esp-idf/components/hal/ecdsa_hal.c

/*
 * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include "hal/assert.h"
#include "hal/ecdsa_ll.h"
#include "hal/ecdsa_hal.h"

#define ECDSA_HAL_P192_COMPONENT_LEN        24
#define ECDSA_HAL_P256_COMPONENT_LEN        32

static void configure_ecdsa_periph(ecdsa_hal_config_t *conf)
{
    ecdsa_ll_set_mode(conf->mode);
    ecdsa_ll_set_curve(conf->curve);
    ecdsa_ll_set_k_mode(conf->k_mode);
    ecdsa_ll_set_z_mode(conf->sha_mode);
}

void ecdsa_hal_gen_signature(ecdsa_hal_config_t *conf, const uint8_t *k, const uint8_t *hash,
                            uint8_t *r_out, uint8_t *s_out, uint16_t len)
{
    if (len != ECDSA_HAL_P192_COMPONENT_LEN && len != ECDSA_HAL_P256_COMPONENT_LEN) {
        HAL_ASSERT(false && "Incorrect length");
    }

    if (conf->k_mode == ECDSA_K_USER_PROVIDED && k == NULL) {
        HAL_ASSERT(false && "Mismatch in K configuration");
    }

    if (conf->sha_mode == ECDSA_Z_USER_PROVIDED && hash == NULL) {
        HAL_ASSERT(false && "Mismatch in SHA configuration");
    }

    if (ecdsa_ll_get_state() != ECDSA_STATE_IDLE) {
        HAL_ASSERT(false && "Incorrect ECDSA state");
    }

    configure_ecdsa_periph(conf);

    ecdsa_ll_set_stage(ECDSA_STAGE_START_CALC);

    while(ecdsa_ll_get_state() != ECDSA_STATE_LOAD) {
        ;
    }

    ecdsa_ll_set_stage(ECDSA_STAGE_LOAD_DONE);

    while (ecdsa_ll_get_state() != ECDSA_STATE_GET) {
        ;
    }

    ecdsa_ll_read_param(ECDSA_PARAM_R, r_out, len);
    ecdsa_ll_read_param(ECDSA_PARAM_S, s_out, len);

    ecdsa_ll_set_stage(ECDSA_STAGE_GET_DONE);

    while (ecdsa_ll_get_state() != ECDSA_STATE_IDLE) {
        ;
    }
}

int ecdsa_hal_verify_signature(ecdsa_hal_config_t *conf, const uint8_t *hash, const uint8_t *r, const uint8_t *s,
                               const uint8_t *pub_x, const uint8_t *pub_y, uint16_t len)
{
    if (len != ECDSA_HAL_P192_COMPONENT_LEN && len != ECDSA_HAL_P256_COMPONENT_LEN) {
        HAL_ASSERT(false && "Incorrect length");
    }

    if (ecdsa_ll_get_state() != ECDSA_STATE_IDLE) {
        HAL_ASSERT(false && "Incorrect ECDSA state");
    }

    configure_ecdsa_periph(conf);

    ecdsa_ll_set_stage(ECDSA_STAGE_START_CALC);

    while(ecdsa_ll_get_state() != ECDSA_STATE_LOAD) {
        ;
    }

    ecdsa_ll_write_param(ECDSA_PARAM_Z, hash, len);
    ecdsa_ll_write_param(ECDSA_PARAM_R, r, len);
    ecdsa_ll_write_param(ECDSA_PARAM_S, s, len);
    ecdsa_ll_write_param(ECDSA_PARAM_QAX, pub_x, len);
    ecdsa_ll_write_param(ECDSA_PARAM_QAY, pub_y, len);

    ecdsa_ll_set_stage(ECDSA_STAGE_LOAD_DONE);

    while (ecdsa_ll_get_state() != ECDSA_STATE_IDLE) {
        ;
    }

    int res = ecdsa_ll_get_verification_result();

    return (res ? 0 : -1);
}