/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2019 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include <stdint.h>
#include "crypto_aead.h"
#include "api.h"
#include <main.h>
//#define DEBUG
#define MAX_LEN 100

#ifdef DEBUG
  #include "SEGGER_RTT.h"
  #include "SEGGER_RTT_Conf.h"
  #define dbg_printf(...) SEGGER_RTT_printf(0, __VA_ARGS__)
#endif

unsigned char c[MAX_LEN];
unsigned long long clen = 0;
unsigned char m[MAX_LEN];
unsigned long long mlen = 0;
unsigned char ad[MAX_LEN];
unsigned long long adlen = 0;
unsigned char text[2] = "OK";

unsigned char nsec[CRYPTO_NSECBYTES];
const unsigned long long nslen = CRYPTO_NSECBYTES;
unsigned char npub[CRYPTO_NPUBBYTES];
const unsigned long long nplen = CRYPTO_NPUBBYTES;
unsigned char k[CRYPTO_KEYBYTES];
const unsigned long long klen = CRYPTO_KEYBYTES;

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void read_variable_serial(unsigned char action);
static void write_variable_serial(unsigned char target[], uint32_t len);

static void read_serial(void *dst, unsigned int len) {
	unsigned char *buf = dst;
  #ifdef DEBUG
  dbg_printf("Reading %d serial bytes\n", len);
  #endif
	for (int i = 0; i < len; i++) {
		while (!LL_USART_IsActiveFlag_RXNE(USART2));
		buf[i] = LL_USART_ReceiveData8(USART2);
	}
  #ifdef DEBUG
  dbg_printf("done.\n", len);
  #endif
}

static void write_serial(const void *src, unsigned int len) {
	const unsigned char *buf = src;
	for (int i = 0; i < len; i++) {
    #ifdef DEBUG
    dbg_printf("Write to serial: %02x\n", buf[i]);
    #endif
    while (!(LL_USART_IsActiveFlag_TXE(USART2)));
		LL_USART_TransmitData8(USART2, buf[i]);
    #ifdef DEBUG
    dbg_printf("Done writing!\n");
    #endif
	}
}

static void read_variable_serial(unsigned char action) {
	uint32_t len;
  #ifdef DEBUG
  dbg_printf("Let's read our variable: %c\n", action);
  #endif
  read_serial(&len, sizeof(len));
  #ifdef DEBUG
  dbg_printf("with length %lu \n", len);
  #endif 
  switch(action) {
		case 'k':
			while (len != CRYPTO_KEYBYTES);
			read_serial(k, len);
			break;
		case 'p':
			if (len != CRYPTO_NPUBBYTES) { 
        #ifdef DEBUG 
        dbg_printf("Assert failed %d != %d\n", len, CRYPTO_NPUBBYTES);
        #endif
        for(;;); 
      }
			read_serial(npub, len);
			break;
		case 's':
			while (len != CRYPTO_NSECBYTES);
			read_serial(nsec, len);
			break;
		case 'a':
			while (len > MAX_LEN);
			adlen = len;
			read_serial(ad, len);
			break;
		case 'm':
			while (len > MAX_LEN);
			mlen = len;
			read_serial(m, len);
			break;
		case 'c':
			while (len > MAX_LEN);
			clen = len;
			read_serial(c, len);
			break;
		default: 
			for (;;);
	}
}

static void write_variable_serial(unsigned char target[], uint32_t len) {
	write_serial(&len, sizeof(len));
	write_serial(target, len);
}


/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */
  

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  

  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SYSCFG);

  NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

  /* System interrupt init*/

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART2_UART_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
	unsigned char rcv;
	int res;

	while (1) {
    #ifdef DEBUG
    dbg_printf("Starting to read form serial..");
    #endif
		read_serial(&rcv, 1);
    #ifdef DEBUG
    dbg_printf("Received action: %c\n", rcv);
    #endif
    switch (rcv) {
			case 'c': 
			case 'm': 
			case 'a': 
			case 'k': 
			case 's': 
			case 'p':
				read_variable_serial(rcv);
				break;

			case 'C': write_variable_serial(c, clen); break;
			case 'M': write_variable_serial(m, mlen); break;
			case 'A': write_variable_serial(ad, adlen); break;
			case 'K': write_variable_serial(k, klen); break;
			case 'S': write_variable_serial(nsec, nslen); break;
			case 'P': write_variable_serial(npub, nplen); break;

			case 'e':
        #ifdef DEBUG
        dbg_printf("m: "); for (int i = 0; i < mlen; i++) dbg_printf("%02x", m[i]); dbg_printf("\n");
        dbg_printf("a: "); for (int i = 0; i < adlen; i++) dbg_printf("%02x", ad[i]); dbg_printf("\n");
        dbg_printf("p: "); for (int i = 0; i < nplen; i++) dbg_printf("%02x", npub[i]); dbg_printf("\n");
        dbg_printf("k: "); for (int i = 0; i < klen; i++) dbg_printf("%02x", k[i]); dbg_printf("\n");
        #endif
        LL_GPIO_ResetOutputPin(GPIOD, LL_GPIO_PIN_7);
        res = crypto_aead_encrypt(c, &clen, m, mlen, ad, adlen, nsec, npub, k);
        LL_GPIO_SetOutputPin(GPIOD, LL_GPIO_PIN_7);
				break;
      
      case 'd':
        #ifdef DEBUG
        dbg_printf("m: "); for (int i = 0; i < mlen; i++) dbg_printf("%02x", m[i]); dbg_printf("\n");
        dbg_printf("a: "); for (int i = 0; i < adlen; i++) dbg_printf("%02x", ad[i]); dbg_printf("\n");
        dbg_printf("p: "); for (int i = 0; i < nplen; i++) dbg_printf("%02x", npub[i]); dbg_printf("\n");
        dbg_printf("k: "); for (int i = 0; i < klen; i++) dbg_printf("%02x", k[i]); dbg_printf("\n");
        #endif

        LL_GPIO_ResetOutputPin(GPIOD, LL_GPIO_PIN_7);
        res = crypto_aead_decrypt(m, &mlen, nsec, c, clen, ad, adlen, npub, k);
        LL_GPIO_SetOutputPin(GPIOD, LL_GPIO_PIN_7);
        break;

      default:
        continue;

		}
		/* USER CODE END WHILE */
	}
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_7);

  if(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_7)
  {
  Error_Handler();  
  }
  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE1);
  LL_PWR_EnableOverDriveMode();
  LL_RCC_HSI_SetCalibTrimming(16);
  LL_RCC_HSI_Enable();

   /* Wait till HSI is ready */
  while(LL_RCC_HSI_IsReady() != 1)
  {
    
  }
  LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI, LL_RCC_PLLM_DIV_8, 216, LL_RCC_PLLP_DIV_2);
  LL_RCC_PLL_Enable();

   /* Wait till PLL is ready */
  while(LL_RCC_PLL_IsReady() != 1)
  {
    
  }
  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_4);
  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_2);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);

   /* Wait till System clock is ready */
  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
  {
  
  }
  LL_Init1msTick(216000000);
  LL_SYSTICK_SetClkSource(LL_SYSTICK_CLKSOURCE_HCLK);
  LL_SetSystemCoreClock(216000000);
  LL_RCC_SetUSARTClockSource(LL_RCC_USART2_CLKSOURCE_PCLK1);
}

/**
  * @brief USART2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART2_UART_Init(void)
{

  /* USER CODE BEGIN USART2_Init 0 */

  /* USER CODE END USART2_Init 0 */

  LL_USART_InitTypeDef USART_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* Peripheral clock enable */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_USART2);
  
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOA);
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOD);
  /**USART2 GPIO Configuration  
  PA3   ------> USART2_RX
  PD5   ------> USART2_TX 
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_3;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_7;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = LL_GPIO_PIN_5;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_7;
  LL_GPIO_Init(GPIOD, &GPIO_InitStruct);

  /* USER CODE BEGIN USART2_Init 1 */

  /* USER CODE END USART2_Init 1 */
  USART_InitStruct.BaudRate = 115200;
  USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
  USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
  USART_InitStruct.Parity = LL_USART_PARITY_NONE;
  USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
  USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
  USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
  LL_USART_Init(USART2, &USART_InitStruct);
  LL_USART_ConfigAsyncMode(USART2);
  LL_USART_Enable(USART2);
  /* USER CODE BEGIN USART2_Init 2 */

  /* USER CODE END USART2_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOC);
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOH);
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOA);
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOB);
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOD);

  /**/
  LL_GPIO_ResetOutputPin(GPIOB, LL_GPIO_PIN_0);

  /**/
  LL_GPIO_ResetOutputPin(LD3_GPIO_Port, LD3_Pin);

  /**/
  LL_GPIO_ResetOutputPin(LD2_GPIO_Port, LD2_Pin);

  /**/
  LL_GPIO_SetOutputPin(GPIOD, LL_GPIO_PIN_7);
  
  /**/
  GPIO_InitStruct.Pin = LL_GPIO_PIN_7;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOD, &GPIO_InitStruct);
  
  /**/
  GPIO_InitStruct.Pin = LL_GPIO_PIN_0;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /**/
  GPIO_InitStruct.Pin = LD3_Pin;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(LD3_GPIO_Port, &GPIO_InitStruct);

  /**/
  GPIO_InitStruct.Pin = LD2_Pin;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(LD2_GPIO_Port, &GPIO_InitStruct);

}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{ 
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/