Tasmota/lib/lib_ssl/esp_wireguard-Tasmota/src/tasmota_crypto.cpp
2025-04-27 20:54:01 +02:00

84 lines
2.9 KiB
C++

/*
tasmota_crypto.cpp - crypto layer to call bearssl from wireguard
Copyright (C) 2025 Theo Arends, Stephan Hadinger
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <Arduino.h>
#include <t_bearssl.h>
#ifdef ESP32
#include "freertos/task.h"
#include "freertos/FreeRTOS.h"
#include "esp_expression_with_stack.h"
#endif // ESP32
//**************************************************************************************************************
// enable AddLog support within a C++ library
extern void AddLog(uint32_t loglevel, PGM_P formatP, ...);
enum LoggingLevels {LOG_LEVEL_NONE, LOG_LEVEL_ERROR, LOG_LEVEL_INFO, LOG_LEVEL_DEBUG, LOG_LEVEL_DEBUG_MORE};
//**************************************************************************************************************
#define BR_EC25519_IMPL br_ec_c25519_m15 // BearSSL implementation for Curve 25519
// we need a global
static struct dh_curve25519_t {
uint8_t q[32];
uint8_t n[32];
int result;
} g_dh_curve25519;
static void run_crypto_scalarmult_curve25519(void) {
g_dh_curve25519.result = BR_EC25519_IMPL.mul(g_dh_curve25519.q, 32, g_dh_curve25519.n, 32, BR_EC_curve25519);
}
extern "C" int crypto_scalarmult_curve25519(unsigned char *q, const unsigned char *n,const unsigned char *p) {
for (int32_t i=0; i<32; i++) {
g_dh_curve25519.q[i] = p[i];
g_dh_curve25519.n[i] = n[31-i];
}
#ifdef ESP32
const char *taskName = pcTaskGetName(NULL);
if (uxTaskGetStackHighWaterMark(nullptr) < 2000) {
//Allocate a stack buffer, from heap or as a static form:
StackType_t *shared_stack = (StackType_t*) heap_caps_malloc(4096 * sizeof(StackType_t), MALLOC_CAP_8BIT | MALLOC_CAP_INTERNAL);
//Allocate a mutex to protect its usage:
SemaphoreHandle_t lock = xSemaphoreCreateMutex();
//Call the desired function using the macro helper:
esp_execute_shared_stack_function(lock,
shared_stack,
4096,
run_crypto_scalarmult_curve25519);
vSemaphoreDelete(lock);
free(shared_stack);
} else {
run_crypto_scalarmult_curve25519();
}
#else
run_crypto_scalarmult_curve25519();
#endif
if (g_dh_curve25519.result) {
for (int32_t i=0; i<32; i++) {
q[i] = g_dh_curve25519.q[i];
}
return 0; // Success
} else {
return 1; // Failure
}
}