ec_util.hpp

// Copyright 2024 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
//
//     http://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.

#pragma once

#include "google3/host_commands.h"

#include "ec_util_interface.hpp"
#include "host_command.hpp"

#include <cstddef>
#include <cstdint>

namespace google
{
namespace hoth
{
namespace internal
{

class CommandNotSupportedException : public std::exception
{
  public:
    explicit CommandNotSupportedException(uint16_t command) : command(command)
    {
        std::stringstream ss;
        ss << "EC Command 0x" << std::hex << command << " not supported";
        this->message = ss.str();
    }
    const char* what() const noexcept override
    {
        return message.c_str();
    }

    uint16_t get_command() const
    {
        return command;
    }

  private:
    uint16_t command;
    std::string message;
};

class CommandRunException : public std::exception
{
  public:
    explicit CommandRunException(uint16_t command, uint16_t result) :
        command(command), result(result)
    {
        std::stringstream ss;
        ss << "EC Command 0x" << std::hex << command << " returned error 0x"
           << std::hex << result;
        this->message = ss.str();
    }
    const char* what() const noexcept override
    {
        return message.c_str();
    }

    uint16_t get_command() const
    {
        return command;
    }
    uint16_t get_result() const
    {
        return result;
    }

  private:
    uint16_t command;
    uint16_t result;
    std::string message;
};

class EcUtilImpl : public EcUtil
{
  public:
    explicit EcUtilImpl(HostCommand* hostCmd) : hostCmd(hostCmd) {}

    // Check wether a command is supported and authorized.
    bool isHostCommandSupported(uint16_t cmd) const override;

    // Get the Hoth statistics by issuing an EC_PRV_CMD_HOTH_GET_STATISTICS
    // Command.
    ec_response_statistics getHothStatistics() const override;

    // Get the hardware information from Hoth chip by issuing an
    // EC_PRV_CMD_HOTH_CHIP_INFO command.
    ec_response_chip_info getHothChipInfo() const override;

    // Check the presence of Hoth peresistent panic info by issuing a single
    // EC_PRV_CMD_HOTH_PERSISTENT_PANIC_INFO command.
    bool checkHothPersistentPanicInfo() const override;

    // Get the Hoth auth record.
    // Only supports record id = 0, which is the only one currently used.
    ec_authz_record_get_response getHothAuthRecord() const override;

    ec_response_key_rotation_status getHothKeyRotationStatus() const override;

    secure_boot_enforcement_state getSecureBootEnforcementState()
        const override;

    // Sets the TPM locality to `locality` via EC_PRV_CMD_HOTH_TPM_CONTROL.
    void setTpmLocality(uint8_t locality) const override;

    // Gets the TPM locality via EC_PRV_CMD_HOTH_TPM_CONTROL.
    uint8_t getTpmLocality() const override;

    payload_status_response getPayloadStatus() const override;

  private:
    [[nodiscard]] std::vector<uint8_t> sendCommand(
        uint16_t command, uint8_t* request_ptr, size_t request_size) const;

    /** @brief Connection to Hoth for sending and receiving host commands */
    HostCommand* hostCmd;
};

} // namespace internal

} // namespace hoth

} // namespace google