From: TJ Date: Tue, 29 Mar 2016 12:34:34 +0000 (+0100) Subject: Broadcom Consumer Router Firmware Header Editor X-Git-Tag: v1.2^0 X-Git-Url: https://iam.tj/gitweb/gitweb.cgi?p=firmware_header_edit.git;a=commitdiff_plain;h=d486b3aca441fce06e614614f47f68e0b7a9156f Broadcom Consumer Router Firmware Header Editor Signed-off-by: TJ --- d486b3aca441fce06e614614f47f68e0b7a9156f diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..a51fdf4 --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +fwheaditor diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..5c2a249 --- /dev/null +++ b/Makefile @@ -0,0 +1,16 @@ +PROG=fwheaditor +SRC=firmware_header_editor.c +CFLAGS=-std=c11 -g + +export PROG + +$(PROG): $(SRC) + $(CC) $(CFLAGS) -o $@ $< + +clean: + -rm -f $(PROG) + +tests: + $(MAKE) -C testsuite + +.PHONY: clean diff --git a/firmware_header_editor.c b/firmware_header_editor.c new file mode 100644 index 0000000..5290f08 --- /dev/null +++ b/firmware_header_editor.c @@ -0,0 +1,363 @@ +static const char *title =\ +"Broadcom Consumer Router Firmware Header Editor" +; +static const float VERSION = 1.2f; + +static const char *copyright = \ +"Copyright 2015-2016 TJ \n" +"Licensed on the terms of the GNU General Public License version 3\n" +; + +static const char *help = \ +"For routers using the Broadcom CFE ((Customer Premises Equipment) CPE Firmware Environment) and firmware update files.\n\n" + +"Avoid the 'Invalid Model Id' error reported by the HTTP firmware upload page in a device with an ISP-specific Model ID (E.g. Eircom F1000 uses 6009 rather than ZyXel VMG8324/VMG8924 generic 6006.\n\n" + +"This tool re-generates the header CRC32 checksum (usually at offset 0xEC - 236) of the package header structure and optionally alters the manufacturer Model ID of the firmware image.\n\n" + +"To identify the current Model ID of the device's firmware connect to its terminal using telnet or ssh and query the manufacturer data that is stored in the ROM image:\n\n" + +" > sys atsh\n" +" ...\n" +" Other Feature Bits :\n" +" 4d 53 60 09 00 00 00 00-00 00 00 00 00 00 00 00\n\n" + +"The first pair of bytes here are ASCII characters 'MS' (code for MitraStar)\n" +"The second pair are the Model ID '6009'\n\n" + +"A firmware update file (usually has a .bin suffix) starts with a 256 byte header that describes the contents and contains data-verification checksums.\n" +"Specific to Mitrastar (MSTC), and therefore also Zyxel, the Model ID is stored in the 'signiture_1' manufacturer-specific info field starting at offset 4.\n" +"This 20-byte field is split into two parts, both ASCII zero-terminated strings:\n\n" + +" a) the manufacturer ID and model ID (e.g. 'MSTC_6006')\n" +" b) the model ID (e.g. '6006')\n\n" + +"By replacing the model ID with one matching the specific device and updating the header CRC32 checksum the device's HTTP firmware update interface will accept the file.\n\n" +"Example usage:\n\n" +"# display detailed help\n" +"fwheaditor -h\n" +"# display current and calculated header based on default values\n" +"fwheaditor V1.00(AAKL.13)C0.bin\n" +"# change Model ID to 6009 and write to file only if current Manufacturer is the default\n" +"fwheaditor -i 6009 -w V1.00(AAKL.13)C0.bin\n" +"# change Model ID to 6009 and write to file only if current Manufacturer is 'BRCM'\n" +"fwheaditor -i 6009 -m BRCM -w V1.00(AAHL.13).bin\n" +; + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static unsigned int MESSAGE_SIZE = 1024; +static unsigned int TAG_VER_LEN = 4; +static unsigned int TAG_SIG_LEN = 20; +static unsigned int MODEL_ID_LEN = 5; +static ssize_t header_len = 236; // 0xEC; default length for Broadcom FILE_TAG header excluding TAG CRC +static char *match_manufacturer_id = "MSTC"; +static char *match_model_id = "6006"; +static char *model_id = "6006"; + +static unsigned int crc32_table[256] = { + 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, + 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, + 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, + 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, + 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, + 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, + 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F, + 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, + 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, + 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, + 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, + 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, + 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, + 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, + 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, + 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, + 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, + 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, + 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7, + 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, + 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, + 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, + 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, + 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, + 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, + 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, + 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, + 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, + 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, + 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, + 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF, + 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D +}; + +static void +pr_usage(int verbose) +{ + fprintf(stderr, + "Usage:\n" + " -i replacement Model ID (default '%s')\n" + " -l bytes to calculate new CRC32 over (default %ld)\n" + " -m current Manufacturer ID to match (default '%s')\n" + " -M current Model ID to match (default '%s')\n" + " -w write to file (default only prints new values)\n" + " -s simulate; don't write to file when -w is given\n" + " -t output for automated test suite\n" + " -q quiet; only display result\n" + " -h show additional help\n" + "\n" + "%s", + model_id, + header_len, + match_manufacturer_id, + match_model_id, + verbose ? help : "" + ); +} + +static void +pr_error_exit(unsigned int usage, const char *error, ...) +{ + va_list args; + char error_message[MESSAGE_SIZE + 1]; + + if (!error) return; + + va_start(args, error); + (void) vsnprintf(error_message, MESSAGE_SIZE + 1, error, args); + va_end(args); + fprintf(stderr, "Error: %s\n", error_message); + + if (usage) pr_usage(usage); + + exit(EXIT_FAILURE); +} + +/* calculate standard CRC32 + * + * @param data pointer to start of input data + * @param len length in bytes of data to be checksummed + * @param crc32 seed value (Broadcom use 0xffffffff) + */ +unsigned int crc32(const unsigned char *data, ssize_t len, unsigned int crc) +{ + for ( ; len > 0; --len ) { + crc = (crc >> 8) ^ crc32_table[ (crc ^ *data++) & 0xff ]; + } + return crc; +} + + +int +main(int argc, char **argv) +{ + unsigned int arg, crc; + FILE *fdata = NULL; + char *filename = NULL; + int fd, fd_mode; + unsigned char *buffer = NULL; + unsigned char *model_id; + unsigned int header_crc_offset = header_len; + unsigned int manufacturer_id_count = 0; + unsigned int model_id_count = 0; + char *format_spec_user = "%-12s Manufacturer: %s Model: %s CRC32: %08x Length: %ld File: %s\n"; + char *format_spec_test = "%-12s %s %s %08x %ld\n"; + char *format_spec = format_spec_user; // default output format + + unsigned int opt_len, opt_model_id, opt_match_manufacturer_id, opt_match_model_id, opt_write, opt_quiet, opt_simulate, opt_testsuite; + opt_len = opt_model_id = opt_match_manufacturer_id = opt_match_model_id = opt_write = opt_quiet = opt_simulate = opt_testsuite = 0; + + fprintf(stderr, "%s\nVersion: %0.2f\n%s\n", title, VERSION, copyright); + + if ((model_id = calloc(MODEL_ID_LEN, 1)) == NULL) { + pr_error_exit(0, "Unable to allocate memory (%d bytes)\n", MODEL_ID_LEN); + } + memcpy(model_id, match_model_id, MODEL_ID_LEN); + + for (arg = 1; arg < (unsigned) argc; ++arg) { + char *p = argv[arg]; + size_t arg_len = strlen(p); + + if (p[0] == '-') { + if(p[1] != 0) { + switch (p[1]) { + case 'l': // length of data to generate CRC32 on + opt_len = 1; + break; + case 'i': // replacement model ID + opt_model_id = 1; + break; + case 'm': // match this manufacturer ID + opt_match_manufacturer_id = 1; + break; + case 'M': // match this model ID + opt_match_model_id = 1; + break; + case 'w': // re-write file header + opt_write = 1; + break; + case 's': // simulate + opt_simulate = 1; + break; + case 't': // display machine-readable output for test suite + opt_testsuite = 1; + format_spec = format_spec_test; + break; + case 'q': // quiet + opt_quiet = 1; + break; + case 'h': // help + pr_usage(1); + exit(0); + } + } else { + pr_error_exit(0, "cannot read data from stdin; provide a filename"); + } + continue; + } + + if (opt_len == 1) { + char *format = "%ld"; + if ( *(p+1) == 'x' || *(p+1) == 'X' ) { // hex length + format = "%lx"; + // FIXME: p = first hex char? + } + if (sscanf(p, format, &header_len)) + ++opt_len; + else + pr_error_exit(0, "Illegal length value (%s)", p); + + } else if (opt_model_id == 1) { + if (arg_len == 4) { + model_id = p; + ++opt_model_id; + } else { + pr_error_exit(0, "Model Id ('%s') must be %d characters", p, MODEL_ID_LEN - 1); + } + } else if (opt_match_manufacturer_id == 1) { + match_manufacturer_id = p; + ++opt_match_manufacturer_id; + } else if (opt_match_model_id == 1) { + match_model_id = p; + ++opt_match_model_id; + } else if (!filename) { // remaining non-option must be the filename + filename = p; + } else { + if (!opt_quiet) + fprintf(stderr, "Can only process one file; ignoring '%s'\n", p); + } + } + + if (!opt_quiet) { + if (opt_write == 1) + fprintf(stdout, "%s\n", "In-place editing of header"); + + if (opt_simulate == 1) + fprintf(stderr, "%s\n", "Simulation mode; no file writes"); + } + + fd_mode = (opt_write && !opt_simulate) ? O_RDWR : O_RDONLY; + + if (filename) { + if ((fd = open(filename, fd_mode)) > 0) { + if ( (buffer = calloc(header_len + sizeof(crc), 1)) != NULL) { + ssize_t qty; + if ( (qty = read(fd, buffer, header_len + sizeof(crc))) < header_len) { + if (!opt_quiet) + fprintf(stderr, "warning: only able to read %ld of %ld bytes\n", qty, header_len); + header_len = qty; + } + } else { + close(fd); + pr_error_exit(0, "unable to allocate memory (%ld bytes)\n", header_len); + } + printf( format_spec, + opt_testsuite ? "" : "Current", + buffer + TAG_VER_LEN, + buffer + TAG_VER_LEN + strlen(buffer + TAG_VER_LEN) + 1, + ntohl( *((unsigned int *)(buffer + header_crc_offset)) ), + header_len, + filename); + + // do the model ID replacement in the memory buffer + if (strstr(buffer + TAG_VER_LEN, match_manufacturer_id) != NULL) { + ++manufacturer_id_count; + unsigned char *p = buffer + TAG_VER_LEN + strlen(match_manufacturer_id) + 1; // step over manufacturer ID + if ( strstr(p, match_model_id) != NULL) + ++model_id_count; + for (; p <= buffer + TAG_VER_LEN + TAG_SIG_LEN - MODEL_ID_LEN; ++p) { + if (strncmp(p, match_model_id, MODEL_ID_LEN) == 0) { + memcpy(p, model_id, MODEL_ID_LEN); + ++model_id_count; + p = p + MODEL_ID_LEN - 1; + } + } + } + + crc = crc32(buffer, header_len, 0xffffffff); + + char tmp_manufacturer[TAG_SIG_LEN]; + strcpy(tmp_manufacturer, match_manufacturer_id); + strcat(tmp_manufacturer, "_"); + strcat(tmp_manufacturer, model_id); + + printf( format_spec, + opt_testsuite ? "" : "Calculated", + tmp_manufacturer, + model_id, + crc, + header_len, + filename + ); + + if (opt_write) { + unsigned int tmp = htonl(crc); + memcpy(buffer + header_crc_offset, &tmp, sizeof(tmp)); + + if (!opt_simulate) { + lseek(fd, 0, SEEK_SET); + write(fd, buffer, header_len); + } + + printf( format_spec, + opt_testsuite ? "" : "Written", + buffer + TAG_VER_LEN, + buffer + TAG_VER_LEN + strlen(buffer + TAG_VER_LEN) + 1, + ntohl(*((unsigned int *)(buffer + 0xEC))), + header_len, + filename + ); + } + + if (!opt_quiet) { + fprintf(stderr, "Manufacturer ID does%s match '%s'\n", + match_manufacturer_id == 0 ? " not" : "", + match_manufacturer_id + ); + if (!manufacturer_id_count) + fprintf(stderr, "Model ID does%s match '%s' (%u replaced)\n", + model_id_count == 0 ? " not" : "", + match_model_id, + model_id_count - ( model_id_count == 0 ? 0 : 1 ) + ); + } + + free(buffer); + close(fd); + } else { + fprintf(stderr, "Unable to open for %s (%s)\n", opt_write ? "writing" : "reading" , filename ); + } + } else { + pr_usage(0); + } + + return 0; +} + diff --git a/testsuite/Makefile b/testsuite/Makefile new file mode 100644 index 0000000..92625b9 --- /dev/null +++ b/testsuite/Makefile @@ -0,0 +1,47 @@ +OPT_i = -i +OPT_l = -l +OPT_m = -m +OPT_M = -M +OPT_s = -s +opt_w = -w + +# test suite formatted output +OPTS = -t -q + +EXE := ../$(PROG) +TEST_DIR := $(shell mktemp --directory ) +SHA1SUM := $(shell which sha1sum ) +HDR_ORIG := header_test.bin +HDR_TEST := $(TEST_DIR)/header_test.bin +CHK_HDR_ORIG=$(shell $(SHA1SUM) $(HDR_TEST) ) + +tests: banner test_nochange test_man_nomatch test_man_match + -rm -rf $(TEST_DIR) + +banner: + @echo "Starting tests" + +tests_dir: $(TEST_DIR) + @echo "Tests directory: $(TEST_DIR)" + +exe: + @test -e $(EXE) || ( echo "executable $(EXE) does not exist" && /bin/false && /bin/false ) + @test -f $(EXE) || ( echo "executable $(EXE) is not a file" && /bin/false && /bin/false ) + @test -x $(EXE) || ( echo "executable $(EXE) is not executable" && /bin/false && /bin/false ) + @echo "Testing $(EXE)" + +checksum: + echo $(CHK_HDR_ORIG) | $(SHA1SUM) --check --quiet + +hdr_duplicate: + cp $(HDR_ORIG) $(HDR_TEST) + +test_nochange: exe tests_dir hdr_duplicate checksum + $(EXE) $(OPTS) $(HDR_TEST) 2>/dev/null + +test_man_nomatch: + +test_man_match: + +.PHONY: tests exe + diff --git a/testsuite/header_test.bin b/testsuite/header_test.bin new file mode 100644 index 0000000..a0996b5 Binary files /dev/null and b/testsuite/header_test.bin differ