mbed-os/source/Security/protocols/sec_prot_keys.c

/*
 * Copyright (c) 2016-2020, Pelion and affiliates.
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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.
 */

#include "nsconfig.h"
#include <string.h>
#include "ns_types.h"
#include "ns_list.h"
#include "ns_trace.h"
#include "nsdynmemLIB.h"
#include "NWK_INTERFACE/Include/protocol.h"
#include "Common_Protocols/ipv6_constants.h"
#include "socket_api.h"
#include "6LoWPAN/ws/ws_config.h"
#include "Security/protocols/sec_prot_cfg.h"
#include "Security/kmp/kmp_addr.h"
#include "Security/kmp/kmp_api.h"
#include "Security/PANA/pana_eap_header.h"
#include "Security/eapol/eapol_helper.h"
#include "Security/protocols/sec_prot_certs.h"
#include "Security/protocols/sec_prot_keys.h"
#include "Security/protocols/sec_prot.h"
#include "Security/protocols/sec_prot_lib.h"

#ifdef HAVE_WS

#define TRACE_GROUP "spke"

static const uint8_t empty_hash[GTK_HASH_LEN] = {0};

sec_prot_keys_t *sec_prot_keys_create(sec_prot_gtk_keys_t *gtks, const sec_prot_certs_t *certs)
{
    sec_prot_keys_t *sec_keys = ns_dyn_mem_alloc(sizeof(sec_prot_keys_t));
    if (!sec_keys) {
        return NULL;
    }

    sec_prot_keys_init(sec_keys, gtks, certs);

    return sec_keys;
}

void sec_prot_keys_init(sec_prot_keys_t *sec_keys, sec_prot_gtk_keys_t *gtks, const sec_prot_certs_t *certs)
{
    memset(sec_keys, 0, sizeof(sec_prot_keys_t));
    sec_keys->pmk_lifetime = 0;
    sec_keys->ptk_lifetime = 0;
    sec_keys->pmk_key_replay_cnt = 0;
    sec_keys->gtks = gtks;
    sec_keys->certs = certs;
    sec_keys->gtkl = 0;
    sec_keys->gtk_set_index = -1;
    sec_keys->pmk_set = false;
    sec_keys->ptk_set = false;
    sec_keys->pmk_key_replay_cnt_set = false;
    sec_keys->updated = false;
    sec_keys->ptk_eui_64_set = false;
    sec_keys->pmk_mismatch = false;
    sec_keys->ptk_mismatch = false;
    sec_prot_keys_ptk_installed_gtk_hash_clear_all(sec_keys);
}

void sec_prot_keys_delete(sec_prot_keys_t *sec_keys)
{
    ns_dyn_mem_free(sec_keys);
}

sec_prot_gtk_keys_t *sec_prot_keys_gtks_create(void)
{
    sec_prot_gtk_keys_t *gtks = ns_dyn_mem_alloc(sizeof(sec_prot_gtk_keys_t));
    if (!gtks) {
        return NULL;
    }

    sec_prot_keys_gtks_init(gtks);

    return gtks;
}

void sec_prot_keys_gtks_init(sec_prot_gtk_keys_t *gtks)
{
    memset(gtks, 0, sizeof(sec_prot_gtk_keys_t));
    gtks->updated = false;
}

void sec_prot_keys_gtks_clear(sec_prot_gtk_keys_t *gtks)
{
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            gtks->updated = true;
        }
    }
    memset(gtks, 0, sizeof(sec_prot_gtk_keys_t));
}

void sec_prot_keys_gtks_delete(sec_prot_gtk_keys_t *gtks)
{
    ns_dyn_mem_free(gtks);
}

void sec_prot_keys_pmk_write(sec_prot_keys_t *sec_keys, uint8_t *pmk, uint32_t pmk_lifetime)
{
    memcpy(sec_keys->pmk, pmk, PMK_LEN);
    sec_keys->pmk_key_replay_cnt = 0;
    sec_keys->pmk_key_replay_cnt_set = false;
    sec_keys->pmk_lifetime = pmk_lifetime;
    sec_keys->pmk_set = true;
    sec_keys->updated = true;
}

void sec_prot_keys_pmk_delete(sec_prot_keys_t *sec_keys)
{
    if (sec_keys->pmk_key_replay_cnt != 0 || sec_keys->pmk_key_replay_cnt_set ||
            sec_keys->pmk_lifetime != 0 || sec_keys->pmk_set) {
        sec_keys->updated = true;
    }
    memset(sec_keys->pmk, 0, PMK_LEN);
    sec_keys->pmk_key_replay_cnt = 0;
    sec_keys->pmk_key_replay_cnt_set = false;
    sec_keys->pmk_lifetime = 0;
    sec_keys->pmk_set = false;
}

uint8_t *sec_prot_keys_pmk_get(sec_prot_keys_t *sec_keys)
{
    if (!sec_keys->pmk_set) {
        return NULL;
    }

    return sec_keys->pmk;
}

uint32_t sec_prot_keys_pmk_lifetime_get(sec_prot_keys_t *sec_keys)
{
    if (!sec_keys->pmk_set) {
        return 0;
    }

    return sec_keys->pmk_lifetime;
}

uint64_t sec_prot_keys_pmk_replay_cnt_get(sec_prot_keys_t *sec_keys)
{
    return sec_keys->pmk_key_replay_cnt;
}

void sec_prot_keys_pmk_replay_cnt_set(sec_prot_keys_t *sec_keys, uint64_t counter)
{
    sec_keys->pmk_key_replay_cnt_set = true;
    sec_keys->pmk_key_replay_cnt = counter;
}
bool sec_prot_keys_pmk_replay_cnt_increment(sec_prot_keys_t *sec_keys)
{
    // Start from zero i.e. does not increment on first call
    if (!sec_keys->pmk_key_replay_cnt_set) {
        sec_keys->pmk_key_replay_cnt_set = true;
        return true;
    }
    // If counter is near to exhaust return error (ignores MSB 32bits which are re-start counter)
    if ((sec_keys->pmk_key_replay_cnt & PMK_KEY_REPLAY_CNT_LIMIT_MASK) > PMK_KEY_REPLAY_CNT_LIMIT) {
        sec_keys->pmk_key_replay_cnt |= 0xFFFF; // Invalidate counter; will result removal of keys
        return false;
    }
    sec_keys->pmk_key_replay_cnt++;
    return true;
}

bool sec_prot_keys_pmk_replay_cnt_compare(uint64_t received_counter, sec_prot_keys_t *sec_keys)
{
    // If previous value is set must be greater
    if (sec_keys->pmk_key_replay_cnt_set && received_counter > sec_keys->pmk_key_replay_cnt) {
        return true;
    } else if (!sec_keys->pmk_key_replay_cnt_set && received_counter >= sec_keys->pmk_key_replay_cnt) {
        // Otherwise allows also same value e.g. zero
        return true;
    }

    return false;
}

void sec_prot_keys_pmk_mismatch_set(sec_prot_keys_t *sec_keys)
{
    sec_keys->pmk_mismatch = true;
}

void sec_prot_keys_pmk_mismatch_reset(sec_prot_keys_t *sec_keys)
{
    sec_keys->pmk_mismatch = false;
}

bool sec_prot_keys_pmk_mismatch_is_set(sec_prot_keys_t *sec_keys)
{
    return sec_keys->pmk_mismatch;
}

bool sec_prot_keys_pmk_lifetime_decrement(sec_prot_keys_t *sec_keys, uint8_t seconds)
{
    if (!sec_keys->pmk_set) {
        return false;
    }

    if (sec_keys->pmk_lifetime > seconds) {
        sec_keys->pmk_lifetime -= seconds;
    } else {
        if (sec_keys->pmk_lifetime > 0) {
            sec_keys->pmk_lifetime = 0;
            sec_prot_keys_ptk_delete(sec_keys);
            sec_prot_keys_pmk_delete(sec_keys);
            return true;
        }
    }
    return false;
}

void sec_prot_keys_ptk_write(sec_prot_keys_t *sec_keys, uint8_t *ptk, uint32_t ptk_lifetime)
{
    memcpy(sec_keys->ptk, ptk, PTK_LEN);
    sec_keys->ptk_lifetime = ptk_lifetime;
    sec_keys->ptk_set = true;
    sec_keys->updated = true;
}

void sec_prot_keys_ptk_delete(sec_prot_keys_t *sec_keys)
{
    if (sec_keys->ptk_lifetime != 0 || sec_keys->ptk_set) {
        sec_keys->updated = true;
    }
    memset(sec_keys->ptk, 0, PTK_LEN);
    sec_keys->ptk_lifetime = 0;
    sec_keys->ptk_set = false;
}

uint8_t *sec_prot_keys_ptk_get(sec_prot_keys_t *sec_keys)
{
    if (!sec_keys->ptk_set) {
        return NULL;
    }

    return sec_keys->ptk;
}

uint32_t sec_prot_keys_ptk_lifetime_get(sec_prot_keys_t *sec_keys)
{
    if (!sec_keys->ptk_set) {
        return 0;
    }

    return sec_keys->ptk_lifetime;
}

void sec_prot_keys_ptk_mismatch_set(sec_prot_keys_t *sec_keys)
{
    sec_keys->ptk_mismatch = true;
}

void sec_prot_keys_ptk_mismatch_reset(sec_prot_keys_t *sec_keys)
{
    sec_keys->ptk_mismatch = false;
}

bool sec_prot_keys_ptk_mismatch_is_set(sec_prot_keys_t *sec_keys)
{
    return sec_keys->ptk_mismatch;
}

void sec_prot_keys_ptk_eui_64_write(sec_prot_keys_t *sec_keys, const uint8_t *eui_64)
{
    memcpy(sec_keys->ptk_eui_64, eui_64, 8);
    sec_keys->ptk_eui_64_set = true;
    sec_keys->updated = true;
}

uint8_t *sec_prot_keys_ptk_eui_64_get(sec_prot_keys_t *sec_keys)
{
    if (!sec_keys->ptk_eui_64_set) {
        return NULL;
    }

    return sec_keys->ptk_eui_64;
}

void sec_prot_keys_ptk_eui_64_delete(sec_prot_keys_t *sec_keys)
{
    if (sec_keys->ptk_eui_64_set) {
        sec_keys->updated = true;
    }
    memset(sec_keys->ptk_eui_64, 0, 8);
    sec_keys->ptk_eui_64_set = false;
}

bool sec_prot_keys_ptk_lifetime_decrement(sec_prot_keys_t *sec_keys, uint8_t seconds)
{
    if (!sec_keys->ptk_set) {
        return false;
    }

    if (sec_keys->ptk_lifetime > seconds) {
        sec_keys->ptk_lifetime -= seconds;
    } else {
        if (sec_keys->ptk_lifetime > 0) {
            sec_prot_keys_ptk_delete(sec_keys);
            sec_keys->ptk_lifetime = 0;
            return true;
        }
    }
    return false;
}

bool sec_prot_keys_are_updated(sec_prot_keys_t *sec_keys)
{
    return sec_keys->updated;
}

void sec_prot_keys_updated_reset(sec_prot_keys_t *sec_keys)
{
    sec_keys->updated = false;
}

uint8_t sec_prot_keys_fresh_gtkl_get(sec_prot_gtk_keys_t *gtks)
{
    uint8_t gtkl = 0;

    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_status_is_live(gtks, i)) {
            gtkl |= 1 << i;
        }
    }

    return gtkl;
}

void sec_prot_keys_gtkl_set(sec_prot_keys_t *sec_keys, uint8_t gtkl)
{
    sec_keys->gtkl = gtkl;
}

bool sec_prot_keys_gtkl_gtk_is_live(sec_prot_keys_t *sec_keys, uint8_t index)
{
    if (index >= GTK_NUM) {
        return false;
    }

    if (sec_keys->gtkl & (1 << index)) {
        return true;
    }

    return false;
}

int8_t sec_prot_keys_gtkl_gtk_live_set(sec_prot_keys_t *sec_keys, uint8_t index)
{
    if (index >= GTK_NUM) {
        return -1;
    }

    sec_keys->gtkl |= (1 << index);

    return 0;
}

int8_t sec_prot_keys_gtk_insert_index_set(sec_prot_keys_t *sec_keys, uint8_t index)
{
    if (index >= GTK_NUM || !sec_keys->gtks->gtk[index].set) {
        return -1;
    }

    sec_keys->gtk_set_index = index;
    return 0;
}

int8_t sec_prot_keys_gtk_insert_index_get(sec_prot_keys_t *sec_keys)
{
    return sec_keys->gtk_set_index;
}

void sec_prot_keys_gtk_insert_index_clear(sec_prot_keys_t *sec_keys)
{
    sec_keys->gtk_set_index = -1;
}

void sec_prot_keys_gtkl_from_gtk_insert_index_set(sec_prot_keys_t *sec_keys)
{
    if (sec_keys->gtk_set_index >= 0) {
        sec_prot_keys_gtkl_gtk_live_set(sec_keys, sec_keys->gtk_set_index);
        sec_prot_keys_gtk_insert_index_clear(sec_keys);
    }
}

int8_t sec_prot_keys_gtk_insert_index_from_gtkl_get(sec_prot_keys_t *sec_keys)
{
    // Get currently active key index
    int8_t active_index = sec_prot_keys_gtk_status_active_get(sec_keys->gtks);

    if (active_index >= 0 && !sec_prot_keys_gtkl_gtk_is_live(sec_keys, active_index)) {
        // If currently active key is not live on remote, inserts it
        sec_prot_keys_gtk_insert_index_set(sec_keys, active_index);
        return active_index;
    }

    // Checks all keys
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_status_is_live(sec_keys->gtks, i) ||
                sec_prot_keys_gtk_status_get(sec_keys->gtks, i) == GTK_STATUS_OLD) {
            /* If key is live, but not indicated on GTKL inserts it. Also old keys indicated
               still on GTK hash are inserted, since supplicants do not know the status of the
               key and might need the key for receive (only) from not updated neighbors  */
            if (!sec_prot_keys_gtkl_gtk_is_live(sec_keys, i)) {
                sec_prot_keys_gtk_insert_index_set(sec_keys, i);
                return i;
            }
        }
    }

    return -1;
}

uint8_t *sec_prot_keys_get_gtk_to_insert(sec_prot_keys_t *sec_keys, uint8_t *index)
{
    if (sec_keys->gtk_set_index >= 0 && sec_keys->gtks->gtk[sec_keys->gtk_set_index].set) {
        *index = sec_keys->gtk_set_index;
        return sec_keys->gtks->gtk[sec_keys->gtk_set_index].key;
    } else {
        return NULL;
    }
}

int8_t sec_prot_keys_gtk_set(sec_prot_gtk_keys_t *gtks, uint8_t index, uint8_t *gtk, uint32_t lifetime)
{
    if (!gtk || index >= GTK_NUM) {
        return -1;
    }

    // If same GTK is given again, do not update
    if (gtks->gtk[index].set && memcmp(gtks->gtk[index].key, gtk, GTK_LEN) == 0) {
        return -1;
    }

    sec_prot_keys_gtk_clear(gtks, index);
    uint8_t install_order = sec_prot_keys_gtk_install_order_last_get(gtks);

    gtks->gtk[index].set = true;
    gtks->gtk[index].lifetime = lifetime;
    gtks->gtk[index].status = GTK_STATUS_NEW;
    gtks->gtk[index].install_order = install_order;
    memcpy(gtks->gtk[index].key, gtk, GTK_LEN);

    gtks->updated = true;

    return 0;
}

int8_t sec_prot_keys_gtk_clear(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (!gtks || index >= GTK_NUM) {
        return -1;
    }

    gtks->gtk[index].set = false;
    gtks->gtk[index].lifetime = 0;   // Should be provided by authenticator
    gtks->gtk[index].status = GTK_STATUS_NEW;
    memset(gtks->gtk[index].key, 0, GTK_LEN);

    gtks->updated = true;

    sec_prot_keys_gtk_install_order_update(gtks);

    return 0;
}

bool sec_prot_keys_gtk_is_set(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return false;
    }

    return true;
}

uint8_t *sec_prot_keys_gtk_get(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return NULL;
    }

    return gtks->gtk[index].key;
}

uint32_t sec_prot_keys_gtk_lifetime_get(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return 0;
    }

    return gtks->gtk[index].lifetime;
}

uint32_t sec_prot_keys_gtk_lifetime_decrement(sec_prot_gtk_keys_t *gtks, uint8_t index, uint64_t current_time, uint32_t seconds, bool gtk_update_enable)
{
    if (gtks->gtk[index].lifetime > seconds) {
        gtks->gtk[index].lifetime -= seconds;
    } else {
        gtks->gtk[index].lifetime = 0;
    }

    // Calculates expiration timestamp for GTK from current time and lifetime
    uint64_t expirytime = current_time + gtks->gtk[index].lifetime;
    uint64_t diff;
    // Compares calculated timestamp to stored one
    if (gtks->gtk[index].expirytime >= expirytime) {
        diff = gtks->gtk[index].expirytime - expirytime;
    } else {
        diff = expirytime - gtks->gtk[index].expirytime;
    }
    // If timestamps differ for more than 5 minutes marks field as updated (and stores to NVM)
    if (diff > 300 && gtk_update_enable) {
        gtks->updated = true;
        sec_prot_keys_gtk_expirytime_set(gtks, index, expirytime);
    }

    return gtks->gtk[index].lifetime;
}

uint64_t sec_prot_keys_gtk_exptime_from_lifetime_get(sec_prot_gtk_keys_t *gtks, uint8_t index, uint64_t current_time)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return 0;
    }

    uint32_t lifetime = gtks->gtk[index].lifetime;
    return current_time + lifetime;
}

int8_t sec_prot_keys_gtk_expirytime_set(sec_prot_gtk_keys_t *gtks, uint8_t index, uint64_t expirytime)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return -1;
    }

    gtks->gtk[index].expirytime = expirytime;

    return 0;
}

bool sec_prot_keys_gtks_are_updated(sec_prot_gtk_keys_t *gtks)
{
    return gtks->updated;
}

void sec_prot_keys_gtks_updated_set(sec_prot_gtk_keys_t *gtks)
{
    gtks->updated = true;
}

void sec_prot_keys_gtks_updated_reset(sec_prot_gtk_keys_t *gtks)
{
    gtks->updated = false;
}

void sec_prot_keys_gtk_status_fresh_set(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return;
    }

    // Active key remains as active, old keys are never reused
    if (gtks->gtk[index].status < GTK_STATUS_FRESH) {
        gtks->gtk[index].status = GTK_STATUS_FRESH;
        gtks->updated = true;
    }
}

void sec_prot_keys_gtk_status_all_fresh_set(sec_prot_gtk_keys_t *gtks)
{
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        sec_prot_keys_gtk_status_fresh_set(gtks, i);
    }
}

int8_t sec_prot_keys_gtk_status_active_set(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return -1;
    }

    // If key is valid to be taken into use sets it active
    if (gtks->gtk[index].status == GTK_STATUS_FRESH) {
        // Sets previously active key old
        for (uint8_t i = 0; i < GTK_NUM; i++) {
            // Sets previously active key old
            if (gtks->gtk[i].status == GTK_STATUS_ACTIVE) {
                gtks->gtk[i].status = GTK_STATUS_OLD;
                gtks->updated = true;
            }
        }
        gtks->gtk[index].status = GTK_STATUS_ACTIVE;
        /* Changing fresh to active does not change the gtks updated state since active
           keys are set to fresh on nvm read on startup */
        return 0;
    }

    return -1;
}

int8_t sec_prot_keys_gtk_status_active_get(sec_prot_gtk_keys_t *gtks)
{
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (gtks->gtk[i].status == GTK_STATUS_ACTIVE) {
            return i;
        }
    }

    return -1;
}

int8_t sec_prot_keys_gtk_status_active_to_fresh_set(sec_prot_gtk_keys_t *gtks)
{
    int8_t index = sec_prot_keys_gtk_status_active_get(gtks);
    if (index < 0) {
        return -1;
    }

    return sec_prot_keys_gtk_status_set(gtks, index, GTK_STATUS_FRESH);
}

bool sec_prot_keys_gtk_status_is_live(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return false;
    }

    if (gtks->gtk[index].status == GTK_STATUS_FRESH || gtks->gtk[index].status == GTK_STATUS_ACTIVE) {
        return true;
    }

    return false;
}

void sec_prot_keys_gtk_status_new_set(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return;
    }

    if (gtks->gtk[index].status != GTK_STATUS_NEW) {
        gtks->updated = true;
    }

    gtks->gtk[index].status = GTK_STATUS_NEW;
}

uint8_t sec_prot_keys_gtk_status_get(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return 0;
    }

    return gtks->gtk[index].status;
}

int8_t sec_prot_keys_gtk_status_set(sec_prot_gtk_keys_t *gtks, uint8_t index, uint8_t status)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return -1;
    }

    if (gtks->gtk[index].status != status) {
        gtks->updated = true;
    }

    gtks->gtk[index].status = status;
    return 0;
}

void sec_prot_keys_gtks_hash_generate(sec_prot_gtk_keys_t *gtks, uint8_t *gtkhash)
{
    memset(gtkhash, 0, GTK_ALL_HASHES_LEN);

    uint8_t *gtk_hash_ptr = gtkhash;

    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            uint8_t *gtk = sec_prot_keys_gtk_get(gtks, i);
            sec_prot_lib_gtkhash_generate(gtk, gtk_hash_ptr);
        }
        gtk_hash_ptr += GTK_HASH_LEN;
    }
}

int8_t sec_prot_keys_gtk_hash_generate(uint8_t *gtk, uint8_t *gtk_hash)
{
    return sec_prot_lib_gtkhash_generate(gtk, gtk_hash);
}

int8_t sec_prot_keys_gtk_valid_check(uint8_t *gtk)
{
    uint8_t gtk_hash[8];
    sec_prot_lib_gtkhash_generate(gtk, gtk_hash);

    // Checks if GTK hash for the GTK would be all zero
    if (memcmp(gtk_hash, empty_hash, GTK_HASH_LEN) == 0) {
        return -1;
    }

    return 0;
}

gtk_mismatch_e sec_prot_keys_gtks_hash_update(sec_prot_gtk_keys_t *gtks, uint8_t *gtkhash, bool del_gtk_on_mismatch)
{
    uint8_t *gtk_hash_ptr = gtkhash;

    gtk_mismatch_e mismatch = GTK_NO_MISMATCH;

    for (uint8_t i = 0; i < GTK_NUM; i++, gtk_hash_ptr += 8) {
        // If hash is not set, stop using the key
        if (sec_prot_keys_gtk_hash_empty(gtk_hash_ptr)) {
            if (sec_prot_keys_gtk_is_set(gtks, i)) {
                uint32_t lifetime = sec_prot_keys_gtk_lifetime_get(gtks, i);
                if (lifetime > GTK_EXPIRE_MISMATCH_TIME) {
                    tr_info("GTK mismatch %i expired time, lifetime: %"PRIu32"", i, lifetime);
                    // Only indicate mismatch in case fresh hash is received
                    if (mismatch < GTK_LIFETIME_MISMATCH && del_gtk_on_mismatch) {
                        mismatch = GTK_LIFETIME_MISMATCH;
                    }
                }
                // Only delete in case fresh hash is received
                if (del_gtk_on_mismatch) {
                    sec_prot_keys_gtk_clear(gtks, i);
                }
            }
        } else {
            // Check is hash matches to existing key
            uint8_t gtk_hash[8];
            uint8_t *gtk = sec_prot_keys_gtk_get(gtks, i);
            if (!gtk) {
                // Hash set but GTK is not known, set mismatch
                tr_info("GTK mismatch: %i", i);
                if (mismatch < GTK_HASH_MISMATCH) {
                    mismatch = GTK_HASH_MISMATCH;
                }
                continue;
            }

            sec_prot_lib_gtkhash_generate(gtk, gtk_hash);

            if (memcmp(gtk_hash, gtk_hash_ptr, 8) == 0) {
                // Key is fresh (or active, if old do not change state)
                sec_prot_keys_gtk_status_fresh_set(gtks, i);
            } else {
                // Hash does not match, set mismatch and delete key
                tr_info("GTK mismatch: %i", i);
                if (mismatch < GTK_HASH_MISMATCH) {
                    mismatch = GTK_HASH_MISMATCH;
                }
                // Only delete in case fresh hash is received
                if (del_gtk_on_mismatch) {
                    sec_prot_keys_gtk_clear(gtks, i);
                }
            }
        }
    }

    return mismatch;
}

bool sec_prot_keys_gtk_hash_empty(uint8_t *gtkhash)
{
    if (memcmp(gtkhash, empty_hash, GTK_HASH_LEN) == 0) {
        return true;
    } else {
        return false;
    }
}

int8_t sec_prot_keys_gtk_install_order_last_get(sec_prot_gtk_keys_t *gtks)
{
    int8_t install_order = -1;

    // Gets the last key index
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            if (gtks->gtk[i].install_order > install_order) {
                install_order = gtks->gtk[i].install_order;
            }
        }
    }

    return install_order + 1;
}

int8_t sec_prot_keys_gtk_install_order_last_index_get(sec_prot_gtk_keys_t *gtks)
{
    int8_t install_order = -1;
    int8_t index = -1;

    // Gets the last key index
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            if (gtks->gtk[i].install_order > install_order) {
                install_order = gtks->gtk[i].install_order;
                index = i;
            }
        }
    }

    return index;
}

uint32_t sec_prot_keys_gtk_install_order_last_lifetime_get(sec_prot_gtk_keys_t *gtks)
{
    uint32_t lifetime = 0;
    int8_t install_order = -1;

    // Gets the last key index
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            if (gtks->gtk[i].install_order > install_order) {
                install_order = gtks->gtk[i].install_order;
                lifetime = gtks->gtk[i].lifetime;
            }
        }
    }

    return lifetime;
}

int8_t sec_prot_keys_gtk_install_order_first_index_get(sec_prot_gtk_keys_t *gtks)
{
    // Gets the first key index
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            if (gtks->gtk[i].install_order == GTK_INSTALL_ORDER_FIRST) {
                return i;
            }
        }
    }

    return -1;
}

int8_t sec_prot_keys_gtk_install_order_second_index_get(sec_prot_gtk_keys_t *gtks)
{
    // Gets the first key index
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            if (gtks->gtk[i].install_order == GTK_INSTALL_ORDER_SECOND) {
                return i;
            }
        }
    }

    return -1;
}

void sec_prot_keys_gtk_install_order_update(sec_prot_gtk_keys_t *gtks)
{
    int8_t ordered_indexes[4] = {-1, -1, -1, -1};

    // Creates table of ordered indexes
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            ordered_indexes[gtks->gtk[i].install_order] = i;
        }
    }

    // Updates indexes of the GTKs
    uint8_t new_install_order = 0;
    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (ordered_indexes[i] >= 0) {
            if (gtks->gtk[ordered_indexes[i]].install_order != new_install_order) {
                gtks->updated = true;
            }
            gtks->gtk[ordered_indexes[i]].install_order = new_install_order++;
        }
    }
}

int8_t sec_prot_keys_gtk_install_index_get(sec_prot_gtk_keys_t *gtks)
{
    // Gets the index of the last key to be installed
    int8_t install_index = sec_prot_keys_gtk_install_order_last_index_get(gtks);
    if (install_index < 0) {
        install_index = 0;
    }

    // Checks if there is free index, and available uses that for new GTK
    for (uint8_t ctr = 0, i = install_index; ctr < GTK_NUM; ctr++) {
        if (!sec_prot_keys_gtk_is_set(gtks, i)) {
            install_index = i;
            break;
        }
        i++;
        if (i >= GTK_NUM) {
            i = 0;
        }
    }

    return install_index;
}

uint8_t sec_prot_keys_gtk_install_order_get(sec_prot_gtk_keys_t *gtks, uint8_t index)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return 0;
    }

    return gtks->gtk[index].install_order;
}

int8_t sec_prot_keys_gtk_install_order_set(sec_prot_gtk_keys_t *gtks, uint8_t index, uint8_t install_order)
{
    if (index >= GTK_NUM || !gtks->gtk[index].set) {
        return -1;
    }
    if (gtks->gtk[index].install_order != install_order) {
        gtks->updated = true;
    }

    gtks->gtk[index].install_order = install_order;
    return 0;
}


uint8_t sec_prot_keys_gtk_count(sec_prot_gtk_keys_t *gtks)
{
    uint8_t count = 0;

    for (uint8_t i = 0; i < GTK_NUM; i++) {
        if (sec_prot_keys_gtk_is_set(gtks, i)) {
            count++;
        }
    }

    return count;
}

void sec_prot_keys_ptk_installed_gtk_hash_clear_all(sec_prot_keys_t *sec_keys)
{
    for (uint8_t index = 0; index < GTK_NUM; index++) {
        memset(sec_keys->ins_gtk_hash[index].hash, 0, INS_GTK_HASH_LEN);
    }
    sec_keys->ins_gtk_hash_set = 0;
    sec_keys->ins_gtk_4wh_hash_set = 0;
}

void sec_prot_keys_ptk_installed_gtk_hash_set(sec_prot_keys_t *sec_keys, bool is_4wh)
{
    if (sec_keys->gtk_set_index >= 0) {
        uint8_t *gtk = sec_prot_keys_gtk_get(sec_keys->gtks, sec_keys->gtk_set_index);
        if (!gtk) {
            return;
        }
        uint8_t gtk_hash[GTK_HASH_LEN];
        if (sec_prot_keys_gtk_hash_generate(gtk, gtk_hash) < 0) {
            return;
        }
        /* Store two byte hash. This is long enough for the GTK installed check, since
         * possible conflict between hashes causes only that 4WH is initiated/is not
         * initiated instead of GKH.
         */
        memcpy(sec_keys->ins_gtk_hash[sec_keys->gtk_set_index].hash, gtk_hash, INS_GTK_HASH_LEN);
        sec_keys->ins_gtk_hash_set |= (1 << sec_keys->gtk_set_index);
        /* If used on 4WH will store the hash in case GKH is initiated later for the
         * same index as 4WH (likely to happen if just GTK update is made). This allows
         * that NVM storage does not need to be updated since hash is already stored. */
        if (is_4wh) {
            sec_keys->ins_gtk_4wh_hash_set |= (1 << sec_keys->gtk_set_index);
        } else {
            sec_keys->ins_gtk_4wh_hash_set &= ~(1 << sec_keys->gtk_set_index);
        }
    }
}

bool sec_prot_keys_ptk_installed_gtk_hash_mismatch_check(sec_prot_keys_t *sec_keys, uint8_t gtk_index)
{
    // If not set or the key has been inserted by 4WH then there is no mismatch
    if ((sec_keys->ins_gtk_hash_set & (1 << sec_keys->gtk_set_index)) == 0 ||
            (sec_keys->ins_gtk_hash_set & (1 << sec_keys->gtk_set_index)) == 1) {
        return false;
    }

    uint8_t *gtk = sec_prot_keys_gtk_get(sec_keys->gtks, gtk_index);
    if (!gtk) {
        return false;
    }

    // Calculated GTK hash for the current GTK on the defined index
    uint8_t gtk_hash[GTK_HASH_LEN];
    if (sec_prot_keys_gtk_hash_generate(gtk, gtk_hash) < 0) {
        return false;
    }

    // If PTK has been used to install different GTK to index than the current one, trigger mismatch
    if (memcmp(sec_keys->ins_gtk_hash[sec_keys->gtk_set_index].hash, gtk_hash, INS_GTK_HASH_LEN) != 0) {
        return true;
    }

    return false;
}

#endif /* HAVE_WS */