ct.proto

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

syntax = "proto3";

package chrome_browser_certificate_transparency;

// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
option optimize_for = LITE_RUNTIME;

message CTTimestamp {
  int64 seconds = 1;

  int32 nanos = 2;
}


// Represents the final state of a log at the time it was made read-only.
message FinalTreeHead {
  // Size of the log at the time it was made read-only.
  uint64 tree_size = 1;
  // Root hash of the log (base64-encoded) at the time it was made read-only.
  string sha256_root_hash = 2;
}

message CTLog {
  // Human-readable description to identify log.
  string description = 1;
  // Public key of the log, as a DER-encoded ASN.1 SubjectPublicKeyInfo
  // structure, then encoded as base64
  // (https://tools.ietf.org/html/rfc5280#section-4.1.2.7).
  string key = 2;
  // The base64-encoded LogID found in SCTs issued by this log
  // (https://tools.ietf.org/html/rfc6962#section-3.2).
  string log_id = 3;
  // Maximum merge delay, in seconds. The log should not take longer than this
  // to incorporate a certificate.
  uint64 mmd_secs = 4;
  // URL of the log's HTTP API.
  string url = 5;

  message Interval {
    CTTimestamp start = 1;
    CTTimestamp end = 2;
  }
  // The log will only accept certificates that expire between those dates.
  // Start time is inclusive, end time is not inclusive.
  Interval temporal_interval = 6;

  enum Purpose {
    UNSET_PURPOSE = 0;
    PROD = 1;
    TEST = 2;
  }
  // Whether the log is for production purposes, or test only.
  Purpose purpose = 7;

  enum CurrentState {
    UNSET_STATE = 0;
    PENDING = 1;
    QUALIFIED = 2;
    USABLE = 3;
    READ_ONLY = 4;
    RETIRED = 5;
    REJECTED = 6;
  }
  message State {
    // Current state of the log.
    CurrentState current_state = 1;
    // Time at which the log entered this state.
    CTTimestamp state_start = 2;
  }
  // State history of the log. Inverse chronological order, first element should
  // be the current state.
  repeated State state = 8;

  message OperatorChange {
    // Name of the log operator.
    string name = 1;
    // Timestamp at which this operator started operating this log.
    CTTimestamp operator_start = 2;
  }
  // History of all log operators that have ever operated this log, including
  // the timestamp at which each started operating it. Inverse chronological
  // order, first element should be the current operator.
  repeated OperatorChange operator_history = 9;

  // State of the log at the time it was made read-only. Should only be set if
  // state is READ_ONLY.
  FinalTreeHead read_only_info = 16;
}

message LogOperator {
  // Name of this log operator.
  string name = 1;
  // Email addresses at which the log operator can be reached.
  repeated string email = 2;
}

message CTLogList {
  // Major version of the list, incremented any time there are changes in the
  // list, except for trivial (i.e. timestamp-only) changes.
  uint64 list_version_major = 1;
  // Minor version of the list, incremented any time the list is modified with
  // only trivial (i.e. timestamp-only) changes. Allows consumers to determine
  // the timestamp at which certain changes occur; for example, if a log is
  // rejected, a consumer can look at the minor version 1 of that major version
  // to determine at what timestamp that change was made.
  uint64 list_version_minor = 2;
  // Log list timestamp. This is meant to be used for freshness checks, and is
  // updated periodically regardless of whether the list contents' have changed.
  // Use list_version_major instead if monitoring for list contents' changes.
  CTTimestamp timestamp = 3;
  // Compatibility version, incremented if the list structure is changed in a
  // non-backwards-compatible way.
  uint64 compatibility_version = 4;
  // Contains all known log operators.
  repeated LogOperator operators = 5;
  // Contains all known logs.
  repeated CTLog logs = 6;
}

// Certificate transparency configuration as used by Chrome.
message CTConfig {
  // Emergency switch to disable all CT enforcement.
  bool disable_ct_enforcement = 1;
  // Logs Chrome should recognize.
  CTLogList log_list = 2;
  // A list of the leaf hashes for the most popular SCTs encountered in Chrome
  // recently. Sorted lexicographically.
  repeated bytes popular_scts = 3;
}