epd42/components/ant/ant_encryption/ant_encrypt_config.c

/* Copyright (c) 2015 Nordic Semiconductor. All Rights Reserved.
 *
 * The information contained herein is property of Nordic Semiconductor ASA.
 * Terms and conditions of usage are described in detail in NORDIC
 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
 *
 * Licensees are granted free, non-transferable use of the information. NO
 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
 * the file.
 *
 */

#include <stdlib.h>
#include <stdbool.h>
#include "ant_encrypt_config.h"
#include "ant_interface.h"
#include "ant_parameters.h"
#include "nrf_error.h"

#ifdef ANT_ENCRYPT_SLAVE_NEGOTIATION_USED
    #include "ant_encrypt_negotiation_slave.h"
#endif

 /*lint -e551 -save*/
/** Flag for checking if stack was configured for encryption. */
static bool m_stack_encryption_configured = false;
 /*lint -restore */
 
 /** Pointer to handler of module's events. */
static ant_encryp_user_handler_t m_ant_enc_evt_handler = NULL;

static ret_code_t ant_enc_advance_burs_config_apply(
    ant_encrypt_adv_burst_settings_t const * const p_adv_burst_set);

ret_code_t ant_stack_encryption_config(ant_encrypt_stack_settings_t const * const p_crypto_set)
{
    ret_code_t err_code;

    for ( uint32_t i = 0; i < p_crypto_set->key_number; i++)
    {
        err_code = sd_ant_crypto_key_set(i, p_crypto_set->pp_key[i]);

        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
    }

    if (p_crypto_set->p_adv_burst_config != NULL)
    {
        err_code = ant_enc_advance_burs_config_apply(p_crypto_set->p_adv_burst_config);

        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
    }

    // subcomands LUT for @ref sd_ant_crypto_info_set calls
    const uint8_t set_enc_info_param_lut[] =
    {
        ENCRYPTION_INFO_SET_CRYPTO_ID,
        ENCRYPTION_INFO_SET_CUSTOM_USER_DATA,
        ENCRYPTION_INFO_SET_RNG_SEED
    };

    for ( uint32_t i = 0; i < sizeof(set_enc_info_param_lut); i++)
    {
        if ( p_crypto_set->info.pp_array[i] != NULL)
        {
            err_code = sd_ant_crypto_info_set(set_enc_info_param_lut[i],
                                              p_crypto_set->info.pp_array[i]);

            if (err_code != NRF_SUCCESS)
            {
                return err_code;
            }
        }
    }

    #ifdef ANT_ENCRYPT_SLAVE_NEGOTIATION_USED
        // all ANT channels have unsupported slave encryption tracking (even master's channel)
        ant_channel_encryp_negotiation_slave_init();
    #endif
    
    m_ant_enc_evt_handler = NULL;
    
    m_stack_encryption_configured = true;

    return NRF_SUCCESS;
}


/**
 * @brief Function for configuring advanced burst settings according to encryption requirements.
 *
 * @param p_adv_burst_set  Pointer to ANT advanced burst settings.
 *
 * @retval Value returned by @ref sd_ant_adv_burst_config_set.
 */
static ret_code_t ant_enc_advance_burs_config_apply(
    ant_encrypt_adv_burst_settings_t const * const p_adv_burst_set)
{
    uint8_t adv_burst_conf_str[ADV_BURST_CFG_MIN_SIZE] =
    { ADV_BURST_MODE_ENABLE, 0, 0, 0, 0, 0, 0, 0 };

    adv_burst_conf_str[ADV_BURST_CFG_PACKET_SIZE_INDEX] = p_adv_burst_set->packet_length;
    adv_burst_conf_str[ADV_BURST_CFG_REQUIRED_FEATURES] = p_adv_burst_set->required_feature;
    adv_burst_conf_str[ADV_BURST_CFG_OPTIONAL_FEATURES] = p_adv_burst_set->optional_feature;

    return sd_ant_adv_burst_config_set(adv_burst_conf_str, sizeof(adv_burst_conf_str));
}


ret_code_t ant_channel_encrypt_config_perform(uint8_t                          channel_number,
                                              ant_encrypt_channel_settings_t * p_crypto_config)
{
    return sd_ant_crypto_channel_enable(channel_number,
                                        p_crypto_config->mode,
                                        p_crypto_config->key_index,
                                        p_crypto_config->decimation_rate);
}


ret_code_t ant_channel_encrypt_config(uint8_t                          channel_type,
                                      uint8_t                          channel_number,
                                      ant_encrypt_channel_settings_t * p_crypto_config)
{
    ret_code_t err_code;

    if (p_crypto_config != NULL)
    {
        // encryption of the stack should be initialized previously
        if (m_stack_encryption_configured == false)
        {
            return MODULE_NOT_INITIALZED;
        }

        switch (channel_type)
        {
            case CHANNEL_TYPE_MASTER:
                err_code = ant_channel_encrypt_config_perform(channel_number, p_crypto_config);
#ifdef ANT_ENCRYPT_SLAVE_NEGOTIATION_USED
                ant_channel_encryp_tracking_state_set(channel_number,
                                                      ANT_ENC_CHANNEL_STAT_TRACKING_UNSUPPORTED);
#endif
                break;

#ifdef ANT_ENCRYPT_SLAVE_NEGOTIATION_USED
            case CHANNEL_TYPE_SLAVE:
                ant_slave_channel_encrypt_config(channel_number, p_crypto_config);

                if (p_crypto_config->mode == ENCRYPTION_DISABLED_MODE)
                {
                    err_code = ant_channel_encrypt_config_perform(channel_number, p_crypto_config);
                    ant_channel_encryp_tracking_state_set(channel_number,
                                                          ANT_ENC_CHANNEL_STAT_TRACKING_UNSUPPORTED);
                }
                else
                {
                    ant_channel_encryp_tracking_state_set(channel_number,
                                                          ANT_ENC_CHANNEL_STAT_NOT_TRACKING);
                    err_code = NRF_SUCCESS;
                }
                break;
#endif

            default:
                err_code = NRF_ERROR_INVALID_PARAM;
                break;
        }
    }
    else
    {
#ifdef ANT_ENCRYPT_SLAVE_NEGOTIATION_USED
        ant_channel_encryp_tracking_state_set(channel_number,
                                              ANT_ENC_CHANNEL_STAT_TRACKING_UNSUPPORTED);
#endif
        err_code = NRF_SUCCESS;
    }

    return err_code;
}

/** @brief Function for calling the handler of module events.*/
static void ant_encrypt_user_handler_try_to_run(uint8_t ant_channel, ant_encrypt_user_evt_t event)
{
    if (m_ant_enc_evt_handler != NULL)
    {
        m_ant_enc_evt_handler(ant_channel, event);
    }
}

void ant_encrypt_event_handler(ant_evt_t * p_ant_evt)
{
    uint8_t const ant_channel = p_ant_evt->channel;
    
#ifdef ANT_ENCRYPT_SLAVE_NEGOTIATION_USED
    ant_slave_encrypt_negotiation(p_ant_evt);
#endif
    
    switch (p_ant_evt->event)
    {
        case EVENT_RX_FAIL_GO_TO_SEARCH:
            ant_encrypt_user_handler_try_to_run(ant_channel, ANT_ENC_EVT_CHANNEL_LOST);
            break;
            
        case EVENT_ENCRYPT_NEGOTIATION_SUCCESS:
             ant_encrypt_user_handler_try_to_run(ant_channel, ANT_ENC_EVT_NEGOTIATION_SUCCESS);
             break;
             
        case EVENT_ENCRYPT_NEGOTIATION_FAIL:
            ant_encrypt_user_handler_try_to_run(ant_channel, ANT_ENC_EVT_NEGOTIATION_FAIL);
            break;
    }
}

void ant_enc_event_handler_register(ant_encryp_user_handler_t user_handler_func)
{
    m_ant_enc_evt_handler = user_handler_func;
}