attestation/common/common.proto

// Copyright 2015 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.

option optimize_for = LITE_RUNTIME;

package attestation;

// Describes key type.
enum KeyType {
  KEY_TYPE_RSA = 1;
  KEY_TYPE_ECC = 2;
}

// Describes allowed key usage.
enum KeyUsage {
  KEY_USAGE_SIGN = 1;
  KEY_USAGE_DECRYPT = 2;
}

// Enumerates various certificate profiles supported by the Attestation CA.
enum CertificateProfile {
  // A certificate intended for enterprise-owned devices.  It has the following
  // subjectName fields:
  //   CN=<stable device identifier>
  //   OU=state:[verified|developer]
  //   O=Chrome Device Enterprise
  ENTERPRISE_MACHINE_CERTIFICATE = 0;

  // A certificate intended for enterprise-owned user accounts.  It has the
  // following subjectName fields:
  //   OU=state:[verified|developer]
  //   O=Chrome Device Enterprise
  ENTERPRISE_USER_CERTIFICATE = 1;

  // A certificate intended for platform verification by providers of protected
  // content.  It has the following subjectName fields:
  //   O=Chrome Device Content Protection
  CONTENT_PROTECTION_CERTIFICATE = 2;

  // Like above, but it also includes a stable ID and origin.
  //   CN=<origin-specific device identifier>
  //   OU=<origin>
  //   O=Chrome Device Content Protection
  CONTENT_PROTECTION_CERTIFICATE_WITH_STABLE_ID = 3;

  // A certificate intended for cast devices.
  CAST_CERTIFICATE = 4;

  GFSC_CERTIFICATE = 5;

  JETSTREAM_CERTIFICATE = 6;

  // A certificate for enterprise enrollment.
  ENTERPRISE_ENROLLMENT_CERTIFICATE = 7;

  // A certificate for signing Android Testsuite Results using CTS-in-a-box.
  XTS_CERTIFICATE = 8;
}

enum TpmVersion {
  TPM_1_2 = 1;  // NOTE: This is the default. It must remain listed first.
  TPM_2_0 = 2;
}

// Holds information about a quote generated by the TPM.
message Quote {
  // The quote; a signature generated with the AIK.
  optional bytes quote = 1;
  // The serialized data that was quoted; this assists in verifying the quote.
  optional bytes quoted_data = 2;
  // The value of the PCR(s) at the time the quote was generated.
  optional bytes quoted_pcr_value = 3;
  // Source data which was originally used to extend the PCR. If this field
  // exists it can be expected that SHA1(pcr_source_hint) was extended into the
  // PCR.
  optional bytes pcr_source_hint = 4;
}

// Holds encrypted data and information required to decrypt it.
message EncryptedData {
  // A key that has been sealed to the TPM or wrapped by another key.
  optional bytes wrapped_key = 2;
  // The initialization vector used during encryption.
  optional bytes iv = 3;
  // MAC of (iv + encrypted_data).
  optional bytes mac = 4;
  optional bytes encrypted_data = 5;
  // An identifier for the wrapping key to assist in decryption.
  optional bytes wrapping_key_id = 6;
}

// The wrapper message of any data and its signature.
message SignedData {
  // The data to be signed.
  optional bytes data = 1;
  // The signature of the data field.
  optional bytes signature = 2;
}

// The first two fields are suitable for passing to Tspi_TPM_ActivateIdentity()
// directly when using TPM 1.2. For TPM 2.0 the first two fields are not used.
message EncryptedIdentityCredential {
  // TPM_ASYM_CA_CONTENTS, encrypted with EK public key.
  optional bytes asym_ca_contents = 1;
  // TPM_SYM_CA_ATTESTATION, encrypted with the key in aysm_ca_contents.
  optional bytes sym_ca_attestation = 2;

  optional TpmVersion tpm_version = 3;

  // The following fields are used only for TPM 2.0. For details see the TPM 2.0
  // specification Part 1 Rev 1.16:
  // - Section 9.5.3.3: General description of the scheme.
  // - Section 24: More details including how to use the seed to compute the
  //               values for 'credential_mac' and 'wrapped_certificate->
  //               wrapped_key'
  // - Section B.10.4: Encrypting the seed with a RSA EK.
  // - Section C.7.4: Encrypting the seed with an EC EK.

  // A seed encrypted with the EK public key. The TPM will use this seed to
  // derive both an HMAC key to verify the 'credential_mac' field and an AES key
  // to unwrap the 'wrapped_certificate->wrapped_key' field.
  optional bytes encrypted_seed = 4;

  // An integrity value computed using HMAC-SHA256 over the
  // 'wrapped_certificate.wrapped_key' field and the 'Name' of the identity key.
  optional bytes credential_mac = 5;

  // A certificate encrypted with a 'credential' that is decrypted by the TPM.
  // The 'wrapped_key' field contains the encrypted credential which is
  // encrypted using AES-256-CFB with a zero IV. The encryption of the
  // certificate itself uses AES-256-CBC with PKCS #5 padding and a random IV.
  // The encryption key is derived from the 'credential' using:
  //   SHA256('ENCRYPT' + credential)
  // The mac uses HMAC-SHA256 with a key derived using:
  //   SHA256('MAC' + credential)
  optional EncryptedData wrapped_certificate = 6;
}