/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2017-2019 Linaro LTD
 * Copyright (c) 2016-2019 JUUL Labs
 * Copyright (c) 2019-2025 Arm Limited
 * Copyright (c) 2025 Nordic Semiconductor ASA
 *
 * Original license:
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

#include <stdint.h>
#include <flash_map_backend/flash_map_backend.h>

#include "bootutil/image.h"
#include "bootutil/security_cnt.h"
#include "bootutil_priv.h"

#include "mcuboot_config/mcuboot_config.h"

/**
 * Reads the value of an image's security counter.
 *
 * @param state         Pointer to the boot state object.
 * @param slot          Slot of the current image to get the security counter of.
 * @param fap           Pointer to a description structure of the image's
 *                      flash area.
 * @param security_cnt  Pointer to store the security counter value.
 *
 * @return              0 on success; nonzero on failure.
 */
int32_t
bootutil_get_img_security_cnt(struct boot_loader_state *state, int slot,
                              const struct flash_area *fap,
                              uint32_t *img_security_cnt)
{
    struct image_tlv_iter it;
    uint32_t off;
    uint16_t len;
    int32_t rc;

    if ((state == NULL) ||
        (boot_img_hdr(state, slot) == NULL) ||
        (fap == NULL) ||
        (img_security_cnt == NULL)) {
        /* Invalid parameter. */
        return BOOT_EBADARGS;
    }

    /* The security counter TLV is in the protected part of the TLV area. */
    if (boot_img_hdr(state, slot)->ih_protect_tlv_size == 0) {
        return BOOT_EBADIMAGE;
    }

#if defined(MCUBOOT_SWAP_USING_OFFSET)
    it.start_off = boot_get_state_secondary_offset(state, fap);
#endif

    rc = bootutil_tlv_iter_begin(&it, boot_img_hdr(state, slot), fap, IMAGE_TLV_SEC_CNT, true);
    if (rc) {
        return rc;
    }

    /* Traverse through the protected TLV area to find
     * the security counter TLV.
     */

    rc = bootutil_tlv_iter_next(&it, &off, &len, NULL);
    if (rc != 0) {
        /* Security counter TLV has not been found. */
        return -1;
    }

    if (len != sizeof(*img_security_cnt)) {
        /* Security counter is not valid. */
        return BOOT_EBADIMAGE;
    }

    rc = LOAD_IMAGE_DATA(boot_img_hdr(state, slot), fap, off, img_security_cnt, len);
    if (rc != 0) {
        return BOOT_EFLASH;
    }

    return 0;
}