mirror of
https://github.com/Lurkars/esp-ena.git
synced 2024-11-25 11:16:12 +01:00
96 lines
3.0 KiB
C
96 lines
3.0 KiB
C
// Copyright 2020 Lukas Haubaum
|
|
//
|
|
// Licensed under the GNU Affero General Public License, Version 3;
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
|
|
// https://www.gnu.org/licenses/agpl-3.0.html
|
|
//
|
|
// 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 "mbedtls/md.h"
|
|
#include "mbedtls/aes.h"
|
|
#include "mbedtls/hkdf.h"
|
|
#include "mbedtls/entropy.h"
|
|
#include "mbedtls/ctr_drbg.h"
|
|
|
|
#include "esp_log.h"
|
|
|
|
#include "ena-crypto.h"
|
|
|
|
#define ESP_CRYPTO_LOG "ESP-CRYPTO"
|
|
|
|
static mbedtls_ctr_drbg_context ctr_drbg;
|
|
|
|
void ena_crypto_init(void)
|
|
{
|
|
mbedtls_entropy_context entropy;
|
|
uint8_t pers[] = "Exposure Notifcation API esp32";
|
|
int ret;
|
|
|
|
mbedtls_entropy_init(&entropy);
|
|
mbedtls_ctr_drbg_init(&ctr_drbg);
|
|
|
|
if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy, pers, sizeof(pers))) != 0)
|
|
{
|
|
ESP_LOGE(ESP_CRYPTO_LOG, " failed\n ! mbedtls_ctr_drbg_init returned -0x%04x\n", -ret);
|
|
}
|
|
}
|
|
|
|
uint32_t ena_crypto_enin(uint32_t unix_epoch_time)
|
|
{
|
|
return unix_epoch_time / ENA_TIME_WINDOW;
|
|
}
|
|
|
|
void ena_crypto_tek(uint8_t *tek)
|
|
{
|
|
int ret;
|
|
if ((ret = mbedtls_ctr_drbg_random(&ctr_drbg, tek, ENA_KEY_LENGTH)) != 0)
|
|
{
|
|
ESP_LOGE(ESP_CRYPTO_LOG, " failed\n ! mbedtls_ctr_drbg_random returned -0x%04x\n", -ret);
|
|
}
|
|
}
|
|
|
|
void ena_crypto_rpik(uint8_t *rpik, uint8_t *tek)
|
|
{
|
|
const uint8_t rpik_info[] = "EN-RPIK";
|
|
mbedtls_hkdf(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), NULL, 0, tek, ENA_KEY_LENGTH, rpik_info, sizeof(rpik_info), rpik, ENA_KEY_LENGTH);
|
|
}
|
|
|
|
void ena_crypto_rpi(uint8_t *rpi, uint8_t *rpik, uint32_t enin)
|
|
{
|
|
uint8_t padded_data[] = "EN-RPI";
|
|
padded_data[12] = (enin & 0x000000ff);
|
|
padded_data[13] = (enin & 0x0000ff00) >> 8;
|
|
padded_data[14] = (enin & 0x00ff0000) >> 16;
|
|
padded_data[15] = (enin & 0xff000000) >> 24;
|
|
|
|
mbedtls_aes_context aes;
|
|
mbedtls_aes_init(&aes);
|
|
mbedtls_aes_setkey_enc(&aes, rpik, ENA_KEY_LENGTH * 8);
|
|
mbedtls_aes_crypt_ecb(&aes, MBEDTLS_AES_ENCRYPT, padded_data, rpi);
|
|
mbedtls_aes_free(&aes);
|
|
}
|
|
|
|
void ena_crypto_aemk(uint8_t *aemk, uint8_t *tek)
|
|
{
|
|
uint8_t aemkInfo[] = "EN-AEMK";
|
|
mbedtls_hkdf(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), NULL, 0, tek, ENA_KEY_LENGTH, aemkInfo, sizeof(aemkInfo), aemk, ENA_KEY_LENGTH);
|
|
}
|
|
|
|
void ena_crypto_aem(uint8_t *aem, uint8_t *aemk, uint8_t *rpi, uint8_t power_level)
|
|
{
|
|
uint8_t metadata[ENA_AEM_METADATA_LENGTH];
|
|
metadata[0] = 0b01000000;
|
|
metadata[1] = power_level;
|
|
size_t count = 0;
|
|
uint8_t sb[16] = {0};
|
|
mbedtls_aes_context aes;
|
|
mbedtls_aes_init(&aes);
|
|
mbedtls_aes_setkey_enc(&aes, aemk, ENA_KEY_LENGTH * 8);
|
|
mbedtls_aes_crypt_ctr(&aes, ENA_AEM_METADATA_LENGTH, &count, rpi, sb, metadata, aem);
|
|
mbedtls_aes_free(&aes);
|
|
} |