// Copyright 2021 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

syntax = "proto3";

package pw.software_update;

import "pw_software_update/tuf.proto";

message UpdateBundle {
  // The timestamp role is used for freshness check of the snapshot. Any
  // project-specific update metadata should go in the top-level
  // targets_metadata or with the TargetFile information
  optional SignedTimestampMetadata timestamp_metadata = 1;

  // The snapshot role is used to ensure that the collection of targets_metadata
  // files is securely consistent (no target metadata mix and match). Any
  // project-specific update metadata should go in the top-level
  // targets_metadata or with the TargetFile information
  optional SignedSnapshotMetadata snapshot_metadata = 2;

  // Map of target metadata name to target metadata.
  // Target metadata name can be an arbitrary name or a path that describes
  // where the file lives relative to the base directory of the repository, as
  // described in the snapshot metadata. e.g. "path/to/target/0".
  map<string, SignedTargetsMetadata> targets_metadata = 3;

  // Map of target file name to target payload bytes.
  // Target file name can be an arbitrary name or a path that describes where
  // the file lives relative to the base directory of the repository, as
  // described in the target metadata. e.g. "path/to/amber_tools/0".
  map<string, bytes> target_payloads = 4;

  // If present, a client will attempt to upgrade its on-device trusted root
  // metadata to the root metadata included in the bundle, following the
  // standard "Update the root role" flow specified in the TUF spec, but
  // without "version climbing".
  //
  // The exact steps are:
  // 1. Check if there is a root metadata in the bundle.
  // 2. If the root metadata IS NOT included, assume on-device root metadata
  //    is up-to-date and continue with the rest of metadata verification.
  // 3. If the root metadata IS included, verify the new root metadata using
  //    the on-device root metadata.
  // 4. If the verification is successful, persist new root metadata and
  //    continue with the rest of metadata verification. Otherwise abort the
  //    update session.
  //
  // The key deviation from standard flow is the client assumes it can always
  // directly upgrade to the single new root metadata in the update bundle,
  // without any step-stone history root metadata. This works only because
  // we are not supporting (more than 1) root key rotations.
  optional SignedRootMetadata root_metadata = 5;
}

// Update bundle metadata
// Designed to inform the update server what the device currently has in-place.
message Manifest {
  map<string, TargetsMetadata> targets_metadata = 2;
}