcceptedLocalesList().isEmpty());
-    response.getAvailableAcceptedLocalesList().forEach(languageTag -> {
-      final Locale locale = Locale.forLanguageTag(languageTag);
-      assertTrue("en".equals(locale.getLanguage()) || "ja".equals(locale.getLanguage()));
-    });
   }
 
   @Test
-  void getRemoteAddress() {
+  void getUserAgent() throws Exception {
-    when(grpcClientConnectionManager.getRemoteAddress(any()))
+    assertEquals(Optional.empty(),
-        .thenReturn(Optional.empty());
+        callWithRequestAttributes(buildRequestAttributes((String) null),
+            RequestAttributesUtil::getUserAgent));
 
-    GrpcTestUtils.assertStatusException(Status.INTERNAL, this::getRequestAttributes);
+    assertEquals(Optional.of("Signal-Desktop/1.2.3 Linux"),
-
+        callWithRequestAttributes(buildRequestAttributes("Signal-Desktop/1.2.3 Linux"),
-    final String remoteAddressString = "6.7.8.9";
+            RequestAttributesUtil::getUserAgent));
-
-    when(grpcClientConnectionManager.getRemoteAddress(any()))
-        .thenReturn(Optional.of(InetAddresses.forString(remoteAddressString)));
-
-    assertEquals(remoteAddressString, getRequestAttributes().getRemoteAddress());
   }
 
-  @Test
+  private static <V> V callWithRequestAttributes(final RequestAttributes requestAttributes, final Callable<V> callable) throws Exception {
-  void getUserAgent() throws UnrecognizedUserAgentException {
+    return Context.current()
-    when(grpcClientConnectionManager.getUserAgent(any()))
+        .withValue(RequestAttributesUtil.REQUEST_ATTRIBUTES_CONTEXT_KEY, requestAttributes)
-        .thenReturn(Optional.empty());
+        .call(callable);
-
-    assertFalse(getRequestAttributes().hasUserAgent());
-
-    final UserAgent userAgent = UserAgentUtil.parseUserAgentString("Signal-Desktop/1.2.3 Linux");
-
-    when(grpcClientConnectionManager.getUserAgent(any()))
-        .thenReturn(Optional.of(userAgent));
-
-    final GetRequestAttributesResponse response = getRequestAttributes();
-    assertTrue(response.hasUserAgent());
-    assertEquals("DESKTOP", response.getUserAgent().getPlatform());
-    assertEquals("1.2.3", response.getUserAgent().getVersion());
-    assertEquals("Linux", response.getUserAgent().getAdditionalSpecifiers());
   }
 
-  @Test
+  private static RequestAttributes buildRequestAttributes(final String userAgent) {
-  void getRawUserAgent() {
+    return buildRequestAttributes(userAgent, Collections.emptyList());
-    when(grpcClientConnectionManager.getRawUserAgent(any()))
-        .thenReturn(Optional.empty());
-
-    assertTrue(getRequestAttributes().getRawUserAgent().isBlank());
-
-    final String userAgentString = "Signal-Desktop/1.2.3 Linux";
-
-    when(grpcClientConnectionManager.getRawUserAgent(any()))
-        .thenReturn(Optional.of(userAgentString));
-
-    assertEquals(userAgentString, getRequestAttributes().getRawUserAgent());
   }
 
-  private GetRequestAttributesResponse getRequestAttributes() {
+  private static RequestAttributes buildRequestAttributes(final List<Locale.LanguageRange> acceptLanguage) {
-    return RequestAttributesGrpc.newBlockingStub(managedChannel)
+    return buildRequestAttributes(null, acceptLanguage);
-        .getRequestAttributes(GetRequestAttributesRequest.newBuilder().build());
+  }
+
+  private static RequestAttributes buildRequestAttributes(@Nullable final String userAgent,
+      final List<Locale.LanguageRange> acceptLanguage) {
+
+    return new RequestAttributes(REMOTE_ADDRESS, userAgent, acceptLanguage);
   }
 }

service/src/test/java/org/whispersystems/textsecuregcm/grpc/net/GrpcClientConnectionManagerTest.java

@@ -1,7 +1,11 @@
 package org.whispersystems.textsecuregcm.grpc.net;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import com.google.common.net.InetAddresses;
-import com.vdurmont.semver4j.Semver;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
@@ -12,6 +16,12 @@ import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.channel.local.LocalAddress;
 import io.netty.channel.local.LocalChannel;
 import io.netty.channel.local.LocalServerChannel;
+import java.net.InetAddress;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+import java.util.Optional;
+import java.util.UUID;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeAll;
@@ -21,20 +31,9 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
+import org.whispersystems.textsecuregcm.grpc.ChannelNotFoundException;
+import org.whispersystems.textsecuregcm.grpc.RequestAttributes;
 import org.whispersystems.textsecuregcm.storage.Device;
-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;
-
-import javax.annotation.Nullable;
-import java.net.InetAddress;
-import java.util.List;
-import java.util.Locale;
-import java.util.Optional;
-import java.util.UUID;
-
-import static org.junit.jupiter.api.Assertions.*;
 
 class GrpcClientConnectionManagerTest {
 
@@ -103,7 +102,7 @@ class GrpcClientConnectionManagerTest {
     grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, maybeAuthenticatedDevice);
 
     assertEquals(maybeAuthenticatedDevice,
-        grpcClientConnectionManager.getAuthenticatedDevice(localChannel.localAddress()));
+        grpcClientConnectionManager.getAuthenticatedDevice(remoteChannel));
   }
 
   private static List<Optional<AuthenticatedDevice>> getAuthenticatedDevice() {
@@ -114,170 +113,115 @@ class GrpcClientConnectionManagerTest {
   }
 
   @Test
-  void getAcceptableLanguages() {
+  void getRequestAttributes() {
     grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, Optional.empty());
 
-    assertEquals(Optional.empty(),
+    assertThrows(IllegalStateException.class, () -> grpcClientConnectionManager.getRequestAttributes(remoteChannel));
-        grpcClientConnectionManager.getAcceptableLanguages(localChannel.localAddress()));
 
-    final List<Locale.LanguageRange> acceptLanguageRanges = Locale.LanguageRange.parse("en,ja");
+    final RequestAttributes requestAttributes = new RequestAttributes(InetAddresses.forString("6.7.8.9"), null, null);
-    remoteChannel.attr(GrpcClientConnectionManager.ACCEPT_LANGUAGE_ATTRIBUTE_KEY).set(acceptLanguageRanges);
+    remoteChannel.attr(GrpcClientConnectionManager.REQUEST_ATTRIBUTES_KEY).set(requestAttributes);
 
-    assertEquals(Optional.of(acceptLanguageRanges),
+    assertEquals(requestAttributes, grpcClientConnectionManager.getRequestAttributes(remoteChannel));
-        grpcClientConnectionManager.getAcceptableLanguages(localChannel.localAddress()));
   }
 
   @Test
-  void getRemoteAddress() {
+  void closeConnection() throws InterruptedException, ChannelNotFoundException {
-    grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, Optional.empty());
-
-    assertEquals(Optional.empty(),
-        grpcClientConnectionManager.getRemoteAddress(localChannel.localAddress()));
-
-    final InetAddress remoteAddress = InetAddresses.forString("6.7.8.9");
-    remoteChannel.attr(GrpcClientConnectionManager.REMOTE_ADDRESS_ATTRIBUTE_KEY).set(remoteAddress);
-
-    assertEquals(Optional.of(remoteAddress),
-        grpcClientConnectionManager.getRemoteAddress(localChannel.localAddress()));
-  }
-
-  @Test
-  void getUserAgent() throws UnrecognizedUserAgentException {
-    grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, Optional.empty());
-
-    assertEquals(Optional.empty(),
-        grpcClientConnectionManager.getUserAgent(localChannel.localAddress()));
-
-    final UserAgent userAgent = UserAgentUtil.parseUserAgentString("Signal-Desktop/1.2.3 Linux");
-    remoteChannel.attr(GrpcClientConnectionManager.PARSED_USER_AGENT_ATTRIBUTE_KEY).set(userAgent);
-
-    assertEquals(Optional.of(userAgent),
-        grpcClientConnectionManager.getUserAgent(localChannel.localAddress()));
-  }
-
-  @Test
-  void closeConnection() throws InterruptedException {
     final AuthenticatedDevice authenticatedDevice = new AuthenticatedDevice(UUID.randomUUID(), Device.PRIMARY_ID);
 
     grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, Optional.of(authenticatedDevice));
 
     assertTrue(remoteChannel.isOpen());
 
-    assertEquals(remoteChannel, grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertEquals(remoteChannel, grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
     assertEquals(List.of(remoteChannel),
         grpcClientConnectionManager.getRemoteChannelsByAuthenticatedDevice(authenticatedDevice));
 
     remoteChannel.close().await();
 
-    assertNull(grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertThrows(ChannelNotFoundException.class,
+        () -> grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
+
     assertNull(grpcClientConnectionManager.getRemoteChannelsByAuthenticatedDevice(authenticatedDevice));
   }
 
-  @Test
+  @ParameterizedTest
-  void handleWebSocketHandshakeCompleteRemoteAddress() {
+  @MethodSource
+  void handleHandshakeCompleteRequestAttributes(final InetAddress preferredRemoteAddress,
+      final String userAgentHeader,
+      final String acceptLanguageHeader,
+      final RequestAttributes expectedRequestAttributes) {
+
     final EmbeddedChannel embeddedChannel = new EmbeddedChannel();
 
-    final InetAddress preferredRemoteAddress = InetAddresses.forString("192.168.1.1");
+    GrpcClientConnectionManager.handleHandshakeComplete(embeddedChannel,
-
-    GrpcClientConnectionManager.handleWebSocketHandshakeComplete(embeddedChannel,
         preferredRemoteAddress,
-        null,
-        null);
-
-    assertEquals(preferredRemoteAddress,
-        embeddedChannel.attr(GrpcClientConnectionManager.REMOTE_ADDRESS_ATTRIBUTE_KEY).get());
-  }
-
-  @ParameterizedTest
-  @MethodSource
-  void handleWebSocketHandshakeCompleteUserAgent(@Nullable final String userAgentHeader,
-      @Nullable final UserAgent expectedParsedUserAgent) {
-
-    final EmbeddedChannel embeddedChannel = new EmbeddedChannel();
-
-    GrpcClientConnectionManager.handleWebSocketHandshakeComplete(embeddedChannel,
-        InetAddresses.forString("127.0.0.1"),
         userAgentHeader,
-        null);
-
-    assertEquals(userAgentHeader,
-        embeddedChannel.attr(GrpcClientConnectionManager.RAW_USER_AGENT_ATTRIBUTE_KEY).get());
-
-    assertEquals(expectedParsedUserAgent,
-        embeddedChannel.attr(GrpcClientConnectionManager.PARSED_USER_AGENT_ATTRIBUTE_KEY).get());
-  }
-
-  private static List<Arguments> handleWebSocketHandshakeCompleteUserAgent() {
-    return List.of(
-        // Recognized user-agent
-        Arguments.of("Signal-Desktop/1.2.3 Linux", new UserAgent(ClientPlatform.DESKTOP, new Semver("1.2.3"), "Linux")),
-
-        // Unrecognized user-agent
-        Arguments.of("Not a valid user-agent string", null),
-
-        // Missing user-agent
-        Arguments.of(null, null)
-    );
-  }
-
-
-  @ParameterizedTest
-  @MethodSource
-  void handleWebSocketHandshakeCompleteAcceptLanguage(@Nullable final String acceptLanguageHeader,
-      @Nullable final List<Locale.LanguageRange> expectedLanguageRanges) {
-
-    final EmbeddedChannel embeddedChannel = new EmbeddedChannel();
-
-    GrpcClientConnectionManager.handleWebSocketHandshakeComplete(embeddedChannel,
-        InetAddresses.forString("127.0.0.1"),
-        null,
         acceptLanguageHeader);
 
-    assertEquals(expectedLanguageRanges,
+    assertEquals(expectedRequestAttributes,
-        embeddedChannel.attr(GrpcClientConnectionManager.ACCEPT_LANGUAGE_ATTRIBUTE_KEY).get());
+        embeddedChannel.attr(GrpcClientConnectionManager.REQUEST_ATTRIBUTES_KEY).get());
   }
 
-  private static List<Arguments> handleWebSocketHandshakeCompleteAcceptLanguage() {
+  private static List<Arguments> handleHandshakeCompleteRequestAttributes() {
+    final InetAddress preferredRemoteAddress = InetAddresses.forString("192.168.1.1");
+
     return List.of(
-        // Parseable list
+        Arguments.argumentSet("Null User-Agent and Accept-Language headers",
-        Arguments.of("ja,en;q=0.4", Locale.LanguageRange.parse("ja,en;q=0.4")),
+            preferredRemoteAddress, null, null,
+            new RequestAttributes(preferredRemoteAddress, null, Collections.emptyList())),
 
-        // Unparsable list
+        Arguments.argumentSet("Recognized User-Agent and null Accept-Language header",
-        Arguments.of("This is not a valid language preference list", null),
+            preferredRemoteAddress, "Signal-Desktop/1.2.3 Linux", null,
+            new RequestAttributes(preferredRemoteAddress, "Signal-Desktop/1.2.3 Linux", Collections.emptyList())),
 
-        // Missing list
+        Arguments.argumentSet("Unparsable User-Agent and null Accept-Language header",
-        Arguments.of(null, null)
+            preferredRemoteAddress, "Not a valid user-agent string", null,
+            new RequestAttributes(preferredRemoteAddress, "Not a valid user-agent string", Collections.emptyList())),
+
+        Arguments.argumentSet("Null User-Agent and parsable Accept-Language header",
+            preferredRemoteAddress, null, "ja,en;q=0.4",
+            new RequestAttributes(preferredRemoteAddress, null, Locale.LanguageRange.parse("ja,en;q=0.4"))),
+
+        Arguments.argumentSet("Null User-Agent and unparsable Accept-Language header",
+            preferredRemoteAddress, null, "This is not a valid language preference list",
+            new RequestAttributes(preferredRemoteAddress, null, Collections.emptyList()))
     );
   }
 
   @Test
-  void handleConnectionEstablishedAuthenticated() throws InterruptedException {
+  void handleConnectionEstablishedAuthenticated() throws InterruptedException, ChannelNotFoundException {
     final AuthenticatedDevice authenticatedDevice = new AuthenticatedDevice(UUID.randomUUID(), Device.PRIMARY_ID);
 
-    assertNull(grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertThrows(ChannelNotFoundException.class,
+        () -> grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
+
     assertNull(grpcClientConnectionManager.getRemoteChannelsByAuthenticatedDevice(authenticatedDevice));
 
     grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, Optional.of(authenticatedDevice));
 
-    assertEquals(remoteChannel, grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertEquals(remoteChannel, grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
     assertEquals(List.of(remoteChannel), grpcClientConnectionManager.getRemoteChannelsByAuthenticatedDevice(authenticatedDevice));
 
     remoteChannel.close().await();
 
-    assertNull(grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertThrows(ChannelNotFoundException.class,
+        () -> grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
+
     assertNull(grpcClientConnectionManager.getRemoteChannelsByAuthenticatedDevice(authenticatedDevice));
   }
 
   @Test
-  void handleConnectionEstablishedAnonymous() throws InterruptedException {
+  void handleConnectionEstablishedAnonymous() throws InterruptedException, ChannelNotFoundException {
-    assertNull(grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertThrows(ChannelNotFoundException.class,
+        () -> grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
 
     grpcClientConnectionManager.handleConnectionEstablished(localChannel, remoteChannel, Optional.empty());
 
-    assertEquals(remoteChannel, grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertEquals(remoteChannel, grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
 
     remoteChannel.close().await();
 
-    assertNull(grpcClientConnectionManager.getRemoteChannelByLocalAddress(localChannel.localAddress()));
+    assertThrows(ChannelNotFoundException.class,
+        () -> grpcClientConnectionManager.getRemoteChannel(localChannel.localAddress()));
   }
 }

service/src/test/java/org/whispersystems/textsecuregcm/grpc/net/NoiseWebSocketTunnelServerIntegrationTest.java

@@ -523,10 +523,7 @@ class NoiseWebSocketTunnelServerIntegrationTest extends AbstractLeakDetectionTes
 
         assertEquals(remoteAddress, response.getRemoteAddress());
         assertEquals(List.of(acceptLanguage), response.getAcceptableLanguagesList());
-
+        assertEquals(userAgent, response.getUserAgent());
-        assertEquals("DESKTOP", response.getUserAgent().getPlatform());
-        assertEquals("1.2.3", response.getUserAgent().getVersion());
-        assertEquals("Linux", response.getUserAgent().getAdditionalSpecifiers());
       } finally {
         channel.shutdown();
       }

service/src/test/java/org/whispersystems/textsecuregcm/grpc/net/WebsocketHandshakeCompleteHandlerTest.java

@@ -4,6 +4,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.params.provider.Arguments.argumentSet;
 import static org.junit.jupiter.params.provider.Arguments.arguments;
 import static org.mockito.Mockito.mock;
 
@@ -16,6 +17,7 @@ import io.netty.channel.local.LocalAddress;
 import io.netty.handler.codec.http.DefaultHttpHeaders;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
+import io.netty.util.Attribute;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
@@ -31,6 +33,7 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.signal.libsignal.protocol.ecc.Curve;
+import org.whispersystems.textsecuregcm.grpc.RequestAttributes;
 import org.whispersystems.textsecuregcm.storage.ClientPublicKeysManager;
 
 class WebsocketHandshakeCompleteHandlerTest extends AbstractLeakDetectionTest {
@@ -134,8 +137,13 @@ class WebsocketHandshakeCompleteHandlerTest extends AbstractLeakDetectionTest {
     embeddedChannel.setRemoteAddress(remoteAddress);
     embeddedChannel.pipeline().fireUserEventTriggered(handshakeCompleteEvent);
 
+
+
     assertEquals(expectedRemoteAddress,
-        embeddedChannel.attr(GrpcClientConnectionManager.REMOTE_ADDRESS_ATTRIBUTE_KEY).get());
+        Optional.ofNullable(embeddedChannel.attr(GrpcClientConnectionManager.REQUEST_ATTRIBUTES_KEY))
+            .map(Attribute::get)
+            .map(RequestAttributes::remoteAddress)
+            .orElse(null));
   }
 
   private static List<Arguments> getRemoteAddress() {
@@ -144,53 +152,53 @@ class WebsocketHandshakeCompleteHandlerTest extends AbstractLeakDetectionTest {
     final InetAddress proxyAddress = InetAddresses.forString("4.3.2.1");
 
     return List.of(
-        // Recognized proxy, single forwarded-for address
+        argumentSet("Recognized proxy, single forwarded-for address",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
-            .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET)
+                .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET)
-            .add(WebsocketHandshakeCompleteHandler.FORWARDED_FOR_HEADER, clientAddress.getHostAddress()),
+                .add(WebsocketHandshakeCompleteHandler.FORWARDED_FOR_HEADER, clientAddress.getHostAddress()),
             remoteAddress,
             clientAddress),
 
-        // Recognized proxy, multiple forwarded-for addresses
+        argumentSet("Recognized proxy, multiple forwarded-for addresses",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
                 .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET)
                 .add(WebsocketHandshakeCompleteHandler.FORWARDED_FOR_HEADER, clientAddress.getHostAddress() + "," + proxyAddress.getHostAddress()),
             remoteAddress,
             proxyAddress),
 
-        // No recognized proxy header, single forwarded-for address
+        argumentSet("No recognized proxy header, single forwarded-for address",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
                 .add(WebsocketHandshakeCompleteHandler.FORWARDED_FOR_HEADER, clientAddress.getHostAddress()),
             remoteAddress,
             remoteAddress.getAddress()),
 
-        // No recognized proxy header, no forwarded-for address
+        argumentSet("No recognized proxy header, no forwarded-for address",
-        Arguments.of(new DefaultHttpHeaders(),
+            new DefaultHttpHeaders(),
             remoteAddress,
             remoteAddress.getAddress()),
 
-        // Incorrect proxy header, single forwarded-for address
+        argumentSet("Incorrect proxy header, single forwarded-for address",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
                 .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET + "-incorrect")
                 .add(WebsocketHandshakeCompleteHandler.FORWARDED_FOR_HEADER, clientAddress.getHostAddress()),
             remoteAddress,
             remoteAddress.getAddress()),
 
-        // Recognized proxy, no forwarded-for address
+        argumentSet("Recognized proxy, no forwarded-for address",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
                 .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET),
             remoteAddress,
             remoteAddress.getAddress()),
 
-        // Recognized proxy, bogus forwarded-for address
+        argumentSet("Recognized proxy, bogus forwarded-for address",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
                 .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET)
                 .add(WebsocketHandshakeCompleteHandler.FORWARDED_FOR_HEADER, "not a valid address"),
             remoteAddress,
             null),
 
-        // No forwarded-for address, non-InetSocketAddress remote address
+        argumentSet("No forwarded-for address, non-InetSocketAddress remote address",
-        Arguments.of(new DefaultHttpHeaders()
+            new DefaultHttpHeaders()
                 .add(WebsocketHandshakeCompleteHandler.RECOGNIZED_PROXY_SECRET_HEADER, RECOGNIZED_PROXY_SECRET),
             new LocalAddress("local-address"),
             null)

service/src/test/proto/request_attributes_service.proto

@@ -23,14 +23,7 @@ message GetRequestAttributesResponse {
   repeated string acceptable_languages = 1;
   repeated string available_accepted_locales = 2;
   string remote_address = 3;
-  string raw_user_agent = 4;
+  string user_agent = 4;
-  UserAgent user_agent = 5;
-}
-
-message UserAgent {
-  string platform = 1;
-  string version = 2;
-  string additional_specifiers = 3;
 }
 
 message GetAuthenticatedDeviceRequest {