/*
 * Copyright (C) 2011-2018 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */


#ifndef _ENCLAVE_H_
#define _ENCLAVE_H_

#include <stdint.h>
#include <sgx_error.h>

/*
 * returns the size of the sealed key pair
 */
int get_sealed_size();

/*
 * returns the length of the hash used in the signature
 */
int get_digest_size();

/*
 * returns the size of the signature created by the enclave
 */
int get_signature_size();

/*
 * returns the size of the public key
 */
int get_public_key_size();

/*
 * returns the size of the private key
 */
int get_private_key_size();

/*
 * @brief generates a secp256r1 key pair and returns it sealed by the TEE
 *
 * @param sealed buffer to hold the sealed key pair
 * @param sealed_size size of the sealed key pair
 *
 * @returns SGX_SUCCESS on success, else sgx error code
 */
sgx_status_t generate_key_pair(uint8_t *sealed, uint32_t sealed_size);

/*
 * @brief returns the public key of the sealed key pair provided to the enclave
 *
 * @param sealed buffer containing the sealed key pair
 * @param sealed_size size of the sealed key pair
 * @param public_key buffer to hold the public key
 *
 * @returns SGX_SUCCESS on success, SGX_ERROR_INVALID_PARAMETER for invalid parameters, else sgx error code
 */
sgx_status_t get_public_key(const uint8_t *sealed, const uint32_t sealed_size, uint8_t *public_key);

/*
 * @brief signs the firmware provided by an authorized employee
 *
 * @param firmware buffer containing the firmware
 * @param firmware_size size of the sealed key pair
 * @param sealed buffer containing the sealed key pair
 * @param sealed_size size of the sealed key pair
 * @param public_key buffer with the employees public key; holds enclaves public key after successful signing
 * @param signature buffer with the employees signature; holds the enclaves signature after successful signing
 *
 * @returns SGX_SUCCESS on success, SGX_ERROR_INVALID_PARAMETER for invalid parameters, else sgx error code
 */
sgx_status_t sign_firmware(const uint8_t *firmware, uint32_t firmware_size, const uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint8_t *signature);

/*
 * @brief verifies a firmware signature provided by an authorized employee or enclave
 *
 * @param firmware buffer containing the firmware
 * @param firmware_size size of the sealed key pair or NULL
 * @param sealed buffer containing the sealed key pair
 * @param sealed_size size of the sealed key pair
 * @param public_key buffer with the employees public key or NULL
 * @param signature buffer with the employees signature
 *
 * @returns SGX_EC_VALID on success, SGX_EC_INVALID for invalid signatures, SGX_ERROR_INVALID_PARAMETER for invalid parameters, else sgx error code
 */
sgx_status_t verify_firmware(const uint8_t *firmware, uint32_t firmware_size, const uint8_t *sealed, uint32_t sealed_size, const uint8_t *public_key, const uint8_t *signature);

#endif /* !_ENCLAVE_H_ */