chromeos/crosapi/mojom/content_protection.mojom

// Copyright 2021 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module crosapi.mojom;

// Status returned by a successful call to QueryWindowStatus.
[Stable]
struct ContentProtectionWindowStatus {
  // The type of connected output links, which is a bit-mask of the LinkType
  // values.
  uint32 link_mask@0;

  // The type of enabled protections, which is a bit-mask of the ProtectionType
  // values.
  uint32 protection_mask@1;
};

// Returned by a successful call to ChallengePlatform. The structure mirrors the
// CdmDocumentService interface to avoid unnecessary conversions.
[Stable]
struct ChallengePlatformResult {
  // The data signed by the platform.
  string signed_data;

  // The signature of the signed data block.
  string signed_data_signature;

  // The device specific certificate for the requested service.
  string platform_key_certificate;
};

// This interface is implemented by Ash-Chrome.
// This allows Lacros to support content protection.
//
// The bitfields in this struct use [Stable] enums defined in
// media/mojo/mojom/output_protection.mojom.
// The input parameter |window_id| should be obtained from
// PlatformWindow::GetWindowUniqueId(). A typical format might be:
// "org.chromium.lacros.9A82A161B2A0B9BADF75E9BB958B9FCB"
//
// Note that the Window abstraction, and its corresponding |window_id| are
// communicated over Wayland IPC. There's no synchronization between Wayland and
// Crosapi, so it's technically possible for Lacros to create a window, and
// then call one of these methods, but for Ash to not yet know about the
// |window_id|. As such, a failure in one of these methods is not considered
// irrecoverable -- it's possible that calling the method again at a later point
// in time will result in success.
[Stable, Uuid="e3020766-dd9b-4cfe-b387-8ed677212b50"]
interface ContentProtection {
  // Returns content-protection related status for a window. Returns null on
  // failure.
  QueryWindowStatus@0(string window_id) =>
      (ContentProtectionWindowStatus? status);

  // Enables content protection for a window.
  // - desired_protection_mask: The desired protection methods, which
  //   is a bit-mask of the ProtectionType values.
  // - success: True when the protection request has been made. This may be
  //   before the protection have actually been applied. Call
  //   QueryWindowStatus() to get protection status. False if it failed to make
  //   the protection request, and in this case there is no need to call
  //   QueryStatus().
  EnableWindowProtection@1(string window_id, uint32 desired_protection_mask) =>
      (bool success);

  // Returns the system hash in hex encoded ascii. This may return an empty
  // string on error.
  // This intentionally mirrors the existing SystemSaltGetter API to avoid
  // unnecessary conversions on both sides of the crosapi interface.
  [MinVersion=1]
  GetSystemSalt@2() => (string salt);

  // Allows authorized services to verify that the underlying platform is
  // trusted. An example of a trusted platform is a Chrome OS device in
  // verified boot mode. This can be used for protected content playback.
  //
  // Input parameters:
  // - |service_id|: the service ID for the |challenge|.
  // - |challenge|: the challenge data.
  // The input parameters mirror the CdmDocumentService interface to avoid
  // unnecessary conversions.
  // Returns null on failure.
  [MinVersion=2]
  ChallengePlatform@3(string service_id, string challenge) =>
      (ChallengePlatformResult? result);
};