SolarEnergy/esp32_device/main/storage.c

#include "constants.h"
#include "storage.h"
#include "nvs_flash.h"
#include "nvs.h"
#include <string.h>

#define STORAGE_NAMESPACE "storage"

#define DEV_NAME_KEY "dev_name"
#define PRIVATE_KEY "prikey"

bool storage_init()
{
    esp_err_t err = nvs_flash_init();
    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND)
    {
        printf("Need to reset storage\n");

        // NVS partition was truncated and needs to be erased
        // Retry nvs_flash_init
        ESP_ERROR_CHECK(nvs_flash_erase());
        err = nvs_flash_init();
    }

    return err == ESP_OK;
}

void storage_set_dev_name(const char *name)
{
    nvs_handle_t my_handle;

    ESP_ERROR_CHECK(nvs_open(STORAGE_NAMESPACE, NVS_READWRITE, &my_handle));

    ESP_ERROR_CHECK(nvs_set_blob(my_handle, DEV_NAME_KEY, name, strlen(name)));

    nvs_close(my_handle);
}

size_t storage_get_dev_name(char *dest)
{
    nvs_handle_t my_handle;

    ESP_ERROR_CHECK(nvs_open(STORAGE_NAMESPACE, NVS_READWRITE, &my_handle));

    size_t len = (dest == NULL ? 0 : DEV_NAME_LEN);
    esp_err_t res = nvs_get_blob(my_handle, DEV_NAME_KEY, dest, &len);

    nvs_close(my_handle);

    if (res == ESP_ERR_NVS_NOT_FOUND || len == 0)
        return 0;

    ESP_ERROR_CHECK(res);

    return len;
}

void storage_set_priv_key(unsigned char *key, size_t len)
{
    nvs_handle_t my_handle;

    ESP_ERROR_CHECK(nvs_open(STORAGE_NAMESPACE, NVS_READWRITE, &my_handle));

    ESP_ERROR_CHECK(nvs_set_blob(my_handle, PRIVATE_KEY, key, len));

    nvs_close(my_handle);
}

size_t storage_get_priv_key(unsigned char *key)
{
    nvs_handle_t my_handle;

    ESP_ERROR_CHECK(nvs_open(STORAGE_NAMESPACE, NVS_READWRITE, &my_handle));

    size_t len = (key == NULL ? 0 : PRV_KEY_DER_MAX_BYTES);
    esp_err_t res = nvs_get_blob(my_handle, PRIVATE_KEY, key, &len);

    nvs_close(my_handle);

    if (res == ESP_ERR_NVS_NOT_FOUND || len == 0)
        return 0;

    ESP_ERROR_CHECK(res);

    return len;
}