android/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h

// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine
// License Agreement.
//
//  Reference implementation of OEMCrypto APIs
//
#ifndef OEMCRYPTO_AUTH_REF_H_
#define OEMCRYPTO_AUTH_REF_H_

#include <stdint.h>
#include <memory>
#include <vector>

#include <openssl/rsa.h>

#include "OEMCryptoCENC.h"  // Needed for enums only.
#include "disallow_copy_and_assign.h"
#include "oemcrypto_key_ref.h"
#include "oemcrypto_keybox_ref.h"
#include "oemcrypto_rsa_key_shared.h"
#include "oemcrypto_types.h"

namespace wvoec_ref {
// The AuthenticationRoot class contains the OEMCrypto information
// which makes up the "root of trust" of a device.
class AuthenticationRoot {
 public:
  AuthenticationRoot() {}
  ~AuthenticationRoot() {}

  // Initializes the root of authentication for the provided
  // |method|.  This will clear any previously initialied data.
  bool Initialize(OEMCrypto_ProvisioningMethod method);

  // General root of trust API.

  // Checks that the auth root has been properly initialized and can
  // be used by the rest of OEMCrypto for the current provisioning
  // method.
  bool IsValid() const;

  // Checks the validity of the underlying Keybox or OEM Certificate
  // depending on the provisioning method.
  // Similar to the expected behavior of OEMCrypto_IsKeyboxOrOEMCertValid().
  OEMCryptoResult IsKeyboxOrOemCertValid() const;

  // Gets the device ID from the root of trust.
  // Similar to the expected behavior of OEMCrypto_GetDeviceID().
  OEMCryptoResult GetDeviceId(uint8_t* device_id,
                              size_t* device_id_length) const;

  // Returns the device ID from the root of trust.  Intended to be used
  // for core message generation.
  std::vector<uint8_t> DeviceId() const;

  // Returns the device key from the root of trust.  For keybox-based
  // devices, this is the device key from the keybox (or test keybox
  // if installed).  For devices that use a non-keybox provisioning
  // method, this will be a device specific key.
  std::vector<uint8_t> DeviceKey() const;

  // Check for the existence of a device key.
  bool HasDeviceKey() const;

  // Clears any test data inside this root of trust.
  void Clear();

  // DRM Certificate-based root of trust API.

  // Returns the shared RSA private key from the built-in DRM
  // Certificate.
  RSA_shared_ptr& SharedRsaKey() {
    return test_rsa_key_.get() != nullptr ? test_rsa_key_ : rsa_key_;
  }
  RSA* rsa_key() {
    return test_rsa_key_.get() != nullptr ? test_rsa_key_.get()
                                          : rsa_key_.get();
  }

  // Loads the system's built-in RSA key.  Only implemented for
  // devices that are that pre-provisioned with a built-in DRM
  // Certificate,
  // This method implements the expected behavior of
  // OEMCrypto_LoadTestRSAKey().
  OEMCryptoResult LoadTestRsaKey();

  // Removes any installed test RSA key.
  void RemoveTestRsaKey() { test_rsa_key_.reset(); }

  // Keybox-based root of trust API.

  // Returns the currently installed keybox (or test keybox) if any
  // present.  The test keybox takes priority over the standard.
  WvKeybox* keybox() const {
    return test_keybox_ ? test_keybox_.get() : keybox_.get();
  }

  // Checks the validity of the keybox regardless of the provisioning
  // method.
  OEMCryptoResult IsKeyboxValid() const;

  // Installs a clear WV keybox as the root of trust.
  // A keybox can only be installed once, however, the provisioning
  // method stated at initialization remains the same.
  //
  // This method is similar to the expected behavior of
  // OEMCrypto_InstallKeyboxOrOEMCert() for keybox devices except
  // that the keybox provided here must be decrypted before installing.
  OEMCryptoResult InstallKeybox(const uint8_t* keybox_data,
                                size_t keybox_length);

  // Installs a clear test WV keybox.  Only settable for devices that
  // uses a keybox for provisioning.
  //
  // This method is similar to the expected behavior of
  // OEMCrypto_LoadTestKeybox() for keybox devices except that
  // the keybox provided here must be decrypted before installing.
  OEMCryptoResult InstallTestKeybox(const uint8_t* keybox_data,
                                    size_t keybox_length);

  // Removes any installed test keybox.
  void RemoveTestKeybox() { test_keybox_.reset(); }

  // Gets the keybox key data.
  // Implements the expected behavior of OEMCrypto_GetKeyData().
  OEMCryptoResult GetKeyData(uint8_t* key_data, size_t* key_data_length) const;

  // OEM Certificate-base root of trust API.

  // For OEM Cert-based devices, returns the OEM Public Certificate
  // component of the OEM Certificate.
  // This method implements the expected behavior of
  // OEMCrypto_GetOEMPublicCertificate().
  OEMCryptoResult GetOemPublicCertificate(uint8_t* public_cert,
                                          size_t* public_cert_length) const;

  // Returns the OEM private key.  Intended to be used when loading
  // the OEM private key into a session.
  // Should only be called for devices that use OEM Certificates
  // for provisioning.
  const std::vector<uint8_t>& GetOemPrivateKey() const;

 private:
  OEMCrypto_ProvisioningMethod prov_method_ = OEMCrypto_ProvisioningError;

  // DRM certificate.
  // TODO(b/168544740): Remove |rsa_key_set_| when RSA_shared_ptr has
  // been replaced with scoped RsaPrivateKey.
  bool rsa_key_set_ = false;
  RSA_shared_ptr rsa_key_;  // If no keybox, this is baked in certificate.
  RSA_shared_ptr test_rsa_key_;

  // Keybox data.
  std::unique_ptr<WvKeybox> keybox_;
  std::unique_ptr<WvKeybox> test_keybox_;

  CORE_DISALLOW_COPY_AND_ASSIGN(AuthenticationRoot);
};
}  // namespace wvoec_ref

#endif  // OEMCRYPTO_AUTH_REF_H_