Feature #41: Add SHA calculation to updater. Has yet to be checked against file. Code not tested

stm-firmware/updater/ram-code/CMakeLists.txt

@@ -21,13 +21,14 @@ set(LINKER_SCRIPT ${CMAKE_CURRENT_SOURCE_DIR}/ram-link.ld)
 set(ELFFILE "${PROJECT_NAME}.elf")
 aux_source_directory("." SRCS)
 aux_source_directory("fatfs" FATFS_SRCS)
+aux_source_directory("3rd-party/sha256" SHA256_SRCS)
 aux_source_directory("fatfs/shimatta_sdio_driver" SDIO_SRCS)
 set(STM_PERIPH_SRCS "../../stm-periph/backup-ram.c" "../../stm-periph/rcc-manager.c" "../../stm-periph/crc-unit.c")
 set(SAFETY_MEMORY_SRCS "../../safety/safety-memory.c")
 
-add_executable(${ELFFILE} ${SRCS} ${FATFS_SRCS} ${SDIO_SRCS} ${STM_PERIPH_SRCS} ${SAFETY_MEMORY_SRCS})
+add_executable(${ELFFILE} ${SRCS} ${FATFS_SRCS} ${SDIO_SRCS} ${STM_PERIPH_SRCS} ${SAFETY_MEMORY_SRCS} ${SHA256_SRCS})
 
-target_include_directories(${ELFFILE} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include ../../include)
+target_include_directories(${ELFFILE} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include ../../include ${CMAKE_CURRENT_SOURCE_DIR}/3rd-party)
 target_compile_options(${ELFFILE} PRIVATE -Wall -Wextra -Wold-style-declaration -Wuninitialized -Wmaybe-uninitialized -Wunused-parameter)
 target_compile_options(${ELFFILE} PRIVATE -mlittle-endian -mthumb -mcpu=cortex-m4 -mthumb-interwork -mfloat-abi=hard -mfpu=fpv4-sp-d16 -nostartfiles -Wimplicit-fallthrough=3 -Wsign-compare -Os -g3)
 target_compile_definitions(${ELFFILE} PRIVATE -DGIT_VER=${GIT_DESCRIBE} -DHSE_VALUE=8000000UL -DSTM32F407xx -DSTM32F4XX -DARM_MATH_CM4 -DSAFETY_MEMORY_STRIPOUT_DUMP)

stm-firmware/updater/ram-code/itoa.c

@@ -51,3 +51,37 @@ uint32_t heapless_itoa(int32_t value, char *buffer, uint32_t base)
     return bufferIdx;
 }
 
+static char num_to_hex_digit(uint8_t num, bool capitalized)
+{
+	char ret = 'U';
+
+	switch (num) {
+	case 0 ... 9:
+		ret = '0' + num;
+		break;
+	case 0xA ... 0xF:
+		if (capitalized)
+			ret = 'A' + num - 0xA;
+		else
+			ret = 'a' + num - 0xA;
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+uint32_t bytes_to_hex_string(uint8_t *input, uint32_t count, char *output_buffer, bool capitalized)
+{
+	uint32_t idx;
+	uint8_t b;
+
+	for (idx = 0; idx < count; idx++) {
+		b = input[idx];
+		output_buffer[idx] = num_to_hex_digit(b >> 4, capitalized);
+		output_buffer[idx+1] = num_to_hex_digit(b & 0xF, capitalized);
+	}
+
+	return 0;
+}

stm-firmware/updater/ram-code/itoa.h

@@ -2,7 +2,10 @@
 #define _ITOA_H_
 
 #include <stdint.h>
+#include <stdbool.h>
 
 uint32_t heapless_itoa(int32_t value, char *buffer, uint32_t base);
 
+uint32_t bytes_to_hex_string(uint8_t *input, uint32_t count, char *output_buffer, bool capitalized);
+
 #endif /* _ITOA_H_ */

stm-firmware/updater/ram-code/main.c

@@ -16,6 +16,7 @@
 #include <string.h>
 #include "uart.h"
 #include "itoa.h"
+#include <sha256/sha-256.h>
 
 static volatile unsigned int wait_tick;
 
@@ -197,6 +198,49 @@ exit_parser_close:
 	return retval;
 }
 
+static int compute_sha256_of_file(const char *fname, uint8_t *sha256_out)
+{
+	FIL _file;
+	int ret = 0;
+	FIL *file = &_file;
+	FRESULT fres;
+	static char workbuff[1024];
+	UINT act_read;
+	struct Sha_256 sha;
+
+	if (!fname || !sha256_out)
+		return -1000;
+
+	fres = f_open(file, fname, FA_READ);
+	if (fres != FR_OK) {
+		ret = -1;
+		goto ret_noact;
+	}
+
+	sha_256_init(&sha, sha256_out);
+	do {
+		fres = f_read(file, workbuff, sizeof(workbuff), &act_read);
+		if (act_read > 0) {
+			sha_256_write(&sha, workbuff, (size_t)act_read);
+		} else {
+			if (f_eof(file)) {
+				break;
+			} else if (f_error(file)) {
+				ret = -2;
+				goto ret_close_file;
+			}
+		}
+	} while (1);
+
+	(void)sha_256_close(&sha);
+	ret = 0;
+
+ret_close_file:
+	(void)f_close(file);
+ret_noact:
+	return ret;
+}
+
 int ram_code_main(void)
 {
 	FRESULT fres;
@@ -207,6 +251,7 @@ int ram_code_main(void)
 	uint32_t count;
 	uint32_t update_size;
 	int retries = 3;
+	uint8_t sha_hash[SIZE_OF_SHA_256_HASH];
 
 
 	SysTick_Config(168000UL);
@@ -237,6 +282,19 @@ int ram_code_main(void)
 	if (res)
 		ram_code_exit(false);
 
+	uart_send_string("Calculating SHA256 checksum\r\n");
+	if (compute_sha256_of_file(filename, sha_hash)) {
+		uart_send_string("Calculation failed!");
+		ram_code_exit(false);
+	}
+
+	uart_send_string("SHA256: ");
+	bytes_to_hex_string(sha_hash, SIZE_OF_SHA_256_HASH, tmp_buff, false);
+	tmp_buff[SIZE_OF_SHA_256_HASH] = 0;
+	uart_send_string(tmp_buff);
+	uart_send_string("\r\n");
+
+
 	uart_send_string("Checking hex file ");
 	uart_send_string(filename);
 	uart_send_string("\r\n");