OpenWrt – Rev 1
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/*
* Builder/viewer/extractor utility for Poray firmware image files
*
* Copyright (C) 2013 Michel Stempin <michel.stempin@wanadoo.fr>
* Copyright (C) 2013 Felix Kaechele <felix@fetzig.org>
* Copyright (C) 2013 <admin@openschemes.com>
*
* This tool is based on:
* TP-Link firmware upgrade tool.
* Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
*
* Itself based on:
* TP-Link WR941 V2 firmware checksum fixing tool.
* Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <libgen.h>
#include <getopt.h>
#include <stdarg.h>
#include <errno.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#if (__BYTE_ORDER == __BIG_ENDIAN)
# define HOST_TO_BE32(x) (x)
# define BE32_TO_HOST(x) (x)
# define HOST_TO_LE32(x) bswap_32(x)
# define LE32_TO_HOST(x) bswap_32(x)
#else
# define HOST_TO_BE32(x) bswap_32(x)
# define BE32_TO_HOST(x) bswap_32(x)
# define HOST_TO_LE32(x) (x)
# define LE32_TO_HOST(x) (x)
#endif
/* Fixed header flags */
#define HEADER_FLAGS 0x020e0000
/* Recognized Hardware ID magic */
#define HWID_HAME_MPR_A1_L8 0x32473352
#define HWID_PORAY_R50B 0x31353033
#define HWID_PORAY_R50D 0x33353033
#define HWID_PORAY_R50E 0x34353033
#define HWID_PORAY_M3 0x31353335
#define HWID_PORAY_M4 0x32353335
#define HWID_PORAY_Q3 0x33353335
#define HWID_PORAY_X5_X6 0x35353335
#define HWID_PORAY_X8 0x36353335
#define HWID_PORAY_X1 0x38353335
#define HWID_NEXX_WT1520 0x30353332
#define HWID_NEXX_WT3020 0x30323033
#define HWID_A5_V11 0x32473352
/* Recognized XOR obfuscation keys */
#define KEY_HAME 0
#define KEY_PORAY_1 1
#define KEY_PORAY_2 2
#define KEY_PORAY_3 3
#define KEY_PORAY_4 4
#define KEY_NEXX_1 5
#define KEY_NEXX_2 6
#define KEY_A5_V11 7
/* XOR key length */
#define KEY_LEN 15
struct file_info {
char *file_name; /* Name of the file */
uint32_t file_size; /* Length of the file */
};
struct fw_header {
uint32_t hw_id; /* Hardware id */
uint32_t firmware_len; /* Firmware data length */
uint32_t flags; /* Header flags */
uint8_t pad[16];
} __attribute__ ((packed));
struct flash_layout {
char *id;
uint32_t fw_max_len;
};
struct board_info {
char *id;
uint32_t hw_id;
char *layout_id;
uint32_t key;
};
/*
* Globals
*/
static char *ofname;
static char *progname;
static char *board_id;
static struct board_info *board;
static char *layout_id;
static struct flash_layout *layout;
static char *opt_hw_id;
static uint32_t hw_id;
static struct file_info firmware_info;
static uint32_t firmware_len = 0;
static int inspect = 0;
static int extract = 0;
static uint8_t key[][KEY_LEN] = {
{0xC8, 0x3C, 0x3A, 0x93, 0xA2, 0x95, 0xC3, 0x63, 0x48, 0x45, 0x58, 0x09, 0x12, 0x03, 0x08},
{0x89, 0x6B, 0x5A, 0x93, 0x92, 0x95, 0xC3, 0x63, 0xD0, 0xA3, 0x9C, 0x92, 0x2E, 0xE6, 0xC7},
{0xC9, 0x1C, 0x3A, 0x93, 0x92, 0x95, 0xC3, 0x63, 0xD0, 0xA3, 0x9C, 0x92, 0x2E, 0xE6, 0xC7},
{0x19, 0x1B, 0x3A, 0x93, 0x92, 0x95, 0xC3, 0x63, 0xD0, 0xA3, 0x9C, 0x92, 0x2E, 0xE6, 0xC7},
{0x79, 0x7B, 0x7A, 0x93, 0x92, 0x95, 0xC3, 0x63, 0xD0, 0xA3, 0x9C, 0x92, 0x2E, 0xE6, 0xC7},
{0x19, 0x1C, 0x4A, 0x93, 0x96, 0x95, 0xC3, 0x63, 0xD0, 0xA3, 0x9C, 0x92, 0x2E, 0x16, 0xC6},
{0x39, 0x1C, 0x4A, 0x93, 0x96, 0x95, 0xC3, 0x63, 0xD0, 0xA3, 0x9C, 0x92, 0x2E, 0x16, 0xC6},
{0xC8, 0x3C, 0x3A, 0x93, 0xA2, 0x95, 0xC3, 0x63, 0x48, 0x45, 0x58, 0x09, 0x20, 0x11, 0x08},
};
static struct flash_layout layouts[] = {
{
.id = "4M",
.fw_max_len = 0x3c0000,
}, {
.id = "8M",
.fw_max_len = 0x7c0000,
}, {
/* terminating entry */
}
};
static struct board_info boards[] = {
{
.id = "A5-V11",
.hw_id = HWID_A5_V11,
.layout_id = "4M",
.key = KEY_A5_V11,
}, {
.id = "MPR-A1",
.hw_id = HWID_HAME_MPR_A1_L8,
.layout_id = "4M",
.key = KEY_HAME,
}, {
.id = "MPR-L8",
.hw_id = HWID_HAME_MPR_A1_L8,
.layout_id = "4M",
.key = KEY_HAME,
}, {
.id = "R50B",
.hw_id = HWID_PORAY_R50B,
.layout_id = "4M",
.key = KEY_PORAY_2,
}, {
.id = "R50D",
.hw_id = HWID_PORAY_R50D,
.layout_id = "4M",
.key = KEY_PORAY_3,
}, {
.id = "R50E",
.hw_id = HWID_PORAY_R50E,
.layout_id = "4M",
.key = KEY_PORAY_4,
}, {
.id = "M3",
.hw_id = HWID_PORAY_M3,
.layout_id = "4M",
.key = KEY_PORAY_1,
}, {
.id = "M4",
.hw_id = HWID_PORAY_M4,
.layout_id = "4M",
.key = KEY_PORAY_1,
}, {
.id = "Q3",
.hw_id = HWID_PORAY_Q3,
.layout_id = "4M",
.key = KEY_PORAY_1,
}, {
.id = "X5 or X6",
.hw_id = HWID_PORAY_X5_X6,
.layout_id = "8M",
.key = KEY_PORAY_1,
}, {
.id = "X5",
.hw_id = HWID_PORAY_X5_X6,
.layout_id = "8M",
.key = KEY_PORAY_1,
}, {
.id = "X6",
.hw_id = HWID_PORAY_X5_X6,
.layout_id = "8M",
.key = KEY_PORAY_1,
}, {
.id = "X8",
.hw_id = HWID_PORAY_X8,
.layout_id = "8M",
.key = KEY_PORAY_1,
}, {
.id = "X1",
.hw_id = HWID_PORAY_X1,
.layout_id = "8M",
.key = KEY_PORAY_1,
}, {
.id = "WT1520",
.hw_id = HWID_NEXX_WT1520,
.layout_id = "4M",
.key = KEY_NEXX_1,
}, {
.id = "WT1520",
.hw_id = HWID_NEXX_WT1520,
.layout_id = "8M",
.key = KEY_NEXX_1,
}, {
.id = "WT3020",
.hw_id = HWID_NEXX_WT3020,
.layout_id = "4M",
.key = KEY_NEXX_2,
}, {
.id = "WT3020",
.hw_id = HWID_NEXX_WT3020,
.layout_id = "8M",
.key = KEY_NEXX_2,
}, {
/* terminating entry */
}
};
/*
* Message macros
*/
#define ERR(fmt, ...) do { \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt "\n", \
progname, ## __VA_ARGS__ ); \
} while (0)
#define ERRS(fmt, ...) do { \
int save = errno; \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt ":%s\n", \
progname, ## __VA_ARGS__, strerror(save)); \
} while (0)
#define DBG(fmt, ...) do { \
fprintf(stderr, "[%s] " fmt "\n", progname, ## __VA_ARGS__ ); \
} while (0)
/*
* Find a board by its name
*/
static struct board_info *find_board(char *id)
{
struct board_info *ret;
struct board_info *board;
ret = NULL;
for (board = boards; board->id != NULL; board++){
if (strcasecmp(id, board->id) == 0) {
ret = board;
break;
}
};
return ret;
}
/*
* Find a board by its hardware ID
*/
static struct board_info *find_board_by_hwid(uint32_t hw_id)
{
struct board_info *board;
for (board = boards; board->id != NULL; board++) {
if (hw_id == board->hw_id)
return board;
};
return NULL;
}
/*
* Find a Flash memory layout by its name
*/
static struct flash_layout *find_layout(char *id)
{
struct flash_layout *ret;
struct flash_layout *l;
ret = NULL;
for (l = layouts; l->id != NULL; l++){
if (strcasecmp(id, l->id) == 0) {
ret = l;
break;
}
};
return ret;
}
/*
* Display usage
*/
static void usage(int status)
{
FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
fprintf(stream,
"\n"
"Options:\n"
" -B <board> create image for the board specified with <board>\n"
" -H <hwid> use hardware id specified with <hwid>\n"
" -F <id> use flash layout specified with <id>\n"
" -f <file> read firmware image from the file <file>\n"
" -o <file> write output to the file <file>\n"
" -i inspect given firmware file (requires -f)\n"
" -x extract combined kernel and rootfs while inspecting (implies -i)\n"
" -h show this screen\n"
);
exit(status);
}
/*
* Get file statistics
*/
static int get_file_stat(struct file_info *fdata)
{
struct stat st;
int res;
if (fdata->file_name == NULL) {
return 0;
}
res = stat(fdata->file_name, &st);
if (res){
ERRS("stat failed on %s", fdata->file_name);
return res;
}
fdata->file_size = st.st_size;
return 0;
}
/*
* Read file into buffer
*/
static int read_to_buf(struct file_info *fdata, uint8_t *buf)
{
FILE *f;
int ret = EXIT_FAILURE;
f = fopen(fdata->file_name, "rb");
if (f == NULL) {
ERRS("could not open \"%s\" for reading", fdata->file_name);
goto out;
}
errno = 0;
fread(buf, fdata->file_size, 1, f);
if (errno != 0) {
ERRS("unable to read from file \"%s\"", fdata->file_name);
goto out_close;
}
ret = EXIT_SUCCESS;
out_close:
fclose(f);
out:
return ret;
}
/*
* Check command line options
*/
static int check_options(void)
{
int ret;
if (firmware_info.file_name == NULL) {
ERR("no firmware image specified");
return -1;
}
ret = get_file_stat(&firmware_info);
if (ret)
return ret;
if (inspect)
return 0;
if (board_id == NULL && opt_hw_id == NULL) {
ERR("either board or hardware id must be specified");
return -1;
}
if (board_id) {
board = find_board(board_id);
if (board == NULL) {
ERR("unknown/unsupported board id \"%s\"", board_id);
return -1;
}
if (layout_id == NULL) {
layout_id = board->layout_id;
}
hw_id = board->hw_id;
} else {
hw_id = strtoul(opt_hw_id, NULL, 0);
board = find_board_by_hwid(hw_id);
if (layout_id == NULL) {
layout_id = board->layout_id;
}
}
layout = find_layout(layout_id);
if (layout == NULL) {
ERR("unknown flash layout \"%s\"", layout_id);
return -1;
}
firmware_len = firmware_info.file_size;
if (firmware_info.file_size >
layout->fw_max_len - sizeof (struct fw_header)) {
ERR("firmware image is too big");
return -1;
}
if (ofname == NULL) {
ERR("no output file specified");
return -1;
}
return 0;
}
/*
* Fill in firmware header
*/
static void fill_header(uint8_t *buf)
{
struct fw_header *hdr = (struct fw_header *) buf;
memset(hdr, 0, sizeof (struct fw_header));
hdr->hw_id = HOST_TO_LE32(hw_id);
hdr->firmware_len = HOST_TO_LE32(firmware_len);
hdr->flags = HOST_TO_LE32(HEADER_FLAGS);
}
/*
* Compute firmware checksum
*/
static uint16_t checksum_fw(uint8_t *data, int len)
{
int i;
int32_t checksum = 0;
for (i = 0; i < len - 1; i += 2) {
checksum += (data[i + 1] << 8) | data[i];
}
if (i < len) {
checksum += data[i];
}
checksum = checksum + (checksum >> 16) + 0xffff;
checksum = ~(checksum + (checksum >> 16)) & 0xffff;
return (uint16_t) checksum;
}
/*
* (De)obfuscate firmware using an XOR operation with a fixed length key
*/
static void xor_fw(uint8_t *data, int len)
{
int i;
for (i = 0; i <= len; i++) {
data[i] ^= key[board->key][i % KEY_LEN];
}
}
/*
* Write firmware to file
*/
static int write_fw(uint8_t *data, int len)
{
FILE *f;
int ret = EXIT_FAILURE;
f = fopen(ofname, "wb");
if (f == NULL) {
ERRS("could not open \"%s\" for writing", ofname);
goto out;
}
errno = 0;
fwrite(data, len, 1, f);
if (errno) {
ERRS("unable to write output file");
goto out_flush;
}
DBG("firmware file \"%s\" completed", ofname);
ret = EXIT_SUCCESS;
out_flush:
fflush(f);
fclose(f);
if (ret != EXIT_SUCCESS) {
unlink(ofname);
}
out:
return ret;
}
/*
* Build firmware file
*/
static int build_fw(void)
{
int buflen;
uint8_t *buf, *p;
int ret = EXIT_FAILURE;
int writelen = 0;
uint16_t checksum;
buflen = layout->fw_max_len;
buf = (uint8_t *) malloc(buflen);
if (!buf) {
ERR("no memory for buffer\n");
goto out;
}
memset(buf, 0xff, buflen);
p = buf + sizeof (struct fw_header);
ret = read_to_buf(&firmware_info, p);
if (ret) {
goto out_free_buf;
}
writelen = sizeof (struct fw_header) + firmware_len + 2;
/* Fill in header */
fill_header(buf);
/* Compute firmware checksum */
checksum = checksum_fw(buf + sizeof (struct fw_header), firmware_len);
/* Cannot use network order function because checksum is not word-aligned */
buf[writelen - 1] = checksum >> 8;
buf[writelen - 2] = checksum & 0xff;
/* XOR obfuscate firmware */
xor_fw(buf + sizeof (struct fw_header), firmware_len + 2);
/* Write firmware file */
ret = write_fw(buf, writelen);
if (ret) {
goto out_free_buf;
}
ret = EXIT_SUCCESS;
out_free_buf:
free(buf);
out:
return ret;
}
/* Helper functions to inspect_fw() representing different output formats */
static inline void inspect_fw_pstr(char *label, char *str)
{
printf("%-23s: %s\n", label, str);
}
static inline void inspect_fw_phex(char *label, uint32_t val)
{
printf("%-23s: 0x%08x\n", label, val);
}
static inline void inspect_fw_phexpost(char *label,
uint32_t val, char *post)
{
printf("%-23s: 0x%08x (%s)\n", label, val, post);
}
static inline void inspect_fw_phexdef(char *label,
uint32_t val, uint32_t defval)
{
printf("%-23s: 0x%08x ", label, val);
if (val == defval) {
printf("(== OpenWrt default)\n");
} else {
printf("(OpenWrt default: 0x%08x)\n", defval);
}
}
static inline void inspect_fw_phexexp(char *label,
uint32_t val, uint32_t expval)
{
printf("%-23s: 0x%08x ", label, val);
if (val == expval) {
printf("(ok)\n");
} else {
printf("(expected: 0x%08x)\n", expval);
}
}
static inline void inspect_fw_phexdec(char *label, uint32_t val)
{
printf("%-23s: 0x%08x / %8u bytes\n", label, val, val);
}
static inline void inspect_fw_pchecksum(char *label,
uint16_t val, uint16_t expval)
{
printf("%-23s: 0x%04x ", label, val);
if (val == expval) {
printf("(ok)\n");
} else {
printf("(expected: 0x%04x)\n", expval);
}
}
static int inspect_fw(void)
{
uint8_t *buf;
struct fw_header *hdr;
int ret = EXIT_FAILURE;
uint16_t computed_checksum, file_checksum;
buf = (uint8_t *) malloc(firmware_info.file_size);
if (!buf) {
ERR("no memory for buffer!\n");
goto out;
}
ret = read_to_buf(&firmware_info, buf);
if (ret) {
goto out_free_buf;
}
hdr = (struct fw_header *)buf;
inspect_fw_pstr("File name", firmware_info.file_name);
inspect_fw_phexdec("File size", firmware_info.file_size);
printf("\n");
inspect_fw_phexdec("Header size", sizeof (struct fw_header));
board = find_board_by_hwid(LE32_TO_HOST(hdr->hw_id));
if (board) {
layout = find_layout(board->layout_id);
inspect_fw_phexpost("Hardware ID",
LE32_TO_HOST( hdr->hw_id), board->id);
} else {
inspect_fw_phexpost("Hardware ID",
LE32_TO_HOST(hdr->hw_id), "unknown");
}
inspect_fw_phexdec("Firmware data length",
LE32_TO_HOST(hdr->firmware_len));
inspect_fw_phexexp("Flags",
LE32_TO_HOST(hdr->flags), HEADER_FLAGS);
printf("\n");
/* XOR unobfuscate firmware */
xor_fw(buf + sizeof (struct fw_header), LE32_TO_HOST(hdr->firmware_len) + 2);
/* Compute firmware checksum */
computed_checksum = checksum_fw(buf + sizeof (struct fw_header), LE32_TO_HOST(hdr->firmware_len));
/* Cannot use network order function because checksum is not word-aligned */
file_checksum = (buf[firmware_info.file_size - 1] << 8) | buf[firmware_info.file_size - 2];
inspect_fw_pchecksum("Firmware checksum", computed_checksum, file_checksum);
/* Verify checksum */
if (computed_checksum != file_checksum) {
ret = -1;
ERR("checksums do not match");
goto out_free_buf;
}
printf("\n");
if (extract) {
FILE *fp;
char *filename;
if (ofname == NULL) {
filename = malloc(strlen(firmware_info.file_name) + 10);
sprintf(filename, "%s-firmware", firmware_info.file_name);
} else {
filename = ofname;
}
printf("Extracting firmware to \"%s\"...\n", filename);
fp = fopen(filename, "wb");
if (fp) {
if (!fwrite(buf + sizeof (struct fw_header),
LE32_TO_HOST(hdr->firmware_len), 1, fp)) {
ERRS("error in fwrite(): %s", strerror(errno));
}
fclose(fp);
} else {
ERRS("error in fopen(): %s", strerror(errno));
}
if (ofname == NULL) {
free(filename);
}
printf("\n");
}
out_free_buf:
free(buf);
out:
return ret;
}
/*
* Main entry point
*/
int main(int argc, char *argv[])
{
int ret = EXIT_FAILURE;
progname = basename(argv[0]);
int c;
while ((c = getopt(argc, argv, "B:H:F:f:o:ixh")) != -1) {
switch (c) {
case 'B':
board_id = optarg;
break;
case 'H':
opt_hw_id = optarg;
break;
case 'F':
layout_id = optarg;
break;
case 'f':
firmware_info.file_name = optarg;
break;
case 'o':
ofname = optarg;
break;
case 'i':
inspect = 1;
break;
case 'x':
inspect = 1;
extract = 1;
break;
case 'h':
usage(EXIT_SUCCESS);
break;
default:
usage(EXIT_FAILURE);
break;
}
}
ret = check_options();
if (ret) {
goto out;
}
if (!inspect) {
ret = build_fw();
} else {
ret = inspect_fw();
}
out:
return ret;
}