Represent device names as byte arrays

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

@@ -8,6 +8,7 @@ import static org.whispersystems.textsecuregcm.util.RegistrationIdValidator.vali
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.google.common.annotations.VisibleForTesting;
 import java.util.Optional;
 import javax.annotation.Nullable;
@@ -30,8 +31,10 @@ public class AccountAttributes {
   private int phoneNumberIdentityRegistrationId;
 
   @JsonProperty
-  @Size(max = 204, message = "This field must be less than 50 characters")
-  private String name;
+  @JsonSerialize(using = ByteArrayAdapter.Serializing.class)
+  @JsonDeserialize(using = ByteArrayAdapter.Deserializing.class)
+  @Size(max = 225)
+  private byte[] name;
 
   @JsonProperty
   private String registrationLock;
@@ -62,7 +65,7 @@ public class AccountAttributes {
       final boolean fetchesMessages,
       final int registrationId,
       final int phoneNumberIdentifierRegistrationId,
-      final String name,
+      final byte[] name,
       final String registrationLock,
       final boolean discoverableByPhoneNumber,
       final DeviceCapabilities capabilities) {
@@ -87,7 +90,7 @@ public class AccountAttributes {
     return phoneNumberIdentityRegistrationId;
   }
 
-  public String getName() {
+  public byte[] getName() {
     return name;
   }
 

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

@@ -5,5 +5,16 @@
 
 package org.whispersystems.textsecuregcm.entities;
 
-public record DeviceInfo(long id, String name, long lastSeen, long created) {
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import org.whispersystems.textsecuregcm.util.ByteArrayAdapter;
+
+public record DeviceInfo(long id,
+
+                         @JsonSerialize(using = ByteArrayAdapter.Serializing.class)
+                         @JsonDeserialize(using = ByteArrayAdapter.Deserializing.class)
+                         byte[] name,
+
+                         long lastSeen,
+                         long created) {
 }

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

@@ -6,19 +6,24 @@
 package org.whispersystems.textsecuregcm.entities;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import org.whispersystems.textsecuregcm.util.ByteArrayAdapter;
 import javax.validation.constraints.NotEmpty;
 import javax.validation.constraints.Size;
 
 public class DeviceName {
 
   @JsonProperty
+  @JsonSerialize(using = ByteArrayAdapter.Serializing.class)
+  @JsonDeserialize(using = ByteArrayAdapter.Deserializing.class)
   @NotEmpty
-  @Size(max = 300, message = "This field must be less than 300 characters")
-  private String deviceName;
+  @Size(max = 225)
+  private byte[] deviceName;
 
   public DeviceName() {}
 
-  public String getDeviceName() {
+  public byte[] getDeviceName() {
     return deviceName;
   }
 }

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

@@ -60,8 +60,8 @@ public class DevicesGrpcService extends ReactorDevicesGrpc.DevicesImplBase {
         .reduce(GetDevicesResponse.newBuilder(), (builder, device) -> {
           final GetDevicesResponse.LinkedDevice.Builder linkedDeviceBuilder = GetDevicesResponse.LinkedDevice.newBuilder();
 
-          if (StringUtils.isNotBlank(device.getName())) {
-            linkedDeviceBuilder.setName(ByteString.copyFrom(Base64.getDecoder().decode(device.getName())));
+          if (device.getName() != null) {
+            linkedDeviceBuilder.setName(ByteString.copyFrom(device.getName()));
           }
 
           return builder.addDevices(linkedDeviceBuilder
@@ -105,7 +105,7 @@ public class DevicesGrpcService extends ReactorDevicesGrpc.DevicesImplBase {
     return Mono.fromFuture(() -> accountsManager.getByAccountIdentifierAsync(authenticatedDevice.accountIdentifier()))
         .map(maybeAccount -> maybeAccount.orElseThrow(Status.UNAUTHENTICATED::asRuntimeException))
         .flatMap(account -> Mono.fromFuture(() -> accountsManager.updateDeviceAsync(account, authenticatedDevice.deviceId(),
-            device -> device.setName(Base64.getEncoder().encodeToString(request.getName().toByteArray())))))
+            device -> device.setName(request.getName().toByteArray()))))
         .thenReturn(SetDeviceNameResponse.newBuilder().build());
   }
 

service/src/main/java/org/whispersystems/textsecuregcm/storage/Device.java

@@ -7,6 +7,7 @@ package org.whispersystems.textsecuregcm.storage;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import java.util.List;
 import java.util.OptionalInt;
 import java.util.concurrent.TimeUnit;
@@ -17,6 +18,7 @@ import org.apache.commons.lang3.StringUtils;
 import org.whispersystems.textsecuregcm.auth.SaltedTokenHash;
 import org.whispersystems.textsecuregcm.entities.ECSignedPreKey;
 import org.whispersystems.textsecuregcm.identity.IdentityType;
+import org.whispersystems.textsecuregcm.util.DeviceNameByteArrayAdapter;
 
 public class Device {
 
@@ -31,7 +33,9 @@ public class Device {
   private byte id;
 
   @JsonProperty
-  private String  name;
+  @JsonSerialize(using = DeviceNameByteArrayAdapter.Serializer.class)
+  @JsonDeserialize(using = DeviceNameByteArrayAdapter.Deserializer.class)
+  private byte[] name;
 
   @JsonProperty
   private String  authToken;
@@ -146,11 +150,11 @@ public class Device {
     this.id = id;
   }
 
-  public String getName() {
+  public byte[] getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(byte[] name) {
     this.name = name;
   }
 

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

@@ -0,0 +1,53 @@
+package org.whispersystems.textsecuregcm.util;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import io.micrometer.core.instrument.Counter;
+import io.micrometer.core.instrument.Metrics;
+import org.whispersystems.textsecuregcm.metrics.MetricsUtil;
+import java.io.IOException;
+import java.util.Base64;
+
+/**
+ * Serializes a byte array as a standard Base64-encoded string and deserializes Base64-encoded strings to byte arrays,
+ * but treats any string that cannot be parsed as Base64 to {@code null}.
+ * <p/>
+ * Historically, device names were passed around as weakly-typed strings with the expectation that clients would provide
+ * Base64 strings, but nothing in the server ever verified that was the case. In the absence of strict validation, some
+ * third-party clients started submitting unencrypted names for devices, and so device names in persistent storage are a
+ * mix of Base64-encoded device name ciphertexts from first-party clients and plaintext device names from third-party
+ * clients. This adapter will discard the latter.
+ */
+public class DeviceNameByteArrayAdapter {
+
+  private static final Counter UNPARSEABLE_DEVICE_NAME_COUNTER =
+      Metrics.counter(MetricsUtil.name(DeviceNameByteArrayAdapter.class, "unparseableDeviceName"));
+
+  public static class Serializer extends JsonSerializer<byte[]> {
+    @Override
+    public void serialize(final byte[] bytes,
+        final JsonGenerator jsonGenerator,
+        final SerializerProvider serializerProvider) throws IOException {
+
+      jsonGenerator.writeString(Base64.getEncoder().encodeToString(bytes));
+    }
+  }
+
+  public static class Deserializer extends JsonDeserializer<byte[]> {
+    @Override
+    public byte[] deserialize(final JsonParser jsonParser,
+        final DeserializationContext deserializationContext) throws IOException {
+
+      try {
+        return Base64.getDecoder().decode(jsonParser.getValueAsString());
+      } catch (final IllegalArgumentException e) {
+        UNPARSEABLE_DEVICE_NAME_COUNTER.increment();
+        return null;
+      }
+    }
+  }
+}