fwupd/libfwupdplugin/fu-dfuse-firmware.c
Richard Hughes 0c51630991 Check firmware magic in a more standard way
Some parsers are ignoring the magic when using _FLAG_IGNORE_CHECKSUM
(which is wrong; fuzzers have no problem with enforcing a static prefix)
and other either disregard the offset or check the magic in an unsafe
way. Also, use FWUPD_ERROR_INVALID_FILE consistently for magic failure.

Add a vfunc, and move all the clever code into one place.
2022-07-14 14:48:15 +01:00

389 lines
9.8 KiB
C

/*
* Copyright (C) 2015 Richard Hughes <richard@hughsie.com>
*
* SPDX-License-Identifier: LGPL-2.1+
*/
#define G_LOG_DOMAIN "FuFirmware"
#include "config.h"
#include <string.h>
#include "fu-byte-array.h"
#include "fu-bytes.h"
#include "fu-chunk-private.h"
#include "fu-common.h"
#include "fu-dfu-firmware-private.h"
#include "fu-dfuse-firmware.h"
#include "fu-mem.h"
/**
* FuDfuseFirmware:
*
* A DfuSe firmware image.
*
* See also: [class@FuDfuFirmware]
*/
G_DEFINE_TYPE(FuDfuseFirmware, fu_dfuse_firmware, FU_TYPE_DFU_FIRMWARE)
/* firmware: LE */
typedef struct __attribute__((packed)) {
guint8 sig[5];
guint8 ver;
guint32 image_size;
guint8 targets;
} DfuSeHdr;
/* image: LE */
typedef struct __attribute__((packed)) {
guint8 sig[6];
guint8 alt_setting;
guint32 target_named;
gchar target_name[255];
guint32 target_size;
guint32 chunks;
} DfuSeImageHdr;
/* element: LE */
typedef struct __attribute__((packed)) {
guint32 address;
guint32 size;
} DfuSeElementHdr;
G_STATIC_ASSERT(sizeof(DfuSeHdr) == 11);
G_STATIC_ASSERT(sizeof(DfuSeImageHdr) == 274);
G_STATIC_ASSERT(sizeof(DfuSeElementHdr) == 8);
static FuChunk *
fu_firmware_image_chunk_parse(FuDfuseFirmware *self, GBytes *bytes, gsize *offset, GError **error)
{
DfuSeElementHdr hdr = {0x0};
gsize bufsz = 0;
gsize ftrlen = fu_dfu_firmware_get_footer_len(FU_DFU_FIRMWARE(self));
const guint8 *buf = g_bytes_get_data(bytes, &bufsz);
g_autoptr(FuChunk) chk = NULL;
g_autoptr(GBytes) blob = NULL;
/* check size */
if (!fu_memcpy_safe((guint8 *)&hdr,
sizeof(hdr),
0x0, /* dst */
buf,
bufsz - ftrlen,
*offset, /* src */
sizeof(hdr),
error))
return NULL;
/* create new chunk */
*offset += sizeof(hdr);
blob = fu_bytes_new_offset(bytes, *offset, GUINT32_FROM_LE(hdr.size), error);
if (blob == NULL)
return NULL;
chk = fu_chunk_bytes_new(blob);
fu_chunk_set_address(chk, GUINT32_FROM_LE(hdr.address));
*offset += fu_chunk_get_data_sz(chk);
/* success */
return g_steal_pointer(&chk);
}
static FuFirmware *
fu_dfuse_firmware_image_parse(FuDfuseFirmware *self, GBytes *bytes, gsize *offset, GError **error)
{
DfuSeImageHdr hdr = {0x0};
gsize bufsz = 0;
const guint8 *buf = g_bytes_get_data(bytes, &bufsz);
g_autoptr(FuFirmware) image = fu_firmware_new();
/* verify image signature */
if (!fu_memcpy_safe((guint8 *)&hdr,
sizeof(hdr),
0x0, /* dst */
buf,
bufsz,
*offset, /* src */
sizeof(hdr),
error))
return NULL;
if (memcmp(hdr.sig, "Target", sizeof(hdr.sig)) != 0) {
g_set_error_literal(error,
FWUPD_ERROR,
FWUPD_ERROR_INVALID_FILE,
"invalid DfuSe target signature");
return NULL;
}
/* set properties */
fu_firmware_set_idx(image, hdr.alt_setting);
if (GUINT32_FROM_LE(hdr.target_named) == 0x01) {
g_autofree gchar *img_id = NULL;
img_id = g_strndup(hdr.target_name, sizeof(hdr.target_name));
fu_firmware_set_id(image, img_id);
}
/* no chunks */
if (hdr.chunks == 0) {
g_set_error_literal(error,
FWUPD_ERROR,
FWUPD_ERROR_INVALID_FILE,
"DfuSe image has no chunks");
return NULL;
}
/* parse chunks */
*offset += sizeof(hdr);
for (guint j = 0; j < GUINT32_FROM_LE(hdr.chunks); j++) {
g_autoptr(FuChunk) chk = NULL;
chk = fu_firmware_image_chunk_parse(self, bytes, offset, error);
if (chk == NULL)
return NULL;
fu_firmware_add_chunk(image, chk);
}
/* success */
return g_steal_pointer(&image);
}
static gboolean
fu_dfuse_firmware_check_magic(FuFirmware *firmware, GBytes *fw, gsize offset, GError **error)
{
guint8 magic[5] = {0x0};
if (!fu_memcpy_safe(magic,
sizeof(magic),
0x0, /* dst */
g_bytes_get_data(fw, NULL),
g_bytes_get_size(fw),
offset, /* src */
sizeof(magic),
error)) {
g_prefix_error(error, "failed to read magic: ");
return FALSE;
}
if (memcmp(magic, "DfuSe", sizeof(magic)) != 0) {
g_set_error_literal(error,
FWUPD_ERROR,
FWUPD_ERROR_INVALID_FILE,
"invalid DfuSe prefix");
return FALSE;
}
/* success */
return TRUE;
}
static gboolean
fu_dfuse_firmware_parse(FuFirmware *firmware,
GBytes *fw,
gsize offset,
FwupdInstallFlags flags,
GError **error)
{
FuDfuFirmware *dfu_firmware = FU_DFU_FIRMWARE(firmware);
gsize bufsz = 0;
guint32 image_size = 0;
guint8 targets = 0;
guint8 ver = 0;
const guint8 *buf = g_bytes_get_data(fw, &bufsz);
/* DFU footer first */
if (!fu_dfu_firmware_parse_footer(dfu_firmware, fw, flags, error))
return FALSE;
/* check the version */
if (!fu_memread_uint8_safe(buf,
bufsz,
offset + G_STRUCT_OFFSET(DfuSeHdr, ver),
&ver,
error))
return FALSE;
if (ver != 0x01) {
g_set_error(error,
FWUPD_ERROR,
FWUPD_ERROR_INTERNAL,
"invalid DfuSe version, got %02x",
ver);
return FALSE;
}
/* check image size */
if (!fu_memread_uint32_safe(buf,
bufsz,
offset + G_STRUCT_OFFSET(DfuSeHdr, image_size),
&image_size,
G_LITTLE_ENDIAN,
error))
return FALSE;
if (image_size != bufsz - fu_dfu_firmware_get_footer_len(dfu_firmware)) {
g_set_error(error,
FWUPD_ERROR,
FWUPD_ERROR_INTERNAL,
"invalid DfuSe image size, "
"got %" G_GUINT32_FORMAT ", "
"expected %" G_GSIZE_FORMAT,
image_size,
bufsz - fu_dfu_firmware_get_footer_len(dfu_firmware));
return FALSE;
}
/* parse the image targets */
if (!fu_memread_uint8_safe(buf,
bufsz,
offset + G_STRUCT_OFFSET(DfuSeHdr, targets),
&targets,
error))
return FALSE;
offset += sizeof(DfuSeHdr);
for (guint i = 0; i < targets; i++) {
g_autoptr(FuFirmware) image = NULL;
image =
fu_dfuse_firmware_image_parse(FU_DFUSE_FIRMWARE(firmware), fw, &offset, error);
if (image == NULL)
return FALSE;
fu_firmware_add_image(firmware, image);
}
return TRUE;
}
static GBytes *
fu_firmware_chunk_write(FuChunk *chk)
{
DfuSeElementHdr hdr = {0x0};
const guint8 *data = fu_chunk_get_data(chk);
gsize length = fu_chunk_get_data_sz(chk);
g_autoptr(GByteArray) buf = NULL;
buf = g_byte_array_sized_new(sizeof(DfuSeElementHdr) + length);
hdr.address = GUINT32_TO_LE(fu_chunk_get_address(chk));
hdr.size = GUINT32_TO_LE(length);
g_byte_array_append(buf, (const guint8 *)&hdr, sizeof(hdr));
g_byte_array_append(buf, data, length);
return g_byte_array_free_to_bytes(g_steal_pointer(&buf));
}
static GBytes *
fu_dfuse_firmware_write_image(FuFirmware *image, GError **error)
{
DfuSeImageHdr hdr = {0x0};
gsize totalsz = 0;
g_autoptr(GByteArray) buf = NULL;
g_autoptr(GPtrArray) blobs = NULL;
g_autoptr(GPtrArray) chunks = NULL;
/* get total size */
blobs = g_ptr_array_new_with_free_func((GDestroyNotify)g_bytes_unref);
chunks = fu_firmware_get_chunks(image, error);
if (chunks == NULL)
return NULL;
for (guint i = 0; i < chunks->len; i++) {
FuChunk *chk = g_ptr_array_index(chunks, i);
GBytes *bytes = fu_firmware_chunk_write(chk);
g_ptr_array_add(blobs, bytes);
totalsz += g_bytes_get_size(bytes);
}
/* mutable output buffer */
buf = g_byte_array_sized_new(sizeof(DfuSeImageHdr) + totalsz);
/* add prefix */
memcpy(hdr.sig, "Target", 6);
hdr.alt_setting = fu_firmware_get_idx(image);
if (fu_firmware_get_id(image) != NULL) {
hdr.target_named = GUINT32_TO_LE(0x01);
(void)g_strlcpy((gchar *)&hdr.target_name,
fu_firmware_get_id(image),
sizeof(hdr.target_name));
}
hdr.target_size = GUINT32_TO_LE(totalsz);
hdr.chunks = GUINT32_TO_LE(chunks->len);
g_byte_array_append(buf, (const guint8 *)&hdr, sizeof(hdr));
/* copy data */
for (guint i = 0; i < blobs->len; i++) {
GBytes *blob = g_ptr_array_index(blobs, i);
fu_byte_array_append_bytes(buf, blob);
}
return g_byte_array_free_to_bytes(g_steal_pointer(&buf));
}
static GBytes *
fu_dfuse_firmware_write(FuFirmware *firmware, GError **error)
{
DfuSeHdr hdr = {0x0};
gsize totalsz = 0;
g_autoptr(GByteArray) buf = NULL;
g_autoptr(GBytes) blob_noftr = NULL;
g_autoptr(GPtrArray) blobs = NULL;
g_autoptr(GPtrArray) images = NULL;
/* create mutable output buffer */
blobs = g_ptr_array_new_with_free_func((GDestroyNotify)g_bytes_unref);
images = fu_firmware_get_images(FU_FIRMWARE(firmware));
for (guint i = 0; i < images->len; i++) {
FuFirmware *img = g_ptr_array_index(images, i);
g_autoptr(GBytes) blob = NULL;
blob = fu_dfuse_firmware_write_image(img, error);
if (blob == NULL)
return NULL;
totalsz += g_bytes_get_size(blob);
g_ptr_array_add(blobs, g_steal_pointer(&blob));
}
buf = g_byte_array_sized_new(sizeof(DfuSeHdr) + totalsz);
/* DfuSe header */
memcpy(hdr.sig, "DfuSe", 5);
hdr.ver = 0x01;
hdr.image_size = GUINT32_TO_LE(sizeof(hdr) + totalsz);
if (images->len > G_MAXUINT8) {
g_set_error(error,
FWUPD_ERROR,
FWUPD_ERROR_INTERNAL,
"too many (%u) images to write DfuSe file",
images->len);
return NULL;
}
hdr.targets = (guint8)images->len;
g_byte_array_append(buf, (const guint8 *)&hdr, sizeof(hdr));
/* copy images */
for (guint i = 0; i < blobs->len; i++) {
GBytes *blob = g_ptr_array_index(blobs, i);
fu_byte_array_append_bytes(buf, blob);
}
/* return blob */
blob_noftr = g_byte_array_free_to_bytes(g_steal_pointer(&buf));
return fu_dfu_firmware_append_footer(FU_DFU_FIRMWARE(firmware), blob_noftr, error);
}
static void
fu_dfuse_firmware_init(FuDfuseFirmware *self)
{
fu_dfu_firmware_set_version(FU_DFU_FIRMWARE(self), FU_DFU_FIRMARE_VERSION_DFUSE);
}
static void
fu_dfuse_firmware_class_init(FuDfuseFirmwareClass *klass)
{
FuFirmwareClass *klass_firmware = FU_FIRMWARE_CLASS(klass);
klass_firmware->check_magic = fu_dfuse_firmware_check_magic;
klass_firmware->parse = fu_dfuse_firmware_parse;
klass_firmware->write = fu_dfuse_firmware_write;
}
/**
* fu_dfuse_firmware_new:
*
* Creates a new #FuFirmware of sub type DfuSe
*
* Since: 1.5.6
**/
FuFirmware *
fu_dfuse_firmware_new(void)
{
return FU_FIRMWARE(g_object_new(FU_TYPE_DFUSE_FIRMWARE, NULL));
}