circuitpython/ports/stm32/mboot/fsload.c
Damien George c6f334272a stm32/mboot: Add support for signed and encrypted firmware updates.
This commit adds support to stm32's mboot for signe, encrypted and
compressed DFU updates.  It is based on inital work done by Andrew Leech.

The feature is enabled by setting MBOOT_ENABLE_PACKING to 1 in the board's
mpconfigboard.mk file, and by providing a header file in the board folder
(usually called mboot_keys.h) with a set of signing and encryption keys
(which can be generated by mboot_pack_dfu.py).  The signing and encryption
is provided by libhydrogen.  Compression is provided by uzlib.  Enabling
packing costs about 3k of flash.

The included mboot_pack_dfu.py script converts a .dfu file to a .pack.dfu
file which can be subsequently deployed to a board with mboot in packing
mode.  This .pack.dfu file is created as follows:
- the firmware from the original .dfu is split into chunks (so the
  decryption can fit in RAM)
- each chunk is compressed, encrypted, a header added, then signed
- a special final chunk is added with a signature of the entire firmware
- all chunks are concatenated to make the final .pack.dfu file

The .pack.dfu file can be deployed over USB or from the internal filesystem
on the device (if MBOOT_FSLOAD is enabled).

See #5267 and #5309 for additional discussion.

Signed-off-by: Damien George <damien@micropython.org>
2021-01-18 12:43:01 +11:00

281 lines
8.0 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019-2020 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <string.h>
#include "py/mphal.h"
#include "mboot.h"
#include "pack.h"
#include "vfs.h"
#if MBOOT_FSLOAD
#if !(MBOOT_VFS_FAT || MBOOT_VFS_LFS1 || MBOOT_VFS_LFS2)
#error Must enable at least one VFS component
#endif
#if MBOOT_ENABLE_PACKING
// Packed DFU files are gzip'd internally, not on the outside, so reads of the file
// just read the file directly.
static void *input_stream_data;
static stream_read_t input_stream_read_meth;
static inline int input_stream_init(void *stream_data, stream_read_t stream_read) {
input_stream_data = stream_data;
input_stream_read_meth = stream_read;
return 0;
}
static inline int input_stream_read(size_t len, uint8_t *buf) {
return input_stream_read_meth(input_stream_data, buf, len);
}
#else
// Standard (non-packed) DFU files must be gzip'd externally / on the outside, so
// reads of the file go through gz_stream.
static inline int input_stream_init(void *stream_data, stream_read_t stream_read) {
return gz_stream_init_from_stream(stream_data, stream_read);
}
static inline int input_stream_read(size_t len, uint8_t *buf) {
return gz_stream_read(len, buf);
}
#endif
static int fsload_program_file(bool write_to_flash) {
// Parse DFU
uint8_t buf[512];
size_t file_offset;
// Read file header, <5sBIB
int res = input_stream_read(11, buf);
if (res != 11) {
return -1;
}
file_offset = 11;
// Validate header, version 1
if (memcmp(buf, "DfuSe\x01", 6) != 0) {
return -1;
}
// Must have only 1 target
if (buf[10] != 1) {
return -2;
}
// Get total size
uint32_t total_size = get_le32(buf + 6);
// Read target header, <6sBi255sII
res = input_stream_read(274, buf);
if (res != 274) {
return -1;
}
file_offset += 274;
// Validate target header, with alt being 0
if (memcmp(buf, "Target\x00", 7) != 0) {
return -1;
}
// Get target size and number of elements
uint32_t target_size = get_le32(buf + 266);
uint32_t num_elems = get_le32(buf + 270);
size_t file_offset_target = file_offset;
// Parse each element
for (size_t elem = 0; elem < num_elems; ++elem) {
// Read element header, <II
res = input_stream_read(8, buf);
if (res != 8) {
return -1;
}
file_offset += 8;
// Get element destination address and size
uint32_t elem_addr = get_le32(buf);
uint32_t elem_size = get_le32(buf + 4);
#if !MBOOT_ENABLE_PACKING
// Erase flash before writing
if (write_to_flash) {
uint32_t addr = elem_addr;
while (addr < elem_addr + elem_size) {
res = do_page_erase(addr, &addr);
if (res != 0) {
return res;
}
}
}
#endif
// Read element data and possibly write to flash
for (uint32_t s = elem_size; s;) {
uint32_t l = s;
if (l > sizeof(buf)) {
l = sizeof(buf);
}
res = input_stream_read(l, buf);
if (res != l) {
return -1;
}
if (write_to_flash) {
res = do_write(elem_addr, buf, l);
if (res != 0) {
return -1;
}
elem_addr += l;
}
s -= l;
}
file_offset += elem_size;
}
if (target_size != file_offset - file_offset_target) {
return -1;
}
if (total_size != file_offset) {
return -1;
}
// Read trailing info
res = input_stream_read(16, buf);
if (res != 16) {
return -1;
}
// TODO validate CRC32
return 0;
}
static int fsload_validate_and_program_file(void *stream, const stream_methods_t *meth, const char *fname) {
// First pass verifies the file, second pass programs it
for (unsigned int pass = 0; pass <= 1; ++pass) {
led_state_all(pass == 0 ? 2 : 4);
int res = meth->open(stream, fname);
if (res == 0) {
res = input_stream_init(stream, meth->read);
if (res == 0) {
res = fsload_program_file(pass == 0 ? false : true);
}
}
meth->close(stream);
if (res != 0) {
return res;
}
}
return 0;
}
int fsload_process(void) {
const uint8_t *elem = elem_search(ELEM_DATA_START, ELEM_TYPE_FSLOAD);
if (elem == NULL || elem[-1] < 2) {
return -1;
}
// Get mount point id and create null-terminated filename
uint8_t mount_point = elem[0];
uint8_t fname_len = elem[-1] - 1;
char fname[256];
memcpy(fname, &elem[1], fname_len);
fname[fname_len] = '\0';
elem = ELEM_DATA_START;
for (;;) {
elem = elem_search(elem, ELEM_TYPE_MOUNT);
if (elem == NULL || elem[-1] != 10) {
// End of elements, or invalid MOUNT element
return -1;
}
if (elem[0] == mount_point) {
uint32_t base_addr = get_le32(&elem[2]);
uint32_t byte_len = get_le32(&elem[6]);
int ret;
union {
#if MBOOT_VFS_FAT
vfs_fat_context_t fat;
#endif
#if MBOOT_VFS_LFS1
vfs_lfs1_context_t lfs1;
#endif
#if MBOOT_VFS_LFS2
vfs_lfs2_context_t lfs2;
#endif
} ctx;
const stream_methods_t *methods;
#if MBOOT_VFS_FAT
if (elem[1] == ELEM_MOUNT_FAT) {
ret = vfs_fat_mount(&ctx.fat, base_addr, byte_len);
methods = &vfs_fat_stream_methods;
} else
#endif
#if MBOOT_VFS_LFS1
if (elem[1] == ELEM_MOUNT_LFS1) {
ret = vfs_lfs1_mount(&ctx.lfs1, base_addr, byte_len);
methods = &vfs_lfs1_stream_methods;
} else
#endif
#if MBOOT_VFS_LFS2
if (elem[1] == ELEM_MOUNT_LFS2) {
ret = vfs_lfs2_mount(&ctx.lfs2, base_addr, byte_len);
methods = &vfs_lfs2_stream_methods;
} else
#endif
{
// Unknown filesystem type
return -1;
}
if (ret == 0) {
ret = fsload_validate_and_program_file(&ctx, methods, fname);
}
// Flash LEDs based on success/failure of update
for (int i = 0; i < 4; ++i) {
if (ret == 0) {
led_state_all(7);
} else {
led_state_all(1);
}
mp_hal_delay_ms(100);
led_state_all(0);
mp_hal_delay_ms(100);
}
return ret;
}
elem += elem[-1];
}
}
#endif // MBOOT_FSLOAD