image_auth.h

/*****************************************************************************
 * File Name:   image_auth.h
 *
 * Description: This file contains function declaration for Image Authentication
 *
 ******************************************************************************
 * Copyright 2024, Cypress Semiconductor Corporation (an Infineon company) or
 * an affiliate of Cypress Semiconductor Corporation.  All rights reserved.
 *
 * This software, including source code, documentation and related
 * materials ("Software") is owned by Cypress Semiconductor Corporation
 * or one of its affiliates ("Cypress") and is protected by and subject to
 * worldwide patent protection (United States and foreign),
 * United States copyright laws and international treaty provisions.
 * Therefore, you may use this Software only as provided in the license
 * agreement accompanying the software package from which you
 * obtained this Software ("EULA").
 * If no EULA applies, Cypress hereby grants you a personal, non-exclusive,
 * non-transferable license to copy, modify, and compile the Software
 * source code solely for use in connection with Cypress's
 * integrated circuit products.  Any reproduction, modification, translation,
 * compilation, or representation of this Software except as specified
 * above is prohibited without the express written permission of Cypress.
 *
 * Disclaimer: THIS SOFTWARE IS PROVIDED AS-IS, WITH NO WARRANTY OF ANY KIND,
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 * does not assume any liability arising out of the application or use of the
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 *****************************************************************************/

#ifndef IMAGE_AUTH_H_
#define IMAGE_AUTH_H_

#if defined(MCUBOOT_IMAGE)
#include "psa/crypto.h"
#endif /* MCUBOOT_IMAGE) */

#define FLASH_SBUS_S_OFFSET         0x32000000

#define SLOT_OFFSET                 0x800000

#if defined(MCUBOOT_IMAGE)
#define IMAGE_MAGIC                 0x96f3b83dU

#define IMAGE_TLV_INFO_MAGIC        0x6907

#define FLASH_ADDR(off)             (FLASH_SBUS_S_OFFSET + SLOT_OFFSET + (off))

#define SFLASH_OEM_KEY0_HASH_ADDR   0x13400A38
#define SFLASH_OEM_KEY1_HASH_ADDR   0x13400A48

#define ECC_KEY_BITS                (256u)


/*
 * Image trailer TLV types.
 *
 * Signature is generated by computing signature over the image hash.
 * Currently the only image hash type is SHA256.
 *
 * Signature comes in the form of 2 TLVs.
 *   1st one identifies the public key which should be used to verify it.
 *   2nd one is the actual signature.
 */

#define IMAGE_TLV_PUBKEY            (0x02)   /* public key */

#define IMAGE_TLV_SHA256            (0x10)   /* SHA256 of image hdr and body */

#define IMAGE_TLV_ECDSA256          (0x22)   /* ECDSA of hash output */

/** Image version.  All fields are in little endian. */
struct image_version {
    uint8_t iv_major;
    uint8_t iv_minor;
    uint16_t iv_revision;
    uint32_t iv_build_num;
};

/** Image header.  All fields are in little endian byte order. */
struct image_header {
    uint32_t ih_magic;
    uint32_t ih_load_addr;
    uint16_t ih_hdr_size;           /* Size of image header (bytes). */
    uint16_t ih_protect_tlv_size;   /* Size of protected TLV area (bytes). */
    uint32_t ih_img_size;           /* Does not include header. */
    uint32_t ih_flags;              /* IMAGE_F_[...]. */
    struct image_version ih_ver;
    uint32_t _pad1;
};

/** Image TLV header.  All fields in little endian. */
struct image_tlv_info {
    uint16_t it_magic;
    uint16_t it_tlv_tot;  /* size of TLV area (including tlv_info header) */
};

/** Image trailer TLV format. All fields in little endian. */
struct image_tlv {
    uint16_t it_type;   /* IMAGE_TLV_[...]. */
    uint16_t it_len;    /* Data length (not including TLV header). */
};

/** Image trailer TLV iterator. */
struct image_tlv_iter {
    uint32_t tlv_off; /* Next TLV offset*/
    uint32_t tlv_end; /* TLV END offset */
};

/*******************************************************************************
* Function Prototypes
*******************************************************************************/

/**
 * @brief TLV iterator initialization function.
 *
 * This function initializes a tlv iterator structure. Once initialization is
 * completed, tlv_iter_next() can be called to read the image tlv.
 *
 * @param  it         The pointer to tlv iterator structure. The function populates the
 *                    structure with address of first tlv offset and tlv end offset.
 * @param  hdr        The pointer to image header structure.
 *
 * @return  0 on success.
 * @return  -1 on failure.
 */
int tlv_iter_begin(struct image_tlv_iter *it, const struct image_header *hdr);

/**
 * @brief Next TLV function.
 *
 * This function reads the TLV pointed by offset provided in image_tlv_iter
 * structure and updates the structure to point to next TLV.
 *
 * @param  it         The pointer to TLV iterator structure. The function uses this
 *                    structure to read TLV and update it to point it to the next TLV.
 * @param  off        The offset of tlv's data field from start of image.
 * @param  len        The length of data field of TLV.
 * @param  type       The tag of TLV.
 *
 * @return 0 on success
 * @return -1 on failure.
 * @return 1 when all TLVs are traversed.
 */
int tlv_iter_next(struct image_tlv_iter *it, uint32_t *off, uint16_t *len, uint16_t *type);

/**
 * @brief Check if image magic is valid.
 *
 * @param  hdr        The pointer to image header structure.
 *
 * @return 0 if magic valid.
 * @return -1 if magic invalid.
 */
int is_img_magic_valid(const struct image_header *hdr);

/**
 * @brief Check if public key is valid.
 *
 * @param  key_addr     The pointer to public key.
 *
 * @return 0 if key is valid.
 * @return -1 if key is invalid.
 */
int is_pub_key_valid(uint8_t *key_addr);

#endif /* MCUBOOT_IMAGE) */

/**
 * @brief Validate an image.
 *
 * @param  boot_addr  The start address of image.
 *
 * @return 0 on success.
 * @return -1 on failure.
 */

int validate_image(uint32_t boot_addr);

#endif /* IMAGE_AUTH_H_ */