// Copyright 2023 Google LLC
//
// 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 privacy.ppn;

import "quiche/blind_sign_auth/proto/any.proto";

option java_multiple_files = true;
option java_outer_classname = "AttestationProto";
option java_package = "com.google.android.libraries.privacy.ppn.proto";

message NonceRequest {}

message NonceResponse {
  // A nonce with the following format:
  // ECDSA(
  //   SHA256(
  //     <random bytes of length [64, 128]>.<expiry time in ms>)).
  bytes nonce = 1;

  // Nonce signature.
  bytes sig = 2;

  // Algorithm used to sign the nonce. Should be "es256".
  bytes alg = 3;
}

message ValidateDeviceRequest {
  // Attestation data that is returned by the client.
  oneof attestation_data {
    AndroidAttestationData android_attestation_data = 1;

    IosAttestationData ios_attestation_data = 2;
  }

  AttestationData attestation = 3;
  string package_name = 4;

  // If attestation is AndroidAttestationData device models should be listed in:
  // https://storage.googleapis.com/play_public/supported_devices.html
  repeated string allowed_models = 5;
}

message ValidateDeviceResponse {
  // True iff all checks passed
  // (integrity token, nonce, hardware properties are legitimate).
  // Hardware properties check will be performed by the calling service
  // as attestation only checks to see if the device's hardware properties
  // are genuine.
  bool device_verified = 1;

  // Detailed information on what specifically passed and what did not.
  VerdictBreakdown breakdown = 2;

  // If verified, contains the device model.
  string verified_device_type = 3;
}

message VerdictBreakdown {
  enum Verdict {
    VERDICT_UNKNOWN = 0;
    VERDICT_PASS = 1;
    VERDICT_FAIL = 2;
  }

  // Integrity verdict as determined by either Play Server or AppAttest.
  Verdict integrity_verdict = 1;

  // Whether nonce check passed.
  Verdict nonce_verdict = 2;

  // Whether or not the device properties sent by the client are
  // legitimate.
  Verdict device_properties_verdict = 3;
}

message PrepareAttestationData {
  bytes attestation_nonce = 2;
}

message AndroidAttestationData {
  // Play IntegrityToken returned by Play Integrity API is detailed in
  // https://developer.android.com/google/play/integrity/verdict.
  string attestation_token = 1;

  // X509 Certificate chain generated by Android Keystore used for
  // Hardware-Backed Key Attestation.
  repeated bytes hardware_backed_certs = 2;
}

message IosAttestationData {
  // AppAttest attestation token.
  // Encoded in CBOR format.
  bytes attestation_token = 1;
}

message AttestationData {
  quiche.protobuf.Any attestation_data = 1;
}