目录
本篇文章介绍如何使用STM32HAL库，移植mbedtls开源库支持mqtt证书加密示例。
GitHub：https://github.com/ARMmbed/mbedtls
硬件：STM32F103CBT6最小系统板
软件：Keil 5.29 + STM32CubeMX6.01
什么是mbedtls：
Mbed TLS是一个C库，实现了密码原语、X.509证书操作以及SSL/TLS和DTLS协议。它的代码占用空间小，因此适合于嵌入式系统。
Mbed TLS包括PSA加密API的参考实现。这是目前仅用于评估目的的预览。
mbedtls遵循 Apache 2.0 开源许可协议。
详情请移步到官网阅读：https://github.com/ARMmbed/mbedtls
mbedtls有什么用处
mbedtls库提供了 TLS / DTLS协议的实现，有了mbedtls库之后意味着：
TCP + TLS = TCP(S)
MQTT + TLS = MQTT(S)
HTTP + TLS = HTTP(S)
COAP + DTLS = COAP(S)
目前的物联网操作系统+各种通信模组方式可以很好的实现TCP/UDP通信，进而提供一些HTTP、MQTT、COAP之类的上层协议，这些协议最大的特点是“明文传输”，一旦有中间人想要截获篡改数据，非常容易。
要想物联网设备和服务器之间具备高安全性，mbedtls库不可或缺。
1、进入GitHub拉取源码
进入版本页
STM32移植v2.24.0，最新版本进行移植过，很多错误，捣鼓很长时间，最终选择了v2.24.0，验证过的问题少些。
2、打开STM32CubeMx生成的keil工程，新建mbedtls文件夹，按照如下步骤进行。
3、把mbedtls\library所有.c文件添加到Keil中来。
4、添加头文件路径
5、编译工程
解决报错问题
1）、添加宏定义mbedconfig配置文件：
MBEDTLS_CONFIG_FILE=<config-mini-tls1_1.h>,
2）、修改config-mini-tls1_1.h 文件
分别注释掉，无需要功能模块：
MBEDTLS_NO_PLATFORM_ENTROPY，单片机无系统所以需要添加该宏。 /**
* \file config-mini-tls1_1.h
*
* \brief Minimal configuration for TLS 1.1 (RFC 4346)
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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.
*/
/*
* Minimal configuration for TLS 1.1 (RFC 4346), implementing only the
* required ciphersuite: MBEDTLS_TLS_RSA_WITH_3DES_EDE_CBC_SHA
*
* See README.txt for usage instructions.
*/
#ifndef MBEDTLS_CONFIG_H
#define MBEDTLS_CONFIG_H
/* System support */
#define MBEDTLS_HAVE_ASM
//#define MBEDTLS_HAVE_TIME
/* mbed TLS feature support */
#define MBEDTLS_CIPHER_MODE_CBC
#define MBEDTLS_PKCS1_V15
#define MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
#define MBEDTLS_SSL_PROTO_TLS1_1
/* mbed TLS modules */
#define MBEDTLS_AES_C
#define MBEDTLS_ASN1_PARSE_C
#define MBEDTLS_ASN1_WRITE_C
#define MBEDTLS_BIGNUM_C
#define MBEDTLS_CIPHER_C
#define MBEDTLS_CTR_DRBG_C
#define MBEDTLS_DES_C
#define MBEDTLS_ENTROPY_C
#define MBEDTLS_MD_C
#define MBEDTLS_MD5_C
//#define MBEDTLS_NET_C
#define MBEDTLS_OID_C
#define MBEDTLS_PK_C
#define MBEDTLS_PK_PARSE_C
#define MBEDTLS_RSA_C
#define MBEDTLS_SHA1_C
#define MBEDTLS_SHA256_C
#define MBEDTLS_SSL_CLI_C
#define MBEDTLS_SSL_SRV_C
#define MBEDTLS_SSL_TLS_C
#define MBEDTLS_X509_CRT_PARSE_C
#define MBEDTLS_X509_USE_C
/* For test certificates */
#define MBEDTLS_BASE64_C
#define MBEDTLS_CERTS_C
#define MBEDTLS_PEM_PARSE_C
/* For testing with compat.sh */
//#define MBEDTLS_FS_IO
#define MBEDTLS_NO_PLATFORM_ENTROPY
#include "mbedtls/check_config.h"
#endif /* MBEDTLS_CONFIG_H */
6、再次编译
7、main.c文件
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* <h2><center>© Copyright (c) 2021 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 "main.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stdio.h"
#include "mbedtls/sha1.h" //使用sha1相关加密函数
#include "string.h" //使用到了strlen函数
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
void sha1_test(void)
{
printf("mbedtls port on STM32F103 core board by champion666\r\n");
/* sha1 test */
char *source_cxt = "champion666";
char encrypt_cxt[64];
printf("source context is:%s\r\n", source_cxt);
mbedtls_sha1_context sha1_ctx;
mbedtls_sha1_init(&sha1_ctx);
mbedtls_sha1_starts(&sha1_ctx);
mbedtls_sha1_update(&sha1_ctx, (unsigned char *)source_cxt, strlen(source_cxt));
mbedtls_sha1_finish(&sha1_ctx, (unsigned char *)encrypt_cxt);
mbedtls_sha1_free(&sha1_ctx);
int i = 0;
printf("sha1 encrypt context is:[");
while (encrypt_cxt[i]) {
printf("%02x", encrypt_cxt[i]);
i++;
}
printf("]\r\n");
}
/* USER CODE END 0 */
/**
* @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. */
HAL_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_USART1_UART_Init();
/* USER CODE BEGIN 2 */
sha1_test();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
/**
* @brief Retargets the C library printf function to the USART.
* @param None
* @retval None
*/
PUTCHAR_PROTOTYPE
{
/* Place your implementation of fputc here */
/* e.g. write a character to the EVAL_COM1 and Loop until the end of transmission */
HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
return ch;
}
int fgetc(FILE * f)
{
uint8_t ch = 0;
HAL_UART_Receive(&huart1, (uint8_t *)&ch, 1, 0xffff);
return ch;
}
/* 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****/
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传送门->代码 (内含有：mbedtls-2.24.0.zip 源码)
参考文章：
1、https://www.it610.com/article/1297797408901636096.htm
2、https://mculover666.blog.csdn.net/article/details/108680779
3、https://blog.csdn.net/qq153471503/article/details/109461794
好了，就介绍到此。